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26b4d766 | 1 | /* Close a shared object opened by `_dl_open'. |
04277e02 | 2 | Copyright (C) 1996-2019 Free Software Foundation, Inc. |
afd4eb37 UD |
3 | This file is part of the GNU C Library. |
4 | ||
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. | |
afd4eb37 UD |
9 | |
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. |
afd4eb37 | 14 | |
41bdb6e2 | 15 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 16 | License along with the GNU C Library; if not, see |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
ba79d61b | 18 | |
7afab53d | 19 | #include <assert.h> |
ba79d61b | 20 | #include <dlfcn.h> |
1100f849 | 21 | #include <errno.h> |
8e17ea58 | 22 | #include <libintl.h> |
bfc832cc | 23 | #include <stddef.h> |
b209e34a | 24 | #include <stdio.h> |
ba79d61b | 25 | #include <stdlib.h> |
8d6468d0 | 26 | #include <string.h> |
9dcafc55 | 27 | #include <unistd.h> |
ec999b8e | 28 | #include <libc-lock.h> |
b8445829 | 29 | #include <ldsodefs.h> |
ba79d61b RM |
30 | #include <sys/types.h> |
31 | #include <sys/mman.h> | |
609cf614 | 32 | #include <sysdep-cancel.h> |
df94b641 | 33 | #include <tls.h> |
815e6fa3 | 34 | #include <stap-probe.h> |
ba79d61b | 35 | |
fcccd512 RM |
36 | #include <dl-unmap-segments.h> |
37 | ||
ba79d61b | 38 | |
dacc8ffa UD |
39 | /* Type of the constructor functions. */ |
40 | typedef void (*fini_t) (void); | |
41 | ||
42 | ||
1100f849 UD |
43 | /* Special l_idx value used to indicate which objects remain loaded. */ |
44 | #define IDX_STILL_USED -1 | |
45 | ||
46 | ||
fc093be1 UD |
47 | /* Returns true we an non-empty was found. */ |
48 | static bool | |
1f0c4a10 RM |
49 | remove_slotinfo (size_t idx, struct dtv_slotinfo_list *listp, size_t disp, |
50 | bool should_be_there) | |
fc093be1 UD |
51 | { |
52 | if (idx - disp >= listp->len) | |
53 | { | |
1f0c4a10 RM |
54 | if (listp->next == NULL) |
55 | { | |
56 | /* The index is not actually valid in the slotinfo list, | |
8265947d RM |
57 | because this object was closed before it was fully set |
58 | up due to some error. */ | |
1f0c4a10 RM |
59 | assert (! should_be_there); |
60 | } | |
61 | else | |
62 | { | |
63 | if (remove_slotinfo (idx, listp->next, disp + listp->len, | |
64 | should_be_there)) | |
65 | return true; | |
fc093be1 | 66 | |
1f0c4a10 RM |
67 | /* No non-empty entry. Search from the end of this element's |
68 | slotinfo array. */ | |
69 | idx = disp + listp->len; | |
70 | } | |
fc093be1 UD |
71 | } |
72 | else | |
73 | { | |
74 | struct link_map *old_map = listp->slotinfo[idx - disp].map; | |
fc093be1 | 75 | |
2430d57a RM |
76 | /* The entry might still be in its unused state if we are closing an |
77 | object that wasn't fully set up. */ | |
a1ffb40e | 78 | if (__glibc_likely (old_map != NULL)) |
2430d57a RM |
79 | { |
80 | assert (old_map->l_tls_modid == idx); | |
81 | ||
82 | /* Mark the entry as unused. */ | |
83 | listp->slotinfo[idx - disp].gen = GL(dl_tls_generation) + 1; | |
84 | listp->slotinfo[idx - disp].map = NULL; | |
85 | } | |
fc093be1 UD |
86 | |
87 | /* If this is not the last currently used entry no need to look | |
88 | further. */ | |
2430d57a | 89 | if (idx != GL(dl_tls_max_dtv_idx)) |
fc093be1 | 90 | return true; |
fc093be1 UD |
91 | } |
92 | ||
06a04e09 | 93 | while (idx - disp > (disp == 0 ? 1 + GL(dl_tls_static_nelem) : 0)) |
fc093be1 UD |
94 | { |
95 | --idx; | |
96 | ||
97 | if (listp->slotinfo[idx - disp].map != NULL) | |
98 | { | |
99 | /* Found a new last used index. */ | |
100 | GL(dl_tls_max_dtv_idx) = idx; | |
101 | return true; | |
102 | } | |
103 | } | |
104 | ||
105 | /* No non-entry in this list element. */ | |
106 | return false; | |
107 | } | |
fc093be1 | 108 | |
79e0cd7b FW |
109 | /* Invoke dstructors for CLOSURE (a struct link_map *). Called with |
110 | exception handling temporarily disabled, to make errors fatal. */ | |
111 | static void | |
112 | call_destructors (void *closure) | |
113 | { | |
114 | struct link_map *map = closure; | |
115 | ||
116 | if (map->l_info[DT_FINI_ARRAY] != NULL) | |
117 | { | |
118 | ElfW(Addr) *array = | |
119 | (ElfW(Addr) *) (map->l_addr | |
120 | + map->l_info[DT_FINI_ARRAY]->d_un.d_ptr); | |
