1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. 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 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $Id: vm_map.c,v 1.10 1995/01/09 16:05:45 davidg Exp $ 65 */ 66 67 /* 68 * Virtual memory mapping module. 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/malloc.h> 74 75 #include <vm/vm.h> 76 #include <vm/vm_page.h> 77 #include <vm/vm_object.h> 78 #include <vm/vm_kern.h> 79 80 /* 81 * Virtual memory maps provide for the mapping, protection, 82 * and sharing of virtual memory objects. In addition, 83 * this module provides for an efficient virtual copy of 84 * memory from one map to another. 85 * 86 * Synchronization is required prior to most operations. 87 * 88 * Maps consist of an ordered doubly-linked list of simple 89 * entries; a single hint is used to speed up lookups. 90 * 91 * In order to properly represent the sharing of virtual 92 * memory regions among maps, the map structure is bi-level. 93 * Top-level ("address") maps refer to regions of sharable 94 * virtual memory. These regions are implemented as 95 * ("sharing") maps, which then refer to the actual virtual 96 * memory objects. When two address maps "share" memory, 97 * their top-level maps both have references to the same 98 * sharing map. When memory is virtual-copied from one 99 * address map to another, the references in the sharing 100 * maps are actually copied -- no copying occurs at the 101 * virtual memory object level. 102 * 103 * Since portions of maps are specified by start/end addreses, 104 * which may not align with existing map entries, all 105 * routines merely "clip" entries to these start/end values. 106 * [That is, an entry is split into two, bordering at a 107 * start or end value.] Note that these clippings may not 108 * always be necessary (as the two resulting entries are then 109 * not changed); however, the clipping is done for convenience. 110 * No attempt is currently made to "glue back together" two 111 * abutting entries. 112 * 113 * As mentioned above, virtual copy operations are performed 114 * by copying VM object references from one sharing map to 115 * another, and then marking both regions as copy-on-write. 116 * It is important to note that only one writeable reference 117 * to a VM object region exists in any map -- this means that 118 * shadow object creation can be delayed until a write operation 119 * occurs. 120 */ 121 122 /* 123 * vm_map_startup: 124 * 125 * Initialize the vm_map module. Must be called before 126 * any other vm_map routines. 127 * 128 * Map and entry structures are allocated from the general 129 * purpose memory pool with some exceptions: 130 * 131 * - The kernel map and kmem submap are allocated statically. 132 * - Kernel map entries are allocated out of a static pool. 133 * 134 * These restrictions are necessary since malloc() uses the 135 * maps and requires map entries. 136 */ 137 138 vm_offset_t kentry_data; 139 vm_size_t kentry_data_size; 140 vm_map_entry_t kentry_free; 141 vm_map_t kmap_free; 142 143 int kentry_count; 144 static vm_offset_t mapvm_start = 0, mapvm = 0, mapvmmax; 145 static int mapvmpgcnt = 0; 146 147 static void _vm_map_clip_end __P((vm_map_t, vm_map_entry_t, vm_offset_t)); 148 static void _vm_map_clip_start __P((vm_map_t, vm_map_entry_t, vm_offset_t)); 149 150 void 151 vm_map_startup() 152 { 153 register int i; 154 register vm_map_entry_t mep; 155 vm_map_t mp; 156 157 /* 158 * Static map structures for allocation before initialization of 159 * kernel map or kmem map. vm_map_create knows how to deal with them. 160 */ 161 kmap_free = mp = (vm_map_t) kentry_data; 162 i = MAX_KMAP; 163 while (--i > 0) { 164 mp->header.next = (vm_map_entry_t) (mp + 1); 165 mp++; 166 } 167 mp++->header.next = NULL; 168 169 /* 170 * Form a free list of statically allocated kernel map entries with 171 * the rest. 172 */ 173 kentry_free = mep = (vm_map_entry_t) mp; 174 kentry_count = i = (kentry_data_size - MAX_KMAP * sizeof *mp) / sizeof *mep; 175 while (--i > 0) { 176 mep->next = mep + 1; 177 mep++; 178 } 179 mep->next = NULL; 180 } 181 182 /* 183 * Allocate a vmspace structure, including a vm_map and pmap, 184 * and initialize those structures. The refcnt is set to 1. 185 * The remaining fields must be initialized by the caller. 186 */ 187 struct vmspace * 188 vmspace_alloc(min, max, pageable) 189 vm_offset_t min, max; 190 int pageable; 191 { 192 register struct vmspace *vm; 193 194 if (mapvmpgcnt == 0 && mapvm == 0) { 195 int s; 196 197 mapvmpgcnt = (cnt.v_page_count * sizeof(struct vm_map_entry) + PAGE_SIZE - 1) / PAGE_SIZE; 198 s = splhigh(); 199 mapvm_start = mapvm = kmem_alloc_pageable(kmem_map, mapvmpgcnt * PAGE_SIZE); 200 mapvmmax = mapvm_start + mapvmpgcnt * PAGE_SIZE; 201 splx(s); 202 if (!mapvm) 203 mapvmpgcnt = 0; 204 } 205 MALLOC(vm, struct vmspace *, sizeof(struct vmspace), M_VMMAP, M_WAITOK); 206 bzero(vm, (caddr_t) &vm->vm_startcopy - (caddr_t) vm); 207 vm_map_init(&vm->vm_map, min, max, pageable); 208 pmap_pinit(&vm->vm_pmap); 209 vm->vm_map.pmap = &vm->vm_pmap; /* XXX */ 210 vm->vm_refcnt = 1; 211 return (vm); 212 } 213 214 void 215 vmspace_free(vm) 216 register struct vmspace *vm; 217 { 218 219 if (--vm->vm_refcnt == 0) { 220 /* 221 * Lock the map, to wait out all other references to it. 222 * Delete all of the mappings and pages they hold, then call 223 * the pmap module to reclaim anything left. 224 */ 225 vm_map_lock(&vm->vm_map); 226 (void) vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 227 vm->vm_map.max_offset); 228 pmap_release(&vm->vm_pmap); 229 FREE(vm, M_VMMAP); 230 } 231 } 232 233 /* 234 * vm_map_create: 235 * 236 * Creates and returns a new empty VM map with 237 * the given physical map structure, and having 238 * the given lower and upper address bounds. 239 */ 240 vm_map_t 241 vm_map_create(pmap, min, max, pageable) 242 pmap_t pmap; 243 vm_offset_t min, max; 244 boolean_t pageable; 245 { 246 register vm_map_t result; 247 248 if (kmem_map == NULL) { 249 result = kmap_free; 250 kmap_free = (vm_map_t) result->header.next; 251 if (result == NULL) 252 panic("vm_map_create: out of maps"); 253 } else 254 MALLOC(result, vm_map_t, sizeof(struct vm_map), 255 M_VMMAP, M_WAITOK); 256 257 vm_map_init(result, min, max, pageable); 258 result->pmap = pmap; 259 return (result); 260 } 261 262 /* 263 * Initialize an existing vm_map structure 264 * such as that in the vmspace structure. 265 * The pmap is set elsewhere. 266 */ 267 void 268 vm_map_init(map, min, max, pageable) 269 register struct vm_map *map; 270 vm_offset_t min, max; 271 boolean_t pageable; 272 { 273 map->header.next = map->header.prev = &map->header; 274 map->nentries = 0; 275 map->size = 0; 276 map->ref_count = 1; 277 map->is_main_map = TRUE; 278 map->min_offset = min; 279 map->max_offset = max; 280 map->entries_pageable = pageable; 281 map->first_free = &map->header; 282 map->hint = &map->header; 283 map->timestamp = 0; 284 lock_init(&map->lock, TRUE); 285 simple_lock_init(&map->ref_lock); 286 simple_lock_init(&map->hint_lock); 287 } 288 289 /* 290 * vm_map_entry_create: [ internal use only ] 291 * 292 * Allocates a VM map entry for insertion. 293 * No entry fields are filled in. This routine is 294 */ 295 static struct vm_map_entry *mappool; 296 static int mappoolcnt; 297 298 vm_map_entry_t 299 vm_map_entry_create(map) 300 vm_map_t map; 301 { 302 vm_map_entry_t entry; 303 int i; 304 305 #define KENTRY_LOW_WATER 64 306 #define MAPENTRY_LOW_WATER 128 307 308 /* 309 * This is a *very* nasty (and sort of incomplete) hack!!!! 310 */ 311 if (kentry_count < KENTRY_LOW_WATER) { 312 if (mapvmpgcnt && mapvm) { 313 vm_page_t m; 314 315 m = vm_page_alloc(kmem_object, 316 mapvm - vm_map_min(kmem_map), 0); 317 if (m) { 318 int newentries; 319 320 newentries = (NBPG / sizeof(struct vm_map_entry)); 321 vm_page_wire(m); 322 m->flags &= ~PG_BUSY; 323 pmap_enter(vm_map_pmap(kmem_map), mapvm, 324 VM_PAGE_TO_PHYS(m), VM_PROT_DEFAULT, 1); 325 326 entry = (vm_map_entry_t) mapvm; 327 mapvm += NBPG; 328 --mapvmpgcnt; 329 330 for (i = 0; i < newentries; i++) { 331 vm_map_entry_dispose(kernel_map, entry); 332 entry++; 333 } 334 } 335 } 336 } 337 if (map == kernel_map || map == kmem_map || map == pager_map) { 338 339 entry = kentry_free; 340 if (entry) { 341 kentry_free = entry->next; 342 --kentry_count; 343 return entry; 344 } 345 entry = mappool; 346 if (entry) { 347 mappool = entry->next; 348 --mappoolcnt; 349 return entry; 350 } 351 } else { 352 entry = mappool; 353 if (entry) { 354 mappool = entry->next; 355 --mappoolcnt; 356 return entry; 357 } 358 MALLOC(entry, vm_map_entry_t, sizeof(struct vm_map_entry), 359 M_VMMAPENT, M_WAITOK); 360 } 361 if (entry == NULL) 362 panic("vm_map_entry_create: out of map entries"); 363 364 return (entry); 365 } 366 367 /* 368 * vm_map_entry_dispose: [ internal use only ] 369 * 370 * Inverse of vm_map_entry_create. 