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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61 /* 62 * Virtual memory mapping module. 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/ktr.h> 71 #include <sys/lock.h> 72 #include <sys/mutex.h> 73 #include <sys/proc.h> 74 #include <sys/vmmeter.h> 75 #include <sys/mman.h> 76 #include <sys/vnode.h> 77 #include <sys/resourcevar.h> 78 #include <sys/file.h> 79 #include <sys/sysent.h> 80 #include <sys/shm.h> 81 82 #include <vm/vm.h> 83 #include <vm/vm_param.h> 84 #include <vm/pmap.h> 85 #include <vm/vm_map.h> 86 #include <vm/vm_page.h> 87 #include <vm/vm_object.h> 88 #include <vm/vm_pager.h> 89 #include <vm/vm_kern.h> 90 #include <vm/vm_extern.h> 91 #include <vm/swap_pager.h> 92 #include <vm/uma.h> 93 94 /* 95 * Virtual memory maps provide for the mapping, protection, 96 * and sharing of virtual memory objects. In addition, 97 * this module provides for an efficient virtual copy of 98 * memory from one map to another. 99 * 100 * Synchronization is required prior to most operations. 101 * 102 * Maps consist of an ordered doubly-linked list of simple 103 * entries; a single hint is used to speed up lookups. 104 * 105 * Since portions of maps are specified by start/end addresses, 106 * which may not align with existing map entries, all 107 * routines merely "clip" entries to these start/end values. 108 * [That is, an entry is split into two, bordering at a 109 * start or end value.] Note that these clippings may not 110 * always be necessary (as the two resulting entries are then 111 * not changed); however, the clipping is done for convenience. 112 * 113 * As mentioned above, virtual copy operations are performed 114 * by copying VM object references from one map to 115 * another, and then marking both regions as copy-on-write. 116 */ 117 118 /* 119 * vm_map_startup: 120 * 121 * Initialize the vm_map module. Must be called before 122 * any other vm_map routines. 123 * 124 * Map and entry structures are allocated from the general 125 * purpose memory pool with some exceptions: 126 * 127 * - The kernel map and kmem submap are allocated statically. 128 * - Kernel map entries are allocated out of a static pool. 129 * 130 * These restrictions are necessary since malloc() uses the 131 * maps and requires map entries. 132 */ 133 134 static struct mtx map_sleep_mtx; 135 static uma_zone_t mapentzone; 136 static uma_zone_t kmapentzone; 137 static uma_zone_t mapzone; 138 static uma_zone_t vmspace_zone; 139 static struct vm_object kmapentobj; 140 static void vmspace_zinit(void *mem, int size); 141 static void vmspace_zfini(void *mem, int size); 142 static void vm_map_zinit(void *mem, int size); 143 static void vm_map_zfini(void *mem, int size); 144 static void _vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max); 145 146 #ifdef INVARIANTS 147 static void vm_map_zdtor(void *mem, int size, void *arg); 148 static void vmspace_zdtor(void *mem, int size, void *arg); 149 #endif 150 151 void 152 vm_map_startup(void) 153 { 154 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 155 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 156 #ifdef INVARIANTS 157 vm_map_zdtor, 158 #else 159 NULL, 160 #endif 161 vm_map_zinit, vm_map_zfini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 162 uma_prealloc(mapzone, MAX_KMAP); 163 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 164 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 165 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 166 uma_prealloc(kmapentzone, MAX_KMAPENT); 167 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 168 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 169 uma_prealloc(mapentzone, MAX_MAPENT); 170 } 171 172 static void 173 vmspace_zfini(void *mem, int size) 174 { 175 struct vmspace *vm; 176 177 vm = (struct vmspace *)mem; 178 179 vm_map_zfini(&vm->vm_map, sizeof(vm->vm_map)); 180 } 181 182 static void 183 vmspace_zinit(void *mem, int size) 184 { 185 struct vmspace *vm; 186 187 vm = (struct vmspace *)mem; 188 189 vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map)); 190 } 191 192 static void 193 vm_map_zfini(void *mem, int size) 194 { 195 vm_map_t map; 196 197 map = (vm_map_t)mem; 198 mtx_destroy(&map->system_mtx); 199 lockdestroy(&map->lock); 200 } 201 202 static void 203 vm_map_zinit(void *mem, int size) 204 { 205 vm_map_t map; 206 207 map = (vm_map_t)mem; 208 map->nentries = 0; 209 map->size = 0; 210 map->infork = 0; 211 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 212 lockinit(&map->lock, PVM, "thrd_sleep", 0, LK_NOPAUSE); 213 } 214 215 #ifdef INVARIANTS 216 static void 217 vmspace_zdtor(void *mem, int size, void *arg) 218 { 219 struct vmspace *vm; 220 221 vm = (struct vmspace *)mem; 222 223 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 224 } 225 static void 226 vm_map_zdtor(void *mem, int size, void *arg) 227 { 228 vm_map_t map; 229 230 map = (vm_map_t)mem; 231 KASSERT(map->nentries == 0, 232 ("map %p nentries == %d on free.", 233 map, map->nentries)); 234 KASSERT(map->size == 0, 235 ("map %p size == %lu on free.", 236 map, (unsigned long)map->size)); 237 KASSERT(map->infork == 0, 238 ("map %p infork == %d on free.", 239 map, map->infork)); 240 } 241 #endif /* INVARIANTS */ 242 243 /* 244 * Allocate a vmspace structure, including a vm_map and pmap, 245 * and initialize those structures. The refcnt is set to 1. 246 * The remaining fields must be initialized by the caller. 247 */ 248 struct vmspace * 249 vmspace_alloc(min, max) 250 vm_offset_t min, max; 251 { 252 struct vmspace *vm; 253 254 vm = uma_zalloc(vmspace_zone, M_WAITOK); 255 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 256 _vm_map_init(&vm->vm_map, min, max); 257 pmap_pinit(vmspace_pmap(vm)); 258 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 259 vm->vm_refcnt = 1; 260 vm->vm_shm = NULL; 261 vm->vm_exitingcnt = 0; 262 return (vm); 263 } 264 265 void 266 vm_init2(void) 267 { 268 uma_zone_set_obj(kmapentzone, &kmapentobj, lmin(cnt.v_page_count, 269 (VM_MAX_KERNEL_ADDRESS - KERNBASE) / PAGE_SIZE) / 8 + 270 maxproc * 2 + maxfiles); 271 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 272 #ifdef INVARIANTS 273 vmspace_zdtor, 274 #else 275 NULL, 276 #endif 277 vmspace_zinit, vmspace_zfini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 278 pmap_init2(); 279 } 280 281 static __inline void 282 vmspace_dofree(struct vmspace *vm) 283 { 284 CTR1(KTR_VM, "vmspace_free: %p", vm); 285 286 /* 287 * Make sure any SysV shm is freed, it might not have been in 288 * exit1(). 289 */ 290 shmexit(vm); 291 292 /* 293 * Lock the map, to wait out all other references to it. 294 * Delete all of the mappings and pages they hold, then call 295 * the pmap module to reclaim anything left. 296 */ 297 vm_map_lock(&vm->vm_map); 298 (void) vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 299 vm->vm_map.max_offset); 300 vm_map_unlock(&vm->vm_map); 301 302 pmap_release(vmspace_pmap(vm)); 303 uma_zfree(vmspace_zone, vm); 304 } 305 306 void 307 vmspace_free(struct vmspace *vm) 308 { 309 GIANT_REQUIRED; 310 311 if (vm->vm_refcnt == 0) 312 panic("vmspace_free: attempt to free already freed vmspace"); 313 314 if (--vm->vm_refcnt == 0 && vm->vm_exitingcnt == 0) 315 vmspace_dofree(vm); 316 } 317 318 void 319 vmspace_exitfree(struct proc *p) 320 { 321 struct vmspace *vm; 322 323 GIANT_REQUIRED; 324 vm = p->p_vmspace; 325 p->p_vmspace = NULL; 326 327 /* 328 * cleanup by parent process wait()ing on exiting child. vm_refcnt 329 * may not be 0 (e.g. fork() and child exits without exec()ing). 330 * exitingcnt may increment above 0 and drop back down to zero 331 * several times while vm_refcnt is held non-zero. vm_refcnt 332 * may also increment above 0 and drop back down to zero several 333 * times while vm_exitingcnt is held non-zero. 334 * 335 * The last wait on the exiting child's vmspace will clean up 336 * the remainder of the vmspace. 337 */ 338 if (--vm->vm_exitingcnt == 0 && vm->vm_refcnt == 0) 339 vmspace_dofree(vm); 340 } 341 342 void 343 _vm_map_lock(vm_map_t map, const char *file, int line) 344 { 345 int error; 346 347 if (map->system_map) 348 _mtx_lock_flags(&map->system_mtx, 0, file, line); 349 else { 350 error = lockmgr(&map->lock, LK_EXCLUSIVE, NULL, curthread); 351 KASSERT(error == 0, ("%s: failed to get lock", __func__)); 352 } 353 map->timestamp++; 354 } 355 356 void 357 _vm_map_unlock(vm_map_t map, const char *file, int line) 358 { 359 360 if (map->system_map) 361 _mtx_unlock_flags(&map->system_mtx, 0, file, line); 362 else 363 lockmgr(&map->lock, LK_RELEASE, NULL, curthread); 364 } 365 366 void 367 _vm_map_lock_read(vm_map_t map, const char *file, int line) 368 { 369 int error; 370 371 if (map->system_map) 372 _mtx_lock_flags(&map->system_mtx, 0, file, line); 373 else { 374 error = lockmgr(&map->lock, LK_EXCLUSIVE, NULL, curthread); 375 KASSERT(error == 0, ("%s: failed to get lock", __func__)); 376 } 377 } 378 379 void 380 _vm_map_unlock_read(vm_map_t map, const char *file, int line) 381 { 382 383 if (map->system_map) 384 _mtx_unlock_flags(&map->system_mtx, 0, file, line); 385 else 386 lockmgr(&map->lock, LK_RELEASE, NULL, curthread); 387 } 388 389 int 390 _vm_map_trylock(vm_map_t map, const char *file, int line) 391 { 392 int error; 393 394 error = map->system_map ? 395 !_mtx_trylock(&map->system_mtx, 0, file, line) : 396 lockmgr(&map->lock, LK_EXCLUSIVE | LK_NOWAIT, NULL, curthread); 397 if (error == 0) 398 map->timestamp++; 399 return (error == 0); 400 } 401 402 int 403 _vm_map_trylock_read(vm_map_t map, const char *file, int line) 404 { 405 int error; 406 407 error = map->system_map ? 408 !_mtx_trylock(&map->system_mtx, 0, file, line) : 409 lockmgr(&map->lock, LK_EXCLUSIVE | LK_NOWAIT, NULL, curthread); 410 return (error == 0); 411 } 412 413 int 414 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 415 { 416 417 if (map->system_map) { 418 #ifdef INVARIANTS 419 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 420 #endif 421 } else 422 KASSERT(lockstatus(&map->lock, curthread) == LK_EXCLUSIVE, 423 ("%s: lock not held", __func__)); 424 map->timestamp++; 425 return (0); 426 } 427 428 void 429 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 430 { 431 432 if (map->system_map) { 433 #ifdef INVARIANTS 434 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 435 #endif 436 } else 437 KASSERT(lockstatus(&map->lock, curthread) == LK_EXCLUSIVE, 438 ("%s: lock not held", __func__)); 439 } 440 441 /* 442 * vm_map_unlock_and_wait: 443 */ 444 int 445 vm_map_unlock_and_wait(vm_map_t map, boolean_t user_wait) 446 { 447 448 mtx_lock(&map_sleep_mtx); 449 vm_map_unlock(map); 450 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 0)); 451 } 452 453 /* 454 * vm_map_wakeup: 455 */ 456 void 457 vm_map_wakeup(vm_map_t map) 458 { 459 460 /* 461 * Acquire and release map_sleep_mtx to prevent a wakeup() 462 * from being performed (and lost) between the vm_map_unlock() 463 * and the msleep() in vm_map_unlock_and_wait(). 