1 /* $NetBSD: uvm_map.c,v 1.359 2019/03/14 19:10:04 kre Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Charles D. Cranor and Washington University. 5 * Copyright (c) 1991, 1993, The Regents of the University of California. 6 * 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * The Mach Operating System project at Carnegie-Mellon University. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vm_map.c 8.3 (Berkeley) 1/12/94 37 * from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp 38 * 39 * 40 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 41 * All rights reserved. 42 * 43 * Permission to use, copy, modify and distribute this software and 44 * its documentation is hereby granted, provided that both the copyright 45 * notice and this permission notice appear in all copies of the 46 * software, derivative works or modified versions, and any portions 47 * thereof, and that both notices appear in supporting documentation. 48 * 49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 52 * 53 * Carnegie Mellon requests users of this software to return to 54 * 55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 56 * School of Computer Science 57 * Carnegie Mellon University 58 * Pittsburgh PA 15213-3890 59 * 60 * any improvements or extensions that they make and grant Carnegie the 61 * rights to redistribute these changes. 62 */ 63 64 /* 65 * uvm_map.c: uvm map operations 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.359 2019/03/14 19:10:04 kre Exp $"); 70 71 #include "opt_ddb.h" 72 #include "opt_pax.h" 73 #include "opt_uvmhist.h" 74 #include "opt_uvm.h" 75 #include "opt_sysv.h" 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/mman.h> 80 #include <sys/proc.h> 81 #include <sys/pool.h> 82 #include <sys/kernel.h> 83 #include <sys/mount.h> 84 #include <sys/pax.h> 85 #include <sys/vnode.h> 86 #include <sys/filedesc.h> 87 #include <sys/lockdebug.h> 88 #include <sys/atomic.h> 89 #include <sys/sysctl.h> 90 #ifndef __USER_VA0_IS_SAFE 91 #include <sys/kauth.h> 92 #include "opt_user_va0_disable_default.h" 93 #endif 94 95 #include <sys/shm.h> 96 97 #include <uvm/uvm.h> 98 #include <uvm/uvm_readahead.h> 99 100 #if defined(DDB) || defined(DEBUGPRINT) 101 #include <uvm/uvm_ddb.h> 102 #endif 103 104 #ifdef UVMHIST 105 #ifndef UVMHIST_MAPHIST_SIZE 106 #define UVMHIST_MAPHIST_SIZE 100 107 #endif 108 #ifndef UVMHIST_PDHIST_SIZE 109 #define UVMHIST_PDHIST_SIZE 100 110 #endif 111 static struct kern_history_ent maphistbuf[UVMHIST_MAPHIST_SIZE]; 112 UVMHIST_DEFINE(maphist) = UVMHIST_INITIALIZER(maphist, maphistbuf); 113 #endif 114 115 #if !defined(UVMMAP_COUNTERS) 116 117 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */ 118 #define UVMMAP_EVCNT_INCR(ev) /* nothing */ 119 #define UVMMAP_EVCNT_DECR(ev) /* nothing */ 120 121 #else /* defined(UVMMAP_NOCOUNTERS) */ 122 123 #include <sys/evcnt.h> 124 #define UVMMAP_EVCNT_DEFINE(name) \ 125 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \ 126 "uvmmap", #name); \ 127 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name); 128 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++ 129 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count-- 130 131 #endif /* defined(UVMMAP_NOCOUNTERS) */ 132 133 UVMMAP_EVCNT_DEFINE(ubackmerge) 134 UVMMAP_EVCNT_DEFINE(uforwmerge) 135 UVMMAP_EVCNT_DEFINE(ubimerge) 136 UVMMAP_EVCNT_DEFINE(unomerge) 137 UVMMAP_EVCNT_DEFINE(kbackmerge) 138 UVMMAP_EVCNT_DEFINE(kforwmerge) 139 UVMMAP_EVCNT_DEFINE(kbimerge) 140 UVMMAP_EVCNT_DEFINE(knomerge) 141 UVMMAP_EVCNT_DEFINE(map_call) 142 UVMMAP_EVCNT_DEFINE(mlk_call) 143 UVMMAP_EVCNT_DEFINE(mlk_hint) 144 UVMMAP_EVCNT_DEFINE(mlk_list) 145 UVMMAP_EVCNT_DEFINE(mlk_tree) 146 UVMMAP_EVCNT_DEFINE(mlk_treeloop) 147 UVMMAP_EVCNT_DEFINE(mlk_listloop) 148 149 const char vmmapbsy[] = "vmmapbsy"; 150 151 /* 152 * cache for vmspace structures. 153 */ 154 155 static struct pool_cache uvm_vmspace_cache; 156 157 /* 158 * cache for dynamically-allocated map entries. 159 */ 160 161 static struct pool_cache uvm_map_entry_cache; 162 163 #ifdef PMAP_GROWKERNEL 164 /* 165 * This global represents the end of the kernel virtual address 166 * space. If we want to exceed this, we must grow the kernel 167 * virtual address space dynamically. 168 * 169 * Note, this variable is locked by kernel_map's lock. 170 */ 171 vaddr_t uvm_maxkaddr; 172 #endif 173 174 #ifndef __USER_VA0_IS_SAFE 175 #ifndef __USER_VA0_DISABLE_DEFAULT 176 #define __USER_VA0_DISABLE_DEFAULT 1 177 #endif 178 #ifdef USER_VA0_DISABLE_DEFAULT /* kernel config option overrides */ 179 #undef __USER_VA0_DISABLE_DEFAULT 180 #define __USER_VA0_DISABLE_DEFAULT USER_VA0_DISABLE_DEFAULT 181 #endif 182 int user_va0_disable = __USER_VA0_DISABLE_DEFAULT; 183 #endif 184 185 /* 186 * macros 187 */ 188 189 /* 190 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging 191 */ 192 extern struct vm_map *pager_map; 193 194 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \ 195 prot, maxprot, inh, adv, wire) \ 196 ((ent)->etype == (type) && \ 197 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE)) == 0 && \ 198 (ent)->object.uvm_obj == (uobj) && \ 199 (ent)->protection == (prot) && \ 200 (ent)->max_protection == (maxprot) && \ 201 (ent)->inheritance == (inh) && \ 202 (ent)->advice == (adv) && \ 203 (ent)->wired_count == (wire)) 204 205 /* 206 * uvm_map_entry_link: insert entry into a map 207 * 208 * => map must be locked 209 */ 210 #define uvm_map_entry_link(map, after_where, entry) do { \ 211 uvm_mapent_check(entry); \ 212 (map)->nentries++; \ 213 (entry)->prev = (after_where); \ 214 (entry)->next = (after_where)->next; \ 215 (entry)->prev->next = (entry); \ 216 (entry)->next->prev = (entry); \ 217 uvm_rb_insert((map), (entry)); \ 218 } while (/*CONSTCOND*/ 0) 219 220 /* 221 * uvm_map_entry_unlink: remove entry from a map 222 * 223 * => map must be locked 224 */ 225 #define uvm_map_entry_unlink(map, entry) do { \ 226 KASSERT((entry) != (map)->first_free); \ 227 KASSERT((entry) != (map)->hint); \ 228 uvm_mapent_check(entry); \ 229 (map)->nentries--; \ 230 (entry)->next->prev = (entry)->prev; \ 231 (entry)->prev->next = (entry)->next; \ 232 uvm_rb_remove((map), (entry)); \ 233 } while (/*CONSTCOND*/ 0) 234 235 /* 236 * SAVE_HINT: saves the specified entry as the hint for future lookups. 237 * 238 * => map need not be locked. 239 */ 240 #define SAVE_HINT(map, check, value) do { \ 241 if ((map)->hint == (check)) \ 242 (map)->hint = (value); \ 243 } while (/*CONSTCOND*/ 0) 244 245 /* 246 * clear_hints: ensure that hints don't point to the entry. 247 * 248 * => map must be write-locked. 249 */ 250 static void 251 clear_hints(struct vm_map *map, struct vm_map_entry *ent) 252 { 253 254 SAVE_HINT(map, ent, ent->prev); 255 if (map->first_free == ent) { 256 map->first_free = ent->prev; 257 } 258 } 259 260 /* 261 * VM_MAP_RANGE_CHECK: check and correct range 262 * 263 * => map must at least be read locked 264 */ 265 266 #define VM_MAP_RANGE_CHECK(map, start, end) do { \ 267 if (start < vm_map_min(map)) \ 268 start = vm_map_min(map); \ 269 if (end > vm_map_max(map)) \ 270 end = vm_map_max(map); \ 271 if (start > end) \ 272 start = end; \ 273 } while (/*CONSTCOND*/ 0) 274 275 /* 276 * local prototypes 277 */ 278 279 static struct vm_map_entry * 280 uvm_mapent_alloc(struct vm_map *, int); 281 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *); 282 static void uvm_mapent_free(struct vm_map_entry *); 283 #if defined(DEBUG) 284 static void _uvm_mapent_check(const struct vm_map_entry *, const char *, 285 int); 286 #define uvm_mapent_check(map) _uvm_mapent_check(map, __FILE__, __LINE__) 287 #else /* defined(DEBUG) */ 288 #define uvm_mapent_check(e) /* nothing */ 289 #endif /* defined(DEBUG) */ 290 291 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *); 292 static void uvm_map_reference_amap(struct vm_map_entry *, int); 293 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int, 294 int, struct vm_map_entry *); 295 static void uvm_map_unreference_amap(struct vm_map_entry *, int); 296 297 int _uvm_map_sanity(struct vm_map *); 298 int _uvm_tree_sanity(struct vm_map *); 299 static vsize_t uvm_rb_maxgap(const struct vm_map_entry *); 300 301 #define ROOT_ENTRY(map) ((struct vm_map_entry *)(map)->rb_tree.rbt_root) 302 #define LEFT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_left) 303 #define RIGHT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_right) 304 #define PARENT_ENTRY(map, entry) \ 305 (ROOT_ENTRY(map) == (entry) \ 306 ? NULL : (struct vm_map_entry *)RB_FATHER(&(entry)->rb_node)) 307 308 /* 309 * These get filled in if/when SYSVSHM shared memory code is loaded 310 * 311 * We do this with function pointers rather the #ifdef SYSVSHM so the 312 * SYSVSHM code can be loaded and unloaded 313 */ 314 void (*uvm_shmexit)(struct vmspace *) = NULL; 315 void (*uvm_shmfork)(struct vmspace *, struct vmspace *) = NULL; 316 317 static int 318 uvm_map_compare_nodes(void *ctx, const void *nparent, const void *nkey) 319 { 320 const struct vm_map_entry *eparent = nparent; 321 const struct vm_map_entry *ekey = nkey; 322 323 KASSERT(eparent->start < ekey->start || eparent->start >= ekey->end); 324 KASSERT(ekey->start < eparent->start || ekey->start >= eparent->end); 325 326 if (eparent->start < ekey->start) 327 return -1; 328 if (eparent->end >= ekey->start) 329 return 1; 330 return 0; 331 } 332 333 static int 334 uvm_map_compare_key(void *ctx, const void *nparent, const void *vkey) 335 { 336 const struct vm_map_entry *eparent = nparent; 337 const vaddr_t va = *(const vaddr_t *) vkey; 338 339 if (eparent->start < va) 340 return -1; 341 if (eparent->end >= va) 342 return 1; 343 return 0; 344 } 345 346 static const rb_tree_ops_t uvm_map_tree_ops = { 347 .rbto_compare_nodes = uvm_map_compare_nodes, 348 .rbto_compare_key = uvm_map_compare_key, 349 .rbto_node_offset = offsetof(struct vm_map_entry, rb_node), 350 .rbto_context = NULL 351 }; 352 353 /* 354 * uvm_rb_gap: return the gap size between our entry and next entry. 355 */ 356 static inline vsize_t 357 uvm_rb_gap(const struct vm_map_entry *entry) 358 { 359 360 KASSERT(entry->next != NULL); 361 return entry->next->start - entry->end; 362 } 363 364 static vsize_t 365 uvm_rb_maxgap(const struct vm_map_entry *entry) 366 { 367 struct vm_map_entry *child; 368 vsize_t maxgap = entry->gap; 369 370 /* 371 * We need maxgap to be the largest gap of us or any of our 372 * descendents. Since each of our children's maxgap is the 373 * cached value of their largest gap of themselves or their 374 * descendents, we can just use that value and avoid recursing 375 * down the tree to calculate it. 376 */ 377 if ((child = LEFT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 378 maxgap = child->maxgap; 379 380 if ((child = RIGHT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 381 maxgap = child->maxgap; 382 383 return maxgap; 384 } 385 386 static void 387 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry) 388 { 389 struct vm_map_entry *parent; 390 391 KASSERT(entry->gap == uvm_rb_gap(entry)); 392 entry->maxgap = uvm_rb_maxgap(entry); 393 394 while ((parent = PARENT_ENTRY(map, entry)) != NULL) { 395 struct vm_map_entry *brother; 396 vsize_t maxgap = parent->gap; 397 unsigned int which; 398 399 KDASSERT(parent->gap == uvm_rb_gap(parent)); 400 if (maxgap < entry->maxgap) 401 maxgap = entry->maxgap; 402 /* 403 * Since we work towards the root, we know entry's maxgap 404 * value is OK, but its brothers may now be out-of-date due 405 * to rebalancing. So refresh it. 406 */ 407 which = RB_POSITION(&entry->rb_node) ^ RB_DIR_OTHER; 408 brother = (struct vm_map_entry *)parent->rb_node.rb_nodes[which]; 409 if (brother != NULL) { 410 KDASSERT(brother->gap == uvm_rb_gap(brother)); 411 brother->maxgap = uvm_rb_maxgap(brother); 412 if (maxgap < brother->maxgap) 413 maxgap = brother->maxgap; 414 } 415 416 parent->maxgap = maxgap; 417 entry = parent; 418 } 419 } 420 421 static void 422 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry) 423 { 424 struct vm_map_entry *ret __diagused; 425 426 entry->gap = entry->maxgap = uvm_rb_gap(entry); 427 if (entry->prev != &map->header) 428 entry->prev->gap = uvm_rb_gap(entry->prev); 429 430 ret = rb_tree_insert_node(&map->rb_tree, entry); 431 KASSERTMSG(ret == entry, 432 "uvm_rb_insert: map %p: duplicate entry %p", map, ret); 433 434 /* 435 * If the previous entry is not our immediate left child, then it's an 436 * ancestor and will be fixed up on the way to the root. We don't 437 * have to check entry->prev against &map->header since &map->header 438 * will never be in the tree. 439 */ 440 uvm_rb_fixup(map, 441 LEFT_ENTRY(entry) == entry->prev ? entry->prev : entry); 442 } 443 444 static void 445 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry) 446 { 447 struct vm_map_entry *prev_parent = NULL, *next_parent = NULL; 448 449 /* 450 * If we are removing an interior node, then an adjacent node will 451 * be used to replace its position in the tree. Therefore we will 452 * need to fixup the tree starting at the parent of the replacement 453 * node. So record their parents for later use. 454 */ 455 if (entry->prev != &map->header) 456 prev_parent = PARENT_ENTRY(map, entry->prev); 457 if (entry->next != &map->header) 458 next_parent = PARENT_ENTRY(map, entry->next); 459 460 rb_tree_remove_node(&map->rb_tree, entry); 461 462 /* 463 * If the previous node has a new parent, fixup the tree starting 464 * at the previous node's old parent. 465 */ 466 if (entry->prev != &map->header) { 467 /* 468 * Update the previous entry's gap due to our absence. 469 */ 470 entry->prev->gap = uvm_rb_gap(entry->prev); 471 uvm_rb_fixup(map, entry->prev); 472 if (prev_parent != NULL 473 && prev_parent != entry 474 && prev_parent != PARENT_ENTRY(map, entry->prev)) 475 uvm_rb_fixup(map, prev_parent); 476 } 477 478 /* 479 * If the next node has a new parent, fixup the tree starting 480 * at the next node's old parent. 481 */ 482 if (entry->next != &map->header) { 483 uvm_rb_fixup(map, entry->next); 484 if (next_parent != NULL 485 && next_parent != entry 486 && next_parent != PARENT_ENTRY(map, entry->next)) 487 uvm_rb_fixup(map, next_parent); 488 } 489 } 490 491 #if defined(DEBUG) 492 int uvm_debug_check_map = 0; 493 int uvm_debug_check_rbtree = 0; 494 #define uvm_map_check(map, name) \ 495 _uvm_map_check((map), (name), __FILE__, __LINE__) 496 static void 497 _uvm_map_check(struct vm_map *map, const char *name, 498 const char *file, int line) 499 { 500 501 if ((uvm_debug_check_map && _uvm_map_sanity(map)) || 502 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) { 503 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)", 504 name, map, file, line); 505 } 506 } 507 #else /* defined(DEBUG) */ 508 #define uvm_map_check(map, name) /* nothing */ 509 #endif /* defined(DEBUG) */ 510 511 #if defined(DEBUG) || defined(DDB) 512 int 513 _uvm_map_sanity(struct vm_map *map) 514 { 515 bool first_free_found = false; 516 bool hint_found = false; 517 const struct vm_map_entry *e; 518 struct vm_map_entry *hint = map->hint; 519 520 e = &map->header; 521 for (;;) { 522 if (map->first_free == e) { 523 first_free_found = true; 524 } else if (!first_free_found && e->next->start > e->end) { 525 printf("first_free %p should be %p\n", 526 map->first_free, e); 527 return -1; 528 } 529 if (hint == e) { 530 hint_found = true; 531 } 532 533 e = e->next; 534 if (e == &map->header) { 535 break; 536 } 537 } 538 if (!first_free_found) { 539 printf("stale first_free\n"); 540 return -1; 541 } 542 if (!hint_found) { 543 printf("stale hint\n"); 544 return -1; 545 } 546 return 0; 547 } 548 549 int 550 _uvm_tree_sanity(struct vm_map *map) 551 { 552 struct vm_map_entry *tmp, *trtmp; 553 int n = 0, i = 1; 554 555 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 556 if (tmp->gap != uvm_rb_gap(tmp)) { 557 printf("%d/%d gap %#lx != %#lx %s\n", 558 n + 1, map->nentries, 559 (ulong)tmp->gap, (ulong)uvm_rb_gap(tmp), 560 tmp->next == &map->header ? "(last)" : ""); 561 goto error; 562 } 563 /* 564 * If any entries are out of order, tmp->gap will be unsigned 565 * and will likely exceed the size of the map. 566 */ 567 if (tmp->gap >= vm_map_max(map) - vm_map_min(map)) { 568 printf("too large gap %zu\n", (size_t)tmp->gap); 569 goto error; 570 } 571 n++; 572 } 573 574 if (n != map->nentries) { 575 printf("nentries: %d vs %d\n", n, map->nentries); 576 goto error; 577 } 578 579 trtmp = NULL; 580 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 581 if (tmp->maxgap != uvm_rb_maxgap(tmp)) { 582 printf("maxgap %#lx != %#lx\n", 583 (ulong)tmp->maxgap, 584 (ulong)uvm_rb_maxgap(tmp)); 585 goto error; 586 } 587 if (trtmp != NULL && trtmp->start >= tmp->start) { 588 printf("corrupt: 0x%"PRIxVADDR"x >= 0x%"PRIxVADDR"x\n", 589 trtmp->start, tmp->start); 590 goto error; 591 } 592 593 trtmp = tmp; 594 } 595 596 for (tmp = map->header.next; tmp != &map->header; 597 tmp = tmp->next, i++) { 598 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_LEFT); 599 if (trtmp == NULL) 600 trtmp = &map->header; 601 if (tmp->prev != trtmp) { 602 printf("lookup: %d: %p->prev=%p: %p\n", 603 i, tmp, tmp->prev, trtmp); 604 goto error; 605 } 606 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_RIGHT); 607 if (trtmp == NULL) 608 trtmp = &map->header; 609 if (tmp->next != trtmp) { 610 printf("lookup: %d: %p->next=%p: %p\n", 611 i, tmp, tmp->next, trtmp); 612 goto error; 613 } 614 trtmp = rb_tree_find_node(&map->rb_tree, &tmp->start); 615 if (trtmp != tmp) { 616 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp, 617 PARENT_ENTRY(map, tmp)); 618 goto error; 619 } 620 } 621 622 return (0); 623 error: 624 return (-1); 625 } 626 #endif /* defined(DEBUG) || defined(DDB) */ 627 628 /* 629 * vm_map_lock: acquire an exclusive (write) lock on a map. 630 * 631 * => The locking protocol provides for guaranteed upgrade from shared -> 632 * exclusive by whichever thread currently has the map marked busy. 633 * See "LOCKING PROTOCOL NOTES" in uvm_map.h. This is horrible; among 634 * other problems, it defeats any fairness guarantees provided by RW 635 * locks. 