| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Close a shared object opened by `_dl_open'. | 
|  | 2 | Copyright (C) 1996-2016 Free Software Foundation, Inc. | 
|  | 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 | 
|  | 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. | 
|  | 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 | 
|  | 13 | Lesser General Public License for more details. | 
|  | 14 |  | 
|  | 15 | You should have received a copy of the GNU Lesser General Public | 
|  | 16 | License along with the GNU C Library; if not, see | 
|  | 17 | <http://www.gnu.org/licenses/>.  */ | 
|  | 18 |  | 
|  | 19 | #include <assert.h> | 
|  | 20 | #include <dlfcn.h> | 
|  | 21 | #include <errno.h> | 
|  | 22 | #include <libintl.h> | 
|  | 23 | #include <stddef.h> | 
|  | 24 | #include <stdio.h> | 
|  | 25 | #include <stdlib.h> | 
|  | 26 | #include <string.h> | 
|  | 27 | #include <unistd.h> | 
|  | 28 | #include <libc-lock.h> | 
|  | 29 | #include <ldsodefs.h> | 
|  | 30 | #include <sys/types.h> | 
|  | 31 | #include <sys/mman.h> | 
|  | 32 | #include <sysdep-cancel.h> | 
|  | 33 | #include <tls.h> | 
|  | 34 | #include <stap-probe.h> | 
|  | 35 |  | 
|  | 36 | #include <dl-unmap-segments.h> | 
|  | 37 |  | 
|  | 38 |  | 
|  | 39 | /* Type of the constructor functions.  */ | 
|  | 40 | typedef void (*fini_t) (void); | 
|  | 41 |  | 
|  | 42 |  | 
|  | 43 | /* Special l_idx value used to indicate which objects remain loaded.  */ | 
|  | 44 | #define IDX_STILL_USED -1 | 
|  | 45 |  | 
|  | 46 |  | 
|  | 47 | /* Returns true we an non-empty was found.  */ | 
|  | 48 | static bool | 
|  | 49 | remove_slotinfo (size_t idx, struct dtv_slotinfo_list *listp, size_t disp, | 
|  | 50 | bool should_be_there) | 
|  | 51 | { | 
|  | 52 | if (idx - disp >= listp->len) | 
|  | 53 | { | 
|  | 54 | if (listp->next == NULL) | 
|  | 55 | { | 
|  | 56 | /* The index is not actually valid in the slotinfo list, | 
|  | 57 | because this object was closed before it was fully set | 
|  | 58 | up due to some error.  */ | 
|  | 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; | 
|  | 66 |  | 
|  | 67 | /* No non-empty entry.  Search from the end of this element's | 
|  | 68 | slotinfo array.  */ | 
|  | 69 | idx = disp + listp->len; | 
|  | 70 | } | 
|  | 71 | } | 
|  | 72 | else | 
|  | 73 | { | 
|  | 74 | struct link_map *old_map = listp->slotinfo[idx - disp].map; | 
|  | 75 |  | 
|  | 76 | /* The entry might still be in its unused state if we are closing an | 
|  | 77 | object that wasn't fully set up.  */ | 
|  | 78 | if (__glibc_likely (old_map != NULL)) | 
|  | 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 | } | 
|  | 86 |  | 
|  | 87 | /* If this is not the last currently used entry no need to look | 
|  | 88 | further.  */ | 
|  | 89 | if (idx != GL(dl_tls_max_dtv_idx)) | 
|  | 90 | return true; | 
|  | 91 | } | 
|  | 92 |  | 
|  | 93 | while (idx - disp > (disp == 0 ? 1 + GL(dl_tls_static_nelem) : 0)) | 
|  | 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 | } | 
|  | 108 |  | 
|  | 109 |  | 
|  | 110 | void | 
|  | 111 | _dl_close_worker (struct link_map *map, bool force) | 
|  | 112 | { | 
|  | 113 | /* One less direct use.  */ | 
|  | 114 | --map->l_direct_opencount; | 
|  | 115 |  | 
|  | 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) | 
|  | 123 | { | 
|  | 124 | if (map->l_direct_opencount == 0 && map->l_type == lt_loaded) | 
|  | 125 | dl_close_state = rerun; | 
|  | 126 |  | 
|  | 127 | /* There are still references to this object.  Do nothing more.  */ | 
|  | 128 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) | 
|  | 129 | _dl_debug_printf ("\nclosing file=%s; direct_opencount=%u\n", | 
