From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12728 invoked by alias); 7 Jul 2009 13:49:02 -0000 Received: (qmail 12719 invoked by uid 22791); 7 Jul 2009 13:49:01 -0000 X-SWARE-Spam-Status: No, hits=-7.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI X-Spam-Check-By: sourceware.org Received: from cantor.suse.de (HELO mx1.suse.de) (195.135.220.2) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 07 Jul 2009 13:48:55 +0000 Received: from relay1.suse.de (relay-ext.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 723638FEA2; Tue, 7 Jul 2009 15:48:52 +0200 (CEST) Date: Tue, 07 Jul 2009 13:49:00 -0000 From: Michael Matz To: "Frank Ch. Eigler" Cc: gdb-patches@sourceware.org, Mark Kettenis Subject: Re: RFC: %ebp-based backtrace patch In-Reply-To: <20090707131932.GA1933@redhat.com> Message-ID: References: <20090706183316.GA26074@caradoc.them.org> <20090707131932.GA1933@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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: 2009-07/txt/msg00193.txt.bz2 Hi, On Tue, 7 Jul 2009, Frank Ch. Eigler wrote: > On Tue, Jul 07, 2009 at 02:15:19PM +0200, Michael Matz wrote: > > [...] > > > Could gdb partially disassemble such functions to check > > > whether %ebp is likely being used as this heuristic expects? > > > > Nope. We don't know the function borders. [...] > > I'm feeling dense, so can you explain why? We have at least a > PC value, which one could map in the symbol table, no? There is no complete symbol table anymore, only the exported symbol table which is empty for executable by default and doesn't contain e.g. static functions for shared libs. That's the whole point. We are talking about stripped objects for which we still want to generate useful backtraces (or at least not disturb backtracing when even just one shared lib in the call stack was stripped) so that bugreports of crashes are not completely useless and misleading. Ciao, Michael.