371 */ 372 void 373 vm_map_entry_dispose(map, entry) 374 vm_map_t map; 375 vm_map_entry_t entry; 376 { 377 if ((kentry_count < KENTRY_LOW_WATER) || 378 ((vm_offset_t) entry >= kentry_data && (vm_offset_t) entry < (kentry_data + kentry_data_size)) || 379 ((vm_offset_t) entry >= mapvm_start && (vm_offset_t) entry < mapvmmax)) { 380 entry->next = kentry_free; 381 kentry_free = entry; 382 ++kentry_count; 383 return; 384 } else { 385 if (mappoolcnt < MAPENTRY_LOW_WATER) { 386 entry->next = mappool; 387 mappool = entry; 388 ++mappoolcnt; 389 return; 390 } 391 FREE(entry, M_VMMAPENT); 392 } 393 } 394 395 /* 396 * vm_map_entry_{un,}link: 397 * 398 * Insert/remove entries from maps. 399 */ 400 #define vm_map_entry_link(map, after_where, entry) \ 401 { \ 402 (map)->nentries++; \ 403 (entry)->prev = (after_where); \ 404 (entry)->next = (after_where)->next; \ 405 (entry)->prev->next = (entry); \ 406 (entry)->next->prev = (entry); \ 407 } 408 #define vm_map_entry_unlink(map, entry) \ 409 { \ 410 (map)->nentries--; \ 411 (entry)->next->prev = (entry)->prev; \ 412 (entry)->prev->next = (entry)->next; \ 413 } 414 415 /* 416 * vm_map_reference: 417 * 418 * Creates another valid reference to the given map. 419 * 420 */ 421 void 422 vm_map_reference(map) 423 register vm_map_t map; 424 { 425 if (map == NULL) 426 return; 427 428 simple_lock(&map->ref_lock); 429 map->ref_count++; 430 simple_unlock(&map->ref_lock); 431 } 432 433 /* 434 * vm_map_deallocate: 435 * 436 * Removes a reference from the specified map, 437 * destroying it if no references remain. 438 * The map should not be locked. 439 */ 440 void 441 vm_map_deallocate(map) 442 register vm_map_t map; 443 { 444 register int c; 445 446 if (map == NULL) 447 return; 448 449 simple_lock(&map->ref_lock); 450 c = --map->ref_count; 451 simple_unlock(&map->ref_lock); 452 453 if (c > 0) { 454 return; 455 } 456 /* 457 * Lock the map, to wait out all other references to it. 458 */ 459 460 vm_map_lock(map); 461 462 (void) vm_map_delete(map, map->min_offset, map->max_offset); 463 464 pmap_destroy(map->pmap); 465 466 FREE(map, M_VMMAP); 467 } 468 469 /* 470 * vm_map_insert: 471 * 472 * Inserts the given whole VM object into the target 473 * map at the specified address range. The object's 474 * size should match that of the address range. 475 * 476 * Requires that the map be locked, and leaves it so. 477 */ 478 int 479 vm_map_insert(map, object, offset, start, end) 480 vm_map_t map; 481 vm_object_t object; 482 vm_offset_t offset; 483 vm_offset_t start; 484 vm_offset_t end; 485 { 486 register vm_map_entry_t new_entry; 487 register vm_map_entry_t prev_entry; 488 vm_map_entry_t temp_entry; 489 490 /* 491 * Check that the start and end points are not bogus. 492 */ 493 494 if ((start < map->min_offset) || (end > map->max_offset) || 495 (start >= end)) 496 return (KERN_INVALID_ADDRESS); 497 498 /* 499 * Find the entry prior to the proposed starting address; if it's part 500 * of an existing entry, this range is bogus. 501 */ 502 503 if (vm_map_lookup_entry(map, start, &temp_entry)) 504 return (KERN_NO_SPACE); 505 506 prev_entry = temp_entry; 507 508 /* 509 * Assert that the next entry doesn't overlap the end point. 510 */ 511 512 if ((prev_entry->next != &map->header) && 513 (prev_entry->next->start < end)) 514 return (KERN_NO_SPACE); 515 516 /* 517 * See if we can avoid creating a new entry by extending one of our 518 * neighbors. 519 */ 520 521 if (object == NULL) { 522 if ((prev_entry != &map->header) && 523 (prev_entry->end == start) && 524 (map->is_main_map) && 525 (prev_entry->is_a_map == FALSE) && 526 (prev_entry->is_sub_map == FALSE) && 527 (prev_entry->inheritance == VM_INHERIT_DEFAULT) && 528 (prev_entry->protection == VM_PROT_DEFAULT) && 529 (prev_entry->max_protection == VM_PROT_DEFAULT) && 530 (prev_entry->wired_count == 0)) { 531 532 if (vm_object_coalesce(prev_entry->object.vm_object, 533 NULL, 534 prev_entry->offset, 535 (vm_offset_t) 0, 536 (vm_size_t) (prev_entry->end 537 - prev_entry->start), 538 (vm_size_t) (end - prev_entry->end))) { 539 /* 540 * Coalesced the two objects - can extend the 541 * previous map entry to include the new 542 * range. 543 */ 544 map->size += (end - prev_entry->end); 545 prev_entry->end = end; 546 return (KERN_SUCCESS); 547 } 548 } 549 } 550 /* 551 * Create a new entry 552 */ 553 554 new_entry = vm_map_entry_create(map); 555 new_entry->start = start; 556 new_entry->end = end; 557 558 new_entry->is_a_map = FALSE; 559 new_entry->is_sub_map = FALSE; 560 new_entry->object.vm_object = object; 561 new_entry->offset = offset; 562 563 new_entry->copy_on_write = FALSE; 564 new_entry->needs_copy = FALSE; 565 566 if (map->is_main_map) { 567 new_entry->inheritance = VM_INHERIT_DEFAULT; 568 new_entry->protection = VM_PROT_DEFAULT; 569 new_entry->max_protection = VM_PROT_DEFAULT; 570 new_entry->wired_count = 0; 571 } 572 /* 573 * Insert the new entry into the list 574 */ 575 576 vm_map_entry_link(map, prev_entry, new_entry); 577 map->size += new_entry->end - new_entry->start; 578 579 /* 580 * Update the free space hint 581 */ 582 583 if ((map->first_free == prev_entry) && (prev_entry->end >= new_entry->start)) 584 map->first_free = new_entry; 585 586 return (KERN_SUCCESS); 587 } 588 589 /* 590 * SAVE_HINT: 591 * 592 * Saves the specified entry as the hint for 593 * future lookups. Performs necessary interlocks. 594 */ 595 #define SAVE_HINT(map,value) \ 596 simple_lock(&(map)->hint_lock); \ 597 (map)->hint = (value); \ 598 simple_unlock(&(map)->hint_lock); 599 600 /* 601 * vm_map_lookup_entry: [ internal use only ] 602 * 603 * Finds the map entry containing (or 604 * immediately preceding) the specified address 605 * in the given map; the entry is returned 606 * in the "entry" parameter. The boolean 607 * result indicates whether the address is 608 * actually contained in the map. 609 */ 610 boolean_t 611 vm_map_lookup_entry(map, address, entry) 612 register vm_map_t map; 613 register vm_offset_t address; 614 vm_map_entry_t *entry; /* OUT */ 615 { 616 register vm_map_entry_t cur; 617 register vm_map_entry_t last; 618 619 /* 620 * Start looking either from the head of the list, or from the hint. 621 */ 622 623 simple_lock(&map->hint_lock); 624 cur = map->hint; 625 simple_unlock(&map->hint_lock); 626 627 if (cur == &map->header) 628 cur = cur->next; 629 630 if (address >= cur->start) { 631 /* 632 * Go from hint to end of list. 633 * 634 * But first, make a quick check to see if we are already looking 635 * at the entry we want (which is usually the case). Note also 636 * that we don't need to save the hint here... it is the same 637 * hint (unless we are at the header, in which case the hint 638 * didn't buy us anything anyway). 639 */ 640 last = &map->header; 641 if ((cur != last) && (cur->end > address)) { 642 *entry = cur; 643 return (TRUE); 644 } 645 } else { 646 /* 647 * Go from start to hint, *inclusively* 648 */ 649 last = cur->next; 650 cur = map->header.next; 651 } 652 653 /* 654 * Search linearly 655 */ 656 657 while (cur != last) { 658 if (cur->end > address) { 659 if (address >= cur->start) { 660 /* 661 * Save this lookup for future hints, and 662 * return 663 */ 664 665 *entry = cur; 666 SAVE_HINT(map, cur); 667 return (TRUE); 668 } 669 break; 670 } 671 cur = cur->next; 672 } 673 *entry = cur->prev; 674 SAVE_HINT(map, *entry); 675 return (FALSE); 676 } 677 678 /* 679 * Find sufficient space for `length' bytes in the given map, starting at 680 * `start'. The map must be locked. Returns 0 on success, 1 on no space. 681 */ 682 int 683 vm_map_findspace(map, start, length, addr) 684 register vm_map_t map; 685 register vm_offset_t start; 686 vm_size_t length; 687 vm_offset_t *addr; 688 { 689 register vm_map_entry_t entry, next; 690 register vm_offset_t end; 691 692 if (start < map->min_offset) 693 start = map->min_offset; 694 if (start > map->max_offset) 695 return (1); 696 697 /* 698 * Look for the first possible address; if there's already something 699 * at this address, we have to start after it. 700 */ 701 if (start == map->min_offset) { 702 if ((entry = map->first_free) != &map->header) 703 start = entry->end; 704 } else { 705 vm_map_entry_t tmp; 706 707 if (vm_map_lookup_entry(map, start, &tmp)) 708 start = tmp->end; 709 entry = tmp; 710 } 711 712 /* 713 * Look through the rest of the map, trying to fit a new region in the 714 * gap between existing regions, or after the very last region. 