From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7725 invoked by alias); 19 Nov 2013 20:24:37 -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 7708 invoked by uid 89); 19 Nov 2013 20:24:36 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.7 required=5.0 tests=AWL,BAYES_00,RDNS_NONE,SPF_HELO_PASS,SPF_PASS autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from Unknown (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 19 Nov 2013 20:24:35 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rAJKOSi8001196 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 19 Nov 2013 15:24:28 -0500 Received: from barimba (ovpn-113-124.phx2.redhat.com [10.3.113.124]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rAJKOQBg014861 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Tue, 19 Nov 2013 15:24:27 -0500 From: Tom Tromey To: Pedro Alves Cc: gdb-patches@sourceware.org Subject: Re: [PATCH 1/2] avoid infinite loop with bad debuginfo References: <1384375873-32160-1-git-send-email-tromey@redhat.com> <1384375873-32160-2-git-send-email-tromey@redhat.com> <52850730.1060109@redhat.com> <87d2lxpo1l.fsf@fleche.redhat.com> <528B7F15.7040605@redhat.com> <87vbzomm78.fsf@fleche.redhat.com> <528B8FF6.7000406@redhat.com> <87siusl10r.fsf@fleche.redhat.com> <528BB700.4000802@redhat.com> Date: Tue, 19 Nov 2013 20:56:00 -0000 In-Reply-To: <528BB700.4000802@redhat.com> (Pedro Alves's message of "Tue, 19 Nov 2013 19:07:44 +0000") Message-ID: <87fvqskumd.fsf@fleche.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-SW-Source: 2013-11/txt/msg00560.txt.bz2 Pedro> I don't think so, because get_prev_frame_1 would not link in Pedro> the dup frame. The loop in question would never see it. Pedro> Hmm, I think one of us is missing something. Haha, yeah, that usually means me :-) No worries. I think I understand this bit now. Pedro> So the bad loop can only ever happen (outside the unwinder code) Pedro> if we ever let outselves get in the dup frame_id situation: >> #4 0x0000007fb7f0956c in clone () from /lib64/libc.so.6 >> #5 0x0000007fb7f0956c in clone () from /lib64/libc.so.6 >> Backtrace stopped: previous frame identical to this frame (corrupt stack?) Pedro> At least, I'm not seeing any other way. Yes, I see now. Really not looking forward to writing the test. Tom