From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/7808 Path: news.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: Progress since 1.1.9 Date: Thu, 28 May 2015 13:45:15 +0200 Message-ID: <20150528114437.GK20259@port70.net> References: <20150527231308.GA10123@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 1432813579 19088 80.91.229.3 (28 May 2015 11:46:19 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 28 May 2015 11:46:19 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-7820-gllmg-musl=m.gmane.org@lists.openwall.com Thu May 28 13:46:19 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 1YxwGQ-0005Ws-7w for gllmg-musl@m.gmane.org; Thu, 28 May 2015 13:46:18 +0200 Original-Received: (qmail 5508 invoked by uid 550); 28 May 2015 11:46:11 -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 5490 invoked from network); 28 May 2015 11:46:10 -0000 Mail-Followup-To: musl@lists.openwall.com Content-Disposition: inline In-Reply-To: <20150527231308.GA10123@brightrain.aerifal.cx> User-Agent: Mutt/1.5.23 (2014-03-12) Xref: news.gmane.org gmane.linux.lib.musl.general:7808 Archived-At: * Rich Felker [2015-05-27 19:13:08 -0400]: > The one roadmap item I don't have any progress on is what to do with > the libgcc_s symbol version mess, and I think we should probably just > hold off until the next release cycle for that now. in case anyone wonders about the issue: libgcc_s has a symbolic reference to an internal deprecated symbol with no default version on x86 (in gcc trunk). (so no @version only @@version which makes it invisible to musl and ld). the deprecated function is a constructor in libgcc_s that initializes an unused struct in libgcc_s. the only reason the symbol got versioned this way is because they want old binaries to work and remove the symbol from libgcc_s for new binaries, while still using the same symbol name in new binaries but with different abi behaviour: now it's only available in libgcc.a to fix their ifunc hack for multi-versioning. since it's a symbol internal to libgcc and the semantics of the symbol changed they could have just used a new name and left the old one alone (so old stuff is guaranteed to not break including musl and new binaries use the new symbol with new semantics). so i still think my proposed libgcc patch makes more sense than versioning: https://gcc.gnu.org/ml/gcc-patches/2015-05/msg00899.html gcc is unlikely to fix this, but this is a nonsense usecase (and there is no other known use of versioning that is broken with musl.. in theory other libs may deprecate symbols in a similar way while still keeping symbolic references to them, but such use was not yet observed). in musl-gcc it can be worked around by preloading a noop __cpu_indicator_init and in a musl based gcc it can be patched out.