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 static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, 140 vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max, 141 int cow); 142 143 #define ENTRY_CHARGED(e) ((e)->cred != NULL || \ 144 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \ 145 !((e)->eflags & MAP_ENTRY_NEEDS_COPY))) 146 147 /* 148 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type 149 * stable. 150 */ 151 #define PROC_VMSPACE_LOCK(p) do { } while (0) 152 #define PROC_VMSPACE_UNLOCK(p) do { } while (0) 153 154 /* 155 * VM_MAP_RANGE_CHECK: [ internal use only ] 156 * 157 * Asserts that the starting and ending region 158 * addresses fall within the valid range of the map. 159 */ 160 #define VM_MAP_RANGE_CHECK(map, start, end) \ 161 { \ 162 if (start < vm_map_min(map)) \ 163 start = vm_map_min(map); \ 164 if (end > vm_map_max(map)) \ 165 end = vm_map_max(map); \ 166 if (start > end) \ 167 start = end; \ 168 } 169 170 /* 171 * vm_map_startup: 172 * 173 * Initialize the vm_map module. Must be called before 174 * any other vm_map routines. 175 * 176 * Map and entry structures are allocated from the general 177 * purpose memory pool with some exceptions: 178 * 179 * - The kernel map and kmem submap are allocated statically. 180 * - Kernel map entries are allocated out of a static pool. 181 * 182 * These restrictions are necessary since malloc() uses the 183 * maps and requires map entries. 184 */ 185 186 void 187 vm_map_startup(void) 188 { 189 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 190 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 191 #ifdef INVARIANTS 192 vm_map_zdtor, 193 #else 194 NULL, 195 #endif 196 vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 197 uma_prealloc(mapzone, MAX_KMAP); 198 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 199 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 200 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 201 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 202 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 203 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 204 #ifdef INVARIANTS 205 vmspace_zdtor, 206 #else 207 NULL, 208 #endif 209 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 210 } 211 212 static int 213 vmspace_zinit(void *mem, int size, int flags) 214 { 215 struct vmspace *vm; 216 217 vm = (struct vmspace *)mem; 218 219 vm->vm_map.pmap = NULL; 220 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); 221 PMAP_LOCK_INIT(vmspace_pmap(vm)); 222 return (0); 223 } 224 225 static int 226 vm_map_zinit(void *mem, int size, int flags) 227 { 228 vm_map_t map; 229 230 map = (vm_map_t)mem; 231 memset(map, 0, sizeof(*map)); 232 mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK); 233 sx_init(&map->lock, "vm map (user)"); 234 return (0); 235 } 236 237 #ifdef INVARIANTS 238 static void 239 vmspace_zdtor(void *mem, int size, void *arg) 240 { 241 struct vmspace *vm; 242 243 vm = (struct vmspace *)mem; 244 245 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 246 } 247 static void 248 vm_map_zdtor(void *mem, int size, void *arg) 249 { 250 vm_map_t map; 251 252 map = (vm_map_t)mem; 253 KASSERT(map->nentries == 0, 254 ("map %p nentries == %d on free.", 255 map, map->nentries)); 256 KASSERT(map->size == 0, 257 ("map %p size == %lu on free.", 258 map, (unsigned long)map->size)); 259 } 260 #endif /* INVARIANTS */ 261 262 /* 263 * Allocate a vmspace structure, including a vm_map and pmap, 264 * and initialize those structures. The refcnt is set to 1. 265 * 266 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit(). 267 */ 268 struct vmspace * 269 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit) 270 { 271 struct vmspace *vm; 272 273 vm = uma_zalloc(vmspace_zone, M_WAITOK); 274 275 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL")); 276 277 if (pinit == NULL) 278 pinit = &pmap_pinit; 279 280 if (!pinit(vmspace_pmap(vm))) { 281 uma_zfree(vmspace_zone, vm); 282 return (NULL); 283 } 284 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 285 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max); 286 vm->vm_refcnt = 1; 287 vm->vm_shm = NULL; 288 vm->vm_swrss = 0; 289 vm->vm_tsize = 0; 290 vm->vm_dsize = 0; 291 vm->vm_ssize = 0; 292 vm->vm_taddr = 0; 293 vm->vm_daddr = 0; 294 vm->vm_maxsaddr = 0; 295 return (vm); 296 } 297 298 static void 299 vmspace_container_reset(struct proc *p) 300 { 301 302 #ifdef RACCT 303 PROC_LOCK(p); 304 racct_set(p, RACCT_DATA, 0); 305 racct_set(p, RACCT_STACK, 0); 306 racct_set(p, RACCT_RSS, 0); 307 racct_set(p, RACCT_MEMLOCK, 0); 308 racct_set(p, RACCT_VMEM, 0); 309 PROC_UNLOCK(p); 310 #endif 311 } 312 313 static inline void 314 vmspace_dofree(struct vmspace *vm) 315 { 316 317 CTR1(KTR_VM, "vmspace_free: %p", vm); 318 319 /* 320 * Make sure any SysV shm is freed, it might not have been in 321 * exit1(). 322 */ 323 shmexit(vm); 324 325 /* 326 * Lock the map, to wait out all other references to it. 327 * Delete all of the mappings and pages they hold, then call 328 * the pmap module to reclaim anything left. 329 */ 330 (void)vm_map_remove(&vm->vm_map, vm->vm_map.min_offset, 331 vm->vm_map.max_offset); 332 333 pmap_release(vmspace_pmap(vm)); 334 vm->vm_map.pmap = NULL; 335 uma_zfree(vmspace_zone, vm); 336 } 337 338 void 339 vmspace_free(struct vmspace *vm) 340 { 341 342 if (vm->vm_refcnt == 0) 343 panic("vmspace_free: attempt to free already freed vmspace"); 344 345 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) 346 vmspace_dofree(vm); 347 } 348 349 void 350 vmspace_exitfree(struct proc *p) 351 { 352 struct vmspace *vm; 353 354 PROC_VMSPACE_LOCK(p); 355 vm = p->p_vmspace; 356 p->p_vmspace = NULL; 357 PROC_VMSPACE_UNLOCK(p); 358 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 359 vmspace_free(vm); 360 } 361 362 void 363 vmspace_exit(struct thread *td) 364 { 365 int refcnt; 366 struct vmspace *vm; 367 struct proc *p; 368 369 /* 370 * Release user portion of address space. 