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 65 /* 66 * Virtual memory mapping module. 67 */ 68 69 #include <sys/cdefs.h> 70 __FBSDID("$FreeBSD$"); 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/ktr.h> 75 #include <sys/lock.h> 76 #include <sys/mutex.h> 77 #include <sys/proc.h> 78 #include <sys/vmmeter.h> 79 #include <sys/mman.h> 80 #include <sys/vnode.h> 81 #include <sys/resourcevar.h> 82 #include <sys/sysent.h> 83 #include <sys/shm.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_param.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_page.h> 90 #include <vm/vm_object.h> 91 #include <vm/vm_pager.h> 92 #include <vm/vm_kern.h> 93 #include <vm/vm_extern.h> 94 #include <vm/swap_pager.h> 95 #include <vm/uma.h> 96 97 /* 98 * Virtual memory maps provide for the mapping, protection, 99 * and sharing of virtual memory objects. In addition, 100 * this module provides for an efficient virtual copy of 101 * memory from one map to another. 102 * 103 * Synchronization is required prior to most operations. 104 * 105 * Maps consist of an ordered doubly-linked list of simple 106 * entries; a single hint is used to speed up lookups. 107 * 108 * Since portions of maps are specified by start/end addresses, 109 * which may not align with existing map entries, all 110 * routines merely "clip" entries to these start/end values. 111 * [That is, an entry is split into two, bordering at a 112 * start or end value.] Note that these clippings may not 113 * always be necessary (as the two resulting entries are then 114 * not changed); however, the clipping is done for convenience. 115 * 116 * As mentioned above, virtual copy operations are performed 117 * by copying VM object references from one map to 118 * another, and then marking both regions as copy-on-write. 119 */ 120 121 /* 122 * vm_map_startup: 123 * 124 * Initialize the vm_map module. Must be called before 125 * any other vm_map routines. 126 * 127 * Map and entry structures are allocated from the general 128 * purpose memory pool with some exceptions: 129 * 130 * - The kernel map and kmem submap are allocated statically. 131 * - Kernel map entries are allocated out of a static pool. 132 * 133 * These restrictions are necessary since malloc() uses the 134 * maps and requires map entries. 135 */ 136 137 static struct mtx map_sleep_mtx; 138 static uma_zone_t mapentzone; 139 static uma_zone_t kmapentzone; 140 static uma_zone_t mapzone; 141 static uma_zone_t vmspace_zone; 142 static struct vm_object kmapentobj; 143 static void vmspace_zinit(void *mem, int size); 144 static void vmspace_zfini(void *mem, int size); 145 static void vm_map_zinit(void *mem, int size); 146 static void vm_map_zfini(void *mem, int size); 147 static void _vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max); 148 149 #ifdef INVARIANTS 150 static void vm_map_zdtor(void *mem, int size, void *arg); 151 static void vmspace_zdtor(void *mem, int size, void *arg); 152 #endif 153 154 void 155 vm_map_startup(void) 156 { 157 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 158 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 159 #ifdef INVARIANTS 160 vm_map_zdtor, 161 #else 162 NULL, 163 #endif 164 vm_map_zinit, vm_map_zfini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 165 uma_prealloc(mapzone, MAX_KMAP); 166 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 167 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 168 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 169 uma_prealloc(kmapentzone, MAX_KMAPENT); 170 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 171 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 172 uma_prealloc(mapentzone, MAX_MAPENT); 173 } 174 175 static void 176 vmspace_zfini(void *mem, int size) 177 { 178 struct vmspace *vm; 179 180 vm = (struct vmspace *)mem; 181 182 vm_map_zfini(&vm->vm_map, sizeof(vm->vm_map)); 183 } 184 185 static void 186 vmspace_zinit(void *mem, int size) 187 { 188 struct vmspace *vm; 189 190 vm = (struct vmspace *)mem; 191 192 vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map)); 193 } 194 195 static void 196 vm_map_zfini(void *mem, int size) 197 { 198 vm_map_t map; 199 200 map = (vm_map_t)mem; 201 mtx_destroy(&map->system_mtx); 202 lockdestroy(&map->lock); 203 } 204 205 static void 206 vm_map_zinit(void *mem, int size) 207 { 208 vm_map_t map; 209 210 map = (vm_map_t)mem; 211 map->nentries = 0; 212 map->size = 0; 213 map->infork = 0; 214 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 215 lockinit(&map->lock, PVM, "thrd_sleep", 0, LK_NOPAUSE); 216 } 217 218 #ifdef INVARIANTS 219 static void 220 vmspace_zdtor(void *mem, int size, void *arg) 221 { 222 struct vmspace *vm; 223 224 vm = (struct vmspace *)mem; 225 226 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 227 } 228 static void 229 vm_map_zdtor(void *mem, int size, void *arg) 230 { 231 vm_map_t map; 232 233 map = (vm_map_t)mem; 234 KASSERT(map->nentries == 0, 235 ("map %p nentries == %d on free.", 236 map, map->nentries)); 237 KASSERT(map->size == 0, 238 ("map %p size == %lu on free.", 239 map, (unsigned long)map->size)); 240 KASSERT(map->infork == 0, 241 ("map %p infork == %d on free.", 242 map, map->infork)); 243 } 244 #endif /* INVARIANTS */ 245 246 /* 247 * Allocate a vmspace structure, including a vm_map and pmap, 248 * and initialize those structures. The refcnt is set to 1. 249 * The remaining fields must be initialized by the caller. 250 */ 251 struct vmspace * 252 vmspace_alloc(min, max) 253 vm_offset_t min, max; 254 { 255 struct vmspace *vm; 256 257 vm = uma_zalloc(vmspace_zone, M_WAITOK); 258 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 259 _vm_map_init(&vm->vm_map, min, max); 260 pmap_pinit(vmspace_pmap(vm)); 261 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 262 vm->vm_refcnt = 1; 263 vm->vm_shm = NULL; 264 vm->vm_exitingcnt = 0; 265 return (vm); 266 } 267 268 void 269 vm_init2(void) 270 { 271 uma_zone_set_obj(kmapentzone, &kmapentobj, lmin(cnt.v_page_count, 272 (VM_MAX_KERNEL_ADDRESS - KERNBASE) / PAGE_SIZE) / 8); 273 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 274 #ifdef INVARIANTS 275 vmspace_zdtor, 276 #else 277 NULL, 278 #endif 279 vmspace_zinit, vmspace_zfini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 280 pmap_init2(); 281 } 282 283 static __inline void 284 vmspace_dofree(struct vmspace *vm) 285 { 286 CTR1(KTR_VM, "vmspace_free: %p", vm); 287 288 /* 289 * Make sure any SysV shm is freed, it might not have been in 290 * exit1(). 291 */ 292 shmexit(vm); 293 294 /* 295 * Lock the map, to wait out all other references to it. 296 * Delete all of the mappings and pages they hold, then call 297 * the pmap module to reclaim anything left. 298 */ 299 vm_map_lock(&vm->vm_map); 300 (void) vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 301 vm->vm_map.max_offset); 302 vm_map_unlock(&vm->vm_map); 303 304 pmap_release(vmspace_pmap(vm)); 305 uma_zfree(vmspace_zone, vm); 306 } 307 308 void 309 vmspace_free(struct vmspace *vm) 310 { 311 GIANT_REQUIRED; 312 313 if (vm->vm_refcnt == 0) 314 panic("vmspace_free: attempt to free already freed vmspace"); 315 316 if (--vm->vm_refcnt == 0 && vm->vm_exitingcnt == 0) 317 vmspace_dofree(vm); 318 } 319 320 void 321 vmspace_exitfree(struct proc *p) 322 { 323 struct vmspace *vm; 324 325 GIANT_REQUIRED; 326 vm = p->p_vmspace; 327 p->p_vmspace = NULL; 328 329 /* 330 * cleanup by parent process wait()ing on exiting child. vm_refcnt 331 * may not be 0 (e.g. fork() and child exits without exec()ing). 332 * exitingcnt may increment above 0 and drop back down to zero 333 * several times while vm_refcnt is held non-zero. vm_refcnt 334 * may also increment above 0 and drop back down to zero several 335 * times while vm_exitingcnt is held non-zero. 336 * 337 * The last wait on the exiting child's vmspace will clean up 338 * the remainder of the vmspace. 339 */ 340 if (--vm->vm_exitingcnt == 0 && vm->vm_refcnt == 0) 341 vmspace_dofree(vm); 342 } 343 344 void 345 _vm_map_lock(vm_map_t map, const char *file, int line) 346 { 347 int error; 348 349 if (map->system_map) 350 _mtx_lock_flags(&map->system_mtx, 0, file, line); 351 else { 352 error = lockmgr(&map->lock, LK_EXCLUSIVE, NULL, curthread); 353 KASSERT(error == 0, ("%s: failed to get lock", __func__)); 354 } 355 map->timestamp++; 356 } 357 358 void 359 _vm_map_unlock(vm_map_t map, const char *file, int line) 360 { 361 362 if (map->system_map) 363 _mtx_unlock_flags(&map->system_mtx, 0, file, line); 364 else 365 lockmgr(&map->lock, LK_RELEASE, NULL, curthread); 366 } 367 368 void 369 _vm_map_lock_read(vm_map_t map, const char *file, int line) 370 { 371 int error; 372 373 if (map->system_map) 374 _mtx_lock_flags(&map->system_mtx, 0, file, line); 375 else { 376 error = lockmgr(&map->lock, LK_EXCLUSIVE, NULL, curthread); 377 KASSERT(error == 0, ("%s: failed to get lock", __func__)); 378 } 379 } 380 381 void 382 _vm_map_unlock_read(vm_map_t map, const char *file, int line) 383 { 384 385 if (map->system_map) 386 _mtx_unlock_flags(&map->system_mtx, 0, file, line); 387 else 388 lockmgr(&map->lock, LK_RELEASE, NULL, curthread); 389 } 390 391 int 392 _vm_map_trylock(vm_map_t map, const char *file, int line) 393 { 394 int error; 395 396 error = map->system_map ? 397 !_mtx_trylock(&map->system_mtx, 0, file, line) : 398 lockmgr(&map->lock, LK_EXCLUSIVE | LK_NOWAIT, NULL, curthread); 399 if (error == 0) 400 map->timestamp++; 401 return (error == 0); 402 } 403 404 int 405 _vm_map_trylock_read(vm_map_t map, const char *file, int line) 406 { 407 int error; 408 409 error = map->system_map ? 410 !_mtx_trylock(&map->system_mtx, 0, file, line) : 411 lockmgr(&map->lock, LK_EXCLUSIVE | LK_NOWAIT, NULL, curthread); 412 return (error == 0); 413 } 414 415 int 416 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 417 { 418 419 if (map->system_map) { 420 #ifdef INVARIANTS 421 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 422 #endif 423 } else 424 KASSERT(lockstatus(&map->lock, curthread) == LK_EXCLUSIVE, 425 ("%s: lock not held", __func__)); 426 map->timestamp++; 427 return (0); 428 } 429 430 void 431 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 432 { 433 434 if (map->system_map) { 435 #ifdef INVARIANTS 436 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 437 #endif 438 } else 439 KASSERT(lockstatus(&map->lock, curthread) == LK_EXCLUSIVE, 440 ("%s: lock not held", __func__)); 441 } 442 443 /* 444 * vm_map_unlock_and_wait: 445 */ 446 int 447 vm_map_unlock_and_wait(vm_map_t map, boolean_t user_wait) 448 { 449 450 mtx_lock(&map_sleep_mtx); 451 vm_map_unlock(map); 452 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 0)); 453 } 454 455 /* 456 * vm_map_wakeup: 457 */ 458 void 459 vm_map_wakeup(vm_map_t map) 460 { 461 462 /* 463 * Acquire and release map_sleep_mtx to prevent a wakeup() 464 * from being performed (and lost) between the vm_map_unlock() 465 * and the msleep() in vm_map_unlock_and_wait(). 