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26b4d766 | 1 | /* Close a shared object opened by `_dl_open'. |
688903eb | 2 | Copyright (C) 1996-2018 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 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://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) | |
305 | /* Return value is ignored. */ | |
306 | (void) afct->objclose (&imap->l_audit[cnt].cookie); | |
307 | ||
308 | afct = afct->next; | |
309 | } | |
310 | } | |
311 | #endif | |
312 | ||
20fe49b9 UD |
313 | /* This object must not be used anymore. */ |
314 | imap->l_removed = 1; | |
aff4519d | 315 | |
20fe49b9 UD |
316 | /* We indeed have an object to remove. */ |
317 | unload_any = true; | |
aff4519d | 318 | |
e8b6b64d UD |
319 | if (imap->l_global) |
320 | ++unload_global; | |
321 | ||
20fe49b9 UD |
322 | /* Remember where the first dynamically loaded object is. */ |
323 | if (i < first_loaded) | |
324 | first_loaded = i; | |
a709dd43 | 325 | } |
c3381f3e | 326 | /* Else used[i]. */ |
20fe49b9 UD |
327 | else if (imap->l_type == lt_loaded) |
328 | { | |
1100f849 UD |
329 | struct r_scope_elem *new_list = NULL; |
330 | ||
331 | if (imap->l_searchlist.r_list == NULL && imap->l_initfini != NULL) | |
20fe49b9 | 332 | { |
bfc832cc | 333 | /* The object is still used. But one of the objects we are |
20fe49b9 UD |
334 | unloading right now is responsible for loading it. If |
335 | the current object does not have it's own scope yet we | |
336 | have to create one. This has to be done before running | |
337 | the finalizers. | |
338 | ||
339 | To do this count the number of dependencies. */ | |
340 | unsigned int cnt; | |
341 | for (cnt = 1; imap->l_initfini[cnt] != NULL; ++cnt) | |
342 | ; | |
343 | ||
344 | /* We simply reuse the l_initfini list. */ | |
345 | imap->l_searchlist.r_list = &imap->l_initfini[cnt + 1]; | |
346 | imap->l_searchlist.r_nlist = cnt; | |
347 | ||
1100f849 | 348 | new_list = &imap->l_searchlist; |
20fe49b9 | 349 | } |
1100f849 UD |
350 | |
351 | /* Count the number of scopes which remain after the unload. | |
352 | When we add the local search list count it. Always add | |
353 | one for the terminating NULL pointer. */ | |
354 | size_t remain = (new_list != NULL) + 1; | |
355 | bool removed_any = false; | |
c0a777e8 | 356 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) |
1100f849 UD |
357 | /* This relies on l_scope[] entries being always set either |
358 | to its own l_symbolic_searchlist address, or some map's | |
359 | l_searchlist address. */ | |
c0a777e8 | 360 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) |
1100f849 UD |
361 | { |
362 | struct link_map *tmap = (struct link_map *) | |
c0a777e8 | 363 | ((char *) imap->l_scope[cnt] |
1100f849 | 364 | - offsetof (struct link_map, l_searchlist)); |
2e81d449 | 365 | assert (tmap->l_ns == nsid); |
1100f849 UD |
366 | if (tmap->l_idx == IDX_STILL_USED) |
367 | ++remain; | |
368 | else | |
369 | removed_any = true; | |
370 | } | |
371 | else | |
372 | ++remain; | |
373 | ||
374 | if (removed_any) | |
1ee2ff20 | 375 | { |
1100f849 UD |
