Date: Wed, 5 Nov 2008 12:28:45 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-7@freebsd.org Subject: svn commit: r184684 - stable/7/libexec/rtld-elf Message-ID: <200811051228.mA5CSjSf026889@svn.freebsd.org>
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Author: kib Date: Wed Nov 5 12:28:44 2008 New Revision: 184684 URL: http://svn.freebsd.org/changeset/base/184684 Log: MFC r183737 (by kan): Allow strong symbols to override weak ones for lookups done through dlsym with RTLD_NEXT/RTLD_SELF handles. Allow symbols from ld-elf.so to be located this way too. Approved by: re (kensmith), kan Modified: stable/7/libexec/rtld-elf/ (props changed) stable/7/libexec/rtld-elf/rtld.c Modified: stable/7/libexec/rtld-elf/rtld.c ============================================================================== --- stable/7/libexec/rtld-elf/rtld.c Wed Nov 5 12:13:10 2008 (r184683) +++ stable/7/libexec/rtld-elf/rtld.c Wed Nov 5 12:28:44 2008 (r184684) @@ -1891,7 +1891,7 @@ do_dlsym(void *handle, const char *name, { DoneList donelist; const Obj_Entry *obj, *defobj; - const Elf_Sym *def; + const Elf_Sym *def, *symp; unsigned long hash; int lockstate; @@ -1917,9 +1917,26 @@ do_dlsym(void *handle, const char *name, if (handle == RTLD_NEXT) obj = obj->next; for (; obj != NULL; obj = obj->next) { - if ((def = symlook_obj(name, hash, obj, ve, flags)) != NULL) { - defobj = obj; - break; + if ((symp = symlook_obj(name, hash, obj, ve, flags)) != NULL) { + if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) { + def = symp; + defobj = obj; + if (ELF_ST_BIND(def->st_info) != STB_WEAK) + break; + } + } + } + /* + * Search the dynamic linker itself, and possibly resolve the + * symbol from there. This is how the application links to + * dynamic linker services such as dlopen. Only the values listed + * in the "exports" array can be resolved from the dynamic linker. + */ + if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { + symp = symlook_obj(name, hash, &obj_rtld, ve, flags); + if (symp != NULL && is_exported(symp)) { + def = symp; + defobj = &obj_rtld; } } } else {
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