From owner-freebsd-current@FreeBSD.ORG  Tue Jan 17 05:58:30 2006
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
X-Original-To: current@freebsd.org
Delivered-To: freebsd-current@FreeBSD.ORG
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 10C2216A41F;
	Tue, 17 Jan 2006 05:58:30 +0000 (GMT)
	(envelope-from scottl@samsco.org)
Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57])
	by mx1.FreeBSD.org (Postfix) with ESMTP id E622943D48;
	Tue, 17 Jan 2006 05:58:21 +0000 (GMT)
	(envelope-from scottl@samsco.org)
Received: from [192.168.254.11] (junior.samsco.home [192.168.254.11])
	(authenticated bits=0)
	by pooker.samsco.org (8.13.4/8.13.4) with ESMTP id k0H5wInf064482;
	Mon, 16 Jan 2006 22:58:18 -0700 (MST)
	(envelope-from scottl@samsco.org)
Message-ID: <43CC877D.2070603@samsco.org>
Date: Mon, 16 Jan 2006 22:58:21 -0700
From: Scott Long <scottl@samsco.org>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.12) Gecko/20051230
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: Daniel Eischen <deischen@freebsd.org>
References: <Pine.GSO.4.43.0601170051260.10462-100000@sea.ntplx.net>
In-Reply-To: <Pine.GSO.4.43.0601170051260.10462-100000@sea.ntplx.net>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
X-Spam-Status: No, score=-1.4 required=3.8 tests=ALL_TRUSTED autolearn=failed 
	version=3.1.0
X-Spam-Checker-Version: SpamAssassin 3.1.0 (2005-09-13) on pooker.samsco.org
Cc: current@freebsd.org
Subject: Re: New malloc breaks old libpthread
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 17 Jan 2006 05:58:30 -0000

Daniel Eischen wrote:
> On Mon, 16 Jan 2006, Doug White wrote:
> 
> 
>>Got this trying to run an old Xorg binary on a -CURRENT machine I don't
>>update very frequently:
>>
>>/libexec/ld-elf.so.1: /usr/lib/libpthread.so.1: Undefined symbol "__malloc_lock"
>>
>>The libpthread.so.1 was from June 2005, prior to the libpthread version
>>bump. Unfortunately this means that RELENG_6 compatibility is broken in
>>-HEAD since the new libc.so.6 is not compatible with libraries built
>>against it prior to the merge date of the new user malloc.
> 
> 
> Don't do that.  We don't guarantee -current libraries built on
> (vastly) different dates will run nicely together.
> 
> 
>>I guess its time libc's version number.  We haven't yet for post-RELENG_6,
>>and this it the usual case calling for the bump.
> 
> 
> No.  There's no need -- this is -current, and we have symbol versioning
> now anyways.
> 
> 

So.......

How exactly does symbol versioning help this case?  It obviously doesn't
magically make all problems go away, so is there a set procude that
one must follow when introducing incompatibilities?  If there is a
procedure, is it published anywhere?

Scott