From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13898 invoked by alias); 31 Oct 2006 19:11:37 -0000 Received: (qmail 13878 invoked by uid 22791); 31 Oct 2006 19:11:35 -0000 X-Spam-Check-By: sourceware.org Received: from ns.suse.de (HELO mx1.suse.de) (195.135.220.2) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 31 Oct 2006 19:11:22 +0000 Received: from Relay2.suse.de (mail2.suse.de [195.135.221.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.suse.de (Postfix) with ESMTP id EDCBDFB0C; Tue, 31 Oct 2006 20:11:18 +0100 (CET) From: Andi Kleen To: Daniel Jacobowitz Subject: Re: [rfa] Handle amd64-linux %orig_rax Date: Tue, 31 Oct 2006 19:11:00 -0000 User-Agent: KMail/1.9.5 Cc: Datoda , gdb-patches@sourceware.org References: <20061031181702.73135.qmail@web53714.mail.yahoo.com> <200610311940.38617.ak@suse.de> <20061031184924.GA30569@nevyn.them.org> In-Reply-To: <20061031184924.GA30569@nevyn.them.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200610312011.20880.ak@suse.de> Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-10/txt/msg00317.txt.bz2 > Oh dear. So if we set registers on the syscall exit path, the > kernel/ISA may just eat them. And we have no reliable way to know > whether we're stopped on the syscall exit path. If you're single stepping over it you can remember it from one instruction before (check if the opcode is SYSCALL or SYSENTER, these are unique 2 byte opcodes each) If someone sets a breakpoint directly on the return point and doesn't single step that wouldn't work, but then you shouldn't care about the previous register state anyways. -Andi