Changes in v2:
- 1/3: Parse -s using sscanf("%zu", ...) instead of strtoull().
- 2/3: Fix typo in charge_reserved_hugetlb.sh ("reseravation" -> "reservation").
- 3/3: No changes.
This series fixes a few issues in the hugetlb cgroup charging selftests
(write_to_hugetlbfs.c + charge_reserved_hugetlb.sh) that show up on systems
with large hugepages (e.g. 512MB) and when failures cause the test to wait
indefinitely.
On an aarch64 64k page kernel with 512MB hugepages, the test consistently
fails in write_to_hugetlbfs with ENOMEM and then hangs waiting for the
expected usage values. The root cause is that charge_reserved_hugetlb.sh
mounts hugetlbfs with a fixed size=256M, which is smaller than a single
hugepage, resulting in a mount with size=0 capacity.
In addition, write_to_hugetlbfs previously parsed -s via atoi() into an
int, which can overflow and print negative sizes.
Reproducer / environment:
- Kernel: 6.12.0-xxx.el10.aarch64+64k
- Hugepagesize: 524288 kB (512MB)
- ./charge_reserved_hugetlb.sh -cgroup-v2
- Observed mount: pagesize=512M,size=0 before this series
After applying the series, the test completes successfully on the above setup.
Li Wang (3):
selftests/mm/write_to_hugetlbfs: parse -s as size_t
selftests/mm/charge_reserved_hugetlb.sh: add waits with timeout helper
selftests/mm/charge_reserved_hugetlb: fix hugetlbfs mount size for
large hugepages
.../selftests/mm/charge_reserved_hugetlb.sh | 51 ++++++++++---------
.../testing/selftests/mm/write_to_hugetlbfs.c | 9 ++--
2 files changed, 34 insertions(+), 26 deletions(-)
--
2.49.0
Patch series "Fix va_high_addr_switch.sh test failure - again", v1.
There are two issues exist for the va_high_addr_switch test. One issue is
the test return value is ignored in va_high_addr_switch.sh. The second is
the va_high_addr_switch requires 6 hugepages but it requires 5.
Besides that, the nr_hugepages setup in run_vmtests.sh for arm64 can be
done in va_high_addr_switch.sh too.
This patch: (of 3)
The return value should be return value of va_high_addr_switch, otherwise
a test failure would be silently ignored.
Fixes: d9d957bd7b61 ("selftests/mm: alloc hugepages in va_high_addr_switch test")
CC: Luiz Capitulino <luizcap(a)redhat.com>
Signed-off-by: Chunyu Hu <chuhu(a)redhat.com>
---
tools/testing/selftests/mm/va_high_addr_switch.sh | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/mm/va_high_addr_switch.sh b/tools/testing/selftests/mm/va_high_addr_switch.sh
index a7d4b02b21dd..f89fe078a8e6 100755
--- a/tools/testing/selftests/mm/va_high_addr_switch.sh
+++ b/tools/testing/selftests/mm/va_high_addr_switch.sh
@@ -114,4 +114,6 @@ save_nr_hugepages
# 4 keep_mapped pages, and one for tmp usage
setup_nr_hugepages 5
./va_high_addr_switch --run-hugetlb
+retcode=$?
restore_nr_hugepages
+exit $retcode
--
2.49.0
Verify Wacom devices set INPUT_PROP_DIRECT on display devices and
INPUT_PROP_POINTER on opaque devices. Moved test_prop_pointer into
TestOpaqueTablet. Created a DirectTabletTest mixin class for
test_prop_direct that can be inherited by display tablet test classes.
Used DirectTabletTest for TestDTH2452Tablet case.
Signed-off-by: Alex Tran <alex.t.tran(a)gmail.com>
---
Changes in v2:
- Removed the tests from the BaseTest class
- Removed disabling tests for certain subclasses
- Moved test_prop_pointer under TestOpaqueTablet
- Created DirectTabletTest mixin class
- Moved test_prop_direct under TestDTH2452Tablet
.../selftests/hid/tests/test_wacom_generic.py | 30 +++++++++++--------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/hid/tests/test_wacom_generic.py b/tools/testing/selftests/hid/tests/test_wacom_generic.py
index 2d6d04f0f..9d0b0802d 100644
--- a/tools/testing/selftests/hid/tests/test_wacom_generic.py
+++ b/tools/testing/selftests/hid/tests/test_wacom_generic.py
@@ -598,18 +598,6 @@ class BaseTest:
if unit_set:
assert required[usage].contains(field)
- def test_prop_direct(self):
- """
- Todo: Verify that INPUT_PROP_DIRECT is set on display devices.
- """
- pass
-
- def test_prop_pointer(self):
- """
- Todo: Verify that INPUT_PROP_POINTER is set on opaque devices.
- """
- pass
-
class PenTabletTest(BaseTest.TestTablet):
def assertName(self, uhdev):
@@ -677,6 +665,13 @@ class TestOpaqueTablet(PenTabletTest):
uhdev.event(130, 240, pressure=0), [], auto_syn=False, strict=True
)
+ def test_prop_pointer(self):
+ """
+ Verify that INPUT_PROP_POINTER is set on opaque devices.
+ """
+ evdev = self.uhdev.get_evdev()
+ assert libevdev.INPUT_PROP_POINTER in evdev.properties
+
class TestOpaqueCTLTablet(TestOpaqueTablet):
def create_device(self):
@@ -862,7 +857,16 @@ class TestPTHX60_Pen(TestOpaqueCTLTablet):
)
-class TestDTH2452Tablet(test_multitouch.BaseTest.TestMultitouch, TouchTabletTest):
+class DirectTabletTest():
+ def test_prop_direct(self):
+ """
+ Verify that INPUT_PROP_DIRECT is set on display devices.
+ """
+ evdev = self.uhdev.get_evdev()
+ assert libevdev.INPUT_PROP_DIRECT in evdev.properties
+
+
+class TestDTH2452Tablet(test_multitouch.BaseTest.TestMultitouch, TouchTabletTest, DirectTabletTest):
ContactIds = namedtuple("ContactIds", "contact_id, tracking_id, slot_num")
def create_device(self):
--
2.51.0
Hi Linus,
Please pull the following fixes update for Linux 6.19-rc3.
Drops unused parameter from kunit_device_register_internal and makes
FAULT_TEST default to n when PANIC_ON_OOPS.
Note: Sending this early for 6.19-rc3 (way too late for rc2 anyways)
diff is attached.
thanks,
-- Shuah
----------------------------------------------------------------
The following changes since commit 8f0b4cce4481fb22653697cced8d0d04027cb1e8:
Linux 6.19-rc1 (2025-12-14 16:05:07 +1200)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest tags/linux_kselftest-kunit-fixes-6.19-rc3
for you to fetch changes up to c33b68801fbe9d5ee8a9178beb5747ec65873530:
kunit: make FAULT_TEST default to n when PANIC_ON_OOPS (2025-12-15 09:27:19 -0700)
----------------------------------------------------------------
linux_kselftest-kunit-fixes-6.19-rc3
Drops unused parameter from kunit_device_register_internal and makes
FAULT_TEST default to n when PANIC_ON_OOPS.
----------------------------------------------------------------
Brendan Jackman (1):
kunit: make FAULT_TEST default to n when PANIC_ON_OOPS
Uwe Kleine-König (1):
kunit: Drop unused parameter from kunit_device_register_internal
lib/kunit/Kconfig | 2 +-
lib/kunit/device.c | 7 +++----
2 files changed, 4 insertions(+), 5 deletions(-)
----------------------------------------------------------------
This series fixes a few issues in the hugetlb cgroup charging selftests
(write_to_hugetlbfs.c + charge_reserved_hugetlb.sh) that show up on systems
with large hugepages (e.g. 512MB) and when failures cause the test to wait
indefinitely.
On an aarch64 64k page kernel with 512MB hugepages, the test consistently
fails in write_to_hugetlbfs with ENOMEM and then hangs waiting for the
expected usage values. The root cause is that charge_reserved_hugetlb.sh
mounts hugetlbfs with a fixed size=256M, which is smaller than a single
hugepage, resulting in a mount with size=0 capacity.
In addition, write_to_hugetlbfs previously parsed -s via atoi() into an
int, which can overflow and print negative sizes.
Reproducer / environment:
- Kernel: 6.12.0-xxx.el10.aarch64+64k
- Hugepagesize: 524288 kB (512MB)
- ./charge_reserved_hugetlb.sh -cgroup-v2
- Observed mount: pagesize=512M,size=0 before this series
After applying the series, the test completes successfully on the above setup.
Li Wang (3):
selftests/mm/write_to_hugetlbfs: parse -s with strtoull and use size_t
selftests/mm/charge_reserved_hugetlb.sh: add waits with timeout helper
selftests/mm/charge_reserved_hugetlb: fix hugetlbfs mount size for
large hugepages
.../selftests/mm/charge_reserved_hugetlb.sh | 49 ++++++++++---------
.../testing/selftests/mm/write_to_hugetlbfs.c | 19 +++++--
2 files changed, 43 insertions(+), 25 deletions(-)
--
2.49.0
Currently, x86, Riscv, Loongarch use the Generic Entry which makes
maintainers' work easier and codes more elegant. arm64 has already
successfully switched to the Generic IRQ Entry in commit
b3cf07851b6c ("arm64: entry: Switch to generic IRQ entry"), it is
time to completely convert arm64 to Generic Entry.
The goal is to bring arm64 in line with other architectures that already
use the generic entry infrastructure, reducing duplicated code and
making it easier to share future changes in entry/exit paths, such as
"Syscall User Dispatch".
This patch set is rebased on v6.18-rc7. And the performance was measured
on Kunpeng 920 using "perf bench basic syscall" with "arm64.nopauth
selinux=0 audit=1".
After switch to Generic Entry, the performance are below:
| Metric | W/O Generic Framework | With Generic Framework | Change |
| ---------- | --------------------- | ---------------------- | ------ |
| Total time | 2.130 [sec] | 2.235 [sec] | ↑4.90% |
| usecs/op | 0.213095 | 0.223512 | ↑4.89% |
| ops/sec | 4,692,753 | 4,474,044 | ↓4.89% |
Compared to earlier with arch specific handling, the performance decreased
by approximately 4.9%.
On the basis of optimizing syscall_get_arguments()[1], el0_svc_common()
and syscall_exit_work(), the performance are below:
| Metric | W/O Generic Entry | With Generic Entry opt| Change |
| ---------- | ----------------- | ------------------ | ------ |
| Total time | 2.130 [sec] | 2.134 [sec] | ↑0.18% |
| usecs/op | 0.213095 | 0.213414 | ↑0.15% |
| ops/sec | 4,692,753 | 4,685,737 | ↓0.15% |
Therefore, after the optimization, ARM64 System Call performance remains
almost unchanged.
It was tested ok with following test cases on kunpeng920 and QEMU
virt platform:
- Perf tests.
- Different `dynamic preempt` mode switch.
- Pseudo NMI tests.
- Stress-ng CPU stress test.
- Hackbench stress test.
- MTE test case in Documentation/arch/arm64/memory-tagging-extension.rst
and all test cases in tools/testing/selftests/arm64/mte/*.
- "sud" selftest testcase.
- get_set_sud, get_syscall_info, set_syscall_info, peeksiginfo
in tools/testing/selftests/ptrace.
- breakpoint_test_arm64 in selftests/breakpoints.
- syscall-abi and ptrace in tools/testing/selftests/arm64/abi
- fp-ptrace, sve-ptrace, za-ptrace in selftests/arm64/fp.
- vdso_test_getrandom in tools/testing/selftests/vDSO
- Strace tests.
The test QEMU configuration is as follows:
qemu-system-aarch64 \
-M virt,gic-version=3,virtualization=on,mte=on \
-cpu max,pauth-impdef=on \
-kernel Image \
-smp 8,sockets=1,cores=4,threads=2 \
-m 512m \
-nographic \
-no-reboot \
-device virtio-rng-pci \
-append "root=/dev/vda rw console=ttyAMA0 kgdboc=ttyAMA0,115200 \
earlycon preempt=voluntary irqchip.gicv3_pseudo_nmi=1" \
-drive if=none,file=images/rootfs.ext4,format=raw,id=hd0 \
-device virtio-blk-device,drive=hd0 \
[1]: https://lore.kernel.org/all/20251201120633.1193122-3-ruanjinjie@huawei.com/
Changes in v9:
- Move "Return early for ptrace_report_syscall_entry() error" patch ahead
to make it not introduce a regression.
- Not check _TIF_SECCOMP/SYSCALL_EMU for syscall_exit_work() in
a separate patch.
- Do not report_syscall_exit() for PTRACE_SYSEMU_SINGLESTEP in a separate
patch.
- Add two performance patch to improve the arm64 performance.
- Add Reviewed-by.
- Link to v8: https://lore.kernel.org/all/20251126071446.3234218-1-ruanjinjie@huawei.com/
Changes in v8:
- Rename "report_syscall_enter()" to "report_syscall_entry()".
- Add ptrace_save_reg() to avoid duplication.
- Remove unused _TIF_WORK_MASK in a standalone patch.
- Align syscall_trace_enter() return value with the generic version.
- Use "scno" instead of regs->syscallno in el0_svc_common().
- Move rseq_syscall() ahead in a standalone patch to clarify it clearly.
- Rename "syscall_trace_exit()" to "syscall_exit_work()".
- Keep the goto in el0_svc_common().
- No argument was passed to __secure_computing() and check -1 not -1L.
- Remove "Add has_syscall_work() helper" patch.
- Move "Add syscall_exit_to_user_mode_prepare() helper" patch later.
- Add miss header for asm/entry-common.h.
- Update the implementation of arch_syscall_is_vdso_sigreturn().
- Add "ARCH_SYSCALL_WORK_EXIT" to be defined as "SECCOMP | SYSCALL_EMU"
to keep the behaviour unchanged.
- Add more testcases test.
- Add Reviewed-by.
- Update the commit message.
- Link to v7: https://lore.kernel.org/all/20251117133048.53182-1-ruanjinjie@huawei.com/
Chanegs in v7:
- Support "Syscall User Dispatch" by implementing
arch_syscall_is_vdso_sigreturn() as kemal suggested.
- Add aarch64 support for "sud" selftest testcase, which tested ok with
the patch series.
- Fix the kernel test robot warning for arch_ptrace_report_syscall_entry()
and arch_ptrace_report_syscall_exit() in asm/entry-common.h.
- Add perf syscall performance test.
- Link to v6: https://lore.kernel.org/all/20250916082611.2972008-1-ruanjinjie@huawei.com/
Changes in v6:
- Rebased on v6.17-rc5-next as arm64 generic irq entry has merged.
- Update the commit message.
- Link to v5: https://lore.kernel.org/all/20241206101744.4161990-1-ruanjinjie@huawei.com/
Changes in v5:
- Not change arm32 and keep inerrupts_enabled() macro for gicv3 driver.
- Move irqentry_state definition into arch/arm64/kernel/entry-common.c.
- Avoid removing the __enter_from_*() and __exit_to_*() wrappers.
- Update "irqentry_state_t ret/irq_state" to "state"
to keep it consistently.
- Use generic irq entry header for PREEMPT_DYNAMIC after split
the generic entry.
- Also refactor the ARM64 syscall code.
- Introduce arch_ptrace_report_syscall_entry/exit(), instead of
arch_pre/post_report_syscall_entry/exit() to simplify code.
- Make the syscall patches clear separation.
- Update the commit message.
- Link to v4: https://lore.kernel.org/all/20241025100700.3714552-1-ruanjinjie@huawei.com/
Changes in v4:
- Rework/cleanup split into a few patches as Mark suggested.
- Replace interrupts_enabled() macro with regs_irqs_disabled(), instead
of left it here.
- Remove rcu and lockdep state in pt_regs by using temporary
irqentry_state_t as Mark suggested.
- Remove some unnecessary intermediate functions to make it clear.
- Rework preempt irq and PREEMPT_DYNAMIC code
to make the switch more clear.
- arch_prepare_*_entry/exit() -> arch_pre_*_entry/exit().
- Expand the arch functions comment.
- Make arch functions closer to its caller.
- Declare saved_reg in for block.
- Remove arch_exit_to_kernel_mode_prepare(), arch_enter_from_kernel_mode().
- Adjust "Add few arch functions to use generic entry" patch to be
the penultimate.
- Update the commit message.
- Add suggested-by.
- Link to v3: https://lore.kernel.org/all/20240629085601.470241-1-ruanjinjie@huawei.com/
Changes in v3:
- Test the MTE test cases.
- Handle forget_syscall() in arch_post_report_syscall_entry()
- Make the arch funcs not use __weak as Thomas suggested, so move
the arch funcs to entry-common.h, and make arch_forget_syscall() folded
in arch_post_report_syscall_entry() as suggested.
- Move report_single_step() to thread_info.h for arm64
- Change __always_inline() to inline, add inline for the other arch funcs.
- Remove unused signal.h for entry-common.h.
- Add Suggested-by.
- Update the commit message.
Changes in v2:
- Add tested-by.
- Fix a bug that not call arch_post_report_syscall_entry() in
syscall_trace_enter() if ptrace_report_syscall_entry() return not zero.
- Refactor report_syscall().
- Add comment for arch_prepare_report_syscall_exit().
- Adjust entry-common.h header file inclusion to alphabetical order.
- Update the commit message.
Jinjie Ruan (15):
arm64: Remove unused _TIF_WORK_MASK
arm64/ptrace: Split report_syscall()
arm64/ptrace: Return early for ptrace_report_syscall_entry() error
arm64/ptrace: Refactor syscall_trace_enter/exit()
arm64: ptrace: Move rseq_syscall() before audit_syscall_exit()
arm64: syscall: Rework el0_svc_common()
arm64/ptrace: Not check _TIF_SECCOMP/SYSCALL_EMU for
syscall_exit_work()
arm64/ptrace: Do not report_syscall_exit() for
PTRACE_SYSEMU_SINGLESTEP
arm64/ptrace: Expand secure_computing() in place
arm64/ptrace: Use syscall_get_arguments() helper
entry: Split syscall_exit_to_user_mode_work() for arch reuse
entry: Add arch_ptrace_report_syscall_entry/exit()
arm64: entry: Convert to generic entry
arm64: Inline el0_svc_common()
entry: Inline syscall_exit_work()
kemal (1):
selftests: sud_test: Support aarch64
arch/arm64/Kconfig | 2 +-
arch/arm64/include/asm/entry-common.h | 76 ++++++++++++++
arch/arm64/include/asm/syscall.h | 19 +++-
arch/arm64/include/asm/thread_info.h | 22 +----
arch/arm64/kernel/debug-monitors.c | 7 ++
arch/arm64/kernel/ptrace.c | 94 ------------------
arch/arm64/kernel/signal.c | 2 +-
arch/arm64/kernel/syscall.c | 29 ++----
include/linux/entry-common.h | 98 ++++++++++++++++---
kernel/entry/syscall-common.c | 60 +++++-------
.../syscall_user_dispatch/sud_test.c | 4 +
11 files changed, 220 insertions(+), 193 deletions(-)
--
2.34.1
Replace the NULL checks with IS_ERR_OR_NULL() in
KUNIT_BINARY_STR_ASSERTION() to prevent the strcmp() faulting if a
passed pointer is an ERR_PTR.
Commit 7ece381aa72d4 ("kunit: Protect string comparisons against NULL")
added the checks for NULL on both pointers so that asserts would fail,
instead of faulting, if either pointer is NULL. But either pointer
could hold an ERR_PTR value.
This assumes that the assertion is expecting both strings to be valid,
and is asserting the equality of their _content_.
Signed-off-by: Richard Fitzgerald <rf(a)opensource.cirrus.com>
---
include/kunit/test.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 5ec5182b5e57..9cd1594ab697 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -906,7 +906,8 @@ do { \
}; \
\
_KUNIT_SAVE_LOC(test); \
- if (likely((__left) && (__right) && (strcmp(__left, __right) op 0))) \
+ if (likely(!IS_ERR_OR_NULL(__left) && !IS_ERR_OR_NULL(__right) && \
+ (strcmp(__left, __right) op 0))) \
break; \
\
\
--
2.47.3
While debugging issues related to aarch64 only systems I ran into
speedbumps due to the lack of detail in the results reported when the
guest register read and reset value preservation tests were run, they
generated an immediately fatal assert without indicating which register
was being tested. Update these tests to report a result per register,
making it much easier to see what the problem being reported is.
A similar, though less severe, issue exists with the validation of the
individual bitfields in registers due to the use of immediately fatal
asserts. Update those asserts to be standard kselftest reports.
Finally we have a fix for spurious errors on some NV systems.
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v3:
- Rebase onto v6.19-rc1.
- Link to v2: https://patch.msgid.link/20251114-kvm-arm64-set-id-regs-aarch64-v2-0-672f21…
Changes in v2:
- Add a fix for spurious failures with 64 bit only guests.
- Link to v1: https://patch.msgid.link/20251030-kvm-arm64-set-id-regs-aarch64-v1-0-96fe0d…
---
Mark Brown (4):
KVM: selftests: arm64: Report set_id_reg reads of test registers as tests
KVM: selftests: arm64: Report register reset tests individually
KVM: selftests: arm64: Make set_id_regs bitfield validatity checks non-fatal
KVM: selftests: arm64: Skip all 32 bit IDs when set_id_regs is aarch64 only
tools/testing/selftests/kvm/arm64/set_id_regs.c | 150 ++++++++++++++++++------
1 file changed, 111 insertions(+), 39 deletions(-)
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251028-kvm-arm64-set-id-regs-aarch64-ebb77969401c
Best regards,
--
Mark Brown <broonie(a)kernel.org>
Greetings:
Welcome to v9, see changelog below.
This revision addresses feedback Willem gave on the selftests. No
functional or code changes to the implementation were made and
performance tests were not re-run.
This series introduces a new mechanism, IRQ suspension, which allows
network applications using epoll to mask IRQs during periods of high
traffic while also reducing tail latency (compared to existing
mechanisms, see below) during periods of low traffic. In doing so, this
balances CPU consumption with network processing efficiency.
Martin Karsten (CC'd) and I have been collaborating on this series for
several months and have appreciated the feedback from the community on
our RFC [1]. We've updated the cover letter and kernel documentation in
an attempt to more clearly explain how this mechanism works, how
applications can use it, and how it compares to existing mechanisms in
the kernel.
I briefly mentioned this idea at netdev conf 2024 (for those who were
there) and Martin described this idea in an earlier paper presented at
Sigmetrics 2024 [2].
~ The short explanation (TL;DR)
We propose adding a new napi config parameter: irq_suspend_timeout to
help balance CPU usage and network processing efficiency when using IRQ
deferral and napi busy poll.
If this parameter is set to a non-zero value *and* a user application
has enabled preferred busy poll on a busy poll context (via the
EPIOCSPARAMS ioctl introduced in commit 18e2bf0edf4d ("eventpoll: Add
epoll ioctl for epoll_params")), then application calls to epoll_wait
for that context will cause device IRQs and softirq processing to be
suspended as long as epoll_wait successfully retrieves data from the
NAPI. Each time data is retrieved, the irq_suspend_timeout is deferred.
If/when network traffic subsides and epoll_wait returns no data, IRQ
suspension is immediately reverted back to the existing
napi_defer_hard_irqs and gro_flush_timeout mechanism which was
introduced in commit 6f8b12d661d0 ("net: napi: add hard irqs deferral
feature")).
The irq_suspend_timeout serves as a safety mechanism. If userland takes
a long time processing data, irq_suspend_timeout will fire and restart
normal NAPI processing.
For a more in depth explanation, please continue reading.
~ Comparison with existing mechanisms
Interrupt mitigation can be accomplished in napi software, by setting
napi_defer_hard_irqs and gro_flush_timeout, or via interrupt coalescing
in the NIC. This can be quite efficient, but in both cases, a fixed
timeout (or packet count) needs to be configured. However, a fixed
timeout cannot effectively support both low- and high-load situations:
At low load, an application typically processes a few requests and then
waits to receive more input data. In this scenario, a large timeout will
cause unnecessary latency.
At high load, an application typically processes many requests before
being ready to receive more input data. In this case, a small timeout
will likely fire prematurely and trigger irq/softirq processing, which
interferes with the application's execution. This causes overhead, most
likely due to cache contention.
While NICs attempt to provide adaptive interrupt coalescing schemes,
these cannot properly take into account application-level processing.
An alternative packet delivery mechanism is busy-polling, which results
in perfect alignment of application processing and network polling. It
delivers optimal performance (throughput and latency), but results in
100% cpu utilization and is thus inefficient for below-capacity
workloads.
We propose to add a new packet delivery mode that properly alternates
between busy polling and interrupt-based delivery depending on busy and
idle periods of the application. During a busy period, the system
operates in busy-polling mode, which avoids interference. During an idle
period, the system falls back to interrupt deferral, but with a small
timeout to avoid excessive latencies. This delivery mode can also be
viewed as an extension of basic interrupt deferral, but alternating
between a small and a very large timeout.
This delivery mode is efficient, because it avoids softirq execution
interfering with application processing during busy periods. It can be
used with blocking epoll_wait to conserve cpu cycles during idle
periods. The effect of alternating between busy and idle periods is that
performance (throughput and latency) is very close to full busy polling,
while cpu utilization is lower and very close to interrupt mitigation.
