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d66e34cd | 1 | /* Look up a symbol in the loaded objects. |
bfff8b1b | 2 | Copyright (C) 1995-2017 Free Software Foundation, Inc. |
afd4eb37 | 3 | This file is part of the GNU C Library. |
d66e34cd | 4 | |
afd4eb37 | 5 | The GNU C Library is free software; you can redistribute it and/or |
41bdb6e2 AJ |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
d66e34cd | 9 | |
afd4eb37 UD |
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 | |
41bdb6e2 | 13 | Lesser General Public License for more details. |
d66e34cd | 14 | |
41bdb6e2 | 15 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
d66e34cd | 18 | |
f671aeab | 19 | #include <alloca.h> |
407fe3bb | 20 | #include <libintl.h> |
cf197e41 | 21 | #include <stdlib.h> |
8d6468d0 | 22 | #include <string.h> |
3db52d94 | 23 | #include <unistd.h> |
a42195db | 24 | #include <ldsodefs.h> |
8f480b4b | 25 | #include <dl-hash.h> |
bc9f6000 | 26 | #include <dl-machine.h> |
4e35ef2c | 27 | #include <sysdep-cancel.h> |
ec999b8e | 28 | #include <libc-lock.h> |
f1cc669a | 29 | #include <tls.h> |
1ec79f26 | 30 | #include <atomic.h> |
c84142e8 | 31 | |
a853022c UD |
32 | #include <assert.h> |
33 | ||
8e25d1e7 CD |
34 | /* Return nonzero if check_match should consider SYM to fail to match a |
35 | symbol reference for some machine-specific reason. */ | |
cb4a2928 JM |
36 | #ifndef ELF_MACHINE_SYM_NO_MATCH |
37 | # define ELF_MACHINE_SYM_NO_MATCH(sym) 0 | |
38 | #endif | |
39 | ||
b0982c4a | 40 | #define VERSTAG(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (tag)) |
266180eb | 41 | |
714a562f | 42 | |
84384f5b UD |
43 | struct sym_val |
44 | { | |
84384f5b | 45 | const ElfW(Sym) *s; |
0c367d92 | 46 | struct link_map *m; |
84384f5b UD |
47 | }; |
48 | ||
49 | ||
1fb05e3d UD |
50 | #define make_string(string, rest...) \ |
51 | ({ \ | |
52 | const char *all[] = { string, ## rest }; \ | |
53 | size_t len, cnt; \ | |
54 | char *result, *cp; \ | |
55 | \ | |
56 | len = 1; \ | |
57 | for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \ | |
58 | len += strlen (all[cnt]); \ | |
59 | \ | |
60 | cp = result = alloca (len); \ | |
61 | for (cnt = 0; cnt < sizeof (all) / sizeof (all[0]); ++cnt) \ | |
da832465 | 62 | cp = __stpcpy (cp, all[cnt]); \ |
1fb05e3d UD |
63 | \ |
64 | result; \ | |
65 | }) | |
66 | ||
8352b484 | 67 | /* Statistics function. */ |
d6b5d570 UD |
68 | #ifdef SHARED |
69 | # define bump_num_relocations() ++GL(dl_num_relocations) | |
be4b5a95 | 70 | #else |
d6b5d570 | 71 | # define bump_num_relocations() ((void) 0) |
be4b5a95 UD |
72 | #endif |
73 | ||
8e25d1e7 CD |
74 | /* Utility function for do_lookup_x. The caller is called with undef_name, |
75 | ref, version, flags and type_class, and those are passed as the first | |
76 | five arguments. The caller then computes sym, symidx, strtab, and map | |
77 | and passes them as the next four arguments. Lastly the caller passes in | |
78 | versioned_sym and num_versions which are modified by check_match during | |
79 | the checking process. */ | |
80 | static const ElfW(Sym) * | |
81 | check_match (const char *const undef_name, | |
82 | const ElfW(Sym) *const ref, | |
83 | const struct r_found_version *const version, | |
84 | const int flags, | |
85 | const int type_class, | |
86 | const ElfW(Sym) *const sym, | |
87 | const Elf_Symndx symidx, | |
88 | const char *const strtab, | |
89 | const struct link_map *const map, | |
90 | const ElfW(Sym) **const versioned_sym, | |
91 | int *const num_versions) | |
92 | { | |
93 | unsigned int stt = ELFW(ST_TYPE) (sym->st_info); | |
94 | assert (ELF_RTYPE_CLASS_PLT == 1); | |
cc7d0447 | 95 | if (__glibc_unlikely ((sym->st_value == 0 /* No value. */ |
8e25d1e7 CD |
96 | && stt != STT_TLS) |
97 | || ELF_MACHINE_SYM_NO_MATCH (sym) | |
cc7d0447 | 98 | || (type_class & (sym->st_shndx == SHN_UNDEF)))) |
8e25d1e7 CD |
99 | return NULL; |
100 | ||
101 | /* Ignore all but STT_NOTYPE, STT_OBJECT, STT_FUNC, | |
102 | STT_COMMON, STT_TLS, and STT_GNU_IFUNC since these are no | |
103 | code/data definitions. */ | |
104 | #define ALLOWED_STT \ | |
105 | ((1 << STT_NOTYPE) | (1 << STT_OBJECT) | (1 << STT_FUNC) \ | |
106 | | (1 << STT_COMMON) | (1 << STT_TLS) | (1 << STT_GNU_IFUNC)) | |
107 | if (__glibc_unlikely (((1 << stt) & ALLOWED_STT) == 0)) | |
108 | return NULL; | |
109 | ||
110 | if (sym != ref && strcmp (strtab + sym->st_name, undef_name)) | |
111 | /* Not the symbol we are looking for. */ | |
112 | return NULL; | |
113 | ||
114 | const ElfW(Half) *verstab = map->l_versyms; | |
115 | if (version != NULL) | |
116 | { | |
117 | if (__glibc_unlikely (verstab == NULL)) | |
118 | { | |
119 | /* We need a versioned symbol but haven't found any. If | |
120 | this is the object which is referenced in the verneed | |
121 | entry it is a bug in the library since a symbol must | |
122 | not simply disappear. | |
123 | ||
124 | It would also be a bug in the object since it means that | |
125 | the list of required versions is incomplete and so the | |
126 | tests in dl-version.c haven't found a problem.*/ | |
127 | assert (version->filename == NULL | |
128 | || ! _dl_name_match_p (version->filename, map)); | |
129 | ||
130 | /* Otherwise we accept the symbol. */ | |
131 | } | |
132 | else | |
133 | { | |
134 | /* We can match the version information or use the | |
135 | default one if it is not hidden. */ | |
136 | ElfW(Half) ndx = verstab[symidx] & 0x7fff; | |
137 | if ((map->l_versions[ndx].hash != version->hash | |
138 | || strcmp (map->l_versions[ndx].name, version->name)) | |
139 | && (version->hidden || map->l_versions[ndx].hash | |
140 | || (verstab[symidx] & 0x8000))) | |
141 | /* It's not the version we want. */ | |