121 | unsigned int sz = (map->l_info[DT_FINI_ARRAYSZ]->d_un.d_val | |
122 | / sizeof (ElfW(Addr))); | |
123 | ||
124 | while (sz-- > 0) | |
125 | ((fini_t) array[sz]) (); | |
126 | } | |
127 | ||
128 | /* Next try the old-style destructor. */ | |
129 | if (map->l_info[DT_FINI] != NULL) | |
130 | DL_CALL_DT_FINI (map, ((void *) map->l_addr | |
131 | + map->l_info[DT_FINI]->d_un.d_ptr)); | |
132 | } | |
fc093be1 | 133 | |
ba79d61b | 134 | void |
02d5e5d9 | 135 | _dl_close_worker (struct link_map *map, bool force) |
ba79d61b | 136 | { |
c0f62c56 | 137 | /* One less direct use. */ |
c0f62c56 UD |
138 | --map->l_direct_opencount; |
139 | ||
bfc832cc UD |
140 | /* If _dl_close is called recursively (some destructor call dlclose), |
141 | just record that the parent _dl_close will need to do garbage collection | |
142 | again and return. */ | |
143 | static enum { not_pending, pending, rerun } dl_close_state; | |
144 | ||
145 | if (map->l_direct_opencount > 0 || map->l_type != lt_loaded | |
146 | || dl_close_state != not_pending) | |
26b4d766 | 147 | { |
0479b305 AS |
148 | if (map->l_direct_opencount == 0 && map->l_type == lt_loaded) |
149 | dl_close_state = rerun; | |
bfc832cc | 150 | |
26b4d766 | 151 | /* There are still references to this object. Do nothing more. */ |
a1ffb40e | 152 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) |
20fe49b9 UD |
153 | _dl_debug_printf ("\nclosing file=%s; direct_opencount=%u\n", |
154 | map->l_name, map->l_direct_opencount); | |
a334319f | 155 | |
26b4d766 UD |
156 | return; |
157 | } | |
ba79d61b | 158 | |
2e81d449 UD |
159 | Lmid_t nsid = map->l_ns; |
160 | struct link_namespaces *ns = &GL(dl_ns)[nsid]; | |
161 | ||
bfc832cc UD |
162 | retry: |
163 | dl_close_state = pending; | |
164 | ||
bfc832cc | 165 | bool any_tls = false; |
2e81d449 | 166 | const unsigned int nloaded = ns->_ns_nloaded; |
c3381f3e UD |
167 | char used[nloaded]; |
168 | char done[nloaded]; | |
20fe49b9 UD |
169 | struct link_map *maps[nloaded]; |
170 | ||
bfc832cc | 171 | /* Run over the list and assign indexes to the link maps and enter |
20fe49b9 UD |
172 | them into the MAPS array. */ |
173 | int idx = 0; | |
2e81d449 | 174 | for (struct link_map *l = ns->_ns_loaded; l != NULL; l = l->l_next) |
20fe49b9 UD |
175 | { |
176 | l->l_idx = idx; | |
177 | maps[idx] = l; | |
178 | ++idx; | |
02d5e5d9 | 179 | |
20fe49b9 UD |
180 | } |
181 | assert (idx == nloaded); | |
c4bb124a | 182 | |
20fe49b9 UD |
183 | /* Prepare the bitmaps. */ |
184 | memset (used, '\0', sizeof (used)); | |
185 | memset (done, '\0', sizeof (done)); | |
0ecb606c | 186 | |
20fe49b9 UD |
187 | /* Keep track of the lowest index link map we have covered already. */ |
188 | int done_index = -1; | |
189 | while (++done_index < nloaded) | |
0ecb606c | 190 | { |
20fe49b9 UD |
191 | struct link_map *l = maps[done_index]; |
192 | ||
c3381f3e | 193 | if (done[done_index]) |
20fe49b9 UD |
194 | /* Already handled. */ |
195 | continue; | |
196 | ||
197 | /* Check whether this object is still used. */ | |
198 | if (l->l_type == lt_loaded | |
199 | && l->l_direct_opencount == 0 | |
f63b7381 | 200 | && l->l_nodelete != link_map_nodelete_active |
90b37cac SP |
201 | /* See CONCURRENCY NOTES in cxa_thread_atexit_impl.c to know why |
202 | acquire is sufficient and correct. */ | |
203 | && atomic_load_acquire (&l->l_tls_dtor_count) == 0 | |
c3381f3e | 204 | && !used[done_index]) |
20fe49b9 UD |
205 | continue; |
206 | ||
207 | /* We need this object and we handle it now. */ | |
c3381f3e UD |
208 | done[done_index] = 1; |
209 | used[done_index] = 1; | |
210 | /* Signal the object is still needed. */ | |
1100f849 | 211 | l->l_idx = IDX_STILL_USED; |
20fe49b9 UD |
212 | |
213 | /* Mark all dependencies as used. */ | |
214 | if (l->l_initfini != NULL) | |
215 | { | |
36129722 CD |
216 | /* We are always the zeroth entry, and since we don't include |
217 | ourselves in the dependency analysis start at 1. */ | |
20fe49b9 UD |
218 | struct link_map **lp = &l->l_initfini[1]; |
219 | while (*lp != NULL) | |
220 | { | |
1100f849 | 221 | if ((*lp)->l_idx != IDX_STILL_USED) |
556224ab | 222 | { |
c3381f3e UD |
223 | assert ((*lp)->l_idx >= 0 && (*lp)->l_idx < nloaded); |
224 | ||
225 | if (!used[(*lp)->l_idx]) | |