371 * This releases references to vnodes, 372 * which could cause I/O if the file has been unlinked. 373 * Need to do this early enough that we can still sleep. 374 * 375 * The last exiting process to reach this point releases as 376 * much of the environment as it can. vmspace_dofree() is the 377 * slower fallback in case another process had a temporary 378 * reference to the vmspace. 379 */ 380 381 p = td->td_proc; 382 vm = p->p_vmspace; 383 atomic_add_int(&vmspace0.vm_refcnt, 1); 384 do { 385 refcnt = vm->vm_refcnt; 386 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 387 /* Switch now since other proc might free vmspace */ 388 PROC_VMSPACE_LOCK(p); 389 p->p_vmspace = &vmspace0; 390 PROC_VMSPACE_UNLOCK(p); 391 pmap_activate(td); 392 } 393 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 394 if (refcnt == 1) { 395 if (p->p_vmspace != vm) { 396 /* vmspace not yet freed, switch back */ 397 PROC_VMSPACE_LOCK(p); 398 p->p_vmspace = vm; 399 PROC_VMSPACE_UNLOCK(p); 400 pmap_activate(td); 401 } 402 pmap_remove_pages(vmspace_pmap(vm)); 403 /* Switch now since this proc will free vmspace */ 404 PROC_VMSPACE_LOCK(p); 405 p->p_vmspace = &vmspace0; 406 PROC_VMSPACE_UNLOCK(p); 407 pmap_activate(td); 408 vmspace_dofree(vm); 409 } 410 vmspace_container_reset(p); 411 } 412 413 /* Acquire reference to vmspace owned by another process. */ 414 415 struct vmspace * 416 vmspace_acquire_ref(struct proc *p) 417 { 418 struct vmspace *vm; 419 int refcnt; 420 421 PROC_VMSPACE_LOCK(p); 422 vm = p->p_vmspace; 423 if (vm == NULL) { 424 PROC_VMSPACE_UNLOCK(p); 425 return (NULL); 426 } 427 do { 428 refcnt = vm->vm_refcnt; 429 if (refcnt <= 0) { /* Avoid 0->1 transition */ 430 PROC_VMSPACE_UNLOCK(p); 431 return (NULL); 432 } 433 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1)); 434 if (vm != p->p_vmspace) { 435 PROC_VMSPACE_UNLOCK(p); 436 vmspace_free(vm); 437 return (NULL); 438 } 439 PROC_VMSPACE_UNLOCK(p); 440 return (vm); 441 } 442 443 void 444 _vm_map_lock(vm_map_t map, const char *file, int line) 445 { 446 447 if (map->system_map) 448 mtx_lock_flags_(&map->system_mtx, 0, file, line); 449 else 450 sx_xlock_(&map->lock, file, line); 451 map->timestamp++; 452 } 453 454 static void 455 vm_map_process_deferred(void) 456 { 457 struct thread *td; 458 vm_map_entry_t entry, next; 459 vm_object_t object; 460 461 td = curthread; 462 entry = td->td_map_def_user; 463 td->td_map_def_user = NULL; 464 while (entry != NULL) { 465 next = entry->next; 466 if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) { 467 /* 468 * Decrement the object's writemappings and 469 * possibly the vnode's v_writecount. 470 */ 471 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 472 ("Submap with writecount")); 473 object = entry->object.vm_object; 474 KASSERT(object != NULL, ("No object for writecount")); 475 vnode_pager_release_writecount(object, entry->start, 476 entry->end); 477 } 478 vm_map_entry_deallocate(entry, FALSE); 479 entry = next; 480 } 481 } 482 483 void 484 _vm_map_unlock(vm_map_t map, const char *file, int line) 485 { 486 487 if (map->system_map) 488 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 489 else { 490 sx_xunlock_(&map->lock, file, line); 491 vm_map_process_deferred(); 492 } 493 } 494 495 void 496 _vm_map_lock_read(vm_map_t map, const char *file, int line) 497 { 498 499 if (map->system_map) 500 mtx_lock_flags_(&map->system_mtx, 0, file, line); 501 else 502 sx_slock_(&map->lock, file, line); 503 } 504 505 void 506 _vm_map_unlock_read(vm_map_t map, const char *file, int line) 507 { 508 509 if (map->system_map) 510 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 511 else { 512 sx_sunlock_(&map->lock, file, line); 513 vm_map_process_deferred(); 514 } 515 } 516 517 int 518 _vm_map_trylock(vm_map_t map, const char *file, int line) 519 { 520 int error; 521 522 error = map->system_map ? 523 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 524 !sx_try_xlock_(&map->lock, file, line); 525 if (error == 0) 526 map->timestamp++; 527 return (error == 0); 528 } 529 530 int 531 _vm_map_trylock_read(vm_map_t map, const char *file, int line) 532 { 533 int error; 534 535 error = map->system_map ? 536 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 537 !sx_try_slock_(&map->lock, file, line); 538 return (error == 0); 539 } 540 541 /* 542 * _vm_map_lock_upgrade: [ internal use only ] 543 * 544 * Tries to upgrade a read (shared) lock on the specified map to a write 545 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 546 * non-zero value if the upgrade fails. If the upgrade fails, the map is 547 * returned without a read or write lock held. 548 * 549 * Requires that the map be read locked. 550 */ 551 int 552 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 553 { 554 unsigned int last_timestamp; 555 556 if (map->system_map) { 557 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 558 } else { 559 if (!sx_try_upgrade_(&map->lock, file, line)) { 560 last_timestamp = map->timestamp; 561 sx_sunlock_(&map->lock, file, line); 562 vm_map_process_deferred(); 563 /* 564 * If the map's timestamp does not change while the 565 * map is unlocked, then the upgrade succeeds. 566 */ 567 sx_xlock_(&map->lock, file, line); 568 if (last_timestamp != map->timestamp) { 569 sx_xunlock_(&map->lock, file, line); 570 return (1); 571 } 572 } 573 } 574 map->timestamp++; 575 return (0); 576 } 577 578 void 579 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 580 { 581 582 if (map->system_map) { 583 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 584 } else 585 sx_downgrade_(&map->lock, file, line); 586 } 587 588 /* 589 * vm_map_locked: 590 * 591 * Returns a non-zero value if the caller holds a write (exclusive) lock 592 * on the specified map and the value "0" otherwise. 