142 | return NULL; | |
143 | } | |
144 | } | |
145 | else | |
146 | { | |
147 | /* No specific version is selected. There are two ways we | |
148 | can got here: | |
149 | ||
150 | - a binary which does not include versioning information | |
151 | is loaded | |
152 | ||
153 | - dlsym() instead of dlvsym() is used to get a symbol which | |
154 | might exist in more than one form | |
155 | ||
156 | If the library does not provide symbol version information | |
157 | there is no problem at all: we simply use the symbol if it | |
158 | is defined. | |
159 | ||
160 | These two lookups need to be handled differently if the | |
161 | library defines versions. In the case of the old | |
162 | unversioned application the oldest (default) version | |
163 | should be used. In case of a dlsym() call the latest and | |
164 | public interface should be returned. */ | |
165 | if (verstab != NULL) | |
166 | { | |
167 | if ((verstab[symidx] & 0x7fff) | |
168 | >= ((flags & DL_LOOKUP_RETURN_NEWEST) ? 2 : 3)) | |
169 | { | |
170 | /* Don't accept hidden symbols. */ | |
171 | if ((verstab[symidx] & 0x8000) == 0 | |
172 | && (*num_versions)++ == 0) | |
173 | /* No version so far. */ | |
174 | *versioned_sym = sym; | |
175 | ||
176 | return NULL; | |
177 | } | |
178 | } | |
179 | } | |
180 | ||
181 | /* There cannot be another entry for this symbol so stop here. */ | |
182 | return sym; | |
183 | } | |
184 | ||
7b8fb2b8 RM |
185 | /* Utility function for do_lookup_unique. Add a symbol to TABLE. */ |
186 | static void | |
187 | enter_unique_sym (struct unique_sym *table, size_t size, | |
188 | unsigned int hash, const char *name, | |
189 | const ElfW(Sym) *sym, const struct link_map *map) | |
190 | { | |
191 | size_t idx = hash % size; | |
192 | size_t hash2 = 1 + hash % (size - 2); | |
193 | while (table[idx].name != NULL) | |
194 | { | |
195 | idx += hash2; | |
196 | if (idx >= size) | |
197 | idx -= size; | |
198 | } | |
199 | ||
200 | table[idx].hashval = hash; | |
201 | table[idx].name = name; | |
202 | table[idx].sym = sym; | |
203 | table[idx].map = map; | |
204 | } | |
205 | ||
f393b4aa WN |
206 | /* Utility function for do_lookup_x. Lookup an STB_GNU_UNIQUE symbol |
207 | in the unique symbol table, creating a new entry if necessary. | |
208 | Return the matching symbol in RESULT. */ | |
209 | static void | |
210 | do_lookup_unique (const char *undef_name, uint_fast32_t new_hash, | |
211 | const struct link_map *map, struct sym_val *result, | |
212 | int type_class, const ElfW(Sym) *sym, const char *strtab, | |
213 | const ElfW(Sym) *ref, const struct link_map *undef_map) | |
214 | { | |
7b8fb2b8 RM |
215 | /* We have to determine whether we already found a symbol with this |
216 | name before. If not then we have to add it to the search table. | |
217 | If we already found a definition we have to use it. */ | |
f393b4aa WN |
218 | |
219 | struct unique_sym_table *tab | |
220 | = &GL(dl_ns)[map->l_ns]._ns_unique_sym_table; | |
221 | ||
222 | __rtld_lock_lock_recursive (tab->lock); | |
223 | ||
224 | struct unique_sym *entries = tab->entries; | |
225 | size_t size = tab->size; | |
226 | if (entries != NULL) | |
227 | { | |
228 | size_t idx = new_hash % size; | |
229 | size_t hash2 = 1 + new_hash % (size - 2); | |
230 | while (1) | |
231 | { | |
232 | if (entries[idx].hashval == new_hash | |
233 | && strcmp (entries[idx].name, undef_name) == 0) | |
234 | { | |
235 | if ((type_class & ELF_RTYPE_CLASS_COPY) != 0) | |
236 | { | |
237 | /* We possibly have to initialize the central | |
238 | copy from the copy addressed through the | |
239 | relocation. */ | |
240 | result->s = sym; | |
241 | result->m = (struct link_map *) map; | |
242 | } | |
243 | else | |
244 | { | |
245 | result->s = entries[idx].sym; | |
246 | result->m = (struct link_map *) entries[idx].map; | |
247 | } | |
248 | __rtld_lock_unlock_recursive (tab->lock); | |
249 | return; | |
250 | } | |
251 | ||
252 | if (entries[idx].name == NULL) | |
253 | break; | |
254 | ||
255 | idx += hash2; | |
256 | if (idx >= size) | |
257 | idx -= size; | |
258 | } | |
259 | ||
260 | if (size * 3 <= tab->n_elements * 4) | |
261 | { | |
262 | /* Expand the table. */ | |
263 | #ifdef RTLD_CHECK_FOREIGN_CALL | |
264 | /* This must not happen during runtime relocations. */ | |
265 | assert (!RTLD_CHECK_FOREIGN_CALL); | |
266 | #endif | |
267 | size_t newsize = _dl_higher_prime_number (size + 1); | |
268 | struct unique_sym *newentries | |
269 | = calloc (sizeof (struct unique_sym), newsize); | |
270 | if (newentries == NULL) | |
271 | { | |
272 | nomem: | |
273 | __rtld_lock_unlock_recursive (tab->lock); | |
274 | _dl_fatal_printf ("out of memory\n"); | |
275 | } | |
276 | ||
277 | for (idx = 0; idx < size; ++idx) | |
278 | if (entries[idx].name != NULL) | |
7b8fb2b8 RM |
279 | enter_unique_sym (newentries, newsize, entries[idx].hashval, |
280 | entries[idx].name, entries[idx].sym, | |
281 | entries[idx].map); | |
f393b4aa WN |
282 | |
283 | tab->free (entries); | |
284 | tab->size = newsize; | |
285 | size = newsize; | |
286 | entries = tab->entries = newentries; | |
287 | tab->free = free; | |
288 | } | |
289 | } | |
290 | else | |
291 | { | |
292 | #ifdef RTLD_CHECK_FOREIGN_CALL | |
293 | /* This must not happen during runtime relocations. */ | |
294 | assert (!RTLD_CHECK_FOREIGN_CALL); | |
295 | #endif | |
296 | ||
297 | #ifdef SHARED | |
298 | /* If tab->entries is NULL, but tab->size is not, it means | |
299 | this is the second, conflict finding, lookup for | |
300 | LD_TRACE_PRELINKING in _dl_debug_bindings. Don't | |
301 | allocate anything and don't enter anything into the | |
302 | hash table. */ | |