464 */ 465 mtx_lock(&map_sleep_mtx); 466 mtx_unlock(&map_sleep_mtx); 467 wakeup(&map->root); 468 } 469 470 long 471 vmspace_resident_count(struct vmspace *vmspace) 472 { 473 return pmap_resident_count(vmspace_pmap(vmspace)); 474 } 475 476 long 477 vmspace_wired_count(struct vmspace *vmspace) 478 { 479 return pmap_wired_count(vmspace_pmap(vmspace)); 480 } 481 482 /* 483 * vm_map_create: 484 * 485 * Creates and returns a new empty VM map with 486 * the given physical map structure, and having 487 * the given lower and upper address bounds. 488 */ 489 vm_map_t 490 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 491 { 492 vm_map_t result; 493 494 result = uma_zalloc(mapzone, M_WAITOK); 495 CTR1(KTR_VM, "vm_map_create: %p", result); 496 _vm_map_init(result, min, max); 497 result->pmap = pmap; 498 return (result); 499 } 500 501 /* 502 * Initialize an existing vm_map structure 503 * such as that in the vmspace structure. 504 * The pmap is set elsewhere. 505 */ 506 static void 507 _vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max) 508 { 509 510 map->header.next = map->header.prev = &map->header; 511 map->needs_wakeup = FALSE; 512 map->system_map = 0; 513 map->min_offset = min; 514 map->max_offset = max; 515 map->first_free = &map->header; 516 map->root = NULL; 517 map->timestamp = 0; 518 } 519 520 void 521 vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max) 522 { 523 _vm_map_init(map, min, max); 524 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 525 lockinit(&map->lock, PVM, "thrd_sleep", 0, LK_NOPAUSE); 526 } 527 528 /* 529 * vm_map_entry_dispose: [ internal use only ] 530 * 531 * Inverse of vm_map_entry_create. 532 */ 533 static void 534 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 535 { 536 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 537 } 538 539 /* 540 * vm_map_entry_create: [ internal use only ] 541 * 542 * Allocates a VM map entry for insertion. 543 * No entry fields are filled in. 544 */ 545 static vm_map_entry_t 546 vm_map_entry_create(vm_map_t map) 547 { 548 vm_map_entry_t new_entry; 549 550 if (map->system_map) 551 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 552 else 553 new_entry = uma_zalloc(mapentzone, M_WAITOK); 554 if (new_entry == NULL) 555 panic("vm_map_entry_create: kernel resources exhausted"); 556 return (new_entry); 557 } 558 559 /* 560 * vm_map_entry_set_behavior: 561 * 562 * Set the expected access behavior, either normal, random, or 563 * sequential. 564 */ 565 static __inline void 566 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 567 { 568 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 569 (behavior & MAP_ENTRY_BEHAV_MASK); 570 } 571 572 /* 573 * vm_map_entry_splay: 574 * 575 * Implements Sleator and Tarjan's top-down splay algorithm. Returns 576 * the vm_map_entry containing the given address. If, however, that 577 * address is not found in the vm_map, returns a vm_map_entry that is 578 * adjacent to the address, coming before or after it. 579 */ 580 static vm_map_entry_t 581 vm_map_entry_splay(vm_offset_t address, vm_map_entry_t root) 582 { 583 struct vm_map_entry dummy; 584 vm_map_entry_t lefttreemax, righttreemin, y; 585 586 if (root == NULL) 587 return (root); 588 lefttreemax = righttreemin = &dummy; 589 for (;; root = y) { 590 if (address < root->start) { 591 if ((y = root->left) == NULL) 592 break; 593 if (address < y->start) { 594 /* Rotate right. */ 595 root->left = y->right; 596 y->right = root; 597 root = y; 598 if ((y = root->left) == NULL) 599 break; 600 } 601 /* Link into the new root's right tree. */ 602 righttreemin->left = root; 603 righttreemin = root; 604 } else if (address >= root->end) { 605 if ((y = root->right) == NULL) 606 break; 607 if (address >= y->end) { 608 /* Rotate left. */ 609 root->right = y->left; 610 y->left = root; 611 root = y; 612 if ((y = root->right) == NULL) 613 break; 614 } 615 /* Link into the new root's left tree. */ 616 lefttreemax->right = root; 617 lefttreemax = root; 618 } else 619 break; 620 } 621 /* Assemble the new root. */ 622 lefttreemax->right = root->left; 623 righttreemin->left = root->right; 624 root->left = dummy.right; 625 root->right = dummy.left; 626 return (root); 627 } 628 629 /* 630 * vm_map_entry_{un,}link: 631 * 632 * Insert/remove entries from maps. 633 */ 634 static void 635 vm_map_entry_link(vm_map_t map, 636 vm_map_entry_t after_where, 637 vm_map_entry_t entry) 638 { 639 640 CTR4(KTR_VM, 641 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 642 map->nentries, entry, after_where); 643 map->nentries++; 644 entry->prev = after_where; 645 entry->next = after_where->next; 646 entry->next->prev = entry; 647 after_where->next = entry; 648 649 if (after_where != &map->header) { 650 if (after_where != map->root) 651 vm_map_entry_splay(after_where->start, map->root); 652 entry->right = after_where->right; 653 entry->left = after_where; 654 after_where->right = NULL; 655 } else { 656 entry->right = map->root; 657 entry->left = NULL; 658 } 659 map->root = entry; 660 } 661 662 static void 663 vm_map_entry_unlink(vm_map_t map, 664 vm_map_entry_t entry) 665 { 666 vm_map_entry_t next, prev, root; 667 668 if (entry != map->root) 669 vm_map_entry_splay(entry->start, map->root); 670 if (entry->left == NULL) 671 root = entry->right; 672 else { 673 root = vm_map_entry_splay(entry->start, entry->left); 674 root->right = entry->right; 675 } 676 map->root = root; 677 678 prev = entry->prev; 679 next = entry->next; 680 next->prev = prev; 681 prev->next = next; 682 map->nentries--; 683 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 684 map->nentries, entry); 685 } 686 687 /* 688 * vm_map_lookup_entry: [ internal use only ] 689 * 690 * Finds the map entry containing (or 691 * immediately preceding) the specified address 692 * in the given map; the entry is returned 693 * in the "entry" parameter. The boolean 694 * result indicates whether the address is 695 * actually contained in the map. 696 */ 697 boolean_t 698 vm_map_lookup_entry( 699 vm_map_t map, 700 vm_offset_t address, 701 vm_map_entry_t *entry) /* OUT */ 702 { 703 vm_map_entry_t cur; 704 705 cur = vm_map_entry_splay(address, map->root); 706 if (cur == NULL) 707 *entry = &map->header; 708 else { 709 map->root = cur; 710 711 if (address >= cur->start) { 712 *entry = cur; 713 if (cur->end > address) 714 return (TRUE); 715 } else 716 *entry = cur->prev; 717 } 718 return (FALSE); 719 } 720 721 /* 722 * vm_map_insert: 723 * 724 * Inserts the given whole VM object into the target 725 * map at the specified address range. The object's 726 * size should match that of the address range. 727 * 728 * Requires that the map be locked, and leaves it so. 729 * 730 * If object is non-NULL, ref count must be bumped by caller 731 * prior to making call to account for the new entry. 732 */ 733 int 734 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 735 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 736 int cow) 737 { 738 vm_map_entry_t new_entry; 739 vm_map_entry_t prev_entry; 740 vm_map_entry_t temp_entry; 741 vm_eflags_t protoeflags; 742 743 /* 744 * Check that the start and end points are not bogus. 745 */ 746 if ((start < map->min_offset) || (end > map->max_offset) || 747 (start >= end)) 748 return (KERN_INVALID_ADDRESS); 749 750 /* 751 * Find the entry prior to the proposed starting address; if it's part 752 * of an existing entry, this range is bogus. 753 */ 754 if (vm_map_lookup_entry(map, start, &temp_entry)) 755 return (KERN_NO_SPACE); 756 757 prev_entry = temp_entry; 758 759 /* 760 * Assert that the next entry doesn't overlap the end point. 761 */ 762 if ((prev_entry->next != &map->header) && 763 (prev_entry->next->start < end)) 764 return (KERN_NO_SPACE); 765 766 protoeflags = 0; 767 768 if (cow & MAP_COPY_ON_WRITE) 769 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 770 771 if (cow & MAP_NOFAULT) { 772 protoeflags |= MAP_ENTRY_NOFAULT; 773 774 KASSERT(object == NULL, 775 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 776 } 777 if (cow & MAP_DISABLE_SYNCER) 778 protoeflags |= MAP_ENTRY_NOSYNC; 779 if (cow & MAP_DISABLE_COREDUMP) 780 protoeflags |= MAP_ENTRY_NOCOREDUMP; 781 782 if (object != NULL) { 783 /* 784 * OBJ_ONEMAPPING must be cleared unless this mapping 785 * is trivially proven to be the only mapping for any 786 * of the object's pages. (Object granularity 787 * reference counting is insufficient to recognize 788 * aliases with precision.) 789 */ 790 VM_OBJECT_LOCK(object); 791 if (object->ref_count > 1 || object->shadow_count != 0) 792 vm_object_clear_flag(object, OBJ_ONEMAPPING); 793 VM_OBJECT_UNLOCK(object); 794 } 795 else if ((prev_entry != &map->header) && 796 (prev_entry->eflags == protoeflags) && 797 (prev_entry->end == start) && 798 (prev_entry->wired_count == 0) && 799 ((prev_entry->object.vm_object == NULL) || 800 vm_object_coalesce(prev_entry->object.vm_object, 801 OFF_TO_IDX(prev_entry->offset), 802 (vm_size_t)(prev_entry->end - prev_entry->start), 803 (vm_size_t)(end - prev_entry->end)))) { 804 /* 805 * We were able to extend the object. Determine if we 806 * can extend the previous map entry to include the 807 * new range as well. 808 */ 809 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 810 (prev_entry->protection == prot) && 811 (prev_entry->max_protection == max)) { 812 map->size += (end - prev_entry->end); 813 prev_entry->end = end; 814 vm_map_simplify_entry(map, prev_entry); 815 return (KERN_SUCCESS); 816 } 817 818 /* 819 * If we can extend the object but cannot extend the 820 * map entry, we have to create a new map entry. We 821 * must bump the ref count on the extended object to 822 * account for it. object may be NULL. 823 */ 824 object = prev_entry->object.vm_object; 825 offset = prev_entry->offset + 826 (prev_entry->end - prev_entry->start); 827 vm_object_reference(object); 828 } 829 830 /* 831 * NOTE: if conditionals fail, object can be NULL here. This occurs 832 * in things like the buffer map where we manage kva but do not manage 833 * backing objects. 834 */ 835 836 /* 837 * Create a new entry 838 */ 839 new_entry = vm_map_entry_create(map); 840 new_entry->start = start; 841 new_entry->end = end; 842 843 new_entry->eflags = protoeflags; 844 new_entry->object.vm_object = object; 845 new_entry->offset = offset; 846 new_entry->avail_ssize = 0; 847 848 new_entry->inheritance = VM_INHERIT_DEFAULT; 849 new_entry->protection = prot; 850 new_entry->max_protection = max; 851 new_entry->wired_count = 0; 852 853 /* 854 * Insert the new entry into the list 855 */ 856 vm_map_entry_link(map, prev_entry, new_entry); 857 map->size += new_entry->end - new_entry->start; 858 859 /* 860 * Update the free space hint 861 */ 862 if ((map->first_free == prev_entry) && 863 (prev_entry->end >= new_entry->start)) { 864 map->first_free = new_entry; 865 } 866 867 #if 0 868 /* 869 * Temporarily removed to avoid MAP_STACK panic, due to 870 * MAP_STACK being a huge hack. Will be added back in 871 * when MAP_STACK (and the user stack mapping) is fixed. 