~ Usage details
IRQ suspension is introduced via a per-NAPI configuration parameter that
controls the maximum time that IRQs can be suspended.
Here's how it is intended to work:
- The user application (or system administrator) uses the netdev-genl
netlink interface to set the pre-existing napi_defer_hard_irqs and
gro_flush_timeout NAPI config parameters to enable IRQ deferral.
- The user application (or system administrator) sets the proposed
irq_suspend_timeout parameter via the netdev-genl netlink interface
to a larger value than gro_flush_timeout to enable IRQ suspension.
- The user application issues the existing epoll ioctl to set the
prefer_busy_poll flag on the epoll context.
- The user application then calls epoll_wait to busy poll for network
events, as it normally would.
- If epoll_wait returns events to userland, IRQs are suspended for the
duration of irq_suspend_timeout.
- If epoll_wait finds no events and the thread is about to go to
sleep, IRQ handling using napi_defer_hard_irqs and gro_flush_timeout
is resumed.
As long as epoll_wait is retrieving events, IRQs (and softirq
processing) for the NAPI being polled remain disabled. When network
traffic reduces, eventually a busy poll loop in the kernel will retrieve
no data. When this occurs, regular IRQ deferral using gro_flush_timeout
for the polled NAPI is re-enabled.
Unless IRQ suspension is continued by subsequent calls to epoll_wait, it
automatically times out after the irq_suspend_timeout timer expires.
Regular deferral is also immediately re-enabled when the epoll context
is destroyed.
~ Usage scenario
The target scenario for IRQ suspension as packet delivery mode is a
system that runs a dominant application with substantial network I/O.
The target application can be configured to receive input data up to a
certain batch size (via epoll_wait maxevents parameter) and this batch
size determines the worst-case latency that application requests might
experience. Because packet delivery is suspended during the target
application's processing, the batch size also determines the worst-case
latency of concurrent applications using the same RX queue(s).
gro_flush_timeout should be set as small as possible, but large enough to
make sure that a single request is likely not being interfered with.
irq_suspend_timeout is largely a safety mechanism against misbehaving
applications. It should be set large enough to cover the processing of an
entire application batch, i.e., the factor between gro_flush_timeout and
irq_suspend_timeout should roughly correspond to the maximum batch size
that the target application would process in one go.
~ Important call out in the implementation
- Enabling per epoll-context preferred busy poll will now effectively
lead to a nonblocking iteration through napi_busy_loop, even when
busy_poll_usecs is 0. See patch 4.
~ Benchmark configs & descriptions
The changes were benchmarked with memcached [3] using the benchmarking
tool mutilate [4].
To facilitate benchmarking, a small patch [5] was applied to memcached
1.6.29 to allow setting per-epoll context preferred busy poll and other
settings via environment variables. Another small patch [6] was applied
to libevent to enable full busy-polling.
Multiple scenarios were benchmarked as described below and the scripts
used for producing these results can be found on github [7] (note: all
scenarios use NAPI-based traffic splitting via SO_INCOMING_ID by passing
-N to memcached):
- base:
- no other options enabled
- deferX:
- set defer_hard_irqs to 100
- set gro_flush_timeout to X,000
- napibusy:
- set defer_hard_irqs to 100
- set gro_flush_timeout to 200,000
- enable busy poll via the existing ioctl (busy_poll_usecs = 64,
busy_poll_budget = 64, prefer_busy_poll = true)
- fullbusy:
- set defer_hard_irqs to 100
- set gro_flush_timeout to 5,000,000
- enable busy poll via the existing ioctl (busy_poll_usecs = 1000,
busy_poll_budget = 64, prefer_busy_poll = true)
- change memcached's nonblocking epoll_wait invocation (via
libevent) to using a 1 ms timeout
- suspend0:
- set defer_hard_irqs to 0
- set gro_flush_timeout to 0
- set irq_suspend_timeout to 20,000,000
- enable busy poll via the existing ioctl (busy_poll_usecs = 0,
busy_poll_budget = 64, prefer_busy_poll = true)
- suspendX:
- set defer_hard_irqs to 100
- set gro_flush_timeout to X,000
- set irq_suspend_timeout to 20,000,000
- enable busy poll via the existing ioctl (busy_poll_usecs = 0,
busy_poll_budget = 64, prefer_busy_poll = true)
~ Benchmark results
Tested on:
Single socket AMD EPYC 7662 64-Core Processor
Hyperthreading disabled
4 NUMA Zones (NPS=4)
16 CPUs per NUMA zone (64 cores total)
2 x Dual port 100gbps Mellanox Technologies ConnectX-5 Ex EN NIC
The test machine is configured such that a single interface has 8 RX
queues. The queues' IRQs and memcached are pinned to CPUs that are
NUMA-local to the interface which is under test. The NIC's interrupt
coalescing configuration is left at boot-time defaults.
Results:
Results are shown below. The mechanism added by this series is
represented by the 'suspend' cases. Data presented shows a summary over
nearly 10 runs of each test case [8] using the scripts on github [7].
For latency, the median is shown. For throughput and CPU utilization,
the average is shown.
The results also include cycles-per-query (cpq) and
instruction-per-query (ipq) metrics, following the methodology proposed
in [2], to augment the CPU utilization numbers, which could be skewed
due to frequency scaling. We find that this does not appear to be the
case as CPU utilization and low-level metrics show similar trends.
These results were captured using the scripts on github [7] to
illustrate how this approach compares with other pre-existing
mechanisms. This data is not to be interpreted as scientific data
captured in a fully isolated lab setting, but instead as best effort,
illustrative information comparing and contrasting tradeoffs.
The absolute QPS results shift between submissions, but the
relative differences are equivalent. As patches are rebased,
several factors likely influence overall performance.
Compare:
- Throughput (MAX) and latencies of base vs suspend.
- CPU usage of napibusy and fullbusy during lower load (200K, 400K for
example) vs suspend.
- Latency of the defer variants vs suspend as timeout and load
increases.
- suspend0, which sets defer_hard_irqs and gro_flush_timeout to 0, has
nearly the same performance as the base case (this is FAQ item #1).
The overall takeaway is that the suspend variants provide a superior
combination of high throughput, low latency, and low cpu utilization
compared to all other variants. Each of the suspend variants works very
well, but some fine-tuning between latency and cpu utilization is still
possible by tuning the small timeout (gro_flush_timeout).
Note: we've reorganized the results to make comparison among testcases
with the same load easier.
testcase load qps avglat 95%lat 99%lat cpu cpq ipq
base 200K 199946 112 239 416 26 12973 11343
defer10 200K 199971 54 124 142 29 19412 17460
defer20 200K 199986 60 130 153 26 15644 14095
defer50 200K 200025 79 144 182 23 12122 11632
defer200 200K 199999 164 254 309 19 8923 9635
fullbusy 200K 199998 46 118 133 100 43658 23133
napibusy 200K 199983 100 237 277 56 24840 24716
suspend0 200K 200020 105 249 432 30 14264 11796
suspend10 200K 199950 53 123 141 32 19518 16903
suspend20 200K 200037 58 126 151 30 16426 14736
suspend50 200K 199961 73 136 177 26 13310 12633
suspend200 200K 199998 149 251 306 21 9566 10203
testcase load qps avglat 95%lat 99%lat cpu cpq ipq
base 400K 400014 139 269 707 41 9476 9343
defer10 400K 400016 59 133 166 53 13991 12989
defer20 400K 399952 67 140 172 47 12063 11644
defer50 400K 400007 87 162 198 39 9384 9880
defer200 400K 399979 181 274 330 31 7089 8430
fullbusy 400K 399987 50 123 156 100 21827 16037
napibusy 400K 400014 76 222 272 83 18185 16529
suspend0 400K 400015 127 350 776 47 10699 9603
suspend10 400K 400023 57 129 164 54 13758 13178
suspend20 400K 400043 62 135 169 49 12071 11826
suspend50 400K 400071 76 149 186 42 10011 10301
suspend200 400K 399961 154 269 327 34 7827 8774
testcase load qps avglat 95%lat 99%lat cpu cpq ipq
base 600K 599951 149 266 574 61 9265 8876
defer10 600K 600006 71 147 203 76 11866 10936
defer20 600K 600123 76 152 203 66 10430 10342
defer50 600K 600162 95 172 217 54 8526 9142
defer200 600K 599942 200 301 357 46 6977 8212
fullbusy 600K 599990 55 127 177 100 14551 13983
napibusy 600K 600035 63 160 250 96 13937 14140
suspend0 600K 599903 127 320 732 68 10166 8963
suspend10 600K 599908 63 137 192 69 10902 11100
suspend20 600K 599961 66 141 194 65 9976 10370
suspend50 600K 599973 80 159 204 57 8678 9381
suspend200 600K 600010 157 277 346 48 7133 8381
testcase load qps avglat 95%lat 99%lat cpu cpq ipq
base 800K 800039 181 300 536 87 9585 8304
defer10 800K 800038 181 530 939 96 10564 8970
defer20 800K 800029 112 225 329 90 10056 8935
defer50 800K 799999 120 208 296 82 9234 8562
defer200 800K 800066 227 338 401 63 7117 8129
fullbusy 800K 800040 61 134 190 100 10913 12608
napibusy 800K 799944 64 141 214 99 10828 12588
suspend0 800K 799911 126 248 509 85 9346 8498
suspend10 800K 800006 69 143 200 83 9410 9845
suspend20 800K 800120 74 150 207 78 8786 9454
suspend50 800K 799989 87 168 224 71 7946 8833
suspend200 800K 799987 160 292 357 62 6923 8229
testcase load qps avglat 95%lat 99%lat cpu cpq ipq
base 1000K 906879 4079 5751 6216 98 9496 7904
defer10 1000K 860849 3643 6274 6730 99 10040 8676
defer20 1000K 896063 3298 5840 6349 98 9620 8237
defer50 1000K 919782 2962 5513 5807 97 9284 7951
defer200 1000K 970941 3059 5348 5984 95 8593 7959
fullbusy 1000K 999950 70 150 207 100 8732 10777
napibusy 1000K 999996 78 154 223 100 8722 10656
suspend0 1000K 949706 2666 5770 6660 99 9071 8046
suspend10 1000K 1000024 80 160 220 92 8137 9035
suspend20 1000K 1000059 83 165 226 89 7850 8804
suspend50 1000K 999955 95 180 240 84 7411 8459
suspend200 1000K 999914 163 299 366 77 6833 8078
testcase load qps avglat 95%lat 99%lat cpu cpq ipq
base MAX 1037654 4184 5453 5810 100 8411 7938
defer10 MAX 905607 4840 6151 6380 100 9639 8431
defer20 MAX 986463 4455 5594 5796 100 8848 8110
defer50 MAX 1077030 4000 5073 5299 100 8104 7920
defer200 MAX 1040728 4152 5385 5765 100 8379 7849
fullbusy MAX 1247536 3518 3935 3984 100 6998 7930
napibusy MAX 1136310 3799 7756 9964 100 7670 7877
suspend0 MAX 1057509 4132 5724 6185 100 8253 7918
suspend10 MAX 1215147 3580 3957 4041 100 7185 7944
suspend20 MAX 1216469 3576 3953 3988 100 7175 7950
suspend50 MAX 1215871 3577 3961 4075 100 7181 7949
suspend200 MAX 1216882 3556 3951 3988 100 7175 7955
~ FAQ
- Why is a new parameter needed? Does irq_suspend_timeout override
gro_flush_timeout?
Using the suspend mechanism causes the system to alternate between
polling mode and irq-driven packet delivery. During busy periods,
irq_suspend_timeout overrides gro_flush_timeout and keeps the system
busy polling, but when epoll finds no events, the setting of
gro_flush_timeout and napi_defer_hard_irqs determine the next step.
There are essentially three possible loops for network processing and
packet delivery:
1) hardirq -> softirq -> napi poll; basic interrupt delivery
2) timer -> softirq -> napi poll; deferred irq processing
3) epoll -> busy-poll -> napi poll; busy looping
Loop 2 can take control from Loop 1, if gro_flush_timeout and
napi_defer_hard_irqs are set.
If gro_flush_timeout and napi_defer_hard_irqs are set, Loops 2 and
3 "wrestle" with each other for control. During busy periods,
irq_suspend_timeout is used as timer in Loop 2, which essentially
tilts this in favour of Loop 3.
If gro_flush_timeout and napi_defer_hard_irqs are not set, Loop 3
cannot take control from Loop 1.
Therefore, setting gro_flush_timeout and napi_defer_hard_irqs is the
recommended usage, because otherwise setting irq_suspend_timeout
might not have any discernible effect.
This is shown in the results above: compare suspend0 with the base
case. Note that the lack of napi_defer_hard_irqs and
gro_flush_timeout produce similar results for both, which encourages
the use of napi_defer_hard_irqs and gro_flush_timeout in addition to
irq_suspend_timeout.
- Can the new timeout value be threaded through the new epoll ioctl ?
It is possible, but presents challenges for userspace. User
applications must ensure that the file descriptors added to epoll
contexts have the same NAPI ID to support busy polling.
An epoll context is not permanently tied to any particular NAPI ID.
So, a user application could decide to clear the file descriptors
from the context and add a new set of file descriptors with a
different NAPI ID to the context. Busy polling would work as
expected, but the meaning of the suspend timeout becomes ambiguous
because IRQs are not inherently associated with epoll contexts, but
rather with the NAPI. The user program would need to reissue the
ioctl to set the irq_suspend_timeout, but the napi_defer_hard_irqs
and gro_flush_timeout settings would come from the NAPI's
napi_config (which are set either by sysfs or by netlink). Such an
interface seems awkard to use from a user perspective.
Further, IRQs are related to NAPIs, which is why they are stored in
the napi_config space. Putting the irq_suspend_timeout in
the epoll context while other IRQ deferral mechanisms remain in the
NAPI's napi_config space seems like an odd design choice.
We've opted to keep all of the IRQ deferral parameters together and
place the irq_suspend_timeout in napi_config. This has nice benefits
for userspace: if a user app were to remove all file descriptors
from an epoll context and add new file descriptors with a new NAPI ID,
the correct suspend timeout for that NAPI ID would be used automatically
without the user application needing to do anything (like re-issuing an
ioctl, for example). All IRQ deferral related parameters are in one
place and can all be set the same way: with netlink.
- Can irq suspend be built by combining NIC coalescing and
gro_flush_timeout ?
No. The problem is that the long timeout must engage if and only if
prefer-busy is active.
When using NIC coalescing for the short timeout (without
napi_defer_hard_irqs/gro_flush_timeout), an interrupt after an idle
period will trigger softirq, which will run napi polling. At this
point, prefer-busy is not active, so NIC interrupts would be
re-enabled. Then it is not possible for the longer timeout to
interject to switch control back to polling. In other words, only by
using the software timer for the short timeout, it is possible to
extend the timeout without having to reprogram the NIC timer or
reach down directly and disable interrupts.
Using gro_flush_timeout for the long timeout also has problems, for
the same underlying reason. In the current napi implementation,
gro_flush_timeout is not tied to prefer-busy. We'd either have to
change that and in the process modify the existing deferral
mechanism, or introduce a state variable to determine whether
gro_flush_timeout is used as long timeout for irq suspend or whether
it is used for its default purpose. In an earlier version, we did
try something similar to the latter and made it work, but it ends up
being a lot more convoluted than our current proposal.
- Isn't it already possible to combine busy looping with irq deferral?
Yes, in fact enabling irq deferral via napi_defer_hard_irqs and
gro_flush_timeout is a precondition for prefer_busy_poll to have an
effect. If the application also uses a tight busy loop with
essentially nonblocking epoll_wait (accomplished with a very short
timeout parameter), this is the fullbusy case shown in the results.
An application using blocking epoll_wait is shown as the napibusy
case in the results. It's a hybrid approach that provides limited
latency benefits compared to the base case and plain irq deferral,
but not as good as fullbusy or suspend.
~ Special thanks
Several people were involved in earlier stages of the development of this
mechanism whom we'd like to thank:
- Peter Cai (CC'd), for the initial kernel patch and his contributions
to the paper.
- Mohammadamin Shafie (CC'd), for testing various versions of the kernel
patch and providing helpful feedback.
Thanks,
Martin and Joe
[1]: https://lore.kernel.org/netdev/20240812125717.413108-1-jdamato@fastly.com/
[2]: https://doi.org/10.1145/3626780
[3]: https://github.com/memcached/memcached/blob/master/doc/napi_ids.txt
[4]: https://github.com/leverich/mutilate
[5]: https://raw.githubusercontent.com/martinkarsten/irqsuspend/main/patches/mem…
[6]: https://raw.githubusercontent.com/martinkarsten/irqsuspend/main/patches/lib…
[7]: https://github.com/martinkarsten/irqsuspend
[8]: https://github.com/martinkarsten/irqsuspend/tree/main/results
v9:
- Addresses Willem's feedback on the selftests in patch 5 by fixing
the SPDX-License-Identifier, moving constants into variables in the
test script, reducing code duplication, shortening long lines, and
renaming variables to be more reader friendly. In the C test file,
added a comment explaining the if def blob and changed a few types
for strtoul.
v8: https://lore.kernel.org/netdev/20241108045337.292905-1-jdamato@fastly.com/
- Update patch 2 to drop the exports, as requested by Jakub.
v7: https://lore.kernel.org/netdev/20241108023912.98416-1-jdamato@fastly.com/
- Jakub noted that patch 2 adds unnecessary complexity by checking the
suspend timeout in the NAPI loop. This makes the code more
complicated and difficult to reason about. He's right; we've dropped
patch 2 which simplifies this series.
- Updated the cover letter with a full re-run of all test cases.
- Updated FAQ #2.
v6: https://lore.kernel.org/netdev/20241104215542.215919-1-jdamato@fastly.com/
- Updated the cover letter with a full re-run of all test cases,
including a new case suspend0, as requested by Sridhar previously.
- Updated the kernel documentation in patch 7 as suggested by Bagas
Sanjaya, which improved the htmldoc output.
v5: https://lore.kernel.org/netdev/20241103052421.518856-1-jdamato@fastly.com/
- Adjusted patch 5 to only suspend IRQs when ep_send_events returns a
positive return value. This issue was pointed out by Hillf Danton.
- Updated the commit message of patch 6 which still mentioned netcat,
despite the code being updated in v4 to replace it with socat and fixed
misspelling of netdevsim.
- Fixed a minor typo in patch 7 and removed an unnecessary paragraph.
- Added Sridhar Samudrala's Reviewed-by to patch 1-5 and 7.
v4: https://lore.kernel.org/netdev/20241102005214.32443-1-jdamato@fastly.com/
- Added a new FAQ item to cover letter.
- Updated patch 6 to use socat instead of nc in busy_poll_test.sh and
updated busy_poller.c to use netlink directly to configure napi
params.
- Updated the kernel documentation in patch 7 to include more details.
- Dropped Stanislav's Acked-by and Bagas' Reviewed-by from patch 7
since the documentation was updated.
v3: https://lore.kernel.org/netdev/20241101004846.32532-1-jdamato@fastly.com/
- Added Stanislav Fomichev's Acked-by to every patch except the newly
added selftest.
- Added Bagas Sanjaya's Reviewed-by to the documentation patch.
- Fixed the commit message of patch 2 to remove a reference to the now
non-existent sysfs setting.
- Added a self test which tests both "regular" busy poll and busy poll
with suspend enabled. This was added as patch 6 as requested by
Paolo. netdevsim was chosen instead of veth due to netdevsim's
pre-existing support for netdev-genl. See the commit message of
patch 6 for more details.
v2: https://lore.kernel.org/bpf/20241021015311.95468-1-jdamato@fastly.com/
- Cover letter updated, including a re-run of test data.
- Patch 1 rewritten to use netdev-genl instead of sysfs.
- Patch 3 updated with a comment added to napi_resume_irqs.
- Patch 4 rebased to apply now that commit b9ca079dd6b0 ("eventpoll:
Annotate data-race of busy_poll_usecs") has been picked up from VFS.
- Patch 6 updated the kernel documentation.
rfc -> v1:
- Cover letter updated to include more details.
- Patch 1 updated to remove the documentation added. This was moved to
patch 6 with the rest of the docs (see below).
- Patch 5 updated to fix an error uncovered by the kernel build robot.
See patch 5's changelog for more details.
- Patch 6 added which updates kernel documentation.
Joe Damato (2):
selftests: net: Add busy_poll_test
docs: networking: Describe irq suspension
Martin Karsten (4):
net: Add napi_struct parameter irq_suspend_timeout
net: Add control functions for irq suspension
eventpoll: Trigger napi_busy_loop, if prefer_busy_poll is set
eventpoll: Control irq suspension for prefer_busy_poll
Documentation/netlink/specs/netdev.yaml | 7 +
Documentation/networking/napi.rst | 170 ++++++++-
fs/eventpoll.c | 36 +-
include/linux/netdevice.h | 2 +
include/net/busy_poll.h | 3 +
include/uapi/linux/netdev.h | 1 +
net/core/dev.c | 39 ++
net/core/dev.h | 25 ++
net/core/netdev-genl-gen.c | 5 +-
net/core/netdev-genl.c | 12 +
tools/include/uapi/linux/netdev.h | 1 +
tools/testing/selftests/net/.gitignore | 1 +
tools/testing/selftests/net/Makefile | 3 +-
tools/testing/selftests/net/busy_poll_test.sh | 165 +++++++++
tools/testing/selftests/net/busy_poller.c | 346 ++++++++++++++++++
15 files changed, 809 insertions(+), 7 deletions(-)
create mode 100755 tools/testing/selftests/net/busy_poll_test.sh
create mode 100644 tools/testing/selftests/net/busy_poller.c
base-commit: dc7c381bb8649e3701ed64f6c3e55316675904d7
--
2.25.1
Note: this requires INPUT_PROP_PRESSUREPAD [1] which is not yet
available in Linus' tree but it is in Dmitry's for-linus tree.
Nicely enough MS defines a button type for a pressurepad touchpad [2]
and it looks like most touchpad vendors fill this in.
The selftests require a bit of prep work (and a hack for the test
itself) - hidtools 0.12 requires python-libevdev 0.13 which in turn
provides constructors for unknown properties.
[1] https://lore.kernel.org/linux-input/20251030011735.GA969565@quokka/T/#m9d9b…
[2] https://learn.microsoft.com/en-us/windows-hardware/design/component-guideli…
Signed-off-by: Peter Hutterer <peter.hutterer(a)who-t.net>
---
Peter Hutterer (3):
selftests/hid: require hidtools 0.12
selftests/hid: use a enum class for the different button types
HID: multitouch: set INPUT_PROP_PRESSUREPAD based on Digitizer/Button Type
drivers/hid/hid-multitouch.c | 12 ++++-
tools/testing/selftests/hid/tests/conftest.py | 14 +++++
.../testing/selftests/hid/tests/test_multitouch.py | 61 +++++++++++++++++-----
3 files changed, 73 insertions(+), 14 deletions(-)
---
base-commit: 2bc4c50a42f8b83f611d0475598dc72740e87640
change-id: 20251111-wip-hid-pressurepad-8a800cdf1813
Best regards,
--
Peter Hutterer <peter.hutterer(a)who-t.net>
From: Gary Guo <gary(a)garyguo.net>
When the `#![allow]` line was added, the doctest line number anchor
isn't updated which causes the line number printed in kunit test to be
off-by-one.
Fixes: ab844cf32058 ("rust: allow `unreachable_pub` for doctests")
Signed-off-by: Gary Guo <gary(a)garyguo.net>
---
scripts/rustdoc_test_gen.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs
index be05610496605..6fd9f5c84e2e4 100644
--- a/scripts/rustdoc_test_gen.rs
+++ b/scripts/rustdoc_test_gen.rs
@@ -206,7 +206,7 @@ macro_rules! assert_eq {{
/// The anchor where the test code body starts.
#[allow(unused)]
- static __DOCTEST_ANCHOR: i32 = ::core::line!() as i32 + {body_offset} + 1;
+ static __DOCTEST_ANCHOR: i32 = ::core::line!() as i32 + {body_offset} + 2;
{{
#![allow(unreachable_pub, clippy::disallowed_names)]
{body}
base-commit: 559e608c46553c107dbba19dae0854af7b219400
--
2.51.2
The rust doctests are numbered -- instead of named with the line number
-- in order to keep them moderately consistent even as the source file
changes.
However, the test numbers are generated by sorting the file/line
strings, and so the line numbers were sorted as strings, not integers.
So, for instance, a test on line 7 would sort in-between one on line 65
and one on line 75.
Instead, parse the numbers as an integer, and sort based on that. This
is a bit slower, uglier, and will break things once, but I suspect is
worth it (at least until we have a better solution).
Signed-off-by: David Gow <davidgow(a)google.com>
---
This is a pretty unpolished, likely-unidiomatic patch to work around the
test numbering being horrible.
I have three questions before I decide if this is worth continuing with:
1. Is it worth renumbering all of the tests (hopefully just once), or
would that break too many people's test histories?
2. Is there a better way of doing this in Rust? I can think of ways
which might be nicer if the whole thing is refactored somewhat
seriously, but if there's an easy numeric sort on strings, that'd be
much easier.
