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c84142e8 | 1 | /* Handle symbol and library versioning. |
04277e02 | 2 | Copyright (C) 1997-2019 Free Software Foundation, Inc. |
c84142e8 UD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
c84142e8 UD |
10 | |
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 | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
c84142e8 | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
c84142e8 UD |
19 | |
20 | #include <elf.h> | |
21 | #include <errno.h> | |
8e17ea58 | 22 | #include <libintl.h> |
c84142e8 UD |
23 | #include <stdlib.h> |
24 | #include <string.h> | |
a42195db | 25 | #include <ldsodefs.h> |
eb96ffb0 | 26 | #include <_itoa.h> |
c84142e8 | 27 | |
a853022c UD |
28 | #include <assert.h> |
29 | ||
c84142e8 | 30 | static inline struct link_map * |
dd9423a6 | 31 | __attribute ((always_inline)) |
762a2918 | 32 | find_needed (const char *name, struct link_map *map) |
c84142e8 | 33 | { |
26b4d766 | 34 | struct link_map *tmap; |
c84142e8 UD |
35 | unsigned int n; |
36 | ||
c0f62c56 UD |
37 | for (tmap = GL(dl_ns)[map->l_ns]._ns_loaded; tmap != NULL; |
38 | tmap = tmap->l_next) | |
26b4d766 UD |
39 | if (_dl_name_match_p (name, tmap)) |
40 | return tmap; | |
c84142e8 | 41 | |
762a2918 UD |
42 | /* The required object is not in the global scope, look to see if it is |
43 | a dependency of the current object. */ | |
be935610 UD |
44 | for (n = 0; n < map->l_searchlist.r_nlist; n++) |
45 | if (_dl_name_match_p (name, map->l_searchlist.r_list[n])) | |
46 | return map->l_searchlist.r_list[n]; | |
762a2918 | 47 | |
c84142e8 UD |
48 | /* Should never happen. */ |
49 | return NULL; | |
50 | } | |
51 | ||
52 | ||
53 | static int | |
75a142a2 | 54 | match_symbol (const char *name, Lmid_t ns, ElfW(Word) hash, const char *string, |
c84142e8 UD |
55 | struct link_map *map, int verbose, int weak) |
56 | { | |
a42195db | 57 | const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); |
714a562f | 58 | ElfW(Addr) def_offset; |
c84142e8 | 59 | ElfW(Verdef) *def; |
6ed623f8 | 60 | /* Initialize to make the compiler happy. */ |
6ed623f8 | 61 | int result = 0; |
2449ae7b | 62 | struct dl_exception exception; |
c84142e8 | 63 | |
8193034b | 64 | /* Display information about what we are doing while debugging. */ |
a1ffb40e | 65 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_VERSIONS)) |
154d10bd | 66 | _dl_debug_printf ("\ |
75a142a2 | 67 | checking for version `%s' in file %s [%lu] required by file %s [%lu]\n", |
b9375348 | 68 | string, DSO_FILENAME (map->l_name), |
75a142a2 | 69 | map->l_ns, name, ns); |
8193034b | 70 | |
a1ffb40e | 71 | if (__glibc_unlikely (map->l_info[VERSYMIDX (DT_VERDEF)] == NULL)) |
c84142e8 UD |
72 | { |
73 | /* The file has no symbol versioning. I.e., the dependent | |
74 | object was linked against another version of this file. We | |
75 | only print a message if verbose output is requested. */ | |
76 | if (verbose) | |
6ed623f8 UD |
77 | { |
78 | /* XXX We cannot translate the messages. */ | |
2449ae7b FW |
79 | _dl_exception_create_format |
80 | (&exception, DSO_FILENAME (map->l_name), | |
81 | "no version information available (required by %s)", name); | |
6ed623f8 UD |
82 | goto call_cerror; |
83 | } | |
c84142e8 UD |
84 | return 0; |
85 | } | |
86 | ||
f420344c | 87 | def_offset = map->l_info[VERSYMIDX (DT_VERDEF)]->d_un.d_ptr; |
714a562f UD |
88 | assert (def_offset != 0); |
89 | ||
90 | def = (ElfW(Verdef) *) ((char *) map->l_addr + def_offset); | |
c84142e8 UD |
91 | while (1) |
92 | { | |
