From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12428 invoked by alias); 30 Mar 2013 20:07:58 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 12386 invoked by uid 89); 30 Mar 2013 20:07:49 -0000 X-Spam-SWARE-Status: No, score=-3.6 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,RCVD_IN_HOSTKARMA_NO,RCVD_IN_HOSTKARMA_W,RCVD_IN_HOSTKARMA_WL autolearn=ham version=3.3.1 Received: from rock.gnat.com (HELO rock.gnat.com) (205.232.38.15) by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Sat, 30 Mar 2013 20:07:47 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id B7A452E7C9; Sat, 30 Mar 2013 16:07:45 -0400 (EDT) Received: from rock.gnat.com ([127.0.0.1]) by localhost (rock.gnat.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id GW7+GUSn4SiS; Sat, 30 Mar 2013 16:07:45 -0400 (EDT) Received: from joel.gnat.com (localhost.localdomain [127.0.0.1]) by rock.gnat.com (Postfix) with ESMTP id 6E2292E4D1; Sat, 30 Mar 2013 16:07:45 -0400 (EDT) Received: by joel.gnat.com (Postfix, from userid 1000) id 46008C2852; Sat, 30 Mar 2013 13:07:43 -0700 (PDT) Date: Sat, 30 Mar 2013 20:07:00 -0000 From: Joel Brobecker To: Jan Kratochvil Cc: Richard Smith , gdb@sourceware.org Subject: Re: Backtraces broken on i386 by unorthodox encoding of push %ebp Message-ID: <20130330200743.GG10614@adacore.com> References: <20130330195008.GA11994@host2.jankratochvil.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130330195008.GA11994@host2.jankratochvil.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-SW-Source: 2013-03/txt/msg00086.txt.bz2 > > However, when I have this form of prologue, gdb doesn't recongnise > > it, and doesn't give a meaningful backtrace. > > You should always provide unwind information and then it is irrelevant which > instructions and/or which their coding you use. Agreed, and that could be the instant fix. But if he cannot get the unwind information with the binary, it might indeed be easy enough to improve the prologue analyzer for x86. On x86_64, on the other hand, we made the conscious design decision to rely more on unwind info, so it's a little more questionable whether we'd want to do that for this target. The thing I wanted to add to Richard is that there is a very high chance that the only way to get this fixed in GDB is by submitting a patch himself (to gdb-patches). -- Joel