From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965887AbXCFOlO (ORCPT ); Tue, 6 Mar 2007 09:41:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965889AbXCFOlN (ORCPT ); Tue, 6 Mar 2007 09:41:13 -0500 Received: from www.osadl.org ([213.239.205.134]:36075 "EHLO mail.tglx.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965887AbXCFOlK (ORCPT ); Tue, 6 Mar 2007 09:41:10 -0500 Subject: Re: 2.6.21-rc2-mm2 From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Con Kolivas Cc: Andrew Morton , linux-kernel@vger.kernel.org, john stultz In-Reply-To: <200703070024.51273.kernel@kolivas.org> References: <20070306004408.d3f6434d.akpm@linux-foundation.org> <200703062258.19940.kernel@kolivas.org> <1173185537.24738.323.camel@localhost.localdomain> <200703070024.51273.kernel@kolivas.org> Content-Type: text/plain Date: Tue, 06 Mar 2007 15:47:13 +0100 Message-Id: <1173192434.24738.333.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2007-03-07 at 00:24 +1100, Con Kolivas wrote: > > printk(KERN_INFO "Time: %s clocksource has been installed.\n", > > clock->name); > > } > > > > So clock seems to be NULL, but was accessed before > > clocksource_calculate_interval() as well. > > It seems to be specifically tripping at c->mult after reading c->shift if I'm > reading it correctly. > > Note again, this is qemu, not real hardware and it will likely be giving very > unrealistic values for timer calibrations. I know, but this does not really explain why the tmp += c->mult/2; results in a NULL pointer access after tmp <<= c->shift; Does disassembling the code in question give some info ? You might also try to look with GDB at it. tglx