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/kernel.h> 71 #include <sys/ktr.h> 72 #include <sys/lock.h> 73 #include <sys/mutex.h> 74 #include <sys/proc.h> 75 #include <sys/vmmeter.h> 76 #include <sys/mman.h> 77 #include <sys/vnode.h> 78 #include <sys/racct.h> 79 #include <sys/resourcevar.h> 80 #include <sys/rwlock.h> 81 #include <sys/file.h> 82 #include <sys/sysctl.h> 83 #include <sys/sysent.h> 84 #include <sys/shm.h> 85 86 #include <vm/vm.h> 87 #include <vm/vm_param.h> 88 #include <vm/pmap.h> 89 #include <vm/vm_map.h> 90 #include <vm/vm_page.h> 91 #include <vm/vm_object.h> 92 #include <vm/vm_pager.h> 93 #include <vm/vm_kern.h> 94 #include <vm/vm_extern.h> 95 #include <vm/vnode_pager.h> 96 #include <vm/swap_pager.h> 97 #include <vm/uma.h> 98 99 /* 100 * Virtual memory maps provide for the mapping, protection, 101 * and sharing of virtual memory objects. In addition, 102 * this module provides for an efficient virtual copy of 103 * memory from one map to another. 104 * 105 * Synchronization is required prior to most operations. 106 * 107 * Maps consist of an ordered doubly-linked list of simple 108 * entries; a self-adjusting binary search tree of these 109 * entries is used to speed up lookups. 110 * 111 * Since portions of maps are specified by start/end addresses, 112 * which may not align with existing map entries, all 113 * routines merely "clip" entries to these start/end values. 114 * [That is, an entry is split into two, bordering at a 115 * start or end value.] Note that these clippings may not 116 * always be necessary (as the two resulting entries are then 117 * not changed); however, the clipping is done for convenience. 118 * 119 * As mentioned above, virtual copy operations are performed 120 * by copying VM object references from one map to 121 * another, and then marking both regions as copy-on-write. 122 */ 123 124 static struct mtx map_sleep_mtx; 125 static uma_zone_t mapentzone; 126 static uma_zone_t kmapentzone; 127 static uma_zone_t mapzone; 128 static uma_zone_t vmspace_zone; 129 static int vmspace_zinit(void *mem, int size, int flags); 130 static int vm_map_zinit(void *mem, int ize, int flags); 131 static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, 132 vm_offset_t max); 133 static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map); 134 static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry); 135 #ifdef INVARIANTS 136 static void vm_map_zdtor(void *mem, int size, void *arg); 137 static void vmspace_zdtor(void *mem, int size, void *arg); 138 #endif 139 140 #define ENTRY_CHARGED(e) ((e)->cred != NULL || \ 141 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \ 142 !((e)->eflags & MAP_ENTRY_NEEDS_COPY))) 143 144 /* 145 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type 146 * stable. 147 */ 148 #define PROC_VMSPACE_LOCK(p) do { } while (0) 149 #define PROC_VMSPACE_UNLOCK(p) do { } while (0) 150 151 /* 152 * VM_MAP_RANGE_CHECK: [ internal use only ] 153 * 154 * Asserts that the starting and ending region 155 * addresses fall within the valid range of the map. 156 */ 157 #define VM_MAP_RANGE_CHECK(map, start, end) \ 158 { \ 159 if (start < vm_map_min(map)) \ 160 start = vm_map_min(map); \ 161 if (end > vm_map_max(map)) \ 162 end = vm_map_max(map); \ 163 if (start > end) \ 164 start = end; \ 165 } 166 167 /* 168 * vm_map_startup: 169 * 170 * Initialize the vm_map module. Must be called before 171 * any other vm_map routines. 172 * 173 * Map and entry structures are allocated from the general 174 * purpose memory pool with some exceptions: 175 * 176 * - The kernel map and kmem submap are allocated statically. 177 * - Kernel map entries are allocated out of a static pool. 178 * 179 * These restrictions are necessary since malloc() uses the 180 * maps and requires map entries. 181 */ 182 183 void 184 vm_map_startup(void) 185 { 186 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 187 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 188 #ifdef INVARIANTS 189 vm_map_zdtor, 190 #else 191 NULL, 192 #endif 193 vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 194 uma_prealloc(mapzone, MAX_KMAP); 195 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 196 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 197 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 198 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 199 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 200 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 201 #ifdef INVARIANTS 202 vmspace_zdtor, 203 #else 204 NULL, 205 #endif 206 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 207 } 208 209 static int 210 vmspace_zinit(void *mem, int size, int flags) 211 { 212 struct vmspace *vm; 213 214 vm = (struct vmspace *)mem; 215 216 vm->vm_map.pmap = NULL; 217 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); 218 PMAP_LOCK_INIT(vmspace_pmap(vm)); 219 return (0); 220 } 221 222 static int 223 vm_map_zinit(void *mem, int size, int flags) 224 { 225 vm_map_t map; 226 227 map = (vm_map_t)mem; 228 memset(map, 0, sizeof(*map)); 229 mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK); 230 sx_init(&map->lock, "vm map (user)"); 231 return (0); 232 } 233 234 #ifdef INVARIANTS 235 static void 236 vmspace_zdtor(void *mem, int size, void *arg) 237 { 238 struct vmspace *vm; 239 240 vm = (struct vmspace *)mem; 241 242 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 243 } 244 static void 245 vm_map_zdtor(void *mem, int size, void *arg) 246 { 247 vm_map_t map; 248 249 map = (vm_map_t)mem; 250 KASSERT(map->nentries == 0, 251 ("map %p nentries == %d on free.", 252 map, map->nentries)); 253 KASSERT(map->size == 0, 254 ("map %p size == %lu on free.", 255 map, (unsigned long)map->size)); 256 } 257 #endif /* INVARIANTS */ 258 259 /* 260 * Allocate a vmspace structure, including a vm_map and pmap, 261 * and initialize those structures. The refcnt is set to 1. 262 * 263 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit(). 264 */ 265 struct vmspace * 266 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit) 267 { 268 struct vmspace *vm; 269 270 vm = uma_zalloc(vmspace_zone, M_WAITOK); 271 272 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL")); 273 274 if (pinit == NULL) 275 pinit = &pmap_pinit; 276 277 if (!pinit(vmspace_pmap(vm))) { 278 uma_zfree(vmspace_zone, vm); 279 return (NULL); 280 } 281 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 282 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max); 283 vm->vm_refcnt = 1; 284 vm->vm_shm = NULL; 285 vm->vm_swrss = 0; 286 vm->vm_tsize = 0; 287 vm->vm_dsize = 0; 288 vm->vm_ssize = 0; 289 vm->vm_taddr = 0; 290 vm->vm_daddr = 0; 291 vm->vm_maxsaddr = 0; 292 return (vm); 293 } 294 295 static void 296 vmspace_container_reset(struct proc *p) 297 { 298 299 #ifdef RACCT 300 PROC_LOCK(p); 301 racct_set(p, RACCT_DATA, 0); 302 racct_set(p, RACCT_STACK, 0); 303 racct_set(p, RACCT_RSS, 0); 304 racct_set(p, RACCT_MEMLOCK, 0); 305 racct_set(p, RACCT_VMEM, 0); 306 PROC_UNLOCK(p); 307 #endif 308 } 309 310 static inline void 311 vmspace_dofree(struct vmspace *vm) 312 { 313 314 CTR1(KTR_VM, "vmspace_free: %p", vm); 315 316 /* 317 * Make sure any SysV shm is freed, it might not have been in 318 * exit1(). 319 */ 320 shmexit(vm); 321 322 /* 323 * Lock the map, to wait out all other references to it. 324 * Delete all of the mappings and pages they hold, then call 325 * the pmap module to reclaim anything left. 326 */ 327 (void)vm_map_remove(&vm->vm_map, vm->vm_map.min_offset, 328 vm->vm_map.max_offset); 329 330 pmap_release(vmspace_pmap(vm)); 331 vm->vm_map.pmap = NULL; 332 uma_zfree(vmspace_zone, vm); 333 } 334 335 void 336 vmspace_free(struct vmspace *vm) 337 { 338 339 if (vm->vm_refcnt == 0) 340 panic("vmspace_free: attempt to free already freed vmspace"); 341 342 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) 343 vmspace_dofree(vm); 344 } 345 346 void 347 vmspace_exitfree(struct proc *p) 348 { 349 struct vmspace *vm; 350 351 PROC_VMSPACE_LOCK(p); 352 vm = p->p_vmspace; 353 p->p_vmspace = NULL; 354 PROC_VMSPACE_UNLOCK(p); 355 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 356 vmspace_free(vm); 357 } 358 359 void 360 vmspace_exit(struct thread *td) 361 { 362 int refcnt; 363 struct vmspace *vm; 364 struct proc *p; 365 366 /* 367 * Release user portion of address space. 368 * This releases references to vnodes, 369 * which could cause I/O if the file has been unlinked. 370 * Need to do this early enough that we can still sleep. 371 * 372 * The last exiting process to reach this point releases as 373 * much of the environment as it can. vmspace_dofree() is the 374 * slower fallback in case another process had a temporary 375 * reference to the vmspace. 376 */ 377 378 p = td->td_proc; 379 vm = p->p_vmspace; 380 atomic_add_int(&vmspace0.vm_refcnt, 1); 381 do { 382 refcnt = vm->vm_refcnt; 383 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 384 /* Switch now since other proc might free vmspace */ 385 PROC_VMSPACE_LOCK(p); 386 p->p_vmspace = &vmspace0; 387 PROC_VMSPACE_UNLOCK(p); 388 pmap_activate(td); 389 } 390 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 391 if (refcnt == 1) { 392 if (p->p_vmspace != vm) { 393 /* vmspace not yet freed, switch back */ 394 PROC_VMSPACE_LOCK(p); 395 p->p_vmspace = vm; 396 PROC_VMSPACE_UNLOCK(p); 397 pmap_activate(td); 398 } 399 pmap_remove_pages(vmspace_pmap(vm)); 400 /* Switch now since this proc will free vmspace */ 401 PROC_VMSPACE_LOCK(p); 402 p->p_vmspace = &vmspace0; 403 PROC_VMSPACE_UNLOCK(p); 404 pmap_activate(td); 405 vmspace_dofree(vm); 406 } 407 vmspace_container_reset(p); 408 } 409 410 /* Acquire reference to vmspace owned by another process. */ 411 412 struct vmspace * 413 vmspace_acquire_ref(struct proc *p) 414 { 415 struct vmspace *vm; 416 int refcnt; 417 418 PROC_VMSPACE_LOCK(p); 419 vm = p->p_vmspace; 420 if (vm == NULL) { 421 PROC_VMSPACE_UNLOCK(p); 422 return (NULL); 423 } 424 do { 425 refcnt = vm->vm_refcnt; 426 if (refcnt <= 0) { /* Avoid 0->1 transition */ 427 PROC_VMSPACE_UNLOCK(p); 428 return (NULL); 429 } 430 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1)); 431 if (vm != p->p_vmspace) { 432 PROC_VMSPACE_UNLOCK(p); 433 vmspace_free(vm); 434 return (NULL); 435 } 436 PROC_VMSPACE_UNLOCK(p); 437 return (vm); 438 } 439 440 void 441 _vm_map_lock(vm_map_t map, const char *file, int line) 442 { 443 444 if (map->system_map) 445 mtx_lock_flags_(&map->system_mtx, 0, file, line); 446 else 447 sx_xlock_(&map->lock, file, line); 448 map->timestamp++; 449 } 450 451 static void 452 vm_map_process_deferred(void) 453 { 454 struct thread *td; 455 vm_map_entry_t entry, next; 456 vm_object_t object; 457 458 td = curthread; 459 entry = td->td_map_def_user; 460 td->td_map_def_user = NULL; 461 while (entry != NULL) { 462 next = entry->next; 463 if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) { 464 /* 465 * Decrement the object's writemappings and 466 * possibly the vnode's v_writecount. 467 */ 468 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 469 ("Submap with writecount")); 470 object = entry->object.vm_object; 471 KASSERT(object != NULL, ("No object for writecount")); 472 vnode_pager_release_writecount(object, entry->start, 473 entry->end); 474 } 475 vm_map_entry_deallocate(entry, FALSE); 476 entry = next; 477 } 478 } 479 480 void 481 _vm_map_unlock(vm_map_t map, const char *file, int line) 482 { 483 484 if (map->system_map) 485 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 486 else { 487 sx_xunlock_(&map->lock, file, line); 488 vm_map_process_deferred(); 489 } 490 } 491 492 void 493 _vm_map_lock_read(vm_map_t map, const char *file, int line) 494 { 495 496 if (map->system_map) 497 mtx_lock_flags_(&map->system_mtx, 0, file, line); 498 else 499 sx_slock_(&map->lock, file, line); 500 } 501 502 void 503 _vm_map_unlock_read(vm_map_t map, const char *file, int line) 504 { 505 506 if (map->system_map) 507 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 508 else { 509 sx_sunlock_(&map->lock, file, line); 510 vm_map_process_deferred(); 511 } 512 } 513 514 int 515 _vm_map_trylock(vm_map_t map, const char *file, int line) 516 { 517 int error; 518 519 error = map->system_map ? 520 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 521 !sx_try_xlock_(&map->lock, file, line); 522 if (error == 0) 523 map->timestamp++; 524 return (error == 0); 525 } 526 527 int 528 _vm_map_trylock_read(vm_map_t map, const char *file, int line) 529 { 530 int error; 531 532 error = map->system_map ? 533 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 534 !sx_try_slock_(&map->lock, file, line); 535 return (error == 0); 536 } 537 538 /* 539 * _vm_map_lock_upgrade: [ internal use only ] 540 * 541 * Tries to upgrade a read (shared) lock on the specified map to a write 542 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 543 * non-zero value if the upgrade fails. If the upgrade fails, the map is 544 * returned without a read or write lock held. 545 * 546 * Requires that the map be read locked. 547 */ 548 int 549 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 550 { 551 unsigned int last_timestamp; 552 553 if (map->system_map) { 554 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 555 } else { 556 if (!sx_try_upgrade_(&map->lock, file, line)) { 557 last_timestamp = map->timestamp; 558 sx_sunlock_(&map->lock, file, line); 559 vm_map_process_deferred(); 560 /* 561 * If the map's timestamp does not change while the 562 * map is unlocked, then the upgrade succeeds. 563 */ 564 sx_xlock_(&map->lock, file, line); 565 if (last_timestamp != map->timestamp) { 566 sx_xunlock_(&map->lock, file, line); 567 return (1); 568 } 569 } 570 } 571 map->timestamp++; 572 return (0); 573 } 574 575 void 576 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 577 { 578 579 if (map->system_map) { 580 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 581 } else 582 sx_downgrade_(&map->lock, file, line); 583 } 584 585 /* 586 * vm_map_locked: 587 * 588 * Returns a non-zero value if the caller holds a write (exclusive) lock 589 * on the specified map and the value "0" otherwise. 590 */ 591 int 592 vm_map_locked(vm_map_t map) 593 { 594 595 if (map->system_map) 596 return (mtx_owned(&map->system_mtx)); 597 else 598 return (sx_xlocked(&map->lock)); 599 } 600 601 #ifdef INVARIANTS 602 static void 603 _vm_map_assert_locked(vm_map_t map, const char *file, int line) 604 { 605 606 if (map->system_map) 607 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 608 else 609 sx_assert_(&map->lock, SA_XLOCKED, file, line); 610 } 611 612 #define VM_MAP_ASSERT_LOCKED(map) \ 613 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 614 #else 615 #define VM_MAP_ASSERT_LOCKED(map) 616 #endif 617 618 /* 619 * _vm_map_unlock_and_wait: 620 * 621 * Atomically releases the lock on the specified map and puts the calling 622 * thread to sleep. The calling thread will remain asleep until either 623 * vm_map_wakeup() is performed on the map or the specified timeout is 624 * exceeded. 