593 */ 594 int 595 vm_map_locked(vm_map_t map) 596 { 597 598 if (map->system_map) 599 return (mtx_owned(&map->system_mtx)); 600 else 601 return (sx_xlocked(&map->lock)); 602 } 603 604 #ifdef INVARIANTS 605 static void 606 _vm_map_assert_locked(vm_map_t map, const char *file, int line) 607 { 608 609 if (map->system_map) 610 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 611 else 612 sx_assert_(&map->lock, SA_XLOCKED, file, line); 613 } 614 615 #define VM_MAP_ASSERT_LOCKED(map) \ 616 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 617 #else 618 #define VM_MAP_ASSERT_LOCKED(map) 619 #endif 620 621 /* 622 * _vm_map_unlock_and_wait: 623 * 624 * Atomically releases the lock on the specified map and puts the calling 625 * thread to sleep. The calling thread will remain asleep until either 626 * vm_map_wakeup() is performed on the map or the specified timeout is 627 * exceeded. 628 * 629 * WARNING! This function does not perform deferred deallocations of 630 * objects and map entries. Therefore, the calling thread is expected to 631 * reacquire the map lock after reawakening and later perform an ordinary 632 * unlock operation, such as vm_map_unlock(), before completing its 633 * operation on the map. 634 */ 635 int 636 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) 637 { 638 639 mtx_lock(&map_sleep_mtx); 640 if (map->system_map) 641 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 642 else 643 sx_xunlock_(&map->lock, file, line); 644 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 645 timo)); 646 } 647 648 /* 649 * vm_map_wakeup: 650 * 651 * Awaken any threads that have slept on the map using 652 * vm_map_unlock_and_wait(). 653 */ 654 void 655 vm_map_wakeup(vm_map_t map) 656 { 657 658 /* 659 * Acquire and release map_sleep_mtx to prevent a wakeup() 660 * from being performed (and lost) between the map unlock 661 * and the msleep() in _vm_map_unlock_and_wait(). 662 */ 663 mtx_lock(&map_sleep_mtx); 664 mtx_unlock(&map_sleep_mtx); 665 wakeup(&map->root); 666 } 667 668 void 669 vm_map_busy(vm_map_t map) 670 { 671 672 VM_MAP_ASSERT_LOCKED(map); 673 map->busy++; 674 } 675 676 void 677 vm_map_unbusy(vm_map_t map) 678 { 679 680 VM_MAP_ASSERT_LOCKED(map); 681 KASSERT(map->busy, ("vm_map_unbusy: not busy")); 682 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { 683 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); 684 wakeup(&map->busy); 685 } 686 } 687 688 void 689 vm_map_wait_busy(vm_map_t map) 690 { 691 692 VM_MAP_ASSERT_LOCKED(map); 693 while (map->busy) { 694 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); 695 if (map->system_map) 696 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); 697 else 698 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); 699 } 700 map->timestamp++; 701 } 702 703 long 704 vmspace_resident_count(struct vmspace *vmspace) 705 { 706 return pmap_resident_count(vmspace_pmap(vmspace)); 707 } 708 709 /* 710 * vm_map_create: 711 * 712 * Creates and returns a new empty VM map with 713 * the given physical map structure, and having 714 * the given lower and upper address bounds. 715 */ 716 vm_map_t 717 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 718 { 719 vm_map_t result; 720 721 result = uma_zalloc(mapzone, M_WAITOK); 722 CTR1(KTR_VM, "vm_map_create: %p", result); 723 _vm_map_init(result, pmap, min, max); 724 return (result); 725 } 726 727 /* 728 * Initialize an existing vm_map structure 729 * such as that in the vmspace structure. 730 */ 731 static void 732 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 733 { 734 735 map->header.next = map->header.prev = &map->header; 736 map->needs_wakeup = FALSE; 737 map->system_map = 0; 738 map->pmap = pmap; 739 map->min_offset = min; 740 map->max_offset = max; 741 map->flags = 0; 742 map->root = NULL; 743 map->timestamp = 0; 744 map->busy = 0; 745 } 746 747 void 748 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 749 { 750 751 _vm_map_init(map, pmap, min, max); 752 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 753 sx_init(&map->lock, "user map"); 754 } 755 756 /* 757 * vm_map_entry_dispose: [ internal use only ] 758 * 759 * Inverse of vm_map_entry_create. 760 */ 761 static void 762 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 763 { 764 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 765 } 766 767 /* 768 * vm_map_entry_create: [ internal use only ] 769 * 770 * Allocates a VM map entry for insertion. 771 * No entry fields are filled in. 772 */ 773 static vm_map_entry_t 774 vm_map_entry_create(vm_map_t map) 775 { 776 vm_map_entry_t new_entry; 777 778 if (map->system_map) 779 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 780 else 781 new_entry = uma_zalloc(mapentzone, M_WAITOK); 782 if (new_entry == NULL) 783 panic("vm_map_entry_create: kernel resources exhausted"); 784 return (new_entry); 785 } 786 787 /* 788 * vm_map_entry_set_behavior: 789 * 790 * Set the expected access behavior, either normal, random, or 791 * sequential. 792 */ 793 static inline void 794 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 795 { 796 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 797 (behavior & MAP_ENTRY_BEHAV_MASK); 798 } 799 800 /* 801 * vm_map_entry_set_max_free: 802 * 803 * Set the max_free field in a vm_map_entry. 804 */ 805 static inline void 806 vm_map_entry_set_max_free(vm_map_entry_t entry) 807 { 808 809 entry->max_free = entry->adj_free; 810 if (entry->left != NULL && entry->left->max_free > entry->max_free) 811 entry->max_free = entry->left->max_free; 812 if (entry->right != NULL && entry->right->max_free > entry->max_free) 813 entry->max_free = entry->right->max_free; 814 } 815 816 /* 817 * vm_map_entry_splay: 818 * 819 * The Sleator and Tarjan top-down splay algorithm with the 820 * following variation. Max_free must be computed bottom-up, so 821 * on the downward pass, maintain the left and right spines in 822 * reverse order. Then, make a second pass up each side to fix 823 * the pointers and compute max_free. The time bound is O(log n) 824 * amortized. 