636 */ 637 638 void 639 vm_map_lock(struct vm_map *map) 640 { 641 642 for (;;) { 643 rw_enter(&map->lock, RW_WRITER); 644 if (map->busy == NULL || map->busy == curlwp) { 645 break; 646 } 647 mutex_enter(&map->misc_lock); 648 rw_exit(&map->lock); 649 if (map->busy != NULL) { 650 cv_wait(&map->cv, &map->misc_lock); 651 } 652 mutex_exit(&map->misc_lock); 653 } 654 map->timestamp++; 655 } 656 657 /* 658 * vm_map_lock_try: try to lock a map, failing if it is already locked. 659 */ 660 661 bool 662 vm_map_lock_try(struct vm_map *map) 663 { 664 665 if (!rw_tryenter(&map->lock, RW_WRITER)) { 666 return false; 667 } 668 if (map->busy != NULL) { 669 rw_exit(&map->lock); 670 return false; 671 } 672 map->timestamp++; 673 return true; 674 } 675 676 /* 677 * vm_map_unlock: release an exclusive lock on a map. 678 */ 679 680 void 681 vm_map_unlock(struct vm_map *map) 682 { 683 684 KASSERT(rw_write_held(&map->lock)); 685 KASSERT(map->busy == NULL || map->busy == curlwp); 686 rw_exit(&map->lock); 687 } 688 689 /* 690 * vm_map_unbusy: mark the map as unbusy, and wake any waiters that 691 * want an exclusive lock. 692 */ 693 694 void 695 vm_map_unbusy(struct vm_map *map) 696 { 697 698 KASSERT(map->busy == curlwp); 699 700 /* 701 * Safe to clear 'busy' and 'waiters' with only a read lock held: 702 * 703 * o they can only be set with a write lock held 704 * o writers are blocked out with a read or write hold 705 * o at any time, only one thread owns the set of values 706 */ 707 mutex_enter(&map->misc_lock); 708 map->busy = NULL; 709 cv_broadcast(&map->cv); 710 mutex_exit(&map->misc_lock); 711 } 712 713 /* 714 * vm_map_lock_read: acquire a shared (read) lock on a map. 715 */ 716 717 void 718 vm_map_lock_read(struct vm_map *map) 719 { 720 721 rw_enter(&map->lock, RW_READER); 722 } 723 724 /* 725 * vm_map_unlock_read: release a shared lock on a map. 726 */ 727 728 void 729 vm_map_unlock_read(struct vm_map *map) 730 { 731 732 rw_exit(&map->lock); 733 } 734 735 /* 736 * vm_map_busy: mark a map as busy. 737 * 738 * => the caller must hold the map write locked 739 */ 740 741 void 742 vm_map_busy(struct vm_map *map) 743 { 744 745 KASSERT(rw_write_held(&map->lock)); 746 KASSERT(map->busy == NULL); 747 748 map->busy = curlwp; 749 } 750 751 /* 752 * vm_map_locked_p: return true if the map is write locked. 753 * 754 * => only for debug purposes like KASSERTs. 755 * => should not be used to verify that a map is not locked. 756 */ 757 758 bool 759 vm_map_locked_p(struct vm_map *map) 760 { 761 762 return rw_write_held(&map->lock); 763 } 764 765 /* 766 * uvm_mapent_alloc: allocate a map entry 767 */ 768 769 static struct vm_map_entry * 770 uvm_mapent_alloc(struct vm_map *map, int flags) 771 { 772 struct vm_map_entry *me; 773 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK; 774 UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist); 775 776 me = pool_cache_get(&uvm_map_entry_cache, pflags); 777 if (__predict_false(me == NULL)) { 778 return NULL; 779 } 780 me->flags = 0; 781 782 UVMHIST_LOG(maphist, "<- new entry=%#jx [kentry=%jd]", (uintptr_t)me, 783 (map == kernel_map), 0, 0); 784 return me; 785 } 786 787 /* 788 * uvm_mapent_free: free map entry 789 */ 790 791 static void 792 uvm_mapent_free(struct vm_map_entry *me) 793 { 794 UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist); 795 796 UVMHIST_LOG(maphist,"<- freeing map entry=%#jx [flags=%jd]", 797 (uintptr_t)me, me->flags, 0, 0); 798 pool_cache_put(&uvm_map_entry_cache, me); 799 } 800 801 /* 802 * uvm_mapent_copy: copy a map entry, preserving flags 803 */ 804 805 static inline void 806 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst) 807 { 808 809 memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) - 810 ((char *)src)); 811 } 812 813 #if defined(DEBUG) 814 static void 815 _uvm_mapent_check(const struct vm_map_entry *entry, const char *file, int line) 816 { 817 818 if (entry->start >= entry->end) { 819 goto bad; 820 } 821 if (UVM_ET_ISOBJ(entry)) { 822 if (entry->object.uvm_obj == NULL) { 823 goto bad; 824 } 825 } else if (UVM_ET_ISSUBMAP(entry)) { 826 if (entry->object.sub_map == NULL) { 827 goto bad; 828 } 829 } else { 830 if (entry->object.uvm_obj != NULL || 831 entry->object.sub_map != NULL) { 832 goto bad; 833 } 834 } 835 if (!UVM_ET_ISOBJ(entry)) { 836 if (entry->offset != 0) { 837 goto bad; 838 } 839 } 840 841 return; 842 843 bad: 844 panic("%s: bad entry %p (%s:%d)", __func__, entry, file, line); 845 } 846 #endif /* defined(DEBUG) */ 847 848 /* 849 * uvm_map_entry_unwire: unwire a map entry 850 * 851 * => map should be locked by caller 852 */ 853 854 static inline void 855 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry) 856 { 857 858 entry->wired_count = 0; 859 uvm_fault_unwire_locked(map, entry->start, entry->end); 860 } 861 862 863 /* 864 * wrapper for calling amap_ref() 865 */ 866 static inline void 867 uvm_map_reference_amap(struct vm_map_entry *entry, int flags) 868 { 869 870 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff, 871 (entry->end - entry->start) >> PAGE_SHIFT, flags); 872 } 873 874 875 /* 876 * wrapper for calling amap_unref() 877 */ 878 static inline void 879 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags) 880 { 881 882 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff, 883 (entry->end - entry->start) >> PAGE_SHIFT, flags); 884 } 885 886 887 /* 888 * uvm_map_init: init mapping system at boot time. 889 */ 890 891 void 892 uvm_map_init(void) 893 { 894 #if defined(UVMHIST) 895 static struct kern_history_ent pdhistbuf[UVMHIST_PDHIST_SIZE]; 896 #endif 897 898 /* 899 * first, init logging system. 900 */ 901 902 UVMHIST_FUNC("uvm_map_init"); 903 UVMHIST_LINK_STATIC(maphist); 904 UVMHIST_INIT_STATIC(pdhist, pdhistbuf); 905 UVMHIST_CALLED(maphist); 906 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0); 907 908 /* 909 * initialize the global lock for kernel map entry. 910 */ 911 912 mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM); 913 } 914 915 /* 916 * uvm_map_init_caches: init mapping system caches. 917 */ 918 void 919 uvm_map_init_caches(void) 920 { 921 /* 922 * initialize caches. 923 */ 924 925 pool_cache_bootstrap(&uvm_map_entry_cache, sizeof(struct vm_map_entry), 926 0, 0, 0, "vmmpepl", NULL, IPL_NONE, NULL, NULL, NULL); 927 pool_cache_bootstrap(&uvm_vmspace_cache, sizeof(struct vmspace), 928 0, 0, 0, "vmsppl", NULL, IPL_NONE, NULL, NULL, NULL); 929 } 930 931 /* 932 * clippers 933 */ 934 935 /* 936 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy. 937 */ 938 939 static void 940 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2, 941 vaddr_t splitat) 942 { 943 vaddr_t adj; 944 945 KASSERT(entry1->start < splitat); 946 KASSERT(splitat < entry1->end); 947 948 adj = splitat - entry1->start; 949 entry1->end = entry2->start = splitat; 950 951 if (entry1->aref.ar_amap) { 952 amap_splitref(&entry1->aref, &entry2->aref, adj); 953 } 954 if (UVM_ET_ISSUBMAP(entry1)) { 955 /* ... unlikely to happen, but play it safe */ 956 uvm_map_reference(entry1->object.sub_map); 957 } else if (UVM_ET_ISOBJ(entry1)) { 958 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */ 959 entry2->offset += adj; 960 if (entry1->object.uvm_obj->pgops && 961 entry1->object.uvm_obj->pgops->pgo_reference) 962 entry1->object.uvm_obj->pgops->pgo_reference( 963 entry1->object.uvm_obj); 964 } 965 } 966 967 /* 968 * uvm_map_clip_start: ensure that the entry begins at or after 969 * the starting address, if it doesn't we split the entry. 970 * 971 * => caller should use UVM_MAP_CLIP_START macro rather than calling 972 * this directly 973 * => map must be locked by caller 974 */ 975 976 void 977 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry, 978 vaddr_t start) 979 { 980 struct vm_map_entry *new_entry; 981 982 /* uvm_map_simplify_entry(map, entry); */ /* XXX */ 983 984 uvm_map_check(map, "clip_start entry"); 985 uvm_mapent_check(entry); 986 987 /* 988 * Split off the front portion. note that we must insert the new 989 * entry BEFORE this one, so that this entry has the specified 990 * starting address. 991 */ 992 new_entry = uvm_mapent_alloc(map, 0); 993 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 994 uvm_mapent_splitadj(new_entry, entry, start); 995 uvm_map_entry_link(map, entry->prev, new_entry); 996 997 uvm_map_check(map, "clip_start leave"); 998 } 999 1000 /* 1001 * uvm_map_clip_end: ensure that the entry ends at or before 1002 * the ending address, if it does't we split the reference 1003 * 1004 * => caller should use UVM_MAP_CLIP_END macro rather than calling 1005 * this directly 1006 * => map must be locked by caller 1007 */ 1008 1009 void 1010 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end) 1011 { 1012 struct vm_map_entry *new_entry; 1013 1014 uvm_map_check(map, "clip_end entry"); 1015 uvm_mapent_check(entry); 1016 1017 /* 1018 * Create a new entry and insert it 1019 * AFTER the specified entry 1020 */ 1021 new_entry = uvm_mapent_alloc(map, 0); 1022 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1023 uvm_mapent_splitadj(entry, new_entry, end); 1024 uvm_map_entry_link(map, entry, new_entry); 1025 1026 uvm_map_check(map, "clip_end leave"); 1027 } 1028 1029 /* 1030 * M A P - m a i n e n t r y p o i n t 1031 */ 1032 /* 1033 * uvm_map: establish a valid mapping in a map 1034 * 1035 * => assume startp is page aligned. 1036 * => assume size is a multiple of PAGE_SIZE. 1037 * => assume sys_mmap provides enough of a "hint" to have us skip 1038 * over text/data/bss area. 1039 * => map must be unlocked (we will lock it) 1040 * => <uobj,uoffset> value meanings (4 cases): 1041 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER 1042 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER 1043 * [3] <uobj,uoffset> == normal mapping 1044 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA 1045 * 1046 * case [4] is for kernel mappings where we don't know the offset until 1047 * we've found a virtual address. note that kernel object offsets are 1048 * always relative to vm_map_min(kernel_map). 1049 * 1050 * => if `align' is non-zero, we align the virtual address to the specified 1051 * alignment. 1052 * this is provided as a mechanism for large pages. 1053 * 1054 * => XXXCDC: need way to map in external amap? 1055 */ 1056 1057 int 1058 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size, 1059 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags) 1060 { 1061 struct uvm_map_args args; 1062 struct vm_map_entry *new_entry; 1063 int error; 1064 1065 KASSERT((size & PAGE_MASK) == 0); 1066 1067 /* 1068 * for pager_map, allocate the new entry first to avoid sleeping 1069 * for memory while we have the map locked. 1070 */ 1071 1072 new_entry = NULL; 1073 if (map == pager_map) { 1074 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT)); 1075 if (__predict_false(new_entry == NULL)) 1076 return ENOMEM; 1077 } 1078 if (map == pager_map) 1079 flags |= UVM_FLAG_NOMERGE; 1080 1081 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align, 1082 flags, &args); 1083 if (!error) { 1084 error = uvm_map_enter(map, &args, new_entry); 1085 *startp = args.uma_start; 1086 } else if (new_entry) { 1087 uvm_mapent_free(new_entry); 1088 } 1089 1090 #if defined(DEBUG) 1091 if (!error && VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 1092 uvm_km_check_empty(map, *startp, *startp + size); 1093 } 1094 #endif /* defined(DEBUG) */ 1095 1096 return error; 1097 } 1098 1099 /* 1100 * uvm_map_prepare: 1101 * 1102 * called with map unlocked. 1103 * on success, returns the map locked. 1104 */ 1105 1106 int 1107 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size, 1108 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags, 1109 struct uvm_map_args *args) 1110 { 1111 struct vm_map_entry *prev_entry; 1112 vm_prot_t prot = UVM_PROTECTION(flags); 1113 vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1114 1115 UVMHIST_FUNC("uvm_map_prepare"); 1116 UVMHIST_CALLED(maphist); 1117 1118 UVMHIST_LOG(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1119 (uintptr_t)map, start, size, flags); 1120 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1121 uoffset,0,0); 1122 1123 /* 1124 * detect a popular device driver bug. 1125 */ 1126 1127 KASSERT(doing_shutdown || curlwp != NULL); 1128 1129 /* 1130 * zero-sized mapping doesn't make any sense. 1131 */ 1132 KASSERT(size > 0); 1133 1134 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0); 1135 1136 uvm_map_check(map, "map entry"); 1137 1138 /* 1139 * check sanity of protection code 1140 */ 1141 1142 if ((prot & maxprot) != prot) { 1143 UVMHIST_LOG(maphist, "<- prot. failure: prot=%#jx, max=%#jx", 1144 prot, maxprot,0,0); 1145 return EACCES; 1146 } 1147 1148 /* 1149 * figure out where to put new VM range 1150 */ 1151 retry: 1152 if (vm_map_lock_try(map) == false) { 1153 if ((flags & UVM_FLAG_TRYLOCK) != 0) { 1154 return EAGAIN; 1155 } 1156 vm_map_lock(map); /* could sleep here */ 1157 } 1158 if (flags & UVM_FLAG_UNMAP) { 1159 KASSERT(flags & UVM_FLAG_FIXED); 1160 KASSERT((flags & UVM_FLAG_NOWAIT) == 0); 1161 1162 /* 1163 * Set prev_entry to what it will need to be after any existing 1164 * entries are removed later in uvm_map_enter(). 1165 */ 1166 1167 if (uvm_map_lookup_entry(map, start, &prev_entry)) { 1168 if (start == prev_entry->start) 1169 prev_entry = prev_entry->prev; 1170 else 1171 UVM_MAP_CLIP_END(map, prev_entry, start); 1172 SAVE_HINT(map, map->hint, prev_entry); 1173 } 1174 } else { 1175 prev_entry = uvm_map_findspace(map, start, size, &start, 1176 uobj, uoffset, align, flags); 1177 } 1178 if (prev_entry == NULL) { 1179 unsigned int timestamp; 1180 1181 timestamp = map->timestamp; 1182 UVMHIST_LOG(maphist,"waiting va timestamp=%#jx", 1183 timestamp,0,0,0); 1184 map->flags |= VM_MAP_WANTVA; 1185 vm_map_unlock(map); 1186 1187 /* 1188 * try to reclaim kva and wait until someone does unmap. 1189 * fragile locking here, so we awaken every second to 1190 * recheck the condition. 1191 */ 1192 1193 mutex_enter(&map->misc_lock); 1194 while ((map->flags & VM_MAP_WANTVA) != 0 && 1195 map->timestamp == timestamp) { 1196 if ((flags & UVM_FLAG_WAITVA) == 0) { 1197 mutex_exit(&map->misc_lock); 1198 UVMHIST_LOG(maphist, 1199 "<- uvm_map_findspace failed!", 0,0,0,0); 1200 return ENOMEM; 1201 } else { 1202 cv_timedwait(&map->cv, &map->misc_lock, hz); 1203 } 1204 } 1205 mutex_exit(&map->misc_lock); 1206 goto retry; 1207 } 1208 1209 #ifdef PMAP_GROWKERNEL 1210 /* 1211 * If the kernel pmap can't map the requested space, 1212 * then allocate more resources for it. 1213 */ 1214 if (map == kernel_map && uvm_maxkaddr < (start + size)) 1215 uvm_maxkaddr = pmap_growkernel(start + size); 1216 #endif 1217 1218 UVMMAP_EVCNT_INCR(map_call); 1219 1220 /* 1221 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER 1222 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in 1223 * either case we want to zero it before storing it in the map entry 1224 * (because it looks strange and confusing when debugging...) 1225 * 1226 * if uobj is not null 1227 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping 1228 * and we do not need to change uoffset. 1229 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset 1230 * now (based on the starting address of the map). this case is 1231 * for kernel object mappings where we don't know the offset until 1232 * the virtual address is found (with uvm_map_findspace). the 1233 * offset is the distance we are from the start of the map. 1234 */ 1235 1236 if (uobj == NULL) { 1237 uoffset = 0; 1238 } else { 1239 if (uoffset == UVM_UNKNOWN_OFFSET) { 1240 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj)); 1241 uoffset = start - vm_map_min(kernel_map); 1242 } 1243 } 1244 1245 args->uma_flags = flags; 1246 args->uma_prev = prev_entry; 1247 args->uma_start = start; 1248 args->uma_size = size; 1249 args->uma_uobj = uobj; 1250 args->uma_uoffset = uoffset; 1251 1252 UVMHIST_LOG(maphist, "<- done!", 0,0,0,0); 1253 return 0; 1254 } 1255 1256 /* 1257 * uvm_map_enter: 1258 * 1259 * called with map locked. 1260 * unlock the map before returning. 1261 */ 1262 1263 int 1264 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args, 1265 struct vm_map_entry *new_entry) 1266 { 1267 struct vm_map_entry *prev_entry = args->uma_prev; 1268 struct vm_map_entry *dead = NULL, *dead_entries = NULL; 1269 1270 const uvm_flag_t flags = args->uma_flags; 1271 const vm_prot_t prot = UVM_PROTECTION(flags); 1272 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1273 const vm_inherit_t inherit = UVM_INHERIT(flags); 1274 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ? 1275 AMAP_EXTEND_NOWAIT : 0; 1276 const int advice = UVM_ADVICE(flags); 1277 1278 vaddr_t start = args->uma_start; 1279 vsize_t size = args->uma_size; 1280 struct uvm_object *uobj = args->uma_uobj; 1281 voff_t uoffset = args->uma_uoffset; 1282 1283 const int kmap = (vm_map_pmap(map) == pmap_kernel()); 1284 int merged = 0; 1285 int error; 1286 int newetype; 1287 1288 UVMHIST_FUNC("uvm_map_enter"); 1289 UVMHIST_CALLED(maphist); 1290 1291 UVMHIST_LOG(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1292 (uintptr_t)map, start, size, flags); 1293 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1294 uoffset,0,0); 1295 1296 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */ 1297 KASSERT(vm_map_locked_p(map)); 1298 KASSERT((flags & (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)) != 1299 (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)); 1300 1301 if (uobj) 1302 newetype = UVM_ET_OBJ; 1303 else 1304 newetype = 0; 1305 1306 if (flags & UVM_FLAG_COPYONW) { 1307 newetype |= UVM_ET_COPYONWRITE; 1308 if ((flags & UVM_FLAG_OVERLAY) == 0) 1309 newetype |= UVM_ET_NEEDSCOPY; 1310 } 1311 1312 /* 1313 * For mappings with unmap, remove any old entries now. Adding the new 1314 * entry cannot fail because that can only happen if UVM_FLAG_NOWAIT 1315 * is set, and we do not support nowait and unmap together. 