303 | if (__glibc_unlikely (tab->size)) | |
304 | { | |
305 | assert (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK); | |
306 | goto success; | |
307 | } | |
308 | #endif | |
309 | ||
310 | #define INITIAL_NUNIQUE_SYM_TABLE 31 | |
311 | size = INITIAL_NUNIQUE_SYM_TABLE; | |
312 | entries = calloc (sizeof (struct unique_sym), size); | |
313 | if (entries == NULL) | |
314 | goto nomem; | |
315 | ||
316 | tab->entries = entries; | |
317 | tab->size = size; | |
318 | tab->free = free; | |
319 | } | |
320 | ||
321 | if ((type_class & ELF_RTYPE_CLASS_COPY) != 0) | |
7b8fb2b8 | 322 | enter_unique_sym (entries, size, new_hash, strtab + sym->st_name, ref, |
f393b4aa WN |
323 | undef_map); |
324 | else | |
325 | { | |
7b8fb2b8 RM |
326 | enter_unique_sym (entries, size, |
327 | new_hash, strtab + sym->st_name, sym, map); | |
f393b4aa WN |
328 | |
329 | if (map->l_type == lt_loaded) | |
330 | /* Make sure we don't unload this object by | |
331 | setting the appropriate flag. */ | |
332 | ((struct link_map *) map)->l_flags_1 |= DF_1_NODELETE; | |
333 | } | |
334 | ++tab->n_elements; | |
335 | ||
336 | #ifdef SHARED | |
337 | success: | |
338 | #endif | |
339 | __rtld_lock_unlock_recursive (tab->lock); | |
340 | ||
341 | result->s = sym; | |
342 | result->m = (struct link_map *) map; | |
343 | } | |
8352b484 | 344 | |
786b74f4 UD |
345 | /* Inner part of the lookup functions. We return a value > 0 if we |
346 | found the symbol, the value 0 if nothing is found and < 0 if | |
347 | something bad happened. */ | |
348 | static int | |
349 | __attribute_noinline__ | |
350 | do_lookup_x (const char *undef_name, uint_fast32_t new_hash, | |
351 | unsigned long int *old_hash, const ElfW(Sym) *ref, | |
352 | struct sym_val *result, struct r_scope_elem *scope, size_t i, | |
353 | const struct r_found_version *const version, int flags, | |
354 | struct link_map *skip, int type_class, struct link_map *undef_map) | |
355 | { | |
356 | size_t n = scope->r_nlist; | |
357 | /* Make sure we read the value before proceeding. Otherwise we | |
358 | might use r_list pointing to the initial scope and r_nlist being | |
359 | the value after a resize. That is the only path in dl-open.c not | |
360 | protected by GSCOPE. A read barrier here might be to expensive. */ | |
361 | __asm volatile ("" : "+r" (n), "+m" (scope->r_list)); | |
362 | struct link_map **list = scope->r_list; | |
363 | ||
364 | do | |
365 | { | |
786b74f4 UD |
366 | const struct link_map *map = list[i]->l_real; |
367 | ||
368 | /* Here come the extra test needed for `_dl_lookup_symbol_skip'. */ | |
369 | if (map == skip) | |
370 | continue; | |
371 | ||
372 | /* Don't search the executable when resolving a copy reloc. */ | |
373 | if ((type_class & ELF_RTYPE_CLASS_COPY) && map->l_type == lt_executable) | |
374 | continue; | |
375 | ||
376 | /* Do not look into objects which are going to be removed. */ | |
377 | if (map->l_removed) | |
378 | continue; | |
379 | ||
380 | /* Print some debugging info if wanted. */ | |
a1ffb40e | 381 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SYMBOLS)) |
786b74f4 | 382 | _dl_debug_printf ("symbol=%s; lookup in file=%s [%lu]\n", |
b9375348 | 383 | undef_name, DSO_FILENAME (map->l_name), |
786b74f4 UD |
384 | map->l_ns); |
385 | ||
386 | /* If the hash table is empty there is nothing to do here. */ | |
387 | if (map->l_nbuckets == 0) | |
388 | continue; | |
389 | ||
f6488e2b WN |
390 | Elf_Symndx symidx; |
391 | int num_versions = 0; | |
392 | const ElfW(Sym) *versioned_sym = NULL; | |
393 | ||
786b74f4 UD |
394 | /* The tables for this map. */ |
395 | const ElfW(Sym) *symtab = (const void *) D_PTR (map, l_info[DT_SYMTAB]); | |
396 | const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); | |
397 | ||
786b74f4 UD |
398 | const ElfW(Sym) *sym; |
399 | const ElfW(Addr) *bitmask = map->l_gnu_bitmask; | |
a1ffb40e | 400 | if (__glibc_likely (bitmask != NULL)) |
786b74f4 UD |
401 | { |
402 | ElfW(Addr) bitmask_word | |
403 | = bitmask[(new_hash / __ELF_NATIVE_CLASS) | |
404 | & map->l_gnu_bitmask_idxbits]; | |
405 | ||
406 | unsigned int hashbit1 = new_hash & (__ELF_NATIVE_CLASS - 1); | |
407 | unsigned int hashbit2 = ((new_hash >> map->l_gnu_shift) | |
408 | & (__ELF_NATIVE_CLASS - 1)); | |
409 | ||
cc7d0447 WN |
410 | if (__glibc_unlikely ((bitmask_word >> hashbit1) |
411 | & (bitmask_word >> hashbit2) & 1)) | |
786b74f4 UD |
412 | { |
413 | Elf32_Word bucket = map->l_gnu_buckets[new_hash | |
414 | % map->l_nbuckets]; | |
415 | if (bucket != 0) | |
416 | { | |
417 | const Elf32_Word *hasharr = &map->l_gnu_chain_zero[bucket]; | |
418 | ||
419 | do | |
420 | if (((*hasharr ^ new_hash) >> 1) == 0) | |
421 | { | |
422 | symidx = hasharr - map->l_gnu_chain_zero; | |
8e25d1e7 CD |
423 | sym = check_match (undef_name, ref, version, flags, |
424 | type_class, &symtab[symidx], symidx, | |
425 | strtab, map, &versioned_sym, | |
426 | &num_versions); | |
786b74f4 UD |
427 | if (sym != NULL) |
428 | goto found_it; | |
429 | } | |
430 | while ((*hasharr++ & 1u) == 0); | |
431 | } | |
432 | } | |
433 | /* No symbol found. */ | |
434 | symidx = SHN_UNDEF; | |
435 | } | |
436 | else | |
437 | { | |
438 | if (*old_hash == 0xffffffff) | |
439 | *old_hash = _dl_elf_hash (undef_name); | |
440 | ||
441 | /* Use the old SysV-style hash table. Search the appropriate | |
442 | hash bucket in this object's symbol table for a definition | |
443 | for the same symbol name. */ | |
444 | for (symidx = map->l_buckets[*old_hash % map->l_nbuckets]; | |
445 | symidx != STN_UNDEF; | |
446 | symidx = map->l_chain[symidx]) | |
447 | { | |
8e25d1e7 CD |
448 | sym = check_match (undef_name, ref, version, flags, |
449 | type_class, &symtab[symidx], symidx, | |
