From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759417AbYHSVsj (ORCPT ); Tue, 19 Aug 2008 17:48:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753882AbYHSVsb (ORCPT ); Tue, 19 Aug 2008 17:48:31 -0400 Received: from gate.crashing.org ([63.228.1.57]:49002 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752466AbYHSVsa (ORCPT ); Tue, 19 Aug 2008 17:48:30 -0400 Subject: Re: ftrace introduces instability into kernel 2.6.27(-rc2,-rc3) From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Mathieu Desnoyers Cc: Eran Liberty , Steven Rostedt , linux-kernel@vger.kernel.org, "Paul E. McKenney" , linuxppc-dev@ozlabs.org, rostedt@goodmis.org In-Reply-To: <20080819130216.GA18001@Krystal> References: <48591941.4070408@extricom.com> <48A92E15.2080709@extricom.com> <48A9901B.1080900@redhat.com> <48A9BEA3.10906@extricom.com> <20080818184158.GA1798@Krystal> <48AA98E4.6060606@extricom.com> <20080819130216.GA18001@Krystal> Content-Type: text/plain Date: Wed, 20 Aug 2008 07:46:44 +1000 Message-Id: <1219182404.7826.14.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Register GPR30 is always zero... (also true for the other oops) >>From my experiments, -a- non volatile register gets corrupted. Not always the same and not always with the same value. The corruption -seems- to happen due to corruption of the location on the stack where it was saved to / restored from in a previous function call or interrupt. I haven't yet tracked down what actually whacks the stack. Ben.