1316 */ 1317 1318 if (flags & UVM_FLAG_UNMAP) { 1319 KASSERT(flags & UVM_FLAG_FIXED); 1320 uvm_unmap_remove(map, start, start + size, &dead_entries, 0); 1321 #ifdef DEBUG 1322 struct vm_map_entry *tmp_entry __diagused; 1323 bool rv __diagused; 1324 1325 rv = uvm_map_lookup_entry(map, start, &tmp_entry); 1326 KASSERT(!rv); 1327 KASSERTMSG(prev_entry == tmp_entry, 1328 "args %p prev_entry %p tmp_entry %p", 1329 args, prev_entry, tmp_entry); 1330 #endif 1331 SAVE_HINT(map, map->hint, prev_entry); 1332 } 1333 1334 /* 1335 * try and insert in map by extending previous entry, if possible. 1336 * XXX: we don't try and pull back the next entry. might be useful 1337 * for a stack, but we are currently allocating our stack in advance. 1338 */ 1339 1340 if (flags & UVM_FLAG_NOMERGE) 1341 goto nomerge; 1342 1343 if (prev_entry->end == start && 1344 prev_entry != &map->header && 1345 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, 0, 1346 prot, maxprot, inherit, advice, 0)) { 1347 1348 if (uobj && prev_entry->offset + 1349 (prev_entry->end - prev_entry->start) != uoffset) 1350 goto forwardmerge; 1351 1352 /* 1353 * can't extend a shared amap. note: no need to lock amap to 1354 * look at refs since we don't care about its exact value. 1355 * if it is one (i.e. we have only reference) it will stay there 1356 */ 1357 1358 if (prev_entry->aref.ar_amap && 1359 amap_refs(prev_entry->aref.ar_amap) != 1) { 1360 goto forwardmerge; 1361 } 1362 1363 if (prev_entry->aref.ar_amap) { 1364 error = amap_extend(prev_entry, size, 1365 amapwaitflag | AMAP_EXTEND_FORWARDS); 1366 if (error) 1367 goto nomerge; 1368 } 1369 1370 if (kmap) { 1371 UVMMAP_EVCNT_INCR(kbackmerge); 1372 } else { 1373 UVMMAP_EVCNT_INCR(ubackmerge); 1374 } 1375 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0); 1376 1377 /* 1378 * drop our reference to uobj since we are extending a reference 1379 * that we already have (the ref count can not drop to zero). 1380 */ 1381 1382 if (uobj && uobj->pgops->pgo_detach) 1383 uobj->pgops->pgo_detach(uobj); 1384 1385 /* 1386 * Now that we've merged the entries, note that we've grown 1387 * and our gap has shrunk. Then fix the tree. 1388 */ 1389 prev_entry->end += size; 1390 prev_entry->gap -= size; 1391 uvm_rb_fixup(map, prev_entry); 1392 1393 uvm_map_check(map, "map backmerged"); 1394 1395 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0); 1396 merged++; 1397 } 1398 1399 forwardmerge: 1400 if (prev_entry->next->start == (start + size) && 1401 prev_entry->next != &map->header && 1402 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, 0, 1403 prot, maxprot, inherit, advice, 0)) { 1404 1405 if (uobj && prev_entry->next->offset != uoffset + size) 1406 goto nomerge; 1407 1408 /* 1409 * can't extend a shared amap. note: no need to lock amap to 1410 * look at refs since we don't care about its exact value. 1411 * if it is one (i.e. we have only reference) it will stay there. 1412 * 1413 * note that we also can't merge two amaps, so if we 1414 * merged with the previous entry which has an amap, 1415 * and the next entry also has an amap, we give up. 1416 * 1417 * Interesting cases: 1418 * amap, new, amap -> give up second merge (single fwd extend) 1419 * amap, new, none -> double forward extend (extend again here) 1420 * none, new, amap -> double backward extend (done here) 1421 * uobj, new, amap -> single backward extend (done here) 1422 * 1423 * XXX should we attempt to deal with someone refilling 1424 * the deallocated region between two entries that are 1425 * backed by the same amap (ie, arefs is 2, "prev" and 1426 * "next" refer to it, and adding this allocation will 1427 * close the hole, thus restoring arefs to 1 and 1428 * deallocating the "next" vm_map_entry)? -- @@@ 1429 */ 1430 1431 if (prev_entry->next->aref.ar_amap && 1432 (amap_refs(prev_entry->next->aref.ar_amap) != 1 || 1433 (merged && prev_entry->aref.ar_amap))) { 1434 goto nomerge; 1435 } 1436 1437 if (merged) { 1438 /* 1439 * Try to extend the amap of the previous entry to 1440 * cover the next entry as well. If it doesn't work 1441 * just skip on, don't actually give up, since we've 1442 * already completed the back merge. 1443 */ 1444 if (prev_entry->aref.ar_amap) { 1445 if (amap_extend(prev_entry, 1446 prev_entry->next->end - 1447 prev_entry->next->start, 1448 amapwaitflag | AMAP_EXTEND_FORWARDS)) 1449 goto nomerge; 1450 } 1451 1452 /* 1453 * Try to extend the amap of the *next* entry 1454 * back to cover the new allocation *and* the 1455 * previous entry as well (the previous merge 1456 * didn't have an amap already otherwise we 1457 * wouldn't be checking here for an amap). If 1458 * it doesn't work just skip on, again, don't 1459 * actually give up, since we've already 1460 * completed the back merge. 1461 */ 1462 else if (prev_entry->next->aref.ar_amap) { 1463 if (amap_extend(prev_entry->next, 1464 prev_entry->end - 1465 prev_entry->start, 1466 amapwaitflag | AMAP_EXTEND_BACKWARDS)) 1467 goto nomerge; 1468 } 1469 } else { 1470 /* 1471 * Pull the next entry's amap backwards to cover this 1472 * new allocation. 1473 */ 1474 if (prev_entry->next->aref.ar_amap) { 1475 error = amap_extend(prev_entry->next, size, 1476 amapwaitflag | AMAP_EXTEND_BACKWARDS); 1477 if (error) 1478 goto nomerge; 1479 } 1480 } 1481 1482 if (merged) { 1483 if (kmap) { 1484 UVMMAP_EVCNT_DECR(kbackmerge); 1485 UVMMAP_EVCNT_INCR(kbimerge); 1486 } else { 1487 UVMMAP_EVCNT_DECR(ubackmerge); 1488 UVMMAP_EVCNT_INCR(ubimerge); 1489 } 1490 } else { 1491 if (kmap) { 1492 UVMMAP_EVCNT_INCR(kforwmerge); 1493 } else { 1494 UVMMAP_EVCNT_INCR(uforwmerge); 1495 } 1496 } 1497 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0); 1498 1499 /* 1500 * drop our reference to uobj since we are extending a reference 1501 * that we already have (the ref count can not drop to zero). 1502 */ 1503 if (uobj && uobj->pgops->pgo_detach) 1504 uobj->pgops->pgo_detach(uobj); 1505 1506 if (merged) { 1507 dead = prev_entry->next; 1508 prev_entry->end = dead->end; 1509 uvm_map_entry_unlink(map, dead); 1510 if (dead->aref.ar_amap != NULL) { 1511 prev_entry->aref = dead->aref; 1512 dead->aref.ar_amap = NULL; 1513 } 1514 } else { 1515 prev_entry->next->start -= size; 1516 if (prev_entry != &map->header) { 1517 prev_entry->gap -= size; 1518 KASSERT(prev_entry->gap == uvm_rb_gap(prev_entry)); 1519 uvm_rb_fixup(map, prev_entry); 1520 } 1521 if (uobj) 1522 prev_entry->next->offset = uoffset; 1523 } 1524 1525 uvm_map_check(map, "map forwardmerged"); 1526 1527 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0); 1528 merged++; 1529 } 1530 1531 nomerge: 1532 if (!merged) { 1533 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0); 1534 if (kmap) { 1535 UVMMAP_EVCNT_INCR(knomerge); 1536 } else { 1537 UVMMAP_EVCNT_INCR(unomerge); 1538 } 1539 1540 /* 1541 * allocate new entry and link it in. 1542 */ 1543 1544 if (new_entry == NULL) { 1545 new_entry = uvm_mapent_alloc(map, 1546 (flags & UVM_FLAG_NOWAIT)); 1547 if (__predict_false(new_entry == NULL)) { 1548 error = ENOMEM; 1549 goto done; 1550 } 1551 } 1552 new_entry->start = start; 1553 new_entry->end = new_entry->start + size; 1554 new_entry->object.uvm_obj = uobj; 1555 new_entry->offset = uoffset; 1556 1557 new_entry->etype = newetype; 1558 1559 if (flags & UVM_FLAG_NOMERGE) { 1560 new_entry->flags |= UVM_MAP_NOMERGE; 1561 } 1562 1563 new_entry->protection = prot; 1564 new_entry->max_protection = maxprot; 1565 new_entry->inheritance = inherit; 1566 new_entry->wired_count = 0; 1567 new_entry->advice = advice; 1568 if (flags & UVM_FLAG_OVERLAY) { 1569 1570 /* 1571 * to_add: for BSS we overallocate a little since we 1572 * are likely to extend 1573 */ 1574 1575 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ? 1576 UVM_AMAP_CHUNK << PAGE_SHIFT : 0; 1577 struct vm_amap *amap = amap_alloc(size, to_add, 1578 (flags & UVM_FLAG_NOWAIT)); 1579 if (__predict_false(amap == NULL)) { 1580 error = ENOMEM; 1581 goto done; 1582 } 1583 new_entry->aref.ar_pageoff = 0; 1584 new_entry->aref.ar_amap = amap; 1585 } else { 1586 new_entry->aref.ar_pageoff = 0; 1587 new_entry->aref.ar_amap = NULL; 1588 } 1589 uvm_map_entry_link(map, prev_entry, new_entry); 1590 1591 /* 1592 * Update the free space hint 1593 */ 1594 1595 if ((map->first_free == prev_entry) && 1596 (prev_entry->end >= new_entry->start)) 1597 map->first_free = new_entry; 1598 1599 new_entry = NULL; 1600 } 1601 1602 map->size += size; 1603 1604 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 1605 1606 error = 0; 1607 1608 done: 1609 vm_map_unlock(map); 1610 1611 if (new_entry) { 1612 uvm_mapent_free(new_entry); 1613 } 1614 if (dead) { 1615 KDASSERT(merged); 1616 uvm_mapent_free(dead); 1617 } 1618 if (dead_entries) 1619 uvm_unmap_detach(dead_entries, 0); 1620 1621 return error; 1622 } 1623 1624 /* 1625 * uvm_map_lookup_entry_bytree: lookup an entry in tree 1626 */ 1627 1628 static inline bool 1629 uvm_map_lookup_entry_bytree(struct vm_map *map, vaddr_t address, 1630 struct vm_map_entry **entry /* OUT */) 1631 { 1632 struct vm_map_entry *prev = &map->header; 1633 struct vm_map_entry *cur = ROOT_ENTRY(map); 1634 1635 while (cur) { 1636 UVMMAP_EVCNT_INCR(mlk_treeloop); 1637 if (address >= cur->start) { 1638 if (address < cur->end) { 1639 *entry = cur; 1640 return true; 1641 } 1642 prev = cur; 1643 cur = RIGHT_ENTRY(cur); 1644 } else 1645 cur = LEFT_ENTRY(cur); 1646 } 1647 *entry = prev; 1648 return false; 1649 } 1650 1651 /* 1652 * uvm_map_lookup_entry: find map entry at or before an address 1653 * 1654 * => map must at least be read-locked by caller 1655 * => entry is returned in "entry" 1656 * => return value is true if address is in the returned entry 1657 */ 1658 1659 bool 1660 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address, 1661 struct vm_map_entry **entry /* OUT */) 1662 { 1663 struct vm_map_entry *cur; 1664 bool use_tree = false; 1665 UVMHIST_FUNC("uvm_map_lookup_entry"); 1666 UVMHIST_CALLED(maphist); 1667 1668 UVMHIST_LOG(maphist,"(map=%#jx,addr=%#jx,ent=%#jx)", 1669 (uintptr_t)map, address, (uintptr_t)entry, 0); 1670 1671 /* 1672 * start looking either from the head of the 1673 * list, or from the hint. 1674 */ 1675 1676 cur = map->hint; 1677 1678 if (cur == &map->header) 1679 cur = cur->next; 1680 1681 UVMMAP_EVCNT_INCR(mlk_call); 1682 if (address >= cur->start) { 1683 1684 /* 1685 * go from hint to end of list. 1686 * 1687 * but first, make a quick check to see if 1688 * we are already looking at the entry we 1689 * want (which is usually the case). 1690 * note also that we don't need to save the hint 1691 * here... it is the same hint (unless we are 1692 * at the header, in which case the hint didn't 1693 * buy us anything anyway). 1694 */ 1695 1696 if (cur != &map->header && cur->end > address) { 1697 UVMMAP_EVCNT_INCR(mlk_hint); 1698 *entry = cur; 1699 UVMHIST_LOG(maphist,"<- got it via hint (%#jx)", 1700 (uintptr_t)cur, 0, 0, 0); 1701 uvm_mapent_check(*entry); 1702 return (true); 1703 } 1704 1705 if (map->nentries > 15) 1706 use_tree = true; 1707 } else { 1708 1709 /* 1710 * invalid hint. use tree. 1711 */ 1712 use_tree = true; 1713 } 1714 1715 uvm_map_check(map, __func__); 1716 1717 if (use_tree) { 1718 /* 1719 * Simple lookup in the tree. Happens when the hint is 1720 * invalid, or nentries reach a threshold. 1721 */ 1722 UVMMAP_EVCNT_INCR(mlk_tree); 1723 if (uvm_map_lookup_entry_bytree(map, address, entry)) { 1724 goto got; 1725 } else { 1726 goto failed; 1727 } 1728 } 1729 1730 /* 1731 * search linearly 1732 */ 1733 1734 UVMMAP_EVCNT_INCR(mlk_list); 1735 while (cur != &map->header) { 1736 UVMMAP_EVCNT_INCR(mlk_listloop); 1737 if (cur->end > address) { 1738 if (address >= cur->start) { 1739 /* 1740 * save this lookup for future 1741 * hints, and return 1742 */ 1743 1744 *entry = cur; 1745 got: 1746 SAVE_HINT(map, map->hint, *entry); 1747 UVMHIST_LOG(maphist,"<- search got it (%#jx)", 1748 (uintptr_t)cur, 0, 0, 0); 1749 KDASSERT((*entry)->start <= address); 1750 KDASSERT(address < (*entry)->end); 1751 uvm_mapent_check(*entry); 1752 return (true); 1753 } 1754 break; 1755 } 1756 cur = cur->next; 1757 } 1758 *entry = cur->prev; 1759 failed: 1760 SAVE_HINT(map, map->hint, *entry); 1761 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0); 1762 KDASSERT((*entry) == &map->header || (*entry)->end <= address); 1763 KDASSERT((*entry)->next == &map->header || 1764 address < (*entry)->next->start); 1765 return (false); 1766 } 1767 1768 /* 1769 * See if the range between start and start + length fits in the gap 1770 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't 1771 * fit, and -1 address wraps around. 1772 */ 1773 static int 1774 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset, 1775 vsize_t align, int flags, int topdown, struct vm_map_entry *entry) 1776 { 1777 vaddr_t end; 1778 1779 #ifdef PMAP_PREFER 1780 /* 1781 * push start address forward as needed to avoid VAC alias problems. 1782 * we only do this if a valid offset is specified. 1783 */ 1784 1785 if (uoffset != UVM_UNKNOWN_OFFSET) 1786 PMAP_PREFER(uoffset, start, length, topdown); 1787 #endif 1788 if ((flags & UVM_FLAG_COLORMATCH) != 0) { 1789 KASSERT(align < uvmexp.ncolors); 1790 if (uvmexp.ncolors > 1) { 1791 const u_int colormask = uvmexp.colormask; 1792 const u_int colorsize = colormask + 1; 1793 vaddr_t hint = atop(*start); 1794 const u_int color = hint & colormask; 1795 if (color != align) { 1796 hint -= color; /* adjust to color boundary */ 1797 KASSERT((hint & colormask) == 0); 1798 if (topdown) { 1799 if (align > color) 1800 hint -= colorsize; 1801 } else { 1802 if (align < color) 1803 hint += colorsize; 1804 } 1805 *start = ptoa(hint + align); /* adjust to color */ 1806 } 1807 } 1808 } else if (align != 0) { 1809 if ((*start & (align - 1)) != 0) { 1810 if (topdown) 1811 *start &= ~(align - 1); 1812 else 1813 *start = roundup(*start, align); 1814 } 1815 /* 1816 * XXX Should we PMAP_PREFER() here again? 1817 * eh...i think we're okay 1818 */ 1819 } 1820 1821 /* 1822 * Find the end of the proposed new region. Be sure we didn't 1823 * wrap around the address; if so, we lose. Otherwise, if the 1824 * proposed new region fits before the next entry, we win. 1825 */ 1826 1827 end = *start + length; 1828 if (end < *start) 1829 return (-1); 1830 1831 if (entry->next->start >= end && *start >= entry->end) 1832 return (1); 1833 1834 return (0); 1835 } 1836 1837 /* 1838 * uvm_map_findspace: find "length" sized space in "map". 1839 * 1840 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is 1841 * set in "flags" (in which case we insist on using "hint"). 1842 * => "result" is VA returned 1843 * => uobj/uoffset are to be used to handle VAC alignment, if required 1844 * => if "align" is non-zero, we attempt to align to that value. 1845 * => caller must at least have read-locked map 1846 * => returns NULL on failure, or pointer to prev. map entry if success 1847 * => note this is a cross between the old vm_map_findspace and vm_map_find 1848 */ 1849 1850 struct vm_map_entry * 1851 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length, 1852 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset, 1853 vsize_t align, int flags) 1854 { 1855 struct vm_map_entry *entry; 1856 struct vm_map_entry *child, *prev, *tmp; 1857 vaddr_t orig_hint __diagused; 1858 const int topdown = map->flags & VM_MAP_TOPDOWN; 1859 UVMHIST_FUNC("uvm_map_findspace"); 1860 UVMHIST_CALLED(maphist); 1861 1862 UVMHIST_LOG(maphist, "(map=%#jx, hint=%#jx, len=%ju, flags=%#jx)", 1863 (uintptr_t)map, hint, length, flags); 1864 KASSERT((flags & UVM_FLAG_COLORMATCH) != 0 || (align & (align - 1)) == 0); 1865 KASSERT((flags & UVM_FLAG_COLORMATCH) == 0 || align < uvmexp.ncolors); 1866 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1867 1868 uvm_map_check(map, "map_findspace entry"); 1869 1870 /* 1871 * remember the original hint. if we are aligning, then we 1872 * may have to try again with no alignment constraint if 1873 * we fail the first time. 1874 */ 1875 1876 orig_hint = hint; 1877 if (hint < vm_map_min(map)) { /* check ranges ... */ 1878 if (flags & UVM_FLAG_FIXED) { 1879 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0); 1880 return (NULL); 1881 } 1882 hint = vm_map_min(map); 1883 } 1884 if (hint > vm_map_max(map)) { 1885 UVMHIST_LOG(maphist,"<- VA %#jx > range [%#jx->%#jx]", 1886 hint, vm_map_min(map), vm_map_max(map), 0); 1887 return (NULL); 1888 } 1889 1890 /* 1891 * Look for the first possible address; if there's already 1892 * something at this address, we have to start after it. 1893 */ 1894 1895 /* 1896 * @@@: there are four, no, eight cases to consider. 1897 * 1898 * 0: found, fixed, bottom up -> fail 1899 * 1: found, fixed, top down -> fail 1900 * 2: found, not fixed, bottom up -> start after entry->end, 1901 * loop up 1902 * 3: found, not fixed, top down -> start before entry->start, 1903 * loop down 1904 * 4: not found, fixed, bottom up -> check entry->next->start, fail 1905 * 5: not found, fixed, top down -> check entry->next->start, fail 1906 * 6: not found, not fixed, bottom up -> check entry->next->start, 1907 * loop up 1908 * 7: not found, not fixed, top down -> check entry->next->start, 1909 * loop down 1910 * 1911 * as you can see, it reduces to roughly five cases, and that 1912 * adding top down mapping only adds one unique case (without 1913 * it, there would be four cases). 