625 * 626 * WARNING! This function does not perform deferred deallocations of 627 * objects and map entries. Therefore, the calling thread is expected to 628 * reacquire the map lock after reawakening and later perform an ordinary 629 * unlock operation, such as vm_map_unlock(), before completing its 630 * operation on the map. 631 */ 632 int 633 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) 634 { 635 636 mtx_lock(&map_sleep_mtx); 637 if (map->system_map) 638 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 639 else 640 sx_xunlock_(&map->lock, file, line); 641 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 642 timo)); 643 } 644 645 /* 646 * vm_map_wakeup: 647 * 648 * Awaken any threads that have slept on the map using 649 * vm_map_unlock_and_wait(). 650 */ 651 void 652 vm_map_wakeup(vm_map_t map) 653 { 654 655 /* 656 * Acquire and release map_sleep_mtx to prevent a wakeup() 657 * from being performed (and lost) between the map unlock 658 * and the msleep() in _vm_map_unlock_and_wait(). 659 */ 660 mtx_lock(&map_sleep_mtx); 661 mtx_unlock(&map_sleep_mtx); 662 wakeup(&map->root); 663 } 664 665 void 666 vm_map_busy(vm_map_t map) 667 { 668 669 VM_MAP_ASSERT_LOCKED(map); 670 map->busy++; 671 } 672 673 void 674 vm_map_unbusy(vm_map_t map) 675 { 676 677 VM_MAP_ASSERT_LOCKED(map); 678 KASSERT(map->busy, ("vm_map_unbusy: not busy")); 679 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { 680 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); 681 wakeup(&map->busy); 682 } 683 } 684 685 void 686 vm_map_wait_busy(vm_map_t map) 687 { 688 689 VM_MAP_ASSERT_LOCKED(map); 690 while (map->busy) { 691 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); 692 if (map->system_map) 693 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); 694 else 695 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); 696 } 697 map->timestamp++; 698 } 699 700 long 701 vmspace_resident_count(struct vmspace *vmspace) 702 { 703 return pmap_resident_count(vmspace_pmap(vmspace)); 704 } 705 706 /* 707 * vm_map_create: 708 * 709 * Creates and returns a new empty VM map with 710 * the given physical map structure, and having 711 * the given lower and upper address bounds. 712 */ 713 vm_map_t 714 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 715 { 716 vm_map_t result; 717 718 result = uma_zalloc(mapzone, M_WAITOK); 719 CTR1(KTR_VM, "vm_map_create: %p", result); 720 _vm_map_init(result, pmap, min, max); 721 return (result); 722 } 723 724 /* 725 * Initialize an existing vm_map structure 726 * such as that in the vmspace structure. 727 */ 728 static void 729 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 730 { 731 732 map->header.next = map->header.prev = &map->header; 733 map->needs_wakeup = FALSE; 734 map->system_map = 0; 735 map->pmap = pmap; 736 map->min_offset = min; 737 map->max_offset = max; 738 map->flags = 0; 739 map->root = NULL; 740 map->timestamp = 0; 741 map->busy = 0; 742 } 743 744 void 745 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 746 { 747 748 _vm_map_init(map, pmap, min, max); 749 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 750 sx_init(&map->lock, "user map"); 751 } 752 753 /* 754 * vm_map_entry_dispose: [ internal use only ] 755 * 756 * Inverse of vm_map_entry_create. 757 */ 758 static void 759 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 760 { 761 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 762 } 763 764 /* 765 * vm_map_entry_create: [ internal use only ] 766 * 767 * Allocates a VM map entry for insertion. 768 * No entry fields are filled in. 769 */ 770 static vm_map_entry_t 771 vm_map_entry_create(vm_map_t map) 772 { 773 vm_map_entry_t new_entry; 774 775 if (map->system_map) 776 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 777 else 778 new_entry = uma_zalloc(mapentzone, M_WAITOK); 779 if (new_entry == NULL) 780 panic("vm_map_entry_create: kernel resources exhausted"); 781 return (new_entry); 782 } 783 784 /* 785 * vm_map_entry_set_behavior: 786 * 787 * Set the expected access behavior, either normal, random, or 788 * sequential. 789 */ 790 static inline void 791 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 792 { 793 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 794 (behavior & MAP_ENTRY_BEHAV_MASK); 795 } 796 797 /* 798 * vm_map_entry_set_max_free: 799 * 800 * Set the max_free field in a vm_map_entry. 801 */ 802 static inline void 803 vm_map_entry_set_max_free(vm_map_entry_t entry) 804 { 805 806 entry->max_free = entry->adj_free; 807 if (entry->left != NULL && entry->left->max_free > entry->max_free) 808 entry->max_free = entry->left->max_free; 809 if (entry->right != NULL && entry->right->max_free > entry->max_free) 810 entry->max_free = entry->right->max_free; 811 } 812 813 /* 814 * vm_map_entry_splay: 815 * 816 * The Sleator and Tarjan top-down splay algorithm with the 817 * following variation. Max_free must be computed bottom-up, so 818 * on the downward pass, maintain the left and right spines in 819 * reverse order. Then, make a second pass up each side to fix 820 * the pointers and compute max_free. The time bound is O(log n) 821 * amortized. 822 * 823 * The new root is the vm_map_entry containing "addr", or else an 824 * adjacent entry (lower or higher) if addr is not in the tree. 825 * 826 * The map must be locked, and leaves it so. 827 * 828 * Returns: the new root. 829 */ 830 static vm_map_entry_t 831 vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root) 832 { 833 vm_map_entry_t llist, rlist; 834 vm_map_entry_t ltree, rtree; 835 vm_map_entry_t y; 836 837 /* Special case of empty tree. */ 838 if (root == NULL) 839 return (root); 840 841 /* 842 * Pass One: Splay down the tree until we find addr or a NULL 843 * pointer where addr would go. llist and rlist are the two 844 * sides in reverse order (bottom-up), with llist linked by 845 * the right pointer and rlist linked by the left pointer in 846 * the vm_map_entry. Wait until Pass Two to set max_free on 847 * the two spines. 848 */ 849 llist = NULL; 850 rlist = NULL; 851 for (;;) { 852 /* root is never NULL in here. */ 853 if (addr < root->start) { 854 y = root->left; 855 if (y == NULL) 856 break; 857 if (addr < y->start && y->left != NULL) { 858 /* Rotate right and put y on rlist. */ 859 root->left = y->right; 860 y->right = root; 861 vm_map_entry_set_max_free(root); 862 root = y->left; 863 y->left = rlist; 864 rlist = y; 865 } else { 866 /* Put root on rlist. */ 867 root->left = rlist; 868 rlist = root; 869 root = y; 870 } 871 } else if (addr >= root->end) { 872 y = root->right; 873 if (y == NULL) 874 break; 875 if (addr >= y->end && y->right != NULL) { 876 /* Rotate left and put y on llist. */ 877 root->right = y->left; 878 y->left = root; 879 vm_map_entry_set_max_free(root); 880 root = y->right; 881 y->right = llist; 882 llist = y; 883 } else { 884 /* Put root on llist. */ 885 root->right = llist; 886 llist = root; 887 root = y; 888 } 889 } else 890 break; 891 } 892 893 /* 894 * Pass Two: Walk back up the two spines, flip the pointers 895 * and set max_free. The subtrees of the root go at the 896 * bottom of llist and rlist. 897 */ 898 ltree = root->left; 899 while (llist != NULL) { 900 y = llist->right; 901 llist->right = ltree; 902 vm_map_entry_set_max_free(llist); 903 ltree = llist; 904 llist = y; 905 } 906 rtree = root->right; 907 while (rlist != NULL) { 908 y = rlist->left; 909 rlist->left = rtree; 910 vm_map_entry_set_max_free(rlist); 911 rtree = rlist; 912 rlist = y; 913 } 914 915 /* 916 * Final assembly: add ltree and rtree as subtrees of root. 917 */ 918 root->left = ltree; 919 root->right = rtree; 920 vm_map_entry_set_max_free(root); 921 922 return (root); 923 } 924 925 /* 926 * vm_map_entry_{un,}link: 927 * 928 * Insert/remove entries from maps. 929 */ 930 static void 931 vm_map_entry_link(vm_map_t map, 932 vm_map_entry_t after_where, 933 vm_map_entry_t entry) 934 { 935 936 CTR4(KTR_VM, 937 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 938 map->nentries, entry, after_where); 939 VM_MAP_ASSERT_LOCKED(map); 940 map->nentries++; 941 entry->prev = after_where; 942 entry->next = after_where->next; 943 entry->next->prev = entry; 944 after_where->next = entry; 945 946 if (after_where != &map->header) { 947 if (after_where != map->root) 948 vm_map_entry_splay(after_where->start, map->root); 949 entry->right = after_where->right; 950 entry->left = after_where; 951 after_where->right = NULL; 952 after_where->adj_free = entry->start - after_where->end; 953 vm_map_entry_set_max_free(after_where); 954 } else { 955 entry->right = map->root; 956 entry->left = NULL; 957 } 958 entry->adj_free = (entry->next == &map->header ? map->max_offset : 959 entry->next->start) - entry->end; 960 vm_map_entry_set_max_free(entry); 961 map->root = entry; 962 } 963 964 static void 965 vm_map_entry_unlink(vm_map_t map, 966 vm_map_entry_t entry) 967 { 968 vm_map_entry_t next, prev, root; 969 970 VM_MAP_ASSERT_LOCKED(map); 971 if (entry != map->root) 972 vm_map_entry_splay(entry->start, map->root); 973 if (entry->left == NULL) 974 root = entry->right; 975 else { 976 root = vm_map_entry_splay(entry->start, entry->left); 977 root->right = entry->right; 978 root->adj_free = (entry->next == &map->header ? map->max_offset : 979 entry->next->start) - root->end; 980 vm_map_entry_set_max_free(root); 981 } 982 map->root = root; 983 984 prev = entry->prev; 985 next = entry->next; 986 next->prev = prev; 987 prev->next = next; 988 map->nentries--; 989 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 990 map->nentries, entry); 991 } 992 993 /* 994 * vm_map_entry_resize_free: 995 * 996 * Recompute the amount of free space following a vm_map_entry 997 * and propagate that value up the tree. Call this function after 998 * resizing a map entry in-place, that is, without a call to 999 * vm_map_entry_link() or _unlink(). 1000 * 1001 * The map must be locked, and leaves it so. 1002 */ 1003 static void 1004 vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry) 1005 { 1006 1007 /* 1008 * Using splay trees without parent pointers, propagating 1009 * max_free up the tree is done by moving the entry to the 1010 * root and making the change there. 1011 */ 1012 if (entry != map->root) 1013 map->root = vm_map_entry_splay(entry->start, map->root); 1014 1015 entry->adj_free = (entry->next == &map->header ? map->max_offset : 1016 entry->next->start) - entry->end; 1017 vm_map_entry_set_max_free(entry); 1018 } 1019 1020 /* 1021 * vm_map_lookup_entry: [ internal use only ] 1022 * 1023 * Finds the map entry containing (or 1024 * immediately preceding) the specified address 1025 * in the given map; the entry is returned 1026 * in the "entry" parameter. The boolean 1027 * result indicates whether the address is 1028 * actually contained in the map. 1029 */ 1030 boolean_t 1031 vm_map_lookup_entry( 1032 vm_map_t map, 1033 vm_offset_t address, 1034 vm_map_entry_t *entry) /* OUT */ 1035 { 1036 vm_map_entry_t cur; 1037 boolean_t locked; 1038 1039 /* 1040 * If the map is empty, then the map entry immediately preceding 1041 * "address" is the map's header. 1042 */ 1043 cur = map->root; 1044 if (cur == NULL) 1045 *entry = &map->header; 1046 else if (address >= cur->start && cur->end > address) { 1047 *entry = cur; 1048 return (TRUE); 1049 } else if ((locked = vm_map_locked(map)) || 1050 sx_try_upgrade(&map->lock)) { 1051 /* 1052 * Splay requires a write lock on the map. However, it only 1053 * restructures the binary search tree; it does not otherwise 1054 * change the map. Thus, the map's timestamp need not change 1055 * on a temporary upgrade. 1056 */ 1057 map->root = cur = vm_map_entry_splay(address, cur); 1058 if (!locked) 1059 sx_downgrade(&map->lock); 1060 1061 /* 1062 * If "address" is contained within a map entry, the new root 1063 * is that map entry. Otherwise, the new root is a map entry 1064 * immediately before or after "address". 1065 */ 1066 if (address >= cur->start) { 1067 *entry = cur; 1068 if (cur->end > address) 1069 return (TRUE); 1070 } else 1071 *entry = cur->prev; 1072 } else 1073 /* 1074 * Since the map is only locked for read access, perform a 1075 * standard binary search tree lookup for "address". 1076 */ 1077 for (;;) { 1078 if (address < cur->start) { 1079 if (cur->left == NULL) { 1080 *entry = cur->prev; 1081 break; 1082 } 1083 cur = cur->left; 1084 } else if (cur->end > address) { 1085 *entry = cur; 1086 return (TRUE); 1087 } else { 1088 if (cur->right == NULL) { 1089 *entry = cur; 1090 break; 1091 } 1092 cur = cur->right; 1093 } 1094 } 1095 return (FALSE); 1096 } 1097 1098 /* 1099 * vm_map_insert: 1100 * 1101 * Inserts the given whole VM object into the target 1102 * map at the specified address range. The object's 1103 * size should match that of the address range. 1104 * 1105 * Requires that the map be locked, and leaves it so. 1106 * 1107 * If object is non-NULL, ref count must be bumped by caller 1108 * prior to making call to account for the new entry. 1109 */ 1110 int 1111 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1112 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 1113 int cow) 1114 { 1115 vm_map_entry_t new_entry; 1116 vm_map_entry_t prev_entry; 1117 vm_map_entry_t temp_entry; 1118 vm_eflags_t protoeflags; 1119 struct ucred *cred; 1120 vm_inherit_t inheritance; 1121 boolean_t charge_prev_obj; 1122 1123 VM_MAP_ASSERT_LOCKED(map); 1124 1125 /* 1126 * Check that the start and end points are not bogus. 1127 */ 1128 if ((start < map->min_offset) || (end > map->max_offset) || 1129 (start >= end)) 1130 return (KERN_INVALID_ADDRESS); 1131 1132 /* 1133 * Find the entry prior to the proposed starting address; if it's part 1134 * of an existing entry, this range is bogus. 1135 */ 1136 if (vm_map_lookup_entry(map, start, &temp_entry)) 1137 return (KERN_NO_SPACE); 1138 1139 prev_entry = temp_entry; 1140 1141 /* 1142 * Assert that the next entry doesn't overlap the end point. 1143 */ 1144 if ((prev_entry->next != &map->header) && 1145 (prev_entry->next->start < end)) 1146 return (KERN_NO_SPACE); 1147 1148 protoeflags = 0; 1149 charge_prev_obj = FALSE; 1150 1151 if (cow & MAP_COPY_ON_WRITE) 1152 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 1153 1154 if (cow & MAP_NOFAULT) { 1155 protoeflags |= MAP_ENTRY_NOFAULT; 1156 1157 KASSERT(object == NULL, 1158 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1159 } 1160 if (cow & MAP_DISABLE_SYNCER) 1161 protoeflags |= MAP_ENTRY_NOSYNC; 1162 if (cow & MAP_DISABLE_COREDUMP) 1163 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1164 if (cow & MAP_VN_WRITECOUNT) 1165 protoeflags |= MAP_ENTRY_VN_WRITECNT; 1166 if (cow & MAP_INHERIT_SHARE) 1167 inheritance = VM_INHERIT_SHARE; 1168 else 1169 inheritance = VM_INHERIT_DEFAULT; 1170 1171 cred = NULL; 1172 KASSERT((object != kmem_object && object != kernel_object) || 1173 ((object == kmem_object || object == kernel_object) && 1174 !(protoeflags & MAP_ENTRY_NEEDS_COPY)), 1175 ("kmem or kernel object and cow")); 1176 if (cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT)) 1177 goto charged; 1178 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1179 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1180 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1181 return (KERN_RESOURCE_SHORTAGE); 1182 KASSERT(object == NULL || (protoeflags & MAP_ENTRY_NEEDS_COPY) || 1183 object->cred == NULL, 1184 ("OVERCOMMIT: vm_map_insert o %p", object)); 1185 cred = curthread->td_ucred; 1186 crhold(cred); 1187 if (object == NULL && !