450 | strtab, map, &versioned_sym, | |
451 | &num_versions); | |
786b74f4 UD |
452 | if (sym != NULL) |
453 | goto found_it; | |
454 | } | |
455 | } | |
456 | ||
457 | /* If we have seen exactly one versioned symbol while we are | |
458 | looking for an unversioned symbol and the version is not the | |
459 | default version we still accept this symbol since there are | |
460 | no possible ambiguities. */ | |
461 | sym = num_versions == 1 ? versioned_sym : NULL; | |
462 | ||
463 | if (sym != NULL) | |
464 | { | |
465 | found_it: | |
62da1e3b L |
466 | /* When UNDEF_MAP is NULL, which indicates we are called from |
467 | do_lookup_x on relocation against protected data, we skip | |
468 | the data definion in the executable from copy reloc. */ | |
469 | if (ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA | |
470 | && undef_map == NULL | |
471 | && map->l_type == lt_executable | |
472 | && type_class == ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA) | |
473 | { | |
474 | const ElfW(Sym) *s; | |
475 | unsigned int i; | |
476 | ||
477 | #if ! ELF_MACHINE_NO_RELA | |
478 | if (map->l_info[DT_RELA] != NULL | |
479 | && map->l_info[DT_RELASZ] != NULL | |
480 | && map->l_info[DT_RELASZ]->d_un.d_val != 0) | |
481 | { | |
482 | const ElfW(Rela) *rela | |
483 | = (const ElfW(Rela) *) D_PTR (map, l_info[DT_RELA]); | |
484 | unsigned int rela_count | |
485 | = map->l_info[DT_RELASZ]->d_un.d_val / sizeof (*rela); | |
486 | ||
487 | for (i = 0; i < rela_count; i++, rela++) | |
488 | if (elf_machine_type_class (ELFW(R_TYPE) (rela->r_info)) | |
489 | == ELF_RTYPE_CLASS_COPY) | |
490 | { | |
491 | s = &symtab[ELFW(R_SYM) (rela->r_info)]; | |
492 | if (!strcmp (strtab + s->st_name, undef_name)) | |
493 | goto skip; | |
494 | } | |
495 | } | |
496 | #endif | |
497 | #if ! ELF_MACHINE_NO_REL | |
498 | if (map->l_info[DT_REL] != NULL | |
499 | && map->l_info[DT_RELSZ] != NULL | |
500 | && map->l_info[DT_RELSZ]->d_un.d_val != 0) | |
501 | { | |
502 | const ElfW(Rel) *rel | |
503 | = (const ElfW(Rel) *) D_PTR (map, l_info[DT_REL]); | |
504 | unsigned int rel_count | |
505 | = map->l_info[DT_RELSZ]->d_un.d_val / sizeof (*rel); | |
506 | ||
507 | for (i = 0; i < rel_count; i++, rel++) | |
508 | if (elf_machine_type_class (ELFW(R_TYPE) (rel->r_info)) | |
509 | == ELF_RTYPE_CLASS_COPY) | |
510 | { | |
511 | s = &symtab[ELFW(R_SYM) (rel->r_info)]; | |
512 | if (!strcmp (strtab + s->st_name, undef_name)) | |
513 | goto skip; | |
514 | } | |
515 | } | |
516 | #endif | |
517 | } | |
518 | ||
b6084a95 MR |
519 | /* Hidden and internal symbols are local, ignore them. */ |
520 | if (__glibc_unlikely (dl_symbol_visibility_binds_local_p (sym))) | |
521 | goto skip; | |
522 | ||
cc7d0447 | 523 | switch (ELFW(ST_BIND) (sym->st_info)) |
786b74f4 UD |
524 | { |
525 | case STB_WEAK: | |
526 | /* Weak definition. Use this value if we don't find another. */ | |
a1ffb40e | 527 | if (__glibc_unlikely (GLRO(dl_dynamic_weak))) |
786b74f4 UD |
528 | { |
529 | if (! result->s) | |
530 | { | |
531 | result->s = sym; | |
532 | result->m = (struct link_map *) map; | |
533 | } | |
534 | break; | |
535 | } | |
536 | /* FALLTHROUGH */ | |
537 | case STB_GLOBAL: | |
786b74f4 UD |
538 | /* Global definition. Just what we need. */ |
539 | result->s = sym; | |
540 | result->m = (struct link_map *) map; | |
541 | return 1; | |
542 | ||
543 | case STB_GNU_UNIQUE:; | |
f393b4aa WN |
544 | do_lookup_unique (undef_name, new_hash, map, result, type_class, |
545 | sym, strtab, ref, undef_map); | |
546 | return 1; | |
786b74f4 UD |
547 | |
548 | default: | |
549 | /* Local symbols are ignored. */ | |
550 | break; | |
551 | } | |
552 | } | |
553 | ||
62da1e3b | 554 | skip: |
786b74f4 UD |
555 | /* If this current map is the one mentioned in the verneed entry |
556 | and we have not found a weak entry, it is a bug. */ | |
557 | if (symidx == STN_UNDEF && version != NULL && version->filename != NULL | |
cc7d0447 | 558 | && __glibc_unlikely (_dl_name_match_p (version->filename, map))) |
786b74f4 UD |
559 | return -1; |
560 | } | |
561 | while (++i < n); | |
562 | ||
563 | /* We have not found anything until now. */ | |
564 | return 0; | |
565 | } | |
84384f5b | 566 | |
84384f5b | 567 | |
871b9158 UD |
568 | static uint_fast32_t |
569 | dl_new_hash (const char *s) | |
570 | { | |
571 | uint_fast32_t h = 5381; | |
572 | for (unsigned char c = *s; c != '\0'; c = *++s) | |
573 | h = h * 33 + c; | |
574 | return h & 0xffffffff; | |
575 | } | |
576 | ||
577 | ||
cf197e41 UD |
578 | /* Add extra dependency on MAP to UNDEF_MAP. */ |
579 | static int | |
80d9c5f0 | 580 | internal_function |
b90395e6 | 581 | add_dependency (struct link_map *undef_map, struct link_map *map, int flags) |
cf197e41 | 582 | { |
c4bb124a | 583 | struct link_map *runp; |
cf197e41 UD |
584 | unsigned int i; |
585 | int result = 0; | |
586 | ||
aff4519d UD |
587 | /* Avoid self-references and references to objects which cannot be |
588 | unloaded anyway. */ | |
c4bb124a UD |
589 | if (undef_map == map) |
590 | return 0; | |
591 | ||
385b4cf4 UD |
592 | /* Avoid references to objects which cannot be unloaded anyway. */ |
593 | assert (map->l_type == lt_loaded); | |
594 | if ((map->l_flags_1 & DF_1_NODELETE) != 0) | |
595 | return 0; | |
596 | ||
597 | struct link_map_reldeps *l_reldeps | |
598 | = atomic_forced_read (undef_map->l_reldeps); | |
599 | ||
600 | /* Make sure l_reldeps is read before l_initfini. */ | |
601 | atomic_read_barrier (); | |
602 | ||
603 | /* Determine whether UNDEF_MAP already has a reference to MAP. First | |
604 | look in the normal dependencies. */ | |
605 | struct link_map **l_initfini = atomic_forced_read (undef_map->l_initfini); | |
