From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.1 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: from second.openwall.net (second.openwall.net [193.110.157.125]) by inbox.vuxu.org (Postfix) with SMTP id 0DC7B24A99 for ; Wed, 28 Feb 2024 19:36:56 +0100 (CET) Received: (qmail 5178 invoked by uid 550); 28 Feb 2024 18:33:16 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 5146 invoked from network); 28 Feb 2024 18:33:15 -0000 Date: Wed, 28 Feb 2024 13:37:00 -0500 From: Rich Felker To: Max Filippov Cc: musl@lists.openwall.com Message-ID: <20240228183700.GP4163@brightrain.aerifal.cx> References: <20240227232430.GM4163@brightrain.aerifal.cx> <20240228001303.GN4163@brightrain.aerifal.cx> <20240228183032.GO4163@brightrain.aerifal.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240228183032.GO4163@brightrain.aerifal.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Subject: Re: [musl] Initial xtensa/fdpic port review On Wed, Feb 28, 2024 at 01:30:32PM -0500, Rich Felker wrote: > On Wed, Feb 28, 2024 at 09:20:33AM -0800, Max Filippov wrote: > > > > > > p->relocated = 1; > > > > } > > > > @@ -1485,7 +1487,7 @@ void __libc_exit_fini() > > > > if (dyn[0] & (1< > > > size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t); > > > > size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n; > > > > - while (n--) ((void (*)(void))*--fn)(); > > > > + while (n--) fpaddr(p, *--fn)(); > > > > > > If this is fixable on the tooling side it really should be fixed > > > there. init/fini arrays should have actual language-level function > > > addresses (descriptor addresses on fdpic), not instruction addresses. > > > > I read libgcc code at > > https://github.com/jcmvbkbc/gcc-xtensa/blob/xtensa-14-8789-fdpic/libgcc/crtstuff.c#L498-L503 > > and the way it's written suggests that this was done on purpose. > > I put it into the WIP pile to figure out later what the purpose was. > > I thought that SH might not have this issue because it just didn't > > use the .array_init/.array_fini. > > I'm pretty sure we're using it -- musl-cross-make always forces it on > via the gcc configure command line -- but it's possible there's some > override disabling it for sh. I'll try some test cases and confirm > whether sh is doing it right. Maybe the arm folks will have input on > this too..? Confirmed both that it works, and that it's working via init_array. GCC emits: .section .init_array,"aw" .align 2 .long foo@FUNCDESC for __attribute__((__constructor__)) void foo() { ... } Also, FWIW, I believe there's something of an application-facing contract that you can declare function pointer arrays with __attribute__((__section__(".init_array"))) and have them work, which would not work if instruction addresses rather than function addresses are expected to be there. Rich