From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755210AbZGUQuM (ORCPT ); Tue, 21 Jul 2009 12:50:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753017AbZGUQuL (ORCPT ); Tue, 21 Jul 2009 12:50:11 -0400 Received: from main.gmane.org ([80.91.229.2]:45061 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752802AbZGUQuK (ORCPT ); Tue, 21 Jul 2009 12:50:10 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Robert Hancock Subject: Re: problems debugging panic with gdb, kdump, and vmcore Date: Tue, 21 Jul 2009 10:52:03 -0600 Message-ID: <4A65F233.9030605@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: s0106000c41bb86e1.ss.shawcable.net User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Thunderbird/3.0b2 In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/20/2009 10:46 PM, Steven Noonan wrote: > Hi folks, > > I've got a kernel panic that is easily reproducible (I am 99% sure > that 2.6.30.2 itself isn't to blame, it's the out-of-tree drm module I > built from here: http://cgit.freedesktop.org/mesa/drm/). I could just > follow the stack trace, but I'd like to learn how to use kexec/kdump > to debug this. So far, I've got kexec successfully loading a kernel on > a panic, and I'm able to copy the vmcore out of /proc to someplace > permanent, but trying to use gdb on it gives very strange results. I > don't know what I'm doing wrong. I've rebuilt the kernel multiple > times and ensured that ccache is cleared each time just in case that > might interfere. Here's what I'm getting with gdb: > > > Alcarin linux # pwd > /usr/src/linux > Alcarin linux # gdb vmlinux /var/tmp/vmcore > GNU gdb 6.8 > Copyright (C) 2008 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "i686-pc-linux-gnu"... > > warning: exec file is newer than core file. Why is the vmlinux file newer than the vmcore file?