diff options
Diffstat (limited to 'elf/dl-sym.c')
-rw-r--r-- | elf/dl-sym.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/elf/dl-sym.c b/elf/dl-sym.c new file mode 100644 index 0000000..441b54f --- /dev/null +++ b/elf/dl-sym.c @@ -0,0 +1,129 @@ +/* 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, &ref, _dl_global_scope, NULL, 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_symbol_skip (name, &ref, l->l_local_scope, + NULL, match); + } + else + { + /* Search the scope of the given object. */ + struct link_map *map = handle; + loadbase = _dl_lookup_symbol (name, &ref, map->l_local_scope, + map->l_name, 0); + } + + 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, &ref, _dl_global_scope, + NULL, &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, &ref, + l->l_local_scope, + NULL, &vers, match); + } + else + { + /* Search the scope of the given object. */ + struct link_map *map = handle; + loadbase = _dl_lookup_versioned_symbol (name, &ref, + map->l_local_scope, + map->l_name, &vers, 0); + } + + if (loadbase) + return (void *) (loadbase + ref->st_value); + + return NULL; +} |