[PATCH] locking/mutex: clear MUTEX_FLAGS if wait_list is empty due to signal

From: qiang . zhang
Date: Fri May 14 2021 - 22:30:41 EST


From: Zqiang <qiang.zhang@xxxxxxxxxxxxx>

Clear MUTEX_FLAGS when call mutex_lock_interruptible()
interrupted by a signal and the lock->wait_list is empty.

Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
---
kernel/locking/mutex.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index cb6b112ce155..4ac354ca092b 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -1081,6 +1081,8 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
err:
__set_current_state(TASK_RUNNING);
mutex_remove_waiter(lock, &waiter, current);
+ if (likely(list_empty(&lock->wait_list)))
+ __mutex_clear_flag(lock, MUTEX_FLAGS);
err_early_kill:
spin_unlock(&lock->wait_lock);
debug_mutex_free_waiter(&waiter);
--
2.25.1