1914 */ 1915 1916 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) { 1917 entry = map->first_free; 1918 } else { 1919 if (uvm_map_lookup_entry(map, hint, &entry)) { 1920 /* "hint" address already in use ... */ 1921 if (flags & UVM_FLAG_FIXED) { 1922 UVMHIST_LOG(maphist, "<- fixed & VA in use", 1923 0, 0, 0, 0); 1924 return (NULL); 1925 } 1926 if (topdown) 1927 /* Start from lower gap. */ 1928 entry = entry->prev; 1929 } else if (flags & UVM_FLAG_FIXED) { 1930 if (entry->next->start >= hint + length && 1931 hint + length > hint) 1932 goto found; 1933 1934 /* "hint" address is gap but too small */ 1935 UVMHIST_LOG(maphist, "<- fixed mapping failed", 1936 0, 0, 0, 0); 1937 return (NULL); /* only one shot at it ... */ 1938 } else { 1939 /* 1940 * See if given hint fits in this gap. 1941 */ 1942 switch (uvm_map_space_avail(&hint, length, 1943 uoffset, align, flags, topdown, entry)) { 1944 case 1: 1945 goto found; 1946 case -1: 1947 goto wraparound; 1948 } 1949 1950 if (topdown) { 1951 /* 1952 * Still there is a chance to fit 1953 * if hint > entry->end. 1954 */ 1955 } else { 1956 /* Start from higher gap. */ 1957 entry = entry->next; 1958 if (entry == &map->header) 1959 goto notfound; 1960 goto nextgap; 1961 } 1962 } 1963 } 1964 1965 /* 1966 * Note that all UVM_FLAGS_FIXED case is already handled. 1967 */ 1968 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1969 1970 /* Try to find the space in the red-black tree */ 1971 1972 /* Check slot before any entry */ 1973 hint = topdown ? entry->next->start - length : entry->end; 1974 switch (uvm_map_space_avail(&hint, length, uoffset, align, flags, 1975 topdown, entry)) { 1976 case 1: 1977 goto found; 1978 case -1: 1979 goto wraparound; 1980 } 1981 1982 nextgap: 1983 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1984 /* If there is not enough space in the whole tree, we fail */ 1985 tmp = ROOT_ENTRY(map); 1986 if (tmp == NULL || tmp->maxgap < length) 1987 goto notfound; 1988 1989 prev = NULL; /* previous candidate */ 1990 1991 /* Find an entry close to hint that has enough space */ 1992 for (; tmp;) { 1993 KASSERT(tmp->next->start == tmp->end + tmp->gap); 1994 if (topdown) { 1995 if (tmp->next->start < hint + length && 1996 (prev == NULL || tmp->end > prev->end)) { 1997 if (tmp->gap >= length) 1998 prev = tmp; 1999 else if ((child = LEFT_ENTRY(tmp)) != NULL 2000 && child->maxgap >= length) 2001 prev = tmp; 2002 } 2003 } else { 2004 if (tmp->end >= hint && 2005 (prev == NULL || tmp->end < prev->end)) { 2006 if (tmp->gap >= length) 2007 prev = tmp; 2008 else if ((child = RIGHT_ENTRY(tmp)) != NULL 2009 && child->maxgap >= length) 2010 prev = tmp; 2011 } 2012 } 2013 if (tmp->next->start < hint + length) 2014 child = RIGHT_ENTRY(tmp); 2015 else if (tmp->end > hint) 2016 child = LEFT_ENTRY(tmp); 2017 else { 2018 if (tmp->gap >= length) 2019 break; 2020 if (topdown) 2021 child = LEFT_ENTRY(tmp); 2022 else 2023 child = RIGHT_ENTRY(tmp); 2024 } 2025 if (child == NULL || child->maxgap < length) 2026 break; 2027 tmp = child; 2028 } 2029 2030 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) { 2031 /* 2032 * Check if the entry that we found satifies the 2033 * space requirement 2034 */ 2035 if (topdown) { 2036 if (hint > tmp->next->start - length) 2037 hint = tmp->next->start - length; 2038 } else { 2039 if (hint < tmp->end) 2040 hint = tmp->end; 2041 } 2042 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2043 flags, topdown, tmp)) { 2044 case 1: 2045 entry = tmp; 2046 goto found; 2047 case -1: 2048 goto wraparound; 2049 } 2050 if (tmp->gap >= length) 2051 goto listsearch; 2052 } 2053 if (prev == NULL) 2054 goto notfound; 2055 2056 if (topdown) { 2057 KASSERT(orig_hint >= prev->next->start - length || 2058 prev->next->start - length > prev->next->start); 2059 hint = prev->next->start - length; 2060 } else { 2061 KASSERT(orig_hint <= prev->end); 2062 hint = prev->end; 2063 } 2064 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2065 flags, topdown, prev)) { 2066 case 1: 2067 entry = prev; 2068 goto found; 2069 case -1: 2070 goto wraparound; 2071 } 2072 if (prev->gap >= length) 2073 goto listsearch; 2074 2075 if (topdown) 2076 tmp = LEFT_ENTRY(prev); 2077 else 2078 tmp = RIGHT_ENTRY(prev); 2079 for (;;) { 2080 KASSERT(tmp && tmp->maxgap >= length); 2081 if (topdown) 2082 child = RIGHT_ENTRY(tmp); 2083 else 2084 child = LEFT_ENTRY(tmp); 2085 if (child && child->maxgap >= length) { 2086 tmp = child; 2087 continue; 2088 } 2089 if (tmp->gap >= length) 2090 break; 2091 if (topdown) 2092 tmp = LEFT_ENTRY(tmp); 2093 else 2094 tmp = RIGHT_ENTRY(tmp); 2095 } 2096 2097 if (topdown) { 2098 KASSERT(orig_hint >= tmp->next->start - length || 2099 tmp->next->start - length > tmp->next->start); 2100 hint = tmp->next->start - length; 2101 } else { 2102 KASSERT(orig_hint <= tmp->end); 2103 hint = tmp->end; 2104 } 2105 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2106 flags, topdown, tmp)) { 2107 case 1: 2108 entry = tmp; 2109 goto found; 2110 case -1: 2111 goto wraparound; 2112 } 2113 2114 /* 2115 * The tree fails to find an entry because of offset or alignment 2116 * restrictions. Search the list instead. 2117 */ 2118 listsearch: 2119 /* 2120 * Look through the rest of the map, trying to fit a new region in 2121 * the gap between existing regions, or after the very last region. 2122 * note: entry->end = base VA of current gap, 2123 * entry->next->start = VA of end of current gap 2124 */ 2125 2126 for (;;) { 2127 /* Update hint for current gap. */ 2128 hint = topdown ? entry->next->start - length : entry->end; 2129 2130 /* See if it fits. */ 2131 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2132 flags, topdown, entry)) { 2133 case 1: 2134 goto found; 2135 case -1: 2136 goto wraparound; 2137 } 2138 2139 /* Advance to next/previous gap */ 2140 if (topdown) { 2141 if (entry == &map->header) { 2142 UVMHIST_LOG(maphist, "<- failed (off start)", 2143 0,0,0,0); 2144 goto notfound; 2145 } 2146 entry = entry->prev; 2147 } else { 2148 entry = entry->next; 2149 if (entry == &map->header) { 2150 UVMHIST_LOG(maphist, "<- failed (off end)", 2151 0,0,0,0); 2152 goto notfound; 2153 } 2154 } 2155 } 2156 2157 found: 2158 SAVE_HINT(map, map->hint, entry); 2159 *result = hint; 2160 UVMHIST_LOG(maphist,"<- got it! (result=%#jx)", hint, 0,0,0); 2161 KASSERTMSG( topdown || hint >= orig_hint, "hint: %jx, orig_hint: %jx", 2162 (uintmax_t)hint, (uintmax_t)orig_hint); 2163 KASSERTMSG(!topdown || hint <= orig_hint, "hint: %jx, orig_hint: %jx", 2164 (uintmax_t)hint, (uintmax_t)orig_hint); 2165 KASSERT(entry->end <= hint); 2166 KASSERT(hint + length <= entry->next->start); 2167 return (entry); 2168 2169 wraparound: 2170 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0); 2171 2172 return (NULL); 2173 2174 notfound: 2175 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0); 2176 2177 return (NULL); 2178 } 2179 2180 /* 2181 * U N M A P - m a i n h e l p e r f u n c t i o n s 2182 */ 2183 2184 /* 2185 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop") 2186 * 2187 * => caller must check alignment and size 2188 * => map must be locked by caller 2189 * => we return a list of map entries that we've remove from the map 2190 * in "entry_list" 2191 */ 2192 2193 void 2194 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end, 2195 struct vm_map_entry **entry_list /* OUT */, int flags) 2196 { 2197 struct vm_map_entry *entry, *first_entry, *next; 2198 vaddr_t len; 2199 UVMHIST_FUNC("uvm_unmap_remove"); UVMHIST_CALLED(maphist); 2200 2201 UVMHIST_LOG(maphist,"(map=%#jx, start=%#jx, end=%#jx)", 2202 (uintptr_t)map, start, end, 0); 2203 VM_MAP_RANGE_CHECK(map, start, end); 2204 2205 uvm_map_check(map, "unmap_remove entry"); 2206 2207 /* 2208 * find first entry 2209 */ 2210 2211 if (uvm_map_lookup_entry(map, start, &first_entry) == true) { 2212 /* clip and go... */ 2213 entry = first_entry; 2214 UVM_MAP_CLIP_START(map, entry, start); 2215 /* critical! prevents stale hint */ 2216 SAVE_HINT(map, entry, entry->prev); 2217 } else { 2218 entry = first_entry->next; 2219 } 2220 2221 /* 2222 * Save the free space hint 2223 */ 2224 2225 if (map->first_free != &map->header && map->first_free->start >= start) 2226 map->first_free = entry->prev; 2227 2228 /* 2229 * note: we now re-use first_entry for a different task. we remove 2230 * a number of map entries from the map and save them in a linked 2231 * list headed by "first_entry". once we remove them from the map 2232 * the caller should unlock the map and drop the references to the 2233 * backing objects [c.f. uvm_unmap_detach]. the object is to 2234 * separate unmapping from reference dropping. why? 2235 * [1] the map has to be locked for unmapping 2236 * [2] the map need not be locked for reference dropping 2237 * [3] dropping references may trigger pager I/O, and if we hit 2238 * a pager that does synchronous I/O we may have to wait for it. 2239 * [4] we would like all waiting for I/O to occur with maps unlocked 2240 * so that we don't block other threads. 2241 */ 2242 2243 first_entry = NULL; 2244 *entry_list = NULL; 2245 2246 /* 2247 * break up the area into map entry sized regions and unmap. note 2248 * that all mappings have to be removed before we can even consider 2249 * dropping references to amaps or VM objects (otherwise we could end 2250 * up with a mapping to a page on the free list which would be very bad) 2251 */ 2252 2253 while ((entry != &map->header) && (entry->start < end)) { 2254 KASSERT((entry->flags & UVM_MAP_STATIC) == 0); 2255 2256 UVM_MAP_CLIP_END(map, entry, end); 2257 next = entry->next; 2258 len = entry->end - entry->start; 2259 2260 /* 2261 * unwire before removing addresses from the pmap; otherwise 2262 * unwiring will put the entries back into the pmap (XXX). 2263 */ 2264 2265 if (VM_MAPENT_ISWIRED(entry)) { 2266 uvm_map_entry_unwire(map, entry); 2267 } 2268 if (flags & UVM_FLAG_VAONLY) { 2269 2270 /* nothing */ 2271 2272 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) { 2273 2274 /* 2275 * if the map is non-pageable, any pages mapped there 2276 * must be wired and entered with pmap_kenter_pa(), 2277 * and we should free any such pages immediately. 2278 * this is mostly used for kmem_map. 2279 */ 2280 KASSERT(vm_map_pmap(map) == pmap_kernel()); 2281 2282 uvm_km_pgremove_intrsafe(map, entry->start, entry->end); 2283 } else if (UVM_ET_ISOBJ(entry) && 2284 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) { 2285 panic("%s: kernel object %p %p\n", 2286 __func__, map, entry); 2287 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) { 2288 /* 2289 * remove mappings the standard way. lock object 2290 * and/or amap to ensure vm_page state does not 2291 * change while in pmap_remove(). 2292 */ 2293 2294 uvm_map_lock_entry(entry); 2295 pmap_remove(map->pmap, entry->start, entry->end); 2296 uvm_map_unlock_entry(entry); 2297 } 2298 2299 #if defined(UVMDEBUG) 2300 /* 2301 * check if there's remaining mapping, 2302 * which is a bug in caller. 2303 */ 2304 2305 vaddr_t va; 2306 for (va = entry->start; va < entry->end; 2307 va += PAGE_SIZE) { 2308 if (pmap_extract(vm_map_pmap(map), va, NULL)) { 2309 panic("%s: %#"PRIxVADDR" has mapping", 2310 __func__, va); 2311 } 2312 } 2313 2314 if (VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 2315 uvm_km_check_empty(map, entry->start, 2316 entry->end); 2317 } 2318 #endif /* defined(UVMDEBUG) */ 2319 2320 /* 2321 * remove entry from map and put it on our list of entries 2322 * that we've nuked. then go to next entry. 2323 */ 2324 2325 UVMHIST_LOG(maphist, " removed map entry %#jx", 2326 (uintptr_t)entry, 0, 0, 0); 2327 2328 /* critical! prevents stale hint */ 2329 SAVE_HINT(map, entry, entry->prev); 2330 2331 uvm_map_entry_unlink(map, entry); 2332 KASSERT(map->size >= len); 2333 map->size -= len; 2334 entry->prev = NULL; 2335 entry->next = first_entry; 2336 first_entry = entry; 2337 entry = next; 2338 } 2339 2340 /* 2341 * Note: if map is dying, leave pmap_update() for pmap_destroy(), 2342 * which will be called later. 2343 */ 2344 if ((map->flags & VM_MAP_DYING) == 0) { 2345 pmap_update(vm_map_pmap(map)); 2346 } else { 2347 KASSERT(vm_map_pmap(map) != pmap_kernel()); 2348 } 2349 2350 uvm_map_check(map, "unmap_remove leave"); 2351 2352 /* 2353 * now we've cleaned up the map and are ready for the caller to drop 2354 * references to the mapped objects. 2355 */ 2356 2357 *entry_list = first_entry; 2358 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 2359 2360 if (map->flags & VM_MAP_WANTVA) { 2361 mutex_enter(&map->misc_lock); 2362 map->flags &= ~VM_MAP_WANTVA; 2363 cv_broadcast(&map->cv); 2364 mutex_exit(&map->misc_lock); 2365 } 2366 } 2367 2368 /* 2369 * uvm_unmap_detach: drop references in a chain of map entries 2370 * 2371 * => we will free the map entries as we traverse the list. 2372 */ 2373 2374 void 2375 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags) 2376 { 2377 struct vm_map_entry *next_entry; 2378 UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist); 2379 2380 while (first_entry) { 2381 KASSERT(!VM_MAPENT_ISWIRED(first_entry)); 2382 UVMHIST_LOG(maphist, 2383 " detach %#jx: amap=%#jx, obj=%#jx, submap?=%jd", 2384 (uintptr_t)first_entry, 2385 (uintptr_t)first_entry->aref.ar_amap, 2386 (uintptr_t)first_entry->object.uvm_obj, 2387 UVM_ET_ISSUBMAP(first_entry)); 2388 2389 /* 2390 * drop reference to amap, if we've got one 2391 */ 2392 2393 if (first_entry->aref.ar_amap) 2394 uvm_map_unreference_amap(first_entry, flags); 2395 2396 /* 2397 * drop reference to our backing object, if we've got one 2398 */ 2399 2400 KASSERT(!UVM_ET_ISSUBMAP(first_entry)); 2401 if (UVM_ET_ISOBJ(first_entry) && 2402 first_entry->object.uvm_obj->pgops->pgo_detach) { 2403 (*first_entry->object.uvm_obj->pgops->pgo_detach) 2404 (first_entry->object.uvm_obj); 2405 } 2406 next_entry = first_entry->next; 2407 uvm_mapent_free(first_entry); 2408 first_entry = next_entry; 2409 } 2410 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 2411 } 2412 2413 /* 2414 * E X T R A C T I O N F U N C T I O N S 2415 */ 2416 2417 /* 2418 * uvm_map_reserve: reserve space in a vm_map for future use. 2419 * 2420 * => we reserve space in a map by putting a dummy map entry in the 2421 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE) 2422 * => map should be unlocked (we will write lock it) 2423 * => we return true if we were able to reserve space 2424 * => XXXCDC: should be inline? 2425 */ 2426 2427 int 2428 uvm_map_reserve(struct vm_map *map, vsize_t size, 2429 vaddr_t offset /* hint for pmap_prefer */, 2430 vsize_t align /* alignment */, 2431 vaddr_t *raddr /* IN:hint, OUT: reserved VA */, 2432 uvm_flag_t flags /* UVM_FLAG_FIXED or UVM_FLAG_COLORMATCH or 0 */) 2433 { 2434 UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist); 2435 2436 UVMHIST_LOG(maphist, "(map=%#jx, size=%#jx, offset=%#jx, addr=%#jx)", 2437 (uintptr_t)map, size, offset, (uintptr_t)raddr); 2438 2439 size = round_page(size); 2440 2441 /* 2442 * reserve some virtual space. 2443 */ 2444 2445 if (uvm_map(map, raddr, size, NULL, offset, align, 2446 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE, 2447 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) { 2448 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 2449 return (false); 2450 } 2451 2452 UVMHIST_LOG(maphist, "<- done (*raddr=%#jx)", *raddr,0,0,0); 2453 return (true); 2454 } 2455 2456 /* 2457 * uvm_map_replace: replace a reserved (blank) area of memory with 2458 * real mappings. 2459 * 2460 * => caller must WRITE-LOCK the map 2461 * => we return true if replacement was a success 2462 * => we expect the newents chain to have nnewents entrys on it and 2463 * we expect newents->prev to point to the last entry on the list 2464 * => note newents is allowed to be NULL 2465 */ 2466 2467 static int 2468 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end, 2469 struct vm_map_entry *newents, int nnewents, vsize_t nsize, 2470 struct vm_map_entry **oldentryp) 2471 { 2472 struct vm_map_entry *oldent, *last; 2473 2474 uvm_map_check(map, "map_replace entry"); 2475 2476 /* 2477 * first find the blank map entry at the specified address 2478 */ 2479 2480 if (!uvm_map_lookup_entry(map, start, &oldent)) { 2481 return (false); 2482 } 2483 2484 /* 2485 * check to make sure we have a proper blank entry 2486 */ 2487 2488 if (end < oldent->end) { 2489 UVM_MAP_CLIP_END(map, oldent, end); 2490 } 2491 if (oldent->start != start || oldent->end != end || 2492 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) { 2493 return (false); 2494 } 2495 2496 #ifdef DIAGNOSTIC 2497 2498 /* 2499 * sanity check the newents chain 2500 */ 2501 2502 { 2503 struct vm_map_entry *tmpent = newents; 2504 int nent = 0; 2505 vsize_t sz = 0; 2506 vaddr_t cur = start; 2507 2508 while (tmpent) { 2509 nent++; 2510 sz += tmpent->end - tmpent->start; 2511 if (tmpent->start < cur) 2512 panic("uvm_map_replace1"); 2513 if (tmpent->start >= tmpent->end || tmpent->end > end) { 2514 panic("uvm_map_replace2: " 2515 "tmpent->start=%#"PRIxVADDR 2516 ", tmpent->end=%#"PRIxVADDR 2517 ", end=%#"PRIxVADDR, 2518 tmpent->start, tmpent->end, end); 2519 } 2520 cur = tmpent->end; 2521 if (tmpent->next) { 2522 if (tmpent->next->prev != tmpent) 2523 panic("uvm_map_replace3"); 2524 } else { 2525 if (newents->prev != tmpent) 2526 panic("uvm_map_replace4"); 2527 } 2528 tmpent = tmpent->next; 2529 } 2530 if (nent != nnewents) 2531 panic("uvm_map_replace5"); 2532 if (sz != nsize) 2533 panic("uvm_map_replace6"); 2534 } 2535 #endif 2536 2537 /* 2538 * map entry is a valid blank! replace it. (this does all the 2539 * work of map entry link/unlink...). 