Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757349AbYCHPH2 (ORCPT ); Sat, 8 Mar 2008 10:07:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755831AbYCHPGY (ORCPT ); Sat, 8 Mar 2008 10:06:24 -0500 Received: from x346.tv-sign.ru ([89.108.83.215]:34560 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755668AbYCHPGX (ORCPT ); Sat, 8 Mar 2008 10:06:23 -0500 Date: Sat, 8 Mar 2008 18:10:25 +0300 From: Oleg Nesterov To: Andrew Morton Cc: Ingo Molnar , Pavel Emelyanov , Roland McGrath , linux-kernel@vger.kernel.org Subject: [PATCH 5/6] signals: unify send_sigqueue/send_group_sigqueue completely Message-ID: <20080308151025.GA25191@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3002 Lines: 114 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 --- 25/kernel/signal.c~5_SSQ_UNIFY 2008-03-08 16:54:57.000000000 +0300 +++ 25/kernel/signal.c 2008-03-08 17:15:59.000000000 +0300 @@ -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, str 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); } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/