xtheadvector is a custom extension that is based upon riscv vector
version 0.7.1 [1]. All of the vector routines have been modified to
support this alternative vector version based upon whether xtheadvector
was determined to be supported at boot.
vlenb is not supported on the existing xtheadvector hardware, so a
devicetree property thead,vlenb is added to provide the vlenb to Linux.
There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is
used to request which thead vendor extensions are supported on the
current platform. This allows future vendors to allocate hwprobe keys
for their vendor.
Support for xtheadvector is also added to the vector kselftests.
Signed-off-by: Charlie Jenkins <charlie(a)rivosinc.com>
[1] https://github.com/T-head-Semi/thead-extension-spec/blob/95358cb2cca9489361…
---
This series is a continuation of a different series that was fragmented
into two other series in an attempt to get part of it merged in the 6.10
merge window. The split-off series did not get merged due to a NAK on
the series that added the generic riscv,vlenb devicetree entry. This
series has converted riscv,vlenb to thead,vlenb to remedy this issue.
The original series is titled "riscv: Support vendor extensions and
xtheadvector" [3].
The series titled "riscv: Extend cpufeature.c to detect vendor
extensions" is still under development and this series is based on that
series! [4]
I have tested this with an Allwinner Nezha board. I ran into issues
booting the board after 6.9-rc1 so I applied these patches to 6.8. There
are a couple of minor merge conflicts that do arrise when doing that, so
please let me know if you have been able to boot this board with a 6.9
kernel. I used SkiffOS [1] to manage building the image, but upgraded
the U-Boot version to Samuel Holland's more up-to-date version [2] and
changed out the device tree used by U-Boot with the device trees that
are present in upstream linux and this series. Thank you Samuel for all
of the work you did to make this task possible.
[1] https://github.com/skiffos/SkiffOS/tree/master/configs/allwinner/nezha
[2] https://github.com/smaeul/u-boot/commit/2e89b706f5c956a70c989cd31665f1429e9…
[3] https://lore.kernel.org/all/20240503-dev-charlie-support_thead_vector_6_9-v…
[4] https://lore.kernel.org/linux-riscv/20240609-support_vendor_extensions-v2-0…
---
Changes in v3:
- Add back Heiko's signed-off-by (Conor)
- Mark RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 as a bitmask
- Link to v2: https://lore.kernel.org/r/20240610-xtheadvector-v2-0-97a48613ad64@rivosinc.…
Changes in v2:
- Removed extraneous references to "riscv,vlenb" (Jess)
- Moved declaration of "thead,vlenb" into cpus.yaml and added
restriction that it's only applicable to thead cores (Conor)
- Check CONFIG_RISCV_ISA_XTHEADVECTOR instead of CONFIG_RISCV_ISA_V for
thead,vlenb (Jess)
- Fix naming of hwprobe variables (Evan)
- Link to v1: https://lore.kernel.org/r/20240609-xtheadvector-v1-0-3fe591d7f109@rivosinc.…
---
Charlie Jenkins (12):
dt-bindings: riscv: Add xtheadvector ISA extension description
dt-bindings: cpus: add a thead vlen register length property
riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree
riscv: Add thead and xtheadvector as a vendor extension
riscv: vector: Use vlenb from DT for thead
riscv: csr: Add CSR encodings for VCSR_VXRM/VCSR_VXSAT
riscv: Add xtheadvector instruction definitions
riscv: vector: Support xtheadvector save/restore
riscv: hwprobe: Add thead vendor extension probing
riscv: hwprobe: Document thead vendor extensions and xtheadvector extension
selftests: riscv: Fix vector tests
selftests: riscv: Support xtheadvector in vector tests
Heiko Stuebner (1):
RISC-V: define the elements of the VCSR vector CSR
Documentation/arch/riscv/hwprobe.rst | 10 +
Documentation/devicetree/bindings/riscv/cpus.yaml | 19 ++
.../devicetree/bindings/riscv/extensions.yaml | 10 +
