From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/14565 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: [PATCH] make relocation time symbol lookup and dlsym consistent Date: Tue, 13 Aug 2019 10:38:44 +0200 Message-ID: <20190813083844.GL22009@port70.net> References: <20190810231811.GK22009@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="193233"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.10.1 (2018-07-13) To: musl@lists.openwall.com Original-X-From: musl-return-14581-gllmg-musl=m.gmane.org@lists.openwall.com Tue Aug 13 10:39:01 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 1hxSKZ-000o6a-JD for gllmg-musl@m.gmane.org; Tue, 13 Aug 2019 10:38:59 +0200 Original-Received: (qmail 7783 invoked by uid 550); 13 Aug 2019 08:38:56 -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 7762 invoked from network); 13 Aug 2019 08:38:56 -0000 Mail-Followup-To: musl@lists.openwall.com Content-Disposition: inline In-Reply-To: <20190810231811.GK22009@port70.net> Xref: news.gmane.org gmane.linux.lib.musl.general:14565 Archived-At: * 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. > + return laddr(def.dso, def.sym->st_value); > } > > int dladdr(const void *addr_arg, Dl_info *info) > -- > 2.21.0 >