825 * 826 * The new root is the vm_map_entry containing "addr", or else an 827 * adjacent entry (lower or higher) if addr is not in the tree. 828 * 829 * The map must be locked, and leaves it so. 830 * 831 * Returns: the new root. 832 */ 833 static vm_map_entry_t 834 vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root) 835 { 836 vm_map_entry_t llist, rlist; 837 vm_map_entry_t ltree, rtree; 838 vm_map_entry_t y; 839 840 /* Special case of empty tree. */ 841 if (root == NULL) 842 return (root); 843 844 /* 845 * Pass One: Splay down the tree until we find addr or a NULL 846 * pointer where addr would go. llist and rlist are the two 847 * sides in reverse order (bottom-up), with llist linked by 848 * the right pointer and rlist linked by the left pointer in 849 * the vm_map_entry. Wait until Pass Two to set max_free on 850 * the two spines. 851 */ 852 llist = NULL; 853 rlist = NULL; 854 for (;;) { 855 /* root is never NULL in here. */ 856 if (addr < root->start) { 857 y = root->left; 858 if (y == NULL) 859 break; 860 if (addr < y->start && y->left != NULL) { 861 /* Rotate right and put y on rlist. */ 862 root->left = y->right; 863 y->right = root; 864 vm_map_entry_set_max_free(root); 865 root = y->left; 866 y->left = rlist; 867 rlist = y; 868 } else { 869 /* Put root on rlist. */ 870 root->left = rlist; 871 rlist = root; 872 root = y; 873 } 874 } else if (addr >= root->end) { 875 y = root->right; 876 if (y == NULL) 877 break; 878 if (addr >= y->end && y->right != NULL) { 879 /* Rotate left and put y on llist. */ 880 root->right = y->left; 881 y->left = root; 882 vm_map_entry_set_max_free(root); 883 root = y->right; 884 y->right = llist; 885 llist = y; 886 } else { 887 /* Put root on llist. */ 888 root->right = llist; 889 llist = root; 890 root = y; 891 } 892 } else 893 break; 894 } 895 896 /* 897 * Pass Two: Walk back up the two spines, flip the pointers 898 * and set max_free. The subtrees of the root go at the 899 * bottom of llist and rlist. 900 */ 901 ltree = root->left; 902 while (llist != NULL) { 903 y = llist->right; 904 llist->right = ltree; 905 vm_map_entry_set_max_free(llist); 906 ltree = llist; 907 llist = y; 908 } 909 rtree = root->right; 910 while (rlist != NULL) { 911 y = rlist->left; 912 rlist->left = rtree; 913 vm_map_entry_set_max_free(rlist); 914 rtree = rlist; 915 rlist = y; 916 } 917 918 /* 919 * Final assembly: add ltree and rtree as subtrees of root. 920 */ 921 root->left = ltree; 922 root->right = rtree; 923 vm_map_entry_set_max_free(root); 924 925 return (root); 926 } 927 928 /* 929 * vm_map_entry_{un,}link: 930 * 931 * Insert/remove entries from maps. 932 */ 933 static void 934 vm_map_entry_link(vm_map_t map, 935 vm_map_entry_t after_where, 936 vm_map_entry_t entry) 937 { 938 939 CTR4(KTR_VM, 940 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 941 map->nentries, entry, after_where); 942 VM_MAP_ASSERT_LOCKED(map); 943 KASSERT(after_where == &map->header || 944 after_where->end <= entry->start, 945 ("vm_map_entry_link: prev end %jx new start %jx overlap", 946 (uintmax_t)after_where->end, (uintmax_t)entry->start)); 947 KASSERT(after_where->next == &map->header || 948 entry->end <= after_where->next->start, 949 ("vm_map_entry_link: new end %jx next start %jx overlap", 950 (uintmax_t)entry->end, (uintmax_t)after_where->next->start)); 951 952 map->nentries++; 953 entry->prev = after_where; 954 entry->next = after_where->next; 955 entry->next->prev = entry; 956 after_where->next = entry; 957 958 if (after_where != &map->header) { 959 if (after_where != map->root) 960 vm_map_entry_splay(after_where->start, map->root); 961 entry->right = after_where->right; 962 entry->left = after_where; 963 after_where->right = NULL; 964 after_where->adj_free = entry->start - after_where->end; 965 vm_map_entry_set_max_free(after_where); 966 } else { 967 entry->right = map->root; 968 entry->left = NULL; 969 } 970 entry->adj_free = (entry->next == &map->header ? map->max_offset : 971 entry->next->start) - entry->end; 972 vm_map_entry_set_max_free(entry); 973 map->root = entry; 974 } 975 976 static void 977 vm_map_entry_unlink(vm_map_t map, 978 vm_map_entry_t entry) 979 { 980 vm_map_entry_t next, prev, root; 981 982 VM_MAP_ASSERT_LOCKED(map); 983 if (entry != map->root) 984 vm_map_entry_splay(entry->start, map->root); 985 if (entry->left == NULL) 986 root = entry->right; 987 else { 988 root = vm_map_entry_splay(entry->start, entry->left); 989 root->right = entry->right; 990 root->adj_free = (entry->next == &map->header ? map->max_offset : 991 entry->next->start) - root->end; 992 vm_map_entry_set_max_free(root); 993 } 994 map->root = root; 995 996 prev = entry->prev; 997 next = entry->next; 998 next->prev = prev; 999 prev->next = next; 1000 map->nentries--; 1001 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 1002 map->nentries, entry); 1003 } 1004 1005 /* 1006 * vm_map_entry_resize_free: 1007 * 1008 * Recompute the amount of free space following a vm_map_entry 1009 * and propagate that value up the tree. Call this function after 1010 * resizing a map entry in-place, that is, without a call to 1011 * vm_map_entry_link() or _unlink(). 1012 * 1013 * The map must be locked, and leaves it so. 1014 */ 1015 static void 1016 vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry) 1017 { 1018 1019 /* 1020 * Using splay trees without parent pointers, propagating 1021 * max_free up the tree is done by moving the entry to the 1022 * root and making the change there. 1023 */ 1024 if (entry != map->root) 1025 map->root = vm_map_entry_splay(entry->start, map->root); 1026 1027 entry->adj_free = (entry->next == &map->header ? map->max_offset : 1028 entry->next->start) - entry->end; 1029 vm_map_entry_set_max_free(entry); 1030 } 1031 1032 /* 1033 * vm_map_lookup_entry: [ internal use only ] 1034 * 1035 * Finds the map entry containing (or 1036 * immediately preceding) the specified address 1037 * in the given map; the entry is returned 1038 * in the "entry" parameter. The boolean 1039 * result indicates whether the address is 1040 * actually contained in the map. 1041 */ 1042 boolean_t 1043 vm_map_lookup_entry( 1044 vm_map_t map, 1045 vm_offset_t address, 1046 vm_map_entry_t *entry) /* OUT */ 1047 { 1048 vm_map_entry_t cur; 1049 boolean_t locked; 1050 1051 /* 1052 * If the map is empty, then the map entry immediately preceding 1053 * "address" is the map's header. 