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authorOleg Nesterov <oleg@tv-sign.ru>2008-04-30 00:52:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 08:29:36 -0700
commite62e6650e99a3dffcd0bf0d063cd818fbc13fa95 (patch)
tree75f79d45eb89fb75014117b6fdc67bae1608f826 /kernel/signal.c
parent4cd4b6d4e0372075f846feb85aea016cbdbfec4c (diff)
downloadop-kernel-dev-e62e6650e99a3dffcd0bf0d063cd818fbc13fa95.zip
op-kernel-dev-e62e6650e99a3dffcd0bf0d063cd818fbc13fa95.tar.gz
signals: unify send_sigqueue/send_group_sigqueue completely
Suggested by Pavel Emelyanov. send_sigqueue/send_group_sigqueue are only differ in how they lock ->siglock. Unify them. send_group_sigqueue() uses spin_lock() because it knows the task can't exit, but in that case lock_task_sighand() can't fail and doesn't hurt. Note that the "sig" argument is ignored, it is always equal to ->si_signo. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c58
1 files changed, 21 insertions, 37 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 87424f7..367c666 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1240,14 +1240,27 @@ void sigqueue_free(struct sigqueue *q)
__sigqueue_free(q);
}
-static int do_send_sigqueue(int sig, struct sigqueue *q, struct task_struct *t,
+static int do_send_sigqueue(struct sigqueue *q, struct task_struct *t,
int group)
{
+ int sig = q->info.si_signo;
struct sigpending *pending;
+ unsigned long flags;
+ int ret;
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
+
+ ret = -1;
+ if (!likely(lock_task_sighand(t, &flags)))
+ goto ret;
+
handle_stop_signal(sig, t);
+ ret = 1;
+ if (sig_ignored(t, sig))
+ goto out;
+
+ ret = 0;
if (unlikely(!list_empty(&q->list))) {
/*
* If an SI_TIMER entry is already queue just increment
@@ -1256,58 +1269,29 @@ static int do_send_sigqueue(int sig, struct sigqueue *q, struct task_struct *t,
BUG_ON(q->info.si_code != SI_TIMER);
q->info.si_overrun++;
- return 0;
+ goto out;
}
- if (sig_ignored(t, sig))
- return 1;
-
signalfd_notify(t, sig);
pending = group ? &t->signal->shared_pending : &t->pending;
list_add_tail(&q->list, &pending->list);
sigaddset(&pending->signal, sig);
complete_signal(sig, t, group);
-
- return 0;
+out:
+ unlock_task_sighand(t, &flags);
+ret:
+ return ret;
}
int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
{
- unsigned long flags;
- int ret = -1;
-
- /*
- * The rcu based delayed sighand destroy makes it possible to
- * run this without tasklist lock held. The task struct itself
- * cannot go away as create_timer did get_task_struct().
- *
- * We return -1, when the task is marked exiting, so
- * posix_timer_event can redirect it to the group leader
- */
- if (!likely(lock_task_sighand(p, &flags)))
- goto out_err;
-
- ret = do_send_sigqueue(sig, q, p, 0);
-
- unlock_task_sighand(p, &flags);
-out_err:
- return ret;
+ return do_send_sigqueue(q, p, 0);
}
int
send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
{
- unsigned long flags;
- int ret;
-
- /* Since it_lock is held, p->sighand cannot be NULL. */
- spin_lock_irqsave(&p->sighand->siglock, flags);
-
- ret = do_send_sigqueue(sig, q, p, 1);
-
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
-
- return ret;
+ return do_send_sigqueue(q, p, 1);
}
/*
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