From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 13 May 2011 14:40:56 +0200 (CEST) Received: from bombadil.infradead.org ([18.85.46.34]:45163 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1491821Ab1EMMj6 convert rfc822-to-8bit (ORCPT ); Fri, 13 May 2011 14:39:58 +0200 Received: from canuck.infradead.org ([134.117.69.58]) by bombadil.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1QKreX-00062e-8B; Fri, 13 May 2011 12:39:33 +0000 Received: from j77219.upc-j.chello.nl ([24.132.77.219] helo=twins) by canuck.infradead.org with esmtpsa (Exim 4.72 #1 (Red Hat Linux)) id 1QKreW-0002OA-50; Fri, 13 May 2011 12:39:32 +0000 Received: by twins (Postfix, from userid 1000) id 4719A812FE74; Fri, 13 May 2011 14:39:30 +0200 (CEST) Subject: Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering From: Peter Zijlstra To: Ingo Molnar Cc: James Morris , Will Drewry , linux-kernel@vger.kernel.org, Steven Rostedt , Frederic Weisbecker , Eric Paris , kees.cook@canonical.com, agl@chromium.org, "Serge E. Hallyn" , Ingo Molnar , Andrew Morton , Tejun Heo , Michal Marek , Oleg Nesterov , Roland McGrath , Jiri Slaby , David Howells , Russell King , Michal Simek , Ralf Baechle , Benjamin Herrenschmidt , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com, Paul Mundt , "David S. Miller" , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, linux-arm-kernel@lists.infradead.org, microblaze-uclinux@itee.uq.edu.au, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, Linus Torvalds In-Reply-To: <20110513122646.GA3924@elte.hu> References: <1304017638.18763.205.camel@gandalf.stny.rr.com> <1305169376-2363-1-git-send-email-wad@chromium.org> <20110512074850.GA9937@elte.hu> <20110512130104.GA2912@elte.hu> <20110513121034.GG21022@elte.hu> <1305289146.2466.8.camel@twins> <20110513122646.GA3924@elte.hu> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Fri, 13 May 2011 14:39:30 +0200 Message-ID: <1305290370.2466.14.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 29983 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: peterz@infradead.org Precedence: bulk X-list: linux-mips On Fri, 2011-05-13 at 14:26 +0200, Ingo Molnar wrote: > * Peter Zijlstra wrote: > > > On Fri, 2011-05-13 at 14:10 +0200, Ingo Molnar wrote: > > > err = event_vfs_getname(result); > > > > I really think we should not do this. Events like we have them should be > > inactive, totally passive entities, only observe but not affect execution > > (other than the bare minimal time delay introduced by observance). > > Well, this patchset already demonstrates that we can use a single event > callback for a rather useful purpose. Can and should are two distinct things. > Either it makes sense to do, in which case we should share facilities as much > as possible, or it makes no sense, in which case we should not merge it at all. And I'm arguing we should _not_. Observing is radically different from Affecting, at the very least the two things should have different permission schemes. We should not confuse these two matters. > > If you want another entity that is more active, please invent a new name for > > it and create a new subsystem for them, now you could have these active > > entities also have an (automatic) passive event side, but that's some detail. > > Why should we have two callbacks next to each other: > > event_vfs_getname(result); > result = check_event_vfs_getname(result); > > if one could do it all? Did you actually read the bit where I said that check_event_* (although I still think that name sucks) could imply a matching event_*?