|  | 130 | map->l_name, map->l_direct_opencount); | 
|  | 131 |  | 
|  | 132 | return; | 
|  | 133 | } | 
|  | 134 |  | 
|  | 135 | Lmid_t nsid = map->l_ns; | 
|  | 136 | struct link_namespaces *ns = &GL(dl_ns)[nsid]; | 
|  | 137 |  | 
|  | 138 | retry: | 
|  | 139 | dl_close_state = pending; | 
|  | 140 |  | 
|  | 141 | bool any_tls = false; | 
|  | 142 | const unsigned int nloaded = ns->_ns_nloaded; | 
|  | 143 | char used[nloaded]; | 
|  | 144 | char done[nloaded]; | 
|  | 145 | struct link_map *maps[nloaded]; | 
|  | 146 |  | 
|  | 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 |  | 
|  | 155 | /* Run over the list and assign indexes to the link maps and enter | 
|  | 156 | them into the MAPS array.  */ | 
|  | 157 | int idx = 0; | 
|  | 158 | for (struct link_map *l = ns->_ns_loaded; l != NULL; l = l->l_next) | 
|  | 159 | { | 
|  | 160 | l->l_idx = idx; | 
|  | 161 | maps[idx] = l; | 
|  | 162 | ++idx; | 
|  | 163 |  | 
|  | 164 | } | 
|  | 165 | assert (idx == nloaded); | 
|  | 166 |  | 
|  | 167 | /* Prepare the bitmaps.  */ | 
|  | 168 | memset (used, '\0', sizeof (used)); | 
|  | 169 | memset (done, '\0', sizeof (done)); | 
|  | 170 |  | 
|  | 171 | /* Keep track of the lowest index link map we have covered already.  */ | 
|  | 172 | int done_index = -1; | 
|  | 173 | while (++done_index < nloaded) | 
|  | 174 | { | 
|  | 175 | struct link_map *l = maps[done_index]; | 
|  | 176 |  | 
|  | 177 | if (done[done_index]) | 
|  | 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 | 
|  | 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 | 
|  | 188 | && !used[done_index]) | 
|  | 189 | continue; | 
|  | 190 |  | 
|  | 191 | /* We need this object and we handle it now.  */ | 
|  | 192 | done[done_index] = 1; | 
|  | 193 | used[done_index] = 1; | 
|  | 194 | /* Signal the object is still needed.  */ | 
|  | 195 | l->l_idx = IDX_STILL_USED; | 
|  | 196 |  | 
|  | 197 | /* Mark all dependencies as used.  */ | 
|  | 198 | if (l->l_initfini != NULL) | 
|  | 199 | { | 
|  | 200 | /* We are always the zeroth entry, and since we don't include | 
|  | 201 | ourselves in the dependency analysis start at 1.  */ | 
|  | 202 | struct link_map **lp = &l->l_initfini[1]; | 
|  | 203 | while (*lp != NULL) | 
|  | 204 | { | 
|  | 205 | if ((*lp)->l_idx != IDX_STILL_USED) | 
|  | 206 | { | 
|  | 207 | assert ((*lp)->l_idx >= 0 && (*lp)->l_idx < nloaded); | 
|  | 208 |  | 
|  | 209 | if (!used[(*lp)->l_idx]) | 
|  | 210 | { | 
|  | 211 | used[(*lp)->l_idx] = 1; | 
|  | 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.  */ | 
|  | 216 | if ((*lp)->l_idx - 1 < done_index) | 
|  | 217 | done_index = (*lp)->l_idx - 1; | 
|  | 218 | } | 
|  | 219 | } | 
|  | 220 |  | 
|  | 221 | ++lp; | 
|  | 222 | } | 
|  | 223 | } | 
|  | 224 | /* And the same for relocation dependencies.  */ | 
|  | 225 | if (l->l_reldeps != NULL) | 
|  | 226 | for (unsigned int j = 0; j < l->l_reldeps->act; ++j) | 
|  | 227 | { | 
|  | 228 | struct link_map *jmap = l->l_reldeps->list[j]; | 
|  | 229 |  | 
|  | 230 | if (jmap->l_idx != IDX_STILL_USED) | 
|  | 231 | { | 
|  | 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 | } | 
|  | 240 | } | 
|  | 241 | } | 
|  | 242 | } | 
|  | 243 |  | 
|  | 244 | /* Sort the entries.  */ | 
|  | 245 | _dl_sort_fini (maps, nloaded, used, nsid); | 
|  | 246 |  | 
|  | 247 | /* Call all termination functions at once.  */ | 
|  | 248 | #ifdef SHARED | 
|  | 249 | bool do_audit = GLRO(dl_naudit) > 0 && !ns->_ns_loaded->l_auditing; | 
|  | 250 | #endif | 
|  | 251 | bool unload_any = false; | 
|  | 252 | bool scope_mem_left = false; | 
|  | 253 | unsigned int unload_global = 0; | 
|  | 254 | unsigned int first_loaded = ~0; | 
|  | 255 | for (unsigned int i = 0; i < nloaded; ++i) | 
