From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764629AbYECRgx (ORCPT ); Sat, 3 May 2008 13:36:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763545AbYECRgO (ORCPT ); Sat, 3 May 2008 13:36:14 -0400 Received: from x346.tv-sign.ru ([89.108.83.215]:47529 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762493AbYECRgL (ORCPT ); Sat, 3 May 2008 13:36:11 -0400 Date: Sat, 3 May 2008 21:35:53 +0400 From: Oleg Nesterov To: Andrew Morton Cc: Austin Clements , Ingo Molnar , john stultz , Linus Torvalds , Michael Kerrisk , Roland McGrath , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: [PATCH 2/4] posix timers: sigqueue_free: don't free sigqueue if it is queued Message-ID: <20080503173553.GA8106@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 Currently sigqueue_free() removes sigqueue from list, but doesn't cancel the pending signal. This is not consistent, the task should either receive the "full" signal along with siginfo_t, or it shouldn't see the signal at all. Change sigqueue_free() to clear SIGQUEUE_PREALLOC but leave sigqueue on list if it is queued. Note: I am not sure we shouldn't do the opposite, free sigqueue + cancel the pending signal, but this needs some ugly changes. Perhaps we should reconsider this change later. See also http://bugzilla.kernel.org/show_bug.cgi?id=10460 Signed-off-by: Oleg Nesterov --- 25/kernel/signal.c~2_SF_DONT_REMOVE 2008-05-03 18:27:03.000000000 +0400 +++ 25/kernel/signal.c 2008-05-03 19:12:36.000000000 +0400 @@ -1240,18 +1240,22 @@ void sigqueue_free(struct sigqueue *q) BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); /* - * If the signal is still pending remove it from the - * pending queue. We must hold ->siglock while testing - * q->list to serialize with collect_signal() or with + * We must hold ->siglock while testing q->list + * to serialize with collect_signal() or with * __exit_signal()->flush_sigqueue(). */ spin_lock_irqsave(lock, flags); + /* + * If it is queued it will be freed when dequeued, + * like the "regular" sigqueue. + */ + q->flags &= ~SIGQUEUE_PREALLOC; if (!list_empty(&q->list)) - list_del_init(&q->list); + q = NULL; spin_unlock_irqrestore(lock, flags); - q->flags &= ~SIGQUEUE_PREALLOC; - __sigqueue_free(q); + if (q) + __sigqueue_free(q); } int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)