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: 50bd5a0c65 ("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>
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