715 */ 716 for (;; start = (entry = next)->end) { 717 /* 718 * Find the end of the proposed new region. Be sure we didn't 719 * go beyond the end of the map, or wrap around the address; 720 * if so, we lose. Otherwise, if this is the last entry, or 721 * if the proposed new region fits before the next entry, we 722 * win. 723 */ 724 end = start + length; 725 if (end > map->max_offset || end < start) 726 return (1); 727 next = entry->next; 728 if (next == &map->header || next->start >= end) 729 break; 730 } 731 SAVE_HINT(map, entry); 732 *addr = start; 733 if (map == kernel_map && round_page(start + length) > kernel_vm_end) 734 pmap_growkernel(round_page(start + length)); 735 return (0); 736 } 737 738 /* 739 * vm_map_find finds an unallocated region in the target address 740 * map with the given length. The search is defined to be 741 * first-fit from the specified address; the region found is 742 * returned in the same parameter. 743 * 744 */ 745 int 746 vm_map_find(map, object, offset, addr, length, find_space) 747 vm_map_t map; 748 vm_object_t object; 749 vm_offset_t offset; 750 vm_offset_t *addr; /* IN/OUT */ 751 vm_size_t length; 752 boolean_t find_space; 753 { 754 register vm_offset_t start; 755 int result, s = 0; 756 757 start = *addr; 758 vm_map_lock(map); 759 760 if (map == kmem_map) 761 s = splhigh(); 762 763 if (find_space) { 764 if (vm_map_findspace(map, start, length, addr)) { 765 vm_map_unlock(map); 766 if (map == kmem_map) 767 splx(s); 768 return (KERN_NO_SPACE); 769 } 770 start = *addr; 771 } 772 result = vm_map_insert(map, object, offset, start, start + length); 773 vm_map_unlock(map); 774 775 if (map == kmem_map) 776 splx(s); 777 778 return (result); 779 } 780 781 /* 782 * vm_map_simplify_entry: [ internal use only ] 783 * 784 * Simplify the given map entry by: 785 * removing extra sharing maps 786 * [XXX maybe later] merging with a neighbor 787 */ 788 void 789 vm_map_simplify_entry(map, entry) 790 vm_map_t map; 791 vm_map_entry_t entry; 792 { 793 #ifdef lint 794 map++; 795 #endif 796 797 /* 798 * If this entry corresponds to a sharing map, then see if we can 799 * remove the level of indirection. If it's not a sharing map, then it 800 * points to a VM object, so see if we can merge with either of our 801 * neighbors. 802 */ 803 804 if (entry->is_sub_map) 805 return; 806 if (entry->is_a_map) { 807 #if 0 808 vm_map_t my_share_map; 809 int count; 810 811 my_share_map = entry->object.share_map; 812 simple_lock(&my_share_map->ref_lock); 813 count = my_share_map->ref_count; 814 simple_unlock(&my_share_map->ref_lock); 815 816 if (count == 1) { 817 /* 818 * Can move the region from entry->start to entry->end 819 * (+ entry->offset) in my_share_map into place of 820 * entry. Later. 821 */ 822 } 823 #endif 824 } else { 825 /* 826 * Try to merge with our neighbors. 827 * 828 * Conditions for merge are: 829 * 830 * 1. entries are adjacent. 2. both entries point to objects 831 * with null pagers. 832 * 833 * If a merge is possible, we replace the two entries with a 834 * single entry, then merge the two objects into a single 835 * object. 836 * 837 * Now, all that is left to do is write the code! 838 */ 839 } 840 } 841 842 /* 843 * vm_map_clip_start: [ internal use only ] 844 * 845 * Asserts that the given entry begins at or after 846 * the specified address; if necessary, 847 * it splits the entry into two. 848 */ 849 #define vm_map_clip_start(map, entry, startaddr) \ 850 { \ 851 if (startaddr > entry->start) \ 852 _vm_map_clip_start(map, entry, startaddr); \ 853 } 854 855 /* 856 * This routine is called only when it is known that 857 * the entry must be split. 858 */ 859 static void 860 _vm_map_clip_start(map, entry, start) 861 register vm_map_t map; 862 register vm_map_entry_t entry; 863 register vm_offset_t start; 864 { 865 register vm_map_entry_t new_entry; 866 867 /* 868 * See if we can simplify this entry first 869 */ 870 871 /* vm_map_simplify_entry(map, entry); */ 872 873 /* 874 * Split off the front portion -- note that we must insert the new 875 * entry BEFORE this one, so that this entry has the specified 876 * starting address. 877 */ 878 879 new_entry = vm_map_entry_create(map); 880 *new_entry = *entry; 881 882 new_entry->end = start; 883 entry->offset += (start - entry->start); 884 entry->start = start; 885 886 vm_map_entry_link(map, entry->prev, new_entry); 887 888 if (entry->is_a_map || entry->is_sub_map) 889 vm_map_reference(new_entry->object.share_map); 890 else 891 vm_object_reference(new_entry->object.vm_object); 892 } 893 894 /* 895 * vm_map_clip_end: [ internal use only ] 896 * 897 * Asserts that the given entry ends at or before 898 * the specified address; if necessary, 899 * it splits the entry into two. 900 */ 901 902 #define vm_map_clip_end(map, entry, endaddr) \ 903 { \ 904 if (endaddr < entry->end) \ 905 _vm_map_clip_end(map, entry, endaddr); \ 906 } 907 908 /* 909 * This routine is called only when it is known that 910 * the entry must be split. 911 */ 912 static void 913 _vm_map_clip_end(map, entry, end) 914 register vm_map_t map; 915 register vm_map_entry_t entry; 916 register vm_offset_t end; 917 { 918 register vm_map_entry_t new_entry; 919 920 /* 921 * Create a new entry and insert it AFTER the specified entry 922 */ 923 924 new_entry = vm_map_entry_create(map); 925 *new_entry = *entry; 926 927 new_entry->start = entry->end = end; 928 new_entry->offset += (end - entry->start); 929 930 vm_map_entry_link(map, entry, new_entry); 931 932 if (entry->is_a_map || entry->is_sub_map) 933 vm_map_reference(new_entry->object.share_map); 934 else 935 vm_object_reference(new_entry->object.vm_object); 936 } 937 938 /* 939 * VM_MAP_RANGE_CHECK: [ internal use only ] 940 * 941 * Asserts that the starting and ending region 942 * addresses fall within the valid range of the map. 943 */ 944 #define VM_MAP_RANGE_CHECK(map, start, end) \ 945 { \ 946 if (start < vm_map_min(map)) \ 947 start = vm_map_min(map); \ 948 if (end > vm_map_max(map)) \ 949 end = vm_map_max(map); \ 950 if (start > end) \ 951 start = end; \ 952 } 953 954 /* 955 * vm_map_submap: [ kernel use only ] 956 * 957 * Mark the given range as handled by a subordinate map. 958 * 959 * This range must have been created with vm_map_find, 960 * and no other operations may have been performed on this 961 * range prior to calling vm_map_submap. 962 * 963 * Only a limited number of operations can be performed 964 * within this rage after calling vm_map_submap: 965 * vm_fault 966 * [Don't try vm_map_copy!] 967 * 968 * To remove a submapping, one must first remove the 969 * range from the superior map, and then destroy the 970 * submap (if desired). [Better yet, don't try it.] 971 */ 972 int 973 vm_map_submap(map, start, end, submap) 974 register vm_map_t map; 975 register vm_offset_t start; 976 register vm_offset_t end; 977 vm_map_t submap; 978 { 979 vm_map_entry_t entry; 980 register int result = KERN_INVALID_ARGUMENT; 981 982 vm_map_lock(map); 983 984 VM_MAP_RANGE_CHECK(map, start, end); 985 986 if (vm_map_lookup_entry(map, start, &entry)) { 987 vm_map_clip_start(map, entry, start); 988 } else 989 entry = entry->next; 990 991 vm_map_clip_end(map, entry, end); 992 993 if ((entry->start == start) && (entry->end == end) && 994 (!entry->is_a_map) && 995 (entry->object.vm_object == NULL) && 996 (!entry->copy_on_write)) { 997 entry->is_a_map = FALSE; 998 entry->is_sub_map = TRUE; 999 vm_map_reference(entry->object.sub_map = submap); 1000 result = KERN_SUCCESS; 1001 } 1002 vm_map_unlock(map); 1003 1004 return (result); 1005 } 1006 1007 /* 1008 * vm_map_protect: 1009 * 1010 * Sets the protection of the specified address 1011 * region in the target map. If "set_max" is 1012 * specified, the maximum protection is to be set; 1013 * otherwise, only the current protection is affected. 1014 */ 1015 int 1016 vm_map_protect(map, start, end, new_prot, set_max) 1017 register vm_map_t map; 1018 register vm_offset_t start; 1019 register vm_offset_t end; 1020 register vm_prot_t new_prot; 1021 register boolean_t set_max; 1022 { 1023 register vm_map_entry_t current; 1024 vm_map_entry_t entry; 1025 1026 vm_map_lock(map); 1027 1028 VM_MAP_RANGE_CHECK(map, start, end); 1029 1030 if (vm_map_lookup_entry(map, start, &entry)) { 1031 vm_map_clip_start(map, entry, start); 1032 } else 1033 entry = entry->next; 1034 1035 /* 1036 * Make a first pass to check for protection violations. 