From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27103 invoked by alias); 27 Apr 2005 22:46:48 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 26267 invoked from network); 27 Apr 2005 22:46:27 -0000 Received: from unknown (HELO mx1.suse.de) (195.135.220.2) by sourceware.org with SMTP; 27 Apr 2005 22:46:27 -0000 Received: from hermes.suse.de (hermes-ext.suse.de [195.135.221.8]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (No client certificate requested) by mx1.suse.de (Postfix) with ESMTP id 5596D160E0F6; Thu, 28 Apr 2005 00:46:27 +0200 (CEST) To: David Lecomber Cc: gdb Subject: Re: GDB locks up -- Cannot find new threads: generic error References: <1114627357.31720.81.camel@cpc4-oxfd5-5-0-cust111.oxfd.cable.ntl.com> <20050427190108.GA28978@nevyn.them.org> From: Andreas Schwab X-Yow: Is it clean in other dimensions? Date: Wed, 27 Apr 2005 22:51:00 -0000 In-Reply-To: <20050427190108.GA28978@nevyn.them.org> (Daniel Jacobowitz's message of "Wed, 27 Apr 2005 15:01:09 -0400") Message-ID: User-Agent: Gnus/5.110002 (No Gnus v0.2) Emacs/22.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-SW-Source: 2005-04/txt/msg00204.txt.bz2 Daniel Jacobowitz writes: > On Wed, Apr 27, 2005 at 07:42:37PM +0100, David Lecomber wrote: >> (gdb) b main >> Breakpoint 1 at 0x804ed18: file >> main.cpp, line 10. >> (gdb) run >> Starting program: a.out >> warning: linux_test_for_tracefork: unexpected result from waitpid >> (28261, >> status 0x117f) >> [Thread debugging using libthread_db enabled] >> Error while reading shared library symbols: >> Cannot find new threads: generic error >> >> at this point GDB does nothing and is unresponsive to any user input. >> >> The system is: >> kernel-2.4.21-27.EL >> glibc-2.3.2-95.30 > > At a guess, your kernel is buggered. You really should never see that > warning. The unexpected signal is SIGCHLD; your kernel has accepted > the SETOPTIONS but obviously failed to stop when the test thread > vforked. I think that can happen when the 32 bit ptrace emulation is incomplete, especially if PTRACE_GETEVENTMSG is not properly emulated. That should be fixed in recent (< 9 months) kernels. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."