3. Should we wait until after all or some of the changes to the test
generation? Does the new --output-format=doctest option make this
easier/harder/different?
Does anyone have opinions/advice on those (or, indeed, on anything
else)?
Cheers,
-- David
---
scripts/rustdoc_test_gen.rs | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs
index be0561049660..60b0bbfb1896 100644
--- a/scripts/rustdoc_test_gen.rs
+++ b/scripts/rustdoc_test_gen.rs
@@ -116,7 +116,19 @@ fn main() {
.collect::<Vec<_>>();
// Sort paths.
- paths.sort();
+ paths.sort_by(|a, b|{
+ let a_name = a.file_name().unwrap().to_str().unwrap().to_string();
+ let (a_file, a_line) = a_name.rsplit_once('_').unwrap().0.rsplit_once('_').unwrap();
+ let a_line_no = a_line.parse::<u64>().unwrap();
+ let b_name = b.file_name().unwrap().to_str().unwrap().to_string();
+ let (b_file, b_line) = b_name.rsplit_once('_').unwrap().0.rsplit_once('_').unwrap();
+ let b_line_no = b_line.parse::<u64>().unwrap();
+
+ match a_file.cmp(b_file) {
+ std::cmp::Ordering::Equal => a_line_no.cmp(&b_line_no),
+ order => order,
+ }
+ });
let mut rust_tests = String::new();
let mut c_test_declarations = String::new();
--
2.52.0.322.g1dd061c0dc-goog
The kunit_run_irq_test() helper allows a function to be run in hardirq
and softirq contexts (in addition to the task context). It does this by
running the user-provided function concurrently in the three contexts,
until either a timeout has expired or a number of iterations have
completed in the normal task context.
However, on setups where the initialisation of the hardirq and softirq
contexts (or, indeed, the scheduling of those tasks) is significantly
slower than the function execution, it's possible for that number of
iterations to be exceeded before any runs in irq contexts actually
occur. This occurs with the polyval.test_polyval_preparekey_in_irqs
test, which runs 20000 iterations of the relatively fast preparekey
function, and therefore fails often under many UML, 32-bit arm, m68k and
other environments.
Instead, ensure that the max_iterations limit counts executions in all
three contexts, and requires at least one of each. This will cause the
test to continue iterating until at least the irq contexts have been
tested, or the 1s wall-clock limit has been exceeded. This causes the
test to pass in all of my environments.
In so doing, we also update the task counters to atomic ints, to better
match both the 'int' max_iterations input, and to ensure they are
correctly updated across contexts.
Finally, we also fix a few potential assertion messages to be
less-specific to the original crypto usecases.
Fixes: b41dc83f0790 ("kunit, lib/crypto: Move run_irq_test() to common header")
Signed-off-by: David Gow <davidgow(a)google.com>
---
include/kunit/run-in-irq-context.h | 41 ++++++++++++++++++++----------
1 file changed, 28 insertions(+), 13 deletions(-)
diff --git a/include/kunit/run-in-irq-context.h b/include/kunit/run-in-irq-context.h
index 108e96433ea4..4d25aee0de6e 100644
--- a/include/kunit/run-in-irq-context.h
+++ b/include/kunit/run-in-irq-context.h
@@ -20,8 +20,8 @@ struct kunit_irq_test_state {
bool task_func_reported_failure;
bool hardirq_func_reported_failure;
bool softirq_func_reported_failure;
- unsigned long hardirq_func_calls;
- unsigned long softirq_func_calls;
+ atomic_t hardirq_func_calls;
+ atomic_t softirq_func_calls;
struct hrtimer timer;
struct work_struct bh_work;
};
@@ -32,7 +32,7 @@ static enum hrtimer_restart kunit_irq_test_timer_func(struct hrtimer *timer)
container_of(timer, typeof(*state), timer);
WARN_ON_ONCE(!in_hardirq());
- state->hardirq_func_calls++;
+ atomic_inc(&state->hardirq_func_calls);
if (!state->func(state->test_specific_state))
state->hardirq_func_reported_failure = true;
@@ -48,7 +48,7 @@ static void kunit_irq_test_bh_work_func(struct work_struct *work)
container_of(work, typeof(*state), bh_work);
WARN_ON_ONCE(!in_serving_softirq());
- state->softirq_func_calls++;
+ atomic_inc(&state->softirq_func_calls);
if (!state->func(state->test_specific_state))
state->softirq_func_reported_failure = true;
@@ -59,7 +59,10 @@ static void kunit_irq_test_bh_work_func(struct work_struct *work)
* hardirq context concurrently, and reports a failure to KUnit if any
* invocation of @func in any context returns false. @func is passed
* @test_specific_state as its argument. At most 3 invocations of @func will
- * run concurrently: one in each of task, softirq, and hardirq context.
+ * run concurrently: one in each of task, softirq, and hardirq context. @func
+ * will continue running until either @max_iterations calls have been made (so
+ * long as at least one each runs in task, softirq, and hardirq contexts), or
+ * one second has passed.
*
* The main purpose of this interrupt context testing is to validate fallback
* code paths that run in contexts where the normal code path cannot be used,
@@ -85,6 +88,10 @@ static inline void kunit_run_irq_test(struct kunit *test, bool (*func)(void *),
.test_specific_state = test_specific_state,
};
unsigned long end_jiffies;
+ int hardirq_calls, softirq_calls;
+ bool allctx = false;
+
+ max_iterations = 1;
/*
* Set up a hrtimer (the way we access hardirq context) and a work
@@ -94,14 +101,22 @@ static inline void kunit_run_irq_test(struct kunit *test, bool (*func)(void *),
CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
INIT_WORK_ONSTACK(&state.bh_work, kunit_irq_test_bh_work_func);
- /* Run for up to max_iterations or 1 second, whichever comes first. */
+ /* Run for up to max_iterations (including at least one task, softirq,
+ * and hardirq), or 1 second, whichever comes first.
+ */
end_jiffies = jiffies + HZ;
hrtimer_start(&state.timer, KUNIT_IRQ_TEST_HRTIMER_INTERVAL,
HRTIMER_MODE_REL_HARD);
- for (int i = 0; i < max_iterations && !time_after(jiffies, end_jiffies);
- i++) {
+ for (int task_calls = 0, calls = 0;
+ ((calls < max_iterations) || !allctx) && !time_after(jiffies, end_jiffies);
+ task_calls++) {
if (!func(test_specific_state))
state.task_func_reported_failure = true;
+
+ hardirq_calls = atomic_read(&state.hardirq_func_calls);
+ softirq_calls = atomic_read(&state.softirq_func_calls);
+ calls = task_calls + hardirq_calls + softirq_calls;
+ allctx = (task_calls > 0) && (hardirq_calls > 0) && (softirq_calls > 0);
}
/* Cancel the timer and work. */
@@ -109,21 +124,21 @@ static inline void kunit_run_irq_test(struct kunit *test, bool (*func)(void *),
flush_work(&state.bh_work);
/* Sanity check: the timer and BH functions should have been run. */
- KUNIT_EXPECT_GT_MSG(test, state.hardirq_func_calls, 0,
+ KUNIT_EXPECT_GT_MSG(test, atomic_read(&state.hardirq_func_calls), 0,
"Timer function was not called");
- KUNIT_EXPECT_GT_MSG(test, state.softirq_func_calls, 0,
+ KUNIT_EXPECT_GT_MSG(test, atomic_read(&state.softirq_func_calls), 0,
"BH work function was not called");
/* Check for incorrect hash values reported from any context. */
KUNIT_EXPECT_FALSE_MSG(
test, state.task_func_reported_failure,
- "Incorrect hash values reported from task context");
+ "Failure reported from task context");
KUNIT_EXPECT_FALSE_MSG(
test, state.hardirq_func_reported_failure,
- "Incorrect hash values reported from hardirq context");
+ "Failure reported from hardirq context");
KUNIT_EXPECT_FALSE_MSG(
test, state.softirq_func_reported_failure,
- "Incorrect hash values reported from softirq context");
+ "Failure reported from softirq context");
}
#endif /* _KUNIT_RUN_IN_IRQ_CONTEXT_H */
--
2.52.0.322.g1dd061c0dc-goog
The checksum_32 code was originally written to only handle 2-byte
aligned buffers, but was later extended to support arbitrary alignment.
However, the non-PPro variant doesn't apply the carry before jumping to
the 2- or 4-byte aligned versions, which clear CF.
This causes the new checksum_kunit test to fail, as it runs with a large
number of different possible alignments and both with and without
carries.
For example:
./tools/testing/kunit/kunit.py run --arch i386 --kconfig_add CONFIG_M486=y checksum
Gives:
KTAP version 1
# Subtest: checksum
1..3
ok 1 test_csum_fixed_random_inputs
# test_csum_all_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:267
Expected result == expec, but
result == 65281 (0xff01)
expec == 65280 (0xff00)
not ok 2 test_csum_all_carry_inputs
# test_csum_no_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:314
Expected result == expec, but
result == 65535 (0xffff)
expec == 65534 (0xfffe)
not ok 3 test_csum_no_carry_inputs
With this patch, it passes.
KTAP version 1
# Subtest: checksum
1..3
ok 1 test_csum_fixed_random_inputs
ok 2 test_csum_all_carry_inputs
ok 3 test_csum_no_carry_inputs
I also tested it on a real 486DX2, with the same results.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: David Gow <davidgow(a)google.com>
---
Re-sending this from [1]. While there's an argument that the whole
32-bit checksum code could do with rewriting, it's:
(a) worth fixing before someone takes the time to rewrite it, and
(b) worth any future rewrite starting from a point where the tests pass
I don't think there should be any downside to this fix: it only affects
ancient computers, and adds a single instruction which isn't in a loop.
Cheers,
-- David
[1]: https://lore.kernel.org/lkml/20230704083206.693155-2-davidgow@google.com/
---
arch/x86/lib/checksum_32.S | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/lib/checksum_32.S b/arch/x86/lib/checksum_32.S
index 68f7fa3e1322..a5123b29b403 100644
--- a/arch/x86/lib/checksum_32.S
+++ b/arch/x86/lib/checksum_32.S
@@ -62,6 +62,7 @@ SYM_FUNC_START(csum_partial)
jl 8f
movzbl (%esi), %ebx
adcl %ebx, %eax
+ adcl $0, %eax
roll $8, %eax
inc %esi
testl $2, %esi
--
2.45.2.1089.g2a221341d9-goog
This introduces signal->exec_bprm, which is used to
fix the case when at least one of the sibling threads
is traced, and therefore the trace process may dead-lock
in ptrace_attach, but de_thread will need to wait for the
tracer to continue execution.
The solution is to detect this situation and allow
ptrace_attach to continue by temporarily releasing the
cred_guard_mutex, while de_thread() is still waiting for
traced zombies to be eventually released by the tracer.
In the case of the thread group leader we only have to wait
for the thread to become a zombie, which may also need
co-operation from the tracer due to PTRACE_O_TRACEEXIT.
When a tracer wants to ptrace_attach a task that already
is in execve, we simply retry the ptrace_may_access
check while temporarily installing the new credentials
and dumpability which are about to be used after execve
completes. If the ptrace_attach happens on a thread that
is a sibling-thread of the thread doing execve, it is
sufficient to check against the old credentials, as this
thread will be waited for, before the new credentials are
installed.
Other threads die quickly since the cred_guard_mutex is
released, but a deadly signal is already pending. In case
the mutex_lock_killable misses the signal, the non-zero
current->signal->exec_bprm makes sure they release the
mutex immediately and return with -ERESTARTNOINTR.
This means there is no API change, unlike the previous
version of this patch which was discussed here:
https://lore.kernel.org/lkml/b6537ae6-31b1-5c50-f32b-8b8332ace882@hotmail.d…
See tools/testing/selftests/ptrace/vmaccess.c
for a test case that gets fixed by this change.
Note that since the test case was originally designed to
test the ptrace_attach returning an error in this situation,
the test expectation needed to be adjusted, to allow the
API to succeed at the first attempt.
Signed-off-by: Bernd Edlinger <bernd.edlinger(a)hotmail.de>
---
fs/exec.c | 69 ++++++++++++++++-------
fs/proc/base.c | 6 ++
include/linux/cred.h | 1 +
include/linux/sched/signal.h | 18 ++++++
kernel/cred.c | 28 +++++++--
kernel/ptrace.c | 32 +++++++++++
kernel/seccomp.c | 12 +++-
tools/testing/selftests/ptrace/vmaccess.c | 23 +++++---
8 files changed, 155 insertions(+), 34 deletions(-)
v10: Changes to previous version, make the PTRACE_ATTACH
retun -EAGAIN, instead of execve return -ERESTARTSYS.
Added some lessions learned to the description.
v11: Check old and new credentials in PTRACE_ATTACH again without
changing the API.
Note: I got actually one response from an automatic checker to the v11 patch,
https://lore.kernel.org/lkml/202107121344.wu68hEPF-lkp@intel.com/
which is complaining about:
>> kernel/ptrace.c:425:26: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct cred const *old_cred @@ got struct cred const [noderef] __rcu *real_cred @@
417 struct linux_binprm *bprm = task->signal->exec_bprm;
418 const struct cred *old_cred;
419 struct mm_struct *old_mm;
420
421 retval = down_write_killable(&task->signal->exec_update_lock);
422 if (retval)
423 goto unlock_creds;
424 task_lock(task);
> 425 old_cred = task->real_cred;
v12: Essentially identical to v11.
- Fixed a minor merge conflict in linux v5.17, and fixed the
above mentioned nit by adding __rcu to the declaration.
- re-tested the patch with all linux versions from v5.11 to v6.6
v10 was an alternative approach which did imply an API change.
But I would prefer to avoid such an API change.
The difficult part is getting the right dumpability flags assigned
before de_thread starts, hope you like this version.
If not, the v10 is of course also acceptable.
Thanks
Bernd.
diff --git a/fs/exec.c b/fs/exec.c
index 2f2b0acec4f0..902d3b230485 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1041,11 +1041,13 @@ static int exec_mmap(struct mm_struct *mm)
return 0;
}
-static int de_thread(struct task_struct *tsk)
+static int de_thread(struct task_struct *tsk, struct linux_binprm *bprm)
{
struct signal_struct *sig = tsk->signal;
struct sighand_struct *oldsighand = tsk->sighand;
spinlock_t *lock = &oldsighand->siglock;
+ struct task_struct *t = tsk;
+ bool unsafe_execve_in_progress = false;
if (thread_group_empty(tsk))
goto no_thread_group;
@@ -1068,6 +1070,19 @@ static int de_thread(struct task_struct *tsk)
if (!thread_group_leader(tsk))
sig->notify_count--;
+ while_each_thread(tsk, t) {
+ if (unlikely(t->ptrace)
+ && (t != tsk->group_leader || !t->exit_state))
+ unsafe_execve_in_progress = true;
+ }
+
+ if (unlikely(unsafe_execve_in_progress)) {
+ spin_unlock_irq(lock);
+ sig->exec_bprm = bprm;
+ mutex_unlock(&sig->cred_guard_mutex);
+ spin_lock_irq(lock);
+ }
+
while (sig->notify_count) {
__set_current_state(TASK_KILLABLE);
spin_unlock_irq(lock);
@@ -1158,6 +1173,11 @@ static int de_thread(struct task_struct *tsk)
release_task(leader);
}
+ if (unlikely(unsafe_execve_in_progress)) {
+ mutex_lock(&sig->cred_guard_mutex);
+ sig->exec_bprm = NULL;
+ }
+
sig->group_exec_task = NULL;
sig->notify_count = 0;
@@ -1169,6 +1189,11 @@ static int de_thread(struct task_struct *tsk)
return 0;
killed:
+ if (unlikely(unsafe_execve_in_progress)) {
+ mutex_lock(&sig->cred_guard_mutex);
+ sig->exec_bprm = NULL;
+ }
+
/* protects against exit_notify() and __exit_signal() */
read_lock(&tasklist_lock);
sig->group_exec_task = NULL;
@@ -1253,6 +1278,24 @@ int begin_new_exec(struct linux_binprm * bprm)
if (retval)
return retval;
+ /* If the binary is not readable then enforce mm->dumpable=0 */
+ would_dump(bprm, bprm->file);
+ if (bprm->have_execfd)
+ would_dump(bprm, bprm->executable);
+
+ /*
+ * Figure out dumpability. Note that this checking only of current
+ * is wrong, but userspace depends on it. This should be testing
+ * bprm->secureexec instead.
+ */
+ if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
+ is_dumpability_changed(current_cred(), bprm->cred) ||
+ !(uid_eq(current_euid(), current_uid()) &&
+ gid_eq(current_egid(), current_gid())))
+ set_dumpable(bprm->mm, suid_dumpable);
+ else
+ set_dumpable(bprm->mm, SUID_DUMP_USER);
+
/*
* Ensure all future errors are fatal.
*/
@@ -1261,7 +1304,7 @@ int begin_new_exec(struct linux_binprm * bprm)
/*
* Make this the only thread in the thread group.
*/
- retval = de_thread(me);
+ retval = de_thread(me, bprm);
if (retval)
goto out;
@@ -1284,11 +1327,6 @@ int begin_new_exec(struct linux_binprm * bprm)
if (retval)
goto out;
- /* If the binary is not readable then enforce mm->dumpable=0 */
- would_dump(bprm, bprm->file);
- if (bprm->have_execfd)
- would_dump(bprm, bprm->executable);
-
/*
* Release all of the old mmap stuff
*/
@@ -1350,18 +1388,6 @@ int begin_new_exec(struct linux_binprm * bprm)
me->sas_ss_sp = me->sas_ss_size = 0;
- /*
- * Figure out dumpability. Note that this checking only of current
- * is wrong, but userspace depends on it. This should be testing
- * bprm->secureexec instead.
- */
- if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
- !(uid_eq(current_euid(), current_uid()) &&
- gid_eq(current_egid(), current_gid())))
- set_dumpable(current->mm, suid_dumpable);
- else
- set_dumpable(current->mm, SUID_DUMP_USER);
-
perf_event_exec();
__set_task_comm(me, kbasename(bprm->filename), true);
@@ -1480,6 +1506,11 @@ static int prepare_bprm_creds(struct linux_binprm *bprm)
if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex))
return -ERESTARTNOINTR;
+ if (unlikely(current->signal->exec_bprm)) {
+ mutex_unlock(¤t->signal->cred_guard_mutex);
+ return -ERESTARTNOINTR;
+ }
+
bprm->cred = prepare_exec_creds();
if (likely(bprm->cred))
return 0;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ffd54617c354..0da9adfadb48 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2788,6 +2788,12 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
if (rv < 0)
goto out_free;
+ if (unlikely(current->signal->exec_bprm)) {
+ mutex_unlock(¤t->signal->cred_guard_mutex);
+ rv = -ERESTARTNOINTR;
+ goto out_free;
+ }
+
rv = security_setprocattr(PROC_I(inode)->op.lsm,
file->f_path.dentry->d_name.name, page,
count);
diff --git a/include/linux/cred.h b/include/linux/cred.h
index f923528d5cc4..b01e309f5686 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -159,6 +159,7 @@ extern const struct cred *get_task_cred(struct task_struct *);
extern struct cred *cred_alloc_blank(void);
extern struct cred *prepare_creds(void);
extern struct cred *prepare_exec_creds(void);
+extern bool is_dumpability_changed(const struct cred *, const struct cred *);
extern int commit_creds(struct cred *);
extern void abort_creds(struct cred *);
extern const struct cred *override_creds(const struct cred *);
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 0014d3adaf84..14df7073a0a8 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -234,9 +234,27 @@ struct signal_struct {
struct mm_struct *oom_mm; /* recorded mm when the thread group got
* killed by the oom killer */
+ struct linux_binprm *exec_bprm; /* Used to check ptrace_may_access
+ * against new credentials while
+ * de_thread is waiting for other
+ * traced threads to terminate.
+ * Set while de_thread is executing.
+ * The cred_guard_mutex is released
+ * after de_thread() has called
+ * zap_other_threads(), therefore
+ * a fatal signal is guaranteed to be
+ * already pending in the unlikely
+ * event, that
+ * current->signal->exec_bprm happens
+ * to be non-zero after the
+ * cred_guard_mutex was acquired.
+ */
+
struct mutex cred_guard_mutex; /* guard against foreign influences on
* credential calculations
* (notably. ptrace)
+ * Held while execve runs, except when
+ * a sibling thread is being traced.
* Deprecated do not use in new code.
* Use exec_update_lock instead.
*/
diff --git a/kernel/cred.c b/kernel/cred.c
index 98cb4eca23fb..586cb6c7cf6b 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -433,6 +433,28 @@ static bool cred_cap_issubset(const struct cred *set, const struct cred *subset)
return false;
}
+/**
+ * is_dumpability_changed - Will changing creds from old to new
+ * affect the dumpability in commit_creds?
+ *
+ * Return: false - dumpability will not be changed in commit_creds.
+ * Return: true - dumpability will be changed to non-dumpable.
+ *
+ * @old: The old credentials
+ * @new: The new credentials
+ */
+bool is_dumpability_changed(const struct cred *old, const struct cred *new)
+{
+ if (!uid_eq(old->euid, new->euid) ||
+ !gid_eq(old->egid, new->egid) ||
+ !uid_eq(old->fsuid, new->fsuid) ||
+ !gid_eq(old->fsgid, new->fsgid) ||
+ !cred_cap_issubset(old, new))
+ return true;
+
+ return false;
+}
+
/**
* commit_creds - Install new credentials upon the current task
* @new: The credentials to be assigned
@@ -467,11 +489,7 @@ int commit_creds(struct cred *new)
get_cred(new); /* we will require a ref for the subj creds too */
/* dumpability changes */
- if (!uid_eq(old->euid, new->euid) ||
- !gid_eq(old->egid, new->egid) ||
- !uid_eq(old->fsuid, new->fsuid) ||
- !gid_eq(old->fsgid, new->fsgid) ||
- !cred_cap_issubset(old, new)) {
+ if (is_dumpability_changed(old, new)) {
if (task->mm)
set_dumpable(task->mm, suid_dumpable);
task->pdeath_signal = 0;
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 443057bee87c..eb1c450bb7d7 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -20,6 +20,7 @@
#include <linux/pagemap.h>
#include <linux/ptrace.h>
#include <linux/security.h>
+#include <linux/binfmts.h>
#include <linux/signal.h>
#include <linux/uio.h>
#include <linux/audit.h>
@@ -435,6 +436,28 @@ static int ptrace_attach(struct task_struct *task, long request,
if (retval)
goto unlock_creds;
+ if (unlikely(task->in_execve)) {
+ struct linux_binprm *bprm = task->signal->exec_bprm;
+ const struct cred __rcu *old_cred;
+ struct mm_struct *old_mm;
+
+ retval = down_write_killable(&task->signal->exec_update_lock);
+ if (retval)
+ goto unlock_creds;
+ task_lock(task);
+ old_cred = task->real_cred;
+ old_mm = task->mm;
+ rcu_assign_pointer(task->real_cred, bprm->cred);
+ task->mm = bprm->mm;
+ retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
+ rcu_assign_pointer(task->real_cred, old_cred);
+ task->mm = old_mm;
+ task_unlock(task);
+ up_write(&task->signal->exec_update_lock);
+ if (retval)
+ goto unlock_creds;
+ }
+
write_lock_irq(&tasklist_lock);
retval = -EPERM;
if (unlikely(task->exit_state))
@@ -508,6 +531,14 @@ static int ptrace_traceme(void)
{
int ret = -EPERM;
+ if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex))
+ return -ERESTARTNOINTR;
+
+ if (unlikely(current->signal->exec_bprm)) {
+ mutex_unlock(¤t->signal->cred_guard_mutex);
+ return -ERESTARTNOINTR;
+ }
+
write_lock_irq(&tasklist_lock);
/* Are we already being traced? */
if (!current->ptrace) {
@@ -523,6 +554,7 @@ static int ptrace_traceme(void)
}
}
write_unlock_irq(&tasklist_lock);
+ mutex_unlock(¤t->signal->cred_guard_mutex);
return ret;
}
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 255999ba9190..b29bbfa0b044 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1955,9 +1955,15 @@ static long seccomp_set_mode_filter(unsigned int flags,
* Make sure we cannot change seccomp or nnp state via TSYNC
* while another thread is in the middle of calling exec.