606 | if (l_initfini != NULL) | |
607 | { | |
608 | for (i = 0; l_initfini[i] != NULL; ++i) | |
609 | if (l_initfini[i] == map) | |
610 | return 0; | |
611 | } | |
612 | ||
613 | /* No normal dependency. See whether we already had to add it | |
614 | to the special list of dynamic dependencies. */ | |
615 | unsigned int l_reldepsact = 0; | |
616 | if (l_reldeps != NULL) | |
617 | { | |
618 | struct link_map **list = &l_reldeps->list[0]; | |
619 | l_reldepsact = l_reldeps->act; | |
620 | for (i = 0; i < l_reldepsact; ++i) | |
621 | if (list[i] == map) | |
622 | return 0; | |
623 | } | |
624 | ||
b90395e6 | 625 | /* Save serial number of the target MAP. */ |
385b4cf4 | 626 | unsigned long long serial = map->l_serial; |
aff4519d | 627 | |
b90395e6 | 628 | /* Make sure nobody can unload the object while we are at it. */ |
a1ffb40e | 629 | if (__glibc_unlikely (flags & DL_LOOKUP_GSCOPE_LOCK)) |
aff4519d | 630 | { |
b90395e6 UD |
631 | /* We can't just call __rtld_lock_lock_recursive (GL(dl_load_lock)) |
632 | here, that can result in ABBA deadlock. */ | |
633 | THREAD_GSCOPE_RESET_FLAG (); | |
634 | __rtld_lock_lock_recursive (GL(dl_load_lock)); | |
b90395e6 UD |
635 | /* While MAP value won't change, after THREAD_GSCOPE_RESET_FLAG () |
636 | it can e.g. point to unallocated memory. So avoid the optimizer | |
637 | treating the above read from MAP->l_serial as ensurance it | |
638 | can safely dereference it. */ | |
639 | map = atomic_forced_read (map); | |
b90395e6 | 640 | |
385b4cf4 UD |
641 | /* From this point on it is unsafe to dereference MAP, until it |
642 | has been found in one of the lists. */ | |
cf197e41 | 643 | |
385b4cf4 UD |
644 | /* Redo the l_initfini check in case undef_map's l_initfini |
645 | changed in the mean time. */ | |
646 | if (undef_map->l_initfini != l_initfini | |
647 | && undef_map->l_initfini != NULL) | |
648 | { | |
649 | l_initfini = undef_map->l_initfini; | |
650 | for (i = 0; l_initfini[i] != NULL; ++i) | |
651 | if (l_initfini[i] == map) | |
652 | goto out_check; | |
653 | } | |
cf197e41 | 654 | |
385b4cf4 UD |
655 | /* Redo the l_reldeps check if undef_map's l_reldeps changed in |
656 | the mean time. */ | |
657 | if (undef_map->l_reldeps != NULL) | |
658 | { | |
659 | if (undef_map->l_reldeps != l_reldeps) | |
660 | { | |
661 | struct link_map **list = &undef_map->l_reldeps->list[0]; | |
662 | l_reldepsact = undef_map->l_reldeps->act; | |
663 | for (i = 0; i < l_reldepsact; ++i) | |
664 | if (list[i] == map) | |
665 | goto out_check; | |
666 | } | |
667 | else if (undef_map->l_reldeps->act > l_reldepsact) | |
668 | { | |
669 | struct link_map **list | |
670 | = &undef_map->l_reldeps->list[0]; | |
671 | i = l_reldepsact; | |
672 | l_reldepsact = undef_map->l_reldeps->act; | |
673 | for (; i < l_reldepsact; ++i) | |
674 | if (list[i] == map) | |
675 | goto out_check; | |
676 | } | |
677 | } | |
c4bb124a | 678 | } |
385b4cf4 UD |
679 | else |
680 | __rtld_lock_lock_recursive (GL(dl_load_lock)); | |
c4bb124a UD |
681 | |
682 | /* The object is not yet in the dependency list. Before we add | |
683 | it make sure just one more time the object we are about to | |
684 | reference is still available. There is a brief period in | |
685 | which the object could have been removed since we found the | |
686 | definition. */ | |
c0f62c56 | 687 | runp = GL(dl_ns)[undef_map->l_ns]._ns_loaded; |
c4bb124a UD |
688 | while (runp != NULL && runp != map) |
689 | runp = runp->l_next; | |
690 | ||
691 | if (runp != NULL) | |
692 | { | |
b90395e6 UD |
693 | /* The object is still available. */ |
694 | ||
695 | /* MAP could have been dlclosed, freed and then some other dlopened | |
696 | library could have the same link_map pointer. */ | |
697 | if (map->l_serial != serial) | |
698 | goto out_check; | |
699 | ||
385b4cf4 UD |
700 | /* Redo the NODELETE check, as when dl_load_lock wasn't held |
701 | yet this could have changed. */ | |
715899d1 | 702 | if ((map->l_flags_1 & DF_1_NODELETE) != 0) |
b90395e6 UD |
703 | goto out; |
704 | ||
705 | /* If the object with the undefined reference cannot be removed ever | |
706 | just make sure the same is true for the object which contains the | |
707 | definition. */ | |
708 | if (undef_map->l_type != lt_loaded | |
709 | || (undef_map->l_flags_1 & DF_1_NODELETE) != 0) | |
710 | { | |
711 | map->l_flags_1 |= DF_1_NODELETE; | |
712 | goto out; | |
713 | } | |
714 | ||
715 | /* Add the reference now. */ | |
a1ffb40e | 716 | if (__glibc_unlikely (l_reldepsact >= undef_map->l_reldepsmax)) |
cf197e41 | 717 | { |
c4bb124a UD |
718 | /* Allocate more memory for the dependency list. Since this |
719 | can never happen during the startup phase we can use | |
720 | `realloc'. */ | |
385b4cf4 UD |
721 | struct link_map_reldeps *newp; |
722 | unsigned int max | |
723 | = undef_map->l_reldepsmax ? undef_map->l_reldepsmax * 2 : 10; | |
724 | ||
b48a267b UD |
725 | #ifdef RTLD_PREPARE_FOREIGN_CALL |
726 | RTLD_PREPARE_FOREIGN_CALL; | |
727 | #endif | |
728 | ||
385b4cf4 UD |
729 | newp = malloc (sizeof (*newp) + max * sizeof (struct link_map *)); |
730 | if (newp == NULL) | |
731 | { | |
732 | /* If we didn't manage to allocate memory for the list this is | |
733 | no fatal problem. We simply make sure the referenced object | |
734 | cannot be unloaded. This is semantically the correct | |
735 | behavior. */ | |
736 | map->l_flags_1 |= DF_1_NODELETE; | |
737 | goto out; | |
738 | } | |
cf197e41 | 739 | else |
385b4cf4 UD |
740 | { |
741 | if (l_reldepsact) | |
742 | memcpy (&newp->list[0], &undef_map->l_reldeps->list[0], | |
743 | l_reldepsact * sizeof (struct link_map *)); | |
744 | newp->list[l_reldepsact] = map; | |