466 */ 467 mtx_lock(&map_sleep_mtx); 468 mtx_unlock(&map_sleep_mtx); 469 wakeup(&map->root); 470 } 471 472 long 473 vmspace_resident_count(struct vmspace *vmspace) 474 { 475 return pmap_resident_count(vmspace_pmap(vmspace)); 476 } 477 478 /* 479 * vm_map_create: 480 * 481 * Creates and returns a new empty VM map with 482 * the given physical map structure, and having 483 * the given lower and upper address bounds. 484 */ 485 vm_map_t 486 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 487 { 488 vm_map_t result; 489 490 result = uma_zalloc(mapzone, M_WAITOK); 491 CTR1(KTR_VM, "vm_map_create: %p", result); 492 _vm_map_init(result, min, max); 493 result->pmap = pmap; 494 return (result); 495 } 496 497 /* 498 * Initialize an existing vm_map structure 499 * such as that in the vmspace structure. 500 * The pmap is set elsewhere. 501 */ 502 static void 503 _vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max) 504 { 505 506 map->header.next = map->header.prev = &map->header; 507 map->needs_wakeup = FALSE; 508 map->system_map = 0; 509 map->min_offset = min; 510 map->max_offset = max; 511 map->first_free = &map->header; 512 map->root = NULL; 513 map->timestamp = 0; 514 } 515 516 void 517 vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max) 518 { 519 _vm_map_init(map, min, max); 520 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 521 lockinit(&map->lock, PVM, "thrd_sleep", 0, LK_NOPAUSE); 522 } 523 524 /* 525 * vm_map_entry_dispose: [ internal use only ] 526 * 527 * Inverse of vm_map_entry_create. 528 */ 529 static void 530 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 531 { 532 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 533 } 534 535 /* 536 * vm_map_entry_create: [ internal use only ] 537 * 538 * Allocates a VM map entry for insertion. 539 * No entry fields are filled in. 540 */ 541 static vm_map_entry_t 542 vm_map_entry_create(vm_map_t map) 543 { 544 vm_map_entry_t new_entry; 545 546 if (map->system_map) 547 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 548 else 549 new_entry = uma_zalloc(mapentzone, M_WAITOK); 550 if (new_entry == NULL) 551 panic("vm_map_entry_create: kernel resources exhausted"); 552 return (new_entry); 553 } 554 555 /* 556 * vm_map_entry_set_behavior: 557 * 558 * Set the expected access behavior, either normal, random, or 559 * sequential. 560 */ 561 static __inline void 562 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 563 { 564 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 565 (behavior & MAP_ENTRY_BEHAV_MASK); 566 } 567 568 /* 569 * vm_map_entry_splay: 570 * 571 * Implements Sleator and Tarjan's top-down splay algorithm. Returns 572 * the vm_map_entry containing the given address. If, however, that 573 * address is not found in the vm_map, returns a vm_map_entry that is 574 * adjacent to the address, coming before or after it. 575 */ 576 static vm_map_entry_t 577 vm_map_entry_splay(vm_offset_t address, vm_map_entry_t root) 578 { 579 struct vm_map_entry dummy; 580 vm_map_entry_t lefttreemax, righttreemin, y; 581 582 if (root == NULL) 583 return (root); 584 lefttreemax = righttreemin = &dummy; 585 for (;; root = y) { 586 if (address < root->start) { 587 if ((y = root->left) == NULL) 588 break; 589 if (address < y->start) { 590 /* Rotate right. */ 591 root->left = y->right; 592 y->right = root; 593 root = y; 594 if ((y = root->left) == NULL) 595 break; 596 } 597 /* Link into the new root's right tree. */ 598 righttreemin->left = root; 599 righttreemin = root; 600 } else if (address >= root->end) { 601 if ((y = root->right) == NULL) 602 break; 603 if (address >= y->end) { 604 /* Rotate left. */ 605 root->right = y->left; 606 y->left = root; 607 root = y; 608 if ((y = root->right) == NULL) 609 break; 610 } 611 /* Link into the new root's left tree. */ 612 lefttreemax->right = root; 613 lefttreemax = root; 614 } else 615 break; 616 } 617 /* Assemble the new root. */ 618 lefttreemax->right = root->left; 619 righttreemin->left = root->right; 620 root->left = dummy.right; 621 root->right = dummy.left; 622 return (root); 623 } 624 625 /* 626 * vm_map_entry_{un,}link: 627 * 628 * Insert/remove entries from maps. 629 */ 630 static void 631 vm_map_entry_link(vm_map_t map, 632 vm_map_entry_t after_where, 633 vm_map_entry_t entry) 634 { 635 636 CTR4(KTR_VM, 637 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 638 map->nentries, entry, after_where); 639 map->nentries++; 640 entry->prev = after_where; 641 entry->next = after_where->next; 642 entry->next->prev = entry; 643 after_where->next = entry; 644 645 if (after_where != &map->header) { 646 if (after_where != map->root) 647 vm_map_entry_splay(after_where->start, map->root); 648 entry->right = after_where->right; 649 entry->left = after_where; 650 after_where->right = NULL; 651 } else { 652 entry->right = map->root; 653 entry->left = NULL; 654 } 655 map->root = entry; 656 } 657 658 static void 659 vm_map_entry_unlink(vm_map_t map, 660 vm_map_entry_t entry) 661 { 662 vm_map_entry_t next, prev, root; 663 664 if (entry != map->root) 665 vm_map_entry_splay(entry->start, map->root); 666 if (entry->left == NULL) 667 root = entry->right; 668 else { 669 root = vm_map_entry_splay(entry->start, entry->left); 670 root->right = entry->right; 671 } 672 map->root = root; 673 674 prev = entry->prev; 675 next = entry->next; 676 next->prev = prev; 677 prev->next = next; 678 map->nentries--; 679 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 680 map->nentries, entry); 681 } 682 683 /* 684 * vm_map_lookup_entry: [ internal use only ] 685 * 686 * Finds the map entry containing (or 687 * immediately preceding) the specified address 688 * in the given map; the entry is returned 689 * in the "entry" parameter. The boolean 690 * result indicates whether the address is 691 * actually contained in the map. 692 */ 693 boolean_t 694 vm_map_lookup_entry( 695 vm_map_t map, 696 vm_offset_t address, 697 vm_map_entry_t *entry) /* OUT */ 698 { 699 vm_map_entry_t cur; 700 701 cur = vm_map_entry_splay(address, map->root); 702 if (cur == NULL) 703 *entry = &map->header; 704 else { 705 map->root = cur; 706 707 if (address >= cur->start) { 708 *entry = cur; 709 if (cur->end > address) 710 return (TRUE); 711 } else 712 *entry = cur->prev; 713 } 714 return (FALSE); 715 } 716 717 /* 718 * vm_map_insert: 719 * 720 * Inserts the given whole VM object into the target 721 * map at the specified address range. The object's 722 * size should match that of the address range. 723 * 724 * Requires that the map be locked, and leaves it so. 725 * 726 * If object is non-NULL, ref count must be bumped by caller 727 * prior to making call to account for the new entry. 728 */ 729 int 730 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 731 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 732 int cow) 733 { 734 vm_map_entry_t new_entry; 735 vm_map_entry_t prev_entry; 736 vm_map_entry_t temp_entry; 737 vm_eflags_t protoeflags; 738 739 /* 740 * Check that the start and end points are not bogus. 741 */ 742 if ((start < map->min_offset) || (end > map->max_offset) || 743 (start >= end)) 744 return (KERN_INVALID_ADDRESS); 745 746 /* 747 * Find the entry prior to the proposed starting address; if it's part 748 * of an existing entry, this range is bogus. 749 */ 750 if (vm_map_lookup_entry(map, start, &temp_entry)) 751 return (KERN_NO_SPACE); 752 753 prev_entry = temp_entry; 754 755 /* 756 * Assert that the next entry doesn't overlap the end point. 757 */ 758 if ((prev_entry->next != &map->header) && 759 (prev_entry->next->start < end)) 760 return (KERN_NO_SPACE); 761 762 protoeflags = 0; 763 764 if (cow & MAP_COPY_ON_WRITE) 765 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 766 767 if (cow & MAP_NOFAULT) { 768 protoeflags |= MAP_ENTRY_NOFAULT; 769 770 KASSERT(object == NULL, 771 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 772 } 773 if (cow & MAP_DISABLE_SYNCER) 774 protoeflags |= MAP_ENTRY_NOSYNC; 775 if (cow & MAP_DISABLE_COREDUMP) 776 protoeflags |= MAP_ENTRY_NOCOREDUMP; 777 778 if (object != NULL) { 779 /* 780 * OBJ_ONEMAPPING must be cleared unless this mapping 781 * is trivially proven to be the only mapping for any 782 * of the object's pages. (Object granularity 783 * reference counting is insufficient to recognize 784 * aliases with precision.) 785 */ 786 VM_OBJECT_LOCK(object); 787 if (object->ref_count > 1 || object->shadow_count != 0) 788 vm_object_clear_flag(object, OBJ_ONEMAPPING); 789 VM_OBJECT_UNLOCK(object); 790 } 791 else if ((prev_entry != &map->header) && 792 (prev_entry->eflags == protoeflags) && 793 (prev_entry->end == start) && 794 (prev_entry->wired_count == 0) && 795 ((prev_entry->object.vm_object == NULL) || 796 vm_object_coalesce(prev_entry->object.vm_object, 797 OFF_TO_IDX(prev_entry->offset), 798 (vm_size_t)(prev_entry->end - prev_entry->start), 799 (vm_size_t)(end - prev_entry->end)))) { 800 /* 801 * We were able to extend the object. Determine if we 802 * can extend the previous map entry to include the 803 * new range as well. 804 */ 805 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 806 (prev_entry->protection == prot) && 807 (prev_entry->max_protection == max)) { 808 map->size += (end - prev_entry->end); 809 prev_entry->end = end; 810 vm_map_simplify_entry(map, prev_entry); 811 return (KERN_SUCCESS); 812 } 813 814 /* 815 * If we can extend the object but cannot extend the 816 * map entry, we have to create a new map entry. We 817 * must bump the ref count on the extended object to 818 * account for it. object may be NULL. 819 */ 820 object = prev_entry->object.vm_object; 821 offset = prev_entry->offset + 822 (prev_entry->end - prev_entry->start); 823 vm_object_reference(object); 824 } 825 826 /* 827 * NOTE: if conditionals fail, object can be NULL here. This occurs 828 * in things like the buffer map where we manage kva but do not manage 829 * backing objects. 830 */ 831 832 /* 833 * Create a new entry 834 */ 835 new_entry = vm_map_entry_create(map); 836 new_entry->start = start; 837 new_entry->end = end; 838 839 new_entry->eflags = protoeflags; 840 new_entry->object.vm_object = object; 841 new_entry->offset = offset; 842 new_entry->avail_ssize = 0; 843 844 new_entry->inheritance = VM_INHERIT_DEFAULT; 845 new_entry->protection = prot; 846 new_entry->max_protection = max; 847 new_entry->wired_count = 0; 848 849 /* 850 * Insert the new entry into the list 851 */ 852 vm_map_entry_link(map, prev_entry, new_entry); 853 map->size += new_entry->end - new_entry->start; 854 855 /* 856 * Update the free space hint 857 */ 858 if ((map->first_free == prev_entry) && 859 (prev_entry->end >= new_entry->start)) { 860 map->first_free = new_entry; 861 } 862 863 #if 0 864 /* 865 * Temporarily removed to avoid MAP_STACK panic, due to 866 * MAP_STACK being a huge hack. Will be added back in 867 * when MAP_STACK (and the user stack mapping) is fixed. 