From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/7614 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: Should we support (not use, support) symbol versioning? Date: Sat, 9 May 2015 22:18:38 -0400 Message-ID: <20150510021838.GM17573@brightrain.aerifal.cx> References: <20150510010359.GA8002@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1431224337 16928 80.91.229.3 (10 May 2015 02:18:57 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 10 May 2015 02:18:57 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-7627-gllmg-musl=m.gmane.org@lists.openwall.com Sun May 10 04:18:53 2015 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1YrGpQ-0003zD-S9 for gllmg-musl@m.gmane.org; Sun, 10 May 2015 04:18:53 +0200 Original-Received: (qmail 28283 invoked by uid 550); 10 May 2015 02:18:51 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 28265 invoked from network); 10 May 2015 02:18:50 -0000 Content-Disposition: inline In-Reply-To: <20150510010359.GA8002@brightrain.aerifal.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:7614 Archived-At: On Sat, May 09, 2015 at 09:03:59PM -0400, Rich Felker wrote: > What we could possibly do, however, is honor the version requested > whenever the library being searched has version information. This > would allow third-party libraries that want to use versioning to do so > while also allowing unversioned libraries to satisfy any program or > library using them (and work correctly as long as it's using the > latest version API, just like now). However I'm mildly concerned that > symbol version tables could get introduced into libraries that don't > want them (including into libc.so) which would then horribly break > things, e.g. if any of libgcc.a's symbols were versioned (in principle > this should not happen, because they're all supposed to be hidden, but > I'm not really happy relying on that). This risk is eliminated just by adding ldso.versym=0; after decode_dyn(&ldso) in the dynamic linker code, to ensure that any version tables that happen to creep into libc.so/ldso are ignored. Rich