(protoeflags & MAP_ENTRY_NEEDS_COPY)) 1188 charge_prev_obj = TRUE; 1189 } 1190 1191 charged: 1192 /* Expand the kernel pmap, if necessary. */ 1193 if (map == kernel_map && end > kernel_vm_end) 1194 pmap_growkernel(end); 1195 if (object != NULL) { 1196 /* 1197 * OBJ_ONEMAPPING must be cleared unless this mapping 1198 * is trivially proven to be the only mapping for any 1199 * of the object's pages. (Object granularity 1200 * reference counting is insufficient to recognize 1201 * aliases with precision.) 1202 */ 1203 VM_OBJECT_WLOCK(object); 1204 if (object->ref_count > 1 || object->shadow_count != 0) 1205 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1206 VM_OBJECT_WUNLOCK(object); 1207 } 1208 else if ((prev_entry != &map->header) && 1209 (prev_entry->eflags == protoeflags) && 1210 (cow & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) == 0 && 1211 (prev_entry->end == start) && 1212 (prev_entry->wired_count == 0) && 1213 (prev_entry->cred == cred || 1214 (prev_entry->object.vm_object != NULL && 1215 (prev_entry->object.vm_object->cred == cred))) && 1216 vm_object_coalesce(prev_entry->object.vm_object, 1217 prev_entry->offset, 1218 (vm_size_t)(prev_entry->end - prev_entry->start), 1219 (vm_size_t)(end - prev_entry->end), charge_prev_obj)) { 1220 /* 1221 * We were able to extend the object. Determine if we 1222 * can extend the previous map entry to include the 1223 * new range as well. 1224 */ 1225 if ((prev_entry->inheritance == inheritance) && 1226 (prev_entry->protection == prot) && 1227 (prev_entry->max_protection == max)) { 1228 map->size += (end - prev_entry->end); 1229 prev_entry->end = end; 1230 vm_map_entry_resize_free(map, prev_entry); 1231 vm_map_simplify_entry(map, prev_entry); 1232 if (cred != NULL) 1233 crfree(cred); 1234 return (KERN_SUCCESS); 1235 } 1236 1237 /* 1238 * If we can extend the object but cannot extend the 1239 * map entry, we have to create a new map entry. We 1240 * must bump the ref count on the extended object to 1241 * account for it. object may be NULL. 1242 */ 1243 object = prev_entry->object.vm_object; 1244 offset = prev_entry->offset + 1245 (prev_entry->end - prev_entry->start); 1246 vm_object_reference(object); 1247 if (cred != NULL && object != NULL && object->cred != NULL && 1248 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1249 /* Object already accounts for this uid. */ 1250 crfree(cred); 1251 cred = NULL; 1252 } 1253 } 1254 1255 /* 1256 * NOTE: if conditionals fail, object can be NULL here. This occurs 1257 * in things like the buffer map where we manage kva but do not manage 1258 * backing objects. 1259 */ 1260 1261 /* 1262 * Create a new entry 1263 */ 1264 new_entry = vm_map_entry_create(map); 1265 new_entry->start = start; 1266 new_entry->end = end; 1267 new_entry->cred = NULL; 1268 1269 new_entry->eflags = protoeflags; 1270 new_entry->object.vm_object = object; 1271 new_entry->offset = offset; 1272 new_entry->avail_ssize = 0; 1273 1274 new_entry->inheritance = inheritance; 1275 new_entry->protection = prot; 1276 new_entry->max_protection = max; 1277 new_entry->wired_count = 0; 1278 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1279 new_entry->next_read = OFF_TO_IDX(offset); 1280 1281 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1282 ("OVERCOMMIT: vm_map_insert leaks vm_map %p", new_entry)); 1283 new_entry->cred = cred; 1284 1285 /* 1286 * Insert the new entry into the list 1287 */ 1288 vm_map_entry_link(map, prev_entry, new_entry); 1289 map->size += new_entry->end - new_entry->start; 1290 1291 /* 1292 * It may be possible to merge the new entry with the next and/or 1293 * previous entries. However, due to MAP_STACK_* being a hack, a 1294 * panic can result from merging such entries. 1295 */ 1296 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0) 1297 vm_map_simplify_entry(map, new_entry); 1298 1299 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 1300 vm_map_pmap_enter(map, start, prot, 1301 object, OFF_TO_IDX(offset), end - start, 1302 cow & MAP_PREFAULT_PARTIAL); 1303 } 1304 1305 return (KERN_SUCCESS); 1306 } 1307 1308 /* 1309 * vm_map_findspace: 1310 * 1311 * Find the first fit (lowest VM address) for "length" free bytes 1312 * beginning at address >= start in the given map. 1313 * 1314 * In a vm_map_entry, "adj_free" is the amount of free space 1315 * adjacent (higher address) to this entry, and "max_free" is the 1316 * maximum amount of contiguous free space in its subtree. This 1317 * allows finding a free region in one path down the tree, so 1318 * O(log n) amortized with splay trees. 1319 * 1320 * The map must be locked, and leaves it so. 1321 * 1322 * Returns: 0 on success, and starting address in *addr, 1323 * 1 if insufficient space. 1324 */ 1325 int 1326 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1327 vm_offset_t *addr) /* OUT */ 1328 { 1329 vm_map_entry_t entry; 1330 vm_offset_t st; 1331 1332 /* 1333 * Request must fit within min/max VM address and must avoid 1334 * address wrap. 1335 */ 1336 if (start < map->min_offset) 1337 start = map->min_offset; 1338 if (start + length > map->max_offset || start + length < start) 1339 return (1); 1340 1341 /* Empty tree means wide open address space. */ 1342 if (map->root == NULL) { 1343 *addr = start; 1344 return (0); 1345 } 1346 1347 /* 1348 * After splay, if start comes before root node, then there 1349 * must be a gap from start to the root. 1350 */ 1351 map->root = vm_map_entry_splay(start, map->root); 1352 if (start + length <= map->root->start) { 1353 *addr = start; 1354 return (0); 1355 } 1356 1357 /* 1358 * Root is the last node that might begin its gap before 1359 * start, and this is the last comparison where address 1360 * wrap might be a problem. 1361 */ 1362 st = (start > map->root->end) ? start : map->root->end; 1363 if (length <= map->root->end + map->root->adj_free - st) { 1364 *addr = st; 1365 return (0); 1366 } 1367 1368 /* With max_free, can immediately tell if no solution. */ 1369 entry = map->root->right; 1370 if (entry == NULL || length > entry->max_free) 1371 return (1); 1372 1373 /* 1374 * Search the right subtree in the order: left subtree, root, 1375 * right subtree (first fit). The previous splay implies that 1376 * all regions in the right subtree have addresses > start. 1377 */ 1378 while (entry != NULL) { 1379 if (entry->left != NULL && entry->left->max_free >= length) 1380 entry = entry->left; 1381 else if (entry->adj_free >= length) { 1382 *addr = entry->end; 1383 return (0); 1384 } else 1385 entry = entry->right; 1386 } 1387 1388 /* Can't get here, so panic if we do. */ 1389 panic("vm_map_findspace: max_free corrupt"); 1390 } 1391 1392 int 1393 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1394 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1395 vm_prot_t max, int cow) 1396 { 1397 vm_offset_t end; 1398 int result; 1399 1400 end = start + length; 1401 vm_map_lock(map); 1402 VM_MAP_RANGE_CHECK(map, start, end); 1403 (void) vm_map_delete(map, start, end); 1404 result = vm_map_insert(map, object, offset, start, end, prot, 1405 max, cow); 1406 vm_map_unlock(map); 1407 return (result); 1408 } 1409 1410 /* 1411 * vm_map_find finds an unallocated region in the target address 1412 * map with the given length. The search is defined to be 1413 * first-fit from the specified address; the region found is 1414 * returned in the same parameter. 1415 * 1416 * If object is non-NULL, ref count must be bumped by caller 1417 * prior to making call to account for the new entry. 1418 */ 1419 int 1420 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1421 vm_offset_t *addr, /* IN/OUT */ 1422 vm_size_t length, vm_offset_t max_addr, int find_space, 1423 vm_prot_t prot, vm_prot_t max, int cow) 1424 { 1425 vm_offset_t alignment, initial_addr, start; 1426 int result; 1427 1428 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 1429 (object->flags & OBJ_COLORED) == 0)) 1430 find_space = VMFS_ANY_SPACE; 1431 if (find_space >> 8 != 0) { 1432 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 1433 alignment = (vm_offset_t)1 << (find_space >> 8); 1434 } else 1435 alignment = 0; 1436 initial_addr = *addr; 1437 again: 1438 start = initial_addr; 1439 vm_map_lock(map); 1440 do { 1441 if (find_space != VMFS_NO_SPACE) { 1442 if (vm_map_findspace(map, start, length, addr) || 1443 (max_addr != 0 && *addr + length > max_addr)) { 1444 vm_map_unlock(map); 1445 if (find_space == VMFS_OPTIMAL_SPACE) { 1446 find_space = VMFS_ANY_SPACE; 1447 goto again; 1448 } 1449 return (KERN_NO_SPACE); 1450 } 1451 switch (find_space) { 1452 case VMFS_SUPER_SPACE: 1453 case VMFS_OPTIMAL_SPACE: 1454 pmap_align_superpage(object, offset, addr, 1455 length); 1456 break; 1457 case VMFS_ANY_SPACE: 1458 break; 1459 default: 1460 if ((*addr & (alignment - 1)) != 0) { 1461 *addr &= ~(alignment - 1); 1462 *addr += alignment; 1463 } 1464 break; 1465 } 1466 1467 start = *addr; 1468 } 1469 result = vm_map_insert(map, object, offset, start, start + 1470 length, prot, max, cow); 1471 } while (result == KERN_NO_SPACE && find_space != VMFS_NO_SPACE && 1472 find_space != VMFS_ANY_SPACE); 1473 vm_map_unlock(map); 1474 return (result); 1475 } 1476 1477 /* 1478 * vm_map_simplify_entry: 1479 * 1480 * Simplify the given map entry by merging with either neighbor. This 1481 * routine also has the ability to merge with both neighbors. 1482 * 1483 * The map must be locked. 1484 * 1485 * This routine guarentees that the passed entry remains valid (though 1486 * possibly extended). When merging, this routine may delete one or 1487 * both neighbors. 1488 */ 1489 void 1490 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1491 { 1492 vm_map_entry_t next, prev; 1493 vm_size_t prevsize, esize; 1494 1495 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) 1496 return; 1497 1498 prev = entry->prev; 1499 if (prev != &map->header) { 1500 prevsize = prev->end - prev->start; 1501 if ( (prev->end == entry->start) && 1502 (prev->object.vm_object == entry->object.vm_object) && 1503 (!prev->object.vm_object || 1504 (prev->offset + prevsize == entry->offset)) && 1505 (prev->eflags == entry->eflags) && 1506 (prev->protection == entry->protection) && 1507 (prev->max_protection == entry->max_protection) && 1508 (prev->inheritance == entry->inheritance) && 1509 (prev->wired_count == entry->wired_count) && 1510 (prev->cred == entry->cred)) { 1511 vm_map_entry_unlink(map, prev); 1512 entry->start = prev->start; 1513 entry->offset = prev->offset; 1514 if (entry->prev != &map->header) 1515 vm_map_entry_resize_free(map, entry->prev); 1516 1517 /* 1518 * If the backing object is a vnode object, 1519 * vm_object_deallocate() calls vrele(). 1520 * However, vrele() does not lock the vnode 1521 * because the vnode has additional 1522 * references. Thus, the map lock can be kept 1523 * without causing a lock-order reversal with 1524 * the vnode lock. 1525 * 1526 * Since we count the number of virtual page 1527 * mappings in object->un_pager.vnp.writemappings, 1528 * the writemappings value should not be adjusted 1529 * when the entry is disposed of. 1530 */ 1531 if (prev->object.vm_object) 1532 vm_object_deallocate(prev->object.vm_object); 1533 if (prev->cred != NULL) 1534 crfree(prev->cred); 1535 vm_map_entry_dispose(map, prev); 1536 } 1537 } 1538 1539 next = entry->next; 1540 if (next != &map->header) { 1541 esize = entry->end - entry->start; 1542 if ((entry->end == next->start) && 1543 (next->object.vm_object == entry->object.vm_object) && 1544 (!entry->object.vm_object || 1545 (entry->offset + esize == next->offset)) && 1546 (next->eflags == entry->eflags) && 1547 (next->protection == entry->protection) && 1548 (next->max_protection == entry->max_protection) && 1549 (next->inheritance == entry->inheritance) && 1550 (next->wired_count == entry->wired_count) && 1551 (next->cred == entry->cred)) { 1552 vm_map_entry_unlink(map, next); 1553 entry->end = next->end; 1554 vm_map_entry_resize_free(map, entry); 1555 1556 /* 1557 * See comment above. 1558 */ 1559 if (next->object.vm_object) 1560 vm_object_deallocate(next->object.vm_object); 1561 if (next->cred != NULL) 1562 crfree(next->cred); 1563 vm_map_entry_dispose(map, next); 1564 } 1565 } 1566 } 1567 /* 1568 * vm_map_clip_start: [ internal use only ] 1569 * 1570 * Asserts that the given entry begins at or after 1571 * the specified address; if necessary, 1572 * it splits the entry into two. 1573 */ 1574 #define vm_map_clip_start(map, entry, startaddr) \ 1575 { \ 1576 if (startaddr > entry->start) \ 1577 _vm_map_clip_start(map, entry, startaddr); \ 1578 } 1579 1580 /* 1581 * This routine is called only when it is known that 1582 * the entry must be split. 1583 */ 1584 static void 1585 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1586 { 1587 vm_map_entry_t new_entry; 1588 1589 VM_MAP_ASSERT_LOCKED(map); 1590 1591 /* 1592 * Split off the front portion -- note that we must insert the new 1593 * entry BEFORE this one, so that this entry has the specified 1594 * starting address. 1595 */ 1596 vm_map_simplify_entry(map, entry); 1597 1598 /* 1599 * If there is no object backing this entry, we might as well create 1600 * one now. If we defer it, an object can get created after the map 1601 * is clipped, and individual objects will be created for the split-up 1602 * map. This is a bit of a hack, but is also about the best place to 1603 * put this improvement. 1604 */ 1605 if (entry->object.vm_object == NULL && !map->system_map) { 1606 vm_object_t object; 1607 object = vm_object_allocate(OBJT_DEFAULT, 1608 atop(entry->end - entry->start)); 1609 entry->object.vm_object = object; 1610 entry->offset = 0; 1611 if (entry->cred != NULL) { 1612 object->cred = entry->cred; 1613 object->charge = entry->end - entry->start; 1614 entry->cred = NULL; 1615 } 1616 } else if (entry->object.vm_object != NULL && 1617 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1618 entry->cred != NULL) { 1619 VM_OBJECT_WLOCK(entry->object.vm_object); 1620 KASSERT(entry->object.vm_object->cred == NULL, 1621 ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry)); 1622 entry->object.vm_object->cred = entry->cred; 1623 entry->object.vm_object->charge = entry->end - entry->start; 1624 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1625 entry->cred = NULL; 1626 } 1627 1628 new_entry = vm_map_entry_create(map); 1629 *new_entry = *entry; 1630 1631 new_entry->end = start; 1632 entry->offset += (start - entry->start); 1633 entry->start = start; 1634 if (new_entry->cred != NULL) 1635 crhold(entry->cred); 1636 1637 vm_map_entry_link(map, entry->prev, new_entry); 1638 1639 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1640 vm_object_reference(new_entry->object.vm_object); 1641 /* 1642 * The object->un_pager.vnp.writemappings for the 1643 * object of MAP_ENTRY_VN_WRITECNT type entry shall be 1644 * kept as is here. The virtual pages are 1645 * re-distributed among the clipped entries, so the sum is 1646 * left the same. 1647 */ 1648 } 1649 } 1650 1651 /* 1652 * vm_map_clip_end: [ internal use only ] 1653 * 1654 * Asserts that the given entry ends at or before 1655 * the specified address; if necessary, 1656 * it splits the entry into two. 1657 */ 1658 #define vm_map_clip_end(map, entry, endaddr) \ 1659 { \ 1660 if ((endaddr) < (entry->end)) \ 1661 _vm_map_clip_end((map), (entry), (endaddr)); \ 1662 } 1663 1664 /* 1665 * This routine is called only when it is known that 1666 * the entry must be split. 