|  | 256 | { | 
|  | 257 | struct link_map *imap = maps[i]; | 
|  | 258 |  | 
|  | 259 | /* All elements must be in the same namespace.  */ | 
|  | 260 | assert (imap->l_ns == nsid); | 
|  | 261 |  | 
|  | 262 | if (!used[i]) | 
|  | 263 | { | 
|  | 264 | assert (imap->l_type == lt_loaded | 
|  | 265 | && (imap->l_flags_1 & DF_1_NODELETE) == 0); | 
|  | 266 |  | 
|  | 267 | /* Call its termination function.  Do not do it for | 
|  | 268 | half-cooked objects.  */ | 
|  | 269 | if (imap->l_init_called) | 
|  | 270 | { | 
|  | 271 | /* When debugging print a message first.  */ | 
|  | 272 | if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, | 
|  | 273 | 0)) | 
|  | 274 | _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n", | 
|  | 275 | imap->l_name, nsid); | 
|  | 276 |  | 
|  | 277 | if (imap->l_info[DT_FINI_ARRAY] != NULL) | 
|  | 278 | { | 
|  | 279 | ElfW(Addr) *array = | 
|  | 280 | (ElfW(Addr) *) (imap->l_addr | 
|  | 281 | + imap->l_info[DT_FINI_ARRAY]->d_un.d_ptr); | 
|  | 282 | unsigned int sz = (imap->l_info[DT_FINI_ARRAYSZ]->d_un.d_val | 
|  | 283 | / sizeof (ElfW(Addr))); | 
|  | 284 |  | 
|  | 285 | while (sz-- > 0) | 
|  | 286 | ((fini_t) array[sz]) (); | 
|  | 287 | } | 
|  | 288 |  | 
|  | 289 | /* Next try the old-style destructor.  */ | 
|  | 290 | if (imap->l_info[DT_FINI] != NULL) | 
|  | 291 | DL_CALL_DT_FINI (imap, ((void *) imap->l_addr | 
|  | 292 | + imap->l_info[DT_FINI]->d_un.d_ptr)); | 
|  | 293 | } | 
|  | 294 |  | 
|  | 295 | #ifdef SHARED | 
|  | 296 | /* Auditing checkpoint: we remove an object.  */ | 
|  | 297 | if (__glibc_unlikely (do_audit)) | 
|  | 298 | { | 
|  | 299 | struct audit_ifaces *afct = GLRO(dl_audit); | 
|  | 300 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | 
|  | 301 | { | 
|  | 302 | if (afct->objclose != NULL) | 
|  | 303 | /* Return value is ignored.  */ | 
|  | 304 | (void) afct->objclose (&imap->l_audit[cnt].cookie); | 
|  | 305 |  | 
|  | 306 | afct = afct->next; | 
|  | 307 | } | 
|  | 308 | } | 
|  | 309 | #endif | 
|  | 310 |  | 
|  | 311 | /* This object must not be used anymore.  */ | 
|  | 312 | imap->l_removed = 1; | 
|  | 313 |  | 
|  | 314 | /* We indeed have an object to remove.  */ | 
|  | 315 | unload_any = true; | 
|  | 316 |  | 
|  | 317 | if (imap->l_global) | 
|  | 318 | ++unload_global; | 
|  | 319 |  | 
|  | 320 | /* Remember where the first dynamically loaded object is.  */ | 
|  | 321 | if (i < first_loaded) | 
|  | 322 | first_loaded = i; | 
|  | 323 | } | 
|  | 324 | /* Else used[i].  */ | 
|  | 325 | else if (imap->l_type == lt_loaded) | 
|  | 326 | { | 
|  | 327 | struct r_scope_elem *new_list = NULL; | 
|  | 328 |  | 
|  | 329 | if (imap->l_searchlist.r_list == NULL && imap->l_initfini != NULL) | 
|  | 330 | { | 
|  | 331 | /* The object is still used.  But one of the objects we are | 
|  | 332 | unloading right now is responsible for loading it.  If | 
|  | 333 | the current object does not have it's own scope yet we | 
|  | 334 | have to create one.  This has to be done before running | 
|  | 335 | the finalizers. | 
|  | 336 |  | 
|  | 337 | To do this count the number of dependencies.  */ | 
|  | 338 | unsigned int cnt; | 
|  | 339 | for (cnt = 1; imap->l_initfini[cnt] != NULL; ++cnt) | 
|  | 340 | ; | 
|  | 341 |  | 
|  | 342 | /* We simply reuse the l_initfini list.  */ | 
|  | 343 | imap->l_searchlist.r_list = &imap->l_initfini[cnt + 1]; | 
|  | 344 | imap->l_searchlist.r_nlist = cnt; | 
|  | 345 |  | 
|  | 346 | new_list = &imap->l_searchlist; | 
|  | 347 | } | 
|  | 348 |  | 
|  | 349 | /* Count the number of scopes which remain after the unload. | 
|  | 350 | When we add the local search list count it.  Always add | 