arch/riscv/Kconfig.vendor | 26 ++
arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi | 3 +-
arch/riscv/include/asm/cpufeature.h | 2 +
arch/riscv/include/asm/csr.h | 13 +
arch/riscv/include/asm/hwprobe.h | 5 +-
arch/riscv/include/asm/switch_to.h | 2 +-
arch/riscv/include/asm/vector.h | 249 +++++++++++++----
arch/riscv/include/asm/vendor_extensions/thead.h | 42 +++
.../include/asm/vendor_extensions/thead_hwprobe.h | 18 ++
.../include/asm/vendor_extensions/vendor_hwprobe.h | 37 +++
arch/riscv/include/uapi/asm/hwprobe.h | 3 +-
arch/riscv/include/uapi/asm/vendor/thead.h | 3 +
arch/riscv/kernel/cpufeature.c | 51 +++-
arch/riscv/kernel/kernel_mode_vector.c | 8 +-
arch/riscv/kernel/process.c | 4 +-
arch/riscv/kernel/signal.c | 6 +-
arch/riscv/kernel/sys_hwprobe.c | 5 +
arch/riscv/kernel/vector.c | 25 +-
arch/riscv/kernel/vendor_extensions.c | 10 +
arch/riscv/kernel/vendor_extensions/Makefile | 2 +
arch/riscv/kernel/vendor_extensions/thead.c | 18 ++
.../riscv/kernel/vendor_extensions/thead_hwprobe.c | 19 ++
tools/testing/selftests/riscv/vector/.gitignore | 3 +-
tools/testing/selftests/riscv/vector/Makefile | 17 +-
.../selftests/riscv/vector/v_exec_initval_nolibc.c | 93 +++++++
tools/testing/selftests/riscv/vector/v_helpers.c | 67 +++++
tools/testing/selftests/riscv/vector/v_helpers.h | 7 +
tools/testing/selftests/riscv/vector/v_initval.c | 22 ++
.../selftests/riscv/vector/v_initval_nolibc.c | 68 -----
.../selftests/riscv/vector/vstate_exec_nolibc.c | 20 +-
.../testing/selftests/riscv/vector/vstate_prctl.c | 295 ++++++++++++---------
34 files changed, 911 insertions(+), 271 deletions(-)
---
base-commit: 11cc01d4d2af304b7288251aad7e03315db8dffc
change-id: 20240530-xtheadvector-833d3d17b423
--
- Charlie
** Background **
Currently, OVS supports several packet sampling mechanisms (sFlow,
per-bridge IPFIX, per-flow IPFIX). These end up being translated into a
userspace action that needs to be handled by ovs-vswitchd's handler
threads only to be forwarded to some third party application that
will somehow process the sample and provide observability on the
datapath.
A particularly interesting use-case is controller-driven
per-flow IPFIX sampling where the OpenFlow controller can add metadata
to samples (via two 32bit integers) and this metadata is then available
to the sample-collecting system for correlation.
** Problem **
The fact that sampled traffic share netlink sockets and handler thread
time with upcalls, apart from being a performance bottleneck in the
sample extraction itself, can severely compromise the datapath,
yielding this solution unfit for highly loaded production systems.
Users are left with little options other than guessing what sampling
rate will be OK for their traffic pattern and system load and dealing
with the lost accuracy.
Looking at available infrastructure, an obvious candidated would be
to use psample. However, it's current state does not help with the
use-case at stake because sampled packets do not contain user-defined
metadata.
** Proposal **
This series is an attempt to fix this situation by extending the
existing psample infrastructure to carry a variable length
user-defined cookie.
The main existing user of psample is tc's act_sample. It is also
extended to forward the action's cookie to psample.
Finally, a new OVS action (OVS_SAMPLE_ATTR_PSAMPLE) is created.
It accepts a group and an optional cookie and uses psample to
multicast the packet and the metadata.
--
v6 -> v7:
- Rebased
- Fixed typo in comment.
v5 -> v6:
- Renamed emit_sample -> psample
- Addressed unused variable and conditionally compilation of function.
v4 -> v5:
- Rebased.
- Removed lefover enum value and wrapped some long lines in selftests.
v3 -> v4:
- Rebased.
- Addressed Jakub's comment on private and unused nla attributes.
v2 -> v3:
- Addressed comments from Simon, Aaron and Ilya.
- Dropped probability propagation in nested sample actions.