376 | /* Always allocate a new array for the scope. This is |
377 | necessary since we must be able to determine the last | |
378 | user of the current array. If possible use the link map's | |
379 | memory. */ | |
380 | size_t new_size; | |
c0a777e8 UD |
381 | struct r_scope_elem **newp; |
382 | ||
383 | #define SCOPE_ELEMS(imap) \ | |
384 | (sizeof (imap->l_scope_mem) / sizeof (imap->l_scope_mem[0])) | |
385 | ||
386 | if (imap->l_scope != imap->l_scope_mem | |
387 | && remain < SCOPE_ELEMS (imap)) | |
1100f849 | 388 | { |
c0a777e8 UD |
389 | new_size = SCOPE_ELEMS (imap); |
390 | newp = imap->l_scope_mem; | |
1100f849 UD |
391 | } |
392 | else | |
393 | { | |
394 | new_size = imap->l_scope_max; | |
c0a777e8 UD |
395 | newp = (struct r_scope_elem **) |
396 | malloc (new_size * sizeof (struct r_scope_elem *)); | |
1100f849 UD |
397 | if (newp == NULL) |
398 | _dl_signal_error (ENOMEM, "dlclose", NULL, | |
399 | N_("cannot create scope list")); | |
400 | } | |
401 | ||
1100f849 UD |
402 | /* Copy over the remaining scope elements. */ |
403 | remain = 0; | |
c0a777e8 | 404 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) |
1ee2ff20 | 405 | { |
c0a777e8 | 406 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) |
1ee2ff20 | 407 | { |
1100f849 | 408 | struct link_map *tmap = (struct link_map *) |
c0a777e8 | 409 | ((char *) imap->l_scope[cnt] |
1100f849 UD |
410 | - offsetof (struct link_map, l_searchlist)); |
411 | if (tmap->l_idx != IDX_STILL_USED) | |
412 | { | |
413 | /* Remove the scope. Or replace with own map's | |
414 | scope. */ | |
415 | if (new_list != NULL) | |
416 | { | |
c0a777e8 | 417 | newp[remain++] = new_list; |
1100f849 UD |
418 | new_list = NULL; |
419 | } | |
420 | continue; | |
421 | } | |
1ee2ff20 | 422 | } |
1100f849 | 423 | |
c0a777e8 | 424 | newp[remain++] = imap->l_scope[cnt]; |
1ee2ff20 | 425 | } |
c0a777e8 | 426 | newp[remain] = NULL; |
1100f849 | 427 | |
c0a777e8 | 428 | struct r_scope_elem **old = imap->l_scope; |
1100f849 | 429 | |
e4eb675d | 430 | imap->l_scope = newp; |
1100f849 UD |
431 | |
432 | /* No user anymore, we can free it now. */ | |
c0a777e8 | 433 | if (old != imap->l_scope_mem) |
e4eb675d UD |
434 | { |
435 | if (_dl_scope_free (old)) | |
436 | /* If _dl_scope_free used THREAD_GSCOPE_WAIT (), | |
437 | no need to repeat it. */ | |
438 | scope_mem_left = false; | |
439 | } | |
440 | else | |
441 | scope_mem_left = true; | |
1100f849 UD |
442 | |
443 | imap->l_scope_max = new_size; | |
1ee2ff20 | 444 | } |
39dd69df AS |
445 | else if (new_list != NULL) |
446 | { | |
447 | /* We didn't change the scope array, so reset the search | |
448 | list. */ | |
449 | imap->l_searchlist.r_list = NULL; | |
450 | imap->l_searchlist.r_nlist = 0; | |
451 | } | |
42c4f32a | 452 | |
c3381f3e | 453 | /* The loader is gone, so mark the object as not having one. |
1100f849 UD |
454 | Note: l_idx != IDX_STILL_USED -> object will be removed. */ |
455 | if (imap->l_loader != NULL | |
456 | && imap->l_loader->l_idx != IDX_STILL_USED) | |
20fe49b9 | 457 | imap->l_loader = NULL; |
aff4519d | 458 | |
20fe49b9 UD |
459 | /* Remember where the first dynamically loaded object is. */ |
