From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765364AbYESWIv (ORCPT ); Mon, 19 May 2008 18:08:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759250AbYESWGB (ORCPT ); Mon, 19 May 2008 18:06:01 -0400 Received: from gw.goop.org ([64.81.55.164]:57293 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765119AbYESWGA (ORCPT ); Mon, 19 May 2008 18:06:00 -0400 Message-ID: <48320777.1000006@goop.org> Date: Tue, 20 May 2008 00:04:23 +0100 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Hugh Dickins CC: Theodore Tso , Gabriel C , Keith Packard , "Pallipadi, Venkatesh" , Eric Anholt , linux-kernel@vger.kernel.org, Ingo Molnar , "Siddha, Suresh B" , bugme-daemon@bugzilla.kernel.org, airlied@linux.ie, "Barnes, Jesse" , Andrew Morton , Linus Torvalds , "Rafael J. Wysocki" Subject: Re: [Bug 10732] REGRESSION: 2.6.26-rc2-git4: X server failed start onX61s laptop References: <924EFEDD5F540B4284297C4DC59F3DEE01119AFE@orsmsx423.amr.corp.intel.com> <20080517154131.GA7651@mit.edu> <924EFEDD5F540B4284297C4DC59F3DEE01119B07@orsmsx423.amr.corp.intel.com> <1211047916.27447.314.camel@koto.keithp.com> <482F24C6.2050705@frugalware.org> <20080517184626.GA16496@mit.edu> In-Reply-To: X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hugh Dickins wrote: > On Sat, 17 May 2008, Theodore Tso wrote: > >> On Sat, May 17, 2008 at 08:32:38PM +0200, Gabriel C wrote: >> >>>> Which repository is commit 1c12c4cf in? >>>> >>> It is in linus-git tree , http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1c12c4cf9411eb130b245fa8d0fbbaf989477c7b >>> >> ...post 2.6.26-rc2-git3. For Linux kernels 2.6.26-rc2-git4 and >> newer, you need to revert this commit or the X Server shipped with >> Ubuntu Gutsy will die horribly when run on an X61s laptop with the >> Intel 965GM video chipset. >> >> So the question is what's the right fix to keep the kernel compatible >> with the X server, besides just reverting the commit entirely? >> > > [PATCH] x86: fix mprotect's NX handling on PAE > > 2.6.26-rc3 with CONFIG_X86_PAE may leave the NX bit set when PROT_EXEC > is intending to clear it, causing irqbalance and others to segfault, > and X startup to fail. > > This comes from an assumption in 1c12c4cf9411eb130b245fa8d0fbbaf989477c7b > mprotect: prevent alteration of the PAT bits, that PTE_MASK is what it's > supposed to be: whereas it's been wrong forever with PAE, staying 32-bit > where 64-bit is needed. > > Jeremy Fitzhardinge already has patches to fix that in Ingo's tree; > but if they're not considered 2.6.26 material, or people want a quick > two-liner to get working, here's a shorter hack to fix up pte_modify. > From what I can tell, my patches haven't caused any regressions, and so if they fix a real bug we could consider them for .26. J