---

yaml
---
r: 64636
b: refs/heads/master
c: 60187d2
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 99db67bc04af0f2e8cb710ac92aaeb9af135a7c6
+refs/heads/master: 60187d2708caa870f0825d753df1612ea688eb9e

trunk/kernel/signal.c

@@ -1300,20 +1300,19 @@ struct sigqueue *sigqueue_alloc(void)
 void sigqueue_free(struct sigqueue *q)
 {
 	unsigned long flags;
+	spinlock_t *lock = &current->sighand->siglock;
+
 	BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
 	/*
 	 * If the signal is still pending remove it from the
-	 * pending queue.
+	 * pending queue. We must hold ->siglock while testing
+	 * q->list to serialize with collect_signal().
 	 */
-	if (unlikely(!list_empty(&q->list))) {
-		spinlock_t *lock = &current->sighand->siglock;
-		read_lock(&tasklist_lock);
-		spin_lock_irqsave(lock, flags);
-		if (!list_empty(&q->list))
-			list_del_init(&q->list);
-		spin_unlock_irqrestore(lock, flags);
-		read_unlock(&tasklist_lock);
-	}
+	spin_lock_irqsave(lock, flags);
+	if (!list_empty(&q->list))
+		list_del_init(&q->list);
+	spin_unlock_irqrestore(lock, flags);
+
 	q->flags &= ~SIGQUEUE_PREALLOC;
 	__sigqueue_free(q);
 }