From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20809 invoked by alias); 16 Sep 2012 06:50:30 -0000 Received: (qmail 20800 invoked by uid 22791); 16 Sep 2012 06:50:29 -0000 X-SWARE-Spam-Status: No, hits=-4.6 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,KHOP_RCVD_TRUST,KHOP_THREADED,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE,TW_GJ X-Spam-Check-By: sourceware.org Received: from mail-qc0-f169.google.com (HELO mail-qc0-f169.google.com) (209.85.216.169) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 16 Sep 2012 06:50:09 +0000 Received: by qcsd16 with SMTP id d16so4994393qcs.0 for ; Sat, 15 Sep 2012 23:50:08 -0700 (PDT) MIME-Version: 1.0 Received: by 10.224.19.80 with SMTP id z16mr6125862qaa.74.1347778208724; Sat, 15 Sep 2012 23:50:08 -0700 (PDT) Received: by 10.49.81.146 with HTTP; Sat, 15 Sep 2012 23:50:08 -0700 (PDT) In-Reply-To: <20120915060824.GA19914@host2.jankratochvil.net> References: <20120915060824.GA19914@host2.jankratochvil.net> Date: Sun, 16 Sep 2012 06:50:00 -0000 Message-ID: Subject: Re: what is the function of EXCEPTIONS_SIGLONGJMP? From: John Smith To: gdb@sourceware.org Content-Type: text/plain; charset=ISO-8859-1 X-IsSubscribed: yes 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 X-SW-Source: 2012-09/txt/msg00041.txt.bz2 I am not trying to step over longjump, I just trace the event loop > procedure of gdb > so why does that exception occured? 2012/9/15 Jan Kratochvil : > On Thu, 13 Sep 2012 11:55:34 +0200, John Smith wrote: >> when I debug gdb using gdb self , after I type "start" command , >> the prompt is as below : >> Warning: >> Cannot insert breakpoint 0. >> Error accessing memory address 0xdb6a5194: /. >> 0xb7589571 in siglongjmp () from /lib/i686/cmov/libc.so.6 >> >> it seem to be some exceptions happened when dealing with break points . > > You are trying to step over longjmp or siglongjmp call. This is supported > only with SystemTap-extended glibc, this is implemented only in recent glibc > and recent GDB. Recent Fedora releases also have it working. > glibc/ > commit 8422c9a560e6e3c854739c8a13ecb1c6714f930f > Author: Roland McGrath > Date: Fri May 25 13:31:57 2012 -0700 > Add systemtap static probe points in setjmp/longjmp on x86. > gdb/ > commit 014135139c612fe1fbe6f11d2350f72325a66f7c > Author: sergiodj > Date: Fri Apr 27 20:48:52 2012 +0000 > 2012-04-27 Sergio Durigan Junior > Tom Tromey > > I just do not understand how that can happen during 'start' command, 'start' > is just doing 'tbreak' and 'run', there is no stepping involved anywhere. > > > Regards, > Jan