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