872 */ 873 /* 874 * It may be possible to simplify the entry 875 */ 876 vm_map_simplify_entry(map, new_entry); 877 #endif 878 879 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 880 vm_map_pmap_enter(map, start, 881 object, OFF_TO_IDX(offset), end - start, 882 cow & MAP_PREFAULT_PARTIAL); 883 } 884 885 return (KERN_SUCCESS); 886 } 887 888 /* 889 * Find sufficient space for `length' bytes in the given map, starting at 890 * `start'. The map must be locked. Returns 0 on success, 1 on no space. 891 */ 892 int 893 vm_map_findspace( 894 vm_map_t map, 895 vm_offset_t start, 896 vm_size_t length, 897 vm_offset_t *addr) 898 { 899 vm_map_entry_t entry, next; 900 vm_offset_t end; 901 902 if (start < map->min_offset) 903 start = map->min_offset; 904 if (start > map->max_offset) 905 return (1); 906 907 /* 908 * Look for the first possible address; if there's already something 909 * at this address, we have to start after it. 910 */ 911 if (start == map->min_offset) { 912 if ((entry = map->first_free) != &map->header) 913 start = entry->end; 914 } else { 915 vm_map_entry_t tmp; 916 917 if (vm_map_lookup_entry(map, start, &tmp)) 918 start = tmp->end; 919 entry = tmp; 920 } 921 922 /* 923 * Look through the rest of the map, trying to fit a new region in the 924 * gap between existing regions, or after the very last region. 925 */ 926 for (;; start = (entry = next)->end) { 927 /* 928 * Find the end of the proposed new region. Be sure we didn't 929 * go beyond the end of the map, or wrap around the address; 930 * if so, we lose. Otherwise, if this is the last entry, or 931 * if the proposed new region fits before the next entry, we 932 * win. 933 */ 934 end = start + length; 935 if (end > map->max_offset || end < start) 936 return (1); 937 next = entry->next; 938 if (next == &map->header || next->start >= end) 939 break; 940 } 941 *addr = start; 942 if (map == kernel_map) { 943 vm_offset_t ksize; 944 if ((ksize = round_page(start + length)) > kernel_vm_end) { 945 pmap_growkernel(ksize); 946 } 947 } 948 return (0); 949 } 950 951 /* 952 * vm_map_find finds an unallocated region in the target address 953 * map with the given length. The search is defined to be 954 * first-fit from the specified address; the region found is 955 * returned in the same parameter. 956 * 957 * If object is non-NULL, ref count must be bumped by caller 958 * prior to making call to account for the new entry. 959 */ 960 int 961 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 962 vm_offset_t *addr, /* IN/OUT */ 963 vm_size_t length, boolean_t find_space, vm_prot_t prot, 964 vm_prot_t max, int cow) 965 { 966 vm_offset_t start; 967 int result, s = 0; 968 969 start = *addr; 970 971 if (map == kmem_map) 972 s = splvm(); 973 974 vm_map_lock(map); 975 if (find_space) { 976 if (vm_map_findspace(map, start, length, addr)) { 977 vm_map_unlock(map); 978 if (map == kmem_map) 979 splx(s); 980 return (KERN_NO_SPACE); 981 } 982 start = *addr; 983 } 984 result = vm_map_insert(map, object, offset, 985 start, start + length, prot, max, cow); 986 vm_map_unlock(map); 987 988 if (map == kmem_map) 989 splx(s); 990 991 return (result); 992 } 993 994 /* 995 * vm_map_simplify_entry: 996 * 997 * Simplify the given map entry by merging with either neighbor. This 998 * routine also has the ability to merge with both neighbors. 999 * 1000 * The map must be locked. 1001 * 1002 * This routine guarentees that the passed entry remains valid (though 1003 * possibly extended). When merging, this routine may delete one or 1004 * both neighbors. 1005 */ 1006 void 1007 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1008 { 1009 vm_map_entry_t next, prev; 1010 vm_size_t prevsize, esize; 1011 1012 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) 1013 return; 1014 1015 prev = entry->prev; 1016 if (prev != &map->header) { 1017 prevsize = prev->end - prev->start; 1018 if ( (prev->end == entry->start) && 1019 (prev->object.vm_object == entry->object.vm_object) && 1020 (!prev->object.vm_object || 1021 (prev->offset + prevsize == entry->offset)) && 1022 (prev->eflags == entry->eflags) && 1023 (prev->protection == entry->protection) && 1024 (prev->max_protection == entry->max_protection) && 1025 (prev->inheritance == entry->inheritance) && 1026 (prev->wired_count == entry->wired_count)) { 1027 if (map->first_free == prev) 1028 map->first_free = entry; 1029 vm_map_entry_unlink(map, prev); 1030 entry->start = prev->start; 1031 entry->offset = prev->offset; 1032 if (prev->object.vm_object) 1033 vm_object_deallocate(prev->object.vm_object); 1034 vm_map_entry_dispose(map, prev); 1035 } 1036 } 1037 1038 next = entry->next; 1039 if (next != &map->header) { 1040 esize = entry->end - entry->start; 1041 if ((entry->end == next->start) && 1042 (next->object.vm_object == entry->object.vm_object) && 1043 (!entry->object.vm_object || 1044 (entry->offset + esize == next->offset)) && 1045 (next->eflags == entry->eflags) && 1046 (next->protection == entry->protection) && 1047 (next->max_protection == entry->max_protection) && 1048 (next->inheritance == entry->inheritance) && 1049 (next->wired_count == entry->wired_count)) { 1050 if (map->first_free == next) 1051 map->first_free = entry; 1052 vm_map_entry_unlink(map, next); 1053 entry->end = next->end; 1054 if (next->object.vm_object) 1055 vm_object_deallocate(next->object.vm_object); 1056 vm_map_entry_dispose(map, next); 1057 } 1058 } 1059 } 1060 /* 1061 * vm_map_clip_start: [ internal use only ] 1062 * 1063 * Asserts that the given entry begins at or after 1064 * the specified address; if necessary, 1065 * it splits the entry into two. 1066 */ 1067 #define vm_map_clip_start(map, entry, startaddr) \ 1068 { \ 1069 if (startaddr > entry->start) \ 1070 _vm_map_clip_start(map, entry, startaddr); \ 1071 } 1072 1073 /* 1074 * This routine is called only when it is known that 1075 * the entry must be split. 1076 */ 1077 static void 1078 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1079 { 1080 vm_map_entry_t new_entry; 1081 1082 /* 1083 * Split off the front portion -- note that we must insert the new 1084 * entry BEFORE this one, so that this entry has the specified 1085 * starting address. 1086 */ 1087 vm_map_simplify_entry(map, entry); 1088 1089 /* 1090 * If there is no object backing this entry, we might as well create 1091 * one now. If we defer it, an object can get created after the map 1092 * is clipped, and individual objects will be created for the split-up 1093 * map. This is a bit of a hack, but is also about the best place to 1094 * put this improvement. 1095 */ 1096 if (entry->object.vm_object == NULL && !map->system_map) { 1097 vm_object_t object; 1098 object = vm_object_allocate(OBJT_DEFAULT, 1099 atop(entry->end - entry->start)); 1100 entry->object.vm_object = object; 1101 entry->offset = 0; 1102 } 1103 1104 new_entry = vm_map_entry_create(map); 1105 *new_entry = *entry; 1106 1107 new_entry->end = start; 1108 entry->offset += (start - entry->start); 1109 entry->start = start; 1110 1111 vm_map_entry_link(map, entry->prev, new_entry); 1112 1113 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1114 vm_object_reference(new_entry->object.vm_object); 1115 } 1116 } 1117 1118 /* 1119 * vm_map_clip_end: [ internal use only ] 1120 * 1121 * Asserts that the given entry ends at or before 1122 * the specified address; if necessary, 1123 * it splits the entry into two. 1124 */ 1125 #define vm_map_clip_end(map, entry, endaddr) \ 1126 { \ 1127 if ((endaddr) < (entry->end)) \ 1128 _vm_map_clip_end((map), (entry), (endaddr)); \ 1129 } 1130 1131 /* 1132 * This routine is called only when it is known that 1133 * the entry must be split. 1134 */ 1135 static void 1136 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1137 { 1138 vm_map_entry_t new_entry; 1139 1140 /* 1141 * If there is no object backing this entry, we might as well create 1142 * one now. If we defer it, an object can get created after the map 1143 * is clipped, and individual objects will be created for the split-up 1144 * map. This is a bit of a hack, but is also about the best place to 1145 * put this improvement. 1146 */ 1147 if (entry->object.vm_object == NULL && !map->system_map) { 1148 vm_object_t object; 1149 object = vm_object_allocate(OBJT_DEFAULT, 1150 atop(entry->end - entry->start)); 1151 entry->object.vm_object = object; 1152 entry->offset = 0; 1153 } 1154 1155 /* 1156 * Create a new entry and insert it AFTER the specified entry 1157 */ 1158 new_entry = vm_map_entry_create(map); 1159 *new_entry = *entry; 1160 1161 new_entry->start = entry->end = end; 1162 new_entry->offset += (end - entry->start); 1163 1164 vm_map_entry_link(map, entry, new_entry); 1165 1166 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1167 vm_object_reference(new_entry->object.vm_object); 1168 } 1169 } 1170 1171 /* 1172 * VM_MAP_RANGE_CHECK: [ internal use only ] 1173 * 1174 * Asserts that the starting and ending region 1175 * addresses fall within the valid range of the map. 1176 */ 1177 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1178 { \ 1179 if (start < vm_map_min(map)) \ 1180 start = vm_map_min(map); \ 1181 if (end > vm_map_max(map)) \ 1182 end = vm_map_max(map); \ 1183 if (start > end) \ 1184 start = end; \ 1185 } 1186 1187 /* 1188 * vm_map_submap: [ kernel use only ] 1189 * 1190 * Mark the given range as handled by a subordinate map. 1191 * 1192 * This range must have been created with vm_map_find, 1193 * and no other operations may have been performed on this 1194 * range prior to calling vm_map_submap. 1195 * 1196 * Only a limited number of operations can be performed 1197 * within this rage after calling vm_map_submap: 1198 * vm_fault 1199 * [Don't try vm_map_copy!] 1200 * 1201 * To remove a submapping, one must first remove the 1202 * range from the superior map, and then destroy the 1203 * submap (if desired). [Better yet, don't try it.] 1204 */ 1205 int 1206 vm_map_submap( 1207 vm_map_t map, 1208 vm_offset_t start, 1209 vm_offset_t end, 1210 vm_map_t submap) 1211 { 1212 vm_map_entry_t entry; 1213 int result = KERN_INVALID_ARGUMENT; 1214 1215 vm_map_lock(map); 1216 1217 VM_MAP_RANGE_CHECK(map, start, end); 1218 1219 if (vm_map_lookup_entry(map, start, &entry)) { 1220 vm_map_clip_start(map, entry, start); 1221 } else 1222 entry = entry->next; 1223 1224 vm_map_clip_end(map, entry, end); 1225 1226 if ((entry->start == start) && (entry->end == end) && 1227 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1228 (entry->object.vm_object == NULL)) { 1229 entry->object.sub_map = submap; 1230 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1231 result = KERN_SUCCESS; 1232 } 1233 vm_map_unlock(map); 1234 1235 return (result); 1236 } 1237 1238 /* 1239 * The maximum number of pages to map 1240 */ 1241 #define MAX_INIT_PT 96 1242 1243 /* 1244 * vm_map_pmap_enter: 1245 * 1246 * Preload the mappings for the given object into the specified 1247 * map. This eliminates the soft faults on process startup and 1248 * immediately after an mmap(2). 