diff options
| author | Peter Zijlstra <[email protected]> | 2019-04-23 22:03:18 +0200 |
|---|---|---|
| committer | Steven Rostedt (VMware) <[email protected]> | 2019-04-26 11:45:03 -0400 |
| commit | d6097c9e4454adf1f8f2c9547c2fa6060d55d952 (patch) | |
| tree | cd9864136dae1127da63fa0b56ad79016cae53c3 | |
| parent | 91862cc7867bba4ee5c8fcf0ca2f1d30427b6129 (diff) | |
trace: Fix preempt_enable_no_resched() abuse
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.
Link: http://lkml.kernel.org/r/[email protected]
Cc: Waiman Long <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: the arch/x86 maintainers <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: huang ying <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: [email protected]
Fixes: 2c2d7329d8af ("tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()")
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
| -rw-r--r-- | kernel/trace/ring_buffer.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 41b6f96e5366..4ee8d8aa3d0f 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -762,7 +762,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu) preempt_disable_notrace(); time = rb_time_stamp(buffer); - preempt_enable_no_resched_notrace(); + preempt_enable_notrace(); return time; } |