|  | 351 | one for the terminating NULL pointer.  */ | 
|  | 352 | size_t remain = (new_list != NULL) + 1; | 
|  | 353 | bool removed_any = false; | 
|  | 354 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) | 
|  | 355 | /* This relies on l_scope[] entries being always set either | 
|  | 356 | to its own l_symbolic_searchlist address, or some map's | 
|  | 357 | l_searchlist address.  */ | 
|  | 358 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) | 
|  | 359 | { | 
|  | 360 | struct link_map *tmap = (struct link_map *) | 
|  | 361 | ((char *) imap->l_scope[cnt] | 
|  | 362 | - offsetof (struct link_map, l_searchlist)); | 
|  | 363 | assert (tmap->l_ns == nsid); | 
|  | 364 | if (tmap->l_idx == IDX_STILL_USED) | 
|  | 365 | ++remain; | 
|  | 366 | else | 
|  | 367 | removed_any = true; | 
|  | 368 | } | 
|  | 369 | else | 
|  | 370 | ++remain; | 
|  | 371 |  | 
|  | 372 | if (removed_any) | 
|  | 373 | { | 
|  | 374 | /* Always allocate a new array for the scope.  This is | 
|  | 375 | necessary since we must be able to determine the last | 
|  | 376 | user of the current array.  If possible use the link map's | 
|  | 377 | memory.  */ | 
|  | 378 | size_t new_size; | 
|  | 379 | struct r_scope_elem **newp; | 
|  | 380 |  | 
|  | 381 | #define SCOPE_ELEMS(imap) \ | 
|  | 382 | (sizeof (imap->l_scope_mem) / sizeof (imap->l_scope_mem[0])) | 
|  | 383 |  | 
|  | 384 | if (imap->l_scope != imap->l_scope_mem | 
|  | 385 | && remain < SCOPE_ELEMS (imap)) | 
|  | 386 | { | 
|  | 387 | new_size = SCOPE_ELEMS (imap); | 
|  | 388 | newp = imap->l_scope_mem; | 
|  | 389 | } | 
|  | 390 | else | 
|  | 391 | { | 
|  | 392 | new_size = imap->l_scope_max; | 
|  | 393 | newp = (struct r_scope_elem **) | 
|  | 394 | malloc (new_size * sizeof (struct r_scope_elem *)); | 
|  | 395 | if (newp == NULL) | 
|  | 396 | _dl_signal_error (ENOMEM, "dlclose", NULL, | 
|  | 397 | N_("cannot create scope list")); | 
|  | 398 | } | 
|  | 399 |  | 
|  | 400 | /* Copy over the remaining scope elements.  */ | 
|  | 401 | remain = 0; | 
|  | 402 | for (size_t cnt = 0; imap->l_scope[cnt] != NULL; ++cnt) | 
|  | 403 | { | 
|  | 404 | if (imap->l_scope[cnt] != &imap->l_symbolic_searchlist) | 
|  | 405 | { | 
|  | 406 | struct link_map *tmap = (struct link_map *) | 
|  | 407 | ((char *) imap->l_scope[cnt] | 
|  | 408 | - offsetof (struct link_map, l_searchlist)); | 
|  | 409 | if (tmap->l_idx != IDX_STILL_USED) | 
|  | 410 | { | 
|  | 411 | /* Remove the scope.  Or replace with own map's | 
|  | 412 | scope.  */ | 
|  | 413 | if (new_list != NULL) | 
|  | 414 | { | 
|  | 415 | newp[remain++] = new_list; | 
|  | 416 | new_list = NULL; | 
|  | 417 | } | 
|  | 418 | continue; | 
|  | 419 | } | 
|  | 420 | } | 
|  | 421 |  | 
|  | 422 | newp[remain++] = imap->l_scope[cnt]; | 
|  | 423 | } | 
|  | 424 | newp[remain] = NULL; | 
|  | 425 |  | 
|  | 426 | struct r_scope_elem **old = imap->l_scope; | 
|  | 427 |  | 
|  | 428 | imap->l_scope = newp; | 
|  | 429 |  | 
|  | 430 | /* No user anymore, we can free it now.  */ | 
|  | 431 | if (old != imap->l_scope_mem) | 
|  | 432 | { | 
|  | 433 | if (_dl_scope_free (old)) | 
|  | 434 | /* If _dl_scope_free used THREAD_GSCOPE_WAIT (), | 
|  | 435 | no need to repeat it.  */ | 
|  | 436 | scope_mem_left = false; | 
|  | 437 | } | 
|  | 438 | else | 
|  | 439 | scope_mem_left = true; | 
|  | 440 |  | 
|  | 441 | imap->l_scope_max = new_size; | 
|  | 442 | } | 
|  | 443 | else if (new_list != NULL) | 
|  | 444 | { | 
|  | 445 | /* We didn't change the scope array, so reset the search | 
|  | 446 | list.  */ | 
|  | 447 | imap->l_searchlist.r_list = NULL; | 
|  | 448 | imap->l_searchlist.r_nlist = 0; | 
|  | 449 | } | 
|  | 450 |  | 
|  | 451 | /* The loader is gone, so mark the object as not having one. | 