1249 */ 1250 void 1251 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, 1252 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1253 { 1254 vm_offset_t tmpidx; 1255 int psize; 1256 vm_page_t p, mpte; 1257 1258 if (object == NULL) 1259 return; 1260 mtx_lock(&Giant); 1261 VM_OBJECT_LOCK(object); 1262 if (object->type == OBJT_DEVICE) { 1263 pmap_object_init_pt(map->pmap, addr, object, pindex, size); 1264 goto unlock_return; 1265 } 1266 1267 psize = atop(size); 1268 1269 if (object->type != OBJT_VNODE || 1270 ((flags & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) && 1271 (object->resident_page_count > MAX_INIT_PT))) { 1272 goto unlock_return; 1273 } 1274 1275 if (psize + pindex > object->size) { 1276 if (object->size < pindex) 1277 goto unlock_return; 1278 psize = object->size - pindex; 1279 } 1280 1281 mpte = NULL; 1282 1283 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1284 if (p->pindex < pindex) { 1285 p = vm_page_splay(pindex, object->root); 1286 if ((object->root = p)->pindex < pindex) 1287 p = TAILQ_NEXT(p, listq); 1288 } 1289 } 1290 /* 1291 * Assert: the variable p is either (1) the page with the 1292 * least pindex greater than or equal to the parameter pindex 1293 * or (2) NULL. 1294 */ 1295 for (; 1296 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1297 p = TAILQ_NEXT(p, listq)) { 1298 /* 1299 * don't allow an madvise to blow away our really 1300 * free pages allocating pv entries. 1301 */ 1302 if ((flags & MAP_PREFAULT_MADVISE) && 1303 cnt.v_free_count < cnt.v_free_reserved) { 1304 break; 1305 } 1306 vm_page_lock_queues(); 1307 if ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL && 1308 (p->busy == 0) && 1309 (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { 1310 if ((p->queue - p->pc) == PQ_CACHE) 1311 vm_page_deactivate(p); 1312 vm_page_busy(p); 1313 vm_page_unlock_queues(); 1314 VM_OBJECT_UNLOCK(object); 1315 mpte = pmap_enter_quick(map->pmap, 1316 addr + ptoa(tmpidx), p, mpte); 1317 VM_OBJECT_LOCK(object); 1318 vm_page_lock_queues(); 1319 vm_page_wakeup(p); 1320 } 1321 vm_page_unlock_queues(); 1322 } 1323 unlock_return: 1324 VM_OBJECT_UNLOCK(object); 1325 mtx_unlock(&Giant); 1326 } 1327 1328 /* 1329 * vm_map_protect: 1330 * 1331 * Sets the protection of the specified address 1332 * region in the target map. If "set_max" is 1333 * specified, the maximum protection is to be set; 1334 * otherwise, only the current protection is affected. 1335 */ 1336 int 1337 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1338 vm_prot_t new_prot, boolean_t set_max) 1339 { 1340 vm_map_entry_t current; 1341 vm_map_entry_t entry; 1342 1343 vm_map_lock(map); 1344 1345 VM_MAP_RANGE_CHECK(map, start, end); 1346 1347 if (vm_map_lookup_entry(map, start, &entry)) { 1348 vm_map_clip_start(map, entry, start); 1349 } else { 1350 entry = entry->next; 1351 } 1352 1353 /* 1354 * Make a first pass to check for protection violations. 1355 */ 1356 current = entry; 1357 while ((current != &map->header) && (current->start < end)) { 1358 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1359 vm_map_unlock(map); 1360 return (KERN_INVALID_ARGUMENT); 1361 } 1362 if ((new_prot & current->max_protection) != new_prot) { 1363 vm_map_unlock(map); 1364 return (KERN_PROTECTION_FAILURE); 1365 } 1366 current = current->next; 1367 } 1368 1369 /* 1370 * Go back and fix up protections. [Note that clipping is not 1371 * necessary the second time.] 1372 */ 1373 current = entry; 1374 while ((current != &map->header) && (current->start < end)) { 1375 vm_prot_t old_prot; 1376 1377 vm_map_clip_end(map, current, end); 1378 1379 old_prot = current->protection; 1380 if (set_max) 1381 current->protection = 1382 (current->max_protection = new_prot) & 1383 old_prot; 1384 else 1385 current->protection = new_prot; 1386 1387 /* 1388 * Update physical map if necessary. Worry about copy-on-write 1389 * here -- CHECK THIS XXX 1390 */ 1391 if (current->protection != old_prot) { 1392 mtx_lock(&Giant); 1393 vm_page_lock_queues(); 1394 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1395 VM_PROT_ALL) 1396 pmap_protect(map->pmap, current->start, 1397 current->end, 1398 current->protection & MASK(current)); 1399 #undef MASK 1400 vm_page_unlock_queues(); 1401 mtx_unlock(&Giant); 1402 } 1403 vm_map_simplify_entry(map, current); 1404 current = current->next; 1405 } 1406 vm_map_unlock(map); 1407 return (KERN_SUCCESS); 1408 } 1409 1410 /* 1411 * vm_map_madvise: 1412 * 1413 * This routine traverses a processes map handling the madvise 1414 * system call. Advisories are classified as either those effecting 1415 * the vm_map_entry structure, or those effecting the underlying 1416 * objects. 1417 */ 1418 int 1419 vm_map_madvise( 1420 vm_map_t map, 1421 vm_offset_t start, 1422 vm_offset_t end, 1423 int behav) 1424 { 1425 vm_map_entry_t current, entry; 1426 int modify_map = 0; 1427 1428 /* 1429 * Some madvise calls directly modify the vm_map_entry, in which case 1430 * we need to use an exclusive lock on the map and we need to perform 1431 * various clipping operations. Otherwise we only need a read-lock 1432 * on the map. 1433 */ 1434 switch(behav) { 1435 case MADV_NORMAL: 1436 case MADV_SEQUENTIAL: 1437 case MADV_RANDOM: 1438 case MADV_NOSYNC: 1439 case MADV_AUTOSYNC: 1440 case MADV_NOCORE: 1441 case MADV_CORE: 1442 modify_map = 1; 1443 vm_map_lock(map); 1444 break; 1445 case MADV_WILLNEED: 1446 case MADV_DONTNEED: 1447 case MADV_FREE: 1448 vm_map_lock_read(map); 1449 break; 1450 default: 1451 return (KERN_INVALID_ARGUMENT); 1452 } 1453 1454 /* 1455 * Locate starting entry and clip if necessary. 1456 */ 1457 VM_MAP_RANGE_CHECK(map, start, end); 1458 1459 if (vm_map_lookup_entry(map, start, &entry)) { 1460 if (modify_map) 1461 vm_map_clip_start(map, entry, start); 1462 } else { 1463 entry = entry->next; 1464 } 1465 1466 if (modify_map) { 1467 /* 1468 * madvise behaviors that are implemented in the vm_map_entry. 1469 * 1470 * We clip the vm_map_entry so that behavioral changes are 1471 * limited to the specified address range. 1472 */ 1473 for (current = entry; 1474 (current != &map->header) && (current->start < end); 1475 current = current->next 1476 ) { 1477 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1478 continue; 1479 1480 vm_map_clip_end(map, current, end); 1481 1482 switch (behav) { 1483 case MADV_NORMAL: 1484 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1485 break; 1486 case MADV_SEQUENTIAL: 1487 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1488 break; 1489 case MADV_RANDOM: 1490 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1491 break; 1492 case MADV_NOSYNC: 1493 current->eflags |= MAP_ENTRY_NOSYNC; 1494 break; 1495 case MADV_AUTOSYNC: 1496 current->eflags &= ~MAP_ENTRY_NOSYNC; 1497 break; 1498 case MADV_NOCORE: 1499 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1500 break; 1501 case MADV_CORE: 1502 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1503 break; 1504 default: 1505 break; 1506 } 1507 vm_map_simplify_entry(map, current); 1508 } 1509 vm_map_unlock(map); 1510 } else { 1511 vm_pindex_t pindex; 1512 int count; 1513 1514 /* 1515 * madvise behaviors that are implemented in the underlying 1516 * vm_object. 1517 * 1518 * Since we don't clip the vm_map_entry, we have to clip 1519 * the vm_object pindex and count. 1520 */ 1521 for (current = entry; 1522 (current != &map->header) && (current->start < end); 1523 current = current->next 1524 ) { 1525 vm_offset_t useStart; 1526 1527 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1528 continue; 1529 1530 pindex = OFF_TO_IDX(current->offset); 1531 count = atop(current->end - current->start); 1532 useStart = current->start; 1533 1534 if (current->start < start) { 1535 pindex += atop(start - current->start); 1536 count -= atop(start - current->start); 1537 useStart = start; 1538 } 1539 if (current->end > end) 1540 count -= atop(current->end - end); 1541 1542 if (count <= 0) 1543 continue; 1544 1545 vm_object_madvise(current->object.vm_object, 1546 pindex, count, behav); 1547 if (behav == MADV_WILLNEED) { 1548 vm_map_pmap_enter(map, 1549 useStart, 1550 current->object.vm_object, 1551 pindex, 1552 (count << PAGE_SHIFT), 1553 MAP_PREFAULT_MADVISE 1554 ); 1555 } 1556 } 1557 vm_map_unlock_read(map); 1558 } 1559 return (0); 1560 } 1561 1562 1563 /* 1564 * vm_map_inherit: 1565 * 1566 * Sets the inheritance of the specified address 1567 * range in the target map. Inheritance 1568 * affects how the map will be shared with 1569 * child maps at the time of vm_map_fork. 1570 */ 1571 int 1572 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 1573 vm_inherit_t new_inheritance) 1574 { 1575 vm_map_entry_t entry; 1576 vm_map_entry_t temp_entry; 1577 1578 switch (new_inheritance) { 1579 case VM_INHERIT_NONE: 1580 case VM_INHERIT_COPY: 1581 case VM_INHERIT_SHARE: 1582 break; 1583 default: 1584 return (KERN_INVALID_ARGUMENT); 1585 } 1586 vm_map_lock(map); 1587 VM_MAP_RANGE_CHECK(map, start, end); 1588 if (vm_map_lookup_entry(map, start, &temp_entry)) { 1589 entry = temp_entry; 1590 vm_map_clip_start(map, entry, start); 1591 } else 1592 entry = temp_entry->next; 1593 while ((entry != &map->header) && (entry->start < end)) { 1594 vm_map_clip_end(map, entry, end); 1595 entry->inheritance = new_inheritance; 1596 vm_map_simplify_entry(map, entry); 1597 entry = entry->next; 1598 } 1599 vm_map_unlock(map); 1600 return (KERN_SUCCESS); 1601 } 1602 1603 /* 1604 * vm_map_unwire: 1605 * 1606 * Implements both kernel and user unwiring. 1607 */ 1608 int 1609 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 1610 int flags) 1611 { 1612 vm_map_entry_t entry, first_entry, tmp_entry; 1613 vm_offset_t saved_start; 1614 unsigned int last_timestamp; 1615 int rv; 1616 boolean_t need_wakeup, result, user_unwire; 1617 1618 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 1619 vm_map_lock(map); 1620 VM_MAP_RANGE_CHECK(map, start, end); 1621 if (!vm_map_lookup_entry(map, start, &first_entry)) { 1622 if (flags & VM_MAP_WIRE_HOLESOK) 1623 first_entry = first_entry->next; 1624 else { 1625 vm_map_unlock(map); 1626 return (KERN_INVALID_ADDRESS); 1627 } 1628 } 1629 last_timestamp = map->timestamp; 1630 entry = first_entry; 1631 while (entry != &map->header && entry->start < end) { 1632 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1633 /* 1634 * We have not yet clipped the entry. 1635 */ 1636 saved_start = (start >= entry->start) ? start : 1637 entry->start; 1638 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1639 if (vm_map_unlock_and_wait(map, user_unwire)) { 1640 /* 1641 * Allow interruption of user unwiring? 