1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61 /* 62 * Virtual memory mapping module. 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/ktr.h> 71 #include <sys/lock.h> 72 #include <sys/mutex.h> 73 #include <sys/proc.h> 74 #include <sys/vmmeter.h> 75 #include <sys/mman.h> 76 #include <sys/vnode.h> 77 #include <sys/resourcevar.h> 78 #include <sys/file.h> 79 #include <sys/sysent.h> 80 #include <sys/shm.h> 81 82 #include <vm/vm.h> 83 #include <vm/vm_param.h> 84 #include <vm/pmap.h> 85 #include <vm/vm_map.h> 86 #include <vm/vm_page.h> 87 #include <vm/vm_object.h> 88 #include <vm/vm_pager.h> 89 #include <vm/vm_kern.h> 90 #include <vm/vm_extern.h> 91 #include <vm/swap_pager.h> 92 #include <vm/uma.h> 93 94 /* 95 * Virtual memory maps provide for the mapping, protection, 96 * and sharing of virtual memory objects. In addition, 97 * this module provides for an efficient virtual copy of 98 * memory from one map to another. 99 * 100 * Synchronization is required prior to most operations. 101 * 102 * Maps consist of an ordered doubly-linked list of simple 103 * entries; a self-adjusting binary search tree of these 104 * entries is used to speed up lookups. 105 * 106 * Since portions of maps are specified by start/end addresses, 107 * which may not align with existing map entries, all 108 * routines merely "clip" entries to these start/end values. 109 * [That is, an entry is split into two, bordering at a 110 * start or end value.] Note that these clippings may not 111 * always be necessary (as the two resulting entries are then 112 * not changed); however, the clipping is done for convenience. 113 * 114 * As mentioned above, virtual copy operations are performed 115 * by copying VM object references from one map to 116 * another, and then marking both regions as copy-on-write. 117 */ 118 119 /* 120 * vm_map_startup: 121 * 122 * Initialize the vm_map module. Must be called before 123 * any other vm_map routines. 124 * 125 * Map and entry structures are allocated from the general 126 * purpose memory pool with some exceptions: 127 * 128 * - The kernel map and kmem submap are allocated statically. 129 * - Kernel map entries are allocated out of a static pool. 130 * 131 * These restrictions are necessary since malloc() uses the 132 * maps and requires map entries. 133 */ 134 135 static struct mtx map_sleep_mtx; 136 static uma_zone_t mapentzone; 137 static uma_zone_t kmapentzone; 138 static uma_zone_t mapzone; 139 static uma_zone_t vmspace_zone; 140 static struct vm_object kmapentobj; 141 static int vmspace_zinit(void *mem, int size, int flags); 142 static void vmspace_zfini(void *mem, int size); 143 static int vm_map_zinit(void *mem, int ize, int flags); 144 static void vm_map_zfini(void *mem, int size); 145 static void _vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max); 146 static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry); 147 #ifdef INVARIANTS 148 static void vm_map_zdtor(void *mem, int size, void *arg); 149 static void vmspace_zdtor(void *mem, int size, void *arg); 150 #endif 151 152 /* 153 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type 154 * stable. 155 */ 156 #define PROC_VMSPACE_LOCK(p) do { } while (0) 157 #define PROC_VMSPACE_UNLOCK(p) do { } while (0) 158 159 /* 160 * VM_MAP_RANGE_CHECK: [ internal use only ] 161 * 162 * Asserts that the starting and ending region 163 * addresses fall within the valid range of the map. 164 */ 165 #define VM_MAP_RANGE_CHECK(map, start, end) \ 166 { \ 167 if (start < vm_map_min(map)) \ 168 start = vm_map_min(map); \ 169 if (end > vm_map_max(map)) \ 170 end = vm_map_max(map); \ 171 if (start > end) \ 172 start = end; \ 173 } 174 175 void 176 vm_map_startup(void) 177 { 178 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 179 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 180 #ifdef INVARIANTS 181 vm_map_zdtor, 182 #else 183 NULL, 184 #endif 185 vm_map_zinit, vm_map_zfini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 186 uma_prealloc(mapzone, MAX_KMAP); 187 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 188 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 189 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 190 uma_prealloc(kmapentzone, MAX_KMAPENT); 191 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 192 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 193 } 194 195 static void 196 vmspace_zfini(void *mem, int size) 197 { 198 struct vmspace *vm; 199 200 vm = (struct vmspace *)mem; 201 vm_map_zfini(&vm->vm_map, sizeof(vm->vm_map)); 202 } 203 204 static int 205 vmspace_zinit(void *mem, int size, int flags) 206 { 207 struct vmspace *vm; 208 209 vm = (struct vmspace *)mem; 210 211 vm->vm_map.pmap = NULL; 212 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); 213 return (0); 214 } 215 216 static void 217 vm_map_zfini(void *mem, int size) 218 { 219 vm_map_t map; 220 221 map = (vm_map_t)mem; 222 mtx_destroy(&map->system_mtx); 223 sx_destroy(&map->lock); 224 } 225 226 static int 227 vm_map_zinit(void *mem, int size, int flags) 228 { 229 vm_map_t map; 230 231 map = (vm_map_t)mem; 232 map->nentries = 0; 233 map->size = 0; 234 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 235 sx_init(&map->lock, "user map"); 236 return (0); 237 } 238 239 #ifdef INVARIANTS 240 static void 241 vmspace_zdtor(void *mem, int size, void *arg) 242 { 243 struct vmspace *vm; 244 245 vm = (struct vmspace *)mem; 246 247 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 248 } 249 static void 250 vm_map_zdtor(void *mem, int size, void *arg) 251 { 252 vm_map_t map; 253 254 map = (vm_map_t)mem; 255 KASSERT(map->nentries == 0, 256 ("map %p nentries == %d on free.", 257 map, map->nentries)); 258 KASSERT(map->size == 0, 259 ("map %p size == %lu on free.", 260 map, (unsigned long)map->size)); 261 } 262 #endif /* INVARIANTS */ 263 264 /* 265 * Allocate a vmspace structure, including a vm_map and pmap, 266 * and initialize those structures. The refcnt is set to 1. 267 */ 268 struct vmspace * 269 vmspace_alloc(min, max) 270 vm_offset_t min, max; 271 { 272 struct vmspace *vm; 273 274 vm = uma_zalloc(vmspace_zone, M_WAITOK); 275 if (vm->vm_map.pmap == NULL && !pmap_pinit(vmspace_pmap(vm))) { 276 uma_zfree(vmspace_zone, vm); 277 return (NULL); 278 } 279 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 280 _vm_map_init(&vm->vm_map, min, max); 281 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 282 vm->vm_refcnt = 1; 283 vm->vm_shm = NULL; 284 vm->vm_swrss = 0; 285 vm->vm_tsize = 0; 286 vm->vm_dsize = 0; 287 vm->vm_ssize = 0; 288 vm->vm_taddr = 0; 289 vm->vm_daddr = 0; 290 vm->vm_maxsaddr = 0; 291 return (vm); 292 } 293 294 void 295 vm_init2(void) 296 { 297 uma_zone_set_obj(kmapentzone, &kmapentobj, lmin(cnt.v_page_count, 298 (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / PAGE_SIZE) / 8 + 299 maxproc * 2 + maxfiles); 300 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 301 #ifdef INVARIANTS 302 vmspace_zdtor, 303 #else 304 NULL, 305 #endif 306 vmspace_zinit, vmspace_zfini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 307 } 308 309 static inline void 310 vmspace_dofree(struct vmspace *vm) 311 { 312 CTR1(KTR_VM, "vmspace_free: %p", vm); 313 314 /* 315 * Make sure any SysV shm is freed, it might not have been in 316 * exit1(). 317 */ 318 shmexit(vm); 319 320 /* 321 * Lock the map, to wait out all other references to it. 322 * Delete all of the mappings and pages they hold, then call 323 * the pmap module to reclaim anything left. 324 */ 325 (void)vm_map_remove(&vm->vm_map, vm->vm_map.min_offset, 326 vm->vm_map.max_offset); 327 328 /* 329 * XXX Comment out the pmap_release call for now. The 330 * vmspace_zone is marked as UMA_ZONE_NOFREE, and bugs cause 331 * pmap.resident_count to be != 0 on exit sometimes. 332 */ 333 /* pmap_release(vmspace_pmap(vm)); */ 334 uma_zfree(vmspace_zone, vm); 335 } 336 337 void 338 vmspace_free(struct vmspace *vm) 339 { 340 int refcnt; 341 342 if (vm->vm_refcnt == 0) 343 panic("vmspace_free: attempt to free already freed vmspace"); 344 345 do 346 refcnt = vm->vm_refcnt; 347 while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 348 if (refcnt == 1) 349 vmspace_dofree(vm); 350 } 351 352 void 353 vmspace_exitfree(struct proc *p) 354 { 355 struct vmspace *vm; 356 357 PROC_VMSPACE_LOCK(p); 358 vm = p->p_vmspace; 359 p->p_vmspace = NULL; 360 PROC_VMSPACE_UNLOCK(p); 361 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 362 vmspace_free(vm); 363 } 364 365 void 366 vmspace_exit(struct thread *td) 367 { 368 int refcnt; 369 struct vmspace *vm; 370 struct proc *p; 371 372 /* 373 * Release user portion of address space. 374 * This releases references to vnodes, 375 * which could cause I/O if the file has been unlinked. 376 * Need to do this early enough that we can still sleep. 377 * 378 * The last exiting process to reach this point releases as 379 * much of the environment as it can. vmspace_dofree() is the 380 * slower fallback in case another process had a temporary 381 * reference to the vmspace. 382 */ 383 384 p = td->td_proc; 385 vm = p->p_vmspace; 386 atomic_add_int(&vmspace0.vm_refcnt, 1); 387 do { 388 refcnt = vm->vm_refcnt; 389 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 390 /* Switch now since other proc might free vmspace */ 391 PROC_VMSPACE_LOCK(p); 392 p->p_vmspace = &vmspace0; 393 PROC_VMSPACE_UNLOCK(p); 394 pmap_activate(td); 395 } 396 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 397 if (refcnt == 1) { 398 if (p->p_vmspace != vm) { 399 /* vmspace not yet freed, switch back */ 400 PROC_VMSPACE_LOCK(p); 401 p->p_vmspace = vm; 402 PROC_VMSPACE_UNLOCK(p); 403 pmap_activate(td); 404 } 405 pmap_remove_pages(vmspace_pmap(vm)); 406 /* Switch now since this proc will free vmspace */ 407 PROC_VMSPACE_LOCK(p); 408 p->p_vmspace = &vmspace0; 409 PROC_VMSPACE_UNLOCK(p); 410 pmap_activate(td); 411 vmspace_dofree(vm); 412 } 413 } 414 415 /* Acquire reference to vmspace owned by another process. */ 416 417 struct vmspace * 418 vmspace_acquire_ref(struct proc *p) 419 { 420 struct vmspace *vm; 421 int refcnt; 422 423 PROC_VMSPACE_LOCK(p); 424 vm = p->p_vmspace; 425 if (vm == NULL) { 426 PROC_VMSPACE_UNLOCK(p); 427 return (NULL); 428 } 429 do { 430 refcnt = vm->vm_refcnt; 431 if (refcnt <= 0) { /* Avoid 0->1 transition */ 432 PROC_VMSPACE_UNLOCK(p); 433 return (NULL); 434 } 435 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1)); 436 if (vm != p->p_vmspace) { 437 PROC_VMSPACE_UNLOCK(p); 438 vmspace_free(vm); 439 return (NULL); 440 } 441 PROC_VMSPACE_UNLOCK(p); 442 return (vm); 443 } 444 445 void 446 _vm_map_lock(vm_map_t map, const char *file, int line) 447 { 448 449 if (map->system_map) 450 _mtx_lock_flags(&map->system_mtx, 0, file, line); 451 else 452 (void)_sx_xlock(&map->lock, 0, file, line); 453 map->timestamp++; 454 } 455 456 void 457 _vm_map_unlock(vm_map_t map, const char *file, int line) 458 { 459 vm_map_entry_t free_entry, entry; 460 vm_object_t object; 461 462 free_entry = map->deferred_freelist; 463 map->deferred_freelist = NULL; 464 465 if (map->system_map) 466 _mtx_unlock_flags(&map->system_mtx, 0, file, line); 467 else 468 _sx_xunlock(&map->lock, file, line); 469 470 while (free_entry != NULL) { 471 entry = free_entry; 472 free_entry = free_entry->next; 473 474 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 475 object = entry->object.vm_object; 476 vm_object_deallocate(object); 477 } 478 479 vm_map_entry_dispose(map, entry); 480 } 481 } 482 483 void 484 _vm_map_lock_read(vm_map_t map, const char *file, int line) 485 { 486 487 if (map->system_map) 488 _mtx_lock_flags(&map->system_mtx, 0, file, line); 489 else 490 (void)_sx_slock(&map->lock, 0, file, line); 491 } 492 493 void 494 _vm_map_unlock_read(vm_map_t map, const char *file, int line) 495 { 496 497 if (map->system_map) 498 _mtx_unlock_flags(&map->system_mtx, 0, file, line); 499 else 500 _sx_sunlock(&map->lock, file, line); 501 } 502 503 int 504 _vm_map_trylock(vm_map_t map, const char *file, int line) 505 { 506 int error; 507 508 error = map->system_map ? 509 !_mtx_trylock(&map->system_mtx, 0, file, line) : 510 !_sx_try_xlock(&map->lock, file, line); 511 if (error == 0) 512 map->timestamp++; 513 return (error == 0); 514 } 515 516 int 517 _vm_map_trylock_read(vm_map_t map, const char *file, int line) 518 { 519 int error; 520 521 error = map->system_map ? 522 !_mtx_trylock(&map->system_mtx, 0, file, line) : 523 !_sx_try_slock(&map->lock, file, line); 524 return (error == 0); 525 } 526 527 /* 528 * _vm_map_lock_upgrade: [ internal use only ] 529 * 530 * Tries to upgrade a read (shared) lock on the specified map to a write 531 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 532 * non-zero value if the upgrade fails. If the upgrade fails, the map is 533 * returned without a read or write lock held. 534 * 535 * Requires that the map be read locked. 