Fixes an issue where TX Timestamps are not arriving on the error queue
when UDP_SEGMENT CMSG type is combined with CMSG type SO_TIMESTAMPING.
Also this updates the UDP GSO selftests to optionally stress test
this condition, and report the reliability and performance of both
TX Timestamping and ZEROCOPY messages.
Fred Klassen (4):
net/udp_gso: Allow TX timestamp with UDP GSO
net/udpgso_bench_tx: options to exercise TX CMSG
net/udpgso_bench_tx: fix sendmmsg on unconnected socket
net/udpgso_bench_tx: audit error queue
net/ipv4/udp_offload.c | 4 +
tools/testing/selftests/net/udpgso_bench_tx.c | 376 ++++++++++++++++++++++++--
2 files changed, 358 insertions(+), 22 deletions(-)
--
2.11.0
Hey,
This is v2 of this patchset.
In accordance with some comments There's a cond_resched() added to the
close loop similar to what is done for close_files().
A common helper pick_file() for __close_fd() and __close_range() has
been split out. This allows to only make a cond_resched() call when
filp_close() has been called similar to what is done in close_files().
Maybe that's not worth it. Jann mentioned that cond_resched() looks
rather cheap.
So it maybe that we could simply do:
while (fd <= max_fd) {
__close(files, fd++);
cond_resched();
}
I also added a missing test for close_range(fd, fd, 0).
Thanks!
Christian
Christian Brauner (2):
open: add close_range()
tests: add close_range() tests
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 1 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
fs/file.c | 62 +++++++-
fs/open.c | 20 +++
include/linux/fdtable.h | 2 +
include/linux/syscalls.h | 2 +
include/uapi/asm-generic/unistd.h | 4 +-
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/core/.gitignore | 1 +
tools/testing/selftests/core/Makefile | 6 +
.../testing/selftests/core/close_range_test.c | 142 ++++++++++++++++++
26 files changed, 249 insertions(+), 9 deletions(-)
create mode 100644 tools/testing/selftests/core/.gitignore
create mode 100644 tools/testing/selftests/core/Makefile
create mode 100644 tools/testing/selftests/core/close_range_test.c
--
2.21.0
This adds basic tests for the new close_range() syscall.
- test that no invalid flags can be passed
- test that a range of file descriptors is correctly closed
- test that a range of file descriptors is correctly closed if there there
are already closed file descriptors in the range
- test that max_fd is correctly capped to the current fdtable maximum
Signed-off-by: Christian Brauner <christian(a)brauner.io>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Cc: Jann Horn <jannh(a)google.com>
Cc: David Howells <dhowells(a)redhat.com>
Cc: Dmitry V. Levin <ldv(a)altlinux.org>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Florian Weimer <fweimer(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: linux-api(a)vger.kernel.org
Cc: linux-kselftest(a)vger.kernel.org
---
v1: unchanged
v2:
- Christian Brauner <christian(a)brauner.io>:
- verify that close_range() correctly closes a single file descriptor
v3:
- Christian Brauner <christian(a)brauner.io>:
- add missing Cc for Shuah
- add missing Cc for linux-kselftest
---
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/core/.gitignore | 1 +
tools/testing/selftests/core/Makefile | 6 +
.../testing/selftests/core/close_range_test.c | 142 ++++++++++++++++++
4 files changed, 150 insertions(+)
create mode 100644 tools/testing/selftests/core/.gitignore
create mode 100644 tools/testing/selftests/core/Makefile
create mode 100644 tools/testing/selftests/core/close_range_test.c
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 9781ca79794a..06e57fabbff9 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -4,6 +4,7 @@ TARGETS += bpf
TARGETS += breakpoints
TARGETS += capabilities
TARGETS += cgroup
+TARGETS += core
TARGETS += cpufreq
TARGETS += cpu-hotplug
TARGETS += drivers/dma-buf
diff --git a/tools/testing/selftests/core/.gitignore b/tools/testing/selftests/core/.gitignore
new file mode 100644
index 000000000000..6e6712ce5817
--- /dev/null
+++ b/tools/testing/selftests/core/.gitignore
@@ -0,0 +1 @@
+close_range_test
diff --git a/tools/testing/selftests/core/Makefile b/tools/testing/selftests/core/Makefile
new file mode 100644
index 000000000000..de3ae68aa345
--- /dev/null
+++ b/tools/testing/selftests/core/Makefile
@@ -0,0 +1,6 @@
+CFLAGS += -g -I../../../../usr/include/ -I../../../../include
+
+TEST_GEN_PROGS := close_range_test
+
+include ../lib.mk
+
diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c
new file mode 100644
index 000000000000..d6e6079d3d53
--- /dev/null
+++ b/tools/testing/selftests/core/close_range_test.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/kernel.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syscall.h>
+#include <unistd.h>
+
+#include "../kselftest.h"
+
+static inline int sys_close_range(unsigned int fd, unsigned int max_fd,
+ unsigned int flags)
+{
+ return syscall(__NR_close_range, fd, max_fd, flags);
+}
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+int main(int argc, char **argv)
+{
+ const char *test_name = "close_range";
+ int i, ret;
+ int open_fds[101];
+ int fd_max, fd_mid, fd_min;
+
+ ksft_set_plan(9);
+
+ for (i = 0; i < ARRAY_SIZE(open_fds); i++) {
+ int fd;
+
+ fd = open("/dev/null", O_RDONLY | O_CLOEXEC);
+ if (fd < 0) {
+ if (errno == ENOENT)
+ ksft_exit_skip(
+ "%s test: skipping test since /dev/null does not exist\n",
+ test_name);
+
+ ksft_exit_fail_msg(
+ "%s test: %s - failed to open /dev/null\n",
+ strerror(errno), test_name);
+ }
+
+ open_fds[i] = fd;
+ }
+
+ fd_min = open_fds[0];
+ fd_max = open_fds[99];
+
+ ret = sys_close_range(fd_min, fd_max, 1);
+ if (!ret)
+ ksft_exit_fail_msg(
+ "%s test: managed to pass invalid flag value\n",
+ test_name);
+ ksft_test_result_pass("do not allow invalid flag values for close_range()\n");
+
+ fd_mid = open_fds[50];
+ ret = sys_close_range(fd_min, fd_mid, 0);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close range of file descriptors from %d to %d\n",
+ test_name, fd_min, fd_mid);
+ ksft_test_result_pass("close_range() from %d to %d\n", fd_min, fd_mid);
+
+ for (i = 0; i <= 50; i++) {
+ ret = fcntl(open_fds[i], F_GETFL);
+ if (ret >= 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close range of file descriptors from %d to %d\n",
+ test_name, fd_min, fd_mid);
+ }
+ ksft_test_result_pass("fcntl() verify closed range from %d to %d\n", fd_min, fd_mid);
+
+ /* create a couple of gaps */
+ close(57);
+ close(78);
+ close(81);
+ close(82);
+ close(84);
+ close(90);
+
+ fd_mid = open_fds[51];
+ /* Choose slightly lower limit and leave some fds for a later test */
+ fd_max = open_fds[92];
+ ret = sys_close_range(fd_mid, fd_max, 0);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close range of file descriptors from 51 to 100\n",
+ test_name);
+ ksft_test_result_pass("close_range() from %d to %d\n", fd_mid, fd_max);
+
+ for (i = 51; i <= 92; i++) {
+ ret = fcntl(open_fds[i], F_GETFL);
+ if (ret >= 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close range of file descriptors from 51 to 100\n",
+ test_name);
+ }
+ ksft_test_result_pass("fcntl() verify closed range from %d to %d\n", fd_mid, fd_max);
+
+ fd_mid = open_fds[93];
+ fd_max = open_fds[99];
+ /* test that the kernel caps and still closes all fds */
+ ret = sys_close_range(fd_mid, UINT_MAX, 0);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close range of file descriptors from 51 to 100\n",
+ test_name);
+ ksft_test_result_pass("close_range() from %d to %d\n", fd_mid, fd_max);
+
+ for (i = 93; i < 100; i++) {
+ ret = fcntl(open_fds[i], F_GETFL);
+ if (ret >= 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close range of file descriptors from 51 to 100\n",
+ test_name);
+ }
+ ksft_test_result_pass("fcntl() verify closed range from %d to %d\n", fd_mid, fd_max);
+
+ ret = sys_close_range(open_fds[100], open_fds[100], 0);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close single file descriptor\n",
+ test_name);
+ ksft_test_result_pass("close_range() closed single file descriptor\n");
+
+ ret = fcntl(open_fds[100], F_GETFL);
+ if (ret >= 0)
+ ksft_exit_fail_msg(
+ "%s test: Failed to close single file descriptor\n",
+ test_name);
+ ksft_test_result_pass("fcntl() verify closed single file descriptor\n");
+
+ return ksft_exit_pass();
+}
--
2.21.0
kselftests exposed a problem in the s390 handling for memory slots.
Right now we only do proper memory slot handling for creation of new
memory slots. Neither MOVE, nor DELETION are handled properly. Let us
implement those.
Signed-off-by: Christian Borntraeger <borntraeger(a)de.ibm.com>
---
arch/s390/kvm/kvm-s390.c | 35 +++++++++++++++++++++--------------
1 file changed, 21 insertions(+), 14 deletions(-)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 871d2e99b156..6ec0685ab2c7 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4525,21 +4525,28 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
const struct kvm_memory_slot *new,
enum kvm_mr_change change)
{
- int rc;
+ int rc = 0;
- /* If the basics of the memslot do not change, we do not want
- * to update the gmap. Every update causes several unnecessary
- * segment translation exceptions. This is usually handled just
- * fine by the normal fault handler + gmap, but it will also
- * cause faults on the prefix page of running guest CPUs.
- */
- if (old->userspace_addr == mem->userspace_addr &&
- old->base_gfn * PAGE_SIZE == mem->guest_phys_addr &&
- old->npages * PAGE_SIZE == mem->memory_size)
- return;
-
- rc = gmap_map_segment(kvm->arch.gmap, mem->userspace_addr,
- mem->guest_phys_addr, mem->memory_size);
+ switch (change) {
+ case KVM_MR_DELETE:
+ rc = gmap_unmap_segment(kvm->arch.gmap, old->base_gfn * PAGE_SIZE,
+ old->npages * PAGE_SIZE);
+ break;
+ case KVM_MR_MOVE:
+ rc = gmap_unmap_segment(kvm->arch.gmap, old->base_gfn * PAGE_SIZE,
+ old->npages * PAGE_SIZE);
+ if (rc)
+ break;
+ /* FALLTHROUGH */
+ case KVM_MR_CREATE:
+ rc = gmap_map_segment(kvm->arch.gmap, mem->userspace_addr,
+ mem->guest_phys_addr, mem->memory_size);
+ break;
+ case KVM_MR_FLAGS_ONLY:
+ break;
+ default:
+ WARN(1, "Unknown KVM MR CHANGE: %d\n", change);
+ }
if (rc)
pr_warn("failed to commit memory region\n");
return;
--
2.21.0
The cgroup testing relies on the root cgroup's subtree_control setting,
If the 'memory' controller isn't set, all test cases will be failed
as following:
$ sudo ./test_memcontrol
not ok 1 test_memcg_subtree_control
not ok 2 test_memcg_current
ok 3 # skip test_memcg_min
not ok 4 test_memcg_low
not ok 5 test_memcg_high
not ok 6 test_memcg_max
not ok 7 test_memcg_oom_events
ok 8 # skip test_memcg_swap_max
not ok 9 test_memcg_sock
not ok 10 test_memcg_oom_group_leaf_events
not ok 11 test_memcg_oom_group_parent_events
not ok 12 test_memcg_oom_group_score_events
To correct this unexpected failure, this patch write the 'memory' to
subtree_control of root to get a right result.
Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Roman Gushchin <guro(a)fb.com>
Cc: Tejun Heo <tj(a)kernel.org>
Cc: Mike Rapoport <rppt(a)linux.vnet.ibm.com>
Cc: Jay Kamat <jgkamat(a)fb.com>
Cc: linux-kselftest(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Reviewed-by: Roman Gushchin <guro(a)fb.com>
---
tools/testing/selftests/cgroup/test_memcontrol.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index 6f339882a6ca..73612d604a2a 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -1205,6 +1205,10 @@ int main(int argc, char **argv)
if (cg_read_strstr(root, "cgroup.controllers", "memory"))
ksft_exit_skip("memory controller isn't available\n");
+ if (cg_read_strstr(root, "cgroup.subtree_control", "memory"))
+ if (cg_write(root, "cgroup.subtree_control", "+memory"))
+ ksft_exit_skip("Failed to set root memory controller\n");
+
for (i = 0; i < ARRAY_SIZE(tests); i++) {
switch (tests[i].fn(root)) {
case KSFT_PASS:
--
2.19.1.856.g8858448bb
The cgroup testing relies on the root cgroup's subtree_control setting,
If the 'memory' controller isn't set, all test cases will be failed
as following:
$ sudo ./test_memcontrol
not ok 1 test_memcg_subtree_control
not ok 2 test_memcg_current
ok 3 # skip test_memcg_min
not ok 4 test_memcg_low
not ok 5 test_memcg_high
not ok 6 test_memcg_max
not ok 7 test_memcg_oom_events
ok 8 # skip test_memcg_swap_max
not ok 9 test_memcg_sock
not ok 10 test_memcg_oom_group_leaf_events
not ok 11 test_memcg_oom_group_parent_events
not ok 12 test_memcg_oom_group_score_events
To correct this unexpected failure, this patch write the 'memory' to
subtree_control of root to get a right result.
Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Roman Gushchin <guro(a)fb.com>
Cc: Tejun Heo <tj(a)kernel.org>
Cc: Mike Rapoport <rppt(a)linux.vnet.ibm.com>
Cc: Jay Kamat <jgkamat(a)fb.com>
Cc: linux-kselftest(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Reviewed-by: Roman Gushchin <guro(a)fb.com>
Acked-by: Tejun Heo <tj(a)kernel.org>
---
tools/testing/selftests/cgroup/test_memcontrol.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index 6f339882a6ca..c19a97dd02d4 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -1205,6 +1205,10 @@ int main(int argc, char **argv)
if (cg_read_strstr(root, "cgroup.controllers", "memory"))
ksft_exit_skip("memory controller isn't available\n");
+ if (cg_read_strstr(root, "cgroup.subtree_control", "memory"))
+ if (cg_write(root, "cgroup.subtree_control", "+memory"))
+ ksft_exit_skip("Failed to set memory controller\n");
+
for (i = 0; i < ARRAY_SIZE(tests); i++) {
switch (tests[i].fn(root)) {
case KSFT_PASS:
--
2.19.1.856.g8858448bb
Fixes an issue where TX Timestamps are not arriving on the error queue
when UDP_SEGMENT CMSG type is combined with CMSG type SO_TIMESTAMPING.
This is version 2 which moves the tests to net-next.
Fred Klassen (1):
net/udp_gso: Allow TX timestamp with UDP GSO
net/ipv4/udp_offload.c | 4 ++++
1 file changed, 4 insertions(+)
--
2.11.0
Hi Linus,
Please pull the following Kselftest fixes update for Linux 5.2-rc2.
This Kselftest fixes update for Linux 5.2-rc2 consists of:
- 2 fixes to regressions introduced in kselftest Makefile test run
output refactoring work from Kees Cook.
- Adding Atom support to syscall_arg_fault test from Tong Bo.
diff is attached.
thanks,
-- Shuah
----------------------------------------------------------------
The following changes since commit a188339ca5a396acc588e5851ed7e19f66b0ebd9:
Linux 5.2-rc1 (2019-05-19 15:47:09 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
tags/linux-kselftest-5.2-rc2
for you to fetch changes up to fe48319243a626c860fd666ca032daacc2ba84a5:
selftests/timers: Add missing fflush(stdout) calls (2019-05-21
09:24:31 -0600)
----------------------------------------------------------------
linux-kselftest-5.2-rc2
This Kselftest fixes update for Linux 5.2-rc2 consists of:
- 2 fixes to regressions introduced in kselftest Makefile test run output
refactoring work from Kees Cook.
- Adding Atom support to syscall_arg_fault test from Tong Bo.
----------------------------------------------------------------
Kees Cook (2):
selftests: Remove forced unbuffering for test running
selftests/timers: Add missing fflush(stdout) calls
Tong Bo (1):
selftests/x86: Support Atom for syscall_arg_fault test
tools/testing/selftests/kselftest/runner.sh | 12 +-----------
tools/testing/selftests/timers/adjtick.c | 1 +
tools/testing/selftests/timers/leapcrash.c | 1 +
tools/testing/selftests/timers/mqueue-lat.c | 1 +
tools/testing/selftests/timers/nanosleep.c | 1 +
tools/testing/selftests/timers/nsleep-lat.c | 1 +
tools/testing/selftests/timers/raw_skew.c | 1 +
tools/testing/selftests/timers/set-tai.c | 1 +
tools/testing/selftests/timers/set-tz.c | 2 ++
tools/testing/selftests/timers/threadtest.c | 1 +
tools/testing/selftests/timers/valid-adjtimex.c | 2 ++
tools/testing/selftests/x86/syscall_arg_fault.c | 10 ++++++++--
12 files changed, 21 insertions(+), 13 deletions(-)
----------------------------------------------------------------
This series of patches move the commonly used bpf_printk macro to
bpf_helpers.h which is already included in all BPF programs which
defined that macro on their own.
v1->v2:
- If HBM_DEBUG is not defined in hbm sample, undefine bpf_printk and set
an empty macro for it.
Michal Rostecki (2):
selftests: bpf: Move bpf_printk to bpf_helpers.h
samples: bpf: Do not define bpf_printk macro
samples/bpf/hbm_kern.h | 11 ++---------
samples/bpf/tcp_basertt_kern.c | 7 -------
samples/bpf/tcp_bufs_kern.c | 7 -------
samples/bpf/tcp_clamp_kern.c | 7 -------
samples/bpf/tcp_cong_kern.c | 7 -------
samples/bpf/tcp_iw_kern.c | 7 -------
samples/bpf/tcp_rwnd_kern.c | 7 -------
samples/bpf/tcp_synrto_kern.c | 7 -------
samples/bpf/tcp_tos_reflect_kern.c | 7 -------
samples/bpf/xdp_sample_pkts_kern.c | 7 -------
tools/testing/selftests/bpf/bpf_helpers.h | 8 ++++++++
.../testing/selftests/bpf/progs/sockmap_parse_prog.c | 7 -------
.../selftests/bpf/progs/sockmap_tcp_msg_prog.c | 7 -------
.../selftests/bpf/progs/sockmap_verdict_prog.c | 7 -------
.../testing/selftests/bpf/progs/test_lwt_seg6local.c | 7 -------
tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 7 -------
tools/testing/selftests/bpf/test_sockmap_kern.h | 7 -------
17 files changed, 10 insertions(+), 114 deletions(-)
--
2.21.0
On 23/05/2019 22:29:36+0530, Jeffrin Thalakkottoor wrote:
> I get the following result when i run "rtctest"
> please see the following....
> -----------------x------------------------x-----------------
> $pwd
> /home/jeffrin/upstream/linux-kselftest/tools/testing/selftests/rtc
> $./rtctest
> [==========] Running 7 tests from 2 test cases.
> [ RUN ] rtc.date_read
> rtctest.c:32:rtc.date_read:Expected -1 (18446744073709551615) !=
> self->fd (18446744073709551615)
> rtc.date_read: Test terminated by assertion
Your user probably doesn't have access to the rtc device file.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
This adds the close_range() syscall. It allows to efficiently close a range
of file descriptors up to all file descriptors of a calling task.
The syscall came up in a recent discussion around the new mount API and
making new file descriptor types cloexec by default. During this
discussion, Al suggested the close_range() syscall (cf. [1]). Note, a
syscall in this manner has been requested by various people over time.
First, it helps to close all file descriptors of an exec()ing task. This
can be done safely via (quoting Al's example from [1] verbatim):
/* that exec is sensitive */
unshare(CLONE_FILES);
/* we don't want anything past stderr here */
close_range(3, ~0U);
execve(....);
The code snippet above is one way of working around the problem that file
descriptors are not cloexec by default. This is aggravated by the fact that
we can't just switch them over without massively regressing userspace. For
a whole class of programs having an in-kernel method of closing all file
descriptors is very helpful (e.g. demons, service managers, programming
language standard libraries, container managers etc.).
(Please note, unshare(CLONE_FILES) should only be needed if the calling
task is multi-threaded and shares the file descriptor table with another
thread in which case two threads could race with one thread allocating
file descriptors and the other one closing them via close_range(). For the
general case close_range() before the execve() is sufficient.)
Second, it allows userspace to avoid implementing closing all file
descriptors by parsing through /proc/<pid>/fd/* and calling close() on each
file descriptor. From looking at various large(ish) userspace code bases
this or similar patterns are very common in:
- service managers (cf. [4])
- libcs (cf. [6])
- container runtimes (cf. [5])
- programming language runtimes/standard libraries
- Python (cf. [2])
- Rust (cf. [7], [8])
As Dmitry pointed out there's even a long-standing glibc bug about missing
kernel support for this task (cf. [3]).
In addition, the syscall will also work for tasks that do not have procfs
mounted and on kernels that do not have procfs support compiled in. In such
situations the only way to make sure that all file descriptors are closed
is to call close() on each file descriptor up to UINT_MAX or RLIMIT_NOFILE,
OPEN_MAX trickery (cf. comment [8] on Rust).
The performance is striking. For good measure, comparing the following
simple close_all_fds() userspace implementation that is essentially just
glibc's version in [6]:
static int close_all_fds(void)
{
int dir_fd;
DIR *dir;
struct dirent *direntp;
dir = opendir("/proc/self/fd");
if (!dir)
return -1;
dir_fd = dirfd(dir);
while ((direntp = readdir(dir))) {
int fd;
if (strcmp(direntp->d_name, ".") == 0)
continue;
if (strcmp(direntp->d_name, "..") == 0)
continue;
fd = atoi(direntp->d_name);
if (fd == dir_fd || fd == 0 || fd == 1 || fd == 2)
continue;
close(fd);
}
closedir(dir);
return 0;
}
to close_range() yields:
1. closing 4 open files:
- close_all_fds(): ~280 us
- close_range(): ~24 us
2. closing 1000 open files:
- close_all_fds(): ~5000 us
- close_range(): ~800 us
close_range() is designed to allow for some flexibility. Specifically, it
does not simply always close all open file descriptors of a task. Instead,
callers can specify an upper bound.
This is e.g. useful for scenarios where specific file descriptors are
created with well-known numbers that are supposed to be excluded from
getting closed.
For extra paranoia close_range() comes with a flags argument. This can e.g.
be used to implement extension. Once can imagine userspace wanting to stop
at the first error instead of ignoring errors under certain circumstances.
There might be other valid ideas in the future. In any case, a flag
argument doesn't hurt and keeps us on the safe side.
>From an implementation side this is kept rather dumb. It saw some input
from David and Jann but all nonsense is obviously my own!
- Errors to close file descriptors are currently ignored. (Could be changed
by setting a flag in the future if needed.)
- __close_range() is a rather simplistic wrapper around __close_fd().
My reasoning behind this is based on the nature of how __close_fd() needs
to release an fd. But maybe I misunderstood specifics:
We take the files_lock and rcu-dereference the fdtable of the calling
task, we find the entry in the fdtable, get the file and need to release
files_lock before calling filp_close().
In the meantime the fdtable might have been altered so we can't just
retake the spinlock and keep the old rcu-reference of the fdtable
around. Instead we need to grab a fresh reference to the fdtable.
If my reasoning is correct then there's really no point in fancyfying
__close_range(): We just need to rcu-dereference the fdtable of the
calling task once to cap the max_fd value correctly and then go on
calling __close_fd() in a loop.
/* References */
[1]: https://lore.kernel.org/lkml/20190516165021.GD17978@ZenIV.linux.org.uk/
[2]: https://github.com/python/cpython/blob/9e4f2f3a6b8ee995c365e86d976937c141d8…
[3]: https://sourceware.org/bugzilla/show_bug.cgi?id=10353#c7
[4]: https://github.com/systemd/systemd/blob/5238e9575906297608ff802a27e2ff9effa…
[5]: https://github.com/lxc/lxc/blob/ddf4b77e11a4d08f09b7b9cd13e593f8c047edc5/sr…
[6]: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/gr…
Note that this is an internal implementation that is not exported.
Currently, libc seems to not provide an exported version of this
because of missing kernel support to do this.
[7]: https://github.com/rust-lang/rust/issues/12148
[8]: https://github.com/rust-lang/rust/blob/5f47c0613ed4eb46fca3633c1297364c09e5…
Rust's solution is slightly different but is equally unperformant.
Rust calls getdtablesize() which is a glibc library function that
simply returns the current RLIMIT_NOFILE or OPEN_MAX values. Rust then
goes on to call close() on each fd. That's obviously overkill for most
tasks. Rarely, tasks - especially non-demons - hit RLIMIT_NOFILE or
OPEN_MAX.
Let's be nice and assume an unprivileged user with RLIMIT_NOFILE set
to 1024. Even in this case, there's a very high chance that in the
common case Rust is calling the close() syscall 1021 times pointlessly
if the task just has 0, 1, and 2 open.
Suggested-by: Al Viro <viro(a)zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <christian(a)brauner.io>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Cc: Jann Horn <jannh(a)google.com>
Cc: David Howells <dhowells(a)redhat.com>
Cc: Dmitry V. Levin <ldv(a)altlinux.org>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Florian Weimer <fweimer(a)redhat.com>
Cc: linux-api(a)vger.kernel.org
---
v1:
- Linus Torvalds <torvalds(a)linux-foundation.org>:
- add cond_resched() to yield cpu when closing a lot of file descriptors
- Al Viro <viro(a)zeniv.linux.org.uk>:
- add cond_resched() to yield cpu when closing a lot of file descriptors
---
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 1 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
fs/file.c | 63 ++++++++++++++++++---
fs/open.c | 20 +++++++
include/linux/fdtable.h | 2 +
include/linux/syscalls.h | 2 +
include/uapi/asm-generic/unistd.h | 4 +-
22 files changed, 100 insertions(+), 9 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 9e7704e44f6d..b55d93af8096 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -473,3 +473,4 @@
541 common fsconfig sys_fsconfig
542 common fsmount sys_fsmount
543 common fspick sys_fspick
+545 common close_range sys_close_range
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index aaf479a9e92d..0125c97c75dd 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -447,3 +447,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index c39e90600bb3..9a3270d29b42 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -886,6 +886,8 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_close_range 435
+__SYSCALL(__NR_close_range, sys_close_range)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index e01df3f2f80d..1a90b464e96f 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -354,3 +354,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 7e3d0734b2f3..2dee2050f9ef 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -433,3 +433,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 26339e417695..923ef69e5a76 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -439,3 +439,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 0e2dd68ade57..967ed9de51cd 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -372,3 +372,4 @@
431 n32 fsconfig sys_fsconfig
432 n32 fsmount sys_fsmount
433 n32 fspick sys_fspick
+435 n32 close_range sys_close_range
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index 5eebfa0d155c..71de731102b1 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -348,3 +348,4 @@
431 n64 fsconfig sys_fsconfig
432 n64 fsmount sys_fsmount
433 n64 fspick sys_fspick
+435 n64 close_range sys_close_range
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 3cc1374e02d0..5a325ab29f88 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -421,3 +421,4 @@
431 o32 fsconfig sys_fsconfig
432 o32 fsmount sys_fsmount
433 o32 fspick sys_fspick
+435 o32 close_range sys_close_range
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index c9e377d59232..dcc0a0879139 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 103655d84b4b..ba2c1f078cbd 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -515,3 +515,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index e822b2964a83..d7c9043d2902 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig sys_fsconfig
432 common fsmount sys_fsmount sys_fsmount
433 common fspick sys_fspick sys_fspick
+435 common close_range sys_close_range sys_close_range
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 016a727d4357..9b5e6bf0ce32 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index e047480b1605..8c674a1e0072 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -479,3 +479,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ad968b7bac72..7f7a89a96707 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@
431 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig
432 i386 fsmount sys_fsmount __ia32_sys_fsmount
433 i386 fspick sys_fspick __ia32_sys_fspick
+435 i386 close_range sys_close_range __ia32_sys_close_range
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b4e6f9e6204a..0f7d47ae921c 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@
431 common fsconfig __x64_sys_fsconfig
432 common fsmount __x64_sys_fsmount
433 common fspick __x64_sys_fspick
+435 common close_range __x64_sys_close_range
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 5fa0ee1c8e00..b489532265d0 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -404,3 +404,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/fs/file.c b/fs/file.c
index 3da91a112bab..54945efa046e 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -615,12 +615,9 @@ void fd_install(unsigned int fd, struct file *file)
EXPORT_SYMBOL(fd_install);
-/*
- * The same warnings as for __alloc_fd()/__fd_install() apply here...
- */
-int __close_fd(struct files_struct *files, unsigned fd)
+static struct file *pick_file(struct files_struct *files, unsigned fd)
{
- struct file *file;
+ struct file *file = NULL;
struct fdtable *fdt;
spin_lock(&files->file_lock);
@@ -632,15 +629,65 @@ int __close_fd(struct files_struct *files, unsigned fd)
goto out_unlock;
rcu_assign_pointer(fdt->fd[fd], NULL);
__put_unused_fd(files, fd);
- spin_unlock(&files->file_lock);
- return filp_close(file, files);
out_unlock:
spin_unlock(&files->file_lock);
- return -EBADF;
+ return file;
+}
+
+/*
+ * The same warnings as for __alloc_fd()/__fd_install() apply here...
+ */
+int __close_fd(struct files_struct *files, unsigned fd)
+{
+ struct file *file;
+
+ file = pick_file(files, fd);
+ if (!file)
+ return -EBADF;
+
+ return filp_close(file, files);
}
EXPORT_SYMBOL(__close_fd); /* for ksys_close() */
+/**
+ * __close_range() - Close all file descriptors in a given range.
+ *
+ * @fd: starting file descriptor to close
+ * @max_fd: last file descriptor to close
+ *
+ * This closes a range of file descriptors. All file descriptors
+ * from @fd up to and including @max_fd are closed.
+ */
+int __close_range(struct files_struct *files, unsigned fd, unsigned max_fd)
+{
+ unsigned int cur_max;
+
+ if (fd > max_fd)
+ return -EINVAL;
+
+ rcu_read_lock();
+ cur_max = files_fdtable(files)->max_fds;
+ rcu_read_unlock();
+
+ /* cap to last valid index into fdtable */
+ if (max_fd >= cur_max)
+ max_fd = cur_max - 1;
+
+ while (fd <= max_fd) {
+ struct file *file;
+
+ file = pick_file(files, fd++);
+ if (!file)
+ continue;
+
+ filp_close(file, files);
+ cond_resched();
+ }
+
+ return 0;
+}
+
/*
* variant of __close_fd that gets a ref on the file for later fput
*/
diff --git a/fs/open.c b/fs/open.c
index 9c7d724a6f67..c7baaee7aa47 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1174,6 +1174,26 @@ SYSCALL_DEFINE1(close, unsigned int, fd)
return retval;
}
+/**
+ * close_range() - Close all file descriptors in a given range.
+ *
+ * @fd: starting file descriptor to close
+ * @max_fd: last file descriptor to close
+ * @flags: reserved for future extensions
+ *
+ * This closes a range of file descriptors. All file descriptors
+ * from @fd up to and including @max_fd are closed.
+ * Currently, errors to close a given file descriptor are ignored.
+ */
+SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd,
+ unsigned int, flags)
+{
+ if (flags)
+ return -EINVAL;
+
+ return __close_range(current->files, fd, max_fd);
+}
+
/*
* This routine simulates a hangup on the tty, to arrange that users
* are given clean terminals at login time.
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index f07c55ea0c22..fcd07181a365 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -121,6 +121,8 @@ extern void __fd_install(struct files_struct *files,
unsigned int fd, struct file *file);
extern int __close_fd(struct files_struct *files,
unsigned int fd);
+extern int __close_range(struct files_struct *files, unsigned int fd,
+ unsigned int max_fd);
extern int __close_fd_get_file(unsigned int fd, struct file **res);
extern struct kmem_cache *files_cachep;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..c0189e223255 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -441,6 +441,8 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group);
asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
umode_t mode);
asmlinkage long sys_close(unsigned int fd);
+asmlinkage long sys_close_range(unsigned int fd, unsigned int max_fd,
+ unsigned int flags);
asmlinkage long sys_vhangup(void);
/* fs/pipe.c */
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index a87904daf103..3f36c8745d24 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -844,9 +844,11 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_close_range 435
+__SYSCALL(__NR_close_range, sys_close_range)
#undef __NR_syscalls
-#define __NR_syscalls 434
+#define __NR_syscalls 436
/*
* 32 bit systems traditionally used different
--
2.21.0
Hi,
Here are patches for making sure the ftracetest testcases
are checkbashisms clean.
This actually needs a patch from Juerg, "selftests/ftrace:
Make the coloring POSIX compliant" to complete the work.
http://lkml.kernel.org/r/20190220161333.28109-1-juergh@canonical.com
(Note that this is still under development)
So as Juerg pointed, recently ftracetest becomes not POSIX
compliant, and such kind of issues happened repeatedly.
To avoid those anymore, I decided to introduce a testcase
which runs checkbasisms on ftracetest and its testcases.
I think this can help us to find out whether it was
written in a way out of POSIX.
Thank you,
---
Masami Hiramatsu (2):
selftests/ftrace: Make a script checkbashisms clean
selftests/ftrace: Add checkbashisms meta-testcase
tools/testing/selftests/ftrace/ftracetest | 1 +
.../ftrace/test.d/kprobe/kprobe_ftrace.tc | 2 +-
.../selftests/ftrace/test.d/selftest/bashisms.tc | 21 ++++++++++++++++++++
3 files changed, 23 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/ftrace/test.d/selftest/bashisms.tc
--
Masami Hiramatsu (Linaro) <mhiramat(a)kernel.org>
Hi,
Commit a745f7af3cbd ("selftests/harness: Add 30 second timeout per
test") wrongly assumed that no individual test would run for more than
30 seconds and this silently broke rtctest.
Please consider the following patches as fixes for v5.2 to avoid having
any non working release.
Thanks,
Alexandre Belloni (2):
selftests/harness: Allow test to configure timeout
selftests: rtc: rtctest: specify timeouts
tools/testing/selftests/kselftest_harness.h | 17 ++++++++++++-----
tools/testing/selftests/rtc/rtctest.c | 6 +++---
2 files changed, 15 insertions(+), 8 deletions(-)
--
2.21.0
From: Peter Zijlstra <peterz(a)infradead.org>
commit 9e298e8604088a600d8100a111a532a9d342af09 upstream.
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_fun
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -294,13 +298,28 @@ int ftrace_int3_handler(struct pt_regs *
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
NOKPROBE_SYMBOL(ftrace_int3_handler);
@@ -859,6 +878,8 @@ void arch_ftrace_update_trampoline(struc
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -960,6 +981,7 @@ static int ftrace_mod_jmp(unsigned long
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
From: Peter Zijlstra <peterz(a)infradead.org>
commit 4b33dadf37666c0860b88f9e52a16d07bf6d0b03 upstream.
In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_r
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
From: Peter Zijlstra <peterz(a)infradead.org>
commit 9e298e8604088a600d8100a111a532a9d342af09 upstream.
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_fun
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -294,13 +298,28 @@ int ftrace_int3_handler(struct pt_regs *
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
static int ftrace_write(unsigned long ip, const char *val, int size)
@@ -858,6 +877,8 @@ void arch_ftrace_update_trampoline(struc
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -959,6 +980,7 @@ static int ftrace_mod_jmp(unsigned long
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
From: Peter Zijlstra <peterz(a)infradead.org>
commit 4b33dadf37666c0860b88f9e52a16d07bf6d0b03 upstream.
In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_r
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
From: Peter Zijlstra <peterz(a)infradead.org>
commit 9e298e8604088a600d8100a111a532a9d342af09 upstream.
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -30,6 +30,7 @@
#include <asm/sections.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -229,6 +230,7 @@ int ftrace_modify_call(struct dyn_ftrace
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -257,6 +259,8 @@ int ftrace_update_ftrace_func(ftrace_fun
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -292,13 +296,28 @@ int ftrace_int3_handler(struct pt_regs *
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
static int ftrace_write(unsigned long ip, const char *val, int size)
@@ -869,6 +888,8 @@ void arch_ftrace_update_trampoline(struc
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -965,6 +986,7 @@ static int ftrace_mod_jmp(unsigned long
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
From: Peter Zijlstra <peterz(a)infradead.org>
commit 9e298e8604088a600d8100a111a532a9d342af09 upstream.
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -228,6 +229,7 @@ int ftrace_modify_call(struct dyn_ftrace
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -256,6 +258,8 @@ int ftrace_update_ftrace_func(ftrace_fun
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -291,13 +295,28 @@ int ftrace_int3_handler(struct pt_regs *
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
static int ftrace_write(unsigned long ip, const char *val, int size)
@@ -868,6 +887,8 @@ void arch_ftrace_update_trampoline(struc
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -964,6 +985,7 @@ static int ftrace_mod_jmp(unsigned long
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
From: Peter Zijlstra <peterz(a)infradead.org>
commit 4b33dadf37666c0860b88f9e52a16d07bf6d0b03 upstream.
In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_r
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
From: Peter Zijlstra <peterz(a)infradead.org>
commit 4b33dadf37666c0860b88f9e52a16d07bf6d0b03 upstream.
In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -38,4 +38,32 @@ extern void *text_poke(void *addr, const
extern int poke_int3_handler(struct pt_regs *regs);
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
These patches try to test the fix made in commit e2f7fc0ac695 ("bpf:
fix undefined behavior in narrow load handling"). The problem existed
in the generated BPF bytecode that was doing a 32bit narrow read of a
64bit field, so to test it the code would need to be executed.
Currently the only such field exists in BPF_PROG_TYPE_PERF_EVENT,
which is not supported by bpf_prog_test_run().
First commit adds the test, but since I can't run it, I'm not sure if
it is even valid (because endianness, for example). Second commit adds
a message to test_verifier when it couldn't run the program because of
lack permissions or program type being not supported. Third commit
fixes a possible problem with errno.
With these patches, I get the following output on my test:
/kernel/tools/testing/selftests/bpf$ sudo ./test_verifier 920 920
#920/p 32bit loads of a 64bit field (both least and most significant words) Did not run the program (not supported) OK
Summary: 1 PASSED, 0 SKIPPED, 0 FAILED
So it looks like I need to pick a different approach.
Krzesimir Nowak (3):
selftests/bpf: Test correctness of narrow 32bit read on 64bit field
selftests/bpf: Print a message when tester could not run a program
selftests/bpf: Avoid a clobbering of errno
tools/testing/selftests/bpf/test_verifier.c | 19 +++++++++++++++----
.../testing/selftests/bpf/verifier/var_off.c | 15 +++++++++++++++
2 files changed, 30 insertions(+), 4 deletions(-)
--
2.20.1
This patch series enables the KVM selftests for s390x. As a first
test, the sync_regs from x86 has been adapted to s390x.
Please note that the ucall() interface is not used yet - since
s390x neither has PIO nor MMIO, this needs some more work first
before it becomes usable (we likely should use a DIAG hypercall
here, which is what the sync_reg test is currently using, too...).
Thomas Huth (4):
KVM: selftests: Guard struct kvm_vcpu_events with
__KVM_HAVE_VCPU_EVENTS
KVM: selftests: Align memory region addresses to 1M on s390x
KVM: selftests: Add processor code for s390x
KVM: selftests: Add the sync_regs test for s390x
MAINTAINERS | 2 +
tools/testing/selftests/kvm/Makefile | 3 +
.../testing/selftests/kvm/include/kvm_util.h | 2 +
.../selftests/kvm/include/s390x/processor.h | 22 ++
tools/testing/selftests/kvm/lib/kvm_util.c | 24 +-
.../selftests/kvm/lib/s390x/processor.c | 277 ++++++++++++++++++
.../selftests/kvm/s390x/sync_regs_test.c | 151 ++++++++++
7 files changed, 476 insertions(+), 5 deletions(-)
create mode 100644 tools/testing/selftests/kvm/include/s390x/processor.h
create mode 100644 tools/testing/selftests/kvm/lib/s390x/processor.c
create mode 100644 tools/testing/selftests/kvm/s390x/sync_regs_test.c
--
2.21.0
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9e298e8604088a600d8100a111a532a9d342af09 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz(a)infradead.org>
Date: Wed, 1 May 2019 15:11:17 +0200
Subject: [PATCH] ftrace/x86_64: Emulate call function while updating in
breakpoint handler
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index ef49517f6bb2..bd553b3af22e 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -294,13 +298,28 @@ int ftrace_int3_handler(struct pt_regs *regs)
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
NOKPROBE_SYMBOL(ftrace_int3_handler);
@@ -859,6 +878,8 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -960,6 +981,7 @@ static int ftrace_mod_jmp(unsigned long ip, void *func)
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9e298e8604088a600d8100a111a532a9d342af09 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz(a)infradead.org>
Date: Wed, 1 May 2019 15:11:17 +0200
Subject: [PATCH] ftrace/x86_64: Emulate call function while updating in
breakpoint handler
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index ef49517f6bb2..bd553b3af22e 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -294,13 +298,28 @@ int ftrace_int3_handler(struct pt_regs *regs)
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
NOKPROBE_SYMBOL(ftrace_int3_handler);
@@ -859,6 +878,8 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -960,6 +981,7 @@ static int ftrace_mod_jmp(unsigned long ip, void *func)
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 4b33dadf37666c0860b88f9e52a16d07bf6d0b03 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz(a)infradead.org>
Date: Wed, 1 May 2019 15:11:17 +0200
Subject: [PATCH] x86_64: Allow breakpoints to emulate call instructions
In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index e85ff65c43c3..05861cc08787 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_regs *regs);
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 4b33dadf37666c0860b88f9e52a16d07bf6d0b03 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz(a)infradead.org>
Date: Wed, 1 May 2019 15:11:17 +0200
Subject: [PATCH] x86_64: Allow breakpoints to emulate call instructions
In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index e85ff65c43c3..05861cc08787 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_regs *regs);
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
## TLDR
I rebased the last patchset on 5.1-rc7 in hopes that we can get this in
5.2.
Shuah, I think you, Greg KH, and myself talked off thread, and we agreed
we would merge through your tree when the time came? Am I remembering
correctly?
## Background
This patch set proposes KUnit, a lightweight unit testing and mocking
framework for the Linux kernel.
Unlike Autotest and kselftest, KUnit is a true unit testing framework;
it does not require installing the kernel on a test machine or in a VM
and does not require tests to be written in userspace running on a host
kernel. Additionally, KUnit is fast: From invocation to completion KUnit
can run several dozen tests in under a second. Currently, the entire
KUnit test suite for KUnit runs in under a second from the initial
invocation (build time excluded).
KUnit is heavily inspired by JUnit, Python's unittest.mock, and
Googletest/Googlemock for C++. KUnit provides facilities for defining
unit test cases, grouping related test cases into test suites, providing
common infrastructure for running tests, mocking, spying, and much more.
## What's so special about unit testing?
A unit test is supposed to test a single unit of code in isolation,
hence the name. There should be no dependencies outside the control of
the test; this means no external dependencies, which makes tests orders
of magnitudes faster. Likewise, since there are no external dependencies,
there are no hoops to jump through to run the tests. Additionally, this
makes unit tests deterministic: a failing unit test always indicates a
problem. Finally, because unit tests necessarily have finer granularity,
they are able to test all code paths easily solving the classic problem
of difficulty in exercising error handling code.
## Is KUnit trying to replace other testing frameworks for the kernel?
No. Most existing tests for the Linux kernel are end-to-end tests, which
have their place. A well tested system has lots of unit tests, a
reasonable number of integration tests, and some end-to-end tests. KUnit
is just trying to address the unit test space which is currently not
being addressed.
## More information on KUnit
There is a bunch of documentation near the end of this patch set that
describes how to use KUnit and best practices for writing unit tests.
For convenience I am hosting the compiled docs here:
https://google.github.io/kunit-docs/third_party/kernel/docs/
Additionally for convenience, I have applied these patches to a branch:
https://kunit.googlesource.com/linux/+/kunit/rfc/v5.1-rc7/v1
The repo may be cloned with:
git clone https://kunit.googlesource.com/linux
This patchset is on the kunit/rfc/v5.1-rc7/v1 branch.
## Changes Since Last Version
None. I just rebased the last patchset on v5.1-rc7.
--
2.21.0.593.g511ec345e18-goog
From: Yonghong Song <yhs(a)fb.com>
[ Upstream commit 6cea33701eb024bc6c920ab83940ee22afd29139 ]
Test test_libbpf.sh failed on my development server with failure
-bash-4.4$ sudo ./test_libbpf.sh
[0] libbpf: Error in bpf_object__probe_name():Operation not permitted(1).
Couldn't load basic 'r0 = 0' BPF program.
test_libbpf: failed at file test_l4lb.o
selftests: test_libbpf [FAILED]
-bash-4.4$
The reason is because my machine has 64KB locked memory by default which
is not enough for this program to get locked memory.
Similar to other bpf selftests, let us increase RLIMIT_MEMLOCK
to infinity, which fixed the issue.
Signed-off-by: Yonghong Song <yhs(a)fb.com>
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/test_libbpf_open.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_libbpf_open.c b/tools/testing/selftests/bpf/test_libbpf_open.c
index 8fcd1c076add0..cbd55f5f8d598 100644
--- a/tools/testing/selftests/bpf/test_libbpf_open.c
+++ b/tools/testing/selftests/bpf/test_libbpf_open.c
@@ -11,6 +11,8 @@ static const char *__doc__ =
#include <bpf/libbpf.h>
#include <getopt.h>
+#include "bpf_rlimit.h"
+
static const struct option long_options[] = {
{"help", no_argument, NULL, 'h' },
{"debug", no_argument, NULL, 'D' },
--
2.20.1
From: Yonghong Song <yhs(a)fb.com>
[ Upstream commit 6cea33701eb024bc6c920ab83940ee22afd29139 ]
Test test_libbpf.sh failed on my development server with failure
-bash-4.4$ sudo ./test_libbpf.sh
[0] libbpf: Error in bpf_object__probe_name():Operation not permitted(1).
Couldn't load basic 'r0 = 0' BPF program.
test_libbpf: failed at file test_l4lb.o
selftests: test_libbpf [FAILED]
-bash-4.4$
The reason is because my machine has 64KB locked memory by default which
is not enough for this program to get locked memory.
Similar to other bpf selftests, let us increase RLIMIT_MEMLOCK
to infinity, which fixed the issue.
Signed-off-by: Yonghong Song <yhs(a)fb.com>
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/test_libbpf_open.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_libbpf_open.c b/tools/testing/selftests/bpf/test_libbpf_open.c
index 8fcd1c076add0..cbd55f5f8d598 100644
--- a/tools/testing/selftests/bpf/test_libbpf_open.c
+++ b/tools/testing/selftests/bpf/test_libbpf_open.c
@@ -11,6 +11,8 @@ static const char *__doc__ =
#include <bpf/libbpf.h>
#include <getopt.h>
+#include "bpf_rlimit.h"
+
static const struct option long_options[] = {
{"help", no_argument, NULL, 'h' },
{"debug", no_argument, NULL, 'D' },
--
2.20.1
From: Yonghong Song <yhs(a)fb.com>
[ Upstream commit 6cea33701eb024bc6c920ab83940ee22afd29139 ]
Test test_libbpf.sh failed on my development server with failure
-bash-4.4$ sudo ./test_libbpf.sh
[0] libbpf: Error in bpf_object__probe_name():Operation not permitted(1).
Couldn't load basic 'r0 = 0' BPF program.
test_libbpf: failed at file test_l4lb.o
selftests: test_libbpf [FAILED]
-bash-4.4$
The reason is because my machine has 64KB locked memory by default which
is not enough for this program to get locked memory.
Similar to other bpf selftests, let us increase RLIMIT_MEMLOCK
to infinity, which fixed the issue.
Signed-off-by: Yonghong Song <yhs(a)fb.com>
Signed-off-by: Alexei Starovoitov <ast(a)kernel.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/bpf/test_libbpf_open.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_libbpf_open.c b/tools/testing/selftests/bpf/test_libbpf_open.c
index 65cbd30704b5a..9e9db202d218a 100644
--- a/tools/testing/selftests/bpf/test_libbpf_open.c
+++ b/tools/testing/selftests/bpf/test_libbpf_open.c
@@ -11,6 +11,8 @@ static const char *__doc__ =
#include <bpf/libbpf.h>
#include <getopt.h>
+#include "bpf_rlimit.h"
+
static const struct option long_options[] = {
{"help", no_argument, NULL, 'h' },
{"debug", no_argument, NULL, 'D' },
--
2.20.1
clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().
In particular, posix_get_hrtimer_res() does:
sec = 0;
ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.
A possible fix is to change the vdso implementation of clock_getres,
keeping a copy of hrtimer_resolution in vdso data and using that
directly [1].
This patchset implements the proposed fix for arm64, powerpc, s390,
nds32 and adds a test to verify that the syscall and the vdso library
implementation of clock_getres return the same values.
Even if these patches are unified by the same topic, there is no
dependency between them, hence they can be merged singularly by each
arch maintainer.
Note: arm64 and nds32 respective fixes have been merged in 5.2-rc1,
hence they have been removed from this series.
[1] https://marc.info/?l=linux-arm-kernel&m=155110381930196&w=2
Changes:
--------
v3:
- Rebased on 5.2-rc1.
- Addressed review comments.
v2:
- Rebased on 5.1-rc5.
- Addressed review comments.
Cc: Christophe Leroy <christophe.leroy(a)c-s.fr>
Cc: Benjamin Herrenschmidt <benh(a)kernel.crashing.org>
Cc: Paul Mackerras <paulus(a)samba.org>
Cc: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky(a)de.ibm.com>
Cc: Heiko Carstens <heiko.carstens(a)de.ibm.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino(a)arm.com>
Vincenzo Frascino (3):
powerpc: Fix vDSO clock_getres()
s390: Fix vDSO clock_getres()
kselftest: Extend vDSO selftest to clock_getres
arch/powerpc/include/asm/vdso_datapage.h | 2 +
arch/powerpc/kernel/asm-offsets.c | 2 +-
arch/powerpc/kernel/time.c | 1 +
arch/powerpc/kernel/vdso32/gettimeofday.S | 7 +-
arch/powerpc/kernel/vdso64/gettimeofday.S | 7 +-
arch/s390/include/asm/vdso.h | 1 +
arch/s390/kernel/asm-offsets.c | 2 +-
arch/s390/kernel/time.c | 1 +
arch/s390/kernel/vdso32/clock_getres.S | 12 +-
arch/s390/kernel/vdso64/clock_getres.S | 10 +-
tools/testing/selftests/vDSO/Makefile | 2 +
.../selftests/vDSO/vdso_clock_getres.c | 137 ++++++++++++++++++
12 files changed, 168 insertions(+), 16 deletions(-)
create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c
--
2.21.0
A test for the basic NAT functionality uses ip command which
needs veth device.There is a condition where the kernel support
for veth is not compiled into the kernel and the test script
breaks.This patch contains code for reasonable error display
and correct code exit.
Signed-off-by: Jeffrin Jose T <jeffrin(a)rajagiritech.edu.in>
---
tools/testing/selftests/netfilter/nft_nat.sh | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/netfilter/nft_nat.sh b/tools/testing/selftests/netfilter/nft_nat.sh
index 8ec76681605c..f25f72a75cf3 100755
--- a/tools/testing/selftests/netfilter/nft_nat.sh
+++ b/tools/testing/selftests/netfilter/nft_nat.sh
@@ -23,7 +23,11 @@ ip netns add ns0
ip netns add ns1
ip netns add ns2
-ip link add veth0 netns ns0 type veth peer name eth0 netns ns1
+ip link add veth0 netns ns0 type veth peer name eth0 netns ns1 > /dev/null 2>&1
+if [ $? -ne 0 ];then
+ echo "SKIP: No virtual ethernet pair device support in kernel"
+ exit $ksft_skip
+fi
ip link add veth1 netns ns0 type veth peer name eth0 netns ns2
ip -net ns0 link set lo up
--
2.20.1
clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().
In particular, posix_get_hrtimer_res() does:
sec = 0;
ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.
A possible fix is to change the vdso implementation of clock_getres,
keeping a copy of hrtimer_resolution in vdso data and using that
directly [1].
This patchset implements the proposed fix for arm64, powerpc, s390,
nds32 and adds a test to verify that the syscall and the vdso library
implementation of clock_getres return the same values.
Even if these patches are unified by the same topic, there is no
dependency between them, hence they can be merged singularly by each
arch maintainer.
[1] https://marc.info/?l=linux-arm-kernel&m=155110381930196&w=2
Changes:
--------
v2:
- Rebased on 5.1-rc5.
- Addressed review comments.
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Will Deacon <will.deacon(a)arm.com>
Cc: Benjamin Herrenschmidt <benh(a)kernel.crashing.org>
Cc: Paul Mackerras <paulus(a)samba.org>
Cc: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky(a)de.ibm.com>
Cc: Heiko Carstens <heiko.carstens(a)de.ibm.com>
Cc: Greentime Hu <green.hu(a)gmail.com>
Cc: Vincent Chen <deanbo422(a)gmail.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino(a)arm.com>
Vincenzo Frascino (5):
arm64: Fix vDSO clock_getres()
powerpc: Fix vDSO clock_getres()
s390: Fix vDSO clock_getres()
nds32: Fix vDSO clock_getres()
kselftest: Extend vDSO selftest to clock_getres
arch/arm64/include/asm/vdso_datapage.h | 1 +
arch/arm64/kernel/asm-offsets.c | 2 +-
arch/arm64/kernel/vdso.c | 2 +
arch/arm64/kernel/vdso/gettimeofday.S | 22 ++--
arch/nds32/include/asm/vdso_datapage.h | 1 +
arch/nds32/kernel/vdso.c | 1 +
arch/nds32/kernel/vdso/gettimeofday.c | 4 +-
arch/powerpc/include/asm/vdso_datapage.h | 2 +
arch/powerpc/kernel/asm-offsets.c | 2 +-
arch/powerpc/kernel/time.c | 1 +
arch/powerpc/kernel/vdso32/gettimeofday.S | 7 +-
arch/powerpc/kernel/vdso64/gettimeofday.S | 7 +-
arch/s390/include/asm/vdso.h | 1 +
arch/s390/kernel/asm-offsets.c | 2 +-
arch/s390/kernel/time.c | 1 +
arch/s390/kernel/vdso32/clock_getres.S | 12 +-
arch/s390/kernel/vdso64/clock_getres.S | 10 +-
tools/testing/selftests/vDSO/Makefile | 2 +
.../selftests/vDSO/vdso_clock_getres.c | 108 ++++++++++++++++++
19 files changed, 159 insertions(+), 29 deletions(-)
create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c
--
2.21.0
This adds the close_range() syscall. It allows to efficiently close a range
of file descriptors up to all file descriptors of a calling task.
The syscall came up in a recent discussion around the new mount API and
making new file descriptor types cloexec by default. During this
discussion, Al suggested the close_range() syscall (cf. [1]). Note, a
syscall in this manner has been requested by various people over time.
First, it helps to close all file descriptors of an exec()ing task. This
can be done safely via (quoting Al's example from [1] verbatim):
/* that exec is sensitive */
unshare(CLONE_FILES);
/* we don't want anything past stderr here */
close_range(3, ~0U);
execve(....);
The code snippet above is one way of working around the problem that file
descriptors are not cloexec by default. This is aggravated by the fact that
we can't just switch them over without massively regressing userspace. For
a whole class of programs having an in-kernel method of closing all file
descriptors is very helpful (e.g. demons, service managers, programming
language standard libraries, container managers etc.).
(Please note, unshare(CLONE_FILES) should only be needed if the calling
task is multi-threaded and shares the file descriptor table with another
thread in which case two threads could race with one thread allocating
file descriptors and the other one closing them via close_range(). For the
general case close_range() before the execve() is sufficient.)
Second, it allows userspace to avoid implementing closing all file
descriptors by parsing through /proc/<pid>/fd/* and calling close() on each
file descriptor. From looking at various large(ish) userspace code bases
this or similar patterns are very common in:
- service managers (cf. [4])
- libcs (cf. [6])
- container runtimes (cf. [5])
- programming language runtimes/standard libraries
- Python (cf. [2])
- Rust (cf. [7], [8])
As Dmitry pointed out there's even a long-standing glibc bug about missing
kernel support for this task (cf. [3]).
In addition, the syscall will also work for tasks that do not have procfs
mounted and on kernels that do not have procfs support compiled in. In such
situations the only way to make sure that all file descriptors are closed
is to call close() on each file descriptor up to UINT_MAX or RLIMIT_NOFILE,
OPEN_MAX trickery (cf. comment [8] on Rust).
