From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759784AbYFZN7e (ORCPT ); Thu, 26 Jun 2008 09:59:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752847AbYFZN7Z (ORCPT ); Thu, 26 Jun 2008 09:59:25 -0400 Received: from wf-out-1314.google.com ([209.85.200.171]:28319 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166AbYFZN7Y (ORCPT ); Thu, 26 Jun 2008 09:59:24 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=cAfix3nZrtU9Ri9QycYeAVsI+Dz2gQoE2ec/xThwdLlqqjkNmZhKaDkyPHBjTgj581 d12NbHbWIDC6jYg2i0BRQ0AXvHS1uWRLMB1xcs9EgF7isCEEzP+ZXYx4fA5l9kNvVqtl 1iqVnvLk4/0dDz2fxdHiEpzQLJAONZImnzUzM= Message-ID: <19f34abd0806260659u7e5d0968i18bef6ed423cb7a8@mail.gmail.com> Date: Thu, 26 Jun 2008 15:59:23 +0200 From: "Vegard Nossum" To: "Jason Wessel" Subject: Re: v2.6.26-rc7: BUG: unable to handle kernel NULL pointer dereference Cc: "Andrew Morton" , "Zhang, Yanmin" , "Ingo Molnar" , "Mike Travis" , "Adrian Bunk" , "Srivatsa Vaddagiri" , linux-kernel@vger.kernel.org, "Gautham R Shenoy" , "Rafael J. Wysocki" , "Zhang, Yanmin" , "Heiko Carstens" , "Rusty Russell" In-Reply-To: <48638E38.5080605@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080622125633.GA8166@damson.getinternet.no> <200806231326.11328.rusty@rustcorp.com.au> <485FD644.80208@sgi.com> <200806241136.52430.rusty@rustcorp.com.au> <1214294783.25608.75.camel@ymzhang> <1214441979.25608.86.camel@ymzhang> <20080625191535.e6e60432.akpm@linux-foundation.org> <19f34abd0806260200r40b46012q9bb4ba8783e8d935@mail.gmail.com> <48638E38.5080605@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 26, 2008 at 2:40 PM, Jason Wessel wrote: >> 4. Page fault in I'm guessing configure_kgdbts() during boot. Never >> seen this before either (screenshot #2). >> > > How often does #4 occur? Only this once yet. > > Perhaps you can email me directly the .config and kernel boot arguments > you used? It would be good to determine if the #4 is a victim or > culprit of the crash. If it is a culprit I would like to try and fix it. I don't think this really has anything to do with the CPU hotplug crashing. It seems to be completely spurious, as this was during boot before userspace had even started. It's not even certain that it has anything to do with kgdb at all. I mean, that stack trace is not very reliable... Command line was: kernel /vmlinuz-2.6.26-rc8-dirty ro root=/dev/VolGroup00/LogVol00 rhgb debug 3 You can find vmlinux and config here: http://www.kernel.org/pub/linux/kernel/people/vegard/kernels/20080626/ ..but it probably takes a bit for the mirrors to pick up. In the meantime, I can provide you with the relevant line numbers: # configure_kgdbts $ addr2line -e vmlinux.20080626 -i c030ab18 | sed 's/.*linux-2.6\///' drivers/misc/kgdbts.c:911 drivers/misc/kgdbts.c:1015 # mtrr_del $ addr2line -e vmlinux.20080626 -i c011007b | sed 's/.*linux-2.6\///' arch/x86/kernel/cpu/mtrr/main.c:548 # loop_init $ addr2line -e vmlinux.20080626 -i c078111a | sed 's/.*linux-2.6\///' drivers/block/loop.c:1550 # init_kgdbts $ addr2line -e vmlinux.20080626 -i c0781163 | sed 's/.*linux-2.6\///' drivers/misc/kgdbts.c:1033 Thanks. Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036