rtmutex: Remove unused argument from rt_mutex_proxy_unlock()

stable inclusion
from linux-4.19.172
commit 29013e4f4b73e2f5ef39a443b05c231ac29c690f
CVE: CVE-2021-3347

--------------------------------

commit 2156ac19 upstream

Nothing uses the argument. Remove it as preparation to use
pi_state_update_owner().
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

kernel/futex.c

@@ -892,7 +892,7 @@ static void put_pi_state(struct futex_pi_state *pi_state)
 			list_del_init(&pi_state->list);
 			raw_spin_unlock(&owner->pi_lock);
 		}
-		rt_mutex_proxy_unlock(&pi_state->pi_mutex, owner);
+		rt_mutex_proxy_unlock(&pi_state->pi_mutex);
 		raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
 	}
 

kernel/locking/rtmutex.c

@@ -1719,8 +1719,7 @@ void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
  * possible because it belongs to the pi_state which is about to be freed
  * and it is not longer visible to other tasks.
  */
-void rt_mutex_proxy_unlock(struct rt_mutex *lock,
-			   struct task_struct *proxy_owner)
+void rt_mutex_proxy_unlock(struct rt_mutex *lock)
 {
 	debug_rt_mutex_proxy_unlock(lock);
 	rt_mutex_set_owner(lock, NULL);

kernel/locking/rtmutex_common.h

@@ -133,8 +133,7 @@ enum rtmutex_chainwalk {
 extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
 extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
 				       struct task_struct *proxy_owner);
-extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
-				  struct task_struct *proxy_owner);
+extern void rt_mutex_proxy_unlock(struct rt_mutex *lock);
 extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
 extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
 				     struct rt_mutex_waiter *waiter,