1667 */ 1668 static void 1669 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1670 { 1671 vm_map_entry_t new_entry; 1672 1673 VM_MAP_ASSERT_LOCKED(map); 1674 1675 /* 1676 * If there is no object backing this entry, we might as well create 1677 * one now. If we defer it, an object can get created after the map 1678 * is clipped, and individual objects will be created for the split-up 1679 * map. This is a bit of a hack, but is also about the best place to 1680 * put this improvement. 1681 */ 1682 if (entry->object.vm_object == NULL && !map->system_map) { 1683 vm_object_t object; 1684 object = vm_object_allocate(OBJT_DEFAULT, 1685 atop(entry->end - entry->start)); 1686 entry->object.vm_object = object; 1687 entry->offset = 0; 1688 if (entry->cred != NULL) { 1689 object->cred = entry->cred; 1690 object->charge = entry->end - entry->start; 1691 entry->cred = NULL; 1692 } 1693 } else if (entry->object.vm_object != NULL && 1694 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1695 entry->cred != NULL) { 1696 VM_OBJECT_WLOCK(entry->object.vm_object); 1697 KASSERT(entry->object.vm_object->cred == NULL, 1698 ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry)); 1699 entry->object.vm_object->cred = entry->cred; 1700 entry->object.vm_object->charge = entry->end - entry->start; 1701 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1702 entry->cred = NULL; 1703 } 1704 1705 /* 1706 * Create a new entry and insert it AFTER the specified entry 1707 */ 1708 new_entry = vm_map_entry_create(map); 1709 *new_entry = *entry; 1710 1711 new_entry->start = entry->end = end; 1712 new_entry->offset += (end - entry->start); 1713 if (new_entry->cred != NULL) 1714 crhold(entry->cred); 1715 1716 vm_map_entry_link(map, entry, new_entry); 1717 1718 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1719 vm_object_reference(new_entry->object.vm_object); 1720 } 1721 } 1722 1723 /* 1724 * vm_map_submap: [ kernel use only ] 1725 * 1726 * Mark the given range as handled by a subordinate map. 1727 * 1728 * This range must have been created with vm_map_find, 1729 * and no other operations may have been performed on this 1730 * range prior to calling vm_map_submap. 1731 * 1732 * Only a limited number of operations can be performed 1733 * within this rage after calling vm_map_submap: 1734 * vm_fault 1735 * [Don't try vm_map_copy!] 1736 * 1737 * To remove a submapping, one must first remove the 1738 * range from the superior map, and then destroy the 1739 * submap (if desired). [Better yet, don't try it.] 1740 */ 1741 int 1742 vm_map_submap( 1743 vm_map_t map, 1744 vm_offset_t start, 1745 vm_offset_t end, 1746 vm_map_t submap) 1747 { 1748 vm_map_entry_t entry; 1749 int result = KERN_INVALID_ARGUMENT; 1750 1751 vm_map_lock(map); 1752 1753 VM_MAP_RANGE_CHECK(map, start, end); 1754 1755 if (vm_map_lookup_entry(map, start, &entry)) { 1756 vm_map_clip_start(map, entry, start); 1757 } else 1758 entry = entry->next; 1759 1760 vm_map_clip_end(map, entry, end); 1761 1762 if ((entry->start == start) && (entry->end == end) && 1763 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1764 (entry->object.vm_object == NULL)) { 1765 entry->object.sub_map = submap; 1766 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1767 result = KERN_SUCCESS; 1768 } 1769 vm_map_unlock(map); 1770 1771 return (result); 1772 } 1773 1774 /* 1775 * The maximum number of pages to map 1776 */ 1777 #define MAX_INIT_PT 96 1778 1779 /* 1780 * vm_map_pmap_enter: 1781 * 1782 * Preload read-only mappings for the specified object's resident pages 1783 * into the target map. If "flags" is MAP_PREFAULT_PARTIAL, then only 1784 * the resident pages within the address range [addr, addr + ulmin(size, 1785 * ptoa(MAX_INIT_PT))) are mapped. Otherwise, all resident pages within 1786 * the specified address range are mapped. This eliminates many soft 1787 * faults on process startup and immediately after an mmap(2). Because 1788 * these are speculative mappings, cached pages are not reactivated and 1789 * mapped. 1790 */ 1791 void 1792 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 1793 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1794 { 1795 vm_offset_t start; 1796 vm_page_t p, p_start; 1797 vm_pindex_t psize, tmpidx; 1798 1799 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 1800 return; 1801 VM_OBJECT_RLOCK(object); 1802 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1803 VM_OBJECT_RUNLOCK(object); 1804 VM_OBJECT_WLOCK(object); 1805 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1806 pmap_object_init_pt(map->pmap, addr, object, pindex, 1807 size); 1808 VM_OBJECT_WUNLOCK(object); 1809 return; 1810 } 1811 VM_OBJECT_LOCK_DOWNGRADE(object); 1812 } 1813 1814 psize = atop(size); 1815 if (psize > MAX_INIT_PT && (flags & MAP_PREFAULT_PARTIAL) != 0) 1816 psize = MAX_INIT_PT; 1817 if (psize + pindex > object->size) { 1818 if (object->size < pindex) { 1819 VM_OBJECT_RUNLOCK(object); 1820 return; 1821 } 1822 psize = object->size - pindex; 1823 } 1824 1825 start = 0; 1826 p_start = NULL; 1827 1828 p = vm_page_find_least(object, pindex); 1829 /* 1830 * Assert: the variable p is either (1) the page with the 1831 * least pindex greater than or equal to the parameter pindex 1832 * or (2) NULL. 1833 */ 1834 for (; 1835 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1836 p = TAILQ_NEXT(p, listq)) { 1837 /* 1838 * don't allow an madvise to blow away our really 1839 * free pages allocating pv entries. 1840 */ 1841 if ((flags & MAP_PREFAULT_MADVISE) && 1842 cnt.v_free_count < cnt.v_free_reserved) { 1843 psize = tmpidx; 1844 break; 1845 } 1846 if (p->valid == VM_PAGE_BITS_ALL) { 1847 if (p_start == NULL) { 1848 start = addr + ptoa(tmpidx); 1849 p_start = p; 1850 } 1851 } else if (p_start != NULL) { 1852 pmap_enter_object(map->pmap, start, addr + 1853 ptoa(tmpidx), p_start, prot); 1854 p_start = NULL; 1855 } 1856 } 1857 if (p_start != NULL) 1858 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 1859 p_start, prot); 1860 VM_OBJECT_RUNLOCK(object); 1861 } 1862 1863 /* 1864 * vm_map_protect: 1865 * 1866 * Sets the protection of the specified address 1867 * region in the target map. If "set_max" is 1868 * specified, the maximum protection is to be set; 1869 * otherwise, only the current protection is affected. 1870 */ 1871 int 1872 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1873 vm_prot_t new_prot, boolean_t set_max) 1874 { 1875 vm_map_entry_t current, entry; 1876 vm_object_t obj; 1877 struct ucred *cred; 1878 vm_prot_t old_prot; 1879 1880 if (start == end) 1881 return (KERN_SUCCESS); 1882 1883 vm_map_lock(map); 1884 1885 VM_MAP_RANGE_CHECK(map, start, end); 1886 1887 if (vm_map_lookup_entry(map, start, &entry)) { 1888 vm_map_clip_start(map, entry, start); 1889 } else { 1890 entry = entry->next; 1891 } 1892 1893 /* 1894 * Make a first pass to check for protection violations. 1895 */ 1896 current = entry; 1897 while ((current != &map->header) && (current->start < end)) { 1898 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1899 vm_map_unlock(map); 1900 return (KERN_INVALID_ARGUMENT); 1901 } 1902 if ((new_prot & current->max_protection) != new_prot) { 1903 vm_map_unlock(map); 1904 return (KERN_PROTECTION_FAILURE); 1905 } 1906 current = current->next; 1907 } 1908 1909 1910 /* 1911 * Do an accounting pass for private read-only mappings that 1912 * now will do cow due to allowed write (e.g. debugger sets 1913 * breakpoint on text segment) 1914 */ 1915 for (current = entry; (current != &map->header) && 1916 (current->start < end); current = current->next) { 1917 1918 vm_map_clip_end(map, current, end); 1919 1920 if (set_max || 1921 ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 || 1922 ENTRY_CHARGED(current)) { 1923 continue; 1924 } 1925 1926 cred = curthread->td_ucred; 1927 obj = current->object.vm_object; 1928 1929 if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) { 1930 if (!swap_reserve(current->end - current->start)) { 1931 vm_map_unlock(map); 1932 return (KERN_RESOURCE_SHORTAGE); 1933 } 1934 crhold(cred); 1935 current->cred = cred; 1936 continue; 1937 } 1938 1939 VM_OBJECT_WLOCK(obj); 1940 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 1941 VM_OBJECT_WUNLOCK(obj); 1942 continue; 1943 } 1944 1945 /* 1946 * Charge for the whole object allocation now, since 1947 * we cannot distinguish between non-charged and 1948 * charged clipped mapping of the same object later. 1949 */ 1950 KASSERT(obj->charge == 0, 1951 ("vm_map_protect: object %p overcharged\n", obj)); 1952 if (!swap_reserve(ptoa(obj->size))) { 1953 VM_OBJECT_WUNLOCK(obj); 1954 vm_map_unlock(map); 1955 return (KERN_RESOURCE_SHORTAGE); 1956 } 1957 1958 crhold(cred); 1959 obj->cred = cred; 1960 obj->charge = ptoa(obj->size); 1961 VM_OBJECT_WUNLOCK(obj); 1962 } 1963 1964 /* 1965 * Go back and fix up protections. [Note that clipping is not 1966 * necessary the second time.] 1967 */ 1968 current = entry; 1969 while ((current != &map->header) && (current->start < end)) { 1970 old_prot = current->protection; 1971 1972 if (set_max) 1973 current->protection = 1974 (current->max_protection = new_prot) & 1975 old_prot; 1976 else 1977 current->protection = new_prot; 1978 1979 if ((current->eflags & (MAP_ENTRY_COW | MAP_ENTRY_USER_WIRED)) 1980 == (MAP_ENTRY_COW | MAP_ENTRY_USER_WIRED) && 1981 (current->protection & VM_PROT_WRITE) != 0 && 1982 (old_prot & VM_PROT_WRITE) == 0) { 1983 vm_fault_copy_entry(map, map, current, current, NULL); 1984 } 1985 1986 /* 1987 * When restricting access, update the physical map. Worry 1988 * about copy-on-write here. 1989 */ 1990 if ((old_prot & ~current->protection) != 0) { 1991 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1992 VM_PROT_ALL) 1993 pmap_protect(map->pmap, current->start, 1994 current->end, 1995 current->protection & MASK(current)); 1996 #undef MASK 1997 } 1998 vm_map_simplify_entry(map, current); 1999 current = current->next; 2000 } 2001 vm_map_unlock(map); 2002 return (KERN_SUCCESS); 2003 } 2004 2005 /* 2006 * vm_map_madvise: 2007 * 2008 * This routine traverses a processes map handling the madvise 2009 * system call. Advisories are classified as either those effecting 2010 * the vm_map_entry structure, or those effecting the underlying 2011 * objects. 2012 */ 2013 int 2014 vm_map_madvise( 2015 vm_map_t map, 2016 vm_offset_t start, 2017 vm_offset_t end, 2018 int behav) 2019 { 2020 vm_map_entry_t current, entry; 2021 int modify_map = 0; 2022 2023 /* 2024 * Some madvise calls directly modify the vm_map_entry, in which case 2025 * we need to use an exclusive lock on the map and we need to perform 2026 * various clipping operations. Otherwise we only need a read-lock 2027 * on the map. 2028 */ 2029 switch(behav) { 2030 case MADV_NORMAL: 2031 case MADV_SEQUENTIAL: 2032 case MADV_RANDOM: 2033 case MADV_NOSYNC: 2034 case MADV_AUTOSYNC: 2035 case MADV_NOCORE: 2036 case MADV_CORE: 2037 if (start == end) 2038 return (KERN_SUCCESS); 2039 modify_map = 1; 2040 vm_map_lock(map); 2041 break; 2042 case MADV_WILLNEED: 2043 case MADV_DONTNEED: 2044 case MADV_FREE: 2045 if (start == end) 2046 return (KERN_SUCCESS); 2047 vm_map_lock_read(map); 2048 break; 2049 default: 2050 return (KERN_INVALID_ARGUMENT); 2051 } 2052 2053 /* 2054 * Locate starting entry and clip if necessary. 2055 */ 2056 VM_MAP_RANGE_CHECK(map, start, end); 2057 2058 if (vm_map_lookup_entry(map, start, &entry)) { 2059 if (modify_map) 2060 vm_map_clip_start(map, entry, start); 2061 } else { 2062 entry = entry->next; 2063 } 2064 2065 if (modify_map) { 2066 /* 2067 * madvise behaviors that are implemented in the vm_map_entry. 2068 * 2069 * We clip the vm_map_entry so that behavioral changes are 2070 * limited to the specified address range. 2071 */ 2072 for (current = entry; 2073 (current != &map->header) && (current->start < end); 2074 current = current->next 2075 ) { 2076 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2077 continue; 2078 2079 vm_map_clip_end(map, current, end); 2080 2081 switch (behav) { 2082 case MADV_NORMAL: 2083 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 2084 break; 2085 case MADV_SEQUENTIAL: 2086 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 2087 break; 2088 case MADV_RANDOM: 2089 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 2090 break; 2091 case MADV_NOSYNC: 2092 current->eflags |= MAP_ENTRY_NOSYNC; 2093 break; 2094 case MADV_AUTOSYNC: 2095 current->eflags &= ~MAP_ENTRY_NOSYNC; 2096 break; 2097 case MADV_NOCORE: 2098 current->eflags |= MAP_ENTRY_NOCOREDUMP; 2099 break; 2100 case MADV_CORE: 2101 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2102 break; 2103 default: 2104 break; 2105 } 2106 vm_map_simplify_entry(map, current); 2107 } 2108 vm_map_unlock(map); 2109 } else { 2110 vm_pindex_t pstart, pend; 2111 2112 /* 2113 * madvise behaviors that are implemented in the underlying 2114 * vm_object. 2115 * 2116 * Since we don't clip the vm_map_entry, we have to clip 2117 * the vm_object pindex and count. 2118 */ 2119 for (current = entry; 2120 (current != &map->header) && (current->start < end); 2121 current = current->next 2122 ) { 2123 vm_offset_t useEnd, useStart; 2124 2125 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2126 continue; 2127 2128 pstart = OFF_TO_IDX(current->offset); 2129 pend = pstart + atop(current->end - current->start); 2130 useStart = current->start; 2131 useEnd = current->end; 2132 2133 if (current->start < start) { 2134 pstart += atop(start - current->start); 2135 useStart = start; 2136 } 2137 if (current->end > end) { 2138 pend -= atop(current->end - end); 2139 useEnd = end; 2140 } 2141 2142 if (pstart >= pend) 2143 continue; 2144 2145 /* 2146 * Perform the pmap_advise() before clearing 2147 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2148 * concurrent pmap operation, such as pmap_remove(), 2149 * could clear a reference in the pmap and set 2150 * PGA_REFERENCED on the page before the pmap_advise() 2151 * had completed. Consequently, the page would appear 2152 * referenced based upon an old reference that 2153 * occurred before this pmap_advise() ran. 2154 */ 2155 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2156 pmap_advise(map->pmap, useStart, useEnd, 2157 behav); 2158 2159 vm_object_madvise(current->object.vm_object, pstart, 2160 pend, behav); 2161 if (behav == MADV_WILLNEED) { 2162 vm_map_pmap_enter(map, 2163 useStart, 2164 current->protection, 2165 current->object.vm_object, 2166 pstart, 2167 ptoa(pend - pstart), 2168 MAP_PREFAULT_MADVISE 2169 ); 2170 } 2171 } 2172 vm_map_unlock_read(map); 2173 } 2174 return (0); 2175 } 2176 2177 2178 /* 2179 * vm_map_inherit: 2180 * 2181 * Sets the inheritance of the specified address 2182 * range in the target map. Inheritance 2183 * affects how the map will be shared with 2184 * child maps at the time of vmspace_fork. 2185 */ 2186 int 2187 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2188 vm_inherit_t new_inheritance) 2189 { 2190 vm_map_entry_t entry; 2191 vm_map_entry_t temp_entry; 2192 2193 switch (new_inheritance) { 2194 case VM_INHERIT_NONE: 2195 case VM_INHERIT_COPY: 2196 case VM_INHERIT_SHARE: 2197 break; 2198 default: 2199 return (KERN_INVALID_ARGUMENT); 2200 } 2201 if (start == end) 2202 return (KERN_SUCCESS); 2203 vm_map_lock(map); 2204 VM_MAP_RANGE_CHECK(map, start, end); 2205 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2206 entry = temp_entry; 2207 vm_map_clip_start(map, entry, start); 2208 } else 2209 entry = temp_entry->next; 2210 while ((entry != &map->header) && (entry->start < end)) { 2211 vm_map_clip_end(map, entry, end); 2212 entry->inheritance = new_inheritance; 2213 vm_map_simplify_entry(map, entry); 2214 entry = entry->next; 2215 } 2216 vm_map_unlock(map); 2217 return (KERN_SUCCESS); 2218 } 2219 2220 /* 2221 * vm_map_unwire: 2222 * 2223 * Implements both kernel and user unwiring. 