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@xxxxxxxxx/ 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