|  | 452 | Note: l_idx != IDX_STILL_USED -> object will be removed.  */ | 
|  | 453 | if (imap->l_loader != NULL | 
|  | 454 | && imap->l_loader->l_idx != IDX_STILL_USED) | 
|  | 455 | imap->l_loader = NULL; | 
|  | 456 |  | 
|  | 457 | /* Remember where the first dynamically loaded object is.  */ | 
|  | 458 | if (i < first_loaded) | 
|  | 459 | first_loaded = i; | 
|  | 460 | } | 
|  | 461 | } | 
|  | 462 |  | 
|  | 463 | /* If there are no objects to unload, do nothing further.  */ | 
|  | 464 | if (!unload_any) | 
|  | 465 | goto out; | 
|  | 466 |  | 
|  | 467 | #ifdef SHARED | 
|  | 468 | /* Auditing checkpoint: we will start deleting objects.  */ | 
|  | 469 | if (__glibc_unlikely (do_audit)) | 
|  | 470 | { | 
|  | 471 | struct link_map *head = ns->_ns_loaded; | 
|  | 472 | struct audit_ifaces *afct = GLRO(dl_audit); | 
|  | 473 | /* Do not call the functions for any auditing object.  */ | 
|  | 474 | if (head->l_auditing == 0) | 
|  | 475 | { | 
|  | 476 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | 
|  | 477 | { | 
|  | 478 | if (afct->activity != NULL) | 
|  | 479 | afct->activity (&head->l_audit[cnt].cookie, LA_ACT_DELETE); | 
|  | 480 |  | 
|  | 481 | afct = afct->next; | 
|  | 482 | } | 
|  | 483 | } | 
|  | 484 | } | 
|  | 485 | #endif | 
|  | 486 |  | 
|  | 487 | /* Notify the debugger we are about to remove some loaded objects.  */ | 
|  | 488 | struct r_debug *r = _dl_debug_initialize (0, nsid); | 
|  | 489 | r->r_state = RT_DELETE; | 
|  | 490 | _dl_debug_state (); | 
|  | 491 | LIBC_PROBE (unmap_start, 2, nsid, r); | 
|  | 492 |  | 
|  | 493 | if (unload_global) | 
|  | 494 | { | 
|  | 495 | /* Some objects are in the global scope list.  Remove them.  */ | 
|  | 496 | struct r_scope_elem *ns_msl = ns->_ns_main_searchlist; | 
|  | 497 | unsigned int i; | 
|  | 498 | unsigned int j = 0; | 
|  | 499 | unsigned int cnt = ns_msl->r_nlist; | 
|  | 500 |  | 
|  | 501 | while (cnt > 0 && ns_msl->r_list[cnt - 1]->l_removed) | 
|  | 502 | --cnt; | 
|  | 503 |  | 
|  | 504 | if (cnt + unload_global == ns_msl->r_nlist) | 
|  | 505 | /* Speed up removing most recently added objects.  */ | 
|  | 506 | j = cnt; | 
|  | 507 | else | 
|  | 508 | for (i = 0; i < cnt; i++) | 
|  | 509 | if (ns_msl->r_list[i]->l_removed == 0) | 
|  | 510 | { | 
|  | 511 | if (i != j) | 
|  | 512 | ns_msl->r_list[j] = ns_msl->r_list[i]; | 
|  | 513 | j++; | 
|  | 514 | } | 
|  | 515 | ns_msl->r_nlist = j; | 
|  | 516 | } | 
|  | 517 |  | 
|  | 518 | if (!RTLD_SINGLE_THREAD_P | 
|  | 519 | && (unload_global | 
|  | 520 | || scope_mem_left | 
|  | 521 | || (GL(dl_scope_free_list) != NULL | 
|  | 522 | && GL(dl_scope_free_list)->count))) | 
|  | 523 | { | 
|  | 524 | THREAD_GSCOPE_WAIT (); | 
|  | 525 |  | 
|  | 526 | /* Now we can free any queued old scopes.  */ | 
|  | 527 | struct dl_scope_free_list *fsl = GL(dl_scope_free_list); | 
|  | 528 | if (fsl != NULL) | 
|  | 529 | while (fsl->count > 0) | 
|  | 530 | free (fsl->list[--fsl->count]); | 
|  | 531 | } | 
|  | 532 |  | 
|  | 533 | size_t tls_free_start; | 
|  | 534 | size_t tls_free_end; | 
|  | 535 | tls_free_start = tls_free_end = NO_TLS_OFFSET; | 
|  | 536 |  | 
|  | 537 | /* We modify the list of loaded objects.  */ | 
|  | 538 | __rtld_lock_lock_recursive (GL(dl_load_write_lock)); | 
|  | 539 |  | 
|  | 540 | /* Check each element of the search list to see if all references to | 
|  | 541 | it are gone.  */ | 
|  | 542 | for (unsigned int i = first_loaded; i < nloaded; ++i) | 
|  | 543 | { | 
|  | 544 | struct link_map *imap = maps[i]; | 
|  | 545 | if (!used[i]) | 
|  | 546 | { | 
|  | 547 | assert (imap->l_type == lt_loaded); | 
|  | 548 |  | 
