From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14745 invoked by alias); 11 Apr 2012 15:54:17 -0000 Received: (qmail 14730 invoked by uid 22791); 11 Apr 2012 15:54:13 -0000 X-SWARE-Spam-Status: No, hits=-7.2 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,KHOP_THREADED,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,SPF_HELO_PASS,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, 11 Apr 2012 15:54:01 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q3BFrwig028601 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 11 Apr 2012 11:53:58 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q3BFruRf007772; Wed, 11 Apr 2012 11:53:57 -0400 Message-ID: <4F85A914.1050908@redhat.com> Date: Wed, 11 Apr 2012 16:45:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120329 Thunderbird/11.0.1 MIME-Version: 1.0 To: Yao Qi CC: Jan Kratochvil , gdb-patches@sourceware.org Subject: Re: [patch] More suggestive displaced-stepping memory error message References: <20120410191955.GB31331@host2.jankratochvil.net> <4F84C2D7.1070203@codesourcery.com> In-Reply-To: <4F84C2D7.1070203@codesourcery.com> Content-Type: text/plain; charset=ISO-8859-1 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: 2012-04/txt/msg00253.txt.bz2 On 04/11/2012 12:31 AM, Yao Qi wrote: > Probably, GDB can be smart enough to not > use displaced stepping when get error on accessing scratch pad. So far, > displaced_step_prepare returns 1 for success and 0 for queued request. > We can add one more return value -1 for `unable to do displaced > stepping', so that caller can go non-displaced-stepping path. We can't just go non-displaced-stepping path in non-stop with the current code because nothing knows to pause all running threads in order to be able to lift the breakpoint and step over it without other threads missing it (like gdbserver knows, with linux-low.c:start_step_over and all that). My patch #1 "all-stop on top of non-stop" patch of the itsets series goes in that direction. -- Pedro Alves