From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/8876 Path: news.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: some odd library loading errors Date: Tue, 17 Nov 2015 17:34:00 +0100 Message-ID: <20151117163359.GH18372@port70.net> References: <20151117121429.GI26951@example.net> <20151117152355.GF18372@port70.net> <20151117152728.GX3818@brightrain.aerifal.cx> <20151117154515.GG18372@port70.net> <20151117155545.GZ3818@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 1447778060 17688 80.91.229.3 (17 Nov 2015 16:34:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 17 Nov 2015 16:34:20 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-8889-gllmg-musl=m.gmane.org@lists.openwall.com Tue Nov 17 17:34:19 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 1ZyjCv-0007hD-EU for gllmg-musl@m.gmane.org; Tue, 17 Nov 2015 17:34:13 +0100 Original-Received: (qmail 3259 invoked by uid 550); 17 Nov 2015 16:34:12 -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 3241 invoked from network); 17 Nov 2015 16:34:11 -0000 Mail-Followup-To: musl@lists.openwall.com Content-Disposition: inline In-Reply-To: <20151117155545.GZ3818@brightrain.aerifal.cx> User-Agent: Mutt/1.5.24 (2015-08-30) Xref: news.gmane.org gmane.linux.lib.musl.general:8876 Archived-At: * Rich Felker [2015-11-17 10:55:45 -0500]: > On Tue, Nov 17, 2015 at 04:45:16PM +0100, Szabolcs Nagy wrote: > > > > i guess --disable-gnu-indirect-function could be the default when > > gcc targets musl (assuming musl will not implement ifuncs anytime soon). > > I think that's a reasonable assumption. Based on what I've seen > lately, rather than finding solutions to the problems we knew about > already, the rabbit hole keeps going deeper... > > If you have reason to believe otherwise could you explain how we might > reasonably support ifunc? > well we can add support for ifunc by.. calling the ifunc resolver during reloc processing when STT_GNU_IFUNC symbol or R_*_IRELATIVE reloc is found and in case of static linking the relocs between __rel_iplt_{start,end} should be processed somehow. the only ugliness is that passing arguments to the resolver is arch specific.. and that there is no guarantee what the resolver might do (but that's the same with glibc and it is something the user should worry about) i think even if musl does the reloc processing in different order than glibc, this might work in practice and if the resolver crashes we can say that it invoked ub.