Merge branch 'linux-2.6' into for-2.6.24

1 files changed, 9 insertions, 10 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index ad63109e413c..3169bed0b4d0 100644
--- a/kernel/signal.c
+++ b/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);
 }