From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29943 invoked by alias); 25 Jul 2012 14:59:31 -0000 Received: (qmail 29930 invoked by uid 22791); 25 Jul 2012 14:59:30 -0000 X-SWARE-Spam-Status: No, hits=-7.5 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,KHOP_THREADED,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,SPF_HELO_PASS,TW_XC,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 25 Jul 2012 14:59:12 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q6PEwuwW014427 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 25 Jul 2012 10:58:56 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q6PEws4Z020750; Wed, 25 Jul 2012 10:58:55 -0400 Message-ID: <501009AE.40901@redhat.com> Date: Wed, 25 Jul 2012 14:59:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Philippe Waroquiers CC: Jan Kratochvil , Joel Brobecker , gdb-patches@sourceware.org Subject: Re: [patch] [i386] Put hlt at the ON_STACK breakpoint [Re: GDB 7.4.91 available for testing] References: <20120718163413.GA17548@adacore.com> <1342739016.2220.32.camel@soleil> <20120720071158.GA7053@host2.jankratochvil.net> <1342817409.2149.41.camel@soleil> <20120722173053.GA22036@host2.jankratochvil.net> <1342983655.2301.55.camel@soleil> <20120723072125.GA12958@host2.jankratochvil.net> <20120723155951.GA24718@adacore.com> <20120723163513.GA1222@host2.jankratochvil.net> <1343074047.2209.23.camel@soleil> <20120723201611.GA19567@host2.jankratochvil.net> <1343075809.2209.53.camel@soleil> In-Reply-To: <1343075809.2209.53.camel@soleil> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit 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: 2012-07/txt/msg00536.txt.bz2 On 07/23/2012 09:36 PM, Philippe Waroquiers wrote: >> So the GDB patch is no longer needed when you have fixed valgrind to put 0xcc >> during Z0? Why valgrind cannot write 0xcc into stack memory when it already >> has to write there to create the stack frame / parameters passed by stack? > Effectively, I have a patch which fixes the problem. > But the patch is a kludge which heuristically guesses that GDB is > pushing an infcall. Why do you have to guess that, rather than just detecting a breakpoint is being set on a stack (or non text) address? If something sets a breakpoint in a data address, it is basically telling valgrind "this is actually code". -- Pedro Alves