1037 */ 1038 1039 current = entry; 1040 while ((current != &map->header) && (current->start < end)) { 1041 if (current->is_sub_map) 1042 return (KERN_INVALID_ARGUMENT); 1043 if ((new_prot & current->max_protection) != new_prot) { 1044 vm_map_unlock(map); 1045 return (KERN_PROTECTION_FAILURE); 1046 } 1047 current = current->next; 1048 } 1049 1050 /* 1051 * Go back and fix up protections. [Note that clipping is not 1052 * necessary the second time.] 1053 */ 1054 1055 current = entry; 1056 1057 while ((current != &map->header) && (current->start < end)) { 1058 vm_prot_t old_prot; 1059 1060 vm_map_clip_end(map, current, end); 1061 1062 old_prot = current->protection; 1063 if (set_max) 1064 current->protection = 1065 (current->max_protection = new_prot) & 1066 old_prot; 1067 else 1068 current->protection = new_prot; 1069 1070 /* 1071 * Update physical map if necessary. Worry about copy-on-write 1072 * here -- CHECK THIS XXX 1073 */ 1074 1075 if (current->protection != old_prot) { 1076 1077 #define MASK(entry) ((entry)->copy_on_write ? ~VM_PROT_WRITE : \ 1078 VM_PROT_ALL) 1079 #define max(a,b) ((a) > (b) ? (a) : (b)) 1080 1081 if (current->is_a_map) { 1082 vm_map_entry_t share_entry; 1083 vm_offset_t share_end; 1084 1085 vm_map_lock(current->object.share_map); 1086 (void) vm_map_lookup_entry( 1087 current->object.share_map, 1088 current->offset, 1089 &share_entry); 1090 share_end = current->offset + 1091 (current->end - current->start); 1092 while ((share_entry != 1093 ¤t->object.share_map->header) && 1094 (share_entry->start < share_end)) { 1095 1096 pmap_protect(map->pmap, 1097 (max(share_entry->start, 1098 current->offset) - 1099 current->offset + 1100 current->start), 1101 min(share_entry->end, 1102 share_end) - 1103 current->offset + 1104 current->start, 1105 current->protection & 1106 MASK(share_entry)); 1107 1108 share_entry = share_entry->next; 1109 } 1110 vm_map_unlock(current->object.share_map); 1111 } else 1112 pmap_protect(map->pmap, current->start, 1113 current->end, 1114 current->protection & MASK(entry)); 1115 #undef max 1116 #undef MASK 1117 } 1118 current = current->next; 1119 } 1120 1121 vm_map_unlock(map); 1122 return (KERN_SUCCESS); 1123 } 1124 1125 /* 1126 * vm_map_inherit: 1127 * 1128 * Sets the inheritance of the specified address 1129 * range in the target map. Inheritance 1130 * affects how the map will be shared with 1131 * child maps at the time of vm_map_fork. 1132 */ 1133 int 1134 vm_map_inherit(map, start, end, new_inheritance) 1135 register vm_map_t map; 1136 register vm_offset_t start; 1137 register vm_offset_t end; 1138 register vm_inherit_t new_inheritance; 1139 { 1140 register vm_map_entry_t entry; 1141 vm_map_entry_t temp_entry; 1142 1143 switch (new_inheritance) { 1144 case VM_INHERIT_NONE: 1145 case VM_INHERIT_COPY: 1146 case VM_INHERIT_SHARE: 1147 break; 1148 default: 1149 return (KERN_INVALID_ARGUMENT); 1150 } 1151 1152 vm_map_lock(map); 1153 1154 VM_MAP_RANGE_CHECK(map, start, end); 1155 1156 if (vm_map_lookup_entry(map, start, &temp_entry)) { 1157 entry = temp_entry; 1158 vm_map_clip_start(map, entry, start); 1159 } else 1160 entry = temp_entry->next; 1161 1162 while ((entry != &map->header) && (entry->start < end)) { 1163 vm_map_clip_end(map, entry, end); 1164 1165 entry->inheritance = new_inheritance; 1166 1167 entry = entry->next; 1168 } 1169 1170 vm_map_unlock(map); 1171 return (KERN_SUCCESS); 1172 } 1173 1174 /* 1175 * vm_map_pageable: 1176 * 1177 * Sets the pageability of the specified address 1178 * range in the target map. Regions specified 1179 * as not pageable require locked-down physical 1180 * memory and physical page maps. 1181 * 1182 * The map must not be locked, but a reference 1183 * must remain to the map throughout the call. 1184 */ 1185 int 1186 vm_map_pageable(map, start, end, new_pageable) 1187 register vm_map_t map; 1188 register vm_offset_t start; 1189 register vm_offset_t end; 1190 register boolean_t new_pageable; 1191 { 1192 register vm_map_entry_t entry; 1193 vm_map_entry_t start_entry; 1194 register vm_offset_t failed = 0; 1195 int rv; 1196 1197 vm_map_lock(map); 1198 1199 VM_MAP_RANGE_CHECK(map, start, end); 1200 1201 /* 1202 * Only one pageability change may take place at one time, since 1203 * vm_fault assumes it will be called only once for each 1204 * wiring/unwiring. Therefore, we have to make sure we're actually 1205 * changing the pageability for the entire region. We do so before 1206 * making any changes. 1207 */ 1208 1209 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) { 1210 vm_map_unlock(map); 1211 return (KERN_INVALID_ADDRESS); 1212 } 1213 entry = start_entry; 1214 1215 /* 1216 * Actions are rather different for wiring and unwiring, so we have 1217 * two separate cases. 1218 */ 1219 1220 if (new_pageable) { 1221 1222 vm_map_clip_start(map, entry, start); 1223 1224 /* 1225 * Unwiring. First ensure that the range to be unwired is 1226 * really wired down and that there are no holes. 1227 */ 1228 while ((entry != &map->header) && (entry->start < end)) { 1229 1230 if (entry->wired_count == 0 || 1231 (entry->end < end && 1232 (entry->next == &map->header || 1233 entry->next->start > entry->end))) { 1234 vm_map_unlock(map); 1235 return (KERN_INVALID_ARGUMENT); 1236 } 1237 entry = entry->next; 1238 } 1239 1240 /* 1241 * Now decrement the wiring count for each region. If a region 1242 * becomes completely unwired, unwire its physical pages and 1243 * mappings. 1244 */ 1245 lock_set_recursive(&map->lock); 1246 1247 entry = start_entry; 1248 while ((entry != &map->header) && (entry->start < end)) { 1249 vm_map_clip_end(map, entry, end); 1250 1251 entry->wired_count--; 1252 if (entry->wired_count == 0) 1253 vm_fault_unwire(map, entry->start, entry->end); 1254 1255 entry = entry->next; 1256 } 1257 lock_clear_recursive(&map->lock); 1258 } else { 1259 /* 1260 * Wiring. We must do this in two passes: 1261 * 1262 * 1. Holding the write lock, we create any shadow or zero-fill 1263 * objects that need to be created. Then we clip each map 1264 * entry to the region to be wired and increment its wiring 1265 * count. We create objects before clipping the map entries 1266 * to avoid object proliferation. 1267 * 1268 * 2. We downgrade to a read lock, and call vm_fault_wire to 1269 * fault in the pages for any newly wired area (wired_count is 1270 * 1). 1271 * 1272 * Downgrading to a read lock for vm_fault_wire avoids a possible 1273 * deadlock with another thread that may have faulted on one 1274 * of the pages to be wired (it would mark the page busy, 1275 * blocking us, then in turn block on the map lock that we 1276 * hold). Because of problems in the recursive lock package, 1277 * we cannot upgrade to a write lock in vm_map_lookup. Thus, 1278 * any actions that require the write lock must be done 1279 * beforehand. Because we keep the read lock on the map, the 1280 * copy-on-write status of the entries we modify here cannot 1281 * change. 1282 */ 1283 1284 /* 1285 * Pass 1. 1286 */ 1287 while ((entry != &map->header) && (entry->start < end)) { 1288 if (entry->wired_count == 0) { 1289 1290 /* 1291 * Perform actions of vm_map_lookup that need 1292 * the write lock on the map: create a shadow 1293 * object for a copy-on-write region, or an 1294 * object for a zero-fill region. 1295 * 1296 * We don't have to do this for entries that 1297 * point to sharing maps, because we won't 1298 * hold the lock on the sharing map. 1299 */ 1300 if (!entry->is_a_map) { 1301 if (entry->needs_copy && 1302 ((entry->protection & VM_PROT_WRITE) != 0)) { 1303 1304 vm_object_shadow(&entry->object.vm_object, 1305 &entry->offset, 1306 (vm_size_t) (entry->end 1307 - entry->start)); 1308 entry->needs_copy = FALSE; 1309 } else if (entry->object.vm_object == NULL) { 1310 entry->object.vm_object = 1311 vm_object_allocate((vm_size_t) (entry->end 1312 - entry->start)); 1313 entry->offset = (vm_offset_t) 0; 1314 } 1315 } 1316 } 1317 vm_map_clip_start(map, entry, start); 1318 vm_map_clip_end(map, entry, end); 1319 entry->wired_count++; 1320 1321 /* 1322 * Check for holes 1323 */ 1324 if (entry->end < end && 1325 (entry->next == &map->header || 1326 entry->next->start > entry->end)) { 1327 /* 1328 * Found one. Object creation actions do not 1329 * need to be undone, but the wired counts 1330 * need to be restored. 1331 */ 1332 while (entry != &map->header && entry->end > start) { 1333 entry->wired_count--; 1334 entry = entry->prev; 1335 } 1336 vm_map_unlock(map); 1337 return (KERN_INVALID_ARGUMENT); 1338 } 1339 entry = entry->next; 1340 } 1341 1342 /* 1343 * Pass 2. 