93 | /* Currently the version number of the definition entry is 1. | |
94 | Make sure all we see is this version. */ | |
7b228b68 | 95 | if (__builtin_expect (def->vd_version, 1) != 1) |
c84142e8 UD |
96 | { |
97 | char buf[20]; | |
98 | buf[sizeof (buf) - 1] = '\0'; | |
8e17ea58 | 99 | /* XXX We cannot translate the message. */ |
2449ae7b FW |
100 | _dl_exception_create_format |
101 | (&exception, DSO_FILENAME (map->l_name), | |
102 | "unsupported version %s of Verdef record", | |
103 | _itoa (def->vd_version, &buf[sizeof (buf) - 1], 10, 0)); | |
6ed623f8 UD |
104 | result = 1; |
105 | goto call_cerror; | |
c84142e8 UD |
106 | } |
107 | ||
108 | /* Compare the hash values. */ | |
109 | if (hash == def->vd_hash) | |
110 | { | |
111 | ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux); | |
112 | ||
113 | /* To be safe, compare the string as well. */ | |
7b228b68 UD |
114 | if (__builtin_expect (strcmp (string, strtab + aux->vda_name), 0) |
115 | == 0) | |
c84142e8 UD |
116 | /* Bingo! */ |
117 | return 0; | |
118 | } | |
119 | ||
120 | /* If no more definitions we failed to find what we want. */ | |
121 | if (def->vd_next == 0) | |
122 | break; | |
123 | ||
124 | /* Next definition. */ | |
125 | def = (ElfW(Verdef) *) ((char *) def + def->vd_next); | |
126 | } | |
127 | ||
128 | /* Symbol not found. If it was a weak reference it is not fatal. */ | |
a1ffb40e | 129 | if (__glibc_likely (weak)) |
c84142e8 UD |
130 | { |
131 | if (verbose) | |
6ed623f8 UD |
132 | { |
133 | /* XXX We cannot translate the message. */ | |
2449ae7b FW |
134 | _dl_exception_create_format |
135 | (&exception, DSO_FILENAME (map->l_name), | |
136 | "weak version `%s' not found (required by %s)", string, name); | |
6ed623f8 UD |
137 | goto call_cerror; |
138 | } | |
c84142e8 UD |
139 | return 0; |
140 | } | |
141 | ||
8e17ea58 | 142 | /* XXX We cannot translate the message. */ |
2449ae7b FW |
143 | _dl_exception_create_format |
144 | (&exception, DSO_FILENAME (map->l_name), | |
145 | "version `%s' not found (required by %s)", string, name); | |
6ed623f8 UD |
146 | result = 1; |
147 | call_cerror: | |
2449ae7b FW |
148 | _dl_signal_cexception (0, &exception, N_("version lookup error")); |
149 | _dl_exception_free (&exception); | |
6ed623f8 | 150 | return result; |
c84142e8 UD |
151 | } |
152 | ||
153 | ||
154 | int | |
145b8413 | 155 | _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode) |
c84142e8 UD |
156 | { |
157 | int result = 0; | |
f41c8091 | 158 | const char *strtab; |
c84142e8 | 159 | /* Pointer to section with needed versions. */ |
f41c8091 | 160 | ElfW(Dyn) *dyn; |
c84142e8 | 161 | /* Pointer to dynamic section with definitions. */ |
f41c8091 | 162 | ElfW(Dyn) *def; |
c84142e8 UD |
163 | /* We need to find out which is the highest version index used |
164 | in a dependecy. */ | |
165 | unsigned int ndx_high = 0; | |
2449ae7b | 166 | struct dl_exception exception; |
6ed623f8 | 167 | /* Initialize to make the compiler happy. */ |
6ed623f8 | 168 | int errval = 0; |
c84142e8 | 169 | |
f41c8091 UD |
170 | /* If we don't have a string table, we must be ok. */ |
171 | if (map->l_info[DT_STRTAB] == NULL) | |
172 | return 0; | |
a42195db | 173 | strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); |
f41c8091 | 174 | |
f420344c UD |
175 | dyn = map->l_info[VERSYMIDX (DT_VERNEED)]; |
176 | def = map->l_info[VERSYMIDX (DT_VERDEF)]; | |
f41c8091 | 177 | |
c84142e8 UD |
178 | if (dyn != NULL) |
179 | { | |
180 | /* This file requires special versions from its dependencies. */ | |
