From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: Re: [RFC][PATCH 2/7][v4] Protect init from unwanted signals more Date: Wed, 24 Dec 2008 17:35:03 +0100 Message-ID: <20081224163503.GF11593@redhat.com> References: <20081224114414.GA7879@us.ibm.com> <20081224115047.GB8020@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20081224115047.GB8020-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Sukadev Bhattiprolu Cc: bastian-yyjItF7Rl6lg9hUCZPvPmw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org, roland-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org List-Id: containers.vger.kernel.org On 12/24, Sukadev Bhattiprolu wrote: > > -static int sig_ignored(struct task_struct *t, int sig) > +static int sig_task_ignored(struct task_struct *t, int sig) > { > void __user *handler; > > + handler = sig_handler(t, sig); > + > + if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && > + (handler == SIG_IGN || handler == SIG_DFL)) > + return 1; > + > + return sig_handler_ignored(handler, sig); Well, really minor nit, but can't resist ;) if we check both SIG_IGN and SIG_DFL, then why do we call sig_handler_ignored() ? We can do if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE)) return handler == SIG_IGN || handler == SIG_DFL; return sig_handler_ignored(handler, sig); Or, we can do if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && handler == SIG_DFL) return 1; return sig_handler_ignored(handler, sig); because sig_handler_ignored() checks SIG_IGN too. Of course, this is a matter of taste only... Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752387AbYLXQhH (ORCPT ); Wed, 24 Dec 2008 11:37:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751174AbYLXQg4 (ORCPT ); Wed, 24 Dec 2008 11:36:56 -0500 Received: from mx2.redhat.com ([66.187.237.31]:60586 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbYLXQgz (ORCPT ); Wed, 24 Dec 2008 11:36:55 -0500 Date: Wed, 24 Dec 2008 17:35:03 +0100 From: Oleg Nesterov To: Sukadev Bhattiprolu Cc: ebiederm@xmission.com, roland@redhat.com, bastian@waldi.eu.org, daniel@hozac.com, xemul@openvz.org, containers@lists.osdl.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 2/7][v4] Protect init from unwanted signals more Message-ID: <20081224163503.GF11593@redhat.com> References: <20081224114414.GA7879@us.ibm.com> <20081224115047.GB8020@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081224115047.GB8020@us.ibm.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 On 12/24, Sukadev Bhattiprolu wrote: > > -static int sig_ignored(struct task_struct *t, int sig) > +static int sig_task_ignored(struct task_struct *t, int sig) > { > void __user *handler; > > + handler = sig_handler(t, sig); > + > + if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && > + (handler == SIG_IGN || handler == SIG_DFL)) > + return 1; > + > + return sig_handler_ignored(handler, sig); Well, really minor nit, but can't resist ;) if we check both SIG_IGN and SIG_DFL, then why do we call sig_handler_ignored() ? We can do if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE)) return handler == SIG_IGN || handler == SIG_DFL; return sig_handler_ignored(handler, sig); Or, we can do if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && handler == SIG_DFL) return 1; return sig_handler_ignored(handler, sig); because sig_handler_ignored() checks SIG_IGN too. Of course, this is a matter of taste only... Oleg.