The performance is striking. For good measure, comparing the following
simple close_all_fds() userspace implementation that is essentially just
glibc's version in [6]:
static int close_all_fds(void)
{
DIR *dir;
struct dirent *direntp;
dir = opendir("/proc/self/fd");
if (!dir)
return -1;
while ((direntp = readdir(dir))) {
int fd;
if (strcmp(direntp->d_name, ".") == 0)
continue;
if (strcmp(direntp->d_name, "..") == 0)
continue;
fd = atoi(direntp->d_name);
if (fd == 0 || fd == 1 || fd == 2)
continue;
close(fd);
}
closedir(dir); /* cannot fail */
return 0;
}
to close_range() yields:
1. closing 4 open files:
- close_all_fds(): ~280 us
- close_range(): ~24 us
2. closing 1000 open files:
- close_all_fds(): ~5000 us
- close_range(): ~800 us
close_range() is designed to allow for some flexibility. Specifically, it
does not simply always close all open file descriptors of a task. Instead,
callers can specify an upper bound.
This is e.g. useful for scenarios where specific file descriptors are
created with well-known numbers that are supposed to be excluded from
getting closed.
For extra paranoia close_range() comes with a flags argument. This can e.g.
be used to implement extension. Once can imagine userspace wanting to stop
at the first error instead of ignoring errors under certain circumstances.
There might be other valid ideas in the future. In any case, a flag
argument doesn't hurt and keeps us on the safe side.
>From an implementation side this is kept rather dumb. It saw some input
from David and Jann but all nonsense is obviously my own!
- Errors to close file descriptors are currently ignored. (Could be changed
by setting a flag in the future if needed.)
- __close_range() is a rather simplistic wrapper around __close_fd().
My reasoning behind this is based on the nature of how __close_fd() needs
to release an fd. But maybe I misunderstood specifics:
We take the files_lock and rcu-dereference the fdtable of the calling
task, we find the entry in the fdtable, get the file and need to release
files_lock before calling filp_close().
In the meantime the fdtable might have been altered so we can't just
retake the spinlock and keep the old rcu-reference of the fdtable
around. Instead we need to grab a fresh reference to the fdtable.
If my reasoning is correct then there's really no point in fancyfying
__close_range(): We just need to rcu-dereference the fdtable of the
calling task once to cap the max_fd value correctly and then go on
calling __close_fd() in a loop.
/* References */
[1]: https://lore.kernel.org/lkml/20190516165021.GD17978@ZenIV.linux.org.uk/
[2]: https://github.com/python/cpython/blob/9e4f2f3a6b8ee995c365e86d976937c141d8…
[3]: https://sourceware.org/bugzilla/show_bug.cgi?id=10353#c7
[4]: https://github.com/systemd/systemd/blob/5238e9575906297608ff802a27e2ff9effa…
[5]: https://github.com/lxc/lxc/blob/ddf4b77e11a4d08f09b7b9cd13e593f8c047edc5/sr…
[6]: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/gr…
Note that this is an internal implementation that is not exported.
Currently, libc seems to not provide an exported version of this
because of missing kernel support to do this.
[7]: https://github.com/rust-lang/rust/issues/12148
[8]: https://github.com/rust-lang/rust/blob/5f47c0613ed4eb46fca3633c1297364c09e5…
Rust's solution is slightly different but is equally unperformant.
Rust calls getdtablesize() which is a glibc library function that
simply returns the current RLIMIT_NOFILE or OPEN_MAX values. Rust then
goes on to call close() on each fd. That's obviously overkill for most
tasks. Rarely, tasks - especially non-demons - hit RLIMIT_NOFILE or
OPEN_MAX.
Let's be nice and assume an unprivileged user with RLIMIT_NOFILE set
to 1024. Even in this case, there's a very high chance that in the
common case Rust is calling the close() syscall 1021 times pointlessly
if the task just has 0, 1, and 2 open.
Suggested-by: Al Viro <viro(a)zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <christian(a)brauner.io>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Cc: Jann Horn <jannh(a)google.com>
Cc: David Howells <dhowells(a)redhat.com>
Cc: Dmitry V. Levin <ldv(a)altlinux.org>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: Florian Weimer <fweimer(a)redhat.com>
Cc: linux-api(a)vger.kernel.org
---
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd32.h | 2 ++
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 1 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
fs/file.c | 30 +++++++++++++++++++++
fs/open.c | 20 ++++++++++++++
include/linux/fdtable.h | 2 ++
include/linux/syscalls.h | 2 ++
include/uapi/asm-generic/unistd.h | 4 ++-
22 files changed, 75 insertions(+), 1 deletion(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 9e7704e44f6d..b55d93af8096 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -473,3 +473,4 @@
541 common fsconfig sys_fsconfig
542 common fsmount sys_fsmount
543 common fspick sys_fspick
+545 common close_range sys_close_range
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index aaf479a9e92d..0125c97c75dd 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -447,3 +447,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index c39e90600bb3..9a3270d29b42 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -886,6 +886,8 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_close_range 435
+__SYSCALL(__NR_close_range, sys_close_range)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index e01df3f2f80d..1a90b464e96f 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -354,3 +354,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 7e3d0734b2f3..2dee2050f9ef 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -433,3 +433,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 26339e417695..923ef69e5a76 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -439,3 +439,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 0e2dd68ade57..967ed9de51cd 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -372,3 +372,4 @@
431 n32 fsconfig sys_fsconfig
432 n32 fsmount sys_fsmount
433 n32 fspick sys_fspick
+435 n32 close_range sys_close_range
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index 5eebfa0d155c..71de731102b1 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -348,3 +348,4 @@
431 n64 fsconfig sys_fsconfig
432 n64 fsmount sys_fsmount
433 n64 fspick sys_fspick
+435 n64 close_range sys_close_range
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 3cc1374e02d0..5a325ab29f88 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -421,3 +421,4 @@
431 o32 fsconfig sys_fsconfig
432 o32 fsmount sys_fsmount
433 o32 fspick sys_fspick
+435 o32 close_range sys_close_range
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index c9e377d59232..dcc0a0879139 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 103655d84b4b..ba2c1f078cbd 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -515,3 +515,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index e822b2964a83..d7c9043d2902 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig sys_fsconfig
432 common fsmount sys_fsmount sys_fsmount
433 common fspick sys_fspick sys_fspick
+435 common close_range sys_close_range sys_close_range
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 016a727d4357..9b5e6bf0ce32 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index e047480b1605..8c674a1e0072 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -479,3 +479,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ad968b7bac72..7f7a89a96707 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@
431 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig
432 i386 fsmount sys_fsmount __ia32_sys_fsmount
433 i386 fspick sys_fspick __ia32_sys_fspick
+435 i386 close_range sys_close_range __ia32_sys_close_range
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b4e6f9e6204a..0f7d47ae921c 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@
431 common fsconfig __x64_sys_fsconfig
432 common fsmount __x64_sys_fsmount
433 common fspick __x64_sys_fspick
+435 common close_range __x64_sys_close_range
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 5fa0ee1c8e00..b489532265d0 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -404,3 +404,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+435 common close_range sys_close_range
diff --git a/fs/file.c b/fs/file.c
index 3da91a112bab..3680977a685a 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -641,6 +641,36 @@ int __close_fd(struct files_struct *files, unsigned fd)
}
EXPORT_SYMBOL(__close_fd); /* for ksys_close() */
+/**
+ * __close_range() - Close all file descriptors in a given range.
+ *
+ * @fd: starting file descriptor to close
+ * @max_fd: last file descriptor to close
+ *
+ * This closes a range of file descriptors. All file descriptors
+ * from @fd up to and including @max_fd are closed.
+ */
+int __close_range(struct files_struct *files, unsigned fd, unsigned max_fd)
+{
+ unsigned int cur_max;
+
+ if (fd > max_fd)
+ return -EINVAL;
+
+ rcu_read_lock();
+ cur_max = files_fdtable(files)->max_fds;
+ rcu_read_unlock();
+
+ /* cap to last valid index into fdtable */
+ if (max_fd >= cur_max)
+ max_fd = cur_max - 1;
+
+ while (fd <= max_fd)
+ __close_fd(files, fd++);
+
+ return 0;
+}
+
/*
* variant of __close_fd that gets a ref on the file for later fput
*/
diff --git a/fs/open.c b/fs/open.c
index 9c7d724a6f67..c7baaee7aa47 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1174,6 +1174,26 @@ SYSCALL_DEFINE1(close, unsigned int, fd)
return retval;
}
+/**
+ * close_range() - Close all file descriptors in a given range.
+ *
+ * @fd: starting file descriptor to close
+ * @max_fd: last file descriptor to close
+ * @flags: reserved for future extensions
+ *
+ * This closes a range of file descriptors. All file descriptors
+ * from @fd up to and including @max_fd are closed.
+ * Currently, errors to close a given file descriptor are ignored.
+ */
+SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd,
+ unsigned int, flags)
+{
+ if (flags)
+ return -EINVAL;
+
+ return __close_range(current->files, fd, max_fd);
+}
+
/*
* This routine simulates a hangup on the tty, to arrange that users
* are given clean terminals at login time.
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index f07c55ea0c22..fcd07181a365 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -121,6 +121,8 @@ extern void __fd_install(struct files_struct *files,
unsigned int fd, struct file *file);
extern int __close_fd(struct files_struct *files,
unsigned int fd);
+extern int __close_range(struct files_struct *files, unsigned int fd,
+ unsigned int max_fd);
extern int __close_fd_get_file(unsigned int fd, struct file **res);
extern struct kmem_cache *files_cachep;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..c0189e223255 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -441,6 +441,8 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group);
asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
umode_t mode);
asmlinkage long sys_close(unsigned int fd);
+asmlinkage long sys_close_range(unsigned int fd, unsigned int max_fd,
+ unsigned int flags);
asmlinkage long sys_vhangup(void);
/* fs/pipe.c */
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index a87904daf103..3f36c8745d24 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -844,9 +844,11 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_close_range 435
+__SYSCALL(__NR_close_range, sys_close_range)
#undef __NR_syscalls
-#define __NR_syscalls 434
+#define __NR_syscalls 436
/*
* 32 bit systems traditionally used different
--
2.21.0
This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
process that is created via traditional fork()/clone() calls that is only
referenced by a PID:
int pidfd = pidfd_open(1234, 0);
ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);
With the introduction of pidfds through CLONE_PIDFD it is possible to
created pidfds at process creation time.
However, a lot of processes get created with traditional PID-based calls
such as fork() or clone() (without CLONE_PIDFD). For these processes a
caller can currently not create a pollable pidfd. This is a problem for
Android's low memory killer (LMK) and service managers such as systemd.
Both are examples of tools that want to make use of pidfds to get reliable
notification of process exit for non-parents (pidfd polling) and race-free
signal sending (pidfd_send_signal()). They intend to switch to this API for
process supervision/management as soon as possible. Having no way to get
pollable pidfds from PID-only processes is one of the biggest blockers for
them in adopting this api. With pidfd_open() making it possible to retrieve
pidfds for PID-based processes we enable them to adopt this api.
In line with Arnd's recent changes to consolidate syscall numbers across
architectures, I have added the pidfd_open() syscall to all architectures
at the same time.
Signed-off-by: Christian Brauner <christian(a)brauner.io>
Reviewed-by: Oleg Nesterov <oleg(a)redhat.com>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Cc: "Eric W. Biederman" <ebiederm(a)xmission.com>
Cc: Kees Cook <keescook(a)chromium.org>
Cc: Joel Fernandes (Google) <joel(a)joelfernandes.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Jann Horn <jannh(a)google.com>
Cc: David Howells <dhowells(a)redhat.com>
Cc: Andy Lutomirsky <luto(a)kernel.org>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
Cc: Aleksa Sarai <cyphar(a)cyphar.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Al Viro <viro(a)zeniv.linux.org.uk>
Cc: linux-api(a)vger.kernel.org
---
v1:
- kbuild test robot <lkp(a)intel.com>:
- add missing entry for pidfd_open to arch/arm/tools/syscall.tbl
- Oleg Nesterov <oleg(a)redhat.com>:
- use simpler thread-group leader check
v2:
- Oleg Nesterov <oleg(a)redhat.com>:
- avoid using additional variable
- remove unneeded comment
- Arnd Bergmann <arnd(a)arndb.de>:
- switch from 428 to 434 since the new mount api has taken it
- bump syscall numbers in arch/arm64/include/asm/unistd.h
- Joel Fernandes (Google) <joel(a)joelfernandes.org>:
- switch from ESRCH to EINVAL when the passed-in pid does not refer to a
thread-group leader
- Christian Brauner <christian(a)brauner.io>:
- rebase on v5.2-rc1
- adapt syscall number to account for new mount api syscalls
---
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd.h | 2 +-
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
include/linux/pid.h | 1 +
include/linux/syscalls.h | 1 +
include/uapi/asm-generic/unistd.h | 4 +-
kernel/fork.c | 2 +-
kernel/pid.c | 43 +++++++++++++++++++++
21 files changed, 66 insertions(+), 3 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 9e7704e44f6d..1db9bbcfb84e 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -473,3 +473,4 @@
541 common fsconfig sys_fsconfig
542 common fsmount sys_fsmount
543 common fspick sys_fspick
+544 common pidfd_open sys_pidfd_open
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index aaf479a9e92d..81e6e1817c45 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -447,3 +447,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 70e6882853c0..e8f7d95a1481 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -44,7 +44,7 @@
#define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5)
#define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800)
-#define __NR_compat_syscalls 434
+#define __NR_compat_syscalls 435
#endif
#define __ARCH_WANT_SYS_CLONE
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index c39e90600bb3..7a3158ccd68e 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -886,6 +886,8 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_pidfd_open 434
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index e01df3f2f80d..ecc44926737b 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -354,3 +354,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 7e3d0734b2f3..9a3eb2558568 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -433,3 +433,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 26339e417695..ad706f83c755 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -439,3 +439,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 0e2dd68ade57..97035e19ad03 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -372,3 +372,4 @@
431 n32 fsconfig sys_fsconfig
432 n32 fsmount sys_fsmount
433 n32 fspick sys_fspick
+434 n32 pidfd_open sys_pidfd_open
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index c9e377d59232..5022b9e179c2 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 103655d84b4b..f2c3bda2d39f 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -515,3 +515,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index e822b2964a83..6ebacfeaf853 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig sys_fsconfig
432 common fsmount sys_fsmount sys_fsmount
433 common fspick sys_fspick sys_fspick
+434 common pidfd_open sys_pidfd_open sys_pidfd_open
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 016a727d4357..834c9c7d79fa 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -436,3 +436,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index e047480b1605..c58e71f21129 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -479,3 +479,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ad968b7bac72..43e4429a5272 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@
431 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig
432 i386 fsmount sys_fsmount __ia32_sys_fsmount
433 i386 fspick sys_fspick __ia32_sys_fspick
+434 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b4e6f9e6204a..1bee0a77fdd3 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@
431 common fsconfig __x64_sys_fsconfig
432 common fsmount __x64_sys_fsmount
433 common fspick __x64_sys_fspick
+434 common pidfd_open __x64_sys_pidfd_open
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 5fa0ee1c8e00..782b81945ccc 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -404,3 +404,4 @@
431 common fsconfig sys_fsconfig
432 common fsmount sys_fsmount
433 common fspick sys_fspick
+434 common pidfd_open sys_pidfd_open
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3c8ef5a199ca..c938a92eab99 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -67,6 +67,7 @@ struct pid
extern struct pid init_struct_pid;
extern const struct file_operations pidfd_fops;
+extern int pidfd_create(struct pid *pid);
static inline struct pid *get_pid(struct pid *pid)
{
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..989055e0b501 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -929,6 +929,7 @@ asmlinkage long sys_clock_adjtime32(clockid_t which_clock,
struct old_timex32 __user *tx);
asmlinkage long sys_syncfs(int fd);
asmlinkage long sys_setns(int fd, int nstype);
+asmlinkage long sys_pidfd_open(pid_t pid, unsigned int flags);
asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg,
unsigned int vlen, unsigned flags);
asmlinkage long sys_process_vm_readv(pid_t pid,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index a87904daf103..e5684a4512c0 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -844,9 +844,11 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
__SYSCALL(__NR_fsmount, sys_fsmount)
#define __NR_fspick 433
__SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_pidfd_open 434
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
#undef __NR_syscalls
-#define __NR_syscalls 434
+#define __NR_syscalls 435
/*
* 32 bit systems traditionally used different
diff --git a/kernel/fork.c b/kernel/fork.c
index b4cba953040a..c3df226f47a1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1724,7 +1724,7 @@ const struct file_operations pidfd_fops = {
* Return: On success, a cloexec pidfd is returned.
* On error, a negative errno number will be returned.
*/
-static int pidfd_create(struct pid *pid)
+int pidfd_create(struct pid *pid)
{
int fd;
diff --git a/kernel/pid.c b/kernel/pid.c
index 89548d35eefb..8fc9d94f6ac1 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -37,6 +37,7 @@
#include <linux/syscalls.h>
#include <linux/proc_ns.h>
#include <linux/proc_fs.h>
+#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/idr.h>
@@ -450,6 +451,48 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
return idr_get_next(&ns->idr, &nr);
}
+/**
+ * pidfd_open() - Open new pid file descriptor.
+ *
+ * @pid: pid for which to retrieve a pidfd
+ * @flags: flags to pass
+ *
+ * This creates a new pid file descriptor with the O_CLOEXEC flag set for
+ * the process identified by @pid. Currently, the process identified by
+ * @pid must be a thread-group leader. This restriction currently exists
+ * for all aspects of pidfds including pidfd creation (CLONE_PIDFD cannot
+ * be used with CLONE_THREAD) and pidfd polling (only supports thread group
+ * leaders).
+ *
+ * Return: On success, a cloexec pidfd is returned.
+ * On error, a negative errno number will be returned.
+ */
+SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
+{
+ int fd, ret;
+ struct pid *p;
+
+ if (flags)
+ return -EINVAL;
+
+ if (pid <= 0)
+ return -EINVAL;
+
+ p = find_get_pid(pid);
+ if (!p)
+ return -ESRCH;
+
+ ret = 0;
+ rcu_read_lock();
+ if (!pid_task(p, PIDTYPE_TGID))
+ ret = -EINVAL;
+ rcu_read_unlock();
+
+ fd = ret ?: pidfd_create(p);
+ put_pid(p);
+ return fd;
+}
+
void __init pid_idr_init(void)
{
/* Verify no one has done anything silly: */
--
2.21.0
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The check for entry->index == 0 is done twice. One time should
be sufficient.
Suggested-by: Vitaly Kuznetsov <vkuznets(a)redhat.com>
Signed-off-by: Thomas Huth <thuth(a)redhat.com>
---
Vitaly already noticed this in his review to the "Fix a condition
in test_hv_cpuid()" patch a couple of days ago, but so far I haven't
seen any patch yet on the list that fixes this ... if I missed it
instead, please simply ignore this patch.
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
index 9a21e912097c..8bdf1e7da6cc 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
@@ -52,9 +52,6 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
TEST_ASSERT(entry->index == 0,
".index field should be zero");
- TEST_ASSERT(entry->index == 0,
- ".index field should be zero");
-
TEST_ASSERT(entry->flags == 0,
".flags field should be zero");
--
2.21.0
The code is trying to check that all the padding is zeroed out and it
does this:
entry->padding[0] == entry->padding[1] == entry->padding[2] == 0
Assume everything is zeroed correctly, then the first comparison is
true, the next comparison is false and false is equal to zero so the
overall condition is true. This bug doesn't affect run time very
badly, but the code should instead just check that all three paddings
are zero individually.
Also the error message was copy and pasted from an earlier error and it
wasn't correct.
Fixes: 7edcb7343327 ("KVM: selftests: Add hyperv_cpuid test")
Signed-off-by: Dan Carpenter <dan.carpenter(a)oracle.com>
---
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
index 9a21e912097c..63b9fc3fdfbe 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
@@ -58,9 +58,8 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
TEST_ASSERT(entry->flags == 0,
".flags field should be zero");
- TEST_ASSERT(entry->padding[0] == entry->padding[1]
- == entry->padding[2] == 0,
- ".index field should be zero");
+ TEST_ASSERT(!entry->padding[0] && !entry->padding[1] &&
+ !entry->padding[2], "padding should be zero");
/*
* If needed for debug:
--
2.20.1
> Hi Alex!
>
> Sorry for the late reply, somehow I missed your e-mails.
>
> The patchset looks good to me, except a typo in subjects/commit logs:
> you probably meant "unexpected failures".
>
> Please, fix and feel free to use:
> Reviewed-by: Roman Gushchin <guro(a)fb.com>
> for the series.
>
Thanks Roman!
BTW, do you know other test cases for cgroup2 function or performance?
Thanks
Alex
The test_core will skip the
test_cgcore_no_internal_process_constraint_on_threads test case if the
'cpu' controller missing in root's subtree_control. In fact we need to
set the 'cpu' in subtree_control, to make the testing meaningful.
./test_core
...
ok 4 # skip test_cgcore_no_internal_process_constraint_on_threads
...
Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Tejun Heo <tj(a)kernel.org>
Cc: Roman Gushchin <guro(a)fb.com>
Cc: Claudio Zumbo <claudioz(a)fb.com>
Cc: Claudio <claudiozumbo(a)gmail.com>
Cc: linux-kselftest(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Reviewed-by: Roman Gushchin <guro(a)fb.com>
---
tools/testing/selftests/cgroup/test_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index b1a570d7c557..2ffc3e07d98d 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -198,7 +198,7 @@ static int test_cgcore_no_internal_process_constraint_on_threads(const char *roo
char *parent = NULL, *child = NULL;
if (cg_read_strstr(root, "cgroup.controllers", "cpu") ||
- cg_read_strstr(root, "cgroup.subtree_control", "cpu")) {
+ cg_write(root, "cgroup.subtree_control", "+cpu")) {
ret = KSFT_SKIP;
goto cleanup;
}
--
2.19.1.856.g8858448bb
The cgroup testing relys on the root cgroup's subtree_control setting,
If the 'memory' controller isn't set, some test cases will be failed
as following:
$sudo ./test_core
not ok 1 test_cgcore_internal_process_constraint
ok 2 test_cgcore_top_down_constraint_enable
not ok 3 test_cgcore_top_down_constraint_disable
...
To correct this unexpected failure, this patch write the 'memory' to
subtree_control of root to get a right result.
Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Tejun Heo <tj(a)kernel.org>
Cc: Roman Gushchin <guro(a)fb.com>
Cc: Claudio Zumbo <claudioz(a)fb.com>
Cc: Claudio <claudiozumbo(a)gmail.com>
Cc: linux-kselftest(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Reviewed-by: Roman Gushchin <guro(a)fb.com>
---
tools/testing/selftests/cgroup/test_core.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index be59f9c34ea2..b1a570d7c557 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -376,6 +376,11 @@ int main(int argc, char *argv[])
if (cg_find_unified_root(root, sizeof(root)))
ksft_exit_skip("cgroup v2 isn't mounted\n");
+
+ if (cg_read_strstr(root, "cgroup.subtree_control", "memory"))
+ if (cg_write(root, "cgroup.subtree_control", "+memory"))
+ ksft_exit_skip("Failed to set root memory controller\n");
+
for (i = 0; i < ARRAY_SIZE(tests); i++) {
switch (tests[i].fn(root)) {
case KSFT_PASS:
--
2.19.1.856.g8858448bb
> Hi Alex!
>
> Sorry for the late reply, somehow I missed your e-mails.
>
> The patchset looks good to me, except a typo in subjects/commit logs:
> you probably meant "unexpected failures".
>
> Please, fix and feel free to use:
> Reviewed-by: Roman Gushchin <guro(a)fb.com>
> for the series.
Hi Roman,
Thanks for the typo correct and review. I will resend them with your suggestion.
BTW, How do you test cgroup2 except kselftest? Any other function/performance testing case?
Thanks a lot!
Alex
This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
process that is created via traditional fork()/clone() calls that is only
referenced by a PID:
int pidfd = pidfd_open(1234, 0);
ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);
With the introduction of pidfds through CLONE_PIDFD it is possible to
created pidfds at process creation time.
However, a lot of processes get created with traditional PID-based calls
such as fork() or clone() (without CLONE_PIDFD). For these processes a
caller can currently not create a pollable pidfd. This is a huge problem
for Android's low memory killer (LMK) and service managers such as systemd.
Both are examples of tools that want to make use of pidfds to get reliable
notification of process exit for non-parents (pidfd polling) and race-free
signal sending (pidfd_send_signal()). They intend to switch to this API for
process supervision/management as soon as possible. Having no way to get
pollable pidfds from PID-only processes is one of the biggest blockers for
them in adopting this api. With pidfd_open() making it possible to retrieve
pidfd for PID-based processes we enable them to adopt this api.
In line with Arnd's recent changes to consolidate syscall numbers across
architectures, I have added the pidfd_open() syscall to all architectures
at the same time.
Signed-off-by: Christian Brauner <christian(a)brauner.io>
Acked-by: Geert Uytterhoeven <geert(a)linux-m68k.org>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Cc: "Eric W. Biederman" <ebiederm(a)xmission.com>
Cc: Kees Cook <keescook(a)chromium.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Jann Horn <jannh(a)google.com>
Cc: David Howells <dhowells(a)redhat.com>
Cc: Andy Lutomirsky <luto(a)kernel.org>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: Aleksa Sarai <cyphar(a)cyphar.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Al Viro <viro(a)zeniv.linux.org.uk>
Cc: linux-api(a)vger.kernel.org
---
v1:
- kbuild test robot <lkp(a)intel.com>:
- add missing entry for pidfd_open to arch/arm/tools/syscall.tbl
- Oleg Nesterov <oleg(a)redhat.com>:
- use simpler thread-group leader check
---
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
include/linux/pid.h | 1 +
include/linux/syscalls.h | 1 +
include/uapi/asm-generic/unistd.h | 4 +-
kernel/fork.c | 2 +-
kernel/pid.c | 50 +++++++++++++++++++++
20 files changed, 72 insertions(+), 2 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 165f268beafc..ddc3c93ad7a7 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -467,3 +467,4 @@
535 common io_uring_setup sys_io_uring_setup
536 common io_uring_enter sys_io_uring_enter
537 common io_uring_register sys_io_uring_register
+538 common pidfd_open sys_pidfd_open
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 0393917eaa57..fc41fb34a636 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -441,3 +441,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index 23f1a44acada..350e2049b4a9 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -874,6 +874,8 @@ __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup)
__SYSCALL(__NR_io_uring_enter, sys_io_uring_enter)
#define __NR_io_uring_register 427
__SYSCALL(__NR_io_uring_register, sys_io_uring_register)
+#define __NR_pidfd_open 428
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index 56e3d0b685e1..7115f6dd347a 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -348,3 +348,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index df4ec3ec71d1..44bf12b16ffe 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -427,3 +427,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 4964947732af..0d32e5152dc0 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -433,3 +433,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 9392dfe33f97..726e107b3c9f 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -366,3 +366,4 @@
425 n32 io_uring_setup sys_io_uring_setup
426 n32 io_uring_enter sys_io_uring_enter
427 n32 io_uring_register sys_io_uring_register
+428 n32 pidfd_open sys_pidfd_open
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index fe8ca623add8..83b46b568d51 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -424,3 +424,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 00f5a63c8d9a..5294d04d7fa5 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -509,3 +509,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index 061418f787c3..dcdb838adf49 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
425 common io_uring_setup sys_io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open sys_pidfd_open
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 480b057556ee..8e66edfbc521 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index a1dd24307b00..d6f3bc686939 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -473,3 +473,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 4cd5f982b1e5..1af6b469160a 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@
425 i386 io_uring_setup sys_io_uring_setup __ia32_sys_io_uring_setup
426 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter
427 i386 io_uring_register sys_io_uring_register __ia32_sys_io_uring_register
+428 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 64ca0d06259a..c18e6ebe3387 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@
425 common io_uring_setup __x64_sys_io_uring_setup
426 common io_uring_enter __x64_sys_io_uring_enter
427 common io_uring_register __x64_sys_io_uring_register
+428 common pidfd_open __x64_sys_pidfd_open
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 30084eaf8422..21ee795f3003 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -398,3 +398,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3c8ef5a199ca..c938a92eab99 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -67,6 +67,7 @@ struct pid
extern struct pid init_struct_pid;
extern const struct file_operations pidfd_fops;
+extern int pidfd_create(struct pid *pid);
static inline struct pid *get_pid(struct pid *pid)
{
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..989055e0b501 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -929,6 +929,7 @@ asmlinkage long sys_clock_adjtime32(clockid_t which_clock,
struct old_timex32 __user *tx);
asmlinkage long sys_syncfs(int fd);
asmlinkage long sys_setns(int fd, int nstype);
+asmlinkage long sys_pidfd_open(pid_t pid, unsigned int flags);
asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg,
unsigned int vlen, unsigned flags);
asmlinkage long sys_process_vm_readv(pid_t pid,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index dee7292e1df6..94a257a93d20 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -832,9 +832,11 @@ __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup)
__SYSCALL(__NR_io_uring_enter, sys_io_uring_enter)
#define __NR_io_uring_register 427
__SYSCALL(__NR_io_uring_register, sys_io_uring_register)
+#define __NR_pidfd_open 428
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
#undef __NR_syscalls
-#define __NR_syscalls 428
+#define __NR_syscalls 429
/*
* 32 bit systems traditionally used different
diff --git a/kernel/fork.c b/kernel/fork.c
index 737db1828437..980cc1d2b8d4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1714,7 +1714,7 @@ const struct file_operations pidfd_fops = {
* Return: On success, a cloexec pidfd is returned.
* On error, a negative errno number will be returned.
*/
-static int pidfd_create(struct pid *pid)
+int pidfd_create(struct pid *pid)
{
int fd;
diff --git a/kernel/pid.c b/kernel/pid.c
index 20881598bdfa..4afca3d6dcb8 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -38,6 +38,7 @@
#include <linux/syscalls.h>
#include <linux/proc_ns.h>
#include <linux/proc_fs.h>
+#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/idr.h>
@@ -451,6 +452,55 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
return idr_get_next(&ns->idr, &nr);
}
+/**
+ * pidfd_open() - Open new pid file descriptor.
+ *
+ * @pid: pid for which to retrieve a pidfd
+ * @flags: flags to pass
+ *
+ * This creates a new pid file descriptor with the O_CLOEXEC flag set for
+ * the process identified by @pid. Currently, the process identified by
+ * @pid must be a thread-group leader. This restriction currently exists
+ * for all aspects of pidfds including pidfd creation (CLONE_PIDFD cannot
+ * be used with CLONE_THREAD) and pidfd polling (only supports thread group
+ * leaders).
+ *
+ * Return: On success, a cloexec pidfd is returned.
+ * On error, a negative errno number will be returned.
+ */
+SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
+{
+ int fd, ret;
+ struct pid *p;
+ struct task_struct *tsk;
+
+ if (flags)
+ return -EINVAL;
+
+ if (pid <= 0)
+ return -EINVAL;
+
+ p = find_get_pid(pid);
+ if (!p)
+ return -ESRCH;
+
+ ret = 0;
+ rcu_read_lock();
+ /*
+ * If this returns non-NULL the pid was used as a thread-group
+ * leader. Note, we race with exec here: If it changes the
+ * thread-group leader we might return the old leader.
+ */
+ tsk = pid_task(p, PIDTYPE_TGID);
+ if (!tsk)
+ ret = -ESRCH;
+ rcu_read_unlock();
+
+ fd = ret ?: pidfd_create(p);
+ put_pid(p);
+ return fd;
+}
+
void __init pid_idr_init(void)
{
/* Verify no one has done anything silly: */
--
2.21.0
Atom-based CPUs trigger stack fault when invoke 32-bit SYSENTER instruction
with invalid register values. So we also need SIGBUS handling in this case.
Following is assembly when the fault exception happens.
(gdb) disassemble $eip
Dump of assembler code for function __kernel_vsyscall:
0xf7fd8fe0 <+0>: push %ecx
0xf7fd8fe1 <+1>: push %edx
0xf7fd8fe2 <+2>: push %ebp
0xf7fd8fe3 <+3>: mov %esp,%ebp
0xf7fd8fe5 <+5>: sysenter
0xf7fd8fe7 <+7>: int $0x80
=> 0xf7fd8fe9 <+9>: pop %ebp
0xf7fd8fea <+10>: pop %edx
0xf7fd8feb <+11>: pop %ecx
0xf7fd8fec <+12>: ret
End of assembler dump.
According to Intel SDM, this could also be a Stack Segment Fault(#SS, 12),
except a normal Page Fault(#PF, 14). Especially, in section 6.9 of Vol.3A,
both stack and page faults are within the 10th(lowest priority) class, and
as it said, "exceptions within each class are implementation-dependent and
may vary from processor to processor". It's expected for processors like
Intel Atom to trigger stack fault(SIGBUS), while we get page fault(SIGSEGV)
from common Core processors.
Signed-off-by: Tong Bo <bo.tong(a)intel.com>
Acked-by: Andy Lutomirski <luto(a)kernel.org>
---
tools/testing/selftests/x86/syscall_arg_fault.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/x86/syscall_arg_fault.c b/tools/testing/selftests/x86/syscall_arg_fault.c
index 7db4fc9..d2548401 100644
--- a/tools/testing/selftests/x86/syscall_arg_fault.c
+++ b/tools/testing/selftests/x86/syscall_arg_fault.c
@@ -43,7 +43,7 @@ static sigjmp_buf jmpbuf;
static volatile sig_atomic_t n_errs;
-static void sigsegv(int sig, siginfo_t *info, void *ctx_void)
+static void sigsegv_or_sigbus(int sig, siginfo_t *info, void *ctx_void)
{
ucontext_t *ctx = (ucontext_t*)ctx_void;
@@ -73,7 +73,13 @@ int main()
if (sigaltstack(&stack, NULL) != 0)
err(1, "sigaltstack");
- sethandler(SIGSEGV, sigsegv, SA_ONSTACK);
+ sethandler(SIGSEGV, sigsegv_or_sigbus, SA_ONSTACK);
+ /*
+ * The actual exception can vary. On Atom CPUs, we get #SS
+ * instead of #PF when the vDSO fails to access the stack when
+ * ESP is too close to 2^32, and #SS causes SIGBUS.
+ */
+ sethandler(SIGBUS, sigsegv_or_sigbus, SA_ONSTACK);
sethandler(SIGILL, sigill, SA_ONSTACK);
/*
--
2.7.4
Hi Linus,
Please pull the following Kselftest update for Linux 5.2-rc1
This kselftest second update for Linux 5.2-rc1 consists of
Kselftest framework fixes from Shuah Khan
- kselftest framework bpf build/test workflow regression fix
- Fix to kselftest install to use default install path
- Fix to kselftest KBUILD_OUTPUT builds to not clutter main
KBUILD_OUTPUT directory with selftest objects
- .gitignore fixes from Kelsey Skunberg
- rseq selftests updates from Mathieu Desnoyers and Martin Schwidefsky:
They change the per-architecture pre-abort signatures to ensure those
are valid trap instructions.
The way exit points are presented to debuggers is enhanced, ensuring
all exit points are present, so debuggers don't have to disassemble
rseq critical section to properly skip over them.
Discussions with the glibc community is reaching a consensus of
exposing a __rseq_handled symbol from glibc to coexist with rseq early
adopters.
Update the rseq selftest code to expose and use this symbol.
Support for compiling asm goto with clang is added with the
"-no-integrated-as" compiler switch, similarly to the top level kernel
Makefile.
- kselftest Makefile test run output refactoring and making test
output TAP13 compliant from Kees Cook:
This re-factors the selftest Makefiles to extract the test running
logic to be reused between "run_tests" and "emit_tests", while also
fixing up the test output to be TAP version 13 compliant:
- added "plan" line
- fixed result line syntax
- moved all test output to be "# "-prefixed as TAP "diagnostic"
lines
The prefixing code includes a fallback mode for limited execution
environments.
Additionally, the plan lines are fixed for all callers of kselftest.h.
diff is attached.
Also, there is a merge conflict with the following commit which went
through the s390 maintainer tree and is now in your master which will
require a minor fix-up.
commit e24e4712efad737ca09ff299276737331cd021d9
Author: Martin Schwidefsky <schwidefsky(a)de.ibm.com>
rseq/selftests: s390: use trap4 for RSEQ_SIG
thanks,
-- Shuah
---------------------------------------------------------------
The following changes since commit d917fb876f6eaeeea8a2b620d2a266ce26372f4d:
selftests: build and run gpio when output directory is the src dir
(2019-04-22 17:02:26 -0600)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
tags/linux-kselftest-5.2-rc1-2
for you to fetch changes up to 61c2018c0743fe0c9ca68e308b5727b8a7c3d544:
selftests: avoid KBUILD_OUTPUT dir cluttering with selftest objects
(2019-05-14 17:37:41 -0600)
----------------------------------------------------------------
linux-kselftest-5.2-rc1-2
This kselftest second update for Linux 5.2-rc1 consists of
Kselftest framework fixes from Shuah Khan
- kselftest framework bpf build/test workflow regression fix
- Fix to kselftest install to use default install path
- Fix to kselftest KBUILD_OUTPUT builds to not clutter main
KBUILD_OUTPUT directory with selftest objects
- .gitignore fixes from Kelsey Skunberg
- rseq selftests updates from Mathieu Desnoyers and Martin Schwidefsky:
They change the per-architecture pre-abort signatures to ensure those
are valid trap instructions.
The way exit points are presented to debuggers is enhanced, ensuring
all exit points are present, so debuggers don't have to disassemble
rseq critical section to properly skip over them.
Discussions with the glibc community is reaching a consensus of exposing
a __rseq_handled symbol from glibc to coexist with rseq early adopters.
Update the rseq selftest code to expose and use this symbol.
Support for compiling asm goto with clang is added with the
"-no-integrated-as" compiler switch, similarly to the top level kernel
Makefile.
- kselftest Makefile test run output refactoring and making test
output TAP13 compliant from Kees Cook:
This re-factors the selftest Makefiles to extract the test running logic
to be reused between "run_tests" and "emit_tests", while also fixing
up the test output to be TAP version 13 compliant:
- added "plan" line
- fixed result line syntax
- moved all test output to be "# "-prefixed as TAP "diagnostic"
lines
The prefixing code includes a fallback mode for limited execution
environments.
Additionally, the plan lines are fixed for all callers of kselftest.h.
----------------------------------------------------------------
Kees Cook (8):
selftests: Extract single-test shell logic from lib.mk
selftests: Use runner.sh for emit targets
selftests: Extract logic for multiple test runs
selftests: Add plan line and fix result line syntax
selftests: Distinguish between missing and non-executable
selftests: Move test output to diagnostic lines
selftests: Remove KSFT_TAP_LEVEL
selftests: Add test plan API to kselftest.h and adjust callers
Kelsey Skunberg (2):
selftests: pidfd: Create .gitignore to include pidfd_test
selftests: drivers: Create .gitignore to include /dma-buf/udmabuf
Martin Schwidefsky (1):
rseq/selftests: s390: use trap4 for RSEQ_SIG
Mathieu Desnoyers (11):
rseq/selftests: x86: Work-around bogus gcc-8 optimisation
rseq/selftests: Add __rseq_exit_point_array section for debuggers
rseq/selftests: Introduce __rseq_cs_ptr_array, rename
__rseq_table to __rseq_cs
rseq/selftests: Use __rseq_handled symbol to coexist with glibc
rseq/selftests: s390: use jg instruction for jumps outside of the asm
rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode
rseq/selftests: arm: use udf instruction for RSEQ_SIG
rseq/selftests: aarch64 code signature: handle big-endian environment
rseq/selftests: powerpc code signature: generate valid instructions
rseq/selftests: mips: use break instruction for RSEQ_SIG
rseq/selftests: add -no-integrated-as for clang
Shuah Khan (3):
selftests: fix install target to use default install path
selftests: fix bpf build/test workflow regression when
KBUILD_OUTPUT is set
selftests: avoid KBUILD_OUTPUT dir cluttering with selftest objects
tools/testing/selftests/.gitignore | 1 -
tools/testing/selftests/Makefile | 39 +--
.../selftests/breakpoints/breakpoint_test.c | 15 +-
.../selftests/breakpoints/breakpoint_test_arm64.c | 3 +-
.../breakpoints/step_after_suspend_test.c | 8 +
tools/testing/selftests/capabilities/test_execve.c | 6 +-
tools/testing/selftests/drivers/.gitignore | 1 +
.../selftests/futex/functional/futex_requeue_pi.c | 1 +
.../functional/futex_requeue_pi_mismatched_ops.c | 1 +
.../functional/futex_requeue_pi_signal_restart.c | 1 +
.../functional/futex_wait_private_mapped_file.c | 1 +
.../futex/functional/futex_wait_timeout.c | 1 +
.../functional/futex_wait_uninitialized_heap.c | 1 +
.../futex/functional/futex_wait_wouldblock.c | 1 +
tools/testing/selftests/kselftest.h | 17 +-
tools/testing/selftests/kselftest/prefix.pl | 23 ++
tools/testing/selftests/kselftest/runner.sh | 86 +++++++
tools/testing/selftests/lib.mk | 76 ++----
.../testing/selftests/membarrier/membarrier_test.c | 1 +
tools/testing/selftests/pidfd/.gitignore | 1 +
tools/testing/selftests/pidfd/pidfd_test.c | 1 +
tools/testing/selftests/rseq/Makefile | 8 +-
tools/testing/selftests/rseq/rseq-arm.h | 132 +++++++++--
tools/testing/selftests/rseq/rseq-arm64.h | 74 +++++-
tools/testing/selftests/rseq/rseq-mips.h | 115 ++++++++-
tools/testing/selftests/rseq/rseq-ppc.h | 90 ++++++-
tools/testing/selftests/rseq/rseq-s390.h | 78 +++++-
tools/testing/selftests/rseq/rseq-x86.h | 264
++++++++++++++-------
tools/testing/selftests/rseq/rseq.c | 55 ++++-
tools/testing/selftests/rseq/rseq.h | 1 +
tools/testing/selftests/sigaltstack/sas.c | 1 +
tools/testing/selftests/sync/sync_test.c | 1 +
32 files changed, 883 insertions(+), 221 deletions(-)
create mode 100644 tools/testing/selftests/drivers/.gitignore
create mode 100755 tools/testing/selftests/kselftest/prefix.pl
create mode 100644 tools/testing/selftests/kselftest/runner.sh
create mode 100644 tools/testing/selftests/pidfd/.gitignore
---------------------------------------------------------------
This series of patches move the commonly used bpf_printk macro to
bpf_helpers.h which is already included in all BPF programs which
defined that macro on their own.
v1->v2:
- If HBM_DEBUG is not defined in hbm sample, undefine bpf_printk and set
an empty macro for it.
Michal Rostecki (2):
selftests: bpf: Move bpf_printk to bpf_helpers.h
samples: bpf: Do not define bpf_printk macro
samples/bpf/hbm_kern.h | 11 ++---------
samples/bpf/tcp_basertt_kern.c | 7 -------
samples/bpf/tcp_bufs_kern.c | 7 -------
samples/bpf/tcp_clamp_kern.c | 7 -------
samples/bpf/tcp_cong_kern.c | 7 -------
samples/bpf/tcp_iw_kern.c | 7 -------
samples/bpf/tcp_rwnd_kern.c | 7 -------
samples/bpf/tcp_synrto_kern.c | 7 -------
samples/bpf/tcp_tos_reflect_kern.c | 7 -------
samples/bpf/xdp_sample_pkts_kern.c | 7 -------
tools/testing/selftests/bpf/bpf_helpers.h | 8 ++++++++
.../testing/selftests/bpf/progs/sockmap_parse_prog.c | 7 -------
.../selftests/bpf/progs/sockmap_tcp_msg_prog.c | 7 -------
.../selftests/bpf/progs/sockmap_verdict_prog.c | 7 -------
.../testing/selftests/bpf/progs/test_lwt_seg6local.c | 7 -------
tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 7 -------
tools/testing/selftests/bpf/test_sockmap_kern.h | 7 -------
17 files changed, 10 insertions(+), 114 deletions(-)
--
2.21.0
This adds the pidfd_open() syscall. It allows a caller to retrieve pollable
pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a
process that is created via traditional fork()/clone() calls that is only
referenced by a PID:
int pidfd = pidfd_open(1234, 0);
ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0);
With the introduction of pidfds through CLONE_PIDFD it is possible to
created pidfds at process creation time.
However, a lot of processes get created with traditional PID-based calls
such as fork() or clone() (without CLONE_PIDFD). For these processes a
caller can currently not create a pollable pidfd. This is a huge problem
for Android's low memory killer (LMK) and service managers such as systemd.
Both are examples of tools that want to make use of pidfds to get reliable
notification of process exit for non-parents (pidfd polling) and race-free
signal sending (pidfd_send_signal()). They intend to switch to this API for
process supervision/management as soon as possible. Having no way to get
pollable pidfds from PID-only processes is one of the biggest blockers for
them in adopting this api. With pidfd_open() making it possible to retrieve
pidfd for PID-based processes we enable them to adopt this api.
In line with Arnd's recent changes to consolidate syscall numbers across
architectures, I have added the pidfd_open() syscall to all architectures
at the same time.
Signed-off-by: Christian Brauner <christian(a)brauner.io>
Cc: Arnd Bergmann <arnd(a)arndb.de>
Cc: "Eric W. Biederman" <ebiederm(a)xmission.com>
Cc: Kees Cook <keescook(a)chromium.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Jann Horn <jannh(a)google.com>
Cc: David Howells <dhowells(a)redhat.com>
Cc: Andy Lutomirsky <luto(a)kernel.org>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: Aleksa Sarai <cyphar(a)cyphar.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Al Viro <viro(a)zeniv.linux.org.uk>
Cc: linux-api(a)vger.kernel.org
---
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
include/linux/pid.h | 1 +
include/linux/syscalls.h | 1 +
include/uapi/asm-generic/unistd.h | 4 +-
kernel/fork.c | 2 +-
kernel/pid.c | 48 +++++++++++++++++++++
19 files changed, 69 insertions(+), 2 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 165f268beafc..ddc3c93ad7a7 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -467,3 +467,4 @@
535 common io_uring_setup sys_io_uring_setup
536 common io_uring_enter sys_io_uring_enter
537 common io_uring_register sys_io_uring_register
+538 common pidfd_open sys_pidfd_open
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index 23f1a44acada..350e2049b4a9 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -874,6 +874,8 @@ __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup)
__SYSCALL(__NR_io_uring_enter, sys_io_uring_enter)
#define __NR_io_uring_register 427
__SYSCALL(__NR_io_uring_register, sys_io_uring_register)
+#define __NR_pidfd_open 428
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
/*
* Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index 56e3d0b685e1..7115f6dd347a 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -348,3 +348,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index df4ec3ec71d1..44bf12b16ffe 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -427,3 +427,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 4964947732af..0d32e5152dc0 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -433,3 +433,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 9392dfe33f97..726e107b3c9f 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -366,3 +366,4 @@
425 n32 io_uring_setup sys_io_uring_setup
426 n32 io_uring_enter sys_io_uring_enter
427 n32 io_uring_register sys_io_uring_register
+428 n32 pidfd_open sys_pidfd_open
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index fe8ca623add8..83b46b568d51 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -424,3 +424,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 00f5a63c8d9a..5294d04d7fa5 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -509,3 +509,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index 061418f787c3..dcdb838adf49 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
425 common io_uring_setup sys_io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open sys_pidfd_open
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 480b057556ee..8e66edfbc521 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -430,3 +430,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index a1dd24307b00..d6f3bc686939 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -473,3 +473,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 4cd5f982b1e5..1af6b469160a 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@
425 i386 io_uring_setup sys_io_uring_setup __ia32_sys_io_uring_setup
426 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter
427 i386 io_uring_register sys_io_uring_register __ia32_sys_io_uring_register
+428 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 64ca0d06259a..c18e6ebe3387 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@
425 common io_uring_setup __x64_sys_io_uring_setup
426 common io_uring_enter __x64_sys_io_uring_enter
427 common io_uring_register __x64_sys_io_uring_register
+428 common pidfd_open __x64_sys_pidfd_open
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 30084eaf8422..21ee795f3003 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -398,3 +398,4 @@
425 common io_uring_setup sys_io_uring_setup
426 common io_uring_enter sys_io_uring_enter
427 common io_uring_register sys_io_uring_register
+428 common pidfd_open sys_pidfd_open
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3c8ef5a199ca..c938a92eab99 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -67,6 +67,7 @@ struct pid
extern struct pid init_struct_pid;
extern const struct file_operations pidfd_fops;
+extern int pidfd_create(struct pid *pid);
static inline struct pid *get_pid(struct pid *pid)
{
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..989055e0b501 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -929,6 +929,7 @@ asmlinkage long sys_clock_adjtime32(clockid_t which_clock,
struct old_timex32 __user *tx);
asmlinkage long sys_syncfs(int fd);
asmlinkage long sys_setns(int fd, int nstype);
+asmlinkage long sys_pidfd_open(pid_t pid, unsigned int flags);
asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg,
unsigned int vlen, unsigned flags);
asmlinkage long sys_process_vm_readv(pid_t pid,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index dee7292e1df6..94a257a93d20 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -832,9 +832,11 @@ __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup)
__SYSCALL(__NR_io_uring_enter, sys_io_uring_enter)
#define __NR_io_uring_register 427
__SYSCALL(__NR_io_uring_register, sys_io_uring_register)
+#define __NR_pidfd_open 428
+__SYSCALL(__NR_pidfd_open, sys_pidfd_open)
#undef __NR_syscalls
-#define __NR_syscalls 428
+#define __NR_syscalls 429
/*
* 32 bit systems traditionally used different
diff --git a/kernel/fork.c b/kernel/fork.c
index 737db1828437..980cc1d2b8d4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1714,7 +1714,7 @@ const struct file_operations pidfd_fops = {
* Return: On success, a cloexec pidfd is returned.
* On error, a negative errno number will be returned.
*/
-static int pidfd_create(struct pid *pid)
+int pidfd_create(struct pid *pid)
{
int fd;
diff --git a/kernel/pid.c b/kernel/pid.c
index 20881598bdfa..237d18d6ecb8 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -38,6 +38,7 @@
#include <linux/syscalls.h>
#include <linux/proc_ns.h>
#include <linux/proc_fs.h>
+#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/idr.h>
@@ -451,6 +452,53 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
return idr_get_next(&ns->idr, &nr);
}
+/**
+ * pidfd_open() - Open new pid file descriptor.
+ *
+ * @pid: pid for which to retrieve a pidfd
+ * @flags: flags to pass
+ *
+ * This creates a new pid file descriptor with the O_CLOEXEC flag set for
+ * the process identified by @pid. Currently, the process identified by
+ * @pid must be a thread-group leader. This restriction currently exists
+ * for all aspects of pidfds including pidfd creation (CLONE_PIDFD cannot
+ * be used with CLONE_THREAD) and pidfd polling (only supports thread group
+ * leaders).
+ *
+ * Return: On success, a cloexec pidfd is returned.
+ * On error, a negative errno number will be returned.
+ */
+SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
+{
+ int fd, ret;
+ struct pid *p;
+ struct task_struct *tsk;
+
+ if (flags)
+ return -EINVAL;
+
+ if (pid <= 0)
+ return -EINVAL;
+
+ p = find_get_pid(pid);
+ if (!p)
+ return -ESRCH;
+
+ rcu_read_lock();
+ tsk = pid_task(p, PIDTYPE_PID);
+ if (!tsk)
+ ret = -ESRCH;
+ else if (unlikely(!thread_group_leader(tsk)))
+ ret = -EINVAL;
+ else
+ ret = 0;
+ rcu_read_unlock();
+
+ fd = ret ?: pidfd_create(p);
+ put_pid(p);
+ return fd;
+}
+
void __init pid_idr_init(void)
{
/* Verify no one has done anything silly: */
--
2.21.0
From: Paolo Bonzini <pbonzini(a)redhat.com>
[ Upstream commit 76d58e0f07ec203bbdfcaabd9a9fc10a5a3ed5ea ]
If a memory slot's size is not a multiple of 64 pages (256K), then
the KVM_CLEAR_DIRTY_LOG API is unusable: clearing the final 64 pages
either requires the requested page range to go beyond memslot->npages,
or requires log->num_pages to be unaligned, and kvm_clear_dirty_log_protect
requires log->num_pages to be both in range and aligned.
To allow this case, allow log->num_pages not to be a multiple of 64 if
it ends exactly on the last page of the slot.
Reported-by: Peter Xu <peterx(a)redhat.com>
Fixes: 98938aa8edd6 ("KVM: validate userspace input in kvm_clear_dirty_log_protect()", 2019-01-02)
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
Documentation/virtual/kvm/api.txt | 5 +++--
tools/testing/selftests/kvm/dirty_log_test.c | 9 ++++++---
virt/kvm/kvm_main.c | 7 ++++---
3 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index ba8927c0d45c4..a1b8e6d92298c 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -3790,8 +3790,9 @@ The ioctl clears the dirty status of pages in a memory slot, according to
the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap
field. Bit 0 of the bitmap corresponds to page "first_page" in the
memory slot, and num_pages is the size in bits of the input bitmap.
-Both first_page and num_pages must be a multiple of 64. For each bit
-that is set in the input bitmap, the corresponding page is marked "clean"
+first_page must be a multiple of 64; num_pages must also be a multiple of
+64 unless first_page + num_pages is the size of the memory slot. For each
+bit that is set in the input bitmap, the corresponding page is marked "clean"
in KVM's dirty bitmap, and dirty tracking is re-enabled for that page
(for example via write-protection, or by clearing the dirty bit in
a page table entry).
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 4715cfba20dce..93f99c6b7d79e 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -288,8 +288,11 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
#endif
max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1;
guest_page_size = (1ul << guest_page_shift);
- /* 1G of guest page sized pages */
- guest_num_pages = (1ul << (30 - guest_page_shift));
+ /*
+ * A little more than 1G of guest page sized pages. Cover the
+ * case where the size is not aligned to 64 pages.
+ */
+ guest_num_pages = (1ul << (30 - guest_page_shift)) + 3;
host_page_size = getpagesize();
host_num_pages = (guest_num_pages * guest_page_size) / host_page_size +
!!((guest_num_pages * guest_page_size) % host_page_size);
@@ -359,7 +362,7 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
#ifdef USE_CLEAR_DIRTY_LOG
kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
- DIV_ROUND_UP(host_num_pages, 64) * 64);
+ host_num_pages);
#endif
vm_dirty_log_verify(bmap);
iteration++;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b4f2d892a1d36..c9b102e65a3a7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1241,7 +1241,7 @@ int kvm_clear_dirty_log_protect(struct kvm *kvm,
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
return -EINVAL;
- if ((log->first_page & 63) || (log->num_pages & 63))
+ if (log->first_page & 63)
return -EINVAL;
slots = __kvm_memslots(kvm, as_id);
@@ -1254,8 +1254,9 @@ int kvm_clear_dirty_log_protect(struct kvm *kvm,
n = kvm_dirty_bitmap_bytes(memslot);
if (log->first_page > memslot->npages ||
- log->num_pages > memslot->npages - log->first_page)
- return -EINVAL;
+ log->num_pages > memslot->npages - log->first_page ||
+ (log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63)))
+ return -EINVAL;
*flush = false;
dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
--
2.20.1
Linus, Greg, Masahiro, Here are some simple fixes for the kheaders feature.
Please consider these patches for an rc release. They are based on Linus's
master branch. The only difference between the last series [1] and this one is
I squashed 1/3 and 3/3 and rebased. Thanks!
[1] https://patchwork.kernel.org/cover/10939557/
Joel Fernandes (Google) (2):
kheaders: Move from proc to sysfs
kheaders: Do not regenerate archive if config is not changed
init/Kconfig | 17 +++++----
kernel/Makefile | 4 +--
kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 17 ++++++---
kernel/kheaders.c | 40 +++++++++------------
4 files changed, 38 insertions(+), 40 deletions(-)
rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (82%)
--
2.21.0.1020.gf2820cf01a-goog
## TLDR
I mostly wanted to incorporate feedback I got over the last week and a
half.
Biggest things to look out for:
- KUnit core now outputs results in TAP14.
- Heavily reworked tools/testing/kunit/kunit.py
- Changed how parsing works.
- Added testing.
- Greg, Logan, you might want to re-review this.
- Added documentation on how to use KUnit on non-UML kernels. You can
see the docs rendered here[1].
There is still some discussion going on on the [PATCH v2 00/17] thread,
but I wanted to get some of these updates out before they got too stale
(and too difficult for me to keep track of). I hope no one minds.
## Background
This patch set proposes KUnit, a lightweight unit testing and mocking
framework for the Linux kernel.
Unlike Autotest and kselftest, KUnit is a true unit testing framework;
it does not require installing the kernel on a test machine or in a VM
(however, KUnit still allows you to run tests on test machines or in VMs
if you want) and does not require tests to be written in userspace
running on a host kernel. Additionally, KUnit is fast: From invocation
to completion KUnit can run several dozen tests in under a second.
Currently, the entire KUnit test suite for KUnit runs in under a second
from the initial invocation (build time excluded).