2224 */ 2225 int 2226 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2227 int flags) 2228 { 2229 vm_map_entry_t entry, first_entry, tmp_entry; 2230 vm_offset_t saved_start; 2231 unsigned int last_timestamp; 2232 int rv; 2233 boolean_t need_wakeup, result, user_unwire; 2234 2235 if (start == end) 2236 return (KERN_SUCCESS); 2237 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2238 vm_map_lock(map); 2239 VM_MAP_RANGE_CHECK(map, start, end); 2240 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2241 if (flags & VM_MAP_WIRE_HOLESOK) 2242 first_entry = first_entry->next; 2243 else { 2244 vm_map_unlock(map); 2245 return (KERN_INVALID_ADDRESS); 2246 } 2247 } 2248 last_timestamp = map->timestamp; 2249 entry = first_entry; 2250 while (entry != &map->header && entry->start < end) { 2251 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2252 /* 2253 * We have not yet clipped the entry. 2254 */ 2255 saved_start = (start >= entry->start) ? start : 2256 entry->start; 2257 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2258 if (vm_map_unlock_and_wait(map, 0)) { 2259 /* 2260 * Allow interruption of user unwiring? 2261 */ 2262 } 2263 vm_map_lock(map); 2264 if (last_timestamp+1 != map->timestamp) { 2265 /* 2266 * Look again for the entry because the map was 2267 * modified while it was unlocked. 2268 * Specifically, the entry may have been 2269 * clipped, merged, or deleted. 2270 */ 2271 if (!vm_map_lookup_entry(map, saved_start, 2272 &tmp_entry)) { 2273 if (flags & VM_MAP_WIRE_HOLESOK) 2274 tmp_entry = tmp_entry->next; 2275 else { 2276 if (saved_start == start) { 2277 /* 2278 * First_entry has been deleted. 2279 */ 2280 vm_map_unlock(map); 2281 return (KERN_INVALID_ADDRESS); 2282 } 2283 end = saved_start; 2284 rv = KERN_INVALID_ADDRESS; 2285 goto done; 2286 } 2287 } 2288 if (entry == first_entry) 2289 first_entry = tmp_entry; 2290 else 2291 first_entry = NULL; 2292 entry = tmp_entry; 2293 } 2294 last_timestamp = map->timestamp; 2295 continue; 2296 } 2297 vm_map_clip_start(map, entry, start); 2298 vm_map_clip_end(map, entry, end); 2299 /* 2300 * Mark the entry in case the map lock is released. (See 2301 * above.) 2302 */ 2303 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2304 entry->wiring_thread == NULL, 2305 ("owned map entry %p", entry)); 2306 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2307 entry->wiring_thread = curthread; 2308 /* 2309 * Check the map for holes in the specified region. 2310 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2311 */ 2312 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2313 (entry->end < end && (entry->next == &map->header || 2314 entry->next->start > entry->end))) { 2315 end = entry->end; 2316 rv = KERN_INVALID_ADDRESS; 2317 goto done; 2318 } 2319 /* 2320 * If system unwiring, require that the entry is system wired. 2321 */ 2322 if (!user_unwire && 2323 vm_map_entry_system_wired_count(entry) == 0) { 2324 end = entry->end; 2325 rv = KERN_INVALID_ARGUMENT; 2326 goto done; 2327 } 2328 entry = entry->next; 2329 } 2330 rv = KERN_SUCCESS; 2331 done: 2332 need_wakeup = FALSE; 2333 if (first_entry == NULL) { 2334 result = vm_map_lookup_entry(map, start, &first_entry); 2335 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2336 first_entry = first_entry->next; 2337 else 2338 KASSERT(result, ("vm_map_unwire: lookup failed")); 2339 } 2340 for (entry = first_entry; entry != &map->header && entry->start < end; 2341 entry = entry->next) { 2342 /* 2343 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2344 * space in the unwired region could have been mapped 2345 * while the map lock was dropped for draining 2346 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 2347 * could be simultaneously wiring this new mapping 2348 * entry. Detect these cases and skip any entries 2349 * marked as in transition by us. 2350 */ 2351 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2352 entry->wiring_thread != curthread) { 2353 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2354 ("vm_map_unwire: !HOLESOK and new/changed entry")); 2355 continue; 2356 } 2357 2358 if (rv == KERN_SUCCESS && (!user_unwire || 2359 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 2360 if (user_unwire) 2361 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2362 entry->wired_count--; 2363 if (entry->wired_count == 0) { 2364 /* 2365 * Retain the map lock. 2366 */ 2367 vm_fault_unwire(map, entry->start, entry->end, 2368 entry->object.vm_object != NULL && 2369 (entry->object.vm_object->flags & 2370 OBJ_FICTITIOUS) != 0); 2371 } 2372 } 2373 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2374 ("vm_map_unwire: in-transition flag missing %p", entry)); 2375 KASSERT(entry->wiring_thread == curthread, 2376 ("vm_map_unwire: alien wire %p", entry)); 2377 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 2378 entry->wiring_thread = NULL; 2379 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2380 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2381 need_wakeup = TRUE; 2382 } 2383 vm_map_simplify_entry(map, entry); 2384 } 2385 vm_map_unlock(map); 2386 if (need_wakeup) 2387 vm_map_wakeup(map); 2388 return (rv); 2389 } 2390 2391 /* 2392 * vm_map_wire: 2393 * 2394 * Implements both kernel and user wiring. 2395 */ 2396 int 2397 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2398 int flags) 2399 { 2400 vm_map_entry_t entry, first_entry, tmp_entry; 2401 vm_offset_t saved_end, saved_start; 2402 unsigned int last_timestamp; 2403 int rv; 2404 boolean_t fictitious, need_wakeup, result, user_wire; 2405 vm_prot_t prot; 2406 2407 if (start == end) 2408 return (KERN_SUCCESS); 2409 prot = 0; 2410 if (flags & VM_MAP_WIRE_WRITE) 2411 prot |= VM_PROT_WRITE; 2412 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2413 vm_map_lock(map); 2414 VM_MAP_RANGE_CHECK(map, start, end); 2415 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2416 if (flags & VM_MAP_WIRE_HOLESOK) 2417 first_entry = first_entry->next; 2418 else { 2419 vm_map_unlock(map); 2420 return (KERN_INVALID_ADDRESS); 2421 } 2422 } 2423 last_timestamp = map->timestamp; 2424 entry = first_entry; 2425 while (entry != &map->header && entry->start < end) { 2426 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2427 /* 2428 * We have not yet clipped the entry. 2429 */ 2430 saved_start = (start >= entry->start) ? start : 2431 entry->start; 2432 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2433 if (vm_map_unlock_and_wait(map, 0)) { 2434 /* 2435 * Allow interruption of user wiring? 2436 */ 2437 } 2438 vm_map_lock(map); 2439 if (last_timestamp + 1 != map->timestamp) { 2440 /* 2441 * Look again for the entry because the map was 2442 * modified while it was unlocked. 2443 * Specifically, the entry may have been 2444 * clipped, merged, or deleted. 2445 */ 2446 if (!vm_map_lookup_entry(map, saved_start, 2447 &tmp_entry)) { 2448 if (flags & VM_MAP_WIRE_HOLESOK) 2449 tmp_entry = tmp_entry->next; 2450 else { 2451 if (saved_start == start) { 2452 /* 2453 * first_entry has been deleted. 2454 */ 2455 vm_map_unlock(map); 2456 return (KERN_INVALID_ADDRESS); 2457 } 2458 end = saved_start; 2459 rv = KERN_INVALID_ADDRESS; 2460 goto done; 2461 } 2462 } 2463 if (entry == first_entry) 2464 first_entry = tmp_entry; 2465 else 2466 first_entry = NULL; 2467 entry = tmp_entry; 2468 } 2469 last_timestamp = map->timestamp; 2470 continue; 2471 } 2472 vm_map_clip_start(map, entry, start); 2473 vm_map_clip_end(map, entry, end); 2474 /* 2475 * Mark the entry in case the map lock is released. (See 2476 * above.) 2477 */ 2478 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2479 entry->wiring_thread == NULL, 2480 ("owned map entry %p", entry)); 2481 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2482 entry->wiring_thread = curthread; 2483 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 2484 || (entry->protection & prot) != prot) { 2485 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 2486 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { 2487 end = entry->end; 2488 rv = KERN_INVALID_ADDRESS; 2489 goto done; 2490 } 2491 goto next_entry; 2492 } 2493 if (entry->wired_count == 0) { 2494 entry->wired_count++; 2495 saved_start = entry->start; 2496 saved_end = entry->end; 2497 fictitious = entry->object.vm_object != NULL && 2498 (entry->object.vm_object->flags & 2499 OBJ_FICTITIOUS) != 0; 2500 /* 2501 * Release the map lock, relying on the in-transition 2502 * mark. Mark the map busy for fork. 2503 */ 2504 vm_map_busy(map); 2505 vm_map_unlock(map); 2506 rv = vm_fault_wire(map, saved_start, saved_end, 2507 fictitious); 2508 vm_map_lock(map); 2509 vm_map_unbusy(map); 2510 if (last_timestamp + 1 != map->timestamp) { 2511 /* 2512 * Look again for the entry because the map was 2513 * modified while it was unlocked. The entry 2514 * may have been clipped, but NOT merged or 2515 * deleted. 2516 */ 2517 result = vm_map_lookup_entry(map, saved_start, 2518 &tmp_entry); 2519 KASSERT(result, ("vm_map_wire: lookup failed")); 2520 if (entry == first_entry) 2521 first_entry = tmp_entry; 2522 else 2523 first_entry = NULL; 2524 entry = tmp_entry; 2525 while (entry->end < saved_end) { 2526 if (rv != KERN_SUCCESS) { 2527 KASSERT(entry->wired_count == 1, 2528 ("vm_map_wire: bad count")); 2529 entry->wired_count = -1; 2530 } 2531 entry = entry->next; 2532 } 2533 } 2534 last_timestamp = map->timestamp; 2535 if (rv != KERN_SUCCESS) { 2536 KASSERT(entry->wired_count == 1, 2537 ("vm_map_wire: bad count")); 2538 /* 2539 * Assign an out-of-range value to represent 2540 * the failure to wire this entry. 2541 */ 2542 entry->wired_count = -1; 2543 end = entry->end; 2544 goto done; 2545 } 2546 } else if (!user_wire || 2547 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2548 entry->wired_count++; 2549 } 2550 /* 2551 * Check the map for holes in the specified region. 2552 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2553 */ 2554 next_entry: 2555 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2556 (entry->end < end && (entry->next == &map->header || 2557 entry->next->start > entry->end))) { 2558 end = entry->end; 2559 rv = KERN_INVALID_ADDRESS; 2560 goto done; 2561 } 2562 entry = entry->next; 2563 } 2564 rv = KERN_SUCCESS; 2565 done: 2566 need_wakeup = FALSE; 2567 if (first_entry == NULL) { 2568 result = vm_map_lookup_entry(map, start, &first_entry); 2569 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2570 first_entry = first_entry->next; 2571 else 2572 KASSERT(result, ("vm_map_wire: lookup failed")); 2573 } 2574 for (entry = first_entry; entry != &map->header && entry->start < end; 2575 entry = entry->next) { 2576 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) 2577 goto next_entry_done; 2578 2579 /* 2580 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2581 * space in the unwired region could have been mapped 2582 * while the map lock was dropped for faulting in the 2583 * pages or draining MAP_ENTRY_IN_TRANSITION. 2584 * Moreover, another thread could be simultaneously 2585 * wiring this new mapping entry. Detect these cases 2586 * and skip any entries marked as in transition by us. 2587 */ 2588 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2589 entry->wiring_thread != curthread) { 2590 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2591 ("vm_map_wire: !HOLESOK and new/changed entry")); 2592 continue; 2593 } 2594 2595 if (rv == KERN_SUCCESS) { 2596 if (user_wire) 2597 entry->eflags |= MAP_ENTRY_USER_WIRED; 2598 } else if (entry->wired_count == -1) { 2599 /* 2600 * Wiring failed on this entry. Thus, unwiring is 2601 * unnecessary. 2602 */ 2603 entry->wired_count = 0; 2604 } else { 2605 if (!user_wire || 2606 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) 2607 entry->wired_count--; 2608 if (entry->wired_count == 0) { 2609 /* 2610 * Retain the map lock. 2611 */ 2612 vm_fault_unwire(map, entry->start, entry->end, 2613 entry->object.vm_object != NULL && 2614 (entry->object.vm_object->flags & 2615 OBJ_FICTITIOUS) != 0); 2616 } 2617 } 2618 next_entry_done: 2619 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2620 ("vm_map_wire: in-transition flag missing %p", entry)); 2621 KASSERT(entry->wiring_thread == curthread, 2622 ("vm_map_wire: alien wire %p", entry)); 2623 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 2624 MAP_ENTRY_WIRE_SKIPPED); 2625 entry->wiring_thread = NULL; 2626 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2627 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2628 need_wakeup = TRUE; 2629 } 2630 vm_map_simplify_entry(map, entry); 2631 } 2632 vm_map_unlock(map); 2633 if (need_wakeup) 2634 vm_map_wakeup(map); 2635 return (rv); 2636 } 2637 2638 /* 2639 * vm_map_sync 2640 * 2641 * Push any dirty cached pages in the address range to their pager. 2642 * If syncio is TRUE, dirty pages are written synchronously. 2643 * If invalidate is TRUE, any cached pages are freed as well. 2644 * 2645 * If the size of the region from start to end is zero, we are 2646 * supposed to flush all modified pages within the region containing 2647 * start. Unfortunately, a region can be split or coalesced with 2648 * neighboring regions, making it difficult to determine what the 2649 * original region was. Therefore, we approximate this requirement by 2650 * flushing the current region containing start. 2651 * 2652 * Returns an error if any part of the specified range is not mapped. 2653 */ 2654 int 2655 vm_map_sync( 2656 vm_map_t map, 2657 vm_offset_t start, 2658 vm_offset_t end, 2659 boolean_t syncio, 2660 boolean_t invalidate) 2661 { 2662 vm_map_entry_t current; 2663 vm_map_entry_t entry; 2664 vm_size_t size; 2665 vm_object_t object; 2666 vm_ooffset_t offset; 2667 unsigned int last_timestamp; 2668 boolean_t failed; 2669 2670 vm_map_lock_read(map); 2671 VM_MAP_RANGE_CHECK(map, start, end); 2672 if (!vm_map_lookup_entry(map, start, &entry)) { 2673 vm_map_unlock_read(map); 2674 return (KERN_INVALID_ADDRESS); 2675 } else if (start == end) { 2676 start = entry->start; 2677 end = entry->end; 2678 } 2679 /* 2680 * Make a first pass to check for user-wired memory and holes. 