Update.
[glibc.git] / elf / dlvsym.c
blobcee0e7f36bc5ae19b9364f68bfbb9d317bacc1de
1 /* Look up a versioned 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. */
20 #include <dlfcn.h>
21 #include <setjmp.h>
22 #include <stddef.h>
23 #include <elf/ldsodefs.h>
25 #include <dl-hash.h>
27 struct dlvsym_args
29 /* The arguments to dlvsym_doit. */
30 void *handle;
31 const char *name;
32 struct r_found_version version;
33 ElfW(Addr) caller;
34 /* The return values of dlvsym_doit. */
35 ElfW(Addr) loadbase;
36 const ElfW(Sym) *ref;
40 static void
41 dlvsym_doit (void *a)
43 struct dlvsym_args *args = (struct dlvsym_args *)a;
44 args->ref = NULL;
46 if (args->handle == RTLD_DEFAULT)
47 /* Search the global scope. */
48 args->loadbase = _dl_lookup_versioned_symbol (args->name, &args->ref,
49 _dl_global_scope,
50 NULL, &args->version, 0);
51 else if (args->handle == RTLD_NEXT)
53 struct link_map *l, *match;
55 /* Find the highest-addressed object that CALLER is not below. */
56 match = NULL;
57 for (l = _dl_loaded; l; l = l->l_next)
58 if (args->caller >= l->l_addr && (!match || match->l_addr < l->l_addr))
59 match = l;
61 if (! match)
62 _dl_signal_error (0, NULL, _("\
63 RTLD_NEXT used in code not dynamically loaded"));
65 l = match;
66 while (l->l_loader)
67 l = l->l_loader;
69 args->loadbase = _dl_lookup_versioned_symbol_skip (args->name,
70 &args->ref,
71 l->l_local_scope,
72 NULL, &args->version,
73 match);
75 else
77 /* Search the scope of the given object. */
78 struct link_map *map = args->handle;
79 args->loadbase = _dl_lookup_versioned_symbol (args->name, &args->ref,
80 map->l_local_scope,
81 map->l_name,
82 &args->version, 0);
86 void *
87 __dlvsym (void *handle, const char *name, const char *version_str)
89 struct dlvsym_args args;
91 args.handle = handle;
92 args.name = name;
93 args.caller = (ElfW(Addr)) __builtin_return_address (0);
95 /* Compute hash value to the version string. */
96 args.version.name = version_str;
97 args.version.hidden = 1;
98 args.version.hash = _dl_elf_hash (version_str);
99 /* We don't have a specific file where the symbol can be found. */
100 args.version.filename = NULL;
102 return (_dlerror_run (dlvsym_doit, &args)
103 ? NULL : (void *) (args.loadbase + args.ref->st_value));
105 weak_alias (__dlvsym, dlvsym)