KUnit is heavily inspired by JUnit, Python's unittest.mock, and
Googletest/Googlemock for C++. KUnit provides facilities for defining
unit test cases, grouping related test cases into test suites, providing
common infrastructure for running tests, mocking, spying, and much more.
## What's so special about unit testing?
A unit test is supposed to test a single unit of code in isolation,
hence the name. There should be no dependencies outside the control of
the test; this means no external dependencies, which makes tests orders
of magnitudes faster. Likewise, since there are no external dependencies,
there are no hoops to jump through to run the tests. Additionally, this
makes unit tests deterministic: a failing unit test always indicates a
problem. Finally, because unit tests necessarily have finer granularity,
they are able to test all code paths easily solving the classic problem
of difficulty in exercising error handling code.
## Is KUnit trying to replace other testing frameworks for the kernel?
No. Most existing tests for the Linux kernel are end-to-end tests, which
have their place. A well tested system has lots of unit tests, a
reasonable number of integration tests, and some end-to-end tests. KUnit
is just trying to address the unit test space which is currently not
being addressed.
## More information on KUnit
There is a bunch of documentation near the end of this patch set that
describes how to use KUnit and best practices for writing unit tests.
For convenience I am hosting the compiled docs here[2].
Additionally for convenience, I have applied these patches to a
branch[3].
The repo may be cloned with:
git clone https://kunit.googlesource.com/linux
This patchset is on the kunit/rfc/v5.1/v3 branch.
## Changes Since Last Version
- Converted KUnit core to print test results in TAP14 format as
suggested by Greg and Frank.
- Heavily reworked tools/testing/kunit/kunit.py
- Changed how parsing works.
- Added testing.
- Added documentation on how to use KUnit on non-UML kernels. You can
see the docs rendered here[1].
- Added a new set of EXPECTs and ASSERTs for pointer comparison.
- Removed more function indirection as suggested by Logan.
- Added a new patch that adds `kunit_try_catch_throw` to objtool's
noreturn list.
- Fixed a number of minorish issues pointed out by Shuah, Masahiro, and
kbuild bot.
[1] https://google.github.io/kunit-docs/third_party/kernel/docs/usage.html#kuni…
[2] https://google.github.io/kunit-docs/third_party/kernel/docs/
[3] https://kunit.googlesource.com/linux/+/kunit/rfc/v5.1/v3
--
2.21.0.1020.gf2820cf01a-goog
The cgroup testing relys on the root cgroup's subtree_control setting,
If the 'memory' controller isn't set, all test cases will be failed
as following:
$ sudo ./test_memcontrol
not ok 1 test_memcg_subtree_control
not ok 2 test_memcg_current
ok 3 # skip test_memcg_min
not ok 4 test_memcg_low
not ok 5 test_memcg_high
not ok 6 test_memcg_max
not ok 7 test_memcg_oom_events
ok 8 # skip test_memcg_swap_max
not ok 9 test_memcg_sock
not ok 10 test_memcg_oom_group_leaf_events
not ok 11 test_memcg_oom_group_parent_events
not ok 12 test_memcg_oom_group_score_events
To correct this unexcepted failure, this patch write the 'memory' to
subtree_control of root to get a right result.
Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Roman Gushchin <guro(a)fb.com>
Cc: Tejun Heo <tj(a)kernel.org>
Cc: Mike Rapoport <rppt(a)linux.vnet.ibm.com>
Cc: Jay Kamat <jgkamat(a)fb.com>
Cc: linux-kselftest(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
---
tools/testing/selftests/cgroup/test_memcontrol.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index 6f339882a6ca..73612d604a2a 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -1205,6 +1205,10 @@ int main(int argc, char **argv)
if (cg_read_strstr(root, "cgroup.controllers", "memory"))
ksft_exit_skip("memory controller isn't available\n");
+ if (cg_read_strstr(root, "cgroup.subtree_control", "memory"))
+ if (cg_write(root, "cgroup.subtree_control", "+memory"))
+ ksft_exit_skip("Failed to set root memory controller\n");
+
for (i = 0; i < ARRAY_SIZE(tests); i++) {
switch (tests[i].fn(root)) {
case KSFT_PASS:
--
2.19.1.856.g8858448bb
Android low memory killer (LMK) needs to know when a process dies once
it is sent the kill signal. It does so by checking for the existence of
/proc/pid which is both racy and slow. For example, if a PID is reused
between when LMK sends a kill signal and checks for existence of the
PID, since the wrong PID is now possibly checked for existence.
This patch adds polling support to pidfd. Using the polling support, LMK
will be able to get notified when a process exists in race-free and fast
way, and allows the LMK to do other things (such as by polling on other
fds) while awaiting the process being killed to die.
For notification to polling processes, we follow the same existing
mechanism in the kernel used when the parent of the task group is to be
notified of a child's death (do_notify_parent). This is precisely when
the tasks waiting on a poll of pidfd are also awakened in this patch.
We have decided to include the waitqueue in struct pid for the following
reasons:
1. The wait queue has to survive for the lifetime of the poll. Including
it in task_struct would not be option in this case because the task can
be reaped and destroyed before the poll returns.
2. By including the struct pid for the waitqueue means that during
de_thread(), the new thread group leader automatically gets the new
waitqueue/pid even though its task_struct is different.
Appropriate test cases are added in the second patch to provide coverage
of all the cases the patch is handling.
Andy had a similar patch [1] in the past which was a good reference
however this patch tries to handle different situations properly related
to thread group existence, and how/where it notifies. And also solves
other bugs (waitqueue lifetime). Daniel had a similar patch [2]
recently which this patch supercedes.
[1] https://lore.kernel.org/patchwork/patch/345098/
[2] https://lore.kernel.org/lkml/20181029175322.189042-1-dancol@google.com/
Cc: Andy Lutomirski <luto(a)amacapital.net>
Cc: Steven Rostedt <rostedt(a)goodmis.org>
Cc: Daniel Colascione <dancol(a)google.com>
Cc: Christian Brauner <christian(a)brauner.io>
Cc: Jann Horn <jannh(a)google.com>
Cc: Tim Murray <timmurray(a)google.com>
Cc: Jonathan Kowalski <bl0pbl33p(a)gmail.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Al Viro <viro(a)zeniv.linux.org.uk>
Cc: Kees Cook <keescook(a)chromium.org>
Cc: David Howells <dhowells(a)redhat.com>
Cc: Oleg Nesterov <oleg(a)redhat.com>
Cc: kernel-team(a)android.com
(Oleg improved the code by showing how to avoid tasklist_lock)
Suggested-by: Oleg Nesterov <oleg(a)redhat.com>
Co-developed-by: Daniel Colascione <dancol(a)google.com>
Signed-off-by: Daniel Colascione <dancol(a)google.com>
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
v1 -> v2:
* Restructure poll code to avoid tasklist_lock (Oleg)
* use task_pid instead of get_pid_task in notify_pidfd (Oleg)
* Added comments to code, commit message nits (Christian)
* Test case nits/improvements (Christian)
RFC -> v1:
* Based on CLONE_PIDFD patches: https://lwn.net/Articles/786244/
* Updated selftests.
* Renamed poll wake function to do_notify_pidfd.
* Removed depending on EXIT flags
* Removed POLLERR flag since semantics are controversial and
we don't have usecases for it right now (later we can add if there's
a need for it).
include/linux/pid.h | 3 +++
kernel/fork.c | 29 +++++++++++++++++++++++++++++
kernel/pid.c | 2 ++
kernel/signal.c | 11 +++++++++++
4 files changed, 45 insertions(+)
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3c8ef5a199ca..1484db6ca8d1 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -3,6 +3,7 @@
#define _LINUX_PID_H
#include <linux/rculist.h>
+#include <linux/wait.h>
enum pid_type
{
@@ -60,6 +61,8 @@ struct pid
unsigned int level;
/* lists of tasks that use this pid */
struct hlist_head tasks[PIDTYPE_MAX];
+ /* wait queue for pidfd notifications */
+ wait_queue_head_t wait_pidfd;
struct rcu_head rcu;
struct upid numbers[1];
};
diff --git a/kernel/fork.c b/kernel/fork.c
index 5525837ed80e..721f8c9d2921 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1685,8 +1685,37 @@ static void pidfd_show_fdinfo(struct seq_file *m, struct file *f)
}
#endif
+/*
+ * Poll support for process exit notification.
+ */
+static unsigned int pidfd_poll(struct file *file, struct poll_table_struct *pts)
+{
+ struct task_struct *task;
+ struct pid *pid = file->private_data;
+ int poll_flags = 0;
+
+ poll_wait(file, &pid->wait_pidfd, pts);
+
+ rcu_read_lock();
+ task = pid_task(pid, PIDTYPE_PID);
+ WARN_ON_ONCE(task && !thread_group_leader(task));
+
+ /*
+ * Inform pollers only when the whole thread group exits, if thread
+ * group leader exits before all other threads in the group, then
+ * poll(2) should block, similar to the wait(2) family.
+ */
+ if (!task || (task->exit_state && thread_group_empty(task)))
+ poll_flags = POLLIN | POLLRDNORM;
+ rcu_read_unlock();
+
+ return poll_flags;
+}
+
+
const struct file_operations pidfd_fops = {
.release = pidfd_release,
+ .poll = pidfd_poll,
#ifdef CONFIG_PROC_FS
.show_fdinfo = pidfd_show_fdinfo,
#endif
diff --git a/kernel/pid.c b/kernel/pid.c
index 20881598bdfa..5c90c239242f 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -214,6 +214,8 @@ struct pid *alloc_pid(struct pid_namespace *ns)
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);
+ init_waitqueue_head(&pid->wait_pidfd);
+
upid = pid->numbers + ns->level;
spin_lock_irq(&pidmap_lock);
if (!(ns->pid_allocated & PIDNS_ADDING))
diff --git a/kernel/signal.c b/kernel/signal.c
index 1581140f2d99..a17fff073c3d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1800,6 +1800,14 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type)
return ret;
}
+static void do_notify_pidfd(struct task_struct *task)
+{
+ struct pid *pid;
+
+ pid = task_pid(task);
+ wake_up_all(&pid->wait_pidfd);
+}
+
/*
* Let a parent know about the death of a child.
* For a stopped/continued status change, use do_notify_parent_cldstop instead.
@@ -1823,6 +1831,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
BUG_ON(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
+ /* Wake up all pidfd waiters */
+ do_notify_pidfd(tsk);
+
if (sig != SIGCHLD) {
/*
* This is only possible if parent == real_parent.
--
2.21.0.593.g511ec345e18-goog
On Wed, May 08, 2019 at 05:39:07PM +0200, Peter Zijlstra wrote:
> On Wed, May 08, 2019 at 07:42:48AM -0500, Josh Poimboeuf wrote:
> > On Wed, May 08, 2019 at 02:04:16PM +0200, Peter Zijlstra wrote:
>
> > > Do the x86_64 variants also want some ORC annotation?
> >
> > Maybe so. Though it looks like regs->ip isn't saved. The saved
> > registers might need to be tweaked. I'll need to look into it.
>
> What all these sites do (and maybe we should look at unifying them
> somehow) is turn a CALL frame (aka RET-IP) into an exception frame (aka
> pt_regs).
>
> So regs->ip will be the return address (which is fixed up to be the CALL
> address in the handler).
But from what I can tell, trampoline_handler() hard-codes regs->ip to
point to kretprobe_trampoline(), and the original return address is
placed in regs->sp.
Masami, is there a reason why regs->ip doesn't have the original return
address and regs->sp doesn't have the original SP? I think that would
help the unwinder understand things.
--
Josh
The following files are generated after building /selftests/bpf/ and
should be added to .gitignore:
- libbpf.pc
- libbpf.so.*
Signed-off-by: Kelsey Skunberg <skunberg.kelsey(a)gmail.com>
---
Change since v1:
- Add libbpf.so.* in replace of libbpf.so.0 and
libbpf.so.0.0.3
- Update commit log to reflect file change
tools/testing/selftests/bpf/.gitignore | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 41e8a689aa77..a877803e4ba8 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -32,3 +32,5 @@ test_tcpnotify_user
test_libbpf
test_tcp_check_syncookie_user
alu32
+libbpf.pc
+libbpf.so.*
--
2.20.1
Hello kbuild, kselftest,
I've been working on a patchset which adds an additional build script to
the toolchain when compiling livepatches. There are a few kernel
section features in which this script does not yet support, but can
detect and abort when it encounters. To test this detection, I've
written a small set of kernel modules that require such sections.
A few questions:
Is build-testing out of scope for kernel selftests? For expediency,
it was really easy to spin out new lib/livepatch kernel modules.
Does kbuild support the notion of expected failure? In this case, the
build script returns a non-zero error and the build stops.
Am I trying to fit a square peg in a round hole? I could easily keep
these build tests in a private branch, but could they exist in a
different format somewhere else in the tree?
Suggestions welcome,
-- Joe
Linus, Greg, Masahiro,
Here are some simple fixes for the kheaders feature. Please consider these
patches for an rc release. They are based on Linus's master branch. Thanks!
Joel Fernandes (Google) (3):
kheaders: Move from proc to sysfs
kheaders: Do not regenerate archive if config is not changed
kheaders: Make it depend on sysfs
init/Kconfig | 17 +++++----
kernel/Makefile | 4 +--
kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 17 ++++++---
kernel/kheaders.c | 40 +++++++++------------
4 files changed, 38 insertions(+), 40 deletions(-)
rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (82%)
--
2.21.0.1020.gf2820cf01a-goog
[Andrew, could you take this patchset into your tree, please?
Besides the patch for hexagon, all patches in this series have
Acked-by or Reviewed-by tags already.
I have been waiting and pinging the hexagon maintainer since November
without any visible effect. The last Acked-by from the hexagon maintainer
in linux.git was in October and the last Signed-off-by was in July. Since
that time not a single change affecting hexagon was able to attract
attention of the hexagon maintainer, so I don't think it's worth waiting
any longer.]
PTRACE_GET_SYSCALL_INFO is a generic ptrace API that lets ptracer obtain
details of the syscall the tracee is blocked in.
There are two reasons for a special syscall-related ptrace request.
Firstly, with the current ptrace API there are cases when ptracer cannot
retrieve necessary information about syscalls. Some examples include:
* The notorious int-0x80-from-64-bit-task issue. See [1] for details.
In short, if a 64-bit task performs a syscall through int 0x80, its tracer
has no reliable means to find out that the syscall was, in fact,
a compat syscall, and misidentifies it.
* Syscall-enter-stop and syscall-exit-stop look the same for the tracer.
Common practice is to keep track of the sequence of ptrace-stops in order
not to mix the two syscall-stops up. But it is not as simple as it looks;
for example, strace had a (just recently fixed) long-standing bug where
attaching strace to a tracee that is performing the execve system call
led to the tracer identifying the following syscall-exit-stop as
syscall-enter-stop, which messed up all the state tracking.
* Since the introduction of commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3
("ptrace: Don't allow accessing an undumpable mm"), both PTRACE_PEEKDATA
and process_vm_readv become unavailable when the process dumpable flag
is cleared. On such architectures as ia64 this results in all syscall
arguments being unavailable for the tracer.
Secondly, ptracers also have to support a lot of arch-specific code for
obtaining information about the tracee. For some architectures, this
requires a ptrace(PTRACE_PEEKUSER, ...) invocation for every syscall
argument and return value.
PTRACE_GET_SYSCALL_INFO returns the following structure:
struct ptrace_syscall_info {
__u8 op; /* PTRACE_SYSCALL_INFO_* */
__u32 arch __attribute__((__aligned__(sizeof(__u32))));
__u64 instruction_pointer;
__u64 stack_pointer;
union {
struct {
__u64 nr;
__u64 args[6];
} entry;
struct {
__s64 rval;
__u8 is_error;
} exit;
struct {
__u64 nr;
__u64 args[6];
__u32 ret_data;
} seccomp;
};
};
The structure was chosen according to [2], except for the following
changes:
* seccomp substructure was added as a superset of entry substructure;
* the type of nr field was changed from int to __u64 because syscall
numbers are, as a practical matter, 64 bits;
* stack_pointer field was added along with instruction_pointer field
since it is readily available and can save the tracer from extra
PTRACE_GETREGS/PTRACE_GETREGSET calls;
* arch is always initialized to aid with tracing system calls
* such as execve();
* instruction_pointer and stack_pointer are always initialized
so they could be easily obtained for non-syscall stops;
* a boolean is_error field was added along with rval field, this way
the tracer can more reliably distinguish a return value
from an error value.
strace has been ported to PTRACE_GET_SYSCALL_INFO.
Starting with release 4.26, strace uses PTRACE_GET_SYSCALL_INFO API
as the preferred mechanism of obtaining syscall information.
[1] https://lore.kernel.org/lkml/CA+55aFzcSVmdDj9Lh_gdbz1OzHyEm6ZrGPBDAJnywm2LF…
[2] https://lore.kernel.org/lkml/CAObL_7GM0n80N7J_DFw_eQyfLyzq+sf4y2AvsCCV88Tb3…
---
Notes:
v11:
* Added more Acked-by.
* Rebased back to mainline as the prerequisite syscall_get_arch patchset
has already been merged via audit tree.
v10:
* Added more Acked-by.
v9:
* Rebased to linux-next again due to syscall_get_arguments() signature change.
v8:
* Moved syscall_get_arch() specific patches to a separate patchset
which is now merged into audit/next tree.
* Rebased to linux-next.
* Moved ptrace_get_syscall_info code under #ifdef CONFIG_HAVE_ARCH_TRACEHOOK,
narrowing down the set of architectures supported by this implementation
back to those 19 that enable CONFIG_HAVE_ARCH_TRACEHOOK because
I failed to get all syscall_get_*(), instruction_pointer(),
and user_stack_pointer() functions implemented on some niche
architectures. This leaves the following architectures out:
alpha, h8300, m68k, microblaze, and unicore32.
v7:
* Rebased to v5.0-rc1.
* 5 arch-specific preparatory patches out of 25 have been merged
into v5.0-rc1 via arch trees.
v6:
* Added syscall_get_arguments and syscall_set_arguments wrappers
to asm-generic/syscall.h, requested by Geert.
* Changed PTRACE_GET_SYSCALL_INFO return code: do not take trailing paddings
into account, use the end of the last field of the structure being written.
* Changed struct ptrace_syscall_info:
* remove .frame_pointer field, is is not needed and not portable;
* make .arch field explicitly aligned, remove no longer needed
padding before .arch field;
* remove trailing pads, they are no longer needed.
v5:
* Merged separate series and patches into the single series.
* Changed PTRACE_EVENTMSG_SYSCALL_{ENTRY,EXIT} values as requested by Oleg.
* Changed struct ptrace_syscall_info: generalized instruction_pointer,
stack_pointer, and frame_pointer fields by moving them from
ptrace_syscall_info.{entry,seccomp} substructures to ptrace_syscall_info
and initializing them for all stops.
* Added PTRACE_SYSCALL_INFO_NONE, set it when not in a syscall stop,
so e.g. "strace -i" could use PTRACE_SYSCALL_INFO_SECCOMP to obtain
instruction_pointer when the tracee is in a signal stop.
* Patched all remaining architectures to provide all necessary
syscall_get_* functions.
* Made available for all architectures: do not conditionalize on
CONFIG_HAVE_ARCH_TRACEHOOK since all syscall_get_* functions
are implemented on all architectures.
* Added a test for PTRACE_GET_SYSCALL_INFO to selftests/ptrace.
v4:
* Revisited PTRACE_EVENT_SECCOMP support:
do not introduce task_struct.ptrace_event, use child->last_siginfo->si_code instead.
* Implemented PTRACE_SYSCALL_INFO_SECCOMP and ptrace_syscall_info.seccomp
support along with PTRACE_SYSCALL_INFO_{ENTRY,EXIT} and
ptrace_syscall_info.{entry,exit}.
v3:
* Changed struct ptrace_syscall_info.
* Added PTRACE_EVENT_SECCOMP support by adding ptrace_event to task_struct.
* Added proper defines for ptrace_syscall_info.op values.
* Renamed PT_SYSCALL_IS_ENTERING and PT_SYSCALL_IS_EXITING to
PTRACE_EVENTMSG_SYSCALL_ENTRY and PTRACE_EVENTMSG_SYSCALL_EXIT
and moved them to uapi.
v2:
* Stopped using task->ptrace.
* Replaced entry_info.is_compat with entry_info.arch, used syscall_get_arch().
* Used addr argument of sys_ptrace to get expected size of the struct;
return full size of the struct.
Dmitry V. Levin (6):
nds32: fix asm/syscall.h # acked
hexagon: define syscall_get_error() and syscall_get_return_value() # waiting for ack since November
mips: define syscall_get_error() # acked
parisc: define syscall_get_error() # acked
powerpc: define syscall_get_error() # acked
selftests/ptrace: add a test case for PTRACE_GET_SYSCALL_INFO # acked
Elvira Khabirova (1):
ptrace: add PTRACE_GET_SYSCALL_INFO request # reviewed
arch/hexagon/include/asm/syscall.h | 14 +
arch/mips/include/asm/syscall.h | 6 +
arch/nds32/include/asm/syscall.h | 27 +-
arch/parisc/include/asm/syscall.h | 7 +
arch/powerpc/include/asm/syscall.h | 10 +
include/linux/tracehook.h | 9 +-
include/uapi/linux/ptrace.h | 35 +++
kernel/ptrace.c | 101 ++++++-
tools/testing/selftests/ptrace/.gitignore | 1 +
tools/testing/selftests/ptrace/Makefile | 2 +-
.../selftests/ptrace/get_syscall_info.c | 271 ++++++++++++++++++
11 files changed, 468 insertions(+), 15 deletions(-)
create mode 100644 tools/testing/selftests/ptrace/get_syscall_info.c
--
ldv
The kheaders archive consisting of the kernel headers used for compiling
bpf programs is in /proc. However there is concern that moving it here
will make it permanent. Let us move it to /sys/kernel as discussed [1].
[1] https://lore.kernel.org/patchwork/patch/1067310/#1265969
Suggested-by: Steven Rostedt <rostedt(a)goodmis.org>
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
This patch applies on top of the previous patch that was applied to the
driver tree:
https://lore.kernel.org/patchwork/patch/1067310/
v2->v3: Fixed sysfs file mode nit (Greg).
v1->v2: Fixed some kconfig nits.
init/Kconfig | 16 ++++-----
kernel/Makefile | 4 +--
kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 2 +-
kernel/kheaders.c | 40 +++++++++------------
4 files changed, 26 insertions(+), 36 deletions(-)
rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (98%)
diff --git a/init/Kconfig b/init/Kconfig
index 26a364a95b57..c3661991b089 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -579,15 +579,13 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
-config IKHEADERS_PROC
- tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
- depends on PROC_FS
- help
- This option enables access to the kernel header and other artifacts that
- are generated during the build process. These can be used to build eBPF
- tracing programs, or similar programs. If you build the headers as a
- module, a module called kheaders.ko is built which can be loaded on-demand
- to get access to the headers.
+config IKHEADERS
+ tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
+ help
+ This option enables access to the in-kernel headers that are generated during
+ the build process. These can be used to build eBPF tracing programs,
+ or similar programs. If you build the headers as a module, a module called
+ kheaders.ko is built which can be loaded on-demand to get access to headers.
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
diff --git a/kernel/Makefile b/kernel/Makefile
index 12399614c350..b32a558fae2f 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,7 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
-obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
+obj-$(CONFIG_IKHEADERS) += kheaders.o
obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -126,7 +126,7 @@ $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
quiet_cmd_genikh = CHK $(obj)/kheaders_data.tar.xz
-cmd_genikh = $(srctree)/kernel/gen_ikh_data.sh $@
+cmd_genikh = $(srctree)/kernel/gen_kheaders.sh $@
$(obj)/kheaders_data.tar.xz: FORCE
$(call cmd,genikh)
diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_kheaders.sh
similarity index 98%
rename from kernel/gen_ikh_data.sh
rename to kernel/gen_kheaders.sh
index 591a94f7b387..581b83534587 100755
--- a/kernel/gen_ikh_data.sh
+++ b/kernel/gen_kheaders.sh
@@ -2,7 +2,7 @@
# SPDX-License-Identifier: GPL-2.0
# This script generates an archive consisting of kernel headers
-# for CONFIG_IKHEADERS_PROC.
+# for CONFIG_IKHEADERS.
set -e
spath="$(dirname "$(readlink -f "$0")")"
kroot="$spath/.."
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
index 70ae6052920d..8f69772af77b 100644
--- a/kernel/kheaders.c
+++ b/kernel/kheaders.c
@@ -8,9 +8,8 @@
#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/proc_fs.h>
+#include <linux/kobject.h>
#include <linux/init.h>
-#include <linux/uaccess.h>
/*
* Define kernel_headers_data and kernel_headers_data_end, within which the
@@ -31,39 +30,32 @@ extern char kernel_headers_data;
extern char kernel_headers_data_end;
static ssize_t
-ikheaders_read_current(struct file *file, char __user *buf,
- size_t len, loff_t *offset)
+ikheaders_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t off, size_t len)
{
- return simple_read_from_buffer(buf, len, offset,
- &kernel_headers_data,
- &kernel_headers_data_end -
- &kernel_headers_data);
+ memcpy(buf, &kernel_headers_data + off, len);
+ return len;
}
-static const struct file_operations ikheaders_file_ops = {
- .read = ikheaders_read_current,
- .llseek = default_llseek,
+static struct bin_attribute kheaders_attr __ro_after_init = {
+ .attr = {
+ .name = "kheaders.tar.xz",
+ .mode = 0444,
+ },
+ .read = &ikheaders_read,
};
static int __init ikheaders_init(void)
{
- struct proc_dir_entry *entry;
-
- /* create the current headers file */
- entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
- &ikheaders_file_ops);
- if (!entry)
- return -ENOMEM;
-
- proc_set_size(entry,
- &kernel_headers_data_end -
- &kernel_headers_data);
- return 0;
+ kheaders_attr.size = (&kernel_headers_data_end -
+ &kernel_headers_data);
+ return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);
}
static void __exit ikheaders_cleanup(void)
{
- remove_proc_entry("kheaders.tar.xz", NULL);
+ sysfs_remove_bin_file(kernel_kobj, &kheaders_attr);
}
module_init(ikheaders_init);
--
2.21.0.1020.gf2820cf01a-goog
This adds a basic framework for running all the "safe" lkdtm tests.
Signed-off-by: Kees Cook <keescook(a)chromium.org>
---
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/lkdtm/Makefile | 11 ++++
tools/testing/selftests/lkdtm/config | 1 +
tools/testing/selftests/lkdtm/run.sh | 86 +++++++++++++++++++++++++
tools/testing/selftests/lkdtm/tests.txt | 64 ++++++++++++++++++
6 files changed, 164 insertions(+)
create mode 100644 tools/testing/selftests/lkdtm/Makefile
create mode 100644 tools/testing/selftests/lkdtm/config
create mode 100755 tools/testing/selftests/lkdtm/run.sh
create mode 100644 tools/testing/selftests/lkdtm/tests.txt
diff --git a/MAINTAINERS b/MAINTAINERS
index 2c2fce72e694..055f1a09b1da 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8977,6 +8977,7 @@ LINUX KERNEL DUMP TEST MODULE (LKDTM)
M: Kees Cook <keescook(a)chromium.org>
S: Maintained
F: drivers/misc/lkdtm/*
+F: tools/testing/selftests/lkdtm/*
LINUX KERNEL MEMORY CONSISTENCY MODEL (LKMM)
M: Alan Stern <stern(a)rowland.harvard.edu>
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 971fc8428117..c2397baeb777 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -23,6 +23,7 @@ TARGETS += kcmp
TARGETS += kvm
TARGETS += lib
TARGETS += livepatch
+TARGETS += lkdtm
TARGETS += membarrier
TARGETS += memfd
TARGETS += memory-hotplug
diff --git a/tools/testing/selftests/lkdtm/Makefile b/tools/testing/selftests/lkdtm/Makefile
new file mode 100644
index 000000000000..f322d281fd8e
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for LKDTM regression tests
+
+include ../lib.mk
+
+# NOTE: $(OUTPUT) won't get default value if used before lib.mk
+TEST_GEN_PROGS = $(patsubst %,$(OUTPUT)/%.sh,$(shell awk '{print $$1}' tests.txt | sed -e 's/\#//'))
+all: $(TEST_GEN_PROGS)
+
+$(OUTPUT)/%: run.sh tests.txt
+ install -m 0744 run.sh $@
diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config
new file mode 100644
index 000000000000..d874990e442b
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/config
@@ -0,0 +1 @@
+CONFIG_LKDTM=y
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh
new file mode 100755
index 000000000000..117349bf78ca
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/run.sh
@@ -0,0 +1,86 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# This reads tests.txt for the list of LKDTM tests to invoke. Any marked
+# with a leading "#" are skipped. The line after the test name is either
+# the text to look for in dmesg for a "success", or the rationale for why
+# a test is marked to be skipped.
+#
+set -e
+TRIGGER=/sys/kernel/debug/provoke-crash/DIRECT
+
+# Verify we have LKDTM available in the kernel.
+if [ ! -r $TRIGGER ] ; then
+ /sbin/modprobe -q lkdtm || true
+ if [ ! -r $TRIGGER ] ; then
+ echo "Cannot find $TRIGGER (missing CONFIG_LKDTM?)"
+ else
+ echo "Cannot write $TRIGGER (need to run as root?)"
+ fi
+ # Skip this test
+ exit 4
+fi
+
+# Figure out which test to run from our script name.
+test=$(basename $0 .sh)
+# Look up details about the test from master list of LKDTM tests.
+line=$(egrep '^#?'"$test"'\b' tests.txt)
+if [ -z "$line" ]; then
+ echo "Skipped: missing test '$test' in tests.txt"
+ exit 4
+fi
+# Check that the test is known to LKDTM.
+if ! egrep -q '^'"$test"'$' "$TRIGGER" ; then
+ echo "Skipped: test '$test' missing in $TRIGGER!"
+ exit 4
+fi
+
+# Extract notes/expected output from test list.
+test=$(echo "$line" | cut -d" " -f1)
+if echo "$line" | grep -q ' ' ; then
+ expect=$(echo "$line" | cut -d" " -f2-)
+else
+ expect=""
+fi
+
+# If the test is commented out, report a skip
+if echo "$test" | grep -q '^#' ; then
+ test=$(echo "$test" | cut -c2-)
+ if [ -z "$expect" ]; then
+ expect="crashes entire system"
+ fi
+ echo "Skipping $test: $expect"
+ exit 4
+fi
+
+# If no expected output given, assume an Oops with back trace is success.
+if [ -z "$expect" ]; then
+ expect="call trace:"
+fi
+
+# Clear out dmesg for output reporting
+dmesg -c >/dev/null
+
+# Prepare log for report checking
+LOG=$(mktemp --tmpdir -t lkdtm-XXXXXX)
+cleanup() {
+ rm -f "$LOG"
+}
+trap cleanup EXIT
+
+# Most shells yell about signals and we're expecting the "cat" process
+# to usually be killed by the kernel. So we have to run it in a sub-shell
+# and silence errors.
+($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true
+
+# Record and dump the results
+dmesg -c >"$LOG"
+cat "$LOG"
+# Check for expected output
+if grep -qi "$expect" "$LOG" ; then
+ echo "$test: saw '$expect': ok"
+ exit 0
+else
+ echo "$test: missing '$expect': [FAIL]"
+ exit 1
+fi
diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt
new file mode 100644
index 000000000000..59df8a23db45
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/tests.txt
@@ -0,0 +1,64 @@
+#PANIC
+BUG kernel BUG at
+WARNING WARNING:
+EXCEPTION BUG: unable to handle kernel
+#LOOP Hangs the system
+#EXHAUST_STACK Corrupts memory on failure
+#CORRUPT_STACK Crashes entire system on success
+#CORRUPT_STACK_STRONG Crashes entire system on success
+CORRUPT_LIST_ADD list_add corruption
+CORRUPT_LIST_DEL list_del corruption
+CORRUPT_USER_DS Invalid address limit on user-mode return
+STACK_GUARD_PAGE_LEADING
+STACK_GUARD_PAGE_TRAILING
+UNALIGNED_LOAD_STORE_WRITE
+#OVERWRITE_ALLOCATION Corrupts memory on failure
+#WRITE_AFTER_FREE Corrupts memory on failure
+READ_AFTER_FREE
+#WRITE_BUDDY_AFTER_FREE Corrupts memory on failure
+READ_BUDDY_AFTER_FREE
+#SOFTLOCKUP Hangs the system
+#HARDLOCKUP Hangs the system
+#SPINLOCKUP Hangs the system
+#HUNG_TASK Hangs the system
+EXEC_DATA
+EXEC_STACK
+EXEC_KMALLOC
+EXEC_VMALLOC
+EXEC_RODATA
+EXEC_USERSPACE
+EXEC_NULL
+ACCESS_USERSPACE
+ACCESS_NULL
+WRITE_RO
+WRITE_RO_AFTER_INIT
+WRITE_KERN
+REFCOUNT_INC_OVERFLOW
+REFCOUNT_ADD_OVERFLOW
+REFCOUNT_INC_NOT_ZERO_OVERFLOW
+REFCOUNT_ADD_NOT_ZERO_OVERFLOW
+REFCOUNT_DEC_ZERO
+REFCOUNT_DEC_NEGATIVE Negative detected: saturated
+REFCOUNT_DEC_AND_TEST_NEGATIVE Negative detected: saturated
+REFCOUNT_SUB_AND_TEST_NEGATIVE Negative detected: saturated
+REFCOUNT_INC_ZERO
+REFCOUNT_ADD_ZERO
+REFCOUNT_INC_SATURATED Saturation detected: still saturated
+REFCOUNT_DEC_SATURATED Saturation detected: still saturated
+REFCOUNT_ADD_SATURATED Saturation detected: still saturated
+REFCOUNT_INC_NOT_ZERO_SATURATED
+REFCOUNT_ADD_NOT_ZERO_SATURATED
+REFCOUNT_DEC_AND_TEST_SATURATED Saturation detected: still saturated
+REFCOUNT_SUB_AND_TEST_SATURATED Saturation detected: still saturated
+#REFCOUNT_TIMING timing only
+#ATOMIC_TIMING timing only
+USERCOPY_HEAP_SIZE_TO
+USERCOPY_HEAP_SIZE_FROM
+USERCOPY_HEAP_WHITELIST_TO
+USERCOPY_HEAP_WHITELIST_FROM
+USERCOPY_STACK_FRAME_TO
+USERCOPY_STACK_FRAME_FROM
+USERCOPY_STACK_BEYOND
+USERCOPY_KERNEL
+USERCOPY_KERNEL_DS
+STACKLEAK_ERASING OK: the rest of the thread stack is properly erased
--
2.17.1
--
Kees Cook
[Andrew, could you take this patchset into your tree, please?]
PTRACE_GET_SYSCALL_INFO is a generic ptrace API that lets ptracer obtain
details of the syscall the tracee is blocked in.
There are two reasons for a special syscall-related ptrace request.
Firstly, with the current ptrace API there are cases when ptracer cannot
retrieve necessary information about syscalls. Some examples include:
* The notorious int-0x80-from-64-bit-task issue. See [1] for details.
In short, if a 64-bit task performs a syscall through int 0x80, its tracer
has no reliable means to find out that the syscall was, in fact,
a compat syscall, and misidentifies it.
* Syscall-enter-stop and syscall-exit-stop look the same for the tracer.
Common practice is to keep track of the sequence of ptrace-stops in order
not to mix the two syscall-stops up. But it is not as simple as it looks;
for example, strace had a (just recently fixed) long-standing bug where
attaching strace to a tracee that is performing the execve system call
led to the tracer identifying the following syscall-exit-stop as
syscall-enter-stop, which messed up all the state tracking.
* Since the introduction of commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3
("ptrace: Don't allow accessing an undumpable mm"), both PTRACE_PEEKDATA
and process_vm_readv become unavailable when the process dumpable flag
is cleared. On such architectures as ia64 this results in all syscall
arguments being unavailable for the tracer.
Secondly, ptracers also have to support a lot of arch-specific code for
obtaining information about the tracee. For some architectures, this
requires a ptrace(PTRACE_PEEKUSER, ...) invocation for every syscall
argument and return value.
PTRACE_GET_SYSCALL_INFO returns the following structure:
struct ptrace_syscall_info {
__u8 op; /* PTRACE_SYSCALL_INFO_* */
__u32 arch __attribute__((__aligned__(sizeof(__u32))));
__u64 instruction_pointer;
__u64 stack_pointer;
union {
struct {
__u64 nr;
__u64 args[6];
} entry;
struct {
__s64 rval;
__u8 is_error;
} exit;
struct {
__u64 nr;
__u64 args[6];
__u32 ret_data;
} seccomp;
};
};
The structure was chosen according to [2], except for the following
changes:
* seccomp substructure was added as a superset of entry substructure;
* the type of nr field was changed from int to __u64 because syscall
numbers are, as a practical matter, 64 bits;
* stack_pointer field was added along with instruction_pointer field
since it is readily available and can save the tracer from extra
PTRACE_GETREGS/PTRACE_GETREGSET calls;
* arch is always initialized to aid with tracing system calls
* such as execve();
* instruction_pointer and stack_pointer are always initialized
so they could be easily obtained for non-syscall stops;
* a boolean is_error field was added along with rval field, this way
the tracer can more reliably distinguish a return value
from an error value.
strace has been ported to PTRACE_GET_SYSCALL_INFO.
Starting with release 4.26, strace uses PTRACE_GET_SYSCALL_INFO API
as the preferred mechanism of obtaining syscall information.
[1] https://lore.kernel.org/lkml/CA+55aFzcSVmdDj9Lh_gdbz1OzHyEm6ZrGPBDAJnywm2LF…
[2] https://lore.kernel.org/lkml/CAObL_7GM0n80N7J_DFw_eQyfLyzq+sf4y2AvsCCV88Tb3…
---
Notes:
v10: added more Acked-by.
v9:
* Rebased to linux-next again due to syscall_get_arguments() signature change.
v8:
* Moved syscall_get_arch() specific patches to a separate patchset
which is now merged into audit/next tree.
* Rebased to linux-next.
* Moved ptrace_get_syscall_info code under #ifdef CONFIG_HAVE_ARCH_TRACEHOOK,
narrowing down the set of architectures supported by this implementation
back to those 19 that enable CONFIG_HAVE_ARCH_TRACEHOOK because
I failed to get all syscall_get_*(), instruction_pointer(),
and user_stack_pointer() functions implemented on some niche
architectures. This leaves the following architectures out:
alpha, h8300, m68k, microblaze, and unicore32.
v7:
* Rebased to v5.0-rc1.
* 5 arch-specific preparatory patches out of 25 have been merged
into v5.0-rc1 via arch trees.
v6:
* Add syscall_get_arguments and syscall_set_arguments wrappers
to asm-generic/syscall.h, requested by Geert.
* Change PTRACE_GET_SYSCALL_INFO return code: do not take trailing paddings
into account, use the end of the last field of the structure being written.
* Change struct ptrace_syscall_info:
* remove .frame_pointer field, is is not needed and not portable;
* make .arch field explicitly aligned, remove no longer needed
padding before .arch field;
* remove trailing pads, they are no longer needed.
v5:
* Merge separate series and patches into the single series.
* Change PTRACE_EVENTMSG_SYSCALL_{ENTRY,EXIT} values as requested by Oleg.
* Change struct ptrace_syscall_info: generalize instruction_pointer,
stack_pointer, and frame_pointer fields by moving them from
ptrace_syscall_info.{entry,seccomp} substructures to ptrace_syscall_info
and initializing them for all stops.
* Add PTRACE_SYSCALL_INFO_NONE, set it when not in a syscall stop,
so e.g. "strace -i" could use PTRACE_SYSCALL_INFO_SECCOMP to obtain
instruction_pointer when the tracee is in a signal stop.
* Patch all remaining architectures to provide all necessary
syscall_get_* functions.
* Make available for all architectures: do not conditionalize on
CONFIG_HAVE_ARCH_TRACEHOOK since all syscall_get_* functions
are implemented on all architectures.
* Add a test for PTRACE_GET_SYSCALL_INFO to selftests/ptrace.
v4:
* Do not introduce task_struct.ptrace_event,
use child->last_siginfo->si_code instead.
* Implement PTRACE_SYSCALL_INFO_SECCOMP and ptrace_syscall_info.seccomp
support along with PTRACE_SYSCALL_INFO_{ENTRY,EXIT} and
ptrace_syscall_info.{entry,exit}.
v3:
* Change struct ptrace_syscall_info.
* Support PTRACE_EVENT_SECCOMP by adding ptrace_event to task_struct.
* Add proper defines for ptrace_syscall_info.op values.
* Rename PT_SYSCALL_IS_ENTERING and PT_SYSCALL_IS_EXITING to
PTRACE_EVENTMSG_SYSCALL_ENTRY and PTRACE_EVENTMSG_SYSCALL_EXIT
* and move them to uapi.
v2:
* Do not use task->ptrace.
* Replace entry_info.is_compat with entry_info.arch, use syscall_get_arch().
* Use addr argument of sys_ptrace to get expected size of the struct;
return full size of the struct.
Dmitry V. Levin (6):
nds32: fix asm/syscall.h # acked
hexagon: define syscall_get_error() and syscall_get_return_value() # waiting for ack since November
mips: define syscall_get_error() # acked
parisc: define syscall_get_error() # acked
powerpc: define syscall_get_error() # waiting for ack since early December
selftests/ptrace: add a test case for PTRACE_GET_SYSCALL_INFO # acked
Elvira Khabirova (1):
ptrace: add PTRACE_GET_SYSCALL_INFO request # reviewed
arch/hexagon/include/asm/syscall.h | 14 +
arch/mips/include/asm/syscall.h | 6 +
arch/nds32/include/asm/syscall.h | 27 +-
arch/parisc/include/asm/syscall.h | 7 +
arch/powerpc/include/asm/syscall.h | 10 +
include/linux/tracehook.h | 9 +-
include/uapi/linux/ptrace.h | 35 +++
kernel/ptrace.c | 103 ++++++-
tools/testing/selftests/ptrace/.gitignore | 1 +
tools/testing/selftests/ptrace/Makefile | 2 +-
.../selftests/ptrace/get_syscall_info.c | 271 ++++++++++++++++++
11 files changed, 470 insertions(+), 15 deletions(-)
create mode 100644 tools/testing/selftests/ptrace/get_syscall_info.c
--
ldv
Summary
------------------------------------------------------------------------
kernel: 5.1.0
git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git branch: master
git commit: unknown
git describe: next-20190509
Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190509
Regressions (compared to build next-20190507)
------------------------------------------------------------------------
No regressions
Fixes (compared to build next-20190507)
------------------------------------------------------------------------
No fixes
In total:
------------------------------------------------------------------------
Ran 0 total tests in the following environments and test suites.
pass 0
fail 0
xfail 0
skip 0
Environments
--------------
- x15 - arm
Test Suites
-----------
Failures
------------------------------------------------------------------------
x15:
Skips
------------------------------------------------------------------------
No skips
--
Linaro LKFT
https://lkft.linaro.org
So the first 3 patches are cleanups and fixes and should probably just go in.
The last patch however is the one Linus hates, it converts i386 to always have
a complete pt_regs. Both Josh and me did a bunch of cleanups and the patch is
now a net reduction in lines.
I still think it is the right thing to do; it removes a whole lot of magic from
the C code (and avoids future surprises), but if this cannot convince Linus,
I'll not pursue this further.
From: Peter Zijlstra <peterz(a)infradead.org>
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index ef49517f6bb2..bd553b3af22e 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -294,13 +298,28 @@ int ftrace_int3_handler(struct pt_regs *regs)
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+#ifdef CONFIG_X86_64
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
+#else
+ if (ftrace_location(ip) || is_ftrace_caller(ip)) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+#endif
- return 1;
+ return 0;
}
NOKPROBE_SYMBOL(ftrace_int3_handler);
@@ -859,6 +878,8 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -960,6 +981,7 @@ static int ftrace_mod_jmp(unsigned long ip, void *func)
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
--
2.20.1
From: Peter Zijlstra <peterz(a)infradead.org>
In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Nicolai Stange <nstange(a)suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index e85ff65c43c3..05861cc08787 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_regs *regs);
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+#ifdef CONFIG_X86_64
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ /*
+ * The int3 handler in entry_64.S adds a gap between the
+ * stack where the break point happened, and the saving of
+ * pt_regs. We can extend the original stack because of
+ * this gap. See the idtentry macro's create_gap option.
+ */
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
--
2.20.1
From: Peter Zijlstra <peterz(a)infradead.org>
In order to allow breakpoints to emulate call functions, they need to push
the return address onto the stack. But because the breakpoint exception
frame is added to the stack when the breakpoint is hit, there's no room to
add the address onto the stack and return to the address of the emulated
called funtion.
To handle this, copy the exception frame on entry of the breakpoint handler
and have leave a gap that can be used to add a return address to the stack
frame and return from the breakpoint to the emulated called function,
allowing for that called function to return back to the location after the
breakpoint was placed.
The helper functions were also added:
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_jmp(): changes the location of the regs->ip to return there.
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Signed-off-by: *** Need Peter Zijlstra's SoB here! ***
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
arch/x86/entry/entry_32.S | 11 +++++++++++
arch/x86/entry/entry_64.S | 14 ++++++++++++--
arch/x86/include/asm/text-patching.h | 20 ++++++++++++++++++++
3 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index d309f30cf7af..50bbf4035baf 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1478,6 +1478,17 @@ ENTRY(int3)
ASM_CLAC
pushl $-1 # mark this as an int
+#ifdef CONFIG_VM86
+ testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
+ jnz .Lfrom_usermode_no_gap
+#endif
+ testl $SEGMENT_RPL_MASK, PT_CS(%esp)
+ jnz .Lfrom_usermode_no_gap
+ .rept 6
+ pushl 5*4(%esp)
+ .endr
+.Lfrom_usermode_no_gap:
+
SAVE_ALL switch_stacks=1
ENCODE_FRAME_POINTER
TRACE_IRQS_OFF
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1f0efdb7b629..834ec1397dab 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -879,7 +879,7 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt
* @paranoid == 2 is special: the stub will never switch stacks. This is for
* #DF: if the thread stack is somehow unusable, we'll still get a useful OOPS.
*/
-.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
+.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 create_gap=0
ENTRY(\sym)
UNWIND_HINT_IRET_REGS offset=\has_error_code*8
@@ -899,6 +899,16 @@ ENTRY(\sym)
jnz .Lfrom_usermode_switch_stack_\@
.endif
+ .if \create_gap == 1
+ testb $3, CS-ORIG_RAX(%rsp)
+ jnz .Lfrom_usermode_no_gap_\@
+ .rept 6
+ pushq 5*8(%rsp)
+ .endr
+ UNWIND_HINT_IRET_REGS offset=8
+.Lfrom_usermode_no_gap_\@:
+ .endif
+
.if \paranoid
call paranoid_entry
.else
@@ -1130,7 +1140,7 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \
#endif /* CONFIG_HYPERV */
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
-idtentry int3 do_int3 has_error_code=0
+idtentry int3 do_int3 has_error_code=0 create_gap=1
idtentry stack_segment do_stack_segment has_error_code=1
#ifdef CONFIG_XEN_PV
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index e85ff65c43c3..ba275b6292db 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -39,4 +39,24 @@ extern int poke_int3_handler(struct pt_regs *regs);
extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
+static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
+{
+ regs->sp -= sizeof(unsigned long);
+ *(unsigned long *)regs->sp = val;
+}
+
+static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
+{
+ regs->ip = ip;
+}
+
+#define INT3_INSN_SIZE 1
+#define CALL_INSN_SIZE 5
+
+static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
+{
+ int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
+ int3_emulate_jmp(regs, func);
+}
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
--
2.20.1
Install target fails when INSTALL_PATH is undefined. Fix install target
to use "output_dir/install as the default install location. "output_dir"
is either the root of selftests directory under kernel source tree or
output directory specified by O= or KBUILD_OUTPUT.
e.g:
make -C tools/testing/selftests install
<installs under tools/testing/selftests/install>
make O=/tmp/kselftest -C tools/testing/selftests install
<installs under /tmp/kselftest/install>
export KBUILD_OUTPUT=/tmp/kselftest
make -C tools/testing/selftests install
<installs under /tmp/kselftest/install>
In addition, add "all" target as dependency to "install" to build and
install using a single command.
Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org>
---
tools/testing/selftests/Makefile | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 9f05448e5e4b..c71a63b923d4 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -163,11 +163,17 @@ clean_hotplug:
run_pstore_crash:
make -C pstore run_crash
-INSTALL_PATH ?= install
+# Use $BUILD as the default install root. $BUILD points to the
+# right output location for the following cases:
+# 1. output_dir=kernel_src
+# 2. a separate output directory is specified using O= KBUILD_OUTPUT
+# 3. a separate output directory is specified using KBUILD_OUTPUT
+#
+INSTALL_PATH ?= $(BUILD)/install
INSTALL_PATH := $(abspath $(INSTALL_PATH))
ALL_SCRIPT := $(INSTALL_PATH)/run_kselftest.sh
-install:
+install: all
ifdef INSTALL_PATH
@# Ask all targets to install their files
mkdir -p $(INSTALL_PATH)/kselftest
--
2.17.1
[
This is the non-RFC version.
It went through and passed all my tests. If there's no objections
I'm going to include this in my pull request. I still have patches
in my INBOX that may still be included, so I need to run those through
my tests as well, so a pull request wont be immediate.
]
Nicolai Stange discovered that Live Kernel Patching can have unforseen
consequences if tracing is enabled when there are functions that are
patched. The reason being, is that Live Kernel patching is built on top
of ftrace, which will have the patched functions call the live kernel
trampoline directly, and that trampoline will modify the regs->ip address
to return to the patched function.
But in the transition between changing the call to the customized
trampoline, the tracing code is needed to have its handler called
an well, so the function fentry location must be changed from calling
the live kernel patching trampoline, to the ftrace_reg_caller trampoline
which will iterate through all the registered ftrace handlers for
that function.
During this transition, a break point is added to do the live code
modifications. But if that break point is hit, it just skips calling
any handler, and makes the call site act as a nop. For tracing, the
worse that can happen is that you miss a function being traced, but
for live kernel patching the affects are more severe, as the old buggy
function is now called.
To solve this, an int3_emulate_call() is created for x86_64 to allow
ftrace on x86_64 to emulate the call to ftrace_regs_caller() which will
make sure all the registered handlers to that function are still called.
And this keeps live kernel patching happy!
To mimimize the changes, and to avoid controversial patches, this
only changes x86_64. Due to the way x86_32 implements the regs->sp
the complexity of emulating calls on that platform is too much for
stable patches, and live kernel patching does not support x86_32 anyway.
Josh Poimboeuf (1):
x86_64: Add gap to int3 to allow for call emulation
Peter Zijlstra (2):
x86_64: Allow breakpoints to emulate call instructions
ftrace/x86_64: Emulate call function while updating in breakpoint handler
----
arch/x86/entry/entry_64.S | 18 ++++++++++++++++--
arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++
arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++-----
3 files changed, 71 insertions(+), 7 deletions(-)
Nicolai Stange discovered that Live Kernel Patching can have unforseen
consequences if tracing is enabled when there are functions that are
patched. The reason being, is that Live Kernel patching is built on top
of ftrace, which will have the patched functions call the live kernel
trampoline directly, and that trampoline will modify the regs->ip address
to return to the patched function.
But in the transition between changing the call to the customized
trampoline, the tracing code is needed to have its handler called
an well, so the function fentry location must be changed from calling
the live kernel patching trampoline, to the ftrace_reg_caller trampoline
which will iterate through all the registered ftrace handlers for
that function.
During this transition, a break point is added to do the live code
modifications. But if that break point is hit, it just skips calling
any handler, and makes the call site act as a nop. For tracing, the
worse that can happen is that you miss a function being traced, but
for live kernel patching the affects are more severe, as the old buggy
function is now called.
To solve this, an int3_emulate_call() is created for x86_64 to allow
ftrace on x86_64 to emulate the call to ftrace_regs_caller() which will
make sure all the registered handlers to that function are still called.
And this keeps live kernel patching happy!
To mimimize the changes, and to avoid controversial patches, this
only changes x86_64. Due to the way x86_32 implements the regs->sp
the complexity of emulating calls on that platform is too much for
stable patches, and live kernel patching does not support x86_32 anyway.
Josh Poimboeuf (1):
x86_64: Add gap to int3 to allow for call emulation
Peter Zijlstra (2):
x86_64: Allow breakpoints to emulate call functions
ftrace/x86_64: Emulate call function while updating in breakpoint handler
----
arch/x86/entry/entry_64.S | 18 ++++++++++++++++--
arch/x86/include/asm/text-patching.h | 22 ++++++++++++++++++++++
arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++-----
3 files changed, 65 insertions(+), 7 deletions(-)
The kheaders archive consisting of the kernel headers used for compiling
bpf programs is in /proc. However there is concern that moving it here
will make it permanent. Let us move it to /sys/kernel as discussed [1].
[1] https://lore.kernel.org/patchwork/patch/1067310/#1265969
Suggested-by: Steven Rostedt <rostedt(a)goodmis.org>
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
This patch applies on top of the previous patch that was applied to the
driver tree:
https://lore.kernel.org/patchwork/patch/1067310/
v1->v2: Fixed some kconfig nits (Masami).
init/Kconfig | 16 ++++-----
kernel/Makefile | 4 +--
kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 2 +-
kernel/kheaders.c | 40 +++++++++------------
4 files changed, 26 insertions(+), 36 deletions(-)
rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (98%)
diff --git a/init/Kconfig b/init/Kconfig
index 26a364a95b57..c3661991b089 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -579,15 +579,13 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
-config IKHEADERS_PROC
- tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
- depends on PROC_FS
- help
- This option enables access to the kernel header and other artifacts that
- are generated during the build process. These can be used to build eBPF
- tracing programs, or similar programs. If you build the headers as a
- module, a module called kheaders.ko is built which can be loaded on-demand
- to get access to the headers.
+config IKHEADERS
+ tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
+ help
+ This option enables access to the in-kernel headers that are generated during
+ the build process. These can be used to build eBPF tracing programs,
+ or similar programs. If you build the headers as a module, a module called
+ kheaders.ko is built which can be loaded on-demand to get access to headers.
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
diff --git a/kernel/Makefile b/kernel/Makefile
index 12399614c350..b32a558fae2f 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,7 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
-obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
+obj-$(CONFIG_IKHEADERS) += kheaders.o
obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -126,7 +126,7 @@ $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
quiet_cmd_genikh = CHK $(obj)/kheaders_data.tar.xz
-cmd_genikh = $(srctree)/kernel/gen_ikh_data.sh $@
+cmd_genikh = $(srctree)/kernel/gen_kheaders.sh $@
$(obj)/kheaders_data.tar.xz: FORCE
$(call cmd,genikh)
diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_kheaders.sh
similarity index 98%
rename from kernel/gen_ikh_data.sh
rename to kernel/gen_kheaders.sh
index 591a94f7b387..581b83534587 100755
--- a/kernel/gen_ikh_data.sh
+++ b/kernel/gen_kheaders.sh
@@ -2,7 +2,7 @@
# SPDX-License-Identifier: GPL-2.0
# This script generates an archive consisting of kernel headers
-# for CONFIG_IKHEADERS_PROC.
+# for CONFIG_IKHEADERS.
set -e
spath="$(dirname "$(readlink -f "$0")")"
kroot="$spath/.."
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
index 70ae6052920d..6a16f8f6898d 100644
--- a/kernel/kheaders.c
+++ b/kernel/kheaders.c
@@ -8,9 +8,8 @@
#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/proc_fs.h>
+#include <linux/kobject.h>
#include <linux/init.h>
-#include <linux/uaccess.h>
/*
* Define kernel_headers_data and kernel_headers_data_end, within which the
@@ -31,39 +30,32 @@ extern char kernel_headers_data;
extern char kernel_headers_data_end;
static ssize_t
-ikheaders_read_current(struct file *file, char __user *buf,
- size_t len, loff_t *offset)
+ikheaders_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t off, size_t len)
{
- return simple_read_from_buffer(buf, len, offset,
- &kernel_headers_data,
- &kernel_headers_data_end -
- &kernel_headers_data);
+ memcpy(buf, &kernel_headers_data + off, len);
+ return len;
}
-static const struct file_operations ikheaders_file_ops = {
- .read = ikheaders_read_current,
- .llseek = default_llseek,
+static struct bin_attribute kheaders_attr __ro_after_init = {
+ .attr = {
+ .name = "kheaders.tar.xz",
+ .mode = S_IRUGO,
+ },
+ .read = &ikheaders_read,
};
static int __init ikheaders_init(void)
{
- struct proc_dir_entry *entry;
-
- /* create the current headers file */
- entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
- &ikheaders_file_ops);
- if (!entry)
- return -ENOMEM;
-
- proc_set_size(entry,
- &kernel_headers_data_end -
- &kernel_headers_data);
- return 0;
+ kheaders_attr.size = (&kernel_headers_data_end -
+ &kernel_headers_data);
+ return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);
}
static void __exit ikheaders_cleanup(void)
{
- remove_proc_entry("kheaders.tar.xz", NULL);
+ sysfs_remove_bin_file(kernel_kobj, &kheaders_attr);
}
module_init(ikheaders_init);
--
2.21.0.1020.gf2820cf01a-goog
From: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
[ Upstream commit 30c04d796b693e22405c38e9b78e9a364e4c77e6 ]
The run_netsocktests will be marked as passed regardless the actual test
result from the ./socket:
selftests: net: run_netsocktests
========================================
--------------------
running socket test
--------------------
[FAIL]
ok 1..6 selftests: net: run_netsocktests [PASS]
This is because the test script itself has been successfully executed.