536 */ 537 int 538 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 539 { 540 unsigned int last_timestamp; 541 542 if (map->system_map) { 543 #ifdef INVARIANTS 544 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 545 #endif 546 } else { 547 if (!_sx_try_upgrade(&map->lock, file, line)) { 548 last_timestamp = map->timestamp; 549 _sx_sunlock(&map->lock, file, line); 550 /* 551 * If the map's timestamp does not change while the 552 * map is unlocked, then the upgrade succeeds. 553 */ 554 (void)_sx_xlock(&map->lock, 0, file, line); 555 if (last_timestamp != map->timestamp) { 556 _sx_xunlock(&map->lock, file, line); 557 return (1); 558 } 559 } 560 } 561 map->timestamp++; 562 return (0); 563 } 564 565 void 566 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 567 { 568 569 if (map->system_map) { 570 #ifdef INVARIANTS 571 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 572 #endif 573 } else 574 _sx_downgrade(&map->lock, file, line); 575 } 576 577 /* 578 * vm_map_locked: 579 * 580 * Returns a non-zero value if the caller holds a write (exclusive) lock 581 * on the specified map and the value "0" otherwise. 582 */ 583 int 584 vm_map_locked(vm_map_t map) 585 { 586 587 if (map->system_map) 588 return (mtx_owned(&map->system_mtx)); 589 else 590 return (sx_xlocked(&map->lock)); 591 } 592 593 #ifdef INVARIANTS 594 static void 595 _vm_map_assert_locked(vm_map_t map, const char *file, int line) 596 { 597 598 if (map->system_map) 599 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 600 else 601 _sx_assert(&map->lock, SA_XLOCKED, file, line); 602 } 603 604 #if 0 605 static void 606 _vm_map_assert_locked_read(vm_map_t map, const char *file, int line) 607 { 608 609 if (map->system_map) 610 _mtx_assert(&map->system_mtx, MA_OWNED, file, line); 611 else 612 _sx_assert(&map->lock, SA_SLOCKED, file, line); 613 } 614 #endif 615 616 #define VM_MAP_ASSERT_LOCKED(map) \ 617 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 618 #define VM_MAP_ASSERT_LOCKED_READ(map) \ 619 _vm_map_assert_locked_read(map, LOCK_FILE, LOCK_LINE) 620 #else 621 #define VM_MAP_ASSERT_LOCKED(map) 622 #define VM_MAP_ASSERT_LOCKED_READ(map) 623 #endif 624 625 /* 626 * vm_map_unlock_and_wait: 627 */ 628 int 629 vm_map_unlock_and_wait(vm_map_t map, int timo) 630 { 631 632 mtx_lock(&map_sleep_mtx); 633 vm_map_unlock(map); 634 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", timo)); 635 } 636 637 /* 638 * vm_map_wakeup: 639 */ 640 void 641 vm_map_wakeup(vm_map_t map) 642 { 643 644 /* 645 * Acquire and release map_sleep_mtx to prevent a wakeup() 646 * from being performed (and lost) between the vm_map_unlock() 647 * and the msleep() in vm_map_unlock_and_wait(). 648 */ 649 mtx_lock(&map_sleep_mtx); 650 mtx_unlock(&map_sleep_mtx); 651 wakeup(&map->root); 652 } 653 654 long 655 vmspace_resident_count(struct vmspace *vmspace) 656 { 657 return pmap_resident_count(vmspace_pmap(vmspace)); 658 } 659 660 long 661 vmspace_wired_count(struct vmspace *vmspace) 662 { 663 return pmap_wired_count(vmspace_pmap(vmspace)); 664 } 665 666 /* 667 * vm_map_create: 668 * 669 * Creates and returns a new empty VM map with 670 * the given physical map structure, and having 671 * the given lower and upper address bounds. 672 */ 673 vm_map_t 674 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 675 { 676 vm_map_t result; 677 678 result = uma_zalloc(mapzone, M_WAITOK); 679 CTR1(KTR_VM, "vm_map_create: %p", result); 680 _vm_map_init(result, min, max); 681 result->pmap = pmap; 682 return (result); 683 } 684 685 /* 686 * Initialize an existing vm_map structure 687 * such as that in the vmspace structure. 688 * The pmap is set elsewhere. 689 */ 690 static void 691 _vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max) 692 { 693 694 map->header.next = map->header.prev = &map->header; 695 map->needs_wakeup = FALSE; 696 map->system_map = 0; 697 map->min_offset = min; 698 map->max_offset = max; 699 map->flags = 0; 700 map->root = NULL; 701 map->timestamp = 0; 702 map->deferred_freelist = NULL; 703 } 704 705 void 706 vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max) 707 { 708 _vm_map_init(map, min, max); 709 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 710 sx_init(&map->lock, "user map"); 711 } 712 713 /* 714 * vm_map_entry_dispose: [ internal use only ] 715 * 716 * Inverse of vm_map_entry_create. 717 */ 718 static void 719 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 720 { 721 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 722 } 723 724 /* 725 * vm_map_entry_create: [ internal use only ] 726 * 727 * Allocates a VM map entry for insertion. 728 * No entry fields are filled in. 729 */ 730 static vm_map_entry_t 731 vm_map_entry_create(vm_map_t map) 732 { 733 vm_map_entry_t new_entry; 734 735 if (map->system_map) 736 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 737 else 738 new_entry = uma_zalloc(mapentzone, M_WAITOK); 739 if (new_entry == NULL) 740 panic("vm_map_entry_create: kernel resources exhausted"); 741 return (new_entry); 742 } 743 744 /* 745 * vm_map_entry_set_behavior: 746 * 747 * Set the expected access behavior, either normal, random, or 748 * sequential. 749 */ 750 static inline void 751 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 752 { 753 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 754 (behavior & MAP_ENTRY_BEHAV_MASK); 755 } 756 757 /* 758 * vm_map_entry_set_max_free: 759 * 760 * Set the max_free field in a vm_map_entry. 761 */ 762 static inline void 763 vm_map_entry_set_max_free(vm_map_entry_t entry) 764 { 765 766 entry->max_free = entry->adj_free; 767 if (entry->left != NULL && entry->left->max_free > entry->max_free) 768 entry->max_free = entry->left->max_free; 769 if (entry->right != NULL && entry->right->max_free > entry->max_free) 770 entry->max_free = entry->right->max_free; 771 } 772 773 /* 774 * vm_map_entry_splay: 775 * 776 * The Sleator and Tarjan top-down splay algorithm with the 777 * following variation. Max_free must be computed bottom-up, so 778 * on the downward pass, maintain the left and right spines in 779 * reverse order. Then, make a second pass up each side to fix 780 * the pointers and compute max_free. The time bound is O(log n) 781 * amortized. 782 * 783 * The new root is the vm_map_entry containing "addr", or else an 784 * adjacent entry (lower or higher) if addr is not in the tree. 785 * 786 * The map must be locked, and leaves it so. 787 * 788 * Returns: the new root. 789 */ 790 static vm_map_entry_t 791 vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root) 792 { 793 vm_map_entry_t llist, rlist; 794 vm_map_entry_t ltree, rtree; 795 vm_map_entry_t y; 796 797 /* Special case of empty tree. */ 798 if (root == NULL) 799 return (root); 800 801 /* 802 * Pass One: Splay down the tree until we find addr or a NULL 803 * pointer where addr would go. llist and rlist are the two 804 * sides in reverse order (bottom-up), with llist linked by 805 * the right pointer and rlist linked by the left pointer in 806 * the vm_map_entry. Wait until Pass Two to set max_free on 807 * the two spines. 808 */ 809 llist = NULL; 810 rlist = NULL; 811 for (;;) { 812 /* root is never NULL in here. */ 813 if (addr < root->start) { 814 y = root->left; 815 if (y == NULL) 816 break; 817 if (addr < y->start && y->left != NULL) { 818 /* Rotate right and put y on rlist. */ 819 root->left = y->right; 820 y->right = root; 821 vm_map_entry_set_max_free(root); 822 root = y->left; 823 y->left = rlist; 824 rlist = y; 825 } else { 826 /* Put root on rlist. */ 827 root->left = rlist; 828 rlist = root; 829 root = y; 830 } 831 } else if (addr >= root->end) { 832 y = root->right; 833 if (y == NULL) 834 break; 835 if (addr >= y->end && y->right != NULL) { 836 /* Rotate left and put y on llist. */ 837 root->right = y->left; 838 y->left = root; 839 vm_map_entry_set_max_free(root); 840 root = y->right; 841 y->right = llist; 842 llist = y; 843 } else { 844 /* Put root on llist. */ 845 root->right = llist; 846 llist = root; 847 root = y; 848 } 849 } else 850 break; 851 } 852 853 /* 854 * Pass Two: Walk back up the two spines, flip the pointers 855 * and set max_free. The subtrees of the root go at the 856 * bottom of llist and rlist. 857 */ 858 ltree = root->left; 859 while (llist != NULL) { 860 y = llist->right; 861 llist->right = ltree; 862 vm_map_entry_set_max_free(llist); 863 ltree = llist; 864 llist = y; 865 } 866 rtree = root->right; 867 while (rlist != NULL) { 868 y = rlist->left; 869 rlist->left = rtree; 870 vm_map_entry_set_max_free(rlist); 871 rtree = rlist; 872 rlist = y; 873 } 874 875 /* 876 * Final assembly: add ltree and rtree as subtrees of root. 877 */ 878 root->left = ltree; 879 root->right = rtree; 880 vm_map_entry_set_max_free(root); 881 882 return (root); 883 } 884 885 /* 886 * vm_map_entry_{un,}link: 887 * 888 * Insert/remove entries from maps. 889 */ 890 static void 891 vm_map_entry_link(vm_map_t map, 892 vm_map_entry_t after_where, 893 vm_map_entry_t entry) 894 { 895 896 CTR4(KTR_VM, 897 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 898 map->nentries, entry, after_where); 899 VM_MAP_ASSERT_LOCKED(map); 900 map->nentries++; 901 entry->prev = after_where; 902 entry->next = after_where->next; 903 entry->next->prev = entry; 904 after_where->next = entry; 905 906 if (after_where != &map->header) { 907 if (after_where != map->root) 908 vm_map_entry_splay(after_where->start, map->root); 909 entry->right = after_where->right; 910 entry->left = after_where; 911 after_where->right = NULL; 912 after_where->adj_free = entry->start - after_where->end; 913 vm_map_entry_set_max_free(after_where); 914 } else { 915 entry->right = map->root; 916 entry->left = NULL; 917 } 918 entry->adj_free = (entry->next == &map->header ? map->max_offset : 919 entry->next->start) - entry->end; 920 vm_map_entry_set_max_free(entry); 921 map->root = entry; 922 } 923 924 static void 925 vm_map_entry_unlink(vm_map_t map, 926 vm_map_entry_t entry) 927 { 928 vm_map_entry_t next, prev, root; 929 930 VM_MAP_ASSERT_LOCKED(map); 931 if (entry != map->root) 932 vm_map_entry_splay(entry->start, map->root); 933 if (entry->left == NULL) 934 root = entry->right; 935 else { 936 root = vm_map_entry_splay(entry->start, entry->left); 937 root->right = entry->right; 938 root->adj_free = (entry->next == &map->header ? map->max_offset : 939 entry->next->start) - root->end; 940 vm_map_entry_set_max_free(root); 941 } 942 map->root = root; 943 944 prev = entry->prev; 945 next = entry->next; 946 next->prev = prev; 947 prev->next = next; 948 map->nentries--; 949 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 950 map->nentries, entry); 951 } 952 953 /* 954 * vm_map_entry_resize_free: 955 * 956 * Recompute the amount of free space following a vm_map_entry 957 * and propagate that value up the tree. Call this function after 958 * resizing a map entry in-place, that is, without a call to 959 * vm_map_entry_link() or _unlink(). 960 * 961 * The map must be locked, and leaves it so. 962 */ 963 static void 964 vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry) 965 { 966 967 /* 968 * Using splay trees without parent pointers, propagating 969 * max_free up the tree is done by moving the entry to the 970 * root and making the change there. 971 */ 972 if (entry != map->root) 973 map->root = vm_map_entry_splay(entry->start, map->root); 974 975 entry->adj_free = (entry->next == &map->header ? map->max_offset : 976 entry->next->start) - entry->end; 977 vm_map_entry_set_max_free(entry); 978 } 979 980 /* 981 * vm_map_lookup_entry: [ internal use only ] 982 * 983 * Finds the map entry containing (or 984 * immediately preceding) the specified address 985 * in the given map; the entry is returned 986 * in the "entry" parameter. The boolean 987 * result indicates whether the address is 988 * actually contained in the map. 989 */ 990 boolean_t 991 vm_map_lookup_entry( 992 vm_map_t map, 993 vm_offset_t address, 994 vm_map_entry_t *entry) /* OUT */ 995 { 996 vm_map_entry_t cur; 997 boolean_t locked; 998 999 /* 1000 * If the map is empty, then the map entry immediately preceding 1001 * "address" is the map's header. 1002 */ 1003 cur = map->root; 1004 if (cur == NULL) 1005 *entry = &map->header; 1006 else if (address >= cur->start && cur->end > address) { 1007 *entry = cur; 1008 return (TRUE); 1009 } else if ((locked = vm_map_locked(map)) || 1010 sx_try_upgrade(&map->lock)) { 1011 /* 1012 * Splay requires a write lock on the map. However, it only 1013 * restructures the binary search tree; it does not otherwise 1014 * change the map. Thus, the map's timestamp need not change 1015 * on a temporary upgrade. 1016 */ 1017 map->root = cur = vm_map_entry_splay(address, cur); 1018 if (!locked) 1019 sx_downgrade(&map->lock); 1020 1021 /* 1022 * If "address" is contained within a map entry, the new root 1023 * is that map entry. Otherwise, the new root is a map entry 1024 * immediately before or after "address". 