From owner-freebsd-questions@FreeBSD.ORG Mon Sep 19 17:57:21 2011 Return-Path: <owner-freebsd-questions@FreeBSD.ORG> Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9EAC4106566B for <freebsd-questions@freebsd.org>; Mon, 19 Sep 2011 17:57:21 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from email2.allantgroup.com (email2.emsphone.com [199.67.51.116]) by mx1.freebsd.org (Postfix) with ESMTP id 62D158FC13 for <freebsd-questions@freebsd.org>; Mon, 19 Sep 2011 17:57:21 +0000 (UTC) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by email2.allantgroup.com (8.14.4/8.14.4) with ESMTP id p8JHvKbZ091949 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for <freebsd-questions@freebsd.org>; Mon, 19 Sep 2011 12:57:20 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (smmsp@localhost [127.0.0.1]) by dan.emsphone.com (8.14.5/8.14.5) with ESMTP id p8JHvKL7070247 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for <freebsd-questions@freebsd.org>; Mon, 19 Sep 2011 12:57:20 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.5/8.14.5/Submit) id p8JHvJC3070245; Mon, 19 Sep 2011 12:57:19 -0500 (CDT) (envelope-from dan) Date: Mon, 19 Sep 2011 12:57:19 -0500 From: Dan Nelson <dnelson@allantgroup.com> To: Unga <unga888@yahoo.com> Message-ID: <20110919175719.GI9801@dan.emsphone.com> References: <1316347805.62034.YahooMailClassic@web160112.mail.bf1.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1316347805.62034.YahooMailClassic@web160112.mail.bf1.yahoo.com> X-OS: FreeBSD 8.2-STABLE User-Agent: Mutt/1.5.21 (2010-09-15) X-Virus-Scanned: clamav-milter 0.97.2 at email2.allantgroup.com X-Virus-Status: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (email2.allantgroup.com [199.67.51.78]); Mon, 19 Sep 2011 12:57:20 -0500 (CDT) X-Scanned-By: MIMEDefang 2.68 on 199.67.51.78 Cc: freebsd-questions@freebsd.org Subject: Re: Segmentation fault, _malloc_prefork () - debugging help needed X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions <freebsd-questions.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, <mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions> List-Post: <mailto:freebsd-questions@freebsd.org> List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, <mailto:freebsd-questions-request@freebsd.org?subject=subscribe> X-List-Received-Date: Mon, 19 Sep 2011 17:57:21 -0000 In the last episode (Sep 18), Unga said: > I'm developing an multi-threaded application on FreeBSD. > > When it is running for sometime, it develops a Segmentation fault. > > The ddd debugger shows following: > Program received signal SIGSEGV, Segmentation fault. > [Switching to Thread 296c6580 (LWP 100137)] > 0x28ee390e in _malloc_prefork () from /lib/libc.so.7 > > How could I know the exact line in source where this issue develops? If you have a full /usr/src tree extracted, you can edit /usr/src/lib/libc/Makefile and add DEBUG_FLAGS=-g at the top, then run "make obj && make depend && make && make install" to install the new libc with debugging symbols. Then your debugger will show more info for functions inside libc. If you don't have a source tree checked out yet, install the devel/subversion-freebsd port, cd into /usr/src/ and run svn co svn://svn.freebsd.org/base/stable/8 . (or base/release/8.2.0, or base/stable/7 or base/head, depending on which version you want; you can browse the branches at http://svnweb.freebsd.org/base/ before you checkout anything) -- Dan Nelson dnelson@allantgroup.com