From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/14569 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: [PATCH] make relocation time symbol lookup and dlsym consistent Date: Tue, 13 Aug 2019 10:24:24 -0400 Message-ID: <20190813142424.GD9017@brightrain.aerifal.cx> References: <20190810231811.GK22009@port70.net> <20190813083844.GL22009@port70.net> Reply-To: musl@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="59329"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.5.21 (2010-09-15) To: musl@lists.openwall.com Original-X-From: musl-return-14585-gllmg-musl=m.gmane.org@lists.openwall.com Tue Aug 13 16:24:40 2019 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1hxXj6-000FIe-3a for gllmg-musl@m.gmane.org; Tue, 13 Aug 2019 16:24:40 +0200 Original-Received: (qmail 32052 invoked by uid 550); 13 Aug 2019 14:24:37 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 32034 invoked from network); 13 Aug 2019 14:24:36 -0000 Content-Disposition: inline In-Reply-To: <20190813083844.GL22009@port70.net> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:14569 Archived-At: On Tue, Aug 13, 2019 at 10:38:44AM +0200, Szabolcs Nagy wrote: > * Szabolcs Nagy [2019-08-11 01:18:11 +0200]: > > static void *do_dlsym(struct dso *p, const char *s, void *ra) > > { > > - size_t i; > > - uint32_t h = 0, gh = 0, *ght; > > - Sym *sym; > > - if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) { > > - if (p == RTLD_DEFAULT) { > > - p = head; > > - } else if (p == RTLD_NEXT) { > > - p = addr2dso((size_t)ra); > > - if (!p) p=head; > > - p = p->next; > > - } > > - struct symdef def = find_sym(p, s, 0); > > - if (!def.sym) goto failed; > > - if ((def.sym->st_info&0xf) == STT_TLS) > > - return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value-DTP_OFFSET}); > > - if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > - return def.dso->funcdescs + (def.sym - def.dso->syms); > > - return laddr(def.dso, def.sym->st_value); > > - } > > - if (__dl_invalid_handle(p)) > > + int use_deps = 0; > > + if (p == head || p == RTLD_DEFAULT) { > > + p = head; > > + } else if (p == RTLD_NEXT) { > > + p = addr2dso((size_t)ra); > > + if (!p) p=head; > > + p = p->next; > > + } else if (__dl_invalid_handle(p)) { > > return 0; > > - if ((ght = p->ghashtab)) { > > - gh = gnu_hash(s); > > - sym = gnu_lookup(gh, ght, p, s); > > - } else { > > - h = sysv_hash(s); > > - sym = sysv_lookup(s, h, p); > > - } > > - if (sym && (sym->st_info&0xf) == STT_TLS) > > - return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value-DTP_OFFSET}); > > - if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > - return p->funcdescs + (sym - p->syms); > > - if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) > > - return laddr(p, sym->st_value); > > - for (i=0; p->deps[i]; i++) { > > - if ((ght = p->deps[i]->ghashtab)) { > > - if (!gh) gh = gnu_hash(s); > > - sym = gnu_lookup(gh, ght, p->deps[i], s); > > - } else { > > - if (!h) h = sysv_hash(s); > > - sym = sysv_lookup(s, h, p->deps[i]); > > - } > > - if (sym && (sym->st_info&0xf) == STT_TLS) > > - return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value-DTP_OFFSET}); > > - if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC) > > - return p->deps[i]->funcdescs + (sym - p->deps[i]->syms); > > - if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES)) > > - return laddr(p->deps[i], sym->st_value); > > - } > > -failed: > > - error("Symbol not found: %s", s); > > - return 0; > > + } else > > + use_deps = 1; > > + struct symdef def = find_sym2(p, s, 0, use_deps); > > + if (!def.sym) { > > + error("Symbol not found: %s", s); > > + return 0; > > + } > > + if ((def.sym->st_info&0xf) == STT_TLS) > > + return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value-DTP_OFFSET}); > > + if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC) > > + return def.dso->funcdescs + (def.sym - def.dso->syms); > > there is another behaviour change i did not notice before: > > st_shndx is no longer checked in DL_FDPIC case here, i assumed > find_sym did that, but there is no fdpic specific logic there. > > the old code was inconsistent in the RTLD_DEFAULT vs shared lib > dlsym case. > > i dont know if this is relevant for fdpic, i didnt test that case. Thanks for catching. I'll take a look at this. Rich