From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1265 invoked by alias); 4 Aug 2006 13:19:18 -0000 Received: (qmail 1255 invoked by uid 22791); 4 Aug 2006 13:19:18 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Fri, 04 Aug 2006 13:19:16 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1G8za5-0007Bs-51; Fri, 04 Aug 2006 09:19:13 -0400 Date: Fri, 04 Aug 2006 13:19:00 -0000 From: Daniel Jacobowitz To: Nick Roberts Cc: gdb@sources.redhat.com Subject: Re: stepping over longjmp Message-ID: <20060804131913.GB26799@nevyn.them.org> Mail-Followup-To: Nick Roberts , gdb@sources.redhat.com References: <17619.308.218261.761948@kahikatea.snap.net.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <17619.308.218261.761948@kahikatea.snap.net.nz> User-Agent: Mutt/1.5.11+cvs20060403 X-IsSubscribed: yes Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2006-08/txt/msg00024.txt.bz2 On Fri, Aug 04, 2006 at 08:11:32PM +1200, Nick Roberts wrote: > > With current CVS GDB and Fedora Core 5 i686 i386 GNU/Linux (2.6.17-1.2157 but > also 2.6.15) when I try to step over longjmp (using next) I get the following > error: > > Warning: > Cannot insert breakpoint -59. > Error accessing memory address 0x226092c5: Input/output error. > > ISTR that this was also the case with FC4 and have only recently realised that > you can step usefully step over a longjmp call after trying it on Mandrake 9 > (2.4.19) > > Is this a known kernel problem or a bug in GDB? Has nothing to do with the kernel. I imagine that this is the problem I discussed on this list a while ago, CC'd to libc-alpha; glibc now uses a canary in the jmp_buf which GDB has no way to access. Does export LD_POINTER_GUARD=0 make a difference? -- Daniel Jacobowitz CodeSourcery