868 */ 869 /* 870 * It may be possible to simplify the entry 871 */ 872 vm_map_simplify_entry(map, new_entry); 873 #endif 874 875 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 876 vm_map_pmap_enter(map, start, 877 object, OFF_TO_IDX(offset), end - start, 878 cow & MAP_PREFAULT_PARTIAL); 879 } 880 881 return (KERN_SUCCESS); 882 } 883 884 /* 885 * Find sufficient space for `length' bytes in the given map, starting at 886 * `start'. The map must be locked. Returns 0 on success, 1 on no space. 887 */ 888 int 889 vm_map_findspace( 890 vm_map_t map, 891 vm_offset_t start, 892 vm_size_t length, 893 vm_offset_t *addr) 894 { 895 vm_map_entry_t entry, next; 896 vm_offset_t end; 897 898 if (start < map->min_offset) 899 start = map->min_offset; 900 if (start > map->max_offset) 901 return (1); 902 903 /* 904 * Look for the first possible address; if there's already something 905 * at this address, we have to start after it. 906 */ 907 if (start == map->min_offset) { 908 if ((entry = map->first_free) != &map->header) 909 start = entry->end; 910 } else { 911 vm_map_entry_t tmp; 912 913 if (vm_map_lookup_entry(map, start, &tmp)) 914 start = tmp->end; 915 entry = tmp; 916 } 917 918 /* 919 * Look through the rest of the map, trying to fit a new region in the 920 * gap between existing regions, or after the very last region. 921 */ 922 for (;; start = (entry = next)->end) { 923 /* 924 * Find the end of the proposed new region. Be sure we didn't 925 * go beyond the end of the map, or wrap around the address; 926 * if so, we lose. Otherwise, if this is the last entry, or 927 * if the proposed new region fits before the next entry, we 928 * win. 929 */ 930 end = start + length; 931 if (end > map->max_offset || end < start) 932 return (1); 933 next = entry->next; 934 if (next == &map->header || next->start >= end) 935 break; 936 } 937 *addr = start; 938 if (map == kernel_map) { 939 vm_offset_t ksize; 940 if ((ksize = round_page(start + length)) > kernel_vm_end) { 941 pmap_growkernel(ksize); 942 } 943 } 944 return (0); 945 } 946 947 /* 948 * vm_map_find finds an unallocated region in the target address 949 * map with the given length. The search is defined to be 950 * first-fit from the specified address; the region found is 951 * returned in the same parameter. 952 * 953 * If object is non-NULL, ref count must be bumped by caller 954 * prior to making call to account for the new entry. 955 */ 956 int 957 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 958 vm_offset_t *addr, /* IN/OUT */ 959 vm_size_t length, boolean_t find_space, vm_prot_t prot, 960 vm_prot_t max, int cow) 961 { 962 vm_offset_t start; 963 int result, s = 0; 964 965 start = *addr; 966 967 if (map == kmem_map) 968 s = splvm(); 969 970 vm_map_lock(map); 971 if (find_space) { 972 if (vm_map_findspace(map, start, length, addr)) { 973 vm_map_unlock(map); 974 if (map == kmem_map) 975 splx(s); 976 return (KERN_NO_SPACE); 977 } 978 start = *addr; 979 } 980 result = vm_map_insert(map, object, offset, 981 start, start + length, prot, max, cow); 982 vm_map_unlock(map); 983 984 if (map == kmem_map) 985 splx(s); 986 987 return (result); 988 } 989 990 /* 991 * vm_map_simplify_entry: 992 * 993 * Simplify the given map entry by merging with either neighbor. This 994 * routine also has the ability to merge with both neighbors. 995 * 996 * The map must be locked. 997 * 998 * This routine guarentees that the passed entry remains valid (though 999 * possibly extended). When merging, this routine may delete one or 1000 * both neighbors. 1001 */ 1002 void 1003 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1004 { 1005 vm_map_entry_t next, prev; 1006 vm_size_t prevsize, esize; 1007 1008 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) 1009 return; 1010 1011 prev = entry->prev; 1012 if (prev != &map->header) { 1013 prevsize = prev->end - prev->start; 1014 if ( (prev->end == entry->start) && 1015 (prev->object.vm_object == entry->object.vm_object) && 1016 (!prev->object.vm_object || 1017 (prev->offset + prevsize == entry->offset)) && 1018 (prev->eflags == entry->eflags) && 1019 (prev->protection == entry->protection) && 1020 (prev->max_protection == entry->max_protection) && 1021 (prev->inheritance == entry->inheritance) && 1022 (prev->wired_count == entry->wired_count)) { 1023 if (map->first_free == prev) 1024 map->first_free = entry; 1025 vm_map_entry_unlink(map, prev); 1026 entry->start = prev->start; 1027 entry->offset = prev->offset; 1028 if (prev->object.vm_object) 1029 vm_object_deallocate(prev->object.vm_object); 1030 vm_map_entry_dispose(map, prev); 1031 } 1032 } 1033 1034 next = entry->next; 1035 if (next != &map->header) { 1036 esize = entry->end - entry->start; 1037 if ((entry->end == next->start) && 1038 (next->object.vm_object == entry->object.vm_object) && 1039 (!entry->object.vm_object || 1040 (entry->offset + esize == next->offset)) && 1041 (next->eflags == entry->eflags) && 1042 (next->protection == entry->protection) && 1043 (next->max_protection == entry->max_protection) && 1044 (next->inheritance == entry->inheritance) && 1045 (next->wired_count == entry->wired_count)) { 1046 if (map->first_free == next) 1047 map->first_free = entry; 1048 vm_map_entry_unlink(map, next); 1049 entry->end = next->end; 1050 if (next->object.vm_object) 1051 vm_object_deallocate(next->object.vm_object); 1052 vm_map_entry_dispose(map, next); 1053 } 1054 } 1055 } 1056 /* 1057 * vm_map_clip_start: [ internal use only ] 1058 * 1059 * Asserts that the given entry begins at or after 1060 * the specified address; if necessary, 1061 * it splits the entry into two. 1062 */ 1063 #define vm_map_clip_start(map, entry, startaddr) \ 1064 { \ 1065 if (startaddr > entry->start) \ 1066 _vm_map_clip_start(map, entry, startaddr); \ 1067 } 1068 1069 /* 1070 * This routine is called only when it is known that 1071 * the entry must be split. 1072 */ 1073 static void 1074 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1075 { 1076 vm_map_entry_t new_entry; 1077 1078 /* 1079 * Split off the front portion -- note that we must insert the new 1080 * entry BEFORE this one, so that this entry has the specified 1081 * starting address. 1082 */ 1083 vm_map_simplify_entry(map, entry); 1084 1085 /* 1086 * If there is no object backing this entry, we might as well create 1087 * one now. If we defer it, an object can get created after the map 1088 * is clipped, and individual objects will be created for the split-up 1089 * map. This is a bit of a hack, but is also about the best place to 1090 * put this improvement. 1091 */ 1092 if (entry->object.vm_object == NULL && !map->system_map) { 1093 vm_object_t object; 1094 object = vm_object_allocate(OBJT_DEFAULT, 1095 atop(entry->end - entry->start)); 1096 entry->object.vm_object = object; 1097 entry->offset = 0; 1098 } 1099 1100 new_entry = vm_map_entry_create(map); 1101 *new_entry = *entry; 1102 1103 new_entry->end = start; 1104 entry->offset += (start - entry->start); 1105 entry->start = start; 1106 1107 vm_map_entry_link(map, entry->prev, new_entry); 1108 1109 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1110 vm_object_reference(new_entry->object.vm_object); 1111 } 1112 } 1113 1114 /* 1115 * vm_map_clip_end: [ internal use only ] 1116 * 1117 * Asserts that the given entry ends at or before 1118 * the specified address; if necessary, 1119 * it splits the entry into two. 1120 */ 1121 #define vm_map_clip_end(map, entry, endaddr) \ 1122 { \ 1123 if ((endaddr) < (entry->end)) \ 1124 _vm_map_clip_end((map), (entry), (endaddr)); \ 1125 } 1126 1127 /* 1128 * This routine is called only when it is known that 1129 * the entry must be split. 1130 */ 1131 static void 1132 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1133 { 1134 vm_map_entry_t new_entry; 1135 1136 /* 1137 * If there is no object backing this entry, we might as well create 1138 * one now. If we defer it, an object can get created after the map 1139 * is clipped, and individual objects will be created for the split-up 1140 * map. This is a bit of a hack, but is also about the best place to 1141 * put this improvement. 1142 */ 1143 if (entry->object.vm_object == NULL && !map->system_map) { 1144 vm_object_t object; 1145 object = vm_object_allocate(OBJT_DEFAULT, 1146 atop(entry->end - entry->start)); 1147 entry->object.vm_object = object; 1148 entry->offset = 0; 1149 } 1150 1151 /* 1152 * Create a new entry and insert it AFTER the specified entry 1153 */ 1154 new_entry = vm_map_entry_create(map); 1155 *new_entry = *entry; 1156 1157 new_entry->start = entry->end = end; 1158 new_entry->offset += (end - entry->start); 1159 1160 vm_map_entry_link(map, entry, new_entry); 1161 1162 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1163 vm_object_reference(new_entry->object.vm_object); 1164 } 1165 } 1166 1167 /* 1168 * VM_MAP_RANGE_CHECK: [ internal use only ] 1169 * 1170 * Asserts that the starting and ending region 1171 * addresses fall within the valid range of the map. 1172 */ 1173 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1174 { \ 1175 if (start < vm_map_min(map)) \ 1176 start = vm_map_min(map); \ 1177 if (end > vm_map_max(map)) \ 1178 end = vm_map_max(map); \ 1179 if (start > end) \ 1180 start = end; \ 1181 } 1182 1183 /* 1184 * vm_map_submap: [ kernel use only ] 1185 * 1186 * Mark the given range as handled by a subordinate map. 1187 * 1188 * This range must have been created with vm_map_find, 1189 * and no other operations may have been performed on this 1190 * range prior to calling vm_map_submap. 1191 * 1192 * Only a limited number of operations can be performed 1193 * within this rage after calling vm_map_submap: 1194 * vm_fault 1195 * [Don't try vm_map_copy!] 1196 * 1197 * To remove a submapping, one must first remove the 1198 * range from the superior map, and then destroy the 1199 * submap (if desired). [Better yet, don't try it.] 1200 */ 1201 int 1202 vm_map_submap( 1203 vm_map_t map, 1204 vm_offset_t start, 1205 vm_offset_t end, 1206 vm_map_t submap) 1207 { 1208 vm_map_entry_t entry; 1209 int result = KERN_INVALID_ARGUMENT; 1210 1211 vm_map_lock(map); 1212 1213 VM_MAP_RANGE_CHECK(map, start, end); 1214 1215 if (vm_map_lookup_entry(map, start, &entry)) { 1216 vm_map_clip_start(map, entry, start); 1217 } else 1218 entry = entry->next; 1219 1220 vm_map_clip_end(map, entry, end); 1221 1222 if ((entry->start == start) && (entry->end == end) && 1223 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1224 (entry->object.vm_object == NULL)) { 1225 entry->object.sub_map = submap; 1226 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1227 result = KERN_SUCCESS; 1228 } 1229 vm_map_unlock(map); 1230 1231 return (result); 1232 } 1233 1234 /* 1235 * The maximum number of pages to map 1236 */ 1237 #define MAX_INIT_PT 96 1238 1239 /* 1240 * vm_map_pmap_enter: 1241 * 1242 * Preload the mappings for the given object into the specified 1243 * map. This eliminates the soft faults on process startup and 1244 * immediately after an mmap(2). 