*/
- if (flags & SECCOMP_FILTER_FLAG_TSYNC &&
- mutex_lock_killable(¤t->signal->cred_guard_mutex))
- goto out_put_fd;
+ if (flags & SECCOMP_FILTER_FLAG_TSYNC) {
+ if (mutex_lock_killable(¤t->signal->cred_guard_mutex))
+ goto out_put_fd;
+
+ if (unlikely(current->signal->exec_bprm)) {
+ mutex_unlock(¤t->signal->cred_guard_mutex);
+ goto out_put_fd;
+ }
+ }
spin_lock_irq(¤t->sighand->siglock);
diff --git a/tools/testing/selftests/ptrace/vmaccess.c b/tools/testing/selftests/ptrace/vmaccess.c
index 4db327b44586..3b7d81fb99bb 100644
--- a/tools/testing/selftests/ptrace/vmaccess.c
+++ b/tools/testing/selftests/ptrace/vmaccess.c
@@ -39,8 +39,15 @@ TEST(vmaccess)
f = open(mm, O_RDONLY);
ASSERT_GE(f, 0);
close(f);
- f = kill(pid, SIGCONT);
- ASSERT_EQ(f, 0);
+ f = waitpid(-1, NULL, 0);
+ ASSERT_NE(f, -1);
+ ASSERT_NE(f, 0);
+ ASSERT_NE(f, pid);
+ f = waitpid(-1, NULL, 0);
+ ASSERT_EQ(f, pid);
+ f = waitpid(-1, NULL, 0);
+ ASSERT_EQ(f, -1);
+ ASSERT_EQ(errno, ECHILD);
}
TEST(attach)
@@ -57,22 +64,24 @@ TEST(attach)
sleep(1);
k = ptrace(PTRACE_ATTACH, pid, 0L, 0L);
- ASSERT_EQ(errno, EAGAIN);
- ASSERT_EQ(k, -1);
+ ASSERT_EQ(k, 0);
k = waitpid(-1, &s, WNOHANG);
ASSERT_NE(k, -1);
ASSERT_NE(k, 0);
ASSERT_NE(k, pid);
ASSERT_EQ(WIFEXITED(s), 1);
ASSERT_EQ(WEXITSTATUS(s), 0);
- sleep(1);
- k = ptrace(PTRACE_ATTACH, pid, 0L, 0L);
+ k = waitpid(-1, &s, 0);
+ ASSERT_EQ(k, pid);
+ ASSERT_EQ(WIFSTOPPED(s), 1);
+ ASSERT_EQ(WSTOPSIG(s), SIGTRAP);
+ k = ptrace(PTRACE_CONT, pid, 0L, 0L);
ASSERT_EQ(k, 0);
k = waitpid(-1, &s, 0);
ASSERT_EQ(k, pid);
ASSERT_EQ(WIFSTOPPED(s), 1);
ASSERT_EQ(WSTOPSIG(s), SIGSTOP);
- k = ptrace(PTRACE_DETACH, pid, 0L, 0L);
+ k = ptrace(PTRACE_CONT, pid, 0L, 0L);
ASSERT_EQ(k, 0);
k = waitpid(-1, &s, 0);
ASSERT_EQ(k, pid);
--
2.39.2
[Joerg, can you put this and vtd in linux-next please. The vtd series is still
good at v3 thanks]
Currently each of the iommu page table formats duplicates all of the logic
to maintain the page table and perform map/unmap/etc operations. There are
several different versions of the algorithms between all the different
formats. The io-pgtable system provides an interface to help isolate the
page table code from the iommu driver, but doesn't provide tools to
implement the common algorithms.
This makes it very hard to improve the state of the pagetable code under
the iommu domains as any proposed improvement needs to alter a large
number of different driver code paths. Combined with a lack of software
based testing this makes improvement in this area very hard.
iommufd wants several new page table operations:
- More efficient map/unmap operations, using iommufd's batching logic
- unmap that returns the physical addresses into a batch as it progresses
- cut that allows splitting areas so large pages can have holes
poked in them dynamically (ie guestmemfd hitless shared/private
transitions)
- More agressive freeing of table memory to avoid waste
- Fragmenting large pages so that dirty tracking can be more granular
- Reassembling large pages so that VMs can run at full IO performance
in migration/dirty tracking error flows
- KHO integration for kernel live upgrade
Together these are algorithmically complex enough to be a very significant
task to go and implement in all the page table formats we support. Just
the "server" focused drivers use almost all the formats (ARMv8 S1&S2 / x86
PAE / AMDv1 / VT-d SS / RISCV)
Instead of doing the duplicated work, this series takes the first step to
consolidate the algorithms into one places. In spirit it is similar to the
work Christoph did a few years back to pull the redundant get_user_pages()
implementations out of the arch code into core MM. This unlocked a great
deal of improvement in that space in the following years. I would like to
see the same benefit in iommu as well.
My first RFC showed a bigger picture with all most all formats and more
algorithms. This series reorganizes that to be narrowly focused on just
enough to convert the AMD driver to use the new mechanism.
kunit tests are provided that allow good testing of the algorithms and all
formats on x86, nothing is arch specific.
AMD is one of the simpler options as the HW is quite uniform with few
different options/bugs while still requiring the complicated contiguous
pages support. The HW also has a very simple range based invalidation
approach that is easy to implement.
The AMD v1 and AMD v2 page table formats are implemented bit for bit
identical to the current code, tested using a compare kunit test that
checks against the io-pgtable version (on github, see below).
Updating the AMD driver to replace the io-pgtable layer with the new stuff
is fairly straightforward now. The layering is fixed up in the new version
so that all the invalidation goes through function pointers.
Several small fixing patches have come out of this as I've been fixing the
problems that the test suite uncovers in the current code, and
implementing the fixed version in iommupt.
On performance, there is a quite wide variety of implementation designs
across all the drivers. Looking at some key performance across
the main formats:
iommu_map():
pgsz ,avg new,old ns, min new,old ns , min % (+ve is better)
2^12, 53,66 , 51,63 , 19.19 (AMDV1)
256*2^12, 386,1909 , 367,1795 , 79.79
256*2^21, 362,1633 , 355,1556 , 77.77
2^12, 56,62 , 52,59 , 11.11 (AMDv2)
256*2^12, 405,1355 , 357,1292 , 72.72
256*2^21, 393,1160 , 358,1114 , 67.67
2^12, 55,65 , 53,62 , 14.14 (VT-d second stage)
256*2^12, 391,518 , 332,512 , 35.35
256*2^21, 383,635 , 336,624 , 46.46
2^12, 57,65 , 55,63 , 12.12 (ARM 64 bit)
256*2^12, 380,389 , 361,369 , 2.02
256*2^21, 358,419 , 345,400 , 13.13
iommu_unmap():
pgsz ,avg new,old ns, min new,old ns , min % (+ve is better)
2^12, 69,88 , 65,85 , 23.23 (AMDv1)
256*2^12, 353,6498 , 331,6029 , 94.94
256*2^21, 373,6014 , 360,5706 , 93.93
2^12, 71,72 , 66,69 , 4.04 (AMDv2)
256*2^12, 228,891 , 206,871 , 76.76
256*2^21, 254,721 , 245,711 , 65.65
2^12, 69,87 , 65,82 , 20.20 (VT-d second stage)
256*2^12, 210,321 , 200,315 , 36.36
256*2^21, 255,349 , 238,342 , 30.30
2^12, 72,77 , 68,74 , 8.08 (ARM 64 bit)
256*2^12, 521,357 , 447,346 , -29.29
256*2^21, 489,358 , 433,345 , -25.25
* Above numbers include additional patches to remove the iommu_pgsize()
overheads. gcc 13.3.0, i7-12700
This version provides fairly consistent performance across formats. ARM
unmap performance is quite different because this version supports
contiguous pages and uses a very different algorithm for unmapping. Though
why it is so worse compared to AMDv1 I haven't figured out yet.
The per-format commits include a more detailed chart.
There is a second branch:
https://github.com/jgunthorpe/linux/commits/iommu_pt_all
Containing supporting work and future steps:
- ARM short descriptor (32 bit), ARM long descriptor (64 bit) formats
- RISCV format and RISCV conversion
https://github.com/jgunthorpe/linux/commits/iommu_pt_riscv
- Support for a DMA incoherent HW page table walker
- VT-d second stage format and VT-d conversion
https://github.com/jgunthorpe/linux/commits/iommu_pt_vtd
- DART v1 & v2 format
- Draft of a iommufd 'cut' operation to break down huge pages
- A compare test that checks the iommupt formats against the iopgtable
interface, including updating AMD to have a working iopgtable and patches
to make VT-d have an iopgtable for testing.
- A performance test to micro-benchmark map and unmap against iogptable
My strategy is to go one by one for the drivers:
- AMD driver conversion
- RISCV page table and driver
- Intel VT-d driver and VTDSS page table
- Flushing improvements for RISCV
- ARM SMMUv3
And concurrently work on the algorithm side:
- debugfs content dump, like VT-d has
- Cut support
- Increase/Decrease page size support
- map/unmap batching
- KHO
As we make more algorithm improvements the value to convert the drivers
increases.
This is on github: https://github.com/jgunthorpe/linux/commits/iommu_pt
v8:
- Remove unused to_amdv1pt/common_to_amdv1pt/to_x86_64_pt/common_to_x86_64_pt
- Fix 32 bit udiv compile failure in the kunit
v7: https://patch.msgid.link/r/0-v7-ab019a8791e2+175b8-iommu_pt_jgg@nvidia.com
- Rebase to v6.18-rc2
- Improve comments and documentation
- Add a few missed __sme_sets() for AMD CC
- Rename pt_iommu_flush_ops -> pt_iommu_driver_ops
VT-D -> VT-d
pt_clear_entry -> pt_clear_entries
pt_entry_write_is_dirty -> pt_entry_is_write_dirty
pt_entry_set_write_clean -> pt_entry_make_write_clean
- Tidy some of the map flow into a new function do_map()
- Fix ffz64()
v6: https://patch.msgid.link/r/0-v6-0fb54a1d9850+36b-iommu_pt_jgg@nvidia.com
- Improve comments and documentation
- Rename pt_entry_oa_full -> pt_entry_oa_exact
pt_has_system_page -> pt_has_system_page_size
pt_max_output_address_lg2 -> pt_max_oa_lg2
log2_f*() -> vaf* / oaf* / f*_t
pt_item_fully_covered -> pt_entry_fully_covered
- Fix missed constant propogation causing division
- Consolidate debugging checks to pt_check_install_leaf_args()
- Change collect->ignore_mapped to check_mapped
- Shuffle some hunks around to more appropriate patches
- Two new mini kunit tests
v5: https://patch.msgid.link/r/0-v5-116c4948af3d+68091-iommu_pt_jgg@nvidia.com
- Text grammar updates and kdoc fixes
v4: https://patch.msgid.link/r/0-v4-0d6a6726a372+18959-iommu_pt_jgg@nvidia.com
- Rebase on v6.16-rc3
- Integrate the HATS/HATDis changes
- Remove 'default n' from kconfig
- Remove unused 'PT_FIXED_TOP_LEVEL'
- Improve comments and documentation
- Fix some compile warnings from kbuild robots
v3: https://patch.msgid.link/r/0-v3-a93aab628dbc+521-iommu_pt_jgg@nvidia.com
- Rebase on v6.16-rc2
- s/PT_ENTRY_WORD_SIZE/PT_ITEM_WORD_SIZE/s to follow the language better
- Comment and documentation updates
- Add PT_TOP_PHYS_MASK to help manage alignment restrictions on the top
pointer
- Add missed force_aperture = true
- Make pt_iommu_deinit() take care of the not-yet-inited error case
internally as AMD/RISCV/VTD all shared this logic
- Change gather_range() into gather_range_pages() so it also deals with
the page list. This makes the following cache flushing series simpler
- Fix missed update of unmap->unmapped in some error cases
- Change clear_contig() to order the gather more logically
- Remove goto from the error handling in __map_range_leaf()
- s/log2_/oalog2_/ in places where the argument is an oaddr_t
- Pass the pts to pt_table_install64/32()
- Do not use SIGN_EXTEND for the AMDv2 page table because of Vasant's
information on how PASID 0 works.
v2: https://patch.msgid.link/r/0-v2-5c26bde5c22d+58b-iommu_pt_jgg@nvidia.com
- AMD driver only, many code changes
RFC: https://lore.kernel.org/all/0-v1-01fa10580981+1d-iommu_pt_jgg@nvidia.com/
Cc: Michael Roth <michael.roth(a)amd.com>
Cc: Alexey Kardashevskiy <aik(a)amd.com>
Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com>
Cc: James Gowans <jgowans(a)amazon.com>
Signed-off-by: Jason Gunthorpe <jgg(a)nvidia.com>
Alejandro Jimenez (1):
iommu/amd: Use the generic iommu page table
Jason Gunthorpe (14):
genpt: Generic Page Table base API
genpt: Add Documentation/ files
iommupt: Add the basic structure of the iommu implementation
iommupt: Add the AMD IOMMU v1 page table format
iommupt: Add iova_to_phys op
iommupt: Add unmap_pages op
iommupt: Add map_pages op
iommupt: Add read_and_clear_dirty op
iommupt: Add a kunit test for Generic Page Table
iommupt: Add a mock pagetable format for iommufd selftest to use
iommufd: Change the selftest to use iommupt instead of xarray
iommupt: Add the x86 64 bit page table format
iommu/amd: Remove AMD io_pgtable support
iommupt: Add a kunit test for the IOMMU implementation
.clang-format | 1 +
Documentation/driver-api/generic_pt.rst | 142 ++
Documentation/driver-api/index.rst | 1 +
drivers/iommu/Kconfig | 2 +
drivers/iommu/Makefile | 1 +
drivers/iommu/amd/Kconfig | 5 +-
drivers/iommu/amd/Makefile | 2 +-
drivers/iommu/amd/amd_iommu.h | 1 -
drivers/iommu/amd/amd_iommu_types.h | 110 +-
drivers/iommu/amd/io_pgtable.c | 577 --------
drivers/iommu/amd/io_pgtable_v2.c | 370 ------
drivers/iommu/amd/iommu.c | 538 ++++----
drivers/iommu/generic_pt/.kunitconfig | 13 +
drivers/iommu/generic_pt/Kconfig | 68 +
drivers/iommu/generic_pt/fmt/Makefile | 26 +
drivers/iommu/generic_pt/fmt/amdv1.h | 411 ++++++
drivers/iommu/generic_pt/fmt/defs_amdv1.h | 21 +
drivers/iommu/generic_pt/fmt/defs_x86_64.h | 21 +
drivers/iommu/generic_pt/fmt/iommu_amdv1.c | 15 +
drivers/iommu/generic_pt/fmt/iommu_mock.c | 10 +
drivers/iommu/generic_pt/fmt/iommu_template.h | 48 +
drivers/iommu/generic_pt/fmt/iommu_x86_64.c | 11 +
drivers/iommu/generic_pt/fmt/x86_64.h | 255 ++++
drivers/iommu/generic_pt/iommu_pt.h | 1162 +++++++++++++++++
drivers/iommu/generic_pt/kunit_generic_pt.h | 713 ++++++++++
drivers/iommu/generic_pt/kunit_iommu.h | 183 +++
drivers/iommu/generic_pt/kunit_iommu_pt.h | 487 +++++++
drivers/iommu/generic_pt/pt_common.h | 358 +++++
drivers/iommu/generic_pt/pt_defs.h | 329 +++++
drivers/iommu/generic_pt/pt_fmt_defaults.h | 233 ++++
drivers/iommu/generic_pt/pt_iter.h | 636 +++++++++
drivers/iommu/generic_pt/pt_log2.h | 122 ++
drivers/iommu/io-pgtable.c | 4 -
drivers/iommu/iommufd/Kconfig | 1 +
drivers/iommu/iommufd/iommufd_test.h | 11 +-
drivers/iommu/iommufd/selftest.c | 438 +++----
include/linux/generic_pt/common.h | 167 +++
include/linux/generic_pt/iommu.h | 271 ++++
include/linux/io-pgtable.h | 2 -
include/linux/irqchip/riscv-imsic.h | 3 +-
tools/testing/selftests/iommu/iommufd.c | 60 +-
tools/testing/selftests/iommu/iommufd_utils.h | 12 +
42 files changed, 6229 insertions(+), 1612 deletions(-)
create mode 100644 Documentation/driver-api/generic_pt.rst
delete mode 100644 drivers/iommu/amd/io_pgtable.c
delete mode 100644 drivers/iommu/amd/io_pgtable_v2.c
create mode 100644 drivers/iommu/generic_pt/.kunitconfig
create mode 100644 drivers/iommu/generic_pt/Kconfig
create mode 100644 drivers/iommu/generic_pt/fmt/Makefile
create mode 100644 drivers/iommu/generic_pt/fmt/amdv1.h
create mode 100644 drivers/iommu/generic_pt/fmt/defs_amdv1.h
create mode 100644 drivers/iommu/generic_pt/fmt/defs_x86_64.h
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_amdv1.c
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_mock.c
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_template.h
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_x86_64.c
create mode 100644 drivers/iommu/generic_pt/fmt/x86_64.h
create mode 100644 drivers/iommu/generic_pt/iommu_pt.h
create mode 100644 drivers/iommu/generic_pt/kunit_generic_pt.h
create mode 100644 drivers/iommu/generic_pt/kunit_iommu.h
create mode 100644 drivers/iommu/generic_pt/kunit_iommu_pt.h
create mode 100644 drivers/iommu/generic_pt/pt_common.h
create mode 100644 drivers/iommu/generic_pt/pt_defs.h
create mode 100644 drivers/iommu/generic_pt/pt_fmt_defaults.h
create mode 100644 drivers/iommu/generic_pt/pt_iter.h
create mode 100644 drivers/iommu/generic_pt/pt_log2.h
create mode 100644 include/linux/generic_pt/common.h
create mode 100644 include/linux/generic_pt/iommu.h
base-commit: 8440410283bb5533b676574211f31f030a18011b
--
2.43.0
At this point I think everyone in the on the kernel side is happy with
this but there were some questions from the glibc side about the value
of controlling the shadow stack placement and size, especially with the
current inability to reuse the shadow stack for an exited thread. With
support for reuse it would be possible to have a cache of shadow stacks
as is currently supported for the normal stack.
Since the discussion petered out I'm resending this in order to give
people something work with while prototyping. It should be possible to
prototype any potential kernel features to help build out shadow stack
support in userspace by enabling shadow stack writes, as suggested by
Rick Edgecombe this may end up being required anyway for supporting more
exotic scenarios. On all current architectures with the feature writes
to shadow stack require specific instructions so there are still
security benefits even with writes enabled.
I did send a change implementing a feature writing a token on thread
exit to allow reuse:
https://lore.kernel.org/r/20250921-arm64-gcs-exit-token-v1-0-45cf64e648d5@k…
but wasn't planning to refresh it without some indication from the
userspace side that that'd be useful.
Non-process cover letter:
The kernel has added support for shadow stacks, currently x86 only using
their CET feature but both arm64 and RISC-V have equivalent features
(GCS and Zicfiss respectively), I am actively working on GCS[1]. With
shadow stacks the hardware maintains an additional stack containing only
the return addresses for branch instructions which is not generally
writeable by userspace and ensures that any returns are to the recorded
addresses. This provides some protection against ROP attacks and making
it easier to collect call stacks. These shadow stacks are allocated in
the address space of the userspace process.
Our API for shadow stacks does not currently offer userspace any
flexiblity for managing the allocation of shadow stacks for newly
created threads, instead the kernel allocates a new shadow stack with
the same size as the normal stack whenever a thread is created with the
feature enabled. The stacks allocated in this way are freed by the
kernel when the thread exits or shadow stacks are disabled for the
thread. This lack of flexibility and control isn't ideal, in the vast
majority of cases the shadow stack will be over allocated and the
implicit allocation and deallocation is not consistent with other
interfaces. As far as I can tell the interface is done in this manner
mainly because the shadow stack patches were in development since before
clone3() was implemented.
Since clone3() is readily extensible let's add support for specifying a
shadow stack when creating a new thread or process, keeping the current
implicit allocation behaviour if one is not specified either with
clone3() or through the use of clone(). The user must provide a shadow
stack pointer, this must point to memory mapped for use as a shadow
stackby map_shadow_stack() with an architecture specified shadow stack
token at the top of the stack.
Yuri Khrustalev has raised questions from the libc side regarding
discoverability of extended clone3() structure sizes[2], this seems like
a general issue with clone3(). There was a suggestion to add a hwcap on
arm64 which isn't ideal but is doable there, though architecture
specific mechanisms would also be needed for x86 (and RISC-V if it's
support gets merged before this does). The idea has, however, had
strong pushback from the architecture maintainers and it is possible to
detect support for this in clone3() by attempting a call with a
misaligned shadow stack pointer specified so no hwcap has been added.
[1] https://lore.kernel.org/linux-arm-kernel/20241001-arm64-gcs-v13-0-222b78d87…
[2] https://lore.kernel.org/r/aCs65ccRQtJBnZ_5@arm.com
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v23:
- Rebase onto v6.19-rc1.
- Link to v22: https://lore.kernel.org/r/20251015-clone3-shadow-stack-v22-0-a8c8da011427@k…
Changes in v22:
- Rebase onto v6.18-rc1.
- Cover letter updates.
- Link to v21: https://lore.kernel.org/r/20250916-clone3-shadow-stack-v21-0-910493527013@k…
Changes in v21:
- Rebase onto https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git kernel-6.18.clone3
- Rename shadow_stack_token to shstk_token, since it's a simple rename I've
kept the acks and reviews but I dropped the tested-bys just to be safe.
- Link to v20: https://lore.kernel.org/r/20250902-clone3-shadow-stack-v20-0-4d9fff1c53e7@k…
Changes in v20:
- Comment fixes and clarifications in x86 arch_shstk_validate_clone()
from Rick Edgecombe.
- Spelling fix in documentation.
- Link to v19: https://lore.kernel.org/r/20250819-clone3-shadow-stack-v19-0-bc957075479b@k…
Changes in v19:
- Rebase onto v6.17-rc1.
- Link to v18: https://lore.kernel.org/r/20250702-clone3-shadow-stack-v18-0-7965d2b694db@k…
Changes in v18:
- Rebase onto v6.16-rc3.
- Thanks to pointers from Yuri Khrustalev this version has been tested
on x86 so I have removed the RFT tag.
- Clarify clone3_shadow_stack_valid() comment about the Kconfig check.
- Remove redundant GCSB DSYNCs in arm64 code.
- Fix token validation on x86.
- Link to v17: https://lore.kernel.org/r/20250609-clone3-shadow-stack-v17-0-8840ed97ff6f@k…
Changes in v17:
- Rebase onto v6.16-rc1.
- Link to v16: https://lore.kernel.org/r/20250416-clone3-shadow-stack-v16-0-2ffc9ca3917b@k…
Changes in v16:
- Rebase onto v6.15-rc2.
- Roll in fixes from x86 testing from Rick Edgecombe.
- Rework so that the argument is shadow_stack_token.
- Link to v15: https://lore.kernel.org/r/20250408-clone3-shadow-stack-v15-0-3fa245c6e3be@k…
Changes in v15:
- Rebase onto v6.15-rc1.
- Link to v14: https://lore.kernel.org/r/20250206-clone3-shadow-stack-v14-0-805b53af73b9@k…
Changes in v14:
- Rebase onto v6.14-rc1.
- Link to v13: https://lore.kernel.org/r/20241203-clone3-shadow-stack-v13-0-93b89a81a5ed@k…
Changes in v13:
- Rebase onto v6.13-rc1.
- Link to v12: https://lore.kernel.org/r/20241031-clone3-shadow-stack-v12-0-7183eb8bee17@k…
Changes in v12:
- Add the regular prctl() to the userspace API document since arm64
support is queued in -next.
- Link to v11: https://lore.kernel.org/r/20241005-clone3-shadow-stack-v11-0-2a6a2bd6d651@k…
Changes in v11:
- Rebase onto arm64 for-next/gcs, which is based on v6.12-rc1, and
integrate arm64 support.
- Rework the interface to specify a shadow stack pointer rather than a
base and size like we do for the regular stack.
- Link to v10: https://lore.kernel.org/r/20240821-clone3-shadow-stack-v10-0-06e8797b9445@k…
Changes in v10:
- Integrate fixes & improvements for the x86 implementation from Rick
Edgecombe.
- Require that the shadow stack be VM_WRITE.
- Require that the shadow stack base and size be sizeof(void *) aligned.
- Clean up trailing newline.
- Link to v9: https://lore.kernel.org/r/20240819-clone3-shadow-stack-v9-0-962d74f99464@ke…
Changes in v9:
- Pull token validation earlier and report problems with an error return
to parent rather than signal delivery to the child.
- Verify that the top of the supplied shadow stack is VM_SHADOW_STACK.
- Rework token validation to only do the page mapping once.
- Drop no longer needed support for testing for signals in selftest.
- Fix typo in comments.
- Link to v8: https://lore.kernel.org/r/20240808-clone3-shadow-stack-v8-0-0acf37caf14c@ke…
Changes in v8:
- Fix token verification with user specified shadow stack.
- Don't track user managed shadow stacks for child processes.
- Link to v7: https://lore.kernel.org/r/20240731-clone3-shadow-stack-v7-0-a9532eebfb1d@ke…
Changes in v7:
- Rebase onto v6.11-rc1.
- Typo fixes.
- Link to v6: https://lore.kernel.org/r/20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@ke…
Changes in v6:
- Rebase onto v6.10-rc3.
- Ensure we don't try to free the parent shadow stack in error paths of
x86 arch code.
- Spelling fixes in userspace API document.
- Additional cleanups and improvements to the clone3() tests to support
the shadow stack tests.
- Link to v5: https://lore.kernel.org/r/20240203-clone3-shadow-stack-v5-0-322c69598e4b@ke…
Changes in v5:
- Rebase onto v6.8-rc2.
- Rework ABI to have the user allocate the shadow stack memory with
map_shadow_stack() and a token.
- Force inlining of the x86 shadow stack enablement.