2681 */ 2682 for (current = entry; current != &map->header && current->start < end; 2683 current = current->next) { 2684 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 2685 vm_map_unlock_read(map); 2686 return (KERN_INVALID_ARGUMENT); 2687 } 2688 if (end > current->end && 2689 (current->next == &map->header || 2690 current->end != current->next->start)) { 2691 vm_map_unlock_read(map); 2692 return (KERN_INVALID_ADDRESS); 2693 } 2694 } 2695 2696 if (invalidate) 2697 pmap_remove(map->pmap, start, end); 2698 failed = FALSE; 2699 2700 /* 2701 * Make a second pass, cleaning/uncaching pages from the indicated 2702 * objects as we go. 2703 */ 2704 for (current = entry; current != &map->header && current->start < end;) { 2705 offset = current->offset + (start - current->start); 2706 size = (end <= current->end ? end : current->end) - start; 2707 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2708 vm_map_t smap; 2709 vm_map_entry_t tentry; 2710 vm_size_t tsize; 2711 2712 smap = current->object.sub_map; 2713 vm_map_lock_read(smap); 2714 (void) vm_map_lookup_entry(smap, offset, &tentry); 2715 tsize = tentry->end - offset; 2716 if (tsize < size) 2717 size = tsize; 2718 object = tentry->object.vm_object; 2719 offset = tentry->offset + (offset - tentry->start); 2720 vm_map_unlock_read(smap); 2721 } else { 2722 object = current->object.vm_object; 2723 } 2724 vm_object_reference(object); 2725 last_timestamp = map->timestamp; 2726 vm_map_unlock_read(map); 2727 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 2728 failed = TRUE; 2729 start += size; 2730 vm_object_deallocate(object); 2731 vm_map_lock_read(map); 2732 if (last_timestamp == map->timestamp || 2733 !vm_map_lookup_entry(map, start, ¤t)) 2734 current = current->next; 2735 } 2736 2737 vm_map_unlock_read(map); 2738 return (failed ? KERN_FAILURE : KERN_SUCCESS); 2739 } 2740 2741 /* 2742 * vm_map_entry_unwire: [ internal use only ] 2743 * 2744 * Make the region specified by this entry pageable. 2745 * 2746 * The map in question should be locked. 2747 * [This is the reason for this routine's existence.] 2748 */ 2749 static void 2750 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2751 { 2752 vm_fault_unwire(map, entry->start, entry->end, 2753 entry->object.vm_object != NULL && 2754 (entry->object.vm_object->flags & OBJ_FICTITIOUS) != 0); 2755 entry->wired_count = 0; 2756 } 2757 2758 static void 2759 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 2760 { 2761 2762 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 2763 vm_object_deallocate(entry->object.vm_object); 2764 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 2765 } 2766 2767 /* 2768 * vm_map_entry_delete: [ internal use only ] 2769 * 2770 * Deallocate the given entry from the target map. 2771 */ 2772 static void 2773 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2774 { 2775 vm_object_t object; 2776 vm_pindex_t offidxstart, offidxend, count, size1; 2777 vm_ooffset_t size; 2778 2779 vm_map_entry_unlink(map, entry); 2780 object = entry->object.vm_object; 2781 size = entry->end - entry->start; 2782 map->size -= size; 2783 2784 if (entry->cred != NULL) { 2785 swap_release_by_cred(size, entry->cred); 2786 crfree(entry->cred); 2787 } 2788 2789 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2790 (object != NULL)) { 2791 KASSERT(entry->cred == NULL || object->cred == NULL || 2792 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 2793 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 2794 count = OFF_TO_IDX(size); 2795 offidxstart = OFF_TO_IDX(entry->offset); 2796 offidxend = offidxstart + count; 2797 VM_OBJECT_WLOCK(object); 2798 if (object->ref_count != 1 && 2799 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2800 object == kernel_object || object == kmem_object)) { 2801 vm_object_collapse(object); 2802 2803 /* 2804 * The option OBJPR_NOTMAPPED can be passed here 2805 * because vm_map_delete() already performed 2806 * pmap_remove() on the only mapping to this range 2807 * of pages. 2808 */ 2809 vm_object_page_remove(object, offidxstart, offidxend, 2810 OBJPR_NOTMAPPED); 2811 if (object->type == OBJT_SWAP) 2812 swap_pager_freespace(object, offidxstart, count); 2813 if (offidxend >= object->size && 2814 offidxstart < object->size) { 2815 size1 = object->size; 2816 object->size = offidxstart; 2817 if (object->cred != NULL) { 2818 size1 -= object->size; 2819 KASSERT(object->charge >= ptoa(size1), 2820 ("vm_map_entry_delete: object->charge < 0")); 2821 swap_release_by_cred(ptoa(size1), object->cred); 2822 object->charge -= ptoa(size1); 2823 } 2824 } 2825 } 2826 VM_OBJECT_WUNLOCK(object); 2827 } else 2828 entry->object.vm_object = NULL; 2829 if (map->system_map) 2830 vm_map_entry_deallocate(entry, TRUE); 2831 else { 2832 entry->next = curthread->td_map_def_user; 2833 curthread->td_map_def_user = entry; 2834 } 2835 } 2836 2837 /* 2838 * vm_map_delete: [ internal use only ] 2839 * 2840 * Deallocates the given address range from the target 2841 * map. 2842 */ 2843 int 2844 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2845 { 2846 vm_map_entry_t entry; 2847 vm_map_entry_t first_entry; 2848 2849 VM_MAP_ASSERT_LOCKED(map); 2850 if (start == end) 2851 return (KERN_SUCCESS); 2852 2853 /* 2854 * Find the start of the region, and clip it 2855 */ 2856 if (!vm_map_lookup_entry(map, start, &first_entry)) 2857 entry = first_entry->next; 2858 else { 2859 entry = first_entry; 2860 vm_map_clip_start(map, entry, start); 2861 } 2862 2863 /* 2864 * Step through all entries in this region 2865 */ 2866 while ((entry != &map->header) && (entry->start < end)) { 2867 vm_map_entry_t next; 2868 2869 /* 2870 * Wait for wiring or unwiring of an entry to complete. 2871 * Also wait for any system wirings to disappear on 2872 * user maps. 2873 */ 2874 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 2875 (vm_map_pmap(map) != kernel_pmap && 2876 vm_map_entry_system_wired_count(entry) != 0)) { 2877 unsigned int last_timestamp; 2878 vm_offset_t saved_start; 2879 vm_map_entry_t tmp_entry; 2880 2881 saved_start = entry->start; 2882 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2883 last_timestamp = map->timestamp; 2884 (void) vm_map_unlock_and_wait(map, 0); 2885 vm_map_lock(map); 2886 if (last_timestamp + 1 != map->timestamp) { 2887 /* 2888 * Look again for the entry because the map was 2889 * modified while it was unlocked. 2890 * Specifically, the entry may have been 2891 * clipped, merged, or deleted. 2892 */ 2893 if (!vm_map_lookup_entry(map, saved_start, 2894 &tmp_entry)) 2895 entry = tmp_entry->next; 2896 else { 2897 entry = tmp_entry; 2898 vm_map_clip_start(map, entry, 2899 saved_start); 2900 } 2901 } 2902 continue; 2903 } 2904 vm_map_clip_end(map, entry, end); 2905 2906 next = entry->next; 2907 2908 /* 2909 * Unwire before removing addresses from the pmap; otherwise, 2910 * unwiring will put the entries back in the pmap. 2911 */ 2912 if (entry->wired_count != 0) { 2913 vm_map_entry_unwire(map, entry); 2914 } 2915 2916 pmap_remove(map->pmap, entry->start, entry->end); 2917 2918 /* 2919 * Delete the entry only after removing all pmap 2920 * entries pointing to its pages. (Otherwise, its 2921 * page frames may be reallocated, and any modify bits 2922 * will be set in the wrong object!) 2923 */ 2924 vm_map_entry_delete(map, entry); 2925 entry = next; 2926 } 2927 return (KERN_SUCCESS); 2928 } 2929 2930 /* 2931 * vm_map_remove: 2932 * 2933 * Remove the given address range from the target map. 2934 * This is the exported form of vm_map_delete. 2935 */ 2936 int 2937 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2938 { 2939 int result; 2940 2941 vm_map_lock(map); 2942 VM_MAP_RANGE_CHECK(map, start, end); 2943 result = vm_map_delete(map, start, end); 2944 vm_map_unlock(map); 2945 return (result); 2946 } 2947 2948 /* 2949 * vm_map_check_protection: 2950 * 2951 * Assert that the target map allows the specified privilege on the 2952 * entire address region given. The entire region must be allocated. 2953 * 2954 * WARNING! This code does not and should not check whether the 2955 * contents of the region is accessible. For example a smaller file 2956 * might be mapped into a larger address space. 2957 * 2958 * NOTE! This code is also called by munmap(). 2959 * 2960 * The map must be locked. A read lock is sufficient. 2961 */ 2962 boolean_t 2963 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2964 vm_prot_t protection) 2965 { 2966 vm_map_entry_t entry; 2967 vm_map_entry_t tmp_entry; 2968 2969 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 2970 return (FALSE); 2971 entry = tmp_entry; 2972 2973 while (start < end) { 2974 if (entry == &map->header) 2975 return (FALSE); 2976 /* 2977 * No holes allowed! 2978 */ 2979 if (start < entry->start) 2980 return (FALSE); 2981 /* 2982 * Check protection associated with entry. 2983 */ 2984 if ((entry->protection & protection) != protection) 2985 return (FALSE); 2986 /* go to next entry */ 2987 start = entry->end; 2988 entry = entry->next; 2989 } 2990 return (TRUE); 2991 } 2992 2993 /* 2994 * vm_map_copy_entry: 2995 * 2996 * Copies the contents of the source entry to the destination 2997 * entry. The entries *must* be aligned properly. 2998 */ 2999 static void 3000 vm_map_copy_entry( 3001 vm_map_t src_map, 3002 vm_map_t dst_map, 3003 vm_map_entry_t src_entry, 3004 vm_map_entry_t dst_entry, 3005 vm_ooffset_t *fork_charge) 3006 { 3007 vm_object_t src_object; 3008 vm_map_entry_t fake_entry; 3009 vm_offset_t size; 3010 struct ucred *cred; 3011 int charged; 3012 3013 VM_MAP_ASSERT_LOCKED(dst_map); 3014 3015 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3016 return; 3017 3018 if (src_entry->wired_count == 0) { 3019 3020 /* 3021 * If the source entry is marked needs_copy, it is already 3022 * write-protected. 3023 */ 3024 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 3025 pmap_protect(src_map->pmap, 3026 src_entry->start, 3027 src_entry->end, 3028 src_entry->protection & ~VM_PROT_WRITE); 3029 } 3030 3031 /* 3032 * Make a copy of the object. 3033 */ 3034 size = src_entry->end - src_entry->start; 3035 if ((src_object = src_entry->object.vm_object) != NULL) { 3036 VM_OBJECT_WLOCK(src_object); 3037 charged = ENTRY_CHARGED(src_entry); 3038 if ((src_object->handle == NULL) && 3039 (src_object->type == OBJT_DEFAULT || 3040 src_object->type == OBJT_SWAP)) { 3041 vm_object_collapse(src_object); 3042 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 3043 vm_object_split(src_entry); 3044 src_object = src_entry->object.vm_object; 3045 } 3046 } 3047 vm_object_reference_locked(src_object); 3048 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3049 if (src_entry->cred != NULL && 3050 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3051 KASSERT(src_object->cred == NULL, 3052 ("OVERCOMMIT: vm_map_copy_entry: cred %p", 3053 src_object)); 3054 src_object->cred = src_entry->cred; 3055 src_object->charge = size; 3056 } 3057 VM_OBJECT_WUNLOCK(src_object); 3058 dst_entry->object.vm_object = src_object; 3059 if (charged) { 3060 cred = curthread->td_ucred; 3061 crhold(cred); 3062 dst_entry->cred = cred; 3063 *fork_charge += size; 3064 if (!(src_entry->eflags & 3065 MAP_ENTRY_NEEDS_COPY)) { 3066 crhold(cred); 3067 src_entry->cred = cred; 3068 *fork_charge += size; 3069 } 3070 } 3071 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3072 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3073 dst_entry->offset = src_entry->offset; 3074 if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3075 /* 3076 * MAP_ENTRY_VN_WRITECNT cannot 3077 * indicate write reference from 3078 * src_entry, since the entry is 3079 * marked as needs copy. Allocate a 3080 * fake entry that is used to 3081 * decrement object->un_pager.vnp.writecount 3082 * at the appropriate time. Attach 3083 * fake_entry to the deferred list. 3084 */ 3085 fake_entry = vm_map_entry_create(dst_map); 3086 fake_entry->eflags = MAP_ENTRY_VN_WRITECNT; 3087 src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT; 3088 vm_object_reference(src_object); 3089 fake_entry->object.vm_object = src_object; 3090 fake_entry->start = src_entry->start; 3091 fake_entry->end = src_entry->end; 3092 fake_entry->next = curthread->td_map_def_user; 3093 curthread->td_map_def_user = fake_entry; 3094 } 3095 } else { 3096 dst_entry->object.vm_object = NULL; 3097 dst_entry->offset = 0; 3098 if (src_entry->cred != NULL) { 3099 dst_entry->cred = curthread->td_ucred; 3100 crhold(dst_entry->cred); 3101 *fork_charge += size; 3102 } 3103 } 3104 3105 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3106 dst_entry->end - dst_entry->start, src_entry->start); 3107 } else { 3108 /* 3109 * Of course, wired down pages can't be set copy-on-write. 3110 * Cause wired pages to be copied into the new map by 3111 * simulating faults (the new pages are pageable) 3112 */ 3113 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 3114 fork_charge); 3115 } 3116 } 3117 3118 /* 3119 * vmspace_map_entry_forked: 3120 * Update the newly-forked vmspace each time a map entry is inherited 3121 * or copied. The values for vm_dsize and vm_tsize are approximate 3122 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 3123 */ 3124 static void 3125 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 3126 vm_map_entry_t entry) 3127 { 3128 vm_size_t entrysize; 3129 vm_offset_t newend; 3130 3131 entrysize = entry->end - entry->start; 3132 vm2->vm_map.size += entrysize; 3133 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 3134 vm2->vm_ssize += btoc(entrysize); 3135 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 3136 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 3137 newend = MIN(entry->end, 3138 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 3139 vm2->vm_dsize += btoc(newend - entry->start); 3140 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 3141 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 3142 newend = MIN(entry->end, 3143 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 3144 vm2->vm_tsize += btoc(newend - entry->start); 3145 } 3146 } 3147 3148 /* 3149 * vmspace_fork: 3150 * Create a new process vmspace structure and vm_map 3151 * based on those of an existing process. The new map 3152 * is based on the old map, according to the inheritance 3153 * values on the regions in that map. 3154 * 3155 * XXX It might be worth coalescing the entries added to the new vmspace. 3156 * 3157 * The source map must not be locked. 3158 */ 3159 struct vmspace * 3160 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 3161 { 3162 struct vmspace *vm2; 3163 vm_map_t new_map, old_map; 3164 vm_map_entry_t new_entry, old_entry; 3165 vm_object_t object; 3166 int locked; 3167 3168 old_map = &vm1->vm_map; 3169 /* Copy immutable fields of vm1 to vm2. */ 3170 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL); 3171 if (vm2 == NULL) 3172 return (NULL); 3173 vm2->vm_taddr = vm1->vm_taddr; 3174 vm2->vm_daddr = vm1->vm_daddr; 3175 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 3176 vm_map_lock(old_map); 3177 if (old_map->busy) 3178 vm_map_wait_busy(old_map); 3179 new_map = &vm2->vm_map; 3180 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 3181 KASSERT(locked, ("vmspace_fork: lock failed")); 3182 3183 old_entry = old_map->header.next; 3184 3185 while (old_entry != &old_map->header) { 3186 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 3187 panic("vm_map_fork: encountered a submap"); 3188 3189 switch (old_entry->inheritance) { 3190 case VM_INHERIT_NONE: 3191 break; 3192 3193 case VM_INHERIT_SHARE: 3194 /* 3195 * Clone the entry, creating the shared object if necessary. 