linux-stable.git/tools/testing/selftests/bpf/progs/timer_lockup.c, branch linux-rolling-stable Linux kernel stable tree 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