|  | 549 | /* That was the last reference, and this was a dlopen-loaded | 
|  | 550 | object.  We can unmap it.  */ | 
|  | 551 |  | 
|  | 552 | /* Remove the object from the dtv slotinfo array if it uses TLS.  */ | 
|  | 553 | if (__glibc_unlikely (imap->l_tls_blocksize > 0)) | 
|  | 554 | { | 
|  | 555 | any_tls = true; | 
|  | 556 |  | 
|  | 557 | if (GL(dl_tls_dtv_slotinfo_list) != NULL | 
|  | 558 | && ! remove_slotinfo (imap->l_tls_modid, | 
|  | 559 | GL(dl_tls_dtv_slotinfo_list), 0, | 
|  | 560 | imap->l_init_called)) | 
|  | 561 | /* All dynamically loaded modules with TLS are unloaded.  */ | 
|  | 562 | GL(dl_tls_max_dtv_idx) = GL(dl_tls_static_nelem); | 
|  | 563 |  | 
|  | 564 | if (imap->l_tls_offset != NO_TLS_OFFSET | 
|  | 565 | && imap->l_tls_offset != FORCED_DYNAMIC_TLS_OFFSET) | 
|  | 566 | { | 
|  | 567 | /* Collect a contiguous chunk built from the objects in | 
|  | 568 | this search list, going in either direction.  When the | 
|  | 569 | whole chunk is at the end of the used area then we can | 
|  | 570 | reclaim it.  */ | 
|  | 571 | #if TLS_TCB_AT_TP | 
|  | 572 | if (tls_free_start == NO_TLS_OFFSET | 
|  | 573 | || (size_t) imap->l_tls_offset == tls_free_start) | 
|  | 574 | { | 
|  | 575 | /* Extend the contiguous chunk being reclaimed.  */ | 
|  | 576 | tls_free_start | 
|  | 577 | = imap->l_tls_offset - imap->l_tls_blocksize; | 
|  | 578 |  | 
|  | 579 | if (tls_free_end == NO_TLS_OFFSET) | 
|  | 580 | tls_free_end = imap->l_tls_offset; | 
|  | 581 | } | 
|  | 582 | else if (imap->l_tls_offset - imap->l_tls_blocksize | 
|  | 583 | == tls_free_end) | 
|  | 584 | /* Extend the chunk backwards.  */ | 
|  | 585 | tls_free_end = imap->l_tls_offset; | 
|  | 586 | else | 
|  | 587 | { | 
|  | 588 | /* This isn't contiguous with the last chunk freed. | 
|  | 589 | One of them will be leaked unless we can free | 
|  | 590 | one block right away.  */ | 
|  | 591 | if (tls_free_end == GL(dl_tls_static_used)) | 
|  | 592 | { | 
|  | 593 | GL(dl_tls_static_used) = tls_free_start; | 
|  | 594 | tls_free_end = imap->l_tls_offset; | 
|  | 595 | tls_free_start | 
|  | 596 | = tls_free_end - imap->l_tls_blocksize; | 
|  | 597 | } | 
|  | 598 | else if ((size_t) imap->l_tls_offset | 
|  | 599 | == GL(dl_tls_static_used)) | 
|  | 600 | GL(dl_tls_static_used) | 
|  | 601 | = imap->l_tls_offset - imap->l_tls_blocksize; | 
|  | 602 | else if (tls_free_end < (size_t) imap->l_tls_offset) | 
|  | 603 | { | 
|  | 604 | /* We pick the later block.  It has a chance to | 
|  | 605 | be freed.  */ | 
|  | 606 | tls_free_end = imap->l_tls_offset; | 
|  | 607 | tls_free_start | 
|  | 608 | = tls_free_end - imap->l_tls_blocksize; | 
|  | 609 | } | 
|  | 610 | } | 
|  | 611 | #elif TLS_DTV_AT_TP | 
|  | 612 | if (tls_free_start == NO_TLS_OFFSET) | 
|  | 613 | { | 
|  | 614 | tls_free_start = imap->l_tls_firstbyte_offset; | 
|  | 615 | tls_free_end = (imap->l_tls_offset | 
|  | 616 | + imap->l_tls_blocksize); | 
|  | 617 | } | 
|  | 618 | else if (imap->l_tls_firstbyte_offset == tls_free_end) | 
|  | 619 | /* Extend the contiguous chunk being reclaimed.  */ | 
|  | 620 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | 
|  | 621 | else if (imap->l_tls_offset + imap->l_tls_blocksize | 
|  | 622 | == tls_free_start) | 
|  | 623 | /* Extend the chunk backwards.  */ | 
|  | 624 | tls_free_start = imap->l_tls_firstbyte_offset; | 
|  | 625 | /* This isn't contiguous with the last chunk freed. | 
|  | 626 | One of them will be leaked unless we can free | 
|  | 627 | one block right away.  */ | 
|  | 628 | else if (imap->l_tls_offset + imap->l_tls_blocksize | 
|  | 629 | == GL(dl_tls_static_used)) | 
|  | 630 | GL(dl_tls_static_used) = imap->l_tls_firstbyte_offset; | 