3196 */ 3197 object = old_entry->object.vm_object; 3198 if (object == NULL) { 3199 object = vm_object_allocate(OBJT_DEFAULT, 3200 atop(old_entry->end - old_entry->start)); 3201 old_entry->object.vm_object = object; 3202 old_entry->offset = 0; 3203 if (old_entry->cred != NULL) { 3204 object->cred = old_entry->cred; 3205 object->charge = old_entry->end - 3206 old_entry->start; 3207 old_entry->cred = NULL; 3208 } 3209 } 3210 3211 /* 3212 * Add the reference before calling vm_object_shadow 3213 * to insure that a shadow object is created. 3214 */ 3215 vm_object_reference(object); 3216 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3217 vm_object_shadow(&old_entry->object.vm_object, 3218 &old_entry->offset, 3219 old_entry->end - old_entry->start); 3220 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3221 /* Transfer the second reference too. */ 3222 vm_object_reference( 3223 old_entry->object.vm_object); 3224 3225 /* 3226 * As in vm_map_simplify_entry(), the 3227 * vnode lock will not be acquired in 3228 * this call to vm_object_deallocate(). 3229 */ 3230 vm_object_deallocate(object); 3231 object = old_entry->object.vm_object; 3232 } 3233 VM_OBJECT_WLOCK(object); 3234 vm_object_clear_flag(object, OBJ_ONEMAPPING); 3235 if (old_entry->cred != NULL) { 3236 KASSERT(object->cred == NULL, ("vmspace_fork both cred")); 3237 object->cred = old_entry->cred; 3238 object->charge = old_entry->end - old_entry->start; 3239 old_entry->cred = NULL; 3240 } 3241 3242 /* 3243 * Assert the correct state of the vnode 3244 * v_writecount while the object is locked, to 3245 * not relock it later for the assertion 3246 * correctness. 3247 */ 3248 if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT && 3249 object->type == OBJT_VNODE) { 3250 KASSERT(((struct vnode *)object->handle)-> 3251 v_writecount > 0, 3252 ("vmspace_fork: v_writecount %p", object)); 3253 KASSERT(object->un_pager.vnp.writemappings > 0, 3254 ("vmspace_fork: vnp.writecount %p", 3255 object)); 3256 } 3257 VM_OBJECT_WUNLOCK(object); 3258 3259 /* 3260 * Clone the entry, referencing the shared object. 3261 */ 3262 new_entry = vm_map_entry_create(new_map); 3263 *new_entry = *old_entry; 3264 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3265 MAP_ENTRY_IN_TRANSITION); 3266 new_entry->wiring_thread = NULL; 3267 new_entry->wired_count = 0; 3268 if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3269 vnode_pager_update_writecount(object, 3270 new_entry->start, new_entry->end); 3271 } 3272 3273 /* 3274 * Insert the entry into the new map -- we know we're 3275 * inserting at the end of the new map. 3276 */ 3277 vm_map_entry_link(new_map, new_map->header.prev, 3278 new_entry); 3279 vmspace_map_entry_forked(vm1, vm2, new_entry); 3280 3281 /* 3282 * Update the physical map 3283 */ 3284 pmap_copy(new_map->pmap, old_map->pmap, 3285 new_entry->start, 3286 (old_entry->end - old_entry->start), 3287 old_entry->start); 3288 break; 3289 3290 case VM_INHERIT_COPY: 3291 /* 3292 * Clone the entry and link into the map. 3293 */ 3294 new_entry = vm_map_entry_create(new_map); 3295 *new_entry = *old_entry; 3296 /* 3297 * Copied entry is COW over the old object. 3298 */ 3299 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3300 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT); 3301 new_entry->wiring_thread = NULL; 3302 new_entry->wired_count = 0; 3303 new_entry->object.vm_object = NULL; 3304 new_entry->cred = NULL; 3305 vm_map_entry_link(new_map, new_map->header.prev, 3306 new_entry); 3307 vmspace_map_entry_forked(vm1, vm2, new_entry); 3308 vm_map_copy_entry(old_map, new_map, old_entry, 3309 new_entry, fork_charge); 3310 break; 3311 } 3312 old_entry = old_entry->next; 3313 } 3314 /* 3315 * Use inlined vm_map_unlock() to postpone handling the deferred 3316 * map entries, which cannot be done until both old_map and 3317 * new_map locks are released. 3318 */ 3319 sx_xunlock(&old_map->lock); 3320 sx_xunlock(&new_map->lock); 3321 vm_map_process_deferred(); 3322 3323 return (vm2); 3324 } 3325 3326 int 3327 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3328 vm_prot_t prot, vm_prot_t max, int cow) 3329 { 3330 vm_map_entry_t new_entry, prev_entry; 3331 vm_offset_t bot, top; 3332 vm_size_t growsize, init_ssize; 3333 int orient, rv; 3334 rlim_t lmemlim, vmemlim; 3335 3336 /* 3337 * The stack orientation is piggybacked with the cow argument. 3338 * Extract it into orient and mask the cow argument so that we 3339 * don't pass it around further. 3340 * NOTE: We explicitly allow bi-directional stacks. 3341 */ 3342 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 3343 KASSERT(orient != 0, ("No stack grow direction")); 3344 3345 if (addrbos < vm_map_min(map) || 3346 addrbos > vm_map_max(map) || 3347 addrbos + max_ssize < addrbos) 3348 return (KERN_NO_SPACE); 3349 3350 growsize = sgrowsiz; 3351 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3352 3353 PROC_LOCK(curproc); 3354 lmemlim = lim_cur(curproc, RLIMIT_MEMLOCK); 3355 vmemlim = lim_cur(curproc, RLIMIT_VMEM); 3356 PROC_UNLOCK(curproc); 3357 3358 vm_map_lock(map); 3359 3360 /* If addr is already mapped, no go */ 3361 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3362 vm_map_unlock(map); 3363 return (KERN_NO_SPACE); 3364 } 3365 3366 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3367 if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) { 3368 vm_map_unlock(map); 3369 return (KERN_NO_SPACE); 3370 } 3371 } 3372 3373 /* If we would blow our VMEM resource limit, no go */ 3374 if (map->size + init_ssize > vmemlim) { 3375 vm_map_unlock(map); 3376 return (KERN_NO_SPACE); 3377 } 3378 3379 /* 3380 * If we can't accomodate max_ssize in the current mapping, no go. 3381 * However, we need to be aware that subsequent user mappings might 3382 * map into the space we have reserved for stack, and currently this 3383 * space is not protected. 3384 * 3385 * Hopefully we will at least detect this condition when we try to 3386 * grow the stack. 3387 */ 3388 if ((prev_entry->next != &map->header) && 3389 (prev_entry->next->start < addrbos + max_ssize)) { 3390 vm_map_unlock(map); 3391 return (KERN_NO_SPACE); 3392 } 3393 3394 /* 3395 * We initially map a stack of only init_ssize. We will grow as 3396 * needed later. Depending on the orientation of the stack (i.e. 3397 * the grow direction) we either map at the top of the range, the 3398 * bottom of the range or in the middle. 3399 * 3400 * Note: we would normally expect prot and max to be VM_PROT_ALL, 3401 * and cow to be 0. Possibly we should eliminate these as input 3402 * parameters, and just pass these values here in the insert call. 3403 */ 3404 if (orient == MAP_STACK_GROWS_DOWN) 3405 bot = addrbos + max_ssize - init_ssize; 3406 else if (orient == MAP_STACK_GROWS_UP) 3407 bot = addrbos; 3408 else 3409 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 3410 top = bot + init_ssize; 3411 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 3412 3413 /* Now set the avail_ssize amount. */ 3414 if (rv == KERN_SUCCESS) { 3415 if (prev_entry != &map->header) 3416 vm_map_clip_end(map, prev_entry, bot); 3417 new_entry = prev_entry->next; 3418 if (new_entry->end != top || new_entry->start != bot) 3419 panic("Bad entry start/end for new stack entry"); 3420 3421 new_entry->avail_ssize = max_ssize - init_ssize; 3422 if (orient & MAP_STACK_GROWS_DOWN) 3423 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3424 if (orient & MAP_STACK_GROWS_UP) 3425 new_entry->eflags |= MAP_ENTRY_GROWS_UP; 3426 } 3427 3428 vm_map_unlock(map); 3429 return (rv); 3430 } 3431 3432 static int stack_guard_page = 0; 3433 TUNABLE_INT("security.bsd.stack_guard_page", &stack_guard_page); 3434 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RW, 3435 &stack_guard_page, 0, 3436 "Insert stack guard page ahead of the growable segments."); 3437 3438 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3439 * desired address is already mapped, or if we successfully grow 3440 * the stack. Also returns KERN_SUCCESS if addr is outside the 3441 * stack range (this is strange, but preserves compatibility with 3442 * the grow function in vm_machdep.c). 3443 */ 3444 int 3445 vm_map_growstack(struct proc *p, vm_offset_t addr) 3446 { 3447 vm_map_entry_t next_entry, prev_entry; 3448 vm_map_entry_t new_entry, stack_entry; 3449 struct vmspace *vm = p->p_vmspace; 3450 vm_map_t map = &vm->vm_map; 3451 vm_offset_t end; 3452 vm_size_t growsize; 3453 size_t grow_amount, max_grow; 3454 rlim_t lmemlim, stacklim, vmemlim; 3455 int is_procstack, rv; 3456 struct ucred *cred; 3457 #ifdef notyet 3458 uint64_t limit; 3459 #endif 3460 #ifdef RACCT 3461 int error; 3462 #endif 3463 3464 Retry: 3465 PROC_LOCK(p); 3466 lmemlim = lim_cur(p, RLIMIT_MEMLOCK); 3467 stacklim = lim_cur(p, RLIMIT_STACK); 3468 vmemlim = lim_cur(p, RLIMIT_VMEM); 3469 PROC_UNLOCK(p); 3470 3471 vm_map_lock_read(map); 3472 3473 /* If addr is already in the entry range, no need to grow.*/ 3474 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 3475 vm_map_unlock_read(map); 3476 return (KERN_SUCCESS); 3477 } 3478 3479 next_entry = prev_entry->next; 3480 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 3481 /* 3482 * This entry does not grow upwards. Since the address lies 3483 * beyond this entry, the next entry (if one exists) has to 3484 * be a downward growable entry. The entry list header is 3485 * never a growable entry, so it suffices to check the flags. 3486 */ 3487 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 3488 vm_map_unlock_read(map); 3489 return (KERN_SUCCESS); 3490 } 3491 stack_entry = next_entry; 3492 } else { 3493 /* 3494 * This entry grows upward. If the next entry does not at 3495 * least grow downwards, this is the entry we need to grow. 3496 * otherwise we have two possible choices and we have to 3497 * select one. 3498 */ 3499 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 3500 /* 3501 * We have two choices; grow the entry closest to 3502 * the address to minimize the amount of growth. 3503 */ 3504 if (addr - prev_entry->end <= next_entry->start - addr) 3505 stack_entry = prev_entry; 3506 else 3507 stack_entry = next_entry; 3508 } else 3509 stack_entry = prev_entry; 3510 } 3511 3512 if (stack_entry == next_entry) { 3513 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 3514 KASSERT(addr < stack_entry->start, ("foo")); 3515 end = (prev_entry != &map->header) ? prev_entry->end : 3516 stack_entry->start - stack_entry->avail_ssize; 3517 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 3518 max_grow = stack_entry->start - end; 3519 } else { 3520 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 3521 KASSERT(addr >= stack_entry->end, ("foo")); 3522 end = (next_entry != &map->header) ? next_entry->start : 3523 stack_entry->end + stack_entry->avail_ssize; 3524 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 3525 max_grow = end - stack_entry->end; 3526 } 3527 3528 if (grow_amount > stack_entry->avail_ssize) { 3529 vm_map_unlock_read(map); 3530 return (KERN_NO_SPACE); 3531 } 3532 3533 /* 3534 * If there is no longer enough space between the entries nogo, and 3535 * adjust the available space. Note: this should only happen if the 3536 * user has mapped into the stack area after the stack was created, 3537 * and is probably an error. 3538 * 3539 * This also effectively destroys any guard page the user might have 3540 * intended by limiting the stack size. 3541 */ 3542 if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) { 3543 if (vm_map_lock_upgrade(map)) 3544 goto Retry; 3545 3546 stack_entry->avail_ssize = max_grow; 3547 3548 vm_map_unlock(map); 3549 return (KERN_NO_SPACE); 3550 } 3551 3552 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 3553 3554 /* 3555 * If this is the main process stack, see if we're over the stack 3556 * limit. 3557 */ 3558 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3559 vm_map_unlock_read(map); 3560 return (KERN_NO_SPACE); 3561 } 3562 #ifdef RACCT 3563 PROC_LOCK(p); 3564 if (is_procstack && 3565 racct_set(p, RACCT_STACK, ctob(vm->vm_ssize) + grow_amount)) { 3566 PROC_UNLOCK(p); 3567 vm_map_unlock_read(map); 3568 return (KERN_NO_SPACE); 3569 } 3570 PROC_UNLOCK(p); 3571 #endif 3572 3573 /* Round up the grow amount modulo sgrowsiz */ 3574 growsize = sgrowsiz; 3575 grow_amount = roundup(grow_amount, growsize); 3576 if (grow_amount > stack_entry->avail_ssize) 3577 grow_amount = stack_entry->avail_ssize; 3578 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3579 grow_amount = trunc_page((vm_size_t)stacklim) - 3580 ctob(vm->vm_ssize); 3581 } 3582 #ifdef notyet 3583 PROC_LOCK(p); 3584 limit = racct_get_available(p, RACCT_STACK); 3585 PROC_UNLOCK(p); 3586 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 3587 grow_amount = limit - ctob(vm->vm_ssize); 3588 #endif 3589 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3590 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 3591 vm_map_unlock_read(map); 3592 rv = KERN_NO_SPACE; 3593 goto out; 3594 } 3595 #ifdef RACCT 3596 PROC_LOCK(p); 3597 if (racct_set(p, RACCT_MEMLOCK, 3598 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 3599 PROC_UNLOCK(p); 3600 vm_map_unlock_read(map); 3601 rv = KERN_NO_SPACE; 3602 goto out; 3603 } 3604 PROC_UNLOCK(p); 3605 #endif 3606 } 3607 /* If we would blow our VMEM resource limit, no go */ 3608 if (map->size + grow_amount > vmemlim) { 3609 vm_map_unlock_read(map); 3610 rv = KERN_NO_SPACE; 3611 goto out; 3612 } 3613 #ifdef RACCT 3614 PROC_LOCK(p); 3615 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 3616 PROC_UNLOCK(p); 3617 vm_map_unlock_read(map); 3618 rv = KERN_NO_SPACE; 3619 goto out; 3620 } 3621 PROC_UNLOCK(p); 3622 #endif 3623 3624 if (vm_map_lock_upgrade(map)) 3625 goto Retry; 3626 3627 if (stack_entry == next_entry) { 3628 /* 3629 * Growing downward. 3630 */ 3631 /* Get the preliminary new entry start value */ 3632 addr = stack_entry->start - grow_amount; 3633 3634 /* 3635 * If this puts us into the previous entry, cut back our 3636 * growth to the available space. Also, see the note above. 3637 */ 3638 if (addr < end) { 3639 stack_entry->avail_ssize = max_grow; 3640 addr = end; 3641 if (stack_guard_page) 3642 addr += PAGE_SIZE; 3643 } 3644 3645 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 3646 next_entry->protection, next_entry->max_protection, 0); 3647 3648 /* Adjust the available stack space by the amount we grew. */ 3649 if (rv == KERN_SUCCESS) { 3650 if (prev_entry != &map->header) 3651 vm_map_clip_end(map, prev_entry, addr); 3652 new_entry = prev_entry->next; 3653 KASSERT(new_entry == stack_entry->prev, ("foo")); 3654 KASSERT(new_entry->end == stack_entry->start, ("foo")); 3655 KASSERT(new_entry->start == addr, ("foo")); 3656 grow_amount = new_entry->end - new_entry->start; 3657 new_entry->avail_ssize = stack_entry->avail_ssize - 3658 grow_amount; 3659 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 3660 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3661 } 3662 } else { 3663 /* 3664 * Growing upward. 