1 /* Look up a symbol in a shared object loaded by `dlopen'.
2 Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
23 #include <elf/ldsodefs.h>
27 /* The arguments to dlsym_doit. */
30 struct r_found_version version;
32 /* The return values of dlsym_doit. */
41 struct dlsym_args *args = (struct dlsym_args *) a;
44 if (args->handle == NULL)
45 /* Search the global scope. */
46 args->loadbase = _dl_lookup_symbol (args->name, &args->ref,
48 ?: _dl_default_scope)[2],
50 else if (args->handle == RTLD_NEXT)
52 struct link_map *l, *match;
54 /* Find the highest-addressed object that CALLER is not below. */
56 for (l = _dl_loaded; l; l = l->l_next)
57 if (args->caller >= l->l_addr && (!match || match->l_addr < l->l_addr))
61 _dl_signal_error (0, NULL, _("\
62 RTLD_NEXT used in code not dynamically loaded"));
69 struct link_map *mapscope[2] = { l, NULL };
70 args->loadbase = _dl_lookup_symbol_skip (args->name, &args->ref,
71 mapscope, NULL, match);
76 /* Search the scope of the given object. */
77 struct link_map *map = args->handle;
78 struct link_map *mapscope[2] = { map, NULL };
79 args->loadbase = _dl_lookup_symbol (args->name, &args->ref, mapscope,
86 dlsym (void *handle, const char *name)
88 struct dlsym_args args;
89 args.caller = (ElfW(Addr)) __builtin_return_address (0);
93 return (_dlerror_run (dlsym_doit, &args)
94 ? NULL : (void *) (args.loadbase + args.ref->st_value));