Linus,
Please pull the latest locking/urgent git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-2023-02-11
# HEAD: db370a8b9f67ae5f17e3d5482493294467784504 rtmutex: Ensure that the top waiter is always woken up
Fix an rtmutex missed-wakeup bug.
Thanks,
Ingo
------------------>
Wander Lairson Costa (1):
rtmutex: Ensure that the top waiter is always woken up
kernel/locking/rtmutex.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 010cf4e6d0b8..728f434de2bb 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -901,8 +901,9 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task,
* then we need to wake the new top waiter up to try
* to get the lock.
*/
- if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
- wake_up_state(waiter->task, waiter->wake_state);
+ top_waiter = rt_mutex_top_waiter(lock);
+ if (prerequeue_top_waiter != top_waiter)
+ wake_up_state(top_waiter->task, top_waiter->wake_state);
raw_spin_unlock_irq(&lock->wait_lock);
return 0;
}