1344 */ 1345 1346 /* 1347 * HACK HACK HACK HACK 1348 * 1349 * If we are wiring in the kernel map or a submap of it, unlock 1350 * the map to avoid deadlocks. We trust that the kernel 1351 * threads are well-behaved, and therefore will not do 1352 * anything destructive to this region of the map while we 1353 * have it unlocked. We cannot trust user threads to do the 1354 * same. 1355 * 1356 * HACK HACK HACK HACK 1357 */ 1358 if (vm_map_pmap(map) == kernel_pmap) { 1359 vm_map_unlock(map); /* trust me ... */ 1360 } else { 1361 lock_set_recursive(&map->lock); 1362 lock_write_to_read(&map->lock); 1363 } 1364 1365 rv = 0; 1366 entry = start_entry; 1367 while (entry != &map->header && entry->start < end) { 1368 /* 1369 * If vm_fault_wire fails for any page we need to undo 1370 * what has been done. We decrement the wiring count 1371 * for those pages which have not yet been wired (now) 1372 * and unwire those that have (later). 1373 * 1374 * XXX this violates the locking protocol on the map, 1375 * needs to be fixed. 1376 */ 1377 if (rv) 1378 entry->wired_count--; 1379 else if (entry->wired_count == 1) { 1380 rv = vm_fault_wire(map, entry->start, entry->end); 1381 if (rv) { 1382 failed = entry->start; 1383 entry->wired_count--; 1384 } 1385 } 1386 entry = entry->next; 1387 } 1388 1389 if (vm_map_pmap(map) == kernel_pmap) { 1390 vm_map_lock(map); 1391 } else { 1392 lock_clear_recursive(&map->lock); 1393 } 1394 if (rv) { 1395 vm_map_unlock(map); 1396 (void) vm_map_pageable(map, start, failed, TRUE); 1397 return (rv); 1398 } 1399 } 1400 1401 vm_map_unlock(map); 1402 1403 return (KERN_SUCCESS); 1404 } 1405 1406 /* 1407 * vm_map_clean 1408 * 1409 * Push any dirty cached pages in the address range to their pager. 1410 * If syncio is TRUE, dirty pages are written synchronously. 1411 * If invalidate is TRUE, any cached pages are freed as well. 1412 * 1413 * Returns an error if any part of the specified range is not mapped. 1414 */ 1415 int 1416 vm_map_clean(map, start, end, syncio, invalidate) 1417 vm_map_t map; 1418 vm_offset_t start; 1419 vm_offset_t end; 1420 boolean_t syncio; 1421 boolean_t invalidate; 1422 { 1423 register vm_map_entry_t current; 1424 vm_map_entry_t entry; 1425 vm_size_t size; 1426 vm_object_t object; 1427 vm_offset_t offset; 1428 1429 vm_map_lock_read(map); 1430 VM_MAP_RANGE_CHECK(map, start, end); 1431 if (!vm_map_lookup_entry(map, start, &entry)) { 1432 vm_map_unlock_read(map); 1433 return (KERN_INVALID_ADDRESS); 1434 } 1435 /* 1436 * Make a first pass to check for holes. 1437 */ 1438 for (current = entry; current->start < end; current = current->next) { 1439 if (current->is_sub_map) { 1440 vm_map_unlock_read(map); 1441 return (KERN_INVALID_ARGUMENT); 1442 } 1443 if (end > current->end && 1444 (current->next == &map->header || 1445 current->end != current->next->start)) { 1446 vm_map_unlock_read(map); 1447 return (KERN_INVALID_ADDRESS); 1448 } 1449 } 1450 1451 /* 1452 * Make a second pass, cleaning/uncaching pages from the indicated 1453 * objects as we go. 1454 */ 1455 for (current = entry; current->start < end; current = current->next) { 1456 offset = current->offset + (start - current->start); 1457 size = (end <= current->end ? end : current->end) - start; 1458 if (current->is_a_map) { 1459 register vm_map_t smap; 1460 vm_map_entry_t tentry; 1461 vm_size_t tsize; 1462 1463 smap = current->object.share_map; 1464 vm_map_lock_read(smap); 1465 (void) vm_map_lookup_entry(smap, offset, &tentry); 1466 tsize = tentry->end - offset; 1467 if (tsize < size) 1468 size = tsize; 1469 object = tentry->object.vm_object; 1470 offset = tentry->offset + (offset - tentry->start); 1471 vm_object_lock(object); 1472 vm_map_unlock_read(smap); 1473 } else { 1474 object = current->object.vm_object; 1475 vm_object_lock(object); 1476 } 1477 /* 1478 * Flush pages if writing is allowed. XXX should we continue 1479 * on an error? 1480 */ 1481 if ((current->protection & VM_PROT_WRITE) && 1482 !vm_object_page_clean(object, offset, offset + size, 1483 syncio, FALSE)) { 1484 vm_object_unlock(object); 1485 vm_map_unlock_read(map); 1486 return (KERN_FAILURE); 1487 } 1488 if (invalidate) 1489 vm_object_page_remove(object, offset, offset + size); 1490 vm_object_unlock(object); 1491 start += size; 1492 } 1493 1494 vm_map_unlock_read(map); 1495 return (KERN_SUCCESS); 1496 } 1497 1498 /* 1499 * vm_map_entry_unwire: [ internal use only ] 1500 * 1501 * Make the region specified by this entry pageable. 1502 * 1503 * The map in question should be locked. 1504 * [This is the reason for this routine's existence.] 1505 */ 1506 void 1507 vm_map_entry_unwire(map, entry) 1508 vm_map_t map; 1509 register vm_map_entry_t entry; 1510 { 1511 vm_fault_unwire(map, entry->start, entry->end); 1512 entry->wired_count = 0; 1513 } 1514 1515 /* 1516 * vm_map_entry_delete: [ internal use only ] 1517 * 1518 * Deallocate the given entry from the target map. 1519 */ 1520 void 1521 vm_map_entry_delete(map, entry) 1522 register vm_map_t map; 1523 register vm_map_entry_t entry; 1524 { 1525 if (entry->wired_count != 0) 1526 vm_map_entry_unwire(map, entry); 1527 1528 vm_map_entry_unlink(map, entry); 1529 map->size -= entry->end - entry->start; 1530 1531 if (entry->is_a_map || entry->is_sub_map) 1532 vm_map_deallocate(entry->object.share_map); 1533 else 1534 vm_object_deallocate(entry->object.vm_object); 1535 1536 vm_map_entry_dispose(map, entry); 1537 } 1538 1539 /* 1540 * vm_map_delete: [ internal use only ] 1541 * 1542 * Deallocates the given address range from the target 1543 * map. 1544 * 1545 * When called with a sharing map, removes pages from 1546 * that region from all physical maps. 1547 */ 1548 int 1549 vm_map_delete(map, start, end) 1550 register vm_map_t map; 1551 vm_offset_t start; 1552 register vm_offset_t end; 1553 { 1554 register vm_map_entry_t entry; 1555 vm_map_entry_t first_entry; 1556 1557 /* 1558 * Find the start of the region, and clip it 1559 */ 1560 1561 if (!vm_map_lookup_entry(map, start, &first_entry)) 1562 entry = first_entry->next; 1563 else { 1564 entry = first_entry; 1565 vm_map_clip_start(map, entry, start); 1566 1567 /* 1568 * Fix the lookup hint now, rather than each time though the 1569 * loop. 1570 */ 1571 1572 SAVE_HINT(map, entry->prev); 1573 } 1574 1575 /* 1576 * Save the free space hint 1577 */ 1578 1579 if (map->first_free->start >= start) 1580 map->first_free = entry->prev; 1581 1582 /* 1583 * Step through all entries in this region 1584 */ 1585 1586 while ((entry != &map->header) && (entry->start < end)) { 1587 vm_map_entry_t next; 1588 register vm_offset_t s, e; 1589 register vm_object_t object; 1590 1591 vm_map_clip_end(map, entry, end); 1592 1593 next = entry->next; 1594 s = entry->start; 1595 e = entry->end; 1596 1597 /* 1598 * Unwire before removing addresses from the pmap; otherwise, 1599 * unwiring will put the entries back in the pmap. 1600 */ 1601 1602 object = entry->object.vm_object; 1603 if (entry->wired_count != 0) 1604 vm_map_entry_unwire(map, entry); 1605 1606 /* 1607 * If this is a sharing map, we must remove *all* references 1608 * to this data, since we can't find all of the physical maps 1609 * which are sharing it. 1610 */ 1611 1612 if (object == kernel_object || object == kmem_object) 1613 vm_object_page_remove(object, entry->offset, 1614 entry->offset + (e - s)); 1615 else if (!map->is_main_map) 1616 vm_object_pmap_remove(object, 1617 entry->offset, 1618 entry->offset + (e - s)); 1619 else 1620 pmap_remove(map->pmap, s, e); 1621 1622 /* 1623 * Delete the entry (which may delete the object) only after 1624 * removing all pmap entries pointing to its pages. 1625 * (Otherwise, its page frames may be reallocated, and any 1626 * modify bits will be set in the wrong object!) 1627 */ 1628 1629 vm_map_entry_delete(map, entry); 1630 entry = next; 1631 } 1632 return (KERN_SUCCESS); 1633 } 1634 1635 /* 1636 * vm_map_remove: 1637 * 1638 * Remove the given address range from the target map. 1639 * This is the exported form of vm_map_delete. 1640 */ 1641 int 1642 vm_map_remove(map, start, end) 1643 register vm_map_t map; 1644 register vm_offset_t start; 1645 register vm_offset_t end; 1646 { 1647 register int result, s = 0; 1648 1649 if (map == kmem_map) 1650 s = splhigh(); 1651 1652 vm_map_lock(map); 1653 VM_MAP_RANGE_CHECK(map, start, end); 1654 result = vm_map_delete(map, start, end); 1655 vm_map_unlock(map); 1656 1657 if (map == kmem_map) 1658 splx(s); 1659 1660 return (result); 1661 } 1662 1663 /* 1664 * vm_map_check_protection: 1665 * 1666 * Assert that the target map allows the specified 1667 * privilege on the entire address region given. 1668 * The entire region must be allocated. 