[PATCH] kill sigqueue->lock

This lock is used in sigqueue_free(), but it is always equal to
current->sighand->siglock, so we don't need to keep it in the struct
sigqueue.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/linux/signal.h b/include/linux/signal.h
index 7be18b5..5dd5f02 100644 (file)
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -25,7 +25,6 @@
 
 struct sigqueue {
        struct list_head list;
-       spinlock_t *lock;
        int flags;
        siginfo_t info;
        struct user_struct *user;

diff --git a/kernel/signal.c b/kernel/signal.c
index 6904bbb..8d6e64d 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -277,7 +277,6 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
        } else {
                INIT_LIST_HEAD(&q->list);
                q->flags = 0;
-               q->lock = NULL;
                q->user = get_uid(t->user);
        }
        return(q);
@@ -1371,11 +1370,12 @@ void sigqueue_free(struct sigqueue *q)
         * pending queue.
         */
        if (unlikely(!list_empty(&q->list))) {
-               read_lock(&tasklist_lock);  
-               spin_lock_irqsave(q->lock, flags);
+               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(q->lock, flags);
+               spin_unlock_irqrestore(lock, flags);
                read_unlock(&tasklist_lock);
        }
        q->flags &= ~SIGQUEUE_PREALLOC;
@@ -1414,7 +1414,6 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
                goto out;
        }
 
-       q->lock = &p->sighand->siglock;
        list_add_tail(&q->list, &p->pending.list);
        sigaddset(&p->pending.signal, sig);
        if (!sigismember(&p->blocked, sig))
@@ -1462,7 +1461,6 @@ send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
         * We always use the shared queue for process-wide signals,
         * to avoid several races.
         */
-       q->lock = &p->sighand->siglock;
        list_add_tail(&q->list, &p->signal->shared_pending.list);
        sigaddset(&p->signal->shared_pending.signal, sig);