1245 */ 1246 void 1247 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, 1248 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1249 { 1250 vm_offset_t tmpidx; 1251 int psize; 1252 vm_page_t p, mpte; 1253 1254 if (object == NULL) 1255 return; 1256 mtx_lock(&Giant); 1257 VM_OBJECT_LOCK(object); 1258 if (object->type == OBJT_DEVICE) { 1259 pmap_object_init_pt(map->pmap, addr, object, pindex, size); 1260 goto unlock_return; 1261 } 1262 1263 psize = atop(size); 1264 1265 if (object->type != OBJT_VNODE || 1266 ((flags & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) && 1267 (object->resident_page_count > MAX_INIT_PT))) { 1268 goto unlock_return; 1269 } 1270 1271 if (psize + pindex > object->size) { 1272 if (object->size < pindex) 1273 goto unlock_return; 1274 psize = object->size - pindex; 1275 } 1276 1277 mpte = NULL; 1278 1279 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1280 if (p->pindex < pindex) { 1281 p = vm_page_splay(pindex, object->root); 1282 if ((object->root = p)->pindex < pindex) 1283 p = TAILQ_NEXT(p, listq); 1284 } 1285 } 1286 /* 1287 * Assert: the variable p is either (1) the page with the 1288 * least pindex greater than or equal to the parameter pindex 1289 * or (2) NULL. 1290 */ 1291 for (; 1292 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1293 p = TAILQ_NEXT(p, listq)) { 1294 /* 1295 * don't allow an madvise to blow away our really 1296 * free pages allocating pv entries. 1297 */ 1298 if ((flags & MAP_PREFAULT_MADVISE) && 1299 cnt.v_free_count < cnt.v_free_reserved) { 1300 break; 1301 } 1302 vm_page_lock_queues(); 1303 if ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL && 1304 (p->busy == 0) && 1305 (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { 1306 if ((p->queue - p->pc) == PQ_CACHE) 1307 vm_page_deactivate(p); 1308 vm_page_busy(p); 1309 vm_page_unlock_queues(); 1310 VM_OBJECT_UNLOCK(object); 1311 mpte = pmap_enter_quick(map->pmap, 1312 addr + ptoa(tmpidx), p, mpte); 1313 VM_OBJECT_LOCK(object); 1314 vm_page_lock_queues(); 1315 vm_page_wakeup(p); 1316 } 1317 vm_page_unlock_queues(); 1318 } 1319 unlock_return: 1320 VM_OBJECT_UNLOCK(object); 1321 mtx_unlock(&Giant); 1322 } 1323 1324 /* 1325 * vm_map_protect: 1326 * 1327 * Sets the protection of the specified address 1328 * region in the target map. If "set_max" is 1329 * specified, the maximum protection is to be set; 1330 * otherwise, only the current protection is affected. 1331 */ 1332 int 1333 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1334 vm_prot_t new_prot, boolean_t set_max) 1335 { 1336 vm_map_entry_t current; 1337 vm_map_entry_t entry; 1338 1339 vm_map_lock(map); 1340 1341 VM_MAP_RANGE_CHECK(map, start, end); 1342 1343 if (vm_map_lookup_entry(map, start, &entry)) { 1344 vm_map_clip_start(map, entry, start); 1345 } else { 1346 entry = entry->next; 1347 } 1348 1349 /* 1350 * Make a first pass to check for protection violations. 1351 */ 1352 current = entry; 1353 while ((current != &map->header) && (current->start < end)) { 1354 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1355 vm_map_unlock(map); 1356 return (KERN_INVALID_ARGUMENT); 1357 } 1358 if ((new_prot & current->max_protection) != new_prot) { 1359 vm_map_unlock(map); 1360 return (KERN_PROTECTION_FAILURE); 1361 } 1362 current = current->next; 1363 } 1364 1365 /* 1366 * Go back and fix up protections. [Note that clipping is not 1367 * necessary the second time.] 1368 */ 1369 current = entry; 1370 while ((current != &map->header) && (current->start < end)) { 1371 vm_prot_t old_prot; 1372 1373 vm_map_clip_end(map, current, end); 1374 1375 old_prot = current->protection; 1376 if (set_max) 1377 current->protection = 1378 (current->max_protection = new_prot) & 1379 old_prot; 1380 else 1381 current->protection = new_prot; 1382 1383 /* 1384 * Update physical map if necessary. Worry about copy-on-write 1385 * here -- CHECK THIS XXX 1386 */ 1387 if (current->protection != old_prot) { 1388 mtx_lock(&Giant); 1389 vm_page_lock_queues(); 1390 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1391 VM_PROT_ALL) 1392 pmap_protect(map->pmap, current->start, 1393 current->end, 1394 current->protection & MASK(current)); 1395 #undef MASK 1396 vm_page_unlock_queues(); 1397 mtx_unlock(&Giant); 1398 } 1399 vm_map_simplify_entry(map, current); 1400 current = current->next; 1401 } 1402 vm_map_unlock(map); 1403 return (KERN_SUCCESS); 1404 } 1405 1406 /* 1407 * vm_map_madvise: 1408 * 1409 * This routine traverses a processes map handling the madvise 1410 * system call. Advisories are classified as either those effecting 1411 * the vm_map_entry structure, or those effecting the underlying 1412 * objects. 1413 */ 1414 int 1415 vm_map_madvise( 1416 vm_map_t map, 1417 vm_offset_t start, 1418 vm_offset_t end, 1419 int behav) 1420 { 1421 vm_map_entry_t current, entry; 1422 int modify_map = 0; 1423 1424 /* 1425 * Some madvise calls directly modify the vm_map_entry, in which case 1426 * we need to use an exclusive lock on the map and we need to perform 1427 * various clipping operations. Otherwise we only need a read-lock 1428 * on the map. 1429 */ 1430 switch(behav) { 1431 case MADV_NORMAL: 1432 case MADV_SEQUENTIAL: 1433 case MADV_RANDOM: 1434 case MADV_NOSYNC: 1435 case MADV_AUTOSYNC: 1436 case MADV_NOCORE: 1437 case MADV_CORE: 1438 modify_map = 1; 1439 vm_map_lock(map); 1440 break; 1441 case MADV_WILLNEED: 1442 case MADV_DONTNEED: 1443 case MADV_FREE: 1444 vm_map_lock_read(map); 1445 break; 1446 default: 1447 return (KERN_INVALID_ARGUMENT); 1448 } 1449 1450 /* 1451 * Locate starting entry and clip if necessary. 1452 */ 1453 VM_MAP_RANGE_CHECK(map, start, end); 1454 1455 if (vm_map_lookup_entry(map, start, &entry)) { 1456 if (modify_map) 1457 vm_map_clip_start(map, entry, start); 1458 } else { 1459 entry = entry->next; 1460 } 1461 1462 if (modify_map) { 1463 /* 1464 * madvise behaviors that are implemented in the vm_map_entry. 1465 * 1466 * We clip the vm_map_entry so that behavioral changes are 1467 * limited to the specified address range. 1468 */ 1469 for (current = entry; 1470 (current != &map->header) && (current->start < end); 1471 current = current->next 1472 ) { 1473 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1474 continue; 1475 1476 vm_map_clip_end(map, current, end); 1477 1478 switch (behav) { 1479 case MADV_NORMAL: 1480 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1481 break; 1482 case MADV_SEQUENTIAL: 1483 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1484 break; 1485 case MADV_RANDOM: 1486 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1487 break; 1488 case MADV_NOSYNC: 1489 current->eflags |= MAP_ENTRY_NOSYNC; 1490 break; 1491 case MADV_AUTOSYNC: 1492 current->eflags &= ~MAP_ENTRY_NOSYNC; 1493 break; 1494 case MADV_NOCORE: 1495 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1496 break; 1497 case MADV_CORE: 1498 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1499 break; 1500 default: 1501 break; 1502 } 1503 vm_map_simplify_entry(map, current); 1504 } 1505 vm_map_unlock(map); 1506 } else { 1507 vm_pindex_t pindex; 1508 int count; 1509 1510 /* 1511 * madvise behaviors that are implemented in the underlying 1512 * vm_object. 1513 * 1514 * Since we don't clip the vm_map_entry, we have to clip 1515 * the vm_object pindex and count. 1516 */ 1517 for (current = entry; 1518 (current != &map->header) && (current->start < end); 1519 current = current->next 1520 ) { 1521 vm_offset_t useStart; 1522 1523 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1524 continue; 1525 1526 pindex = OFF_TO_IDX(current->offset); 1527 count = atop(current->end - current->start); 1528 useStart = current->start; 1529 1530 if (current->start < start) { 1531 pindex += atop(start - current->start); 1532 count -= atop(start - current->start); 1533 useStart = start; 1534 } 1535 if (current->end > end) 1536 count -= atop(current->end - end); 1537 1538 if (count <= 0) 1539 continue; 1540 1541 vm_object_madvise(current->object.vm_object, 1542 pindex, count, behav); 1543 if (behav == MADV_WILLNEED) { 1544 vm_map_pmap_enter(map, 1545 useStart, 1546 current->object.vm_object, 1547 pindex, 1548 (count << PAGE_SHIFT), 1549 MAP_PREFAULT_MADVISE 1550 ); 1551 } 1552 } 1553 vm_map_unlock_read(map); 1554 } 1555 return (0); 1556 } 1557 1558 1559 /* 1560 * vm_map_inherit: 1561 * 1562 * Sets the inheritance of the specified address 1563 * range in the target map. Inheritance 1564 * affects how the map will be shared with 1565 * child maps at the time of vm_map_fork. 1566 */ 1567 int 1568 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 1569 vm_inherit_t new_inheritance) 1570 { 1571 vm_map_entry_t entry; 1572 vm_map_entry_t temp_entry; 1573 1574 switch (new_inheritance) { 1575 case VM_INHERIT_NONE: 1576 case VM_INHERIT_COPY: 1577 case VM_INHERIT_SHARE: 1578 break; 1579 default: 1580 return (KERN_INVALID_ARGUMENT); 1581 } 1582 vm_map_lock(map); 1583 VM_MAP_RANGE_CHECK(map, start, end); 1584 if (vm_map_lookup_entry(map, start, &temp_entry)) { 1585 entry = temp_entry; 1586 vm_map_clip_start(map, entry, start); 1587 } else 1588 entry = temp_entry->next; 1589 while ((entry != &map->header) && (entry->start < end)) { 1590 vm_map_clip_end(map, entry, end); 1591 entry->inheritance = new_inheritance; 1592 vm_map_simplify_entry(map, entry); 1593 entry = entry->next; 1594 } 1595 vm_map_unlock(map); 1596 return (KERN_SUCCESS); 1597 } 1598 1599 /* 1600 * vm_map_unwire: 1601 * 1602 * Implements both kernel and user unwiring. 1603 */ 1604 int 1605 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 1606 int flags) 1607 { 1608 vm_map_entry_t entry, first_entry, tmp_entry; 1609 vm_offset_t saved_start; 1610 unsigned int last_timestamp; 1611 int rv; 1612 boolean_t need_wakeup, result, user_unwire; 1613 1614 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 1615 vm_map_lock(map); 1616 VM_MAP_RANGE_CHECK(map, start, end); 1617 if (!vm_map_lookup_entry(map, start, &first_entry)) { 1618 if (flags & VM_MAP_WIRE_HOLESOK) 1619 first_entry = map->header.next; 1620 else { 1621 vm_map_unlock(map); 1622 return (KERN_INVALID_ADDRESS); 1623 } 1624 } 1625 last_timestamp = map->timestamp; 1626 entry = first_entry; 1627 while (entry != &map->header && entry->start < end) { 1628 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1629 /* 1630 * We have not yet clipped the entry. 1631 */ 1632 saved_start = (start >= entry->start) ? start : 1633 entry->start; 1634 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1635 if (vm_map_unlock_and_wait(map, user_unwire)) { 1636 /* 1637 * Allow interruption of user unwiring? 1638 */ 1639 } 1640 vm_map_lock(map); 1641 if (last_timestamp+1 != map->timestamp) { 1642 /* 1643 * Look again for the entry because the map was 1644 * modified while it was unlocked. 1645 * Specifically, the entry may have been 1646 * clipped, merged, or deleted. 1647 */ 1648 if (!vm_map_lookup_entry(map, saved_start, 1649 &tmp_entry)) { 1650 if (saved_start == start) { 1651 /* 1652 * First_entry has been deleted. 