- Dropped patch v2's 7/9 in favor of a userspace implementation and
consume skb if emit_sample is the last action, same as we do with
userspace.
- Split ovs-dpctl.py features in independent patches.
v1 -> v2:
- Create a new action ("emit_sample") rather than reuse existing
"sample" one.
- Add probability semantics to psample's sampling rate.
- Store sampling probability in skb's cb area and use it in emit_sample.
- Test combining "emit_sample" with "trunc"
- Drop group_id filtering and tracepoint in psample.
rfc_v2 -> v1:
- Accommodate Ilya's comments.
- Split OVS's attribute in two attributes and simplify internal
handling of psample arguments.
- Extend psample and tc with a user-defined cookie.
- Add a tracepoint to psample to facilitate troubleshooting.
rfc_v1 -> rfc_v2:
- Use psample instead of a new OVS-only multicast group.
- Extend psample and tc with a user-defined cookie.
Adrian Moreno (10):
net: psample: add user cookie
net: sched: act_sample: add action cookie to sample
net: psample: skip packet copy if no listeners
net: psample: allow using rate as probability
net: openvswitch: add psample action
net: openvswitch: store sampling probability in cb.
selftests: openvswitch: add psample action
selftests: openvswitch: add userspace parsing
selftests: openvswitch: parse trunc action
selftests: openvswitch: add psample test
Documentation/netlink/specs/ovs_flow.yaml | 17 ++
include/net/psample.h | 5 +-
include/uapi/linux/openvswitch.h | 31 +-
include/uapi/linux/psample.h | 11 +-
net/openvswitch/Kconfig | 1 +
net/openvswitch/actions.c | 65 ++++-
net/openvswitch/datapath.h | 3 +
net/openvswitch/flow_netlink.c | 32 ++-
net/openvswitch/vport.c | 1 +
net/psample/psample.c | 16 +-
net/sched/act_sample.c | 12 +
.../selftests/net/openvswitch/openvswitch.sh | 115 +++++++-
.../selftests/net/openvswitch/ovs-dpctl.py | 272 +++++++++++++++++-
13 files changed, 565 insertions(+), 16 deletions(-)
--
2.45.2
Adrian Moreno (10):
net: psample: add user cookie
net: sched: act_sample: add action cookie to sample
net: psample: skip packet copy if no listeners
net: psample: allow using rate as probability
net: openvswitch: add psample action
net: openvswitch: store sampling probability in cb.
selftests: openvswitch: add psample action
selftests: openvswitch: add userspace parsing
selftests: openvswitch: parse trunc action
selftests: openvswitch: add psample test
Documentation/netlink/specs/ovs_flow.yaml | 17 ++
include/net/psample.h | 5 +-
include/uapi/linux/openvswitch.h | 31 +-
include/uapi/linux/psample.h | 11 +-
net/openvswitch/Kconfig | 1 +
net/openvswitch/actions.c | 65 ++++-
net/openvswitch/datapath.h | 3 +
net/openvswitch/flow_netlink.c | 32 ++-
net/openvswitch/vport.c | 1 +
net/psample/psample.c | 16 +-
net/sched/act_sample.c | 12 +
.../selftests/net/openvswitch/openvswitch.sh | 115 +++++++-
.../selftests/net/openvswitch/ovs-dpctl.py | 272 +++++++++++++++++-
13 files changed, 565 insertions(+), 16 deletions(-)
--
2.45.2
In this series, 4 tests are being conformed to TAP.
Muhammad Usama Anjum (4):
selftests: x86: check_initial_reg_state: conform test to TAP format
output
selftests: x86: corrupt_xstate_header: conform test to TAP format
output
selftests: fsgsbase_restore: conform test to TAP format output
selftests: entry_from_vm86: conform test to TAP format output
.../selftests/x86/check_initial_reg_state.c | 24 ++--
.../selftests/x86/corrupt_xstate_header.c | 30 +++--
tools/testing/selftests/x86/entry_from_vm86.c | 109 ++++++++--------
.../testing/selftests/x86/fsgsbase_restore.c | 117 +++++++++---------
4 files changed, 139 insertions(+), 141 deletions(-)
--
2.39.2
There are no maintainers specified for tools/testing/selftests/x86.
