From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-return-42739-listarch-gdb=sources.redhat.com@sourceware.org>
Received: (qmail 17165 invoked by alias); 28 Oct 2013 16:12:17 -0000
Mailing-List: contact gdb-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb.sourceware.org>
List-Subscribe: <mailto:gdb-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb/>
List-Post: <mailto:gdb@sourceware.org>
List-Help: <mailto:gdb-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gdb-owner@sourceware.org
Received: (qmail 17150 invoked by uid 89); 28 Oct 2013 16:12:16 -0000
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-3.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_SOFTFAIL autolearn=no version=3.3.2
X-HELO: mtaout20.012.net.il
Received: from mtaout20.012.net.il (HELO mtaout20.012.net.il) (80.179.55.166) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 28 Oct 2013 16:12:15 +0000
Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0MVD00A00ZKXI700@a-mtaout20.012.net.il> for gdb@sourceware.org; Mon, 28 Oct 2013 18:12:06 +0200 (IST)
Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MVD00A8IZO568A0@a-mtaout20.012.net.il>; Mon, 28 Oct 2013 18:12:06 +0200 (IST)
Date: Mon, 28 Oct 2013 16:12:00 -0000
From: Eli Zaretskii <eliz@gnu.org>
Subject: Re: Fwd: gdb on Cygwin cannot give correct call stacks for segment faults
In-reply-to: <CALX7UOiD9AxWH2aqPsDdwOHQj3wAOsOXA+qSCJv4LTOuoND96g@mail.gmail.com>
To: Pan ruochen <panruochen@gmail.com>
Cc: gdb@sourceware.org
Reply-to: Eli Zaretskii <eliz@gnu.org>
Message-id: <83a9htfk8a.fsf@gnu.org>
References: <CALX7UOgBuWzx_8dO+Aev=1MfLLSma6CQdcQqi6iURCA1HR7snA@mail.gmail.com> <CALX7UOiD9AxWH2aqPsDdwOHQj3wAOsOXA+qSCJv4LTOuoND96g@mail.gmail.com>
X-IsSubscribed: yes
X-SW-Source: 2013-10/txt/msg00163.txt.bz2

> Date: Mon, 28 Oct 2013 12:00:17 +0800
> From: Pan ruochen <panruochen@gmail.com>
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x61138b61 in _fwrite_r () from /usr/bin/cygwin1.dll
> (gdb) backtrace
> #0  0x61138b61 in _fwrite_r () from /usr/bin/cygwin1.dll
> #1  0x76bd1194 in WaitForSingleObjectEx ()
>    from /cygdrive/c/windows/syswow64/kernel32.dll
> #2  0x76bd1148 in WaitForSingleObject ()
>    from /cygdrive/c/windows/syswow64/kernel32.dll
> #3  0x610dd558 in sig_send(_pinfo*, siginfo_t&, _cygtls*) ()
>    from /usr/bin/cygwin1.dll
> #4  0x610303b4 in exception::handle(_EXCEPTION_RECORD*,
> _exception_list*, _CONTEXT*, void*) () from /usr/bin/cygwin1.dll
> #5  0x77a5b499 in ntdll!LdrRemoveLoadAsDataTable ()
>    from /cygdrive/c/windows/system32/ntdll.dll
> #6  0x0028a6ac in ?? ()
> #7  0x77a5b46b in ntdll!LdrRemoveLoadAsDataTable ()
>    from /cygdrive/c/windows/system32/ntdll.dll
> #8  0x0028a6ac in ?? ()
> #9  0x77a10133 in ntdll!KiUserExceptionDispatcher ()
>    from /cygdrive/c/windows/system32/ntdll.dll
> #10 0x0028a6ac in ?? ()
> #11 0x61138c75 in fwrite () from /usr/bin/cygwin1.dll
> #12 0x610d75e5 in _sigfe () from /usr/bin/cygwin1.dll
> #13 0x0000000d in ?? ()
> #14 0x00000000 in ?? ()
> 
> does not give any useful clues where the segment faults arise.
> So what is wrong?

My crystal ball says you are looking at the wrong thread.  Try "thread
apply all backtrace".