460 | if (i < first_loaded) | |
461 | first_loaded = i; | |
462 | } | |
a709dd43 UD |
463 | } |
464 | ||
20fe49b9 UD |
465 | /* If there are no objects to unload, do nothing further. */ |
466 | if (!unload_any) | |
467 | goto out; | |
468 | ||
9dcafc55 UD |
469 | #ifdef SHARED |
470 | /* Auditing checkpoint: we will start deleting objects. */ | |
a1ffb40e | 471 | if (__glibc_unlikely (do_audit)) |
9dcafc55 | 472 | { |
2e81d449 | 473 | struct link_map *head = ns->_ns_loaded; |
9dcafc55 UD |
474 | struct audit_ifaces *afct = GLRO(dl_audit); |
475 | /* Do not call the functions for any auditing object. */ | |
476 | if (head->l_auditing == 0) | |
477 | { | |
478 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
479 | { | |
480 | if (afct->activity != NULL) | |
481 | afct->activity (&head->l_audit[cnt].cookie, LA_ACT_DELETE); | |
482 | ||
483 | afct = afct->next; | |
484 | } | |
485 | } | |
486 | } | |
487 | #endif | |
488 | ||
4d6acc61 | 489 | /* Notify the debugger we are about to remove some loaded objects. */ |
2e81d449 | 490 | struct r_debug *r = _dl_debug_initialize (0, nsid); |
9dcafc55 UD |
491 | r->r_state = RT_DELETE; |
492 | _dl_debug_state (); | |
815e6fa3 | 493 | LIBC_PROBE (unmap_start, 2, nsid, r); |
4d6acc61 | 494 | |
e8b6b64d UD |
495 | if (unload_global) |
496 | { | |
497 | /* Some objects are in the global scope list. Remove them. */ | |
498 | struct r_scope_elem *ns_msl = ns->_ns_main_searchlist; | |
499 | unsigned int i; | |
500 | unsigned int j = 0; | |
501 | unsigned int cnt = ns_msl->r_nlist; | |
502 | ||
503 | while (cnt > 0 && ns_msl->r_list[cnt - 1]->l_removed) | |
504 | --cnt; | |
505 | ||
506 | if (cnt + unload_global == ns_msl->r_nlist) | |
507 | /* Speed up removing most recently added objects. */ | |
508 | j = cnt; | |
509 | else | |
b7c08a66 | 510 | for (i = 0; i < cnt; i++) |
e8b6b64d UD |
511 | if (ns_msl->r_list[i]->l_removed == 0) |
512 | { | |
513 | if (i != j) | |
514 | ns_msl->r_list[j] = ns_msl->r_list[i]; | |
515 | j++; | |
516 | } | |
517 | ns_msl->r_nlist = j; | |
e4eb675d | 518 | } |
e8b6b64d | 519 | |
e4eb675d UD |
520 | if (!RTLD_SINGLE_THREAD_P |
521 | && (unload_global | |
522 | || scope_mem_left | |
523 | || (GL(dl_scope_free_list) != NULL | |
524 | && GL(dl_scope_free_list)->count))) | |
525 | { | |
526 | THREAD_GSCOPE_WAIT (); | |
527 | ||
528 | /* Now we can free any queued old scopes. */ | |
385b4cf4 | 529 | struct dl_scope_free_list *fsl = GL(dl_scope_free_list); |
e4eb675d UD |
530 | if (fsl != NULL) |
531 | while (fsl->count > 0) | |
532 | free (fsl->list[--fsl->count]); | |
e8b6b64d UD |
533 | } |
534 | ||
541765b6 UD |
535 | size_t tls_free_start; |
536 | size_t tls_free_end; | |
537 | tls_free_start = tls_free_end = NO_TLS_OFFSET; | |
c877418f | 538 | |
5a2a1d75 AS |
539 | /* We modify the list of loaded objects. */ |
540 | __rtld_lock_lock_recursive (GL(dl_load_write_lock)); | |
541 | ||
ba79d61b RM |
542 | /* Check each element of the search list to see if all references to |
543 | it are gone. */ | |
ffd0e1b7 | 544 | for (unsigned int i = first_loaded; i < nloaded; ++i) |