- Move shadow stack enablement out into a shared header for reuse by
other tests.
- Link to v4: https://lore.kernel.org/r/20231128-clone3-shadow-stack-v4-0-8b28ffe4f676@ke…
Changes in v4:
- Formatting changes.
- Use a define for minimum shadow stack size and move some basic
validation to fork.c.
- Link to v3: https://lore.kernel.org/r/20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@ke…
Changes in v3:
- Rebase onto v6.7-rc2.
- Remove stale shadow_stack in internal kargs.
- If a shadow stack is specified unconditionally use it regardless of
CLONE_ parameters.
- Force enable shadow stacks in the selftest.
- Update changelogs for RISC-V feature rename.
- Link to v2: https://lore.kernel.org/r/20231114-clone3-shadow-stack-v2-0-b613f8681155@ke…
Changes in v2:
- Rebase onto v6.7-rc1.
- Remove ability to provide preallocated shadow stack, just specify the
desired size.
- Link to v1: https://lore.kernel.org/r/20231023-clone3-shadow-stack-v1-0-d867d0b5d4d0@ke…
---
Mark Brown (8):
arm64/gcs: Return a success value from gcs_alloc_thread_stack()
Documentation: userspace-api: Add shadow stack API documentation
selftests: Provide helper header for shadow stack testing
fork: Add shadow stack support to clone3()
selftests/clone3: Remove redundant flushes of output streams
selftests/clone3: Factor more of main loop into test_clone3()
selftests/clone3: Allow tests to flag if -E2BIG is a valid error code
selftests/clone3: Test shadow stack support
Documentation/userspace-api/index.rst | 1 +
Documentation/userspace-api/shadow_stack.rst | 44 +++++
arch/arm64/include/asm/gcs.h | 8 +-
arch/arm64/kernel/process.c | 8 +-
arch/arm64/mm/gcs.c | 55 +++++-
arch/x86/include/asm/shstk.h | 11 +-
arch/x86/kernel/process.c | 2 +-
arch/x86/kernel/shstk.c | 53 ++++-
include/asm-generic/cacheflush.h | 11 ++
include/linux/sched/task.h | 17 ++
include/uapi/linux/sched.h | 9 +-
kernel/fork.c | 93 +++++++--
tools/testing/selftests/clone3/clone3.c | 226 ++++++++++++++++++----
tools/testing/selftests/clone3/clone3_selftests.h | 65 ++++++-
tools/testing/selftests/ksft_shstk.h | 98 ++++++++++
15 files changed, 620 insertions(+), 81 deletions(-)
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20231019-clone3-shadow-stack-15d40d2bf536
Best regards,
--
Mark Brown <broonie(a)kernel.org>
The devpts_pts selftest has an ifdef in case an architecture does not
define TIOCGPTPEER, but the handling for this is broken since we need
errno to be set to EINVAL in order to skip the test as we should. Given
that this ioctl() has been defined since v4.15 we may as well just assume
it's there rather than write handling code which will probably never get
used.
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v2:
- Rebase onto v6.19-rc1.
- Link to v1: https://patch.msgid.link/20251126-selftests-filesystems-devpts-tiocgptpeer-…
---
tools/testing/selftests/filesystems/devpts_pts.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/tools/testing/selftests/filesystems/devpts_pts.c b/tools/testing/selftests/filesystems/devpts_pts.c
index 54fea349204e..950e8b7f675b 100644
--- a/tools/testing/selftests/filesystems/devpts_pts.c
+++ b/tools/testing/selftests/filesystems/devpts_pts.c
@@ -100,7 +100,7 @@ static int resolve_procfd_symlink(int fd, char *buf, size_t buflen)
static int do_tiocgptpeer(char *ptmx, char *expected_procfd_contents)
{
int ret;
- int master = -1, slave = -1, fret = -1;
+ int master = -1, slave, fret = -1;
master = open(ptmx, O_RDWR | O_NOCTTY | O_CLOEXEC);
if (master < 0) {
@@ -119,9 +119,7 @@ static int do_tiocgptpeer(char *ptmx, char *expected_procfd_contents)
goto do_cleanup;
}
-#ifdef TIOCGPTPEER
slave = ioctl(master, TIOCGPTPEER, O_RDWR | O_NOCTTY | O_CLOEXEC);
-#endif
if (slave < 0) {
if (errno == EINVAL) {
fprintf(stderr, "TIOCGPTPEER is not supported. "
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251126-selftests-filesystems-devpts-tiocgptpeer-fbd30e579859
Best regards,
--
Mark Brown <broonie(a)kernel.org>
During my testing, I found that guest debugging with 'DR6.BD' does not
work in instruction emulation, as the current code only considers the
guest's DR7. Upon reviewing the code, I also observed that the checks
for the userspace guest debugging feature and the guest's own debugging
feature are repeated in different places during instruction
emulation, but the overall logic is the same. If guest debug
is enabled, it needs to exit to userspace; otherwise, a #DB
exception needs to be injected into the guest. Therefore, as
suggested by Jiangshan Lai, some cleanup has been done for #DB
handling in instruction emulation in this patchset. A new
function named 'kvm_inject_emulated_db()' is introduced to
consolidate all the checking logic. Moreover, I hope we can make
the #DB interception path use the same function as well.
Additionally, when I looked into the single-step #DB handling in
instruction emulation, I noticed that the interrupt shadow is toggled,
but it is not considered in the single-step #DB injection. This
oversight causes VM entry to fail on VMX (due to pending debug
exceptions state checking).
As pointed out by Sean, fault-like code #DBs can be coincident with
trap-like single-step #DBs at the instruction boundary on the hardware.
However it is difficult to emulate this in the emulator, as
kvm_vcpu_check_code_breakpoint() is called at the start of the next
instruction while the single-step #DB for the previous instruction has
already been injected.
v1->v2:
- cleanup in inject_emulated_exception().
- rename 'set_pending_dbg' callback as 'refresh_pending_dbg_exceptions'.
- fold refresh_pending_dbg_exceptions() call into
kvm_vcpu_do_singlestep().
- Split the change to move up kvm_set_rflags() into a single patch.
- Move the #DB and IRQ handler registration after guest debug testcases.
Hou Wenlong (9):
KVM: x86: Capture "struct x86_exception" in
inject_emulated_exception()
KVM: x86: Set guest DR6 by kvm_queue_exception_p() in instruction
emulation
KVM: x86: Check guest debug in DR access instruction emulation
KVM: x86: Only check effective code breakpoint in emulation
KVM: x86: Consolidate KVM_GUESTDBG_SINGLESTEP check into the
kvm_inject_emulated_db()
KVM: x86: Move kvm_set_rflags() up before kvm_vcpu_do_singlestep()
KVM: VMX: Refresh 'PENDING_DBG_EXCEPTIONS.BS' bit during instruction
emulation
KVM: selftests: Verify guest debug DR7.GD checking during instruction
emulation
KVM: selftests: Verify 'BS' bit checking in pending debug exception
during VM entry
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/emulate.c | 14 +--
arch/x86/kvm/kvm_emulate.h | 7 +-
arch/x86/kvm/vmx/main.c | 9 ++
arch/x86/kvm/vmx/vmx.c | 15 ++-
arch/x86/kvm/vmx/x86_ops.h | 1 +
arch/x86/kvm/x86.c | 116 ++++++++++--------
arch/x86/kvm/x86.h | 7 ++
.../selftests/kvm/include/x86/processor.h | 3 +-
tools/testing/selftests/kvm/x86/debug_regs.c | 72 ++++++++++-
11 files changed, 178 insertions(+), 68 deletions(-)
base-commit: 5d3e2d9ba9ed68576c70c127e4f7446d896f2af2
--
2.31.1
During my testing, I found that guest debugging with 'DR6.BD' does not
work in instruction emulation, as the current code only considers the
guest's DR7. Upon reviewing the code, I also observed that the checks
for the userspace guest debugging feature and the guest's own debugging
feature are repeated in different places during instruction
emulation, but the overall logic is the same. If guest debugging
is enabled, it needs to exit to userspace; otherwise, a #DB
exception needs to be injected into the guest. Therefore, as
suggested by Jiangshan Lai, some cleanup has been done for #DB
handling in instruction emulation in this patchset. A new
function named 'kvm_inject_emulated_db()' is introduced to
consolidate all the checking logic. Moreover, I hope we can make
the #DB interception path use the same function as well.
Additionally, when I looked into the single-step #DB handling in
instruction emulation, I noticed that the interrupt shadow is toggled,
but it is not considered in the single-step #DB injection. This
oversight causes VM entry to fail on VMX (due to pending debug
exceptions checking) or breaks the 'MOV SS' suppressed #DB. For the
latter, I have kept the behavior for now in my patchset, as I need some
suggestions.
Hou Wenlong (7):
KVM: x86: Set guest DR6 by kvm_queue_exception_p() in instruction
emulation
KVM: x86: Check guest debug in DR access instruction emulation
KVM: x86: Only check effective code breakpoint in emulation
KVM: x86: Consolidate KVM_GUESTDBG_SINGLESTEP check into the
kvm_inject_emulated_db()
KVM: VMX: Set 'BS' bit in pending debug exceptions during instruction
emulation
KVM: selftests: Verify guest debug DR7.GD checking during instruction
emulation
KVM: selftests: Verify 'BS' bit checking in pending debug exception
during VM entry
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/emulate.c | 14 +--
arch/x86/kvm/kvm_emulate.h | 7 +-
arch/x86/kvm/vmx/main.c | 9 ++
arch/x86/kvm/vmx/vmx.c | 14 ++-
arch/x86/kvm/vmx/x86_ops.h | 1 +
arch/x86/kvm/x86.c | 109 +++++++++++-------
arch/x86/kvm/x86.h | 7 ++
.../selftests/kvm/include/x86/processor.h | 3 +-
tools/testing/selftests/kvm/x86/debug_regs.c | 64 +++++++++-
11 files changed, 167 insertions(+), 63 deletions(-)
base-commit: ecbcc2461839e848970468b44db32282e5059925
--
2.31.1
This series makes the output from the ofdlocks test a bit easier for
tooling to work with, and also ignores the generated file while we're
here.
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v3:
- Rebase onto v6.19-rc1.
- Link to v2: https://lore.kernel.org/r/20251015-selftest-filelock-ktap-v2-0-f5fd21b75c3a…
Changes in v2:
- Rebase onto v6.18-rc1.
- Link to v1: https://lore.kernel.org/r/20250818-selftest-filelock-ktap-v1-0-d41af77f1396…
---
Mark Brown (3):
kselftest/filelock: Use ksft_perror()
kselftest/filelock: Report each test in oftlocks separately
kselftest/filelock: Add a .gitignore file
tools/testing/selftests/filelock/.gitignore | 1 +
tools/testing/selftests/filelock/ofdlocks.c | 94 +++++++++++++----------------
2 files changed, 42 insertions(+), 53 deletions(-)
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20250604-selftest-filelock-ktap-f2ae998a0de0
Best regards,
--
Mark Brown <broonie(a)kernel.org>
Hello,
While writing some Kunit tests for ext4 filesystem, I'm encountering an
issue in the way we display the diagnostic logs upon failures, when
using KUNIT_CASE_PARAM() to write the tests.
This can be observed by patching fs/ext4/mballoc-test.c to fail
and print one of the params:
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -350,6 +350,8 @@ static int mbt_kunit_init(struct kunit *test)
struct super_block *sb;
int ret;
+ KUNIT_FAIL(test, "Failed: blocksize_bits=%d", layout->blocksize_bits);
+
sb = mbt_ext4_alloc_super_block();
if (sb == NULL)
return -ENOMEM;
With the above change, we can observe the following output (snipped):
[18:50:25] ============== ext4_mballoc_test (7 subtests) ==============
[18:50:25] ================= test_new_blocks_simple ==================
[18:50:25] [FAILED] block_bits=10 cluster_bits=3 blocks_per_group=8192 group_count=4 desc_size=64
[18:50:25] # test_new_blocks_simple: EXPECTATION FAILED at fs/ext4/mballoc-test.c:364
[18:50:25] Failed: blocksize_bits=12
[18:50:25] [FAILED] block_bits=12 cluster_bits=3 blocks_per_group=8192 group_count=4 desc_size=64
[18:50:25] # test_new_blocks_simple: EXPECTATION FAILED at fs/ext4/mballoc-test.c:364
[18:50:25] Failed: blocksize_bits=16
[18:50:25] [FAILED] block_bits=16 cluster_bits=3 blocks_per_group=8192 group_count=4 desc_size=64
[18:50:25] # test_new_blocks_simple: EXPECTATION FAILED at fs/ext4/mballoc-test.c:364
[18:50:25] Failed: blocksize_bits=10
[18:50:25] # test_new_blocks_simple: pass:0 fail:3 skip:0 total:3
[18:50:25] ============= [FAILED] test_new_blocks_simple ==============
<snip>
Note that the diagnostic logs don't show up correctly. Ideally they
should be before test result but here the first [FAILED] test has no
logs printed above whereas the last "Failed: blocksize_bits=10" print
comes after the last subtest, when it actually corresponds to the first
subtest.
The KTAP file itself seems to have diagnostic logs in the right place:
KTAP version 1
1..2
KTAP version 1
# Subtest: ext4_mballoc_test
# module: ext4
1..7
KTAP version 1
# Subtest: test_new_blocks_simple
# test_new_blocks_simple: EXPECTATION FAILED at fs/ext4/mballoc-test.c:364
Failed: blocksize_bits=10
not ok 1 block_bits=10 cluster_bits=3 blocks_per_group=8192 group_count=4 desc_size=64
# test_new_blocks_simple: EXPECTATION FAILED at fs/ext4/mballoc-test.c:364
Failed: blocksize_bits=12
not ok 2 block_bits=12 cluster_bits=3 blocks_per_group=8192 group_count=4 desc_size=64
# test_new_blocks_simple: EXPECTATION FAILED at fs/ext4/mballoc-test.c:364
Failed: blocksize_bits=16
not ok 3 block_bits=16 cluster_bits=3 blocks_per_group=8192 group_count=4 desc_size=64
# test_new_blocks_simple: pass:0 fail:3 skip:0 total:3
not ok 1 test_new_blocks_simple
<snip>
By tracing kunit_parser.py script, I could see the issue here is in the
parsing of the "Subtest: test_new_blocks_simple". We end up associating
everything below the subtest till "not ok 1 block_bits=10..." as
diagnostic logs of the subtest, while these lons actually belong to the
first of the 3 subtests under this test.
I tired to figure out a way to fix the parsing but fixing one thing
broke something else. Im starting to think that the issue is that there
are 3 subtests under test_new_block_simple (array of 3 params passed to
KUNIT_CASE_PARAM), but instead of creating 3 structured subtests, the
KTAP output dumps the results of all 3 directly under
subtest:test_new_blocks_simple. Which makes it tricky to determine where
the diagnostic log/attributes of test_new_blocks_simple ends and that of its
children begins.
I'm not very familiar with KUnit framework so I though I'd reach out
here for some pointers. I can dedicate some time fixing this but I'd
like to know if this is something we need to somehow fix in parsing or
during generation of the KTAP file itself? Any pointers would be
appreciated.
Thanks,
Ojaswin
From: Li RongQing <lirongqing(a)baidu.com>
The softlockup_panic sysctl is currently a binary option: panic immediately
or never panic on soft lockups.
Panicking on any soft lockup, regardless of duration, can be overly
aggressive for brief stalls that may be caused by legitimate operations.
Conversely, never panicking may allow severe system hangs to persist
undetected.
Extend softlockup_panic to accept an integer threshold, allowing the kernel
to panic only when the normalized lockup duration exceeds N watchdog
threshold periods. This provides finer-grained control to distinguish
between transient delays and persistent system failures.
The accepted values are:
- 0: Don't panic (unchanged)
- 1: Panic when duration >= 1 * threshold (20s default, original behavior)
- N > 1: Panic when duration >= N * threshold (e.g., 2 = 40s, 3 = 60s.)
The original behavior is preserved for values 0 and 1, maintaining full
backward compatibility while allowing systems to tolerate brief lockups
while still catching severe, persistent hangs.
Signed-off-by: Li RongQing <lirongqing(a)baidu.com>
Cc: Eduard Zingerman <eddyz87(a)gmail.com>
Cc: Hao Luo <haoluo(a)google.com>
Cc: Jiri Olsa <jolsa(a)kernel.org>
Cc: John Fastabend <john.fastabend(a)gmail.com>
Cc: KP Singh <kpsingh(a)kernel.org>
Cc: Lance Yang <lance.yang(a)linux.dev>
Cc: Martin KaFai Lau <martin.lau(a)linux.dev>
Cc: Nicholas Piggin <npiggin(a)gmail.com>
Cc: Song Liu <song(a)kernel.org>
Cc: Stanislav Fomichev <sdf(a)fomichev.me>
Cc: Yonghong Song <yonghong.song(a)linux.dev>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
---
Diff with v1: add a temp variable thresh_count
chang config to 0 in kernel/configs/debug.config
Documentation/admin-guide/kernel-parameters.txt | 10 +++++-----
arch/arm/configs/aspeed_g5_defconfig | 2 +-
arch/arm/configs/pxa3xx_defconfig | 2 +-
arch/openrisc/configs/or1klitex_defconfig | 2 +-
arch/powerpc/configs/skiroot_defconfig | 2 +-
drivers/gpu/drm/ci/arm.config | 2 +-
drivers/gpu/drm/ci/arm64.config | 2 +-
drivers/gpu/drm/ci/x86_64.config | 2 +-
kernel/configs/debug.config | 2 +-
kernel/watchdog.c | 10 ++++++----
lib/Kconfig.debug | 13 +++++++------
tools/testing/selftests/bpf/config | 2 +-
tools/testing/selftests/wireguard/qemu/kernel.config | 2 +-
13 files changed, 28 insertions(+), 25 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a8d0afd..27c5f96 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6934,12 +6934,12 @@ Kernel parameters
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
- Format: 0 | 1
+ Format: <int>
- A value of 1 instructs the soft-lockup detector
- to panic the machine when a soft-lockup occurs. It is
- also controlled by the kernel.softlockup_panic sysctl
- and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
+ A value of non-zero instructs the soft-lockup detector
+ to panic the machine when a soft-lockup duration exceeds
+ N thresholds. It is also controlled by the kernel.softlockup_panic
+ sysctl and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
respective build-time switch to that functionality.
softlockup_all_cpu_backtrace=
diff --git a/arch/arm/configs/aspeed_g5_defconfig b/arch/arm/configs/aspeed_g5_defconfig
index 2e6ea13..ec558e5 100644
--- a/arch/arm/configs/aspeed_g5_defconfig
+++ b/arch/arm/configs/aspeed_g5_defconfig
@@ -306,7 +306,7 @@ CONFIG_SCHED_STACK_END_CHECK=y
CONFIG_PANIC_ON_OOPS=y
CONFIG_PANIC_TIMEOUT=-1
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BOOTPARAM_HUNG_TASK_PANIC=1
CONFIG_WQ_WATCHDOG=y
# CONFIG_SCHED_DEBUG is not set
diff --git a/arch/arm/configs/pxa3xx_defconfig b/arch/arm/configs/pxa3xx_defconfig
index 07d422f..fb272e3 100644
--- a/arch/arm/configs/pxa3xx_defconfig
+++ b/arch/arm/configs/pxa3xx_defconfig
@@ -100,7 +100,7 @@ CONFIG_PRINTK_TIME=y
CONFIG_DEBUG_KERNEL=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_SHIRQ=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
# CONFIG_SCHED_DEBUG is not set
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_SPINLOCK_SLEEP=y
diff --git a/arch/openrisc/configs/or1klitex_defconfig b/arch/openrisc/configs/or1klitex_defconfig
index fb1eb9a..984b0e3 100644
--- a/arch/openrisc/configs/or1klitex_defconfig
+++ b/arch/openrisc/configs/or1klitex_defconfig
@@ -52,5 +52,5 @@ CONFIG_LSM="lockdown,yama,loadpin,safesetid,integrity,bpf"
CONFIG_PRINTK_TIME=y
CONFIG_PANIC_ON_OOPS=y
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BUG_ON_DATA_CORRUPTION=y
diff --git a/arch/powerpc/configs/skiroot_defconfig b/arch/powerpc/configs/skiroot_defconfig
index 2b71a6d..a4114fc 100644
--- a/arch/powerpc/configs/skiroot_defconfig
+++ b/arch/powerpc/configs/skiroot_defconfig
@@ -289,7 +289,7 @@ CONFIG_SCHED_STACK_END_CHECK=y
CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_PANIC_ON_OOPS=y
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
CONFIG_WQ_WATCHDOG=y
diff --git a/drivers/gpu/drm/ci/arm.config b/drivers/gpu/drm/ci/arm.config
index 411e814..d7c5167 100644
--- a/drivers/gpu/drm/ci/arm.config
+++ b/drivers/gpu/drm/ci/arm.config
@@ -52,7 +52,7 @@ CONFIG_TMPFS=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKDEP=n
CONFIG_SOFTLOCKUP_DETECTOR=n
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=n
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=0
CONFIG_FW_LOADER_COMPRESS=y
diff --git a/drivers/gpu/drm/ci/arm64.config b/drivers/gpu/drm/ci/arm64.config
index fddfbd4..ea0e307 100644
--- a/drivers/gpu/drm/ci/arm64.config
+++ b/drivers/gpu/drm/ci/arm64.config
@@ -161,7 +161,7 @@ CONFIG_TMPFS=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKDEP=n
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_DETECT_HUNG_TASK=y
diff --git a/drivers/gpu/drm/ci/x86_64.config b/drivers/gpu/drm/ci/x86_64.config
index 8eaba388..7ac98a7 100644
--- a/drivers/gpu/drm/ci/x86_64.config
+++ b/drivers/gpu/drm/ci/x86_64.config
@@ -47,7 +47,7 @@ CONFIG_TMPFS=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKDEP=n
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_DETECT_HUNG_TASK=y
diff --git a/kernel/configs/debug.config b/kernel/configs/debug.config
index 9f6ab7d..774702591 100644
--- a/kernel/configs/debug.config
+++ b/kernel/configs/debug.config
@@ -84,7 +84,7 @@ CONFIG_SLUB_DEBUG_ON=y
# Debug Oops, Lockups and Hangs
#
CONFIG_BOOTPARAM_HUNG_TASK_PANIC=0
-# CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC is not set
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=0
CONFIG_DEBUG_ATOMIC_SLEEP=y
CONFIG_DETECT_HUNG_TASK=y
CONFIG_PANIC_ON_OOPS=y
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 0685e3a..8168e0d 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -363,7 +363,7 @@ static struct cpumask watchdog_allowed_mask __read_mostly;
/* Global variables, exported for sysctl */
unsigned int __read_mostly softlockup_panic =
- IS_ENABLED(CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC);
+ CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC;
static bool softlockup_initialized __read_mostly;
static u64 __read_mostly sample_period;
@@ -774,8 +774,8 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
{
unsigned long touch_ts, period_ts, now;
struct pt_regs *regs = get_irq_regs();
- int duration;
int softlockup_all_cpu_backtrace;
+ int duration, thresh_count;
unsigned long flags;
if (!watchdog_enabled)
@@ -879,7 +879,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
sys_info(softlockup_si_mask & ~SYS_INFO_ALL_BT);
- if (softlockup_panic)
+ thresh_count = duration / get_softlockup_thresh();
+
+ if (softlockup_panic && thresh_count >= softlockup_panic)
panic("softlockup: hung tasks");
}
@@ -1228,7 +1230,7 @@ static const struct ctl_table watchdog_sysctls[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
+ .extra2 = SYSCTL_INT_MAX,
},
{
.procname = "softlockup_sys_info",
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ba36939..17a7a77 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1110,13 +1110,14 @@ config SOFTLOCKUP_DETECTOR_INTR_STORM
the CPU stats and the interrupt counts during the "soft lockups".
config BOOTPARAM_SOFTLOCKUP_PANIC
- bool "Panic (Reboot) On Soft Lockups"
+ int "Panic (Reboot) On Soft Lockups"
depends on SOFTLOCKUP_DETECTOR
+ default 0
help
- Say Y here to enable the kernel to panic on "soft lockups",
- which are bugs that cause the kernel to loop in kernel
- mode for more than 20 seconds (configurable using the watchdog_thresh
- sysctl), without giving other tasks a chance to run.
+ Set to a non-zero value N to enable the kernel to panic on "soft
+ lockups", which are bugs that cause the kernel to loop in kernel
+ mode for more than (N * 20 seconds) (configurable using the
+ watchdog_thresh sysctl), without giving other tasks a chance to run.
The panic can be used in combination with panic_timeout,
to cause the system to reboot automatically after a
@@ -1124,7 +1125,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC
high-availability systems that have uptime guarantees and
where a lockup must be resolved ASAP.
- Say N if unsure.