745 | newp->act = l_reldepsact + 1; | |
746 | atomic_write_barrier (); | |
747 | void *old = undef_map->l_reldeps; | |
748 | undef_map->l_reldeps = newp; | |
749 | undef_map->l_reldepsmax = max; | |
750 | if (old) | |
751 | _dl_scope_free (old); | |
752 | } | |
cf197e41 | 753 | } |
715899d1 | 754 | else |
385b4cf4 UD |
755 | { |
756 | undef_map->l_reldeps->list[l_reldepsact] = map; | |
757 | atomic_write_barrier (); | |
758 | undef_map->l_reldeps->act = l_reldepsact + 1; | |
759 | } | |
c4bb124a | 760 | |
c4bb124a | 761 | /* Display information if we are debugging. */ |
a1ffb40e | 762 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) |
154d10bd | 763 | _dl_debug_printf ("\ |
c0f62c56 | 764 | \nfile=%s [%lu]; needed by %s [%lu] (relocation dependency)\n\n", |
b9375348 | 765 | DSO_FILENAME (map->l_name), |
c0f62c56 | 766 | map->l_ns, |
b9375348 | 767 | DSO_FILENAME (undef_map->l_name), |
c0f62c56 | 768 | undef_map->l_ns); |
cf197e41 | 769 | } |
c4bb124a UD |
770 | else |
771 | /* Whoa, that was bad luck. We have to search again. */ | |
772 | result = -1; | |
cf197e41 | 773 | |
c4bb124a | 774 | out: |
cf197e41 | 775 | /* Release the lock. */ |
d3c9f895 | 776 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); |
cf197e41 | 777 | |
a1ffb40e | 778 | if (__glibc_unlikely (flags & DL_LOOKUP_GSCOPE_LOCK)) |
385b4cf4 UD |
779 | THREAD_GSCOPE_SET_FLAG (); |
780 | ||
cf197e41 | 781 | return result; |
b90395e6 UD |
782 | |
783 | out_check: | |
784 | if (map->l_serial != serial) | |
785 | result = -1; | |
786 | goto out; | |
cf197e41 UD |
787 | } |
788 | ||
32e6df36 UD |
789 | static void |
790 | internal_function | |
791 | _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, | |
c0a777e8 | 792 | const ElfW(Sym) **ref, struct sym_val *value, |
7969407a UD |
793 | const struct r_found_version *version, int type_class, |
794 | int protected); | |
647eb037 | 795 | |
84384f5b | 796 | |
bdf4a4f1 | 797 | /* Search loaded objects' symbol tables for a definition of the symbol |
609cf614 UD |
798 | UNDEF_NAME, perhaps with a requested version for the symbol. |
799 | ||
800 | We must never have calls to the audit functions inside this function | |
801 | or in any function which gets called. If this would happen the audit | |
802 | code might create a thread which can throw off all the scope locking. */ | |
c0282c06 | 803 | lookup_t |
d0fc4041 | 804 | internal_function |
bdf4a4f1 UD |
805 | _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, |
806 | const ElfW(Sym) **ref, | |
807 | struct r_scope_elem *symbol_scope[], | |
808 | const struct r_found_version *version, | |
809 | int type_class, int flags, struct link_map *skip_map) | |
84384f5b | 810 | { |
871b9158 UD |
811 | const uint_fast32_t new_hash = dl_new_hash (undef_name); |
812 | unsigned long int old_hash = 0xffffffff; | |
0c367d92 | 813 | struct sym_val current_value = { NULL, NULL }; |
bdf4a4f1 | 814 | struct r_scope_elem **scope = symbol_scope; |
84384f5b | 815 | |
be4b5a95 | 816 | bump_num_relocations (); |
48f6496e | 817 | |
b90395e6 UD |
818 | /* No other flag than DL_LOOKUP_ADD_DEPENDENCY or DL_LOOKUP_GSCOPE_LOCK |
819 | is allowed if we look up a versioned symbol. */ | |
820 | assert (version == NULL | |
821 | || (flags & ~(DL_LOOKUP_ADD_DEPENDENCY | DL_LOOKUP_GSCOPE_LOCK)) | |
822 | == 0); | |
c84142e8 | 823 | |
bdf4a4f1 | 824 | size_t i = 0; |
a1ffb40e | 825 | if (__glibc_unlikely (skip_map != NULL)) |
3c457089 UD |
826 | /* Search the relevant loaded objects for a definition. */ |
827 | while ((*scope)->r_list[i] != skip_map) | |
828 | ++i; | |
32e6df36 | 829 | |
c84142e8 | 830 | /* Search the relevant loaded objects for a definition. */ |
bdf4a4f1 | 831 | for (size_t start = i; *scope != NULL; start = 0, ++scope) |
1fb05e3d | 832 | { |
871b9158 UD |
833 | int res = do_lookup_x (undef_name, new_hash, &old_hash, *ref, |
834 | ¤t_value, *scope, start, version, flags, | |
415ac3df | 835 | skip_map, type_class, undef_map); |
1fb05e3d | 836 | if (res > 0) |
78575a84 | 837 | break; |
1fb05e3d | 838 | |
cc7d0447 | 839 | if (__glibc_unlikely (res < 0) && skip_map == NULL) |
3f933dc2 UD |
840 | { |
841 | /* Oh, oh. The file named in the relocation entry does not | |
bdf4a4f1 UD |
842 | contain the needed symbol. This code is never reached |
843 | for unversioned lookups. */ | |
844 | assert (version != NULL); | |
50727aa7 | 845 | const char *reference_name = undef_map ? undef_map->l_name : ""; |
c90b5d28 | 846 | |
8e17ea58 | 847 | /* XXX We cannot translate the message. */ |
b9375348 | 848 | _dl_signal_cerror (0, DSO_FILENAME (reference_name), |
407fe3bb | 849 | N_("relocation error"), |
3f933dc2 UD |
850 | make_string ("symbol ", undef_name, ", version ", |
851 | version->name, | |
852 | " not defined in file ", | |
853 | version->filename, | |
854 | " with link time reference", | |
855 | res == -2 | |
856 | ? " (no version symbols)" : "")); | |
857 | *ref = NULL; | |
858 | return 0; | |
859 | } | |
1fb05e3d | 860 | } |
c84142e8 | 861 | |
a1ffb40e | 862 | if (__glibc_unlikely (current_value.s == NULL)) |
0c367d92 | 863 | { |
bdf4a4f1 | 864 | if ((*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK) |
ff9f1c5f | 865 | && !(GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)) |
c90b5d28 UD |
866 | { |
867 | /* We could find no value for a strong reference. */ | |
9363dbb8 | 868 | const char *reference_name = undef_map ? undef_map->l_name : ""; |
bdf4a4f1 UD |
869 | const char *versionstr = version ? ", version " : ""; |
870 | const char *versionname = (version && version->name | |
871 | ? version->name : ""); | |
c90b5d28 UD |
872 | |
873 | /* XXX We cannot translate the message. */ | |