1025 */ 1026 if (address >= cur->start) { 1027 *entry = cur; 1028 if (cur->end > address) 1029 return (TRUE); 1030 } else 1031 *entry = cur->prev; 1032 } else 1033 /* 1034 * Since the map is only locked for read access, perform a 1035 * standard binary search tree lookup for "address". 1036 */ 1037 for (;;) { 1038 if (address < cur->start) { 1039 if (cur->left == NULL) { 1040 *entry = cur->prev; 1041 break; 1042 } 1043 cur = cur->left; 1044 } else if (cur->end > address) { 1045 *entry = cur; 1046 return (TRUE); 1047 } else { 1048 if (cur->right == NULL) { 1049 *entry = cur; 1050 break; 1051 } 1052 cur = cur->right; 1053 } 1054 } 1055 return (FALSE); 1056 } 1057 1058 /* 1059 * vm_map_insert: 1060 * 1061 * Inserts the given whole VM object into the target 1062 * map at the specified address range. The object's 1063 * size should match that of the address range. 1064 * 1065 * Requires that the map be locked, and leaves it so. 1066 * 1067 * If object is non-NULL, ref count must be bumped by caller 1068 * prior to making call to account for the new entry. 1069 */ 1070 int 1071 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1072 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 1073 int cow) 1074 { 1075 vm_map_entry_t new_entry; 1076 vm_map_entry_t prev_entry; 1077 vm_map_entry_t temp_entry; 1078 vm_eflags_t protoeflags; 1079 1080 VM_MAP_ASSERT_LOCKED(map); 1081 1082 /* 1083 * Check that the start and end points are not bogus. 1084 */ 1085 if ((start < map->min_offset) || (end > map->max_offset) || 1086 (start >= end)) 1087 return (KERN_INVALID_ADDRESS); 1088 1089 /* 1090 * Find the entry prior to the proposed starting address; if it's part 1091 * of an existing entry, this range is bogus. 1092 */ 1093 if (vm_map_lookup_entry(map, start, &temp_entry)) 1094 return (KERN_NO_SPACE); 1095 1096 prev_entry = temp_entry; 1097 1098 /* 1099 * Assert that the next entry doesn't overlap the end point. 1100 */ 1101 if ((prev_entry->next != &map->header) && 1102 (prev_entry->next->start < end)) 1103 return (KERN_NO_SPACE); 1104 1105 protoeflags = 0; 1106 1107 if (cow & MAP_COPY_ON_WRITE) 1108 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 1109 1110 if (cow & MAP_NOFAULT) { 1111 protoeflags |= MAP_ENTRY_NOFAULT; 1112 1113 KASSERT(object == NULL, 1114 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1115 } 1116 if (cow & MAP_DISABLE_SYNCER) 1117 protoeflags |= MAP_ENTRY_NOSYNC; 1118 if (cow & MAP_DISABLE_COREDUMP) 1119 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1120 1121 if (object != NULL) { 1122 /* 1123 * OBJ_ONEMAPPING must be cleared unless this mapping 1124 * is trivially proven to be the only mapping for any 1125 * of the object's pages. (Object granularity 1126 * reference counting is insufficient to recognize 1127 * aliases with precision.) 1128 */ 1129 VM_OBJECT_LOCK(object); 1130 if (object->ref_count > 1 || object->shadow_count != 0) 1131 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1132 VM_OBJECT_UNLOCK(object); 1133 } 1134 else if ((prev_entry != &map->header) && 1135 (prev_entry->eflags == protoeflags) && 1136 (prev_entry->end == start) && 1137 (prev_entry->wired_count == 0) && 1138 ((prev_entry->object.vm_object == NULL) || 1139 vm_object_coalesce(prev_entry->object.vm_object, 1140 prev_entry->offset, 1141 (vm_size_t)(prev_entry->end - prev_entry->start), 1142 (vm_size_t)(end - prev_entry->end)))) { 1143 /* 1144 * We were able to extend the object. Determine if we 1145 * can extend the previous map entry to include the 1146 * new range as well. 1147 */ 1148 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 1149 (prev_entry->protection == prot) && 1150 (prev_entry->max_protection == max)) { 1151 map->size += (end - prev_entry->end); 1152 prev_entry->end = end; 1153 vm_map_entry_resize_free(map, prev_entry); 1154 vm_map_simplify_entry(map, prev_entry); 1155 return (KERN_SUCCESS); 1156 } 1157 1158 /* 1159 * If we can extend the object but cannot extend the 1160 * map entry, we have to create a new map entry. We 1161 * must bump the ref count on the extended object to 1162 * account for it. object may be NULL. 1163 */ 1164 object = prev_entry->object.vm_object; 1165 offset = prev_entry->offset + 1166 (prev_entry->end - prev_entry->start); 1167 vm_object_reference(object); 1168 } 1169 1170 /* 1171 * NOTE: if conditionals fail, object can be NULL here. This occurs 1172 * in things like the buffer map where we manage kva but do not manage 1173 * backing objects. 1174 */ 1175 1176 /* 1177 * Create a new entry 1178 */ 1179 new_entry = vm_map_entry_create(map); 1180 new_entry->start = start; 1181 new_entry->end = end; 1182 1183 new_entry->eflags = protoeflags; 1184 new_entry->object.vm_object = object; 1185 new_entry->offset = offset; 1186 new_entry->avail_ssize = 0; 1187 1188 new_entry->inheritance = VM_INHERIT_DEFAULT; 1189 new_entry->protection = prot; 1190 new_entry->max_protection = max; 1191 new_entry->wired_count = 0; 1192 1193 /* 1194 * Insert the new entry into the list 1195 */ 1196 vm_map_entry_link(map, prev_entry, new_entry); 1197 map->size += new_entry->end - new_entry->start; 1198 1199 #if 0 1200 /* 1201 * Temporarily removed to avoid MAP_STACK panic, due to 1202 * MAP_STACK being a huge hack. Will be added back in 1203 * when MAP_STACK (and the user stack mapping) is fixed. 1204 */ 1205 /* 1206 * It may be possible to simplify the entry 1207 */ 1208 vm_map_simplify_entry(map, new_entry); 1209 #endif 1210 1211 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 1212 vm_map_pmap_enter(map, start, prot, 1213 object, OFF_TO_IDX(offset), end - start, 1214 cow & MAP_PREFAULT_PARTIAL); 1215 } 1216 1217 return (KERN_SUCCESS); 1218 } 1219 1220 /* 1221 * vm_map_findspace: 1222 * 1223 * Find the first fit (lowest VM address) for "length" free bytes 1224 * beginning at address >= start in the given map. 1225 * 1226 * In a vm_map_entry, "adj_free" is the amount of free space 1227 * adjacent (higher address) to this entry, and "max_free" is the 1228 * maximum amount of contiguous free space in its subtree. This 1229 * allows finding a free region in one path down the tree, so 1230 * O(log n) amortized with splay trees. 1231 * 1232 * The map must be locked, and leaves it so. 1233 * 1234 * Returns: 0 on success, and starting address in *addr, 1235 * 1 if insufficient space. 1236 */ 1237 int 1238 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1239 vm_offset_t *addr) /* OUT */ 1240 { 1241 vm_map_entry_t entry; 1242 vm_offset_t end, st; 1243 1244 /* 1245 * Request must fit within min/max VM address and must avoid 1246 * address wrap. 1247 */ 1248 if (start < map->min_offset) 1249 start = map->min_offset; 1250 if (start + length > map->max_offset || start + length < start) 1251 return (1); 1252 1253 /* Empty tree means wide open address space. */ 1254 if (map->root == NULL) { 1255 *addr = start; 1256 goto found; 1257 } 1258 1259 /* 1260 * After splay, if start comes before root node, then there 1261 * must be a gap from start to the root. 1262 */ 1263 map->root = vm_map_entry_splay(start, map->root); 1264 if (start + length <= map->root->start) { 1265 *addr = start; 1266 goto found; 1267 } 1268 1269 /* 1270 * Root is the last node that might begin its gap before 1271 * start, and this is the last comparison where address 1272 * wrap might be a problem. 1273 */ 1274 st = (start > map->root->end) ? start : map->root->end; 1275 if (length <= map->root->end + map->root->adj_free - st) { 1276 *addr = st; 1277 goto found; 1278 } 1279 1280 /* With max_free, can immediately tell if no solution. */ 1281 entry = map->root->right; 1282 if (entry == NULL || length > entry->max_free) 1283 return (1); 1284 1285 /* 1286 * Search the right subtree in the order: left subtree, root, 1287 * right subtree (first fit). The previous splay implies that 1288 * all regions in the right subtree have addresses > start. 1289 */ 1290 while (entry != NULL) { 1291 if (entry->left != NULL && entry->left->max_free >= length) 1292 entry = entry->left; 1293 else if (entry->adj_free >= length) { 1294 *addr = entry->end; 1295 goto found; 1296 } else 1297 entry = entry->right; 1298 } 1299 1300 /* Can't get here, so panic if we do. */ 1301 panic("vm_map_findspace: max_free corrupt"); 1302 1303 found: 1304 /* Expand the kernel pmap, if necessary. */ 1305 if (map == kernel_map) { 1306 end = round_page(*addr + length); 1307 if (end > kernel_vm_end) 1308 pmap_growkernel(end); 1309 } 1310 return (0); 1311 } 1312 1313 int 1314 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1315 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1316 vm_prot_t max, int cow) 1317 { 1318 vm_offset_t end; 1319 int result; 1320 1321 end = start + length; 1322 vm_map_lock(map); 1323 VM_MAP_RANGE_CHECK(map, start, end); 1324 (void) vm_map_delete(map, start, end); 1325 result = vm_map_insert(map, object, offset, start, end, prot, 1326 max, cow); 1327 vm_map_unlock(map); 1328 return (result); 1329 } 1330 1331 /* 1332 * vm_map_find finds an unallocated region in the target address 1333 * map with the given length. The search is defined to be 1334 * first-fit from the specified address; the region found is 1335 * returned in the same parameter. 1336 * 1337 * If object is non-NULL, ref count must be bumped by caller 1338 * prior to making call to account for the new entry. 1339 */ 1340 int 1341 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1342 vm_offset_t *addr, /* IN/OUT */ 1343 vm_size_t length, int find_space, vm_prot_t prot, 1344 vm_prot_t max, int cow) 1345 { 1346 vm_offset_t start; 1347 int result; 1348 1349 start = *addr; 1350 vm_map_lock(map); 1351 do { 1352 if (find_space != VMFS_NO_SPACE) { 1353 if (vm_map_findspace(map, start, length, addr)) { 1354 vm_map_unlock(map); 1355 return (KERN_NO_SPACE); 1356 } 1357 if (find_space == VMFS_ALIGNED_SPACE) 1358 pmap_align_superpage(object, offset, addr, 1359 length); 1360 start = *addr; 1361 } 1362 result = vm_map_insert(map, object, offset, start, start + 1363 length, prot, max, cow); 1364 } while (result == KERN_NO_SPACE && find_space == VMFS_ALIGNED_SPACE); 1365 vm_map_unlock(map); 1366 return (result); 1367 } 1368 1369 /* 1370 * vm_map_simplify_entry: 1371 * 1372 * Simplify the given map entry by merging with either neighbor. This 1373 * routine also has the ability to merge with both neighbors. 1374 * 1375 * The map must be locked. 1376 * 1377 * This routine guarentees that the passed entry remains valid (though 1378 * possibly extended). When merging, this routine may delete one or 1379 * both neighbors. 1380 */ 1381 void 1382 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1383 { 1384 vm_map_entry_t next, prev; 1385 vm_size_t prevsize, esize; 1386 1387 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) 1388 return; 1389 1390 prev = entry->prev; 1391 if (prev != &map->header) { 1392 prevsize = prev->end - prev->start; 1393 if ( (prev->end == entry->start) && 1394 (prev->object.vm_object == entry->object.vm_object) && 1395 (!prev->object.vm_object || 1396 (prev->offset + prevsize == entry->offset)) && 1397 (prev->eflags == entry->eflags) && 1398 (prev->protection == entry->protection) && 1399 (prev->max_protection == entry->max_protection) && 1400 (prev->inheritance == entry->inheritance) && 1401 (prev->wired_count == entry->wired_count)) { 1402 vm_map_entry_unlink(map, prev); 1403 entry->start = prev->start; 1404 entry->offset = prev->offset; 1405 if (entry->prev != &map->header) 1406 vm_map_entry_resize_free(map, entry->prev); 1407 1408 /* 1409 * If the backing object is a vnode object, 1410 * vm_object_deallocate() calls vrele(). 1411 * However, vrele() does not lock the vnode 1412 * because the vnode has additional 1413 * references. Thus, the map lock can be kept 1414 * without causing a lock-order reversal with 1415 * the vnode lock. 1416 */ 1417 if (prev->object.vm_object) 1418 vm_object_deallocate(prev->object.vm_object); 1419 vm_map_entry_dispose(map, prev); 1420 } 1421 } 1422 1423 next = entry->next; 1424 if (next != &map->header) { 1425 esize = entry->end - entry->start; 1426 if ((entry->end == next->start) && 1427 (next->object.vm_object == entry->object.vm_object) && 1428 (!entry->object.vm_object || 1429 (entry->offset + esize == next->offset)) && 1430 (next->eflags == entry->eflags) && 1431 (next->protection == entry->protection) && 1432 (next->max_protection == entry->max_protection) && 1433 (next->inheritance == entry->inheritance) && 1434 (next->wired_count == entry->wired_count)) { 1435 vm_map_entry_unlink(map, next); 1436 entry->end = next->end; 1437 vm_map_entry_resize_free(map, entry); 1438 1439 /* 1440 * See comment above. 