Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755999AbYHTVwY (ORCPT ); Wed, 20 Aug 2008 17:52:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752340AbYHTVwQ (ORCPT ); Wed, 20 Aug 2008 17:52:16 -0400 Received: from gate.crashing.org ([63.228.1.57]:55007 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752138AbYHTVwP (ORCPT ); Wed, 20 Aug 2008 17:52:15 -0400 Subject: Re: ftrace introduces instability into kernel 2.6.27(-rc2,-rc3) From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Steven Rostedt Cc: "Paul E. McKenney" , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Steven Rostedt , Scott Wood , Eran Liberty , Alan Modra , Segher Boessenkool In-Reply-To: References: <48591941.4070408@extricom.com> <48A92E15.2080709@extricom.com> <48A9901B.1080900@redhat.com> <20080818154746.GA26835@Krystal> <48A9AFA7.8080508@freescale.com> <1219110814.8062.2.camel@pasglop> <1219113549.8062.13.camel@pasglop> <1219114600.8062.15.camel@pasglop> <1219119431.8062.35.camel@pasglop> <1219216705.21386.46.camel@pasglop> Content-Type: text/plain Date: Thu, 21 Aug 2008 07:36:29 +1000 Message-Id: <1219268189.21386.65.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 Content-Length: 739 Lines: 22 > > As you can see, it restores r1 -before- it pops r24..r31 off > > the stack ! I let you imagine what happens if an interrupt happens > > just in between those two instructions (mr and lmw). We don't do > > redzones on our ABI, so basically, the registers end up corrupted > > by the interrupt. > > Ouch! You've disassembled this without -pg too, and it does not have this > bug? What version of gcc do you have? Oops, should have mentioned it ;-) 4.2.3 (Ubuntu 4.2.3-2ubuntu7) Ben. -- 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/