Shuah has mentioned [1] that the patches should go through x86 tree or
in special cases directly to Shuah's tree after getting ack-ed from x86
maintainers. Different people have been confused when sending patches as
correct maintainers aren't found by get_maintainer.pl script. Fix
this by adding entry to MAINTAINERS file.
[1] https://lore.kernel.org/all/90dc0dfc-4c67-4ea1-b705-0585d6e2ec47@linuxfound…
Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 523d84b2d6139..f3a17e5d954a3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24378,6 +24378,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/core
F: Documentation/arch/x86/
F: Documentation/devicetree/bindings/x86/
F: arch/x86/
+F: tools/testing/selftests/x86
X86 ENTRY CODE
M: Andy Lutomirski <luto(a)kernel.org>
--
2.39.2
Conform individual tests to TAP output. One patch conform one test. With
this series, all vDSO tests become TAP conformant.
First patch conform the test by using kselftest_harness.h. Other patches
are conforming using default kselftest.h helpers.
All tests have been tested multiple times before and after these
patches. They are working correctly and outputting TAP messaging to find
failures quikly when they happen.
---
Changes since v1:
- Update cover letter
- Update commit message of first patch
Muhammad Usama Anjum (4):
kselftests: vdso: vdso_test_clock_getres: conform test to TAP output
kselftests: vdso: vdso_test_correctness: conform test to TAP output
kselftests: vdso: vdso_test_getcpu: conform test to TAP output
kselftests: vdso: vdso_test_gettimeofday: conform test to TAP output
.../selftests/vDSO/vdso_test_clock_getres.c | 68 ++++----
.../selftests/vDSO/vdso_test_correctness.c | 146 +++++++++---------
.../testing/selftests/vDSO/vdso_test_getcpu.c | 16 +-
.../selftests/vDSO/vdso_test_gettimeofday.c | 23 +--
4 files changed, 126 insertions(+), 127 deletions(-)
--
2.39.2
Don't print that 88 sub-tests are going to be executed. But then skip.
The error is printed that executed test was only 1 while 88 should have
run:
Old output:
TAP version 13
1..88
ok 2 # SKIP all tests require euid == 0
# Planned tests != run tests (88 != 1)
# Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
New and correct output:
TAP version 13
1..0 # SKIP all tests require euid == 0
Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com>
---
tools/testing/selftests/openat2/resolve_test.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/openat2/resolve_test.c b/tools/testing/selftests/openat2/resolve_test.c
index bbafad440893c..5472ec478d227 100644
--- a/tools/testing/selftests/openat2/resolve_test.c
+++ b/tools/testing/selftests/openat2/resolve_test.c
@@ -508,12 +508,13 @@ void test_openat2_opath_tests(void)
int main(int argc, char **argv)
{
ksft_print_header();
- ksft_set_plan(NUM_TESTS);
/* NOTE: We should be checking for CAP_SYS_ADMIN here... */
- if (geteuid() != 0)
+ if (geteuid())
ksft_exit_skip("all tests require euid == 0\n");
+ ksft_set_plan(NUM_TESTS);
+
test_openat2_opath_tests();
if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
--
2.39.2
From: Geliang Tang <tanggeliang(a)kylinos.cn>
Run this BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, a kernel panic occurs:
'''
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G OE 6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
... ...
ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
PRMD: 0000000c (PPLV0 +PIE +PWE)
EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
BADV: 0000000000000040
PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160
Code: ...
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
.text @ 0x9000000003710000
.data @ 0x9000000004d70000
.bss @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
'''
This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.
This crash is because a NULL pointer is passed to page_address() in
sk_msg_recvmsg(). Due to the difference implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on X86 platform. So this bug was hidden on X86 platform
for a while, but now it is exposed on Loongarch platform.
The root cause is an empty skb (skb->len == 0) is put on the queue.
This empty skb is a TCP FIN package, which is sent by shutdown(), invoked
in test_sockmap_skb_verdict_shutdown():
shutdown(p1, SHUT_WR);
In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.
And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL-page to copy_page_to_iter(), it passed to
kmap_local_page() and page_address(), then kernel panics.
