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-rw-r--r--kernel/mutex.c7
1 files changed, 2 insertions, 5 deletions
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 4f45d4b658ef..357c6d221efe 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -129,7 +129,6 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
129{ 129{
130 struct task_struct *task = current; 130 struct task_struct *task = current;
131 struct mutex_waiter waiter; 131 struct mutex_waiter waiter;
132 unsigned int old_val;
133 unsigned long flags; 132 unsigned long flags;
134 133
135 spin_lock_mutex(&lock->wait_lock, flags); 134 spin_lock_mutex(&lock->wait_lock, flags);
@@ -142,8 +141,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
142 list_add_tail(&waiter.list, &lock->wait_list); 141 list_add_tail(&waiter.list, &lock->wait_list);
143 waiter.task = task; 142 waiter.task = task;
144 143
145 old_val = atomic_xchg(&lock->count, -1); 144 if (atomic_xchg(&lock->count, -1) == 1)
146 if (old_val == 1)
147 goto done; 145 goto done;
148 146
149 lock_contended(&lock->dep_map, ip); 147 lock_contended(&lock->dep_map, ip);
@@ -158,8 +156,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
158 * that when we release the lock, we properly wake up the 156 * that when we release the lock, we properly wake up the
159 * other waiters: 157 * other waiters:
160 */ 158 */
161 old_val = atomic_xchg(&lock->count, -1); 159 if (atomic_xchg(&lock->count, -1) == 1)
162 if (old_val == 1)
163 break; 160 break;
164 161
165 /* 162 /*