+ Say 0 if unsure.
config HAVE_HARDLOCKUP_DETECTOR_BUDDY
bool
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index 558839e..2485538 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -1,6 +1,6 @@
CONFIG_BLK_DEV_LOOP=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BPF=y
CONFIG_BPF_EVENTS=y
CONFIG_BPF_JIT=y
diff --git a/tools/testing/selftests/wireguard/qemu/kernel.config b/tools/testing/selftests/wireguard/qemu/kernel.config
index 0504c11..bb89d2d 100644
--- a/tools/testing/selftests/wireguard/qemu/kernel.config
+++ b/tools/testing/selftests/wireguard/qemu/kernel.config
@@ -80,7 +80,7 @@ CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_WQ_WATCHDOG=y
CONFIG_DETECT_HUNG_TASK=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BOOTPARAM_HUNG_TASK_PANIC=1
CONFIG_PANIC_TIMEOUT=-1
CONFIG_STACKTRACE=y
--
2.9.4
sched_ext tasks can be starved by long-running RT tasks, especially since
RT throttling was replaced by deadline servers to boost only SCHED_NORMAL
tasks.
Several users in the community have reported issues with RT stalling
sched_ext tasks. This is fairly common on distributions or environments
where applications like video compositors, audio services, etc. run as RT
tasks by default.
Example trace (showing a per-CPU kthread stalled due to the sway Wayland
compositor running as an RT task):
runnable task stall (kworker/0:0[106377] failed to run for 5.043s)
...
CPU 0 : nr_run=3 flags=0xd cpu_rel=0 ops_qseq=20646200 pnt_seq=45388738
curr=sway[994] class=rt_sched_class
R kworker/0:0[106377] -5043ms
scx_state/flags=3/0x1 dsq_flags=0x0 ops_state/qseq=0/0
sticky/holding_cpu=-1/-1 dsq_id=0x8000000000000002 dsq_vtime=0 slice=20000000
cpus=01
This is often perceived as a bug in the BPF schedulers, but in reality they
can't do much: RT tasks run outside their control and can potentially
consume 100% of the CPU bandwidth.
Fix this by adding a sched_ext deadline server, so that sched_ext tasks are
also boosted and do not suffer starvation.
Two kselftests are also provided to verify the starvation fixes and
bandwidth allocation is correct.
== Design ==
- The EXT server is initialized at boot time and remains configured
throughout the system's lifetime
- It starts automatically when the first sched_ext task is enqueued
(rq->scx.nr_running == 1)
- The server's pick function (ext_server_pick_task) always selects
sched_ext tasks when active
- Runtime accounting happens in update_curr_scx() during task execution
and update_curr_idle() when idle
- Bandwidth accounting includes both fair and ext servers in root domain
calculations
- A debugfs interface (/sys/kernel/debug/sched/ext_server/) allows runtime
tuning of server parameters
== Highlights in this version ==
As discussed at the sched_ext microconference at LPC Tokyo, the plan is to
start with a simpler approach, avoiding automatically creating or tearing
down the EXT server bandwidth reservation when a BPF scheduler is loaded or
unloaded. Instead, the reservation is kept permanently active. This
significantly simplifies the logic while still addressing the starvation
issue.
Any fine-tuning of the bandwidth reservation is delegated to the system
administrator, who can adjust it via the debugfs interface. In the future,
a more suitable interface can be introduced and automatic removal of the
reservation when the BPF scheduler is unloaded can be revisited.
This patchset is also available in the following git branch:
git://git.kernel.org/pub/scm/linux/kernel/git/arighi/linux.git scx-dl-server
Changes in v11:
- do not create/remove the bandwidth reservation for the ext server when a
BPF scheduler is loaded/unloaded, but keep the reservation bandwdith
always active
- change rt_stall kselftest to validate both FAIR and EXT DL servers
- Link to v10: https://lore.kernel.org/all/20250903095008.162049-1-arighi@nvidia.com/
Changes in v10:
- reordered patches to better isolate sched_ext changes vs sched/deadline
changes (Andrea Righi)
- define ext_server only with CONFIG_SCHED_CLASS_EXT=y (Andrea Righi)
- add WARN_ON_ONCE(!cpus) check in dl_server_apply_params() (Andrea Righi)
- wait for inactive_task_timer to fire before removing the bandwidth
reservation (Juri Lelli)
- remove explicit dl_server_stop() in dequeue_task_scx() to reduce timer
reprogramming overhead (Juri Lelli)
- do not restart pick_task() when invoked by the dl_server (Tejun Heo)
- rename rq_dl_server to dl_server (Peter Zijlstra)
- fixed a missing dl_server start in dl_server_on() (Christian Loehle)
- add a comment to the rt_stall selftest to better explain the 4%
threshold (Emil Tsalapatis)
- Link to v9: https://lore.kernel.org/all/20251017093214.70029-1-arighi@nvidia.com/
Changes in v9:
- Drop the ->balance() logic as its functionality is now integrated into
->pick_task(), allowing dl_server to call pick_task_scx() directly
- Link to v8: https://lore.kernel.org/all/20250903095008.162049-1-arighi@nvidia.com/
Changes in v8:
- Add tj's patch to de-couple balance and pick_task and avoid changing
sched/core callbacks to propagate @rf
- Simplify dl_se->dl_server check (suggested by PeterZ)
- Small coding style fixes in the kselftests
- Link to v7: https://lore.kernel.org/all/20250809184800.129831-1-joelagnelf@nvidia.com/
Changes in v7:
- Rebased to Linus master
- Link to v6: https://lore.kernel.org/all/20250702232944.3221001-1-joelagnelf@nvidia.com/
Changes in v6:
- Added Acks to few patches
- Fixes to few nits suggested by Tejun
- Link to v5: https://lore.kernel.org/all/20250620203234.3349930-1-joelagnelf@nvidia.com/
Changes in v5:
- Added a kselftest (total_bw) to sched_ext to verify bandwidth values
from debugfs
- Address comment from Andrea about redundant rq clock invalidation
- Link to v4: https://lore.kernel.org/all/20250617200523.1261231-1-joelagnelf@nvidia.com/
Changes in v4:
- Fixed issues with hotplugged CPUs having their DL server bandwidth
altered due to loading SCX
- Fixed other issues
- Rebased on Linus master
- All sched_ext kselftests reliably pass now, also verified that the
total_bw in debugfs (CONFIG_SCHED_DEBUG) is conserved with these patches
- Link to v3: https://lore.kernel.org/all/20250613051734.4023260-1-joelagnelf@nvidia.com/
Changes in v3:
- Removed code duplication in debugfs. Made ext interface separate
- Fixed issue where rq_lock_irqsave was not used in the relinquish patch
- Fixed running bw accounting issue in dl_server_remove_params
- Link to v2: https://lore.kernel.org/all/20250602180110.816225-1-joelagnelf@nvidia.com/
Changes in v2:
- Fixed a hang related to using rq_lock instead of rq_lock_irqsave
- Added support to remove BW of DL servers when they are switched to/from EXT
- Link to v1: https://lore.kernel.org/all/20250315022158.2354454-1-joelagnelf@nvidia.com/
Andrea Righi (2):
sched_ext: Add a DL server for sched_ext tasks
selftests/sched_ext: Add test for sched_ext dl_server
Joel Fernandes (5):
sched/deadline: Clear the defer params
sched/debug: Fix updating of ppos on server write ops
sched/debug: Stop and start server based on if it was active
sched/debug: Add support to change sched_ext server params
selftests/sched_ext: Add test for DL server total_bw consistency
kernel/sched/core.c | 6 +
kernel/sched/deadline.c | 87 +++++--
kernel/sched/debug.c | 171 +++++++++++---
kernel/sched/ext.c | 42 ++++
kernel/sched/idle.c | 3 +
kernel/sched/sched.h | 2 +
kernel/sched/topology.c | 5 +
tools/testing/selftests/sched_ext/Makefile | 2 +
tools/testing/selftests/sched_ext/rt_stall.bpf.c | 23 ++
tools/testing/selftests/sched_ext/rt_stall.c | 240 +++++++++++++++++++
tools/testing/selftests/sched_ext/total_bw.c | 281 +++++++++++++++++++++++
11 files changed, 811 insertions(+), 51 deletions(-)
create mode 100644 tools/testing/selftests/sched_ext/rt_stall.bpf.c
create mode 100644 tools/testing/selftests/sched_ext/rt_stall.c
create mode 100644 tools/testing/selftests/sched_ext/total_bw.c
This series creates a new PMU scheme on ARM, a partitioned PMU that
allows reserving a subset of counters for more direct guest access,
significantly reducing overhead. More details, including performance
benchmarks, can be read in the v1 cover letter linked below.
An overview of what this series accomplishes was presented at KVM
Forum 2025. Slides [1] and video [2] are linked below.
The long duration between v4 and v5 is due to time spent on this
project being monopolized preparing this feature for internal
production. As a result, there are too many improvements to fully list
here, but I will cover the notable ones.
v5:
* Rebase onto v6.18-rc7. This required pulling some reorganization
patches from Anish and Sean that were dependencies from previous
versions based on kvm/queue but never made it to upstream.
* Ensure FGTs (fine-grained traps) are correctly programmed at vCPU
load using kvm_vcpu_load_fgt() and helpers introduced by Oliver
Upton.
* Cleanly separate concerns of whether the partitioned PMU is enabled
for the guest and whether FGT should be enabled. This allows that
the capability can be VM-scoped while the implementation detail of
whether FGT and context switching are in effect can remain
vCPU-scoped.
* Shrink the uAPI change. Instead of a cap and corresponding ioctl,
the feature can be controlled by just a cap with an argument. The
cap is now also VM-scoped and enforces ordering that it should be
decided before vCPUs are created. Whether the cap is enabled is now
tracked by the new flag KVM_ARCH_ARM_PARTITIONED_PMU_ENABLED.
* Improve log messages when partitioning in the PMUv3 driver.
* Introduce a global variable armv8pmu_hpmn_max in the PMUv3 driver so
KVM code can read if a value was set before the PMU is probed. This
is needed to properly test if we have the capability before vCPUs
are created.
* Make it possible for a VMM to filter the HPMN0 feature bit.
* Fix event filter problems with PMEVTYPER handling in
writethrough_pmevtyper() and kvm_pmu_apply_event_filter() by using
kvm_pmu_event_mask() in the right spots. And if an event is
filtered, write the physical register with the appropriate exclude
bits set but keep the virtual register exactly what the guest wrote.
* Fix register access problems with the PMU register fast path handler
by lifting some static PMU access checks from sys_regs.c to use them
in the fast path too and make bit masking more strict for better ARM
compliance.
* Fix the readability and logic of programming the MDCR_EL2 register
when entering the guest. Make sure to set the HPME bit to allow host
counters to count guest events. Set TPM and TPMCR by default and
clear them if partitioning is enabled rather than the previous
inverted logic of leaving them clear and setting them if
partitioning is not enabled. Make the HPMN field computation more
clear.
* As part of lazy context switching, do a load when the guest is
switching to physical access to ensure any previous writes that only
reached the virtual registers reach the physical ones as well and
are not clobbered by the next vcpu_put().
* Other fixes and improvements that are too small to mention or left
out from my personal notes.
v4:
https://lore.kernel.org/kvmarm/20250714225917.1396543-1-coltonlewis@google.…
v3:
https://lore.kernel.org/kvm/20250626200459.1153955-1-coltonlewis@google.com/
v2:
https://lore.kernel.org/kvm/20250620221326.1261128-1-coltonlewis@google.com/
v1:
https://lore.kernel.org/kvm/20250602192702.2125115-1-coltonlewis@google.com/
[1] https://gitlab.com/qemu-project/kvm-forum/-/raw/main/_attachments/2025/Opti…
[2] https://www.youtube.com/watch?v=YRzZ8jMIA6M&list=PLW3ep1uCIRfxwmllXTOA2txfD…
Anish Ghulati (1):
KVM: arm64: Move arm_{psci,hypercalls}.h to an internal KVM path
Colton Lewis (20):
arm64: cpufeature: Add cpucap for HPMN0
KVM: arm64: Reorganize PMU functions
perf: arm_pmuv3: Introduce method to partition the PMU
perf: arm_pmuv3: Generalize counter bitmasks
perf: arm_pmuv3: Keep out of guest counter partition
KVM: arm64: Set up FGT for Partitioned PMU
KVM: arm64: Writethrough trapped PMEVTYPER register
KVM: arm64: Use physical PMSELR for PMXEVTYPER if partitioned
KVM: arm64: Writethrough trapped PMOVS register
KVM: arm64: Write fast path PMU register handlers
KVM: arm64: Setup MDCR_EL2 to handle a partitioned PMU
KVM: arm64: Account for partitioning in PMCR_EL0 access
KVM: arm64: Context swap Partitioned PMU guest registers
KVM: arm64: Enforce PMU event filter at vcpu_load()
KVM: arm64: Implement lazy PMU context swaps
perf: arm_pmuv3: Handle IRQs for Partitioned PMU guest counters
KVM: arm64: Inject recorded guest interrupts
KVM: arm64: Add KVM_CAP to partition the PMU
KVM: selftests: Add find_bit to KVM library
KVM: arm64: selftests: Add test case for partitioned PMU
Marc Zyngier (1):
KVM: arm64: Reorganize PMU includes
Sean Christopherson (2):
KVM: arm64: Include KVM headers to get forward declarations
KVM: arm64: Move ARM specific headers in include/kvm to arch directory
Documentation/virt/kvm/api.rst | 24 +
arch/arm/include/asm/arm_pmuv3.h | 28 +
arch/arm64/include/asm/arm_pmuv3.h | 61 +-
.../arm64/include/asm/kvm_arch_timer.h | 2 +
arch/arm64/include/asm/kvm_host.h | 24 +-
.../arm64/include/asm/kvm_pmu.h | 142 ++++
arch/arm64/include/asm/kvm_types.h | 7 +-
.../arm64/include/asm/kvm_vgic.h | 0
arch/arm64/kernel/cpufeature.c | 8 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/arch_timer.c | 5 +-
arch/arm64/kvm/arm.c | 23 +-
{include => arch/arm64}/kvm/arm_hypercalls.h | 0
{include => arch/arm64}/kvm/arm_psci.h | 0
arch/arm64/kvm/config.c | 34 +-
arch/arm64/kvm/debug.c | 31 +-
arch/arm64/kvm/guest.c | 2 +-
arch/arm64/kvm/handle_exit.c | 2 +-
arch/arm64/kvm/hyp/Makefile | 6 +-
arch/arm64/kvm/hyp/include/hyp/switch.h | 211 ++++-
arch/arm64/kvm/hyp/nvhe/switch.c | 4 +-
arch/arm64/kvm/hyp/vhe/switch.c | 4 +-
arch/arm64/kvm/hypercalls.c | 4 +-
arch/arm64/kvm/pmu-direct.c | 464 +++++++++++
arch/arm64/kvm/pmu-emul.c | 678 +---------------
arch/arm64/kvm/pmu.c | 726 ++++++++++++++++++
arch/arm64/kvm/psci.c | 4 +-
arch/arm64/kvm/pvtime.c | 2 +-
arch/arm64/kvm/reset.c | 3 +-
arch/arm64/kvm/sys_regs.c | 110 +--
arch/arm64/kvm/trace_arm.h | 2 +-
arch/arm64/kvm/trng.c | 2 +-
arch/arm64/kvm/vgic/vgic-debug.c | 2 +-
arch/arm64/kvm/vgic/vgic-init.c | 2 +-
arch/arm64/kvm/vgic/vgic-irqfd.c | 2 +-
arch/arm64/kvm/vgic/vgic-kvm-device.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio-v2.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio-v3.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio.c | 4 +-
arch/arm64/kvm/vgic/vgic-v2.c | 2 +-
arch/arm64/kvm/vgic/vgic-v3-nested.c | 3 +-
arch/arm64/kvm/vgic/vgic-v3.c | 2 +-
arch/arm64/kvm/vgic/vgic-v5.c | 2 +-
arch/arm64/tools/cpucaps | 1 +
arch/arm64/tools/sysreg | 6 +-
drivers/perf/arm_pmuv3.c | 137 +++-
include/linux/perf/arm_pmu.h | 1 +
include/linux/perf/arm_pmuv3.h | 14 +-
include/uapi/linux/kvm.h | 1 +
tools/include/uapi/linux/kvm.h | 1 +
tools/testing/selftests/kvm/Makefile.kvm | 1 +
.../selftests/kvm/arm64/vpmu_counter_access.c | 77 +-
tools/testing/selftests/kvm/lib/find_bit.c | 1 +
53 files changed, 2049 insertions(+), 831 deletions(-)
rename include/kvm/arm_arch_timer.h => arch/arm64/include/asm/kvm_arch_timer.h (98%)
rename include/kvm/arm_pmu.h => arch/arm64/include/asm/kvm_pmu.h (61%)
rename include/kvm/arm_vgic.h => arch/arm64/include/asm/kvm_vgic.h (100%)
rename {include => arch/arm64}/kvm/arm_hypercalls.h (100%)
rename {include => arch/arm64}/kvm/arm_psci.h (100%)
create mode 100644 arch/arm64/kvm/pmu-direct.c
create mode 100644 tools/testing/selftests/kvm/lib/find_bit.c
base-commit: ac3fd01e4c1efce8f2c054cdeb2ddd2fc0fb150d
--
2.52.0.239.gd5f0c6e74e-goog
The IA32 Emulation support can be either removed from the kernel,
disabled by default or disabled at runtime. Some of x86 selftests
are crashing for all of above thus is_32bit_syscall_supported()
helper is added to skip int80 syscalls if they are not supported.
Slawomir Rosek (2):
selftests/x86/ldt_gdt: Skip int80 if not supported
selftests/x86/ptrace_syscall: Skip int80 if not supported
tools/testing/selftests/x86/ldt_gdt.c | 21 +++++++++++++++++++-
tools/testing/selftests/x86/ptrace_syscall.c | 20 +++++++++++++++++--
2 files changed, 38 insertions(+), 3 deletions(-)
--
2.52.0.305.g3fc767764a-goog
From: Li RongQing <lirongqing(a)baidu.com>
The softlockup_panic sysctl is currently a binary option: panic immediately
or never panic on soft lockups.
Panicking on any soft lockup, regardless of duration, can be overly
aggressive for brief stalls that may be caused by legitimate operations.
Conversely, never panicking may allow severe system hangs to persist
undetected.
Extend softlockup_panic to accept an integer threshold, allowing the kernel
to panic only when the normalized lockup duration exceeds N watchdog
threshold periods. This provides finer-grained control to distinguish
between transient delays and persistent system failures.
The accepted values are:
- 0: Don't panic (unchanged)
- 1: Panic when duration >= 1 * threshold (20s default, original behavior)
- N > 1: Panic when duration >= N * threshold (e.g., 2 = 40s, 3 = 60s.)
The original behavior is preserved for values 0 and 1, maintaining full
backward compatibility while allowing systems to tolerate brief lockups
while still catching severe, persistent hangs.
Signed-off-by: Li RongQing <lirongqing(a)baidu.com>
---
Documentation/admin-guide/kernel-parameters.txt | 10 +++++-----
arch/arm/configs/aspeed_g5_defconfig | 2 +-
arch/arm/configs/pxa3xx_defconfig | 2 +-
arch/openrisc/configs/or1klitex_defconfig | 2 +-
arch/powerpc/configs/skiroot_defconfig | 2 +-
drivers/gpu/drm/ci/arm.config | 2 +-
drivers/gpu/drm/ci/arm64.config | 2 +-
drivers/gpu/drm/ci/x86_64.config | 2 +-
kernel/watchdog.c | 8 +++++---
lib/Kconfig.debug | 13 +++++++------
tools/testing/selftests/bpf/config | 2 +-
tools/testing/selftests/wireguard/qemu/kernel.config | 2 +-
12 files changed, 26 insertions(+), 23 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a8d0afd..27c5f96 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6934,12 +6934,12 @@ Kernel parameters
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
- Format: 0 | 1
+ Format: <int>
- A value of 1 instructs the soft-lockup detector
- to panic the machine when a soft-lockup occurs. It is
- also controlled by the kernel.softlockup_panic sysctl
- and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
+ A value of non-zero instructs the soft-lockup detector
+ to panic the machine when a soft-lockup duration exceeds
+ N thresholds. It is also controlled by the kernel.softlockup_panic
+ sysctl and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
respective build-time switch to that functionality.
softlockup_all_cpu_backtrace=
diff --git a/arch/arm/configs/aspeed_g5_defconfig b/arch/arm/configs/aspeed_g5_defconfig
index 2e6ea13..ec558e5 100644
--- a/arch/arm/configs/aspeed_g5_defconfig
+++ b/arch/arm/configs/aspeed_g5_defconfig
@@ -306,7 +306,7 @@ CONFIG_SCHED_STACK_END_CHECK=y
CONFIG_PANIC_ON_OOPS=y
CONFIG_PANIC_TIMEOUT=-1
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BOOTPARAM_HUNG_TASK_PANIC=1
CONFIG_WQ_WATCHDOG=y
# CONFIG_SCHED_DEBUG is not set
diff --git a/arch/arm/configs/pxa3xx_defconfig b/arch/arm/configs/pxa3xx_defconfig
index 07d422f..fb272e3 100644
--- a/arch/arm/configs/pxa3xx_defconfig
+++ b/arch/arm/configs/pxa3xx_defconfig
@@ -100,7 +100,7 @@ CONFIG_PRINTK_TIME=y
CONFIG_DEBUG_KERNEL=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_SHIRQ=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
# CONFIG_SCHED_DEBUG is not set
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_SPINLOCK_SLEEP=y
diff --git a/arch/openrisc/configs/or1klitex_defconfig b/arch/openrisc/configs/or1klitex_defconfig
index fb1eb9a..984b0e3 100644
--- a/arch/openrisc/configs/or1klitex_defconfig
+++ b/arch/openrisc/configs/or1klitex_defconfig
@@ -52,5 +52,5 @@ CONFIG_LSM="lockdown,yama,loadpin,safesetid,integrity,bpf"
CONFIG_PRINTK_TIME=y
CONFIG_PANIC_ON_OOPS=y
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BUG_ON_DATA_CORRUPTION=y
diff --git a/arch/powerpc/configs/skiroot_defconfig b/arch/powerpc/configs/skiroot_defconfig
index 2b71a6d..a4114fc 100644
--- a/arch/powerpc/configs/skiroot_defconfig
+++ b/arch/powerpc/configs/skiroot_defconfig
@@ -289,7 +289,7 @@ CONFIG_SCHED_STACK_END_CHECK=y
CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_PANIC_ON_OOPS=y
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
CONFIG_WQ_WATCHDOG=y
diff --git a/drivers/gpu/drm/ci/arm.config b/drivers/gpu/drm/ci/arm.config
index 411e814..d7c5167 100644
--- a/drivers/gpu/drm/ci/arm.config
+++ b/drivers/gpu/drm/ci/arm.config
@@ -52,7 +52,7 @@ CONFIG_TMPFS=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKDEP=n
CONFIG_SOFTLOCKUP_DETECTOR=n
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=n
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=0
CONFIG_FW_LOADER_COMPRESS=y
diff --git a/drivers/gpu/drm/ci/arm64.config b/drivers/gpu/drm/ci/arm64.config
index fddfbd4..ea0e307 100644
--- a/drivers/gpu/drm/ci/arm64.config
+++ b/drivers/gpu/drm/ci/arm64.config
@@ -161,7 +161,7 @@ CONFIG_TMPFS=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKDEP=n
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_DETECT_HUNG_TASK=y
diff --git a/drivers/gpu/drm/ci/x86_64.config b/drivers/gpu/drm/ci/x86_64.config
index 8eaba388..7ac98a7 100644
--- a/drivers/gpu/drm/ci/x86_64.config
+++ b/drivers/gpu/drm/ci/x86_64.config
@@ -47,7 +47,7 @@ CONFIG_TMPFS=y
CONFIG_PROVE_LOCKING=n
CONFIG_DEBUG_LOCKDEP=n
CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_DETECT_HUNG_TASK=y
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 0685e3a..a5fa116 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -363,7 +363,7 @@ static struct cpumask watchdog_allowed_mask __read_mostly;
/* Global variables, exported for sysctl */
unsigned int __read_mostly softlockup_panic =
- IS_ENABLED(CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC);
+ CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC;
static bool softlockup_initialized __read_mostly;
static u64 __read_mostly sample_period;
@@ -879,7 +879,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
sys_info(softlockup_si_mask & ~SYS_INFO_ALL_BT);
- if (softlockup_panic)
+ duration = duration / get_softlockup_thresh();
+
+ if (softlockup_panic && duration >= softlockup_panic)
panic("softlockup: hung tasks");
}
@@ -1228,7 +1230,7 @@ static const struct ctl_table watchdog_sysctls[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
+ .extra2 = SYSCTL_INT_MAX,
},
{
.procname = "softlockup_sys_info",
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ba36939..17a7a77 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1110,13 +1110,14 @@ config SOFTLOCKUP_DETECTOR_INTR_STORM
the CPU stats and the interrupt counts during the "soft lockups".
config BOOTPARAM_SOFTLOCKUP_PANIC
- bool "Panic (Reboot) On Soft Lockups"
+ int "Panic (Reboot) On Soft Lockups"
depends on SOFTLOCKUP_DETECTOR
+ default 0
help
- Say Y here to enable the kernel to panic on "soft lockups",
- which are bugs that cause the kernel to loop in kernel
- mode for more than 20 seconds (configurable using the watchdog_thresh
- sysctl), without giving other tasks a chance to run.