Fix this by exit 1 when the test failed.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/run_netsocktests | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/run_netsocktests b/tools/testing/selftests/net/run_netsocktests
index c09a682df56a..19486dab2379 100644
--- a/tools/testing/selftests/net/run_netsocktests
+++ b/tools/testing/selftests/net/run_netsocktests
@@ -6,7 +6,7 @@ echo "--------------------"
./socket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ exit 1
else
echo "[PASS]"
fi
-
--
2.20.1
From: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
[ Upstream commit 30c04d796b693e22405c38e9b78e9a364e4c77e6 ]
The run_netsocktests will be marked as passed regardless the actual test
result from the ./socket:
selftests: net: run_netsocktests
========================================
--------------------
running socket test
--------------------
[FAIL]
ok 1..6 selftests: net: run_netsocktests [PASS]
This is because the test script itself has been successfully executed.
Fix this by exit 1 when the test failed.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/run_netsocktests | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/run_netsocktests b/tools/testing/selftests/net/run_netsocktests
index 16058bbea7a8..c195b4478662 100755
--- a/tools/testing/selftests/net/run_netsocktests
+++ b/tools/testing/selftests/net/run_netsocktests
@@ -6,7 +6,7 @@ echo "--------------------"
./socket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ exit 1
else
echo "[PASS]"
fi
-
--
2.20.1
From: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
[ Upstream commit 30c04d796b693e22405c38e9b78e9a364e4c77e6 ]
The run_netsocktests will be marked as passed regardless the actual test
result from the ./socket:
selftests: net: run_netsocktests
========================================
--------------------
running socket test
--------------------
[FAIL]
ok 1..6 selftests: net: run_netsocktests [PASS]
This is because the test script itself has been successfully executed.
Fix this by exit 1 when the test failed.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/run_netsocktests | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/run_netsocktests b/tools/testing/selftests/net/run_netsocktests
index 16058bbea7a8..c195b4478662 100755
--- a/tools/testing/selftests/net/run_netsocktests
+++ b/tools/testing/selftests/net/run_netsocktests
@@ -6,7 +6,7 @@ echo "--------------------"
./socket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ exit 1
else
echo "[PASS]"
fi
-
--
2.20.1
From: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
[ Upstream commit 30c04d796b693e22405c38e9b78e9a364e4c77e6 ]
The run_netsocktests will be marked as passed regardless the actual test
result from the ./socket:
selftests: net: run_netsocktests
========================================
--------------------
running socket test
--------------------
[FAIL]
ok 1..6 selftests: net: run_netsocktests [PASS]
This is because the test script itself has been successfully executed.
Fix this by exit 1 when the test failed.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/run_netsocktests | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/run_netsocktests b/tools/testing/selftests/net/run_netsocktests
index b093f39c298c..14e41faf2c57 100755
--- a/tools/testing/selftests/net/run_netsocktests
+++ b/tools/testing/selftests/net/run_netsocktests
@@ -7,7 +7,7 @@ echo "--------------------"
./socket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ exit 1
else
echo "[PASS]"
fi
-
--
2.20.1
From: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
[ Upstream commit 30c04d796b693e22405c38e9b78e9a364e4c77e6 ]
The run_netsocktests will be marked as passed regardless the actual test
result from the ./socket:
selftests: net: run_netsocktests
========================================
--------------------
running socket test
--------------------
[FAIL]
ok 1..6 selftests: net: run_netsocktests [PASS]
This is because the test script itself has been successfully executed.
Fix this by exit 1 when the test failed.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/run_netsocktests | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/run_netsocktests b/tools/testing/selftests/net/run_netsocktests
index b093f39c298c..14e41faf2c57 100755
--- a/tools/testing/selftests/net/run_netsocktests
+++ b/tools/testing/selftests/net/run_netsocktests
@@ -7,7 +7,7 @@ echo "--------------------"
./socket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ exit 1
else
echo "[PASS]"
fi
-
--
2.20.1
From: David Ahern <dsahern(a)gmail.com>
[ Upstream commit a5f622984a623df9a84cf43f6b098d8dd76fbe05 ]
A couple of tests are verifying a route has been removed. The helper
expects the prefix as the first part of the expected output. When
checking that a route has been deleted the prefix is empty leading
to an invalid ip command:
$ ip ro ls match
Command line is not complete. Try option "help"
Fix by moving the comparison of expected output and output to a new
function that is used by both check_route and check_route6. Use the
new helper for the 2 checks on route removal.
Also, remove the reset of 'set -x' in route_setup which overrides the
user managed setting.
Fixes: d69faad76584c ("selftests: fib_tests: Add prefix route tests with metric")
Signed-off-by: David Ahern <dsahern(a)gmail.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/fib_tests.sh | 94 ++++++++++--------------
1 file changed, 40 insertions(+), 54 deletions(-)
diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
index a4ccde0e473b..2f190aa8fc5f 100755
--- a/tools/testing/selftests/net/fib_tests.sh
+++ b/tools/testing/selftests/net/fib_tests.sh
@@ -602,6 +602,39 @@ run_cmd()
return $rc
}
+check_expected()
+{
+ local out="$1"
+ local expected="$2"
+ local rc=0
+
+ [ "${out}" = "${expected}" ] && return 0
+
+ if [ -z "${out}" ]; then
+ if [ "$VERBOSE" = "1" ]; then
+ printf "\nNo route entry found\n"
+ printf "Expected:\n"
+ printf " ${expected}\n"
+ fi
+ return 1
+ fi
+
+ # tricky way to convert output to 1-line without ip's
+ # messy '\'; this drops all extra white space
+ out=$(echo ${out})
+ if [ "${out}" != "${expected}" ]; then
+ rc=1
+ if [ "${VERBOSE}" = "1" ]; then
+ printf " Unexpected route entry. Have:\n"
+ printf " ${out}\n"
+ printf " Expected:\n"
+ printf " ${expected}\n\n"
+ fi
+ fi
+
+ return $rc
+}
+
# add route for a prefix, flushing any existing routes first
# expected to be the first step of a test
add_route6()
@@ -646,31 +679,7 @@ check_route6()
local rc=0
out=$($IP -6 ro ls match ${pfx} | sed -e 's/ pref medium//')
- [ "${out}" = "${expected}" ] && return 0
-
- if [ -z "${out}" ]; then
- if [ "$VERBOSE" = "1" ]; then
- printf "\nNo route entry found\n"
- printf "Expected:\n"
- printf " ${expected}\n"
- fi
- return 1
- fi
-
- # tricky way to convert output to 1-line without ip's
- # messy '\'; this drops all extra white space
- out=$(echo ${out})
- if [ "${out}" != "${expected}" ]; then
- rc=1
- if [ "${VERBOSE}" = "1" ]; then
- printf " Unexpected route entry. Have:\n"
- printf " ${out}\n"
- printf " Expected:\n"
- printf " ${expected}\n\n"
- fi
- fi
-
- return $rc
+ check_expected "${out}" "${expected}"
}
route_cleanup()
@@ -714,7 +723,7 @@ route_setup()
$IP addr add 172.16.103.2/24 dev veth4
$IP addr add 172.16.104.1/24 dev dummy1
- set +ex
+ set +e
}
# assumption is that basic add of a single path route works
@@ -949,7 +958,8 @@ ipv6_addr_metric_test()
run_cmd "$IP li set dev dummy2 down"
rc=$?
if [ $rc -eq 0 ]; then
- check_route6 ""
+ out=$($IP -6 ro ls match 2001:db8:104::/64)
+ check_expected "${out}" ""
rc=$?
fi
log_test $rc 0 "Prefix route removed on link down"
@@ -1009,34 +1019,9 @@ check_route()
local pfx="172.16.104.0/24"
local expected="$1"
local out
- local rc=0
out=$($IP ro ls match ${pfx})
- [ "${out}" = "${expected}" ] && return 0
-
- if [ -z "${out}" ]; then
- if [ "$VERBOSE" = "1" ]; then
- printf "\nNo route entry found\n"
- printf "Expected:\n"
- printf " ${expected}\n"
- fi
- return 1
- fi
-
- # tricky way to convert output to 1-line without ip's
- # messy '\'; this drops all extra white space
- out=$(echo ${out})
- if [ "${out}" != "${expected}" ]; then
- rc=1
- if [ "${VERBOSE}" = "1" ]; then
- printf " Unexpected route entry. Have:\n"
- printf " ${out}\n"
- printf " Expected:\n"
- printf " ${expected}\n\n"
- fi
- fi
-
- return $rc
+ check_expected "${out}" "${expected}"
}
# assumption is that basic add of a single path route works
@@ -1301,7 +1286,8 @@ ipv4_addr_metric_test()
run_cmd "$IP li set dev dummy2 down"
rc=$?
if [ $rc -eq 0 ]; then
- check_route ""
+ out=$($IP ro ls match 172.16.104.0/24)
+ check_expected "${out}" ""
rc=$?
fi
log_test $rc 0 "Prefix route removed on link down"
--
2.20.1
From: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
[ Upstream commit 8c03557c3f25271e62e39154af66ebdd1b59c9ca ]
The run_afpackettests will be marked as passed regardless the return
value of those sub-tests in the script:
--------------------
running psock_tpacket test
--------------------
[FAIL]
selftests: run_afpackettests [PASS]
Fix this by changing the return value for each tests.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/run_afpackettests | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/tools/testing/selftests/net/run_afpackettests b/tools/testing/selftests/net/run_afpackettests
index 2dc95fda7ef7..ea5938ec009a 100755
--- a/tools/testing/selftests/net/run_afpackettests
+++ b/tools/testing/selftests/net/run_afpackettests
@@ -6,12 +6,14 @@ if [ $(id -u) != 0 ]; then
exit 0
fi
+ret=0
echo "--------------------"
echo "running psock_fanout test"
echo "--------------------"
./in_netns.sh ./psock_fanout
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ ret=1
else
echo "[PASS]"
fi
@@ -22,6 +24,7 @@ echo "--------------------"
./in_netns.sh ./psock_tpacket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ ret=1
else
echo "[PASS]"
fi
@@ -32,6 +35,8 @@ echo "--------------------"
./in_netns.sh ./txring_overwrite
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ ret=1
else
echo "[PASS]"
fi
+exit $ret
--
2.20.1
From: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
[ Upstream commit 30c04d796b693e22405c38e9b78e9a364e4c77e6 ]
The run_netsocktests will be marked as passed regardless the actual test
result from the ./socket:
selftests: net: run_netsocktests
========================================
--------------------
running socket test
--------------------
[FAIL]
ok 1..6 selftests: net: run_netsocktests [PASS]
This is because the test script itself has been successfully executed.
Fix this by exit 1 when the test failed.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/run_netsocktests | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/run_netsocktests b/tools/testing/selftests/net/run_netsocktests
index b093f39c298c..14e41faf2c57 100755
--- a/tools/testing/selftests/net/run_netsocktests
+++ b/tools/testing/selftests/net/run_netsocktests
@@ -7,7 +7,7 @@ echo "--------------------"
./socket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ exit 1
else
echo "[PASS]"
fi
-
--
2.20.1
From: David Ahern <dsahern(a)gmail.com>
[ Upstream commit a5f622984a623df9a84cf43f6b098d8dd76fbe05 ]
A couple of tests are verifying a route has been removed. The helper
expects the prefix as the first part of the expected output. When
checking that a route has been deleted the prefix is empty leading
to an invalid ip command:
$ ip ro ls match
Command line is not complete. Try option "help"
Fix by moving the comparison of expected output and output to a new
function that is used by both check_route and check_route6. Use the
new helper for the 2 checks on route removal.
Also, remove the reset of 'set -x' in route_setup which overrides the
user managed setting.
Fixes: d69faad76584c ("selftests: fib_tests: Add prefix route tests with metric")
Signed-off-by: David Ahern <dsahern(a)gmail.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/net/fib_tests.sh | 94 ++++++++++--------------
1 file changed, 40 insertions(+), 54 deletions(-)
diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
index 1080ff55a788..0d2a5f4f1e63 100755
--- a/tools/testing/selftests/net/fib_tests.sh
+++ b/tools/testing/selftests/net/fib_tests.sh
@@ -605,6 +605,39 @@ run_cmd()
return $rc
}
+check_expected()
+{
+ local out="$1"
+ local expected="$2"
+ local rc=0
+
+ [ "${out}" = "${expected}" ] && return 0
+
+ if [ -z "${out}" ]; then
+ if [ "$VERBOSE" = "1" ]; then
+ printf "\nNo route entry found\n"
+ printf "Expected:\n"
+ printf " ${expected}\n"
+ fi
+ return 1
+ fi
+
+ # tricky way to convert output to 1-line without ip's
+ # messy '\'; this drops all extra white space
+ out=$(echo ${out})
+ if [ "${out}" != "${expected}" ]; then
+ rc=1
+ if [ "${VERBOSE}" = "1" ]; then
+ printf " Unexpected route entry. Have:\n"
+ printf " ${out}\n"
+ printf " Expected:\n"
+ printf " ${expected}\n\n"
+ fi
+ fi
+
+ return $rc
+}
+
# add route for a prefix, flushing any existing routes first
# expected to be the first step of a test
add_route6()
@@ -652,31 +685,7 @@ check_route6()
pfx=$1
out=$($IP -6 ro ls match ${pfx} | sed -e 's/ pref medium//')
- [ "${out}" = "${expected}" ] && return 0
-
- if [ -z "${out}" ]; then
- if [ "$VERBOSE" = "1" ]; then
- printf "\nNo route entry found\n"
- printf "Expected:\n"
- printf " ${expected}\n"
- fi
- return 1
- fi
-
- # tricky way to convert output to 1-line without ip's
- # messy '\'; this drops all extra white space
- out=$(echo ${out})
- if [ "${out}" != "${expected}" ]; then
- rc=1
- if [ "${VERBOSE}" = "1" ]; then
- printf " Unexpected route entry. Have:\n"
- printf " ${out}\n"
- printf " Expected:\n"
- printf " ${expected}\n\n"
- fi
- fi
-
- return $rc
+ check_expected "${out}" "${expected}"
}
route_cleanup()
@@ -725,7 +734,7 @@ route_setup()
ip -netns ns2 addr add 172.16.103.2/24 dev veth4
ip -netns ns2 addr add 172.16.104.1/24 dev dummy1
- set +ex
+ set +e
}
# assumption is that basic add of a single path route works
@@ -960,7 +969,8 @@ ipv6_addr_metric_test()
run_cmd "$IP li set dev dummy2 down"
rc=$?
if [ $rc -eq 0 ]; then
- check_route6 ""
+ out=$($IP -6 ro ls match 2001:db8:104::/64)
+ check_expected "${out}" ""
rc=$?
fi
log_test $rc 0 "Prefix route removed on link down"
@@ -1091,38 +1101,13 @@ check_route()
local pfx
local expected="$1"
local out
- local rc=0
set -- $expected
pfx=$1
[ "${pfx}" = "unreachable" ] && pfx=$2
out=$($IP ro ls match ${pfx})
- [ "${out}" = "${expected}" ] && return 0
-
- if [ -z "${out}" ]; then
- if [ "$VERBOSE" = "1" ]; then
- printf "\nNo route entry found\n"
- printf "Expected:\n"
- printf " ${expected}\n"
- fi
- return 1
- fi
-
- # tricky way to convert output to 1-line without ip's
- # messy '\'; this drops all extra white space
- out=$(echo ${out})
- if [ "${out}" != "${expected}" ]; then
- rc=1
- if [ "${VERBOSE}" = "1" ]; then
- printf " Unexpected route entry. Have:\n"
- printf " ${out}\n"
- printf " Expected:\n"
- printf " ${expected}\n\n"
- fi
- fi
-
- return $rc
+ check_expected "${out}" "${expected}"
}
# assumption is that basic add of a single path route works
@@ -1387,7 +1372,8 @@ ipv4_addr_metric_test()
run_cmd "$IP li set dev dummy2 down"
rc=$?
if [ $rc -eq 0 ]; then
- check_route ""
+ out=$($IP ro ls match 172.16.104.0/24)
+ check_expected "${out}" ""
rc=$?
fi
log_test $rc 0 "Prefix route removed on link down"
--
2.20.1
Hi Linus,
Please pull the following Kselftest update for Linux 5.2-rc1
This Kselftest update for Linux 5.2-rc1 consists of
- fixes to seccomp test, and kselftest framework
- cleanups to remove duplicate header defines
- fixes to efivarfs "make clean" target
- cgroup cleanup path
- Moving the IMA kexec_load selftest to selftests/kexec work from
Mimi Johar and Petr Vorel
- A framework to kselftest for writing kernel test modules addition
from Tobin C. Harding
diff is attached.
thanks,
-- Shuah
----------------------------------------------------------------
The following changes since commit 15ade5d2e7775667cf191cf2f94327a4889f8b9d:
Linux 5.1-rc4 (2019-04-07 14:09:59 -1000)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
tags/linux-kselftest-5.2-rc1
for you to fetch changes up to d917fb876f6eaeeea8a2b620d2a266ce26372f4d:
selftests: build and run gpio when output directory is the src dir
(2019-04-22 17:02:26 -0600)
----------------------------------------------------------------
linux-kselftest-5.2-rc1
This Kselftest update for Linux 5.2-rc1 consists of
- fixes to seccomp test, and kselftest framework
- cleanups to remove duplicate header defines
- fixes to efivarfs "make clean" target
- cgroup cleanup path
- Moving the IMA kexec_load selftest to selftests/kexec work from
Mimi Johar and Petr Vorel
- A framework to kselftest for writing kernel test modules addition
from Tobin C. Harding
----------------------------------------------------------------
Kees Cook (3):
selftests/seccomp: Handle namespace failures gracefully
selftests/harness: Add 30 second timeout per test
selftests/ipc: Fix msgque compiler warnings
Mathieu Desnoyers (1):
rseq/selftests: Adapt number of threads to the number of detected
cpus
Mimi Zohar (9):
selftests/kexec: move the IMA kexec_load selftest to selftests/kexec
selftests/kexec: cleanup the kexec selftest
selftests/kexec: define a set of common functions
selftests/kexec: define common logging functions
selftests/kexec: define "require_root_privileges"
selftests/kexec: kexec_file_load syscall test
selftests/kexec: check kexec_load and kexec_file_load are enabled
selftests/kexec: make kexec_load test independent of IMA being
enabled
selftests/kexec: update get_secureboot_mode
Petr Vorel (1):
selftests/kexec: Add missing '=y' to config options
Po-Hsu Lin (1):
selftests/efivarfs: clean up test files from test_create*()
Roman Gushchin (1):
selftests: cgroup: fix cleanup path in test_memcg_subtree_control()
Sabyasachi Gupta (4):
selftest/x86/mpx-dig.c: Remove duplicate header
selftest/timers: Remove duplicate header
selftest/rseq: Remove duplicate header
selftest/gpio: Remove duplicate header
Shuah Khan (2):
selftests: fix headers_install circular dependency
selftests: build and run gpio when output directory is the src dir
Tobin C. Harding (6):
lib/test_printf: Add empty module_exit function
kselftest: Add test runner creation script
kselftest: Add test module framework header
lib: Use new kselftest header
lib/string: Add strscpy_pad() function
lib: Add test module for strscpy_pad
ZhangXiaoxu (1):
selftests: efivarfs: remove the test_create_read file if it was exist
Documentation/dev-tools/kselftest.rst | 94 ++++++++-
include/linux/string.h | 4 +
lib/Kconfig.debug | 3 +
lib/Makefile | 1 +
lib/string.c | 47 ++++-
lib/test_bitmap.c | 20 +-
lib/test_printf.c | 17 +-
lib/test_strscpy.c | 150 ++++++++++++++
tools/testing/selftests/Makefile | 63 +++++-
tools/testing/selftests/cgroup/test_memcontrol.c | 38 ++--
tools/testing/selftests/efivarfs/efivarfs.sh | 28 ++-
tools/testing/selftests/gpio/gpio-mockup-chardev.c | 1 -
tools/testing/selftests/ima/config | 4 -
tools/testing/selftests/ima/test_kexec_load.sh | 54 -----
tools/testing/selftests/ipc/msgque.c | 11 +-
tools/testing/selftests/{ima => kexec}/Makefile | 5 +-
tools/testing/selftests/kexec/config | 3 +
tools/testing/selftests/kexec/kexec_common_lib.sh | 220
+++++++++++++++++++++
.../selftests/kexec/test_kexec_file_load.sh | 208
+++++++++++++++++++
tools/testing/selftests/kexec/test_kexec_load.sh | 47 +++++
tools/testing/selftests/kselftest_harness.h | 2 +
tools/testing/selftests/kselftest_module.h | 48 +++++
tools/testing/selftests/kselftest_module.sh | 84 ++++++++
tools/testing/selftests/lib.mk | 38 +++-
tools/testing/selftests/lib/Makefile | 2 +-
tools/testing/selftests/lib/bitmap.sh | 18 +-
tools/testing/selftests/lib/config | 1 +
tools/testing/selftests/lib/prime_numbers.sh | 17 +-
tools/testing/selftests/lib/printf.sh | 19 +-
tools/testing/selftests/lib/strscpy.sh | 3 +
tools/testing/selftests/rseq/rseq.h | 1 -
tools/testing/selftests/rseq/run_param_test.sh | 7 +-
tools/testing/selftests/seccomp/seccomp_bpf.c | 43 ++--
tools/testing/selftests/timers/skew_consistency.c | 1 -
tools/testing/selftests/x86/mpx-dig.c | 2 -
35 files changed, 1081 insertions(+), 223 deletions(-)
create mode 100644 lib/test_strscpy.c
delete mode 100644 tools/testing/selftests/ima/config
delete mode 100755 tools/testing/selftests/ima/test_kexec_load.sh
rename tools/testing/selftests/{ima => kexec}/Makefile (59%)
create mode 100644 tools/testing/selftests/kexec/config
create mode 100755 tools/testing/selftests/kexec/kexec_common_lib.sh
create mode 100755 tools/testing/selftests/kexec/test_kexec_file_load.sh
create mode 100755 tools/testing/selftests/kexec/test_kexec_load.sh
create mode 100644 tools/testing/selftests/kselftest_module.h
create mode 100755 tools/testing/selftests/kselftest_module.sh
create mode 100755 tools/testing/selftests/lib/strscpy.sh
----------------------------------------------------------------
=== Overview
arm64 has a feature called Top Byte Ignore, which allows to embed pointer
tags into the top byte of each pointer. Userspace programs (such as
HWASan, a memory debugging tool [1]) might use this feature and pass
tagged user pointers to the kernel through syscalls or other interfaces.
Right now the kernel is already able to handle user faults with tagged
pointers, due to these patches:
1. 81cddd65 ("arm64: traps: fix userspace cache maintenance emulation on a
tagged pointer")
2. 7dcd9dd8 ("arm64: hw_breakpoint: fix watchpoint matching for tagged
pointers")
3. 276e9327 ("arm64: entry: improve data abort handling of tagged
pointers")
This patchset extends tagged pointer support to syscall arguments.
As per the proposed ABI change [3], tagged pointers are only allowed to be
passed to syscalls when they point to memory ranges obtained by anonymous
mmap() or sbrk() (see the patchset [3] for more details).
For non-memory syscalls this is done by untaging user pointers when the
kernel performs pointer checking to find out whether the pointer comes
from userspace (most notably in access_ok). The untagging is done only
when the pointer is being checked, the tag is preserved as the pointer
makes its way through the kernel and stays tagged when the kernel
dereferences the pointer when perfoming user memory accesses.
Memory syscalls (mmap, mprotect, etc.) don't do user memory accesses but
rather deal with memory ranges, and untagged pointers are better suited to
describe memory ranges internally. Thus for memory syscalls we untag
pointers completely when they enter the kernel.
=== Other approaches
One of the alternative approaches to untagging that was considered is to
completely strip the pointer tag as the pointer enters the kernel with
some kind of a syscall wrapper, but that won't work with the countless
number of different ioctl calls. With this approach we would need a custom
wrapper for each ioctl variation, which doesn't seem practical.
An alternative approach to untagging pointers in memory syscalls prologues
is to inspead allow tagged pointers to be passed to find_vma() (and other
vma related functions) and untag them there. Unfortunately, a lot of
find_vma() callers then compare or subtract the returned vma start and end
fields against the pointer that was being searched. Thus this approach
would still require changing all find_vma() callers.
=== Testing
The following testing approaches has been taken to find potential issues
with user pointer untagging:
1. Static testing (with sparse [2] and separately with a custom static
analyzer based on Clang) to track casts of __user pointers to integer
types to find places where untagging needs to be done.
2. Static testing with grep to find parts of the kernel that call
find_vma() (and other similar functions) or directly compare against
vm_start/vm_end fields of vma.
3. Static testing with grep to find parts of the kernel that compare
user pointers with TASK_SIZE or other similar consts and macros.
4. Dynamic testing: adding BUG_ON(has_tag(addr)) to find_vma() and running
a modified syzkaller version that passes tagged pointers to the kernel.
Based on the results of the testing the requried patches have been added
to the patchset.
=== Notes
This patchset is meant to be merged together with "arm64 relaxed ABI" [3].
This patchset is a prerequisite for ARM's memory tagging hardware feature
support [4].
This patchset has been merged into the Pixel 2 & 3 kernel trees and is
now being used to enable testing of Pixel phones with HWASan.
Thanks!
[1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html
[2] https://github.com/lucvoo/sparse-dev/commit/5f960cb10f56ec2017c128ef9d16060…
[3] https://lkml.org/lkml/2019/3/18/819
[4] https://community.arm.com/processors/b/blog/posts/arm-a-profile-architectur…
Changes in v14:
- Moved untagging for most memory syscalls to an arm64 specific
implementation, instead of doing that in the common code.
- Dropped "net, arm64: untag user pointers in tcp_zerocopy_receive", since
the provided user pointers don't come from an anonymous map and thus are
not covered by this ABI relaxation.
- Dropped "kernel, arm64: untag user pointers in prctl_set_mm*".
- Moved untagging from __check_mem_type() to tee_shm_register().
- Updated untagging for the amdgpu and radeon drivers to cover the MMU
notifier, as suggested by Felix.
- Since this ABI relaxation doesn't actually allow tagged instruction
pointers, dropped the following patches:
- Dropped "tracing, arm64: untag user pointers in seq_print_user_ip".
- Dropped "uprobes, arm64: untag user pointers in find_active_uprobe".
- Dropped "bpf, arm64: untag user pointers in stack_map_get_build_id_offset".
- Rebased onto 5.1-rc7 (37624b58).
Changes in v13:
- Simplified untagging in tcp_zerocopy_receive().
- Looked at find_vma() callers in drivers/, which allowed to identify a
few other places where untagging is needed.
- Added patch "mm, arm64: untag user pointers in get_vaddr_frames".
- Added patch "drm/amdgpu, arm64: untag user pointers in
amdgpu_ttm_tt_get_user_pages".
- Added patch "drm/radeon, arm64: untag user pointers in
radeon_ttm_tt_pin_userptr".
- Added patch "IB/mlx4, arm64: untag user pointers in mlx4_get_umem_mr".
- Added patch "media/v4l2-core, arm64: untag user pointers in
videobuf_dma_contig_user_get".
- Added patch "tee/optee, arm64: untag user pointers in check_mem_type".
- Added patch "vfio/type1, arm64: untag user pointers".
Changes in v12:
- Changed untagging in tcp_zerocopy_receive() to also untag zc->address.
- Fixed untagging in prctl_set_mm* to only untag pointers for vma lookups
and validity checks, but leave them as is for actual user space accesses.
- Updated the link to the v2 of the "arm64 relaxed ABI" patchset [3].
- Dropped the documentation patch, as the "arm64 relaxed ABI" patchset [3]
handles that.
Changes in v11:
- Added "uprobes, arm64: untag user pointers in find_active_uprobe" patch.
- Added "bpf, arm64: untag user pointers in stack_map_get_build_id_offset"
patch.
- Fixed "tracing, arm64: untag user pointers in seq_print_user_ip" to
correctly perform subtration with a tagged addr.
- Moved untagged_addr() from SYSCALL_DEFINE3(mprotect) and
SYSCALL_DEFINE4(pkey_mprotect) to do_mprotect_pkey().
- Moved untagged_addr() definition for other arches from
include/linux/memory.h to include/linux/mm.h.
- Changed untagging in strn*_user() to perform userspace accesses through
tagged pointers.
- Updated the documentation to mention that passing tagged pointers to
memory syscalls is allowed.
- Updated the test to use malloc'ed memory instead of stack memory.
Changes in v10:
- Added "mm, arm64: untag user pointers passed to memory syscalls" back.
- New patch "fs, arm64: untag user pointers in fs/userfaultfd.c".
- New patch "net, arm64: untag user pointers in tcp_zerocopy_receive".
- New patch "kernel, arm64: untag user pointers in prctl_set_mm*".
- New patch "tracing, arm64: untag user pointers in seq_print_user_ip".
Changes in v9:
- Rebased onto 4.20-rc6.
- Used u64 instead of __u64 in type casts in the untagged_addr macro for
arm64.
- Added braces around (addr) in the untagged_addr macro for other arches.
Changes in v8:
- Rebased onto 65102238 (4.20-rc1).
- Added a note to the cover letter on why syscall wrappers/shims that untag
user pointers won't work.
- Added a note to the cover letter that this patchset has been merged into
the Pixel 2 kernel tree.
- Documentation fixes, in particular added a list of syscalls that don't
support tagged user pointers.
Changes in v7:
- Rebased onto 17b57b18 (4.19-rc6).
- Dropped the "arm64: untag user address in __do_user_fault" patch, since
the existing patches already handle user faults properly.
- Dropped the "usb, arm64: untag user addresses in devio" patch, since the
passed pointer must come from a vma and therefore be untagged.
- Dropped the "arm64: annotate user pointers casts detected by sparse"
patch (see the discussion to the replies of the v6 of this patchset).
- Added more context to the cover letter.
- Updated Documentation/arm64/tagged-pointers.txt.
Changes in v6:
- Added annotations for user pointer casts found by sparse.
- Rebased onto 050cdc6c (4.19-rc1+).
Changes in v5:
- Added 3 new patches that add untagging to places found with static
analysis.
- Rebased onto 44c929e1 (4.18-rc8).
Changes in v4:
- Added a selftest for checking that passing tagged pointers to the
kernel succeeds.
- Rebased onto 81e97f013 (4.18-rc1+).
Changes in v3:
- Rebased onto e5c51f30 (4.17-rc6+).
- Added linux-arch@ to the list of recipients.
Changes in v2:
- Rebased onto 2d618bdf (4.17-rc3+).
- Removed excessive untagging in gup.c.
- Removed untagging pointers returned from __uaccess_mask_ptr.
Changes in v1:
- Rebased onto 4.17-rc1.
Changes in RFC v2:
- Added "#ifndef untagged_addr..." fallback in linux/uaccess.h instead of
defining it for each arch individually.
- Updated Documentation/arm64/tagged-pointers.txt.
- Dropped "mm, arm64: untag user addresses in memory syscalls".
- Rebased onto 3eb2ce82 (4.16-rc7).
Signed-off-by: Andrey Konovalov <andreyknvl(a)google.com>
Andrey Konovalov (17):
uaccess: add untagged_addr definition for other arches
arm64: untag user pointers in access_ok and __uaccess_mask_ptr
lib, arm64: untag user pointers in strn*_user
mm: add ksys_ wrappers to memory syscalls
arms64: untag user pointers passed to memory syscalls
mm: untag user pointers in do_pages_move
mm, arm64: untag user pointers in mm/gup.c
mm, arm64: untag user pointers in get_vaddr_frames
fs, arm64: untag user pointers in copy_mount_options
fs, arm64: untag user pointers in fs/userfaultfd.c
drm/amdgpu, arm64: untag user pointers
drm/radeon, arm64: untag user pointers
IB/mlx4, arm64: untag user pointers in mlx4_get_umem_mr
media/v4l2-core, arm64: untag user pointers in
videobuf_dma_contig_user_get
tee, arm64: untag user pointers in tee_shm_register
vfio/type1, arm64: untag user pointers in vaddr_get_pfn
selftests, arm64: add a selftest for passing tagged pointers to kernel
arch/arm64/include/asm/uaccess.h | 10 +-
arch/arm64/kernel/sys.c | 128 ++++++++++++++++-
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 2 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 2 +
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 2 +-
drivers/gpu/drm/radeon/radeon_gem.c | 2 +
drivers/gpu/drm/radeon/radeon_ttm.c | 2 +-
drivers/infiniband/hw/mlx4/mr.c | 7 +-
drivers/media/v4l2-core/videobuf-dma-contig.c | 9 +-
drivers/tee/tee_shm.c | 1 +
drivers/vfio/vfio_iommu_type1.c | 2 +
fs/namespace.c | 2 +-
fs/userfaultfd.c | 5 +
include/linux/mm.h | 4 +
include/linux/syscalls.h | 22 +++
ipc/shm.c | 7 +-
lib/strncpy_from_user.c | 3 +-
lib/strnlen_user.c | 3 +-
mm/frame_vector.c | 2 +
mm/gup.c | 4 +
mm/madvise.c | 129 +++++++++---------
mm/mempolicy.c | 21 ++-
mm/migrate.c | 1 +
mm/mincore.c | 57 ++++----
mm/mlock.c | 20 ++-
mm/mmap.c | 30 +++-
mm/mprotect.c | 6 +-
mm/mremap.c | 27 ++--
mm/msync.c | 35 +++--
tools/testing/selftests/arm64/.gitignore | 1 +
tools/testing/selftests/arm64/Makefile | 11 ++
.../testing/selftests/arm64/run_tags_test.sh | 12 ++
tools/testing/selftests/arm64/tags_test.c | 21 +++
33 files changed, 431 insertions(+), 159 deletions(-)
create mode 100644 tools/testing/selftests/arm64/.gitignore
create mode 100644 tools/testing/selftests/arm64/Makefile
create mode 100755 tools/testing/selftests/arm64/run_tags_test.sh
create mode 100644 tools/testing/selftests/arm64/tags_test.c
--
2.21.0.593.g511ec345e18-goog
On Fri, May 3, 2019 at 10:08 PM Linus Torvalds
<torvalds(a)linux-foundation.org> wrote:
>
> I'll look at it tomorrow, but I think this actually makes unnecessary changes.
>
> In particular, I think we could keep the existing entry code almost unchanged with this whole approach.
So here's what I *think* should work. Note that I also removed your
test-case code, because it really didn't have a chance in hell of
working. Doing that
int3_emulate_call(regs, (unsigned long)&int3_magic);
inside of int3_exception_notify() could not possibly be valid, since
int3_emulate_call() returns the new pt_regs that need to be used, and
throwing it away is clearly wrong.
So you can't use a register_die_notifier() to try to intercept the
'int3' error and then do it manually, it needs to be done by the
ftrace_int3_handler() code that actually returns the new regs, and
where do_kernel_int3() will then return it to the low-level handler.
End result: I haven't actually tested this code, but I've looked
through the patch something like ten times without finding any new
errors.
I've also tried *very* hard to make the patch minimal, with the
exception of the comments, which I tried to make extensive for any of
the subtle cases.
But without testing, it's probably still buggy.
I have to say, I finally like the end result here. Maybe it's because
I got to make my mark and pee in the snow, but I will say that
(a) the actual entry code modifications really are minimal now
(b) the instruction emulation really is very simple and straightforward
(c) yes, we play some stack tricks (and yes, we play them differently
on x86-64 and x86-32), but the tricks are again at least
straightforward, and we never really change the layout of any stack.
So on the whole, I think this is about as good as it gets. Did I get
all the details actually right, and it _works_? I guess we'll see.
Linus
Given that the entry_*.S changes for this functionality are somewhat
tricky, make sure the paths are tested every boot, instead of on the
rare occasion when we trip an INT3 while rewriting text.
Getting the INT3 frame setup even slightly wrong will make this come
unstuck something spectacular.
Requested-by: Andy Lutomirski <luto(a)kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
---
arch/x86/kernel/alternative.c | 81 ++++++++++++++++++++++++++++++++++++++++---
1 file changed, 77 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 4db9c0d29bc1..2b853c2ab894 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -613,11 +613,83 @@ extern struct paravirt_patch_site __start_parainstructions[],
__stop_parainstructions[];
#endif /* CONFIG_PARAVIRT */
+/*
+ * Self-test for the INT3 based CALL emulation code.
+ *
+ * This exercises int3_emulate_call() to make sure INT3 pt_regs are set up
+ * properly and that there is a stack gap between the INT3 frame and the
+ * previous context. Without this gap doing a virtual PUSH on the interrupted
+ * stack would corrupt the INT3 IRET frame.
+ *
+ * See entry_{32,64}.S for more details.
+ */
+static void __init int3_magic(unsigned int *ptr)
+{
+ *ptr = 1;
+}
+
+extern __initdata unsigned long int3_selftest_ip; /* defined in asm below */
+
+static int __init
+int3_exception_notify(struct notifier_block *self, unsigned long val, void *data)
+{
+ struct die_args *args = data;
+ struct pt_regs *regs = args->regs;
+
+ if (!regs || user_mode(regs))
+ return NOTIFY_DONE;
+
+ if (val != DIE_INT3)
+ return NOTIFY_DONE;
+
+ if (regs->ip - INT3_INSN_SIZE != int3_selftest_ip)
+ return NOTIFY_DONE;
+
+ int3_emulate_call(regs, (unsigned long)&int3_magic);
+ return NOTIFY_STOP;
+}
+
+static void __init int3_selftest(void)
+{
+ static __initdata struct notifier_block int3_exception_nb = {
+ .notifier_call = int3_exception_notify,
+ .priority = INT_MAX-1, /* last */
+ };
+ unsigned int val = 0;
+
+ BUG_ON(register_die_notifier(&int3_exception_nb));
+
+ /*
+ * Basically: int3_magic(&val); but really complicated :-)
+ *
+ * Stick the address of the INT3 instruction into int3_selftest_ip,
+ * then trigger the INT3, padded with NOPs to match a CALL instruction
+ * length.
+ */
+ asm volatile ("1: int3; nop; nop; nop; nop\n\t"
+ ".pushsection .init.data,\"aw\"\n\t"
+ ".align " __ASM_SEL(4, 8) "\n\t"
+ ".type int3_selftest_ip, @object\n\t"
+ ".size int3_selftest_ip, " __ASM_SEL(4, 8) "\n\t"
+ "int3_selftest_ip:\n\t"
+ __ASM_SEL(.long, .quad) " 1b\n\t"
+ ".popsection\n\t"
+ : : __ASM_SEL_RAW(a, D) (&val) : "memory");
+
+ BUG_ON(val != 1);
+
+ unregister_die_notifier(&int3_exception_nb);
+}
+
void __init alternative_instructions(void)
{
- /* The patching is not fully atomic, so try to avoid local interruptions
- that might execute the to be patched code.
- Other CPUs are not running. */
+ int3_selftest();
+
+ /*
+ * The patching is not fully atomic, so try to avoid local
+ * interruptions that might execute the to be patched code.
+ * Other CPUs are not running.
+ */
stop_nmi();
/*
@@ -642,10 +714,11 @@ void __init alternative_instructions(void)
_text, _etext);
}
- if (!uniproc_patched || num_possible_cpus() == 1)
+ if (!uniproc_patched || num_possible_cpus() == 1) {
free_init_pages("SMP alternatives",
(unsigned long)__smp_locks,
(unsigned long)__smp_locks_end);
+ }
#endif
apply_paravirt(__parainstructions, __parainstructions_end);
Introduce in-kernel headers which are made available as an archive
through proc (/proc/kheaders.tar.xz file). This archive makes it
possible to run eBPF and other tracing programs that need to extend the
kernel for tracing purposes without any dependency on the file system
having headers.
A github PR is sent for the corresponding BCC patch at:
https://github.com/iovisor/bcc/pull/2312
On Android and embedded systems, it is common to switch kernels but not
have kernel headers available on the file system. Further once a
different kernel is booted, any headers stored on the file system will
no longer be useful. This is an issue even well known to distros.
By storing the headers as a compressed archive within the kernel, we can
avoid these issues that have been a hindrance for a long time.
The best way to use this feature is by building it in. Several users
have a need for this, when they switch debug kernels, they do not want to
update the filesystem or worry about it where to store the headers on
it. However, the feature is also buildable as a module in case the user
desires it not being part of the kernel image. This makes it possible to
load and unload the headers from memory on demand. A tracing program can
load the module, do its operations, and then unload the module to save
kernel memory. The total memory needed is 3.3MB.
By having the archive available at a fixed location independent of
filesystem dependencies and conventions, all debugging tools can
directly refer to the fixed location for the archive, without concerning
with where the headers on a typical filesystem which significantly
simplifies tooling that needs kernel headers.
The code to read the headers is based on /proc/config.gz code and uses
the same technique to embed the headers.
Other approaches were discussed such as having an in-memory mountable
filesystem, but that has drawbacks such as requiring an in-kernel xz
decompressor which we don't have today, and requiring usage of 42 MB of
kernel memory to host the decompressed headers at anytime. Also this
approach is simpler than such approaches.
Reviewed-by: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
(Just a resend with Masahiro's Reviewed-by tag added)
v6 -> v7:
- Minor nits from Masahiro Yamada are addressed.
v5 -> v6: (Masahiro Yamada suggestions mostly)
- Dropped support for module building.
- Rebuild archive if script changes.
- Move archive file list to script.
- Move build script to kernel directory.
v4 -> v5:
(v4 was Tested-by the following folks)
Tested-by: qais.yousef(a)arm.com
Tested-by: dietmar.eggemann(a)arm.com
Tested-by: linux(a)manojrajarao.com
(Thanks to Masahiro Yamada for several excellent suggestions)
- used incbin instead of bin2c (Masahiro did similar idea)
- added module.lds if ia64 otherwise ia64 may fail to build.
- added clean-files rule to Makefile
- removed strip-comments script and doing it inline
- added set -e to header generated to die on errorsr
- fixed a minor issue where find command was noisy.
- removed unneeded tar.xz rule from kernel/.gitignore
- added Tested-by tags from ARM folks.
Changes since v3:
- Blank tar was being generated because of a one line I
forgot to push. It is updated now.
- Added module.lds since arm64 needs it to build modules.
Changes since v2:
(Thanks to Masahiro Yamada for several excellent suggestions)
- Added support for out of tree builds.
- Added incremental build support bringing down build time of
incremental builds from 50 seconds to 5 seconds.
- Fixed various small nits / cleanups.
- clean ups to kheaders.c pointed by Alexey Dobriyan.
- Fixed MODULE_LICENSE in test module and kheaders.c
- Dropped Module.symvers from archive due to circular dependency.
Changes since v1:
- removed IKH_EXTRA variable, not needed (Masahiro Yamada)
- small fix ups to selftest
- added target to main Makefile etc
- added MODULE_LICENSE to test module
- made selftest more quiet
Changes since RFC:
Both changes bring size down to 3.8MB:
- use xz for compression
- strip comments except SPDX lines
- Call out the module name in Kconfig
- Also added selftests in second patch to ensure headers are always
working.
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
init/Kconfig | 10 +++++
kernel/.gitignore | 1 +
kernel/Makefile | 10 +++++
kernel/gen_ikh_data.sh | 89 ++++++++++++++++++++++++++++++++++++++++++
kernel/kheaders.c | 74 +++++++++++++++++++++++++++++++++++
5 files changed, 184 insertions(+)
create mode 100755 kernel/gen_ikh_data.sh
create mode 100644 kernel/kheaders.c
diff --git a/init/Kconfig b/init/Kconfig
index 4592bf7997c0..47c0db6e63a5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -580,6 +580,16 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
+config IKHEADERS_PROC
+ tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
+ depends on PROC_FS
+ help
+ This option enables access to the kernel header and other artifacts that
+ are generated during the build process. These can be used to build eBPF
+ tracing programs, or similar programs. If you build the headers as a
+ module, a module called kheaders.ko is built which can be loaded on-demand
+ to get access to the headers.
+
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
range 12 25
diff --git a/kernel/.gitignore b/kernel/.gitignore
index 6e699100872f..34d1e77ee9df 100644
--- a/kernel/.gitignore
+++ b/kernel/.gitignore
@@ -1,5 +1,6 @@
#
# Generated files
#
+kheaders.md5
timeconst.h
hz.bc
diff --git a/kernel/Makefile b/kernel/Makefile
index 6c57e78817da..12399614c350 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
+obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -121,3 +122,12 @@ $(obj)/configs.o: $(obj)/config_data.gz
targets += config_data.gz
$(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(call if_changed,gzip)
+
+$(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
+
+quiet_cmd_genikh = CHK $(obj)/kheaders_data.tar.xz
+cmd_genikh = $(srctree)/kernel/gen_ikh_data.sh $@
+$(obj)/kheaders_data.tar.xz: FORCE
+ $(call cmd,genikh)
+
+clean-files := kheaders_data.tar.xz kheaders.md5
diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_ikh_data.sh
new file mode 100755
index 000000000000..591a94f7b387
--- /dev/null
+++ b/kernel/gen_ikh_data.sh
@@ -0,0 +1,89 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This script generates an archive consisting of kernel headers
+# for CONFIG_IKHEADERS_PROC.
+set -e
+spath="$(dirname "$(readlink -f "$0")")"
+kroot="$spath/.."
+outdir="$(pwd)"
+tarfile=$1
+cpio_dir=$outdir/$tarfile.tmp
+
+# Script filename relative to the kernel source root
+# We add it to the archive because it is small and any changes
+# to this script will also cause a rebuild of the archive.
+sfile="$(realpath --relative-to $kroot "$(readlink -f "$0")")"
+
+src_file_list="
+include/
+arch/$SRCARCH/include/
+$sfile
+"
+
+obj_file_list="
+include/
+arch/$SRCARCH/include/
+"
+
+# Support incremental builds by skipping archive generation
+# if timestamps of files being archived are not changed.
+
+# This block is useful for debugging the incremental builds.
+# Uncomment it for debugging.
+# iter=1
+# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter;
+# else; iter=$(($(cat /tmp/iter) + 1)); fi
+# find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter
+# find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter
+
+# include/generated/compile.h is ignored because it is touched even when none
+# of the source files changed. This causes pointless regeneration, so let us
+# ignore them for md5 calculation.
+pushd $kroot > /dev/null
+src_files_md5="$(find $src_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+popd > /dev/null
+obj_files_md5="$(find $obj_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+
+if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
+if [ -f kernel/kheaders.md5 ] &&
+ [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
+ exit
+fi
+
+if [ "${quiet}" != "silent_" ]; then
+ echo " GEN $tarfile"
+fi
+
+rm -rf $cpio_dir
+mkdir $cpio_dir
+
+pushd $kroot > /dev/null
+for f in $src_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir
+popd > /dev/null
+
+# The second CPIO can complain if files already exist which can
+# happen with out of tree builds. Just silence CPIO for now.
+for f in $obj_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
+
+# Remove comments except SDPX lines
+find $cpio_dir -type f -print0 |
+ xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
+
+tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
+
+echo "$src_files_md5" > kernel/kheaders.md5
+echo "$obj_files_md5" >> kernel/kheaders.md5
+echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
+
+rm -rf $cpio_dir
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
new file mode 100644
index 000000000000..70ae6052920d
--- /dev/null
+++ b/kernel/kheaders.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Provide kernel headers useful to build tracing programs
+ * such as for running eBPF tracing tools.
+ *
+ * (Borrowed code from kernel/configs.c)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/uaccess.h>
+
+/*
+ * Define kernel_headers_data and kernel_headers_data_end, within which the
+ * compressed kernel headers are stored. The file is first compressed with xz.
+ */
+
+asm (
+" .pushsection .rodata, \"a\" \n"
+" .global kernel_headers_data \n"
+"kernel_headers_data: \n"
+" .incbin \"kernel/kheaders_data.tar.xz\" \n"
+" .global kernel_headers_data_end \n"
+"kernel_headers_data_end: \n"
+" .popsection \n"
+);
+
+extern char kernel_headers_data;
+extern char kernel_headers_data_end;
+
+static ssize_t
+ikheaders_read_current(struct file *file, char __user *buf,
+ size_t len, loff_t *offset)
+{
+ return simple_read_from_buffer(buf, len, offset,
+ &kernel_headers_data,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+}
+
+static const struct file_operations ikheaders_file_ops = {
+ .read = ikheaders_read_current,
+ .llseek = default_llseek,
+};
+
+static int __init ikheaders_init(void)
+{
+ struct proc_dir_entry *entry;
+
+ /* create the current headers file */
+ entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
+ &ikheaders_file_ops);
+ if (!entry)
+ return -ENOMEM;
+
+ proc_set_size(entry,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+ return 0;
+}
+
+static void __exit ikheaders_cleanup(void)
+{
+ remove_proc_entry("kheaders.tar.xz", NULL);
+}
+
+module_init(ikheaders_init);
+module_exit(ikheaders_cleanup);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joel Fernandes");
+MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");
--
2.21.0.593.g511ec345e18-goog
In one of my rcutorture tests the TSC clocksource got marked unstable
due to a large difference in the TSC value. I'm not sure if the guest
run for a long time with disabled interrupts or if the host was very
busy and didn't schedule the guest for some time.
I took a look on the qemu/KVM options and decided to update the options:
- Use kvm{32|64} as CPU. We could probably use `host' (like ARM does)
for maximum available features but since we don't run any userland I'm
not sure if it makes any difference.
- Drop the "noapic" option, enable TSC deadline timer. There is no
history why the APIC was disabled, I see no reason for it. The
deadline timer is probably "nicer".
- Additional config options. It ensures that the kernel knowns that it
runs as a kvm guest and can use virt devices like the kvm-clock as
clocksource. The kvm-clock was the main motivation here.
- I didn't add a random HW device. It would make the random device ready
earlier (not it doesn't complete the initialisation at all) but I
doubt that there is any need for this.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
---
tools/testing/selftests/rcutorture/bin/functions.sh | 13 ++++++++++++-
.../selftests/rcutorture/configs/rcu/CFcommon | 4 ++++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh
index 6bcb8b5b2ff22..be3c5c73d7e79 100644
--- a/tools/testing/selftests/rcutorture/bin/functions.sh
+++ b/tools/testing/selftests/rcutorture/bin/functions.sh
@@ -172,7 +172,7 @@ identify_qemu_append () {
local console=ttyS0
case "$1" in
qemu-system-x86_64|qemu-system-i386)
- echo noapic selinux=0 initcall_debug debug
+ echo selinux=0 initcall_debug debug
;;
qemu-system-aarch64)
console=ttyAMA0
@@ -191,8 +191,19 @@ identify_qemu_append () {
# Output arguments for qemu arguments based on the TORTURE_QEMU_MAC
# and TORTURE_QEMU_INTERACTIVE environment variables.
identify_qemu_args () {
+ local KVM_CPU=""
+ case "$1" in
+ qemu-system-x86_64)
+ KVM_CPU=kvm64
+ ;;
+ qemu-system-i386)
+ KVM_CPU=kvm32
+ ;;
+ esac
case "$1" in
qemu-system-x86_64|qemu-system-i386)
+ echo -machine q35,accel=kvm
+ echo -cpu ${KVM_CPU},x2apic=on,tsc-deadline=on,hypervisor=on,tsc_adjust=on
;;
qemu-system-aarch64)
echo -machine virt,gic-version=host -cpu host
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
index d2d2a86139db1..322d5d40443cd 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
+++ b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
@@ -1,2 +1,6 @@
CONFIG_RCU_TORTURE_TEST=y
CONFIG_PRINTK_TIME=y
+CONFIG_HYPERVISOR_GUEST=y
+CONFIG_PARAVIRT=y
+CONFIG_PARAVIRT_SPINLOCKS=y
+CONFIG_KVM_GUEST=y
--
2.20.1
From: Peter Zijlstra <peterz(a)infradead.org>
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_…
Cc: Andy Lutomirski <luto(a)kernel.org>
Cc: Nicolai Stange <nstange(a)suse.de>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Ingo Molnar <mingo(a)redhat.com>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: the arch/x86 maintainers <x86(a)kernel.org>
Cc: Josh Poimboeuf <jpoimboe(a)redhat.com>
Cc: Jiri Kosina <jikos(a)kernel.org>
Cc: Miroslav Benes <mbenes(a)suse.cz>
Cc: Petr Mladek <pmladek(a)suse.com>
Cc: Joe Lawrence <joe.lawrence(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com>
Cc: Tim Chen <tim.c.chen(a)linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Cc: Mimi Zohar <zohar(a)linux.ibm.com>
Cc: Juergen Gross <jgross(a)suse.com>
Cc: Nick Desaulniers <ndesaulniers(a)google.com>
Cc: Nayna Jain <nayna(a)linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Joerg Roedel <jroedel(a)suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Signed-off-by: *** Need SoB From Peter Zijlstra ***
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
arch/x86/kernel/ftrace.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index ef49517f6bb2..fd152f5a937b 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -29,6 +29,7 @@
#include <asm/kprobes.h>
#include <asm/ftrace.h>
#include <asm/nops.h>
+#include <asm/text-patching.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
}
static unsigned long ftrace_update_func;
+static unsigned long ftrace_update_func_call;
static int update_ftrace_func(unsigned long ip, void *new)
{
@@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -294,13 +298,21 @@ int ftrace_int3_handler(struct pt_regs *regs)
if (WARN_ON_ONCE(!regs))
return 0;
- ip = regs->ip - 1;
- if (!ftrace_location(ip) && !is_ftrace_caller(ip))
- return 0;
+ ip = regs->ip - INT3_INSN_SIZE;
- regs->ip += MCOUNT_INSN_SIZE - 1;
+ if (ftrace_location(ip)) {
+ int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ if (!ftrace_update_func_call) {
+ int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
+ return 1;
+ }
+ int3_emulate_call(regs, ftrace_update_func_call);
+ return 1;
+ }
- return 1;
+ return 0;
}
NOKPROBE_SYMBOL(ftrace_int3_handler);
@@ -859,6 +871,8 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -960,6 +974,7 @@ static int ftrace_mod_jmp(unsigned long ip, void *func)
{
unsigned char *new;
+ ftrace_update_func_call = 0UL;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
--
2.20.1
On Mon, Apr 29, 2019 at 12:13 PM Linus Torvalds
<torvalds(a)linux-foundation.org> wrote:
>
>
>
> On Mon, Apr 29, 2019, 12:02 Linus Torvalds <torvalds(a)linux-foundation.org> wrote:
>>
>>
>>
>> If nmi were to break it, it would be a cpu bug.
>
>
> Side note: we *already* depend on sti shadow working in other parts of the kernel, namely sti->iret.
>
Where? STI; IRET would be nuts.
Before:
commit 4214a16b02971c60960afd675d03544e109e0d75
Author: Andy Lutomirski <luto(a)kernel.org>
Date: Thu Apr 2 17:12:12 2015 -0700
x86/asm/entry/64/compat: Use SYSRETL to return from compat mode SYSENTER
we did sti; sysxit, but, when we discussed this, I don't recall anyone
speaking up in favor of the safely of the old code.
Not to mention that the crash we'll get if we get an NMI and a
rescheduling interrupt in this path will be very, very hard to debug.
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3],
Linus suggested using per CPU data along with special trampolines[4] to emulate
the calls.
Linus's solution was for text poke (which was mostly what the static_call
code did), but as ftrace has its own mechanism, it required doing its own
thing.