ba79d61b | 545 | { |
20fe49b9 | 546 | struct link_map *imap = maps[i]; |
c3381f3e | 547 | if (!used[i]) |
ba79d61b | 548 | { |
20fe49b9 | 549 | assert (imap->l_type == lt_loaded); |
a8a1269d | 550 | |
ba79d61b RM |
551 | /* That was the last reference, and this was a dlopen-loaded |
552 | object. We can unmap it. */ | |
ba79d61b | 553 | |
1f0c4a10 | 554 | /* Remove the object from the dtv slotinfo array if it uses TLS. */ |
a1ffb40e | 555 | if (__glibc_unlikely (imap->l_tls_blocksize > 0)) |
a04586d8 | 556 | { |
a04586d8 | 557 | any_tls = true; |
bb4cb252 | 558 | |
9dcafc55 UD |
559 | if (GL(dl_tls_dtv_slotinfo_list) != NULL |
560 | && ! remove_slotinfo (imap->l_tls_modid, | |
561 | GL(dl_tls_dtv_slotinfo_list), 0, | |
562 | imap->l_init_called)) | |
fc093be1 UD |
563 | /* All dynamically loaded modules with TLS are unloaded. */ |
564 | GL(dl_tls_max_dtv_idx) = GL(dl_tls_static_nelem); | |
c877418f | 565 | |
4c533566 UD |
566 | if (imap->l_tls_offset != NO_TLS_OFFSET |
567 | && imap->l_tls_offset != FORCED_DYNAMIC_TLS_OFFSET) | |
c877418f RM |
568 | { |
569 | /* Collect a contiguous chunk built from the objects in | |
570 | this search list, going in either direction. When the | |
571 | whole chunk is at the end of the used area then we can | |
572 | reclaim it. */ | |
11bf311e | 573 | #if TLS_TCB_AT_TP |
541765b6 UD |
574 | if (tls_free_start == NO_TLS_OFFSET |
575 | || (size_t) imap->l_tls_offset == tls_free_start) | |
576 | { | |
577 | /* Extend the contiguous chunk being reclaimed. */ | |
578 | tls_free_start | |
579 | = imap->l_tls_offset - imap->l_tls_blocksize; | |
580 | ||
581 | if (tls_free_end == NO_TLS_OFFSET) | |
582 | tls_free_end = imap->l_tls_offset; | |
583 | } | |
584 | else if (imap->l_tls_offset - imap->l_tls_blocksize | |
585 | == tls_free_end) | |
586 | /* Extend the chunk backwards. */ | |
587 | tls_free_end = imap->l_tls_offset; | |
588 | else | |
589 | { | |
590 | /* This isn't contiguous with the last chunk freed. | |
591 | One of them will be leaked unless we can free | |
592 | one block right away. */ | |
593 | if (tls_free_end == GL(dl_tls_static_used)) | |
594 | { | |
595 | GL(dl_tls_static_used) = tls_free_start; | |
596 | tls_free_end = imap->l_tls_offset; | |
597 | tls_free_start | |
598 | = tls_free_end - imap->l_tls_blocksize; | |
599 | } | |
600 | else if ((size_t) imap->l_tls_offset | |
601 | == GL(dl_tls_static_used)) | |
602 | GL(dl_tls_static_used) | |
603 | = imap->l_tls_offset - imap->l_tls_blocksize; | |
604 | else if (tls_free_end < (size_t) imap->l_tls_offset) | |
605 | { | |
606 | /* We pick the later block. It has a chance to | |
607 | be freed. */ | |
608 | tls_free_end = imap->l_tls_offset; | |
609 | tls_free_start | |
610 | = tls_free_end - imap->l_tls_blocksize; | |
611 | } | |
612 | } | |
11bf311e | 613 | #elif TLS_DTV_AT_TP |
66bdbaa4 AM |
614 | if (tls_free_start == NO_TLS_OFFSET) |
615 | { | |
616 | tls_free_start = imap->l_tls_firstbyte_offset; | |
617 | tls_free_end = (imap->l_tls_offset | |
618 | + imap->l_tls_blocksize); | |
619 | } | |
620 | else if (imap->l_tls_firstbyte_offset == tls_free_end) | |
