From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14445 invoked by alias); 30 Aug 2012 16:11:31 -0000 Received: (qmail 14432 invoked by uid 22791); 30 Aug 2012 16:11:28 -0000 X-SWARE-Spam-Status: No, hits=-3.5 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED,RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from server-nat-6.cs.umd.edu (HELO bacon.cs.umd.edu) (128.8.127.149) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 30 Aug 2012 16:11:16 +0000 Received: from wireless-206-196-164-53.umd.edu (wireless-206-196-164-53.umd.edu [206.196.164.53]) (Authenticated sender: khooyp) by bacon.cs.umd.edu (Postfix) with ESMTPSA id 3CD08B40228; Thu, 30 Aug 2012 12:11:03 -0400 (EDT) Subject: Re: Disable -lmcheck when Python has threads (Re: [BUG] gdb crash when "python import gtk") Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii From: Khoo Yit Phang In-Reply-To: <41429A68-82EE-4B57-BAB3-559D2907A71B@cs.umd.edu> Date: Thu, 30 Aug 2012 16:11:00 -0000 Cc: Jan Kratochvil , Hui Zhu , gdb@sourceware.org Content-Transfer-Encoding: quoted-printable Message-Id: <2E2CF815-7C3F-40D1-A8FB-CEB190731F20@cs.umd.edu> References: <20120719073959.GA10044@host2.jankratochvil.net> <20120830160438.GA25469@host2.jankratochvil.net> <41429A68-82EE-4B57-BAB3-559D2907A71B@cs.umd.edu> To: Khoo Yit Phang X-CSD-MailScanner-ID: 3CD08B40228.A63CD X-CSD-MailScanner: Found to be clean X-CSD-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-50, required 5, autolearn=not spam, ALL_TRUSTED -50.00) X-CSD-MailScanner-From: khooyp@cs.umd.edu X-CSD-MailScanner-Watermark: 1346947865.26676@ysJSUhC+Uz37mOsFRUbJqA Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2012-08/txt/msg00098.txt.bz2 Hi, Here's the corresponding bug report for glibc stating that it is by design:= http://sourceware.org/bugzilla/show_bug.cgi?id=3D9939 Yit August 30, 2012 On Aug 30, 2012, at 12:08 PM, Khoo Yit Phang wrote: > Hi, >=20 > On Aug 30, 2012, at 12:04 PM, Jan Kratochvil wrote: >=20 >> Hi, >>=20 >> On Thu, 30 Aug 2012 18:00:46 +0200, Khoo Yit Phang wrote: >>> I ran into a similar issue as below and tracked it down: the "memory >>> clobbered before allocated block" (and other related messages) because >>> -lmcheck is not thread safe, and triggers spuriously when threads are u= sed >>> in Python (e.g., the "gtk" module). >>=20 >> this needs some references to glibc/gtk/python maintainers statements et= c. >>=20 >> -lmcheck is AFAIK thread safe in glibc itself. >=20 > -lmcheck is definitely not thread safe, at least as of glibc 2.13 (Ubuntu= 11.04). See the first answer of http://stackoverflow.com/questions/314931/= glibcs-lmcheck-option-and-multithreading. >=20 > Yit > August 30, 2012