Having ftrace use its own per CPU data and having its own set of specialized
trampolines solves the issue of missed calls that live kernel patching
suffers.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145…
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=…
Inspired-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: stable(a)vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
Changes since v2:
- Moved inline asm to ftrace_64.S
- Used PER_CPU_VAR() and TRACE_IRQS_ON macros in assembly
- Renamed trampolines to be a little more coherent
- Created assembly version of STACK_FRAME_NON_STANDARD() in asm/frame.h
- Call ftrace_regs_caller instead of ftrace_caller
- No longer support 32 bit (it crashed badly on tests, and I couldn't figure it out)
arch/x86/include/asm/frame.h | 15 ++++++
arch/x86/kernel/ftrace.c | 102 ++++++++++++++++++++++++++++++++++-
arch/x86/kernel/ftrace_64.S | 56 +++++++++++++++++++
3 files changed, 172 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/frame.h b/arch/x86/include/asm/frame.h
index 5cbce6fbb534..04892b374b93 100644
--- a/arch/x86/include/asm/frame.h
+++ b/arch/x86/include/asm/frame.h
@@ -42,4 +42,19 @@
#endif /* CONFIG_FRAME_POINTER */
+#ifdef __ASSEMBLY__
+#ifdef CONFIG_STACK_VALIDATION
+#define STACK_FRAME_NON_STANDARD(func) \
+.section .discard.func_stack_frame_non_standard,"aw"; \
+.align 8; \
+.type __func_stack_frame_non_standard_##func, @object; \
+.size __func_stack_frame_non_standard_##func, 8; \
+__func_stack_frame_non_standard_##func: \
+.quad func; \
+.previous
+#else /* !CONFIG_STACK_VALIDATION */
+#define STACK_FRAME_NON_STANDARD(func)
+#endif /* CONFIG_STACK_VALIDATION */
+#endif /* __ASSEMBLY__ */
+
#endif /* _ASM_X86_FRAME_H */
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index ef49517f6bb2..634fc0d4fe97 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -232,6 +232,9 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
static unsigned long ftrace_update_func;
+/* Used within inline asm below */
+unsigned long ftrace_update_func_call;
+
static int update_ftrace_func(unsigned long ip, void *new)
{
unsigned char old[MCOUNT_INSN_SIZE];
@@ -259,6 +262,8 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned char *new;
int ret;
+ ftrace_update_func_call = (unsigned long)func;
+
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -280,6 +285,46 @@ static nokprobe_inline int is_ftrace_caller(unsigned long ip)
return 0;
}
+#ifdef CONFIG_X86_64
+/*
+ * We need to handle the "call func1" -> "call func2" case.
+ * Just skipping the call is not sufficient as it will be like
+ * changing to "nop" first and then updating the call. But some
+ * users of ftrace require calls never to be missed.
+ *
+ * To emulate the call while converting the call site with a breakpoint,
+ * some trampolines are used along with per CPU buffers.
+ * There are three trampolines for the call sites and three trampolines
+ * for the updating of the call in ftrace trampoline. The three
+ * trampolines are:
+ *
+ * 1) Interrupts are enabled when the breakpoint is hit
+ * 2) Interrupts are disabled when the breakpoint is hit
+ * 3) The breakpoint was hit in an NMI
+ *
+ * As per CPU data is used, interrupts must be disabled to prevent them
+ * from corrupting the data. A separate NMI trampoline is used for the
+ * NMI case. If interrupts are already disabled, then the return path
+ * of where the breakpoint was hit (saved in the per CPU data) is pushed
+ * on the stack and then a jump to either the ftrace_caller (which will
+ * loop through all registered ftrace_ops handlers depending on the ip
+ * address), or if its a ftrace trampoline call update, it will call
+ * ftrace_update_func_call which will hold the call that should be
+ * called.
+ */
+extern asmlinkage void ftrace_emulate_call_sti(void);
+extern asmlinkage void ftrace_emulate_call(void);
+extern asmlinkage void ftrace_emulate_call_nmi(void);
+extern asmlinkage void ftrace_emulate_call_update_sti(void);
+extern asmlinkage void ftrace_emulate_call_update(void);
+extern asmlinkage void ftrace_emulate_call_update_nmi(void);
+
+DEFINE_PER_CPU(void *, ftrace_bp_call_return);
+DEFINE_PER_CPU(void *, ftrace_bp_call_nmi_return);
+
+/* To hold the ftrace_regs_caller address to push on the stack */
+void *ftrace_caller_func = (void *)ftrace_regs_caller;
+
/*
* A breakpoint was added to the code address we are about to
* modify, and this is the handle that will just skip over it.
@@ -291,6 +336,58 @@ int ftrace_int3_handler(struct pt_regs *regs)
{
unsigned long ip;
+ if (WARN_ON_ONCE(!regs))
+ return 0;
+
+ ip = regs->ip - 1;
+ if (ftrace_location(ip)) {
+ /* A breakpoint at the beginning of the function was hit */
+ if (in_nmi()) {
+ /* NMIs have their own trampoline */
+ this_cpu_write(ftrace_bp_call_nmi_return, (void *)ip + MCOUNT_INSN_SIZE);
+ regs->ip = (unsigned long) ftrace_emulate_call_nmi;
+ return 1;
+ }
+ this_cpu_write(ftrace_bp_call_return, (void *)ip + MCOUNT_INSN_SIZE);
+ if (regs->flags & X86_EFLAGS_IF) {
+ regs->flags &= ~X86_EFLAGS_IF;
+ regs->ip = (unsigned long) ftrace_emulate_call_sti;
+ /* Tell lockdep here we are enabling interrupts */
+ lockdep_hardirqs_on(_THIS_IP_);
+ } else {
+ regs->ip = (unsigned long) ftrace_emulate_call;
+ }
+ return 1;
+ } else if (is_ftrace_caller(ip)) {
+ /* An ftrace trampoline is being updated */
+ if (!ftrace_update_func_call) {
+ /* If it's a jump, just need to skip it */
+ regs->ip += MCOUNT_INSN_SIZE -1;
+ return 1;
+ }
+ if (in_nmi()) {
+ /* NMIs have their own trampoline */
+ this_cpu_write(ftrace_bp_call_nmi_return, (void *)ip + MCOUNT_INSN_SIZE);
+ regs->ip = (unsigned long) ftrace_emulate_call_update_nmi;
+ return 1;
+ }
+ this_cpu_write(ftrace_bp_call_return, (void *)ip + MCOUNT_INSN_SIZE);
+ if (regs->flags & X86_EFLAGS_IF) {
+ regs->flags &= ~X86_EFLAGS_IF;
+ regs->ip = (unsigned long) ftrace_emulate_call_update_sti;
+ } else {
+ regs->ip = (unsigned long) ftrace_emulate_call_update;
+ }
+ return 1;
+ }
+
+ return 0;
+}
+#else /* !X86_64 */
+int ftrace_int3_handler(struct pt_regs *regs)
+{
+ unsigned long ip;
+
if (WARN_ON_ONCE(!regs))
return 0;
@@ -299,9 +396,9 @@ int ftrace_int3_handler(struct pt_regs *regs)
return 0;
regs->ip += MCOUNT_INSN_SIZE - 1;
-
return 1;
}
+#endif
NOKPROBE_SYMBOL(ftrace_int3_handler);
static int ftrace_write(unsigned long ip, const char *val, int size)
@@ -859,6 +956,8 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
func = ftrace_ops_get_func(ops);
+ ftrace_update_func_call = (unsigned long)func;
+
/* Do a safe modify in case the trampoline is executing */
new = ftrace_call_replace(ip, (unsigned long)func);
ret = update_ftrace_func(ip, new);
@@ -960,6 +1059,7 @@ static int ftrace_mod_jmp(unsigned long ip, void *func)
{
unsigned char *new;
+ ftrace_update_func_call = 0;
new = ftrace_jmp_replace(ip, (unsigned long)func);
return update_ftrace_func(ip, new);
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 75f2b36b41a6..8642e1719370 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -9,6 +9,9 @@
#include <asm/export.h>
#include <asm/nospec-branch.h>
#include <asm/unwind_hints.h>
+#include <asm/irqflags.h>
+#include <asm/percpu.h>
+#include <asm/frame.h>
.code64
.section .entry.text, "ax"
@@ -262,6 +265,59 @@ GLOBAL(ftrace_regs_caller_end)
ENDPROC(ftrace_regs_caller)
+/* Trampoline for function update with interrupts enabled */
+GLOBAL(ftrace_emulate_call_sti)
+ push PER_CPU_VAR(ftrace_bp_call_return)
+ push ftrace_caller_func
+ TRACE_IRQS_ON
+ sti
+ ret
+ENDPROC(ftrace_emulate_call_sti)
+
+/* Trampoline for function update with interrupts disabled*/
+GLOBAL(ftrace_emulate_call)
+ push PER_CPU_VAR(ftrace_bp_call_return)
+ push ftrace_caller_func
+ ret
+ENDPROC(ftrace_emulate_call)
+
+/* Trampoline for function update in an NMI */
+GLOBAL(ftrace_emulate_call_nmi)
+ push PER_CPU_VAR(ftrace_bp_call_nmi_return)
+ push ftrace_caller_func
+ ret
+ENDPROC(ftrace_emulate_call_nmi)
+
+/* Trampoline for ftrace trampoline call update with interrupts enabled */
+GLOBAL(ftrace_emulate_call_update_sti)
+ push PER_CPU_VAR(ftrace_bp_call_return)
+ push ftrace_update_func_call
+ TRACE_IRQS_ON
+ sti
+ ret
+ENDPROC(ftrace_emulate_call_update_sti)
+
+/* Trampoline for ftrace trampoline call update with interrupts disabled */
+GLOBAL(ftrace_emulate_call_update)
+ push PER_CPU_VAR(ftrace_bp_call_return)
+ push ftrace_update_func_call
+ ret
+ENDPROC(ftrace_emulate_call_update)
+
+/* Trampoline for ftrace trampoline call update in an NMI */
+GLOBAL(ftrace_emulate_call_update_nmi)
+ push PER_CPU_VAR(ftrace_bp_call_nmi_return)
+ push ftrace_update_func_call
+ ret
+ENDPROC(ftrace_emulate_call_update_nmi)
+
+STACK_FRAME_NON_STANDARD(ftrace_emulate_call_sti)
+STACK_FRAME_NON_STANDARD(ftrace_emulate_call)
+STACK_FRAME_NON_STANDARD(ftrace_emulate_call_nmi)
+STACK_FRAME_NON_STANDARD(ftrace_emulate_call_update_sti)
+STACK_FRAME_NON_STANDARD(ftrace_emulate_call_update)
+STACK_FRAME_NON_STANDARD(ftrace_emulate_call_update_nmi)
+
#else /* ! CONFIG_DYNAMIC_FTRACE */
ENTRY(function_hook)
--
2.20.1
pidfd are file descriptors referring to a process created with the
CLONE_PIDFD clone(2) flag. Android low memory killer (LMK) needs pidfd
polling support to replace code that currently checks for existence of
/proc/pid for knowing that a process that is signalled to be killed has
died, which is both racy and slow. The pidfd poll approach is race-free,
and also allows the LMK to do other things (such as by polling on other
fds) while awaiting the process being killed to die.
It prevents a situation where a PID is reused between when LMK sends a
kill signal and checks for existence of the PID, since the wrong PID is
now possibly checked for existence.
In this patch, we follow the same existing mechanism in the kernel used
when the parent of the task group is to be notified (do_notify_parent).
This is when the tasks waiting on a poll of pidfd are also awakened.
We have decided to include the waitqueue in struct pid for the following
reasons:
1. The wait queue has to survive for the lifetime of the poll. Including
it in task_struct would not be option in this case because the task can
be reaped and destroyed before the poll returns.
2. By including the struct pid for the waitqueue means that during
de_thread(), the new thread group leader automatically gets the new
waitqueue/pid even though its task_struct is different.
Appropriate test cases are added in the second patch to provide coverage
of all the cases the patch is handling.
Andy had a similar patch [1] in the past which was a good reference
however this patch tries to handle different situations properly related
to thread group existence, and how/where it notifies. And also solves
other bugs (waitqueue lifetime). Daniel had a similar patch [2]
recently which this patch supercedes.
[1] https://lore.kernel.org/patchwork/patch/345098/
[2] https://lore.kernel.org/lkml/20181029175322.189042-1-dancol@google.com/
Cc: luto(a)amacapital.net
Cc: rostedt(a)goodmis.org
Cc: dancol(a)google.com
Cc: sspatil(a)google.com
Cc: christian(a)brauner.io
Cc: jannh(a)google.com
Cc: surenb(a)google.com
Cc: timmurray(a)google.com
Cc: Jonathan Kowalski <bl0pbl33p(a)gmail.com>
Cc: torvalds(a)linux-foundation.org
Cc: kernel-team(a)android.com
Co-developed-by: Daniel Colascione <dancol(a)google.com>
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
RFC -> v1:
* Based on CLONE_PIDFD patches: https://lwn.net/Articles/786244/
* Updated selftests.
* Renamed poll wake function to do_notify_pidfd.
* Removed depending on EXIT flags
* Removed POLLERR flag since semantics are controversial and
we don't have usecases for it right now (later we can add if there's
a need for it).
include/linux/pid.h | 3 +++
kernel/fork.c | 33 +++++++++++++++++++++++++++++++++
kernel/pid.c | 2 ++
kernel/signal.c | 14 ++++++++++++++
4 files changed, 52 insertions(+)
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 3c8ef5a199ca..1484db6ca8d1 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -3,6 +3,7 @@
#define _LINUX_PID_H
#include <linux/rculist.h>
+#include <linux/wait.h>
enum pid_type
{
@@ -60,6 +61,8 @@ struct pid
unsigned int level;
/* lists of tasks that use this pid */
struct hlist_head tasks[PIDTYPE_MAX];
+ /* wait queue for pidfd notifications */
+ wait_queue_head_t wait_pidfd;
struct rcu_head rcu;
struct upid numbers[1];
};
diff --git a/kernel/fork.c b/kernel/fork.c
index 5525837ed80e..fb3b614f6456 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1685,8 +1685,41 @@ static void pidfd_show_fdinfo(struct seq_file *m, struct file *f)
}
#endif
+static unsigned int pidfd_poll(struct file *file, struct poll_table_struct *pts)
+{
+ struct task_struct *task;
+ struct pid *pid;
+ int poll_flags = 0;
+
+ /*
+ * tasklist_lock must be held because to avoid racing with
+ * changes in exit_state and wake up. Basically to avoid:
+ *
+ * P0: read exit_state = 0
+ * P1: write exit_state = EXIT_DEAD
+ * P1: Do a wake up - wq is empty, so do nothing
+ * P0: Queue for polling - wait forever.
+ */
+ read_lock(&tasklist_lock);
+ pid = file->private_data;
+ task = pid_task(pid, PIDTYPE_PID);
+ WARN_ON_ONCE(task && !thread_group_leader(task));
+
+ if (!task || (task->exit_state && thread_group_empty(task)))
+ poll_flags = POLLIN | POLLRDNORM;
+
+ if (!poll_flags)
+ poll_wait(file, &pid->wait_pidfd, pts);
+
+ read_unlock(&tasklist_lock);
+
+ return poll_flags;
+}
+
+
const struct file_operations pidfd_fops = {
.release = pidfd_release,
+ .poll = pidfd_poll,
#ifdef CONFIG_PROC_FS
.show_fdinfo = pidfd_show_fdinfo,
#endif
diff --git a/kernel/pid.c b/kernel/pid.c
index 20881598bdfa..5c90c239242f 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -214,6 +214,8 @@ struct pid *alloc_pid(struct pid_namespace *ns)
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);
+ init_waitqueue_head(&pid->wait_pidfd);
+
upid = pid->numbers + ns->level;
spin_lock_irq(&pidmap_lock);
if (!(ns->pid_allocated & PIDNS_ADDING))
diff --git a/kernel/signal.c b/kernel/signal.c
index 1581140f2d99..16e7718316e5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1800,6 +1800,17 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type)
return ret;
}
+static void do_notify_pidfd(struct task_struct *task)
+{
+ struct pid *pid;
+
+ lockdep_assert_held(&tasklist_lock);
+
+ pid = get_task_pid(task, PIDTYPE_PID);
+ wake_up_all(&pid->wait_pidfd);
+ put_pid(pid);
+}
+
/*
* Let a parent know about the death of a child.
* For a stopped/continued status change, use do_notify_parent_cldstop instead.
@@ -1823,6 +1834,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
BUG_ON(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
+ /* Wake up all pidfd waiters */
+ do_notify_pidfd(tsk);
+
if (sig != SIGCHLD) {
/*
* This is only possible if parent == real_parent.
--
2.21.0.593.g511ec345e18-goog
Hi,
this series is the result of the discussion to the RFC patch found at [1].
The goal is to make x86' ftrace_int3_handler() not to simply skip over
the trapping instruction as this is problematic in the context of
the live patching consistency model. For details, c.f. the commit message
of [3/4] ("x86/ftrace: make ftrace_int3_handler() not to skip fops
invocation").
Everything is based on v5.1-rc6, please let me know in case you want me to
rebase on somehing else.
For x86_64, the live patching selftest added in [4/4] succeeds with this
series applied and fails without it. On 32 bits I only compile-tested.
checkpatch reports warnings about
- an overlong line in assembly -- I chose to ignore that
- MAINTAINERS perhaps needing updates due to the new files
arch/x86/kernel/ftrace_int3_stubs.S and
tools/testing/selftests/livepatch/test-livepatch-vs-ftrace.sh.
As the existing arch/x86/kernel/ftrace_{32,64}.S haven't got an
explicit entry either, this one is probably Ok? The selftest
definitely is.
Changes to the RFC patch:
- s/trampoline/stub/ to avoid confusion with the ftrace_ops' trampolines,
- use a fixed size stack kept in struct thread_info for passing the
(adjusted) ->ip values from ftrace_int3_handler() to the stubs,
- provide one stub for each of the two possible jump targets and hardcode
those,
- add the live patching selftest.
Thanks,
Nicolai
Nicolai Stange (4):
x86/thread_info: introduce ->ftrace_int3_stack member
ftrace: drop 'static' qualifier from ftrace_ops_list_func()
x86/ftrace: make ftrace_int3_handler() not to skip fops invocation
selftests/livepatch: add "ftrace a live patched function" test
arch/x86/include/asm/thread_info.h | 11 +++
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/asm-offsets.c | 8 +++
arch/x86/kernel/ftrace.c | 79 +++++++++++++++++++---
arch/x86/kernel/ftrace_int3_stubs.S | 61 +++++++++++++++++
kernel/trace/ftrace.c | 8 +--
tools/testing/selftests/livepatch/Makefile | 3 +-
.../livepatch/test-livepatch-vs-ftrace.sh | 44 ++++++++++++
8 files changed, 199 insertions(+), 16 deletions(-)
create mode 100644 arch/x86/kernel/ftrace_int3_stubs.S
create mode 100755 tools/testing/selftests/livepatch/test-livepatch-vs-ftrace.sh
--
2.13.7
On Mon, Apr 29, 2019 at 11:53 AM Linus Torvalds
<torvalds(a)linux-foundation.org> wrote:
>
>
>
> On Mon, Apr 29, 2019, 11:42 Andy Lutomirski <luto(a)kernel.org> wrote:
>>
>>
>> I'm less than 100% convinced about this argument. Sure, an NMI right
>> there won't cause a problem. But an NMI followed by an interrupt will
>> kill us if preemption is on. I can think of three solutions:
>
>
> No, because either the sti shadow disables nmi too (that's the case on some CPUs at least) or the iret from nmi does.
>
> Otherwise you could never trust the whole sti shadow thing - and it very much is part of the architecture.
>
Is this documented somewhere? And do you actually believe that this
is true under KVM, Hyper-V, etc? As I recall, Andrew Cooper dug in to
the way that VMX dealt with this stuff and concluded that the SDM was
blatantly wrong in many cases, which leads me to believe that Xen
HVM/PVH is the *only* hypervisor that gets it right.
Steven's point about batched updates is quite valid, though. My
personal favorite solution to this whole mess is to rework the whole
thing so that the int3 handler simply returns and retries and to
replace the sync_core() broadcast with an SMI broadcast. I don't know
whether this will actually work on real CPUs and on VMs and whether
it's going to crash various BIOSes out there.
On Mon, Apr 29, 2019 at 12:02 PM Linus Torvalds
<torvalds(a)linux-foundation.org> wrote:
>
> If nmi were to break it, it would be a cpu bug. I'm pretty sure I've
> seen the "shadow stops even nmi" documented for some uarch, but as
> mentioned it's not necessarily the only way to guarantee the shadow.
In fact, the documentation is simply the official Intel instruction
docs for "STI":
The IF flag and the STI and CLI instructions do not prohibit the
generation of exceptions and NMI interrupts. NMI interrupts (and
SMIs) may be blocked for one macroinstruction following an STI.
note the "may be blocked". As mentioned, that's just one option for
not having NMI break the STI shadow guarantee, but it's clearly one
that Intel has done at times, and clearly even documents as having
done so.
There is absolutely no question that the sti shadow is real, and that
people have depended on it for _decades_. It would be a horrible
errata if the shadow can just be made to go away by randomly getting
an NMI or SMI.
Linus
On Mon, 29 Apr 2019 11:59:04 -0700
Linus Torvalds <torvalds(a)linux-foundation.org> wrote:
> I really don't care. Just do what I suggested, and if you have numbers to
> show problems, then maybe I'll care.
>
Are you suggesting that I rewrite the code to do it one function at a
time? This has always been batch mode. This is not something new. The
function tracer has been around longer than the text poke code.
> Right now you're just making excuses for this. I described the solution
> months ago, now I've written a patch, if that's not good enough then we can
> just skip this all entirely.
>
> Honestly, if you need to rewrite tens of thousands of calls, maybe you're
> doing something wrong?
>
# cd /sys/kernel/debug/tracing
# cat available_filter_functions | wc -l
45856
# cat enabled_functions | wc -l
0
# echo function > current_tracer
# cat enabled_functions | wc -l
45856
There, I just enabled 45,856 function call sites in one shot!
How else do you want to update them? Every function in the kernel has a
nop, that turns into a call to the ftrace_handler, if I add another
user of that code, it will change each one as well.
-- Steve
The entries within __rseq_table are aligned on 32 bytes due to
linux/rseq.h struct rseq_cs uapi requirements, but the start of the
__rseq_table section is not guaranteed to be 32-byte aligned. It can
cause padding to be added at the start of the section, which makes it
hard to use as an array of items by debuggers.
Considering that __rseq_table does not really consist of a table due to
the presence of padding, rename this section to __rseq_cs.
Create a new __rseq_cs_ptr_array section which contains 64-bit packed
pointers to entries within the __rseq_cs section.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
CC: Thomas Gleixner <tglx(a)linutronix.de>
CC: Joel Fernandes <joelaf(a)google.com>
CC: Peter Zijlstra <peterz(a)infradead.org>
CC: Catalin Marinas <catalin.marinas(a)arm.com>
CC: Dave Watson <davejwatson(a)fb.com>
CC: Will Deacon <will.deacon(a)arm.com>
CC: Shuah Khan <shuah(a)kernel.org>
CC: Andi Kleen <andi(a)firstfloor.org>
CC: linux-kselftest(a)vger.kernel.org
CC: "H . Peter Anvin" <hpa(a)zytor.com>
CC: Chris Lameter <cl(a)linux.com>
CC: Russell King <linux(a)arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages(a)gmail.com>
CC: "Paul E . McKenney" <paulmck(a)linux.vnet.ibm.com>
CC: Paul Turner <pjt(a)google.com>
CC: Boqun Feng <boqun.feng(a)gmail.com>
CC: Josh Triplett <josh(a)joshtriplett.org>
CC: Steven Rostedt <rostedt(a)goodmis.org>
CC: Ben Maurer <bmaurer(a)fb.com>
CC: linux-api(a)vger.kernel.org
CC: Andy Lutomirski <luto(a)amacapital.net>
CC: Andrew Morton <akpm(a)linux-foundation.org>
CC: Linus Torvalds <torvalds(a)linux-foundation.org>
---
tools/testing/selftests/rseq/rseq-arm.h | 32 +++++++++++++++++--------------
tools/testing/selftests/rseq/rseq-arm64.h | 9 ++++++---
tools/testing/selftests/rseq/rseq-mips.h | 32 +++++++++++++++++--------------
tools/testing/selftests/rseq/rseq-ppc.h | 22 +++++++++++++--------
tools/testing/selftests/rseq/rseq-s390.h | 18 +++++++++++------
tools/testing/selftests/rseq/rseq-x86.h | 19 ++++++++++++------
6 files changed, 81 insertions(+), 51 deletions(-)
diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 17e8d231943a..5f262c54364f 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -30,24 +30,28 @@ do { \
#include "rseq-skip.h"
#else /* !RSEQ_SKIP_FASTPATH */
-#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \
+#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
+ __rseq_str(label) ":\n\t" \
".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".word " __rseq_str(label) "b, 0x0\n\t" \
".popsection\n\t"
-#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \
- __RSEQ_ASM_DEFINE_TABLE(0x0, 0x0, start_ip, \
+#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
+ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -99,7 +103,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -166,7 +170,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -237,7 +241,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
#endif
@@ -292,7 +296,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -367,7 +371,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -443,7 +447,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -527,7 +531,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -651,7 +655,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index 2079f71e0ca2..b41a2a48e965 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -82,13 +82,16 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
post_commit_offset, abort_ip) \
- " .pushsection __rseq_table, \"aw\"\n" \
+ " .pushsection __rseq_cs, \"aw\"\n" \
" .balign 32\n" \
__rseq_str(label) ":\n" \
" .long " __rseq_str(version) ", " __rseq_str(flags) "\n" \
" .quad " __rseq_str(start_ip) ", " \
__rseq_str(post_commit_offset) ", " \
__rseq_str(abort_ip) "\n" \
+ " .popsection\n\t" \
+ " .pushsection __rseq_cs_ptr_array, \"aw\"\n" \
+ " .quad " __rseq_str(label) "b\n" \
" .popsection\n"
#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
@@ -99,8 +102,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index 25d10ff54769..fe3eabcdcbe5 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -54,26 +54,30 @@ do { \
# error unsupported _MIPS_SZLONG
#endif
-#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \
+#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
+ __rseq_str(label) ":\n\t" \
".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(label) "b") "\n\t" \
".popsection\n\t"
-#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \
- __RSEQ_ASM_DEFINE_TABLE(0x0, 0x0, start_ip, \
+#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
+ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -127,7 +131,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -192,7 +196,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -261,7 +265,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
#endif
@@ -316,7 +320,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -389,7 +393,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -463,7 +467,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -543,7 +547,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -664,7 +668,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 24f95649d71e..9df18487fa9f 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -33,8 +33,8 @@ do { \
#else /* !RSEQ_SKIP_FASTPATH */
/*
- * The __rseq_table section can be used by debuggers to better handle
- * single-stepping through the restartable critical sections.
+ * The __rseq_cs_ptr_array and __rseq_cs sections can be used by debuggers to
+ * better handle single-stepping through the restartable critical sections.
*/
#ifdef __PPC64__
@@ -46,11 +46,14 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".quad " __rseq_str(label) "b\n\t" \
".popsection\n\t"
#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
@@ -67,8 +70,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -85,20 +88,23 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
/* 32-bit only supported on BE */ \
".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".long 0x0, " __rseq_str(label) "b\n\t" \
".popsection\n\t"
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index b8b5b6f900af..fbb97815d71c 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -37,19 +37,22 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".quad " __rseq_str(label) "b\n\t" \
".popsection\n\t"
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -61,19 +64,22 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".long 0x0, " __rseq_str(label) "b\n\t" \
".popsection\n\t"
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 0668608d3674..03095236f6fa 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -47,13 +47,17 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".quad " __rseq_str(label) "b\n\t" \
".popsection\n\t"
+
#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
__RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
@@ -62,8 +66,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -566,11 +570,14 @@ do { \
*/
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".long " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".long " __rseq_str(label) "b, 0x0\n\t" \
".popsection\n\t"
#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
@@ -581,8 +588,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
--
2.11.0
This patch set proposes KUnit, a lightweight unit testing and mocking
framework for the Linux kernel.
Unlike Autotest and kselftest, KUnit is a true unit testing framework;
it does not require installing the kernel on a test machine or in a VM
and does not require tests to be written in userspace running on a host
kernel. Additionally, KUnit is fast: From invocation to completion KUnit
can run several dozen tests in under a second. Currently, the entire
KUnit test suite for KUnit runs in under a second from the initial
invocation (build time excluded).
KUnit is heavily inspired by JUnit, Python's unittest.mock, and
Googletest/Googlemock for C++. KUnit provides facilities for defining
unit test cases, grouping related test cases into test suites, providing
common infrastructure for running tests, mocking, spying, and much more.
## What's so special about unit testing?
A unit test is supposed to test a single unit of code in isolation,
hence the name. There should be no dependencies outside the control of
the test; this means no external dependencies, which makes tests orders
of magnitudes faster. Likewise, since there are no external dependencies,
there are no hoops to jump through to run the tests. Additionally, this
makes unit tests deterministic: a failing unit test always indicates a
problem. Finally, because unit tests necessarily have finer granularity,
they are able to test all code paths easily solving the classic problem
of difficulty in exercising error handling code.
## Is KUnit trying to replace other testing frameworks for the kernel?
No. Most existing tests for the Linux kernel are end-to-end tests, which
have their place. A well tested system has lots of unit tests, a
reasonable number of integration tests, and some end-to-end tests. KUnit
is just trying to address the unit test space which is currently not
being addressed.
## More information on KUnit
There is a bunch of documentation near the end of this patch set that
describes how to use KUnit and best practices for writing unit tests.
For convenience I am hosting the compiled docs here:
https://google.github.io/kunit-docs/third_party/kernel/docs/
Additionally for convenience, I have applied these patches to a branch:
https://kunit.googlesource.com/linux/+/kunit/rfc/v5.1-rc2/v1
The repo may be cloned with:
git clone https://kunit.googlesource.com/linux
This patchset is on the kunit/rfc/v5.1-rc2/v1 branch.
## Changes Since Last Version
Last version was RFC v4. It seemed we were pretty much done with the RFC
phase, so I started the numbering over again. Sorry if anyone finds that
confusing.
- Reduced usage of object oriented style of member functions as
suggested by Frank.
- Did a bunch of heavy clean up of the kunit_abort stuff as suggested
by Frank and Stephen:
- Biggest change was to reduce the usage of direct calls of member
functions.
- Added a better explanation of what abort is for and further
explained the rationale for KUNIT_ASSERT_* vs. KUNIT_EXPECT_*
- Dropped BUG() usage
- Also moved try_catch interface to a new file since it seemed
obscured by being mixed in with the code that used it.
- Fixed some other minor issues pointed out by Stephen.
- Updated email address of one of the contributors.
- Dropped DT unittest port since it seemed like there was a lot more
discussion to be had: it wasn't ready to leave the RFC phase.
Instead, I added a KUnit test written by Iurii for PROC SYSCTL that
was requested by Luis some time ago.
For reference, RFC v4 can be found here:
https://lkml.org/lkml/2019/2/14/1144
--
2.21.0.392.gf8f6787159e-goog
This refactors the selftest Makefiles to extract the test running logic
to be reused between "run_tests" and "emit_tests", while also fixing
up the test output to be TAP version 13 compliant:
- added "plan" line
- fixed result line syntax
- moved all test output to be "# "-prefixed as TAP "diagnostic" lines
The prefixing code includes a fallback mode for limited execution
environments.
Additionally, the plan lines are fixed for all callers of kselftest.h.
-Kees
v2:
- fix external make variable "summary=1" through-out series (shuah)
- fix plan line output for all kselftest.h users
Kees Cook (8):
selftests: Extract single-test shell logic from lib.mk
selftests: Use runner.sh for emit targets
selftests: Extract logic for multiple test runs
selftests: Add plan line and fix result line syntax
selftests: Distinguish between missing and non-executable
selftests: Move test output to diagnostic lines
selftests: Remove KSFT_TAP_LEVEL
selftests: Add test plan API to kselftest.h and adjust callers
tools/testing/selftests/.gitignore | 1 -
tools/testing/selftests/Makefile | 24 ++----
.../selftests/breakpoints/breakpoint_test.c | 15 +++-
.../breakpoints/breakpoint_test_arm64.c | 3 +-
.../breakpoints/step_after_suspend_test.c | 8 ++
.../selftests/capabilities/test_execve.c | 6 +-
.../futex/functional/futex_requeue_pi.c | 1 +
.../futex_requeue_pi_mismatched_ops.c | 1 +
.../futex_requeue_pi_signal_restart.c | 1 +
.../futex_wait_private_mapped_file.c | 1 +
.../futex/functional/futex_wait_timeout.c | 1 +
.../futex_wait_uninitialized_heap.c | 1 +
.../futex/functional/futex_wait_wouldblock.c | 1 +
tools/testing/selftests/kselftest.h | 17 +++-
tools/testing/selftests/kselftest/prefix.pl | 23 +++++
tools/testing/selftests/kselftest/runner.sh | 86 +++++++++++++++++++
tools/testing/selftests/lib.mk | 64 +++-----------
.../selftests/membarrier/membarrier_test.c | 1 +
tools/testing/selftests/pidfd/pidfd_test.c | 1 +
tools/testing/selftests/sigaltstack/sas.c | 1 +
tools/testing/selftests/sync/sync_test.c | 1 +
21 files changed, 178 insertions(+), 80 deletions(-)
create mode 100755 tools/testing/selftests/kselftest/prefix.pl
create mode 100644 tools/testing/selftests/kselftest/runner.sh
--
2.17.1
This is just sending out the tweaked fix from Tycho and the selftest
changes needed to support it. I intend to send this to Linus directly
after it's been in -next for a few days for v5.1 fixes.
Thanks!
-Kees
Kees Cook (1):
selftests/seccomp: Prepare for exclusive seccomp flags
Tycho Andersen (1):
seccomp: Make NEW_LISTENER and TSYNC flags exclusive
kernel/seccomp.c | 17 ++++++++--
tools/testing/selftests/seccomp/seccomp_bpf.c | 34 ++++++++++++++-----
2 files changed, 40 insertions(+), 11 deletions(-)
--
2.17.1
Use udf as the guard instruction for the restartable sequence abort
handler.
Previously, the chosen signature was not a valid instruction, based
on the assumption that it could always sit in a literal pool. However,
there are compilation environments in which literal pools are not
availble, for instance execute-only code. Therefore, we need to
choose a signature value that is also a valid instruction.
Handle compiling with -mbig-endian on ARMv6+, which generates binaries
with mixed code vs data endianness (little endian code, big endian
data).
Else mismatch between code endianness for the generated signatures and
data endianness for the RSEQ_SIG parameter passed to the rseq
registration will trigger application segmentation faults when the
kernel try to abort rseq critical sections.
Prior to ARMv6, -mbig-endian generates big-endian code and data, so
endianness should not be reversed in that case.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
CC: Peter Zijlstra <peterz(a)infradead.org>
CC: Thomas Gleixner <tglx(a)linutronix.de>
CC: Joel Fernandes <joelaf(a)google.com>
CC: Catalin Marinas <catalin.marinas(a)arm.com>
CC: Dave Watson <davejwatson(a)fb.com>
CC: Will Deacon <will.deacon(a)arm.com>
CC: Shuah Khan <shuah(a)kernel.org>
CC: Andi Kleen <andi(a)firstfloor.org>
CC: linux-kselftest(a)vger.kernel.org
CC: "H . Peter Anvin" <hpa(a)zytor.com>
CC: Chris Lameter <cl(a)linux.com>
CC: Russell King <linux(a)arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages(a)gmail.com>
CC: "Paul E . McKenney" <paulmck(a)linux.vnet.ibm.com>
CC: Paul Turner <pjt(a)google.com>
CC: Boqun Feng <boqun.feng(a)gmail.com>
CC: Josh Triplett <josh(a)joshtriplett.org>
CC: Steven Rostedt <rostedt(a)goodmis.org>
CC: Ben Maurer <bmaurer(a)fb.com>
CC: linux-api(a)vger.kernel.org
CC: Andy Lutomirski <luto(a)amacapital.net>
CC: Andrew Morton <akpm(a)linux-foundation.org>
CC: Linus Torvalds <torvalds(a)linux-foundation.org>
---
tools/testing/selftests/rseq/rseq-arm.h | 52 +++++++++++++++++++++++++++++++--
1 file changed, 50 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 5f262c54364f..e8ccfc37d685 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -5,7 +5,54 @@
* (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
*/
-#define RSEQ_SIG 0x53053053
+/*
+ * RSEQ_SIG uses the udf A32 instruction with an uncommon immediate operand
+ * value 0x5de3. This traps if user-space reaches this instruction by mistake,
+ * and the uncommon operand ensures the kernel does not move the instruction
+ * pointer to attacker-controlled code on rseq abort.
+ *
+ * The instruction pattern in the A32 instruction set is:
+ *
+ * e7f5def3 udf #24035 ; 0x5de3
+ *
+ * This translates to the following instruction pattern in the T16 instruction
+ * set:
+ *
+ * little endian:
+ * def3 udf #243 ; 0xf3
+ * e7f5 b.n <7f5>
+ *
+ * pre-ARMv6 big endian code:
+ * e7f5 b.n <7f5>
+ * def3 udf #243 ; 0xf3
+ *
+ * ARMv6+ -mbig-endian generates mixed endianness code vs data: little-endian
+ * code and big-endian data. Ensure the RSEQ_SIG data signature matches code
+ * endianness. Prior to ARMv6, -mbig-endian generates big-endian code and data
+ * (which match), so there is no need to reverse the endianness of the data
+ * representation of the signature. However, the choice between BE32 and BE8
+ * is done by the linker, so we cannot know whether code and data endianness
+ * will be mixed before the linker is invoked.
+ */
+
+#define RSEQ_SIG_CODE 0xe7f5def3
+
+#ifndef __ASSEMBLER__
+
+#define RSEQ_SIG_DATA \
+ ({ \
+ int sig; \
+ asm volatile ( "b 2f\n\t" \
+ "1: .inst " __rseq_str(RSEQ_SIG_CODE) "\n\t" \
+ "2:\n\t" \
+ "ldr %[sig], 1b\n\t" \
+ : [sig] "=r" (sig)); \
+ sig; \
+ })
+
+#define RSEQ_SIG RSEQ_SIG_DATA
+
+#endif
#define rseq_smp_mb() __asm__ __volatile__ ("dmb" ::: "memory", "cc")
#define rseq_smp_rmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc")
@@ -78,7 +125,8 @@ do { \
__rseq_str(table_label) ":\n\t" \
".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
- ".word " __rseq_str(RSEQ_SIG) "\n\t" \
+ ".arm\n\t" \
+ ".inst " __rseq_str(RSEQ_SIG_CODE) "\n\t" \
__rseq_str(label) ":\n\t" \
teardown \
"b %l[" __rseq_str(abort_label) "]\n\t"
--
2.11.0
The entries within __rseq_table are aligned on 32 bytes due to
linux/rseq.h struct rseq_cs uapi requirements, but the start of the
__rseq_table section is not guaranteed to be 32-byte aligned. It can
cause padding to be added at the start of the section, which makes it
hard to use as an array of items by debuggers.
Considering that __rseq_table does not really consist of a table due to
the presence of padding, rename this section to __rseq_cs.
Create a new __rseq_cs_ptr_array section which contains 64-bit packed
pointers to entries within the __rseq_cs section.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
CC: Thomas Gleixner <tglx(a)linutronix.de>
CC: Joel Fernandes <joelaf(a)google.com>
CC: Peter Zijlstra <peterz(a)infradead.org>
CC: Catalin Marinas <catalin.marinas(a)arm.com>
CC: Dave Watson <davejwatson(a)fb.com>
CC: Will Deacon <will.deacon(a)arm.com>
CC: Shuah Khan <shuah(a)kernel.org>
CC: Andi Kleen <andi(a)firstfloor.org>
CC: linux-kselftest(a)vger.kernel.org
CC: "H . Peter Anvin" <hpa(a)zytor.com>
CC: Chris Lameter <cl(a)linux.com>
CC: Russell King <linux(a)arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages(a)gmail.com>
CC: "Paul E . McKenney" <paulmck(a)linux.vnet.ibm.com>
CC: Paul Turner <pjt(a)google.com>
CC: Boqun Feng <boqun.feng(a)gmail.com>
CC: Josh Triplett <josh(a)joshtriplett.org>
CC: Steven Rostedt <rostedt(a)goodmis.org>
CC: Ben Maurer <bmaurer(a)fb.com>
CC: linux-api(a)vger.kernel.org
CC: Andy Lutomirski <luto(a)amacapital.net>
CC: Andrew Morton <akpm(a)linux-foundation.org>
CC: Linus Torvalds <torvalds(a)linux-foundation.org>
---
tools/testing/selftests/rseq/rseq-arm.h | 32 +++++++++++++++++--------------
tools/testing/selftests/rseq/rseq-arm64.h | 9 ++++++---
tools/testing/selftests/rseq/rseq-mips.h | 32 +++++++++++++++++--------------
tools/testing/selftests/rseq/rseq-ppc.h | 22 +++++++++++++--------
tools/testing/selftests/rseq/rseq-s390.h | 18 +++++++++++------
tools/testing/selftests/rseq/rseq-x86.h | 19 ++++++++++++------
6 files changed, 81 insertions(+), 51 deletions(-)
diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 17e8d231943a..5f262c54364f 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -30,24 +30,28 @@ do { \
#include "rseq-skip.h"
#else /* !RSEQ_SKIP_FASTPATH */
-#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \
+#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
+ __rseq_str(label) ":\n\t" \
".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".word " __rseq_str(label) "b, 0x0\n\t" \
".popsection\n\t"
-#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \
- __RSEQ_ASM_DEFINE_TABLE(0x0, 0x0, start_ip, \
+#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
+ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -99,7 +103,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -166,7 +170,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -237,7 +241,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
#endif
@@ -292,7 +296,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -367,7 +371,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -443,7 +447,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -527,7 +531,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -651,7 +655,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index 2079f71e0ca2..b41a2a48e965 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -82,13 +82,16 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
post_commit_offset, abort_ip) \
- " .pushsection __rseq_table, \"aw\"\n" \
+ " .pushsection __rseq_cs, \"aw\"\n" \
" .balign 32\n" \
__rseq_str(label) ":\n" \
" .long " __rseq_str(version) ", " __rseq_str(flags) "\n" \
" .quad " __rseq_str(start_ip) ", " \
__rseq_str(post_commit_offset) ", " \
__rseq_str(abort_ip) "\n" \
+ " .popsection\n\t" \
+ " .pushsection __rseq_cs_ptr_array, \"aw\"\n" \
+ " .quad " __rseq_str(label) "b\n" \
" .popsection\n"
#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
@@ -99,8 +102,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index 25d10ff54769..fe3eabcdcbe5 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -54,26 +54,30 @@ do { \
# error unsupported _MIPS_SZLONG
#endif
-#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \
+#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
+ __rseq_str(label) ":\n\t" \
".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ LONG " " U32_U64_PAD(__rseq_str(label) "b") "\n\t" \
".popsection\n\t"
-#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \
- __RSEQ_ASM_DEFINE_TABLE(0x0, 0x0, start_ip, \
+#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
+ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -127,7 +131,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -192,7 +196,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -261,7 +265,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
#endif
@@ -316,7 +320,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -389,7 +393,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -463,7 +467,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -543,7 +547,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
@@ -664,7 +668,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
- RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
+ RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 24f95649d71e..9df18487fa9f 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -33,8 +33,8 @@ do { \
#else /* !RSEQ_SKIP_FASTPATH */
/*
- * The __rseq_table section can be used by debuggers to better handle
- * single-stepping through the restartable critical sections.
+ * The __rseq_cs_ptr_array and __rseq_cs sections can be used by debuggers to
+ * better handle single-stepping through the restartable critical sections.
*/
#ifdef __PPC64__
@@ -46,11 +46,14 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".quad " __rseq_str(label) "b\n\t" \
".popsection\n\t"
#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
@@ -67,8 +70,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -85,20 +88,23 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
/* 32-bit only supported on BE */ \
".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".long 0x0, " __rseq_str(label) "b\n\t" \
".popsection\n\t"
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index b8b5b6f900af..fbb97815d71c 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -37,19 +37,22 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".quad " __rseq_str(label) "b\n\t" \
".popsection\n\t"
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -61,19 +64,22 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".long 0x0, " __rseq_str(label) "b\n\t" \
".popsection\n\t"
/*
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 0668608d3674..03095236f6fa 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -47,13 +47,17 @@ do { \
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".quad " __rseq_str(label) "b\n\t" \
".popsection\n\t"
+
#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
__RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
@@ -62,8 +66,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
@@ -566,11 +570,14 @@ do { \
*/
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
- ".pushsection __rseq_table, \"aw\"\n\t" \
+ ".pushsection __rseq_cs, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".long " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
+ ".popsection\n\t" \
+ ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
+ ".long " __rseq_str(label) "b, 0x0\n\t" \
".popsection\n\t"
#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
@@ -581,8 +588,8 @@ do { \
* Exit points of a rseq critical section consist of all instructions outside
* of the critical section where a critical section can either branch to or
* reach through the normal course of its execution. The abort IP and the
- * post-commit IP are already part of the __rseq_table section and should not
- * be explicitly defined as additional exit points. Knowing all exit points is
+ * post-commit IP are already part of the __rseq_cs section and should not be
+ * explicitly defined as additional exit points. Knowing all exit points is
* useful to assist debuggers stepping over the critical section.
*/
#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
--
2.11.0
pidfd are /proc/pid directory file descriptors referring to a task group
leader. Android low memory killer (LMK) needs pidfd polling support to
replace code that currently checks for existence of /proc/pid for
knowing a process that is signalled to be killed has died, which is both
racy and slow. The pidfd poll approach is race-free, and also allows the
LMK to do other things (such as by polling on other fds) while awaiting
the process being killed to die.
It prevents a situation where a PID is reused between when LMK sends a
kill signal and checks for existence of the PID, since the wrong PID is
now possibly checked for existence.
In this patch, we follow the same mechanism used uhen the parent of the
task group is to be notified, that is when the tasks waiting on a poll
of pidfd are also awakened.
We have decided to include the waitqueue in struct pid for the following
reasons:
1. The wait queue has to survive for the lifetime of the poll. Including
it in task_struct would not be option in this case because the task can
be reaped and destroyed before the poll returns.
2. By including the struct pid for the waitqueue means that during
de_exec, the thread doing de_thread() automatically gets the new
waitqueue/pid even though its task_struct is different.
Appropriate test cases are added in the second patch to provide coverage
of all the cases the patch is handling.
Andy had a similar patch [1] in the past which was a good reference
however this patch tries to handle different situations properly related
to thread group existence, and how/where it notifies. And also solves
other bugs (existence of taks_struct). Daniel had a similar patch [2]
recently which this patch supercedes.
[1] https://lore.kernel.org/patchwork/patch/345098/
[2] https://lore.kernel.org/lkml/20181029175322.189042-1-dancol@google.com/
Cc: luto(a)amacapital.net
Cc: rostedt(a)goodmis.org
Cc: dancol(a)google.com
Cc: christian(a)brauner.io
Cc: jannh(a)google.com
Cc: surenb(a)google.com
Cc: torvalds(a)linux-foundation.org
Co-developed-by: Daniel Colascione <dancol(a)google.com>
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
fs/proc/base.c | 39 +++++++++++++++++++++++++++++++++++++++
include/linux/pid.h | 3 +++
kernel/exit.c | 1 -
kernel/pid.c | 2 ++
kernel/signal.c | 14 ++++++++++++++
5 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 6a803a0b75df..879900082647 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3069,8 +3069,47 @@ static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
}
+static unsigned int proc_tgid_base_poll(struct file *file, struct poll_table_struct *pts)
+{
+ int poll_flags = 0;
+ struct task_struct *task;
+ struct pid *pid;
+
+ task = get_proc_task(file->f_path.dentry->d_inode);
+
+ WARN_ON_ONCE(task && !thread_group_leader(task));
+
+ /*
+ * tasklist_lock must be held because to avoid racing with
+ * changes in exit_state and wake up. Basically to avoid:
+ *
+ * P0: read exit_state = 0
+ * P1: write exit_state = EXIT_DEAD
+ * P1: Do a wake up - wq is empty, so do nothing
+ * P0: Queue for polling - wait forever.
+ */
+ read_lock(&tasklist_lock);
+ if (!task)
+ poll_flags = POLLIN | POLLRDNORM | POLLERR;
+ else if (task->exit_state == EXIT_DEAD)
+ poll_flags = POLLIN | POLLRDNORM;
+ else if (task->exit_state == EXIT_ZOMBIE && thread_group_empty(task))
+ poll_flags = POLLIN | POLLRDNORM;
+
+ if (!poll_flags) {
+ pid = proc_pid(file->f_path.dentry->d_inode);
+ poll_wait(file, &pid->wait_pidfd, pts);
+ }
+ read_unlock(&tasklist_lock);
+
+ if (task)
+ put_task_struct(task);
+ return poll_flags;
+}
+
static const struct file_operations proc_tgid_base_operations = {
.read = generic_read_dir,
+ .poll = proc_tgid_base_poll,
.iterate_shared = proc_tgid_base_readdir,
.llseek = generic_file_llseek,
};
diff --git a/include/linux/pid.h b/include/linux/pid.h
index b6f4ba16065a..2e0dcbc6d14e 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -3,6 +3,7 @@
#define _LINUX_PID_H
#include <linux/rculist.h>
+#include <linux/wait.h>
enum pid_type
{
@@ -60,6 +61,8 @@ struct pid
unsigned int level;
/* lists of tasks that use this pid */
struct hlist_head tasks[PIDTYPE_MAX];
+ /* wait queue for pidfd pollers */
+ wait_queue_head_t wait_pidfd;
struct rcu_head rcu;
struct upid numbers[1];
};
diff --git a/kernel/exit.c b/kernel/exit.c
index 2166c2d92ddc..c386ec52687d 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -181,7 +181,6 @@ static void delayed_put_task_struct(struct rcu_head *rhp)
put_task_struct(tsk);
}
-
void release_task(struct task_struct *p)
{
struct task_struct *leader;
diff --git a/kernel/pid.c b/kernel/pid.c
index 20881598bdfa..5c90c239242f 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -214,6 +214,8 @@ struct pid *alloc_pid(struct pid_namespace *ns)
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);
+ init_waitqueue_head(&pid->wait_pidfd);
+
upid = pid->numbers + ns->level;
spin_lock_irq(&pidmap_lock);
if (!(ns->pid_allocated & PIDNS_ADDING))
diff --git a/kernel/signal.c b/kernel/signal.c
index f98448cf2def..e3781703ef7e 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1800,6 +1800,17 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type)
return ret;
}
+static void do_wakeup_pidfd_pollers(struct task_struct *task)
+{
+ struct pid *pid;
+
+ lockdep_assert_held(&tasklist_lock);
+
+ pid = get_task_pid(task, PIDTYPE_PID);
+ wake_up_all(&pid->wait_pidfd);
+ put_pid(pid);
+}
+
/*
* Let a parent know about the death of a child.
* For a stopped/continued status change, use do_notify_parent_cldstop instead.
@@ -1823,6 +1834,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
BUG_ON(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
+ /* Wake up all pidfd waiters */
+ do_wakeup_pidfd_pollers(tsk);
+
if (sig != SIGCHLD) {
/*
* This is only possible if parent == real_parent.
--
2.21.0.392.gf8f6787159e-goog
This refactors the selftest Makefiles to extract the test running logic
to be reused between "run_tests" and "emit_tests", while also fixing
up the test output to be TAP version 13 compliant:
- added "plan" line
- fixed result line syntax
- moved all test output to be "# "-prefixed as TAP "diagnostic" lines
The prefixing code includes a fallback mode for limited execution
environments.
-Kees
Kees Cook (6):
selftests: Extract single-test shell logic from lib.mk
selftests: Use runner.sh for emit targets
selftests: Extract logic for multiple test runs
selftests/runner: Add plan line and fix result line syntax
selftests/runner: Distinguish between missing and non-executable
selftests: Move test output to diagnostic lines
tools/testing/selftests/.gitignore | 1 -
tools/testing/selftests/Makefile | 18 +++--
tools/testing/selftests/kselftest/prefix.pl | 23 ++++++
tools/testing/selftests/kselftest/runner.sh | 80 +++++++++++++++++++++
tools/testing/selftests/lib.mk | 61 +++-------------
5 files changed, 119 insertions(+), 64 deletions(-)
create mode 100755 tools/testing/selftests/kselftest/prefix.pl
create mode 100644 tools/testing/selftests/kselftest/runner.sh
--
2.17.1
This is version 4 of the MSI interrupts for ntb_transport patchset.
It's mostly a resend of v3 but with spelling and grammar fixes found by Bjorn.
I've addressed the feedback so far and rebased on the latest kernel
and would like this to be considered for merging this cycle.
The only outstanding issue I know of is that it still will not work
with IDT hardware, but ntb_transport doesn't work with IDT hardware
and there is still no sensible common infrastructure to support
ntb_peer_mw_set_trans(). Thus, I decline to consider that complication
in this patchset. However, I'll be happy to review work that adds this
feature in the future.
Also, as the port number and resource index stuff is a bit complicated,
I made a quick out of tree test fixture to ensure it's correct[1]. As
an excerise I also wrote some test code[2] using the upcomming KUnit
feature.
Logan
[1] https://repl.it/repls/ExcitingPresentFile
[2] https://github.com/sbates130272/linux-p2pmem/commits/ntb_kunit
--
Changes in v4:
* Rebased onto v5.1-rc6 (No changes)
* Numerous grammar and spelling mistakes spotted by Bjorn
--
Changes in v3:
* Rebased onto v5.1-rc1 (Dropped the first two patches as they have
been merged, and cleaned up some minor conflicts in the PCI tree)
* Added a new patch (#3) to calculate logical port numbers that
are port numbers from 0 to (number of ports - 1). This is
then used in ntb_peer_resource_idx() to fix the issues brought
up by Serge.
* Fixed missing __iomem and iowrite calls (as noticed by Serge)
* Added patch 10 which describes ntb_msi_test in the documentation
file (as requested by Serge)
* A couple other minor nits and documentation fixes
--
Changes in v2:
* Cleaned up the changes in intel_irq_remapping.c to make them
less confusing and add a comment. (Per discussion with Jacob and
Joerg)
* Fixed a nit from Bjorn and collected his Ack
* Added a Kconfig dependancy on CONFIG_PCI_MSI for CONFIG_NTB_MSI
as the Kbuild robot hit a random config that didn't build
without it.
* Worked in a callback for when the MSI descriptor changes so that
the clients can resend the new address and data values to the peer.
On my test system this was never necessary, but there may be
other platforms where this can occur. I tested this by hacking
in a path to rewrite the MSI descriptor when I change the cpu
affinity of an IRQ. There's a bit of uncertainty over the latency
of the change, but without hardware this can acctually occur on
we can't test this. This was the result of a discussion with Dave.
--
This patch series adds optional support for using MSI interrupts instead
of NTB doorbells in ntb_transport. This is desirable seeing doorbells on
current hardware are quite slow and therefore switching to MSI interrupts
provides a significant performance gain. On switchtec hardware, a simple
apples-to-apples comparison shows ntb_netdev/iperf numbers going from
3.88Gb/s to 14.1Gb/s when switching to MSI interrupts.
To do this, a couple changes are required outside of the NTB tree:
1) The IOMMU must know to accept MSI requests from aliased bused numbers
seeing NTB hardware typically sends proxied request IDs through
additional requester IDs. The first patch in this series adds support
for the Intel IOMMU. A quirk to add these aliases for switchtec hardware
was already accepted. See commit ad281ecf1c7d ("PCI: Add DMA alias quirk
for Microsemi Switchtec NTB") for a description of NTB proxy IDs and why
this is necessary.
2) NTB transport (and other clients) may often need more MSI interrupts
than the NTB hardware actually advertises support for. However, seeing
these interrupts will not be triggered by the hardware but through an
NTB memory window, the hardware does not actually need support or need
to know about them. Therefore we add the concept of Virtual MSI
interrupts which are allocated just like any other MSI interrupt but
are not programmed into the hardware's MSI table. This is done in
Patch 2 and then made use of in Patch 3.
The remaining patches in this series add a library for dealing with MSI
interrupts, a test client and finally support in ntb_transport.
The series is based off of v5.1-rc6 plus the patches in ntb-next.
A git repo is available here:
https://github.com/sbates130272/linux-p2pmem/ ntb_transport_msi_v4
Thanks,
Logan
--
Logan Gunthorpe (10):
PCI/MSI: Support allocating virtual MSI interrupts
PCI/switchtec: Add module parameter to request more interrupts
NTB: Introduce helper functions to calculate logical port number
NTB: Introduce functions to calculate multi-port resource index
NTB: Rename ntb.c to support multiple source files in the module
NTB: Introduce MSI library
NTB: Introduce NTB MSI Test Client
NTB: Add ntb_msi_test support to ntb_test
NTB: Add MSI interrupt support to ntb_transport
NTB: Describe the ntb_msi_test client in the documentation.
