Merge git://git.linux-xtensa.org/kernel/xtensa-feed

[karo-tx-linux.git] / kernel / signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index b27c01a66448a4bee1e023ccd809b28b0b719b36..3169bed0b4d0e44166b37c48ed663d516a9ccba5 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -378,7 +378,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
        /* We only dequeue private signals from ourselves, we don't let
         * signalfd steal them
         */
-       if (tsk == current)
+       if (likely(tsk == current))
                signr = __dequeue_signal(&tsk->pending, mask, info);
        if (!signr) {
                signr = __dequeue_signal(&tsk->signal->shared_pending,
@@ -425,7 +425,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
                if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
                        tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
        }
-       if ( signr &&
+       if (signr && likely(tsk == current) &&
             ((info->si_code & __SI_MASK) == __SI_TIMER) &&
             info->si_sys_private){
                /*
@@ -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);
 }