181 | ElfW(Verneed) *ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); | |
182 | ||
183 | /* Currently the version number of the needed entry is 1. | |
184 | Make sure all we see is this version. */ | |
7b228b68 | 185 | if (__builtin_expect (ent->vn_version, 1) != 1) |
c84142e8 UD |
186 | { |
187 | char buf[20]; | |
188 | buf[sizeof (buf) - 1] = '\0'; | |
8e17ea58 | 189 | /* XXX We cannot translate the message. */ |
2449ae7b FW |
190 | _dl_exception_create_format |
191 | (&exception, DSO_FILENAME (map->l_name), | |
192 | "unsupported version %s of Verneed record", | |
193 | _itoa (ent->vn_version, &buf[sizeof (buf) - 1], 10, 0)); | |
6ed623f8 | 194 | call_error: |
2449ae7b | 195 | _dl_signal_exception (errval, &exception, NULL); |
c84142e8 UD |
196 | } |
197 | ||
198 | while (1) | |
199 | { | |
200 | ElfW(Vernaux) *aux; | |
762a2918 | 201 | struct link_map *needed = find_needed (strtab + ent->vn_file, map); |
c84142e8 UD |
202 | |
203 | /* If NEEDED is NULL this means a dependency was not found | |
204 | and no stub entry was created. This should never happen. */ | |
205 | assert (needed != NULL); | |
206 | ||
145b8413 UD |
207 | /* Make sure this is no stub we created because of a missing |
208 | dependency. */ | |
7b228b68 | 209 | if (__builtin_expect (! trace_mode, 1) |
a881e0a0 | 210 | || ! __builtin_expect (needed->l_faked, 0)) |
c84142e8 | 211 | { |
145b8413 UD |
212 | /* NEEDED is the map for the file we need. Now look for the |
213 | dependency symbols. */ | |
214 | aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); | |
215 | while (1) | |
216 | { | |
217 | /* Match the symbol. */ | |
b9375348 | 218 | result |= match_symbol (DSO_FILENAME (map->l_name), |
75a142a2 | 219 | map->l_ns, aux->vna_hash, |
145b8413 | 220 | strtab + aux->vna_name, |
c0f62c56 | 221 | needed->l_real, verbose, |
145b8413 UD |
222 | aux->vna_flags & VER_FLG_WEAK); |
223 | ||
224 | /* Compare the version index. */ | |
225 | if ((unsigned int) (aux->vna_other & 0x7fff) > ndx_high) | |
226 | ndx_high = aux->vna_other & 0x7fff; | |
227 | ||
228 | if (aux->vna_next == 0) | |
229 | /* No more symbols. */ | |
230 | break; | |
231 | ||
232 | /* Next symbol. */ | |
233 | aux = (ElfW(Vernaux) *) ((char *) aux + aux->vna_next); | |
234 | } | |
c84142e8 UD |
235 | } |
236 | ||
237 | if (ent->vn_next == 0) | |
238 | /* No more dependencies. */ | |
239 | break; | |
240 | ||
241 | /* Next dependency. */ | |
242 | ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); | |
243 | } | |
244 | } | |
245 | ||
246 | /* We also must store the names of the defined versions. Determine | |
247 | the maximum index here as well. | |
248 | ||
249 | XXX We could avoid the loop by just taking the number of definitions | |
250 | as an upper bound of new indeces. */ | |
251 | if (def != NULL) | |
252 | { | |
253 | ElfW(Verdef) *ent; | |
714a562f | 254 | ent = (ElfW(Verdef) *) (map->l_addr + def->d_un.d_ptr); |
c84142e8 UD |
255 | while (1) |
256 | { | |
c131718c | 257 | if ((unsigned int) (ent->vd_ndx & 0x7fff) > ndx_high) |
c84142e8 UD |
258 | ndx_high = ent->vd_ndx & 0x7fff; |
259 | ||
260 | if (ent->vd_next == 0) | |
261 | /* No more definitions. */ | |
262 | break; | |
263 | ||
264 | ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next); | |
265 | } | |
266 | } | |
267 | ||
268 | if (ndx_high > 0) | |
269 | { | |
270 | /* Now we are ready to build the array with the version names | |
271 | which can be indexed by the version index in the VERSYM | |
272 | section. */ | |
1fb05e3d | 273 | map->l_versions = (struct r_found_version *) |