1642 */ 1643 } 1644 vm_map_lock(map); 1645 if (last_timestamp+1 != map->timestamp) { 1646 /* 1647 * Look again for the entry because the map was 1648 * modified while it was unlocked. 1649 * Specifically, the entry may have been 1650 * clipped, merged, or deleted. 1651 */ 1652 if (!vm_map_lookup_entry(map, saved_start, 1653 &tmp_entry)) { 1654 if (flags & VM_MAP_WIRE_HOLESOK) 1655 tmp_entry = tmp_entry->next; 1656 else { 1657 if (saved_start == start) { 1658 /* 1659 * First_entry has been deleted. 1660 */ 1661 vm_map_unlock(map); 1662 return (KERN_INVALID_ADDRESS); 1663 } 1664 end = saved_start; 1665 rv = KERN_INVALID_ADDRESS; 1666 goto done; 1667 } 1668 } 1669 if (entry == first_entry) 1670 first_entry = tmp_entry; 1671 else 1672 first_entry = NULL; 1673 entry = tmp_entry; 1674 } 1675 last_timestamp = map->timestamp; 1676 continue; 1677 } 1678 vm_map_clip_start(map, entry, start); 1679 vm_map_clip_end(map, entry, end); 1680 /* 1681 * Mark the entry in case the map lock is released. (See 1682 * above.) 1683 */ 1684 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1685 /* 1686 * Check the map for holes in the specified region. 1687 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 1688 */ 1689 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 1690 (entry->end < end && (entry->next == &map->header || 1691 entry->next->start > entry->end))) { 1692 end = entry->end; 1693 rv = KERN_INVALID_ADDRESS; 1694 goto done; 1695 } 1696 /* 1697 * Require that the entry is wired. 1698 */ 1699 if (entry->wired_count == 0 || (user_unwire && 1700 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0)) { 1701 end = entry->end; 1702 rv = KERN_INVALID_ARGUMENT; 1703 goto done; 1704 } 1705 entry = entry->next; 1706 } 1707 rv = KERN_SUCCESS; 1708 done: 1709 need_wakeup = FALSE; 1710 if (first_entry == NULL) { 1711 result = vm_map_lookup_entry(map, start, &first_entry); 1712 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 1713 first_entry = first_entry->next; 1714 else 1715 KASSERT(result, ("vm_map_unwire: lookup failed")); 1716 } 1717 entry = first_entry; 1718 while (entry != &map->header && entry->start < end) { 1719 if (rv == KERN_SUCCESS) { 1720 if (user_unwire) 1721 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 1722 entry->wired_count--; 1723 if (entry->wired_count == 0) { 1724 /* 1725 * Retain the map lock. 1726 */ 1727 vm_fault_unwire(map, entry->start, entry->end); 1728 } 1729 } 1730 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1731 ("vm_map_unwire: in-transition flag missing")); 1732 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1733 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1734 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1735 need_wakeup = TRUE; 1736 } 1737 vm_map_simplify_entry(map, entry); 1738 entry = entry->next; 1739 } 1740 vm_map_unlock(map); 1741 if (need_wakeup) 1742 vm_map_wakeup(map); 1743 return (rv); 1744 } 1745 1746 /* 1747 * vm_map_wire: 1748 * 1749 * Implements both kernel and user wiring. 1750 */ 1751 int 1752 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 1753 int flags) 1754 { 1755 vm_map_entry_t entry, first_entry, tmp_entry; 1756 vm_offset_t saved_end, saved_start; 1757 unsigned int last_timestamp; 1758 int rv; 1759 boolean_t need_wakeup, result, user_wire; 1760 1761 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 1762 vm_map_lock(map); 1763 VM_MAP_RANGE_CHECK(map, start, end); 1764 if (!vm_map_lookup_entry(map, start, &first_entry)) { 1765 if (flags & VM_MAP_WIRE_HOLESOK) 1766 first_entry = first_entry->next; 1767 else { 1768 vm_map_unlock(map); 1769 return (KERN_INVALID_ADDRESS); 1770 } 1771 } 1772 last_timestamp = map->timestamp; 1773 entry = first_entry; 1774 while (entry != &map->header && entry->start < end) { 1775 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1776 /* 1777 * We have not yet clipped the entry. 1778 */ 1779 saved_start = (start >= entry->start) ? start : 1780 entry->start; 1781 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1782 if (vm_map_unlock_and_wait(map, user_wire)) { 1783 /* 1784 * Allow interruption of user wiring? 1785 */ 1786 } 1787 vm_map_lock(map); 1788 if (last_timestamp + 1 != map->timestamp) { 1789 /* 1790 * Look again for the entry because the map was 1791 * modified while it was unlocked. 1792 * Specifically, the entry may have been 1793 * clipped, merged, or deleted. 1794 */ 1795 if (!vm_map_lookup_entry(map, saved_start, 1796 &tmp_entry)) { 1797 if (flags & VM_MAP_WIRE_HOLESOK) 1798 tmp_entry = tmp_entry->next; 1799 else { 1800 if (saved_start == start) { 1801 /* 1802 * first_entry has been deleted. 1803 */ 1804 vm_map_unlock(map); 1805 return (KERN_INVALID_ADDRESS); 1806 } 1807 end = saved_start; 1808 rv = KERN_INVALID_ADDRESS; 1809 goto done; 1810 } 1811 } 1812 if (entry == first_entry) 1813 first_entry = tmp_entry; 1814 else 1815 first_entry = NULL; 1816 entry = tmp_entry; 1817 } 1818 last_timestamp = map->timestamp; 1819 continue; 1820 } 1821 vm_map_clip_start(map, entry, start); 1822 vm_map_clip_end(map, entry, end); 1823 /* 1824 * Mark the entry in case the map lock is released. (See 1825 * above.) 1826 */ 1827 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1828 /* 1829 * 1830 */ 1831 if (entry->wired_count == 0) { 1832 entry->wired_count++; 1833 saved_start = entry->start; 1834 saved_end = entry->end; 1835 /* 1836 * Release the map lock, relying on the in-transition 1837 * mark. 1838 */ 1839 vm_map_unlock(map); 1840 rv = vm_fault_wire(map, saved_start, saved_end, 1841 user_wire); 1842 vm_map_lock(map); 1843 if (last_timestamp + 1 != map->timestamp) { 1844 /* 1845 * Look again for the entry because the map was 1846 * modified while it was unlocked. The entry 1847 * may have been clipped, but NOT merged or 1848 * deleted. 1849 */ 1850 result = vm_map_lookup_entry(map, saved_start, 1851 &tmp_entry); 1852 KASSERT(result, ("vm_map_wire: lookup failed")); 1853 if (entry == first_entry) 1854 first_entry = tmp_entry; 1855 else 1856 first_entry = NULL; 1857 entry = tmp_entry; 1858 while (entry->end < saved_end) { 1859 if (rv != KERN_SUCCESS) { 1860 KASSERT(entry->wired_count == 1, 1861 ("vm_map_wire: bad count")); 1862 entry->wired_count = -1; 1863 } 1864 entry = entry->next; 1865 } 1866 } 1867 last_timestamp = map->timestamp; 1868 if (rv != KERN_SUCCESS) { 1869 KASSERT(entry->wired_count == 1, 1870 ("vm_map_wire: bad count")); 1871 /* 1872 * Assign an out-of-range value to represent 1873 * the failure to wire this entry. 1874 */ 1875 entry->wired_count = -1; 1876 end = entry->end; 1877 goto done; 1878 } 1879 } else if (!user_wire || 1880 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 1881 entry->wired_count++; 1882 } 1883 /* 1884 * Check the map for holes in the specified region. 1885 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 1886 */ 1887 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 1888 (entry->end < end && (entry->next == &map->header || 1889 entry->next->start > entry->end))) { 1890 end = entry->end; 1891 rv = KERN_INVALID_ADDRESS; 1892 goto done; 1893 } 1894 entry = entry->next; 1895 } 1896 rv = KERN_SUCCESS; 1897 done: 1898 need_wakeup = FALSE; 1899 if (first_entry == NULL) { 1900 result = vm_map_lookup_entry(map, start, &first_entry); 1901 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 1902 first_entry = first_entry->next; 1903 else 1904 KASSERT(result, ("vm_map_wire: lookup failed")); 1905 } 1906 entry = first_entry; 1907 while (entry != &map->header && entry->start < end) { 1908 if (rv == KERN_SUCCESS) { 1909 if (user_wire) 1910 entry->eflags |= MAP_ENTRY_USER_WIRED; 1911 } else if (entry->wired_count == -1) { 1912 /* 1913 * Wiring failed on this entry. Thus, unwiring is 1914 * unnecessary. 1915 */ 1916 entry->wired_count = 0; 1917 } else { 1918 if (!user_wire || 1919 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) 1920 entry->wired_count--; 1921 if (entry->wired_count == 0) { 1922 /* 1923 * Retain the map lock. 1924 */ 1925 vm_fault_unwire(map, entry->start, entry->end); 1926 } 1927 } 1928 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1929 ("vm_map_wire: in-transition flag missing")); 1930 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1931 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1932 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1933 need_wakeup = TRUE; 1934 } 1935 vm_map_simplify_entry(map, entry); 1936 entry = entry->next; 1937 } 1938 vm_map_unlock(map); 1939 if (need_wakeup) 1940 vm_map_wakeup(map); 1941 return (rv); 1942 } 1943 1944 /* 1945 * vm_map_sync 1946 * 1947 * Push any dirty cached pages in the address range to their pager. 1948 * If syncio is TRUE, dirty pages are written synchronously. 1949 * If invalidate is TRUE, any cached pages are freed as well. 1950 * 1951 * If the size of the region from start to end is zero, we are 1952 * supposed to flush all modified pages within the region containing 1953 * start. Unfortunately, a region can be split or coalesced with 1954 * neighboring regions, making it difficult to determine what the 1955 * original region was. Therefore, we approximate this requirement by 1956 * flushing the current region containing start. 1957 * 1958 * Returns an error if any part of the specified range is not mapped. 1959 */ 1960 int 1961 vm_map_sync( 1962 vm_map_t map, 1963 vm_offset_t start, 1964 vm_offset_t end, 1965 boolean_t syncio, 1966 boolean_t invalidate) 1967 { 1968 vm_map_entry_t current; 1969 vm_map_entry_t entry; 1970 vm_size_t size; 1971 vm_object_t object; 1972 vm_ooffset_t offset; 1973 1974 vm_map_lock_read(map); 1975 VM_MAP_RANGE_CHECK(map, start, end); 1976 if (!vm_map_lookup_entry(map, start, &entry)) { 1977 vm_map_unlock_read(map); 1978 return (KERN_INVALID_ADDRESS); 1979 } else if (start == end) { 1980 start = entry->start; 1981 end = entry->end; 1982 } 1983 /* 1984 * Make a first pass to check for user-wired memory and holes. 1985 */ 1986 for (current = entry; current->start < end; current = current->next) { 1987 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 1988 vm_map_unlock_read(map); 1989 return (KERN_INVALID_ARGUMENT); 1990 } 1991 if (end > current->end && 1992 (current->next == &map->header || 1993 current->end != current->next->start)) { 1994 vm_map_unlock_read(map); 1995 return (KERN_INVALID_ADDRESS); 1996 } 1997 } 1998 1999 if (invalidate) { 2000 mtx_lock(&Giant); 2001 vm_page_lock_queues(); 2002 pmap_remove(map->pmap, start, end); 2003 vm_page_unlock_queues(); 2004 mtx_unlock(&Giant); 2005 } 2006 /* 2007 * Make a second pass, cleaning/uncaching pages from the indicated 2008 * objects as we go. 2009 */ 2010 for (current = entry; current->start < end; current = current->next) { 2011 offset = current->offset + (start - current->start); 2012 size = (end <= current->end ? end : current->end) - start; 2013 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2014 vm_map_t smap; 2015 vm_map_entry_t tentry; 2016 vm_size_t tsize; 2017 2018 smap = current->object.sub_map; 2019 vm_map_lock_read(smap); 2020 (void) vm_map_lookup_entry(smap, offset, &tentry); 2021 tsize = tentry->end - offset; 2022 if (tsize < size) 2023 size = tsize; 2024 object = tentry->object.vm_object; 2025 offset = tentry->offset + (offset - tentry->start); 2026 vm_map_unlock_read(smap); 2027 } else { 2028 object = current->object.vm_object; 2029 } 2030 vm_object_sync(object, offset, size, syncio, invalidate); 2031 start += size; 2032 } 2033 2034 vm_map_unlock_read(map); 2035 return (KERN_SUCCESS); 2036 } 2037 2038 /* 2039 * vm_map_entry_unwire: [ internal use only ] 2040 * 2041 * Make the region specified by this entry pageable. 