1 /* Handle symbol and library versioning.
2 Copyright (C) 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
28 #include <stdio-common/_itoa.h>
31 /* Set in rtld.c at startup. */
32 extern char **_dl_argv;
34 #define VERSTAG(tag) (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (tag))
37 #define make_string(string, rest...) \
39 const char *all[] = { string, ## rest }; \
44 for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \
45 len += strlen (all[cnt]); \
47 cp = result = alloca (len); \
48 for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \
49 cp = __stpcpy (cp, all[cnt]); \
55 static inline struct link_map *
56 find_needed (const char *name, struct link_map *map)
58 struct link_map *tmap;
61 for (tmap = _dl_loaded; tmap != NULL; tmap = tmap->l_next)
62 if (_dl_name_match_p (name, tmap))
65 /* The required object is not in the global scope, look to see if it is
66 a dependency of the current object. */
67 for (n = 0; n < map->l_nsearchlist; n++)
68 if (_dl_name_match_p (name, map->l_searchlist[n]))
69 return map->l_searchlist[n];
71 /* Should never happen. */
77 match_symbol (const char *name, ElfW(Word) hash, const char *string,
78 struct link_map *map, int verbose, int weak)
80 const char *strtab = (const char *) (map->l_addr
81 + map->l_info[DT_STRTAB]->d_un.d_ptr);
82 ElfW(Addr) def_offset;
85 if (map->l_info[VERSTAG (DT_VERDEF)] == NULL)
87 /* The file has no symbol versioning. I.e., the dependent
88 object was linked against another version of this file. We
89 only print a message if verbose output is requested. */
91 _dl_signal_error (0, map->l_name, make_string ("\
92 no version information available (required by ",
97 def_offset = map->l_info[VERSTAG (DT_VERDEF)]->d_un.d_ptr;
98 assert (def_offset != 0);
100 def = (ElfW(Verdef) *) ((char *) map->l_addr + def_offset);
103 /* Currently the version number of the definition entry is 1.
104 Make sure all we see is this version. */
105 if (def->vd_version != 1)
108 buf[sizeof (buf) - 1] = '\0';
109 _dl_signal_error (0, map->l_name,
110 make_string ("unsupported version ",
111 _itoa_word (def->vd_version,
112 &buf[sizeof (buf) - 1],
114 " of Verdef record"));
118 /* Compare the hash values. */
119 if (hash == def->vd_hash)
121 ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
123 /* To be safe, compare the string as well. */
124 if (strcmp (string, strtab + aux->vda_name) == 0)
129 /* If no more definitions we failed to find what we want. */
130 if (def->vd_next == 0)
133 /* Next definition. */
134 def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
137 /* Symbol not found. If it was a weak reference it is not fatal. */
141 _dl_signal_error (0, map->l_name,
142 make_string ("weak version `", string,
143 "' not found (required by ", name,
148 _dl_signal_error (0, map->l_name,
149 make_string ("version `", string,
150 "' not found (required by ", name, ")"));
156 _dl_check_map_versions (struct link_map *map, int verbose)
160 /* Pointer to section with needed versions. */
162 /* Pointer to dynamic section with definitions. */
164 /* We need to find out which is the highest version index used
166 unsigned int ndx_high = 0;
168 /* If we don't have a string table, we must be ok. */
169 if (map->l_info[DT_STRTAB] == NULL)
171 strtab = (const char *) (map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr);
173 dyn = map->l_info[VERSTAG (DT_VERNEED)];
174 def = map->l_info[VERSTAG (DT_VERDEF)];
178 /* This file requires special versions from its dependencies. */
179 ElfW(Verneed) *ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
181 /* Currently the version number of the needed entry is 1.