1669 */ 1670 boolean_t 1671 vm_map_check_protection(map, start, end, protection) 1672 register vm_map_t map; 1673 register vm_offset_t start; 1674 register vm_offset_t end; 1675 register vm_prot_t protection; 1676 { 1677 register vm_map_entry_t entry; 1678 vm_map_entry_t tmp_entry; 1679 1680 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 1681 return (FALSE); 1682 } 1683 entry = tmp_entry; 1684 1685 while (start < end) { 1686 if (entry == &map->header) { 1687 return (FALSE); 1688 } 1689 /* 1690 * No holes allowed! 1691 */ 1692 1693 if (start < entry->start) { 1694 return (FALSE); 1695 } 1696 /* 1697 * Check protection associated with entry. 1698 */ 1699 1700 if ((entry->protection & protection) != protection) { 1701 return (FALSE); 1702 } 1703 /* go to next entry */ 1704 1705 start = entry->end; 1706 entry = entry->next; 1707 } 1708 return (TRUE); 1709 } 1710 1711 /* 1712 * vm_map_copy_entry: 1713 * 1714 * Copies the contents of the source entry to the destination 1715 * entry. The entries *must* be aligned properly. 1716 */ 1717 void 1718 vm_map_copy_entry(src_map, dst_map, src_entry, dst_entry) 1719 vm_map_t src_map, dst_map; 1720 register vm_map_entry_t src_entry, dst_entry; 1721 { 1722 vm_object_t temp_object; 1723 1724 if (src_entry->is_sub_map || dst_entry->is_sub_map) 1725 return; 1726 1727 if (dst_entry->object.vm_object != NULL && 1728 (dst_entry->object.vm_object->flags & OBJ_INTERNAL) == 0) 1729 printf("vm_map_copy_entry: copying over permanent data!\n"); 1730 1731 /* 1732 * If our destination map was wired down, unwire it now. 1733 */ 1734 1735 if (dst_entry->wired_count != 0) 1736 vm_map_entry_unwire(dst_map, dst_entry); 1737 1738 /* 1739 * If we're dealing with a sharing map, we must remove the destination 1740 * pages from all maps (since we cannot know which maps this sharing 1741 * map belongs in). 1742 */ 1743 1744 if (dst_map->is_main_map) 1745 pmap_remove(dst_map->pmap, dst_entry->start, dst_entry->end); 1746 else 1747 vm_object_pmap_remove(dst_entry->object.vm_object, 1748 dst_entry->offset, 1749 dst_entry->offset + 1750 (dst_entry->end - dst_entry->start)); 1751 1752 if (src_entry->wired_count == 0) { 1753 1754 boolean_t src_needs_copy; 1755 1756 /* 1757 * If the source entry is marked needs_copy, it is already 1758 * write-protected. 1759 */ 1760 if (!src_entry->needs_copy) { 1761 1762 boolean_t su; 1763 1764 /* 1765 * If the source entry has only one mapping, we can 1766 * just protect the virtual address range. 1767 */ 1768 if (!(su = src_map->is_main_map)) { 1769 simple_lock(&src_map->ref_lock); 1770 su = (src_map->ref_count == 1); 1771 simple_unlock(&src_map->ref_lock); 1772 } 1773 if (su) { 1774 pmap_protect(src_map->pmap, 1775 src_entry->start, 1776 src_entry->end, 1777 src_entry->protection & ~VM_PROT_WRITE); 1778 } else { 1779 vm_object_pmap_copy(src_entry->object.vm_object, 1780 src_entry->offset, 1781 src_entry->offset + (src_entry->end 1782 - src_entry->start)); 1783 } 1784 } 1785 /* 1786 * Make a copy of the object. 1787 */ 1788 temp_object = dst_entry->object.vm_object; 1789 vm_object_copy(src_entry->object.vm_object, 1790 src_entry->offset, 1791 (vm_size_t) (src_entry->end - 1792 src_entry->start), 1793 &dst_entry->object.vm_object, 1794 &dst_entry->offset, 1795 &src_needs_copy); 1796 /* 1797 * If we didn't get a copy-object now, mark the source map 1798 * entry so that a shadow will be created to hold its changed 1799 * pages. 1800 */ 1801 if (src_needs_copy) 1802 src_entry->needs_copy = TRUE; 1803 1804 /* 1805 * The destination always needs to have a shadow created. 1806 */ 1807 dst_entry->needs_copy = TRUE; 1808 1809 /* 1810 * Mark the entries copy-on-write, so that write-enabling the 1811 * entry won't make copy-on-write pages writable. 1812 */ 1813 src_entry->copy_on_write = TRUE; 1814 dst_entry->copy_on_write = TRUE; 1815 /* 1816 * Get rid of the old object. 1817 */ 1818 vm_object_deallocate(temp_object); 1819 1820 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 1821 dst_entry->end - dst_entry->start, src_entry->start); 1822 } else { 1823 /* 1824 * Of course, wired down pages can't be set copy-on-write. 1825 * Cause wired pages to be copied into the new map by 1826 * simulating faults (the new pages are pageable) 1827 */ 1828 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 1829 } 1830 } 1831 1832 /* 1833 * vm_map_copy: 1834 * 1835 * Perform a virtual memory copy from the source 1836 * address map/range to the destination map/range. 1837 * 1838 * If src_destroy or dst_alloc is requested, 1839 * the source and destination regions should be 1840 * disjoint, not only in the top-level map, but 1841 * in the sharing maps as well. [The best way 1842 * to guarantee this is to use a new intermediate 1843 * map to make copies. This also reduces map 1844 * fragmentation.] 1845 */ 1846 int 1847 vm_map_copy(dst_map, src_map, 1848 dst_addr, len, src_addr, 1849 dst_alloc, src_destroy) 1850 vm_map_t dst_map; 1851 vm_map_t src_map; 1852 vm_offset_t dst_addr; 1853 vm_size_t len; 1854 vm_offset_t src_addr; 1855 boolean_t dst_alloc; 1856 boolean_t src_destroy; 1857 { 1858 register 1859 vm_map_entry_t src_entry; 1860 register 1861 vm_map_entry_t dst_entry; 1862 vm_map_entry_t tmp_entry; 1863 vm_offset_t src_start; 1864 vm_offset_t src_end; 1865 vm_offset_t dst_start; 1866 vm_offset_t dst_end; 1867 vm_offset_t src_clip; 1868 vm_offset_t dst_clip; 1869 int result; 1870 boolean_t old_src_destroy; 1871 1872 /* 1873 * XXX While we figure out why src_destroy screws up, we'll do it by 1874 * explicitly vm_map_delete'ing at the end. 1875 */ 1876 1877 old_src_destroy = src_destroy; 1878 src_destroy = FALSE; 1879 1880 /* 1881 * Compute start and end of region in both maps 1882 */ 1883 1884 src_start = src_addr; 1885 src_end = src_start + len; 1886 dst_start = dst_addr; 1887 dst_end = dst_start + len; 1888 1889 /* 1890 * Check that the region can exist in both source and destination. 1891 */ 1892 1893 if ((dst_end < dst_start) || (src_end < src_start)) 1894 return (KERN_NO_SPACE); 1895 1896 /* 1897 * Lock the maps in question -- we avoid deadlock by ordering lock 1898 * acquisition by map value 1899 */ 1900 1901 if (src_map == dst_map) { 1902 vm_map_lock(src_map); 1903 } else if ((int) src_map < (int) dst_map) { 1904 vm_map_lock(src_map); 1905 vm_map_lock(dst_map); 1906 } else { 1907 vm_map_lock(dst_map); 1908 vm_map_lock(src_map); 1909 } 1910 1911 result = KERN_SUCCESS; 1912 1913 /* 1914 * Check protections... source must be completely readable and 1915 * destination must be completely writable. [Note that if we're 1916 * allocating the destination region, we don't have to worry about 1917 * protection, but instead about whether the region exists.] 1918 */ 1919 1920 if (src_map->is_main_map && dst_map->is_main_map) { 1921 if (!vm_map_check_protection(src_map, src_start, src_end, 1922 VM_PROT_READ)) { 1923 result = KERN_PROTECTION_FAILURE; 1924 goto Return; 1925 } 1926 if (dst_alloc) { 1927 /* XXX Consider making this a vm_map_find instead */ 1928 if ((result = vm_map_insert(dst_map, NULL, 1929 (vm_offset_t) 0, dst_start, dst_end)) != KERN_SUCCESS) 1930 goto Return; 1931 } else if (!vm_map_check_protection(dst_map, dst_start, dst_end, 1932 VM_PROT_WRITE)) { 1933 result = KERN_PROTECTION_FAILURE; 1934 goto Return; 1935 } 1936 } 1937 /* 1938 * Find the start entries and clip. 1939 * 1940 * Note that checking protection asserts that the lookup cannot fail. 1941 * 1942 * Also note that we wait to do the second lookup until we have done the 1943 * first clip, as the clip may affect which entry we get! 1944 */ 1945 1946 (void) vm_map_lookup_entry(src_map, src_addr, &tmp_entry); 1947 src_entry = tmp_entry; 1948 vm_map_clip_start(src_map, src_entry, src_start); 1949 1950 (void) vm_map_lookup_entry(dst_map, dst_addr, &tmp_entry); 1951 dst_entry = tmp_entry; 1952 vm_map_clip_start(dst_map, dst_entry, dst_start); 1953 1954 /* 1955 * If both source and destination entries are the same, retry the 1956 * first lookup, as it may have changed. 1957 */ 1958 1959 if (src_entry == dst_entry) { 1960 (void) vm_map_lookup_entry(src_map, src_addr, &tmp_entry); 1961 src_entry = tmp_entry; 1962 } 1963 /* 1964 * If source and destination entries are still the same, a null copy 1965 * is being performed. 1966 */ 1967 1968 if (src_entry == dst_entry) 1969 goto Return; 1970 1971 /* 1972 * Go through entries until we get to the end of the region. 1973 */ 1974 1975 while (src_start < src_end) { 1976 /* 1977 * Clip the entries to the endpoint of the entire region. 1978 */ 1979 1980 vm_map_clip_end(src_map, src_entry, src_end); 1981 vm_map_clip_end(dst_map, dst_entry, dst_end); 1982 1983 /* 1984 * Clip each entry to the endpoint of the other entry. 