/* Look up a symbol in a shared object loaded by `dlopen'. Copyright (C) 1999 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <stddef.h> #include <setjmp.h> #include <libintl.h> #include <dlfcn.h> #include <ldsodefs.h> #include <dl-hash.h> void * internal_function _dl_sym (void *handle, const char *name, void *who) { ElfW(Addr) loadbase; const ElfW(Sym) *ref = NULL; if (handle == RTLD_DEFAULT) /* Search the global scope. */ loadbase = _dl_lookup_symbol (name, NULL, &ref, _dl_global_scope, 0); else { struct link_map *l, *match; ElfW(Addr) caller = (ElfW(Addr)) who; /* Find the highest-addressed object that CALLER is not below. */ match = NULL; for (l = _dl_loaded; l; l = l->l_next) if (caller >= l->l_addr && (!match || match->l_addr < l->l_addr)) match = l; if (handle != RTLD_NEXT) { /* Search the scope of the given object. */ struct link_map *map = handle; if (match == NULL) /* If the address is not recognized the call comes from the main program (we hope). */ match = _dl_loaded; loadbase = _dl_lookup_symbol (name, match, &ref, map->l_local_scope, 0); } else { if (! match) _dl_signal_error (0, NULL, _("\ RTLD_NEXT used in code not dynamically loaded")); l = match; while (l->l_loader) l = l->l_loader; loadbase = _dl_lookup_symbol_skip (name, l, &ref, l->l_local_scope, match); } } if (loadbase) return (void *) (loadbase + ref->st_value); return NULL; } void * internal_function _dl_vsym (void *handle, const char *name, const char *version, void *who) { ElfW(Addr) loadbase; const ElfW(Sym) *ref = NULL; struct r_found_version vers; /* Compute hash value to the version string. */ vers.name = version; vers.hidden = 1; vers.hash = _dl_elf_hash (version); /* We don't have a specific file where the symbol can be found. */ vers.filename = NULL; if (handle == RTLD_DEFAULT) /* Search the global scope. */ loadbase = _dl_lookup_versioned_symbol (name, NULL, &ref, _dl_global_scope, &vers, 0); else if (handle == RTLD_NEXT) { struct link_map *l, *match; ElfW(Addr) caller = (ElfW(Addr)) who; /* Find the highest-addressed object that CALLER is not below. */ match = NULL; for (l = _dl_loaded; l; l = l->l_next) if (caller >= l->l_addr && (!match || match->l_addr < l->l_addr)) match = l; if (! match) _dl_signal_error (0, NULL, _("\ RTLD_NEXT used in code not dynamically loaded")); l = match; while (l->l_loader) l = l->l_loader; loadbase = _dl_lookup_versioned_symbol_skip (name, l, &ref, l->l_local_scope, &vers, match); } else { /* Search the scope of the given object. */ struct link_map *map = handle; loadbase = _dl_lookup_versioned_symbol (name, map, &ref, map->l_local_scope, &vers, 0); } if (loadbase) return (void *) (loadbase + ref->st_value); return NULL; }