c877418f | 621 | /* Extend the contiguous chunk being reclaimed. */ |
66bdbaa4 | 622 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; |
c877418f RM |
623 | else if (imap->l_tls_offset + imap->l_tls_blocksize |
624 | == tls_free_start) | |
625 | /* Extend the chunk backwards. */ | |
66bdbaa4 AM |
626 | tls_free_start = imap->l_tls_firstbyte_offset; |
627 | /* This isn't contiguous with the last chunk freed. | |
628 | One of them will be leaked unless we can free | |
629 | one block right away. */ | |
630 | else if (imap->l_tls_offset + imap->l_tls_blocksize | |
631 | == GL(dl_tls_static_used)) | |
632 | GL(dl_tls_static_used) = imap->l_tls_firstbyte_offset; | |
633 | else if (tls_free_end == GL(dl_tls_static_used)) | |
c877418f | 634 | { |
66bdbaa4 AM |
635 | GL(dl_tls_static_used) = tls_free_start; |
636 | tls_free_start = imap->l_tls_firstbyte_offset; | |
637 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | |
638 | } | |
639 | else if (tls_free_end < imap->l_tls_firstbyte_offset) | |
640 | { | |
641 | /* We pick the later block. It has a chance to | |
642 | be freed. */ | |
643 | tls_free_start = imap->l_tls_firstbyte_offset; | |
644 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | |
c877418f | 645 | } |
11bf311e UD |
646 | #else |
647 | # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" | |
648 | #endif | |
c877418f | 649 | } |
a04586d8 | 650 | } |
a04586d8 | 651 | |
02d5e5d9 PK |
652 | /* Reset unique symbols if forced. */ |
653 | if (force) | |
654 | { | |
655 | struct unique_sym_table *tab = &ns->_ns_unique_sym_table; | |
656 | __rtld_lock_lock_recursive (tab->lock); | |
657 | struct unique_sym *entries = tab->entries; | |
658 | if (entries != NULL) | |
659 | { | |
660 | size_t idx, size = tab->size; | |
661 | for (idx = 0; idx < size; ++idx) | |
662 | { | |
663 | /* Clear unique symbol entries that belong to this | |
664 | object. */ | |
665 | if (entries[idx].name != NULL | |
666 | && entries[idx].map == imap) | |
667 | { | |
668 | entries[idx].name = NULL; | |
669 | entries[idx].hashval = 0; | |
670 | tab->n_elements--; | |
671 | } | |
672 | } | |
673 | } | |
674 | __rtld_lock_unlock_recursive (tab->lock); | |
675 | } | |
676 | ||
a8a1269d | 677 | /* We can unmap all the maps at once. We determined the |
4ce636da UD |
678 | start address and length when we loaded the object and |
679 | the `munmap' call does the rest. */ | |
09bf6406 | 680 | DL_UNMAP (imap); |
22bc7978 | 681 | |
ba79d61b | 682 | /* Finally, unlink the data structure and free it. */ |
2bd2cad9 RM |
683 | #if DL_NNS == 1 |
684 | /* The assert in the (imap->l_prev == NULL) case gives | |
685 | the compiler license to warn that NS points outside | |
686 | the dl_ns array bounds in that case (as nsid != LM_ID_BASE | |
687 | is tantamount to nsid >= DL_NNS). That should be impossible | |
688 | in this configuration, so just assert about it instead. */ | |
689 | assert (nsid == LM_ID_BASE); | |
690 | assert (imap->l_prev != NULL); | |
691 | #else | |
692 | if (imap->l_prev == NULL) | |
c0f62c56 | 693 | { |
2e81d449 | 694 | assert (nsid != LM_ID_BASE); |
b7c08a66 RM |
