bpf: Reject bpf_timer for PREEMPT_RT

[ Upstream commit e25ddfb388c8b7e5f20e3bf38d627fb485003781 ]

When enable CONFIG_PREEMPT_RT, the kernel will warn when run timer
selftests by './test_progs -t timer':

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

In order to avoid such warning, reject bpf_timer in verifier when
PREEMPT_RT is enabled.

Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20250910125740.52172-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Leon Hwang 2025-09-10 20:57:39 +08:00 committed by Greg Kroah-Hartman
parent f577bec983
commit b6b7db6530

View File

@ -8405,6 +8405,10 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno,
verifier_bug(env, "Two map pointers in a timer helper");
return -EFAULT;
}
if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
verbose(env, "bpf_timer cannot be used for PREEMPT_RT.\n");
return -EOPNOTSUPP;
}
meta->map_uid = reg->map_uid;
meta->map_ptr = map;
return 0;