2540 */ 2541 2542 if (newents) { 2543 last = newents->prev; 2544 2545 /* critical: flush stale hints out of map */ 2546 SAVE_HINT(map, map->hint, newents); 2547 if (map->first_free == oldent) 2548 map->first_free = last; 2549 2550 last->next = oldent->next; 2551 last->next->prev = last; 2552 2553 /* Fix RB tree */ 2554 uvm_rb_remove(map, oldent); 2555 2556 newents->prev = oldent->prev; 2557 newents->prev->next = newents; 2558 map->nentries = map->nentries + (nnewents - 1); 2559 2560 /* Fixup the RB tree */ 2561 { 2562 int i; 2563 struct vm_map_entry *tmp; 2564 2565 tmp = newents; 2566 for (i = 0; i < nnewents && tmp; i++) { 2567 uvm_rb_insert(map, tmp); 2568 tmp = tmp->next; 2569 } 2570 } 2571 } else { 2572 /* NULL list of new entries: just remove the old one */ 2573 clear_hints(map, oldent); 2574 uvm_map_entry_unlink(map, oldent); 2575 } 2576 map->size -= end - start - nsize; 2577 2578 uvm_map_check(map, "map_replace leave"); 2579 2580 /* 2581 * now we can free the old blank entry and return. 2582 */ 2583 2584 *oldentryp = oldent; 2585 return (true); 2586 } 2587 2588 /* 2589 * uvm_map_extract: extract a mapping from a map and put it somewhere 2590 * (maybe removing the old mapping) 2591 * 2592 * => maps should be unlocked (we will write lock them) 2593 * => returns 0 on success, error code otherwise 2594 * => start must be page aligned 2595 * => len must be page sized 2596 * => flags: 2597 * UVM_EXTRACT_REMOVE: remove mappings from srcmap 2598 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only) 2599 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs 2600 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go 2601 * UVM_EXTRACT_PROT_ALL: set prot to UVM_PROT_ALL as we go 2602 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<< 2603 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only 2604 * be used from within the kernel in a kernel level map <<< 2605 */ 2606 2607 int 2608 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len, 2609 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags) 2610 { 2611 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge; 2612 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry, 2613 *deadentry, *oldentry; 2614 struct vm_map_entry *resentry = NULL; /* a dummy reservation entry */ 2615 vsize_t elen __unused; 2616 int nchain, error, copy_ok; 2617 vsize_t nsize; 2618 UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist); 2619 2620 UVMHIST_LOG(maphist,"(srcmap=%#jx,start=%#jx, len=%#jx", 2621 (uintptr_t)srcmap, start, len, 0); 2622 UVMHIST_LOG(maphist," ...,dstmap=%#jx, flags=%#jx)", 2623 (uintptr_t)dstmap, flags, 0, 0); 2624 2625 /* 2626 * step 0: sanity check: start must be on a page boundary, length 2627 * must be page sized. can't ask for CONTIG/QREF if you asked for 2628 * REMOVE. 2629 */ 2630 2631 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0); 2632 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 || 2633 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0); 2634 2635 /* 2636 * step 1: reserve space in the target map for the extracted area 2637 */ 2638 2639 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2640 dstaddr = vm_map_min(dstmap); 2641 if (!uvm_map_reserve(dstmap, len, start, 2642 atop(start) & uvmexp.colormask, &dstaddr, 2643 UVM_FLAG_COLORMATCH)) 2644 return (ENOMEM); 2645 KASSERT((atop(start ^ dstaddr) & uvmexp.colormask) == 0); 2646 *dstaddrp = dstaddr; /* pass address back to caller */ 2647 UVMHIST_LOG(maphist, " dstaddr=%#jx", dstaddr,0,0,0); 2648 } else { 2649 dstaddr = *dstaddrp; 2650 } 2651 2652 /* 2653 * step 2: setup for the extraction process loop by init'ing the 2654 * map entry chain, locking src map, and looking up the first useful 2655 * entry in the map. 2656 */ 2657 2658 end = start + len; 2659 newend = dstaddr + len; 2660 chain = endchain = NULL; 2661 nchain = 0; 2662 nsize = 0; 2663 vm_map_lock(srcmap); 2664 2665 if (uvm_map_lookup_entry(srcmap, start, &entry)) { 2666 2667 /* "start" is within an entry */ 2668 if (flags & UVM_EXTRACT_QREF) { 2669 2670 /* 2671 * for quick references we don't clip the entry, so 2672 * the entry may map space "before" the starting 2673 * virtual address... this is the "fudge" factor 2674 * (which can be non-zero only the first time 2675 * through the "while" loop in step 3). 2676 */ 2677 2678 fudge = start - entry->start; 2679 } else { 2680 2681 /* 2682 * normal reference: we clip the map to fit (thus 2683 * fudge is zero) 2684 */ 2685 2686 UVM_MAP_CLIP_START(srcmap, entry, start); 2687 SAVE_HINT(srcmap, srcmap->hint, entry->prev); 2688 fudge = 0; 2689 } 2690 } else { 2691 2692 /* "start" is not within an entry ... skip to next entry */ 2693 if (flags & UVM_EXTRACT_CONTIG) { 2694 error = EINVAL; 2695 goto bad; /* definite hole here ... */ 2696 } 2697 2698 entry = entry->next; 2699 fudge = 0; 2700 } 2701 2702 /* save values from srcmap for step 6 */ 2703 orig_entry = entry; 2704 orig_fudge = fudge; 2705 2706 /* 2707 * step 3: now start looping through the map entries, extracting 2708 * as we go. 2709 */ 2710 2711 while (entry->start < end && entry != &srcmap->header) { 2712 2713 /* if we are not doing a quick reference, clip it */ 2714 if ((flags & UVM_EXTRACT_QREF) == 0) 2715 UVM_MAP_CLIP_END(srcmap, entry, end); 2716 2717 /* clear needs_copy (allow chunking) */ 2718 if (UVM_ET_ISNEEDSCOPY(entry)) { 2719 amap_copy(srcmap, entry, 2720 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end); 2721 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */ 2722 error = ENOMEM; 2723 goto bad; 2724 } 2725 2726 /* amap_copy could clip (during chunk)! update fudge */ 2727 if (fudge) { 2728 fudge = start - entry->start; 2729 orig_fudge = fudge; 2730 } 2731 } 2732 2733 /* calculate the offset of this from "start" */ 2734 oldoffset = (entry->start + fudge) - start; 2735 2736 /* allocate a new map entry */ 2737 newentry = uvm_mapent_alloc(dstmap, 0); 2738 if (newentry == NULL) { 2739 error = ENOMEM; 2740 goto bad; 2741 } 2742 2743 /* set up new map entry */ 2744 newentry->next = NULL; 2745 newentry->prev = endchain; 2746 newentry->start = dstaddr + oldoffset; 2747 newentry->end = 2748 newentry->start + (entry->end - (entry->start + fudge)); 2749 if (newentry->end > newend || newentry->end < newentry->start) 2750 newentry->end = newend; 2751 newentry->object.uvm_obj = entry->object.uvm_obj; 2752 if (newentry->object.uvm_obj) { 2753 if (newentry->object.uvm_obj->pgops->pgo_reference) 2754 newentry->object.uvm_obj->pgops-> 2755 pgo_reference(newentry->object.uvm_obj); 2756 newentry->offset = entry->offset + fudge; 2757 } else { 2758 newentry->offset = 0; 2759 } 2760 newentry->etype = entry->etype; 2761 if (flags & UVM_EXTRACT_PROT_ALL) { 2762 newentry->protection = newentry->max_protection = 2763 UVM_PROT_ALL; 2764 } else { 2765 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ? 2766 entry->max_protection : entry->protection; 2767 newentry->max_protection = entry->max_protection; 2768 } 2769 newentry->inheritance = entry->inheritance; 2770 newentry->wired_count = 0; 2771 newentry->aref.ar_amap = entry->aref.ar_amap; 2772 if (newentry->aref.ar_amap) { 2773 newentry->aref.ar_pageoff = 2774 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT); 2775 uvm_map_reference_amap(newentry, AMAP_SHARED | 2776 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0)); 2777 } else { 2778 newentry->aref.ar_pageoff = 0; 2779 } 2780 newentry->advice = entry->advice; 2781 if ((flags & UVM_EXTRACT_QREF) != 0) { 2782 newentry->flags |= UVM_MAP_NOMERGE; 2783 } 2784 2785 /* now link it on the chain */ 2786 nchain++; 2787 nsize += newentry->end - newentry->start; 2788 if (endchain == NULL) { 2789 chain = endchain = newentry; 2790 } else { 2791 endchain->next = newentry; 2792 endchain = newentry; 2793 } 2794 2795 /* end of 'while' loop! */ 2796 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end && 2797 (entry->next == &srcmap->header || 2798 entry->next->start != entry->end)) { 2799 error = EINVAL; 2800 goto bad; 2801 } 2802 entry = entry->next; 2803 fudge = 0; 2804 } 2805 2806 /* 2807 * step 4: close off chain (in format expected by uvm_map_replace) 2808 */ 2809 2810 if (chain) 2811 chain->prev = endchain; 2812 2813 /* 2814 * step 5: attempt to lock the dest map so we can pmap_copy. 2815 * note usage of copy_ok: 2816 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5) 2817 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7 2818 */ 2819 2820 if (srcmap == dstmap || vm_map_lock_try(dstmap) == true) { 2821 copy_ok = 1; 2822 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2823 nchain, nsize, &resentry)) { 2824 if (srcmap != dstmap) 2825 vm_map_unlock(dstmap); 2826 error = EIO; 2827 goto bad; 2828 } 2829 } else { 2830 copy_ok = 0; 2831 /* replace defered until step 7 */ 2832 } 2833 2834 /* 2835 * step 6: traverse the srcmap a second time to do the following: 2836 * - if we got a lock on the dstmap do pmap_copy 2837 * - if UVM_EXTRACT_REMOVE remove the entries 2838 * we make use of orig_entry and orig_fudge (saved in step 2) 2839 */ 2840 2841 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) { 2842 2843 /* purge possible stale hints from srcmap */ 2844 if (flags & UVM_EXTRACT_REMOVE) { 2845 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev); 2846 if (srcmap->first_free != &srcmap->header && 2847 srcmap->first_free->start >= start) 2848 srcmap->first_free = orig_entry->prev; 2849 } 2850 2851 entry = orig_entry; 2852 fudge = orig_fudge; 2853 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */ 2854 2855 while (entry->start < end && entry != &srcmap->header) { 2856 if (copy_ok) { 2857 oldoffset = (entry->start + fudge) - start; 2858 elen = MIN(end, entry->end) - 2859 (entry->start + fudge); 2860 pmap_copy(dstmap->pmap, srcmap->pmap, 2861 dstaddr + oldoffset, elen, 2862 entry->start + fudge); 2863 } 2864 2865 /* we advance "entry" in the following if statement */ 2866 if (flags & UVM_EXTRACT_REMOVE) { 2867 uvm_map_lock_entry(entry); 2868 pmap_remove(srcmap->pmap, entry->start, 2869 entry->end); 2870 uvm_map_unlock_entry(entry); 2871 oldentry = entry; /* save entry */ 2872 entry = entry->next; /* advance */ 2873 uvm_map_entry_unlink(srcmap, oldentry); 2874 /* add to dead list */ 2875 oldentry->next = deadentry; 2876 deadentry = oldentry; 2877 } else { 2878 entry = entry->next; /* advance */ 2879 } 2880 2881 /* end of 'while' loop */ 2882 fudge = 0; 2883 } 2884 pmap_update(srcmap->pmap); 2885 2886 /* 2887 * unlock dstmap. we will dispose of deadentry in 2888 * step 7 if needed 2889 */ 2890 2891 if (copy_ok && srcmap != dstmap) 2892 vm_map_unlock(dstmap); 2893 2894 } else { 2895 deadentry = NULL; 2896 } 2897 2898 /* 2899 * step 7: we are done with the source map, unlock. if copy_ok 2900 * is 0 then we have not replaced the dummy mapping in dstmap yet 2901 * and we need to do so now. 2902 */ 2903 2904 vm_map_unlock(srcmap); 2905 if ((flags & UVM_EXTRACT_REMOVE) && deadentry) 2906 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */ 2907 2908 /* now do the replacement if we didn't do it in step 5 */ 2909 if (copy_ok == 0) { 2910 vm_map_lock(dstmap); 2911 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2912 nchain, nsize, &resentry); 2913 vm_map_unlock(dstmap); 2914 2915 if (error == false) { 2916 error = EIO; 2917 goto bad2; 2918 } 2919 } 2920 2921 if (resentry != NULL) 2922 uvm_mapent_free(resentry); 2923 2924 return (0); 2925 2926 /* 2927 * bad: failure recovery 2928 */ 2929 bad: 2930 vm_map_unlock(srcmap); 2931 bad2: /* src already unlocked */ 2932 if (chain) 2933 uvm_unmap_detach(chain, 2934 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0); 2935 2936 if (resentry != NULL) 2937 uvm_mapent_free(resentry); 2938 2939 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2940 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */ 2941 } 2942 return (error); 2943 } 2944 2945 /* end of extraction functions */ 2946 2947 /* 2948 * uvm_map_submap: punch down part of a map into a submap 2949 * 2950 * => only the kernel_map is allowed to be submapped 2951 * => the purpose of submapping is to break up the locking granularity 2952 * of a larger map 2953 * => the range specified must have been mapped previously with a uvm_map() 2954 * call [with uobj==NULL] to create a blank map entry in the main map. 2955 * [And it had better still be blank!] 2956 * => maps which contain submaps should never be copied or forked. 2957 * => to remove a submap, use uvm_unmap() on the main map 2958 * and then uvm_map_deallocate() the submap. 2959 * => main map must be unlocked. 2960 * => submap must have been init'd and have a zero reference count. 2961 * [need not be locked as we don't actually reference it] 2962 */ 2963 2964 int 2965 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end, 2966 struct vm_map *submap) 2967 { 2968 struct vm_map_entry *entry; 2969 int error; 2970 2971 vm_map_lock(map); 2972 VM_MAP_RANGE_CHECK(map, start, end); 2973 2974 if (uvm_map_lookup_entry(map, start, &entry)) { 2975 UVM_MAP_CLIP_START(map, entry, start); 2976 UVM_MAP_CLIP_END(map, entry, end); /* to be safe */ 2977 } else { 2978 entry = NULL; 2979 } 2980 2981 if (entry != NULL && 2982 entry->start == start && entry->end == end && 2983 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL && 2984 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) { 2985 entry->etype |= UVM_ET_SUBMAP; 2986 entry->object.sub_map = submap; 2987 entry->offset = 0; 2988 uvm_map_reference(submap); 2989 error = 0; 2990 } else { 2991 error = EINVAL; 2992 } 2993 vm_map_unlock(map); 2994 2995 return error; 2996 } 2997 2998 /* 2999 * uvm_map_protect_user: change map protection on behalf of the user. 3000 * Enforces PAX settings as necessary. 3001 */ 3002 int 3003 uvm_map_protect_user(struct lwp *l, vaddr_t start, vaddr_t end, 3004 vm_prot_t new_prot) 3005 { 3006 int error; 3007 3008 if ((error = PAX_MPROTECT_VALIDATE(l, new_prot))) 3009 return error; 3010 3011 return uvm_map_protect(&l->l_proc->p_vmspace->vm_map, start, end, 3012 new_prot, false); 3013 } 3014 3015 3016 /* 3017 * uvm_map_protect: change map protection 3018 * 3019 * => set_max means set max_protection. 3020 * => map must be unlocked. 3021 */ 3022 3023 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \ 3024 ~VM_PROT_WRITE : VM_PROT_ALL) 3025 3026 int 3027 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 3028 vm_prot_t new_prot, bool set_max) 3029 { 3030 struct vm_map_entry *current, *entry; 3031 int error = 0; 3032 UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist); 3033 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_prot=%#jx)", 3034 (uintptr_t)map, start, end, new_prot); 3035 3036 vm_map_lock(map); 3037 VM_MAP_RANGE_CHECK(map, start, end); 3038 if (uvm_map_lookup_entry(map, start, &entry)) { 3039 UVM_MAP_CLIP_START(map, entry, start); 3040 } else { 3041 entry = entry->next; 3042 } 3043 3044 /* 3045 * make a first pass to check for protection violations. 3046 */ 3047 3048 current = entry; 3049 while ((current != &map->header) && (current->start < end)) { 3050 if (UVM_ET_ISSUBMAP(current)) { 3051 error = EINVAL; 3052 goto out; 3053 } 3054 if ((new_prot & current->max_protection) != new_prot) { 3055 error = EACCES; 3056 goto out; 3057 } 3058 /* 3059 * Don't allow VM_PROT_EXECUTE to be set on entries that 3060 * point to vnodes that are associated with a NOEXEC file 3061 * system. 3062 */ 3063 if (UVM_ET_ISOBJ(current) && 3064 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) { 3065 struct vnode *vp = 3066 (struct vnode *) current->object.uvm_obj; 3067 3068 if ((new_prot & VM_PROT_EXECUTE) != 0 && 3069 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { 3070 error = EACCES; 3071 goto out; 3072 } 3073 } 3074 3075 current = current->next; 3076 } 3077 3078 /* go back and fix up protections (no need to clip this time). */ 3079 3080 current = entry; 3081 while ((current != &map->header) && (current->start < end)) { 3082 vm_prot_t old_prot; 3083 3084 UVM_MAP_CLIP_END(map, current, end); 3085 old_prot = current->protection; 3086 if (set_max) 3087 current->protection = 3088 (current->max_protection = new_prot) & old_prot; 3089 else 3090 current->protection = new_prot; 3091 3092 /* 3093 * update physical map if necessary. worry about copy-on-write 3094 * here -- CHECK THIS XXX 3095 */ 3096 3097 if (current->protection != old_prot) { 3098 /* update pmap! */ 3099 uvm_map_lock_entry(current); 3100 pmap_protect(map->pmap, current->start, current->end, 3101 current->protection & MASK(current)); 3102 uvm_map_unlock_entry(current); 3103 3104 /* 3105 * If this entry points at a vnode, and the 3106 * protection includes VM_PROT_EXECUTE, mark 3107 * the vnode as VEXECMAP. 3108 */ 3109 if (UVM_ET_ISOBJ(current)) { 3110 struct uvm_object *uobj = 3111 current->object.uvm_obj; 3112 3113 if (UVM_OBJ_IS_VNODE(uobj) && 3114 (current->protection & VM_PROT_EXECUTE)) { 3115 vn_markexec((struct vnode *) uobj); 3116 } 3117 } 3118 } 3119 3120 /* 3121 * If the map is configured to lock any future mappings, 3122 * wire this entry now if the old protection was VM_PROT_NONE 3123 * and the new protection is not VM_PROT_NONE. 3124 */ 3125 3126 if ((map->flags & VM_MAP_WIREFUTURE) != 0 && 3127 VM_MAPENT_ISWIRED(current) == 0 && 3128 old_prot == VM_PROT_NONE && 3129 new_prot != VM_PROT_NONE) { 3130 if (uvm_map_pageable(map, current->start, 3131 current->end, false, 3132 UVM_LK_ENTER|UVM_LK_EXIT) != 0) { 3133 3134 /* 3135 * If locking the entry fails, remember the 3136 * error if it's the first one. Note we 3137 * still continue setting the protection in 3138 * the map, but will return the error 3139 * condition regardless. 