From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 520 invoked by alias); 27 Jan 2010 00:08:37 -0000 Received: (qmail 512 invoked by uid 22791); 27 Jan 2010 00:08:37 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 27 Jan 2010 00:08:29 +0000 Received: (qmail 1440 invoked from network); 27 Jan 2010 00:08:28 -0000 Received: from unknown (HELO caradoc.them.org) (dan@127.0.0.2) by mail.codesourcery.com with ESMTPA; 27 Jan 2010 00:08:28 -0000 Date: Wed, 27 Jan 2010 00:08:00 -0000 From: Daniel Jacobowitz To: "H.J. Lu" Cc: GDB Subject: Re: Is CLONE_VM really needed in gdbserver? Message-ID: <20100127000821.GA29862@caradoc.them.org> Mail-Followup-To: "H.J. Lu" , GDB References: <6dc9ffc81001261551j6221db6v88e96713d6dd9497@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6dc9ffc81001261551j6221db6v88e96713d6dd9497@mail.gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) 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: 2010-01/txt/msg00195.txt.bz2 On Tue, Jan 26, 2010 at 03:51:38PM -0800, H.J. Lu wrote: > Hi, > > There is a race condition between gdbserver and ld.so on Linux/x86-64: > > http://www.sourceware.org/bugzilla/show_bug.cgi?id=11214 > > Is CLONE_VM really needed? In general, CLONE_VM is a very bad > idea if there is any symbol lookup in both parent and child processes. It is necessary because gdbserver supports uClinux. However, on Linux we might be able to get away with fork (see linux_tracefork_child in gdb/linux-nat.c). -- Daniel Jacobowitz CodeSourcery