1441 */ 1442 if (next->object.vm_object) 1443 vm_object_deallocate(next->object.vm_object); 1444 vm_map_entry_dispose(map, next); 1445 } 1446 } 1447 } 1448 /* 1449 * vm_map_clip_start: [ internal use only ] 1450 * 1451 * Asserts that the given entry begins at or after 1452 * the specified address; if necessary, 1453 * it splits the entry into two. 1454 */ 1455 #define vm_map_clip_start(map, entry, startaddr) \ 1456 { \ 1457 if (startaddr > entry->start) \ 1458 _vm_map_clip_start(map, entry, startaddr); \ 1459 } 1460 1461 /* 1462 * This routine is called only when it is known that 1463 * the entry must be split. 1464 */ 1465 static void 1466 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1467 { 1468 vm_map_entry_t new_entry; 1469 1470 VM_MAP_ASSERT_LOCKED(map); 1471 1472 /* 1473 * Split off the front portion -- note that we must insert the new 1474 * entry BEFORE this one, so that this entry has the specified 1475 * starting address. 1476 */ 1477 vm_map_simplify_entry(map, entry); 1478 1479 /* 1480 * If there is no object backing this entry, we might as well create 1481 * one now. If we defer it, an object can get created after the map 1482 * is clipped, and individual objects will be created for the split-up 1483 * map. This is a bit of a hack, but is also about the best place to 1484 * put this improvement. 1485 */ 1486 if (entry->object.vm_object == NULL && !map->system_map) { 1487 vm_object_t object; 1488 object = vm_object_allocate(OBJT_DEFAULT, 1489 atop(entry->end - entry->start)); 1490 entry->object.vm_object = object; 1491 entry->offset = 0; 1492 } 1493 1494 new_entry = vm_map_entry_create(map); 1495 *new_entry = *entry; 1496 1497 new_entry->end = start; 1498 entry->offset += (start - entry->start); 1499 entry->start = start; 1500 1501 vm_map_entry_link(map, entry->prev, new_entry); 1502 1503 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1504 vm_object_reference(new_entry->object.vm_object); 1505 } 1506 } 1507 1508 /* 1509 * vm_map_clip_end: [ internal use only ] 1510 * 1511 * Asserts that the given entry ends at or before 1512 * the specified address; if necessary, 1513 * it splits the entry into two. 1514 */ 1515 #define vm_map_clip_end(map, entry, endaddr) \ 1516 { \ 1517 if ((endaddr) < (entry->end)) \ 1518 _vm_map_clip_end((map), (entry), (endaddr)); \ 1519 } 1520 1521 /* 1522 * This routine is called only when it is known that 1523 * the entry must be split. 1524 */ 1525 static void 1526 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1527 { 1528 vm_map_entry_t new_entry; 1529 1530 VM_MAP_ASSERT_LOCKED(map); 1531 1532 /* 1533 * If there is no object backing this entry, we might as well create 1534 * one now. If we defer it, an object can get created after the map 1535 * is clipped, and individual objects will be created for the split-up 1536 * map. This is a bit of a hack, but is also about the best place to 1537 * put this improvement. 1538 */ 1539 if (entry->object.vm_object == NULL && !map->system_map) { 1540 vm_object_t object; 1541 object = vm_object_allocate(OBJT_DEFAULT, 1542 atop(entry->end - entry->start)); 1543 entry->object.vm_object = object; 1544 entry->offset = 0; 1545 } 1546 1547 /* 1548 * Create a new entry and insert it AFTER the specified entry 1549 */ 1550 new_entry = vm_map_entry_create(map); 1551 *new_entry = *entry; 1552 1553 new_entry->start = entry->end = end; 1554 new_entry->offset += (end - entry->start); 1555 1556 vm_map_entry_link(map, entry, new_entry); 1557 1558 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1559 vm_object_reference(new_entry->object.vm_object); 1560 } 1561 } 1562 1563 /* 1564 * vm_map_submap: [ kernel use only ] 1565 * 1566 * Mark the given range as handled by a subordinate map. 1567 * 1568 * This range must have been created with vm_map_find, 1569 * and no other operations may have been performed on this 1570 * range prior to calling vm_map_submap. 1571 * 1572 * Only a limited number of operations can be performed 1573 * within this rage after calling vm_map_submap: 1574 * vm_fault 1575 * [Don't try vm_map_copy!] 1576 * 1577 * To remove a submapping, one must first remove the 1578 * range from the superior map, and then destroy the 1579 * submap (if desired). [Better yet, don't try it.] 1580 */ 1581 int 1582 vm_map_submap( 1583 vm_map_t map, 1584 vm_offset_t start, 1585 vm_offset_t end, 1586 vm_map_t submap) 1587 { 1588 vm_map_entry_t entry; 1589 int result = KERN_INVALID_ARGUMENT; 1590 1591 vm_map_lock(map); 1592 1593 VM_MAP_RANGE_CHECK(map, start, end); 1594 1595 if (vm_map_lookup_entry(map, start, &entry)) { 1596 vm_map_clip_start(map, entry, start); 1597 } else 1598 entry = entry->next; 1599 1600 vm_map_clip_end(map, entry, end); 1601 1602 if ((entry->start == start) && (entry->end == end) && 1603 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1604 (entry->object.vm_object == NULL)) { 1605 entry->object.sub_map = submap; 1606 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1607 result = KERN_SUCCESS; 1608 } 1609 vm_map_unlock(map); 1610 1611 return (result); 1612 } 1613 1614 /* 1615 * The maximum number of pages to map 1616 */ 1617 #define MAX_INIT_PT 96 1618 1619 /* 1620 * vm_map_pmap_enter: 1621 * 1622 * Preload read-only mappings for the given object's resident pages into 1623 * the given map. This eliminates the soft faults on process startup and 1624 * immediately after an mmap(2). Because these are speculative mappings, 1625 * cached pages are not reactivated and mapped. 1626 */ 1627 void 1628 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 1629 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1630 { 1631 vm_offset_t start; 1632 vm_page_t p, p_start; 1633 vm_pindex_t psize, tmpidx; 1634 boolean_t are_queues_locked; 1635 1636 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 1637 return; 1638 VM_OBJECT_LOCK(object); 1639 if (object->type == OBJT_DEVICE) { 1640 pmap_object_init_pt(map->pmap, addr, object, pindex, size); 1641 goto unlock_return; 1642 } 1643 1644 psize = atop(size); 1645 1646 if (object->type != OBJT_VNODE || 1647 ((flags & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) && 1648 (object->resident_page_count > MAX_INIT_PT))) { 1649 goto unlock_return; 1650 } 1651 1652 if (psize + pindex > object->size) { 1653 if (object->size < pindex) 1654 goto unlock_return; 1655 psize = object->size - pindex; 1656 } 1657 1658 are_queues_locked = FALSE; 1659 start = 0; 1660 p_start = NULL; 1661 1662 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1663 if (p->pindex < pindex) { 1664 p = vm_page_splay(pindex, object->root); 1665 if ((object->root = p)->pindex < pindex) 1666 p = TAILQ_NEXT(p, listq); 1667 } 1668 } 1669 /* 1670 * Assert: the variable p is either (1) the page with the 1671 * least pindex greater than or equal to the parameter pindex 1672 * or (2) NULL. 1673 */ 1674 for (; 1675 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1676 p = TAILQ_NEXT(p, listq)) { 1677 /* 1678 * don't allow an madvise to blow away our really 1679 * free pages allocating pv entries. 1680 */ 1681 if ((flags & MAP_PREFAULT_MADVISE) && 1682 cnt.v_free_count < cnt.v_free_reserved) { 1683 psize = tmpidx; 1684 break; 1685 } 1686 if ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) { 1687 if (p_start == NULL) { 1688 start = addr + ptoa(tmpidx); 1689 p_start = p; 1690 } 1691 } else if (p_start != NULL) { 1692 if (!are_queues_locked) { 1693 are_queues_locked = TRUE; 1694 vm_page_lock_queues(); 1695 } 1696 pmap_enter_object(map->pmap, start, addr + 1697 ptoa(tmpidx), p_start, prot); 1698 p_start = NULL; 1699 } 1700 } 1701 if (p_start != NULL) { 1702 if (!are_queues_locked) { 1703 are_queues_locked = TRUE; 1704 vm_page_lock_queues(); 1705 } 1706 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 1707 p_start, prot); 1708 } 1709 if (are_queues_locked) 1710 vm_page_unlock_queues(); 1711 unlock_return: 1712 VM_OBJECT_UNLOCK(object); 1713 } 1714 1715 /* 1716 * vm_map_protect: 1717 * 1718 * Sets the protection of the specified address 1719 * region in the target map. If "set_max" is 1720 * specified, the maximum protection is to be set; 1721 * otherwise, only the current protection is affected. 1722 */ 1723 int 1724 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1725 vm_prot_t new_prot, boolean_t set_max) 1726 { 1727 vm_map_entry_t current; 1728 vm_map_entry_t entry; 1729 1730 vm_map_lock(map); 1731 1732 VM_MAP_RANGE_CHECK(map, start, end); 1733 1734 if (vm_map_lookup_entry(map, start, &entry)) { 1735 vm_map_clip_start(map, entry, start); 1736 } else { 1737 entry = entry->next; 1738 } 1739 1740 /* 1741 * Make a first pass to check for protection violations. 1742 */ 1743 current = entry; 1744 while ((current != &map->header) && (current->start < end)) { 1745 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1746 vm_map_unlock(map); 1747 return (KERN_INVALID_ARGUMENT); 1748 } 1749 if ((new_prot & current->max_protection) != new_prot) { 1750 vm_map_unlock(map); 1751 return (KERN_PROTECTION_FAILURE); 1752 } 1753 current = current->next; 1754 } 1755 1756 /* 1757 * Go back and fix up protections. [Note that clipping is not 1758 * necessary the second time.] 1759 */ 1760 current = entry; 1761 while ((current != &map->header) && (current->start < end)) { 1762 vm_prot_t old_prot; 1763 1764 vm_map_clip_end(map, current, end); 1765 1766 old_prot = current->protection; 1767 if (set_max) 1768 current->protection = 1769 (current->max_protection = new_prot) & 1770 old_prot; 1771 else 1772 current->protection = new_prot; 1773 1774 /* 1775 * Update physical map if necessary. Worry about copy-on-write 1776 * here. 1777 */ 1778 if (current->protection != old_prot) { 1779 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1780 VM_PROT_ALL) 1781 pmap_protect(map->pmap, current->start, 1782 current->end, 1783 current->protection & MASK(current)); 1784 #undef MASK 1785 } 1786 vm_map_simplify_entry(map, current); 1787 current = current->next; 1788 } 1789 vm_map_unlock(map); 1790 return (KERN_SUCCESS); 1791 } 1792 1793 /* 1794 * vm_map_madvise: 1795 * 1796 * This routine traverses a processes map handling the madvise 1797 * system call. Advisories are classified as either those effecting 1798 * the vm_map_entry structure, or those effecting the underlying 1799 * objects. 1800 */ 1801 int 1802 vm_map_madvise( 1803 vm_map_t map, 1804 vm_offset_t start, 1805 vm_offset_t end, 1806 int behav) 1807 { 1808 vm_map_entry_t current, entry; 1809 int modify_map = 0; 1810 1811 /* 1812 * Some madvise calls directly modify the vm_map_entry, in which case 1813 * we need to use an exclusive lock on the map and we need to perform 1814 * various clipping operations. Otherwise we only need a read-lock 1815 * on the map. 1816 */ 1817 switch(behav) { 1818 case MADV_NORMAL: 1819 case MADV_SEQUENTIAL: 1820 case MADV_RANDOM: 1821 case MADV_NOSYNC: 1822 case MADV_AUTOSYNC: 1823 case MADV_NOCORE: 1824 case MADV_CORE: 1825 modify_map = 1; 1826 vm_map_lock(map); 1827 break; 1828 case MADV_WILLNEED: 1829 case MADV_DONTNEED: 1830 case MADV_FREE: 1831 vm_map_lock_read(map); 1832 break; 1833 default: 1834 return (KERN_INVALID_ARGUMENT); 1835 } 1836 1837 /* 1838 * Locate starting entry and clip if necessary. 1839 */ 1840 VM_MAP_RANGE_CHECK(map, start, end); 1841 1842 if (vm_map_lookup_entry(map, start, &entry)) { 1843 if (modify_map) 1844 vm_map_clip_start(map, entry, start); 1845 } else { 1846 entry = entry->next; 1847 } 1848 1849 if (modify_map) { 1850 /* 1851 * madvise behaviors that are implemented in the vm_map_entry. 1852 * 1853 * We clip the vm_map_entry so that behavioral changes are 1854 * limited to the specified address range. 1855 */ 1856 for (current = entry; 1857 (current != &map->header) && (current->start < end); 1858 current = current->next 1859 ) { 1860 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1861 continue; 1862 1863 vm_map_clip_end(map, current, end); 1864 1865 switch (behav) { 1866 case MADV_NORMAL: 1867 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1868 break; 1869 case MADV_SEQUENTIAL: 1870 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1871 break; 1872 case MADV_RANDOM: 1873 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1874 break; 1875 case MADV_NOSYNC: 1876 current->eflags |= MAP_ENTRY_NOSYNC; 1877 break; 1878 case MADV_AUTOSYNC: 1879 current->eflags &= ~MAP_ENTRY_NOSYNC; 1880 break; 1881 case MADV_NOCORE: 1882 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1883 break; 1884 case MADV_CORE: 1885 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1886 break; 1887 default: 1888 break; 1889 } 1890 vm_map_simplify_entry(map, current); 1891 } 1892 vm_map_unlock(map); 1893 } else { 1894 vm_pindex_t pindex; 1895 int count; 1896 1897 /* 1898 * madvise behaviors that are implemented in the underlying 1899 * vm_object. 1900 * 1901 * Since we don't clip the vm_map_entry, we have to clip 1902 * the vm_object pindex and count. 