3140 * 3141 * XXX Ignore what the actual error is, 3142 * XXX just call it a resource shortage 3143 * XXX so that it doesn't get confused 3144 * XXX what uvm_map_protect() itself would 3145 * XXX normally return. 3146 */ 3147 3148 error = ENOMEM; 3149 } 3150 } 3151 current = current->next; 3152 } 3153 pmap_update(map->pmap); 3154 3155 out: 3156 vm_map_unlock(map); 3157 3158 UVMHIST_LOG(maphist, "<- done, error=%jd",error,0,0,0); 3159 return error; 3160 } 3161 3162 #undef MASK 3163 3164 /* 3165 * uvm_map_inherit: set inheritance code for range of addrs in map. 3166 * 3167 * => map must be unlocked 3168 * => note that the inherit code is used during a "fork". see fork 3169 * code for details. 3170 */ 3171 3172 int 3173 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end, 3174 vm_inherit_t new_inheritance) 3175 { 3176 struct vm_map_entry *entry, *temp_entry; 3177 UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist); 3178 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_inh=%#jx)", 3179 (uintptr_t)map, start, end, new_inheritance); 3180 3181 switch (new_inheritance) { 3182 case MAP_INHERIT_NONE: 3183 case MAP_INHERIT_COPY: 3184 case MAP_INHERIT_SHARE: 3185 case MAP_INHERIT_ZERO: 3186 break; 3187 default: 3188 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3189 return EINVAL; 3190 } 3191 3192 vm_map_lock(map); 3193 VM_MAP_RANGE_CHECK(map, start, end); 3194 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3195 entry = temp_entry; 3196 UVM_MAP_CLIP_START(map, entry, start); 3197 } else { 3198 entry = temp_entry->next; 3199 } 3200 while ((entry != &map->header) && (entry->start < end)) { 3201 UVM_MAP_CLIP_END(map, entry, end); 3202 entry->inheritance = new_inheritance; 3203 entry = entry->next; 3204 } 3205 vm_map_unlock(map); 3206 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3207 return 0; 3208 } 3209 3210 /* 3211 * uvm_map_advice: set advice code for range of addrs in map. 3212 * 3213 * => map must be unlocked 3214 */ 3215 3216 int 3217 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice) 3218 { 3219 struct vm_map_entry *entry, *temp_entry; 3220 UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist); 3221 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_adv=%#jx)", 3222 (uintptr_t)map, start, end, new_advice); 3223 3224 vm_map_lock(map); 3225 VM_MAP_RANGE_CHECK(map, start, end); 3226 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3227 entry = temp_entry; 3228 UVM_MAP_CLIP_START(map, entry, start); 3229 } else { 3230 entry = temp_entry->next; 3231 } 3232 3233 /* 3234 * XXXJRT: disallow holes? 3235 */ 3236 3237 while ((entry != &map->header) && (entry->start < end)) { 3238 UVM_MAP_CLIP_END(map, entry, end); 3239 3240 switch (new_advice) { 3241 case MADV_NORMAL: 3242 case MADV_RANDOM: 3243 case MADV_SEQUENTIAL: 3244 /* nothing special here */ 3245 break; 3246 3247 default: 3248 vm_map_unlock(map); 3249 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3250 return EINVAL; 3251 } 3252 entry->advice = new_advice; 3253 entry = entry->next; 3254 } 3255 3256 vm_map_unlock(map); 3257 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3258 return 0; 3259 } 3260 3261 /* 3262 * uvm_map_willneed: apply MADV_WILLNEED 3263 */ 3264 3265 int 3266 uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end) 3267 { 3268 struct vm_map_entry *entry; 3269 UVMHIST_FUNC("uvm_map_willneed"); UVMHIST_CALLED(maphist); 3270 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx)", 3271 (uintptr_t)map, start, end, 0); 3272 3273 vm_map_lock_read(map); 3274 VM_MAP_RANGE_CHECK(map, start, end); 3275 if (!uvm_map_lookup_entry(map, start, &entry)) { 3276 entry = entry->next; 3277 } 3278 while (entry->start < end) { 3279 struct vm_amap * const amap = entry->aref.ar_amap; 3280 struct uvm_object * const uobj = entry->object.uvm_obj; 3281 3282 KASSERT(entry != &map->header); 3283 KASSERT(start < entry->end); 3284 /* 3285 * For now, we handle only the easy but commonly-requested case. 3286 * ie. start prefetching of backing uobj pages. 3287 * 3288 * XXX It might be useful to pmap_enter() the already-in-core 3289 * pages by inventing a "weak" mode for uvm_fault() which would 3290 * only do the PGO_LOCKED pgo_get(). 3291 */ 3292 if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) { 3293 off_t offset; 3294 off_t size; 3295 3296 offset = entry->offset; 3297 if (start < entry->start) { 3298 offset += entry->start - start; 3299 } 3300 size = entry->offset + (entry->end - entry->start); 3301 if (entry->end < end) { 3302 size -= end - entry->end; 3303 } 3304 uvm_readahead(uobj, offset, size); 3305 } 3306 entry = entry->next; 3307 } 3308 vm_map_unlock_read(map); 3309 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3310 return 0; 3311 } 3312 3313 /* 3314 * uvm_map_pageable: sets the pageability of a range in a map. 3315 * 3316 * => wires map entries. should not be used for transient page locking. 3317 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). 3318 * => regions specified as not pageable require lock-down (wired) memory 3319 * and page tables. 3320 * => map must never be read-locked 3321 * => if islocked is true, map is already write-locked 3322 * => we always unlock the map, since we must downgrade to a read-lock 3323 * to call uvm_fault_wire() 3324 * => XXXCDC: check this and try and clean it up. 3325 */ 3326 3327 int 3328 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 3329 bool new_pageable, int lockflags) 3330 { 3331 struct vm_map_entry *entry, *start_entry, *failed_entry; 3332 int rv; 3333 #ifdef DIAGNOSTIC 3334 u_int timestamp_save; 3335 #endif 3336 UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist); 3337 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_pageable=%ju)", 3338 (uintptr_t)map, start, end, new_pageable); 3339 KASSERT(map->flags & VM_MAP_PAGEABLE); 3340 3341 if ((lockflags & UVM_LK_ENTER) == 0) 3342 vm_map_lock(map); 3343 VM_MAP_RANGE_CHECK(map, start, end); 3344 3345 /* 3346 * only one pageability change may take place at one time, since 3347 * uvm_fault_wire assumes it will be called only once for each 3348 * wiring/unwiring. therefore, we have to make sure we're actually 3349 * changing the pageability for the entire region. we do so before 3350 * making any changes. 3351 */ 3352 3353 if (uvm_map_lookup_entry(map, start, &start_entry) == false) { 3354 if ((lockflags & UVM_LK_EXIT) == 0) 3355 vm_map_unlock(map); 3356 3357 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0); 3358 return EFAULT; 3359 } 3360 entry = start_entry; 3361 3362 if (start == end) { /* nothing required */ 3363 if ((lockflags & UVM_LK_EXIT) == 0) 3364 vm_map_unlock(map); 3365 3366 UVMHIST_LOG(maphist,"<- done (nothing)",0,0,0,0); 3367 return 0; 3368 } 3369 3370 /* 3371 * handle wiring and unwiring separately. 3372 */ 3373 3374 if (new_pageable) { /* unwire */ 3375 UVM_MAP_CLIP_START(map, entry, start); 3376 3377 /* 3378 * unwiring. first ensure that the range to be unwired is 3379 * really wired down and that there are no holes. 3380 */ 3381 3382 while ((entry != &map->header) && (entry->start < end)) { 3383 if (entry->wired_count == 0 || 3384 (entry->end < end && 3385 (entry->next == &map->header || 3386 entry->next->start > entry->end))) { 3387 if ((lockflags & UVM_LK_EXIT) == 0) 3388 vm_map_unlock(map); 3389 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0); 3390 return EINVAL; 3391 } 3392 entry = entry->next; 3393 } 3394 3395 /* 3396 * POSIX 1003.1b - a single munlock call unlocks a region, 3397 * regardless of the number of mlock calls made on that 3398 * region. 3399 */ 3400 3401 entry = start_entry; 3402 while ((entry != &map->header) && (entry->start < end)) { 3403 UVM_MAP_CLIP_END(map, entry, end); 3404 if (VM_MAPENT_ISWIRED(entry)) 3405 uvm_map_entry_unwire(map, entry); 3406 entry = entry->next; 3407 } 3408 if ((lockflags & UVM_LK_EXIT) == 0) 3409 vm_map_unlock(map); 3410 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3411 return 0; 3412 } 3413 3414 /* 3415 * wire case: in two passes [XXXCDC: ugly block of code here] 3416 * 3417 * 1: holding the write lock, we create any anonymous maps that need 3418 * to be created. then we clip each map entry to the region to 3419 * be wired and increment its wiring count. 3420 * 3421 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 3422 * in the pages for any newly wired area (wired_count == 1). 3423 * 3424 * downgrading to a read lock for uvm_fault_wire avoids a possible 3425 * deadlock with another thread that may have faulted on one of 3426 * the pages to be wired (it would mark the page busy, blocking 3427 * us, then in turn block on the map lock that we hold). because 3428 * of problems in the recursive lock package, we cannot upgrade 3429 * to a write lock in vm_map_lookup. thus, any actions that 3430 * require the write lock must be done beforehand. because we 3431 * keep the read lock on the map, the copy-on-write status of the 3432 * entries we modify here cannot change. 3433 */ 3434 3435 while ((entry != &map->header) && (entry->start < end)) { 3436 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3437 3438 /* 3439 * perform actions of vm_map_lookup that need the 3440 * write lock on the map: create an anonymous map 3441 * for a copy-on-write region, or an anonymous map 3442 * for a zero-fill region. (XXXCDC: submap case 3443 * ok?) 3444 */ 3445 3446 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3447 if (UVM_ET_ISNEEDSCOPY(entry) && 3448 ((entry->max_protection & VM_PROT_WRITE) || 3449 (entry->object.uvm_obj == NULL))) { 3450 amap_copy(map, entry, 0, start, end); 3451 /* XXXCDC: wait OK? */ 3452 } 3453 } 3454 } 3455 UVM_MAP_CLIP_START(map, entry, start); 3456 UVM_MAP_CLIP_END(map, entry, end); 3457 entry->wired_count++; 3458 3459 /* 3460 * Check for holes 3461 */ 3462 3463 if (entry->protection == VM_PROT_NONE || 3464 (entry->end < end && 3465 (entry->next == &map->header || 3466 entry->next->start > entry->end))) { 3467 3468 /* 3469 * found one. amap creation actions do not need to 3470 * be undone, but the wired counts need to be restored. 3471 */ 3472 3473 while (entry != &map->header && entry->end > start) { 3474 entry->wired_count--; 3475 entry = entry->prev; 3476 } 3477 if ((lockflags & UVM_LK_EXIT) == 0) 3478 vm_map_unlock(map); 3479 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); 3480 return EINVAL; 3481 } 3482 entry = entry->next; 3483 } 3484 3485 /* 3486 * Pass 2. 3487 */ 3488 3489 #ifdef DIAGNOSTIC 3490 timestamp_save = map->timestamp; 3491 #endif 3492 vm_map_busy(map); 3493 vm_map_unlock(map); 3494 3495 rv = 0; 3496 entry = start_entry; 3497 while (entry != &map->header && entry->start < end) { 3498 if (entry->wired_count == 1) { 3499 rv = uvm_fault_wire(map, entry->start, entry->end, 3500 entry->max_protection, 1); 3501 if (rv) { 3502 3503 /* 3504 * wiring failed. break out of the loop. 3505 * we'll clean up the map below, once we 3506 * have a write lock again. 3507 */ 3508 3509 break; 3510 } 3511 } 3512 entry = entry->next; 3513 } 3514 3515 if (rv) { /* failed? */ 3516 3517 /* 3518 * Get back to an exclusive (write) lock. 3519 */ 3520 3521 vm_map_lock(map); 3522 vm_map_unbusy(map); 3523 3524 #ifdef DIAGNOSTIC 3525 if (timestamp_save + 1 != map->timestamp) 3526 panic("uvm_map_pageable: stale map"); 3527 #endif 3528 3529 /* 3530 * first drop the wiring count on all the entries 3531 * which haven't actually been wired yet. 3532 */ 3533 3534 failed_entry = entry; 3535 while (entry != &map->header && entry->start < end) { 3536 entry->wired_count--; 3537 entry = entry->next; 3538 } 3539 3540 /* 3541 * now, unwire all the entries that were successfully 3542 * wired above. 3543 */ 3544 3545 entry = start_entry; 3546 while (entry != failed_entry) { 3547 entry->wired_count--; 3548 if (VM_MAPENT_ISWIRED(entry) == 0) 3549 uvm_map_entry_unwire(map, entry); 3550 entry = entry->next; 3551 } 3552 if ((lockflags & UVM_LK_EXIT) == 0) 3553 vm_map_unlock(map); 3554 UVMHIST_LOG(maphist, "<- done (RV=%jd)", rv,0,0,0); 3555 return (rv); 3556 } 3557 3558 if ((lockflags & UVM_LK_EXIT) == 0) { 3559 vm_map_unbusy(map); 3560 } else { 3561 3562 /* 3563 * Get back to an exclusive (write) lock. 3564 */ 3565 3566 vm_map_lock(map); 3567 vm_map_unbusy(map); 3568 } 3569 3570 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3571 return 0; 3572 } 3573 3574 /* 3575 * uvm_map_pageable_all: special case of uvm_map_pageable - affects 3576 * all mapped regions. 3577 * 3578 * => map must not be locked. 3579 * => if no flags are specified, all regions are unwired. 3580 * => XXXJRT: has some of the same problems as uvm_map_pageable() above. 3581 */ 3582 3583 int 3584 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit) 3585 { 3586 struct vm_map_entry *entry, *failed_entry; 3587 vsize_t size; 3588 int rv; 3589 #ifdef DIAGNOSTIC 3590 u_int timestamp_save; 3591 #endif 3592 UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist); 3593 UVMHIST_LOG(maphist,"(map=%#jx,flags=%#jx)", (uintptr_t)map, flags, 3594 0, 0); 3595 3596 KASSERT(map->flags & VM_MAP_PAGEABLE); 3597 3598 vm_map_lock(map); 3599 3600 /* 3601 * handle wiring and unwiring separately. 3602 */ 3603 3604 if (flags == 0) { /* unwire */ 3605 3606 /* 3607 * POSIX 1003.1b -- munlockall unlocks all regions, 3608 * regardless of how many times mlockall has been called. 3609 */ 3610 3611 for (entry = map->header.next; entry != &map->header; 3612 entry = entry->next) { 3613 if (VM_MAPENT_ISWIRED(entry)) 3614 uvm_map_entry_unwire(map, entry); 3615 } 3616 map->flags &= ~VM_MAP_WIREFUTURE; 3617 vm_map_unlock(map); 3618 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3619 return 0; 3620 } 3621 3622 if (flags & MCL_FUTURE) { 3623 3624 /* 3625 * must wire all future mappings; remember this. 3626 */ 3627 3628 map->flags |= VM_MAP_WIREFUTURE; 3629 } 3630 3631 if ((flags & MCL_CURRENT) == 0) { 3632 3633 /* 3634 * no more work to do! 3635 */ 3636 3637 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); 3638 vm_map_unlock(map); 3639 return 0; 3640 } 3641 3642 /* 3643 * wire case: in three passes [XXXCDC: ugly block of code here] 3644 * 3645 * 1: holding the write lock, count all pages mapped by non-wired 3646 * entries. if this would cause us to go over our limit, we fail. 3647 * 3648 * 2: still holding the write lock, we create any anonymous maps that 3649 * need to be created. then we increment its wiring count. 3650 * 3651 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault 3652 * in the pages for any newly wired area (wired_count == 1). 3653 * 3654 * downgrading to a read lock for uvm_fault_wire avoids a possible 3655 * deadlock with another thread that may have faulted on one of 3656 * the pages to be wired (it would mark the page busy, blocking 3657 * us, then in turn block on the map lock that we hold). because 3658 * of problems in the recursive lock package, we cannot upgrade 3659 * to a write lock in vm_map_lookup. thus, any actions that 3660 * require the write lock must be done beforehand. because we 3661 * keep the read lock on the map, the copy-on-write status of the 3662 * entries we modify here cannot change. 3663 */ 3664 3665 for (size = 0, entry = map->header.next; entry != &map->header; 3666 entry = entry->next) { 3667 if (entry->protection != VM_PROT_NONE && 3668 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3669 size += entry->end - entry->start; 3670 } 3671 } 3672 3673 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { 3674 vm_map_unlock(map); 3675 return ENOMEM; 3676 } 3677 3678 if (limit != 0 && 3679 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { 3680 vm_map_unlock(map); 3681 return ENOMEM; 3682 } 3683 3684 /* 3685 * Pass 2. 3686 */ 3687 3688 for (entry = map->header.next; entry != &map->header; 3689 entry = entry->next) { 3690 if (entry->protection == VM_PROT_NONE) 3691 continue; 3692 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3693 3694 /* 3695 * perform actions of vm_map_lookup that need the 3696 * write lock on the map: create an anonymous map 3697 * for a copy-on-write region, or an anonymous map 3698 * for a zero-fill region. (XXXCDC: submap case 3699 * ok?) 3700 */ 3701 3702 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3703 if (UVM_ET_ISNEEDSCOPY(entry) && 3704 ((entry->max_protection & VM_PROT_WRITE) || 3705 (entry->object.uvm_obj == NULL))) { 3706 amap_copy(map, entry, 0, entry->start, 3707 entry->end); 3708 /* XXXCDC: wait OK? */ 3709 } 3710 } 3711 } 3712 entry->wired_count++; 3713 } 3714 3715 /* 3716 * Pass 3. 3717 */ 3718 3719 #ifdef DIAGNOSTIC 3720 timestamp_save = map->timestamp; 3721 #endif 3722 vm_map_busy(map); 3723 vm_map_unlock(map); 3724 3725 rv = 0; 3726 for (entry = map->header.next; entry != &map->header; 3727 entry = entry->next) { 3728 if (entry->wired_count == 1) { 3729 rv = uvm_fault_wire(map, entry->start, entry->end, 3730 entry->max_protection, 1); 3731 if (rv) { 3732 3733 /* 3734 * wiring failed. break out of the loop. 3735 * we'll clean up the map below, once we 3736 * have a write lock again. 3737 */ 3738 3739 break; 3740 } 3741 } 3742 } 3743 3744 if (rv) { 3745 3746 /* 3747 * Get back an exclusive (write) lock. 3748 */ 3749 3750 vm_map_lock(map); 3751 vm_map_unbusy(map); 3752 3753 #ifdef DIAGNOSTIC 3754 if (timestamp_save + 1 != map->timestamp) 3755 panic("uvm_map_pageable_all: stale map"); 3756 #endif 3757 3758 /* 3759 * first drop the wiring count on all the entries 3760 * which haven't actually been wired yet. 3761 * 3762 * Skip VM_PROT_NONE entries like we did above. 3763 */ 3764 3765 failed_entry = entry; 3766 for (/* nothing */; entry != &map->header; 3767 entry = entry->next) { 3768 if (entry->protection == VM_PROT_NONE) 3769 continue; 3770 entry->wired_count--; 3771 } 3772 3773 /* 3774 * now, unwire all the entries that were successfully 3775 * wired above. 