|  | 631 | else if (tls_free_end == GL(dl_tls_static_used)) | 
|  | 632 | { | 
|  | 633 | GL(dl_tls_static_used) = tls_free_start; | 
|  | 634 | tls_free_start = imap->l_tls_firstbyte_offset; | 
|  | 635 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | 
|  | 636 | } | 
|  | 637 | else if (tls_free_end < imap->l_tls_firstbyte_offset) | 
|  | 638 | { | 
|  | 639 | /* We pick the later block.  It has a chance to | 
|  | 640 | be freed.  */ | 
|  | 641 | tls_free_start = imap->l_tls_firstbyte_offset; | 
|  | 642 | tls_free_end = imap->l_tls_offset + imap->l_tls_blocksize; | 
|  | 643 | } | 
|  | 644 | #else | 
|  | 645 | # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" | 
|  | 646 | #endif | 
|  | 647 | } | 
|  | 648 | } | 
|  | 649 |  | 
|  | 650 | /* Reset unique symbols if forced.  */ | 
|  | 651 | if (force) | 
|  | 652 | { | 
|  | 653 | struct unique_sym_table *tab = &ns->_ns_unique_sym_table; | 
|  | 654 | __rtld_lock_lock_recursive (tab->lock); | 
|  | 655 | struct unique_sym *entries = tab->entries; | 
|  | 656 | if (entries != NULL) | 
|  | 657 | { | 
|  | 658 | size_t idx, size = tab->size; | 
|  | 659 | for (idx = 0; idx < size; ++idx) | 
|  | 660 | { | 
|  | 661 | /* Clear unique symbol entries that belong to this | 
|  | 662 | object.  */ | 
|  | 663 | if (entries[idx].name != NULL | 
|  | 664 | && entries[idx].map == imap) | 
|  | 665 | { | 
|  | 666 | entries[idx].name = NULL; | 
|  | 667 | entries[idx].hashval = 0; | 
|  | 668 | tab->n_elements--; | 
|  | 669 | } | 
|  | 670 | } | 
|  | 671 | } | 
|  | 672 | __rtld_lock_unlock_recursive (tab->lock); | 
|  | 673 | } | 
|  | 674 |  | 
|  | 675 | /* We can unmap all the maps at once.  We determined the | 
|  | 676 | start address and length when we loaded the object and | 
|  | 677 | the `munmap' call does the rest.  */ | 
|  | 678 | DL_UNMAP (imap); | 
|  | 679 |  | 
|  | 680 | /* Finally, unlink the data structure and free it.  */ | 
|  | 681 | #if DL_NNS == 1 | 
|  | 682 | /* The assert in the (imap->l_prev == NULL) case gives | 
|  | 683 | the compiler license to warn that NS points outside | 
|  | 684 | the dl_ns array bounds in that case (as nsid != LM_ID_BASE | 
|  | 685 | is tantamount to nsid >= DL_NNS).  That should be impossible | 
|  | 686 | in this configuration, so just assert about it instead.  */ | 
|  | 687 | assert (nsid == LM_ID_BASE); | 
|  | 688 | assert (imap->l_prev != NULL); | 
|  | 689 | #else | 
|  | 690 | if (imap->l_prev == NULL) | 
|  | 691 | { | 
|  | 692 | assert (nsid != LM_ID_BASE); | 
|  | 693 | ns->_ns_loaded = imap->l_next; | 
|  | 694 |  | 
|  | 695 | /* Update the pointer to the head of the list | 
|  | 696 | we leave for debuggers to examine.  */ | 
|  | 697 | r->r_map = (void *) ns->_ns_loaded; | 
|  | 698 | } | 
|  | 699 | else | 
|  | 700 | #endif | 
|  | 701 | imap->l_prev->l_next = imap->l_next; | 
|  | 702 |  | 
|  | 703 | --ns->_ns_nloaded; | 
|  | 704 | if (imap->l_next != NULL) | 
|  | 705 | imap->l_next->l_prev = imap->l_prev; | 
|  | 706 |  | 
|  | 707 | free (imap->l_versions); | 
|  | 708 | if (imap->l_origin != (char *) -1) | 
|  | 709 | free ((char *) imap->l_origin); | 
|  | 710 |  | 
|  | 711 | free (imap->l_reldeps); | 
|  | 712 |  | 
|  | 713 | /* Print debugging message.  */ | 
|  | 714 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) | 
|  | 715 | _dl_debug_printf ("\nfile=%s [%lu];  destroying link map\n", | 
|  | 716 | imap->l_name, imap->l_ns); | 
|  | 717 |  | 
|  | 718 | /* This name always is allocated.  */ | 
|  | 719 | free (imap->l_name); | 
|  | 720 | /* Remove the list with all the names of the shared object.  */ | 
|  | 721 |  | 
|  | 722 | struct libname_list *lnp = imap->l_libname; | 
|  | 723 | do | 
|  | 724 | { | 