Documentation/ntb.txt | 27 ++
drivers/ntb/Kconfig | 11 +
drivers/ntb/Makefile | 3 +
drivers/ntb/{ntb.c => core.c} | 0
drivers/ntb/msi.c | 415 +++++++++++++++++++++++
drivers/ntb/ntb_transport.c | 169 ++++++++-
drivers/ntb/test/Kconfig | 9 +
drivers/ntb/test/Makefile | 1 +
drivers/ntb/test/ntb_msi_test.c | 433 ++++++++++++++++++++++++
drivers/pci/msi.c | 54 ++-
drivers/pci/switch/switchtec.c | 12 +-
include/linux/msi.h | 8 +
include/linux/ntb.h | 196 ++++++++++-
include/linux/pci.h | 9 +
tools/testing/selftests/ntb/ntb_test.sh | 54 ++-
15 files changed, 1386 insertions(+), 15 deletions(-)
rename drivers/ntb/{ntb.c => core.c} (100%)
create mode 100644 drivers/ntb/msi.c
create mode 100644 drivers/ntb/test/ntb_msi_test.c
--
2.20.1
From: Sean Christopherson <sean.j.christopherson(a)intel.com>
[ Upstream commit 0f73bbc851ed32d22bbd86be09e0365c460bcd2e ]
Documentation/virtual/kvm/api.txt states:
NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR and
KVM_EXIT_EPR the corresponding operations are complete (and guest
state is consistent) only after userspace has re-entered the
kernel with KVM_RUN. The kernel side will first finish incomplete
operations and then check for pending signals. Userspace can
re-enter the guest with an unmasked signal pending to complete
pending operations.
Because guest state may be inconsistent, starting state migration after
an IO exit without first completing IO may result in test failures, e.g.
a proposed change to KVM's handling of %rip in its fast PIO handling[1]
will cause the new VM, i.e. the post-migration VM, to have its %rip set
to the IN instruction that triggered KVM_EXIT_IO, leading to a test
assertion due to a stage mismatch.
For simplicitly, require KVM_CAP_IMMEDIATE_EXIT to complete IO and skip
the test if it's not available. The addition of KVM_CAP_IMMEDIATE_EXIT
predates the state selftest by more than a year.
[1] https://patchwork.kernel.org/patch/10848545/
Fixes: fa3899add1056 ("kvm: selftests: add basic test for state save and restore")
Reported-by: Jim Mattson <jmattson(a)google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson(a)intel.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal(a)kernel.org>
---
tools/testing/selftests/kvm/include/kvm_util.h | 1 +
tools/testing/selftests/kvm/lib/kvm_util.c | 16 ++++++++++++++++
.../testing/selftests/kvm/x86_64/state_test.c | 18 ++++++++++++++++--
3 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index a84785b02557..07b71ad9734a 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -102,6 +102,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva);
struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid);
void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
+void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid);
void vcpu_set_mp_state(struct kvm_vm *vm, uint32_t vcpuid,
struct kvm_mp_state *mp_state);
void vcpu_regs_get(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_regs *regs);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index b52cfdefecbf..efa0aad8b3c6 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1121,6 +1121,22 @@ int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
return rc;
}
+void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid)
+{
+ struct vcpu *vcpu = vcpu_find(vm, vcpuid);
+ int ret;
+
+ TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);
+
+ vcpu->state->immediate_exit = 1;
+ ret = ioctl(vcpu->fd, KVM_RUN, NULL);
+ vcpu->state->immediate_exit = 0;
+
+ TEST_ASSERT(ret == -1 && errno == EINTR,
+ "KVM_RUN IOCTL didn't exit immediately, rc: %i, errno: %i",
+ ret, errno);
+}
+
/*
* VM VCPU Set MP State
*
diff --git a/tools/testing/selftests/kvm/x86_64/state_test.c b/tools/testing/selftests/kvm/x86_64/state_test.c
index 4b3f556265f1..30f75856cf39 100644
--- a/tools/testing/selftests/kvm/x86_64/state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/state_test.c
@@ -134,6 +134,11 @@ int main(int argc, char *argv[])
struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
+ if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) {
+ fprintf(stderr, "immediate_exit not available, skipping test\n");
+ exit(KSFT_SKIP);
+ }
+
/* Create VM */
vm = vm_create_default(VCPU_ID, 0, guest_code);
vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
@@ -156,8 +161,6 @@ int main(int argc, char *argv[])
stage, run->exit_reason,
exit_reason_str(run->exit_reason));
- memset(®s1, 0, sizeof(regs1));
- vcpu_regs_get(vm, VCPU_ID, ®s1);
switch (get_ucall(vm, VCPU_ID, &uc)) {
case UCALL_ABORT:
TEST_ASSERT(false, "%s at %s:%d", (const char *)uc.args[0],
@@ -176,6 +179,17 @@ int main(int argc, char *argv[])
uc.args[1] == stage, "Unexpected register values vmexit #%lx, got %lx",
stage, (ulong)uc.args[1]);
+ /*
+ * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees
+ * guest state is consistent only after userspace re-enters the
+ * kernel with KVM_RUN. Complete IO prior to migrating state
+ * to a new VM.
+ */
+ vcpu_run_complete_io(vm, VCPU_ID);
+
+ memset(®s1, 0, sizeof(regs1));
+ vcpu_regs_get(vm, VCPU_ID, ®s1);
+
state = vcpu_save_state(vm, VCPU_ID);
kvm_vm_release(vm);
--
2.19.1
From: Sean Christopherson <sean.j.christopherson(a)intel.com>
[ Upstream commit ffac839d040619847217647434b2b02469926871 ]
Since 4.8.3, gcc has enabled -fstack-protector by default. This is
problematic for the KVM selftests as they do not configure fs or gs
segments (the stack canary is pulled from fs:0x28). With the default
behavior, gcc will insert a stack canary on any function that creates
buffers of 8 bytes or more. As a result, ucall() will hit a triple
fault shutdown due to reading a bad fs segment when inserting its
stack canary, i.e. every test fails with an unexpected SHUTDOWN.
Fixes: 14c47b7530e2d ("kvm: selftests: introduce ucall")
Signed-off-by: Sean Christopherson <sean.j.christopherson(a)intel.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal(a)kernel.org>
---
tools/testing/selftests/kvm/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 212b8f0032ae..cb4a992d6dd3 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -28,8 +28,8 @@ LIBKVM += $(LIBKVM_$(UNAME_M))
INSTALL_HDR_PATH = $(top_srcdir)/usr
LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
-CFLAGS += -O2 -g -std=gnu99 -no-pie -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -Iinclude/$(UNAME_M) -I..
-LDFLAGS += -pthread
+CFLAGS += -O2 -g -std=gnu99 -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -Iinclude/$(UNAME_M) -I..
+LDFLAGS += -pthread -no-pie
# After inclusion, $(OUTPUT) is defined and
# $(TEST_GEN_PROGS) starts with $(OUTPUT)/
--
2.19.1
From: Sean Christopherson <sean.j.christopherson(a)intel.com>
[ Upstream commit 0a3f29b5a77d6c27796d7a7adabafd199dc066d5 ]
KVM selftests embed the guest "image" as a function in the test itself
and extract the guest code at runtime by manually parsing the elf
headers. The parsing is very simple and doesn't supporting fancy things
like position independent executables. Recent versions of gcc enable
pie by default, which results in triple fault shutdowns in the guest due
to the virtual address in the headers not matching up with the virtual
address retrieved from the function pointer.
Signed-off-by: Sean Christopherson <sean.j.christopherson(a)intel.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal(a)kernel.org>
---
tools/testing/selftests/kvm/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index f9a0e9938480..212b8f0032ae 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -28,7 +28,7 @@ LIBKVM += $(LIBKVM_$(UNAME_M))
INSTALL_HDR_PATH = $(top_srcdir)/usr
LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
-CFLAGS += -O2 -g -std=gnu99 -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -Iinclude/$(UNAME_M) -I..
+CFLAGS += -O2 -g -std=gnu99 -no-pie -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -Iinclude/$(UNAME_M) -I..
LDFLAGS += -pthread
# After inclusion, $(OUTPUT) is defined and
--
2.19.1
Rename the blockdev documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.
The drbd sub-directory contains some graphs and data flows.
Add those too to the documentation.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung(a)kernel.org>
---
.../admin-guide/kernel-parameters.txt | 18 +-
...structure-v9.txt => data-structure-v9.rst} | 6 +-
Documentation/blockdev/drbd/figures.rst | 28 +++
.../blockdev/drbd/{README.txt => index.rst} | 15 +-
.../blockdev/{floppy.txt => floppy.rst} | 88 ++++----
Documentation/blockdev/index.rst | 16 ++
Documentation/blockdev/{nbd.txt => nbd.rst} | 1 +
.../blockdev/{paride.txt => paride.rst} | 144 +++++++------
.../blockdev/{ramdisk.txt => ramdisk.rst} | 55 ++---
Documentation/blockdev/{zram.txt => zram.rst} | 195 ++++++++++++------
MAINTAINERS | 8 +-
drivers/block/Kconfig | 8 +-
drivers/block/floppy.c | 2 +-
drivers/block/zram/Kconfig | 6 +-
tools/testing/selftests/zram/README | 2 +-
15 files changed, 374 insertions(+), 218 deletions(-)
rename Documentation/blockdev/drbd/{data-structure-v9.txt => data-structure-v9.rst} (94%)
create mode 100644 Documentation/blockdev/drbd/figures.rst
rename Documentation/blockdev/drbd/{README.txt => index.rst} (55%)
rename Documentation/blockdev/{floppy.txt => floppy.rst} (81%)
create mode 100644 Documentation/blockdev/index.rst
rename Documentation/blockdev/{nbd.txt => nbd.rst} (96%)
rename Documentation/blockdev/{paride.txt => paride.rst} (85%)
rename Documentation/blockdev/{ramdisk.txt => ramdisk.rst} (84%)
rename Documentation/blockdev/{zram.txt => zram.rst} (76%)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 65d66010b134..a6297aff5598 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1248,7 +1248,7 @@
See also Documentation/fault-injection/.
floppy= [HW]
- See Documentation/blockdev/floppy.txt.
+ See Documentation/blockdev/floppy.rst.
force_pal_cache_flush
[IA-64] Avoid check_sal_cache_flush which may hang on
@@ -2227,7 +2227,7 @@
memblock=debug [KNL] Enable memblock debug messages.
load_ramdisk= [RAM] List of ramdisks to load from floppy
- See Documentation/blockdev/ramdisk.txt.
+ See Documentation/blockdev/ramdisk.rst.
lockd.nlm_grace_period=P [NFS] Assign grace period.
Format: <integer>
@@ -3197,7 +3197,7 @@
pcd. [PARIDE]
See header of drivers/block/paride/pcd.c.
- See also Documentation/blockdev/paride.txt.
+ See also Documentation/blockdev/paride.rst.
pci=option[,option...] [PCI] various PCI subsystem options.
@@ -3439,7 +3439,7 @@
needed on a platform with proper driver support.
pd. [PARIDE]
- See Documentation/blockdev/paride.txt.
+ See Documentation/blockdev/paride.rst.
pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
boot time.
@@ -3454,10 +3454,10 @@
and performance comparison.
pf. [PARIDE]
- See Documentation/blockdev/paride.txt.
+ See Documentation/blockdev/paride.rst.
pg. [PARIDE]
- See Documentation/blockdev/paride.txt.
+ See Documentation/blockdev/paride.rst.
pirq= [SMP,APIC] Manual mp-table setup
See Documentation/x86/i386/IO-APIC.txt.
@@ -3569,7 +3569,7 @@
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
before loading.
- See Documentation/blockdev/ramdisk.txt.
+ See Documentation/blockdev/ramdisk.rst.
psi= [KNL] Enable or disable pressure stall information
tracking.
@@ -3591,7 +3591,7 @@
pstore.backend= Specify the name of the pstore backend to use
pt. [PARIDE]
- See Documentation/blockdev/paride.txt.
+ See Documentation/blockdev/paride.rst.
pti= [X86_64] Control Page Table Isolation of user and
kernel address spaces. Disabling this feature
@@ -3620,7 +3620,7 @@
See Documentation/admin-guide/md.rst.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
- See Documentation/blockdev/ramdisk.txt.
+ See Documentation/blockdev/ramdisk.rst.
random.trust_cpu={on,off}
[KNL] Enable or disable trusting the use of the
diff --git a/Documentation/blockdev/drbd/data-structure-v9.txt b/Documentation/blockdev/drbd/data-structure-v9.rst
similarity index 94%
rename from Documentation/blockdev/drbd/data-structure-v9.txt
rename to Documentation/blockdev/drbd/data-structure-v9.rst
index 1e52a0e32624..66036b901644 100644
--- a/Documentation/blockdev/drbd/data-structure-v9.txt
+++ b/Documentation/blockdev/drbd/data-structure-v9.rst
@@ -1,3 +1,7 @@
+================================
+kernel data structure for DRBD-9
+================================
+
This describes the in kernel data structure for DRBD-9. Starting with
Linux v3.14 we are reorganizing DRBD to use this data structure.
@@ -10,7 +14,7 @@ device is represented by a block device locally.
The DRBD objects are interconnected to form a matrix as depicted below; a
drbd_peer_device object sits at each intersection between a drbd_device and a
-drbd_connection:
+drbd_connection::
/--------------+---------------+.....+---------------\
| resource | device | | device |
diff --git a/Documentation/blockdev/drbd/figures.rst b/Documentation/blockdev/drbd/figures.rst
new file mode 100644
index 000000000000..3e3fd4b8a478
--- /dev/null
+++ b/Documentation/blockdev/drbd/figures.rst
@@ -0,0 +1,28 @@
+.. The here included files are intended to help understand the implementation
+
+Data flows that Relate some functions, and write packets
+========================================================
+
+.. kernel-figure:: DRBD-8.3-data-packets.svg
+ :alt: DRBD-8.3-data-packets.svg
+ :align: center
+
+.. kernel-figure:: DRBD-data-packets.svg
+ :alt: DRBD-data-packets.svg
+ :align: center
+
+
+Sub graphs of DRBD's state transitions
+======================================
+
+.. kernel-figure:: conn-states-8.dot
+ :alt: conn-states-8.dot
+ :align: center
+
+.. kernel-figure:: disk-states-8.dot
+ :alt: disk-states-8.dot
+ :align: center
+
+.. kernel-figure:: node-states-8.dot
+ :alt: node-states-8.dot
+ :align: center
diff --git a/Documentation/blockdev/drbd/README.txt b/Documentation/blockdev/drbd/index.rst
similarity index 55%
rename from Documentation/blockdev/drbd/README.txt
rename to Documentation/blockdev/drbd/index.rst
index 627b0a1bf35e..68ecd5c113e9 100644
--- a/Documentation/blockdev/drbd/README.txt
+++ b/Documentation/blockdev/drbd/index.rst
@@ -1,4 +1,9 @@
+==========================================
+Distributed Replicated Block Device - DRBD
+==========================================
+
Description
+===========
DRBD is a shared-nothing, synchronously replicated block device. It
is designed to serve as a building block for high availability
@@ -7,10 +12,8 @@ Description
Please visit http://www.drbd.org to find out more.
-The here included files are intended to help understand the implementation
+.. toctree::
+ :maxdepth: 1
-DRBD-8.3-data-packets.svg, DRBD-data-packets.svg
- relates some functions, and write packets.
-
-conn-states-8.dot, disk-states-8.dot, node-states-8.dot
- The sub graphs of DRBD's state transitions
+ data-structure-v9
+ figures
diff --git a/Documentation/blockdev/floppy.txt b/Documentation/blockdev/floppy.rst
similarity index 81%
rename from Documentation/blockdev/floppy.txt
rename to Documentation/blockdev/floppy.rst
index e2240f5ab64d..4a8f31cf4139 100644
--- a/Documentation/blockdev/floppy.txt
+++ b/Documentation/blockdev/floppy.rst
@@ -1,35 +1,37 @@
-This file describes the floppy driver.
+=============
+Floppy Driver
+=============
FAQ list:
=========
- A FAQ list may be found in the fdutils package (see below), and also
+A FAQ list may be found in the fdutils package (see below), and also
at <http://fdutils.linux.lu/faq.html>.
LILO configuration options (Thinkpad users, read this)
======================================================
- The floppy driver is configured using the 'floppy=' option in
+The floppy driver is configured using the 'floppy=' option in
lilo. This option can be typed at the boot prompt, or entered in the
lilo configuration file.
- Example: If your kernel is called linux-2.6.9, type the following line
-at the lilo boot prompt (if you have a thinkpad):
+Example: If your kernel is called linux-2.6.9, type the following line
+at the lilo boot prompt (if you have a thinkpad)::
linux-2.6.9 floppy=thinkpad
You may also enter the following line in /etc/lilo.conf, in the description
-of linux-2.6.9:
+of linux-2.6.9::
append = "floppy=thinkpad"
- Several floppy related options may be given, example:
+Several floppy related options may be given, example::
linux-2.6.9 floppy=daring floppy=two_fdc
append = "floppy=daring floppy=two_fdc"
- If you give options both in the lilo config file and on the boot
+If you give options both in the lilo config file and on the boot
prompt, the option strings of both places are concatenated, the boot
prompt options coming last. That's why there are also options to
restore the default behavior.
@@ -38,21 +40,23 @@ restore the default behavior.
Module configuration options
============================
- If you use the floppy driver as a module, use the following syntax:
-modprobe floppy floppy="<options>"
+If you use the floppy driver as a module, use the following syntax::
-Example:
- modprobe floppy floppy="omnibook messages"
+ modprobe floppy floppy="<options>"
- If you need certain options enabled every time you load the floppy driver,
-you can put:
+Example::
- options floppy floppy="omnibook messages"
+ modprobe floppy floppy="omnibook messages"
+
+If you need certain options enabled every time you load the floppy driver,
+you can put::
+
+ options floppy floppy="omnibook messages"
in a configuration file in /etc/modprobe.d/.
- The floppy driver related options are:
+The floppy driver related options are:
floppy=asus_pci
Sets the bit mask to allow only units 0 and 1. (default)
@@ -70,8 +74,7 @@ in a configuration file in /etc/modprobe.d/.
Tells the floppy driver that you have only one floppy controller.
(default)
- floppy=two_fdc
- floppy=<address>,two_fdc
+ floppy=two_fdc / floppy=<address>,two_fdc
Tells the floppy driver that you have two floppy controllers.
The second floppy controller is assumed to be at <address>.
This option is not needed if the second controller is at address
@@ -84,8 +87,7 @@ in a configuration file in /etc/modprobe.d/.
floppy=0,thinkpad
Tells the floppy driver that you don't have a Thinkpad.
- floppy=omnibook
- floppy=nodma
+ floppy=omnibook / floppy=nodma
Tells the floppy driver not to use Dma for data transfers.
This is needed on HP Omnibooks, which don't have a workable
DMA channel for the floppy driver. This option is also useful
@@ -144,14 +146,16 @@ in a configuration file in /etc/modprobe.d/.
described in the physical CMOS), or if your BIOS uses
non-standard CMOS types. The CMOS types are:
- 0 - Use the value of the physical CMOS
- 1 - 5 1/4 DD
- 2 - 5 1/4 HD
- 3 - 3 1/2 DD
- 4 - 3 1/2 HD
- 5 - 3 1/2 ED
- 6 - 3 1/2 ED
- 16 - unknown or not installed
+ == ==================================
+ 0 Use the value of the physical CMOS
+ 1 5 1/4 DD
+ 2 5 1/4 HD
+ 3 3 1/2 DD
+ 4 3 1/2 HD
+ 5 3 1/2 ED
+ 6 3 1/2 ED
+ 16 unknown or not installed
+ == ==================================
(Note: there are two valid types for ED drives. This is because 5 was
initially chosen to represent floppy *tapes*, and 6 for ED drives.
@@ -162,8 +166,7 @@ in a configuration file in /etc/modprobe.d/.
Print a warning message when an unexpected interrupt is received.
(default)
- floppy=no_unexpected_interrupts
- floppy=L40SX
+ floppy=no_unexpected_interrupts / floppy=L40SX
Don't print a message when an unexpected interrupt is received. This
is needed on IBM L40SX laptops in certain video modes. (There seems
to be an interaction between video and floppy. The unexpected
@@ -199,47 +202,54 @@ in a configuration file in /etc/modprobe.d/.
Sets the floppy DMA channel to <nr> instead of 2.
floppy=slow
- Use PS/2 stepping rate:
- " PS/2 floppies have much slower step rates than regular floppies.
+ Use PS/2 stepping rate::
+
+ PS/2 floppies have much slower step rates than regular floppies.
It's been recommended that take about 1/4 of the default speed
- in some more extreme cases."
+ in some more extreme cases.
Supporting utilities and additional documentation:
==================================================
- Additional parameters of the floppy driver can be configured at
+Additional parameters of the floppy driver can be configured at
runtime. Utilities which do this can be found in the fdutils package.
This package also contains a new version of mtools which allows to
access high capacity disks (up to 1992K on a high density 3 1/2 disk!).
It also contains additional documentation about the floppy driver.
The latest version can be found at fdutils homepage:
+
http://fdutils.linux.lu
The fdutils releases can be found at:
+
http://fdutils.linux.lu/download.html
+
http://www.tux.org/pub/knaff/fdutils/
+
ftp://metalab.unc.edu/pub/Linux/utils/disk-management/
Reporting problems about the floppy driver
==========================================
- If you have a question or a bug report about the floppy driver, mail
+If you have a question or a bug report about the floppy driver, mail
me at Alain.Knaff(a)poboxes.com . If you post to Usenet, preferably use
comp.os.linux.hardware. As the volume in these groups is rather high,
be sure to include the word "floppy" (or "FLOPPY") in the subject
line. If the reported problem happens when mounting floppy disks, be
sure to mention also the type of the filesystem in the subject line.
- Be sure to read the FAQ before mailing/posting any bug reports!
+Be sure to read the FAQ before mailing/posting any bug reports!
- Alain
+Alain
Changelog
=========
-10-30-2004 : Cleanup, updating, add reference to module configuration.
+10-30-2004 :
+ Cleanup, updating, add reference to module configuration.
James Nelson <james4765(a)gmail.com>
-6-3-2000 : Original Document
+6-3-2000 :
+ Original Document
diff --git a/Documentation/blockdev/index.rst b/Documentation/blockdev/index.rst
new file mode 100644
index 000000000000..a9af6ed8b4aa
--- /dev/null
+++ b/Documentation/blockdev/index.rst
@@ -0,0 +1,16 @@
+:orphan:
+
+===========================
+The Linux RapidIO Subsystem
+===========================
+
+.. toctree::
+ :maxdepth: 1
+
+ floppy
+ nbd
+ paride
+ ramdisk
+ zram
+
+ drbd/index
diff --git a/Documentation/blockdev/nbd.txt b/Documentation/blockdev/nbd.rst
similarity index 96%
rename from Documentation/blockdev/nbd.txt
rename to Documentation/blockdev/nbd.rst
index db242ea2bce8..db0c96e46661 100644
--- a/Documentation/blockdev/nbd.txt
+++ b/Documentation/blockdev/nbd.rst
@@ -1,3 +1,4 @@
+==================================
Network Block Device (TCP version)
==================================
diff --git a/Documentation/blockdev/paride.txt b/Documentation/blockdev/paride.rst
similarity index 85%
rename from Documentation/blockdev/paride.txt
rename to Documentation/blockdev/paride.rst
index ee6717e3771d..b7fdd77513ab 100644
--- a/Documentation/blockdev/paride.txt
+++ b/Documentation/blockdev/paride.rst
@@ -1,9 +1,11 @@
-
- Linux and parallel port IDE devices
+===================================
+Linux and parallel port IDE devices
+===================================
PARIDE v1.03 (c) 1997-8 Grant Guenther <grant(a)torque.net>
1. Introduction
+===============
Owing to the simplicity and near universality of the parallel port interface
to personal computers, many external devices such as portable hard-disk,
@@ -35,17 +37,17 @@ devices. It does not cover parallel port SCSI devices, "ditto" tape
drives or scanners. Many different devices are supported by the
parallel port IDE subsystem, including:
- MicroSolutions backpack CD-ROM
- MicroSolutions backpack PD/CD
- MicroSolutions backpack hard-drives
- MicroSolutions backpack 8000t tape drive
- SyQuest EZ-135, EZ-230 & SparQ drives
- Avatar Shark
- Imation Superdisk LS-120
- Maxell Superdisk LS-120
- FreeCom Power CD
- Hewlett-Packard 5GB and 8GB tape drives
- Hewlett-Packard 7100 and 7200 CD-RW drives
+ - MicroSolutions backpack CD-ROM
+ - MicroSolutions backpack PD/CD
+ - MicroSolutions backpack hard-drives
+ - MicroSolutions backpack 8000t tape drive
+ - SyQuest EZ-135, EZ-230 & SparQ drives
+ - Avatar Shark
+ - Imation Superdisk LS-120
+ - Maxell Superdisk LS-120
+ - FreeCom Power CD
+ - Hewlett-Packard 5GB and 8GB tape drives
+ - Hewlett-Packard 7100 and 7200 CD-RW drives
as well as most of the clone and no-name products on the market.
@@ -55,11 +57,13 @@ paride module which provides a registry and some common methods for
accessing the parallel ports. The second component is a set of
high-level drivers for each of the different types of supported devices:
+ === =============
pd IDE disk
pcd ATAPI CD-ROM
pf ATAPI disk
pt ATAPI tape
pg ATAPI generic
+ === =============
(Currently, the pg driver is only used with CD-R drives).
@@ -69,6 +73,7 @@ for each of the parallel port IDE adapter chips. Thanks to the interest
and encouragement of Linux users from many parts of the world,
support is available for almost all known adapter protocols:
+ ==== ====================================== ====
aten ATEN EH-100 (HK)
bpck Microsolutions backpack (US)
comm DataStor (old-type) "commuter" adapter (TW)
@@ -83,9 +88,11 @@ support is available for almost all known adapter protocols:
ktti KT Technology PHd adapter (SG)
on20 OnSpec 90c20 (US)
on26 OnSpec 90c26 (US)
+ ==== ====================================== ====
2. Using the PARIDE subsystem
+=============================
While configuring the Linux kernel, you may choose either to build
the PARIDE drivers into your kernel, or to build them as modules.
@@ -105,8 +112,9 @@ subsystem to try them all for you.
For the "brand-name" products listed above, here are the protocol
and high-level drivers that you would use:
+ ================ ============ ====== ========
Manufacturer Model Driver Protocol
-
+ ================ ============ ====== ========
MicroSolutions CD-ROM pcd bpck
MicroSolutions PD drive pf bpck
MicroSolutions hard-drive pd bpck
@@ -119,8 +127,10 @@ and high-level drivers that you would use:
Hewlett-Packard 5GB Tape pt epat
Hewlett-Packard 7200e (CD) pcd epat
Hewlett-Packard 7200e (CD-R) pg epat
+ ================ ============ ====== ========
2.1 Configuring built-in drivers
+---------------------------------
We recommend that you get to know how the drivers work and how to
configure them as loadable modules, before attempting to compile a
@@ -143,7 +153,7 @@ protocol identification number and, for some devices, the drive's
chain ID. While your system is booting, a number of messages are
displayed on the console. Like all such messages, they can be
reviewed with the 'dmesg' command. Among those messages will be
-some lines like:
+some lines like::
paride: bpck registered as protocol 0
paride: epat registered as protocol 1
@@ -161,7 +171,7 @@ As an example, let's assume that you have a MicroSolutions PD/CD drive
with unit ID number 36 connected to the parallel port at 0x378, a SyQuest
EZ-135 connected to the chained port on the PD/CD drive and also an
Imation Superdisk connected to port 0x278. You could give the following
-options on your boot command:
+options on your boot command::
pd.drive0=0x378,1 pf.drive0=0x278,1 pf.drive1=0x378,0,36
@@ -175,18 +185,21 @@ PARPORT parallel port sharing system that is included by the
if you want to use chains of devices on the same parallel port.
2.2 Loading and configuring PARIDE as modules
+----------------------------------------------
It is much faster and simpler to get to understand the PARIDE drivers
if you use them as loadable kernel modules.
-Note 1: using these drivers with the "kerneld" automatic module loading
-system is not recommended for beginners, and is not documented here.
+Note 1:
+ using these drivers with the "kerneld" automatic module loading
+ system is not recommended for beginners, and is not documented here.
-Note 2: if you build PARPORT support as a loadable module, PARIDE must
-also be built as loadable modules, and PARPORT must be loaded before the
-PARIDE modules.
+Note 2:
+ if you build PARPORT support as a loadable module, PARIDE must
+ also be built as loadable modules, and PARPORT must be loaded before
+ the PARIDE modules.
-To use PARIDE, you must begin by
+To use PARIDE, you must begin by::
insmod paride
@@ -196,7 +209,7 @@ among other tasks.
Then, load as many of the protocol modules as you think you might need.
As you load each module, it will register the protocols that it supports,
and print a log message to your kernel log file and your console. For
-example:
+example::
# insmod epat
paride: epat registered as protocol 0
@@ -211,7 +224,7 @@ individual co-ordinates when you load the driver.
For example, if you had two no-name CD-ROM drives both using the
KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc
-you could give the following command:
+you could give the following command::
# insmod pcd drive0=0x378,1 drive1=0x3bc,1
@@ -220,7 +233,7 @@ but check the source files in linux/drivers/block/paride for more
information. (Hopefully someone will write some man pages one day !).
As another example, here's what happens when PARPORT is installed, and
-a SyQuest EZ-135 is attached to port 0x378:
+a SyQuest EZ-135 is attached to port 0x378::
# insmod paride
paride: version 1.0 installed
@@ -237,46 +250,47 @@ Note that the last line is the output from the generic partition table
scanner - in this case it reports that it has found a disk with one partition.
2.3 Using a PARIDE device
+--------------------------
Once the drivers have been loaded, you can access PARIDE devices in the
same way as their traditional counterparts. You will probably need to
create the device "special files". Here is a simple script that you can
-cut to a file and execute:
+cut to a file and execute::
-#!/bin/bash
-#
-# mkd -- a script to create the device special files for the PARIDE subsystem
-#
-function mkdev {
- mknod $1 $2 $3 $4 ; chmod 0660 $1 ; chown root:disk $1
-}
-#
-function pd {
- D=$( printf \\$( printf "x%03x" $[ $1 + 97 ] ) )
- mkdev pd$D b 45 $[ $1 * 16 ]
- for P in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
- do mkdev pd$D$P b 45 $[ $1 * 16 + $P ]
- done
-}
-#
-cd /dev
-#
-for u in 0 1 2 3 ; do pd $u ; done
-for u in 0 1 2 3 ; do mkdev pcd$u b 46 $u ; done
-for u in 0 1 2 3 ; do mkdev pf$u b 47 $u ; done
-for u in 0 1 2 3 ; do mkdev pt$u c 96 $u ; done
-for u in 0 1 2 3 ; do mkdev npt$u c 96 $[ $u + 128 ] ; done
-for u in 0 1 2 3 ; do mkdev pg$u c 97 $u ; done
-#
-# end of mkd
+ #!/bin/bash
+ #
+ # mkd -- a script to create the device special files for the PARIDE subsystem
+ #
+ function mkdev {
+ mknod $1 $2 $3 $4 ; chmod 0660 $1 ; chown root:disk $1
+ }
+ #
+ function pd {
+ D=$( printf \\$( printf "x%03x" $[ $1 + 97 ] ) )
+ mkdev pd$D b 45 $[ $1 * 16 ]
+ for P in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
+ do mkdev pd$D$P b 45 $[ $1 * 16 + $P ]
+ done
+ }
+ #
+ cd /dev
+ #
+ for u in 0 1 2 3 ; do pd $u ; done
+ for u in 0 1 2 3 ; do mkdev pcd$u b 46 $u ; done
+ for u in 0 1 2 3 ; do mkdev pf$u b 47 $u ; done
+ for u in 0 1 2 3 ; do mkdev pt$u c 96 $u ; done
+ for u in 0 1 2 3 ; do mkdev npt$u c 96 $[ $u + 128 ] ; done
+ for u in 0 1 2 3 ; do mkdev pg$u c 97 $u ; done
+ #
+ # end of mkd
With the device files and drivers in place, you can access PARIDE devices
-like any other Linux device. For example, to mount a CD-ROM in pcd0, use:
+like any other Linux device. For example, to mount a CD-ROM in pcd0, use::
mount /dev/pcd0 /cdrom
If you have a fresh Avatar Shark cartridge, and the drive is pda, you
-might do something like:
+might do something like::
fdisk /dev/pda -- make a new partition table with
partition 1 of type 83
@@ -289,13 +303,14 @@ might do something like:
Devices like the Imation superdisk work in the same way, except that
they do not have a partition table. For example to make a 120MB
-floppy that you could share with a DOS system:
+floppy that you could share with a DOS system::
mkdosfs /dev/pf0
mount /dev/pf0 /mnt
2.4 The pf driver
+------------------
The pf driver is intended for use with parallel port ATAPI disk
devices. The most common devices in this category are PD drives
@@ -304,6 +319,7 @@ partitioned. Consequently, the pf driver does not support partitioned
media. This may be changed in a future version of the driver.
2.5 Using the pt driver
+------------------------
The pt driver for parallel port ATAPI tape drives is a minimal driver.
It does not yet support many of the standard tape ioctl operations.
@@ -311,6 +327,7 @@ For best performance, a block size of 32KB should be used. You will
probably want to set the parallel port delay to 0, if you can.
2.6 Using the pg driver
+------------------------
The pg driver can be used in conjunction with the cdrecord program
to create CD-ROMs. Please get cdrecord version 1.6.1 or later
@@ -322,8 +339,10 @@ in EPP mode, try to use "bidirectional" or "PS/2" mode and 1x speeds only.
3. Troubleshooting
+==================
3.1 Use EPP mode if you can
+----------------------------
The most common problems that people report with the PARIDE drivers
concern the parallel port CMOS settings. At this time, none of the
@@ -332,6 +351,7 @@ If you are able to do so, please set your parallel port into EPP mode
using your CMOS setup procedure.
3.2 Check the port delay
+-------------------------
Some parallel ports cannot reliably transfer data at full speed. To
offset the errors, the PARIDE protocol modules introduce a "port
@@ -347,6 +367,7 @@ read the comments at the beginning of the driver source files in
linux/drivers/block/paride.
3.3 Some drives need a printer reset
+-------------------------------------
There appear to be a number of "noname" external drives on the market
that do not always power up correctly. We have noticed this with some
@@ -354,7 +375,7 @@ drives based on OnSpec and older Freecom adapters. In these rare cases,
the adapter can often be reinitialised by issuing a "printer reset" on
the parallel port. As the reset operation is potentially disruptive in
multiple device environments, the PARIDE drivers will not do it
-automatically. You can however, force a printer reset by doing:
+automatically. You can however, force a printer reset by doing::
insmod lp reset=1
rmmod lp
@@ -364,6 +385,7 @@ your paride drivers as modules, and arrange to do the printer reset
before loading the PARIDE drivers.
3.4 Use the verbose option and dmesg if you need help
+------------------------------------------------------
While a lot of testing has gone into these drivers to make them work
as smoothly as possible, problems will arise. If you do have problems,
@@ -373,7 +395,7 @@ clues, then please make sure that only one drive is hooked to your system,
and that either (a) PARPORT is enabled or (b) no other device driver
is using your parallel port (check in /proc/ioports). Then, load the
appropriate drivers (you can load several protocol modules if you want)
-as in:
+as in::
# insmod paride
# insmod epat
@@ -394,12 +416,14 @@ by e-mail to grant(a)torque.net, or join the linux-parport mailing list
and post your report there.
3.5 For more information or help
+---------------------------------
You can join the linux-parport mailing list by sending a mail message
-to
+to:
+
linux-parport-request(a)torque.net
-with the single word
+with the single word::
subscribe
@@ -412,6 +436,6 @@ have in your mail headers, when sending mail to the list server.
You might also find some useful information on the linux-parport
web pages (although they are not always up to date) at
- http://web.archive.org/web/*/http://www.torque.net/parport/
+ http://web.archive.org/web/%2E/http://www.torque.net/parport/
diff --git a/Documentation/blockdev/ramdisk.txt b/Documentation/blockdev/ramdisk.rst
similarity index 84%
rename from Documentation/blockdev/ramdisk.txt
rename to Documentation/blockdev/ramdisk.rst
index 501e12e0323e..b7c2268f8dec 100644
--- a/Documentation/blockdev/ramdisk.txt
+++ b/Documentation/blockdev/ramdisk.rst
@@ -1,7 +1,8 @@
+==========================================
Using the RAM disk block device with Linux
-------------------------------------------
+==========================================
-Contents:
+.. Contents:
1) Overview
2) Kernel Command Line Parameters
@@ -42,7 +43,7 @@ rescue floppy disk.
2a) Kernel Command Line Parameters
ramdisk_size=N
- ==============
+ Size of the ramdisk.
This parameter tells the RAM disk driver to set up RAM disks of N k size. The
default is 4096 (4 MB).
@@ -50,16 +51,13 @@ default is 4096 (4 MB).
2b) Module parameters
rd_nr
- =====
- /dev/ramX devices created.
+ /dev/ramX devices created.
max_part
- ========
- Maximum partition number.
+ Maximum partition number.
rd_size
- =======
- See ramdisk_size.
+ See ramdisk_size.
3) Using "rdev -r"
------------------
@@ -71,11 +69,11 @@ to 2 MB (2^11) of where to find the RAM disk (this used to be the size). Bit
prompt/wait sequence is to be given before trying to read the RAM disk. Since
the RAM disk dynamically grows as data is being written into it, a size field
is not required. Bits 11 to 13 are not currently used and may as well be zero.
-These numbers are no magical secrets, as seen below:
+These numbers are no magical secrets, as seen below::
-./arch/x86/kernel/setup.c:#define RAMDISK_IMAGE_START_MASK 0x07FF
-./arch/x86/kernel/setup.c:#define RAMDISK_PROMPT_FLAG 0x8000
-./arch/x86/kernel/setup.c:#define RAMDISK_LOAD_FLAG 0x4000
+ ./arch/x86/kernel/setup.c:#define RAMDISK_IMAGE_START_MASK 0x07FF
+ ./arch/x86/kernel/setup.c:#define RAMDISK_PROMPT_FLAG 0x8000
+ ./arch/x86/kernel/setup.c:#define RAMDISK_LOAD_FLAG 0x4000
Consider a typical two floppy disk setup, where you will have the
kernel on disk one, and have already put a RAM disk image onto disk #2.
@@ -92,20 +90,23 @@ sequence so that you have a chance to switch floppy disks.
The command line equivalent is: "prompt_ramdisk=1"
Putting that together gives 2^15 + 2^14 + 0 = 49152 for an rdev word.
-So to create disk one of the set, you would do:
+So to create disk one of the set, you would do::
/usr/src/linux# cat arch/x86/boot/zImage > /dev/fd0
/usr/src/linux# rdev /dev/fd0 /dev/fd0
/usr/src/linux# rdev -r /dev/fd0 49152
-If you make a boot disk that has LILO, then for the above, you would use:
+If you make a boot disk that has LILO, then for the above, you would use::
+
append = "ramdisk_start=0 load_ramdisk=1 prompt_ramdisk=1"
-Since the default start = 0 and the default prompt = 1, you could use:
+
+Since the default start = 0 and the default prompt = 1, you could use::
+
append = "load_ramdisk=1"
4) An Example of Creating a Compressed RAM Disk
-----------------------------------------------
+-----------------------------------------------
To create a RAM disk image, you will need a spare block device to
construct it on. This can be the RAM disk device itself, or an
@@ -120,11 +121,11 @@ a) Decide on the RAM disk size that you want. Say 2 MB for this example.
Create it by writing to the RAM disk device. (This step is not currently
required, but may be in the future.) It is wise to zero out the
area (esp. for disks) so that maximal compression is achieved for
- the unused blocks of the image that you are about to create.
+ the unused blocks of the image that you are about to create::
dd if=/dev/zero of=/dev/ram0 bs=1k count=2048
-b) Make a filesystem on it. Say ext2fs for this example.
+b) Make a filesystem on it. Say ext2fs for this example::
mke2fs -vm0 /dev/ram0 2048
@@ -133,11 +134,11 @@ c) Mount it, copy the files you want to it (eg: /etc/* /dev/* ...)
d) Compress the contents of the RAM disk. The level of compression
will be approximately 50% of the space used by the files. Unused
- space on the RAM disk will compress to almost nothing.
+ space on the RAM disk will compress to almost nothing::
dd if=/dev/ram0 bs=1k count=2048 | gzip -v9 > /tmp/ram_image.gz
-e) Put the kernel onto the floppy
+e) Put the kernel onto the floppy::
dd if=zImage of=/dev/fd0 bs=1k
@@ -146,13 +147,13 @@ f) Put the RAM disk image onto the floppy, after the kernel. Use an offset
(possibly larger) kernel onto the same floppy later without overlapping
the RAM disk image. An offset of 400 kB for kernels about 350 kB in
size would be reasonable. Make sure offset+size of ram_image.gz is
- not larger than the total space on your floppy (usually 1440 kB).
+ not larger than the total space on your floppy (usually 1440 kB)::
dd if=/tmp/ram_image.gz of=/dev/fd0 bs=1k seek=400
g) Use "rdev" to set the boot device, RAM disk offset, prompt flag, etc.
For prompt_ramdisk=1, load_ramdisk=1, ramdisk_start=400, one would
- have 2^15 + 2^14 + 400 = 49552.
+ have 2^15 + 2^14 + 400 = 49552::
rdev /dev/fd0 /dev/fd0
rdev -r /dev/fd0 49552
@@ -160,15 +161,17 @@ g) Use "rdev" to set the boot device, RAM disk offset, prompt flag, etc.
That is it. You now have your boot/root compressed RAM disk floppy. Some
users may wish to combine steps (d) and (f) by using a pipe.
---------------------------------------------------------------------------
+
Paul Gortmaker 12/95
Changelog:
----------
-10-22-04 : Updated to reflect changes in command line options, remove
+10-22-04 :
+ Updated to reflect changes in command line options, remove
obsolete references, general cleanup.
James Nelson (james4765(a)gmail.com)
-12-95 : Original Document
+12-95 :
+ Original Document
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.rst
similarity index 76%
rename from Documentation/blockdev/zram.txt
rename to Documentation/blockdev/zram.rst
index 4df0ce271085..2111231c9c0f 100644
--- a/Documentation/blockdev/zram.txt
+++ b/Documentation/blockdev/zram.rst
@@ -1,7 +1,9 @@
+========================================
zram: Compressed RAM based block devices
-----------------------------------------
+========================================
-* Introduction
+Introduction
+============
The zram module creates RAM based block devices named /dev/zram<id>
(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
@@ -12,9 +14,11 @@ use as swap disks, various caches under /var and maybe many more :)
Statistics for individual zram devices are exported through sysfs nodes at
/sys/block/zram<id>/
-* Usage
+Usage
+=====
There are several ways to configure and manage zram device(-s):
+
a) using zram and zram_control sysfs attributes
b) using zramctl utility, provided by util-linux (util-linux(a)vger.kernel.org).
@@ -22,7 +26,7 @@ In this document we will describe only 'manual' zram configuration steps,
IOW, zram and zram_control sysfs attributes.
In order to get a better idea about zramctl please consult util-linux
-documentation, zramctl man-page or `zramctl --help'. Please be informed
+documentation, zramctl man-page or `zramctl --help`. Please be informed
that zram maintainers do not develop/maintain util-linux or zramctl, should
you have any questions please contact util-linux(a)vger.kernel.org
@@ -30,19 +34,23 @@ Following shows a typical sequence of steps for using zram.
WARNING
=======
+
For the sake of simplicity we skip error checking parts in most of the
examples below. However, it is your sole responsibility to handle errors.
zram sysfs attributes always return negative values in case of errors.
The list of possible return codes:
--EBUSY -- an attempt to modify an attribute that cannot be changed once
-the device has been initialised. Please reset device first;
--ENOMEM -- zram was not able to allocate enough memory to fulfil your
-needs;
--EINVAL -- invalid input has been provided.
+
+======== =============================================================
+-EBUSY an attempt to modify an attribute that cannot be changed once
+ the device has been initialised. Please reset device first;
+-ENOMEM zram was not able to allocate enough memory to fulfil your
+ needs;
+-EINVAL invalid input has been provided.
+======== =============================================================
If you use 'echo', the returned value that is changed by 'echo' utility,
-and, in general case, something like:
+and, in general case, something like::
echo 3 > /sys/block/zram0/max_comp_streams
if [ $? -ne 0 ];
@@ -51,7 +59,11 @@ and, in general case, something like:
should suffice.
-1) Load Module:
+1) Load Module
+==============
+
+::
+
modprobe zram num_devices=4
This creates 4 devices: /dev/zram{0,1,2,3}
@@ -59,6 +71,8 @@ num_devices parameter is optional and tells zram how many devices should be
pre-created. Default: 1.
2) Set max number of compression streams
+========================================
+
Regardless the value passed to this attribute, ZRAM will always
allocate multiple compression streams - one per online CPUs - thus
allowing several concurrent compression operations. The number of
@@ -66,16 +80,20 @@ allocated compression streams goes down when some of the CPUs
become offline. There is no single-compression-stream mode anymore,
unless you are running a UP system or has only 1 CPU online.
-To find out how many streams are currently available:
+To find out how many streams are currently available::
+
cat /sys/block/zram0/max_comp_streams
3) Select compression algorithm
+===============================
+
Using comp_algorithm device attribute one can see available and
currently selected (shown in square brackets) compression algorithms,
change selected compression algorithm (once the device is initialised
there is no way to change compression algorithm).
-Examples:
+Examples::
+
#show supported compression algorithms
cat /sys/block/zram0/comp_algorithm
lzo [lz4]
@@ -83,20 +101,23 @@ Examples:
#select lzo compression algorithm
echo lzo > /sys/block/zram0/comp_algorithm
-For the time being, the `comp_algorithm' content does not necessarily
+For the time being, the `comp_algorithm` content does not necessarily
show every compression algorithm supported by the kernel. We keep this
list primarily to simplify device configuration and one can configure
a new device with a compression algorithm that is not listed in
-`comp_algorithm'. The thing is that, internally, ZRAM uses Crypto API
+`comp_algorithm`. The thing is that, internally, ZRAM uses Crypto API
and, if some of the algorithms were built as modules, it's impossible
to list all of them using, for instance, /proc/crypto or any other
method. This, however, has an advantage of permitting the usage of
custom crypto compression modules (implementing S/W or H/W compression).
4) Set Disksize
+===============
+
Set disk size by writing the value to sysfs node 'disksize'.
The value can be either in bytes or you can use mem suffixes.
-Examples:
+Examples::
+
# Initialize /dev/zram0 with 50MB disksize
echo $((50*1024*1024)) > /sys/block/zram0/disksize
@@ -111,10 +132,13 @@ since we expect a 2:1 compression ratio. Note that zram uses about 0.1% of the
size of the disk when not in use so a huge zram is wasteful.
5) Set memory limit: Optional
+=============================
+
Set memory limit by writing the value to sysfs node 'mem_limit'.
The value can be either in bytes or you can use mem suffixes.
In addition, you could change the value in runtime.
-Examples:
+Examples::
+
# limit /dev/zram0 with 50MB memory
echo $((50*1024*1024)) > /sys/block/zram0/mem_limit
@@ -126,7 +150,11 @@ Examples:
# To disable memory limit
echo 0 > /sys/block/zram0/mem_limit
-6) Activate:
+6) Activate
+===========
+
+::
+
mkswap /dev/zram0
swapon /dev/zram0
@@ -134,6 +162,7 @@ Examples:
mount /dev/zram1 /tmp
7) Add/remove zram devices
+==========================
zram provides a control interface, which enables dynamic (on-demand) device
addition and removal.
@@ -142,37 +171,44 @@ In order to add a new /dev/zramX device, perform read operation on hot_add
attribute. This will return either new device's device id (meaning that you
can use /dev/zram<id>) or error code.
-Example:
+Example::
+
cat /sys/class/zram-control/hot_add
1
To remove the existing /dev/zramX device (where X is a device id)
-execute
+execute::
+
echo X > /sys/class/zram-control/hot_remove
-8) Stats:
+8) Stats
+========
+
Per-device statistics are exported as various nodes under /sys/block/zram<id>/
A brief description of exported device attributes. For more details please
read Documentation/ABI/testing/sysfs-block-zram.
+====================== ====== ===============================================
Name access description
----- ------ -----------
+====================== ====== ===============================================
disksize RW show and set the device's disk size
initstate RO shows the initialization state of the device
reset WO trigger device reset
-mem_used_max WO reset the `mem_used_max' counter (see later)
-mem_limit WO specifies the maximum amount of memory ZRAM can use
- to store the compressed data
-writeback_limit WO specifies the maximum amount of write IO zram can
- write out to backing device as 4KB unit
+mem_used_max WO reset the `mem_used_max` counter (see later)
+mem_limit WO specifies the maximum amount of memory ZRAM can
+ use to store the compressed data
+writeback_limit WO specifies the maximum amount of write IO zram
+ can write out to backing device as 4KB unit
writeback_limit_enable RW show and set writeback_limit feature
-max_comp_streams RW the number of possible concurrent compress operations
+max_comp_streams RW the number of possible concurrent compress
+ operations
comp_algorithm RW show and change the compression algorithm
compact WO trigger memory compaction
debug_stat RO this file is used for zram debugging purposes
backing_dev RW set up backend storage for zram to write out
idle WO mark allocated slot as idle
+====================== ====== ===============================================
User space is advised to use the following files to read the device statistics.
@@ -188,23 +224,31 @@ The stat file represents device's I/O statistics not accounted by block
layer and, thus, not available in zram<id>/stat file. It consists of a
single line of text and contains the following stats separated by
whitespace:
- failed_reads the number of failed reads
- failed_writes the number of failed writes
- invalid_io the number of non-page-size-aligned I/O requests
+
+ ============= =============================================================
+ failed_reads The number of failed reads
+ failed_writes The number of failed writes
+ invalid_io The number of non-page-size-aligned I/O requests
notify_free Depending on device usage scenario it may account
+
a) the number of pages freed because of swap slot free
- notifications or b) the number of pages freed because of
- REQ_OP_DISCARD requests sent by bio. The former ones are
- sent to a swap block device when a swap slot is freed,
- which implies that this disk is being used as a swap disk.
+ notifications
+ b) the number of pages freed because of
+ REQ_OP_DISCARD requests sent by bio. The former ones are
+ sent to a swap block device when a swap slot is freed,
+ which implies that this disk is being used as a swap disk.
+
The latter ones are sent by filesystem mounted with
discard option, whenever some data blocks are getting
discarded.
+ ============= =============================================================
File /sys/block/zram<id>/mm_stat
The stat file represents device's mm statistics. It consists of a single
line of text and contains the following stats separated by whitespace:
+
+ ================ =============================================================
orig_data_size uncompressed size of data stored in this disk.
This excludes same-element-filled pages (same_pages) since
no memory is allocated for them.
@@ -223,58 +267,71 @@ line of text and contains the following stats separated by whitespace:
No memory is allocated for such pages.
pages_compacted the number of pages freed during compaction
huge_pages the number of incompressible pages
+ ================ =============================================================
File /sys/block/zram<id>/bd_stat
The stat file represents device's backing device statistics. It consists of
a single line of text and contains the following stats separated by whitespace:
+
+ ============== =============================================================
bd_count size of data written in backing device.
Unit: 4K bytes
bd_reads the number of reads from backing device
Unit: 4K bytes
bd_writes the number of writes to backing device
Unit: 4K bytes
+ ============== =============================================================
+
+9) Deactivate
+=============
+
+::
-9) Deactivate:
swapoff /dev/zram0
umount /dev/zram1
-10) Reset:
- Write any positive value to 'reset' sysfs node
- echo 1 > /sys/block/zram0/reset
- echo 1 > /sys/block/zram1/reset
+10) Reset
+=========
+
+ Write any positive value to 'reset' sysfs node::
+
+ echo 1 > /sys/block/zram0/reset
+ echo 1 > /sys/block/zram1/reset
This frees all the memory allocated for the given device and
resets the disksize to zero. You must set the disksize again
before reusing the device.
-* Optional Feature
+Optional Feature
+================
-= writeback
+writeback
+---------
With CONFIG_ZRAM_WRITEBACK, zram can write idle/incompressible page
to backing storage rather than keeping it in memory.
-To use the feature, admin should set up backing device via
+To use the feature, admin should set up backing device via::
- "echo /dev/sda5 > /sys/block/zramX/backing_dev"
+ echo /dev/sda5 > /sys/block/zramX/backing_dev
before disksize setting. It supports only partition at this moment.
-If admin want to use incompressible page writeback, they could do via
+If admin want to use incompressible page writeback, they could do via::
- "echo huge > /sys/block/zramX/write"
+ echo huge > /sys/block/zramX/write
To use idle page writeback, first, user need to declare zram pages
-as idle.
+as idle::
- "echo all > /sys/block/zramX/idle"
+ echo all > /sys/block/zramX/idle
From now on, any pages on zram are idle pages. The idle mark
will be removed until someone request access of the block.
IOW, unless there is access request, those pages are still idle pages.
-Admin can request writeback of those idle pages at right timing via
+Admin can request writeback of those idle pages at right timing via::
- "echo idle > /sys/block/zramX/writeback"
+ echo idle > /sys/block/zramX/writeback
With the command, zram writeback idle pages from memory to the storage.
@@ -285,7 +342,7 @@ to guarantee storage health for entire product life.
To overcome the concern, zram supports "writeback_limit" feature.
The "writeback_limit_enable"'s default value is 0 so that it doesn't limit
any writeback. IOW, if admin want to apply writeback budget, he should
-enable writeback_limit_enable via
+enable writeback_limit_enable via::
$ echo 1 > /sys/block/zramX/writeback_limit_enable
@@ -296,7 +353,7 @@ until admin set the budget via /sys/block/zramX/writeback_limit.
assigned via /sys/block/zramX/writeback_limit is meaninless.)
If admin want to limit writeback as per-day 400M, he could do it
-like below.
+like below::
$ MB_SHIFT=20
$ 4K_SHIFT=12
@@ -305,16 +362,16 @@ like below.
$ echo 1 > /sys/block/zram0/writeback_limit_enable
If admin want to allow further write again once the bugdet is exausted,
-he could do it like below
+he could do it like below::
$ echo $((400<<MB_SHIFT>>4K_SHIFT)) > \
/sys/block/zram0/writeback_limit
-If admin want to see remaining writeback budget since he set,
+If admin want to see remaining writeback budget since he set::
$ cat /sys/block/zramX/writeback_limit
-If admin want to disable writeback limit, he could do
+If admin want to disable writeback limit, he could do::
$ echo 0 > /sys/block/zramX/writeback_limit_enable
@@ -326,25 +383,35 @@ budget in next setting is user's job.
If admin want to measure writeback count in a certain period, he could
know it via /sys/block/zram0/bd_stat's 3rd column.
-= memory tracking
+memory tracking
+===============
With CONFIG_ZRAM_MEMORY_TRACKING, user can know information of the
zram block. It could be useful to catch cold or incompressible
pages of the process with*pagemap.
+
If you enable the feature, you could see block state via
-/sys/kernel/debug/zram/zram0/block_state". The output is as follows,
+/sys/kernel/debug/zram/zram0/block_state". The output is as follows::
300 75.033841 .wh.
301 63.806904 s...
302 63.806919 ..hi
-First column is zram's block index.
-Second column is access time since the system was booted
-Third column is state of the block.
-(s: same page
-w: written page to backing store
-h: huge page
-i: idle page)
+First column
+ zram's block index.
+Second column
+ access time since the system was booted
+Third column
+ state of the block:
+
+ s:
+ same page
+ w:
+ written page to backing store
+ h:
+ huge page
+ i:
+ idle page
First line of above example says 300th block is accessed at 75.033841sec
and the block's state is huge so it is written back to the backing
diff --git a/MAINTAINERS b/MAINTAINERS
index ca1d09d0c44b..3ed27c0c36d8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10823,7 +10823,7 @@ M: Josef Bacik <josef(a)toxicpanda.com>
S: Maintained
L: linux-block(a)vger.kernel.org
L: nbd(a)other.debian.org
-F: Documentation/blockdev/nbd.txt
+F: Documentation/blockdev/nbd.rst
F: drivers/block/nbd.c
F: include/uapi/linux/nbd.h
@@ -11801,7 +11801,7 @@ PARIDE DRIVERS FOR PARALLEL PORT IDE DEVICES
M: Tim Waugh <tim(a)cyberelk.net>
L: linux-parport(a)lists.infradead.org (subscribers-only)
S: Maintained
-F: Documentation/blockdev/paride.txt
+F: Documentation/blockdev/paride.rst
F: drivers/block/paride/
PARISC ARCHITECTURE
@@ -13077,7 +13077,7 @@ F: drivers/net/wireless/ralink/rt2x00/
RAMDISK RAM BLOCK DEVICE DRIVER
M: Jens Axboe <axboe(a)kernel.dk>
S: Maintained
-F: Documentation/blockdev/ramdisk.txt
+F: Documentation/blockdev/ramdisk.rst
F: drivers/block/brd.c
RANCHU VIRTUAL BOARD FOR MIPS
@@ -17360,7 +17360,7 @@ R: Sergey Senozhatsky <sergey.senozhatsky.work(a)gmail.com>
L: linux-kernel(a)vger.kernel.org
S: Maintained
F: drivers/block/zram/
-F: Documentation/blockdev/zram.txt
+F: Documentation/blockdev/zram.rst
ZS DECSTATION Z85C30 SERIAL DRIVER
M: "Maciej W. Rozycki" <macro(a)linux-mips.org>
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 96ec7e0fc1ea..c43690b973d8 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -31,7 +31,7 @@ config BLK_DEV_FD
If you want to use the floppy disk drive(s) of your PC under Linux,
say Y. Information about this driver, especially important for IBM
Thinkpad users, is contained in
- <file:Documentation/blockdev/floppy.txt>.
