Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754597AbZJESNR (ORCPT ); Mon, 5 Oct 2009 14:13:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754586AbZJESNR (ORCPT ); Mon, 5 Oct 2009 14:13:17 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:56461 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754462AbZJESNQ (ORCPT ); Mon, 5 Oct 2009 14:13:16 -0400 Date: Mon, 5 Oct 2009 11:12:55 -0700 From: Sukadev Bhattiprolu To: Oleg Nesterov Cc: Andrew Morton , Daniel Lezcano , Sukadev Bhattiprolu , Linux Containers , roland@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] signals: send_signal: use si_fromuser() to detect from_ancestor_ns Message-ID: <20091005181255.GE30442@us.ibm.com> References: <4AC608BE.9020805@fr.ibm.com> <20091003171029.GA30442@us.ibm.com> <20091004021844.GA21006@redhat.com> <20091004021954.GC21006@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091004021954.GC21006@redhat.com> X-Operating-System: Linux 2.0.32 on an i486 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 Content-Length: 2065 Lines: 53 Oleg Nesterov [oleg@redhat.com] wrote: | Change send_signal() to use si_fromuser(). From now SEND_SIG_NOINFO | triggers the "from_ancestor_ns" check. | | This fixes reparent_thread()->group_send_sig_info(pdeath_signal) | behaviour, before this patch send_signal() does not detect the | cross-namespace case when the child of the dying parent belongs | to the sub-namespace. | | This patch can affect the behaviour of send_sig(), kill_pgrp() and | kill_pid() when the caller sends the signal to the sub-namespace | with "priv == 0" but surprisingly all callers seem to use them | correctly, including disassociate_ctty(on_exit). | | Except: drivers/staging/comedi/drivers/addi-data/*.c incorrectly | use send_sig(priv => 0). But his is minor and should be fixed | anyway. | | Reported-by: Daniel Lezcano | Signed-off-by: Oleg Nesterov | --- | | kernel/signal.c | 5 ++--- | 1 file changed, 2 insertions(+), 3 deletions(-) | | --- TTT_32/kernel/signal.c~FU_2_SEND_SIGNAL 2009-10-04 02:21:55.000000000 +0200 | +++ TTT_32/kernel/signal.c 2009-10-04 03:09:44.000000000 +0200 | @@ -928,9 +928,8 @@ static int send_signal(int sig, struct s | int from_ancestor_ns = 0; | | #ifdef CONFIG_PID_NS | - if (!is_si_special(info) && SI_FROMUSER(info) && | - task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0) | - from_ancestor_ns = 1; | + from_ancestor_ns = si_fromuser(info) && | + !task_pid_nr_ns(current, task_active_pid_ns(t)); Makes sense. And we had mentioned earlier that container-init is immune to suicide but should we add a check for 'current == t' above to cover the send_sig(SIGKILL, current, 0); in load_aout_binary() and friends from_ancestor_ns = si_fromuser(info) && (current == t || !task_pid_nr_ns(current, task_active_pid_ns(t))); Sukadev. -- 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/