To solve this, we should skip the empty sge on the queue. So in
sk_msg_recvmsg(), if msg_rx->sg.end is zero, that means it's an empty sge,
skip it.
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Geliang Tang <tanggeliang(a)kylinos.cn>
---
v4:
- skmsg: skip empty sge in sk_msg_recvmsg
v3:
- skmsg: prevent empty ingress skb from enqueuing
v2:
- skmsg: null check for sg_page in sk_msg_recvmsg
---
net/core/skmsg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index fd20aae30be2..66db1631852b 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -421,7 +421,7 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
while (copied != len) {
struct scatterlist *sge;
- if (unlikely(!msg_rx))
+ if (unlikely(!msg_rx || !msg_rx->sg.end))
break;
i = msg_rx->sg.start;
--
2.43.0
`MFD_NOEXEC_SEAL` should remove the executable bits and set `F_SEAL_EXEC`
to prevent further modifications to the executable bits as per the comment
in the uapi header file:
not executable and sealed to prevent changing to executable
However, commit 105ff5339f498a ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
that introduced this feature made it so that `MFD_NOEXEC_SEAL` unsets
`F_SEAL_SEAL`, essentially acting as a superset of `MFD_ALLOW_SEALING`.
Nothing implies that it should be so, and indeed up until the second version
of the of the patchset[0] that introduced `MFD_EXEC` and `MFD_NOEXEC_SEAL`,
`F_SEAL_SEAL` was not removed, however, it was changed in the third revision
of the patchset[1] without a clear explanation.
This behaviour is surprising for application developers, there is no
documentation that would reveal that `MFD_NOEXEC_SEAL` has the additional
effect of `MFD_ALLOW_SEALING`. Additionally, combined with `vm.memfd_noexec=2`
it has the effect of making all memfds initially sealable.
So do not remove `F_SEAL_SEAL` when `MFD_NOEXEC_SEAL` is requested,
thereby returning to the pre-Linux 6.3 behaviour of only allowing
sealing when `MFD_ALLOW_SEALING` is specified.
Now, this is technically a uapi break. However, the damage is expected
to be minimal. To trigger user visible change, a program has to do the
following steps:
- create memfd:
- with `MFD_NOEXEC_SEAL`,
- without `MFD_ALLOW_SEALING`;
- try to add seals / check the seals.
But that seems unlikely to happen intentionally since this change
essentially reverts the kernel's behaviour to that of Linux <6.3,
so if a program worked correctly on those older kernels, it will
likely work correctly after this change.
I have used Debian Code Search and GitHub to try to find potential
breakages, and I could only find a single one. dbus-broker's
memfd_create() wrapper is aware of this implicit `MFD_ALLOW_SEALING`
behaviour, and tries to work around it[2]. This workaround will
break. Luckily, this only affects the test suite, it does not affect
the normal operations of dbus-broker. There is a PR with a fix[3].
I also carried out a smoke test by building a kernel with this change
and booting an Arch Linux system into GNOME and Plasma sessions.
There was also a previous attempt to address this peculiarity by
introducing a new flag[4].
[0]: https://lore.kernel.org/lkml/20220805222126.142525-3-jeffxu@google.com/
[1]: https://lore.kernel.org/lkml/20221202013404.163143-3-jeffxu@google.com/
[2]: https://github.com/bus1/dbus-broker/blob/9eb0b7e5826fc76cad7b025bc46f267d4a…
[3]: https://github.com/bus1/dbus-broker/pull/366
[4]: https://lore.kernel.org/lkml/20230714114753.170814-1-david@readahead.eu/
Cc: stable(a)vger.kernel.org
Signed-off-by: Barnabás Pőcze <pobrn(a)protonmail.com>
---
* v3: https://lore.kernel.org/linux-mm/20240611231409.3899809-1-jeffxu@chromium.o…
* v2: https://lore.kernel.org/linux-mm/20240524033933.135049-1-jeffxu@google.com/
* v1: https://lore.kernel.org/linux-mm/20240513191544.94754-1-pobrn@protonmail.co…
This fourth version returns to removing the inconsistency as opposed to documenting
its existence, with the same code change as v1 but with a somewhat extended commit
message. This is sent because I believe it is worth at least a try; it can be easily
reverted if bigger application breakages are discovered than initially imagined.