+ <file:Documentation/blockdev/floppy.rst>.
That file also contains the location of the Floppy driver FAQ as
well as location of the fdutils package used to configure additional
parameters of the driver at run time.
@@ -96,7 +96,7 @@ config PARIDE
your computer's parallel port. Most of them are actually IDE devices
using a parallel port IDE adapter. This option enables the PARIDE
subsystem which contains drivers for many of these external drives.
- Read <file:Documentation/blockdev/paride.txt> for more information.
+ Read <file:Documentation/blockdev/paride.rst> for more information.
If you have said Y to the "Parallel-port support" configuration
option, you may share a single port between your printer and other
@@ -261,7 +261,7 @@ config BLK_DEV_NBD
userland (making server and client physically the same computer,
communicating using the loopback network device).
- Read <file:Documentation/blockdev/nbd.txt> for more information,
+ Read <file:Documentation/blockdev/nbd.rst> for more information,
especially about where to find the server code, which runs in user
space and does not need special kernel support.
@@ -303,7 +303,7 @@ config BLK_DEV_RAM
during the initial install of Linux.
Note that the kernel command line option "ramdisk=XX" is now obsolete.
- For details, read <file:Documentation/blockdev/ramdisk.txt>.
+ For details, read <file:Documentation/blockdev/ramdisk.rst>.
To compile this driver as a module, choose M here: the
module will be called brd. An alias "rd" has been defined
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index b8998abd86a5..14701be9f916 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4423,7 +4423,7 @@ static int __init floppy_setup(char *str)
pr_cont("\n");
} else
DPRINT("botched floppy option\n");
- DPRINT("Read Documentation/blockdev/floppy.txt\n");
+ DPRINT("Read Documentation/blockdev/floppy.rst\n");
return 0;
}
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 1ffc64770643..e06b99d54816 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -12,7 +12,7 @@ config ZRAM
It has several use cases, for example: /tmp storage, use as swap
disks and maybe many more.
- See Documentation/blockdev/zram.txt for more information.
+ See Documentation/blockdev/zram.rst for more information.
config ZRAM_WRITEBACK
bool "Write back incompressible or idle page to backing device"
@@ -26,7 +26,7 @@ config ZRAM_WRITEBACK
With /sys/block/zramX/{idle,writeback}, application could ask
idle page's writeback to the backing device to save in memory.
- See Documentation/blockdev/zram.txt for more information.
+ See Documentation/blockdev/zram.rst for more information.
config ZRAM_MEMORY_TRACKING
bool "Track zRam block status"
@@ -36,4 +36,4 @@ config ZRAM_MEMORY_TRACKING
of zRAM. Admin could see the information via
/sys/kernel/debug/zram/zramX/block_state.
- See Documentation/blockdev/zram.txt for more information.
+ See Documentation/blockdev/zram.rst for more information.
diff --git a/tools/testing/selftests/zram/README b/tools/testing/selftests/zram/README
index 7972cc512408..5fa378391d3b 100644
--- a/tools/testing/selftests/zram/README
+++ b/tools/testing/selftests/zram/README
@@ -37,4 +37,4 @@ Commands required for testing:
- mkfs/ mkfs.ext4
For more information please refer:
-kernel-source-tree/Documentation/blockdev/zram.txt
+kernel-source-tree/Documentation/blockdev/zram.rst
--
2.20.1
The run_afpackettests will be marked as passed regardless the return
value of those sub-tests in the script:
--------------------
running psock_tpacket test
--------------------
[FAIL]
selftests: run_afpackettests [PASS]
Fix this by changing the return value for each tests.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
---
tools/testing/selftests/net/run_afpackettests | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/tools/testing/selftests/net/run_afpackettests b/tools/testing/selftests/net/run_afpackettests
index 2dc95fd..ea5938e 100755
--- a/tools/testing/selftests/net/run_afpackettests
+++ b/tools/testing/selftests/net/run_afpackettests
@@ -6,12 +6,14 @@ if [ $(id -u) != 0 ]; then
exit 0
fi
+ret=0
echo "--------------------"
echo "running psock_fanout test"
echo "--------------------"
./in_netns.sh ./psock_fanout
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ ret=1
else
echo "[PASS]"
fi
@@ -22,6 +24,7 @@ echo "--------------------"
./in_netns.sh ./psock_tpacket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ ret=1
else
echo "[PASS]"
fi
@@ -32,6 +35,8 @@ echo "--------------------"
./in_netns.sh ./txring_overwrite
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ ret=1
else
echo "[PASS]"
fi
+exit $ret
--
2.7.4
Build and run gpio when output directory is the src dir. gpio has
dependency on tools/gpio and builds tools/gpio objects in the src
directory in all cases making the src repo dirty even when object
relocation is specified.
This fixes the following commands from generating gpio objects in
the source repository:
make O=dir kselftest
export KBUILD_OUTPUT=dir; make kselftest
make O=dir -C tools/testing/selftests
expoert KBUILD_OUTPUT=dir; make -C tools/testing/selftests
The following still don't work (need fixing in gpio Makefile):
make O=dir kselftest TARGETS="gpio"
export KBUILD_OUTPUT=dir; make kselftest TARGETS="gpio"
make O=dir -C tools/testing/selftests TARGETS="gpio"
expoert KBUILD_OUTPUT=dir; make -C tools/testing/selftests TARGETS="gpio"
Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org>
---
tools/testing/selftests/Makefile | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index b43c5f41fb3e..f2ebf8cf4686 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -99,6 +99,15 @@ ARCH ?= $(SUBARCH)
export KSFT_KHDR_INSTALL_DONE := 1
export BUILD
+# build and run gpio when output directory is the src dir.
+# gpio has dependency on tools/gpio and builds tools/gpio
+# objects in the src directory in all cases making the src
+# repo dirty even when objects are relocated.
+ifneq (1,$(DEFAULT_INSTALL_HDR_PATH))
+ TMP := $(filter-out gpio, $(TARGETS))
+ TARGETS := $(TMP)
+endif
+
# set default goal to all, so make without a target runs all, even when
# all isn't the first target in the file.
.DEFAULT_GOAL := all
--
2.17.1
On smaller systems, running a test with 200 threads can take a long
time on machines with smaller number of CPUs.
Detect the number of online cpus at test runtime, and multiply that
by 6 to have 6 rseq threads per cpu preempting each other.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Joel Fernandes <joelaf(a)google.com>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Dave Watson <davejwatson(a)fb.com>
Cc: Will Deacon <will.deacon(a)arm.com>
Cc: Andi Kleen <andi(a)firstfloor.org>
Cc: linux-kselftest(a)vger.kernel.org
Cc: "H . Peter Anvin" <hpa(a)zytor.com>
Cc: Chris Lameter <cl(a)linux.com>
Cc: Russell King <linux(a)arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages(a)gmail.com>
Cc: "Paul E . McKenney" <paulmck(a)linux.vnet.ibm.com>
Cc: Paul Turner <pjt(a)google.com>
Cc: Boqun Feng <boqun.feng(a)gmail.com>
Cc: Josh Triplett <josh(a)joshtriplett.org>
Cc: Steven Rostedt <rostedt(a)goodmis.org>
Cc: Ben Maurer <bmaurer(a)fb.com>
Cc: Andy Lutomirski <luto(a)amacapital.net>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
---
tools/testing/selftests/rseq/run_param_test.sh | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/rseq/run_param_test.sh b/tools/testing/selftests/rseq/run_param_test.sh
index 3acd6d75ff9f..e426304fd4a0 100755
--- a/tools/testing/selftests/rseq/run_param_test.sh
+++ b/tools/testing/selftests/rseq/run_param_test.sh
@@ -1,6 +1,8 @@
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0+ or MIT
+NR_CPUS=`grep '^processor' /proc/cpuinfo | wc -l`
+
EXTRA_ARGS=${@}
OLDIFS="$IFS"
@@ -28,15 +30,16 @@ IFS="$OLDIFS"
REPS=1000
SLOW_REPS=100
+NR_THREADS=$((6*${NR_CPUS}))
function do_tests()
{
local i=0
while [ "$i" -lt "${#TEST_LIST[@]}" ]; do
echo "Running test ${TEST_NAME[$i]}"
- ./param_test ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1
+ ./param_test ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
echo "Running compare-twice test ${TEST_NAME[$i]}"
- ./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1
+ ./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
let "i++"
done
}
--
2.11.0
"make kselftest" fails with "Circular Makefile.o <- prepare dependency
dropped." error, when lib.mk invokes "make headers_install".
Make level 0: Main make calls selftests run_tests target
...
Make level n: selftests lib.mk invokes main make's headers_install
The secondary level make inherits builtin-rules which will use the rule
to generate Makefile.o and runs into "Circular Makefile.o <- prepare
dependency dropped." error, and kselftest compile fails.
Invoke headers_install target with --no-builtin-rules to avoid circular
error.
In addition, lib.mk installs headers in the default HDR_PATH, even when
build relocation is requested with O= or export KBUILD_OUTPUT. Fix the
problem by passing in INSTALL_HDR_PATH. The headers are installed under
the specified output "dir/usr".
Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org>
---
Changes since v1:
lib.mk needs DEFAULT_GOAL to run all
tools/testing/selftests/Makefile | 52 +++++++++++++++++++++++++++-----
tools/testing/selftests/lib.mk | 38 +++++++++++++++++++++--
2 files changed, 80 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 971fc8428117..743cd374d07d 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -75,12 +75,15 @@ ifneq ($(KBUILD_SRC),)
override LDFLAGS =
endif
-BUILD := $(O)
-ifndef BUILD
- BUILD := $(KBUILD_OUTPUT)
-endif
-ifndef BUILD
- BUILD := $(shell pwd)
+ifneq ($(O),)
+ BUILD := $(O)
+else
+ ifneq ($(KBUILD_OUTPUT),)
+ BUILD := $(KBUILD_OUTPUT)
+ else
+ BUILD := $(shell pwd)
+ DEFAULT_INSTALL_HDR_PATH := 1
+ endif
endif
# KSFT_TAP_LEVEL is used from KSFT framework to prevent nested TAP header
@@ -89,8 +92,41 @@ endif
# with system() call. Export it here to cover override RUN_TESTS defines.
export KSFT_TAP_LEVEL=`echo 1`
+# Prepare for headers install
+top_srcdir ?= ../../..
+include $(top_srcdir)/scripts/subarch.include
+ARCH ?= $(SUBARCH)
+export KSFT_KHDR_INSTALL_DONE := 1
export BUILD
-all:
+
+# set default goal to all, so make without a target runs all, even when
+# all isn't the first target in the file.
+.DEFAULT_GOAL := all
+
+# Install headers here once for all tests. KSFT_KHDR_INSTALL_DONE
+# is used to avoid running headers_install from lib.mk.
+# Invoke headers install with --no-builtin-rules to avoid circular
+# dependency in "make kselftest" case. In this case, second level
+# make inherits builtin-rules which will use the rule generate
+# Makefile.o and runs into
+# "Circular Makefile.o <- prepare dependency dropped."
+# and headers_install fails and test compile fails.
+#
+# O= KBUILD_OUTPUT cases don't run into this error, since main Makefile
+# invokes them as sub-makes and --no-builtin-rules is not necessary,
+# but doesn't cause any failures. Keep it simple and use the same
+# flags in both cases.
+# Local build cases: "make kselftest", "make -C" - headers are installed
+# in the default INSTALL_HDR_PATH usr/include.
+khdr:
+ifeq (1,$(DEFAULT_INSTALL_HDR_PATH))
+ make --no-builtin-rules ARCH=$(ARCH) -C $(top_srcdir) headers_install
+else
+ make --no-builtin-rules INSTALL_HDR_PATH=$$BUILD/usr \
+ ARCH=$(ARCH) -C $(top_srcdir) headers_install
+endif
+
+all: khdr
@for TARGET in $(TARGETS); do \
BUILD_TARGET=$$BUILD/$$TARGET; \
mkdir $$BUILD_TARGET -p; \
@@ -173,4 +209,4 @@ clean:
make OUTPUT=$$BUILD_TARGET -C $$TARGET clean;\
done;
-.PHONY: all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean
+.PHONY: khdr all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 8b0f16409ed7..5979fdc4f36c 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -3,7 +3,16 @@
CC := $(CROSS_COMPILE)gcc
ifeq (0,$(MAKELEVEL))
-OUTPUT := $(shell pwd)
+ ifneq ($(O),)
+ OUTPUT := $(O)
+ else
+ ifneq ($(KBUILD_OUTPUT),)
+ OUTPUT := $(KBUILD_OUTPUT)
+ else
+ OUTPUT := $(shell pwd)
+ DEFAULT_INSTALL_HDR_PATH := 1
+ endif
+ endif
endif
# The following are built by lib.mk common compile rules.
@@ -21,9 +30,34 @@ top_srcdir ?= ../../../..
include $(top_srcdir)/scripts/subarch.include
ARCH ?= $(SUBARCH)
+# set default goal to all, so make without a target runs all, even when
+# all isn't the first target in the file.
+.DEFAULT_GOAL := all
+
+# Invoke headers install with --no-builtin-rules to avoid circular
+# dependency in "make kselftest" case. In this case, second level
+# make inherits builtin-rules which will use the rule generate
+# Makefile.o and runs into
+# "Circular Makefile.o <- prepare dependency dropped."
+# and headers_install fails and test compile fails.
+# O= KBUILD_OUTPUT cases don't run into this error, since main Makefile
+# invokes them as sub-makes and --no-builtin-rules is not necessary,
+# but doesn't cause any failures. Keep it simple and use the same
+# flags in both cases.
+# Note that the support to install headers from lib.mk is necessary
+# when test Makefile is run directly with "make -C".
+# When local build is done, headers are installed in the default
+# INSTALL_HDR_PATH usr/include.
.PHONY: khdr
khdr:
- make ARCH=$(ARCH) -C $(top_srcdir) headers_install
+ifndef KSFT_KHDR_INSTALL_DONE
+ifeq (1,$(DEFAULT_INSTALL_HDR_PATH))
+ make --no-builtin-rules ARCH=$(ARCH) -C $(top_srcdir) headers_install
+else
+ make --no-builtin-rules INSTALL_HDR_PATH=$$OUTPUT/usr \
+ ARCH=$(ARCH) -C $(top_srcdir) headers_install
+endif
+endif
all: khdr $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES)
else
--
2.17.1
Hi Shuah,
This pull request moves the existing kexec_load test to the
selftests/kexec directory, defines a set of local "common" shell
functions, and defines a new kexec_file_load test. The local "common"
shell functions could be the basis for a generic set of "common" shell
functions.
Thanks,
Mimi
The following changes since commit 15ade5d2e7775667cf191cf2f94327a4889f8b9d:
Linux 5.1-rc4 (2019-04-07 14:09:59 -1000)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git next-integrity-for-shuah
for you to fetch changes up to eaa219ab1fd2c2a81704556aefd3dcde904dda33:
selftests/kexec: update get_secureboot_mode (2019-04-11 19:12:10 -0400)
----------------------------------------------------------------
Mimi Zohar (9):
selftests/kexec: move the IMA kexec_load selftest to selftests/kexec
selftests/kexec: cleanup the kexec selftest
selftests/kexec: define a set of common functions
selftests/kexec: define common logging functions
selftests/kexec: define "require_root_privileges"
selftests/kexec: kexec_file_load syscall test
selftests/kexec: check kexec_load and kexec_file_load are enabled
selftests/kexec: make kexec_load test independent of IMA being enabled
selftests/kexec: update get_secureboot_mode
Petr Vorel (1):
selftests/kexec: Add missing '=y' to config options
tools/testing/selftests/Makefile | 2 +-
tools/testing/selftests/ima/config | 4 -
tools/testing/selftests/ima/test_kexec_load.sh | 54 -----
tools/testing/selftests/{ima => kexec}/Makefile | 5 +-
tools/testing/selftests/kexec/config | 3 +
tools/testing/selftests/kexec/kexec_common_lib.sh | 220 +++++++++++++++++++++
.../selftests/kexec/test_kexec_file_load.sh | 208 +++++++++++++++++++
tools/testing/selftests/kexec/test_kexec_load.sh | 47 +++++
8 files changed, 482 insertions(+), 61 deletions(-)
delete mode 100644 tools/testing/selftests/ima/config
delete mode 100755 tools/testing/selftests/ima/test_kexec_load.sh
rename tools/testing/selftests/{ima => kexec}/Makefile (59%)
create mode 100644 tools/testing/selftests/kexec/config
create mode 100755 tools/testing/selftests/kexec/kexec_common_lib.sh
create mode 100755 tools/testing/selftests/kexec/test_kexec_file_load.sh
create mode 100755 tools/testing/selftests/kexec/test_kexec_load.sh
Fix KBUILD_OUTPUT usage instructions. The current documentation is
incorrect. Update and fix outdated information about summary option.
Add a reference to kselftest wiki for additional information on the
framework and tips on writing new tests.
Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org>
---
Changes since v1:
-- Fixed the confusing language about output directory
-- Updated outdated instructions on summary option.
-- Regenerated patch with current email address.
Documentation/dev-tools/kselftest.rst | 42 ++++++++++++++++++---------
1 file changed, 29 insertions(+), 13 deletions(-)
diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst
index c8c03388b9de..25604904fa6e 100644
--- a/Documentation/dev-tools/kselftest.rst
+++ b/Documentation/dev-tools/kselftest.rst
@@ -7,6 +7,11 @@ directory. These are intended to be small tests to exercise individual code
paths in the kernel. Tests are intended to be run after building, installing
and booting a kernel.
+You can find additional information on Kselftest framework, how to
+write new tests using the framework on Kselftest wiki:
+
+https://kselftest.wiki.kernel.org/
+
On some systems, hot-plug tests could hang forever waiting for cpu and
memory to be ready to be offlined. A special hot-plug target is created
to run the full range of hot-plug tests. In default mode, hot-plug tests run
@@ -35,17 +40,32 @@ To build and run the tests with a single command, use::
Note that some tests will require root privileges.
-Build and run from user specific object directory (make O=dir)::
+Kselftest supports saving output files in a separate directory and then
+running tests. To locate output files in a separate directory two syntaxes
+are supported. In both cases the working directory must be the root of the
+kernel src. This is applicable to "Running a subset of selftests" section
+below.
+
+To build, save output files in a separate directory with O= ::
$ make O=/tmp/kselftest kselftest
-Build and run KBUILD_OUTPUT directory (make KBUILD_OUTPUT=)::
+To build, save output files in a separate directory with KBUILD_OUTPUT ::
+
+ $ export KBUILD_OUTPUT=/tmp/kselftest; make kselftest
- $ make KBUILD_OUTPUT=/tmp/kselftest kselftest
+The O= assignment takes precedence over the KBUILD_OUTPUT environment
+variable.
-The above commands run the tests and print pass/fail summary to make it
-easier to understand the test results. Please find the detailed individual
-test results for each test in /tmp/testname file(s).
+The above commands by default run the tests and print full pass/fail report.
+Kselftest supports "summary" option to make it easier to understand the test
+results. Please find the detailed individual test results for each test in
+/tmp/testname file(s) when summary option is specified. This is applicable
+to "Running a subset of selftests" section below.
+
+To run kselftest with summary option enabled ::
+
+ $ make summary=1 kselftest
Running a subset of selftests
=============================
@@ -61,17 +81,13 @@ You can specify multiple tests to build and run::
$ make TARGETS="size timers" kselftest
-Build and run from user specific object directory (make O=dir)::
+To build, save output files in a separate directory with O= ::
$ make O=/tmp/kselftest TARGETS="size timers" kselftest
-Build and run KBUILD_OUTPUT directory (make KBUILD_OUTPUT=)::
-
- $ make KBUILD_OUTPUT=/tmp/kselftest TARGETS="size timers" kselftest
+To build, save output files in a separate directory with KBUILD_OUTPUT ::
-The above commands run the tests and print pass/fail summary to make it
-easier to understand the test results. Please find the detailed individual
-test results for each test in /tmp/testname file(s).
+ $ export KBUILD_OUTPUT=/tmp/kselftest; make TARGETS="size timers" kselftest
See the top-level tools/testing/selftests/Makefile for the list of all
possible targets.
--
2.17.1
Test files created by test_create() and test_create_empty() tests will
stay in the $efivarfs_mount directory until the system was rebooted.
When the tester tries to run this efivarfs test again on the same
system, the immutable characteristics in that directory will cause some
"Operation not permitted" noises, and a false-positve test result as the
file was created in previous run.
--------------------
running test_create
--------------------
./efivarfs.sh: line 59: /sys/firmware/efi/efivars/test_create-210be57c-9849-4fc7-a635-e6382d1aec27: Operation not permitted
[PASS]
--------------------
running test_create_empty
--------------------
./efivarfs.sh: line 78: /sys/firmware/efi/efivars/test_create_empty-210be57c-9849-4fc7-a635-e6382d1aec27: Operation not permitted
[PASS]
--------------------
Create a file_cleanup() to remove those test files in the end of each
test to solve this issue.
For the test_create_read, we can move the clean up task to the end of
the test to ensure the system is clean.
Also, use this function to replace the existing file removal code.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
---
tools/testing/selftests/efivarfs/efivarfs.sh | 32 +++++++++++-----------------
1 file changed, 13 insertions(+), 19 deletions(-)
diff --git a/tools/testing/selftests/efivarfs/efivarfs.sh b/tools/testing/selftests/efivarfs/efivarfs.sh
index d386610..a90f394 100755
--- a/tools/testing/selftests/efivarfs/efivarfs.sh
+++ b/tools/testing/selftests/efivarfs/efivarfs.sh
@@ -7,6 +7,12 @@ test_guid=210be57c-9849-4fc7-a635-e6382d1aec27
# Kselftest framework requirement - SKIP code is 4.
ksft_skip=4
+file_cleanup()
+{
+ chattr -i $1
+ rm -f $1
+}
+
check_prereqs()
{
local msg="skip all tests:"
@@ -58,8 +64,10 @@ test_create()
if [ $(stat -c %s $file) -ne 5 ]; then
echo "$file has invalid size" >&2
+ file_cleanup $file
exit 1
fi
+ file_cleanup $file
}
test_create_empty()
@@ -72,16 +80,14 @@ test_create_empty()
echo "$file can not be created without writing" >&2
exit 1
fi
+ file_cleanup $file
}
test_create_read()
{
local file=$efivarfs_mount/$FUNCNAME-$test_guid
- if [ -f $file]; then
- chattr -i $file
- rm -rf $file
- fi
./create-read $file
+ file_cleanup $file
}
test_delete()
@@ -96,11 +102,7 @@ test_delete()
exit 1
fi
- rm $file 2>/dev/null
- if [ $? -ne 0 ]; then
- chattr -i $file
- rm $file
- fi
+ file_cleanup $file
if [ -e $file ]; then
echo "$file couldn't be deleted" >&2
@@ -154,11 +156,7 @@ test_valid_filenames()
echo "$file could not be created" >&2
ret=1
else
- rm $file 2>/dev/null
- if [ $? -ne 0 ]; then
- chattr -i $file
- rm $file
- fi
+ file_cleanup $file
fi
done
@@ -191,11 +189,7 @@ test_invalid_filenames()
if [ -e $file ]; then
echo "Creating $file should have failed" >&2
- rm $file 2>/dev/null
- if [ $? -ne 0 ]; then
- chattr -i $file
- rm $file
- fi
+ file_cleanup $file
ret=1
fi
done
--
2.7.4
Test files created by test_create*() tests will stay in the
$efivarfs_mount directory unless the system was rebooted.
When the tester tries to run this efivarfs test again on the same
system, the immutable characteristics in that directory will cause some
"Operation not permitted" noises and a false-positve test result to the
test_create_read() test.
--------------------
running test_create
--------------------
./efivarfs.sh: line 59: /sys/firmware/efi/efivars/test_create-210be57c-9849-4fc7-a635-e6382d1aec27: Operation not permitted
[PASS]
--------------------
running test_create_empty
--------------------
./efivarfs.sh: line 78: /sys/firmware/efi/efivars/test_create_empty-210be57c-9849-4fc7-a635-e6382d1aec27: Operation not permitted
[PASS]
--------------------
running test_create_read
--------------------
open(O_WRONLY): Operation not permitted
[FAIL]
--------------------
Create a file_cleanup() to remove those test files in the end of each
test to solve this issue.
Also, use this function to replace the existing file removal code.
Link: https://bugs.launchpad.net/bugs/1809704
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
---
tools/testing/selftests/efivarfs/efivarfs.sh | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
mode change 100755 => 100644 tools/testing/selftests/efivarfs/efivarfs.sh
diff --git a/tools/testing/selftests/efivarfs/efivarfs.sh b/tools/testing/selftests/efivarfs/efivarfs.sh
old mode 100755
new mode 100644
index a47029a..14fa6fe
--- a/tools/testing/selftests/efivarfs/efivarfs.sh
+++ b/tools/testing/selftests/efivarfs/efivarfs.sh
@@ -7,6 +7,12 @@ test_guid=210be57c-9849-4fc7-a635-e6382d1aec27
# Kselftest framework requirement - SKIP code is 4.
ksft_skip=4
+file_cleanup()
+{
+ chattr -i $1
+ rm $1
+}
+
check_prereqs()
{
local msg="skip all tests:"
@@ -58,8 +64,10 @@ test_create()
if [ $(stat -c %s $file) -ne 5 ]; then
echo "$file has invalid size" >&2
+ file_cleanup $file
exit 1
fi
+ file_cleanup $file
}
test_create_empty()
@@ -72,12 +80,14 @@ test_create_empty()
echo "$file can not be created without writing" >&2
exit 1
fi
+ file_cleanup $file
}
test_create_read()
{
local file=$efivarfs_mount/$FUNCNAME-$test_guid
./create-read $file
+ file_cleanup $file
}
test_delete()
@@ -94,8 +104,7 @@ test_delete()
rm $file 2>/dev/null
if [ $? -ne 0 ]; then
- chattr -i $file
- rm $file
+ file_cleanup $file
fi
if [ -e $file ]; then
@@ -152,8 +161,7 @@ test_valid_filenames()
else
rm $file 2>/dev/null
if [ $? -ne 0 ]; then
- chattr -i $file
- rm $file
+ file_cleanup $file
fi
fi
done
@@ -189,8 +197,7 @@ test_invalid_filenames()
echo "Creating $file should have failed" >&2
rm $file 2>/dev/null
if [ $? -ne 0 ]; then
- chattr -i $file
- rm $file
+ file_cleanup $file
fi
ret=1
fi
--
2.7.4
The run_netsocktests will be marked as passed regardless the actual test
result from the ./socket:
selftests: net: run_netsocktests
========================================
--------------------
running socket test
--------------------
[FAIL]
ok 1..6 selftests: net: run_netsocktests [PASS]
This is because the test script itself has been successfully executed.
Fix this by exit 1 when the test failed.
Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com>
---
tools/testing/selftests/net/run_netsocktests | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/run_netsocktests b/tools/testing/selftests/net/run_netsocktests
index b093f39c2..14e41fa 100755
--- a/tools/testing/selftests/net/run_netsocktests
+++ b/tools/testing/selftests/net/run_netsocktests
@@ -7,7 +7,7 @@ echo "--------------------"
./socket
if [ $? -ne 0 ]; then
echo "[FAIL]"
+ exit 1
else
echo "[PASS]"
fi
-
--
2.7.4
Summary
------------------------------------------------------------------------
git repo: not informed
git branch: not informed
git commit: not informed
git describe: not informed
Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190417
Regressions (compared to build next-20190416)
------------------------------------------------------------------------
No regressions
Fixes (compared to build next-20190416)
------------------------------------------------------------------------
No fixes
In total:
------------------------------------------------------------------------
Ran 0 total tests in the following environments and test suites.
pass 0
fail 0
xfail 0
skip 0
Environments
--------------
- dragonboard-410c - arm64
- hi6220-hikey - arm64
- i386
- juno-r2 - arm64
- x15 - arm
- x86_64
Test Suites
-----------
Failures
------------------------------------------------------------------------
juno-r2:
i386:
x86:
x15:
dragonboard-410c:
hi6220-hikey:
Skips
------------------------------------------------------------------------
No skips
--
Linaro LKFT
https://lkft.linaro.org
Fix KBUILD_OUTPUT usage instructions. The current documentation
is incorrect.
Signed-off-by: Shuah Khan <shuah(a)kernel.org>
---
Documentation/dev-tools/kselftest.rst | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst
index c8c03388b9de..6c910ddaa9f9 100644
--- a/Documentation/dev-tools/kselftest.rst
+++ b/Documentation/dev-tools/kselftest.rst
@@ -39,9 +39,9 @@ Build and run from user specific object directory (make O=dir)::
$ make O=/tmp/kselftest kselftest
-Build and run KBUILD_OUTPUT directory (make KBUILD_OUTPUT=)::
+Build and run from KBUILD_OUTPUT directory (make KBUILD_OUTPUT=)::
- $ make KBUILD_OUTPUT=/tmp/kselftest kselftest
+ $ export KBUILD_OUTPUT=/tmp/kselftest; make kselftest
The above commands run the tests and print pass/fail summary to make it
easier to understand the test results. Please find the detailed individual
@@ -65,9 +65,9 @@ Build and run from user specific object directory (make O=dir)::
$ make O=/tmp/kselftest TARGETS="size timers" kselftest
-Build and run KBUILD_OUTPUT directory (make KBUILD_OUTPUT=)::
+Build and run from KBUILD_OUTPUT directory (make KBUILD_OUTPUT=)::
- $ make KBUILD_OUTPUT=/tmp/kselftest TARGETS="size timers" kselftest
+ $ export KBUILD_OUTPUT=/tmp/kselftest; make TARGETS="size timers" kselftest
The above commands run the tests and print pass/fail summary to make it
easier to understand the test results. Please find the detailed individual
--
2.17.1
Introduce in-kernel headers and other artifacts which are made available
as an archive through proc (/proc/kheaders.tar.xz file). This archive makes
it possible to build kernel modules, run eBPF programs, and other
tracing programs that need to extend the kernel for tracing purposes
without any dependency on the file system having headers and build
artifacts.
On Android and embedded systems, it is common to switch kernels but not
have kernel headers available on the file system. Further once a
different kernel is booted, any headers stored on the file system will
no longer be useful. By storing the headers as a compressed archive
within the kernel, we can avoid these issues that have been a hindrance
for a long time.
The best way to use this feature is by building it in. Several users
have a need for this, when they switch debug kernels, they donot want to
update the filesystem or worry about it where to store the headers on
it. However, the feature is also buildable as a module in case the user
desires it not being part of the kernel image. This makes it possible to
load and unload the headers from memory on demand. A tracing program, or
a kernel module builder can load the module, do its operations, and then
unload the module to save kernel memory. The total memory needed is 3.8MB.
By having the archive available at a fixed location independent of
filesystem dependencies and conventions, all debugging tools can
directly refer to the fixed location for the archive, without concerning
with where the headers on a typical filesystem which significantly
simplifies tooling that needs kernel headers.
The code to read the headers is based on /proc/config.gz code and uses
the same technique to embed the headers.
To build a module, the below steps have been tested on an x86 machine:
modprobe kheaders
rm -rf $HOME/headers
mkdir -p $HOME/headers
tar -xvf /proc/kheaders.tar.xz -C $HOME/headers >/dev/null
cd my-kernel-module
make -C $HOME/headers M=$(pwd) modules
rmmod kheaders
Additional notes:
(1) external modules must be built on the same arch as the host that
built vmlinux. This can be done either in a qemu emulated chroot on the
target, or natively. This is due to host arch dependency of kernel
scripts.
(2)
If module building is used, since Module.symvers is not available in the
archive due to a cyclic dependency with building of the archive into the
kernel or module binaries, the modules built using the archive will not
contain symbol versioning (modversion). This is usually not an issue
since the idea of this patch is to build a kernel module on the fly and
load it into the same kernel. An appropriate warning is already printed
by the kernel to alert the user of modules not having modversions when
built using the archive. For building with modversions, the user can use
traditional header packages. For our tracing usecases, we build modules
on the fly with this so it is not a concern.
(3) I have left IKHD_ST and IKHD_ED markers as is to facilitate
future patches that would extract the headers from a kernel or module
image.
(v4 was Tested-by the following folks,
v5 only has minor changes and has passed my testing).
Tested-by: qais.yousef(a)arm.com
Tested-by: dietmar.eggemann(a)arm.com
Tested-by: linux(a)manojrajarao.com
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
v4 -> v5:
(Thanks to Masahiro Yamada for several excellent suggestions)
- used incbin instead of bin2c (Masahiro did similar idea)
- added module.lds if ia64 otherwise ia64 may fail to build.
- added clean-files rule to Makefile
- removed strip-comments script and doing it inline
- added set -e to header generated to die on errorsr
- fixed a minor issue where find command was noisy.
- removed unneeded tar.xz rule from kernel/.gitignore
- added Tested-by tags from ARM folks.
Changes since v3:
- Blank tar was being generated because of a one line I
forgot to push. It is updated now.
- Added module.lds since arm64 needs it to build modules.
Changes since v2:
(Thanks to Masahiro Yamada for several excellent suggestions)
- Added support for out of tree builds.
- Added incremental build support bringing down build time of
incremental builds from 50 seconds to 5 seconds.
- Fixed various small nits / cleanups.
- clean ups to kheaders.c pointed by Alexey Dobriyan.
- Fixed MODULE_LICENSE in test module and kheaders.c
- Dropped Module.symvers from archive due to circular dependency.
Changes since v1:
- removed IKH_EXTRA variable, not needed (Masahiro Yamada)
- small fix ups to selftest
- added target to main Makefile etc
- added MODULE_LICENSE to test module
- made selftest more quiet
Changes since RFC:
Both changes bring size down to 3.8MB:
- use xz for compression
- strip comments except SPDX lines
- Call out the module name in Kconfig
- Also added selftests in second patch to ensure headers are always
working.
init/Kconfig | 11 ++++++
kernel/.gitignore | 1 +
kernel/Makefile | 28 ++++++++++++++
kernel/kheaders.c | 73 +++++++++++++++++++++++++++++++++++
scripts/gen_ikh_data.sh | 84 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 197 insertions(+)
create mode 100644 kernel/kheaders.c
create mode 100755 scripts/gen_ikh_data.sh
diff --git a/init/Kconfig b/init/Kconfig
index 4592bf7997c0..ea75bfbf7dfa 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -580,6 +580,17 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
+config IKHEADERS_PROC
+ tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
+ depends on PROC_FS
+ help
+ This option enables access to the kernel header and other artifacts that
+ are generated during the build process. These can be used to build kernel
+ modules or by other in-kernel programs such as those generated by eBPF
+ and systemtap tools. If you build the headers as a module, a module
+ called kheaders.ko is built which can be loaded on-demand to get access
+ to the headers.
+
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
range 12 25
diff --git a/kernel/.gitignore b/kernel/.gitignore
index 6e699100872f..34d1e77ee9df 100644
--- a/kernel/.gitignore
+++ b/kernel/.gitignore
@@ -1,5 +1,6 @@
#
# Generated files
#
+kheaders.md5
timeconst.h
hz.bc
diff --git a/kernel/Makefile b/kernel/Makefile
index 6c57e78817da..7c486bc25fd7 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
+obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -121,3 +122,30 @@ $(obj)/configs.o: $(obj)/config_data.gz
targets += config_data.gz
$(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(call if_changed,gzip)
+
+# Build a list of in-kernel headers for building kernel modules
+ikh_file_list := include/
+ikh_file_list += arch/$(SRCARCH)/Makefile
+ikh_file_list += arch/$(SRCARCH)/include/
+ikh_file_list += arch/$(SRCARCH)/module.lds
+ikh_file_list += arch/$(SRCARCH)/kernel/module.lds
+ikh_file_list += scripts/
+ikh_file_list += Makefile
+
+# Things we need from the $objtree. "OBJDIR" is for the gen_ikh_data.sh
+# script to identify that this comes from the $objtree directory
+ikh_file_list += OBJDIR/scripts/
+ikh_file_list += OBJDIR/include/
+ikh_file_list += OBJDIR/arch/$(SRCARCH)/include/
+ifeq ($(CONFIG_STACK_VALIDATION), y)
+ikh_file_list += OBJDIR/tools/objtool/objtool
+endif
+
+$(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
+
+quiet_cmd_genikh = GEN $(obj)/kheaders_data.tar.xz
+cmd_genikh = $(srctree)/scripts/gen_ikh_data.sh $@ $(ikh_file_list)
+$(obj)/kheaders_data.tar.xz: FORCE
+ $(call cmd,genikh)
+
+clean-files := kheaders_data.tar.xz kheaders.md5
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
new file mode 100644
index 000000000000..d072a958a8f1
--- /dev/null
+++ b/kernel/kheaders.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * kernel/kheaders.c
+ * Provide headers and artifacts needed to build kernel modules.
+ * (Borrowed code from kernel/configs.c)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/uaccess.h>
+
+/*
+ * Define kernel_headers_data and kernel_headers_data_end, within which the the
+ * compressed kernel headers are stpred. The file is first compressed with xz.
+ */
+
+asm (
+" .pushsection .rodata, \"a\" \n"
+" .global kernel_headers_data \n"
+"kernel_headers_data: \n"
+" .incbin \"kernel/kheaders_data.tar.xz\" \n"
+" .global kernel_headers_data_end \n"
+"kernel_headers_data_end: \n"
+" .popsection \n"
+);
+
+extern char kernel_headers_data;
+extern char kernel_headers_data_end;
+
+static ssize_t
+ikheaders_read_current(struct file *file, char __user *buf,
+ size_t len, loff_t *offset)
+{
+ return simple_read_from_buffer(buf, len, offset,
+ &kernel_headers_data,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+}
+
+static const struct file_operations ikheaders_file_ops = {
+ .read = ikheaders_read_current,
+ .llseek = default_llseek,
+};
+
+static int __init ikheaders_init(void)
+{
+ struct proc_dir_entry *entry;
+
+ /* create the current headers file */
+ entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
+ &ikheaders_file_ops);
+ if (!entry)
+ return -ENOMEM;
+
+ proc_set_size(entry,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+ return 0;
+}
+
+static void __exit ikheaders_cleanup(void)
+{
+ remove_proc_entry("kheaders.tar.xz", NULL);
+}
+
+module_init(ikheaders_init);
+module_exit(ikheaders_cleanup);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joel Fernandes");
+MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");
diff --git a/scripts/gen_ikh_data.sh b/scripts/gen_ikh_data.sh
new file mode 100755
index 000000000000..3f9cae72c2a4
--- /dev/null
+++ b/scripts/gen_ikh_data.sh
@@ -0,0 +1,84 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This script generates an archive consisting of kernel headers
+# for CONFIG_IKHEADERS_PROC.
+set -e
+
+spath="$(dirname "$(readlink -f "$0")")"
+kroot="$spath/.."
+outdir="$(pwd)"
+tarfile=$1
+cpio_dir=$outdir/$tarfile.tmp
+
+file_list=${@:2}
+
+src_file_list=""
+for f in $file_list; do
+ if [ ! -f "$kroot/$f" ] && [ ! -d "$kroot/$f" ]; then continue; fi
+ src_file_list="$src_file_list $(echo $f | grep -v OBJDIR)"
+done
+
+obj_file_list=""
+for f in $file_list; do
+ f=$(echo $f | grep OBJDIR | sed -e 's/OBJDIR\///g')
+ if [ ! -f $f ] && [ ! -d $f ]; then continue; fi
+ obj_file_list="$obj_file_list $f";
+done
+
+# Support incremental builds by skipping archive generation
+# if timestamps of files being archived are not changed.
+
+# This block is useful for debugging the incremental builds.
+# Uncomment it for debugging.
+# iter=1
+# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter;
+# else; iter=$(($(cat /tmp/iter) + 1)); fi
+# find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter
+# find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter
+
+# modules.order and include/generated/compile.h are ignored because these are
+# touched even when none of the source files changed. This causes pointless
+# regeneration, so let us ignore them for md5 calculation.
+pushd $kroot > /dev/null
+src_files_md5="$(find $src_file_list -type f ! -name modules.order |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+popd > /dev/null
+obj_files_md5="$(find $obj_file_list -type f ! -name modules.order |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+
+if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
+if [ -f kernel/kheaders.md5 ] &&
+ [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
+ exit
+fi
+
+rm -rf $cpio_dir
+mkdir $cpio_dir
+
+pushd $kroot > /dev/null
+for f in $src_file_list;
+ do find "$f" ! -name "*.c" ! -name "*.o" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir
+popd > /dev/null
+
+# The second CPIO can complain if files already exist which can
+# happen with out of tree builds. Just silence CPIO for now.
+for f in $obj_file_list;
+ do find "$f" ! -name "*.c" ! -name "*.o" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
+
+find $cpio_dir -type f -print0 |
+ xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
+
+tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
+
+echo "$src_files_md5" > kernel/kheaders.md5
+echo "$obj_files_md5" >> kernel/kheaders.md5
+echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
+
+rm -rf $cpio_dir
--
2.21.0.225.g810b269d1ac-goog
"make kselftest" fails with "Circular Makefile.o <- prepare dependency
dropped." error, when lib.mk invokes "make headers_install".
Make level 0: Main make calls selftests run_tests target
...
Make level n: selftests lib.mk invokes main make's headers_install
The secondary level make inherits builtin-rules which will use the rule
to generate Makefile.o and runs into "Circular Makefile.o <- prepare
dependency dropped." error, and kselftest compile fails.
Invoke headers_install target with --no-builtin-rules to avoid circular
error.
In addition, lib.mk installs headers in the default HDR_PATH, even when
build relocation is requested with O= or export KBUILD_OUTPUT. Fix the
problem by passing in INSTALL_HDR_PATH. The headers are installed under
the specified output "dir/usr".
Signed-off-by: Shuah Khan <shuah(a)kernel.org>
---
tools/testing/selftests/Makefile | 52 +++++++++++++++++++++++++++-----
tools/testing/selftests/lib.mk | 34 +++++++++++++++++++--
2 files changed, 76 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 971fc8428117..743cd374d07d 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -75,12 +75,15 @@ ifneq ($(KBUILD_SRC),)
override LDFLAGS =
endif
-BUILD := $(O)
-ifndef BUILD
- BUILD := $(KBUILD_OUTPUT)
-endif
-ifndef BUILD
- BUILD := $(shell pwd)
+ifneq ($(O),)
+ BUILD := $(O)
+else
+ ifneq ($(KBUILD_OUTPUT),)
+ BUILD := $(KBUILD_OUTPUT)
+ else
+ BUILD := $(shell pwd)
+ DEFAULT_INSTALL_HDR_PATH := 1
+ endif
endif
# KSFT_TAP_LEVEL is used from KSFT framework to prevent nested TAP header
@@ -89,8 +92,41 @@ endif
# with system() call. Export it here to cover override RUN_TESTS defines.
export KSFT_TAP_LEVEL=`echo 1`
+# Prepare for headers install
+top_srcdir ?= ../../..
+include $(top_srcdir)/scripts/subarch.include
+ARCH ?= $(SUBARCH)
+export KSFT_KHDR_INSTALL_DONE := 1
export BUILD
-all:
+
+# set default goal to all, so make without a target runs all, even when
+# all isn't the first target in the file.
+.DEFAULT_GOAL := all
+
+# Install headers here once for all tests. KSFT_KHDR_INSTALL_DONE
+# is used to avoid running headers_install from lib.mk.
+# Invoke headers install with --no-builtin-rules to avoid circular
+# dependency in "make kselftest" case. In this case, second level
+# make inherits builtin-rules which will use the rule generate
+# Makefile.o and runs into
+# "Circular Makefile.o <- prepare dependency dropped."
+# and headers_install fails and test compile fails.
+#
+# O= KBUILD_OUTPUT cases don't run into this error, since main Makefile
+# invokes them as sub-makes and --no-builtin-rules is not necessary,
+# but doesn't cause any failures. Keep it simple and use the same
+# flags in both cases.
+# Local build cases: "make kselftest", "make -C" - headers are installed
+# in the default INSTALL_HDR_PATH usr/include.
+khdr:
+ifeq (1,$(DEFAULT_INSTALL_HDR_PATH))
+ make --no-builtin-rules ARCH=$(ARCH) -C $(top_srcdir) headers_install
+else
+ make --no-builtin-rules INSTALL_HDR_PATH=$$BUILD/usr \
+ ARCH=$(ARCH) -C $(top_srcdir) headers_install
+endif
+
+all: khdr
@for TARGET in $(TARGETS); do \
BUILD_TARGET=$$BUILD/$$TARGET; \
mkdir $$BUILD_TARGET -p; \
@@ -173,4 +209,4 @@ clean:
make OUTPUT=$$BUILD_TARGET -C $$TARGET clean;\
done;
-.PHONY: all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean
+.PHONY: khdr all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 8b0f16409ed7..f888522a34e9 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -3,7 +3,16 @@
CC := $(CROSS_COMPILE)gcc
ifeq (0,$(MAKELEVEL))
-OUTPUT := $(shell pwd)
+ ifneq ($(O),)
+ OUTPUT := $(O)
+ else
+ ifneq ($(KBUILD_OUTPUT),)
+ OUTPUT := $(KBUILD_OUTPUT)
+ else
+ OUTPUT := $(shell pwd)
+ DEFAULT_INSTALL_HDR_PATH := 1
+ endif
+ endif
endif
# The following are built by lib.mk common compile rules.
@@ -21,9 +30,30 @@ top_srcdir ?= ../../../..
include $(top_srcdir)/scripts/subarch.include
ARCH ?= $(SUBARCH)
+# Invoke headers install with --no-builtin-rules to avoid circular
+# dependency in "make kselftest" case. In this case, second level
+# make inherits builtin-rules which will use the rule generate
+# Makefile.o and runs into
+# "Circular Makefile.o <- prepare dependency dropped."
+# and headers_install fails and test compile fails.
+# O= KBUILD_OUTPUT cases don't run into this error, since main Makefile
+# invokes them as sub-makes and --no-builtin-rules is not necessary,
+# but doesn't cause any failures. Keep it simple and use the same
+# flags in both cases.
+# Note that the support to install headers from lib.mk is necessary
+# when test Makefile is run directly with "make -C".
+# When local build is done, headers are installed in the default
+# INSTALL_HDR_PATH usr/include.
.PHONY: khdr
khdr:
- make ARCH=$(ARCH) -C $(top_srcdir) headers_install
+ifndef KSFT_KHDR_INSTALL_DONE
+ifeq (1,$(DEFAULT_INSTALL_HDR_PATH))
+ make --no-builtin-rules ARCH=$(ARCH) -C $(top_srcdir) headers_install
+else
+ make --no-builtin-rules INSTALL_HDR_PATH=$$OUTPUT/usr \
+ ARCH=$(ARCH) -C $(top_srcdir) headers_install
+endif
+endif
all: khdr $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES)
else
--
2.17.1
Summary
------------------------------------------------------------------------
git repo: not informed
git branch: not informed
git commit: not informed
git describe: not informed
Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190416
Regressions (compared to build next-20190415)
------------------------------------------------------------------------
No regressions
Fixes (compared to build next-20190415)
------------------------------------------------------------------------
No fixes
In total:
------------------------------------------------------------------------
Ran 0 total tests in the following environments and test suites.
pass 0
fail 0
xfail 0
skip 0
Environments
--------------
- dragonboard-410c - arm64
- hi6220-hikey - arm64
- i386
- juno-r2 - arm64
- x15 - arm
- x86_64
Test Suites
-----------
Failures
------------------------------------------------------------------------
x86:
i386:
dragonboard-410c:
hi6220-hikey:
juno-r2:
x15:
Skips
------------------------------------------------------------------------
No skips
--
Linaro LKFT
https://lkft.linaro.org
TEST_PROGS variable is for test shell scripts and common clean target
in lib.mk doesn't touch them. TEST_GEN_PROGS are removed by it.
Fix it to use TEST_PROGS for test shell scripts and TEST_PROGS_EXTENDED
for common functions.sh.
Signed-off-by: Shuah Khan <shuah(a)kernel.org>
---
tools/testing/selftests/livepatch/Makefile | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile
index af4aee79bebb..fd405402c3ff 100644
--- a/tools/testing/selftests/livepatch/Makefile
+++ b/tools/testing/selftests/livepatch/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
-TEST_GEN_PROGS := \
+TEST_PROGS_EXTENDED := functions.sh
+TEST_PROGS := \
test-livepatch.sh \
test-callbacks.sh \
test-shadow-vars.sh
--
2.17.1
Summary
------------------------------------------------------------------------
git repo: not informed
git branch: not informed
git commit: not informed
git describe: not informed
Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190415
Regressions (compared to build next-20190412)
------------------------------------------------------------------------
No regressions
Fixes (compared to build next-20190412)
------------------------------------------------------------------------
No fixes
In total:
------------------------------------------------------------------------
Ran 0 total tests in the following environments and test suites.
pass 0
fail 0
xfail 0
skip 0
Environments
--------------
- dragonboard-410c - arm64
- hi6220-hikey - arm64
- i386
- juno-r2 - arm64
- x15 - arm
- x86_64
Test Suites
-----------
Failures
------------------------------------------------------------------------
i386:
juno-r2:
hi6220-hikey:
x15:
x86:
dragonboard-410c:
Skips
------------------------------------------------------------------------
No skips
--
Linaro LKFT
https://lkft.linaro.org
---------- Forwarded message ---------
From: Jeffrin Thalakkottoor <jeffrin(a)rajagiritech.edu.in>
Date: Sat, Apr 13, 2019 at 6:09 PM
Subject: Re: [PATCH] selftests : netfilter: Wrote a error and exit
code for a command which needed veth kernel module.
To: Shuah Khan <shuah(a)kernel.org>
Cc: Florian Westphal <fw(a)strlen.de>, <linu-kselftest(a)vger.kernel.org>,
<pablo(a)netfilter.org>, lkml <linux-kernel(a)vger.kernel.org>
Hello Shuah,
did you get the mail related stuff below ?
On Fri, Apr 5, 2019 at 10:17 PM Florian Westphal <fw(a)strlen.de> wrote:
>
> Jeffrin Jose T <jeffrin(a)rajagiritech.edu.in> wrote:
> > A test for the basic NAT functionality uses ip command which
> > needs veth device.There is a condition where the kernel support
> > for veth is not compiled into the kernel and the test script
> > breaks.This patch contains code for reasonable error display
> > and correct code exit.
>
> Looks good to me, thanks for following up on this.
>
> Acked-by: Florian Westphal <fw(a)strlen.de>
--
software engineer
rajagiri school of engineering and technology
--
software engineer
rajagiri school of engineering and technology
Introduce in-kernel headers which are made available as an archive
through proc (/proc/kheaders.tar.xz file). This archive makes it
possible to run eBPF and other tracing programs tracing programs that
need to extend the kernel for tracing purposes without any dependency on
the file system having headers.
On Android and embedded systems, it is common to switch kernels but not
have kernel headers available on the file system. Further once a
different kernel is booted, any headers stored on the file system will
no longer be useful. By storing the headers as a compressed archive
within the kernel, we can avoid these issues that have been a hindrance
for a long time.
The best way to use this feature is by building it in. Several users
have a need for this, when they switch debug kernels, they donot want to
update the filesystem or worry about it where to store the headers on
it. However, the feature is also buildable as a module in case the user
desires it not being part of the kernel image. This makes it possible to
load and unload the headers from memory on demand. A tracing program, or
a kernel module builder can load the module, do its operations, and then
unload the module to save kernel memory. The total memory needed is 3.8MB.
By having the archive available at a fixed location independent of
filesystem dependencies and conventions, all debugging tools can
directly refer to the fixed location for the archive, without concerning
with where the headers on a typical filesystem which significantly
simplifies tooling that needs kernel headers.
The code to read the headers is based on /proc/config.gz code and uses
the same technique to embed the headers.
IKHD_ST and IKHD_ED markers as is to facilitate future patches that
would extract the headers from a kernel or module image.
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
v5 -> v6: (Masahiro Yamada suggestions mostly)
- Dropped support for module building.
- Rebuild archive if script changes.
- Move archive file list to script.
- Move build script to kernel directory.
v4 -> v5:
(v4 was Tested-by the following folks)
Tested-by: qais.yousef(a)arm.com
Tested-by: dietmar.eggemann(a)arm.com
Tested-by: linux(a)manojrajarao.com
(Thanks to Masahiro Yamada for several excellent suggestions)
- used incbin instead of bin2c (Masahiro did similar idea)
- added module.lds if ia64 otherwise ia64 may fail to build.
- added clean-files rule to Makefile
- removed strip-comments script and doing it inline
- added set -e to header generated to die on errorsr
- fixed a minor issue where find command was noisy.
- removed unneeded tar.xz rule from kernel/.gitignore
- added Tested-by tags from ARM folks.
Changes since v3:
- Blank tar was being generated because of a one line I
forgot to push. It is updated now.
- Added module.lds since arm64 needs it to build modules.
Changes since v2:
(Thanks to Masahiro Yamada for several excellent suggestions)
- Added support for out of tree builds.
- Added incremental build support bringing down build time of
incremental builds from 50 seconds to 5 seconds.
- Fixed various small nits / cleanups.
- clean ups to kheaders.c pointed by Alexey Dobriyan.
- Fixed MODULE_LICENSE in test module and kheaders.c
- Dropped Module.symvers from archive due to circular dependency.
Changes since v1:
- removed IKH_EXTRA variable, not needed (Masahiro Yamada)
- small fix ups to selftest
- added target to main Makefile etc
- added MODULE_LICENSE to test module
- made selftest more quiet
Changes since RFC:
Both changes bring size down to 3.8MB:
- use xz for compression
- strip comments except SPDX lines
- Call out the module name in Kconfig
- Also added selftests in second patch to ensure headers are always
working.
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
init/Kconfig | 11 ++++++
kernel/.gitignore | 1 +
kernel/Makefile | 10 +++++
kernel/gen_ikh_data.sh | 84 ++++++++++++++++++++++++++++++++++++++++++
kernel/kheaders.c | 73 ++++++++++++++++++++++++++++++++++++
5 files changed, 179 insertions(+)
create mode 100755 kernel/gen_ikh_data.sh
create mode 100644 kernel/kheaders.c
diff --git a/init/Kconfig b/init/Kconfig
index 4592bf7997c0..ea75bfbf7dfa 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -580,6 +580,17 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
+config IKHEADERS_PROC
+ tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
+ depends on PROC_FS
+ help
+ This option enables access to the kernel header and other artifacts that
+ are generated during the build process. These can be used to build kernel
+ modules or by other in-kernel programs such as those generated by eBPF
+ and systemtap tools. If you build the headers as a module, a module
+ called kheaders.ko is built which can be loaded on-demand to get access
+ to the headers.
+
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
range 12 25
diff --git a/kernel/.gitignore b/kernel/.gitignore
index 6e699100872f..34d1e77ee9df 100644
--- a/kernel/.gitignore
+++ b/kernel/.gitignore
@@ -1,5 +1,6 @@
#
# Generated files
#
+kheaders.md5
timeconst.h
hz.bc
diff --git a/kernel/Makefile b/kernel/Makefile
index 6c57e78817da..e3c581d8cde7 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
+obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -121,3 +122,12 @@ $(obj)/configs.o: $(obj)/config_data.gz
targets += config_data.gz
$(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(call if_changed,gzip)
+
+$(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
+
+quiet_cmd_genikh = GEN $(obj)/kheaders_data.tar.xz
+cmd_genikh = $(srctree)/kernel/gen_ikh_data.sh $@
+$(obj)/kheaders_data.tar.xz: FORCE
+ $(call cmd,genikh)
+
+clean-files := kheaders_data.tar.xz kheaders.md5
diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_ikh_data.sh
new file mode 100755
index 000000000000..ef72c2740d01
--- /dev/null
+++ b/kernel/gen_ikh_data.sh
@@ -0,0 +1,84 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This script generates an archive consisting of kernel headers
+# for CONFIG_IKHEADERS_PROC.
+set -e
+spath="$(dirname "$(readlink -f "$0")")"
+kroot="$spath/.."
+outdir="$(pwd)"
+tarfile=$1
+cpio_dir=$outdir/$tarfile.tmp
+
+# Script filename relative to the kernel source root
+# We add it to the archive because it is small and any changes
+# to this script will also cause a rebuild of the archive.
+sfile="$(realpath --relative-to $kroot "$(readlink -f "$0")")"
+
+src_file_list="
+include/
+arch/$SRCARCH/include/
+$sfile
+"
+
+obj_file_list="
+include/
+arch/$SRCARCH/include/
+"
+
+# Support incremental builds by skipping archive generation
+# if timestamps of files being archived are not changed.
+
+# This block is useful for debugging the incremental builds.