1903 */ 1904 for (current = entry; 1905 (current != &map->header) && (current->start < end); 1906 current = current->next 1907 ) { 1908 vm_offset_t useStart; 1909 1910 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1911 continue; 1912 1913 pindex = OFF_TO_IDX(current->offset); 1914 count = atop(current->end - current->start); 1915 useStart = current->start; 1916 1917 if (current->start < start) { 1918 pindex += atop(start - current->start); 1919 count -= atop(start - current->start); 1920 useStart = start; 1921 } 1922 if (current->end > end) 1923 count -= atop(current->end - end); 1924 1925 if (count <= 0) 1926 continue; 1927 1928 vm_object_madvise(current->object.vm_object, 1929 pindex, count, behav); 1930 if (behav == MADV_WILLNEED) { 1931 vm_map_pmap_enter(map, 1932 useStart, 1933 current->protection, 1934 current->object.vm_object, 1935 pindex, 1936 (count << PAGE_SHIFT), 1937 MAP_PREFAULT_MADVISE 1938 ); 1939 } 1940 } 1941 vm_map_unlock_read(map); 1942 } 1943 return (0); 1944 } 1945 1946 1947 /* 1948 * vm_map_inherit: 1949 * 1950 * Sets the inheritance of the specified address 1951 * range in the target map. Inheritance 1952 * affects how the map will be shared with 1953 * child maps at the time of vmspace_fork. 1954 */ 1955 int 1956 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 1957 vm_inherit_t new_inheritance) 1958 { 1959 vm_map_entry_t entry; 1960 vm_map_entry_t temp_entry; 1961 1962 switch (new_inheritance) { 1963 case VM_INHERIT_NONE: 1964 case VM_INHERIT_COPY: 1965 case VM_INHERIT_SHARE: 1966 break; 1967 default: 1968 return (KERN_INVALID_ARGUMENT); 1969 } 1970 vm_map_lock(map); 1971 VM_MAP_RANGE_CHECK(map, start, end); 1972 if (vm_map_lookup_entry(map, start, &temp_entry)) { 1973 entry = temp_entry; 1974 vm_map_clip_start(map, entry, start); 1975 } else 1976 entry = temp_entry->next; 1977 while ((entry != &map->header) && (entry->start < end)) { 1978 vm_map_clip_end(map, entry, end); 1979 entry->inheritance = new_inheritance; 1980 vm_map_simplify_entry(map, entry); 1981 entry = entry->next; 1982 } 1983 vm_map_unlock(map); 1984 return (KERN_SUCCESS); 1985 } 1986 1987 /* 1988 * vm_map_unwire: 1989 * 1990 * Implements both kernel and user unwiring. 1991 */ 1992 int 1993 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 1994 int flags) 1995 { 1996 vm_map_entry_t entry, first_entry, tmp_entry; 1997 vm_offset_t saved_start; 1998 unsigned int last_timestamp; 1999 int rv; 2000 boolean_t need_wakeup, result, user_unwire; 2001 2002 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2003 vm_map_lock(map); 2004 VM_MAP_RANGE_CHECK(map, start, end); 2005 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2006 if (flags & VM_MAP_WIRE_HOLESOK) 2007 first_entry = first_entry->next; 2008 else { 2009 vm_map_unlock(map); 2010 return (KERN_INVALID_ADDRESS); 2011 } 2012 } 2013 last_timestamp = map->timestamp; 2014 entry = first_entry; 2015 while (entry != &map->header && entry->start < end) { 2016 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2017 /* 2018 * We have not yet clipped the entry. 2019 */ 2020 saved_start = (start >= entry->start) ? start : 2021 entry->start; 2022 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2023 if (vm_map_unlock_and_wait(map, 0)) { 2024 /* 2025 * Allow interruption of user unwiring? 2026 */ 2027 } 2028 vm_map_lock(map); 2029 if (last_timestamp+1 != map->timestamp) { 2030 /* 2031 * Look again for the entry because the map was 2032 * modified while it was unlocked. 2033 * Specifically, the entry may have been 2034 * clipped, merged, or deleted. 2035 */ 2036 if (!vm_map_lookup_entry(map, saved_start, 2037 &tmp_entry)) { 2038 if (flags & VM_MAP_WIRE_HOLESOK) 2039 tmp_entry = tmp_entry->next; 2040 else { 2041 if (saved_start == start) { 2042 /* 2043 * First_entry has been deleted. 2044 */ 2045 vm_map_unlock(map); 2046 return (KERN_INVALID_ADDRESS); 2047 } 2048 end = saved_start; 2049 rv = KERN_INVALID_ADDRESS; 2050 goto done; 2051 } 2052 } 2053 if (entry == first_entry) 2054 first_entry = tmp_entry; 2055 else 2056 first_entry = NULL; 2057 entry = tmp_entry; 2058 } 2059 last_timestamp = map->timestamp; 2060 continue; 2061 } 2062 vm_map_clip_start(map, entry, start); 2063 vm_map_clip_end(map, entry, end); 2064 /* 2065 * Mark the entry in case the map lock is released. (See 2066 * above.) 2067 */ 2068 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2069 /* 2070 * Check the map for holes in the specified region. 2071 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2072 */ 2073 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2074 (entry->end < end && (entry->next == &map->header || 2075 entry->next->start > entry->end))) { 2076 end = entry->end; 2077 rv = KERN_INVALID_ADDRESS; 2078 goto done; 2079 } 2080 /* 2081 * If system unwiring, require that the entry is system wired. 2082 */ 2083 if (!user_unwire && 2084 vm_map_entry_system_wired_count(entry) == 0) { 2085 end = entry->end; 2086 rv = KERN_INVALID_ARGUMENT; 2087 goto done; 2088 } 2089 entry = entry->next; 2090 } 2091 rv = KERN_SUCCESS; 2092 done: 2093 need_wakeup = FALSE; 2094 if (first_entry == NULL) { 2095 result = vm_map_lookup_entry(map, start, &first_entry); 2096 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2097 first_entry = first_entry->next; 2098 else 2099 KASSERT(result, ("vm_map_unwire: lookup failed")); 2100 } 2101 entry = first_entry; 2102 while (entry != &map->header && entry->start < end) { 2103 if (rv == KERN_SUCCESS && (!user_unwire || 2104 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 2105 if (user_unwire) 2106 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2107 entry->wired_count--; 2108 if (entry->wired_count == 0) { 2109 /* 2110 * Retain the map lock. 2111 */ 2112 vm_fault_unwire(map, entry->start, entry->end, 2113 entry->object.vm_object != NULL && 2114 entry->object.vm_object->type == OBJT_DEVICE); 2115 } 2116 } 2117 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 2118 ("vm_map_unwire: in-transition flag missing")); 2119 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 2120 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2121 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2122 need_wakeup = TRUE; 2123 } 2124 vm_map_simplify_entry(map, entry); 2125 entry = entry->next; 2126 } 2127 vm_map_unlock(map); 2128 if (need_wakeup) 2129 vm_map_wakeup(map); 2130 return (rv); 2131 } 2132 2133 /* 2134 * vm_map_wire: 2135 * 2136 * Implements both kernel and user wiring. 2137 */ 2138 int 2139 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2140 int flags) 2141 { 2142 vm_map_entry_t entry, first_entry, tmp_entry; 2143 vm_offset_t saved_end, saved_start; 2144 unsigned int last_timestamp; 2145 int rv; 2146 boolean_t fictitious, need_wakeup, result, user_wire; 2147 2148 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2149 vm_map_lock(map); 2150 VM_MAP_RANGE_CHECK(map, start, end); 2151 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2152 if (flags & VM_MAP_WIRE_HOLESOK) 2153 first_entry = first_entry->next; 2154 else { 2155 vm_map_unlock(map); 2156 return (KERN_INVALID_ADDRESS); 2157 } 2158 } 2159 last_timestamp = map->timestamp; 2160 entry = first_entry; 2161 while (entry != &map->header && entry->start < end) { 2162 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2163 /* 2164 * We have not yet clipped the entry. 2165 */ 2166 saved_start = (start >= entry->start) ? start : 2167 entry->start; 2168 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2169 if (vm_map_unlock_and_wait(map, 0)) { 2170 /* 2171 * Allow interruption of user wiring? 2172 */ 2173 } 2174 vm_map_lock(map); 2175 if (last_timestamp + 1 != map->timestamp) { 2176 /* 2177 * Look again for the entry because the map was 2178 * modified while it was unlocked. 2179 * Specifically, the entry may have been 2180 * clipped, merged, or deleted. 2181 */ 2182 if (!vm_map_lookup_entry(map, saved_start, 2183 &tmp_entry)) { 2184 if (flags & VM_MAP_WIRE_HOLESOK) 2185 tmp_entry = tmp_entry->next; 2186 else { 2187 if (saved_start == start) { 2188 /* 2189 * first_entry has been deleted. 2190 */ 2191 vm_map_unlock(map); 2192 return (KERN_INVALID_ADDRESS); 2193 } 2194 end = saved_start; 2195 rv = KERN_INVALID_ADDRESS; 2196 goto done; 2197 } 2198 } 2199 if (entry == first_entry) 2200 first_entry = tmp_entry; 2201 else 2202 first_entry = NULL; 2203 entry = tmp_entry; 2204 } 2205 last_timestamp = map->timestamp; 2206 continue; 2207 } 2208 vm_map_clip_start(map, entry, start); 2209 vm_map_clip_end(map, entry, end); 2210 /* 2211 * Mark the entry in case the map lock is released. (See 2212 * above.) 2213 */ 2214 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2215 /* 2216 * 2217 */ 2218 if (entry->wired_count == 0) { 2219 if ((entry->protection & (VM_PROT_READ|VM_PROT_EXECUTE)) 2220 == 0) { 2221 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { 2222 end = entry->end; 2223 rv = KERN_INVALID_ADDRESS; 2224 goto done; 2225 } 2226 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 2227 goto next_entry; 2228 } 2229 entry->wired_count++; 2230 saved_start = entry->start; 2231 saved_end = entry->end; 2232 fictitious = entry->object.vm_object != NULL && 2233 entry->object.vm_object->type == OBJT_DEVICE; 2234 /* 2235 * Release the map lock, relying on the in-transition 2236 * mark. 2237 */ 2238 vm_map_unlock(map); 2239 rv = vm_fault_wire(map, saved_start, saved_end, 2240 user_wire, fictitious); 2241 vm_map_lock(map); 2242 if (last_timestamp + 1 != map->timestamp) { 2243 /* 2244 * Look again for the entry because the map was 2245 * modified while it was unlocked. The entry 2246 * may have been clipped, but NOT merged or 2247 * deleted. 2248 */ 2249 result = vm_map_lookup_entry(map, saved_start, 2250 &tmp_entry); 2251 KASSERT(result, ("vm_map_wire: lookup failed")); 2252 if (entry == first_entry) 2253 first_entry = tmp_entry; 2254 else 2255 first_entry = NULL; 2256 entry = tmp_entry; 2257 while (entry->end < saved_end) { 2258 if (rv != KERN_SUCCESS) { 2259 KASSERT(entry->wired_count == 1, 2260 ("vm_map_wire: bad count")); 2261 entry->wired_count = -1; 2262 } 2263 entry = entry->next; 2264 } 2265 } 2266 last_timestamp = map->timestamp; 2267 if (rv != KERN_SUCCESS) { 2268 KASSERT(entry->wired_count == 1, 2269 ("vm_map_wire: bad count")); 2270 /* 2271 * Assign an out-of-range value to represent 2272 * the failure to wire this entry. 2273 */ 2274 entry->wired_count = -1; 2275 end = entry->end; 2276 goto done; 2277 } 2278 } else if (!user_wire || 2279 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2280 entry->wired_count++; 2281 } 2282 /* 2283 * Check the map for holes in the specified region. 2284 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2285 */ 2286 next_entry: 2287 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2288 (entry->end < end && (entry->next == &map->header || 2289 entry->next->start > entry->end))) { 2290 end = entry->end; 2291 rv = KERN_INVALID_ADDRESS; 2292 goto done; 2293 } 2294 entry = entry->next; 2295 } 2296 rv = KERN_SUCCESS; 2297 done: 2298 need_wakeup = FALSE; 2299 if (first_entry == NULL) { 2300 result = vm_map_lookup_entry(map, start, &first_entry); 2301 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2302 first_entry = first_entry->next; 2303 else 2304 KASSERT(result, ("vm_map_wire: lookup failed")); 2305 } 2306 entry = first_entry; 2307 while (entry != &map->header && entry->start < end) { 2308 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) 2309 goto next_entry_done; 2310 if (rv == KERN_SUCCESS) { 2311 if (user_wire) 2312 entry->eflags |= MAP_ENTRY_USER_WIRED; 2313 } else if (entry->wired_count == -1) { 2314 /* 2315 * Wiring failed on this entry. Thus, unwiring is 2316 * unnecessary. 2317 */ 2318 entry->wired_count = 0; 2319 } else { 2320 if (!user_wire || 2321 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) 2322 entry->wired_count--; 2323 if (entry->wired_count == 0) { 2324 /* 2325 * Retain the map lock. 2326 */ 2327 vm_fault_unwire(map, entry->start, entry->end, 2328 entry->object.vm_object != NULL && 2329 entry->object.vm_object->type == OBJT_DEVICE); 2330 } 2331 } 2332 next_entry_done: 2333 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 2334 ("vm_map_wire: in-transition flag missing")); 2335 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION|MAP_ENTRY_WIRE_SKIPPED); 2336 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2337 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2338 need_wakeup = TRUE; 2339 } 2340 vm_map_simplify_entry(map, entry); 2341 entry = entry->next; 2342 } 2343 vm_map_unlock(map); 2344 if (need_wakeup) 2345 vm_map_wakeup(map); 2346 return (rv); 2347 } 2348 2349 /* 2350 * vm_map_sync 2351 * 2352 * Push any dirty cached pages in the address range to their pager. 2353 * If syncio is TRUE, dirty pages are written synchronously. 