---
mm/memfd.c | 9 ++++-----
tools/testing/selftests/memfd/memfd_test.c | 2 +-
2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/mm/memfd.c b/mm/memfd.c
index 7d8d3ab3fa37..8b7f6afee21d 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -356,12 +356,11 @@ SYSCALL_DEFINE2(memfd_create,
inode->i_mode &= ~0111;
file_seals = memfd_file_seals_ptr(file);
- if (file_seals) {
- *file_seals &= ~F_SEAL_SEAL;
+ if (file_seals)
*file_seals |= F_SEAL_EXEC;
- }
- } else if (flags & MFD_ALLOW_SEALING) {
- /* MFD_EXEC and MFD_ALLOW_SEALING are set */
+ }
+
+ if (flags & MFD_ALLOW_SEALING) {
file_seals = memfd_file_seals_ptr(file);
if (file_seals)
*file_seals &= ~F_SEAL_SEAL;
diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c
index 95af2d78fd31..7b78329f65b6 100644
--- a/tools/testing/selftests/memfd/memfd_test.c
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -1151,7 +1151,7 @@ static void test_noexec_seal(void)
mfd_def_size,
MFD_CLOEXEC | MFD_NOEXEC_SEAL);
mfd_assert_mode(fd, 0666);
- mfd_assert_has_seals(fd, F_SEAL_EXEC);
+ mfd_assert_has_seals(fd, F_SEAL_SEAL | F_SEAL_EXEC);
mfd_fail_chmod(fd, 0777);
close(fd);
}
--
2.45.2
From: Quan Zhou <zhouquan(a)iscas.ac.cn>
Due to the path that modifies a0 in syscall_enter_from_user_mode before the
actual execution of syscall_handler [1], the kernel currently saves a0 to
orig_a0 at the entry point of do_trap_ecall_u as an original copy of a0.
Once the syscall is interrupted and later resumed, the restarted syscall
will use orig_a0 to continue execution.
The above rules generally apply except for ptrace(PTRACE_SETREGSET,),
where the kernel will ignore the tracer's setting of tracee/a0 and
will restart with the tracee/orig_a0. For the current kernel implementation
of ptrace, projects like CRIU/Proot will encounter issues where the a0
setting becomes ineffective when performing ptrace(PTRACE_SETREGSET,).
Here is a suggested solution, expose orig_a0 to userspace so that ptrace
can choose whether to set orig_a0 based on the actual scenario. In fact,
x86/orig_eax and loongArch/orig_a0 have adopted similar solutions.
[1] link:
https://lore.kernel.org/lkml/20230403-crisping-animosity-04ed8a45c625@spud/…
---
Changes from RFC->v1:
- Rebased on Linux 6.10-rc5.
- Updated the patch description.
- Adjust MAX_REG_OFFSET to match the new bottom of pt_regs (Charlie).
- Simplify selftest to verify if a0 can be set (Charlie).
- Fix .gitignore error (Charlie).
---
RFC link:
https://lore.kernel.org/all/cover.1718693532.git.zhouquan@iscas.ac.cn/
Quan Zhou (2):
riscv: Expose orig_a0 in the user_regs_struct structure
riscv: selftests: Add a ptrace test to verify syscall parameter
modification
arch/riscv/include/asm/ptrace.h | 7 +-
arch/riscv/include/uapi/asm/ptrace.h | 2 +
tools/testing/selftests/riscv/Makefile | 2 +-
tools/testing/selftests/riscv/abi/.gitignore | 1 +
tools/testing/selftests/riscv/abi/Makefile | 12 ++
tools/testing/selftests/riscv/abi/ptrace.c | 124 +++++++++++++++++++
6 files changed, 144 insertions(+), 4 deletions(-)
create mode 100644 tools/testing/selftests/riscv/abi/.gitignore
create mode 100644 tools/testing/selftests/riscv/abi/Makefile
create mode 100644 tools/testing/selftests/riscv/abi/ptrace.c
base-commit: f2661062f16b2de5d7b6a5c42a9a5c96326b8454
--
2.34.1