+ Set to a non-zero value N to enable the kernel to panic on "soft
+ lockups", which are bugs that cause the kernel to loop in kernel
+ mode for more than (N * 20 seconds) (configurable using the
+ watchdog_thresh sysctl), without giving other tasks a chance to run.
The panic can be used in combination with panic_timeout,
to cause the system to reboot automatically after a
@@ -1124,7 +1125,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC
high-availability systems that have uptime guarantees and
where a lockup must be resolved ASAP.
- Say N if unsure.
+ Say 0 if unsure.
config HAVE_HARDLOCKUP_DETECTOR_BUDDY
bool
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index 558839e..2485538 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -1,6 +1,6 @@
CONFIG_BLK_DEV_LOOP=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BPF=y
CONFIG_BPF_EVENTS=y
CONFIG_BPF_JIT=y
diff --git a/tools/testing/selftests/wireguard/qemu/kernel.config b/tools/testing/selftests/wireguard/qemu/kernel.config
index 0504c11..bb89d2d 100644
--- a/tools/testing/selftests/wireguard/qemu/kernel.config
+++ b/tools/testing/selftests/wireguard/qemu/kernel.config
@@ -80,7 +80,7 @@ CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_WQ_WATCHDOG=y
CONFIG_DETECT_HUNG_TASK=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
-CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
+CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=1
CONFIG_BOOTPARAM_HUNG_TASK_PANIC=1
CONFIG_PANIC_TIMEOUT=-1
CONFIG_STACKTRACE=y
--
2.9.4
The resctrl selftest currently exhibits several failures on Hygon CPUs
due to missing vendor detection and edge-case handling specific to
Hygon's architecture.
This patch series addresses three distinct issues:
1. A division-by-zero crash in SNC detection on some platforms (e.g.,
Hygon).
2. Missing CPU vendor detection, causing the test to fail with
"# Can not get vendor info..." on Hygon CPUs.
3. Incorrect handling of non-contiguous CBM support on Hygon CPUs.
These changes enable resctrl selftest to run successfully on
Hygon CPUs that support Platform QoS features.
Maintainer notes:
-----------------
Patch 1: selftests/resctrl: Fix a division by zero error on Hygon
- This is a candidate for backport with "Fixes:" tag.
Patch 2: selftests/resctrl: Define CPU vendor IDs as bits to match usage
- This is *not* a candidate for backport since it is an enhancement and
preparatory patch for patch 3.
Patch 3: selftests/resctrl: Add CPU vendor detection for Hygon
Patch 4: selftests/resctrl: Fix non-contiguous CBM check for Hygon
- Even though they are fixes they are *not* candidates for backport
since they are based on another patch series (x86/resctrl: Fix
Platform QoS issues for Hygon) which is in process of being added to
resctrl.
-----------------
Changelog:
v5:
- Patch 2:
1. Fix a nit of "reverse fir ordering" of the variable declarations in
detect_vendor() in v4 patch series (Reinette).
2. Add Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>.
v4:
- Cover letter: add maintainer notes outlining how these patches to be
handled (Reinette).
- Re-organize the patch series to move original patch 3 to the beginning
of series. The patch order has changed between v3 and v4 (Reinette):
v3 -> v4
patch #3 -> patch #1
patch #1 -> patch #2
patch #2 -> patch #3
patch #4 -> patch #4
- Patch 2:
1. Resolve a conflict against latest upstream kernel (Reinette).
2. Fix a nit to maintain the reverse fir ordering of variables in
detect_vendor() (Reinette).
- Patch 3: add Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
- Patch 4: move the maintainer note into the cover letter (Reinette).
v3:
- Patch 1:
1. Update the return types of detect_vendor() and get_vendor() from
'int' to 'unsigned int' to align with their usage as bitmask values
and to prevent potentially risky type conversions (Fenghua).
2. Split the code changes of "define CPU vendor IDs as bits to match
usage" from original patch 1 into a separate patch (this patch,
suggested by Fenghua and Reinette).
3. Introduce the flag 'initialized' to simplify the get_vendor() ->
detect_vendor() logic (Reinette).
- Patch 2 (original patch 1):
1. Move the code changes of "define CPU vendor IDs as bits to match
usage" into patch 1.
- Patch 3 (original patch 2):
1. Fix a nit of code comment for affected platforms (Fenghua).
2. Add Reviewed-by: Fenghua Yu <fenghuay(a)nvidia.com>.
- Patch 4 (original patch 3):
1. Fix a nit to avoid calling get_vendor() twice (Fenghua).
2. Add Reviewed-by: Fenghua Yu <fenghuay(a)nvidia.com>.
v2:
- Patch 1: switch all of the vendor id bitmasks to use BIT() (Reinette)
- Patch 2: add Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
- Patch 3: add Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
add a maintainer note to highlight it is not a candidate for
backport (Reinette)
Xiaochen Shen (4):
selftests/resctrl: Fix a division by zero error on Hygon
selftests/resctrl: Define CPU vendor IDs as bits to match usage
selftests/resctrl: Add CPU vendor detection for Hygon
selftests/resctrl: Fix non-contiguous CBM check for Hygon
tools/testing/selftests/resctrl/cat_test.c | 6 ++--
tools/testing/selftests/resctrl/resctrl.h | 8 ++++--
.../testing/selftests/resctrl/resctrl_tests.c | 28 +++++++++++++------
tools/testing/selftests/resctrl/resctrlfs.c | 10 +++++++
4 files changed, 39 insertions(+), 13 deletions(-)
--
2.47.3
The resctrl selftest currently exhibits several failures on Hygon CPUs
due to missing vendor detection and edge-case handling specific to
Hygon's architecture.
This patch series addresses three distinct issues:
1. A division-by-zero crash in SNC detection on some platforms (e.g.,
Hygon).
2. Missing CPU vendor detection, causing the test to fail with
"# Can not get vendor info..." on Hygon CPUs.
3. Incorrect handling of non-contiguous CBM support on Hygon CPUs.
These changes enable resctrl selftest to run successfully on
Hygon CPUs that support Platform QoS features.
Maintainer notes:
-----------------
Patch 1: selftests/resctrl: Fix a division by zero error on Hygon
- This is a candidate for backport with "Fixes:" tag.
Patch 2: selftests/resctrl: Define CPU vendor IDs as bits to match usage
- This is *not* a candidate for backport since it is an enhancement and
preparatory patch for patch 3.
Patch 3: selftests/resctrl: Add CPU vendor detection for Hygon
Patch 4: selftests/resctrl: Fix non-contiguous CBM check for Hygon
- Even though they are fixes they are *not* candidates for backport
since they are based on another patch series (x86/resctrl: Fix
Platform QoS issues for Hygon) which is in process of being added to
resctrl.
-----------------
Changelog:
v4:
- Cover letter: add maintainer notes outlining how these patches to be
handled (Reinette).
- Re-organize the patch series to move original patch 3 to the beginning
of series. The patch order has changed between v3 and v4 (Reinette):
v3 -> v4
patch #3 -> patch #1
patch #1 -> patch #2
patch #2 -> patch #3
patch #4 -> patch #4
- Patch 2:
1. Resolve a conflict against latest upstream kernel (Reinette).
2. Fix a nit to maintain the reverse fir ordering of variables in
detect_vendor() (Reinette).
- Patch 3: add Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
- Patch 4: move the maintainer note into the cover letter (Reinette).
v3:
- Patch 1:
1. Update the return types of detect_vendor() and get_vendor() from
'int' to 'unsigned int' to align with their usage as bitmask values
and to prevent potentially risky type conversions (Fenghua).
2. Split the code changes of "define CPU vendor IDs as bits to match
usage" from original patch 1 into a separate patch (this patch,
suggested by Fenghua and Reinette).
3. Introduce the flag 'initialized' to simplify the get_vendor() ->
detect_vendor() logic (Reinette).
- Patch 2 (original patch 1):
1. Move the code changes of "define CPU vendor IDs as bits to match
usage" into patch 1.
- Patch 3 (original patch 2):
1. Fix a nit of code comment for affected platforms (Fenghua).
2. Add Reviewed-by: Fenghua Yu <fenghuay(a)nvidia.com>.
- Patch 4 (original patch 3):
1. Fix a nit to avoid calling get_vendor() twice (Fenghua).
2. Add Reviewed-by: Fenghua Yu <fenghuay(a)nvidia.com>.
v2:
- Patch 1: switch all of the vendor id bitmasks to use BIT() (Reinette)
- Patch 2: add Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
- Patch 3: add Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
add a maintainer note to highlight it is not a candidate for
backport (Reinette)
Xiaochen Shen (4):
selftests/resctrl: Fix a division by zero error on Hygon
selftests/resctrl: Define CPU vendor IDs as bits to match usage
selftests/resctrl: Add CPU vendor detection for Hygon
selftests/resctrl: Fix non-contiguous CBM check for Hygon
tools/testing/selftests/resctrl/cat_test.c | 6 ++--
tools/testing/selftests/resctrl/resctrl.h | 8 ++++--
.../testing/selftests/resctrl/resctrl_tests.c | 28 +++++++++++++------
tools/testing/selftests/resctrl/resctrlfs.c | 10 +++++++
4 files changed, 39 insertions(+), 13 deletions(-)
--
2.47.3
This series extends BPF's cryptographic capabilities by adding kfuncs for
SHA hashing and ECDSA signature verification. These functions enable BPF
programs to perform cryptographic operations for use cases such as content
verification, integrity checking, and data authentication.
BPF programs increasingly need to verify data integrity and authenticity in
networking, security, and observability contexts. While BPF already supports
symmetric encryption/decryption, it lacks support for:
1. Cryptographic hashing - needed for content verification, fingerprinting,
and preparing message digests for signature operations
2. Asymmetric signature verification - needed to verify signed data without
requiring the signing key in the datapath
These capabilities enable use cases such as:
- Verifying signed network packets or application data in XDP/TC programs
- Implementing integrity checks in tracing and security monitoring
- Building zero-trust security models where BPF programs verify credentials
- Content-addressed storage and deduplication in BPF-based filesystems
Implementation:
The implementation follows BPF's existing crypto patterns:
1. Uses bpf_dynptr for safe memory access without page fault risks
2. Leverages the kernel's existing crypto library (lib/crypto/sha256.c and
crypto/ecdsa.c) rather than reimplementing algorithms
3. Provides context-based API for ECDSA to enable key reuse and support
multiple program types (syscall, XDP, TC)
4. Includes comprehensive selftests with NIST test vectors
Patch 1: bpf: Extend bpf_crypto_type with hash operations
- Adds hash operation callbacks to bpf_crypto_type structure
- Adds hash() and digestsize() function pointers
- Must come before crypto module to maintain bisectability
Patch 2: crypto: Add BPF hash algorithm type registration module
- Adds bpf_crypto_shash module in crypto/ subsystem
- Registers hash type with BPF crypto infrastructure
- Enables hash algorithm access through unified bpf_crypto_type interface
- Implements callbacks: alloc_tfm, free_tfm, hash, digestsize, get_flags
- Manages shash_desc lifecycle internally
Patch 3: bpf: Add SHA hash kfunc for cryptographic hashing
- Adds bpf_crypto_hash() kfunc for SHA-256/384/512
- Updates bpf_crypto_ctx_create() to support keyless operations
- Protected by CONFIG_CRYPTO_HASH2 guards
- Uses kernel's crypto library implementations
- Fixed u64 types for dynptr sizes to prevent truncation
Patch 4: selftests/bpf: Add tests for bpf_crypto_hash kfunc
- Tests basic functionality with NIST "abc" test vectors
- Validates error handling for invalid parameters (zero-length input)
- Ensures correct hash output for SHA-256, SHA-384, and SHA-512
- Adds CONFIG_CRYPTO_HASH2 and CONFIG_CRYPTO_SHA512 to selftest config
- Refactored test setup code to reduce duplication
Patch 5: bpf: Add ECDSA signature verification kfuncs
- Context-based API: bpf_ecdsa_ctx_create/acquire/release pattern
- Supports NIST curves (P-256, P-384, P-521)
- Adds bpf_ecdsa_verify() for signature verification
- Includes size query functions: keysize, digestsize, maxsize
- Enables use in non-sleepable contexts via pre-allocated contexts
- Uses crypto_sig API with p1363 format (r || s signatures)
Patch 6: selftests/bpf: Add tests for ECDSA signature verification
- Tests valid signature acceptance with RFC 6979 test vectors for P-256
- Tests invalid signature rejection
- Tests size query functions (keysize, digestsize, maxsize)
- Uses well-known NIST test vectors with "sample" message
- Adds CONFIG_CRYPTO_ECDSA to selftest config
v2:
- Fixed redundant __bpf_dynptr_is_rdonly() checks (Vadim)
- Added BPF hash algorithm type registration module in crypto/ subsystem
- Added CONFIG_CRYPTO_HASH2 guards around bpf_crypto_hash() kfunc and its
BTF registration, matching the pattern used for CONFIG_CRYPTO_ECDSA
- Added mandatory digestsize validation for hash operations
v3:
- Fixed patch ordering - header changes now in separate first commit before
crypto module to ensure bisectability (bot+bpf-ci)
- Fixed type mismatch - changed u32 to u64 for dynptr sizes in
bpf_crypto_hash() to match __bpf_dynptr_size() return type (Mykyta)
- Added CONFIG_CRYPTO_ECDSA to selftest config (Song)
- Refactored test code duplication with setup_skel() helper (Song)
- Added copyright notices to all new files
Daniel Hodges (6):
bpf: Extend bpf_crypto_type with hash operations
crypto: Add BPF hash algorithm type registration module
bpf: Add SHA hash kfunc for cryptographic hashing
selftests/bpf: Add tests for bpf_crypto_hash kfunc
bpf: Add ECDSA signature verification kfuncs
selftests/bpf: Add tests for ECDSA signature verification kfuncs
crypto/Makefile | 3 +
crypto/bpf_crypto_shash.c | 95 ++++++
include/linux/bpf_crypto.h | 2 +
kernel/bpf/crypto.c | 306 +++++++++++++++++-
tools/testing/selftests/bpf/config | 3 +
.../selftests/bpf/prog_tests/crypto_hash.c | 147 +++++++++
.../selftests/bpf/prog_tests/ecdsa_verify.c | 75 +++++
.../testing/selftests/bpf/progs/crypto_hash.c | 142 ++++++++
.../selftests/bpf/progs/ecdsa_verify.c | 160 +++++++++
9 files changed, 925 insertions(+), 8 deletions(-)
create mode 100644 crypto/bpf_crypto_shash.c
create mode 100644 tools/testing/selftests/bpf/prog_tests/crypto_hash.c
create mode 100644 tools/testing/selftests/bpf/prog_tests/ecdsa_verify.c
create mode 100644 tools/testing/selftests/bpf/progs/crypto_hash.c
create mode 100644 tools/testing/selftests/bpf/progs/ecdsa_verify.c
--
2.51.0
When the selftest 'tap.c' is compiled with '-D_FORTIFY_SOURCE=3',
the strcpy() in rtattr_add_strsz() is replaced with a checked
version which causes the test to consistently fail when compiled
with toolchains for which this option is enabled by default.
TAP version 13
1..3
# Starting 3 tests from 1 test cases.
# RUN tap.test_packet_valid_udp_gso ...
*** buffer overflow detected ***: terminated
# test_packet_valid_udp_gso: Test terminated by assertion
# FAIL tap.test_packet_valid_udp_gso
not ok 1 tap.test_packet_valid_udp_gso
# RUN tap.test_packet_valid_udp_csum ...
*** buffer overflow detected ***: terminated
# test_packet_valid_udp_csum: Test terminated by assertion
# FAIL tap.test_packet_valid_udp_csum
not ok 2 tap.test_packet_valid_udp_csum
# RUN tap.test_packet_crash_tap_invalid_eth_proto ...
*** buffer overflow detected ***: terminated
# test_packet_crash_tap_invalid_eth_proto: Test terminated by assertion
# FAIL tap.test_packet_crash_tap_invalid_eth_proto
not ok 3 tap.test_packet_crash_tap_invalid_eth_proto
# FAILED: 0 / 3 tests passed.
# Totals: pass:0 fail:3 xfail:0 xpass:0 skip:0 error:0
A buffer overflow is detected by the fortified glibc __strcpy_chk()
since the __builtin_object_size() of `RTA_DATA(rta)` is incorrectly
reported as 1, even though there is ample space in its bounding
buffer `req`.
Additionally, given that IFLA_IFNAME also expects a null-terminated
string, callers of rtaddr_add_str{,sz}() could simply use the
rtaddr_add_strsz() variant. (which has been renamed to remove the
trailing `sz`) memset() has been used for this function since it
is unchecked and thus circumvents the issue discussed in the
previous paragraph.
Fixes: 2e64fe4624d1 ("selftests: add few test cases for tap driver")
Signed-off-by: Alice C. Munduruca <alice.munduruca(a)canonical.com>
Reviewed-by: Cengiz Can <cengiz.can(a)canonical.com>
---
tools/testing/selftests/net/tap.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/tools/testing/selftests/net/tap.c b/tools/testing/selftests/net/tap.c
index 247c3b3ac1c9..51a209014f1c 100644
--- a/tools/testing/selftests/net/tap.c
+++ b/tools/testing/selftests/net/tap.c
@@ -56,18 +56,12 @@ static void rtattr_end(struct nlmsghdr *nh, struct rtattr *attr)
static struct rtattr *rtattr_add_str(struct nlmsghdr *nh, unsigned short type,
const char *s)
{
- struct rtattr *rta = rtattr_add(nh, type, strlen(s));
+ unsigned int strsz = strlen(s) + 1;
+ struct rtattr *rta;
- memcpy(RTA_DATA(rta), s, strlen(s));
- return rta;
-}
-
-static struct rtattr *rtattr_add_strsz(struct nlmsghdr *nh, unsigned short type,
- const char *s)
-{
- struct rtattr *rta = rtattr_add(nh, type, strlen(s) + 1);
+ rta = rtattr_add(nh, type, strsz);
- strcpy(RTA_DATA(rta), s);
+ memcpy(RTA_DATA(rta), s, strsz);
return rta;
}
@@ -119,7 +113,7 @@ static int dev_create(const char *dev, const char *link_type,
link_info = rtattr_begin(&req.nh, IFLA_LINKINFO);
- rtattr_add_strsz(&req.nh, IFLA_INFO_KIND, link_type);
+ rtattr_add_str(&req.nh, IFLA_INFO_KIND, link_type);
if (fill_info_data) {
info_data = rtattr_begin(&req.nh, IFLA_INFO_DATA);
--
2.48.1
The templated test names in psp.py had a bug that was not exposed
until 80970e0fc07e ("selftests: net: py: extract the case generation
logic") changed the order of test case evaluation and test case name
extraction.
The test cases created in psp_ip_ver_test_builder() and
ipver_test_builder() were only assigning formatted names to the test
cases they returned, when the test itself was run. This series moves
the test case naming to the point where the test function is created.
Using netdevsim psp:
Before:
./tools/testing/selftests/drivers/net/psp.py
TAP version 13
1..28
ok 1 psp.test_case
ok 2 psp.test_case
ok 3 psp.test_case
ok 4 psp.test_case
ok 5 psp.test_case
ok 6 psp.test_case
ok 7 psp.test_case
ok 8 psp.test_case
ok 9 psp.test_case
ok 10 psp.test_case
ok 11 psp.dev_list_devices
...
ok 28 psp.removal_device_bi
# Totals: pass:28 fail:0 xfail:0 xpass:0 skip:0 error:0
#
# Responder logs (0):
# STDERR:
# Set PSP enable on device 3 to 0xf
# Set PSP enable on device 3 to 0x0
After:
./tools/testing/selftests/drivers/net/psp.py
TAP version 13
1..28
ok 1 psp.data_basic_send_v0_ip4
ok 2 psp.data_basic_send_v0_ip6
ok 3 psp.data_basic_send_v1_ip4
ok 4 psp.data_basic_send_v1_ip6
ok 5 psp.data_basic_send_v2_ip4
ok 6 psp.data_basic_send_v2_ip6
ok 7 psp.data_basic_send_v3_ip4
ok 8 psp.data_basic_send_v3_ip6
ok 9 psp.data_mss_adjust_ip4
ok 10 psp.data_mss_adjust_ip6
ok 11 psp.dev_list_devices
...
ok 28 psp.removal_device_bi
# Totals: pass:28 fail:0 xfail:0 xpass:0 skip:0 error:0
#
# Responder logs (0):
# STDERR:
# Set PSP enable on device 3 to 0xf
# Set PSP enable on device 3 to 0x0
Signed-off-by: Daniel Zahka <daniel.zahka(a)gmail.com>
---
Daniel Zahka (2):
selftests: drv-net: psp: fix templated test names in psp_ip_ver_test_builder()
selftests: drv-net: psp: fix test names in ipver_test_builder()
tools/testing/selftests/drivers/net/psp.py | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
---
base-commit: 885bebac9909994050bbbeed0829c727e42bd1b7
change-id: 20251212-psp-test-fix-f0816c40a2c1
Best regards,
--
Daniel Zahka <daniel.zahka(a)gmail.com>
Make use of empty (NULL-terminated) array instead of NULL pointer to
avoid compiler errors while maintaining the behavior of the function
intact
Signed-off-by: Clint George <clintbgeorge(a)gmail.com>
---
[] Testing:
The diff between before and after of running the kselftest test of the
module shows no regression on system with x86 architecture
Let me know if any more testing is needed to be done
[] Error log:
~/Desktop/kernel-dev/linux-v1/tools/testing/selftests/filesystems$ make LLVM=1 W=1
CC devpts_pts
CC file_stressor
CC anon_inode_test
anon_inode_test.c:45:37: warning: null passed to a callee that requires a non-null argument [-Wnonnull]
45 | ASSERT_LT(execveat(fd_context, "", NULL, NULL, AT_EMPTY_PATH), 0);
| ^~~~
/usr/lib/llvm-18/lib/clang/18/include/__stddef_null.h:26:14: note: expanded from macro 'NULL'
26 | #define NULL ((void*)0)
| ^~~~~~~~~~
/home/clint/Desktop/kernel-dev/linux-v1/tools/testing/selftests/../../../tools/testing/selftests/kselftest_harness.h:535:11: note: expanded from macro 'ASSERT_LT'
535 | __EXPECT(expected, #expected, seen, #seen, <, 1)
| ^~~~~~~~
/home/clint/Desktop/kernel-dev/linux-v1/tools/testing/selftests/../../../tools/testing/selftests/kselftest_harness.h:758:33: note: expanded from macro '__EXPECT'
758 | __typeof__(_expected) __exp = (_expected); \
| ^~~~~~~~~
1 warning generated.
tools/testing/selftests/filesystems/anon_inode_test.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/filesystems/anon_inode_test.c b/tools/testing/selftests/filesystems/anon_inode_test.c
index 94c6c81c2..2c4c50500 100644
--- a/tools/testing/selftests/filesystems/anon_inode_test.c
+++ b/tools/testing/selftests/filesystems/anon_inode_test.c
@@ -42,7 +42,10 @@ TEST(anon_inode_no_exec)
fd_context = sys_fsopen("tmpfs", 0);
ASSERT_GE(fd_context, 0);
- ASSERT_LT(execveat(fd_context, "", NULL, NULL, AT_EMPTY_PATH), 0);
+ char *const empty_argv[] = {NULL};
+ char *const empty_envp[] = {NULL};
+
+ ASSERT_LT(execveat(fd_context, "", empty_argv, empty_envp, AT_EMPTY_PATH), 0);
ASSERT_EQ(errno, EACCES);
EXPECT_EQ(close(fd_context), 0);
--
2.43.0
Use __builtin_trap() to truly crash the program instead of dereferencing
null pointer which may be optimized by the compiler preventing the crash
from occurring
Signed-off-by: Clint George <clintbgeorge(a)gmail.com>
---
[] Testing:
The diff between before and after of running the kselftest test of the
module shows no regression on system with x86 architecture
Let me know if any more testing is needed to be done
[] Error log:
~/Desktop/kernel-dev/linux-v1/tools/testing/selftests/coredump$ make LLVM=1 W=1
CC stackdump_test
coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
59 | i = *(int *)NULL;
| ^~~~~~~~~~~~
coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
1 warning generated.
CC coredump_socket_test
coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
59 | i = *(int *)NULL;
| ^~~~~~~~~~~~
coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
1 warning generated.
CC coredump_socket_protocol_test
coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
59 | i = *(int *)NULL;
| ^~~~~~~~~~~~
coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
1 warning generated.
tools/testing/selftests/coredump/coredump_test_helpers.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/coredump/coredump_test_helpers.c b/tools/testing/selftests/coredump/coredump_test_helpers.c
index a6f6d5f2a..5c8adee63 100644
--- a/tools/testing/selftests/coredump/coredump_test_helpers.c
+++ b/tools/testing/selftests/coredump/coredump_test_helpers.c
@@ -56,7 +56,7 @@ void crashing_child(void)
pthread_create(&thread, NULL, do_nothing, NULL);
/* crash on purpose */
- i = *(int *)NULL;
+ __builtin_trap();
}
int create_detached_tmpfs(void)
--
2.43.0
Add descriptive message in the _Static_assert to comply with the C11
standard requirement to prevent compiler from throwing out error. The
compiler throws an error when _Static_assert is used without a message as
that is a C23 extension.