2354 * If invalidate is TRUE, any cached pages are freed as well. 2355 * 2356 * If the size of the region from start to end is zero, we are 2357 * supposed to flush all modified pages within the region containing 2358 * start. Unfortunately, a region can be split or coalesced with 2359 * neighboring regions, making it difficult to determine what the 2360 * original region was. Therefore, we approximate this requirement by 2361 * flushing the current region containing start. 2362 * 2363 * Returns an error if any part of the specified range is not mapped. 2364 */ 2365 int 2366 vm_map_sync( 2367 vm_map_t map, 2368 vm_offset_t start, 2369 vm_offset_t end, 2370 boolean_t syncio, 2371 boolean_t invalidate) 2372 { 2373 vm_map_entry_t current; 2374 vm_map_entry_t entry; 2375 vm_size_t size; 2376 vm_object_t object; 2377 vm_ooffset_t offset; 2378 unsigned int last_timestamp; 2379 2380 vm_map_lock_read(map); 2381 VM_MAP_RANGE_CHECK(map, start, end); 2382 if (!vm_map_lookup_entry(map, start, &entry)) { 2383 vm_map_unlock_read(map); 2384 return (KERN_INVALID_ADDRESS); 2385 } else if (start == end) { 2386 start = entry->start; 2387 end = entry->end; 2388 } 2389 /* 2390 * Make a first pass to check for user-wired memory and holes. 2391 */ 2392 for (current = entry; current != &map->header && current->start < end; 2393 current = current->next) { 2394 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 2395 vm_map_unlock_read(map); 2396 return (KERN_INVALID_ARGUMENT); 2397 } 2398 if (end > current->end && 2399 (current->next == &map->header || 2400 current->end != current->next->start)) { 2401 vm_map_unlock_read(map); 2402 return (KERN_INVALID_ADDRESS); 2403 } 2404 } 2405 2406 if (invalidate) 2407 pmap_remove(map->pmap, start, end); 2408 2409 /* 2410 * Make a second pass, cleaning/uncaching pages from the indicated 2411 * objects as we go. 2412 */ 2413 for (current = entry; current != &map->header && current->start < end;) { 2414 offset = current->offset + (start - current->start); 2415 size = (end <= current->end ? end : current->end) - start; 2416 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2417 vm_map_t smap; 2418 vm_map_entry_t tentry; 2419 vm_size_t tsize; 2420 2421 smap = current->object.sub_map; 2422 vm_map_lock_read(smap); 2423 (void) vm_map_lookup_entry(smap, offset, &tentry); 2424 tsize = tentry->end - offset; 2425 if (tsize < size) 2426 size = tsize; 2427 object = tentry->object.vm_object; 2428 offset = tentry->offset + (offset - tentry->start); 2429 vm_map_unlock_read(smap); 2430 } else { 2431 object = current->object.vm_object; 2432 } 2433 vm_object_reference(object); 2434 last_timestamp = map->timestamp; 2435 vm_map_unlock_read(map); 2436 vm_object_sync(object, offset, size, syncio, invalidate); 2437 start += size; 2438 vm_object_deallocate(object); 2439 vm_map_lock_read(map); 2440 if (last_timestamp == map->timestamp || 2441 !vm_map_lookup_entry(map, start, ¤t)) 2442 current = current->next; 2443 } 2444 2445 vm_map_unlock_read(map); 2446 return (KERN_SUCCESS); 2447 } 2448 2449 /* 2450 * vm_map_entry_unwire: [ internal use only ] 2451 * 2452 * Make the region specified by this entry pageable. 2453 * 2454 * The map in question should be locked. 2455 * [This is the reason for this routine's existence.] 2456 */ 2457 static void 2458 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2459 { 2460 vm_fault_unwire(map, entry->start, entry->end, 2461 entry->object.vm_object != NULL && 2462 entry->object.vm_object->type == OBJT_DEVICE); 2463 entry->wired_count = 0; 2464 } 2465 2466 /* 2467 * vm_map_entry_delete: [ internal use only ] 2468 * 2469 * Deallocate the given entry from the target map. 2470 */ 2471 static void 2472 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2473 { 2474 vm_object_t object; 2475 vm_pindex_t offidxstart, offidxend, count; 2476 2477 vm_map_entry_unlink(map, entry); 2478 map->size -= entry->end - entry->start; 2479 2480 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2481 (object = entry->object.vm_object) != NULL) { 2482 count = OFF_TO_IDX(entry->end - entry->start); 2483 offidxstart = OFF_TO_IDX(entry->offset); 2484 offidxend = offidxstart + count; 2485 VM_OBJECT_LOCK(object); 2486 if (object->ref_count != 1 && 2487 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2488 object == kernel_object || object == kmem_object)) { 2489 vm_object_collapse(object); 2490 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2491 if (object->type == OBJT_SWAP) 2492 swap_pager_freespace(object, offidxstart, count); 2493 if (offidxend >= object->size && 2494 offidxstart < object->size) 2495 object->size = offidxstart; 2496 } 2497 VM_OBJECT_UNLOCK(object); 2498 } else 2499 entry->object.vm_object = NULL; 2500 } 2501 2502 /* 2503 * vm_map_delete: [ internal use only ] 2504 * 2505 * Deallocates the given address range from the target 2506 * map. 2507 */ 2508 int 2509 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2510 { 2511 vm_map_entry_t entry; 2512 vm_map_entry_t first_entry; 2513 2514 VM_MAP_ASSERT_LOCKED(map); 2515 2516 /* 2517 * Find the start of the region, and clip it 2518 */ 2519 if (!vm_map_lookup_entry(map, start, &first_entry)) 2520 entry = first_entry->next; 2521 else { 2522 entry = first_entry; 2523 vm_map_clip_start(map, entry, start); 2524 } 2525 2526 /* 2527 * Step through all entries in this region 2528 */ 2529 while ((entry != &map->header) && (entry->start < end)) { 2530 vm_map_entry_t next; 2531 2532 /* 2533 * Wait for wiring or unwiring of an entry to complete. 2534 * Also wait for any system wirings to disappear on 2535 * user maps. 2536 */ 2537 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 2538 (vm_map_pmap(map) != kernel_pmap && 2539 vm_map_entry_system_wired_count(entry) != 0)) { 2540 unsigned int last_timestamp; 2541 vm_offset_t saved_start; 2542 vm_map_entry_t tmp_entry; 2543 2544 saved_start = entry->start; 2545 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2546 last_timestamp = map->timestamp; 2547 (void) vm_map_unlock_and_wait(map, 0); 2548 vm_map_lock(map); 2549 if (last_timestamp + 1 != map->timestamp) { 2550 /* 2551 * Look again for the entry because the map was 2552 * modified while it was unlocked. 2553 * Specifically, the entry may have been 2554 * clipped, merged, or deleted. 2555 */ 2556 if (!vm_map_lookup_entry(map, saved_start, 2557 &tmp_entry)) 2558 entry = tmp_entry->next; 2559 else { 2560 entry = tmp_entry; 2561 vm_map_clip_start(map, entry, 2562 saved_start); 2563 } 2564 } 2565 continue; 2566 } 2567 vm_map_clip_end(map, entry, end); 2568 2569 next = entry->next; 2570 2571 /* 2572 * Unwire before removing addresses from the pmap; otherwise, 2573 * unwiring will put the entries back in the pmap. 2574 */ 2575 if (entry->wired_count != 0) { 2576 vm_map_entry_unwire(map, entry); 2577 } 2578 2579 pmap_remove(map->pmap, entry->start, entry->end); 2580 2581 /* 2582 * Delete the entry only after removing all pmap 2583 * entries pointing to its pages. (Otherwise, its 2584 * page frames may be reallocated, and any modify bits 2585 * will be set in the wrong object!) 2586 */ 2587 vm_map_entry_delete(map, entry); 2588 entry->next = map->deferred_freelist; 2589 map->deferred_freelist = entry; 2590 entry = next; 2591 } 2592 return (KERN_SUCCESS); 2593 } 2594 2595 /* 2596 * vm_map_remove: 2597 * 2598 * Remove the given address range from the target map. 2599 * This is the exported form of vm_map_delete. 2600 */ 2601 int 2602 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2603 { 2604 int result; 2605 2606 vm_map_lock(map); 2607 VM_MAP_RANGE_CHECK(map, start, end); 2608 result = vm_map_delete(map, start, end); 2609 vm_map_unlock(map); 2610 return (result); 2611 } 2612 2613 /* 2614 * vm_map_check_protection: 2615 * 2616 * Assert that the target map allows the specified privilege on the 2617 * entire address region given. The entire region must be allocated. 2618 * 2619 * WARNING! This code does not and should not check whether the 2620 * contents of the region is accessible. For example a smaller file 2621 * might be mapped into a larger address space. 2622 * 2623 * NOTE! This code is also called by munmap(). 2624 * 2625 * The map must be locked. A read lock is sufficient. 2626 */ 2627 boolean_t 2628 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2629 vm_prot_t protection) 2630 { 2631 vm_map_entry_t entry; 2632 vm_map_entry_t tmp_entry; 2633 2634 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 2635 return (FALSE); 2636 entry = tmp_entry; 2637 2638 while (start < end) { 2639 if (entry == &map->header) 2640 return (FALSE); 2641 /* 2642 * No holes allowed! 2643 */ 2644 if (start < entry->start) 2645 return (FALSE); 2646 /* 2647 * Check protection associated with entry. 2648 */ 2649 if ((entry->protection & protection) != protection) 2650 return (FALSE); 2651 /* go to next entry */ 2652 start = entry->end; 2653 entry = entry->next; 2654 } 2655 return (TRUE); 2656 } 2657 2658 /* 2659 * vm_map_copy_entry: 2660 * 2661 * Copies the contents of the source entry to the destination 2662 * entry. The entries *must* be aligned properly. 2663 */ 2664 static void 2665 vm_map_copy_entry( 2666 vm_map_t src_map, 2667 vm_map_t dst_map, 2668 vm_map_entry_t src_entry, 2669 vm_map_entry_t dst_entry) 2670 { 2671 vm_object_t src_object; 2672 2673 VM_MAP_ASSERT_LOCKED(dst_map); 2674 2675 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 2676 return; 2677 2678 if (src_entry->wired_count == 0) { 2679 2680 /* 2681 * If the source entry is marked needs_copy, it is already 2682 * write-protected. 2683 */ 2684 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 2685 pmap_protect(src_map->pmap, 2686 src_entry->start, 2687 src_entry->end, 2688 src_entry->protection & ~VM_PROT_WRITE); 2689 } 2690 2691 /* 2692 * Make a copy of the object. 2693 */ 2694 if ((src_object = src_entry->object.vm_object) != NULL) { 2695 VM_OBJECT_LOCK(src_object); 2696 if ((src_object->handle == NULL) && 2697 (src_object->type == OBJT_DEFAULT || 2698 src_object->type == OBJT_SWAP)) { 2699 vm_object_collapse(src_object); 2700 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 2701 vm_object_split(src_entry); 2702 src_object = src_entry->object.vm_object; 2703 } 2704 } 2705 vm_object_reference_locked(src_object); 2706 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 2707 VM_OBJECT_UNLOCK(src_object); 2708 dst_entry->object.vm_object = src_object; 2709 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2710 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2711 dst_entry->offset = src_entry->offset; 2712 } else { 2713 dst_entry->object.vm_object = NULL; 2714 dst_entry->offset = 0; 2715 } 2716 2717 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 2718 dst_entry->end - dst_entry->start, src_entry->start); 2719 } else { 2720 /* 2721 * Of course, wired down pages can't be set copy-on-write. 2722 * Cause wired pages to be copied into the new map by 2723 * simulating faults (the new pages are pageable) 2724 */ 2725 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 2726 } 2727 } 2728 2729 /* 2730 * vmspace_map_entry_forked: 2731 * Update the newly-forked vmspace each time a map entry is inherited 2732 * or copied. The values for vm_dsize and vm_tsize are approximate 2733 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 2734 */ 2735 static void 2736 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 2737 vm_map_entry_t entry) 2738 { 2739 vm_size_t entrysize; 2740 vm_offset_t newend; 2741 2742 entrysize = entry->end - entry->start; 2743 vm2->vm_map.size += entrysize; 2744 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 2745 vm2->vm_ssize += btoc(entrysize); 2746 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 2747 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 2748 newend = MIN(entry->end, 2749 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 2750 vm2->vm_dsize += btoc(newend - entry->start); 2751 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 2752 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 2753 newend = MIN(entry->end, 2754 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 2755 vm2->vm_tsize += btoc(newend - entry->start); 2756 } 2757 } 2758 2759 /* 2760 * vmspace_fork: 2761 * Create a new process vmspace structure and vm_map 2762 * based on those of an existing process. The new map 2763 * is based on the old map, according to the inheritance 2764 * values on the regions in that map. 2765 * 2766 * XXX It might be worth coalescing the entries added to the new vmspace. 2767 * 2768 * The source map must not be locked. 