1653 */ 1654 vm_map_unlock(map); 1655 return (KERN_INVALID_ADDRESS); 1656 } 1657 end = saved_start; 1658 rv = KERN_INVALID_ADDRESS; 1659 goto done; 1660 } 1661 if (entry == first_entry) 1662 first_entry = tmp_entry; 1663 else 1664 first_entry = NULL; 1665 entry = tmp_entry; 1666 } 1667 last_timestamp = map->timestamp; 1668 continue; 1669 } 1670 vm_map_clip_start(map, entry, start); 1671 vm_map_clip_end(map, entry, end); 1672 /* 1673 * Mark the entry in case the map lock is released. (See 1674 * above.) 1675 */ 1676 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1677 /* 1678 * Check the map for holes in the specified region. 1679 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 1680 */ 1681 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 1682 (entry->end < end && (entry->next == &map->header || 1683 entry->next->start > entry->end))) { 1684 end = entry->end; 1685 rv = KERN_INVALID_ADDRESS; 1686 goto done; 1687 } 1688 /* 1689 * Require that the entry is wired. 1690 */ 1691 if (entry->wired_count == 0 || (user_unwire && 1692 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0)) { 1693 end = entry->end; 1694 rv = KERN_INVALID_ARGUMENT; 1695 goto done; 1696 } 1697 entry = entry->next; 1698 } 1699 rv = KERN_SUCCESS; 1700 done: 1701 need_wakeup = FALSE; 1702 if (first_entry == NULL) { 1703 result = vm_map_lookup_entry(map, start, &first_entry); 1704 KASSERT(result, ("vm_map_unwire: lookup failed")); 1705 } 1706 entry = first_entry; 1707 while (entry != &map->header && entry->start < end) { 1708 if (rv == KERN_SUCCESS) { 1709 if (user_unwire) 1710 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 1711 entry->wired_count--; 1712 if (entry->wired_count == 0) { 1713 /* 1714 * Retain the map lock. 1715 */ 1716 vm_fault_unwire(map, entry->start, entry->end); 1717 } 1718 } 1719 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1720 ("vm_map_unwire: in-transition flag missing")); 1721 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1722 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1723 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1724 need_wakeup = TRUE; 1725 } 1726 vm_map_simplify_entry(map, entry); 1727 entry = entry->next; 1728 } 1729 vm_map_unlock(map); 1730 if (need_wakeup) 1731 vm_map_wakeup(map); 1732 return (rv); 1733 } 1734 1735 /* 1736 * vm_map_wire: 1737 * 1738 * Implements both kernel and user wiring. 1739 */ 1740 int 1741 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 1742 int flags) 1743 { 1744 vm_map_entry_t entry, first_entry, tmp_entry; 1745 vm_offset_t saved_end, saved_start; 1746 unsigned int last_timestamp; 1747 int rv; 1748 boolean_t need_wakeup, result, user_wire; 1749 1750 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 1751 vm_map_lock(map); 1752 VM_MAP_RANGE_CHECK(map, start, end); 1753 if (!vm_map_lookup_entry(map, start, &first_entry)) { 1754 if (flags & VM_MAP_WIRE_HOLESOK) 1755 first_entry = map->header.next; 1756 else { 1757 vm_map_unlock(map); 1758 return (KERN_INVALID_ADDRESS); 1759 } 1760 } 1761 last_timestamp = map->timestamp; 1762 entry = first_entry; 1763 while (entry != &map->header && entry->start < end) { 1764 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1765 /* 1766 * We have not yet clipped the entry. 1767 */ 1768 saved_start = (start >= entry->start) ? start : 1769 entry->start; 1770 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1771 if (vm_map_unlock_and_wait(map, user_wire)) { 1772 /* 1773 * Allow interruption of user wiring? 1774 */ 1775 } 1776 vm_map_lock(map); 1777 if (last_timestamp + 1 != map->timestamp) { 1778 /* 1779 * Look again for the entry because the map was 1780 * modified while it was unlocked. 1781 * Specifically, the entry may have been 1782 * clipped, merged, or deleted. 1783 */ 1784 if (!vm_map_lookup_entry(map, saved_start, 1785 &tmp_entry)) { 1786 if (saved_start == start) { 1787 /* 1788 * first_entry has been deleted. 1789 */ 1790 vm_map_unlock(map); 1791 return (KERN_INVALID_ADDRESS); 1792 } 1793 end = saved_start; 1794 rv = KERN_INVALID_ADDRESS; 1795 goto done; 1796 } 1797 if (entry == first_entry) 1798 first_entry = tmp_entry; 1799 else 1800 first_entry = NULL; 1801 entry = tmp_entry; 1802 } 1803 last_timestamp = map->timestamp; 1804 continue; 1805 } 1806 vm_map_clip_start(map, entry, start); 1807 vm_map_clip_end(map, entry, end); 1808 /* 1809 * Mark the entry in case the map lock is released. (See 1810 * above.) 1811 */ 1812 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1813 /* 1814 * 1815 */ 1816 if (entry->wired_count == 0) { 1817 entry->wired_count++; 1818 saved_start = entry->start; 1819 saved_end = entry->end; 1820 /* 1821 * Release the map lock, relying on the in-transition 1822 * mark. 1823 */ 1824 vm_map_unlock(map); 1825 rv = vm_fault_wire(map, saved_start, saved_end, 1826 user_wire); 1827 vm_map_lock(map); 1828 if (last_timestamp + 1 != map->timestamp) { 1829 /* 1830 * Look again for the entry because the map was 1831 * modified while it was unlocked. The entry 1832 * may have been clipped, but NOT merged or 1833 * deleted. 1834 */ 1835 result = vm_map_lookup_entry(map, saved_start, 1836 &tmp_entry); 1837 KASSERT(result, ("vm_map_wire: lookup failed")); 1838 if (entry == first_entry) 1839 first_entry = tmp_entry; 1840 else 1841 first_entry = NULL; 1842 entry = tmp_entry; 1843 while (entry->end < saved_end) { 1844 if (rv != KERN_SUCCESS) { 1845 KASSERT(entry->wired_count == 1, 1846 ("vm_map_wire: bad count")); 1847 entry->wired_count = -1; 1848 } 1849 entry = entry->next; 1850 } 1851 } 1852 last_timestamp = map->timestamp; 1853 if (rv != KERN_SUCCESS) { 1854 KASSERT(entry->wired_count == 1, 1855 ("vm_map_wire: bad count")); 1856 /* 1857 * Assign an out-of-range value to represent 1858 * the failure to wire this entry. 1859 */ 1860 entry->wired_count = -1; 1861 end = entry->end; 1862 goto done; 1863 } 1864 } else if (!user_wire || 1865 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 1866 entry->wired_count++; 1867 } 1868 /* 1869 * Check the map for holes in the specified region. 1870 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 1871 */ 1872 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 1873 (entry->end < end && (entry->next == &map->header || 1874 entry->next->start > entry->end))) { 1875 end = entry->end; 1876 rv = KERN_INVALID_ADDRESS; 1877 goto done; 1878 } 1879 entry = entry->next; 1880 } 1881 rv = KERN_SUCCESS; 1882 done: 1883 need_wakeup = FALSE; 1884 if (first_entry == NULL) { 1885 result = vm_map_lookup_entry(map, start, &first_entry); 1886 KASSERT(result, ("vm_map_wire: lookup failed")); 1887 } 1888 entry = first_entry; 1889 while (entry != &map->header && entry->start < end) { 1890 if (rv == KERN_SUCCESS) { 1891 if (user_wire) 1892 entry->eflags |= MAP_ENTRY_USER_WIRED; 1893 } else if (entry->wired_count == -1) { 1894 /* 1895 * Wiring failed on this entry. Thus, unwiring is 1896 * unnecessary. 1897 */ 1898 entry->wired_count = 0; 1899 } else { 1900 if (!user_wire || 1901 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) 1902 entry->wired_count--; 1903 if (entry->wired_count == 0) { 1904 /* 1905 * Retain the map lock. 1906 */ 1907 vm_fault_unwire(map, entry->start, entry->end); 1908 } 1909 } 1910 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1911 ("vm_map_wire: in-transition flag missing")); 1912 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1913 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1914 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1915 need_wakeup = TRUE; 1916 } 1917 vm_map_simplify_entry(map, entry); 1918 entry = entry->next; 1919 } 1920 vm_map_unlock(map); 1921 if (need_wakeup) 1922 vm_map_wakeup(map); 1923 return (rv); 1924 } 1925 1926 /* 1927 * vm_map_clean 1928 * 1929 * Push any dirty cached pages in the address range to their pager. 1930 * If syncio is TRUE, dirty pages are written synchronously. 1931 * If invalidate is TRUE, any cached pages are freed as well. 1932 * 1933 * Returns an error if any part of the specified range is not mapped. 1934 */ 1935 int 1936 vm_map_clean( 1937 vm_map_t map, 1938 vm_offset_t start, 1939 vm_offset_t end, 1940 boolean_t syncio, 1941 boolean_t invalidate) 1942 { 1943 vm_map_entry_t current; 1944 vm_map_entry_t entry; 1945 vm_size_t size; 1946 vm_object_t object; 1947 vm_ooffset_t offset; 1948 1949 GIANT_REQUIRED; 1950 1951 vm_map_lock_read(map); 1952 VM_MAP_RANGE_CHECK(map, start, end); 1953 if (!vm_map_lookup_entry(map, start, &entry)) { 1954 vm_map_unlock_read(map); 1955 return (KERN_INVALID_ADDRESS); 1956 } 1957 /* 1958 * Make a first pass to check for holes. 1959 */ 1960 for (current = entry; current->start < end; current = current->next) { 1961 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1962 vm_map_unlock_read(map); 1963 return (KERN_INVALID_ARGUMENT); 1964 } 1965 if (end > current->end && 1966 (current->next == &map->header || 1967 current->end != current->next->start)) { 1968 vm_map_unlock_read(map); 1969 return (KERN_INVALID_ADDRESS); 1970 } 1971 } 1972 1973 if (invalidate) { 1974 vm_page_lock_queues(); 1975 pmap_remove(map->pmap, start, end); 1976 vm_page_unlock_queues(); 1977 } 1978 /* 1979 * Make a second pass, cleaning/uncaching pages from the indicated 1980 * objects as we go. 1981 */ 1982 for (current = entry; current->start < end; current = current->next) { 1983 offset = current->offset + (start - current->start); 1984 size = (end <= current->end ? end : current->end) - start; 1985 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1986 vm_map_t smap; 1987 vm_map_entry_t tentry; 1988 vm_size_t tsize; 1989 1990 smap = current->object.sub_map; 1991 vm_map_lock_read(smap); 1992 (void) vm_map_lookup_entry(smap, offset, &tentry); 1993 tsize = tentry->end - offset; 1994 if (tsize < size) 1995 size = tsize; 1996 object = tentry->object.vm_object; 1997 offset = tentry->offset + (offset - tentry->start); 1998 vm_map_unlock_read(smap); 1999 } else { 2000 object = current->object.vm_object; 2001 } 2002 /* 2003 * Note that there is absolutely no sense in writing out 2004 * anonymous objects, so we track down the vnode object 2005 * to write out. 2006 * We invalidate (remove) all pages from the address space 2007 * anyway, for semantic correctness. 2008 * 2009 * note: certain anonymous maps, such as MAP_NOSYNC maps, 2010 * may start out with a NULL object. 2011 */ 2012 while (object && object->backing_object) { 2013 object = object->backing_object; 2014 offset += object->backing_object_offset; 2015 if (object->size < OFF_TO_IDX(offset + size)) 2016 size = IDX_TO_OFF(object->size) - offset; 2017 } 2018 if (object && (object->type == OBJT_VNODE) && 2019 (current->protection & VM_PROT_WRITE)) { 2020 /* 2021 * Flush pages if writing is allowed, invalidate them 2022 * if invalidation requested. Pages undergoing I/O 2023 * will be ignored by vm_object_page_remove(). 