3776 * 3777 * Skip VM_PROT_NONE entries like we did above. 3778 */ 3779 3780 for (entry = map->header.next; entry != failed_entry; 3781 entry = entry->next) { 3782 if (entry->protection == VM_PROT_NONE) 3783 continue; 3784 entry->wired_count--; 3785 if (VM_MAPENT_ISWIRED(entry)) 3786 uvm_map_entry_unwire(map, entry); 3787 } 3788 vm_map_unlock(map); 3789 UVMHIST_LOG(maphist,"<- done (RV=%jd)", rv,0,0,0); 3790 return (rv); 3791 } 3792 3793 vm_map_unbusy(map); 3794 3795 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3796 return 0; 3797 } 3798 3799 /* 3800 * uvm_map_clean: clean out a map range 3801 * 3802 * => valid flags: 3803 * if (flags & PGO_CLEANIT): dirty pages are cleaned first 3804 * if (flags & PGO_SYNCIO): dirty pages are written synchronously 3805 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean 3806 * if (flags & PGO_FREE): any cached pages are freed after clean 3807 * => returns an error if any part of the specified range isn't mapped 3808 * => never a need to flush amap layer since the anonymous memory has 3809 * no permanent home, but may deactivate pages there 3810 * => called from sys_msync() and sys_madvise() 3811 * => caller must not write-lock map (read OK). 3812 * => we may sleep while cleaning if SYNCIO [with map read-locked] 3813 */ 3814 3815 int 3816 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 3817 { 3818 struct vm_map_entry *current, *entry; 3819 struct uvm_object *uobj; 3820 struct vm_amap *amap; 3821 struct vm_anon *anon, *anon_tofree; 3822 struct vm_page *pg; 3823 vaddr_t offset; 3824 vsize_t size; 3825 voff_t uoff; 3826 int error, refs; 3827 UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist); 3828 3829 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,flags=%#jx)", 3830 (uintptr_t)map, start, end, flags); 3831 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) != 3832 (PGO_FREE|PGO_DEACTIVATE)); 3833 3834 vm_map_lock_read(map); 3835 VM_MAP_RANGE_CHECK(map, start, end); 3836 if (uvm_map_lookup_entry(map, start, &entry) == false) { 3837 vm_map_unlock_read(map); 3838 return EFAULT; 3839 } 3840 3841 /* 3842 * Make a first pass to check for holes and wiring problems. 3843 */ 3844 3845 for (current = entry; current->start < end; current = current->next) { 3846 if (UVM_ET_ISSUBMAP(current)) { 3847 vm_map_unlock_read(map); 3848 return EINVAL; 3849 } 3850 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) { 3851 vm_map_unlock_read(map); 3852 return EBUSY; 3853 } 3854 if (end <= current->end) { 3855 break; 3856 } 3857 if (current->end != current->next->start) { 3858 vm_map_unlock_read(map); 3859 return EFAULT; 3860 } 3861 } 3862 3863 error = 0; 3864 for (current = entry; start < end; current = current->next) { 3865 amap = current->aref.ar_amap; /* upper layer */ 3866 uobj = current->object.uvm_obj; /* lower layer */ 3867 KASSERT(start >= current->start); 3868 3869 /* 3870 * No amap cleaning necessary if: 3871 * 3872 * (1) There's no amap. 3873 * 3874 * (2) We're not deactivating or freeing pages. 3875 */ 3876 3877 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) 3878 goto flush_object; 3879 3880 offset = start - current->start; 3881 size = MIN(end, current->end) - start; 3882 anon_tofree = NULL; 3883 3884 amap_lock(amap); 3885 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { 3886 anon = amap_lookup(¤t->aref, offset); 3887 if (anon == NULL) 3888 continue; 3889 3890 KASSERT(anon->an_lock == amap->am_lock); 3891 pg = anon->an_page; 3892 if (pg == NULL) { 3893 continue; 3894 } 3895 if (pg->flags & PG_BUSY) { 3896 continue; 3897 } 3898 3899 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { 3900 3901 /* 3902 * In these first 3 cases, we just deactivate the page. 3903 */ 3904 3905 case PGO_CLEANIT|PGO_FREE: 3906 case PGO_CLEANIT|PGO_DEACTIVATE: 3907 case PGO_DEACTIVATE: 3908 deactivate_it: 3909 /* 3910 * skip the page if it's loaned or wired, 3911 * since it shouldn't be on a paging queue 3912 * at all in these cases. 3913 */ 3914 3915 mutex_enter(&uvm_pageqlock); 3916 if (pg->loan_count != 0 || 3917 pg->wire_count != 0) { 3918 mutex_exit(&uvm_pageqlock); 3919 continue; 3920 } 3921 KASSERT(pg->uanon == anon); 3922 uvm_pagedeactivate(pg); 3923 mutex_exit(&uvm_pageqlock); 3924 continue; 3925 3926 case PGO_FREE: 3927 3928 /* 3929 * If there are multiple references to 3930 * the amap, just deactivate the page. 3931 */ 3932 3933 if (amap_refs(amap) > 1) 3934 goto deactivate_it; 3935 3936 /* skip the page if it's wired */ 3937 if (pg->wire_count != 0) { 3938 continue; 3939 } 3940 amap_unadd(¤t->aref, offset); 3941 refs = --anon->an_ref; 3942 if (refs == 0) { 3943 anon->an_link = anon_tofree; 3944 anon_tofree = anon; 3945 } 3946 continue; 3947 } 3948 } 3949 uvm_anon_freelst(amap, anon_tofree); 3950 3951 flush_object: 3952 /* 3953 * flush pages if we've got a valid backing object. 3954 * note that we must always clean object pages before 3955 * freeing them since otherwise we could reveal stale 3956 * data from files. 3957 */ 3958 3959 uoff = current->offset + (start - current->start); 3960 size = MIN(end, current->end) - start; 3961 if (uobj != NULL) { 3962 mutex_enter(uobj->vmobjlock); 3963 if (uobj->pgops->pgo_put != NULL) 3964 error = (uobj->pgops->pgo_put)(uobj, uoff, 3965 uoff + size, flags | PGO_CLEANIT); 3966 else 3967 error = 0; 3968 } 3969 start += size; 3970 } 3971 vm_map_unlock_read(map); 3972 return (error); 3973 } 3974 3975 3976 /* 3977 * uvm_map_checkprot: check protection in map 3978 * 3979 * => must allow specified protection in a fully allocated region. 3980 * => map must be read or write locked by caller. 3981 */ 3982 3983 bool 3984 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end, 3985 vm_prot_t protection) 3986 { 3987 struct vm_map_entry *entry; 3988 struct vm_map_entry *tmp_entry; 3989 3990 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) { 3991 return (false); 3992 } 3993 entry = tmp_entry; 3994 while (start < end) { 3995 if (entry == &map->header) { 3996 return (false); 3997 } 3998 3999 /* 4000 * no holes allowed 4001 */ 4002 4003 if (start < entry->start) { 4004 return (false); 4005 } 4006 4007 /* 4008 * check protection associated with entry 4009 */ 4010 4011 if ((entry->protection & protection) != protection) { 4012 return (false); 4013 } 4014 start = entry->end; 4015 entry = entry->next; 4016 } 4017 return (true); 4018 } 4019 4020 /* 4021 * uvmspace_alloc: allocate a vmspace structure. 4022 * 4023 * - structure includes vm_map and pmap 4024 * - XXX: no locking on this structure 4025 * - refcnt set to 1, rest must be init'd by caller 4026 */ 4027 struct vmspace * 4028 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax, bool topdown) 4029 { 4030 struct vmspace *vm; 4031 UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist); 4032 4033 vm = pool_cache_get(&uvm_vmspace_cache, PR_WAITOK); 4034 uvmspace_init(vm, NULL, vmin, vmax, topdown); 4035 UVMHIST_LOG(maphist,"<- done (vm=%#jx)", (uintptr_t)vm, 0, 0, 0); 4036 return (vm); 4037 } 4038 4039 /* 4040 * uvmspace_init: initialize a vmspace structure. 4041 * 4042 * - XXX: no locking on this structure 4043 * - refcnt set to 1, rest must be init'd by caller 4044 */ 4045 void 4046 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, 4047 vaddr_t vmax, bool topdown) 4048 { 4049 UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist); 4050 4051 UVMHIST_LOG(maphist, "(vm=%#jx, pmap=%#jx, vmin=%#jx, vmax=%#jx", 4052 (uintptr_t)vm, (uintptr_t)pmap, vmin, vmax); 4053 UVMHIST_LOG(maphist, " topdown=%ju)", topdown, 0, 0, 0); 4054 4055 memset(vm, 0, sizeof(*vm)); 4056 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE 4057 | (topdown ? VM_MAP_TOPDOWN : 0) 4058 ); 4059 if (pmap) 4060 pmap_reference(pmap); 4061 else 4062 pmap = pmap_create(); 4063 vm->vm_map.pmap = pmap; 4064 vm->vm_refcnt = 1; 4065 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4066 } 4067 4068 /* 4069 * uvmspace_share: share a vmspace between two processes 4070 * 4071 * - used for vfork, threads(?) 4072 */ 4073 4074 void 4075 uvmspace_share(struct proc *p1, struct proc *p2) 4076 { 4077 4078 uvmspace_addref(p1->p_vmspace); 4079 p2->p_vmspace = p1->p_vmspace; 4080 } 4081 4082 #if 0 4083 4084 /* 4085 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace 4086 * 4087 * - XXX: no locking on vmspace 4088 */ 4089 4090 void 4091 uvmspace_unshare(struct lwp *l) 4092 { 4093 struct proc *p = l->l_proc; 4094 struct vmspace *nvm, *ovm = p->p_vmspace; 4095 4096 if (ovm->vm_refcnt == 1) 4097 /* nothing to do: vmspace isn't shared in the first place */ 4098 return; 4099 4100 /* make a new vmspace, still holding old one */ 4101 nvm = uvmspace_fork(ovm); 4102 4103 kpreempt_disable(); 4104 pmap_deactivate(l); /* unbind old vmspace */ 4105 p->p_vmspace = nvm; 4106 pmap_activate(l); /* switch to new vmspace */ 4107 kpreempt_enable(); 4108 4109 uvmspace_free(ovm); /* drop reference to old vmspace */ 4110 } 4111 4112 #endif 4113 4114 4115 /* 4116 * uvmspace_spawn: a new process has been spawned and needs a vmspace 4117 */ 4118 4119 void 4120 uvmspace_spawn(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4121 { 4122 struct proc *p = l->l_proc; 4123 struct vmspace *nvm; 4124 4125 #ifdef __HAVE_CPU_VMSPACE_EXEC 4126 cpu_vmspace_exec(l, start, end); 4127 #endif 4128 4129 nvm = uvmspace_alloc(start, end, topdown); 4130 kpreempt_disable(); 4131 p->p_vmspace = nvm; 4132 pmap_activate(l); 4133 kpreempt_enable(); 4134 } 4135 4136 /* 4137 * uvmspace_exec: the process wants to exec a new program 4138 */ 4139 4140 void 4141 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4142 { 4143 struct proc *p = l->l_proc; 4144 struct vmspace *nvm, *ovm = p->p_vmspace; 4145 struct vm_map *map; 4146 4147 KASSERT(ovm != NULL); 4148 #ifdef __HAVE_CPU_VMSPACE_EXEC 4149 cpu_vmspace_exec(l, start, end); 4150 #endif 4151 4152 map = &ovm->vm_map; 4153 /* 4154 * see if more than one process is using this vmspace... 4155 */ 4156 4157 if (ovm->vm_refcnt == 1 4158 && topdown == ((ovm->vm_map.flags & VM_MAP_TOPDOWN) != 0)) { 4159 4160 /* 4161 * if p is the only process using its vmspace then we can safely 4162 * recycle that vmspace for the program that is being exec'd. 4163 * But only if TOPDOWN matches the requested value for the new 4164 * vm space! 4165 */ 4166 4167 /* 4168 * SYSV SHM semantics require us to kill all segments on an exec 4169 */ 4170 if (uvm_shmexit && ovm->vm_shm) 4171 (*uvm_shmexit)(ovm); 4172 4173 /* 4174 * POSIX 1003.1b -- "lock future mappings" is revoked 4175 * when a process execs another program image. 4176 */ 4177 4178 map->flags &= ~VM_MAP_WIREFUTURE; 4179 4180 /* 4181 * now unmap the old program 4182 */ 4183 4184 pmap_remove_all(map->pmap); 4185 uvm_unmap(map, vm_map_min(map), vm_map_max(map)); 4186 KASSERT(map->header.prev == &map->header); 4187 KASSERT(map->nentries == 0); 4188 4189 /* 4190 * resize the map 4191 */ 4192 4193 vm_map_setmin(map, start); 4194 vm_map_setmax(map, end); 4195 } else { 4196 4197 /* 4198 * p's vmspace is being shared, so we can't reuse it for p since 4199 * it is still being used for others. allocate a new vmspace 4200 * for p 4201 */ 4202 4203 nvm = uvmspace_alloc(start, end, topdown); 4204 4205 /* 4206 * install new vmspace and drop our ref to the old one. 4207 */ 4208 4209 kpreempt_disable(); 4210 pmap_deactivate(l); 4211 p->p_vmspace = nvm; 4212 pmap_activate(l); 4213 kpreempt_enable(); 4214 4215 uvmspace_free(ovm); 4216 } 4217 } 4218 4219 /* 4220 * uvmspace_addref: add a referece to a vmspace. 4221 */ 4222 4223 void 4224 uvmspace_addref(struct vmspace *vm) 4225 { 4226 struct vm_map *map = &vm->vm_map; 4227 4228 KASSERT((map->flags & VM_MAP_DYING) == 0); 4229 4230 mutex_enter(&map->misc_lock); 4231 KASSERT(vm->vm_refcnt > 0); 4232 vm->vm_refcnt++; 4233 mutex_exit(&map->misc_lock); 4234 } 4235 4236 /* 4237 * uvmspace_free: free a vmspace data structure 4238 */ 4239 4240 void 4241 uvmspace_free(struct vmspace *vm) 4242 { 4243 struct vm_map_entry *dead_entries; 4244 struct vm_map *map = &vm->vm_map; 4245 int n; 4246 4247 UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist); 4248 4249 UVMHIST_LOG(maphist,"(vm=%#jx) ref=%jd", (uintptr_t)vm, vm->vm_refcnt, 4250 0, 0); 4251 mutex_enter(&map->misc_lock); 4252 n = --vm->vm_refcnt; 4253 mutex_exit(&map->misc_lock); 4254 if (n > 0) 4255 return; 4256 4257 /* 4258 * at this point, there should be no other references to the map. 4259 * delete all of the mappings, then destroy the pmap. 4260 */ 4261 4262 map->flags |= VM_MAP_DYING; 4263 pmap_remove_all(map->pmap); 4264 4265 /* Get rid of any SYSV shared memory segments. */ 4266 if (uvm_shmexit && vm->vm_shm != NULL) 4267 (*uvm_shmexit)(vm); 4268 4269 if (map->nentries) { 4270 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map), 4271 &dead_entries, 0); 4272 if (dead_entries != NULL) 4273 uvm_unmap_detach(dead_entries, 0); 4274 } 4275 KASSERT(map->nentries == 0); 4276 KASSERT(map->size == 0); 4277 4278 mutex_destroy(&map->misc_lock); 4279 rw_destroy(&map->lock); 4280 cv_destroy(&map->cv); 4281 pmap_destroy(map->pmap); 4282 pool_cache_put(&uvm_vmspace_cache, vm); 4283 } 4284 4285 static struct vm_map_entry * 4286 uvm_mapent_clone(struct vm_map *new_map, struct vm_map_entry *old_entry, 4287 int flags) 4288 { 4289 struct vm_map_entry *new_entry; 4290 4291 new_entry = uvm_mapent_alloc(new_map, 0); 4292 /* old_entry -> new_entry */ 4293 uvm_mapent_copy(old_entry, new_entry); 4294 4295 /* new pmap has nothing wired in it */ 4296 new_entry->wired_count = 0; 4297 4298 /* 4299 * gain reference to object backing the map (can't 4300 * be a submap, already checked this case). 4301 */ 4302 4303 if (new_entry->aref.ar_amap) 4304 uvm_map_reference_amap(new_entry, flags); 4305 4306 if (new_entry->object.uvm_obj && 4307 new_entry->object.uvm_obj->pgops->pgo_reference) 4308 new_entry->object.uvm_obj->pgops->pgo_reference( 4309 new_entry->object.uvm_obj); 4310 4311 /* insert entry at end of new_map's entry list */ 4312 uvm_map_entry_link(new_map, new_map->header.prev, 4313 new_entry); 4314 4315 return new_entry; 4316 } 4317 4318 /* 4319 * share the mapping: this means we want the old and 4320 * new entries to share amaps and backing objects. 4321 */ 4322 static void 4323 uvm_mapent_forkshared(struct vm_map *new_map, struct vm_map *old_map, 4324 struct vm_map_entry *old_entry) 4325 { 4326 /* 4327 * if the old_entry needs a new amap (due to prev fork) 4328 * then we need to allocate it now so that we have 4329 * something we own to share with the new_entry. [in 4330 * other words, we need to clear needs_copy] 4331 */ 4332 4333 if (UVM_ET_ISNEEDSCOPY(old_entry)) { 4334 /* get our own amap, clears needs_copy */ 4335 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK, 4336 0, 0); 4337 /* XXXCDC: WAITOK??? */ 4338 } 4339 4340 uvm_mapent_clone(new_map, old_entry, AMAP_SHARED); 4341 } 4342 4343 4344 static void 4345 uvm_mapent_forkcopy(struct vm_map *new_map, struct vm_map *old_map, 4346 struct vm_map_entry *old_entry) 4347 { 4348 struct vm_map_entry *new_entry; 4349 4350 /* 4351 * copy-on-write the mapping (using mmap's 4352 * MAP_PRIVATE semantics) 4353 * 4354 * allocate new_entry, adjust reference counts. 4355 * (note that new references are read-only). 4356 */ 4357 4358 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4359 4360 new_entry->etype |= 4361 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4362 4363 /* 4364 * the new entry will need an amap. it will either 4365 * need to be copied from the old entry or created 4366 * from scratch (if the old entry does not have an 4367 * amap). can we defer this process until later 4368 * (by setting "needs_copy") or do we need to copy 4369 * the amap now? 4370 * 4371 * we must copy the amap now if any of the following 4372 * conditions hold: 4373 * 1. the old entry has an amap and that amap is 4374 * being shared. this means that the old (parent) 4375 * process is sharing the amap with another 4376 * process. if we do not clear needs_copy here 4377 * we will end up in a situation where both the 4378 * parent and child process are refering to the 4379 * same amap with "needs_copy" set. if the 4380 * parent write-faults, the fault routine will 4381 * clear "needs_copy" in the parent by allocating 4382 * a new amap. this is wrong because the 4383 * parent is supposed to be sharing the old amap 4384 * and the new amap will break that. 4385 * 4386 * 2. if the old entry has an amap and a non-zero 4387 * wire count then we are going to have to call 4388 * amap_cow_now to avoid page faults in the 4389 * parent process. since amap_cow_now requires 4390 * "needs_copy" to be clear we might as well 4391 * clear it here as well. 4392 * 4393 */ 4394 4395 if (old_entry->aref.ar_amap != NULL) { 4396 if ((amap_flags(old_entry->aref.ar_amap) & AMAP_SHARED) != 0 || 4397 VM_MAPENT_ISWIRED(old_entry)) { 4398 4399 amap_copy(new_map, new_entry, 4400 AMAP_COPY_NOCHUNK, 0, 0); 4401 /* XXXCDC: M_WAITOK ... ok? */ 4402 } 4403 } 4404 4405 /* 4406 * if the parent's entry is wired down, then the 4407 * parent process does not want page faults on 4408 * access to that memory. this means that we 4409 * cannot do copy-on-write because we can't write 4410 * protect the old entry. in this case we 4411 * resolve all copy-on-write faults now, using 4412 * amap_cow_now. note that we have already 4413 * allocated any needed amap (above). 4414 */ 4415 4416 if (VM_MAPENT_ISWIRED(old_entry)) { 4417 4418 /* 4419 * resolve all copy-on-write faults now 4420 * (note that there is nothing to do if 4421 * the old mapping does not have an amap). 