2042 * 2043 * The map in question should be locked. 2044 * [This is the reason for this routine's existence.] 2045 */ 2046 static void 2047 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2048 { 2049 vm_fault_unwire(map, entry->start, entry->end); 2050 entry->wired_count = 0; 2051 } 2052 2053 /* 2054 * vm_map_entry_delete: [ internal use only ] 2055 * 2056 * Deallocate the given entry from the target map. 2057 */ 2058 static void 2059 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2060 { 2061 vm_object_t object; 2062 vm_pindex_t offidxstart, offidxend, count; 2063 2064 vm_map_entry_unlink(map, entry); 2065 map->size -= entry->end - entry->start; 2066 2067 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2068 (object = entry->object.vm_object) != NULL) { 2069 count = OFF_TO_IDX(entry->end - entry->start); 2070 offidxstart = OFF_TO_IDX(entry->offset); 2071 offidxend = offidxstart + count; 2072 VM_OBJECT_LOCK(object); 2073 if (object->ref_count != 1 && 2074 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2075 object == kernel_object || object == kmem_object) && 2076 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2077 vm_object_collapse(object); 2078 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2079 if (object->type == OBJT_SWAP) 2080 swap_pager_freespace(object, offidxstart, count); 2081 if (offidxend >= object->size && 2082 offidxstart < object->size) 2083 object->size = offidxstart; 2084 } 2085 VM_OBJECT_UNLOCK(object); 2086 vm_object_deallocate(object); 2087 } 2088 2089 vm_map_entry_dispose(map, entry); 2090 } 2091 2092 /* 2093 * vm_map_delete: [ internal use only ] 2094 * 2095 * Deallocates the given address range from the target 2096 * map. 2097 */ 2098 int 2099 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2100 { 2101 vm_map_entry_t entry; 2102 vm_map_entry_t first_entry; 2103 2104 /* 2105 * Find the start of the region, and clip it 2106 */ 2107 if (!vm_map_lookup_entry(map, start, &first_entry)) 2108 entry = first_entry->next; 2109 else { 2110 entry = first_entry; 2111 vm_map_clip_start(map, entry, start); 2112 } 2113 2114 /* 2115 * Save the free space hint 2116 */ 2117 if (entry == &map->header) { 2118 map->first_free = &map->header; 2119 } else if (map->first_free->start >= start) { 2120 map->first_free = entry->prev; 2121 } 2122 2123 /* 2124 * Step through all entries in this region 2125 */ 2126 while ((entry != &map->header) && (entry->start < end)) { 2127 vm_map_entry_t next; 2128 2129 /* 2130 * Wait for wiring or unwiring of an entry to complete. 2131 */ 2132 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0) { 2133 unsigned int last_timestamp; 2134 vm_offset_t saved_start; 2135 vm_map_entry_t tmp_entry; 2136 2137 saved_start = entry->start; 2138 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2139 last_timestamp = map->timestamp; 2140 (void) vm_map_unlock_and_wait(map, FALSE); 2141 vm_map_lock(map); 2142 if (last_timestamp + 1 != map->timestamp) { 2143 /* 2144 * Look again for the entry because the map was 2145 * modified while it was unlocked. 2146 * Specifically, the entry may have been 2147 * clipped, merged, or deleted. 2148 */ 2149 if (!vm_map_lookup_entry(map, saved_start, 2150 &tmp_entry)) 2151 entry = tmp_entry->next; 2152 else { 2153 entry = tmp_entry; 2154 vm_map_clip_start(map, entry, 2155 saved_start); 2156 } 2157 } 2158 continue; 2159 } 2160 vm_map_clip_end(map, entry, end); 2161 2162 next = entry->next; 2163 2164 /* 2165 * Unwire before removing addresses from the pmap; otherwise, 2166 * unwiring will put the entries back in the pmap. 2167 */ 2168 if (entry->wired_count != 0) { 2169 vm_map_entry_unwire(map, entry); 2170 } 2171 2172 if (!map->system_map) 2173 mtx_lock(&Giant); 2174 vm_page_lock_queues(); 2175 pmap_remove(map->pmap, entry->start, entry->end); 2176 vm_page_unlock_queues(); 2177 if (!map->system_map) 2178 mtx_unlock(&Giant); 2179 2180 /* 2181 * Delete the entry (which may delete the object) only after 2182 * removing all pmap entries pointing to its pages. 2183 * (Otherwise, its page frames may be reallocated, and any 2184 * modify bits will be set in the wrong object!) 2185 */ 2186 vm_map_entry_delete(map, entry); 2187 entry = next; 2188 } 2189 return (KERN_SUCCESS); 2190 } 2191 2192 /* 2193 * vm_map_remove: 2194 * 2195 * Remove the given address range from the target map. 2196 * This is the exported form of vm_map_delete. 2197 */ 2198 int 2199 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2200 { 2201 int result, s = 0; 2202 2203 if (map == kmem_map) 2204 s = splvm(); 2205 2206 vm_map_lock(map); 2207 VM_MAP_RANGE_CHECK(map, start, end); 2208 result = vm_map_delete(map, start, end); 2209 vm_map_unlock(map); 2210 2211 if (map == kmem_map) 2212 splx(s); 2213 2214 return (result); 2215 } 2216 2217 /* 2218 * vm_map_check_protection: 2219 * 2220 * Assert that the target map allows the specified privilege on the 2221 * entire address region given. The entire region must be allocated. 2222 * 2223 * WARNING! This code does not and should not check whether the 2224 * contents of the region is accessible. For example a smaller file 2225 * might be mapped into a larger address space. 2226 * 2227 * NOTE! This code is also called by munmap(). 2228 * 2229 * The map must be locked. A read lock is sufficient. 2230 */ 2231 boolean_t 2232 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2233 vm_prot_t protection) 2234 { 2235 vm_map_entry_t entry; 2236 vm_map_entry_t tmp_entry; 2237 2238 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 2239 return (FALSE); 2240 entry = tmp_entry; 2241 2242 while (start < end) { 2243 if (entry == &map->header) 2244 return (FALSE); 2245 /* 2246 * No holes allowed! 2247 */ 2248 if (start < entry->start) 2249 return (FALSE); 2250 /* 2251 * Check protection associated with entry. 2252 */ 2253 if ((entry->protection & protection) != protection) 2254 return (FALSE); 2255 /* go to next entry */ 2256 start = entry->end; 2257 entry = entry->next; 2258 } 2259 return (TRUE); 2260 } 2261 2262 /* 2263 * vm_map_copy_entry: 2264 * 2265 * Copies the contents of the source entry to the destination 2266 * entry. The entries *must* be aligned properly. 2267 */ 2268 static void 2269 vm_map_copy_entry( 2270 vm_map_t src_map, 2271 vm_map_t dst_map, 2272 vm_map_entry_t src_entry, 2273 vm_map_entry_t dst_entry) 2274 { 2275 vm_object_t src_object; 2276 2277 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 2278 return; 2279 2280 if (src_entry->wired_count == 0) { 2281 2282 /* 2283 * If the source entry is marked needs_copy, it is already 2284 * write-protected. 2285 */ 2286 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 2287 vm_page_lock_queues(); 2288 pmap_protect(src_map->pmap, 2289 src_entry->start, 2290 src_entry->end, 2291 src_entry->protection & ~VM_PROT_WRITE); 2292 vm_page_unlock_queues(); 2293 } 2294 2295 /* 2296 * Make a copy of the object. 2297 */ 2298 if ((src_object = src_entry->object.vm_object) != NULL) { 2299 VM_OBJECT_LOCK(src_object); 2300 if ((src_object->handle == NULL) && 2301 (src_object->type == OBJT_DEFAULT || 2302 src_object->type == OBJT_SWAP)) { 2303 vm_object_collapse(src_object); 2304 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 2305 vm_object_split(src_entry); 2306 src_object = src_entry->object.vm_object; 2307 } 2308 } 2309 vm_object_reference_locked(src_object); 2310 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 2311 VM_OBJECT_UNLOCK(src_object); 2312 dst_entry->object.vm_object = src_object; 2313 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2314 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2315 dst_entry->offset = src_entry->offset; 2316 } else { 2317 dst_entry->object.vm_object = NULL; 2318 dst_entry->offset = 0; 2319 } 2320 2321 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 2322 dst_entry->end - dst_entry->start, src_entry->start); 2323 } else { 2324 /* 2325 * Of course, wired down pages can't be set copy-on-write. 2326 * Cause wired pages to be copied into the new map by 2327 * simulating faults (the new pages are pageable) 2328 */ 2329 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 2330 } 2331 } 2332 2333 /* 2334 * vmspace_fork: 2335 * Create a new process vmspace structure and vm_map 2336 * based on those of an existing process. The new map 2337 * is based on the old map, according to the inheritance 2338 * values on the regions in that map. 2339 * 2340 * The source map must not be locked. 2341 */ 2342 struct vmspace * 2343 vmspace_fork(struct vmspace *vm1) 2344 { 2345 struct vmspace *vm2; 2346 vm_map_t old_map = &vm1->vm_map; 2347 vm_map_t new_map; 2348 vm_map_entry_t old_entry; 2349 vm_map_entry_t new_entry; 2350 vm_object_t object; 2351 2352 GIANT_REQUIRED; 2353 2354 vm_map_lock(old_map); 2355 old_map->infork = 1; 2356 2357 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 2358 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 2359 (caddr_t) &vm1->vm_endcopy - (caddr_t) &vm1->vm_startcopy); 2360 new_map = &vm2->vm_map; /* XXX */ 2361 new_map->timestamp = 1; 2362 2363 /* Do not inherit the MAP_WIREFUTURE property. */ 2364 if ((new_map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) 2365 new_map->flags &= ~MAP_WIREFUTURE; 2366 2367 old_entry = old_map->header.next; 2368 2369 while (old_entry != &old_map->header) { 2370 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 2371 panic("vm_map_fork: encountered a submap"); 2372 2373 switch (old_entry->inheritance) { 2374 case VM_INHERIT_NONE: 2375 break; 2376 2377 case VM_INHERIT_SHARE: 2378 /* 2379 * Clone the entry, creating the shared object if necessary. 2380 */ 2381 object = old_entry->object.vm_object; 2382 if (object == NULL) { 2383 object = vm_object_allocate(OBJT_DEFAULT, 2384 atop(old_entry->end - old_entry->start)); 2385 old_entry->object.vm_object = object; 2386 old_entry->offset = (vm_offset_t) 0; 2387 } 2388 2389 /* 2390 * Add the reference before calling vm_object_shadow 2391 * to insure that a shadow object is created. 