Signed-off-by: Clint George <clintbgeorge(a)gmail.com>
---
[] Testing:
The diff between before and after of running the kselftest test of the
module shows no regression on system with x86 architecture
Let me know if any more testing is needed to be done
[] Error log:
~/Desktop/kernel-dev/linux-v1/tools/testing/selftests/ublk$ make LLVM=1 W=1
CC kublk
In file included from kublk.c:6:
./kublk.h:220:43: error: '_Static_assert' with no message is a C23 extension [-Werror,-Wc23-extensions]
220 | _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7);
| ^
| , ""
1 error generated.
In file included from null.c:3:
./kublk.h:220:43: error: '_Static_assert' with no message is a C23 extension [-Werror,-Wc23-extensions]
220 | _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7);
| ^
| , ""
1 error generated.
In file included from file_backed.c:3:
./kublk.h:220:43: error: '_Static_assert' with no message is a C23 extension [-Werror,-Wc23-extensions]
220 | _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7);
| ^
| , ""
1 error generated.
In file included from common.c:3:
./kublk.h:220:43: error: '_Static_assert' with no message is a C23 extension [-Werror,-Wc23-extensions]
220 | _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7);
| ^
| , ""
1 error generated.
In file included from stripe.c:3:
./kublk.h:220:43: error: '_Static_assert' with no message is a C23 extension [-Werror,-Wc23-extensions]
220 | _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7);
| ^
| , ""
1 error generated.
In file included from fault_inject.c:11:
./kublk.h:220:43: error: '_Static_assert' with no message is a C23 extension [-Werror,-Wc23-extensions]
220 | _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7);
| ^
| , ""
1 error generated.
make: *** [../lib.mk:225: /home/clint/Desktop/kernel-dev/linux-v1/tools/testing/selftests/ublk/kublk] Error 1
tools/testing/selftests/ublk/kublk.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h
index fe42705c6..e5eb5f762 100644
--- a/tools/testing/selftests/ublk/kublk.h
+++ b/tools/testing/selftests/ublk/kublk.h
@@ -217,7 +217,7 @@ static inline __u64 build_user_data(unsigned tag, unsigned op,
unsigned tgt_data, unsigned q_id, unsigned is_target_io)
{
/* we only have 7 bits to encode q_id */
- _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7);
+ _Static_assert(UBLK_MAX_QUEUES_SHIFT <= 7, "UBLK_MAX_QUEUES_SHIFT must be <= 7");
assert(!(tag >> 16) && !(op >> 8) && !(tgt_data >> 16) && !(q_id >> 7));
return tag | (op << 16) | (tgt_data << 24) |
--
2.43.0
On the Android arm32 platform, when performing the futex_requeue test, it will
most likely return a failure. The specific reason is detailed in a commit[1]
previously submitted by Edward Liaw. However, this commit cannot perfectly
solve the problem. This is because using a barrier does not guarantee that
the child thread will wait on futex_wait.
This series of patches attempts to solve this problem by checking whether
the child thread is in a sleeping state. This is because when the child thread
goes to sleep, it indicates that it is waiting for the futex lock.
v1->v2:
- Solve the compilation problems found by the kernel test robot
- Cleanup the atomic library code for futex test
Link: https://lore.kernel.org/all/20240918231102.234253-1-edliaw@google.com/
In the thread_state_get() function, the logic to find the thread's state
character was using `sizeof(header) - 1` to calculate the offset from
the "State:\t" string.
The `header` variable is a `const char *` pointer. `sizeof()` on a
pointer returns the size of the pointer itself, not the length of the
string literal it points to. This makes the code's behavior dependent
on the architecture's pointer size.
This bug was identified on a 32-bit ARM build (`gsi_tv_arm`) for
Android, running on an ARMv8-based device, compiled with Clang 19.0.1.
On this 32-bit architecture, `sizeof(char *)` is 4. The expression
`sizeof(header) - 1` resulted in an incorrect offset of 3, causing the
test to read the wrong character from `/proc/[tid]/status` and fail.
On 64-bit architectures, `sizeof(char *)` is 8, so the expression
coincidentally evaluates to 7, which matches the length of "State:\t".
This is why the bug likely remained hidden on 64-bit builds.
To fix this and make the code portable and correct across all
architectures, this patch replaces `sizeof(header) - 1` with
`strlen(header)`. The `strlen()` function correctly calculates the
string's length, ensuring the correct offset is always used.
Signed-off-by: Wake Liu <wakel(a)google.com>
---
tools/testing/selftests/mm/uffd-unit-tests.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index f4807242c5b2..6f5e404a446c 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -1317,7 +1317,7 @@ static thread_state thread_state_get(pid_t tid)
p = strstr(tmp, header);
if (p) {
/* For example, "State:\tD (disk sleep)" */
- c = *(p + sizeof(header) - 1);
+ c = *(p + strlen(header));
return c == 'D' ?
THR_STATE_UNINTERRUPTIBLE : THR_STATE_UNKNOWN;
}
--
2.52.0.223.gf5cc29aaa4-goog
This patch series adds __rust_helper to every single rust helper. The
patches do not depend on each other, so maintainers please go ahead and
pick up any patches relevant to your subsystem! Or provide your Acked-by
so that Miguel can pick them up.
These changes were generated by adding __rust_helper and running
ClangFormat. Unrelated formatting changes were removed manually.
Why is __rust_helper needed?
============================
Currently, C helpers cannot be inlined into Rust even when using LTO
because LLVM detects slightly different options on the codegen units.
* LLVM doesn't want to inline functions compiled with
`-fno-delete-null-pointer-checks` with code compiled without. The C
CGUs all have this enabled and Rust CGUs don't. Inlining is okay since
this is one of the hardening features that does not change the ABI,
and we shouldn't have null pointer dereferences in these helpers.
* LLVM doesn't want to inline functions with different list of builtins. C
side has `-fno-builtin-wcslen`; `wcslen` is not a Rust builtin, so
they should be compatible, but LLVM does not perform inlining due to
attributes mismatch.
* clang and Rust doesn't have the exact target string. Clang generates
`+cmov,+cx8,+fxsr` but Rust doesn't enable them (in fact, Rust will
complain if `-Ctarget-feature=+cmov,+cx8,+fxsr` is used). x86-64
always enable these features, so they are in fact the same target
string, but LLVM doesn't understand this and so inlining is inhibited.
This can be bypassed with `--ignore-tti-inline-compatible`, but this
is a hidden option.
(This analysis was written by Gary Guo.)
How is this fixed?
==================
To fix this we need to add __always_inline to all helpers when compiling
with LTO. However, it should not be added when running bindgen as
bindgen will ignore functions marked inline. To achieve this, we are
using a #define called __rust_helper that is defined differently
depending on whether bindgen is running or not.
Note that __rust_helper is currently always #defined to nothing.
Changing it to __always_inline will happen separately in another patch
series.
Signed-off-by: Alice Ryhl <aliceryhl(a)google.com>
---
Alice Ryhl (46):
rust: auxiliary: add __rust_helper to helpers
rust: barrier: add __rust_helper to helpers
rust: binder: add __rust_helper to helpers
rust: bitmap: add __rust_helper to helpers
rust: bitops: add __rust_helper to helpers
rust: blk: add __rust_helper to helpers
rust: bug: add __rust_helper to helpers
rust: clk: add __rust_helper to helpers
rust: completion: add __rust_helper to helpers
rust: cpu: add __rust_helper to helpers
rust: cpufreq: add __rust_helper to helpers
rust: cpumask: add __rust_helper to helpers
rust: cred: add __rust_helper to helpers
rust: device: add __rust_helper to helpers
rust: dma: add __rust_helper to helpers
rust: drm: add __rust_helper to helpers
rust: err: add __rust_helper to helpers
rust: fs: add __rust_helper to helpers
rust: io: add __rust_helper to helpers
rust: irq: add __rust_helper to helpers
rust: jump_label: add __rust_helper to helpers
rust: kunit: add __rust_helper to helpers
rust: maple_tree: add __rust_helper to helpers
rust: mm: add __rust_helper to helpers
rust: of: add __rust_helper to helpers
rust: pci: add __rust_helper to helpers
rust: pid_namespace: add __rust_helper to helpers
rust: platform: add __rust_helper to helpers
rust: poll: add __rust_helper to helpers
rust: processor: add __rust_helper to helpers
rust: property: add __rust_helper to helpers
rust: rbtree: add __rust_helper to helpers
rust: rcu: add __rust_helper to helpers
rust: refcount: add __rust_helper to helpers
rust: regulator: add __rust_helper to helpers
rust: scatterlist: add __rust_helper to helpers
rust: security: add __rust_helper to helpers
rust: slab: add __rust_helper to helpers
rust: sync: add __rust_helper to helpers
rust: task: add __rust_helper to helpers
rust: time: add __rust_helper to helpers
rust: uaccess: add __rust_helper to helpers
rust: usb: add __rust_helper to helpers
rust: wait: add __rust_helper to helpers
rust: workqueue: add __rust_helper to helpers
rust: xarray: add __rust_helper to helpers
rust/helpers/auxiliary.c | 6 +++--
rust/helpers/barrier.c | 6 ++---
rust/helpers/binder.c | 13 ++++-----
rust/helpers/bitmap.c | 6 +++--
rust/helpers/bitops.c | 11 +++++---
rust/helpers/blk.c | 4 +--
rust/helpers/bug.c | 4 +--
rust/helpers/build_bug.c | 2 +-
rust/helpers/clk.c | 24 +++++++++--------
rust/helpers/completion.c | 2 +-
rust/helpers/cpu.c | 2 +-
rust/helpers/cpufreq.c | 3 ++-
rust/helpers/cpumask.c | 32 +++++++++++++---------
rust/helpers/cred.c | 4 +--
rust/helpers/device.c | 16 +++++------
rust/helpers/dma.c | 15 ++++++-----
rust/helpers/drm.c | 7 ++---
rust/helpers/err.c | 6 ++---
rust/helpers/fs.c | 2 +-
rust/helpers/io.c | 64 +++++++++++++++++++++++---------------------
rust/helpers/irq.c | 6 +++--
rust/helpers/jump_label.c | 2 +-
rust/helpers/kunit.c | 2 +-
rust/helpers/maple_tree.c | 3 ++-
rust/helpers/mm.c | 20 +++++++-------
rust/helpers/mutex.c | 13 ++++-----
rust/helpers/of.c | 2 +-
rust/helpers/page.c | 9 ++++---
rust/helpers/pci.c | 13 +++++----
rust/helpers/pid_namespace.c | 8 +++---
rust/helpers/platform.c | 2 +-
rust/helpers/poll.c | 5 ++--
rust/helpers/processor.c | 2 +-
rust/helpers/property.c | 2 +-
rust/helpers/rbtree.c | 5 ++--
rust/helpers/rcu.c | 4 +--
rust/helpers/refcount.c | 10 +++----
rust/helpers/regulator.c | 24 ++++++++++-------
rust/helpers/scatterlist.c | 12 +++++----
rust/helpers/security.c | 26 ++++++++++--------
rust/helpers/signal.c | 2 +-
rust/helpers/slab.c | 14 +++++-----
rust/helpers/spinlock.c | 13 ++++-----
rust/helpers/sync.c | 4 +--
rust/helpers/task.c | 24 ++++++++---------
rust/helpers/time.c | 12 ++++-----
rust/helpers/uaccess.c | 8 +++---
rust/helpers/usb.c | 3 ++-
rust/helpers/vmalloc.c | 7 ++---
rust/helpers/wait.c | 2 +-
rust/helpers/workqueue.c | 8 +++---
rust/helpers/xarray.c | 10 +++----
52 files changed, 280 insertions(+), 226 deletions(-)
---
base-commit: 54e3eae855629702c566bd2e130d9f40e7f35bde
change-id: 20251202-define-rust-helper-f7b531813007
Best regards,
--
Alice Ryhl <aliceryhl(a)google.com>
When the selftest 'tap.c' is compiled with '-D_FORTIFY_SOURCE=3', the
strcpy() in rtattr_add_strsz() is replaced with a checked version which
causes the test to consistently fail when compiled with toolchains for
which this option is enabled by default.
TAP version 13
1..3
# Starting 3 tests from 1 test cases.
# RUN tap.test_packet_valid_udp_gso ...
*** buffer overflow detected ***: terminated
# test_packet_valid_udp_gso: Test terminated by assertion
# FAIL tap.test_packet_valid_udp_gso
not ok 1 tap.test_packet_valid_udp_gso
# RUN tap.test_packet_valid_udp_csum ...
*** buffer overflow detected ***: terminated
# test_packet_valid_udp_csum: Test terminated by assertion
# FAIL tap.test_packet_valid_udp_csum
not ok 2 tap.test_packet_valid_udp_csum
# RUN tap.test_packet_crash_tap_invalid_eth_proto ...
*** buffer overflow detected ***: terminated
# test_packet_crash_tap_invalid_eth_proto: Test terminated by assertion
# FAIL tap.test_packet_crash_tap_invalid_eth_proto
not ok 3 tap.test_packet_crash_tap_invalid_eth_proto
# FAILED: 0 / 3 tests passed.
# Totals: pass:0 fail:3 xfail:0 xpass:0 skip:0 error:0
A buffer overflow is detected by the fortified glibc __strcpy_chk()
since the __builtin_object_size() of `RTA_DATA(rta)` is incorrectly
reported as 1, even though there is ample space in its bounding buffer
`req`.
Using the unchecked function memcpy() here instead allows us to match
the way rtattr_add_str() is written while avoiding the spurious test
failure.
Fixes: 2e64fe4624d1 ("selftests: add few test cases for tap driver")
Signed-off-by: Alice C. Munduruca <alice.munduruca(a)canonical.com>
---
tools/testing/selftests/net/tap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/tap.c b/tools/testing/selftests/net/tap.c
index 247c3b3ac1c9..dd961b629295 100644
--- a/tools/testing/selftests/net/tap.c
+++ b/tools/testing/selftests/net/tap.c
@@ -67,7 +67,7 @@ static struct rtattr *rtattr_add_strsz(struct nlmsghdr *nh, unsigned short type,
{
struct rtattr *rta = rtattr_add(nh, type, strlen(s) + 1);
- strcpy(RTA_DATA(rta), s);
+ memcpy(RTA_DATA(rta), s, strlen(s) + 1);
return rta;
}
--
2.48.1
From: Jack Thomson <jackabt(a)amazon.com>
This patch series adds ARM64 support for the KVM_PRE_FAULT_MEMORY
feature, which was previously only available on x86 [1]. This allows us
to reduce the number of stage-2 faults during execution. This is of
benefit in post-copy migration scenarios, particularly in memory
intensive applications, where we are experiencing high latencies due to
the stage-2 faults.
Patch Overview:
- The first patch adds support for the KVM_PRE_FAULT_MEMORY ioctl
on arm64.
- The second patch updates the pre_fault_memory_test to support
arm64.
- The last patch extends the pre_fault_memory_test to cover
different vm memory backings.
=== Changes Since v2 [2] ===
- Update fault info synthesize value. Thanks Suzuki
- Remove change to selftests for unaligned mmap allocations. Thanks
Sean
[1]: https://lore.kernel.org/kvm/20240710174031.312055-1-pbonzini@redhat.com
[2]: https://lore.kernel.org/linux-arm-kernel/20251013151502.6679-1-jackabt.amaz…
Jack Thomson (3):
KVM: arm64: Add pre_fault_memory implementation
KVM: selftests: Enable pre_fault_memory_test for arm64
KVM: selftests: Add option for different backing in pre-fault tests
Documentation/virt/kvm/api.rst | 3 +-
arch/arm64/kvm/Kconfig | 1 +
arch/arm64/kvm/arm.c | 1 +
arch/arm64/kvm/mmu.c | 73 +++++++++++-
tools/testing/selftests/kvm/Makefile.kvm | 1 +
.../selftests/kvm/pre_fault_memory_test.c | 110 ++++++++++++++----
6 files changed, 159 insertions(+), 30 deletions(-)
base-commit: 8a4821412cf2c1429fffa07c012dd150f2edf78c
--
2.43.0
Make use of empty (NULL-terminated) array instead of NULL pointer to
avoid compiler errors while maintaining the behavior of the function
intact
Signed-off-by: Clint George <clintbgeorge(a)gmail.com>
---
[] Testing:
The diff between before and after of running the kselftest test of the
module shows no regression on system with x86 architecture
Let me know if any more testing is needed to be done
[] Error log:
~/Desktop/kernel-dev/linux-v1/tools/testing/selftests/filesystems$ make LLVM=1 W=1
CC devpts_pts
CC file_stressor
CC anon_inode_test
anon_inode_test.c:45:37: warning: null passed to a callee that requires a non-null argument [-Wnonnull]
45 | ASSERT_LT(execveat(fd_context, "", NULL, NULL, AT_EMPTY_PATH), 0);
| ^~~~
/usr/lib/llvm-18/lib/clang/18/include/__stddef_null.h:26:14: note: expanded from macro 'NULL'
26 | #define NULL ((void*)0)
| ^~~~~~~~~~
/home/clint/Desktop/kernel-dev/linux-v1/tools/testing/selftests/../../../tools/testing/selftests/kselftest_harness.h:535:11: note: expanded from macro 'ASSERT_LT'
535 | __EXPECT(expected, #expected, seen, #seen, <, 1)
| ^~~~~~~~
/home/clint/Desktop/kernel-dev/linux-v1/tools/testing/selftests/../../../tools/testing/selftests/kselftest_harness.h:758:33: note: expanded from macro '__EXPECT'
758 | __typeof__(_expected) __exp = (_expected); \
| ^~~~~~~~~
1 warning generated.
tools/testing/selftests/filesystems/anon_inode_test.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/filesystems/anon_inode_test.c b/tools/testing/selftests/filesystems/anon_inode_test.c
index 94c6c81c2..2c4c50500 100644
--- a/tools/testing/selftests/filesystems/anon_inode_test.c
+++ b/tools/testing/selftests/filesystems/anon_inode_test.c
@@ -42,7 +42,10 @@ TEST(anon_inode_no_exec)
fd_context = sys_fsopen("tmpfs", 0);
ASSERT_GE(fd_context, 0);
- ASSERT_LT(execveat(fd_context, "", NULL, NULL, AT_EMPTY_PATH), 0);
+ char *const empty_argv[] = {NULL};
+ char *const empty_envp[] = {NULL};
+
+ ASSERT_LT(execveat(fd_context, "", empty_argv, empty_envp, AT_EMPTY_PATH), 0);
ASSERT_EQ(errno, EACCES);
EXPECT_EQ(close(fd_context), 0);
--
2.43.0
Use __builtin_trap() to truly crash the program instead of dereferencing
null pointer which may be optimized by the compiler preventing the crash
from occurring
Signed-off-by: Clint George <clintbgeorge(a)gmail.com>
---
[] Testing:
The diff between before and after of running the kselftest test of the
module shows no regression on system with x86 architecture
Let me know if any more testing is needed to be done
[] Error log:
~/Desktop/kernel-dev/linux-v1/tools/testing/selftests/coredump$ make LLVM=1 W=1
CC stackdump_test
coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
59 | i = *(int *)NULL;
| ^~~~~~~~~~~~
coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
1 warning generated.
CC coredump_socket_test
coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
59 | i = *(int *)NULL;
| ^~~~~~~~~~~~
coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
1 warning generated.
CC coredump_socket_protocol_test
coredump_test_helpers.c:59:6: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]
59 | i = *(int *)NULL;
| ^~~~~~~~~~~~
coredump_test_helpers.c:59:6: note: consider using __builtin_trap() or qualifying pointer with 'volatile'
1 warning generated.
tools/testing/selftests/coredump/coredump_test_helpers.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/coredump/coredump_test_helpers.c b/tools/testing/selftests/coredump/coredump_test_helpers.c
index a6f6d5f2a..5c8adee63 100644
--- a/tools/testing/selftests/coredump/coredump_test_helpers.c
+++ b/tools/testing/selftests/coredump/coredump_test_helpers.c
@@ -56,7 +56,7 @@ void crashing_child(void)
pthread_create(&thread, NULL, do_nothing, NULL);
/* crash on purpose */
- i = *(int *)NULL;
+ __builtin_trap();
}
int create_detached_tmpfs(void)
--
2.43.0
On the Android arm32 platform, when performing the futex_requeue test, it will
most likely return a failure. The specific reason is detailed in a commit[1]
previously submitted by Edward Liaw. However, this commit cannot perfectly
solve the problem. This is because using a barrier does not guarantee that
the child thread will wait on futex_wait.
This series of patches attempts to solve this problem by checking whether
the child thread is in a sleeping state. This is because when the child thread
goes to sleep, it indicates that it is waiting for the futex lock.
Link: https://lore.kernel.org/all/20240918231102.234253-1-edliaw@google.com/
On Thu, 11 Dec 2025, Jiaqi Yan wrote:
> CONFIGs seem alright to me. Do you boot kernel with cmdline options like "default_hugepagesz=1G hugepagesz=1G hugepages=64", or dynamically set up
> huge pages via "echo 64 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages"?
Neither of these. When I do the test is skipped:
# echo 64 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
# ./arm64/sea_to_user
Random seed: 0x6b8b4567
# Mapped 0x40000 pages: gva=0x80000000 to gpa=0xff80000000
# Before EINJect: data=0xbaadcafe
# EINJ_GVA=0x81234bad, einj_gpa=0xff81234bad, einj_hva=0xffff41234bad,
einj_hpa=0x80241234bad
ok 1 # SKIP EINJ module probably not loaded?sh: line 1:
/sys/kernel/debug/apei/einj/error_type: No such file or directory
Bail out! Failed to write EINJ entry: No such file or directory (2)
# 1 skipped test(s) detected. Consider enabling relevant config options to
improve coverage.
# Planned tests != run tests (0 != 1)
# Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
This patch series suggests fixes for several corner cases in the RISC-V
vector ptrace implementation:
- init vector context with proper vlenb, to avoid reading zero vlenb
by an early attached debugger
- follow gdbserver expectations and return ENODATA instead of EINVAL
if vector extension is supported but not yet activated for the
traced process
- validate input vector csr registers in ptrace, to maintain an accurate
view of the tracee's vector context across multiple halt/resume
debug cycles
For detailed description see the appropriate commit messages. A new test
suite validate_v_ptrace is added to the tools/testing/selftests/riscv/vector
to verify some of the vector ptrace functionality and corner cases.
So far tested on the following platforms:
- test in QEMU rv32/rv64
- test on c908 (BananaPi CanMV K230D Zero)
- test on c906 (MangoPi MQ Pro)
Previous versions:
- v4: https://lore.kernel.org/linux-riscv/20251108194207.1257866-1-geomatsi@gmail…
- v3: https://lore.kernel.org/linux-riscv/20251025210655.43099-1-geomatsi@gmail.c…
- v2: https://lore.kernel.org/linux-riscv/20250821173957.563472-1-geomatsi@gmail.…
- v1: https://lore.kernel.org/linux-riscv/20251007115840.2320557-1-geomatsi@gmail…
Changes in v5:
- add support and minimal set of tests for XTheadVector
Changes in v4:
The form 'vsetvli x0, x0, ...' can only be used if VLMAX remains
unchanged, see spec 6.2. This condition was not met by the initial
values in the selftests w.r.t. the initial zeroed context. QEMU accepted
such values, but actual hardware (c908, BananaPi CanMV Zero board) did
not, setting vill. So fix the selftests after testing on hardware:
- replace 'vsetvli x0, x0, ...' by 'vsetvli rd, x0, ...'
- fixed instruction returns VLMAX, so use it in checks as well
- replace fixed vlenb == 16 in the syscall test
Changes in v3:
Address the review comments by Andy Chiu and rework the approach:
- drop forced vector context save entirely
- perform strict validation of vector csr regs in ptrace
Changes in v2:
- add thread_info flag to allow to force vector context save
- force vector context save after vector ptrace to ensure valid vector
context in the next ptrace operations
- force vector context save on the first context switch after vector
context init to get proper vlenb
---
Ilya Mamay (1):
riscv: ptrace: return ENODATA for inactive vector extension
Sergey Matyukevich (8):
riscv: vector: init vector context with proper vlenb
riscv: csr: define vtype register elements
riscv: ptrace: validate input vector csr registers
selftests: riscv: test ptrace vector interface
selftests: riscv: verify initial vector state with ptrace
selftests: riscv: verify syscalls discard vector context
selftests: riscv: verify ptrace rejects invalid vector csr inputs
selftests: riscv: verify ptrace accepts valid vector csr values
arch/riscv/include/asm/csr.h | 17 +
arch/riscv/kernel/ptrace.c | 98 +-
arch/riscv/kernel/vector.c | 12 +-
.../testing/selftests/riscv/vector/.gitignore | 2 +
tools/testing/selftests/riscv/vector/Makefile | 10 +-
.../selftests/riscv/vector/v_helpers.c | 23 +
.../selftests/riscv/vector/v_helpers.h | 2 +
.../riscv/vector/validate_v_ptrace.c | 919 ++++++++++++++++++
8 files changed, 1075 insertions(+), 8 deletions(-)
create mode 100644 tools/testing/selftests/riscv/vector/validate_v_ptrace.c
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
--
2.52.0