From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7225 invoked by alias); 15 Mar 2012 04:14:59 -0000 Received: (qmail 7085 invoked by uid 22791); 15 Mar 2012 04:14:56 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 15 Mar 2012 04:14:43 +0000 From: "jason at cornsyrup dot org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/52590] std::thread Segmentation fault static linking Date: Thu, 15 Mar 2012 04:47:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jason at cornsyrup dot org X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-03/txt/msg01309.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52590 --- Comment #3 from Jason Toffaletti 2012-03-15 04:14:40 UTC --- $ g++-4.7 -Wl,-M -v -static -pthread -std=c++0x -o thread thread.cc shows all of libpthread being linked. With a bit more digging I traced the problem to /usr/include/c++/4.7.0/x86_64-linux-gnu/bits/gthr-posix.h declaring all of its symbols with __attribute__((weakref)) even when linking statically. Which caused the __gthread_* symbols to resolve to zero. I found this for some background info http://gcc.gnu.org/ml/gcc/2005-10/msg00235.html This change made my example work: $ g++ -D_GLIBCXX_GTHREAD_USE_WEAK=0 -static -pthread -std=c++0x -o thread thread.cc $ ./thread pthread_create works std::thread works However, if I change the code to call std::thread::detach instead of join, then it crashes again with std::thread::detach being resolved to zero. Program received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () (gdb) bt #0 0x0000000000000000 in ?? () #1 0x0000000000439785 in std::thread::detach() () #2 0x0000000000401f52 in main ()