2024 * 2025 * We cannot lock the vnode and then wait for paging 2026 * to complete without deadlocking against vm_fault. 2027 * Instead we simply call vm_object_page_remove() and 2028 * allow it to block internally on a page-by-page 2029 * basis when it encounters pages undergoing async 2030 * I/O. 2031 */ 2032 int flags; 2033 2034 vm_object_reference(object); 2035 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY, curthread); 2036 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 2037 flags |= invalidate ? OBJPC_INVAL : 0; 2038 VM_OBJECT_LOCK(object); 2039 vm_object_page_clean(object, 2040 OFF_TO_IDX(offset), 2041 OFF_TO_IDX(offset + size + PAGE_MASK), 2042 flags); 2043 VM_OBJECT_UNLOCK(object); 2044 VOP_UNLOCK(object->handle, 0, curthread); 2045 vm_object_deallocate(object); 2046 } 2047 if (object && invalidate && 2048 ((object->type == OBJT_VNODE) || 2049 (object->type == OBJT_DEVICE))) { 2050 VM_OBJECT_LOCK(object); 2051 vm_object_page_remove(object, 2052 OFF_TO_IDX(offset), 2053 OFF_TO_IDX(offset + size + PAGE_MASK), 2054 FALSE); 2055 VM_OBJECT_UNLOCK(object); 2056 } 2057 start += size; 2058 } 2059 2060 vm_map_unlock_read(map); 2061 return (KERN_SUCCESS); 2062 } 2063 2064 /* 2065 * vm_map_entry_unwire: [ internal use only ] 2066 * 2067 * Make the region specified by this entry pageable. 2068 * 2069 * The map in question should be locked. 2070 * [This is the reason for this routine's existence.] 2071 */ 2072 static void 2073 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2074 { 2075 vm_fault_unwire(map, entry->start, entry->end); 2076 entry->wired_count = 0; 2077 } 2078 2079 /* 2080 * vm_map_entry_delete: [ internal use only ] 2081 * 2082 * Deallocate the given entry from the target map. 2083 */ 2084 static void 2085 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2086 { 2087 vm_map_entry_unlink(map, entry); 2088 map->size -= entry->end - entry->start; 2089 2090 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 2091 vm_object_deallocate(entry->object.vm_object); 2092 } 2093 2094 vm_map_entry_dispose(map, entry); 2095 } 2096 2097 /* 2098 * vm_map_delete: [ internal use only ] 2099 * 2100 * Deallocates the given address range from the target 2101 * map. 2102 */ 2103 int 2104 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2105 { 2106 vm_object_t object; 2107 vm_map_entry_t entry; 2108 vm_map_entry_t first_entry; 2109 2110 /* 2111 * Find the start of the region, and clip it 2112 */ 2113 if (!vm_map_lookup_entry(map, start, &first_entry)) 2114 entry = first_entry->next; 2115 else { 2116 entry = first_entry; 2117 vm_map_clip_start(map, entry, start); 2118 } 2119 2120 /* 2121 * Save the free space hint 2122 */ 2123 if (entry == &map->header) { 2124 map->first_free = &map->header; 2125 } else if (map->first_free->start >= start) { 2126 map->first_free = entry->prev; 2127 } 2128 2129 /* 2130 * Step through all entries in this region 2131 */ 2132 while ((entry != &map->header) && (entry->start < end)) { 2133 vm_map_entry_t next; 2134 vm_offset_t s, e; 2135 vm_pindex_t offidxstart, offidxend, count; 2136 2137 /* 2138 * Wait for wiring or unwiring of an entry to complete. 2139 */ 2140 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0) { 2141 unsigned int last_timestamp; 2142 vm_offset_t saved_start; 2143 vm_map_entry_t tmp_entry; 2144 2145 saved_start = entry->start; 2146 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2147 last_timestamp = map->timestamp; 2148 (void) vm_map_unlock_and_wait(map, FALSE); 2149 vm_map_lock(map); 2150 if (last_timestamp + 1 != map->timestamp) { 2151 /* 2152 * Look again for the entry because the map was 2153 * modified while it was unlocked. 2154 * Specifically, the entry may have been 2155 * clipped, merged, or deleted. 2156 */ 2157 if (!vm_map_lookup_entry(map, saved_start, 2158 &tmp_entry)) 2159 entry = tmp_entry->next; 2160 else { 2161 entry = tmp_entry; 2162 vm_map_clip_start(map, entry, 2163 saved_start); 2164 } 2165 } 2166 continue; 2167 } 2168 vm_map_clip_end(map, entry, end); 2169 2170 s = entry->start; 2171 e = entry->end; 2172 next = entry->next; 2173 2174 offidxstart = OFF_TO_IDX(entry->offset); 2175 count = OFF_TO_IDX(e - s); 2176 object = entry->object.vm_object; 2177 2178 /* 2179 * Unwire before removing addresses from the pmap; otherwise, 2180 * unwiring will put the entries back in the pmap. 2181 */ 2182 if (entry->wired_count != 0) { 2183 vm_map_entry_unwire(map, entry); 2184 } 2185 2186 offidxend = offidxstart + count; 2187 2188 if (object == kernel_object || object == kmem_object) { 2189 VM_OBJECT_LOCK(object); 2190 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2191 VM_OBJECT_UNLOCK(object); 2192 } else { 2193 mtx_lock(&Giant); 2194 vm_page_lock_queues(); 2195 pmap_remove(map->pmap, s, e); 2196 vm_page_unlock_queues(); 2197 if (object != NULL) { 2198 VM_OBJECT_LOCK(object); 2199 if (object->ref_count != 1 && 2200 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING && 2201 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2202 vm_object_collapse(object); 2203 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2204 if (object->type == OBJT_SWAP) 2205 swap_pager_freespace(object, offidxstart, count); 2206 if (offidxend >= object->size && 2207 offidxstart < object->size) 2208 object->size = offidxstart; 2209 } 2210 VM_OBJECT_UNLOCK(object); 2211 } 2212 mtx_unlock(&Giant); 2213 } 2214 2215 /* 2216 * Delete the entry (which may delete the object) only after 2217 * removing all pmap entries pointing to its pages. 2218 * (Otherwise, its page frames may be reallocated, and any 2219 * modify bits will be set in the wrong object!) 2220 */ 2221 vm_map_entry_delete(map, entry); 2222 entry = next; 2223 } 2224 return (KERN_SUCCESS); 2225 } 2226 2227 /* 2228 * vm_map_remove: 2229 * 2230 * Remove the given address range from the target map. 2231 * This is the exported form of vm_map_delete. 2232 */ 2233 int 2234 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2235 { 2236 int result, s = 0; 2237 2238 if (map == kmem_map) 2239 s = splvm(); 2240 2241 vm_map_lock(map); 2242 VM_MAP_RANGE_CHECK(map, start, end); 2243 result = vm_map_delete(map, start, end); 2244 vm_map_unlock(map); 2245 2246 if (map == kmem_map) 2247 splx(s); 2248 2249 return (result); 2250 } 2251 2252 /* 2253 * vm_map_check_protection: 2254 * 2255 * Assert that the target map allows the specified privilege on the 2256 * entire address region given. The entire region must be allocated. 2257 * 2258 * WARNING! This code does not and should not check whether the 2259 * contents of the region is accessible. For example a smaller file 2260 * might be mapped into a larger address space. 2261 * 2262 * NOTE! This code is also called by munmap(). 2263 */ 2264 boolean_t 2265 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2266 vm_prot_t protection) 2267 { 2268 vm_map_entry_t entry; 2269 vm_map_entry_t tmp_entry; 2270 2271 vm_map_lock_read(map); 2272 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 2273 vm_map_unlock_read(map); 2274 return (FALSE); 2275 } 2276 entry = tmp_entry; 2277 2278 while (start < end) { 2279 if (entry == &map->header) { 2280 vm_map_unlock_read(map); 2281 return (FALSE); 2282 } 2283 /* 2284 * No holes allowed! 2285 */ 2286 if (start < entry->start) { 2287 vm_map_unlock_read(map); 2288 return (FALSE); 2289 } 2290 /* 2291 * Check protection associated with entry. 2292 */ 2293 if ((entry->protection & protection) != protection) { 2294 vm_map_unlock_read(map); 2295 return (FALSE); 2296 } 2297 /* go to next entry */ 2298 start = entry->end; 2299 entry = entry->next; 2300 } 2301 vm_map_unlock_read(map); 2302 return (TRUE); 2303 } 2304 2305 /* 2306 * vm_map_copy_entry: 2307 * 2308 * Copies the contents of the source entry to the destination 2309 * entry. The entries *must* be aligned properly. 2310 */ 2311 static void 2312 vm_map_copy_entry( 2313 vm_map_t src_map, 2314 vm_map_t dst_map, 2315 vm_map_entry_t src_entry, 2316 vm_map_entry_t dst_entry) 2317 { 2318 vm_object_t src_object; 2319 2320 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 2321 return; 2322 2323 if (src_entry->wired_count == 0) { 2324 2325 /* 2326 * If the source entry is marked needs_copy, it is already 2327 * write-protected. 2328 */ 2329 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 2330 vm_page_lock_queues(); 2331 pmap_protect(src_map->pmap, 2332 src_entry->start, 2333 src_entry->end, 2334 src_entry->protection & ~VM_PROT_WRITE); 2335 vm_page_unlock_queues(); 2336 } 2337 2338 /* 2339 * Make a copy of the object. 2340 */ 2341 if ((src_object = src_entry->object.vm_object) != NULL) { 2342 2343 if ((src_object->handle == NULL) && 2344 (src_object->type == OBJT_DEFAULT || 2345 src_object->type == OBJT_SWAP)) { 2346 VM_OBJECT_LOCK(src_object); 2347 vm_object_collapse(src_object); 2348 VM_OBJECT_UNLOCK(src_object); 2349 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 2350 vm_object_split(src_entry); 2351 src_object = src_entry->object.vm_object; 2352 } 2353 } 2354 2355 vm_object_reference(src_object); 2356 VM_OBJECT_LOCK(src_object); 2357 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 2358 VM_OBJECT_UNLOCK(src_object); 2359 dst_entry->object.vm_object = src_object; 2360 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2361 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2362 dst_entry->offset = src_entry->offset; 2363 } else { 2364 dst_entry->object.vm_object = NULL; 2365 dst_entry->offset = 0; 2366 } 2367 2368 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 2369 dst_entry->end - dst_entry->start, src_entry->start); 2370 } else { 2371 /* 2372 * Of course, wired down pages can't be set copy-on-write. 2373 * Cause wired pages to be copied into the new map by 2374 * simulating faults (the new pages are pageable) 2375 */ 2376 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 2377 } 2378 } 2379 2380 /* 2381 * vmspace_fork: 2382 * Create a new process vmspace structure and vm_map 2383 * based on those of an existing process. The new map 2384 * is based on the old map, according to the inheritance 2385 * values on the regions in that map. 2386 * 2387 * The source map must not be locked. 2388 */ 2389 struct vmspace * 2390 vmspace_fork(struct vmspace *vm1) 2391 { 2392 struct vmspace *vm2; 2393 vm_map_t old_map = &vm1->vm_map; 2394 vm_map_t new_map; 2395 vm_map_entry_t old_entry; 2396 vm_map_entry_t new_entry; 2397 vm_object_t object; 2398 2399 GIANT_REQUIRED; 2400 2401 vm_map_lock(old_map); 2402 old_map->infork = 1; 2403 2404 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 2405 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 2406 (caddr_t) &vm1->vm_endcopy - (caddr_t) &vm1->vm_startcopy); 2407 new_map = &vm2->vm_map; /* XXX */ 2408 new_map->timestamp = 1; 2409 2410 /* Do not inherit the MAP_WIREFUTURE property. */ 2411 if ((new_map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) 2412 new_map->flags &= ~MAP_WIREFUTURE; 2413 2414 old_entry = old_map->header.next; 2415 2416 while (old_entry != &old_map->header) { 2417 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 2418 panic("vm_map_fork: encountered a submap"); 2419 2420 switch (old_entry->inheritance) { 2421 case VM_INHERIT_NONE: 2422 break; 2423 2424 case VM_INHERIT_SHARE: 2425 /* 2426 * Clone the entry, creating the shared object if necessary. 