Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755818AbXFTXiS (ORCPT ); Wed, 20 Jun 2007 19:38:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752937AbXFTXiJ (ORCPT ); Wed, 20 Jun 2007 19:38:09 -0400 Received: from mx1.redhat.com ([66.187.233.31]:46681 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752585AbXFTXiI (ORCPT ); Wed, 20 Jun 2007 19:38:08 -0400 Date: Wed, 20 Jun 2007 19:24:00 -0400 From: Dave Jones To: Arjan van de Ven Cc: Linus Torvalds , Ian McDonald , Andrew Morton , LKML , Miklos Szeredi , Ingo Molnar , "Darrick J. Wong" , Andi Kleen , Bj?rn Steinbrink , William Cohen , "S. P. Prasanna" , Antonino Daplas , Olaf Hering , Ville Syrj?l? , Jean Delvare , Rudolf Marek , Soeren Sonnenburg , Michal Piotrowski Subject: Re: [1/2] 2.6.22-rc5: known regressions with patches Message-ID: <20070620232400.GA18549@redhat.com> Mail-Followup-To: Dave Jones , Arjan van de Ven , Linus Torvalds , Ian McDonald , Andrew Morton , LKML , Miklos Szeredi , Ingo Molnar , "Darrick J. Wong" , Andi Kleen , Bj?rn Steinbrink , William Cohen , "S. P. Prasanna" , Antonino Daplas , Olaf Hering , Ville Syrj?l? , Jean Delvare , Rudolf Marek , Soeren Sonnenburg , Michal Piotrowski References: <467543FA.60905@googlemail.com> <5640c7e00706201508g3c1fc40eq82a1db05c9156b5d@mail.gmail.com> <20070620230751.GA15092@redhat.com> <1182381354.2701.4.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1182381354.2701.4.camel@laptopd505.fenrus.org> User-Agent: Mutt/1.5.14 (2007-02-12) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1917 Lines: 41 On Wed, Jun 20, 2007 at 04:15:53PM -0700, Arjan van de Ven wrote: > On Wed, 2007-06-20 at 19:07 -0400, Dave Jones wrote: > > On Wed, Jun 20, 2007 at 03:38:06PM -0700, Linus Torvalds wrote: > > > > > And yes, that patch already got merged. However, the patch to *allow* > > > Kprobes with DEBUG_RODATA is not, and will not be. It's not a regression, > > > and quite frankly, I don't think I would even want that patch. > > > > > > Kprobes fundamntally disagrees with DEBUG_RODATA, there's no point in > > > "working around it". Better just admit it. > > > > Surely the fundamental disagreement is only due to DEBUG_RODATA > > covering write-protection of both .text, and .rodata ? > > I can see value in having a kernel that supports kprobes, whilst > > at the same point, raising red flags if something writes into > > a const string. With my distro kernel maintainer hat on, I always > > hate these 'pick one' decisions, because I always get convincing > > arguments from proponents of both sides. > > > > Was it always this way? I thought DEBUG_RODATA initially just > > covered, well.. rodata. And kprobes only wants to change .text > > doesn't it ? > > no this got "fixed" recently. It used to only cover data. > Andi merged a patch to make it cover text too.. imo we should reverse > that, or make the check better and not have it cover text if kprobes is > active. I can do the later if people are ok with that, it's > approximately 3 lines of code. Having the text as a separate option makes sense to me. (Or at the least we should rename DEBUG_RODATA, as it's now misleading). Dave -- http://www.codemonkey.org.uk - 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/