From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932883AbZKXUHA (ORCPT ); Tue, 24 Nov 2009 15:07:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932829AbZKXUHA (ORCPT ); Tue, 24 Nov 2009 15:07:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:8659 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757320AbZKXUG7 (ORCPT ); Tue, 24 Nov 2009 15:06:59 -0500 Date: Tue, 24 Nov 2009 21:01:35 +0100 From: Oleg Nesterov To: Alexey Dobriyan , Ananth Mavinakayanahalli , Christoph Hellwig , "Frank Ch. Eigler" , Ingo Molnar , Peter Zijlstra , Roland McGrath Cc: linux-kernel@vger.kernel.org, utrace-devel@redhat.com Subject: [RFC,PATCH 02/14] signals: check ->group_stop_count after tracehook_get_signal() Message-ID: <20091124200135.GA5761@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 (already in mm: signals-check-group_stop_count-after-tracehook_get_signal.patch) Move the call to do_signal_stop() down, after tracehook call. This makes ->group_stop_count condition visible to tracers before do_signal_stop() will participate in this group-stop. Currently the patch has no effect, tracehook_get_signal() always returns 0. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath --- kernel/signal.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- V1/kernel/signal.c~2_DO_SIGNAL_STOP_AFTER_TRACEHOOK 2009-11-24 19:46:51.000000000 +0100 +++ V1/kernel/signal.c 2009-11-24 19:51:13.000000000 +0100 @@ -1807,11 +1807,6 @@ relock: for (;;) { struct k_sigaction *ka; - - if (unlikely(signal->group_stop_count > 0) && - do_signal_stop(0)) - goto relock; - /* * Tracing can induce an artifical signal and choose sigaction. * The return value in @signr determines the default action, @@ -1823,6 +1818,10 @@ relock: if (unlikely(signr != 0)) ka = return_ka; else { + if (unlikely(signal->group_stop_count > 0) && + do_signal_stop(0)) + goto relock; + signr = dequeue_signal(current, ¤t->blocked, info);