+# Uncomment it for debugging.
+# iter=1
+# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter;
+# else; iter=$(($(cat /tmp/iter) + 1)); fi
+# find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter
+# find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter
+
+# include/generated/compile.h is ignored because it is touched even when none
+# of the source files changed. This causes pointless regeneration, so let us
+# ignore them for md5 calculation.
+pushd $kroot > /dev/null
+src_files_md5="$(find $src_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+popd > /dev/null
+obj_files_md5="$(find $obj_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+
+if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
+if [ -f kernel/kheaders.md5 ] &&
+ [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
+ exit
+fi
+
+rm -rf $cpio_dir
+mkdir $cpio_dir
+
+pushd $kroot > /dev/null
+for f in $src_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir
+popd > /dev/null
+
+# The second CPIO can complain if files already exist which can
+# happen with out of tree builds. Just silence CPIO for now.
+for f in $obj_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
+
+find $cpio_dir -type f -print0 |
+ xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
+
+tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
+
+echo "$src_files_md5" > kernel/kheaders.md5
+echo "$obj_files_md5" >> kernel/kheaders.md5
+echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
+
+rm -rf $cpio_dir
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
new file mode 100644
index 000000000000..d072a958a8f1
--- /dev/null
+++ b/kernel/kheaders.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * kernel/kheaders.c
+ * Provide headers and artifacts needed to build kernel modules.
+ * (Borrowed code from kernel/configs.c)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/uaccess.h>
+
+/*
+ * Define kernel_headers_data and kernel_headers_data_end, within which the the
+ * compressed kernel headers are stpred. The file is first compressed with xz.
+ */
+
+asm (
+" .pushsection .rodata, \"a\" \n"
+" .global kernel_headers_data \n"
+"kernel_headers_data: \n"
+" .incbin \"kernel/kheaders_data.tar.xz\" \n"
+" .global kernel_headers_data_end \n"
+"kernel_headers_data_end: \n"
+" .popsection \n"
+);
+
+extern char kernel_headers_data;
+extern char kernel_headers_data_end;
+
+static ssize_t
+ikheaders_read_current(struct file *file, char __user *buf,
+ size_t len, loff_t *offset)
+{
+ return simple_read_from_buffer(buf, len, offset,
+ &kernel_headers_data,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+}
+
+static const struct file_operations ikheaders_file_ops = {
+ .read = ikheaders_read_current,
+ .llseek = default_llseek,
+};
+
+static int __init ikheaders_init(void)
+{
+ struct proc_dir_entry *entry;
+
+ /* create the current headers file */
+ entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
+ &ikheaders_file_ops);
+ if (!entry)
+ return -ENOMEM;
+
+ proc_set_size(entry,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+ return 0;
+}
+
+static void __exit ikheaders_cleanup(void)
+{
+ remove_proc_entry("kheaders.tar.xz", NULL);
+}
+
+module_init(ikheaders_init);
+module_exit(ikheaders_cleanup);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joel Fernandes");
+MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");
--
2.21.0.392.gf8f6787159e-goog
Introduce in-kernel headers which are made available as an archive
through proc (/proc/kheaders.tar.xz file). This archive makes it
possible to run eBPF and other tracing programs that need to extend the
kernel for tracing purposes without any dependency on the file system
having headers.
A github PR is sent for the corresponding BCC patch at:
https://github.com/iovisor/bcc/pull/2312
On Android and embedded systems, it is common to switch kernels but not
have kernel headers available on the file system. Further once a
different kernel is booted, any headers stored on the file system will
no longer be useful. This is an issue even well known to distros.
By storing the headers as a compressed archive within the kernel, we can
avoid these issues that have been a hindrance for a long time.
The best way to use this feature is by building it in. Several users
have a need for this, when they switch debug kernels, they do not want to
update the filesystem or worry about it where to store the headers on
it. However, the feature is also buildable as a module in case the user
desires it not being part of the kernel image. This makes it possible to
load and unload the headers from memory on demand. A tracing program can
load the module, do its operations, and then unload the module to save
kernel memory. The total memory needed is 3.3MB.
By having the archive available at a fixed location independent of
filesystem dependencies and conventions, all debugging tools can
directly refer to the fixed location for the archive, without concerning
with where the headers on a typical filesystem which significantly
simplifies tooling that needs kernel headers.
The code to read the headers is based on /proc/config.gz code and uses
the same technique to embed the headers.
Other approaches were discussed such as having an in-memory mountable
filesystem, but that has drawbacks such as requiring an in-kernel xz
decompressor which we don't have today, and requiring usage of 42 MB of
kernel memory to host the decompressed headers at anytime. Also this
approach is simpler than such approaches.
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
---
v6 -> v7:
- Minor nits from Masahiro Yamada are addressed.
v5 -> v6: (Masahiro Yamada suggestions mostly)
- Dropped support for module building.
- Rebuild archive if script changes.
- Move archive file list to script.
- Move build script to kernel directory.
v4 -> v5:
(v4 was Tested-by the following folks)
Tested-by: qais.yousef(a)arm.com
Tested-by: dietmar.eggemann(a)arm.com
Tested-by: linux(a)manojrajarao.com
(Thanks to Masahiro Yamada for several excellent suggestions)
- used incbin instead of bin2c (Masahiro did similar idea)
- added module.lds if ia64 otherwise ia64 may fail to build.
- added clean-files rule to Makefile
- removed strip-comments script and doing it inline
- added set -e to header generated to die on errorsr
- fixed a minor issue where find command was noisy.
- removed unneeded tar.xz rule from kernel/.gitignore
- added Tested-by tags from ARM folks.
Changes since v3:
- Blank tar was being generated because of a one line I
forgot to push. It is updated now.
- Added module.lds since arm64 needs it to build modules.
Changes since v2:
(Thanks to Masahiro Yamada for several excellent suggestions)
- Added support for out of tree builds.
- Added incremental build support bringing down build time of
incremental builds from 50 seconds to 5 seconds.
- Fixed various small nits / cleanups.
- clean ups to kheaders.c pointed by Alexey Dobriyan.
- Fixed MODULE_LICENSE in test module and kheaders.c
- Dropped Module.symvers from archive due to circular dependency.
Changes since v1:
- removed IKH_EXTRA variable, not needed (Masahiro Yamada)
- small fix ups to selftest
- added target to main Makefile etc
- added MODULE_LICENSE to test module
- made selftest more quiet
Changes since RFC:
Both changes bring size down to 3.8MB:
- use xz for compression
- strip comments except SPDX lines
- Call out the module name in Kconfig
- Also added selftests in second patch to ensure headers are always
working.
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
init/Kconfig | 10 +++++
kernel/.gitignore | 1 +
kernel/Makefile | 10 +++++
kernel/gen_ikh_data.sh | 89 ++++++++++++++++++++++++++++++++++++++++++
kernel/kheaders.c | 74 +++++++++++++++++++++++++++++++++++
5 files changed, 184 insertions(+)
create mode 100755 kernel/gen_ikh_data.sh
create mode 100644 kernel/kheaders.c
diff --git a/init/Kconfig b/init/Kconfig
index 4592bf7997c0..47c0db6e63a5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -580,6 +580,16 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
+config IKHEADERS_PROC
+ tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
+ depends on PROC_FS
+ help
+ This option enables access to the kernel header and other artifacts that
+ are generated during the build process. These can be used to build eBPF
+ tracing programs, or similar programs. If you build the headers as a
+ module, a module called kheaders.ko is built which can be loaded on-demand
+ to get access to the headers.
+
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
range 12 25
diff --git a/kernel/.gitignore b/kernel/.gitignore
index 6e699100872f..34d1e77ee9df 100644
--- a/kernel/.gitignore
+++ b/kernel/.gitignore
@@ -1,5 +1,6 @@
#
# Generated files
#
+kheaders.md5
timeconst.h
hz.bc
diff --git a/kernel/Makefile b/kernel/Makefile
index 6c57e78817da..12399614c350 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
+obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -121,3 +122,12 @@ $(obj)/configs.o: $(obj)/config_data.gz
targets += config_data.gz
$(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(call if_changed,gzip)
+
+$(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
+
+quiet_cmd_genikh = CHK $(obj)/kheaders_data.tar.xz
+cmd_genikh = $(srctree)/kernel/gen_ikh_data.sh $@
+$(obj)/kheaders_data.tar.xz: FORCE
+ $(call cmd,genikh)
+
+clean-files := kheaders_data.tar.xz kheaders.md5
diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_ikh_data.sh
new file mode 100755
index 000000000000..591a94f7b387
--- /dev/null
+++ b/kernel/gen_ikh_data.sh
@@ -0,0 +1,89 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This script generates an archive consisting of kernel headers
+# for CONFIG_IKHEADERS_PROC.
+set -e
+spath="$(dirname "$(readlink -f "$0")")"
+kroot="$spath/.."
+outdir="$(pwd)"
+tarfile=$1
+cpio_dir=$outdir/$tarfile.tmp
+
+# Script filename relative to the kernel source root
+# We add it to the archive because it is small and any changes
+# to this script will also cause a rebuild of the archive.
+sfile="$(realpath --relative-to $kroot "$(readlink -f "$0")")"
+
+src_file_list="
+include/
+arch/$SRCARCH/include/
+$sfile
+"
+
+obj_file_list="
+include/
+arch/$SRCARCH/include/
+"
+
+# Support incremental builds by skipping archive generation
+# if timestamps of files being archived are not changed.
+
+# This block is useful for debugging the incremental builds.
+# Uncomment it for debugging.
+# iter=1
+# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter;
+# else; iter=$(($(cat /tmp/iter) + 1)); fi
+# find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter
+# find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter
+
+# include/generated/compile.h is ignored because it is touched even when none
+# of the source files changed. This causes pointless regeneration, so let us
+# ignore them for md5 calculation.
+pushd $kroot > /dev/null
+src_files_md5="$(find $src_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+popd > /dev/null
+obj_files_md5="$(find $obj_file_list -type f |
+ grep -v "include/generated/compile.h" |
+ xargs ls -lR | md5sum | cut -d ' ' -f1)"
+
+if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
+if [ -f kernel/kheaders.md5 ] &&
+ [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
+ [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
+ exit
+fi
+
+if [ "${quiet}" != "silent_" ]; then
+ echo " GEN $tarfile"
+fi
+
+rm -rf $cpio_dir
+mkdir $cpio_dir
+
+pushd $kroot > /dev/null
+for f in $src_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir
+popd > /dev/null
+
+# The second CPIO can complain if files already exist which can
+# happen with out of tree builds. Just silence CPIO for now.
+for f in $obj_file_list;
+ do find "$f" ! -name "*.cmd" ! -name ".*";
+done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
+
+# Remove comments except SDPX lines
+find $cpio_dir -type f -print0 |
+ xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
+
+tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
+
+echo "$src_files_md5" > kernel/kheaders.md5
+echo "$obj_files_md5" >> kernel/kheaders.md5
+echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
+
+rm -rf $cpio_dir
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
new file mode 100644
index 000000000000..19526294a4e8
--- /dev/null
+++ b/kernel/kheaders.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Provide kernel headers useful to build tracing programs
+ * such as for running eBPF tracing tools.
+ *
+ * (Borrowed code from kernel/configs.c)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/uaccess.h>
+
+/*
+ * Define kernel_headers_data and kernel_headers_data_end, within which the the
+ * compressed kernel headers are stpred. The file is first compressed with xz.
+ */
+
+asm (
+" .pushsection .rodata, \"a\" \n"
+" .global kernel_headers_data \n"
+"kernel_headers_data: \n"
+" .incbin \"kernel/kheaders_data.tar.xz\" \n"
+" .global kernel_headers_data_end \n"
+"kernel_headers_data_end: \n"
+" .popsection \n"
+);
+
+extern char kernel_headers_data;
+extern char kernel_headers_data_end;
+
+static ssize_t
+ikheaders_read_current(struct file *file, char __user *buf,
+ size_t len, loff_t *offset)
+{
+ return simple_read_from_buffer(buf, len, offset,
+ &kernel_headers_data,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+}
+
+static const struct file_operations ikheaders_file_ops = {
+ .read = ikheaders_read_current,
+ .llseek = default_llseek,
+};
+
+static int __init ikheaders_init(void)
+{
+ struct proc_dir_entry *entry;
+
+ /* create the current headers file */
+ entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
+ &ikheaders_file_ops);
+ if (!entry)
+ return -ENOMEM;
+
+ proc_set_size(entry,
+ &kernel_headers_data_end -
+ &kernel_headers_data);
+ return 0;
+}
+
+static void __exit ikheaders_cleanup(void)
+{
+ remove_proc_entry("kheaders.tar.xz", NULL);
+}
+
+module_init(ikheaders_init);
+module_exit(ikheaders_cleanup);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joel Fernandes");
+MODULE_DESCRIPTION("Echo the kernel header artifacts used to build the kernel");
--
2.21.0.392.gf8f6787159e-goog
[Resending due to accidental HTML. I need to take Joel's advice and
switch to a real email client]
On Fri, Apr 12, 2019 at 5:54 PM Daniel Colascione <dancol(a)google.com> wrote:
>
> On Fri, Apr 12, 2019 at 5:09 PM Joel Fernandes <joel(a)joelfernandes.org> wrote:
>>
>> Hi Andy!
>>
>> On Fri, Apr 12, 2019 at 02:32:53PM -0700, Andy Lutomirski wrote:
>> > On Thu, Apr 11, 2019 at 10:51 AM Joel Fernandes (Google)
>> > <joel(a)joelfernandes.org> wrote:
>> > >
>> > > pidfd are /proc/pid directory file descriptors referring to a task group
>> > > leader. Android low memory killer (LMK) needs pidfd polling support to
>> > > replace code that currently checks for existence of /proc/pid for
>> > > knowing a process that is signalled to be killed has died, which is both
>> > > racy and slow. The pidfd poll approach is race-free, and also allows the
>> > > LMK to do other things (such as by polling on other fds) while awaiting
>> > > the process being killed to die.
>> > >
>> > > It prevents a situation where a PID is reused between when LMK sends a
>> > > kill signal and checks for existence of the PID, since the wrong PID is
>> > > now possibly checked for existence.
>> > >
>> > > In this patch, we follow the same mechanism used uhen the parent of the
>> > > task group is to be notified, that is when the tasks waiting on a poll
>> > > of pidfd are also awakened.
>> > >
>> > > We have decided to include the waitqueue in struct pid for the following
>> > > reasons:
>> > > 1. The wait queue has to survive for the lifetime of the poll. Including
>> > > it in task_struct would not be option in this case because the task can
>> > > be reaped and destroyed before the poll returns.
>> >
>> > Are you sure? I admit I'm not all that familiar with the innards of
>> > poll() on Linux, but I thought that the waitqueue only had to survive
>> > long enough to kick the polling thread and did *not* have to survive
>> > until poll() actually returned.
>>
>> I am not sure now. I thought epoll(2) was based on the wait_event APIs,
>> however more closely looking at the eventpoll code, it looks like there are 2
>> waitqueues involved, one that we pass and the other that is a part of the
>> eventpoll session itself, so you could be right about that. Daniel Colascione
>> may have some more thoughts about it since he brought up the possiblity of a
>> wq life-time issue. Daniel? We were just playing it safe.
I think you (Joel) and Andy are talking about different meanings of
poll(). Joel is talking about the VFS method; Andy is talking about
the system call. ISTM that the lifetime of wait queue we give to
poll_wait needs to last through the poll. Normally the wait queue gets
pinned by the struct file that we give to poll_wait (which takes a
reference on the struct file), but the pidfd struct file doesn't pin
the struct task, so we can't use a wait queue in struct task.
(remove_wait_queue, which poll implementations call to undo wait queue
additions, takes the wait queue head we pass to poll_wait, and we
don't want to pass a dangling pointer to remove_wait_queue.) If the
lifetime requirements for the queue aren't this strict, I don't see it
documented anywhere. Besides: if we don't actually need to pin the
waitqueue lifetime for the duration of the poll, why bother taking a
reference on the polled struct file?
=== Overview
arm64 has a feature called Top Byte Ignore, which allows to embed pointer
tags into the top byte of each pointer. Userspace programs (such as
HWASan, a memory debugging tool [1]) might use this feature and pass
tagged user pointers to the kernel through syscalls or other interfaces.
Right now the kernel is already able to handle user faults with tagged
pointers, due to these patches:
1. 81cddd65 ("arm64: traps: fix userspace cache maintenance emulation on a
tagged pointer")
2. 7dcd9dd8 ("arm64: hw_breakpoint: fix watchpoint matching for tagged
pointers")
3. 276e9327 ("arm64: entry: improve data abort handling of tagged
pointers")
This patchset extends tagged pointer support to syscall arguments.
As per the proposed ABI change [3], tagged pointers are only allowed to be
passed to syscalls when they point to memory ranges obtained by anonymous
mmap() or brk().
For non-memory syscalls this is done by untaging user pointers when the
kernel performs pointer checking to find out whether the pointer comes
from userspace (most notably in access_ok). The untagging is done only
when the pointer is being checked, the tag is preserved as the pointer
makes its way through the kernel and stays tagged when the kernel
dereferences the pointer when perfoming user memory accesses.
Memory syscalls (mmap, mprotect, etc.) don't do user memory accesses but
rather deal with memory ranges, and untagged pointers are better suited to
describe memory ranges internally. Thus for memory syscalls we untag
pointers completely when they enter the kernel.
=== Other approaches
One of the alternative approaches to untagging that was considered is to
completely strip the pointer tag as the pointer enters the kernel with
some kind of a syscall wrapper, but that won't work with the countless
number of different ioctl calls. With this approach we would need a custom
wrapper for each ioctl variation, which doesn't seem practical.
An alternative approach to untagging pointers in memory syscalls prologues
is to inspead allow tagged pointers to be passed to find_vma() (and other
vma related functions) and untag them there. Unfortunately, a lot of
find_vma() callers then compare or subtract the returned vma start and end
fields against the pointer that was being searched. Thus this approach
would still require changing all find_vma() callers.
=== Testing
The following testing approaches has been taken to find potential issues
with user pointer untagging:
1. Static testing (with sparse [2] and separately with a custom static
analyzer based on Clang) to track casts of __user pointers to integer
types to find places where untagging needs to be done.
2. Static testing with grep to find parts of the kernel that call
find_vma() (and other similar functions) or directly compare against
vm_start/vm_end fields of vma.
3. Static testing with grep to find parts of the kernel that compare
user pointers with TASK_SIZE or other similar consts and macros.
4. Dynamic testing: adding BUG_ON(has_tag(addr)) to find_vma() and running
a modified syzkaller version that passes tagged pointers to the kernel.
Based on the results of the testing the requried patches have been added
to the patchset.
=== Notes
This patchset is meant to be merged together with "arm64 relaxed ABI" [3].
This patchset is a prerequisite for ARM's memory tagging hardware feature
support [4].
This patchset has been merged into the Pixel 2 kernel tree and is now
being used to enable testing of Pixel 2 phones with HWASan.
Thanks!
[1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html
[2] https://github.com/lucvoo/sparse-dev/commit/5f960cb10f56ec2017c128ef9d16060…
[3] https://lkml.org/lkml/2018/12/10/402
[4] https://community.arm.com/processors/b/blog/posts/arm-a-profile-architectur…
Changes in v11:
- Added "uprobes, arm64: untag user pointers in find_active_uprobe" patch.
- Added "bpf, arm64: untag user pointers in stack_map_get_build_id_offset"
patch.
- Fixed "tracing, arm64: untag user pointers in seq_print_user_ip" to
correctly perform subtration with a tagged addr.
- Moved untagged_addr() from SYSCALL_DEFINE3(mprotect) and
SYSCALL_DEFINE4(pkey_mprotect) to do_mprotect_pkey().
- Moved untagged_addr() definition for other arches from
include/linux/memory.h to include/linux/mm.h.
- Changed untagging in strn*_user() to perform userspace accesses through
tagged pointers.
- Updated the documentation to mention that passing tagged pointers to
memory syscalls is allowed.
- Updated the test to use malloc'ed memory instead of stack memory.
Changes in v10:
- Added "mm, arm64: untag user pointers passed to memory syscalls" back.
- New patch "fs, arm64: untag user pointers in fs/userfaultfd.c".
- New patch "net, arm64: untag user pointers in tcp_zerocopy_receive".
- New patch "kernel, arm64: untag user pointers in prctl_set_mm*".
- New patch "tracing, arm64: untag user pointers in seq_print_user_ip".
Changes in v9:
- Rebased onto 4.20-rc6.
- Used u64 instead of __u64 in type casts in the untagged_addr macro for
arm64.
- Added braces around (addr) in the untagged_addr macro for other arches.
Changes in v8:
- Rebased onto 65102238 (4.20-rc1).
- Added a note to the cover letter on why syscall wrappers/shims that untag
user pointers won't work.
- Added a note to the cover letter that this patchset has been merged into
the Pixel 2 kernel tree.
- Documentation fixes, in particular added a list of syscalls that don't
support tagged user pointers.
Changes in v7:
- Rebased onto 17b57b18 (4.19-rc6).
- Dropped the "arm64: untag user address in __do_user_fault" patch, since
the existing patches already handle user faults properly.
- Dropped the "usb, arm64: untag user addresses in devio" patch, since the
passed pointer must come from a vma and therefore be untagged.
- Dropped the "arm64: annotate user pointers casts detected by sparse"
patch (see the discussion to the replies of the v6 of this patchset).
- Added more context to the cover letter.
- Updated Documentation/arm64/tagged-pointers.txt.
Changes in v6:
- Added annotations for user pointer casts found by sparse.
- Rebased onto 050cdc6c (4.19-rc1+).
Changes in v5:
- Added 3 new patches that add untagging to places found with static
analysis.
- Rebased onto 44c929e1 (4.18-rc8).
Changes in v4:
- Added a selftest for checking that passing tagged pointers to the
kernel succeeds.
- Rebased onto 81e97f013 (4.18-rc1+).
Changes in v3:
- Rebased onto e5c51f30 (4.17-rc6+).
- Added linux-arch@ to the list of recipients.
Changes in v2:
- Rebased onto 2d618bdf (4.17-rc3+).
- Removed excessive untagging in gup.c.
- Removed untagging pointers returned from __uaccess_mask_ptr.
Changes in v1:
- Rebased onto 4.17-rc1.
Changes in RFC v2:
- Added "#ifndef untagged_addr..." fallback in linux/uaccess.h instead of
defining it for each arch individually.
- Updated Documentation/arm64/tagged-pointers.txt.
- Dropped "mm, arm64: untag user addresses in memory syscalls".
- Rebased onto 3eb2ce82 (4.16-rc7).
Andrey Konovalov (14):
uaccess: add untagged_addr definition for other arches
arm64: untag user pointers in access_ok and __uaccess_mask_ptr
lib, arm64: untag user pointers in strn*_user
mm, arm64: untag user pointers passed to memory syscalls
mm, arm64: untag user pointers in mm/gup.c
fs, arm64: untag user pointers in copy_mount_options
fs, arm64: untag user pointers in fs/userfaultfd.c
net, arm64: untag user pointers in tcp_zerocopy_receive
kernel, arm64: untag user pointers in prctl_set_mm*
tracing, arm64: untag user pointers in seq_print_user_ip
uprobes, arm64: untag user pointers in find_active_uprobe
bpf, arm64: untag user pointers in stack_map_get_build_id_offset
arm64: update Documentation/arm64/tagged-pointers.txt
selftests, arm64: add a selftest for passing tagged pointers to kernel
Documentation/arm64/tagged-pointers.txt | 18 +++++++---------
arch/arm64/include/asm/uaccess.h | 10 +++++----
fs/namespace.c | 2 +-
fs/userfaultfd.c | 5 +++++
include/linux/mm.h | 4 ++++
ipc/shm.c | 2 ++
kernel/bpf/stackmap.c | 6 ++++--
kernel/events/uprobes.c | 2 ++
kernel/sys.c | 14 +++++++++++++
kernel/trace/trace_output.c | 5 +++--
lib/strncpy_from_user.c | 3 ++-
lib/strnlen_user.c | 3 ++-
mm/gup.c | 4 ++++
mm/madvise.c | 2 ++
mm/mempolicy.c | 5 +++++
mm/migrate.c | 1 +
mm/mincore.c | 2 ++
mm/mlock.c | 5 +++++
mm/mmap.c | 7 +++++++
mm/mprotect.c | 1 +
mm/mremap.c | 2 ++
mm/msync.c | 2 ++
net/ipv4/tcp.c | 2 ++
tools/testing/selftests/arm64/.gitignore | 1 +
tools/testing/selftests/arm64/Makefile | 11 ++++++++++
.../testing/selftests/arm64/run_tags_test.sh | 12 +++++++++++
tools/testing/selftests/arm64/tags_test.c | 21 +++++++++++++++++++
27 files changed, 131 insertions(+), 21 deletions(-)
create mode 100644 tools/testing/selftests/arm64/.gitignore
create mode 100644 tools/testing/selftests/arm64/Makefile
create mode 100755 tools/testing/selftests/arm64/run_tags_test.sh
create mode 100644 tools/testing/selftests/arm64/tags_test.c
--
2.21.0.360.g471c308f928-goog
Summary
------------------------------------------------------------------------
git repo: not informed
git branch: not informed
git commit: not informed
git describe: not informed
Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190412
Regressions (compared to build next-20190411)
------------------------------------------------------------------------
No regressions
Fixes (compared to build next-20190411)
------------------------------------------------------------------------
No fixes
In total:
------------------------------------------------------------------------
Ran 0 total tests in the following environments and test suites.
pass 0
fail 0
xfail 0
skip 0
Environments
--------------
- dragonboard-410c - arm64
- hi6220-hikey - arm64
- i386
- juno-r2 - arm64
- x15 - arm
- x86_64
Test Suites
-----------
Failures
------------------------------------------------------------------------
dragonboard-410c:
x86:
hi6220-hikey:
i386:
x15:
juno-r2:
Skips
------------------------------------------------------------------------
No skips
--
Linaro LKFT
https://lkft.linaro.org
Extend bpf_skb_adjust_room growth to mark inner MAC header so that
L2 encapsulation can be used for tc tunnels.
Patch #1 extends the existing test_tc_tunnel to support UDP
encapsulation; later we want to be able to test MPLS over UDP and
MPLS over GRE encapsulation.
Patch #2 adds the BPF_F_ADJ_ROOM_ENCAP_L2(len) macro, which
allows specification of inner mac length. Other approaches were
explored prior to taking this approach. Specifically, I tried
automatically computing the inner mac length on the basis of the
specified flags (so inner maclen for GRE/IPv4 encap is the len_diff
specified to bpf_skb_adjust_room minus GRE + IPv4 header length
for example). Problem with this is that we don't know for sure
what form of GRE/UDP header we have; is it a full GRE header,
or is it a FOU UDP header or generic UDP encap header? My fear
here was we'd end up with an explosion of flags. The other approach
tried was to support inner L2 header marking as a separate room
adjustment, i.e. adjust for L3/L4 encap, then call
bpf_skb_adjust_room for L2 encap. This can be made to work but
because it imposed an order on operations, felt a bit clunky.
Patch #3 syncs tools/ bpf.h.
Patch #4 extends the tests again to support MPLSoverGRE,
MPLSoverUDP, and transparent ethernet bridging (TEB) where
the inner L2 header is an ethernet header. Testing of BPF
encap against tunnels is done for cases where configuration
of such tunnels is possible (MPLSoverGRE[6], MPLSoverUDP,
gre[6]tap), and skipped otherwise. Testing of BPF encap/decap
is always carried out.
Changes since v2:
- updated tools/testing/selftest/bpf/config with FOU/MPLS CONFIG
variables (patches 1, 4)
- reduced noise in patch 1 by avoiding unnecessary movement of code
- eliminated inner_mac variable in bpf_skb_net_grow (patch 2)
Changes since v1:
- fixed formatting of commit references.
- BPF_F_ADJ_ROOM_FIXED_GSO flag enabled on all variants (patch 1)
- fixed fou6 options for UDP encap; checksum errors observed were
due to the fact fou6 tunnel was not set up with correct ipproto
options (41 -6). 0 checksums work fine (patch 1)
- added definitions for mask and shift used in setting L2 length
(patch 2)
- allow udp encap with fixed GSO (patch 2)
- changed "elen" to "l2_len" to be more descriptive (patch 4)
Alan Maguire (4):
selftests_bpf: extend test_tc_tunnel for UDP encap
bpf: add layer 2 encap support to bpf_skb_adjust_room
bpf: sync bpf.h to tools/ for BPF_F_ADJ_ROOM_ENCAP_L2
selftests_bpf: add L2 encap to test_tc_tunnel
include/uapi/linux/bpf.h | 10 +
net/core/filter.c | 12 +-
tools/include/uapi/linux/bpf.h | 10 +
tools/testing/selftests/bpf/config | 8 +
tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 321 +++++++++++++++++----
tools/testing/selftests/bpf/test_tc_tunnel.sh | 136 +++++++--
6 files changed, 417 insertions(+), 80 deletions(-)
--
1.8.3.1
Summary
------------------------------------------------------------------------
git repo: not informed
git branch: not informed
git commit: not informed
git describe: not informed
Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190411
Regressions (compared to build next-20190410)
------------------------------------------------------------------------
No regressions
Fixes (compared to build next-20190410)
------------------------------------------------------------------------
No fixes
In total:
------------------------------------------------------------------------
Ran 0 total tests in the following environments and test suites.
pass 0
fail 0
xfail 0
skip 0
Environments
--------------
- dragonboard-410c - arm64
- hi6220-hikey - arm64
- i386
- juno-r2 - arm64
- x15 - arm
- x86_64
Test Suites
-----------
Failures
------------------------------------------------------------------------
i386:
x15:
x86:
dragonboard-410c:
hi6220-hikey:
juno-r2:
Skips
------------------------------------------------------------------------
No skips
--
Linaro LKFT
https://lkft.linaro.org
Hi Kees,
secomp_bpf test hangs after global.user_notification_sibling_pid_ns
when a non-root user runs it on 5.1-rc4
I thought you fixed the problem with this commit:
commit 3d244c192afeee7dd4f5fb1b916ea4e47420d401
Author: Kees Cook <keescook(a)chromium.org>
Date: Wed Jan 16 16:35:25 2019 -0800
selftests/seccomp: Abort without user notification support
seccomp_bpf.c:3380:global.user_notification_sibling_pid_ns:Expected
unshare(CLONE_NEWPID) (18446744073709551615) == 0 (0)
seccomp_bpf.c:3381:global.user_notification_sibling_pid_ns:Expected
errno (1) == 0 (0)
seccomp_bpf.c:3365:global.user_notification_sibling_pid_ns:Expected
unshare(CLONE_NEWPID) (18446744073709551615) == 0 (0)
seccomp_bpf.c:3392:global.user_notification_sibling_pid_ns:Expected
req.pid (23610) == 0 (0)
hangs right after the above message,
root:
[ RUN ] global.user_notification_sibling_pid_ns
[ OK ] global.user_notification_sibling_pid_ns
[ RUN ] global.user_notification_fault_recv
[ OK ] global.user_notification_fault_recv
[ RUN ] global.seccomp_get_notif_sizes
[ OK ] global.seccomp_get_notif_sizes
[==========] 74 / 74 tests passed.
[ PASSED ]
I would debug this myself, double edged sword of harness, makes it
hard to debug:)
Can you take a look. "make kselftest" just hangs now and doesn't
complete.
thanks,
-- Shuah
Summary
------------------------------------------------------------------------
git repo: not informed
git branch: not informed
git commit: not informed
git describe: not informed
Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190410
Regressions (compared to build next-20190409)
------------------------------------------------------------------------
No regressions
Fixes (compared to build next-20190409)
------------------------------------------------------------------------
No fixes
In total:
------------------------------------------------------------------------
Ran 0 total tests in the following environments and test suites.
pass 0
fail 0
xfail 0
skip 0
Environments
--------------
- dragonboard-410c - arm64
- hi6220-hikey - arm64
- i386
- juno-r2 - arm64
- x15 - arm
- x86_64
Test Suites
-----------
Failures
------------------------------------------------------------------------
dragonboard-410c:
x15:
i386:
x86:
juno-r2:
hi6220-hikey:
Skips
------------------------------------------------------------------------
No skips
--
Linaro LKFT
https://lkft.linaro.org
This changes the selftest output is several ways:
- total test count is reported at start.
- each test's result is on a single line with "# SKIP" as needed per spec.
- each test's output is prefixed with "# " as a "diagnostic line".
This creates a bit of a kernel-specific TAP dialect where the diagnostics
precede the results. The TAP spec isn't entirely clear about this, though,
so I think it's the correct solution so as to keep interactive runs making
sense. If the output _followed_ the result line in the spec-suggested
YAML form, each test would dump all of its output at once instead of as
it went, making debugging harder.
This does, however, solve the recursive TAP output problem, as sub-tests
will simply be prefixed by "# ". Parsing sub-tests becomes a simple
problem of just removing the first two characters of a given top-level
test's diagnostic output, and parsing the results.
Note that the shell construct needed to both get an exit code from
the first command in a pipe and still filter the pipe (to add the "# "
prefix) uses a POSIX solution rather than the bash "pipefail" option
which is not supported by dash.
Example:
$ tools/testing/selftests
$ make --silent -C x86 run_tests
TAP version 13
1..15 selftests: x86
# selftests: x86: single_step_syscall_64
# [RUN] Set TF and check nop
# [OK] Survived with TF set and 9 traps
# [RUN] Set TF and check syscall-less opportunistic sysret
# [OK] Survived with TF set and 12 traps
# [RUN] Set TF and check a fast syscall
# [OK] Survived with TF set and 22 traps
# [RUN] Fast syscall with TF cleared
# [OK] Nothing unexpected happened
ok 1 selftests: x86: single_step_syscall_64
# selftests: x86: sysret_ss_attrs_64
# [RUN] Syscalls followed by SS validation
# [OK] We survived
ok 2 selftests: x86: sysret_ss_attrs_64
# selftests: x86: syscall_nt_64
# [RUN] Set NT and issue a syscall
# [OK] The syscall worked and flags are still set
# [RUN] Set NT|TF and issue a syscall
# [OK] The syscall worked and flags are still set
ok 3 selftests: x86: syscall_nt_64
...[skipping example output]...
ok 15 selftests: x86: sysret_rip_64
$ make --silent -C x86 run_tests | tappy
............F..
======================================================================
FAIL: <file=stream>
selftests: x86: mov_ss_trap_64
----------------------------------------------------------------------
----------------------------------------------------------------------
Ran 15 tests in 0.000s
FAILED (failures=1)
Signed-off-by: Kees Cook <keescook(a)chromium.org>
---
No longer RFC! :)
---
tools/testing/selftests/lib.mk | 59 ++++++++++++++++++-------------
tools/testing/selftests/prefix.pl | 23 ++++++++++++
2 files changed, 57 insertions(+), 25 deletions(-)
create mode 100755 tools/testing/selftests/prefix.pl
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 8b0f16409ed7..d3267c08a7b1 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -5,6 +5,8 @@ CC := $(CROSS_COMPILE)gcc
ifeq (0,$(MAKELEVEL))
OUTPUT := $(shell pwd)
endif
+testname = $(notdir $(shell pwd))
+selfdir = $(realpath $(dir $(filter %/lib.mk,$(MAKEFILE_LIST))))
# The following are built by lib.mk common compile rules.
# TEST_CUSTOM_PROGS should be used by tests that require
@@ -32,38 +34,45 @@ endif
.ONESHELL:
define RUN_TEST_PRINT_RESULT
- TEST_HDR_MSG="selftests: "`basename $$PWD`:" $$BASENAME_TEST"; \
- echo $$TEST_HDR_MSG; \
- echo "========================================"; \
+ TEST_HDR_MSG="selftests: $(testname): $$BASENAME_TEST"; \
if [ ! -x $$TEST ]; then \
- echo "$$TEST_HDR_MSG: Warning: file $$BASENAME_TEST is not executable, correct this.";\
- echo "not ok 1..$$test_num $$TEST_HDR_MSG [FAIL]"; \
- else \
- cd `dirname $$TEST` > /dev/null; \
- if [ "X$(summary)" != "X" ]; then \
- (./$$BASENAME_TEST > /tmp/$$BASENAME_TEST 2>&1 && \
- echo "ok 1..$$test_num $$TEST_HDR_MSG [PASS]") || \
- (if [ $$? -eq $$skip ]; then \
- echo "not ok 1..$$test_num $$TEST_HDR_MSG [SKIP]"; \
- else echo "not ok 1..$$test_num $$TEST_HDR_MSG [FAIL]"; \
- fi;) \
- else \
- (./$$BASENAME_TEST && \
- echo "ok 1..$$test_num $$TEST_HDR_MSG [PASS]") || \
- (if [ $$? -eq $$skip ]; then \
- echo "not ok 1..$$test_num $$TEST_HDR_MSG [SKIP]"; \
- else echo "not ok 1..$$test_num $$TEST_HDR_MSG [FAIL]"; \
- fi;) \
- fi; \
- cd - > /dev/null; \
+ if [ "X$(summary)" = "X" ]; then \
+ echo "# warning: 'file $$TEST is not executable, correct this.'";\
+ fi; \
+ echo "not ok $$test_num $$TEST_HDR_MSG"; \
+ else \
+ cd `dirname $$TEST` > /dev/null; \
+ if [ "X$(summary)" != "X" ]; then \
+ (./$$BASENAME_TEST > /tmp/$$BASENAME_TEST 2>&1 &&\
+ echo "ok $$test_num $$TEST_HDR_MSG") || \
+ (if [ $$? -eq $$skip ]; then \
+ echo "not ok $$test_num $$TEST_HDR_MSG # SKIP"; \
+ else \
+ echo "not ok $$test_num $$TEST_HDR_MSG";\
+ fi); \
+ else \
+ echo "# $$TEST_HDR_MSG"; \
+ (((((stdbuf -i0 -o0 -e0 ./$$BASENAME_TEST 2>&1; echo $$? >&3) | \
+ $(selfdir)/prefix.pl >&4) 3>&1) | \
+ (read xs; exit $$xs)) 4>&1 && \
+ echo "ok $$test_num $$TEST_HDR_MSG") || \
+ (if [ $$? -eq $$skip ]; then \
+ echo "not ok $$test_num $$TEST_HDR_MSG # SKIP"; \
+ else \
+ echo "not ok $$test_num $$TEST_HDR_MSG";\
+ fi); \
+ fi; \
+ cd - > /dev/null; \
fi;
endef
define RUN_TESTS
@export KSFT_TAP_LEVEL=`echo 1`; \
- test_num=`echo 0`; \
- skip=`echo 4`; \
+ test_num=0; \
+ total=`echo "$(1)" | wc -w`; \
+ skip=4; \
echo "TAP version 13"; \
+ echo "1..$$total selftests: $(testname)"; \
for TEST in $(1); do \
BASENAME_TEST=`basename $$TEST`; \
test_num=`echo $$test_num+1 | bc`; \
diff --git a/tools/testing/selftests/prefix.pl b/tools/testing/selftests/prefix.pl
new file mode 100755
index 000000000000..ec7e48118183
--- /dev/null
+++ b/tools/testing/selftests/prefix.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/perl
+# SPDX-License-Identifier: GPL-2.0
+# Prefix all lines with "# ", unbuffered. Command being piped in may need
+# to have unbuffering forced with "stdbuf -i0 -o0 -e0 $cmd".
+use strict;
+
+binmode STDIN;
+binmode STDOUT;
+
+STDOUT->autoflush(1);
+
+my $needed = 1;
+while (1) {
+ my $char;
+ my $bytes = sysread(STDIN, $char, 1);
+ exit 0 if ($bytes == 0);
+ if ($needed) {
+ print "# ";
+ $needed = 0;
+ }
+ print $char;
+ $needed = 1 if ($char eq "\n");
+}
--
2.17.1
--
Kees Cook
This adds most of the non-system-crashing selftests that exist in LKDTM.
The ones that leave the system in an unstable state are marked as "SKIP"
in the test run. Since output can change based on architecture and other
kernel configs, all output is reported during the tests.
Example output:
# cd tools/testing/selftests
# make --silent -C lkdtm run_tests
TAP version 13
1..64 selftests: lkdtm
# selftests: lkdtm: PANIC.sh
# PANIC: crashes entire system [SKIP]
not ok 1 selftests: lkdtm: PANIC.sh # SKIP
# selftests: lkdtm: BUG.sh
# [19716.955023] lkdtm: Performing direct entry BUG
# [19716.956236] ------------[ cut here ]------------
# [19716.957318] kernel BUG at drivers/misc/lkdtm/bugs.c:63!
...
# BUG: saw 'call trace:': ok
ok 2 selftests: lkdtm: BUG.sh
...
Signed-off-by: Kees Cook <keescook(a)chromium.org>
---
MAINTAINERS | 1 +
tools/testing/selftests/lkdtm/.gitignore | 1 +
tools/testing/selftests/lkdtm/Makefile | 11 +++
tools/testing/selftests/lkdtm/config | 1 +
tools/testing/selftests/lkdtm/run.sh | 86 ++++++++++++++++++++++++
tools/testing/selftests/lkdtm/tests.txt | 64 ++++++++++++++++++
6 files changed, 164 insertions(+)
create mode 100644 tools/testing/selftests/lkdtm/.gitignore
create mode 100644 tools/testing/selftests/lkdtm/Makefile
create mode 100644 tools/testing/selftests/lkdtm/config
create mode 100755 tools/testing/selftests/lkdtm/run.sh
create mode 100644 tools/testing/selftests/lkdtm/tests.txt
diff --git a/MAINTAINERS b/MAINTAINERS
index 3e5a5d263f29..716d6f0fbd0c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8976,6 +8976,7 @@ LINUX KERNEL DUMP TEST MODULE (LKDTM)
M: Kees Cook <keescook(a)chromium.org>
S: Maintained
F: drivers/misc/lkdtm/*
+F: tools/testing/selftests/lkdtm/*
LINUX KERNEL MEMORY CONSISTENCY MODEL (LKMM)
M: Alan Stern <stern(a)rowland.harvard.edu>
diff --git a/tools/testing/selftests/lkdtm/.gitignore b/tools/testing/selftests/lkdtm/.gitignore
new file mode 100644
index 000000000000..09df4a4da272
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/.gitignore
@@ -0,0 +1 @@
+[A-Z][A-Z]*.sh
diff --git a/tools/testing/selftests/lkdtm/Makefile b/tools/testing/selftests/lkdtm/Makefile
new file mode 100644
index 000000000000..f322d281fd8e
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for LKDTM regression tests
+
+include ../lib.mk
+
+# NOTE: $(OUTPUT) won't get default value if used before lib.mk
+TEST_GEN_PROGS = $(patsubst %,$(OUTPUT)/%.sh,$(shell awk '{print $$1}' tests.txt | sed -e 's/\#//'))
+all: $(TEST_GEN_PROGS)
+
+$(OUTPUT)/%: run.sh tests.txt
+ install -m 0744 run.sh $@
diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config
new file mode 100644
index 000000000000..d874990e442b
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/config
@@ -0,0 +1 @@
+CONFIG_LKDTM=y
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh
new file mode 100755
index 000000000000..a166b925c43d
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/run.sh
@@ -0,0 +1,86 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# This reads tests.txt for the list of LKDTM tests to invoke. Any marked
+# with a leading "#" are skipped. The line after the test name is either
+# the text to look for in dmesg for a "success", or the rationale for why
+# a test is marked to be skipped.
+#
+set -e
+TRIGGER=/sys/kernel/debug/provoke-crash/DIRECT
+
+# Verify we have LKDTM available in the kernel.
+if [ ! -r $TRIGGER ] ; then
+ /sbin/modprobe -q lkdtm || true
+ if [ ! -r $TRIGGER ] ; then
+ echo "Cannot find $TRIGGER (missing CONFIG_LKDTM?) [SKIP]"
+ else
+ echo "Cannot write $TRIGGER (need to run as root?) [SKIP]"
+ fi
+ # Skip this test
+ exit 4
+fi
+
+# Figure out which test to run from our script name.
+test=$(basename $0 .sh)
+# Look up details about the test from master list of LKDTM tests.
+line=$(egrep '^#?'"$test"'\b' tests.txt)
+if [ -z "$line" ]; then
+ echo "Missing test '$test' [SKIP]"
+ exit 4
+fi
+# Check that the test is known to LKDTM.
+if ! egrep -q '^'"$test"'$' "$TRIGGER" ; then
+ echo "'$test' missing in $TRIGGER! [SKIP]"
+ exit 4
+fi
+
+# Extract notes/expected output from test list.
+test=$(echo "$line" | cut -d" " -f1)
+if echo "$line" | grep -q ' ' ; then
+ expect=$(echo "$line" | cut -d" " -f2-)
+else
+ expect=""
+fi
+
+# If the test is commented out, report a skip
+if echo "$test" | grep -q '^#' ; then
+ test=$(echo "$test" | cut -c2-)
+ if [ -z "$expect" ]; then
+ expect="crashes entire system"
+ fi
+ echo "$test: $expect [SKIP]"
+ exit 4
+fi
+
+# If no expected output given, assume an Oops with back trace is success.
+if [ -z "$expect" ]; then
+ expect="call trace:"
+fi
+
+# Clear out dmesg for output reporting
+dmesg -c >/dev/null
+
+# Prepare log for report checking
+LOG=$(mktemp --tmpdir -t lkdtm-XXXXXX)
+cleanup() {
+ rm -f "$LOG"
+}
+trap cleanup EXIT
+
+# Most shells yell about signals and we're expecting the "cat" process
+# to usually be killed by the kernel. So we have to run it in a sub-shell
+# and silence errors.
+($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true
+
+# Record and dump the results
+dmesg -c >"$LOG"
+cat "$LOG"
+# Check for expected output
+if grep -qi "$expect" "$LOG" ; then
+ echo "$test: saw '$expect': ok"
+ exit 0
+else
+ echo "$test: missing '$expect': [FAIL]"
+ exit 1
+fi
diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt
new file mode 100644
index 000000000000..3ee43df87d71
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/tests.txt
@@ -0,0 +1,64 @@
+#PANIC
+BUG
+WARNING
+EXCEPTION
+#LOOP Hangs the system
+#EXHAUST_STACK Corrupts memory on failure
+#CORRUPT_STACK Crashes entire system on success
+#CORRUPT_STACK_STRONG Crashes entire system on success
+CORRUPT_LIST_ADD
+CORRUPT_LIST_DEL
+CORRUPT_USER_DS
+STACK_GUARD_PAGE_LEADING
+STACK_GUARD_PAGE_TRAILING
+UNALIGNED_LOAD_STORE_WRITE
+#OVERWRITE_ALLOCATION Corrupts memory on failure
+#WRITE_AFTER_FREE Corrupts memory on failure
+READ_AFTER_FREE
+#WRITE_BUDDY_AFTER_FREE Corrupts memory on failure
+READ_BUDDY_AFTER_FREE
+#SOFTLOCKUP Hangs the system
+#HARDLOCKUP Hangs the system
+#SPINLOCKUP Hangs the system
+#HUNG_TASK Hangs the system
+EXEC_DATA
+EXEC_STACK
+EXEC_KMALLOC
+EXEC_VMALLOC
+EXEC_RODATA
+EXEC_USERSPACE
+EXEC_NULL
+ACCESS_USERSPACE
+ACCESS_NULL
+WRITE_RO
+WRITE_RO_AFTER_INIT
+WRITE_KERN
+REFCOUNT_INC_OVERFLOW
+REFCOUNT_ADD_OVERFLOW
+REFCOUNT_INC_NOT_ZERO_OVERFLOW
+REFCOUNT_ADD_NOT_ZERO_OVERFLOW
+REFCOUNT_DEC_ZERO
+REFCOUNT_DEC_NEGATIVE Negative detected: saturated
+REFCOUNT_DEC_AND_TEST_NEGATIVE Negative detected: saturated
+REFCOUNT_SUB_AND_TEST_NEGATIVE Negative detected: saturated
+REFCOUNT_INC_ZERO
+REFCOUNT_ADD_ZERO
+REFCOUNT_INC_SATURATED Saturation detected: still saturated
+REFCOUNT_DEC_SATURATED Saturation detected: still saturated
+REFCOUNT_ADD_SATURATED Saturation detected: still saturated
+REFCOUNT_INC_NOT_ZERO_SATURATED
+REFCOUNT_ADD_NOT_ZERO_SATURATED
+REFCOUNT_DEC_AND_TEST_SATURATED Saturation detected: still saturated
+REFCOUNT_SUB_AND_TEST_SATURATED Saturation detected: still saturated
+#REFCOUNT_TIMING timing only
+#ATOMIC_TIMING timing only
+USERCOPY_HEAP_SIZE_TO
+USERCOPY_HEAP_SIZE_FROM
+USERCOPY_HEAP_WHITELIST_TO
+USERCOPY_HEAP_WHITELIST_FROM
+USERCOPY_STACK_FRAME_TO
+USERCOPY_STACK_FRAME_FROM
+USERCOPY_STACK_BEYOND
+USERCOPY_KERNEL
+USERCOPY_KERNEL_DS
+STACKLEAK_ERASING
--
2.17.1
--
Kees Cook
This changes the selftest output is several ways:
- total test count is reported at start.
- each test's result is on a single line with "# SKIP" as needed per spec.
- each test's output is report _before_ the result line as a commented
"diagnostic" line.
This creates a bit of a kernel-specific TAP output where the diagnostics
precede the results. The TAP spec isn't entirely clear about this, though,
so I think it's the correct solution so as to not keep interactive
runs making sense. If the output _followed_ the result line in the
spec-suggested YAML form, each test would dump all of its output at once
instead of as it went, making debugging harder.
Also, while "sed -u" is used to add the "# " line prefixes, this
still doesn't work for all output. For example, the "timer" lists
print out text, then do the work, then print a result and a newline.
This isn't visible any more. And some tests still show nothing until
they finish. I haven't found a way to force the prefixing while keeping
the output entirely unbuffered. :(
Note that the shell construct needed to both get an exit code from
the first command in a pipe and still filter the pipe (to add the "# "
prefix) uses a POSIX solution rather than the bash "pipefail" option
which is not supported by dash.
Signed-off-by: Kees Cook <keescook(a)chromium.org>
---
tools/testing/selftests/lib.mk | 54 +++++++++++++++++++---------------
1 file changed, 31 insertions(+), 23 deletions(-)
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 8b0f16409ed7..056dac8f5701 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -5,6 +5,7 @@ CC := $(CROSS_COMPILE)gcc
ifeq (0,$(MAKELEVEL))
OUTPUT := $(shell pwd)
endif
+srcdir = $(notdir $(shell pwd))
# The following are built by lib.mk common compile rules.
# TEST_CUSTOM_PROGS should be used by tests that require
@@ -32,38 +33,45 @@ endif
.ONESHELL:
define RUN_TEST_PRINT_RESULT
- TEST_HDR_MSG="selftests: "`basename $$PWD`:" $$BASENAME_TEST"; \
- echo $$TEST_HDR_MSG; \
- echo "========================================"; \
+ TEST_HDR_MSG="selftests: $(srcdir): $$BASENAME_TEST"; \
if [ ! -x $$TEST ]; then \
- echo "$$TEST_HDR_MSG: Warning: file $$BASENAME_TEST is not executable, correct this.";\
- echo "not ok 1..$$test_num $$TEST_HDR_MSG [FAIL]"; \
- else \
- cd `dirname $$TEST` > /dev/null; \
- if [ "X$(summary)" != "X" ]; then \
- (./$$BASENAME_TEST > /tmp/$$BASENAME_TEST 2>&1 && \
- echo "ok 1..$$test_num $$TEST_HDR_MSG [PASS]") || \
- (if [ $$? -eq $$skip ]; then \
- echo "not ok 1..$$test_num $$TEST_HDR_MSG [SKIP]"; \
- else echo "not ok 1..$$test_num $$TEST_HDR_MSG [FAIL]"; \
- fi;) \
- else \
- (./$$BASENAME_TEST && \
- echo "ok 1..$$test_num $$TEST_HDR_MSG [PASS]") || \
- (if [ $$? -eq $$skip ]; then \
- echo "not ok 1..$$test_num $$TEST_HDR_MSG [SKIP]"; \
- else echo "not ok 1..$$test_num $$TEST_HDR_MSG [FAIL]"; \
- fi;) \
- fi; \
- cd - > /dev/null; \
+ if [ "X$(summary)" = "X" ]; then \
+ echo "# warning: 'file $$TEST is not executable, correct this.'";\
+ fi; \
+ echo "not ok $$test_num $$TEST_HDR_MSG"; \
+ else \
+ cd `dirname $$TEST` > /dev/null; \
+ if [ "X$(summary)" != "X" ]; then \
+ (./$$BASENAME_TEST > /tmp/$$BASENAME_TEST 2>&1 &&\
+ echo "ok $$test_num $$TEST_HDR_MSG") || \
+ (if [ $$? -eq $$skip ]; then \
+ echo "not ok $$test_num $$TEST_HDR_MSG # SKIP"; \
+ else \
+ echo "not ok $$test_num $$TEST_HDR_MSG";\
+ fi); \
+ else \
+ echo "# $$TEST_HDR_MSG"; \
+ (((((./$$BASENAME_TEST 2>&1; echo $$? >&3) | \
+ sed -ue 's/^/# /' >&4) 3>&1) | \
+ (read xs; exit $$xs)) 4>&1 && \
+ echo "ok $$test_num $$TEST_HDR_MSG") || \
+ (if [ $$? -eq $$skip ]; then \
+ echo "not ok $$test_num $$TEST_HDR_MSG # SKIP"; \
+ else \
+ echo "not ok $$test_num $$TEST_HDR_MSG";\
+ fi); \
+ fi; \
+ cd - > /dev/null; \
fi;
endef
define RUN_TESTS
@export KSFT_TAP_LEVEL=`echo 1`; \
test_num=`echo 0`; \
+ total=`echo "$(1)" | wc -w`; \
skip=`echo 4`; \
echo "TAP version 13"; \
+ echo "1..$$total selftests: $(srcdir)"; \
for TEST in $(1); do \
BASENAME_TEST=`basename $$TEST`; \
test_num=`echo $$test_num+1 | bc`; \
--
2.17.1
--
Kees Cook
Extend bpf_skb_adjust_room growth to mark inner MAC header so that
L2 encapsulation can be used for tc tunnels.
Patch #1 extends the existing test_tc_tunnel to support UDP
encapsulation; later we want to be able to test MPLS over UDP and
MPLS over GRE encapsulation.
Patch #2 adds the BPF_F_ADJ_ROOM_ENCAP_L2(len) macro, which
allows specification of inner mac length. Other approaches were
explored prior to taking this approach. Specifically, I tried
automatically computing the inner mac length on the basis of the
specified flags (so inner maclen for GRE/IPv4 encap is the len_diff
specified to bpf_skb_adjust_room minus GRE + IPv4 header length
for example). Problem with this is that we don't know for sure
what form of GRE/UDP header we have; is it a full GRE header,
or is it a FOU UDP header or generic UDP encap header? My fear
here was we'd end up with an explosion of flags. The other approach
tried was to support inner L2 header marking as a separate room
adjustment, i.e. adjust for L3/L4 encap, then call
bpf_skb_adjust_room for L2 encap. This can be made to work but
because it imposed an order on operations, felt a bit clunky.
Patch #3 syncs tools/ bpf.h.
Patch #4 extends the tests again to support MPLSoverGRE,
MPLSoverUDP, and transparent ethernet bridging (TEB) where
the inner L2 header is an ethernet header. Testing of BPF
encap against tunnels is done for cases where configuration
of such tunnels is possible (MPLSoverGRE[6], MPLSoverUDP,
gre[6]tap), and skipped otherwise. Testing of BPF encap/decap
is always carried out.
Changes since v1:
- fixed formatting of commit references.
- BPF_F_ADJ_ROOM_FIXED_GSO flag enabled on all variants (patch 1)
- fixed fou6 options for UDP encap; checksum errors observed were
due to the fact fou6 tunnel was not set up with correct ipproto
options (41 -6). 0 checksums work fine (patch 1)
- added definitions for mask and shift used in setting L2 length
(patch 2)
- allow udp encap with fixed GSO (patch 2)
- changed "elen" to "l2_len" to be more descriptive (patch 4)
- added support for ethernet L2 encap to tests; testing against
gre[6]tap tunnels (patch 4).
Alan Maguire (4):
selftests_bpf: add UDP encap to test_tc_tunnel
bpf: add layer 2 encap support to bpf_skb_adjust_room
bpf: sync bpf.h to tools/ for BPF_F_ADJ_ROOM_ENCAP_L2
selftests_bpf: add L2 encap to test_tc_tunnel
include/uapi/linux/bpf.h | 10 +
net/core/filter.c | 15 +-
tools/include/uapi/linux/bpf.h | 10 +
tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 335 +++++++++++++++++----
tools/testing/selftests/bpf/test_tc_tunnel.sh | 147 +++++++--
5 files changed, 427 insertions(+), 90 deletions(-)
--
1.8.3.1