2769 */ 2770 struct vmspace * 2771 vmspace_fork(struct vmspace *vm1) 2772 { 2773 struct vmspace *vm2; 2774 vm_map_t old_map = &vm1->vm_map; 2775 vm_map_t new_map; 2776 vm_map_entry_t old_entry; 2777 vm_map_entry_t new_entry; 2778 vm_object_t object; 2779 int locked; 2780 2781 vm_map_lock(old_map); 2782 2783 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 2784 if (vm2 == NULL) 2785 goto unlock_and_return; 2786 vm2->vm_taddr = vm1->vm_taddr; 2787 vm2->vm_daddr = vm1->vm_daddr; 2788 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 2789 new_map = &vm2->vm_map; /* XXX */ 2790 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 2791 KASSERT(locked, ("vmspace_fork: lock failed")); 2792 new_map->timestamp = 1; 2793 2794 old_entry = old_map->header.next; 2795 2796 while (old_entry != &old_map->header) { 2797 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 2798 panic("vm_map_fork: encountered a submap"); 2799 2800 switch (old_entry->inheritance) { 2801 case VM_INHERIT_NONE: 2802 break; 2803 2804 case VM_INHERIT_SHARE: 2805 /* 2806 * Clone the entry, creating the shared object if necessary. 2807 */ 2808 object = old_entry->object.vm_object; 2809 if (object == NULL) { 2810 object = vm_object_allocate(OBJT_DEFAULT, 2811 atop(old_entry->end - old_entry->start)); 2812 old_entry->object.vm_object = object; 2813 old_entry->offset = 0; 2814 } 2815 2816 /* 2817 * Add the reference before calling vm_object_shadow 2818 * to insure that a shadow object is created. 2819 */ 2820 vm_object_reference(object); 2821 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 2822 vm_object_shadow(&old_entry->object.vm_object, 2823 &old_entry->offset, 2824 atop(old_entry->end - old_entry->start)); 2825 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 2826 /* Transfer the second reference too. */ 2827 vm_object_reference( 2828 old_entry->object.vm_object); 2829 2830 /* 2831 * As in vm_map_simplify_entry(), the 2832 * vnode lock will not be acquired in 2833 * this call to vm_object_deallocate(). 2834 */ 2835 vm_object_deallocate(object); 2836 object = old_entry->object.vm_object; 2837 } 2838 VM_OBJECT_LOCK(object); 2839 vm_object_clear_flag(object, OBJ_ONEMAPPING); 2840 VM_OBJECT_UNLOCK(object); 2841 2842 /* 2843 * Clone the entry, referencing the shared object. 2844 */ 2845 new_entry = vm_map_entry_create(new_map); 2846 *new_entry = *old_entry; 2847 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 2848 MAP_ENTRY_IN_TRANSITION); 2849 new_entry->wired_count = 0; 2850 2851 /* 2852 * Insert the entry into the new map -- we know we're 2853 * inserting at the end of the new map. 2854 */ 2855 vm_map_entry_link(new_map, new_map->header.prev, 2856 new_entry); 2857 vmspace_map_entry_forked(vm1, vm2, new_entry); 2858 2859 /* 2860 * Update the physical map 2861 */ 2862 pmap_copy(new_map->pmap, old_map->pmap, 2863 new_entry->start, 2864 (old_entry->end - old_entry->start), 2865 old_entry->start); 2866 break; 2867 2868 case VM_INHERIT_COPY: 2869 /* 2870 * Clone the entry and link into the map. 2871 */ 2872 new_entry = vm_map_entry_create(new_map); 2873 *new_entry = *old_entry; 2874 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 2875 MAP_ENTRY_IN_TRANSITION); 2876 new_entry->wired_count = 0; 2877 new_entry->object.vm_object = NULL; 2878 vm_map_entry_link(new_map, new_map->header.prev, 2879 new_entry); 2880 vmspace_map_entry_forked(vm1, vm2, new_entry); 2881 vm_map_copy_entry(old_map, new_map, old_entry, 2882 new_entry); 2883 break; 2884 } 2885 old_entry = old_entry->next; 2886 } 2887 unlock_and_return: 2888 vm_map_unlock(old_map); 2889 if (vm2 != NULL) 2890 vm_map_unlock(new_map); 2891 2892 return (vm2); 2893 } 2894 2895 int 2896 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 2897 vm_prot_t prot, vm_prot_t max, int cow) 2898 { 2899 vm_map_entry_t new_entry, prev_entry; 2900 vm_offset_t bot, top; 2901 vm_size_t init_ssize; 2902 int orient, rv; 2903 rlim_t vmemlim; 2904 2905 /* 2906 * The stack orientation is piggybacked with the cow argument. 2907 * Extract it into orient and mask the cow argument so that we 2908 * don't pass it around further. 2909 * NOTE: We explicitly allow bi-directional stacks. 2910 */ 2911 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 2912 cow &= ~orient; 2913 KASSERT(orient != 0, ("No stack grow direction")); 2914 2915 if (addrbos < vm_map_min(map) || 2916 addrbos > vm_map_max(map) || 2917 addrbos + max_ssize < addrbos) 2918 return (KERN_NO_SPACE); 2919 2920 init_ssize = (max_ssize < sgrowsiz) ? max_ssize : sgrowsiz; 2921 2922 PROC_LOCK(curthread->td_proc); 2923 vmemlim = lim_cur(curthread->td_proc, RLIMIT_VMEM); 2924 PROC_UNLOCK(curthread->td_proc); 2925 2926 vm_map_lock(map); 2927 2928 /* If addr is already mapped, no go */ 2929 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 2930 vm_map_unlock(map); 2931 return (KERN_NO_SPACE); 2932 } 2933 2934 /* If we would blow our VMEM resource limit, no go */ 2935 if (map->size + init_ssize > vmemlim) { 2936 vm_map_unlock(map); 2937 return (KERN_NO_SPACE); 2938 } 2939 2940 /* 2941 * If we can't accomodate max_ssize in the current mapping, no go. 2942 * However, we need to be aware that subsequent user mappings might 2943 * map into the space we have reserved for stack, and currently this 2944 * space is not protected. 2945 * 2946 * Hopefully we will at least detect this condition when we try to 2947 * grow the stack. 2948 */ 2949 if ((prev_entry->next != &map->header) && 2950 (prev_entry->next->start < addrbos + max_ssize)) { 2951 vm_map_unlock(map); 2952 return (KERN_NO_SPACE); 2953 } 2954 2955 /* 2956 * We initially map a stack of only init_ssize. We will grow as 2957 * needed later. Depending on the orientation of the stack (i.e. 2958 * the grow direction) we either map at the top of the range, the 2959 * bottom of the range or in the middle. 2960 * 2961 * Note: we would normally expect prot and max to be VM_PROT_ALL, 2962 * and cow to be 0. Possibly we should eliminate these as input 2963 * parameters, and just pass these values here in the insert call. 2964 */ 2965 if (orient == MAP_STACK_GROWS_DOWN) 2966 bot = addrbos + max_ssize - init_ssize; 2967 else if (orient == MAP_STACK_GROWS_UP) 2968 bot = addrbos; 2969 else 2970 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 2971 top = bot + init_ssize; 2972 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 2973 2974 /* Now set the avail_ssize amount. */ 2975 if (rv == KERN_SUCCESS) { 2976 if (prev_entry != &map->header) 2977 vm_map_clip_end(map, prev_entry, bot); 2978 new_entry = prev_entry->next; 2979 if (new_entry->end != top || new_entry->start != bot) 2980 panic("Bad entry start/end for new stack entry"); 2981 2982 new_entry->avail_ssize = max_ssize - init_ssize; 2983 if (orient & MAP_STACK_GROWS_DOWN) 2984 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 2985 if (orient & MAP_STACK_GROWS_UP) 2986 new_entry->eflags |= MAP_ENTRY_GROWS_UP; 2987 } 2988 2989 vm_map_unlock(map); 2990 return (rv); 2991 } 2992 2993 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 2994 * desired address is already mapped, or if we successfully grow 2995 * the stack. Also returns KERN_SUCCESS if addr is outside the 2996 * stack range (this is strange, but preserves compatibility with 2997 * the grow function in vm_machdep.c). 2998 */ 2999 int 3000 vm_map_growstack(struct proc *p, vm_offset_t addr) 3001 { 3002 vm_map_entry_t next_entry, prev_entry; 3003 vm_map_entry_t new_entry, stack_entry; 3004 struct vmspace *vm = p->p_vmspace; 3005 vm_map_t map = &vm->vm_map; 3006 vm_offset_t end; 3007 size_t grow_amount, max_grow; 3008 rlim_t stacklim, vmemlim; 3009 int is_procstack, rv; 3010 3011 Retry: 3012 PROC_LOCK(p); 3013 stacklim = lim_cur(p, RLIMIT_STACK); 3014 vmemlim = lim_cur(p, RLIMIT_VMEM); 3015 PROC_UNLOCK(p); 3016 3017 vm_map_lock_read(map); 3018 3019 /* If addr is already in the entry range, no need to grow.*/ 3020 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 3021 vm_map_unlock_read(map); 3022 return (KERN_SUCCESS); 3023 } 3024 3025 next_entry = prev_entry->next; 3026 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 3027 /* 3028 * This entry does not grow upwards. Since the address lies 3029 * beyond this entry, the next entry (if one exists) has to 3030 * be a downward growable entry. The entry list header is 3031 * never a growable entry, so it suffices to check the flags. 3032 */ 3033 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 3034 vm_map_unlock_read(map); 3035 return (KERN_SUCCESS); 3036 } 3037 stack_entry = next_entry; 3038 } else { 3039 /* 3040 * This entry grows upward. If the next entry does not at 3041 * least grow downwards, this is the entry we need to grow. 3042 * otherwise we have two possible choices and we have to 3043 * select one. 3044 */ 3045 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 3046 /* 3047 * We have two choices; grow the entry closest to 3048 * the address to minimize the amount of growth. 3049 */ 3050 if (addr - prev_entry->end <= next_entry->start - addr) 3051 stack_entry = prev_entry; 3052 else 3053 stack_entry = next_entry; 3054 } else 3055 stack_entry = prev_entry; 3056 } 3057 3058 if (stack_entry == next_entry) { 3059 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 3060 KASSERT(addr < stack_entry->start, ("foo")); 3061 end = (prev_entry != &map->header) ? prev_entry->end : 3062 stack_entry->start - stack_entry->avail_ssize; 3063 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 3064 max_grow = stack_entry->start - end; 3065 } else { 3066 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 3067 KASSERT(addr >= stack_entry->end, ("foo")); 3068 end = (next_entry != &map->header) ? next_entry->start : 3069 stack_entry->end + stack_entry->avail_ssize; 3070 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 3071 max_grow = end - stack_entry->end; 3072 } 3073 3074 if (grow_amount > stack_entry->avail_ssize) { 3075 vm_map_unlock_read(map); 3076 return (KERN_NO_SPACE); 3077 } 3078 3079 /* 3080 * If there is no longer enough space between the entries nogo, and 3081 * adjust the available space. Note: this should only happen if the 3082 * user has mapped into the stack area after the stack was created, 3083 * and is probably an error. 3084 * 3085 * This also effectively destroys any guard page the user might have 3086 * intended by limiting the stack size. 3087 */ 3088 if (grow_amount > max_grow) { 3089 if (vm_map_lock_upgrade(map)) 3090 goto Retry; 3091 3092 stack_entry->avail_ssize = max_grow; 3093 3094 vm_map_unlock(map); 3095 return (KERN_NO_SPACE); 3096 } 3097 3098 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 3099 3100 /* 3101 * If this is the main process stack, see if we're over the stack 3102 * limit. 3103 */ 3104 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3105 vm_map_unlock_read(map); 3106 return (KERN_NO_SPACE); 3107 } 3108 3109 /* Round up the grow amount modulo SGROWSIZ */ 3110 grow_amount = roundup (grow_amount, sgrowsiz); 3111 if (grow_amount > stack_entry->avail_ssize) 3112 grow_amount = stack_entry->avail_ssize; 3113 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3114 grow_amount = stacklim - ctob(vm->vm_ssize); 3115 } 3116 3117 /* If we would blow our VMEM resource limit, no go */ 3118 if (map->size + grow_amount > vmemlim) { 3119 vm_map_unlock_read(map); 3120 return (KERN_NO_SPACE); 3121 } 3122 3123 if (vm_map_lock_upgrade(map)) 3124 goto Retry; 3125 3126 if (stack_entry == next_entry) { 3127 /* 3128 * Growing downward. 3129 */ 3130 /* Get the preliminary new entry start value */ 3131 addr = stack_entry->start - grow_amount; 3132 3133 /* 3134 * If this puts us into the previous entry, cut back our 3135 * growth to the available space. Also, see the note above. 3136 */ 3137 if (addr < end) { 3138 stack_entry->avail_ssize = max_grow; 3139 addr = end; 3140 } 3141 3142 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 3143 p->p_sysent->sv_stackprot, VM_PROT_ALL, 0); 3144 3145 /* Adjust the available stack space by the amount we grew. */ 3146 if (rv == KERN_SUCCESS) { 3147 if (prev_entry != &map->header) 3148 vm_map_clip_end(map, prev_entry, addr); 3149 new_entry = prev_entry->next; 3150 KASSERT(new_entry == stack_entry->prev, ("foo")); 3151 KASSERT(new_entry->end == stack_entry->start, ("foo")); 3152 KASSERT(new_entry->start == addr, ("foo")); 3153 grow_amount = new_entry->end - new_entry->start; 3154 new_entry->avail_ssize = stack_entry->avail_ssize - 3155 grow_amount; 3156 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 3157 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3158 } 3159 } else { 3160 /* 3161 * Growing upward. 3162 */ 3163 addr = stack_entry->end + grow_amount; 3164 3165 /* 3166 * If this puts us into the next entry, cut back our growth 3167 * to the available space. Also, see the note above. 