695 | ns->_ns_loaded = imap->l_next; |
696 | ||
697 | /* Update the pointer to the head of the list | |
698 | we leave for debuggers to examine. */ | |
699 | r->r_map = (void *) ns->_ns_loaded; | |
c0f62c56 | 700 | } |
2bd2cad9 RM |
701 | else |
702 | #endif | |
703 | imap->l_prev->l_next = imap->l_next; | |
c0f62c56 | 704 | |
2e81d449 | 705 | --ns->_ns_nloaded; |
c0f62c56 | 706 | if (imap->l_next != NULL) |
af69217f | 707 | imap->l_next->l_prev = imap->l_prev; |
a8a1269d | 708 | |
556224ab UD |
709 | free (imap->l_versions); |
710 | if (imap->l_origin != (char *) -1) | |
a8a1269d UD |
711 | free ((char *) imap->l_origin); |
712 | ||
20fe49b9 | 713 | free (imap->l_reldeps); |
4b4fcf99 | 714 | |
ac53c9c6 | 715 | /* Print debugging message. */ |
a1ffb40e | 716 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) |
ac53c9c6 UD |
717 | _dl_debug_printf ("\nfile=%s [%lu]; destroying link map\n", |
718 | imap->l_name, imap->l_ns); | |
719 | ||
4ce636da | 720 | /* This name always is allocated. */ |
a8a1269d | 721 | free (imap->l_name); |
4ce636da | 722 | /* Remove the list with all the names of the shared object. */ |
20fe49b9 UD |
723 | |
724 | struct libname_list *lnp = imap->l_libname; | |
a8a1269d UD |
725 | do |
726 | { | |
76156ea1 | 727 | struct libname_list *this = lnp; |
a8a1269d | 728 | lnp = lnp->next; |
11810621 UD |
729 | if (!this->dont_free) |
730 | free (this); | |
a8a1269d UD |
731 | } |
732 | while (lnp != NULL); | |
a8a1269d | 733 | |
4ce636da | 734 | /* Remove the searchlists. */ |
20fe49b9 | 735 | free (imap->l_initfini); |
4ce636da | 736 | |
5a21d307 | 737 | /* Remove the scope array if we allocated it. */ |
c0a777e8 UD |
738 | if (imap->l_scope != imap->l_scope_mem) |
739 | free (imap->l_scope); | |
5a21d307 | 740 | |
7bcaca43 | 741 | if (imap->l_phdr_allocated) |
15925412 | 742 | free ((void *) imap->l_phdr); |
7bcaca43 | 743 | |
f55727ca UD |
744 | if (imap->l_rpath_dirs.dirs != (void *) -1) |
745 | free (imap->l_rpath_dirs.dirs); | |
746 | if (imap->l_runpath_dirs.dirs != (void *) -1) | |
747 | free (imap->l_runpath_dirs.dirs); | |
748 | ||
af69217f | 749 | free (imap); |
ba79d61b RM |
750 | } |
751 | } | |
752 | ||
5a2a1d75 AS |
753 | __rtld_lock_unlock_recursive (GL(dl_load_write_lock)); |
754 | ||
c877418f | 755 | /* If we removed any object which uses TLS bump the generation counter. */ |
bb4cb252 | 756 | if (any_tls) |
c877418f | 757 | { |
a1ffb40e | 758 | if (__glibc_unlikely (++GL(dl_tls_generation) == 0)) |
8b748aed | 759 | _dl_fatal_printf ("TLS generation counter wrapped! Please report as described in "REPORT_BUGS_TO".\n"); |
c877418f RM |
760 | |
761 | if (tls_free_end == GL(dl_tls_static_used)) | |
762 | GL(dl_tls_static_used) = tls_free_start; | |
763 | } | |
a04586d8 | 764 | |
9dcafc55 UD |
765 | #ifdef SHARED |
766 | /* Auditing checkpoint: we have deleted all objects. */ | |
a1ffb40e | 767 | if (__glibc_unlikely (do_audit)) |
9dcafc55 | 768 | { |
2e81d449 | 769 | struct link_map *head = ns->_ns_loaded; |
9dcafc55 UD |
770 | /* Do not call the functions for any auditing object. */ |
771 | if (head->l_auditing == 0) | |
772 | { | |
