diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2018-11-29 14:44:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-05 17:58:49 +0100 |
| commit | 2368e6d3bcf4a6941082725a65efd8a6200f7e6e (patch) | |
| tree | 641381a0bcccd3386cec8a2a660e88065146145f /include | |
| parent | 653a1dbcb0119cc8092ffb53b9f865e25facadff (diff) | |
futex: Fix (possible) missed wakeup
[ Upstream commit b061c38bef43406df8e73c5be06cbfacad5ee6ad ]
We must not rely on wake_q_add() to delay the wakeup; in particular
commit:
1d0dcb3ad9d3 ("futex: Implement lockless wakeups")
moved wake_q_add() before smp_store_release(&q->lock_ptr, NULL), which
could result in futex_wait() waking before observing ->lock_ptr ==
NULL and going back to sleep again.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 1d0dcb3ad9d3 ("futex: Implement lockless wakeups")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions