linux-stable.git/tools/testing/selftests/bpf/prog_tests/timer_lockup.c, branch linux-rolling-stable Linux kernel stable tree selftests/bpf: Skip timer cases when bpf_timer is not supported 2025-10-02T11:48:29+00:00 Leon Hwang leon.hwang@linux.dev 2025-09-10T12:57:40+00:00 966877e96d022dbb9094a46b1e3dbc9593f0682c [ Upstream commit fbdd61c94bcb09b0c0eb0655917bf4193d07aac1 ] When enable CONFIG_PREEMPT_RT, verifier will reject bpf_timer with returning -EOPNOTSUPP. Therefore, skip test cases when errno is EOPNOTSUPP. cd tools/testing/selftests/bpf ./test_progs -t timer 125 free_timer:SKIP 456 timer:SKIP 457/1 timer_crash/array:SKIP 457/2 timer_crash/hash:SKIP 457 timer_crash:SKIP 458 timer_lockup:SKIP 459 timer_mim:SKIP Summary: 5/0 PASSED, 6 SKIPPED, 0 FAILED Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20250910125740.52172-3-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fbdd61c94bcb09b0c0eb0655917bf4193d07aac1 ]

When enable CONFIG_PREEMPT_RT, verifier will reject bpf_timer with
returning -EOPNOTSUPP.

Therefore, skip test cases when errno is EOPNOTSUPP.

cd tools/testing/selftests/bpf
./test_progs -t timer
125     free_timer:SKIP
456     timer:SKIP
457/1   timer_crash/array:SKIP
457/2   timer_crash/hash:SKIP
457     timer_crash:SKIP
458     timer_lockup:SKIP
459     timer_mim:SKIP
Summary: 5/0 PASSED, 6 SKIPPED, 0 FAILED

Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20250910125740.52172-3-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
selftests/bpf: skip the timer_lockup test for single-CPU nodes 2024-11-11T16:18:46+00:00 Viktor Malik vmalik@redhat.com 2024-11-07T11:52:31+00:00 937a1c29a287e8f48c4cea714c76a13e14d989ac The timer_lockup test needs 2 CPUs to work, on single-CPU nodes it fails to set thread affinity to CPU 1 since it doesn't exist: # ./test_progs -t timer_lockup test_timer_lockup:PASS:timer_lockup__open_and_load 0 nsec test_timer_lockup:PASS:pthread_create thread1 0 nsec test_timer_lockup:PASS:pthread_create thread2 0 nsec timer_lockup_thread:PASS:cpu affinity 0 nsec timer_lockup_thread:FAIL:cpu affinity unexpected error: 22 (errno 0) test_timer_lockup:PASS: 0 nsec #406 timer_lockup:FAIL Skip the test if only 1 CPU is available. Signed-off-by: Viktor Malik <vmalik@redhat.com> Fixes: 50bd5a0c658d1 ("selftests/bpf: Add timer lockup selftest") Tested-by: Philo Lu <lulie@linux.alibaba.com> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241107115231.75200-1-vmalik@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> 
The timer_lockup test needs 2 CPUs to work, on single-CPU nodes it fails
to set thread affinity to CPU 1 since it doesn't exist:

    # ./test_progs -t timer_lockup
    test_timer_lockup:PASS:timer_lockup__open_and_load 0 nsec
    test_timer_lockup:PASS:pthread_create thread1 0 nsec
    test_timer_lockup:PASS:pthread_create thread2 0 nsec
    timer_lockup_thread:PASS:cpu affinity 0 nsec
    timer_lockup_thread:FAIL:cpu affinity unexpected error: 22 (errno 0)
    test_timer_lockup:PASS: 0 nsec
    #406     timer_lockup:FAIL

Skip the test if only 1 CPU is available.

Signed-off-by: Viktor Malik <vmalik@redhat.com>
Fixes: 50bd5a0c658d1 ("selftests/bpf: Add timer lockup selftest")
Tested-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241107115231.75200-1-vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
selftests/bpf: Add timer lockup selftest 2024-07-11T08:18:31+00:00 Kumar Kartikeya Dwivedi memxor@gmail.com 2024-07-11T05:27:09+00:00 50bd5a0c658d132507673c4d59347c025dd149ed Add a selftest that tries to trigger a situation where two timer callbacks are attempting to cancel each other's timer. By running them continuously, we hit a condition where both run in parallel and cancel each other. Without the fix in the previous patch, this would cause a lockup as hrtimer_cancel on either side will wait for forward progress from the callback. Ensure that this situation leads to a EDEADLK error. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240711052709.2148616-1-memxor@gmail.com 
Add a selftest that tries to trigger a situation where two timer callbacks
are attempting to cancel each other's timer. By running them continuously,
we hit a condition where both run in parallel and cancel each other.

Without the fix in the previous patch, this would cause a lockup as
hrtimer_cancel on either side will wait for forward progress from the
callback.

Ensure that this situation leads to a EDEADLK error.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240711052709.2148616-1-memxor@gmail.com