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authorThomas Zimmermann <tzimmermann@suse.de>2024-02-07 13:01:19 +0100
committerThomas Zimmermann <tzimmermann@suse.de>2024-02-07 13:02:20 +0100
commit0e85f1ae4ac6dae238b0f35232d1aa52e1b6943f (patch)
tree75b387bc359637c15b90ababb1ff073ca68b5bd8 /kernel/futex/pi.c
parent2c8ba564a42c7418a726367c73d7c88454848fdc (diff)
parentf8e4806e0dfa8796b3d7076a7fe054455a59c38b (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/pi.c')
-rw-r--r--kernel/futex/pi.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/futex/pi.c b/kernel/futex/pi.c
index 90e5197f4e56..5722467f2737 100644
--- a/kernel/futex/pi.c
+++ b/kernel/futex/pi.c
@@ -1135,6 +1135,7 @@ retry:
hb = futex_hash(&key);
spin_lock(&hb->lock);
+retry_hb:
/*
* Check waiters first. We do not trust user space values at
@@ -1177,12 +1178,17 @@ retry:
/*
* Futex vs rt_mutex waiter state -- if there are no rt_mutex
* waiters even though futex thinks there are, then the waiter
- * is leaving and the uncontended path is safe to take.
+ * is leaving. The entry needs to be removed from the list so a
+ * new futex_lock_pi() is not using this stale PI-state while
+ * the futex is available in user space again.
+ * There can be more than one task on its way out so it needs
+ * to retry.
*/
rt_waiter = rt_mutex_top_waiter(&pi_state->pi_mutex);
if (!rt_waiter) {
+ __futex_unqueue(top_waiter);
raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
- goto do_uncontended;
+ goto retry_hb;
}
get_pi_state(pi_state);
@@ -1217,7 +1223,6 @@ retry:
return ret;
}
-do_uncontended:
/*
* We have no kernel internal state, i.e. no waiters in the
* kernel. Waiters which are about to queue themselves are stuck