3168 */ 3169 if (addr > end) { 3170 stack_entry->avail_ssize = end - stack_entry->end; 3171 addr = end; 3172 } 3173 3174 grow_amount = addr - stack_entry->end; 3175 3176 /* Grow the underlying object if applicable. */ 3177 if (stack_entry->object.vm_object == NULL || 3178 vm_object_coalesce(stack_entry->object.vm_object, 3179 stack_entry->offset, 3180 (vm_size_t)(stack_entry->end - stack_entry->start), 3181 (vm_size_t)grow_amount)) { 3182 map->size += (addr - stack_entry->end); 3183 /* Update the current entry. */ 3184 stack_entry->end = addr; 3185 stack_entry->avail_ssize -= grow_amount; 3186 vm_map_entry_resize_free(map, stack_entry); 3187 rv = KERN_SUCCESS; 3188 3189 if (next_entry != &map->header) 3190 vm_map_clip_start(map, next_entry, addr); 3191 } else 3192 rv = KERN_FAILURE; 3193 } 3194 3195 if (rv == KERN_SUCCESS && is_procstack) 3196 vm->vm_ssize += btoc(grow_amount); 3197 3198 vm_map_unlock(map); 3199 3200 /* 3201 * Heed the MAP_WIREFUTURE flag if it was set for this process. 3202 */ 3203 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 3204 vm_map_wire(map, 3205 (stack_entry == next_entry) ? addr : addr - grow_amount, 3206 (stack_entry == next_entry) ? stack_entry->start : addr, 3207 (p->p_flag & P_SYSTEM) 3208 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 3209 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 3210 } 3211 3212 return (rv); 3213 } 3214 3215 /* 3216 * Unshare the specified VM space for exec. If other processes are 3217 * mapped to it, then create a new one. The new vmspace is null. 3218 */ 3219 int 3220 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 3221 { 3222 struct vmspace *oldvmspace = p->p_vmspace; 3223 struct vmspace *newvmspace; 3224 3225 newvmspace = vmspace_alloc(minuser, maxuser); 3226 if (newvmspace == NULL) 3227 return (ENOMEM); 3228 newvmspace->vm_swrss = oldvmspace->vm_swrss; 3229 /* 3230 * This code is written like this for prototype purposes. The 3231 * goal is to avoid running down the vmspace here, but let the 3232 * other process's that are still using the vmspace to finally 3233 * run it down. Even though there is little or no chance of blocking 3234 * here, it is a good idea to keep this form for future mods. 3235 */ 3236 PROC_VMSPACE_LOCK(p); 3237 p->p_vmspace = newvmspace; 3238 PROC_VMSPACE_UNLOCK(p); 3239 if (p == curthread->td_proc) 3240 pmap_activate(curthread); 3241 vmspace_free(oldvmspace); 3242 return (0); 3243 } 3244 3245 /* 3246 * Unshare the specified VM space for forcing COW. This 3247 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3248 */ 3249 int 3250 vmspace_unshare(struct proc *p) 3251 { 3252 struct vmspace *oldvmspace = p->p_vmspace; 3253 struct vmspace *newvmspace; 3254 3255 if (oldvmspace->vm_refcnt == 1) 3256 return (0); 3257 newvmspace = vmspace_fork(oldvmspace); 3258 if (newvmspace == NULL) 3259 return (ENOMEM); 3260 PROC_VMSPACE_LOCK(p); 3261 p->p_vmspace = newvmspace; 3262 PROC_VMSPACE_UNLOCK(p); 3263 if (p == curthread->td_proc) 3264 pmap_activate(curthread); 3265 vmspace_free(oldvmspace); 3266 return (0); 3267 } 3268 3269 /* 3270 * vm_map_lookup: 3271 * 3272 * Finds the VM object, offset, and 3273 * protection for a given virtual address in the 3274 * specified map, assuming a page fault of the 3275 * type specified. 3276 * 3277 * Leaves the map in question locked for read; return 3278 * values are guaranteed until a vm_map_lookup_done 3279 * call is performed. Note that the map argument 3280 * is in/out; the returned map must be used in 3281 * the call to vm_map_lookup_done. 3282 * 3283 * A handle (out_entry) is returned for use in 3284 * vm_map_lookup_done, to make that fast. 3285 * 3286 * If a lookup is requested with "write protection" 3287 * specified, the map may be changed to perform virtual 3288 * copying operations, although the data referenced will 3289 * remain the same. 3290 */ 3291 int 3292 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3293 vm_offset_t vaddr, 3294 vm_prot_t fault_typea, 3295 vm_map_entry_t *out_entry, /* OUT */ 3296 vm_object_t *object, /* OUT */ 3297 vm_pindex_t *pindex, /* OUT */ 3298 vm_prot_t *out_prot, /* OUT */ 3299 boolean_t *wired) /* OUT */ 3300 { 3301 vm_map_entry_t entry; 3302 vm_map_t map = *var_map; 3303 vm_prot_t prot; 3304 vm_prot_t fault_type = fault_typea; 3305 3306 RetryLookup:; 3307 3308 vm_map_lock_read(map); 3309 3310 /* 3311 * Lookup the faulting address. 3312 */ 3313 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 3314 vm_map_unlock_read(map); 3315 return (KERN_INVALID_ADDRESS); 3316 } 3317 3318 entry = *out_entry; 3319 3320 /* 3321 * Handle submaps. 3322 */ 3323 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3324 vm_map_t old_map = map; 3325 3326 *var_map = map = entry->object.sub_map; 3327 vm_map_unlock_read(old_map); 3328 goto RetryLookup; 3329 } 3330 3331 /* 3332 * Check whether this task is allowed to have this page. 3333 * Note the special case for MAP_ENTRY_COW 3334 * pages with an override. This is to implement a forced 3335 * COW for debuggers. 3336 */ 3337 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3338 prot = entry->max_protection; 3339 else 3340 prot = entry->protection; 3341 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3342 if ((fault_type & prot) != fault_type) { 3343 vm_map_unlock_read(map); 3344 return (KERN_PROTECTION_FAILURE); 3345 } 3346 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3347 (entry->eflags & MAP_ENTRY_COW) && 3348 (fault_type & VM_PROT_WRITE) && 3349 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 3350 vm_map_unlock_read(map); 3351 return (KERN_PROTECTION_FAILURE); 3352 } 3353 3354 /* 3355 * If this page is not pageable, we have to get it for all possible 3356 * accesses. 3357 */ 3358 *wired = (entry->wired_count != 0); 3359 if (*wired) 3360 prot = fault_type = entry->protection; 3361 3362 /* 3363 * If the entry was copy-on-write, we either ... 3364 */ 3365 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3366 /* 3367 * If we want to write the page, we may as well handle that 3368 * now since we've got the map locked. 3369 * 3370 * If we don't need to write the page, we just demote the 3371 * permissions allowed. 3372 */ 3373 if (fault_type & VM_PROT_WRITE) { 3374 /* 3375 * Make a new object, and place it in the object 3376 * chain. Note that no new references have appeared 3377 * -- one just moved from the map to the new 3378 * object. 3379 */ 3380 if (vm_map_lock_upgrade(map)) 3381 goto RetryLookup; 3382 3383 vm_object_shadow( 3384 &entry->object.vm_object, 3385 &entry->offset, 3386 atop(entry->end - entry->start)); 3387 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3388 3389 vm_map_lock_downgrade(map); 3390 } else { 3391 /* 3392 * We're attempting to read a copy-on-write page -- 3393 * don't allow writes. 3394 */ 3395 prot &= ~VM_PROT_WRITE; 3396 } 3397 } 3398 3399 /* 3400 * Create an object if necessary. 3401 */ 3402 if (entry->object.vm_object == NULL && 3403 !map->system_map) { 3404 if (vm_map_lock_upgrade(map)) 3405 goto RetryLookup; 3406 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 3407 atop(entry->end - entry->start)); 3408 entry->offset = 0; 3409 vm_map_lock_downgrade(map); 3410 } 3411 3412 /* 3413 * Return the object/offset from this entry. If the entry was 3414 * copy-on-write or empty, it has been fixed up. 3415 */ 3416 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3417 *object = entry->object.vm_object; 3418 3419 *out_prot = prot; 3420 return (KERN_SUCCESS); 3421 } 3422 3423 /* 3424 * vm_map_lookup_locked: 3425 * 3426 * Lookup the faulting address. A version of vm_map_lookup that returns 3427 * KERN_FAILURE instead of blocking on map lock or memory allocation. 3428 */ 3429 int 3430 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 3431 vm_offset_t vaddr, 3432 vm_prot_t fault_typea, 3433 vm_map_entry_t *out_entry, /* OUT */ 3434 vm_object_t *object, /* OUT */ 3435 vm_pindex_t *pindex, /* OUT */ 3436 vm_prot_t *out_prot, /* OUT */ 3437 boolean_t *wired) /* OUT */ 3438 { 3439 vm_map_entry_t entry; 3440 vm_map_t map = *var_map; 3441 vm_prot_t prot; 3442 vm_prot_t fault_type = fault_typea; 3443 3444 /* 3445 * Lookup the faulting address. 3446 */ 3447 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 3448 return (KERN_INVALID_ADDRESS); 3449 3450 entry = *out_entry; 3451 3452 /* 3453 * Fail if the entry refers to a submap. 3454 */ 3455 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 3456 return (KERN_FAILURE); 3457 3458 /* 3459 * Check whether this task is allowed to have this page. 3460 * Note the special case for MAP_ENTRY_COW 3461 * pages with an override. This is to implement a forced 3462 * COW for debuggers. 3463 */ 3464 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3465 prot = entry->max_protection; 3466 else 3467 prot = entry->protection; 3468 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 3469 if ((fault_type & prot) != fault_type) 3470 return (KERN_PROTECTION_FAILURE); 3471 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3472 (entry->eflags & MAP_ENTRY_COW) && 3473 (fault_type & VM_PROT_WRITE) && 3474 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) 3475 return (KERN_PROTECTION_FAILURE); 3476 3477 /* 3478 * If this page is not pageable, we have to get it for all possible 3479 * accesses. 3480 */ 3481 *wired = (entry->wired_count != 0); 3482 if (*wired) 3483 prot = fault_type = entry->protection; 3484 3485 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3486 /* 3487 * Fail if the entry was copy-on-write for a write fault. 3488 */ 3489 if (fault_type & VM_PROT_WRITE) 3490 return (KERN_FAILURE); 3491 /* 3492 * We're attempting to read a copy-on-write page -- 3493 * don't allow writes. 3494 */ 3495 prot &= ~VM_PROT_WRITE; 3496 } 3497 3498 /* 3499 * Fail if an object should be created. 3500 */ 3501 if (entry->object.vm_object == NULL && !map->system_map) 3502 return (KERN_FAILURE); 3503 3504 /* 3505 * Return the object/offset from this entry. If the entry was 3506 * copy-on-write or empty, it has been fixed up. 3507 */ 3508 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3509 *object = entry->object.vm_object; 3510 3511 *out_prot = prot; 3512 return (KERN_SUCCESS); 3513 } 3514 3515 /* 3516 * vm_map_lookup_done: 3517 * 3518 * Releases locks acquired by a vm_map_lookup 3519 * (according to the handle returned by that lookup). 3520 */ 3521 void 3522 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 3523 { 3524 /* 3525 * Unlock the main-level map 3526 */ 3527 vm_map_unlock_read(map); 3528 } 3529 3530 #include "opt_ddb.h" 3531 #ifdef DDB 3532 #include <sys/kernel.h> 3533 3534 #include <ddb/ddb.h> 3535 3536 /* 3537 * vm_map_print: [ debug ] 3538 */ 3539 DB_SHOW_COMMAND(map, vm_map_print) 3540 { 3541 static int nlines; 3542 /* XXX convert args. */ 3543 vm_map_t map = (vm_map_t)addr; 3544 boolean_t full = have_addr; 3545 3546 vm_map_entry_t entry; 3547 3548 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 3549 (void *)map, 3550 (void *)map->pmap, map->nentries, map->timestamp); 3551 nlines++; 3552 3553 if (!full && db_indent) 3554 return; 3555 3556 db_indent += 2; 3557 for (entry = map->header.next; entry != &map->header; 3558 entry = entry->next) { 3559 db_iprintf("map entry %p: start=%p, end=%p\n", 3560 (void *)entry, (void *)entry->start, (void *)entry->end); 3561 nlines++; 3562 { 3563 static char *inheritance_name[4] = 3564 {"share", "copy", "none", "donate_copy"}; 3565 3566 db_iprintf(" prot=%x/%x/%s", 3567 entry->protection, 3568 entry->max_protection, 3569 inheritance_name[(int)(unsigned char)entry->inheritance]); 3570 if (entry->wired_count != 0) 3571 db_printf(", wired"); 3572 } 3573 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3574 db_printf(", share=%p, offset=0x%jx\n", 3575 (void *)entry->object.sub_map, 3576 (uintmax_t)entry->offset); 3577 nlines++; 3578 if ((entry->prev == &map->header) || 3579 (entry->prev->object.sub_map != 3580 entry->object.sub_map)) { 3581 db_indent += 2; 3582 vm_map_print((db_expr_t)(intptr_t) 3583 entry->object.sub_map, 3584 full, 0, (char *)0); 3585 db_indent -= 2; 3586 } 3587 } else { 3588 db_printf(", object=%p, offset=0x%jx", 3589 (void *)entry->object.vm_object, 3590 (uintmax_t)entry->offset); 3591 if (entry->eflags & MAP_ENTRY_COW) 3592 db_printf(", copy (%s)", 3593 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 3594 db_printf("\n"); 3595 nlines++; 3596 3597 if ((entry->prev == &map->header) || 3598 (entry->prev->object.vm_object != 3599 entry->object.vm_object)) { 3600 db_indent += 2; 3601 vm_object_print((db_expr_t)(intptr_t) 3602 entry->object.vm_object, 3603 full, 0, (char *)0); 3604 nlines += 4; 3605 db_indent -= 2; 3606 } 3607 } 3608 } 3609 db_indent -= 2; 3610 if (db_indent == 0) 3611 nlines = 0; 3612 } 3613 3614 3615 DB_SHOW_COMMAND(procvm, procvm) 3616 { 3617 struct proc *p; 3618 3619 if (have_addr) { 3620 p = (struct proc *) addr; 3621 } else { 3622 p = curproc; 3623 } 3624 3625 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 3626 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 3627 (void *)vmspace_pmap(p->p_vmspace)); 3628 3629 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 3630 } 3631 3632 #endif /* DDB */ 3633