3665 */ 3666 addr = stack_entry->end + grow_amount; 3667 3668 /* 3669 * If this puts us into the next entry, cut back our growth 3670 * to the available space. Also, see the note above. 3671 */ 3672 if (addr > end) { 3673 stack_entry->avail_ssize = end - stack_entry->end; 3674 addr = end; 3675 if (stack_guard_page) 3676 addr -= PAGE_SIZE; 3677 } 3678 3679 grow_amount = addr - stack_entry->end; 3680 cred = stack_entry->cred; 3681 if (cred == NULL && stack_entry->object.vm_object != NULL) 3682 cred = stack_entry->object.vm_object->cred; 3683 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 3684 rv = KERN_NO_SPACE; 3685 /* Grow the underlying object if applicable. */ 3686 else if (stack_entry->object.vm_object == NULL || 3687 vm_object_coalesce(stack_entry->object.vm_object, 3688 stack_entry->offset, 3689 (vm_size_t)(stack_entry->end - stack_entry->start), 3690 (vm_size_t)grow_amount, cred != NULL)) { 3691 map->size += (addr - stack_entry->end); 3692 /* Update the current entry. */ 3693 stack_entry->end = addr; 3694 stack_entry->avail_ssize -= grow_amount; 3695 vm_map_entry_resize_free(map, stack_entry); 3696 rv = KERN_SUCCESS; 3697 3698 if (next_entry != &map->header) 3699 vm_map_clip_start(map, next_entry, addr); 3700 } else 3701 rv = KERN_FAILURE; 3702 } 3703 3704 if (rv == KERN_SUCCESS && is_procstack) 3705 vm->vm_ssize += btoc(grow_amount); 3706 3707 vm_map_unlock(map); 3708 3709 /* 3710 * Heed the MAP_WIREFUTURE flag if it was set for this process. 3711 */ 3712 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 3713 vm_map_wire(map, 3714 (stack_entry == next_entry) ? addr : addr - grow_amount, 3715 (stack_entry == next_entry) ? stack_entry->start : addr, 3716 (p->p_flag & P_SYSTEM) 3717 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 3718 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 3719 } 3720 3721 out: 3722 #ifdef RACCT 3723 if (rv != KERN_SUCCESS) { 3724 PROC_LOCK(p); 3725 error = racct_set(p, RACCT_VMEM, map->size); 3726 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 3727 if (!old_mlock) { 3728 error = racct_set(p, RACCT_MEMLOCK, 3729 ptoa(pmap_wired_count(map->pmap))); 3730 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 3731 } 3732 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 3733 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 3734 PROC_UNLOCK(p); 3735 } 3736 #endif 3737 3738 return (rv); 3739 } 3740 3741 /* 3742 * Unshare the specified VM space for exec. If other processes are 3743 * mapped to it, then create a new one. The new vmspace is null. 3744 */ 3745 int 3746 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 3747 { 3748 struct vmspace *oldvmspace = p->p_vmspace; 3749 struct vmspace *newvmspace; 3750 3751 newvmspace = vmspace_alloc(minuser, maxuser, NULL); 3752 if (newvmspace == NULL) 3753 return (ENOMEM); 3754 newvmspace->vm_swrss = oldvmspace->vm_swrss; 3755 /* 3756 * This code is written like this for prototype purposes. The 3757 * goal is to avoid running down the vmspace here, but let the 3758 * other process's that are still using the vmspace to finally 3759 * run it down. Even though there is little or no chance of blocking 3760 * here, it is a good idea to keep this form for future mods. 3761 */ 3762 PROC_VMSPACE_LOCK(p); 3763 p->p_vmspace = newvmspace; 3764 PROC_VMSPACE_UNLOCK(p); 3765 if (p == curthread->td_proc) 3766 pmap_activate(curthread); 3767 vmspace_free(oldvmspace); 3768 return (0); 3769 } 3770 3771 /* 3772 * Unshare the specified VM space for forcing COW. This 3773 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3774 */ 3775 int 3776 vmspace_unshare(struct proc *p) 3777 { 3778 struct vmspace *oldvmspace = p->p_vmspace; 3779 struct vmspace *newvmspace; 3780 vm_ooffset_t fork_charge; 3781 3782 if (oldvmspace->vm_refcnt == 1) 3783 return (0); 3784 fork_charge = 0; 3785 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 3786 if (newvmspace == NULL) 3787 return (ENOMEM); 3788 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 3789 vmspace_free(newvmspace); 3790 return (ENOMEM); 3791 } 3792 PROC_VMSPACE_LOCK(p); 3793 p->p_vmspace = newvmspace; 3794 PROC_VMSPACE_UNLOCK(p); 3795 if (p == curthread->td_proc) 3796 pmap_activate(curthread); 3797 vmspace_free(oldvmspace); 3798 return (0); 3799 } 3800 3801 /* 3802 * vm_map_lookup: 3803 * 3804 * Finds the VM object, offset, and 3805 * protection for a given virtual address in the 3806 * specified map, assuming a page fault of the 3807 * type specified. 3808 * 3809 * Leaves the map in question locked for read; return 3810 * values are guaranteed until a vm_map_lookup_done 3811 * call is performed. Note that the map argument 3812 * is in/out; the returned map must be used in 3813 * the call to vm_map_lookup_done. 3814 * 3815 * A handle (out_entry) is returned for use in 3816 * vm_map_lookup_done, to make that fast. 3817 * 3818 * If a lookup is requested with "write protection" 3819 * specified, the map may be changed to perform virtual 3820 * copying operations, although the data referenced will 3821 * remain the same. 3822 */ 3823 int 3824 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3825 vm_offset_t vaddr, 3826 vm_prot_t fault_typea, 3827 vm_map_entry_t *out_entry, /* OUT */ 3828 vm_object_t *object, /* OUT */ 3829 vm_pindex_t *pindex, /* OUT */ 3830 vm_prot_t *out_prot, /* OUT */ 3831 boolean_t *wired) /* OUT */ 3832 { 3833 vm_map_entry_t entry; 3834 vm_map_t map = *var_map; 3835 vm_prot_t prot; 3836 vm_prot_t fault_type = fault_typea; 3837 vm_object_t eobject; 3838 vm_size_t size; 3839 struct ucred *cred; 3840 3841 RetryLookup:; 3842 3843 vm_map_lock_read(map); 3844 3845 /* 3846 * Lookup the faulting address. 3847 */ 3848 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 3849 vm_map_unlock_read(map); 3850 return (KERN_INVALID_ADDRESS); 3851 } 3852 3853 entry = *out_entry; 3854 3855 /* 3856 * Handle submaps. 3857 */ 3858 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3859 vm_map_t old_map = map; 3860 3861 *var_map = map = entry->object.sub_map; 3862 vm_map_unlock_read(old_map); 3863 goto RetryLookup; 3864 } 3865 3866 /* 3867 * Check whether this task is allowed to have this page. 3868 */ 3869 prot = entry->protection; 3870 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3871 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 3872 vm_map_unlock_read(map); 3873 return (KERN_PROTECTION_FAILURE); 3874 } 3875 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3876 (entry->eflags & MAP_ENTRY_COW) && 3877 (fault_type & VM_PROT_WRITE)) { 3878 vm_map_unlock_read(map); 3879 return (KERN_PROTECTION_FAILURE); 3880 } 3881 if ((fault_typea & VM_PROT_COPY) != 0 && 3882 (entry->max_protection & VM_PROT_WRITE) == 0 && 3883 (entry->eflags & MAP_ENTRY_COW) == 0) { 3884 vm_map_unlock_read(map); 3885 return (KERN_PROTECTION_FAILURE); 3886 } 3887 3888 /* 3889 * If this page is not pageable, we have to get it for all possible 3890 * accesses. 3891 */ 3892 *wired = (entry->wired_count != 0); 3893 if (*wired) 3894 fault_type = entry->protection; 3895 size = entry->end - entry->start; 3896 /* 3897 * If the entry was copy-on-write, we either ... 3898 */ 3899 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3900 /* 3901 * If we want to write the page, we may as well handle that 3902 * now since we've got the map locked. 3903 * 3904 * If we don't need to write the page, we just demote the 3905 * permissions allowed. 3906 */ 3907 if ((fault_type & VM_PROT_WRITE) != 0 || 3908 (fault_typea & VM_PROT_COPY) != 0) { 3909 /* 3910 * Make a new object, and place it in the object 3911 * chain. Note that no new references have appeared 3912 * -- one just moved from the map to the new 3913 * object. 3914 */ 3915 if (vm_map_lock_upgrade(map)) 3916 goto RetryLookup; 3917 3918 if (entry->cred == NULL) { 3919 /* 3920 * The debugger owner is charged for 3921 * the memory. 3922 */ 3923 cred = curthread->td_ucred; 3924 crhold(cred); 3925 if (!swap_reserve_by_cred(size, cred)) { 3926 crfree(cred); 3927 vm_map_unlock(map); 3928 return (KERN_RESOURCE_SHORTAGE); 3929 } 3930 entry->cred = cred; 3931 } 3932 vm_object_shadow(&entry->object.vm_object, 3933 &entry->offset, size); 3934 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3935 eobject = entry->object.vm_object; 3936 if (eobject->cred != NULL) { 3937 /* 3938 * The object was not shadowed. 3939 */ 3940 swap_release_by_cred(size, entry->cred); 3941 crfree(entry->cred); 3942 entry->cred = NULL; 3943 } else if (entry->cred != NULL) { 3944 VM_OBJECT_WLOCK(eobject); 3945 eobject->cred = entry->cred; 3946 eobject->charge = size; 3947 VM_OBJECT_WUNLOCK(eobject); 3948 entry->cred = NULL; 3949 } 3950 3951 vm_map_lock_downgrade(map); 3952 } else { 3953 /* 3954 * We're attempting to read a copy-on-write page -- 3955 * don't allow writes. 3956 */ 3957 prot &= ~VM_PROT_WRITE; 3958 } 3959 } 3960 3961 /* 3962 * Create an object if necessary. 3963 */ 3964 if (entry->object.vm_object == NULL && 3965 !map->system_map) { 3966 if (vm_map_lock_upgrade(map)) 3967 goto RetryLookup; 3968 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 3969 atop(size)); 3970 entry->offset = 0; 3971 if (entry->cred != NULL) { 3972 VM_OBJECT_WLOCK(entry->object.vm_object); 3973 entry->object.vm_object->cred = entry->cred; 3974 entry->object.vm_object->charge = size; 3975 VM_OBJECT_WUNLOCK(entry->object.vm_object); 3976 entry->cred = NULL; 3977 } 3978 vm_map_lock_downgrade(map); 3979 } 3980 3981 /* 3982 * Return the object/offset from this entry. If the entry was 3983 * copy-on-write or empty, it has been fixed up. 3984 */ 3985 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3986 *object = entry->object.vm_object; 3987 3988 *out_prot = prot; 3989 return (KERN_SUCCESS); 3990 } 3991 3992 /* 3993 * vm_map_lookup_locked: 3994 * 3995 * Lookup the faulting address. A version of vm_map_lookup that returns 3996 * KERN_FAILURE instead of blocking on map lock or memory allocation. 3997 */ 3998 int 3999 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4000 vm_offset_t vaddr, 4001 vm_prot_t fault_typea, 4002 vm_map_entry_t *out_entry, /* OUT */ 4003 vm_object_t *object, /* OUT */ 4004 vm_pindex_t *pindex, /* OUT */ 4005 vm_prot_t *out_prot, /* OUT */ 4006 boolean_t *wired) /* OUT */ 4007 { 4008 vm_map_entry_t entry; 4009 vm_map_t map = *var_map; 4010 vm_prot_t prot; 4011 vm_prot_t fault_type = fault_typea; 4012 4013 /* 4014 * Lookup the faulting address. 4015 */ 4016 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4017 return (KERN_INVALID_ADDRESS); 4018 4019 entry = *out_entry; 4020 4021 /* 4022 * Fail if the entry refers to a submap. 4023 */ 4024 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4025 return (KERN_FAILURE); 4026 4027 /* 4028 * Check whether this task is allowed to have this page. 4029 */ 4030 prot = entry->protection; 4031 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4032 if ((fault_type & prot) != fault_type) 4033 return (KERN_PROTECTION_FAILURE); 4034 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 4035 (entry->eflags & MAP_ENTRY_COW) && 4036 (fault_type & VM_PROT_WRITE)) 4037 return (KERN_PROTECTION_FAILURE); 4038 4039 /* 4040 * If this page is not pageable, we have to get it for all possible 4041 * accesses. 4042 */ 4043 *wired = (entry->wired_count != 0); 4044 if (*wired) 4045 fault_type = entry->protection; 4046 4047 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4048 /* 4049 * Fail if the entry was copy-on-write for a write fault. 4050 */ 4051 if (fault_type & VM_PROT_WRITE) 4052 return (KERN_FAILURE); 4053 /* 4054 * We're attempting to read a copy-on-write page -- 4055 * don't allow writes. 4056 */ 4057 prot &= ~VM_PROT_WRITE; 4058 } 4059 4060 /* 4061 * Fail if an object should be created. 4062 */ 4063 if (entry->object.vm_object == NULL && !map->system_map) 4064 return (KERN_FAILURE); 4065 4066 /* 4067 * Return the object/offset from this entry. If the entry was 4068 * copy-on-write or empty, it has been fixed up. 4069 */ 4070 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4071 *object = entry->object.vm_object; 4072 4073 *out_prot = prot; 4074 return (KERN_SUCCESS); 4075 } 4076 4077 /* 4078 * vm_map_lookup_done: 4079 * 4080 * Releases locks acquired by a vm_map_lookup 4081 * (according to the handle returned by that lookup). 4082 */ 4083 void 4084 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4085 { 4086 /* 4087 * Unlock the main-level map 4088 */ 4089 vm_map_unlock_read(map); 4090 } 4091 4092 #include "opt_ddb.h" 4093 #ifdef DDB 4094 #include <sys/kernel.h> 4095 4096 #include <ddb/ddb.h> 4097 4098 static void 4099 vm_map_print(vm_map_t map) 4100 { 4101 vm_map_entry_t entry; 4102 4103 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4104 (void *)map, 4105 (void *)map->pmap, map->nentries, map->timestamp); 4106 4107 db_indent += 2; 4108 for (entry = map->header.next; entry != &map->header; 4109 entry = entry->next) { 4110 db_iprintf("map entry %p: start=%p, end=%p\n", 4111 (void *)entry, (void *)entry->start, (void *)entry->end); 4112 { 4113 static char *inheritance_name[4] = 4114 {"share", "copy", "none", "donate_copy"}; 4115 4116 db_iprintf(" prot=%x/%x/%s", 4117 entry->protection, 4118 entry->max_protection, 4119 inheritance_name[(int)(unsigned char)entry->inheritance]); 4120 if (entry->wired_count != 0) 4121 db_printf(", wired"); 4122 } 4123 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4124 db_printf(", share=%p, offset=0x%jx\n", 4125 (void *)entry->object.sub_map, 4126 (uintmax_t)entry->offset); 4127 if ((entry->prev == &map->header) || 4128 (entry->prev->object.sub_map != 4129 entry->object.sub_map)) { 4130 db_indent += 2; 4131 vm_map_print((vm_map_t)entry->object.sub_map); 4132 db_indent -= 2; 4133 } 4134 } else { 4135 if (entry->cred != NULL) 4136 db_printf(", ruid %d", entry->cred->cr_ruid); 4137 db_printf(", object=%p, offset=0x%jx", 4138 (void *)entry->object.vm_object, 4139 (uintmax_t)entry->offset); 4140 if (entry->object.vm_object && entry->object.vm_object->cred) 4141 db_printf(", obj ruid %d charge %jx", 4142 entry->object.vm_object->cred->cr_ruid, 4143 (uintmax_t)entry->object.vm_object->charge); 4144 if (entry->eflags & MAP_ENTRY_COW) 4145 db_printf(", copy (%s)", 4146 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4147 db_printf("\n"); 4148 4149 if ((entry->prev == &map->header) || 4150 (entry->prev->object.vm_object != 4151 entry->object.vm_object)) { 4152 db_indent += 2; 4153 vm_object_print((db_expr_t)(intptr_t) 4154 entry->object.vm_object, 4155 1, 0, (char *)0); 4156 db_indent -= 2; 4157 } 4158 } 4159 } 4160 db_indent -= 2; 4161 } 4162 4163 DB_SHOW_COMMAND(map, map) 4164 { 4165 4166 if (!have_addr) { 4167 db_printf("usage: show map <addr>\n"); 4168 return; 4169 } 4170 vm_map_print((vm_map_t)addr); 4171 } 4172 4173 DB_SHOW_COMMAND(procvm, procvm) 4174 { 4175 struct proc *p; 4176 4177 if (have_addr) { 4178 p = (struct proc *) addr; 4179 } else { 4180 p = curproc; 4181 } 4182 4183 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4184 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4185 (void *)vmspace_pmap(p->p_vmspace)); 4186 4187 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 4188 } 4189 4190 #endif /* DDB */ 4191