From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 911 invoked by alias); 13 Dec 2006 21:41:07 -0000 Received: (qmail 897 invoked by uid 22791); 13 Dec 2006 21:41:05 -0000 X-Spam-Check-By: sourceware.org Received: from smtp-vbr14.xs4all.nl (HELO smtp-vbr14.xs4all.nl) (194.109.24.34) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 13 Dec 2006 21:40:58 +0000 Received: from webmail.xs4all.nl (dovemail3.xs4all.nl [194.109.26.5]) by smtp-vbr14.xs4all.nl (8.13.8/8.13.8) with ESMTP id kBDLepo9043989; Wed, 13 Dec 2006 22:40:51 +0100 (CET) (envelope-from mark.kettenis@xs4all.nl) Received: from 82.92.89.47 (SquirrelMail authenticated user sibelius) by webmail.xs4all.nl with HTTP; Wed, 13 Dec 2006 22:40:52 +0100 (CET) Message-ID: <23342.82.92.89.47.1166046052.squirrel@webmail.xs4all.nl> In-Reply-To: <20061213210357.GA27039@nevyn.them.org> References: <20061211190300.GA4372@host0.dyn.jankratochvil.net> <20061211224022.AD76E1800E7@magilla.sf.frob.com> <20061212155233.GH29911@devserv.devel.redhat.com> <20061213204603.GA11741@host0.dyn.jankratochvil.net> <20061213210357.GA27039@nevyn.them.org> Date: Wed, 13 Dec 2006 21:41:00 -0000 Subject: Re: [PATCH] Re: Unwinding CFI gcc practice of assumed `same value' regs From: "Mark Kettenis" To: "Jan Kratochvil" , gdb-patches@sourceware.org User-Agent: SquirrelMail/1.4.8 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-12/txt/msg00180.txt.bz2 > On Wed, Dec 13, 2006 at 09:46:04PM +0100, Jan Kratochvil wrote: > > Attaching patch for current gdb CVS to properly terminate on return > > address 0. > > The check was already present there but it got applied one backward step > > later. > > > > I hope these three patches are be 100% reliable and also backward > > compatible. > > Please read the previous discussion and patch on this topic: > http://sourceware.org/ml/gdb-patches/2006-07/msg00392.html > > Mark, I don't suppose you find it convincing that the libgcc unwinder > terminates on PC == 0 too? It's a perfectly reasonable thing for the libgcc unwinder to do (just as it is for us in GDB). But in a debugger I want to see that PC == 0 if it is an abnormal backtrace termination. What really needs to be done is making the DWARF2 unwinder recognize the condition and return a suitable frame id for that. Mark