1054 */ 1055 cur = map->root; 1056 if (cur == NULL) 1057 *entry = &map->header; 1058 else if (address >= cur->start && cur->end > address) { 1059 *entry = cur; 1060 return (TRUE); 1061 } else if ((locked = vm_map_locked(map)) || 1062 sx_try_upgrade(&map->lock)) { 1063 /* 1064 * Splay requires a write lock on the map. However, it only 1065 * restructures the binary search tree; it does not otherwise 1066 * change the map. Thus, the map's timestamp need not change 1067 * on a temporary upgrade. 1068 */ 1069 map->root = cur = vm_map_entry_splay(address, cur); 1070 if (!locked) 1071 sx_downgrade(&map->lock); 1072 1073 /* 1074 * If "address" is contained within a map entry, the new root 1075 * is that map entry. Otherwise, the new root is a map entry 1076 * immediately before or after "address". 1077 */ 1078 if (address >= cur->start) { 1079 *entry = cur; 1080 if (cur->end > address) 1081 return (TRUE); 1082 } else 1083 *entry = cur->prev; 1084 } else 1085 /* 1086 * Since the map is only locked for read access, perform a 1087 * standard binary search tree lookup for "address". 1088 */ 1089 for (;;) { 1090 if (address < cur->start) { 1091 if (cur->left == NULL) { 1092 *entry = cur->prev; 1093 break; 1094 } 1095 cur = cur->left; 1096 } else if (cur->end > address) { 1097 *entry = cur; 1098 return (TRUE); 1099 } else { 1100 if (cur->right == NULL) { 1101 *entry = cur; 1102 break; 1103 } 1104 cur = cur->right; 1105 } 1106 } 1107 return (FALSE); 1108 } 1109 1110 /* 1111 * vm_map_insert: 1112 * 1113 * Inserts the given whole VM object into the target 1114 * map at the specified address range. The object's 1115 * size should match that of the address range. 1116 * 1117 * Requires that the map be locked, and leaves it so. 1118 * 1119 * If object is non-NULL, ref count must be bumped by caller 1120 * prior to making call to account for the new entry. 1121 */ 1122 int 1123 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1124 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow) 1125 { 1126 vm_map_entry_t new_entry, prev_entry, temp_entry; 1127 vm_eflags_t protoeflags; 1128 struct ucred *cred; 1129 vm_inherit_t inheritance; 1130 1131 VM_MAP_ASSERT_LOCKED(map); 1132 KASSERT((object != kmem_object && object != kernel_object) || 1133 (cow & MAP_COPY_ON_WRITE) == 0, 1134 ("vm_map_insert: kmem or kernel object and COW")); 1135 KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0, 1136 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1137 1138 /* 1139 * Check that the start and end points are not bogus. 1140 */ 1141 if ((start < map->min_offset) || (end > map->max_offset) || 1142 (start >= end)) 1143 return (KERN_INVALID_ADDRESS); 1144 1145 /* 1146 * Find the entry prior to the proposed starting address; if it's part 1147 * of an existing entry, this range is bogus. 1148 */ 1149 if (vm_map_lookup_entry(map, start, &temp_entry)) 1150 return (KERN_NO_SPACE); 1151 1152 prev_entry = temp_entry; 1153 1154 /* 1155 * Assert that the next entry doesn't overlap the end point. 1156 */ 1157 if ((prev_entry->next != &map->header) && 1158 (prev_entry->next->start < end)) 1159 return (KERN_NO_SPACE); 1160 1161 protoeflags = 0; 1162 if (cow & MAP_COPY_ON_WRITE) 1163 protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY; 1164 if (cow & MAP_NOFAULT) 1165 protoeflags |= MAP_ENTRY_NOFAULT; 1166 if (cow & MAP_DISABLE_SYNCER) 1167 protoeflags |= MAP_ENTRY_NOSYNC; 1168 if (cow & MAP_DISABLE_COREDUMP) 1169 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1170 if (cow & MAP_STACK_GROWS_DOWN) 1171 protoeflags |= MAP_ENTRY_GROWS_DOWN; 1172 if (cow & MAP_STACK_GROWS_UP) 1173 protoeflags |= MAP_ENTRY_GROWS_UP; 1174 if (cow & MAP_VN_WRITECOUNT) 1175 protoeflags |= MAP_ENTRY_VN_WRITECNT; 1176 if (cow & MAP_INHERIT_SHARE) 1177 inheritance = VM_INHERIT_SHARE; 1178 else 1179 inheritance = VM_INHERIT_DEFAULT; 1180 1181 cred = NULL; 1182 if (cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT)) 1183 goto charged; 1184 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1185 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1186 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1187 return (KERN_RESOURCE_SHORTAGE); 1188 KASSERT(object == NULL || (protoeflags & MAP_ENTRY_NEEDS_COPY) || 1189 object->cred == NULL, 1190 ("OVERCOMMIT: vm_map_insert o %p", object)); 1191 cred = curthread->td_ucred; 1192 } 1193 1194 charged: 1195 /* Expand the kernel pmap, if necessary. */ 1196 if (map == kernel_map && end > kernel_vm_end) 1197 pmap_growkernel(end); 1198 if (object != NULL) { 1199 /* 1200 * OBJ_ONEMAPPING must be cleared unless this mapping 1201 * is trivially proven to be the only mapping for any 1202 * of the object's pages. (Object granularity 1203 * reference counting is insufficient to recognize 1204 * aliases with precision.) 