182 Make sure all we see is this version. */
183 if (ent->vn_version != 1)
186 buf[sizeof (buf) - 1] = '\0';
187 _dl_signal_error (0, (*map->l_name ? map->l_name : _dl_argv[0]),
188 make_string ("unsupported version ",
189 _itoa_word (ent->vn_version,
190 &buf[sizeof (buf) - 1],
192 " of Verneed record\n"));
199 struct link_map *needed = find_needed (strtab + ent->vn_file, map);
201 /* If NEEDED is NULL this means a dependency was not found
202 and no stub entry was created. This should never happen. */
203 assert (needed != NULL);
205 /* NEEDED is the map for the file we need. Now look for the
206 dependency symbols. */
207 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
210 /* Match the symbol. */
211 result |= match_symbol ((*map->l_name
212 ? map->l_name : _dl_argv[0]),
214 strtab + aux->vna_name,
216 aux->vna_flags & VER_FLG_WEAK);
218 /* Compare the version index. */
219 if ((unsigned int) (aux->vna_other & 0x7fff) > ndx_high)
220 ndx_high = aux->vna_other & 0x7fff;
222 if (aux->vna_next == 0)
223 /* No more symbols. */
227 aux = (ElfW(Vernaux) *) ((char *) aux + aux->vna_next);
230 if (ent->vn_next == 0)
231 /* No more dependencies. */
234 /* Next dependency. */
235 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
239 /* We also must store the names of the defined versions. Determine
240 the maximum index here as well.
242 XXX We could avoid the loop by just taking the number of definitions
243 as an upper bound of new indeces. */
247 ent = (ElfW(Verdef) *) (map->l_addr + def->d_un.d_ptr);
250 if ((unsigned int) (ent->vd_ndx & 0x7fff) > ndx_high)
251 ndx_high = ent->vd_ndx & 0x7fff;
253 if (ent->vd_next == 0)
254 /* No more definitions. */
257 ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next);
263 /* Now we are ready to build the array with the version names
264 which can be indexed by the version index in the VERSYM
266 map->l_versions = (struct r_found_version *)
267 calloc (ndx_high + 1, sizeof (*map->l_versions));
268 if (map->l_versions == NULL)
270 _dl_signal_error (ENOMEM, (*map->l_name ? map->l_name : _dl_argv[0]),
271 "cannot allocate version reference table");
276 /* Store the number of available symbols. */
277 map->l_nversions = ndx_high + 1;
282 ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr);
286 aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux);
289 ElfW(Half) ndx = aux->vna_other & 0x7fff;
290 map->l_versions[ndx].hash = aux->vna_hash;
291 map->l_versions[ndx].hidden = aux->vna_other & 0x8000;
292 map->l_versions[ndx].name = &strtab[aux->vna_name];
293 map->l_versions[ndx].filename = &strtab[ent->vn_file];
295 if (aux->vna_next == 0)
296 /* No more symbols. */
299 /* Advance to next symbol. */
300 aux = (ElfW(Vernaux) *) ((char *) aux + aux->vna_next);
303 if (ent->vn_next == 0)
304 /* No more dependencies. */
307 /* Advance to next dependency. */
308 ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next);
312 /* And insert the defined versions. */
316 ent = (ElfW(Verdef) *) (map->l_addr + def->d_un.d_ptr);
320 aux = (ElfW(Verdaux) *) ((char *) ent + ent->vd_aux);
322 if ((ent->vd_flags & VER_FLG_BASE) == 0)
324 /* The name of the base version should not be
325 available for matching a versioned symbol. */
326 ElfW(Half) ndx = ent->vd_ndx & 0x7fff;
327 map->l_versions[ndx].hash = ent->vd_hash;
328 map->l_versions[ndx].name = &strtab[aux->vda_name];
329 map->l_versions[ndx].filename = NULL;
332 if (ent->vd_next == 0)
333 /* No more definitions. */
336 ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next);
347 _dl_check_all_versions (struct link_map *map, int verbose)
352 for (l = map; l != NULL; l = l->l_next)
353 result |= l->l_opencount != 0 && _dl_check_map_versions (l, verbose);