1985 */ 1986 1987 src_clip = src_entry->start + (dst_entry->end - dst_entry->start); 1988 vm_map_clip_end(src_map, src_entry, src_clip); 1989 1990 dst_clip = dst_entry->start + (src_entry->end - src_entry->start); 1991 vm_map_clip_end(dst_map, dst_entry, dst_clip); 1992 1993 /* 1994 * Both entries now match in size and relative endpoints. 1995 * 1996 * If both entries refer to a VM object, we can deal with them 1997 * now. 1998 */ 1999 2000 if (!src_entry->is_a_map && !dst_entry->is_a_map) { 2001 vm_map_copy_entry(src_map, dst_map, src_entry, 2002 dst_entry); 2003 } else { 2004 register vm_map_t new_dst_map; 2005 vm_offset_t new_dst_start; 2006 vm_size_t new_size; 2007 vm_map_t new_src_map; 2008 vm_offset_t new_src_start; 2009 2010 /* 2011 * We have to follow at least one sharing map. 2012 */ 2013 2014 new_size = (dst_entry->end - dst_entry->start); 2015 2016 if (src_entry->is_a_map) { 2017 new_src_map = src_entry->object.share_map; 2018 new_src_start = src_entry->offset; 2019 } else { 2020 new_src_map = src_map; 2021 new_src_start = src_entry->start; 2022 lock_set_recursive(&src_map->lock); 2023 } 2024 2025 if (dst_entry->is_a_map) { 2026 vm_offset_t new_dst_end; 2027 2028 new_dst_map = dst_entry->object.share_map; 2029 new_dst_start = dst_entry->offset; 2030 2031 /* 2032 * Since the destination sharing entries will 2033 * be merely deallocated, we can do that now, 2034 * and replace the region with a null object. 2035 * [This prevents splitting the source map to 2036 * match the form of the destination map.] 2037 * Note that we can only do so if the source 2038 * and destination do not overlap. 2039 */ 2040 2041 new_dst_end = new_dst_start + new_size; 2042 2043 if (new_dst_map != new_src_map) { 2044 vm_map_lock(new_dst_map); 2045 (void) vm_map_delete(new_dst_map, 2046 new_dst_start, 2047 new_dst_end); 2048 (void) vm_map_insert(new_dst_map, 2049 NULL, 2050 (vm_offset_t) 0, 2051 new_dst_start, 2052 new_dst_end); 2053 vm_map_unlock(new_dst_map); 2054 } 2055 } else { 2056 new_dst_map = dst_map; 2057 new_dst_start = dst_entry->start; 2058 lock_set_recursive(&dst_map->lock); 2059 } 2060 2061 /* 2062 * Recursively copy the sharing map. 2063 */ 2064 2065 (void) vm_map_copy(new_dst_map, new_src_map, 2066 new_dst_start, new_size, new_src_start, 2067 FALSE, FALSE); 2068 2069 if (dst_map == new_dst_map) 2070 lock_clear_recursive(&dst_map->lock); 2071 if (src_map == new_src_map) 2072 lock_clear_recursive(&src_map->lock); 2073 } 2074 2075 /* 2076 * Update variables for next pass through the loop. 2077 */ 2078 2079 src_start = src_entry->end; 2080 src_entry = src_entry->next; 2081 dst_start = dst_entry->end; 2082 dst_entry = dst_entry->next; 2083 2084 /* 2085 * If the source is to be destroyed, here is the place to do 2086 * it. 2087 */ 2088 2089 if (src_destroy && src_map->is_main_map && 2090 dst_map->is_main_map) 2091 vm_map_entry_delete(src_map, src_entry->prev); 2092 } 2093 2094 /* 2095 * Update the physical maps as appropriate 2096 */ 2097 2098 if (src_map->is_main_map && dst_map->is_main_map) { 2099 if (src_destroy) 2100 pmap_remove(src_map->pmap, src_addr, src_addr + len); 2101 } 2102 /* 2103 * Unlock the maps 2104 */ 2105 2106 Return:; 2107 2108 if (old_src_destroy) 2109 vm_map_delete(src_map, src_addr, src_addr + len); 2110 2111 vm_map_unlock(src_map); 2112 if (src_map != dst_map) 2113 vm_map_unlock(dst_map); 2114 2115 return (result); 2116 } 2117 2118 /* 2119 * vmspace_fork: 2120 * Create a new process vmspace structure and vm_map 2121 * based on those of an existing process. The new map 2122 * is based on the old map, according to the inheritance 2123 * values on the regions in that map. 2124 * 2125 * The source map must not be locked. 2126 */ 2127 struct vmspace * 2128 vmspace_fork(vm1) 2129 register struct vmspace *vm1; 2130 { 2131 register struct vmspace *vm2; 2132 vm_map_t old_map = &vm1->vm_map; 2133 vm_map_t new_map; 2134 vm_map_entry_t old_entry; 2135 vm_map_entry_t new_entry; 2136 pmap_t new_pmap; 2137 2138 vm_map_lock(old_map); 2139 2140 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, 2141 old_map->entries_pageable); 2142 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 2143 (caddr_t) (vm1 + 1) - (caddr_t) &vm1->vm_startcopy); 2144 new_pmap = &vm2->vm_pmap; /* XXX */ 2145 new_map = &vm2->vm_map; /* XXX */ 2146 2147 old_entry = old_map->header.next; 2148 2149 while (old_entry != &old_map->header) { 2150 if (old_entry->is_sub_map) 2151 panic("vm_map_fork: encountered a submap"); 2152 2153 switch (old_entry->inheritance) { 2154 case VM_INHERIT_NONE: 2155 break; 2156 2157 case VM_INHERIT_SHARE: 2158 /* 2159 * If we don't already have a sharing map: 2160 */ 2161 2162 if (!old_entry->is_a_map) { 2163 vm_map_t new_share_map; 2164 vm_map_entry_t new_share_entry; 2165 2166 /* 2167 * Create a new sharing map 2168 */ 2169 2170 new_share_map = vm_map_create(NULL, 2171 old_entry->start, 2172 old_entry->end, 2173 TRUE); 2174 new_share_map->is_main_map = FALSE; 2175 2176 /* 2177 * Create the only sharing entry from the old 2178 * task map entry. 2179 */ 2180 2181 new_share_entry = 2182 vm_map_entry_create(new_share_map); 2183 *new_share_entry = *old_entry; 2184 new_share_entry->wired_count = 0; 2185 2186 /* 2187 * Insert the entry into the new sharing map 2188 */ 2189 2190 vm_map_entry_link(new_share_map, 2191 new_share_map->header.prev, 2192 new_share_entry); 2193 2194 /* 2195 * Fix up the task map entry to refer to the 2196 * sharing map now. 2197 */ 2198 2199 old_entry->is_a_map = TRUE; 2200 old_entry->object.share_map = new_share_map; 2201 old_entry->offset = old_entry->start; 2202 } 2203 /* 2204 * Clone the entry, referencing the sharing map. 2205 */ 2206 2207 new_entry = vm_map_entry_create(new_map); 2208 *new_entry = *old_entry; 2209 new_entry->wired_count = 0; 2210 vm_map_reference(new_entry->object.share_map); 2211 2212 /* 2213 * Insert the entry into the new map -- we know we're 2214 * inserting at the end of the new map. 2215 */ 2216 2217 vm_map_entry_link(new_map, new_map->header.prev, 2218 new_entry); 2219 2220 /* 2221 * Update the physical map 2222 */ 2223 2224 pmap_copy(new_map->pmap, old_map->pmap, 2225 new_entry->start, 2226 (old_entry->end - old_entry->start), 2227 old_entry->start); 2228 break; 2229 2230 case VM_INHERIT_COPY: 2231 /* 2232 * Clone the entry and link into the map. 2233 */ 2234 2235 new_entry = vm_map_entry_create(new_map); 2236 *new_entry = *old_entry; 2237 new_entry->wired_count = 0; 2238 new_entry->object.vm_object = NULL; 2239 new_entry->is_a_map = FALSE; 2240 vm_map_entry_link(new_map, new_map->header.prev, 2241 new_entry); 2242 if (old_entry->is_a_map) { 2243 int check; 2244 2245 check = vm_map_copy(new_map, 2246 old_entry->object.share_map, 2247 new_entry->start, 2248 (vm_size_t) (new_entry->end - 2249 new_entry->start), 2250 old_entry->offset, 2251 FALSE, FALSE); 2252 if (check != KERN_SUCCESS) 2253 printf("vm_map_fork: copy in share_map region failed\n"); 2254 } else { 2255 vm_map_copy_entry(old_map, new_map, old_entry, 2256 new_entry); 2257 } 2258 break; 2259 } 2260 old_entry = old_entry->next; 2261 } 2262 2263 new_map->size = old_map->size; 2264 vm_map_unlock(old_map); 2265 2266 return (vm2); 2267 } 2268 2269 /* 2270 * vm_map_lookup: 2271 * 2272 * Finds the VM object, offset, and 2273 * protection for a given virtual address in the 2274 * specified map, assuming a page fault of the 2275 * type specified. 2276 * 2277 * Leaves the map in question locked for read; return 2278 * values are guaranteed until a vm_map_lookup_done 2279 * call is performed. Note that the map argument 2280 * is in/out; the returned map must be used in 2281 * the call to vm_map_lookup_done. 2282 * 2283 * A handle (out_entry) is returned for use in 2284 * vm_map_lookup_done, to make that fast. 2285 * 2286 * If a lookup is requested with "write protection" 2287 * specified, the map may be changed to perform virtual 2288 * copying operations, although the data referenced will 2289 * remain the same. 2290 */ 2291 int 2292 vm_map_lookup(var_map, vaddr, fault_type, out_entry, 2293 object, offset, out_prot, wired, single_use) 2294 vm_map_t *var_map; /* IN/OUT */ 2295 register vm_offset_t vaddr; 2296 register vm_prot_t fault_type; 2297 2298 vm_map_entry_t *out_entry; /* OUT */ 2299 vm_object_t *object; /* OUT */ 2300 vm_offset_t *offset; /* OUT */ 2301 vm_prot_t *out_prot; /* OUT */ 2302 boolean_t *wired; /* OUT */ 2303 boolean_t *single_use; /* OUT */ 2304 { 2305 vm_map_t share_map; 2306 vm_offset_t share_offset; 2307 register vm_map_entry_t entry; 2308 register vm_map_t map = *var_map; 2309 register vm_prot_t prot; 2310 register boolean_t su; 2311 2312 RetryLookup:; 2313 2314 /* 2315 * Lookup the faulting address. 