From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22958 invoked by alias); 5 Mar 2014 20:38:38 -0000 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 Received: (qmail 22948 invoked by uid 89); 5 Mar 2014 20:38:38 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 05 Mar 2014 20:38:37 +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 s25KcYli022197 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 5 Mar 2014 15:38:34 -0500 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 s25KcWKc027425; Wed, 5 Mar 2014 15:38:33 -0500 Message-ID: <53178B48.5060003@redhat.com> Date: Wed, 05 Mar 2014 20:38:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Tom Tromey CC: gdb-patches@sourceware.org, Joel Brobecker Subject: Re: [RFC v2] fix regressions with target-async References: <1393609699-26407-1-git-send-email-tromey@redhat.com> <5310D2F9.2090507@redhat.com> <87mwh7cks4.fsf@fleche.redhat.com> <5314AFEA.8020705@redhat.com> <87y50q9h3e.fsf@fleche.redhat.com> <531644AE.1070404@redhat.com> <53166C73.2070308@redhat.com> <87txbc7b2s.fsf@fleche.redhat.com> In-Reply-To: <87txbc7b2s.fsf@fleche.redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SW-Source: 2014-03/txt/msg00140.txt.bz2 On 03/05/2014 06:30 PM, Tom Tromey wrote: > Pedro> Confirmed, building with expat makes threaded debugging work: > ... > Pedro> (You can find an expat build at ~palves:/home/palves/opt/) > > Thanks. With this I was able to verify that your theory about the AIX > to_attach method was correct -- I could make my patched gdb crash by > debugging a multi-threaded inferior and then "attach"ing to a new > process. OK. > The patch to aix-thread is pretty simple. It regression tests > reasonably well, but not perfectly... the test suite on AIX provokes a > number of internal errors, and with my patch they can be reported > against different tests. I suspect this is timing sensitive though, > perhaps latent races in the existing code, as the internal errors in > question are all preceded by a failing call to > aix-thread.c:ptrace_check. > > For example: > > (gdb) next > thread_function (arg=0x0) at ../../../gdb/gdb/testsuite/gdb.threads/pending-step > .c:57 > 57 (*myp) ++; /* insert breakpoint here */ > aix-thread: ptrace (50, 38011047) returned -1 (errno = 22 Invalid argument) > (gdb) next > ../../gdb/gdb/breakpoint.c:15064: internal-error: insert_single_step_breakpoint: > Assertion `single_step_breakpoints[1] == NULL' failed. > > I wonder whether this is good enough. Yes, I can't imagine this being related. -- Pedro Alves