---

yaml --- r: 15321 b: refs/heads/master c: 8e31108 h: refs/heads/master i: 15319: 79a471b v: v3
git-mirror · Dec 24, 2005 · b52b945 · b52b945
1 parent 01c9947
commit b52b945
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6003a93e7bf6c02f33c02976ff364785d4273295
+refs/heads/master: 8e31108b9f41069d55cb9b019ac8262c55fd2616
diff --git a/trunk/kernel/futex.c b/trunk/kernel/futex.c
@@ -270,7 +270,13 @@ static void wake_futex(struct futex_q *q)
 	/*
 	 * The waiting task can free the futex_q as soon as this is written,
 	 * without taking any locks.  This must come last.
+	 *
+	 * A memory barrier is required here to prevent the following store
+	 * to lock_ptr from getting ahead of the wakeup. Clearing the lock
+	 * at the end of wake_up_all() does not prevent this store from
+	 * moving.
 	 */
+	wmb();
 	q->lock_ptr = NULL;
 }