1205 */ 1206 VM_OBJECT_WLOCK(object); 1207 if (object->ref_count > 1 || object->shadow_count != 0) 1208 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1209 VM_OBJECT_WUNLOCK(object); 1210 } 1211 else if ((prev_entry != &map->header) && 1212 (prev_entry->eflags == protoeflags) && 1213 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 && 1214 (prev_entry->end == start) && 1215 (prev_entry->wired_count == 0) && 1216 (prev_entry->cred == cred || 1217 (prev_entry->object.vm_object != NULL && 1218 (prev_entry->object.vm_object->cred == cred))) && 1219 vm_object_coalesce(prev_entry->object.vm_object, 1220 prev_entry->offset, 1221 (vm_size_t)(prev_entry->end - prev_entry->start), 1222 (vm_size_t)(end - prev_entry->end), cred != NULL && 1223 (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) { 1224 /* 1225 * We were able to extend the object. Determine if we 1226 * can extend the previous map entry to include the 1227 * new range as well. 1228 */ 1229 if ((prev_entry->inheritance == inheritance) && 1230 (prev_entry->protection == prot) && 1231 (prev_entry->max_protection == max)) { 1232 map->size += (end - prev_entry->end); 1233 prev_entry->end = end; 1234 vm_map_entry_resize_free(map, prev_entry); 1235 vm_map_simplify_entry(map, prev_entry); 1236 return (KERN_SUCCESS); 1237 } 1238 1239 /* 1240 * If we can extend the object but cannot extend the 1241 * map entry, we have to create a new map entry. We 1242 * must bump the ref count on the extended object to 1243 * account for it. object may be NULL. 1244 */ 1245 object = prev_entry->object.vm_object; 1246 offset = prev_entry->offset + 1247 (prev_entry->end - prev_entry->start); 1248 vm_object_reference(object); 1249 if (cred != NULL && object != NULL && object->cred != NULL && 1250 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1251 /* Object already accounts for this uid. */ 1252 cred = NULL; 1253 } 1254 } 1255 if (cred != NULL) 1256 crhold(cred); 1257 1258 /* 1259 * Create a new entry 1260 */ 1261 new_entry = vm_map_entry_create(map); 1262 new_entry->start = start; 1263 new_entry->end = end; 1264 new_entry->cred = NULL; 1265 1266 new_entry->eflags = protoeflags; 1267 new_entry->object.vm_object = object; 1268 new_entry->offset = offset; 1269 new_entry->avail_ssize = 0; 1270 1271 new_entry->inheritance = inheritance; 1272 new_entry->protection = prot; 1273 new_entry->max_protection = max; 1274 new_entry->wired_count = 0; 1275 new_entry->wiring_thread = NULL; 1276 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1277 new_entry->next_read = OFF_TO_IDX(offset); 1278 1279 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1280 ("OVERCOMMIT: vm_map_insert leaks vm_map %p", new_entry)); 1281 new_entry->cred = cred; 1282 1283 /* 1284 * Insert the new entry into the list 1285 */ 1286 vm_map_entry_link(map, prev_entry, new_entry); 1287 map->size += new_entry->end - new_entry->start; 1288 1289 /* 1290 * Try to coalesce the new entry with both the previous and next 1291 * entries in the list. Previously, we only attempted to coalesce 1292 * with the previous entry when object is NULL. Here, we handle the 1293 * other cases, which are less common. 1294 */ 1295 vm_map_simplify_entry(map, new_entry); 1296 1297 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 1298 vm_map_pmap_enter(map, start, prot, 1299 object, OFF_TO_IDX(offset), end - start, 1300 cow & MAP_PREFAULT_PARTIAL); 1301 } 1302 1303 return (KERN_SUCCESS); 1304 } 1305 1306 /* 1307 * vm_map_findspace: 1308 * 1309 * Find the first fit (lowest VM address) for "length" free bytes 1310 * beginning at address >= start in the given map. 1311 * 1312 * In a vm_map_entry, "adj_free" is the amount of free space 1313 * adjacent (higher address) to this entry, and "max_free" is the 1314 * maximum amount of contiguous free space in its subtree. This 1315 * allows finding a free region in one path down the tree, so 1316 * O(log n) amortized with splay trees. 1317 * 1318 * The map must be locked, and leaves it so. 1319 * 1320 * Returns: 0 on success, and starting address in *addr, 1321 * 1 if insufficient space. 1322 */ 1323 int 1324 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1325 vm_offset_t *addr) /* OUT */ 1326 { 1327 vm_map_entry_t entry; 1328 vm_offset_t st; 1329 1330 /* 1331 * Request must fit within min/max VM address and must avoid 1332 * address wrap. 1333 */ 1334 if (start < map->min_offset) 1335 start = map->min_offset; 1336 if (start + length > map->max_offset || start + length < start) 1337 return (1); 1338 1339 /* Empty tree means wide open address space. */ 1340 if (map->root == NULL) { 1341 *addr = start; 1342 return (0); 1343 } 1344 1345 /* 1346 * After splay, if start comes before root node, then there 1347 * must be a gap from start to the root. 1348 */ 1349 map->root = vm_map_entry_splay(start, map->root); 1350 if (start + length <= map->root->start) { 1351 *addr = start; 1352 return (0); 1353 } 1354 1355 /* 1356 * Root is the last node that might begin its gap before 1357 * start, and this is the last comparison where address 1358 * wrap might be a problem. 1359 */ 1360 st = (start > map->root->end) ? start : map->root->end; 1361 if (length <= map->root->end + map->root->adj_free - st) { 1362 *addr = st; 1363 return (0); 1364 } 1365 1366 /* With max_free, can immediately tell if no solution. */ 1367 entry = map->root->right; 1368 if (entry == NULL || length > entry->max_free) 1369 return (1); 1370 1371 /* 1372 * Search the right subtree in the order: left subtree, root, 1373 * right subtree (first fit). The previous splay implies that 1374 * all regions in the right subtree have addresses > start. 1375 */ 1376 while (entry != NULL) { 1377 if (entry->left != NULL && entry->left->max_free >= length) 1378 entry = entry->left; 1379 else if (entry->adj_free >= length) { 1380 *addr = entry->end; 1381 return (0); 1382 } else 1383 entry = entry->right; 1384 } 1385 1386 /* Can't get here, so panic if we do. */ 1387 panic("vm_map_findspace: max_free corrupt"); 1388 } 1389 1390 int 1391 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1392 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1393 vm_prot_t max, int cow) 1394 { 1395 vm_offset_t end; 1396 int result; 1397 1398 end = start + length; 1399 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1400 object == NULL, 1401 ("vm_map_fixed: non-NULL backing object for stack")); 1402 vm_map_lock(map); 1403 VM_MAP_RANGE_CHECK(map, start, end); 1404 if ((cow & MAP_CHECK_EXCL) == 0) 1405 vm_map_delete(map, start, end); 1406 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1407 result = vm_map_stack_locked(map, start, length, sgrowsiz, 1408 prot, max, cow); 1409 } else { 1410 result = vm_map_insert(map, object, offset, start, end, 1411 prot, max, cow); 1412 } 1413 vm_map_unlock(map); 1414 return (result); 1415 } 1416 1417 /* 1418 * vm_map_find finds an unallocated region in the target address 1419 * map with the given length. The search is defined to be 1420 * first-fit from the specified address; the region found is 1421 * returned in the same parameter. 