From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261206AbUEZXdt (ORCPT ); Wed, 26 May 2004 19:33:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261210AbUEZXdt (ORCPT ); Wed, 26 May 2004 19:33:49 -0400 Received: from cantor.suse.de ([195.135.220.2]:15811 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S261206AbUEZXdm (ORCPT ); Wed, 26 May 2004 19:33:42 -0400 Date: Thu, 27 May 2004 01:33:39 +0200 From: Andi Kleen To: Chris.Gottbrath@etnus.com Cc: chrisg@etnus.com, marcelo@conectiva.com.br, discuss@x86-64.org, linux-kernel@vger.kernel.org, jdelsign@etnus.com Subject: Re: [PATCH] x86-64 only: ia32entry.S reg changes dropped during debugging Message-Id: <20040527013339.60f590cf.ak@suse.de> In-Reply-To: References: X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 26 May 2004 18:50:11 -0400 (EDT) Chris Gottbrath wrote: > > Andi, > > We develop a debugger for linux x86-64 called TotalView. We have > recently tracked down a problem to the fact that some register changes > made by the debugger in the target are getting discarded. This is only > happening with the 2.4.x kernels on x86-64. It appears that the > bug may have been fixed as a side effect of some other change in 2.6.x. > > The scenario is that the debugger uses ptrace(PTRACE_SYSCALL,) and > changes some registers in the process while it is stopped in a > system call. We are finding that the system call entry code discards > changes to R15, R14, R13, R12, RBP, and RBX. > > The following patch is against arch/x86_64/ia32/ia32entry.S in 2.4.26. Looks good. Thanks. -Andi