Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755071Ab0H0Rta (ORCPT ); Fri, 27 Aug 2010 13:49:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53540 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751276Ab0H0Rt1 (ORCPT ); Fri, 27 Aug 2010 13:49:27 -0400 Subject: Re: [PATCH] audit: speedup for syscalls when auditing is disabled From: Eric Paris To: Anton Blanchard Cc: Michael Neuling , linux-audit@redhat.com, linux-kernel@vger.kernel.org, Al Viro , sgrubb@redhat.com In-Reply-To: <20100826033456.GB17882@kryten> References: <29151.1282270393@neuling.org> <1282586177.2681.43.camel@localhost.localdomain> <20887.1282615880@neuling.org> <1282621410.26616.406.camel@localhost.localdomain> <15180.1282705886@neuling.org> <1282737584.13142.153.camel@localhost.localdomain> <20100826033456.GB17882@kryten> Content-Type: text/plain; charset="UTF-8" Date: Fri, 27 Aug 2010 13:49:15 -0400 Message-ID: <1282931355.3284.84.camel@dhcp231-106.rdu.redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1170 Lines: 30 On Thu, 2010-08-26 at 13:34 +1000, Anton Blanchard wrote: > Hi Eric, > > Here's another approach Mikey and I were discussing. We allocate the > tsk->audit_context as before, but we avoid setting the TIF_SYSCALL_AUDIT until > the first rule gets added. > > We could look at clearing the flag when the rules go back to zero, but this > simple patch covers the most common case I think. It just dawned on me where we are going to have problems. We have things other than syscall filter rules that can cause us to want the collected audit info. Namely SELinux (or other LSM) denials. Crap. So the change in audit_alloc() should probably be conditionalized on more than just audit_n_rules(). Not exactly sure what that is though. It might also make our syscall entry/exit speedups not as great of an idea as I thought. I need to look for other audit users to see how these things are oging to affect them :( -Eric -- 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/