From e62e6650e99a3dffcd0bf0d063cd818fbc13fa95 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 30 Apr 2008 00:52:56 -0700 Subject: 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 Signed-off-by: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 58 +++++++++++++++++++++------------------------------------ 1 file changed, 21 insertions(+), 37 deletions(-) (limited to 'kernel/signal.c') diff --git a/kernel/signal.c b/kernel/signal.c index 87424f7a4f3..367c6662b12 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); } /* -- cgit v1.2.3