b9375348 | 874 | _dl_signal_cerror (0, DSO_FILENAME (reference_name), |
24a07b1f | 875 | N_("symbol lookup error"), |
d6d06225 | 876 | make_string ("undefined symbol: ", undef_name, |
bdf4a4f1 | 877 | versionstr, versionname)); |
c90b5d28 | 878 | } |
0c367d92 UD |
879 | *ref = NULL; |
880 | return 0; | |
881 | } | |
882 | ||
bdf4a4f1 UD |
883 | int protected = (*ref |
884 | && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED); | |
a1ffb40e | 885 | if (__glibc_unlikely (protected != 0)) |
6aa29abe | 886 | { |
78575a84 | 887 | /* It is very tricky. We need to figure out what value to |
2af63968 | 888 | return for the protected symbol. */ |
697119d6 | 889 | if (type_class == ELF_RTYPE_CLASS_PLT) |
6aa29abe | 890 | { |
697119d6 UD |
891 | if (current_value.s != NULL && current_value.m != undef_map) |
892 | { | |
893 | current_value.s = *ref; | |
894 | current_value.m = undef_map; | |
895 | } | |
896 | } | |
897 | else | |
898 | { | |
899 | struct sym_val protected_value = { NULL, NULL }; | |
900 | ||
9363dbb8 | 901 | for (scope = symbol_scope; *scope != NULL; i = 0, ++scope) |
871b9158 UD |
902 | if (do_lookup_x (undef_name, new_hash, &old_hash, *ref, |
903 | &protected_value, *scope, i, version, flags, | |
62da1e3b L |
904 | skip_map, |
905 | (ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA | |
906 | && ELFW(ST_TYPE) ((*ref)->st_info) == STT_OBJECT | |
907 | && type_class == ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA) | |
908 | ? ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA | |
909 | : ELF_RTYPE_CLASS_PLT, NULL) != 0) | |
697119d6 UD |
910 | break; |
911 | ||
9363dbb8 | 912 | if (protected_value.s != NULL && protected_value.m != undef_map) |
697119d6 UD |
913 | { |
914 | current_value.s = *ref; | |
915 | current_value.m = undef_map; | |
916 | } | |
6aa29abe | 917 | } |
6aa29abe | 918 | } |
32e6df36 | 919 | |
78575a84 UD |
920 | /* We have to check whether this would bind UNDEF_MAP to an object |
921 | in the global scope which was dynamically loaded. In this case | |
922 | we have to prevent the latter from being unloaded unless the | |
923 | UNDEF_MAP object is also unloaded. */ | |
cc7d0447 | 924 | if (__glibc_unlikely (current_value.m->l_type == lt_loaded) |
78575a84 UD |
925 | /* Don't do this for explicit lookups as opposed to implicit |
926 | runtime lookups. */ | |
bdf4a4f1 | 927 | && (flags & DL_LOOKUP_ADD_DEPENDENCY) != 0 |
78575a84 | 928 | /* Add UNDEF_MAP to the dependencies. */ |
b90395e6 | 929 | && add_dependency (undef_map, current_value.m, flags) < 0) |
78575a84 UD |
930 | /* Something went wrong. Perhaps the object we tried to reference |
931 | was just removed. Try finding another definition. */ | |
b90395e6 UD |
932 | return _dl_lookup_symbol_x (undef_name, undef_map, ref, |
933 | (flags & DL_LOOKUP_GSCOPE_LOCK) | |
934 | ? undef_map->l_scope : symbol_scope, | |
e4eb675d | 935 | version, type_class, flags, skip_map); |
78575a84 | 936 | |
7a11603d | 937 | /* The object is used. */ |
a1ffb40e | 938 | if (__glibc_unlikely (current_value.m->l_used == 0)) |
2af63968 | 939 | current_value.m->l_used = 1; |
7a11603d | 940 | |
cc7d0447 WN |
941 | if (__glibc_unlikely (GLRO(dl_debug_mask) |
942 | & (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK))) | |
c0a777e8 | 943 | _dl_debug_bindings (undef_name, undef_map, ref, |
32e6df36 UD |
944 | ¤t_value, version, type_class, protected); |
945 | ||
946 | *ref = current_value.s; | |
947 | return LOOKUP_VALUE (current_value.m); | |
c84142e8 UD |
948 | } |
949 | ||
950 | ||
d66e34cd RM |
951 | /* Cache the location of MAP's hash table. */ |
952 | ||
953 | void | |
d0fc4041 | 954 | internal_function |
d66e34cd RM |
955 | _dl_setup_hash (struct link_map *map) |
956 | { | |
a1eca9f3 | 957 | Elf_Symndx *hash; |
f41c8091 | 958 | |
cc7d0447 | 959 | if (__glibc_likely (map->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM |
2af63968 | 960 | + DT_THISPROCNUM + DT_VERSIONTAGNUM |
cc7d0447 | 961 | + DT_EXTRANUM + DT_VALNUM] != NULL)) |
871b9158 UD |
962 | { |
963 | Elf32_Word *hash32 | |
964 | = (void *) D_PTR (map, l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM | |
965 | + DT_THISPROCNUM + DT_VERSIONTAGNUM | |
966 | + DT_EXTRANUM + DT_VALNUM]); | |
967 | map->l_nbuckets = *hash32++; | |
968 | Elf32_Word symbias = *hash32++; | |
969 | Elf32_Word bitmask_nwords = *hash32++; | |
970 | /* Must be a power of two. */ | |
971 | assert ((bitmask_nwords & (bitmask_nwords - 1)) == 0); | |
972 | map->l_gnu_bitmask_idxbits = bitmask_nwords - 1; | |
973 | map->l_gnu_shift = *hash32++; | |
974 | ||
975 | map->l_gnu_bitmask = (ElfW(Addr) *) hash32; | |
976 | hash32 += __ELF_NATIVE_CLASS / 32 * bitmask_nwords; | |
977 | ||
978 | map->l_gnu_buckets = hash32; | |
979 | hash32 += map->l_nbuckets; | |
980 | map->l_gnu_chain_zero = hash32 - symbias; | |
981 | return; | |
982 | } | |
983 | ||
f41c8091 UD |
984 | if (!map->l_info[DT_HASH]) |
985 | return; | |
9a88a2d7 | 986 | hash = (void *) D_PTR (map, l_info[DT_HASH]); |
f41c8091 | 987 | |
d66e34cd | 988 | map->l_nbuckets = *hash++; |
1bc33071 UD |
989 | /* Skip nchain. */ |
990 | hash++; | |
d66e34cd RM |
991 | map->l_buckets = hash; |
992 | hash += map->l_nbuckets; | |
993 | map->l_chain = hash; | |
994 | } | |
80d9c5f0 | 995 | |
f9f2a150 | 996 | |
32e6df36 UD |
997 | static void |
998 | internal_function | |
999 | _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, | |
c0a777e8 | 1000 | const ElfW(Sym) **ref, struct sym_val *value, |
f9f2a150 UD |
1001 | const struct r_found_version *version, int type_class, |
1002 | int protected) | |
32e6df36 UD |
1003 | { |
1004 | const char *reference_name = undef_map->l_name; | |
1005 | ||
afdca0f2 | 1006 | if (GLRO(dl_debug_mask) & DL_DEBUG_BINDINGS) |
