From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756923AbXGBWD7 (ORCPT ); Mon, 2 Jul 2007 18:03:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755988AbXGBWDv (ORCPT ); Mon, 2 Jul 2007 18:03:51 -0400 Received: from mx1.redhat.com ([66.187.233.31]:52508 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755887AbXGBWDu (ORCPT ); Mon, 2 Jul 2007 18:03:50 -0400 Message-ID: <46897642.9030407@redhat.com> Date: Mon, 02 Jul 2007 18:03:46 -0400 From: Chuck Ebbert Organization: Red Hat User-Agent: Thunderbird 1.5.0.12 (X11/20070530) MIME-Version: 1.0 To: Jason Wessel CC: lkml , stable@kernel.org Subject: Re: [PATCH] i386 - Fix regression, endless loop in ptrace singlestep over an int80 References: <468965D8.7020405@windriver.com> In-Reply-To: <468965D8.7020405@windriver.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 07/02/2007 04:53 PM, Jason Wessel wrote: > > Attached is a patch with a complete test case to fix the regression > introduced by the commit: 635cf99a80f4ebee59d70eb64bb85ce829e4591f. > > This patch is against kernel 2.6.21 but the fix is applicable to 2.6.21 > and up. Prior to the commit that introduced the regression the ltp > ptrace tests would complete correctly. I augmented the test case from > the original patch header to include the problem case that shows up in > the lpt tests. > > The brief summary is that the the TIF_SINGLESTEP state needs to be > altered on the exit path and not the entry path to a syscall, else it > can loop forever on the same instruction right after the syscall is > executed in certain cases. Where does it loop?