2392 */ 2393 vm_object_reference(object); 2394 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 2395 vm_object_shadow(&old_entry->object.vm_object, 2396 &old_entry->offset, 2397 atop(old_entry->end - old_entry->start)); 2398 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 2399 /* Transfer the second reference too. */ 2400 vm_object_reference( 2401 old_entry->object.vm_object); 2402 vm_object_deallocate(object); 2403 object = old_entry->object.vm_object; 2404 } 2405 VM_OBJECT_LOCK(object); 2406 vm_object_clear_flag(object, OBJ_ONEMAPPING); 2407 VM_OBJECT_UNLOCK(object); 2408 2409 /* 2410 * Clone the entry, referencing the shared object. 2411 */ 2412 new_entry = vm_map_entry_create(new_map); 2413 *new_entry = *old_entry; 2414 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2415 new_entry->wired_count = 0; 2416 2417 /* 2418 * Insert the entry into the new map -- we know we're 2419 * inserting at the end of the new map. 2420 */ 2421 vm_map_entry_link(new_map, new_map->header.prev, 2422 new_entry); 2423 2424 /* 2425 * Update the physical map 2426 */ 2427 pmap_copy(new_map->pmap, old_map->pmap, 2428 new_entry->start, 2429 (old_entry->end - old_entry->start), 2430 old_entry->start); 2431 break; 2432 2433 case VM_INHERIT_COPY: 2434 /* 2435 * Clone the entry and link into the map. 2436 */ 2437 new_entry = vm_map_entry_create(new_map); 2438 *new_entry = *old_entry; 2439 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2440 new_entry->wired_count = 0; 2441 new_entry->object.vm_object = NULL; 2442 vm_map_entry_link(new_map, new_map->header.prev, 2443 new_entry); 2444 vm_map_copy_entry(old_map, new_map, old_entry, 2445 new_entry); 2446 break; 2447 } 2448 old_entry = old_entry->next; 2449 } 2450 2451 new_map->size = old_map->size; 2452 old_map->infork = 0; 2453 vm_map_unlock(old_map); 2454 2455 return (vm2); 2456 } 2457 2458 int 2459 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 2460 vm_prot_t prot, vm_prot_t max, int cow) 2461 { 2462 vm_map_entry_t new_entry, prev_entry; 2463 vm_offset_t bot, top; 2464 vm_size_t init_ssize; 2465 int orient, rv; 2466 rlim_t vmemlim; 2467 2468 /* 2469 * The stack orientation is piggybacked with the cow argument. 2470 * Extract it into orient and mask the cow argument so that we 2471 * don't pass it around further. 2472 * NOTE: We explicitly allow bi-directional stacks. 2473 */ 2474 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 2475 cow &= ~orient; 2476 KASSERT(orient != 0, ("No stack grow direction")); 2477 2478 if (addrbos < vm_map_min(map) || addrbos > map->max_offset) 2479 return (KERN_NO_SPACE); 2480 2481 init_ssize = (max_ssize < sgrowsiz) ? max_ssize : sgrowsiz; 2482 2483 PROC_LOCK(curthread->td_proc); 2484 vmemlim = lim_cur(curthread->td_proc, RLIMIT_VMEM); 2485 PROC_UNLOCK(curthread->td_proc); 2486 2487 vm_map_lock(map); 2488 2489 /* If addr is already mapped, no go */ 2490 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 2491 vm_map_unlock(map); 2492 return (KERN_NO_SPACE); 2493 } 2494 2495 /* If we would blow our VMEM resource limit, no go */ 2496 if (map->size + init_ssize > vmemlim) { 2497 vm_map_unlock(map); 2498 return (KERN_NO_SPACE); 2499 } 2500 2501 /* 2502 * If we can't accomodate max_ssize in the current mapping, no go. 2503 * However, we need to be aware that subsequent user mappings might 2504 * map into the space we have reserved for stack, and currently this 2505 * space is not protected. 2506 * 2507 * Hopefully we will at least detect this condition when we try to 2508 * grow the stack. 2509 */ 2510 if ((prev_entry->next != &map->header) && 2511 (prev_entry->next->start < addrbos + max_ssize)) { 2512 vm_map_unlock(map); 2513 return (KERN_NO_SPACE); 2514 } 2515 2516 /* 2517 * We initially map a stack of only init_ssize. We will grow as 2518 * needed later. Depending on the orientation of the stack (i.e. 2519 * the grow direction) we either map at the top of the range, the 2520 * bottom of the range or in the middle. 2521 * 2522 * Note: we would normally expect prot and max to be VM_PROT_ALL, 2523 * and cow to be 0. Possibly we should eliminate these as input 2524 * parameters, and just pass these values here in the insert call. 2525 */ 2526 if (orient == MAP_STACK_GROWS_DOWN) 2527 bot = addrbos + max_ssize - init_ssize; 2528 else if (orient == MAP_STACK_GROWS_UP) 2529 bot = addrbos; 2530 else 2531 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 2532 top = bot + init_ssize; 2533 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 2534 2535 /* Now set the avail_ssize amount. */ 2536 if (rv == KERN_SUCCESS) { 2537 if (prev_entry != &map->header) 2538 vm_map_clip_end(map, prev_entry, bot); 2539 new_entry = prev_entry->next; 2540 if (new_entry->end != top || new_entry->start != bot) 2541 panic("Bad entry start/end for new stack entry"); 2542 2543 new_entry->avail_ssize = max_ssize - init_ssize; 2544 if (orient & MAP_STACK_GROWS_DOWN) 2545 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 2546 if (orient & MAP_STACK_GROWS_UP) 2547 new_entry->eflags |= MAP_ENTRY_GROWS_UP; 2548 } 2549 2550 vm_map_unlock(map); 2551 return (rv); 2552 } 2553 2554 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 2555 * desired address is already mapped, or if we successfully grow 2556 * the stack. Also returns KERN_SUCCESS if addr is outside the 2557 * stack range (this is strange, but preserves compatibility with 2558 * the grow function in vm_machdep.c). 2559 */ 2560 int 2561 vm_map_growstack(struct proc *p, vm_offset_t addr) 2562 { 2563 vm_map_entry_t next_entry, prev_entry; 2564 vm_map_entry_t new_entry, stack_entry; 2565 struct vmspace *vm = p->p_vmspace; 2566 vm_map_t map = &vm->vm_map; 2567 vm_offset_t end; 2568 size_t grow_amount, max_grow; 2569 rlim_t stacklim, vmemlim; 2570 int is_procstack, rv; 2571 2572 Retry: 2573 PROC_LOCK(p); 2574 stacklim = lim_cur(p, RLIMIT_STACK); 2575 vmemlim = lim_cur(p, RLIMIT_VMEM); 2576 PROC_UNLOCK(p); 2577 2578 vm_map_lock_read(map); 2579 2580 /* If addr is already in the entry range, no need to grow.*/ 2581 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 2582 vm_map_unlock_read(map); 2583 return (KERN_SUCCESS); 2584 } 2585 2586 next_entry = prev_entry->next; 2587 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 2588 /* 2589 * This entry does not grow upwards. Since the address lies 2590 * beyond this entry, the next entry (if one exists) has to 2591 * be a downward growable entry. The entry list header is 2592 * never a growable entry, so it suffices to check the flags. 2593 */ 2594 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 2595 vm_map_unlock_read(map); 2596 return (KERN_SUCCESS); 2597 } 2598 stack_entry = next_entry; 2599 } else { 2600 /* 2601 * This entry grows upward. If the next entry does not at 2602 * least grow downwards, this is the entry we need to grow. 2603 * otherwise we have two possible choices and we have to 2604 * select one. 2605 */ 2606 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 2607 /* 2608 * We have two choices; grow the entry closest to 2609 * the address to minimize the amount of growth. 2610 */ 2611 if (addr - prev_entry->end <= next_entry->start - addr) 2612 stack_entry = prev_entry; 2613 else 2614 stack_entry = next_entry; 2615 } else 2616 stack_entry = prev_entry; 2617 } 2618 2619 if (stack_entry == next_entry) { 2620 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 2621 KASSERT(addr < stack_entry->start, ("foo")); 2622 end = (prev_entry != &map->header) ? prev_entry->end : 2623 stack_entry->start - stack_entry->avail_ssize; 2624 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 2625 max_grow = stack_entry->start - end; 2626 } else { 2627 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 2628 KASSERT(addr >= stack_entry->end, ("foo")); 2629 end = (next_entry != &map->header) ? next_entry->start : 2630 stack_entry->end + stack_entry->avail_ssize; 2631 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 2632 max_grow = end - stack_entry->end; 2633 } 2634 2635 if (grow_amount > stack_entry->avail_ssize) { 2636 vm_map_unlock_read(map); 2637 return (KERN_NO_SPACE); 2638 } 2639 2640 /* 2641 * If there is no longer enough space between the entries nogo, and 2642 * adjust the available space. Note: this should only happen if the 2643 * user has mapped into the stack area after the stack was created, 2644 * and is probably an error. 2645 * 2646 * This also effectively destroys any guard page the user might have 2647 * intended by limiting the stack size. 2648 */ 2649 if (grow_amount > max_grow) { 2650 if (vm_map_lock_upgrade(map)) 2651 goto Retry; 2652 2653 stack_entry->avail_ssize = max_grow; 2654 2655 vm_map_unlock(map); 2656 return (KERN_NO_SPACE); 2657 } 2658 2659 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 2660 2661 /* 2662 * If this is the main process stack, see if we're over the stack 2663 * limit. 2664 */ 2665 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 2666 vm_map_unlock_read(map); 2667 return (KERN_NO_SPACE); 2668 } 2669 2670 /* Round up the grow amount modulo SGROWSIZ */ 2671 grow_amount = roundup (grow_amount, sgrowsiz); 2672 if (grow_amount > stack_entry->avail_ssize) 2673 grow_amount = stack_entry->avail_ssize; 2674 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 2675 grow_amount = stacklim - ctob(vm->vm_ssize); 2676 } 2677 2678 /* If we would blow our VMEM resource limit, no go */ 2679 if (map->size + grow_amount > vmemlim) { 2680 vm_map_unlock_read(map); 2681 return (KERN_NO_SPACE); 2682 } 2683 2684 if (vm_map_lock_upgrade(map)) 2685 goto Retry; 2686 2687 if (stack_entry == next_entry) { 2688 /* 2689 * Growing downward. 2690 */ 2691 /* Get the preliminary new entry start value */ 2692 addr = stack_entry->start - grow_amount; 2693 2694 /* 2695 * If this puts us into the previous entry, cut back our 2696 * growth to the available space. Also, see the note above. 2697 */ 2698 if (addr < end) { 2699 stack_entry->avail_ssize = max_grow; 2700 addr = end; 2701 } 2702 2703 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 2704 p->p_sysent->sv_stackprot, VM_PROT_ALL, 0); 2705 2706 /* Adjust the available stack space by the amount we grew. */ 2707 if (rv == KERN_SUCCESS) { 2708 if (prev_entry != &map->header) 2709 vm_map_clip_end(map, prev_entry, addr); 2710 new_entry = prev_entry->next; 2711 KASSERT(new_entry == stack_entry->prev, ("foo")); 2712 KASSERT(new_entry->end == stack_entry->start, ("foo")); 2713 KASSERT(new_entry->start == addr, ("foo")); 2714 grow_amount = new_entry->end - new_entry->start; 2715 new_entry->avail_ssize = stack_entry->avail_ssize - 2716 grow_amount; 2717 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 2718 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 2719 } 2720 } else { 2721 /* 2722 * Growing upward. 2723 */ 2724 addr = stack_entry->end + grow_amount; 2725 2726 /* 2727 * If this puts us into the next entry, cut back our growth 2728 * to the available space. Also, see the note above. 