diff options
author | Thomas Zimmermann <tzimmermann@suse.de> | 2024-02-07 13:01:19 +0100 |
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committer | Thomas Zimmermann <tzimmermann@suse.de> | 2024-02-07 13:02:20 +0100 |
commit | 0e85f1ae4ac6dae238b0f35232d1aa52e1b6943f (patch) | |
tree | 75b387bc359637c15b90ababb1ff073ca68b5bd8 /kernel/futex/core.c | |
parent | 2c8ba564a42c7418a726367c73d7c88454848fdc (diff) | |
parent | f8e4806e0dfa8796b3d7076a7fe054455a59c38b (diff) |
Merge drm/drm-next into drm-misc-next
Backmerging to update drm-misc-next to the state of v6.8-rc3. Also
fixes a build problem with xe.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Diffstat (limited to 'kernel/futex/core.c')
-rw-r--r-- | kernel/futex/core.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/kernel/futex/core.c b/kernel/futex/core.c index e0e853412c15..1e78ef24321e 100644 --- a/kernel/futex/core.c +++ b/kernel/futex/core.c @@ -627,12 +627,21 @@ retry: } /* - * PI futexes can not be requeued and must remove themselves from the - * hash bucket. The hash bucket lock (i.e. lock_ptr) is held. + * PI futexes can not be requeued and must remove themselves from the hash + * bucket. The hash bucket lock (i.e. lock_ptr) is held. */ void futex_unqueue_pi(struct futex_q *q) { - __futex_unqueue(q); + /* + * If the lock was not acquired (due to timeout or signal) then the + * rt_waiter is removed before futex_q is. If this is observed by + * an unlocker after dropping the rtmutex wait lock and before + * acquiring the hash bucket lock, then the unlocker dequeues the + * futex_q from the hash bucket list to guarantee consistent state + * vs. userspace. Therefore the dequeue here must be conditional. + */ + if (!plist_node_empty(&q->list)) + __futex_unqueue(q); BUG_ON(!q->pi_state); put_pi_state(q->pi_state); |