2427 */ 2428 object = old_entry->object.vm_object; 2429 if (object == NULL) { 2430 object = vm_object_allocate(OBJT_DEFAULT, 2431 atop(old_entry->end - old_entry->start)); 2432 old_entry->object.vm_object = object; 2433 old_entry->offset = (vm_offset_t) 0; 2434 } 2435 2436 /* 2437 * Add the reference before calling vm_object_shadow 2438 * to insure that a shadow object is created. 2439 */ 2440 vm_object_reference(object); 2441 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 2442 vm_object_shadow(&old_entry->object.vm_object, 2443 &old_entry->offset, 2444 atop(old_entry->end - old_entry->start)); 2445 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 2446 /* Transfer the second reference too. */ 2447 vm_object_reference( 2448 old_entry->object.vm_object); 2449 vm_object_deallocate(object); 2450 object = old_entry->object.vm_object; 2451 } 2452 VM_OBJECT_LOCK(object); 2453 vm_object_clear_flag(object, OBJ_ONEMAPPING); 2454 VM_OBJECT_UNLOCK(object); 2455 2456 /* 2457 * Clone the entry, referencing the shared object. 2458 */ 2459 new_entry = vm_map_entry_create(new_map); 2460 *new_entry = *old_entry; 2461 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2462 new_entry->wired_count = 0; 2463 2464 /* 2465 * Insert the entry into the new map -- we know we're 2466 * inserting at the end of the new map. 2467 */ 2468 vm_map_entry_link(new_map, new_map->header.prev, 2469 new_entry); 2470 2471 /* 2472 * Update the physical map 2473 */ 2474 pmap_copy(new_map->pmap, old_map->pmap, 2475 new_entry->start, 2476 (old_entry->end - old_entry->start), 2477 old_entry->start); 2478 break; 2479 2480 case VM_INHERIT_COPY: 2481 /* 2482 * Clone the entry and link into the map. 2483 */ 2484 new_entry = vm_map_entry_create(new_map); 2485 *new_entry = *old_entry; 2486 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2487 new_entry->wired_count = 0; 2488 new_entry->object.vm_object = NULL; 2489 vm_map_entry_link(new_map, new_map->header.prev, 2490 new_entry); 2491 vm_map_copy_entry(old_map, new_map, old_entry, 2492 new_entry); 2493 break; 2494 } 2495 old_entry = old_entry->next; 2496 } 2497 2498 new_map->size = old_map->size; 2499 old_map->infork = 0; 2500 vm_map_unlock(old_map); 2501 2502 return (vm2); 2503 } 2504 2505 int 2506 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 2507 vm_prot_t prot, vm_prot_t max, int cow) 2508 { 2509 vm_map_entry_t prev_entry; 2510 vm_map_entry_t new_stack_entry; 2511 vm_size_t init_ssize; 2512 int rv; 2513 2514 if (addrbos < vm_map_min(map)) 2515 return (KERN_NO_SPACE); 2516 if (addrbos > map->max_offset) 2517 return (KERN_NO_SPACE); 2518 if (max_ssize < sgrowsiz) 2519 init_ssize = max_ssize; 2520 else 2521 init_ssize = sgrowsiz; 2522 2523 vm_map_lock(map); 2524 2525 /* If addr is already mapped, no go */ 2526 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 2527 vm_map_unlock(map); 2528 return (KERN_NO_SPACE); 2529 } 2530 2531 /* If we would blow our VMEM resource limit, no go */ 2532 if (map->size + init_ssize > 2533 curthread->td_proc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 2534 vm_map_unlock(map); 2535 return (KERN_NO_SPACE); 2536 } 2537 2538 /* If we can't accomodate max_ssize in the current mapping, 2539 * no go. However, we need to be aware that subsequent user 2540 * mappings might map into the space we have reserved for 2541 * stack, and currently this space is not protected. 2542 * 2543 * Hopefully we will at least detect this condition 2544 * when we try to grow the stack. 2545 */ 2546 if ((prev_entry->next != &map->header) && 2547 (prev_entry->next->start < addrbos + max_ssize)) { 2548 vm_map_unlock(map); 2549 return (KERN_NO_SPACE); 2550 } 2551 2552 /* We initially map a stack of only init_ssize. We will 2553 * grow as needed later. Since this is to be a grow 2554 * down stack, we map at the top of the range. 2555 * 2556 * Note: we would normally expect prot and max to be 2557 * VM_PROT_ALL, and cow to be 0. Possibly we should 2558 * eliminate these as input parameters, and just 2559 * pass these values here in the insert call. 2560 */ 2561 rv = vm_map_insert(map, NULL, 0, addrbos + max_ssize - init_ssize, 2562 addrbos + max_ssize, prot, max, cow); 2563 2564 /* Now set the avail_ssize amount */ 2565 if (rv == KERN_SUCCESS){ 2566 if (prev_entry != &map->header) 2567 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize); 2568 new_stack_entry = prev_entry->next; 2569 if (new_stack_entry->end != addrbos + max_ssize || 2570 new_stack_entry->start != addrbos + max_ssize - init_ssize) 2571 panic ("Bad entry start/end for new stack entry"); 2572 2573 new_stack_entry->avail_ssize = max_ssize - init_ssize; 2574 new_stack_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 2575 } 2576 2577 vm_map_unlock(map); 2578 return (rv); 2579 } 2580 2581 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 2582 * desired address is already mapped, or if we successfully grow 2583 * the stack. Also returns KERN_SUCCESS if addr is outside the 2584 * stack range (this is strange, but preserves compatibility with 2585 * the grow function in vm_machdep.c). 2586 */ 2587 int 2588 vm_map_growstack(struct proc *p, vm_offset_t addr) 2589 { 2590 vm_map_entry_t next_entry, prev_entry; 2591 vm_map_entry_t new_entry, stack_entry; 2592 struct vmspace *vm = p->p_vmspace; 2593 vm_map_t map = &vm->vm_map; 2594 vm_offset_t end; 2595 size_t grow_amount, max_grow; 2596 int is_procstack, rv; 2597 2598 GIANT_REQUIRED; 2599 2600 Retry: 2601 vm_map_lock_read(map); 2602 2603 /* If addr is already in the entry range, no need to grow.*/ 2604 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 2605 vm_map_unlock_read(map); 2606 return (KERN_SUCCESS); 2607 } 2608 2609 next_entry = prev_entry->next; 2610 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 2611 /* 2612 * This entry does not grow upwards. Since the address lies 2613 * beyond this entry, the next entry (if one exists) has to 2614 * be a downward growable entry. The entry list header is 2615 * never a growable entry, so it suffices to check the flags. 2616 */ 2617 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 2618 vm_map_unlock_read(map); 2619 return (KERN_SUCCESS); 2620 } 2621 stack_entry = next_entry; 2622 } else { 2623 /* 2624 * This entry grows upward. If the next entry does not at 2625 * least grow downwards, this is the entry we need to grow. 2626 * otherwise we have two possible choices and we have to 2627 * select one. 2628 */ 2629 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 2630 /* 2631 * We have two choices; grow the entry closest to 2632 * the address to minimize the amount of growth. 2633 */ 2634 if (addr - prev_entry->end <= next_entry->start - addr) 2635 stack_entry = prev_entry; 2636 else 2637 stack_entry = next_entry; 2638 } else 2639 stack_entry = prev_entry; 2640 } 2641 2642 if (stack_entry == next_entry) { 2643 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 2644 KASSERT(addr < stack_entry->start, ("foo")); 2645 end = (prev_entry != &map->header) ? prev_entry->end : 2646 stack_entry->start - stack_entry->avail_ssize; 2647 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 2648 max_grow = stack_entry->start - end; 2649 } else { 2650 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 2651 KASSERT(addr > stack_entry->end, ("foo")); 2652 end = (next_entry != &map->header) ? next_entry->start : 2653 stack_entry->end + stack_entry->avail_ssize; 2654 grow_amount = roundup(addr - stack_entry->end, PAGE_SIZE); 2655 max_grow = end - stack_entry->end; 2656 } 2657 2658 if (grow_amount > stack_entry->avail_ssize) { 2659 vm_map_unlock_read(map); 2660 return (KERN_NO_SPACE); 2661 } 2662 2663 /* 2664 * If there is no longer enough space between the entries nogo, and 2665 * adjust the available space. Note: this should only happen if the 2666 * user has mapped into the stack area after the stack was created, 2667 * and is probably an error. 2668 * 2669 * This also effectively destroys any guard page the user might have 2670 * intended by limiting the stack size. 2671 */ 2672 if (grow_amount > max_grow) { 2673 if (vm_map_lock_upgrade(map)) 2674 goto Retry; 2675 2676 stack_entry->avail_ssize = max_grow; 2677 2678 vm_map_unlock(map); 2679 return (KERN_NO_SPACE); 2680 } 2681 2682 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 2683 2684 /* 2685 * If this is the main process stack, see if we're over the stack 2686 * limit. 2687 */ 2688 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 2689 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 2690 vm_map_unlock_read(map); 2691 return (KERN_NO_SPACE); 2692 } 2693 2694 /* Round up the grow amount modulo SGROWSIZ */ 2695 grow_amount = roundup (grow_amount, sgrowsiz); 2696 if (grow_amount > stack_entry->avail_ssize) 2697 grow_amount = stack_entry->avail_ssize; 2698 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 2699 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 2700 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 2701 ctob(vm->vm_ssize); 2702 } 2703 2704 /* If we would blow our VMEM resource limit, no go */ 2705 if (map->size + grow_amount > 2706 curthread->td_proc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 2707 vm_map_unlock_read(map); 2708 return (KERN_NO_SPACE); 2709 } 2710 2711 if (vm_map_lock_upgrade(map)) 2712 goto Retry; 2713 2714 if (stack_entry == next_entry) { 2715 /* 2716 * Growing downward. 2717 */ 2718 /* Get the preliminary new entry start value */ 2719 addr = stack_entry->start - grow_amount; 2720 2721 /* 2722 * If this puts us into the previous entry, cut back our 2723 * growth to the available space. Also, see the note above. 2724 */ 2725 if (addr < end) { 2726 stack_entry->avail_ssize = max_grow; 2727 addr = end; 2728 } 2729 2730 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 2731 p->p_sysent->sv_stackprot, VM_PROT_ALL, 0); 2732 2733 /* Adjust the available stack space by the amount we grew. */ 2734 if (rv == KERN_SUCCESS) { 2735 if (prev_entry != &map->header) 2736 vm_map_clip_end(map, prev_entry, addr); 2737 new_entry = prev_entry->next; 2738 KASSERT(new_entry == stack_entry->prev, ("foo")); 2739 KASSERT(new_entry->end == stack_entry->start, ("foo")); 2740 KASSERT(new_entry->start == addr, ("foo")); 2741 grow_amount = new_entry->end - new_entry->start; 2742 new_entry->avail_ssize = stack_entry->avail_ssize - 2743 grow_amount; 2744 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 2745 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 2746 } 2747 } else { 2748 /* 2749 * Growing upward. 