2316 */ 2317 2318 vm_map_lock_read(map); 2319 2320 #define RETURN(why) \ 2321 { \ 2322 vm_map_unlock_read(map); \ 2323 return(why); \ 2324 } 2325 2326 /* 2327 * If the map has an interesting hint, try it before calling full 2328 * blown lookup routine. 2329 */ 2330 2331 simple_lock(&map->hint_lock); 2332 entry = map->hint; 2333 simple_unlock(&map->hint_lock); 2334 2335 *out_entry = entry; 2336 2337 if ((entry == &map->header) || 2338 (vaddr < entry->start) || (vaddr >= entry->end)) { 2339 vm_map_entry_t tmp_entry; 2340 2341 /* 2342 * Entry was either not a valid hint, or the vaddr was not 2343 * contained in the entry, so do a full lookup. 2344 */ 2345 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) 2346 RETURN(KERN_INVALID_ADDRESS); 2347 2348 entry = tmp_entry; 2349 *out_entry = entry; 2350 } 2351 /* 2352 * Handle submaps. 2353 */ 2354 2355 if (entry->is_sub_map) { 2356 vm_map_t old_map = map; 2357 2358 *var_map = map = entry->object.sub_map; 2359 vm_map_unlock_read(old_map); 2360 goto RetryLookup; 2361 } 2362 /* 2363 * Check whether this task is allowed to have this page. 2364 */ 2365 2366 prot = entry->protection; 2367 if ((fault_type & (prot)) != fault_type) 2368 RETURN(KERN_PROTECTION_FAILURE); 2369 2370 /* 2371 * If this page is not pageable, we have to get it for all possible 2372 * accesses. 2373 */ 2374 2375 *wired = (entry->wired_count != 0); 2376 if (*wired) 2377 prot = fault_type = entry->protection; 2378 2379 /* 2380 * If we don't already have a VM object, track it down. 2381 */ 2382 2383 su = !entry->is_a_map; 2384 if (su) { 2385 share_map = map; 2386 share_offset = vaddr; 2387 } else { 2388 vm_map_entry_t share_entry; 2389 2390 /* 2391 * Compute the sharing map, and offset into it. 2392 */ 2393 2394 share_map = entry->object.share_map; 2395 share_offset = (vaddr - entry->start) + entry->offset; 2396 2397 /* 2398 * Look for the backing store object and offset 2399 */ 2400 2401 vm_map_lock_read(share_map); 2402 2403 if (!vm_map_lookup_entry(share_map, share_offset, 2404 &share_entry)) { 2405 vm_map_unlock_read(share_map); 2406 RETURN(KERN_INVALID_ADDRESS); 2407 } 2408 entry = share_entry; 2409 } 2410 2411 /* 2412 * If the entry was copy-on-write, we either ... 2413 */ 2414 2415 if (entry->needs_copy) { 2416 /* 2417 * If we want to write the page, we may as well handle that 2418 * now since we've got the sharing map locked. 2419 * 2420 * If we don't need to write the page, we just demote the 2421 * permissions allowed. 2422 */ 2423 2424 if (fault_type & VM_PROT_WRITE) { 2425 /* 2426 * Make a new object, and place it in the object 2427 * chain. Note that no new references have appeared 2428 * -- one just moved from the share map to the new 2429 * object. 2430 */ 2431 2432 if (lock_read_to_write(&share_map->lock)) { 2433 if (share_map != map) 2434 vm_map_unlock_read(map); 2435 goto RetryLookup; 2436 } 2437 vm_object_shadow( 2438 &entry->object.vm_object, 2439 &entry->offset, 2440 (vm_size_t) (entry->end - entry->start)); 2441 2442 entry->needs_copy = FALSE; 2443 2444 lock_write_to_read(&share_map->lock); 2445 } else { 2446 /* 2447 * We're attempting to read a copy-on-write page -- 2448 * don't allow writes. 2449 */ 2450 2451 prot &= (~VM_PROT_WRITE); 2452 } 2453 } 2454 /* 2455 * Create an object if necessary. 2456 */ 2457 if (entry->object.vm_object == NULL) { 2458 2459 if (lock_read_to_write(&share_map->lock)) { 2460 if (share_map != map) 2461 vm_map_unlock_read(map); 2462 goto RetryLookup; 2463 } 2464 entry->object.vm_object = vm_object_allocate( 2465 (vm_size_t) (entry->end - entry->start)); 2466 entry->offset = 0; 2467 lock_write_to_read(&share_map->lock); 2468 } 2469 /* 2470 * Return the object/offset from this entry. If the entry was 2471 * copy-on-write or empty, it has been fixed up. 2472 */ 2473 2474 *offset = (share_offset - entry->start) + entry->offset; 2475 *object = entry->object.vm_object; 2476 2477 /* 2478 * Return whether this is the only map sharing this data. 2479 */ 2480 2481 if (!su) { 2482 simple_lock(&share_map->ref_lock); 2483 su = (share_map->ref_count == 1); 2484 simple_unlock(&share_map->ref_lock); 2485 } 2486 *out_prot = prot; 2487 *single_use = su; 2488 2489 return (KERN_SUCCESS); 2490 2491 #undef RETURN 2492 } 2493 2494 /* 2495 * vm_map_lookup_done: 2496 * 2497 * Releases locks acquired by a vm_map_lookup 2498 * (according to the handle returned by that lookup). 2499 */ 2500 2501 void 2502 vm_map_lookup_done(map, entry) 2503 register vm_map_t map; 2504 vm_map_entry_t entry; 2505 { 2506 /* 2507 * If this entry references a map, unlock it first. 2508 */ 2509 2510 if (entry->is_a_map) 2511 vm_map_unlock_read(entry->object.share_map); 2512 2513 /* 2514 * Unlock the main-level map 2515 */ 2516 2517 vm_map_unlock_read(map); 2518 } 2519 2520 /* 2521 * Routine: vm_map_simplify 2522 * Purpose: 2523 * Attempt to simplify the map representation in 2524 * the vicinity of the given starting address. 2525 * Note: 2526 * This routine is intended primarily to keep the 2527 * kernel maps more compact -- they generally don't 2528 * benefit from the "expand a map entry" technology 2529 * at allocation time because the adjacent entry 2530 * is often wired down. 2531 */ 2532 void 2533 vm_map_simplify(map, start) 2534 vm_map_t map; 2535 vm_offset_t start; 2536 { 2537 vm_map_entry_t this_entry; 2538 vm_map_entry_t prev_entry; 2539 2540 vm_map_lock(map); 2541 if ( 2542 (vm_map_lookup_entry(map, start, &this_entry)) && 2543 ((prev_entry = this_entry->prev) != &map->header) && 2544 2545 (prev_entry->end == start) && 2546 (map->is_main_map) && 2547 2548 (prev_entry->is_a_map == FALSE) && 2549 (prev_entry->is_sub_map == FALSE) && 2550 2551 (this_entry->is_a_map == FALSE) && 2552 (this_entry->is_sub_map == FALSE) && 2553 2554 (prev_entry->inheritance == this_entry->inheritance) && 2555 (prev_entry->protection == this_entry->protection) && 2556 (prev_entry->max_protection == this_entry->max_protection) && 2557 (prev_entry->wired_count == this_entry->wired_count) && 2558 2559 (prev_entry->copy_on_write == this_entry->copy_on_write) && 2560 (prev_entry->needs_copy == this_entry->needs_copy) && 2561 2562 (prev_entry->object.vm_object == this_entry->object.vm_object) && 2563 ((prev_entry->offset + (prev_entry->end - prev_entry->start)) 2564 == this_entry->offset) 2565 ) { 2566 if (map->first_free == this_entry) 2567 map->first_free = prev_entry; 2568 2569 if (!this_entry->object.vm_object->paging_in_progress) { 2570 SAVE_HINT(map, prev_entry); 2571 vm_map_entry_unlink(map, this_entry); 2572 prev_entry->end = this_entry->end; 2573 vm_object_deallocate(this_entry->object.vm_object); 2574 vm_map_entry_dispose(map, this_entry); 2575 } 2576 } 2577 vm_map_unlock(map); 2578 } 2579 2580 /* 2581 * vm_map_print: [ debug ] 2582 */ 2583 void 2584 vm_map_print(map, full) 2585 register vm_map_t map; 2586 boolean_t full; 2587 { 2588 register vm_map_entry_t entry; 2589 extern int indent; 2590 2591 iprintf("%s map 0x%x: pmap=0x%x,ref=%d,nentries=%d,version=%d\n", 2592 (map->is_main_map ? "Task" : "Share"), 2593 (int) map, (int) (map->pmap), map->ref_count, map->nentries, 2594 map->timestamp); 2595 2596 if (!full && indent) 2597 return; 2598 2599 indent += 2; 2600 for (entry = map->header.next; entry != &map->header; 2601 entry = entry->next) { 2602 iprintf("map entry 0x%x: start=0x%x, end=0x%x, ", 2603 (int) entry, (int) entry->start, (int) entry->end); 2604 if (map->is_main_map) { 2605 static char *inheritance_name[4] = 2606 {"share", "copy", "none", "donate_copy"}; 2607 2608 printf("prot=%x/%x/%s, ", 2609 entry->protection, 2610 entry->max_protection, 2611 inheritance_name[entry->inheritance]); 2612 if (entry->wired_count != 0) 2613 printf("wired, "); 2614 } 2615 if (entry->is_a_map || entry->is_sub_map) { 2616 printf("share=0x%x, offset=0x%x\n", 2617 (int) entry->object.share_map, 2618 (int) entry->offset); 2619 if ((entry->prev == &map->header) || 2620 (!entry->prev->is_a_map) || 2621 (entry->prev->object.share_map != 2622 entry->object.share_map)) { 2623 indent += 2; 2624 vm_map_print(entry->object.share_map, full); 2625 indent -= 2; 2626 } 2627 } else { 2628 printf("object=0x%x, offset=0x%x", 2629 (int) entry->object.vm_object, 2630 (int) entry->offset); 2631 if (entry->copy_on_write) 2632 printf(", copy (%s)", 2633 entry->needs_copy ? "needed" : "done"); 2634 printf("\n"); 2635 2636 if ((entry->prev == &map->header) || 2637 (entry->prev->is_a_map) || 2638 (entry->prev->object.vm_object != 2639 entry->object.vm_object)) { 2640 indent += 2; 2641 vm_object_print(entry->object.vm_object, full); 2642 indent -= 2; 2643 } 2644 } 2645 } 2646 indent -= 2; 2647 } 2648