2729 */ 2730 if (addr > end) { 2731 stack_entry->avail_ssize = end - stack_entry->end; 2732 addr = end; 2733 } 2734 2735 grow_amount = addr - stack_entry->end; 2736 2737 /* Grow the underlying object if applicable. */ 2738 if (stack_entry->object.vm_object == NULL || 2739 vm_object_coalesce(stack_entry->object.vm_object, 2740 OFF_TO_IDX(stack_entry->offset), 2741 (vm_size_t)(stack_entry->end - stack_entry->start), 2742 (vm_size_t)grow_amount)) { 2743 map->size += (addr - stack_entry->end); 2744 /* Update the current entry. */ 2745 stack_entry->end = addr; 2746 stack_entry->avail_ssize -= grow_amount; 2747 rv = KERN_SUCCESS; 2748 2749 if (next_entry != &map->header) 2750 vm_map_clip_start(map, next_entry, addr); 2751 } else 2752 rv = KERN_FAILURE; 2753 } 2754 2755 if (rv == KERN_SUCCESS && is_procstack) 2756 vm->vm_ssize += btoc(grow_amount); 2757 2758 vm_map_unlock(map); 2759 2760 /* 2761 * Heed the MAP_WIREFUTURE flag if it was set for this process. 2762 */ 2763 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 2764 vm_map_wire(map, 2765 (stack_entry == next_entry) ? addr : addr - grow_amount, 2766 (stack_entry == next_entry) ? stack_entry->start : addr, 2767 (p->p_flag & P_SYSTEM) 2768 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 2769 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 2770 } 2771 2772 return (rv); 2773 } 2774 2775 /* 2776 * Unshare the specified VM space for exec. If other processes are 2777 * mapped to it, then create a new one. The new vmspace is null. 2778 */ 2779 void 2780 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 2781 { 2782 struct vmspace *oldvmspace = p->p_vmspace; 2783 struct vmspace *newvmspace; 2784 2785 GIANT_REQUIRED; 2786 newvmspace = vmspace_alloc(minuser, maxuser); 2787 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 2788 (caddr_t) &newvmspace->vm_endcopy - 2789 (caddr_t) &newvmspace->vm_startcopy); 2790 /* 2791 * This code is written like this for prototype purposes. The 2792 * goal is to avoid running down the vmspace here, but let the 2793 * other process's that are still using the vmspace to finally 2794 * run it down. Even though there is little or no chance of blocking 2795 * here, it is a good idea to keep this form for future mods. 2796 */ 2797 p->p_vmspace = newvmspace; 2798 if (p == curthread->td_proc) /* XXXKSE ? */ 2799 pmap_activate(curthread); 2800 vmspace_free(oldvmspace); 2801 } 2802 2803 /* 2804 * Unshare the specified VM space for forcing COW. This 2805 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 2806 */ 2807 void 2808 vmspace_unshare(struct proc *p) 2809 { 2810 struct vmspace *oldvmspace = p->p_vmspace; 2811 struct vmspace *newvmspace; 2812 2813 GIANT_REQUIRED; 2814 if (oldvmspace->vm_refcnt == 1) 2815 return; 2816 newvmspace = vmspace_fork(oldvmspace); 2817 p->p_vmspace = newvmspace; 2818 if (p == curthread->td_proc) /* XXXKSE ? */ 2819 pmap_activate(curthread); 2820 vmspace_free(oldvmspace); 2821 } 2822 2823 /* 2824 * vm_map_lookup: 2825 * 2826 * Finds the VM object, offset, and 2827 * protection for a given virtual address in the 2828 * specified map, assuming a page fault of the 2829 * type specified. 2830 * 2831 * Leaves the map in question locked for read; return 2832 * values are guaranteed until a vm_map_lookup_done 2833 * call is performed. Note that the map argument 2834 * is in/out; the returned map must be used in 2835 * the call to vm_map_lookup_done. 2836 * 2837 * A handle (out_entry) is returned for use in 2838 * vm_map_lookup_done, to make that fast. 2839 * 2840 * If a lookup is requested with "write protection" 2841 * specified, the map may be changed to perform virtual 2842 * copying operations, although the data referenced will 2843 * remain the same. 2844 */ 2845 int 2846 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 2847 vm_offset_t vaddr, 2848 vm_prot_t fault_typea, 2849 vm_map_entry_t *out_entry, /* OUT */ 2850 vm_object_t *object, /* OUT */ 2851 vm_pindex_t *pindex, /* OUT */ 2852 vm_prot_t *out_prot, /* OUT */ 2853 boolean_t *wired) /* OUT */ 2854 { 2855 vm_map_entry_t entry; 2856 vm_map_t map = *var_map; 2857 vm_prot_t prot; 2858 vm_prot_t fault_type = fault_typea; 2859 2860 RetryLookup:; 2861 /* 2862 * Lookup the faulting address. 2863 */ 2864 2865 vm_map_lock_read(map); 2866 #define RETURN(why) \ 2867 { \ 2868 vm_map_unlock_read(map); \ 2869 return (why); \ 2870 } 2871 2872 /* 2873 * If the map has an interesting hint, try it before calling full 2874 * blown lookup routine. 2875 */ 2876 entry = map->root; 2877 *out_entry = entry; 2878 if (entry == NULL || 2879 (vaddr < entry->start) || (vaddr >= entry->end)) { 2880 /* 2881 * Entry was either not a valid hint, or the vaddr was not 2882 * contained in the entry, so do a full lookup. 2883 */ 2884 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 2885 RETURN(KERN_INVALID_ADDRESS); 2886 2887 entry = *out_entry; 2888 } 2889 2890 /* 2891 * Handle submaps. 2892 */ 2893 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2894 vm_map_t old_map = map; 2895 2896 *var_map = map = entry->object.sub_map; 2897 vm_map_unlock_read(old_map); 2898 goto RetryLookup; 2899 } 2900 2901 /* 2902 * Check whether this task is allowed to have this page. 2903 * Note the special case for MAP_ENTRY_COW 2904 * pages with an override. This is to implement a forced 2905 * COW for debuggers. 2906 */ 2907 if (fault_type & VM_PROT_OVERRIDE_WRITE) 2908 prot = entry->max_protection; 2909 else 2910 prot = entry->protection; 2911 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 2912 if ((fault_type & prot) != fault_type) { 2913 RETURN(KERN_PROTECTION_FAILURE); 2914 } 2915 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 2916 (entry->eflags & MAP_ENTRY_COW) && 2917 (fault_type & VM_PROT_WRITE) && 2918 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 2919 RETURN(KERN_PROTECTION_FAILURE); 2920 } 2921 2922 /* 2923 * If this page is not pageable, we have to get it for all possible 2924 * accesses. 2925 */ 2926 *wired = (entry->wired_count != 0); 2927 if (*wired) 2928 prot = fault_type = entry->protection; 2929 2930 /* 2931 * If the entry was copy-on-write, we either ... 2932 */ 2933 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 2934 /* 2935 * If we want to write the page, we may as well handle that 2936 * now since we've got the map locked. 2937 * 2938 * If we don't need to write the page, we just demote the 2939 * permissions allowed. 2940 */ 2941 if (fault_type & VM_PROT_WRITE) { 2942 /* 2943 * Make a new object, and place it in the object 2944 * chain. Note that no new references have appeared 2945 * -- one just moved from the map to the new 2946 * object. 2947 */ 2948 if (vm_map_lock_upgrade(map)) 2949 goto RetryLookup; 2950 2951 vm_object_shadow( 2952 &entry->object.vm_object, 2953 &entry->offset, 2954 atop(entry->end - entry->start)); 2955 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 2956 2957 vm_map_lock_downgrade(map); 2958 } else { 2959 /* 2960 * We're attempting to read a copy-on-write page -- 2961 * don't allow writes. 2962 */ 2963 prot &= ~VM_PROT_WRITE; 2964 } 2965 } 2966 2967 /* 2968 * Create an object if necessary. 2969 */ 2970 if (entry->object.vm_object == NULL && 2971 !map->system_map) { 2972 if (vm_map_lock_upgrade(map)) 2973 goto RetryLookup; 2974 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 2975 atop(entry->end - entry->start)); 2976 entry->offset = 0; 2977 vm_map_lock_downgrade(map); 2978 } 2979 2980 /* 2981 * Return the object/offset from this entry. If the entry was 2982 * copy-on-write or empty, it has been fixed up. 2983 */ 2984 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 2985 *object = entry->object.vm_object; 2986 2987 /* 2988 * Return whether this is the only map sharing this data. 2989 */ 2990 *out_prot = prot; 2991 return (KERN_SUCCESS); 2992 2993 #undef RETURN 2994 } 2995 2996 /* 2997 * vm_map_lookup_done: 2998 * 2999 * Releases locks acquired by a vm_map_lookup 3000 * (according to the handle returned by that lookup). 3001 */ 3002 void 3003 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 3004 { 3005 /* 3006 * Unlock the main-level map 3007 */ 3008 vm_map_unlock_read(map); 3009 } 3010 3011 #include "opt_ddb.h" 3012 #ifdef DDB 3013 #include <sys/kernel.h> 3014 3015 #include <ddb/ddb.h> 3016 3017 /* 3018 * vm_map_print: [ debug ] 3019 */ 3020 DB_SHOW_COMMAND(map, vm_map_print) 3021 { 3022 static int nlines; 3023 /* XXX convert args. */ 3024 vm_map_t map = (vm_map_t)addr; 3025 boolean_t full = have_addr; 3026 3027 vm_map_entry_t entry; 3028 3029 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 3030 (void *)map, 3031 (void *)map->pmap, map->nentries, map->timestamp); 3032 nlines++; 3033 3034 if (!full && db_indent) 3035 return; 3036 3037 db_indent += 2; 3038 for (entry = map->header.next; entry != &map->header; 3039 entry = entry->next) { 3040 db_iprintf("map entry %p: start=%p, end=%p\n", 3041 (void *)entry, (void *)entry->start, (void *)entry->end); 3042 nlines++; 3043 { 3044 static char *inheritance_name[4] = 3045 {"share", "copy", "none", "donate_copy"}; 3046 3047 db_iprintf(" prot=%x/%x/%s", 3048 entry->protection, 3049 entry->max_protection, 3050 inheritance_name[(int)(unsigned char)entry->inheritance]); 3051 if (entry->wired_count != 0) 3052 db_printf(", wired"); 3053 } 3054 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3055 db_printf(", share=%p, offset=0x%jx\n", 3056 (void *)entry->object.sub_map, 3057 (uintmax_t)entry->offset); 3058 nlines++; 3059 if ((entry->prev == &map->header) || 3060 (entry->prev->object.sub_map != 3061 entry->object.sub_map)) { 3062 db_indent += 2; 3063 vm_map_print((db_expr_t)(intptr_t) 3064 entry->object.sub_map, 3065 full, 0, (char *)0); 3066 db_indent -= 2; 3067 } 3068 } else { 3069 db_printf(", object=%p, offset=0x%jx", 3070 (void *)entry->object.vm_object, 3071 (uintmax_t)entry->offset); 3072 if (entry->eflags & MAP_ENTRY_COW) 3073 db_printf(", copy (%s)", 3074 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 3075 db_printf("\n"); 3076 nlines++; 3077 3078 if ((entry->prev == &map->header) || 3079 (entry->prev->object.vm_object != 3080 entry->object.vm_object)) { 3081 db_indent += 2; 3082 vm_object_print((db_expr_t)(intptr_t) 3083 entry->object.vm_object, 3084 full, 0, (char *)0); 3085 nlines += 4; 3086 db_indent -= 2; 3087 } 3088 } 3089 } 3090 db_indent -= 2; 3091 if (db_indent == 0) 3092 nlines = 0; 3093 } 3094 3095 3096 DB_SHOW_COMMAND(procvm, procvm) 3097 { 3098 struct proc *p; 3099 3100 if (have_addr) { 3101 p = (struct proc *) addr; 3102 } else { 3103 p = curproc; 3104 } 3105 3106 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 3107 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 3108 (void *)vmspace_pmap(p->p_vmspace)); 3109 3110 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 3111 } 3112 3113 #endif /* DDB */ 3114