32e6df36 | 1007 | { |
21e2d3a4 | 1008 | _dl_debug_printf ("binding file %s [%lu] to %s [%lu]: %s symbol `%s'", |
b9375348 | 1009 | DSO_FILENAME (reference_name), |
21e2d3a4 | 1010 | undef_map->l_ns, |
b9375348 | 1011 | DSO_FILENAME (value->m->l_name), |
21e2d3a4 | 1012 | value->m->l_ns, |
154d10bd | 1013 | protected ? "protected" : "normal", undef_name); |
32e6df36 UD |
1014 | if (version) |
1015 | _dl_debug_printf_c (" [%s]\n", version->name); | |
1016 | else | |
1017 | _dl_debug_printf_c ("\n"); | |
1018 | } | |
1019 | #ifdef SHARED | |
afdca0f2 | 1020 | if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) |
32e6df36 | 1021 | { |
f3d18efb L |
1022 | /* ELF_RTYPE_CLASS_XXX must match RTYPE_CLASS_XXX used by prelink with |
1023 | LD_TRACE_PRELINKING. */ | |
1024 | #define RTYPE_CLASS_VALID 8 | |
1025 | #define RTYPE_CLASS_PLT (8|1) | |
1026 | #define RTYPE_CLASS_COPY (8|2) | |
1027 | #define RTYPE_CLASS_TLS (8|4) | |
1028 | #if ELF_RTYPE_CLASS_PLT != 0 && ELF_RTYPE_CLASS_PLT != 1 | |
1029 | # error ELF_RTYPE_CLASS_PLT must be 0 or 1! | |
1030 | #endif | |
1031 | #if ELF_RTYPE_CLASS_COPY != 0 && ELF_RTYPE_CLASS_COPY != 2 | |
1032 | # error ELF_RTYPE_CLASS_COPY must be 0 or 2! | |
1033 | #endif | |
32e6df36 UD |
1034 | int conflict = 0; |
1035 | struct sym_val val = { NULL, NULL }; | |
1036 | ||
afdca0f2 | 1037 | if ((GLRO(dl_trace_prelink_map) == NULL |
c0f62c56 UD |
1038 | || GLRO(dl_trace_prelink_map) == GL(dl_ns)[LM_ID_BASE]._ns_loaded) |
1039 | && undef_map != GL(dl_ns)[LM_ID_BASE]._ns_loaded) | |
32e6df36 | 1040 | { |
871b9158 UD |
1041 | const uint_fast32_t new_hash = dl_new_hash (undef_name); |
1042 | unsigned long int old_hash = 0xffffffff; | |
4ad43b62 UD |
1043 | struct unique_sym *saved_entries |
1044 | = GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries; | |
32e6df36 | 1045 | |
4ad43b62 | 1046 | GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries = NULL; |
871b9158 | 1047 | do_lookup_x (undef_name, new_hash, &old_hash, *ref, &val, |
bdf4a4f1 | 1048 | undef_map->l_local_scope[0], 0, version, 0, NULL, |
415ac3df | 1049 | type_class, undef_map); |
32e6df36 UD |
1050 | if (val.s != value->s || val.m != value->m) |
1051 | conflict = 1; | |
cc7d0447 | 1052 | else if (__glibc_unlikely (undef_map->l_symbolic_in_local_scope) |
4ad43b62 | 1053 | && val.s |
cc7d0447 WN |
1054 | && __glibc_unlikely (ELFW(ST_BIND) (val.s->st_info) |
1055 | == STB_GNU_UNIQUE)) | |
4ad43b62 UD |
1056 | { |
1057 | /* If it is STB_GNU_UNIQUE and undef_map's l_local_scope | |
1058 | contains any DT_SYMBOLIC libraries, unfortunately there | |
1059 | can be conflicts even if the above is equal. As symbol | |
1060 | resolution goes from the last library to the first and | |
1061 | if a STB_GNU_UNIQUE symbol is found in some late DT_SYMBOLIC | |
1062 | library, it would be the one that is looked up. */ | |
1063 | struct sym_val val2 = { NULL, NULL }; | |
1064 | size_t n; | |
1065 | struct r_scope_elem *scope = undef_map->l_local_scope[0]; | |
1066 | ||
1067 | for (n = 0; n < scope->r_nlist; n++) | |
1068 | if (scope->r_list[n] == val.m) | |
1069 | break; | |
1070 | ||
1071 | for (n++; n < scope->r_nlist; n++) | |
1072 | if (scope->r_list[n]->l_info[DT_SYMBOLIC] != NULL | |
1073 | && do_lookup_x (undef_name, new_hash, &old_hash, *ref, | |
1074 | &val2, | |
1075 | &scope->r_list[n]->l_symbolic_searchlist, | |
1076 | 0, version, 0, NULL, type_class, | |
1077 | undef_map) > 0) | |
1078 | { | |
1079 | conflict = 1; | |
1080 | val = val2; | |
1081 | break; | |
1082 | } | |
1083 | } | |
1084 | GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries = saved_entries; | |
32e6df36 UD |
1085 | } |
1086 | ||
02125962 JJ |
1087 | if (value->s) |
1088 | { | |
f3d18efb L |
1089 | /* Keep only ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY |
1090 | bits since since prelink only uses them. */ | |
1091 | type_class &= ELF_RTYPE_CLASS_PLT | ELF_RTYPE_CLASS_COPY; | |
cc7d0447 WN |
1092 | if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info) |
1093 | == STT_TLS)) | |
f3d18efb L |
1094 | /* Clear the RTYPE_CLASS_VALID bit in RTYPE_CLASS_TLS. */ |
1095 | type_class = RTYPE_CLASS_TLS & ~RTYPE_CLASS_VALID; | |
cc7d0447 WN |
1096 | else if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info) |
1097 | == STT_GNU_IFUNC)) | |
f3d18efb L |
1098 | /* Set the RTYPE_CLASS_VALID bit. */ |
1099 | type_class |= RTYPE_CLASS_VALID; | |
02125962 | 1100 | } |
1d0ad773 | 1101 | |
32e6df36 | 1102 | if (conflict |
afdca0f2 UD |
1103 | || GLRO(dl_trace_prelink_map) == undef_map |
1104 | || GLRO(dl_trace_prelink_map) == NULL | |
02125962 | 1105 | || type_class >= 4) |
32e6df36 UD |
1106 | { |
1107 | _dl_printf ("%s 0x%0*Zx 0x%0*Zx -> 0x%0*Zx 0x%0*Zx ", | |
1108 | conflict ? "conflict" : "lookup", | |
32e6df36 | 1109 | (int) sizeof (ElfW(Addr)) * 2, |
d347a4ab | 1110 | (size_t) undef_map->l_map_start, |
32e6df36 | 1111 | (int) sizeof (ElfW(Addr)) * 2, |
d347a4ab | 1112 | (size_t) (((ElfW(Addr)) *ref) - undef_map->l_map_start), |
32e6df36 | 1113 | (int) sizeof (ElfW(Addr)) * 2, |
d347a4ab UD |
1114 | (size_t) (value->s ? value->m->l_map_start : 0), |
1115 | (int) sizeof (ElfW(Addr)) * 2, | |
1116 | (size_t) (value->s ? value->s->st_value : 0)); | |
32e6df36 UD |
1117 | |
1118 | if (conflict) | |
1119 | _dl_printf ("x 0x%0*Zx 0x%0*Zx ", | |
1120 | (int) sizeof (ElfW(Addr)) * 2, | |
d347a4ab | 1121 | (size_t) (val.s ? val.m->l_map_start : 0), |
32e6df36 | 1122 | (int) sizeof (ElfW(Addr)) * 2, |
d347a4ab | 1123 | (size_t) (val.s ? val.s->st_value : 0)); |
32e6df36 UD |
1124 | |
1125 | _dl_printf ("/%x %s\n", type_class, undef_name); | |
1126 | } | |
1127 | } | |
1128 | #endif | |
1129 | } |