|  | 725 | struct libname_list *this = lnp; | 
|  | 726 | lnp = lnp->next; | 
|  | 727 | if (!this->dont_free) | 
|  | 728 | free (this); | 
|  | 729 | } | 
|  | 730 | while (lnp != NULL); | 
|  | 731 |  | 
|  | 732 | /* Remove the searchlists.  */ | 
|  | 733 | free (imap->l_initfini); | 
|  | 734 |  | 
|  | 735 | /* Remove the scope array if we allocated it.  */ | 
|  | 736 | if (imap->l_scope != imap->l_scope_mem) | 
|  | 737 | free (imap->l_scope); | 
|  | 738 |  | 
|  | 739 | if (imap->l_phdr_allocated) | 
|  | 740 | free ((void *) imap->l_phdr); | 
|  | 741 |  | 
|  | 742 | if (imap->l_rpath_dirs.dirs != (void *) -1) | 
|  | 743 | free (imap->l_rpath_dirs.dirs); | 
|  | 744 | if (imap->l_runpath_dirs.dirs != (void *) -1) | 
|  | 745 | free (imap->l_runpath_dirs.dirs); | 
|  | 746 |  | 
|  | 747 | free (imap); | 
|  | 748 | } | 
|  | 749 | } | 
|  | 750 |  | 
|  | 751 | __rtld_lock_unlock_recursive (GL(dl_load_write_lock)); | 
|  | 752 |  | 
|  | 753 | /* If we removed any object which uses TLS bump the generation counter.  */ | 
|  | 754 | if (any_tls) | 
|  | 755 | { | 
|  | 756 | if (__glibc_unlikely (++GL(dl_tls_generation) == 0)) | 
|  | 757 | _dl_fatal_printf ("TLS generation counter wrapped!  Please report as described in "REPORT_BUGS_TO".\n"); | 
|  | 758 |  | 
|  | 759 | if (tls_free_end == GL(dl_tls_static_used)) | 
|  | 760 | GL(dl_tls_static_used) = tls_free_start; | 
|  | 761 | } | 
|  | 762 |  | 
|  | 763 | #ifdef SHARED | 
|  | 764 | /* Auditing checkpoint: we have deleted all objects.  */ | 
|  | 765 | if (__glibc_unlikely (do_audit)) | 
|  | 766 | { | 
|  | 767 | struct link_map *head = ns->_ns_loaded; | 
|  | 768 | /* Do not call the functions for any auditing object.  */ | 
|  | 769 | if (head->l_auditing == 0) | 
|  | 770 | { | 
|  | 771 | struct audit_ifaces *afct = GLRO(dl_audit); | 
|  | 772 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) | 
|  | 773 | { | 
|  | 774 | if (afct->activity != NULL) | 
|  | 775 | afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT); | 
|  | 776 |  | 
|  | 777 | afct = afct->next; | 
|  | 778 | } | 
|  | 779 | } | 
|  | 780 | } | 
|  | 781 | #endif | 
|  | 782 |  | 
|  | 783 | if (__builtin_expect (ns->_ns_loaded == NULL, 0) | 
|  | 784 | && nsid == GL(dl_nns) - 1) | 
|  | 785 | do | 
|  | 786 | --GL(dl_nns); | 
|  | 787 | while (GL(dl_ns)[GL(dl_nns) - 1]._ns_loaded == NULL); | 
|  | 788 |  | 
|  | 789 | /* Notify the debugger those objects are finalized and gone.  */ | 
|  | 790 | r->r_state = RT_CONSISTENT; | 
|  | 791 | _dl_debug_state (); | 
|  | 792 | LIBC_PROBE (unmap_complete, 2, nsid, r); | 
|  | 793 |  | 
|  | 794 | /* Recheck if we need to retry, release the lock.  */ | 
|  | 795 | out: | 
|  | 796 | if (dl_close_state == rerun) | 
|  | 797 | goto retry; | 
|  | 798 |  | 
|  | 799 | dl_close_state = not_pending; | 
|  | 800 | } | 
|  | 801 |  | 
|  | 802 |  | 
|  | 803 | void | 
|  | 804 | _dl_close (void *_map) | 
|  | 805 | { | 
|  | 806 | struct link_map *map = _map; | 
|  | 807 |  | 
|  | 808 | /* First see whether we can remove the object at all.  */ | 
|  | 809 | if (__glibc_unlikely (map->l_flags_1 & DF_1_NODELETE)) | 
|  | 810 | { | 
|  | 811 | assert (map->l_init_called); | 
|  | 812 | /* Nope.  Do nothing.  */ | 
|  | 813 | return; | 
|  | 814 | } | 
|  | 815 |  | 
|  | 816 | if (__builtin_expect (map->l_direct_opencount, 1) == 0) | 
|  | 817 | GLRO(dl_signal_error) (0, map->l_name, NULL, N_("shared object not open")); | 
|  | 818 |  | 
|  | 819 | /* Acquire the lock.  */ | 
|  | 820 | __rtld_lock_lock_recursive (GL(dl_load_lock)); | 
|  | 821 |  | 
|  | 822 | _dl_close_worker (map, false); | 
|  | 823 |  | 
|  | 824 | __rtld_lock_unlock_recursive (GL(dl_load_lock)); | 
|  | 825 | } |