From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754225AbaDNPpB (ORCPT ); Mon, 14 Apr 2014 11:45:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57498 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753910AbaDNPo7 (ORCPT ); Mon, 14 Apr 2014 11:44:59 -0400 Date: Mon, 14 Apr 2014 17:20:18 +0200 From: Oleg Nesterov To: Andrew Morton , Peter Zijlstra Cc: Al Viro , David Woodhouse , Frederic Weisbecker , Geert Uytterhoeven , Ingo Molnar , Mathieu Desnoyers , Richard Weinberger , Steven Rostedt , Tejun Heo , linux-kernel@vger.kernel.org Subject: [PATCH RESEND 09/11] signals: disallow_signal() should flush the potentially pending signal Message-ID: <20140414152018.GA22022@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140414151929.GA21470@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org disallow_signal() simply sets SIG_IGN, this is not enough and recalc_sigpending() is simply pointless because in can never change the state of TIF_SIGPENDING. If we ignore a signal, we also need to do flush_sigqueue_mask() for the case when this signal is pending, this way recalc_sigpending() can actually clear TIF_SIGPENDING and we do not "leak" the allocated siginfo's. Signed-off-by: Oleg Nesterov --- kernel/signal.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 3eec27b..4bab1b7 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3084,8 +3084,15 @@ EXPORT_SYMBOL(allow_signal); void disallow_signal(int sig) { + sigset_t mask; + + sigemptyset(&mask); + sigaddset(&mask, sig); + spin_lock_irq(¤t->sighand->siglock); current->sighand->action[(sig)-1].sa.sa_handler = SIG_IGN; + flush_sigqueue_mask(&mask, ¤t->signal->shared_pending); + flush_sigqueue_mask(&mask, ¤t->pending); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); } -- 1.5.5.1