226 | { | |
227 | used[(*lp)->l_idx] = 1; | |
36129722 CD |
228 | /* If we marked a new object as used, and we've |
229 | already processed it, then we need to go back | |
230 | and process again from that point forward to | |
231 | ensure we keep all of its dependencies also. */ | |
c3381f3e UD |
232 | if ((*lp)->l_idx - 1 < done_index) |
233 | done_index = (*lp)->l_idx - 1; | |
234 | } | |
556224ab | 235 | } |
556224ab | 236 | |
20fe49b9 UD |
237 | ++lp; |
238 | } | |
239 | } | |
240 | /* And the same for relocation dependencies. */ | |
241 | if (l->l_reldeps != NULL) | |
385b4cf4 | 242 | for (unsigned int j = 0; j < l->l_reldeps->act; ++j) |
20fe49b9 | 243 | { |
385b4cf4 | 244 | struct link_map *jmap = l->l_reldeps->list[j]; |
20fe49b9 | 245 | |
1100f849 | 246 | if (jmap->l_idx != IDX_STILL_USED) |
556224ab | 247 | { |
c3381f3e UD |
248 | assert (jmap->l_idx >= 0 && jmap->l_idx < nloaded); |
249 | ||
250 | if (!used[jmap->l_idx]) | |
251 | { | |
252 | used[jmap->l_idx] = 1; | |
253 | if (jmap->l_idx - 1 < done_index) | |
254 | done_index = jmap->l_idx - 1; | |
255 | } | |
556224ab UD |
256 | } |
257 | } | |
20fe49b9 | 258 | } |
42c4f32a | 259 | |
c2c299fd AS |
260 | /* Sort the entries. We can skip looking for the binary itself which is |
261 | at the front of the search list for the main namespace. */ | |
262 | _dl_sort_maps (maps + (nsid == LM_ID_BASE), nloaded - (nsid == LM_ID_BASE), | |
263 | used + (nsid == LM_ID_BASE), true); | |
c3381f3e | 264 | |
a709dd43 | 265 | /* Call all termination functions at once. */ |
29f97654 | 266 | #ifdef SHARED |
2e81d449 | 267 | bool do_audit = GLRO(dl_naudit) > 0 && !ns->_ns_loaded->l_auditing; |
29f97654 | 268 | #endif |
20fe49b9 | 269 | bool unload_any = false; |
e4eb675d | 270 | bool scope_mem_left = false; |
e8b6b64d | 271 | unsigned int unload_global = 0; |
20fe49b9 | 272 | unsigned int first_loaded = ~0; |
ffd0e1b7 | 273 | for (unsigned int i = 0; i < nloaded; ++i) |
a709dd43 | 274 | { |
20fe49b9 | 275 | struct link_map *imap = maps[i]; |
9dcafc55 UD |
276 | |
277 | /* All elements must be in the same namespace. */ | |
2e81d449 | 278 | assert (imap->l_ns == nsid); |
9dcafc55 | 279 | |
c3381f3e | 280 | if (!used[i]) |
a709dd43 | 281 | { |
20fe49b9 | 282 | assert (imap->l_type == lt_loaded |
f63b7381 | 283 | && imap->l_nodelete != link_map_nodelete_active); |
20fe49b9 | 284 | |
aff4519d | 285 | /* Call its termination function. Do not do it for |
79e0cd7b FW |
286 | half-cooked objects. Temporarily disable exception |
287 | handling, so that errors are fatal. */ | |
aff4519d | 288 | if (imap->l_init_called) |
dacc8ffa | 289 | { |
ac53c9c6 UD |
290 | /* When debugging print a message first. */ |
291 | if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, | |
292 | 0)) | |
293 | _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n", | |
2e81d449 | 294 | imap->l_name, nsid); |
ac53c9c6 | 295 | |
79e0cd7b FW |
296 | if (imap->l_info[DT_FINI_ARRAY] != NULL |
297 | || imap->l_info[DT_FINI] != NULL) | |
298 | _dl_catch_exception (NULL, call_destructors, imap); | |
dacc8ffa UD |
299 | } |
300 | ||
9dcafc55 | 301 | #ifdef SHARED |
a3d731d3 | 302 | /* Auditing checkpoint: we remove an object. */ |
a1ffb40e | 303 | if (__glibc_unlikely (do_audit)) |
9dcafc55 UD |
304 | { |
305 | struct audit_ifaces *afct = GLRO(dl_audit); | |
306 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
307 | { | |
308 | if (afct->objclose != NULL) | |
e1d559f3 FW |
309 | { |
310 | struct auditstate *state | |
311 | = link_map_audit_state (imap, cnt); | |
312 | /* Return value is ignored. */ | |
313 | (void) afct->objclose (&state->cookie); | |
314 | } | |
9dcafc55 UD |
315 | |
316 | afct = afct->next; | |
317 | } | |
318 | } | |
319 | #endif | |
320 | ||
20fe49b9 UD |
321 | /* This object must not be used anymore. */ |
322 | imap->l_removed = 1; | |
aff4519d | 323 | |
20fe49b9 UD |
324 | /* We indeed have an object to remove. */ |
325 | unload_any = true; | |
aff4519d | 326 | |
e8b6b64d UD |
327 | if (imap->l_global) |
328 | ++unload_global; | |
329 | ||
20fe49b9 UD |
330 | /* Remember where the first dynamically loaded object is. */ |
331 | if (i < first_loaded) | |
332 | first_loaded = i; | |
a709dd43 | 333 | } |
c3381f3e | 334 | /* Else used[i]. */ |
20fe49b9 UD |
335 | else if (imap->l_type == lt_loaded) |
336 | { | |
1100f849 UD |
337 | struct r_scope_elem *new_list = NULL; |
338 | ||
339 | if (imap->l_searchlist.r_list == NULL && imap->l_initfini != NULL) | |
20fe49b9 | 340 | { |
bfc832cc | 341 | /* The object is still used. But one of the objects we are |
20fe49b9 UD |
342 | unloading right now is responsible for loading it. If |
343 | the current object does not have it's own scope yet we | |
344 | have to create one. This has to be done before running | |
345 | the finalizers. | |
346 | ||
347 | To do this count the number of dependencies. */ | |
348 | unsigned int cnt; | |
349 | for (cnt = 1; imap->l_initfini[cnt] != NULL; ++cnt) | |
350 | ; | |
351 | ||
352 | /* We simply reuse the l_initfini list. */ | |
353 | imap->l_searchlist.r_list = &imap->l_initfini[cnt + 1]; | |
354 | imap->l_searchlist.r_nlist = cnt; | |
355 | ||
1100f849 | 356 | new_list = &imap->l_searchlist; |
20fe49b9 | 357 | } |
1100f849 UD |
358 | |
359 | /* Count the number of scopes which remain after the unload. | |
360 | When we add the local search list count it. Always add | |
361 | one for the terminating NULL pointer. */ | |
362 | size_t remain = (new_list != NULL) + 1; | |
363 | bool removed_any = false; | |
c0a777e8 | 364 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) |
1100f849 UD |
365 | /* This relies on l_scope[] entries being always set either |
366 | to its own l_symbolic_searchlist address, or some map's | |
367 | l_searchlist address. */ | |
c0a777e8 | 368 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) |
1100f849 UD |
369 | { |
370 | struct link_map *tmap = (struct link_map *) | |
c0a777e8 | 371 | ((char *) imap->l_scope[cnt] |
1100f849 | 372 | - offsetof (struct link_map, l_searchlist)); |
2e81d449 | 373 | assert (tmap->l_ns == nsid); |
1100f849 UD |
374 | if (tmap->l_idx == IDX_STILL_USED) |
375 | ++remain; | |
376 | else | |
377 | removed_any = true; | |
378 | } | |
379 | else | |
380 | ++remain; | |
381 | ||
382 | if (removed_any) | |
1ee2ff20 | 383 | { |
1100f849 UD |
384 | /* Always allocate a new array for the scope. This is |
385 | necessary since we must be able to determine the last | |
386 | user of the current array. If possible use the link map's | |
387 | memory. */ | |
388 | size_t new_size; | |
c0a777e8 UD |
389 | struct r_scope_elem **newp; |
390 | ||
391 | #define SCOPE_ELEMS(imap) \ | |
392 | (sizeof (imap->l_scope_mem) / sizeof (imap->l_scope_mem[0])) | |
393 | ||
394 | if (imap->l_scope != imap->l_scope_mem | |
395 | && remain < SCOPE_ELEMS (imap)) | |
1100f849 | 396 | { |
c0a777e8 UD |
397 | new_size = SCOPE_ELEMS (imap); |
398 | newp = imap->l_scope_mem; | |
1100f849 UD |
399 | } |
400 | else | |
401 | { | |
402 | new_size = imap->l_scope_max; | |
c0a777e8 UD |
403 | newp = (struct r_scope_elem **) |
404 | malloc (new_size * sizeof (struct r_scope_elem *)); | |
1100f849 UD |
405 | if (newp == NULL) |
406 | _dl_signal_error (ENOMEM, "dlclose", NULL, | |
407 | N_("cannot create scope list")); | |
408 | } | |
409 | ||
1100f849 UD |
410 | /* Copy over the remaining scope elements. */ |
411 | remain = 0; | |
c0a777e8 | 412 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) |
1ee2ff20 | 413 | { |
c0a777e8 | 414 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) |
1ee2ff20 | 415 | { |
1100f849 | 416 | struct link_map *tmap = (struct link_map *) |
c0a777e8 | 417 | ((char *) imap->l_scope[cnt] |
1100f849 UD |
418 | - offsetof (struct link_map, l_searchlist)); |
419 | if (tmap->l_idx != IDX_STILL_USED) | |
420 | { | |
421 | /* Remove the scope. Or replace with own map's | |
422 | scope. */ | |
423 | if (new_list != NULL) | |
424 | { | |
c0a777e8 | 425 | newp[remain++] = new_list; |
1100f849 UD |
426 | new_list = NULL; |
427 | } | |
428 | continue; | |
429 | } | |
1ee2ff20 | 430 | } |
1100f849 | 431 | |
c0a777e8 | 432 | newp[remain++] = imap->l_scope[cnt]; |
1ee2ff20 | 433 | } |
c0a777e8 | 434 | newp[remain] = NULL; |
1100f849 | 435 | |
c0a777e8 | 436 | struct r_scope_elem **old = imap->l_scope; |
1100f849 | 437 | |
e4eb675d | 438 | imap->l_scope = newp; |
1100f849 UD |
439 | |
440 | /* No user anymore, we can free it now. */ | |
c0a777e8 | 441 | if (old != imap->l_scope_mem) |
e4eb675d UD |
442 | { |
443 | if (_dl_scope_free (old)) | |
444 | /* If _dl_scope_free used THREAD_GSCOPE_WAIT (), | |
445 | no need to repeat it. */ | |
446 | scope_mem_left = false; | |
447 | } | |
448 | else | |
449 | scope_mem_left = true; | |
1100f849 UD |
450 | |
451 | imap->l_scope_max = new_size; | |
1ee2ff20 | 452 | } |
39dd69df AS |
453 | else if (new_list != NULL) |
454 | { | |
455 | /* We didn't change the scope array, so reset the search | |
456 | list. */ | |
457 | imap->l_searchlist.r_list = NULL; | |
458 | imap->l_searchlist.r_nlist = 0; | |
459 | } | |
42c4f32a | 460 | |
c3381f3e | 461 | /* The loader is gone, so mark the object as not having one. |
1100f849 UD |
462 | Note: l_idx != IDX_STILL_USED -> object will be removed. */ |
463 | if (imap->l_loader != NULL | |
464 | && imap->l_loader->l_idx != IDX_STILL_USED) | |
20fe49b9 | 465 | imap->l_loader = NULL; |
aff4519d | 466 | |
20fe49b9 UD |
467 | /* Remember where the first dynamically loaded object is. */ |
468 | if (i < first_loaded) | |
469 | first_loaded = i; | |
470 | } | |
a709dd43 UD |
471 | } |
472 | ||
20fe49b9 UD |
473 | /* If there are no objects to unload, do nothing further. */ |
474 | if (!unload_any) | |
475 | goto out; | |
476 | ||
9dcafc55 UD |
477 | #ifdef SHARED |
478 | /* Auditing checkpoint: we will start deleting objects. */ | |
a1ffb40e | 479 | if (__glibc_unlikely (do_audit)) |
9dcafc55 | 480 | { |
2e81d449 | 481 | struct link_map *head = ns->_ns_loaded; |
9dcafc55 UD |
482 | struct audit_ifaces *afct = GLRO(dl_audit); |
483 | /* Do not call the functions for any auditing object. */ | |
484 | if (head->l_auditing == 0) | |
485 | { | |
486 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
487 | { | |
488 | if (afct->activity != NULL) | |
e1d559f3 FW |
489 | { |
490 | struct auditstate *state = link_map_audit_state (head, cnt); | |
491 | afct->activity (&state->cookie, LA_ACT_DELETE); | |
492 | } | |
9dcafc55 UD |
493 | |
494 | afct = afct->next; | |
495 | } | |
496 | } | |
497 | } | |
498 | #endif | |
499 | ||
4d6acc61 | 500 | /* Notify the debugger we are about to remove some loaded objects. */ |
2e81d449 | 501 | struct r_debug *r = _dl_debug_initialize (0, nsid); |
9dcafc55 UD |
502 | r->r_state = RT_DELETE; |
503 | _dl_debug_state (); | |
815e6fa3 | 504 | LIBC_PROBE (unmap_start, 2, nsid, r); |
4d6acc61 | 505 | |
e8b6b64d UD |
506 | if (unload_global) |
507 | { | |
508 | /* Some objects are in the global scope list. Remove them. */ | |
509 | struct r_scope_elem *ns_msl = ns->_ns_main_searchlist; | |
510 | unsigned int i; | |
511 | unsigned int j = 0; | |
512 | unsigned int cnt = ns_msl->r_nlist; | |
513 | ||
514 | while (cnt > 0 && ns_msl->r_list[cnt - 1]->l_removed) | |
515 | --cnt; | |
516 | ||
517 | if (cnt + unload_global == ns_msl->r_nlist) | |
518 | /* Speed up removing most recently added objects. */ | |
519 | j = cnt; | |
520 | else | |
b7c08a66 | 521 | for (i = 0; i < cnt; i++) |
e8b6b64d UD |
522 | if (ns_msl->r_list[i]->l_removed == 0) |
523 | { | |
524 | if (i != j) | |
525 | ns_msl->r_list[j] = ns_msl->r_list[i]; | |
526 | j++; | |
527 | } | |
528 | ns_msl->r_nlist = j; | |
e4eb675d | 529 | } |
e8b6b64d | 530 | |
e4eb675d UD |
531 | if (!RTLD_SINGLE_THREAD_P |
532 | && (unload_global | |
533 | || scope_mem_left | |
534 | || (GL(dl_scope_free_list) != NULL | |
535 | && GL(dl_scope_free_list)->count))) | |
536 | { | |
537 | THREAD_GSCOPE_WAIT (); | |
538 | ||
539 | /* Now we can free any queued old scopes. */ | |
385b4cf4 | 540 | struct dl_scope_free_list *fsl = GL(dl_scope_free_list); |
e4eb675d UD |
541 | if (fsl != NULL) |
542 | while (fsl->count > 0) | |
543 | free (fsl->list[--fsl->count]); | |
e8b6b64d UD |
544 | } |
545 | ||
541765b6 UD |
546 | size_t tls_free_start; |
547 | size_t tls_free_end; | |
548 | tls_free_start = tls_free_end = NO_TLS_OFFSET; | |
c877418f | 549 | |
5a2a1d75 AS |
550 | /* We modify the list of loaded objects. */ |
551 | __rtld_lock_lock_recursive (GL(dl_load_write_lock)); | |
552 | ||
ba79d61b RM |
553 | /* Check each element of the search list to see if all references to |
554 | it are gone. */ | |
ffd0e1b7 | 555 | for (unsigned int i = first_loaded; i < nloaded; ++i) |
ba79d61b | 556 | { |
20fe49b9 | 557 | struct link_map *imap = maps[i]; |
c3381f3e | 558 | if (!used[i]) |
ba79d61b | 559 | { |
20fe49b9 | 560 | assert (imap->l_type == lt_loaded); |
a8a1269d | 561 | |
ba79d61b RM |
562 | /* That was the last reference, and this was a dlopen-loaded |
563 | object. We can unmap it. */ | |
ba79d61b | 564 | |
1f0c4a10 | 565 | /* Remove the object from the dtv slotinfo array if it uses TLS. */ |
a1ffb40e | 566 | if (__glibc_unlikely (imap->l_tls_blocksize > 0)) |
a04586d8 | 567 | { |
a04586d8 | 568 | any_tls = true; |
bb4cb252 | 569 | |
9dcafc55 UD |
570 | if (GL(dl_tls_dtv_slotinfo_list) != NULL |
571 | && ! remove_slotinfo (imap->l_tls_modid, | |
572 | GL(dl_tls_dtv_slotinfo_list), 0, | |
573 | imap->l_init_called)) | |
fc093be1 UD |
574 | /* All dynamically loaded modules with TLS are unloaded. */ |
575 | GL(dl_tls_max_dtv_idx) = GL(dl_tls_static_nelem); | |
c877418f | 576 | |
4c533566 UD |
577 | if (imap->l_tls_offset != NO_TLS_OFFSET |
578 | && imap->l_tls_offset != FORCED_DYNAMIC_TLS_OFFSET) | |
c877418f RM |
579 | { |
580 | /* Collect a contiguous chunk built from the objects in | |
581 | this search list, going in either direction. When the | |
582 | whole chunk is at the end of the used area then we can | |
583 | reclaim it. */ | |
11bf311e | 584 | #if TLS_TCB_AT_TP |
541765b6 UD |
585 | if (tls_free_start == NO_TLS_OFFSET |
586 | || (size_t) imap->l_tls_offset == tls_free_start) | |
587 | { | |
588 | /* Extend the contiguous chunk being reclaimed. */ | |
589 | tls_free_start | |
590 | = imap->l_tls_offset - imap->l_tls_blocksize; | |
591 | ||
592 | if (tls_free_end == NO_TLS_OFFSET) | |
593 | tls_free_end = imap->l_tls_offset; | |
594 | } | |
595 | else if (imap->l_tls_offset - imap->l_tls_blocksize | |
596 | == tls_free_end) | |
597 | /* Extend the chunk backwards. */ | |
598 | tls_free_end = imap->l_tls_offset; | |
599 | else | |
600 | { | |
601 | /* This isn't contiguous with the last chunk freed. | |
602 | One of them will be leaked unless we can free | |
603 | one block right away. */ | |
604 | if (tls_free_end == GL(dl_tls_static_used)) | |
605 | { | |
606 | GL(dl_tls_static_used) = tls_free_start; | |
607 | tls_free_end = imap->l_tls_offset; | |
608 | tls_free_start | |
609 | = tls_free_end - imap->l_tls_blocksize; | |
610 | } | |
611 | else if ((size_t) imap->l_tls_offset | |
612 | == GL(dl_tls_static_used)) | |
613 | GL(dl_tls_static_used) | |
614 | = imap->l_tls_offset - imap->l_tls_blocksize; | |
615 | else if (tls_free_end < (size_t) imap->l_tls_offset) | |
616 | { | |
617 | /* We pick the later block. It has a chance to | |
618 | be freed. */ | |
619 | tls_free_end = imap->l_tls_offset; | |
620 | tls_free_start | |
621 | = tls_free_end - imap->l_tls_blocksize; | |
622 | } | |
623 | } | |
11bf311e | 624 | #elif TLS_DTV_AT_TP |
66bdbaa4 AM |
625 | if (tls_free_start == NO_TLS_OFFSET) |
626 | { | |
627 | tls_free_start = imap->l_tls_firstbyte_offset; | |
628 | tls_free_end = (imap->l_tls_offset | |
629 | + imap->l_tls_blocksize); | |
630 | } | |
631 | else if (imap->l_tls_firstbyte_offset == tls_free_end) | |
c877418f | 632 | /* Extend the contiguous chunk being reclaimed. */ |
66bdbaa4 | 633 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; |
c877418f RM |
634 | else if (imap->l_tls_offset + imap->l_tls_blocksize |
635 | == tls_free_start) | |
636 | /* Extend the chunk backwards. */ | |
66bdbaa4 AM |
637 | tls_free_start = imap->l_tls_firstbyte_offset; |
638 | /* This isn't contiguous with the last chunk freed. | |
639 | One of them will be leaked unless we can free | |
640 | one block right away. */ | |
641 | else if (imap->l_tls_offset + imap->l_tls_blocksize | |
642 | == GL(dl_tls_static_used)) | |
643 | GL(dl_tls_static_used) = imap->l_tls_firstbyte_offset; | |
644 | else if (tls_free_end == GL(dl_tls_static_used)) | |
c877418f | 645 | { |
66bdbaa4 AM |
646 | GL(dl_tls_static_used) = tls_free_start; |
647 | tls_free_start = imap->l_tls_firstbyte_offset; | |
648 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | |
649 | } | |
650 | else if (tls_free_end < imap->l_tls_firstbyte_offset) | |
651 | { | |
652 | /* We pick the later block. It has a chance to | |
653 | be freed. */ | |
654 | tls_free_start = imap->l_tls_firstbyte_offset; | |
655 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | |
c877418f | 656 | } |
11bf311e UD |
657 | #else |
658 | # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" | |
659 | #endif | |
c877418f | 660 | } |
a04586d8 | 661 | } |
a04586d8 | 662 | |
02d5e5d9 PK |
663 | /* Reset unique symbols if forced. */ |
664 | if (force) | |
665 | { | |
666 | struct unique_sym_table *tab = &ns->_ns_unique_sym_table; | |
667 | __rtld_lock_lock_recursive (tab->lock); | |
668 | struct unique_sym *entries = tab->entries; | |
669 | if (entries != NULL) | |
670 | { | |
671 | size_t idx, size = tab->size; | |
672 | for (idx = 0; idx < size; ++idx) | |
673 | { | |
674 | /* Clear unique symbol entries that belong to this | |
675 | object. */ | |
676 | if (entries[idx].name != NULL | |
677 | && entries[idx].map == imap) | |
678 | { | |
679 | entries[idx].name = NULL; | |
680 | entries[idx].hashval = 0; | |
681 | tab->n_elements--; | |
682 | } | |
683 | } | |
684 | } | |
685 | __rtld_lock_unlock_recursive (tab->lock); | |
686 | } | |
687 | ||
a8a1269d | 688 | /* We can unmap all the maps at once. We determined the |
4ce636da UD |
689 | start address and length when we loaded the object and |
690 | the `munmap' call does the rest. */ | |
09bf6406 | 691 | DL_UNMAP (imap); |
22bc7978 | 692 | |
ba79d61b | 693 | /* Finally, unlink the data structure and free it. */ |
2bd2cad9 RM |
694 | #if DL_NNS == 1 |
695 | /* The assert in the (imap->l_prev == NULL) case gives | |
696 | the compiler license to warn that NS points outside | |
697 | the dl_ns array bounds in that case (as nsid != LM_ID_BASE | |
698 | is tantamount to nsid >= DL_NNS). That should be impossible | |
699 | in this configuration, so just assert about it instead. */ | |
700 | assert (nsid == LM_ID_BASE); | |
701 | assert (imap->l_prev != NULL); | |
702 | #else | |
703 | if (imap->l_prev == NULL) | |
c0f62c56 | 704 | { |
2e81d449 | 705 | assert (nsid != LM_ID_BASE); |
b7c08a66 RM |
706 | ns->_ns_loaded = imap->l_next; |
707 | ||
708 | /* Update the pointer to the head of the list | |
709 | we leave for debuggers to examine. */ | |
710 | r->r_map = (void *) ns->_ns_loaded; | |
c0f62c56 | 711 | } |
2bd2cad9 RM |
712 | else |
713 | #endif | |
714 | imap->l_prev->l_next = imap->l_next; | |
c0f62c56 | 715 | |
2e81d449 | 716 | --ns->_ns_nloaded; |
c0f62c56 | 717 | if (imap->l_next != NULL) |
af69217f | 718 | imap->l_next->l_prev = imap->l_prev; |
a8a1269d | 719 | |
556224ab UD |
720 | free (imap->l_versions); |
721 | if (imap->l_origin != (char *) -1) | |
a8a1269d UD |
722 | free ((char *) imap->l_origin); |
723 | ||
20fe49b9 | 724 | free (imap->l_reldeps); |
4b4fcf99 | 725 | |
ac53c9c6 | 726 | /* Print debugging message. */ |
a1ffb40e | 727 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) |
ac53c9c6 UD |
728 | _dl_debug_printf ("\nfile=%s [%lu]; destroying link map\n", |
729 | imap->l_name, imap->l_ns); | |
730 | ||
4ce636da | 731 | /* This name always is allocated. */ |
a8a1269d | 732 | free (imap->l_name); |
4ce636da | 733 | /* Remove the list with all the names of the shared object. */ |
20fe49b9 UD |
734 | |
735 | struct libname_list *lnp = imap->l_libname; | |
a8a1269d UD |
736 | do |
737 | { | |
76156ea1 | 738 | struct libname_list *this = lnp; |
a8a1269d | 739 | lnp = lnp->next; |
11810621 UD |
740 | if (!this->dont_free) |
741 | free (this); | |
a8a1269d UD |
742 | } |
743 | while (lnp != NULL); | |
a8a1269d | 744 | |
4ce636da | 745 | /* Remove the searchlists. */ |
20fe49b9 | 746 | free (imap->l_initfini); |
4ce636da | 747 | |
5a21d307 | 748 | /* Remove the scope array if we allocated it. */ |
c0a777e8 UD |
749 | if (imap->l_scope != imap->l_scope_mem) |
750 | free (imap->l_scope); | |
5a21d307 | 751 | |
7bcaca43 | 752 | if (imap->l_phdr_allocated) |
15925412 | 753 | free ((void *) imap->l_phdr); |
7bcaca43 | 754 | |
f55727ca UD |
755 | if (imap->l_rpath_dirs.dirs != (void *) -1) |
756 | free (imap->l_rpath_dirs.dirs); | |
757 | if (imap->l_runpath_dirs.dirs != (void *) -1) | |
758 | free (imap->l_runpath_dirs.dirs); | |
759 | ||
af69217f | 760 | free (imap); |
ba79d61b RM |
761 | } |
762 | } | |
763 | ||
5a2a1d75 AS |
764 | __rtld_lock_unlock_recursive (GL(dl_load_write_lock)); |
765 | ||
c877418f | 766 | /* If we removed any object which uses TLS bump the generation counter. */ |
bb4cb252 | 767 | if (any_tls) |
c877418f | 768 | { |
a1ffb40e | 769 | if (__glibc_unlikely (++GL(dl_tls_generation) == 0)) |
8b748aed | 770 | _dl_fatal_printf ("TLS generation counter wrapped! Please report as described in "REPORT_BUGS_TO".\n"); |
c877418f RM |
771 | |
772 | if (tls_free_end == GL(dl_tls_static_used)) | |
773 | GL(dl_tls_static_used) = tls_free_start; | |
774 | } | |
a04586d8 | 775 | |
9dcafc55 UD |
776 | #ifdef SHARED |
777 | /* Auditing checkpoint: we have deleted all objects. */ | |
a1ffb40e | 778 | if (__glibc_unlikely (do_audit)) |
9dcafc55 | 779 | { |
2e81d449 | 780 | struct link_map *head = ns->_ns_loaded; |
9dcafc55 UD |
781 | /* Do not call the functions for any auditing object. */ |
782 | if (head->l_auditing == 0) | |
783 | { | |
784 | struct audit_ifaces *afct = GLRO(dl_audit); | |
785 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
786 | { | |
787 | if (afct->activity != NULL) | |
e1d559f3 FW |
788 | { |
789 | struct auditstate *state = link_map_audit_state (head, cnt); | |
790 | afct->activity (&state->cookie, LA_ACT_CONSISTENT); | |
791 | } | |
9dcafc55 UD |
792 | |
793 | afct = afct->next; | |
794 | } | |
795 | } | |
796 | } | |
797 | #endif | |
798 | ||
22c83193 UD |
799 | if (__builtin_expect (ns->_ns_loaded == NULL, 0) |
800 | && nsid == GL(dl_nns) - 1) | |
801 | do | |
0d23a5c1 | 802 | --GL(dl_nns); |
22c83193 UD |
803 | while (GL(dl_ns)[GL(dl_nns) - 1]._ns_loaded == NULL); |
804 | ||
e3e5f672 | 805 | /* Notify the debugger those objects are finalized and gone. */ |
9dcafc55 UD |
806 | r->r_state = RT_CONSISTENT; |
807 | _dl_debug_state (); | |
815e6fa3 | 808 | LIBC_PROBE (unmap_complete, 2, nsid, r); |
4b4fcf99 | 809 | |
bfc832cc | 810 | /* Recheck if we need to retry, release the lock. */ |
20fe49b9 | 811 | out: |
bfc832cc UD |
812 | if (dl_close_state == rerun) |
813 | goto retry; | |
814 | ||
815 | dl_close_state = not_pending; | |
131c4428 UD |
816 | } |
817 | ||
818 | ||
819 | void | |
820 | _dl_close (void *_map) | |
821 | { | |
822 | struct link_map *map = _map; | |
823 | ||
57707b7f CD |
824 | /* We must take the lock to examine the contents of map and avoid |
825 | concurrent dlopens. */ | |
826 | __rtld_lock_lock_recursive (GL(dl_load_lock)); | |
827 | ||
828 | /* At this point we are guaranteed nobody else is touching the list of | |
829 | loaded maps, but a concurrent dlclose might have freed our map | |
830 | before we took the lock. There is no way to detect this (see below) | |
831 | so we proceed assuming this isn't the case. First see whether we | |
832 | can remove the object at all. */ | |
f63b7381 | 833 | if (__glibc_unlikely (map->l_nodelete == link_map_nodelete_active)) |
131c4428 | 834 | { |
131c4428 | 835 | /* Nope. Do nothing. */ |
57707b7f | 836 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); |
131c4428 UD |
837 | return; |
838 | } | |
839 | ||
57707b7f CD |
840 | /* At present this is an unreliable check except in the case where the |
841 | caller has recursively called dlclose and we are sure the link map | |
842 | has not been freed. In a non-recursive dlclose the map itself | |
843 | might have been freed and this access is potentially a data race | |
844 | with whatever other use this memory might have now, or worse we | |
845 | might silently corrupt memory if it looks enough like a link map. | |
846 | POSIX has language in dlclose that appears to guarantee that this | |
847 | should be a detectable case and given that dlclose should be threadsafe | |
848 | we need this to be a reliable detection. | |
849 | This is bug 20990. */ | |
131c4428 | 850 | if (__builtin_expect (map->l_direct_opencount, 1) == 0) |
57707b7f CD |
851 | { |
852 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); | |
853 | _dl_signal_error (0, map->l_name, NULL, N_("shared object not open")); | |
854 | } | |
131c4428 | 855 | |
02d5e5d9 | 856 | _dl_close_worker (map, false); |
131c4428 | 857 | |
d3c9f895 | 858 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); |
e3e5f672 | 859 | } |