From: Peter Zijlstra peterz@infradead.org
[ Upstream commit 0edd6b64d1939e9e9168ff27947995bb7751db5d ]
Unless the very next line is schedule(), or implies it, one must not use preempt_enable_no_resched(). It can cause a preemption to go missing and thereby cause arbitrary delays, breaking the PREEMPT=y invariant.
Cc: Roman Gushchin guro@fb.com Cc: Alexei Starovoitov ast@kernel.org Cc: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/bpf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e734f163bd0b9..1fbd7672e4b37 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -455,7 +455,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, } \ _out: \ rcu_read_unlock(); \ - preempt_enable_no_resched(); \ + preempt_enable(); \ _ret; \ })