1422 * 1423 * If object is non-NULL, ref count must be bumped by caller 1424 * prior to making call to account for the new entry. 1425 */ 1426 int 1427 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1428 vm_offset_t *addr, /* IN/OUT */ 1429 vm_size_t length, vm_offset_t max_addr, int find_space, 1430 vm_prot_t prot, vm_prot_t max, int cow) 1431 { 1432 vm_offset_t alignment, initial_addr, start; 1433 int result; 1434 1435 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1436 object == NULL, 1437 ("vm_map_find: non-NULL backing object for stack")); 1438 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 1439 (object->flags & OBJ_COLORED) == 0)) 1440 find_space = VMFS_ANY_SPACE; 1441 if (find_space >> 8 != 0) { 1442 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 1443 alignment = (vm_offset_t)1 << (find_space >> 8); 1444 } else 1445 alignment = 0; 1446 initial_addr = *addr; 1447 again: 1448 start = initial_addr; 1449 vm_map_lock(map); 1450 do { 1451 if (find_space != VMFS_NO_SPACE) { 1452 if (vm_map_findspace(map, start, length, addr) || 1453 (max_addr != 0 && *addr + length > max_addr)) { 1454 vm_map_unlock(map); 1455 if (find_space == VMFS_OPTIMAL_SPACE) { 1456 find_space = VMFS_ANY_SPACE; 1457 goto again; 1458 } 1459 return (KERN_NO_SPACE); 1460 } 1461 switch (find_space) { 1462 case VMFS_SUPER_SPACE: 1463 case VMFS_OPTIMAL_SPACE: 1464 pmap_align_superpage(object, offset, addr, 1465 length); 1466 break; 1467 case VMFS_ANY_SPACE: 1468 break; 1469 default: 1470 if ((*addr & (alignment - 1)) != 0) { 1471 *addr &= ~(alignment - 1); 1472 *addr += alignment; 1473 } 1474 break; 1475 } 1476 1477 start = *addr; 1478 } 1479 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1480 result = vm_map_stack_locked(map, start, length, 1481 sgrowsiz, prot, max, cow); 1482 } else { 1483 result = vm_map_insert(map, object, offset, start, 1484 start + length, prot, max, cow); 1485 } 1486 } while (result == KERN_NO_SPACE && find_space != VMFS_NO_SPACE && 1487 find_space != VMFS_ANY_SPACE); 1488 vm_map_unlock(map); 1489 return (result); 1490 } 1491 1492 /* 1493 * vm_map_simplify_entry: 1494 * 1495 * Simplify the given map entry by merging with either neighbor. This 1496 * routine also has the ability to merge with both neighbors. 1497 * 1498 * The map must be locked. 1499 * 1500 * This routine guarentees that the passed entry remains valid (though 1501 * possibly extended). When merging, this routine may delete one or 1502 * both neighbors. 1503 */ 1504 void 1505 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1506 { 1507 vm_map_entry_t next, prev; 1508 vm_size_t prevsize, esize; 1509 1510 if ((entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | 1511 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) != 0) 1512 return; 1513 1514 prev = entry->prev; 1515 if (prev != &map->header) { 1516 prevsize = prev->end - prev->start; 1517 if ( (prev->end == entry->start) && 1518 (prev->object.vm_object == entry->object.vm_object) && 1519 (!prev->object.vm_object || 1520 (prev->offset + prevsize == entry->offset)) && 1521 (prev->eflags == entry->eflags) && 1522 (prev->protection == entry->protection) && 1523 (prev->max_protection == entry->max_protection) && 1524 (prev->inheritance == entry->inheritance) && 1525 (prev->wired_count == entry->wired_count) && 1526 (prev->cred == entry->cred)) { 1527 vm_map_entry_unlink(map, prev); 1528 entry->start = prev->start; 1529 entry->offset = prev->offset; 1530 if (entry->prev != &map->header) 1531 vm_map_entry_resize_free(map, entry->prev); 1532 1533 /* 1534 * If the backing object is a vnode object, 1535 * vm_object_deallocate() calls vrele(). 1536 * However, vrele() does not lock the vnode 1537 * because the vnode has additional 1538 * references. Thus, the map lock can be kept 1539 * without causing a lock-order reversal with 1540 * the vnode lock. 1541 * 1542 * Since we count the number of virtual page 1543 * mappings in object->un_pager.vnp.writemappings, 1544 * the writemappings value should not be adjusted 1545 * when the entry is disposed of. 1546 */ 1547 if (prev->object.vm_object) 1548 vm_object_deallocate(prev->object.vm_object); 1549 if (prev->cred != NULL) 1550 crfree(prev->cred); 1551 vm_map_entry_dispose(map, prev); 1552 } 1553 } 1554 1555 next = entry->next; 1556 if (next != &map->header) { 1557 esize = entry->end - entry->start; 1558 if ((entry->end == next->start) && 1559 (next->object.vm_object == entry->object.vm_object) && 1560 (!entry->object.vm_object || 1561 (entry->offset + esize == next->offset)) && 1562 (next->eflags == entry->eflags) && 1563 (next->protection == entry->protection) && 1564 (next->max_protection == entry->max_protection) && 1565 (next->inheritance == entry->inheritance) && 1566 (next->wired_count == entry->wired_count) && 1567 (next->cred == entry->cred)) { 1568 vm_map_entry_unlink(map, next); 1569 entry->end = next->end; 1570 vm_map_entry_resize_free(map, entry); 1571 1572 /* 1573 * See comment above. 1574 */ 1575 if (next->object.vm_object) 1576 vm_object_deallocate(next->object.vm_object); 1577 if (next->cred != NULL) 1578 crfree(next->cred); 1579 vm_map_entry_dispose(map, next); 1580 } 1581 } 1582 } 1583 /* 1584 * vm_map_clip_start: [ internal use only ] 1585 * 1586 * Asserts that the given entry begins at or after 1587 * the specified address; if necessary, 1588 * it splits the entry into two. 1589 */ 1590 #define vm_map_clip_start(map, entry, startaddr) \ 1591 { \ 1592 if (startaddr > entry->start) \ 1593 _vm_map_clip_start(map, entry, startaddr); \ 1594 } 1595 1596 /* 1597 * This routine is called only when it is known that 1598 * the entry must be split. 