X-Recipient: archive-cygwin AT delorie DOT com X-Spam-Check-By: sourceware.org Date: Sun, 24 Jan 2010 13:01:50 -0500 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: question on gdb Message-ID: <20100124180150.GA19092@ednor.casa.cgf.cx> Reply-To: cygwin AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com References: <641935 DOT 96746 DOT qm AT web25504 DOT mail DOT ukl DOT yahoo DOT com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <641935.96746.qm@web25504.mail.ukl.yahoo.com> User-Agent: Mutt/1.5.20 (2009-06-14) Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com On Sun, Jan 24, 2010 at 07:42:32AM +0000, Marco Atzeri wrote: >Hi, >recently, after some change in the source, the octave >development branch started to SIGSEV on exit. >The strange issue is that this happen only >for cygwin and not on the other platforms. >I have not yet found a solution, only a possible workaround >removing some specific C++ "free" actions, so to fallback to >libstdc++ cleaning activity. > >My question however is about the gdb backtrace, is the >"Cannot access memory at address 0x1a" at # 9 normal ? >Unfortunately I am not really an expert on gdb: It happens sometimes but it does seem like something is screwed up somewhere sinc eyou have _sigfe in the stack trace with functions from other DLLs below it. That doesn't seem right. It looks like the stack is damaged. Can you set a breakpoint at cygwin_exit and (eventually) step into atexit to see where the problem is occurring? It sounds like a destructor is having problems. cgf >Here the gdb session >---------------------------------------------- >octave:1> exit > > >Program received signal SIGSEGV, Segmentation fault. >0x20f414d0 in ?? () >(gdb) backtrace >#0 0x20f414d0 in ?? () >#1 0x6112e117 in __call_exitprocs () from /usr/bin/cygwin1.dll >#2 0x6110b6da in exit () from /usr/bin/cygwin1.dll >#3 0x61004e5a in cygwin_exit () from /usr/bin/cygwin1.dll >#4 0x610b6838 in _sigfe () from /usr/bin/cygwin1.dll >#5 0x0022bba8 in ?? () >#6 0x6c4e401e in cygstdc++-6!_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc () > from /usr/bin/cygstdc++-6.dll >#7 0x6e5c8c65 in _fu4930___ZSt4cerr () at ../../octave_clone/src/toplev.cc:625 >#8 0x6e58fd9c in _fu4441___ZN8file_ops14static_members8instanceE () > at ../../octave_clone/src/octave.cc:876 >#9 0x00401167 in main (argc=Cannot access memory at address 0x1a >) at ../../octave_clone/src/main.c:35 >(gdb) >------------------------------------------- -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple