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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 UD |
108 | |
109 | ||
ba79d61b | 110 | void |
02d5e5d9 | 111 | _dl_close_worker (struct link_map *map, bool force) |
ba79d61b | 112 | { |
c0f62c56 | 113 | /* One less direct use. */ |
c0f62c56 UD |
114 | --map->l_direct_opencount; |
115 | ||
bfc832cc UD |
116 | /* If _dl_close is called recursively (some destructor call dlclose), |
117 | just record that the parent _dl_close will need to do garbage collection | |
118 | again and return. */ | |
119 | static enum { not_pending, pending, rerun } dl_close_state; | |
120 | ||
121 | if (map->l_direct_opencount > 0 || map->l_type != lt_loaded | |
122 | || dl_close_state != not_pending) | |
26b4d766 | 123 | { |
0479b305 AS |
124 | if (map->l_direct_opencount == 0 && map->l_type == lt_loaded) |
125 | dl_close_state = rerun; | |
bfc832cc | 126 | |
26b4d766 | 127 | /* There are still references to this object. Do nothing more. */ |
a1ffb40e | 128 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) |
20fe49b9 UD |
129 | _dl_debug_printf ("\nclosing file=%s; direct_opencount=%u\n", |
130 | map->l_name, map->l_direct_opencount); | |
a334319f | 131 | |
26b4d766 UD |
132 | return; |
133 | } | |
ba79d61b | 134 | |
2e81d449 UD |
135 | Lmid_t nsid = map->l_ns; |
136 | struct link_namespaces *ns = &GL(dl_ns)[nsid]; | |
137 | ||
bfc832cc UD |
138 | retry: |
139 | dl_close_state = pending; | |
140 | ||
bfc832cc | 141 | bool any_tls = false; |
2e81d449 | 142 | const unsigned int nloaded = ns->_ns_nloaded; |
c3381f3e UD |
143 | char used[nloaded]; |
144 | char done[nloaded]; | |
20fe49b9 UD |
145 | struct link_map *maps[nloaded]; |
146 | ||
f25238ff MO |
147 | /* Clear DF_1_NODELETE to force object deletion. We don't need to touch |
148 | l_tls_dtor_count because forced object deletion only happens when an | |
149 | error occurs during object load. Destructor registration for TLS | |
150 | non-POD objects should not have happened till then for this | |
151 | object. */ | |
152 | if (force) | |
153 | map->l_flags_1 &= ~DF_1_NODELETE; | |
154 | ||
bfc832cc | 155 | /* Run over the list and assign indexes to the link maps and enter |
20fe49b9 UD |
156 | them into the MAPS array. */ |
157 | int idx = 0; | |
2e81d449 | 158 | for (struct link_map *l = ns->_ns_loaded; l != NULL; l = l->l_next) |
20fe49b9 UD |
159 | { |
160 | l->l_idx = idx; | |
161 | maps[idx] = l; | |
162 | ++idx; | |
02d5e5d9 | 163 | |
20fe49b9 UD |
164 | } |
165 | assert (idx == nloaded); | |
c4bb124a | 166 | |
20fe49b9 UD |
167 | /* Prepare the bitmaps. */ |
168 | memset (used, '\0', sizeof (used)); | |
169 | memset (done, '\0', sizeof (done)); | |
0ecb606c | 170 | |
20fe49b9 UD |
171 | /* Keep track of the lowest index link map we have covered already. */ |
172 | int done_index = -1; | |
173 | while (++done_index < nloaded) | |
0ecb606c | 174 | { |
20fe49b9 UD |
175 | struct link_map *l = maps[done_index]; |
176 | ||
c3381f3e | 177 | if (done[done_index]) |
20fe49b9 UD |
178 | /* Already handled. */ |
179 | continue; | |
180 | ||
181 | /* Check whether this object is still used. */ | |
182 | if (l->l_type == lt_loaded | |
183 | && l->l_direct_opencount == 0 | |
184 | && (l->l_flags_1 & DF_1_NODELETE) == 0 | |
90b37cac SP |
185 | /* See CONCURRENCY NOTES in cxa_thread_atexit_impl.c to know why |
186 | acquire is sufficient and correct. */ | |
187 | && atomic_load_acquire (&l->l_tls_dtor_count) == 0 | |
c3381f3e | 188 | && !used[done_index]) |
20fe49b9 UD |
189 | continue; |
190 | ||
191 | /* We need this object and we handle it now. */ | |
c3381f3e UD |
192 | done[done_index] = 1; |
193 | used[done_index] = 1; | |
194 | /* Signal the object is still needed. */ | |
1100f849 | 195 | l->l_idx = IDX_STILL_USED; |
20fe49b9 UD |
196 | |
197 | /* Mark all dependencies as used. */ | |
198 | if (l->l_initfini != NULL) | |
199 | { | |
36129722 CD |
200 | /* We are always the zeroth entry, and since we don't include |
201 | ourselves in the dependency analysis start at 1. */ | |
20fe49b9 UD |
202 | struct link_map **lp = &l->l_initfini[1]; |
203 | while (*lp != NULL) | |
204 | { | |
1100f849 | 205 | if ((*lp)->l_idx != IDX_STILL_USED) |
556224ab | 206 | { |
c3381f3e UD |
207 | assert ((*lp)->l_idx >= 0 && (*lp)->l_idx < nloaded); |
208 | ||
209 | if (!used[(*lp)->l_idx]) | |
210 | { | |
211 | used[(*lp)->l_idx] = 1; | |
36129722 CD |
212 | /* If we marked a new object as used, and we've |
213 | already processed it, then we need to go back | |
214 | and process again from that point forward to | |
215 | ensure we keep all of its dependencies also. */ | |
c3381f3e UD |
216 | if ((*lp)->l_idx - 1 < done_index) |
217 | done_index = (*lp)->l_idx - 1; | |
218 | } | |
556224ab | 219 | } |
556224ab | 220 | |
20fe49b9 UD |
221 | ++lp; |
222 | } | |
223 | } | |
224 | /* And the same for relocation dependencies. */ | |
225 | if (l->l_reldeps != NULL) | |
385b4cf4 | 226 | for (unsigned int j = 0; j < l->l_reldeps->act; ++j) |
20fe49b9 | 227 | { |
385b4cf4 | 228 | struct link_map *jmap = l->l_reldeps->list[j]; |
20fe49b9 | 229 | |
1100f849 | 230 | if (jmap->l_idx != IDX_STILL_USED) |
556224ab | 231 | { |
c3381f3e UD |
232 | assert (jmap->l_idx >= 0 && jmap->l_idx < nloaded); |
233 | ||
234 | if (!used[jmap->l_idx]) | |
235 | { | |
236 | used[jmap->l_idx] = 1; | |
237 | if (jmap->l_idx - 1 < done_index) | |
238 | done_index = jmap->l_idx - 1; | |
239 | } | |
556224ab UD |
240 | } |
241 | } | |
20fe49b9 | 242 | } |
42c4f32a | 243 | |
c2c299fd AS |
244 | /* Sort the entries. We can skip looking for the binary itself which is |
245 | at the front of the search list for the main namespace. */ | |
246 | _dl_sort_maps (maps + (nsid == LM_ID_BASE), nloaded - (nsid == LM_ID_BASE), | |
247 | used + (nsid == LM_ID_BASE), true); | |
c3381f3e | 248 | |
a709dd43 | 249 | /* Call all termination functions at once. */ |
29f97654 | 250 | #ifdef SHARED |
2e81d449 | 251 | bool do_audit = GLRO(dl_naudit) > 0 && !ns->_ns_loaded->l_auditing; |
29f97654 | 252 | #endif |
20fe49b9 | 253 | bool unload_any = false; |
e4eb675d | 254 | bool scope_mem_left = false; |
e8b6b64d | 255 | unsigned int unload_global = 0; |
20fe49b9 | 256 | unsigned int first_loaded = ~0; |
ffd0e1b7 | 257 | for (unsigned int i = 0; i < nloaded; ++i) |
a709dd43 | 258 | { |
20fe49b9 | 259 | struct link_map *imap = maps[i]; |
9dcafc55 UD |
260 | |
261 | /* All elements must be in the same namespace. */ | |
2e81d449 | 262 | assert (imap->l_ns == nsid); |
9dcafc55 | 263 | |
c3381f3e | 264 | if (!used[i]) |
a709dd43 | 265 | { |
20fe49b9 UD |
266 | assert (imap->l_type == lt_loaded |
267 | && (imap->l_flags_1 & DF_1_NODELETE) == 0); | |
268 | ||
aff4519d UD |
269 | /* Call its termination function. Do not do it for |
270 | half-cooked objects. */ | |
271 | if (imap->l_init_called) | |
dacc8ffa | 272 | { |
ac53c9c6 UD |
273 | /* When debugging print a message first. */ |
274 | if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, | |
275 | 0)) | |
276 | _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n", | |
2e81d449 | 277 | imap->l_name, nsid); |
ac53c9c6 | 278 | |
aff4519d UD |
279 | if (imap->l_info[DT_FINI_ARRAY] != NULL) |
280 | { | |
281 | ElfW(Addr) *array = | |
282 | (ElfW(Addr) *) (imap->l_addr | |
283 | + imap->l_info[DT_FINI_ARRAY]->d_un.d_ptr); | |
284 | unsigned int sz = (imap->l_info[DT_FINI_ARRAYSZ]->d_un.d_val | |
285 | / sizeof (ElfW(Addr))); | |
aff4519d | 286 | |
62f29da7 UD |
287 | while (sz-- > 0) |
288 | ((fini_t) array[sz]) (); | |
aff4519d UD |
289 | } |
290 | ||
291 | /* Next try the old-style destructor. */ | |
292 | if (imap->l_info[DT_FINI] != NULL) | |
daf75146 GM |
293 | DL_CALL_DT_FINI (imap, ((void *) imap->l_addr |
294 | + imap->l_info[DT_FINI]->d_un.d_ptr)); | |
dacc8ffa UD |
295 | } |
296 | ||
9dcafc55 | 297 | #ifdef SHARED |
a3d731d3 | 298 | /* Auditing checkpoint: we remove an object. */ |
a1ffb40e | 299 | if (__glibc_unlikely (do_audit)) |
9dcafc55 UD |
300 | { |
301 | struct audit_ifaces *afct = GLRO(dl_audit); | |
302 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
303 | { | |
304 | if (afct->objclose != NULL) | |
e1d559f3 FW |
305 | { |
306 | struct auditstate *state | |
307 | = link_map_audit_state (imap, cnt); | |
308 | /* Return value is ignored. */ | |
309 | (void) afct->objclose (&state->cookie); | |
310 | } | |
9dcafc55 UD |
311 | |
312 | afct = afct->next; | |
313 | } | |
314 | } | |
315 | #endif | |
316 | ||
20fe49b9 UD |
317 | /* This object must not be used anymore. */ |
318 | imap->l_removed = 1; | |
aff4519d | 319 | |
20fe49b9 UD |
320 | /* We indeed have an object to remove. */ |
321 | unload_any = true; | |
aff4519d | 322 | |
e8b6b64d UD |
323 | if (imap->l_global) |
324 | ++unload_global; | |
325 | ||
20fe49b9 UD |
326 | /* Remember where the first dynamically loaded object is. */ |
327 | if (i < first_loaded) | |
328 | first_loaded = i; | |
a709dd43 | 329 | } |
c3381f3e | 330 | /* Else used[i]. */ |
20fe49b9 UD |
331 | else if (imap->l_type == lt_loaded) |
332 | { | |
1100f849 UD |
333 | struct r_scope_elem *new_list = NULL; |
334 | ||
335 | if (imap->l_searchlist.r_list == NULL && imap->l_initfini != NULL) | |
20fe49b9 | 336 | { |
bfc832cc | 337 | /* The object is still used. But one of the objects we are |
20fe49b9 UD |
338 | unloading right now is responsible for loading it. If |
339 | the current object does not have it's own scope yet we | |
340 | have to create one. This has to be done before running | |
341 | the finalizers. | |
342 | ||
343 | To do this count the number of dependencies. */ | |
344 | unsigned int cnt; | |
345 | for (cnt = 1; imap->l_initfini[cnt] != NULL; ++cnt) | |
346 | ; | |
347 | ||
348 | /* We simply reuse the l_initfini list. */ | |
349 | imap->l_searchlist.r_list = &imap->l_initfini[cnt + 1]; | |
350 | imap->l_searchlist.r_nlist = cnt; | |
351 | ||
1100f849 | 352 | new_list = &imap->l_searchlist; |
20fe49b9 | 353 | } |
1100f849 UD |
354 | |
355 | /* Count the number of scopes which remain after the unload. | |
356 | When we add the local search list count it. Always add | |
357 | one for the terminating NULL pointer. */ | |
358 | size_t remain = (new_list != NULL) + 1; | |
359 | bool removed_any = false; | |
c0a777e8 | 360 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) |
1100f849 UD |
361 | /* This relies on l_scope[] entries being always set either |
362 | to its own l_symbolic_searchlist address, or some map's | |
363 | l_searchlist address. */ | |
c0a777e8 | 364 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) |
1100f849 UD |
365 | { |
366 | struct link_map *tmap = (struct link_map *) | |
c0a777e8 | 367 | ((char *) imap->l_scope[cnt] |
1100f849 | 368 | - offsetof (struct link_map, l_searchlist)); |
2e81d449 | 369 | assert (tmap->l_ns == nsid); |
1100f849 UD |
370 | if (tmap->l_idx == IDX_STILL_USED) |
371 | ++remain; | |
372 | else | |
373 | removed_any = true; | |
374 | } | |
375 | else | |
376 | ++remain; | |
377 | ||
378 | if (removed_any) | |
1ee2ff20 | 379 | { |
1100f849 UD |
380 | /* Always allocate a new array for the scope. This is |
381 | necessary since we must be able to determine the last | |
382 | user of the current array. If possible use the link map's | |
383 | memory. */ | |
384 | size_t new_size; | |
c0a777e8 UD |
385 | struct r_scope_elem **newp; |
386 | ||
387 | #define SCOPE_ELEMS(imap) \ | |
388 | (sizeof (imap->l_scope_mem) / sizeof (imap->l_scope_mem[0])) | |
389 | ||
390 | if (imap->l_scope != imap->l_scope_mem | |
391 | && remain < SCOPE_ELEMS (imap)) | |
1100f849 | 392 | { |
c0a777e8 UD |
393 | new_size = SCOPE_ELEMS (imap); |
394 | newp = imap->l_scope_mem; | |
1100f849 UD |
395 | } |
396 | else | |
397 | { | |
398 | new_size = imap->l_scope_max; | |
c0a777e8 UD |
399 | newp = (struct r_scope_elem **) |
400 | malloc (new_size * sizeof (struct r_scope_elem *)); | |
1100f849 UD |
401 | if (newp == NULL) |
402 | _dl_signal_error (ENOMEM, "dlclose", NULL, | |
403 | N_("cannot create scope list")); | |
404 | } | |
405 | ||
1100f849 UD |
406 | /* Copy over the remaining scope elements. */ |
407 | remain = 0; | |
c0a777e8 | 408 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) |
1ee2ff20 | 409 | { |
c0a777e8 | 410 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) |
1ee2ff20 | 411 | { |
1100f849 | 412 | struct link_map *tmap = (struct link_map *) |
c0a777e8 | 413 | ((char *) imap->l_scope[cnt] |
1100f849 UD |
414 | - offsetof (struct link_map, l_searchlist)); |
415 | if (tmap->l_idx != IDX_STILL_USED) | |
416 | { | |
417 | /* Remove the scope. Or replace with own map's | |
418 | scope. */ | |
419 | if (new_list != NULL) | |
420 | { | |
c0a777e8 | 421 | newp[remain++] = new_list; |
1100f849 UD |
422 | new_list = NULL; |
423 | } | |
424 | continue; | |
425 | } | |
1ee2ff20 | 426 | } |
1100f849 | 427 | |
c0a777e8 | 428 | newp[remain++] = imap->l_scope[cnt]; |
1ee2ff20 | 429 | } |
c0a777e8 | 430 | newp[remain] = NULL; |
1100f849 | 431 | |
c0a777e8 | 432 | struct r_scope_elem **old = imap->l_scope; |
1100f849 | 433 | |
e4eb675d | 434 | imap->l_scope = newp; |
1100f849 UD |
435 | |
436 | /* No user anymore, we can free it now. */ | |
c0a777e8 | 437 | if (old != imap->l_scope_mem) |
e4eb675d UD |
438 | { |
439 | if (_dl_scope_free (old)) | |
440 | /* If _dl_scope_free used THREAD_GSCOPE_WAIT (), | |
441 | no need to repeat it. */ | |
442 | scope_mem_left = false; | |
443 | } | |
444 | else | |
445 | scope_mem_left = true; | |
1100f849 UD |
446 | |
447 | imap->l_scope_max = new_size; | |
1ee2ff20 | 448 | } |
39dd69df AS |
449 | else if (new_list != NULL) |
450 | { | |
451 | /* We didn't change the scope array, so reset the search | |
452 | list. */ | |
453 | imap->l_searchlist.r_list = NULL; | |
454 | imap->l_searchlist.r_nlist = 0; | |
455 | } | |
42c4f32a | 456 | |
c3381f3e | 457 | /* The loader is gone, so mark the object as not having one. |
1100f849 UD |
458 | Note: l_idx != IDX_STILL_USED -> object will be removed. */ |
459 | if (imap->l_loader != NULL | |
460 | && imap->l_loader->l_idx != IDX_STILL_USED) | |
20fe49b9 | 461 | imap->l_loader = NULL; |
aff4519d | 462 | |
20fe49b9 UD |
463 | /* Remember where the first dynamically loaded object is. */ |
464 | if (i < first_loaded) | |
465 | first_loaded = i; | |
466 | } | |
a709dd43 UD |
467 | } |
468 | ||
20fe49b9 UD |
469 | /* If there are no objects to unload, do nothing further. */ |
470 | if (!unload_any) | |
471 | goto out; | |
472 | ||
9dcafc55 UD |
473 | #ifdef SHARED |
474 | /* Auditing checkpoint: we will start deleting objects. */ | |
a1ffb40e | 475 | if (__glibc_unlikely (do_audit)) |
9dcafc55 | 476 | { |
2e81d449 | 477 | struct link_map *head = ns->_ns_loaded; |
9dcafc55 UD |
478 | struct audit_ifaces *afct = GLRO(dl_audit); |
479 | /* Do not call the functions for any auditing object. */ | |
480 | if (head->l_auditing == 0) | |
481 | { | |
482 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
483 | { | |
484 | if (afct->activity != NULL) | |
e1d559f3 FW |
485 | { |
486 | struct auditstate *state = link_map_audit_state (head, cnt); | |
487 | afct->activity (&state->cookie, LA_ACT_DELETE); | |
488 | } | |
9dcafc55 UD |
489 | |
490 | afct = afct->next; | |
491 | } | |
492 | } | |
493 | } | |
494 | #endif | |
495 | ||
4d6acc61 | 496 | /* Notify the debugger we are about to remove some loaded objects. */ |
2e81d449 | 497 | struct r_debug *r = _dl_debug_initialize (0, nsid); |
9dcafc55 UD |
498 | r->r_state = RT_DELETE; |
499 | _dl_debug_state (); | |
815e6fa3 | 500 | LIBC_PROBE (unmap_start, 2, nsid, r); |
4d6acc61 | 501 | |
e8b6b64d UD |
502 | if (unload_global) |
503 | { | |
504 | /* Some objects are in the global scope list. Remove them. */ | |
505 | struct r_scope_elem *ns_msl = ns->_ns_main_searchlist; | |
506 | unsigned int i; | |
507 | unsigned int j = 0; | |
508 | unsigned int cnt = ns_msl->r_nlist; | |
509 | ||
510 | while (cnt > 0 && ns_msl->r_list[cnt - 1]->l_removed) | |
511 | --cnt; | |
512 | ||
513 | if (cnt + unload_global == ns_msl->r_nlist) | |
514 | /* Speed up removing most recently added objects. */ | |
515 | j = cnt; | |
516 | else | |
b7c08a66 | 517 | for (i = 0; i < cnt; i++) |
e8b6b64d UD |
518 | if (ns_msl->r_list[i]->l_removed == 0) |
519 | { | |
520 | if (i != j) | |
521 | ns_msl->r_list[j] = ns_msl->r_list[i]; | |
522 | j++; | |
523 | } | |
524 | ns_msl->r_nlist = j; | |
e4eb675d | 525 | } |
e8b6b64d | 526 | |
e4eb675d UD |
527 | if (!RTLD_SINGLE_THREAD_P |
528 | && (unload_global | |
529 | || scope_mem_left | |
530 | || (GL(dl_scope_free_list) != NULL | |
531 | && GL(dl_scope_free_list)->count))) | |
532 | { | |
533 | THREAD_GSCOPE_WAIT (); | |
534 | ||
535 | /* Now we can free any queued old scopes. */ | |
385b4cf4 | 536 | struct dl_scope_free_list *fsl = GL(dl_scope_free_list); |
e4eb675d UD |
537 | if (fsl != NULL) |
538 | while (fsl->count > 0) | |
539 | free (fsl->list[--fsl->count]); | |
e8b6b64d UD |
540 | } |
541 | ||
541765b6 UD |
542 | size_t tls_free_start; |
543 | size_t tls_free_end; | |
544 | tls_free_start = tls_free_end = NO_TLS_OFFSET; | |
c877418f | 545 | |
5a2a1d75 AS |
546 | /* We modify the list of loaded objects. */ |
547 | __rtld_lock_lock_recursive (GL(dl_load_write_lock)); | |
548 | ||
ba79d61b RM |
549 | /* Check each element of the search list to see if all references to |
550 | it are gone. */ | |
ffd0e1b7 | 551 | for (unsigned int i = first_loaded; i < nloaded; ++i) |
ba79d61b | 552 | { |
20fe49b9 | 553 | struct link_map *imap = maps[i]; |
c3381f3e | 554 | if (!used[i]) |
ba79d61b | 555 | { |
20fe49b9 | 556 | assert (imap->l_type == lt_loaded); |
a8a1269d | 557 | |
ba79d61b RM |
558 | /* That was the last reference, and this was a dlopen-loaded |
559 | object. We can unmap it. */ | |
ba79d61b | 560 | |
1f0c4a10 | 561 | /* Remove the object from the dtv slotinfo array if it uses TLS. */ |
a1ffb40e | 562 | if (__glibc_unlikely (imap->l_tls_blocksize > 0)) |
a04586d8 | 563 | { |
a04586d8 | 564 | any_tls = true; |
bb4cb252 | 565 | |
9dcafc55 UD |
566 | if (GL(dl_tls_dtv_slotinfo_list) != NULL |
567 | && ! remove_slotinfo (imap->l_tls_modid, | |
568 | GL(dl_tls_dtv_slotinfo_list), 0, | |
569 | imap->l_init_called)) | |
fc093be1 UD |
570 | /* All dynamically loaded modules with TLS are unloaded. */ |
571 | GL(dl_tls_max_dtv_idx) = GL(dl_tls_static_nelem); | |
c877418f | 572 | |
4c533566 UD |
573 | if (imap->l_tls_offset != NO_TLS_OFFSET |
574 | && imap->l_tls_offset != FORCED_DYNAMIC_TLS_OFFSET) | |
c877418f RM |
575 | { |
576 | /* Collect a contiguous chunk built from the objects in | |
577 | this search list, going in either direction. When the | |
578 | whole chunk is at the end of the used area then we can | |
579 | reclaim it. */ | |
11bf311e | 580 | #if TLS_TCB_AT_TP |
541765b6 UD |
581 | if (tls_free_start == NO_TLS_OFFSET |
582 | || (size_t) imap->l_tls_offset == tls_free_start) | |
583 | { | |
584 | /* Extend the contiguous chunk being reclaimed. */ | |
585 | tls_free_start | |
586 | = imap->l_tls_offset - imap->l_tls_blocksize; | |
587 | ||
588 | if (tls_free_end == NO_TLS_OFFSET) | |
589 | tls_free_end = imap->l_tls_offset; | |
590 | } | |
591 | else if (imap->l_tls_offset - imap->l_tls_blocksize | |
592 | == tls_free_end) | |
593 | /* Extend the chunk backwards. */ | |
594 | tls_free_end = imap->l_tls_offset; | |
595 | else | |
596 | { | |
597 | /* This isn't contiguous with the last chunk freed. | |
598 | One of them will be leaked unless we can free | |
599 | one block right away. */ | |
600 | if (tls_free_end == GL(dl_tls_static_used)) | |
601 | { | |
602 | GL(dl_tls_static_used) = tls_free_start; | |
603 | tls_free_end = imap->l_tls_offset; | |
604 | tls_free_start | |
605 | = tls_free_end - imap->l_tls_blocksize; | |
606 | } | |
607 | else if ((size_t) imap->l_tls_offset | |
608 | == GL(dl_tls_static_used)) | |
609 | GL(dl_tls_static_used) | |
610 | = imap->l_tls_offset - imap->l_tls_blocksize; | |
611 | else if (tls_free_end < (size_t) imap->l_tls_offset) | |
612 | { | |
613 | /* We pick the later block. It has a chance to | |
614 | be freed. */ | |
615 | tls_free_end = imap->l_tls_offset; | |
616 | tls_free_start | |
617 | = tls_free_end - imap->l_tls_blocksize; | |
618 | } | |
619 | } | |
11bf311e | 620 | #elif TLS_DTV_AT_TP |
66bdbaa4 AM |
621 | if (tls_free_start == NO_TLS_OFFSET) |
622 | { | |
623 | tls_free_start = imap->l_tls_firstbyte_offset; | |
624 | tls_free_end = (imap->l_tls_offset | |
625 | + imap->l_tls_blocksize); | |
626 | } | |
627 | else if (imap->l_tls_firstbyte_offset == tls_free_end) | |
c877418f | 628 | /* Extend the contiguous chunk being reclaimed. */ |
66bdbaa4 | 629 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; |
c877418f RM |
630 | else if (imap->l_tls_offset + imap->l_tls_blocksize |
631 | == tls_free_start) | |
632 | /* Extend the chunk backwards. */ | |
66bdbaa4 AM |
633 | tls_free_start = imap->l_tls_firstbyte_offset; |
634 | /* This isn't contiguous with the last chunk freed. | |
635 | One of them will be leaked unless we can free | |
636 | one block right away. */ | |
637 | else if (imap->l_tls_offset + imap->l_tls_blocksize | |
638 | == GL(dl_tls_static_used)) | |
639 | GL(dl_tls_static_used) = imap->l_tls_firstbyte_offset; | |
640 | else if (tls_free_end == GL(dl_tls_static_used)) | |
c877418f | 641 | { |
66bdbaa4 AM |
642 | GL(dl_tls_static_used) = tls_free_start; |
643 | tls_free_start = imap->l_tls_firstbyte_offset; | |
644 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | |
645 | } | |
646 | else if (tls_free_end < imap->l_tls_firstbyte_offset) | |
647 | { | |
648 | /* We pick the later block. It has a chance to | |
649 | be freed. */ | |
650 | tls_free_start = imap->l_tls_firstbyte_offset; | |
651 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | |
c877418f | 652 | } |
11bf311e UD |
653 | #else |
654 | # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" | |
655 | #endif | |
c877418f | 656 | } |
a04586d8 | 657 | } |
a04586d8 | 658 | |
02d5e5d9 PK |
659 | /* Reset unique symbols if forced. */ |
660 | if (force) | |
661 | { | |
662 | struct unique_sym_table *tab = &ns->_ns_unique_sym_table; | |
663 | __rtld_lock_lock_recursive (tab->lock); | |
664 | struct unique_sym *entries = tab->entries; | |
665 | if (entries != NULL) | |
666 | { | |
667 | size_t idx, size = tab->size; | |
668 | for (idx = 0; idx < size; ++idx) | |
669 | { | |
670 | /* Clear unique symbol entries that belong to this | |
671 | object. */ | |
672 | if (entries[idx].name != NULL | |
673 | && entries[idx].map == imap) | |
674 | { | |
675 | entries[idx].name = NULL; | |
676 | entries[idx].hashval = 0; | |
677 | tab->n_elements--; | |
678 | } | |
679 | } | |
680 | } | |
681 | __rtld_lock_unlock_recursive (tab->lock); | |
682 | } | |
683 | ||
a8a1269d | 684 | /* We can unmap all the maps at once. We determined the |
4ce636da UD |
685 | start address and length when we loaded the object and |
686 | the `munmap' call does the rest. */ | |
09bf6406 | 687 | DL_UNMAP (imap); |
22bc7978 | 688 | |
ba79d61b | 689 | /* Finally, unlink the data structure and free it. */ |
2bd2cad9 RM |
690 | #if DL_NNS == 1 |
691 | /* The assert in the (imap->l_prev == NULL) case gives | |
692 | the compiler license to warn that NS points outside | |
693 | the dl_ns array bounds in that case (as nsid != LM_ID_BASE | |
694 | is tantamount to nsid >= DL_NNS). That should be impossible | |
695 | in this configuration, so just assert about it instead. */ | |
696 | assert (nsid == LM_ID_BASE); | |
697 | assert (imap->l_prev != NULL); | |
698 | #else | |
699 | if (imap->l_prev == NULL) | |
c0f62c56 | 700 | { |
2e81d449 | 701 | assert (nsid != LM_ID_BASE); |
b7c08a66 RM |
702 | ns->_ns_loaded = imap->l_next; |
703 | ||
704 | /* Update the pointer to the head of the list | |
705 | we leave for debuggers to examine. */ | |
706 | r->r_map = (void *) ns->_ns_loaded; | |
c0f62c56 | 707 | } |
2bd2cad9 RM |
708 | else |
709 | #endif | |
710 | imap->l_prev->l_next = imap->l_next; | |
c0f62c56 | 711 | |
2e81d449 | 712 | --ns->_ns_nloaded; |
c0f62c56 | 713 | if (imap->l_next != NULL) |
af69217f | 714 | imap->l_next->l_prev = imap->l_prev; |
a8a1269d | 715 | |
556224ab UD |
716 | free (imap->l_versions); |
717 | if (imap->l_origin != (char *) -1) | |
a8a1269d UD |
718 | free ((char *) imap->l_origin); |
719 | ||
20fe49b9 | 720 | free (imap->l_reldeps); |
4b4fcf99 | 721 | |
ac53c9c6 | 722 | /* Print debugging message. */ |
a1ffb40e | 723 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) |
ac53c9c6 UD |
724 | _dl_debug_printf ("\nfile=%s [%lu]; destroying link map\n", |
725 | imap->l_name, imap->l_ns); | |
726 | ||
4ce636da | 727 | /* This name always is allocated. */ |
a8a1269d | 728 | free (imap->l_name); |
4ce636da | 729 | /* Remove the list with all the names of the shared object. */ |
20fe49b9 UD |
730 | |
731 | struct libname_list *lnp = imap->l_libname; | |
a8a1269d UD |
732 | do |
733 | { | |
76156ea1 | 734 | struct libname_list *this = lnp; |
a8a1269d | 735 | lnp = lnp->next; |
11810621 UD |
736 | if (!this->dont_free) |
737 | free (this); | |
a8a1269d UD |
738 | } |
739 | while (lnp != NULL); | |
a8a1269d | 740 | |
4ce636da | 741 | /* Remove the searchlists. */ |
20fe49b9 | 742 | free (imap->l_initfini); |
4ce636da | 743 | |
5a21d307 | 744 | /* Remove the scope array if we allocated it. */ |
c0a777e8 UD |
745 | if (imap->l_scope != imap->l_scope_mem) |
746 | free (imap->l_scope); | |
5a21d307 | 747 | |
7bcaca43 | 748 | if (imap->l_phdr_allocated) |
15925412 | 749 | free ((void *) imap->l_phdr); |
7bcaca43 | 750 | |
f55727ca UD |
751 | if (imap->l_rpath_dirs.dirs != (void *) -1) |
752 | free (imap->l_rpath_dirs.dirs); | |
753 | if (imap->l_runpath_dirs.dirs != (void *) -1) | |
754 | free (imap->l_runpath_dirs.dirs); | |
755 | ||
af69217f | 756 | free (imap); |
ba79d61b RM |
757 | } |
758 | } | |
759 | ||
5a2a1d75 AS |
760 | __rtld_lock_unlock_recursive (GL(dl_load_write_lock)); |
761 | ||
c877418f | 762 | /* If we removed any object which uses TLS bump the generation counter. */ |
bb4cb252 | 763 | if (any_tls) |
c877418f | 764 | { |
a1ffb40e | 765 | if (__glibc_unlikely (++GL(dl_tls_generation) == 0)) |
8b748aed | 766 | _dl_fatal_printf ("TLS generation counter wrapped! Please report as described in "REPORT_BUGS_TO".\n"); |
c877418f RM |
767 | |
768 | if (tls_free_end == GL(dl_tls_static_used)) | |
769 | GL(dl_tls_static_used) = tls_free_start; | |
770 | } | |
a04586d8 | 771 | |
9dcafc55 UD |
772 | #ifdef SHARED |
773 | /* Auditing checkpoint: we have deleted all objects. */ | |
a1ffb40e | 774 | if (__glibc_unlikely (do_audit)) |
9dcafc55 | 775 | { |
2e81d449 | 776 | struct link_map *head = ns->_ns_loaded; |
9dcafc55 UD |
777 | /* Do not call the functions for any auditing object. */ |
778 | if (head->l_auditing == 0) | |
779 | { | |
780 | struct audit_ifaces *afct = GLRO(dl_audit); | |
781 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
782 | { | |
783 | if (afct->activity != NULL) | |
e1d559f3 FW |
784 | { |
785 | struct auditstate *state = link_map_audit_state (head, cnt); | |
786 | afct->activity (&state->cookie, LA_ACT_CONSISTENT); | |
787 | } | |
9dcafc55 UD |
788 | |
789 | afct = afct->next; | |
790 | } | |
791 | } | |
792 | } | |
793 | #endif | |
794 | ||
22c83193 UD |
795 | if (__builtin_expect (ns->_ns_loaded == NULL, 0) |
796 | && nsid == GL(dl_nns) - 1) | |
797 | do | |
0d23a5c1 | 798 | --GL(dl_nns); |
22c83193 UD |
799 | while (GL(dl_ns)[GL(dl_nns) - 1]._ns_loaded == NULL); |
800 | ||
e3e5f672 | 801 | /* Notify the debugger those objects are finalized and gone. */ |
9dcafc55 UD |
802 | r->r_state = RT_CONSISTENT; |
803 | _dl_debug_state (); | |
815e6fa3 | 804 | LIBC_PROBE (unmap_complete, 2, nsid, r); |
4b4fcf99 | 805 | |
bfc832cc | 806 | /* Recheck if we need to retry, release the lock. */ |
20fe49b9 | 807 | out: |
bfc832cc UD |
808 | if (dl_close_state == rerun) |
809 | goto retry; | |
810 | ||
811 | dl_close_state = not_pending; | |
131c4428 UD |
812 | } |
813 | ||
814 | ||
815 | void | |
816 | _dl_close (void *_map) | |
817 | { | |
818 | struct link_map *map = _map; | |
819 | ||
57707b7f CD |
820 | /* We must take the lock to examine the contents of map and avoid |
821 | concurrent dlopens. */ | |
822 | __rtld_lock_lock_recursive (GL(dl_load_lock)); | |
823 | ||
824 | /* At this point we are guaranteed nobody else is touching the list of | |
825 | loaded maps, but a concurrent dlclose might have freed our map | |
826 | before we took the lock. There is no way to detect this (see below) | |
827 | so we proceed assuming this isn't the case. First see whether we | |
828 | can remove the object at all. */ | |
a1ffb40e | 829 | if (__glibc_unlikely (map->l_flags_1 & DF_1_NODELETE)) |
131c4428 | 830 | { |
131c4428 | 831 | /* Nope. Do nothing. */ |
57707b7f | 832 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); |
131c4428 UD |
833 | return; |
834 | } | |
835 | ||
57707b7f CD |
836 | /* At present this is an unreliable check except in the case where the |
837 | caller has recursively called dlclose and we are sure the link map | |
838 | has not been freed. In a non-recursive dlclose the map itself | |
839 | might have been freed and this access is potentially a data race | |
840 | with whatever other use this memory might have now, or worse we | |
841 | might silently corrupt memory if it looks enough like a link map. | |
842 | POSIX has language in dlclose that appears to guarantee that this | |
843 | should be a detectable case and given that dlclose should be threadsafe | |
844 | we need this to be a reliable detection. | |
845 | This is bug 20990. */ | |
131c4428 | 846 | if (__builtin_expect (map->l_direct_opencount, 1) == 0) |
57707b7f CD |
847 | { |
848 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); | |
849 | _dl_signal_error (0, map->l_name, NULL, N_("shared object not open")); | |
850 | } | |
131c4428 | 851 | |
02d5e5d9 | 852 | _dl_close_worker (map, false); |
131c4428 | 853 | |
d3c9f895 | 854 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); |
e3e5f672 | 855 | } |