c131718c | 274 | calloc (ndx_high + 1, sizeof (*map->l_versions)); |
a1ffb40e | 275 | if (__glibc_unlikely (map->l_versions == NULL)) |
c84142e8 | 276 | { |
2449ae7b FW |
277 | _dl_exception_create |
278 | (&exception, DSO_FILENAME (map->l_name), | |
279 | N_("cannot allocate version reference table")); | |
6ed623f8 UD |
280 | errval = ENOMEM; |
281 | goto call_error; | |
c84142e8 | 282 | } |
c84142e8 | 283 | |
6ed623f8 UD |
284 | /* Store the number of available symbols. */ |
285 | map->l_nversions = ndx_high + 1; | |
286 | ||
287 | /* Compute the pointer to the version symbols. */ | |
288 | map->l_versyms = (void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]); | |
0c367d92 | 289 | |
6ed623f8 UD |
290 | if (dyn != NULL) |
291 | { | |
292 | ElfW(Verneed) *ent; | |
293 | ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); | |
294 | while (1) | |
c84142e8 | 295 | { |
6ed623f8 UD |
296 | ElfW(Vernaux) *aux; |
297 | aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); | |
c84142e8 UD |
298 | while (1) |
299 | { | |
6ed623f8 | 300 | ElfW(Half) ndx = aux->vna_other & 0x7fff; |
18a26b30 | 301 | /* In trace mode, dependencies may be missing. */ |
a1ffb40e | 302 | if (__glibc_likely (ndx < map->l_nversions)) |
18a26b30 AS |
303 | { |
304 | map->l_versions[ndx].hash = aux->vna_hash; | |
305 | map->l_versions[ndx].hidden = aux->vna_other & 0x8000; | |
306 | map->l_versions[ndx].name = &strtab[aux->vna_name]; | |
307 | map->l_versions[ndx].filename = &strtab[ent->vn_file]; | |
308 | } | |
6ed623f8 UD |
309 | |
310 | if (aux->vna_next == 0) | |
311 | /* No more symbols. */ | |
c84142e8 UD |
312 | break; |
313 | ||
6ed623f8 UD |
314 | /* Advance to next symbol. */ |
315 | aux = (ElfW(Vernaux) *) ((char *) aux + aux->vna_next); | |
c84142e8 | 316 | } |
6ed623f8 UD |
317 | |
318 | if (ent->vn_next == 0) | |
319 | /* No more dependencies. */ | |
320 | break; | |
321 | ||
322 | /* Advance to next dependency. */ | |
323 | ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); | |
c84142e8 | 324 | } |
6ed623f8 | 325 | } |
c84142e8 | 326 | |
6ed623f8 UD |
327 | /* And insert the defined versions. */ |
328 | if (def != NULL) | |
329 | { | |
330 | ElfW(Verdef) *ent; | |
331 | ent = (ElfW(Verdef) *) (map->l_addr + def->d_un.d_ptr); | |
332 | while (1) | |
c84142e8 | 333 | { |
6ed623f8 UD |
334 | ElfW(Verdaux) *aux; |
335 | aux = (ElfW(Verdaux) *) ((char *) ent + ent->vd_aux); | |
c84142e8 | 336 | |
6ed623f8 UD |
337 | if ((ent->vd_flags & VER_FLG_BASE) == 0) |
338 | { | |
339 | /* The name of the base version should not be | |
340 | available for matching a versioned symbol. */ | |
341 | ElfW(Half) ndx = ent->vd_ndx & 0x7fff; | |
342 | map->l_versions[ndx].hash = ent->vd_hash; | |
343 | map->l_versions[ndx].name = &strtab[aux->vda_name]; | |
344 | map->l_versions[ndx].filename = NULL; | |
c84142e8 | 345 | } |
6ed623f8 UD |
346 | |
347 | if (ent->vd_next == 0) | |
348 | /* No more definitions. */ | |
349 | break; | |
350 | ||
351 | ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next); | |
c84142e8 UD |
352 | } |
353 | } | |
354 | } | |
355 | ||
356 | return result; | |
357 | } | |
358 | ||
359 | ||
360 | int | |
145b8413 | 361 | _dl_check_all_versions (struct link_map *map, int verbose, int trace_mode) |
c84142e8 UD |
362 | { |
363 | struct link_map *l; | |
364 | int result = 0; | |
365 | ||
366 | for (l = map; l != NULL; l = l->l_next) | |
7969407a | 367 | result |= (! l->l_faked |
154d10bd | 368 | && _dl_check_map_versions (l, verbose, trace_mode)); |
c84142e8 UD |
369 | |
370 | return result; | |
371 | } |