2750 */ 2751 addr = stack_entry->end + grow_amount; 2752 2753 /* 2754 * If this puts us into the next entry, cut back our growth 2755 * to the available space. Also, see the note above. 2756 */ 2757 if (addr > end) { 2758 stack_entry->avail_ssize = end - stack_entry->end; 2759 addr = end; 2760 } 2761 2762 grow_amount = addr - stack_entry->end; 2763 2764 /* Grow the underlying object if applicable. */ 2765 if (stack_entry->object.vm_object == NULL || 2766 vm_object_coalesce(stack_entry->object.vm_object, 2767 OFF_TO_IDX(stack_entry->offset), 2768 (vm_size_t)(stack_entry->end - stack_entry->start), 2769 (vm_size_t)grow_amount)) { 2770 /* Update the current entry. */ 2771 stack_entry->end = addr; 2772 rv = KERN_SUCCESS; 2773 2774 if (next_entry != &map->header) 2775 vm_map_clip_start(map, next_entry, addr); 2776 } else 2777 rv = KERN_FAILURE; 2778 } 2779 2780 if (rv == KERN_SUCCESS && is_procstack) 2781 vm->vm_ssize += btoc(grow_amount); 2782 2783 vm_map_unlock(map); 2784 2785 /* 2786 * Heed the MAP_WIREFUTURE flag if it was set for this process. 2787 */ 2788 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 2789 vm_map_wire(map, 2790 (stack_entry == next_entry) ? addr : addr - grow_amount, 2791 (stack_entry == next_entry) ? stack_entry->start : addr, 2792 (p->p_flag & P_SYSTEM) 2793 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 2794 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 2795 } 2796 2797 return (rv); 2798 } 2799 2800 /* 2801 * Unshare the specified VM space for exec. If other processes are 2802 * mapped to it, then create a new one. The new vmspace is null. 2803 */ 2804 void 2805 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 2806 { 2807 struct vmspace *oldvmspace = p->p_vmspace; 2808 struct vmspace *newvmspace; 2809 2810 GIANT_REQUIRED; 2811 newvmspace = vmspace_alloc(minuser, maxuser); 2812 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 2813 (caddr_t) (newvmspace + 1) - (caddr_t) &newvmspace->vm_startcopy); 2814 /* 2815 * This code is written like this for prototype purposes. The 2816 * goal is to avoid running down the vmspace here, but let the 2817 * other process's that are still using the vmspace to finally 2818 * run it down. Even though there is little or no chance of blocking 2819 * here, it is a good idea to keep this form for future mods. 2820 */ 2821 p->p_vmspace = newvmspace; 2822 pmap_pinit2(vmspace_pmap(newvmspace)); 2823 vmspace_free(oldvmspace); 2824 if (p == curthread->td_proc) /* XXXKSE ? */ 2825 pmap_activate(curthread); 2826 } 2827 2828 /* 2829 * Unshare the specified VM space for forcing COW. This 2830 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 2831 */ 2832 void 2833 vmspace_unshare(struct proc *p) 2834 { 2835 struct vmspace *oldvmspace = p->p_vmspace; 2836 struct vmspace *newvmspace; 2837 2838 GIANT_REQUIRED; 2839 if (oldvmspace->vm_refcnt == 1) 2840 return; 2841 newvmspace = vmspace_fork(oldvmspace); 2842 p->p_vmspace = newvmspace; 2843 pmap_pinit2(vmspace_pmap(newvmspace)); 2844 vmspace_free(oldvmspace); 2845 if (p == curthread->td_proc) /* XXXKSE ? */ 2846 pmap_activate(curthread); 2847 } 2848 2849 /* 2850 * vm_map_lookup: 2851 * 2852 * Finds the VM object, offset, and 2853 * protection for a given virtual address in the 2854 * specified map, assuming a page fault of the 2855 * type specified. 2856 * 2857 * Leaves the map in question locked for read; return 2858 * values are guaranteed until a vm_map_lookup_done 2859 * call is performed. Note that the map argument 2860 * is in/out; the returned map must be used in 2861 * the call to vm_map_lookup_done. 2862 * 2863 * A handle (out_entry) is returned for use in 2864 * vm_map_lookup_done, to make that fast. 2865 * 2866 * If a lookup is requested with "write protection" 2867 * specified, the map may be changed to perform virtual 2868 * copying operations, although the data referenced will 2869 * remain the same. 2870 */ 2871 int 2872 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 2873 vm_offset_t vaddr, 2874 vm_prot_t fault_typea, 2875 vm_map_entry_t *out_entry, /* OUT */ 2876 vm_object_t *object, /* OUT */ 2877 vm_pindex_t *pindex, /* OUT */ 2878 vm_prot_t *out_prot, /* OUT */ 2879 boolean_t *wired) /* OUT */ 2880 { 2881 vm_map_entry_t entry; 2882 vm_map_t map = *var_map; 2883 vm_prot_t prot; 2884 vm_prot_t fault_type = fault_typea; 2885 2886 RetryLookup:; 2887 /* 2888 * Lookup the faulting address. 2889 */ 2890 2891 vm_map_lock_read(map); 2892 #define RETURN(why) \ 2893 { \ 2894 vm_map_unlock_read(map); \ 2895 return (why); \ 2896 } 2897 2898 /* 2899 * If the map has an interesting hint, try it before calling full 2900 * blown lookup routine. 2901 */ 2902 entry = map->root; 2903 *out_entry = entry; 2904 if (entry == NULL || 2905 (vaddr < entry->start) || (vaddr >= entry->end)) { 2906 /* 2907 * Entry was either not a valid hint, or the vaddr was not 2908 * contained in the entry, so do a full lookup. 2909 */ 2910 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 2911 RETURN(KERN_INVALID_ADDRESS); 2912 2913 entry = *out_entry; 2914 } 2915 2916 /* 2917 * Handle submaps. 2918 */ 2919 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2920 vm_map_t old_map = map; 2921 2922 *var_map = map = entry->object.sub_map; 2923 vm_map_unlock_read(old_map); 2924 goto RetryLookup; 2925 } 2926 2927 /* 2928 * Check whether this task is allowed to have this page. 2929 * Note the special case for MAP_ENTRY_COW 2930 * pages with an override. This is to implement a forced 2931 * COW for debuggers. 2932 */ 2933 if (fault_type & VM_PROT_OVERRIDE_WRITE) 2934 prot = entry->max_protection; 2935 else 2936 prot = entry->protection; 2937 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 2938 if ((fault_type & prot) != fault_type) { 2939 RETURN(KERN_PROTECTION_FAILURE); 2940 } 2941 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 2942 (entry->eflags & MAP_ENTRY_COW) && 2943 (fault_type & VM_PROT_WRITE) && 2944 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 2945 RETURN(KERN_PROTECTION_FAILURE); 2946 } 2947 2948 /* 2949 * If this page is not pageable, we have to get it for all possible 2950 * accesses. 2951 */ 2952 *wired = (entry->wired_count != 0); 2953 if (*wired) 2954 prot = fault_type = entry->protection; 2955 2956 /* 2957 * If the entry was copy-on-write, we either ... 2958 */ 2959 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 2960 /* 2961 * If we want to write the page, we may as well handle that 2962 * now since we've got the map locked. 2963 * 2964 * If we don't need to write the page, we just demote the 2965 * permissions allowed. 2966 */ 2967 if (fault_type & VM_PROT_WRITE) { 2968 /* 2969 * Make a new object, and place it in the object 2970 * chain. Note that no new references have appeared 2971 * -- one just moved from the map to the new 2972 * object. 2973 */ 2974 if (vm_map_lock_upgrade(map)) 2975 goto RetryLookup; 2976 2977 vm_object_shadow( 2978 &entry->object.vm_object, 2979 &entry->offset, 2980 atop(entry->end - entry->start)); 2981 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 2982 2983 vm_map_lock_downgrade(map); 2984 } else { 2985 /* 2986 * We're attempting to read a copy-on-write page -- 2987 * don't allow writes. 2988 */ 2989 prot &= ~VM_PROT_WRITE; 2990 } 2991 } 2992 2993 /* 2994 * Create an object if necessary. 2995 */ 2996 if (entry->object.vm_object == NULL && 2997 !map->system_map) { 2998 if (vm_map_lock_upgrade(map)) 2999 goto RetryLookup; 3000 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 3001 atop(entry->end - entry->start)); 3002 entry->offset = 0; 3003 vm_map_lock_downgrade(map); 3004 } 3005 3006 /* 3007 * Return the object/offset from this entry. If the entry was 3008 * copy-on-write or empty, it has been fixed up. 3009 */ 3010 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3011 *object = entry->object.vm_object; 3012 3013 /* 3014 * Return whether this is the only map sharing this data. 3015 */ 3016 *out_prot = prot; 3017 return (KERN_SUCCESS); 3018 3019 #undef RETURN 3020 } 3021 3022 /* 3023 * vm_map_lookup_done: 3024 * 3025 * Releases locks acquired by a vm_map_lookup 3026 * (according to the handle returned by that lookup). 3027 */ 3028 void 3029 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 3030 { 3031 /* 3032 * Unlock the main-level map 3033 */ 3034 vm_map_unlock_read(map); 3035 } 3036 3037 #include "opt_ddb.h" 3038 #ifdef DDB 3039 #include <sys/kernel.h> 3040 3041 #include <ddb/ddb.h> 3042 3043 /* 3044 * vm_map_print: [ debug ] 3045 */ 3046 DB_SHOW_COMMAND(map, vm_map_print) 3047 { 3048 static int nlines; 3049 /* XXX convert args. */ 3050 vm_map_t map = (vm_map_t)addr; 3051 boolean_t full = have_addr; 3052 3053 vm_map_entry_t entry; 3054 3055 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 3056 (void *)map, 3057 (void *)map->pmap, map->nentries, map->timestamp); 3058 nlines++; 3059 3060 if (!full && db_indent) 3061 return; 3062 3063 db_indent += 2; 3064 for (entry = map->header.next; entry != &map->header; 3065 entry = entry->next) { 3066 db_iprintf("map entry %p: start=%p, end=%p\n", 3067 (void *)entry, (void *)entry->start, (void *)entry->end); 3068 nlines++; 3069 { 3070 static char *inheritance_name[4] = 3071 {"share", "copy", "none", "donate_copy"}; 3072 3073 db_iprintf(" prot=%x/%x/%s", 3074 entry->protection, 3075 entry->max_protection, 3076 inheritance_name[(int)(unsigned char)entry->inheritance]); 3077 if (entry->wired_count != 0) 3078 db_printf(", wired"); 3079 } 3080 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3081 db_printf(", share=%p, offset=0x%jx\n", 3082 (void *)entry->object.sub_map, 3083 (uintmax_t)entry->offset); 3084 nlines++; 3085 if ((entry->prev == &map->header) || 3086 (entry->prev->object.sub_map != 3087 entry->object.sub_map)) { 3088 db_indent += 2; 3089 vm_map_print((db_expr_t)(intptr_t) 3090 entry->object.sub_map, 3091 full, 0, (char *)0); 3092 db_indent -= 2; 3093 } 3094 } else { 3095 db_printf(", object=%p, offset=0x%jx", 3096 (void *)entry->object.vm_object, 3097 (uintmax_t)entry->offset); 3098 if (entry->eflags & MAP_ENTRY_COW) 3099 db_printf(", copy (%s)", 3100 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 3101 db_printf("\n"); 3102 nlines++; 3103 3104 if ((entry->prev == &map->header) || 3105 (entry->prev->object.vm_object != 3106 entry->object.vm_object)) { 3107 db_indent += 2; 3108 vm_object_print((db_expr_t)(intptr_t) 3109 entry->object.vm_object, 3110 full, 0, (char *)0); 3111 nlines += 4; 3112 db_indent -= 2; 3113 } 3114 } 3115 } 3116 db_indent -= 2; 3117 if (db_indent == 0) 3118 nlines = 0; 3119 } 3120 3121 3122 DB_SHOW_COMMAND(procvm, procvm) 3123 { 3124 struct proc *p; 3125 3126 if (have_addr) { 3127 p = (struct proc *) addr; 3128 } else { 3129 p = curproc; 3130 } 3131 3132 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 3133 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 3134 (void *)vmspace_pmap(p->p_vmspace)); 3135 3136 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 3137 } 3138 3139 #endif /* DDB */ 3140