773 | struct audit_ifaces *afct = GLRO(dl_audit); | |
774 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | |
775 | { | |
776 | if (afct->activity != NULL) | |
777 | afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT); | |
778 | ||
779 | afct = afct->next; | |
780 | } | |
781 | } | |
782 | } | |
783 | #endif | |
784 | ||
22c83193 UD |
785 | if (__builtin_expect (ns->_ns_loaded == NULL, 0) |
786 | && nsid == GL(dl_nns) - 1) | |
787 | do | |
0d23a5c1 | 788 | --GL(dl_nns); |
22c83193 UD |
789 | while (GL(dl_ns)[GL(dl_nns) - 1]._ns_loaded == NULL); |
790 | ||
e3e5f672 | 791 | /* Notify the debugger those objects are finalized and gone. */ |
9dcafc55 UD |
792 | r->r_state = RT_CONSISTENT; |
793 | _dl_debug_state (); | |
815e6fa3 | 794 | LIBC_PROBE (unmap_complete, 2, nsid, r); |
4b4fcf99 | 795 | |
bfc832cc | 796 | /* Recheck if we need to retry, release the lock. */ |
20fe49b9 | 797 | out: |
bfc832cc UD |
798 | if (dl_close_state == rerun) |
799 | goto retry; | |
800 | ||
801 | dl_close_state = not_pending; | |
131c4428 UD |
802 | } |
803 | ||
804 | ||
805 | void | |
806 | _dl_close (void *_map) | |
807 | { | |
808 | struct link_map *map = _map; | |
809 | ||
57707b7f CD |
810 | /* We must take the lock to examine the contents of map and avoid |
811 | concurrent dlopens. */ | |
812 | __rtld_lock_lock_recursive (GL(dl_load_lock)); | |
813 | ||
814 | /* At this point we are guaranteed nobody else is touching the list of | |
815 | loaded maps, but a concurrent dlclose might have freed our map | |
816 | before we took the lock. There is no way to detect this (see below) | |
817 | so we proceed assuming this isn't the case. First see whether we | |
818 | can remove the object at all. */ | |
a1ffb40e | 819 | if (__glibc_unlikely (map->l_flags_1 & DF_1_NODELETE)) |
131c4428 | 820 | { |
131c4428 | 821 | /* Nope. Do nothing. */ |
57707b7f | 822 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); |
131c4428 UD |
823 | return; |
824 | } | |
825 | ||
57707b7f CD |
826 | /* At present this is an unreliable check except in the case where the |
827 | caller has recursively called dlclose and we are sure the link map | |
828 | has not been freed. In a non-recursive dlclose the map itself | |
829 | might have been freed and this access is potentially a data race | |
830 | with whatever other use this memory might have now, or worse we | |
831 | might silently corrupt memory if it looks enough like a link map. | |
832 | POSIX has language in dlclose that appears to guarantee that this | |
833 | should be a detectable case and given that dlclose should be threadsafe | |
834 | we need this to be a reliable detection. | |
835 | This is bug 20990. */ | |
131c4428 | 836 | if (__builtin_expect (map->l_direct_opencount, 1) == 0) |
57707b7f CD |
837 | { |
838 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); | |
839 | _dl_signal_error (0, map->l_name, NULL, N_("shared object not open")); | |
840 | } | |
131c4428 | 841 | |
02d5e5d9 | 842 | _dl_close_worker (map, false); |
131c4428 | 843 | |
d3c9f895 | 844 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); |
e3e5f672 | 845 | } |