[PATCH bpf v3 0/2] bpf: Reject bpf_timer for PREEMPT_RT

[Leon Hwang <leon.hwang@linux.dev>]

While running './test_progs -t timer' to validate the test case from
"selftests/bpf: Introduce experimental bpf_in_interrupt()"[0] for
PREEMPT_RT, I encountered a kernel warning:

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48

To address this, reject bpf_timer usage in the verifier when
PREEMPT_RT is enabled, and skip the corresponding timer selftests.

Changes:
v2 -> v3:
* Drop skipping test case 'timer_interrupt'.
* Address comments from Alexei:
  * Respin targeting bpf tree.
  * Trim commit log.

v1 -> v2:
* Skip test case 'timer_interrupt'.

Links:
[0] https://lore.kernel.org/bpf/20250903140438.59517-1-leon.hwang@linux.dev/

Leon Hwang (2):
  bpf: Reject bpf_timer for PREEMPT_RT
  selftests/bpf: Skip timer cases when bpf_timer is not supported

 kernel/bpf/verifier.c                                 | 4 ++++
 tools/testing/selftests/bpf/prog_tests/free_timer.c   | 4 ++++
 tools/testing/selftests/bpf/prog_tests/timer.c        | 4 ++++
 tools/testing/selftests/bpf/prog_tests/timer_crash.c  | 4 ++++
 tools/testing/selftests/bpf/prog_tests/timer_lockup.c | 4 ++++
 tools/testing/selftests/bpf/prog_tests/timer_mim.c    | 4 ++++
 6 files changed, 24 insertions(+)

--
2.50.1