Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761506AbYALG7u (ORCPT ); Sat, 12 Jan 2008 01:59:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751416AbYALG7m (ORCPT ); Sat, 12 Jan 2008 01:59:42 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:40576 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751250AbYALG7m (ORCPT ); Sat, 12 Jan 2008 01:59:42 -0500 Date: Sat, 12 Jan 2008 07:59:21 +0100 From: Ingo Molnar To: Valdis.Kletnieks@vt.edu Cc: Roland McGrath , Thomas Gleixner , "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [PATCH x86/mm] x86_64 save_i387_ia32 snafu Message-ID: <20080112065921.GB9572@elte.hu> References: <4786A9CA.2090008@zytor.com> <20080111004422.2B3F926F9A6@magilla.localdomain> <4786BE15.6040604@zytor.com> <20080111024929.37FDB26F9A9@magilla.localdomain> <4786DB3B.8070808@zytor.com> <20080111104357.8364826F9A9@magilla.localdomain> <20080111104932.GA1589@elte.hu> <20080111213147.EBE0C26F9A9@magilla.localdomain> <5212.1200117118@turing-police.cc.vt.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5212.1200117118@turing-police.cc.vt.edu> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1223 Lines: 27 * Valdis.Kletnieks@vt.edu wrote: > On Fri, 11 Jan 2008 13:31:47 PST, Roland McGrath said: > > > thanks, applied. Does this explain the crash/hang problems with 32-bit > > > apps on 64-bit kernels? What was the exact failure mode? > > > > It does. Any 32-bit process trying to run a signal handler when it had > > used the FPU, would clobber "current" with FP bits. The observed failure > > mode was shortly after this in the signal handler setup code, when it > > crashed due to current->mm being zero (current->pid also being zero, and > > the whole first 512 bytes of the task_struct being garbage). > > For what it's worth, this patch fixes a problem I had in 24-rc6-mm1 > with kernel panics when certain X programs exited (Eterm being the > biggest cause), that I had bisected to "somewhere in > git-x86.patch".... ok, good. Yesterday's x86.git update has this fix included so the next -mm iteration should have the fix as well. Ingo -- 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/