4422 */ 4423 if (old_entry->aref.ar_amap) 4424 amap_cow_now(new_map, new_entry); 4425 4426 } else { 4427 /* 4428 * setup mappings to trigger copy-on-write faults 4429 * we must write-protect the parent if it has 4430 * an amap and it is not already "needs_copy"... 4431 * if it is already "needs_copy" then the parent 4432 * has already been write-protected by a previous 4433 * fork operation. 4434 */ 4435 if (old_entry->aref.ar_amap && 4436 !UVM_ET_ISNEEDSCOPY(old_entry)) { 4437 if (old_entry->max_protection & VM_PROT_WRITE) { 4438 pmap_protect(old_map->pmap, 4439 old_entry->start, old_entry->end, 4440 old_entry->protection & ~VM_PROT_WRITE); 4441 } 4442 old_entry->etype |= UVM_ET_NEEDSCOPY; 4443 } 4444 } 4445 } 4446 4447 /* 4448 * zero the mapping: the new entry will be zero initialized 4449 */ 4450 static void 4451 uvm_mapent_forkzero(struct vm_map *new_map, struct vm_map *old_map, 4452 struct vm_map_entry *old_entry) 4453 { 4454 struct vm_map_entry *new_entry; 4455 4456 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4457 4458 new_entry->etype |= 4459 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4460 4461 if (new_entry->aref.ar_amap) { 4462 uvm_map_unreference_amap(new_entry, 0); 4463 new_entry->aref.ar_pageoff = 0; 4464 new_entry->aref.ar_amap = NULL; 4465 } 4466 4467 if (UVM_ET_ISOBJ(new_entry)) { 4468 if (new_entry->object.uvm_obj->pgops->pgo_detach) 4469 new_entry->object.uvm_obj->pgops->pgo_detach( 4470 new_entry->object.uvm_obj); 4471 new_entry->object.uvm_obj = NULL; 4472 new_entry->etype &= ~UVM_ET_OBJ; 4473 } 4474 } 4475 4476 /* 4477 * F O R K - m a i n e n t r y p o i n t 4478 */ 4479 /* 4480 * uvmspace_fork: fork a process' main map 4481 * 4482 * => create a new vmspace for child process from parent. 4483 * => parent's map must not be locked. 4484 */ 4485 4486 struct vmspace * 4487 uvmspace_fork(struct vmspace *vm1) 4488 { 4489 struct vmspace *vm2; 4490 struct vm_map *old_map = &vm1->vm_map; 4491 struct vm_map *new_map; 4492 struct vm_map_entry *old_entry; 4493 UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist); 4494 4495 vm_map_lock(old_map); 4496 4497 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map), 4498 vm1->vm_map.flags & VM_MAP_TOPDOWN); 4499 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy, 4500 (char *) (vm1 + 1) - (char *) &vm1->vm_startcopy); 4501 new_map = &vm2->vm_map; /* XXX */ 4502 4503 old_entry = old_map->header.next; 4504 new_map->size = old_map->size; 4505 4506 /* 4507 * go entry-by-entry 4508 */ 4509 4510 while (old_entry != &old_map->header) { 4511 4512 /* 4513 * first, some sanity checks on the old entry 4514 */ 4515 4516 KASSERT(!UVM_ET_ISSUBMAP(old_entry)); 4517 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) || 4518 !UVM_ET_ISNEEDSCOPY(old_entry)); 4519 4520 switch (old_entry->inheritance) { 4521 case MAP_INHERIT_NONE: 4522 /* 4523 * drop the mapping, modify size 4524 */ 4525 new_map->size -= old_entry->end - old_entry->start; 4526 break; 4527 4528 case MAP_INHERIT_SHARE: 4529 uvm_mapent_forkshared(new_map, old_map, old_entry); 4530 break; 4531 4532 case MAP_INHERIT_COPY: 4533 uvm_mapent_forkcopy(new_map, old_map, old_entry); 4534 break; 4535 4536 case MAP_INHERIT_ZERO: 4537 uvm_mapent_forkzero(new_map, old_map, old_entry); 4538 break; 4539 default: 4540 KASSERT(0); 4541 break; 4542 } 4543 old_entry = old_entry->next; 4544 } 4545 4546 pmap_update(old_map->pmap); 4547 vm_map_unlock(old_map); 4548 4549 if (uvm_shmfork && vm1->vm_shm) 4550 (*uvm_shmfork)(vm1, vm2); 4551 4552 #ifdef PMAP_FORK 4553 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap); 4554 #endif 4555 4556 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4557 return (vm2); 4558 } 4559 4560 4561 /* 4562 * uvm_mapent_trymerge: try to merge an entry with its neighbors. 4563 * 4564 * => called with map locked. 4565 * => return non zero if successfully merged. 4566 */ 4567 4568 int 4569 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags) 4570 { 4571 struct uvm_object *uobj; 4572 struct vm_map_entry *next; 4573 struct vm_map_entry *prev; 4574 vsize_t size; 4575 int merged = 0; 4576 bool copying; 4577 int newetype; 4578 4579 if (entry->aref.ar_amap != NULL) { 4580 return 0; 4581 } 4582 if ((entry->flags & UVM_MAP_NOMERGE) != 0) { 4583 return 0; 4584 } 4585 4586 uobj = entry->object.uvm_obj; 4587 size = entry->end - entry->start; 4588 copying = (flags & UVM_MERGE_COPYING) != 0; 4589 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype; 4590 4591 next = entry->next; 4592 if (next != &map->header && 4593 next->start == entry->end && 4594 ((copying && next->aref.ar_amap != NULL && 4595 amap_refs(next->aref.ar_amap) == 1) || 4596 (!copying && next->aref.ar_amap == NULL)) && 4597 UVM_ET_ISCOMPATIBLE(next, newetype, 4598 uobj, entry->flags, entry->protection, 4599 entry->max_protection, entry->inheritance, entry->advice, 4600 entry->wired_count) && 4601 (uobj == NULL || entry->offset + size == next->offset)) { 4602 int error; 4603 4604 if (copying) { 4605 error = amap_extend(next, size, 4606 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS); 4607 } else { 4608 error = 0; 4609 } 4610 if (error == 0) { 4611 if (uobj) { 4612 if (uobj->pgops->pgo_detach) { 4613 uobj->pgops->pgo_detach(uobj); 4614 } 4615 } 4616 4617 entry->end = next->end; 4618 clear_hints(map, next); 4619 uvm_map_entry_unlink(map, next); 4620 if (copying) { 4621 entry->aref = next->aref; 4622 entry->etype &= ~UVM_ET_NEEDSCOPY; 4623 } 4624 uvm_map_check(map, "trymerge forwardmerge"); 4625 uvm_mapent_free(next); 4626 merged++; 4627 } 4628 } 4629 4630 prev = entry->prev; 4631 if (prev != &map->header && 4632 prev->end == entry->start && 4633 ((copying && !merged && prev->aref.ar_amap != NULL && 4634 amap_refs(prev->aref.ar_amap) == 1) || 4635 (!copying && prev->aref.ar_amap == NULL)) && 4636 UVM_ET_ISCOMPATIBLE(prev, newetype, 4637 uobj, entry->flags, entry->protection, 4638 entry->max_protection, entry->inheritance, entry->advice, 4639 entry->wired_count) && 4640 (uobj == NULL || 4641 prev->offset + prev->end - prev->start == entry->offset)) { 4642 int error; 4643 4644 if (copying) { 4645 error = amap_extend(prev, size, 4646 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS); 4647 } else { 4648 error = 0; 4649 } 4650 if (error == 0) { 4651 if (uobj) { 4652 if (uobj->pgops->pgo_detach) { 4653 uobj->pgops->pgo_detach(uobj); 4654 } 4655 entry->offset = prev->offset; 4656 } 4657 4658 entry->start = prev->start; 4659 clear_hints(map, prev); 4660 uvm_map_entry_unlink(map, prev); 4661 if (copying) { 4662 entry->aref = prev->aref; 4663 entry->etype &= ~UVM_ET_NEEDSCOPY; 4664 } 4665 uvm_map_check(map, "trymerge backmerge"); 4666 uvm_mapent_free(prev); 4667 merged++; 4668 } 4669 } 4670 4671 return merged; 4672 } 4673 4674 /* 4675 * uvm_map_setup: init map 4676 * 4677 * => map must not be in service yet. 4678 */ 4679 4680 void 4681 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags) 4682 { 4683 4684 rb_tree_init(&map->rb_tree, &uvm_map_tree_ops); 4685 map->header.next = map->header.prev = &map->header; 4686 map->nentries = 0; 4687 map->size = 0; 4688 map->ref_count = 1; 4689 vm_map_setmin(map, vmin); 4690 vm_map_setmax(map, vmax); 4691 map->flags = flags; 4692 map->first_free = &map->header; 4693 map->hint = &map->header; 4694 map->timestamp = 0; 4695 map->busy = NULL; 4696 4697 rw_init(&map->lock); 4698 cv_init(&map->cv, "vm_map"); 4699 mutex_init(&map->misc_lock, MUTEX_DRIVER, IPL_NONE); 4700 } 4701 4702 /* 4703 * U N M A P - m a i n e n t r y p o i n t 4704 */ 4705 4706 /* 4707 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop") 4708 * 4709 * => caller must check alignment and size 4710 * => map must be unlocked (we will lock it) 4711 * => flags is UVM_FLAG_QUANTUM or 0. 4712 */ 4713 4714 void 4715 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 4716 { 4717 struct vm_map_entry *dead_entries; 4718 UVMHIST_FUNC("uvm_unmap"); UVMHIST_CALLED(maphist); 4719 4720 KASSERT(start < end); 4721 UVMHIST_LOG(maphist, " (map=%#jx, start=%#jx, end=%#jx)", 4722 (uintptr_t)map, start, end, 0); 4723 if (map == kernel_map) { 4724 LOCKDEBUG_MEM_CHECK((void *)start, end - start); 4725 } 4726 4727 /* 4728 * work now done by helper functions. wipe the pmap's and then 4729 * detach from the dead entries... 4730 */ 4731 vm_map_lock(map); 4732 uvm_unmap_remove(map, start, end, &dead_entries, flags); 4733 vm_map_unlock(map); 4734 4735 if (dead_entries != NULL) 4736 uvm_unmap_detach(dead_entries, 0); 4737 4738 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 4739 } 4740 4741 4742 /* 4743 * uvm_map_reference: add reference to a map 4744 * 4745 * => map need not be locked (we use misc_lock). 4746 */ 4747 4748 void 4749 uvm_map_reference(struct vm_map *map) 4750 { 4751 mutex_enter(&map->misc_lock); 4752 map->ref_count++; 4753 mutex_exit(&map->misc_lock); 4754 } 4755 4756 bool 4757 vm_map_starved_p(struct vm_map *map) 4758 { 4759 4760 if ((map->flags & VM_MAP_WANTVA) != 0) { 4761 return true; 4762 } 4763 /* XXX */ 4764 if ((vm_map_max(map) - vm_map_min(map)) / 16 * 15 < map->size) { 4765 return true; 4766 } 4767 return false; 4768 } 4769 4770 void 4771 uvm_map_lock_entry(struct vm_map_entry *entry) 4772 { 4773 4774 if (entry->aref.ar_amap != NULL) { 4775 amap_lock(entry->aref.ar_amap); 4776 } 4777 if (UVM_ET_ISOBJ(entry)) { 4778 mutex_enter(entry->object.uvm_obj->vmobjlock); 4779 } 4780 } 4781 4782 void 4783 uvm_map_unlock_entry(struct vm_map_entry *entry) 4784 { 4785 4786 if (UVM_ET_ISOBJ(entry)) { 4787 mutex_exit(entry->object.uvm_obj->vmobjlock); 4788 } 4789 if (entry->aref.ar_amap != NULL) { 4790 amap_unlock(entry->aref.ar_amap); 4791 } 4792 } 4793 4794 #if defined(DDB) || defined(DEBUGPRINT) 4795 4796 /* 4797 * uvm_map_printit: actually prints the map 4798 */ 4799 4800 void 4801 uvm_map_printit(struct vm_map *map, bool full, 4802 void (*pr)(const char *, ...)) 4803 { 4804 struct vm_map_entry *entry; 4805 4806 (*pr)("MAP %p: [%#lx->%#lx]\n", map, vm_map_min(map), 4807 vm_map_max(map)); 4808 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=%#x\n", 4809 map->nentries, map->size, map->ref_count, map->timestamp, 4810 map->flags); 4811 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap, 4812 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap)); 4813 if (!full) 4814 return; 4815 for (entry = map->header.next; entry != &map->header; 4816 entry = entry->next) { 4817 (*pr)(" - %p: %#lx->%#lx: obj=%p/%#llx, amap=%p/%d\n", 4818 entry, entry->start, entry->end, entry->object.uvm_obj, 4819 (long long)entry->offset, entry->aref.ar_amap, 4820 entry->aref.ar_pageoff); 4821 (*pr)( 4822 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, " 4823 "wc=%d, adv=%d\n", 4824 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F', 4825 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F', 4826 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F', 4827 entry->protection, entry->max_protection, 4828 entry->inheritance, entry->wired_count, entry->advice); 4829 } 4830 } 4831 4832 void 4833 uvm_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 4834 { 4835 struct vm_map *map; 4836 4837 for (map = kernel_map;;) { 4838 struct vm_map_entry *entry; 4839 4840 if (!uvm_map_lookup_entry_bytree(map, (vaddr_t)addr, &entry)) { 4841 break; 4842 } 4843 (*pr)("%p is %p+%zu from VMMAP %p\n", 4844 (void *)addr, (void *)entry->start, 4845 (size_t)(addr - (uintptr_t)entry->start), map); 4846 if (!UVM_ET_ISSUBMAP(entry)) { 4847 break; 4848 } 4849 map = entry->object.sub_map; 4850 } 4851 } 4852 4853 #endif /* DDB || DEBUGPRINT */ 4854 4855 #ifndef __USER_VA0_IS_SAFE 4856 static int 4857 sysctl_user_va0_disable(SYSCTLFN_ARGS) 4858 { 4859 struct sysctlnode node; 4860 int t, error; 4861 4862 node = *rnode; 4863 node.sysctl_data = &t; 4864 t = user_va0_disable; 4865 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 4866 if (error || newp == NULL) 4867 return (error); 4868 4869 if (!t && user_va0_disable && 4870 kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MAP_VA_ZERO, 0, 4871 NULL, NULL, NULL)) 4872 return EPERM; 4873 4874 user_va0_disable = !!t; 4875 return 0; 4876 } 4877 #endif 4878 4879 static int 4880 fill_vmentry(struct lwp *l, struct proc *p, struct kinfo_vmentry *kve, 4881 struct vm_map *m, struct vm_map_entry *e) 4882 { 4883 #ifndef _RUMPKERNEL 4884 int error; 4885 4886 memset(kve, 0, sizeof(*kve)); 4887 KASSERT(e != NULL); 4888 if (UVM_ET_ISOBJ(e)) { 4889 struct uvm_object *uobj = e->object.uvm_obj; 4890 KASSERT(uobj != NULL); 4891 kve->kve_ref_count = uobj->uo_refs; 4892 kve->kve_count = uobj->uo_npages; 4893 if (UVM_OBJ_IS_VNODE(uobj)) { 4894 struct vattr va; 4895 struct vnode *vp = (struct vnode *)uobj; 4896 vn_lock(vp, LK_SHARED | LK_RETRY); 4897 error = VOP_GETATTR(vp, &va, l->l_cred); 4898 VOP_UNLOCK(vp); 4899 kve->kve_type = KVME_TYPE_VNODE; 4900 if (error == 0) { 4901 kve->kve_vn_size = vp->v_size; 4902 kve->kve_vn_type = (int)vp->v_type; 4903 kve->kve_vn_mode = va.va_mode; 4904 kve->kve_vn_rdev = va.va_rdev; 4905 kve->kve_vn_fileid = va.va_fileid; 4906 kve->kve_vn_fsid = va.va_fsid; 4907 error = vnode_to_path(kve->kve_path, 4908 sizeof(kve->kve_path) / 2, vp, l, p); 4909 #ifdef DIAGNOSTIC 4910 if (error) 4911 printf("%s: vp %p error %d\n", __func__, 4912 vp, error); 4913 #endif 4914 } 4915 } else if (UVM_OBJ_IS_KERN_OBJECT(uobj)) { 4916 kve->kve_type = KVME_TYPE_KERN; 4917 } else if (UVM_OBJ_IS_DEVICE(uobj)) { 4918 kve->kve_type = KVME_TYPE_DEVICE; 4919 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 4920 kve->kve_type = KVME_TYPE_ANON; 4921 } else { 4922 kve->kve_type = KVME_TYPE_OBJECT; 4923 } 4924 } else if (UVM_ET_ISSUBMAP(e)) { 4925 struct vm_map *map = e->object.sub_map; 4926 KASSERT(map != NULL); 4927 kve->kve_ref_count = map->ref_count; 4928 kve->kve_count = map->nentries; 4929 kve->kve_type = KVME_TYPE_SUBMAP; 4930 } else 4931 kve->kve_type = KVME_TYPE_UNKNOWN; 4932 4933 kve->kve_start = e->start; 4934 kve->kve_end = e->end; 4935 kve->kve_offset = e->offset; 4936 kve->kve_wired_count = e->wired_count; 4937 kve->kve_inheritance = e->inheritance; 4938 kve->kve_attributes = e->map_attrib; 4939 kve->kve_advice = e->advice; 4940 #define PROT(p) (((p) & VM_PROT_READ) ? KVME_PROT_READ : 0) | \ 4941 (((p) & VM_PROT_WRITE) ? KVME_PROT_WRITE : 0) | \ 4942 (((p) & VM_PROT_EXECUTE) ? KVME_PROT_EXEC : 0) 4943 kve->kve_protection = PROT(e->protection); 4944 kve->kve_max_protection = PROT(e->max_protection); 4945 kve->kve_flags |= (e->etype & UVM_ET_COPYONWRITE) 4946 ? KVME_FLAG_COW : 0; 4947 kve->kve_flags |= (e->etype & UVM_ET_NEEDSCOPY) 4948 ? KVME_FLAG_NEEDS_COPY : 0; 4949 kve->kve_flags |= (m->flags & VM_MAP_TOPDOWN) 4950 ? KVME_FLAG_GROWS_DOWN : KVME_FLAG_GROWS_UP; 4951 kve->kve_flags |= (m->flags & VM_MAP_PAGEABLE) 4952 ? KVME_FLAG_PAGEABLE : 0; 4953 #endif 4954 return 0; 4955 } 4956 4957 static int 4958 fill_vmentries(struct lwp *l, pid_t pid, u_int elem_size, void *oldp, 4959 size_t *oldlenp) 4960 { 4961 int error; 4962 struct proc *p; 4963 struct kinfo_vmentry *vme; 4964 struct vmspace *vm; 4965 struct vm_map *map; 4966 struct vm_map_entry *entry; 4967 char *dp; 4968 size_t count, vmesize; 4969 4970 if (elem_size == 0 || elem_size > 2 * sizeof(*vme)) 4971 return EINVAL; 4972 4973 if (oldp) { 4974 if (*oldlenp > 10UL * 1024UL * 1024UL) 4975 return E2BIG; 4976 count = *oldlenp / elem_size; 4977 if (count == 0) 4978 return ENOMEM; 4979 vmesize = count * sizeof(*vme); 4980 } else 4981 vmesize = 0; 4982 4983 if ((error = proc_find_locked(l, &p, pid)) != 0) 4984 return error; 4985 4986 vme = NULL; 4987 count = 0; 4988 4989 if ((error = proc_vmspace_getref(p, &vm)) != 0) 4990 goto out; 4991 4992 map = &vm->vm_map; 4993 vm_map_lock_read(map); 4994 4995 dp = oldp; 4996 if (oldp) 4997 vme = kmem_alloc(vmesize, KM_SLEEP); 4998 for (entry = map->header.next; entry != &map->header; 4999 entry = entry->next) { 5000 if (oldp && (dp - (char *)oldp) < vmesize) { 5001 error = fill_vmentry(l, p, &vme[count], map, entry); 5002 if (error) 5003 goto out; 5004 dp += elem_size; 5005 } 5006 count++; 5007 } 5008 vm_map_unlock_read(map); 5009 uvmspace_free(vm); 5010 5011 out: 5012 if (pid != -1) 5013 mutex_exit(p->p_lock); 5014 if (error == 0) { 5015 const u_int esize = uimin(sizeof(*vme), elem_size); 5016 dp = oldp; 5017 for (size_t i = 0; i < count; i++) { 5018 if (oldp && (dp - (char *)oldp) < vmesize) { 5019 error = sysctl_copyout(l, &vme[i], dp, esize); 5020 if (error) 5021 break; 5022 dp += elem_size; 5023 } else 5024 break; 5025 } 5026 count *= elem_size; 5027 if (oldp != NULL && *oldlenp < count) 5028 error = ENOSPC; 5029 *oldlenp = count; 5030 } 5031 if (vme) 5032 kmem_free(vme, vmesize); 5033 return error; 5034 } 5035 5036 static int 5037 sysctl_vmproc(SYSCTLFN_ARGS) 5038 { 5039 int error; 5040 5041 if (namelen == 1 && name[0] == CTL_QUERY) 5042 return (sysctl_query(SYSCTLFN_CALL(rnode))); 5043 5044 if (namelen == 0) 5045 return EINVAL; 5046 5047 switch (name[0]) { 5048 case VM_PROC_MAP: 5049 if (namelen != 3) 5050 return EINVAL; 5051 sysctl_unlock(); 5052 error = fill_vmentries(l, name[1], name[2], oldp, oldlenp); 5053 sysctl_relock(); 5054 return error; 5055 default: 5056 return EINVAL; 5057 } 5058 } 5059 5060 SYSCTL_SETUP(sysctl_uvmmap_setup, "sysctl uvmmap setup") 5061 { 5062 5063 sysctl_createv(clog, 0, NULL, NULL, 5064 CTLFLAG_PERMANENT, 5065 CTLTYPE_STRUCT, "proc", 5066 SYSCTL_DESCR("Process vm information"), 5067 sysctl_vmproc, 0, NULL, 0, 5068 CTL_VM, VM_PROC, CTL_EOL); 5069 #ifndef __USER_VA0_IS_SAFE 5070 sysctl_createv(clog, 0, NULL, NULL, 5071 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 5072 CTLTYPE_INT, "user_va0_disable", 5073 SYSCTL_DESCR("Disable VA 0"), 5074 sysctl_user_va0_disable, 0, &user_va0_disable, 0, 5075 CTL_VM, CTL_CREATE, CTL_EOL); 5076 #endif 5077 } 5078