From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32103 invoked by alias); 30 Jul 2015 17:46:26 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 32093 invoked by uid 89); 30 Jul 2015 17:46:25 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-la0-f65.google.com Received: from mail-la0-f65.google.com (HELO mail-la0-f65.google.com) (209.85.215.65) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Thu, 30 Jul 2015 17:46:24 +0000 Received: by laah7 with SMTP id h7so2038147laa.1 for ; Thu, 30 Jul 2015 10:46:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=gY1wDeL9kgQHtD60Mk7ck4deMnf8bacTxNqO6KvbKGw=; b=VDu3hbP+GZ0/cCLa0yu1/0WPx4sx1g2Jpmh3TqIjL3a071WVZM1+nebooQwQElAHAw V9d+PMZWtYjqNgv0bSGatceqPVmJpUaG1HkMyYuONqIHE4lNeGpuFwYgXM8z2csF6pDA DordI6rBe/9GrYEJQ7FBdIYcIo6jnepVn8znUKH51JOmXVXp7MUOXYkuduEZfgzO+84l /VjiGWGXHAAJNJWHZWxydyRhRQrQDl2ihdV1vBGM6gpzEiSCfRPeu9ZfYlXdRxyKD+0z z4D7hTKpFdHlvDayUpCGP+EYjCw/b7MSK4xFr2LYtKnc83EZsiNG7jbMIwFEwdSkApr3 I+kQ== X-Gm-Message-State: ALoCoQk44YItdR0S0nMWqDpBSYEmj+483d/kM94jcTUq5bJZOe5MWxOXwVPBZ/DFe0oO0F7gOzIp MIME-Version: 1.0 X-Received: by 10.113.10.164 with SMTP id eb4mr46287275lbd.9.1438278380610; Thu, 30 Jul 2015 10:46:20 -0700 (PDT) Received: by 10.152.110.129 with HTTP; Thu, 30 Jul 2015 10:46:20 -0700 (PDT) In-Reply-To: <55BA373A.4020909@dronecode.org.uk> References: <55BA373A.4020909@dronecode.org.uk> Date: Thu, 30 Jul 2015 17:46:00 -0000 Message-ID: Subject: Re: Analyzing a SEG FAULT that gdb doesn't help with From: Michael Enright To: cygwin@cygwin.com Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2015-07/txt/msg00459.txt.bz2 On Thu, Jul 30, 2015 at 7:39 AM, Jon TURNEY wrote: > You need to install the 'cygwin-debuginfo' package for debug symbols for > cygwin1.dll I missed this in my searches. I see now that I should have used the "debug" category. > > You also need to point addr2line at those detached debug symbols, as (unlike > gdb) it doesn't follow .gnu_debuglink pointers. > > (I'm assuming you've typoed 6155d363 here and it should be 0x6115D363 as the > strace output says) I've been having trouble getting that number right > > # addr2line -e /usr/lib/debug/usr/bin/cygwin1.dbg 0x6115D363 > /usr/src/debug/cygwin-2.1.0-1/newlib/libc/machine/i386/strlen.S:64 Another problem is that there's only one stack frame in the stack dump, so knowing that it's a strlen just means I have to crank out some grep commands and hopefully one of them is vulnerable to a special case that now happens all the time. > > Are you sure the crashing process is the direct > inferior of gdb, and not some wrapper process which runs it? (uninstalled > libtool generated binaries do this, for e.g.) > The crashing executable is just a client of SpiderMonkey (via libmozjs185) with several extensions to JavaScript in order to emulate some of the Windows cscript utility and to emulate another environment that happens to be a massive annoyance to run scripts in. The executable is built using a textbook Makefile. -- 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