1599 */ 1600 static void 1601 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1602 { 1603 vm_map_entry_t new_entry; 1604 1605 VM_MAP_ASSERT_LOCKED(map); 1606 1607 /* 1608 * Split off the front portion -- note that we must insert the new 1609 * entry BEFORE this one, so that this entry has the specified 1610 * starting address. 1611 */ 1612 vm_map_simplify_entry(map, entry); 1613 1614 /* 1615 * If there is no object backing this entry, we might as well create 1616 * one now. If we defer it, an object can get created after the map 1617 * is clipped, and individual objects will be created for the split-up 1618 * map. This is a bit of a hack, but is also about the best place to 1619 * put this improvement. 1620 */ 1621 if (entry->object.vm_object == NULL && !map->system_map) { 1622 vm_object_t object; 1623 object = vm_object_allocate(OBJT_DEFAULT, 1624 atop(entry->end - entry->start)); 1625 entry->object.vm_object = object; 1626 entry->offset = 0; 1627 if (entry->cred != NULL) { 1628 object->cred = entry->cred; 1629 object->charge = entry->end - entry->start; 1630 entry->cred = NULL; 1631 } 1632 } else if (entry->object.vm_object != NULL && 1633 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1634 entry->cred != NULL) { 1635 VM_OBJECT_WLOCK(entry->object.vm_object); 1636 KASSERT(entry->object.vm_object->cred == NULL, 1637 ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry)); 1638 entry->object.vm_object->cred = entry->cred; 1639 entry->object.vm_object->charge = entry->end - entry->start; 1640 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1641 entry->cred = NULL; 1642 } 1643 1644 new_entry = vm_map_entry_create(map); 1645 *new_entry = *entry; 1646 1647 new_entry->end = start; 1648 entry->offset += (start - entry->start); 1649 entry->start = start; 1650 if (new_entry->cred != NULL) 1651 crhold(entry->cred); 1652 1653 vm_map_entry_link(map, entry->prev, new_entry); 1654 1655 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1656 vm_object_reference(new_entry->object.vm_object); 1657 /* 1658 * The object->un_pager.vnp.writemappings for the 1659 * object of MAP_ENTRY_VN_WRITECNT type entry shall be 1660 * kept as is here. The virtual pages are 1661 * re-distributed among the clipped entries, so the sum is 1662 * left the same. 1663 */ 1664 } 1665 } 1666 1667 /* 1668 * vm_map_clip_end: [ internal use only ] 1669 * 1670 * Asserts that the given entry ends at or before 1671 * the specified address; if necessary, 1672 * it splits the entry into two. 1673 */ 1674 #define vm_map_clip_end(map, entry, endaddr) \ 1675 { \ 1676 if ((endaddr) < (entry->end)) \ 1677 _vm_map_clip_end((map), (entry), (endaddr)); \ 1678 } 1679 1680 /* 1681 * This routine is called only when it is known that 1682 * the entry must be split. 1683 */ 1684 static void 1685 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1686 { 1687 vm_map_entry_t new_entry; 1688 1689 VM_MAP_ASSERT_LOCKED(map); 1690 1691 /* 1692 * If there is no object backing this entry, we might as well create 1693 * one now. If we defer it, an object can get created after the map 1694 * is clipped, and individual objects will be created for the split-up 1695 * map. This is a bit of a hack, but is also about the best place to 1696 * put this improvement. 1697 */ 1698 if (entry->object.vm_object == NULL && !map->system_map) { 1699 vm_object_t object; 1700 object = vm_object_allocate(OBJT_DEFAULT, 1701 atop(entry->end - entry->start)); 1702 entry->object.vm_object = object; 1703 entry->offset = 0; 1704 if (entry->cred != NULL) { 1705 object->cred = entry->cred; 1706 object->charge = entry->end - entry->start; 1707 entry->cred = NULL; 1708 } 1709 } else if (entry->object.vm_object != NULL && 1710 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1711 entry->cred != NULL) { 1712 VM_OBJECT_WLOCK(entry->object.vm_object); 1713 KASSERT(entry->object.vm_object->cred == NULL, 1714 ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry)); 1715 entry->object.vm_object->cred = entry->cred; 1716 entry->object.vm_object->charge = entry->end - entry->start; 1717 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1718 entry->cred = NULL; 1719 } 1720 1721 /* 1722 * Create a new entry and insert it AFTER the specified entry 1723 */ 1724 new_entry = vm_map_entry_create(map); 1725 *new_entry = *entry; 1726 1727 new_entry->start = entry->end = end; 1728 new_entry->offset += (end - entry->start); 1729 if (new_entry->cred != NULL) 1730 crhold(entry->cred); 1731 1732 vm_map_entry_link(map, entry, new_entry); 1733 1734 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1735 vm_object_reference(new_entry->object.vm_object); 1736 } 1737 } 1738 1739 /* 1740 * vm_map_submap: [ kernel use only ] 1741 * 1742 * Mark the given range as handled by a subordinate map. 1743 * 1744 * This range must have been created with vm_map_find, 1745 * and no other operations may have been performed on this 1746 * range prior to calling vm_map_submap. 1747 * 1748 * Only a limited number of operations can be performed 1749 * within this rage after calling vm_map_submap: 1750 * vm_fault 1751 * [Don't try vm_map_copy!] 1752 * 1753 * To remove a submapping, one must first remove the 1754 * range from the superior map, and then destroy the 1755 * submap (if desired). [Better yet, don't try it.] 1756 */ 1757 int 1758 vm_map_submap( 1759 vm_map_t map, 1760 vm_offset_t start, 1761 vm_offset_t end, 1762 vm_map_t submap) 1763 { 1764 vm_map_entry_t entry; 1765 int result = KERN_INVALID_ARGUMENT; 1766 1767 vm_map_lock(map); 1768 1769 VM_MAP_RANGE_CHECK(map, start, end); 1770 1771 if (vm_map_lookup_entry(map, start, &entry)) { 1772 vm_map_clip_start(map, entry, start); 1773 } else 1774 entry = entry->next; 1775 1776 vm_map_clip_end(map, entry, end); 1777 1778 if ((entry->start == start) && (entry->end == end) && 1779 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1780 (entry->object.vm_object == NULL)) { 1781 entry->object.sub_map = submap; 1782 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1783 result = KERN_SUCCESS; 1784 } 1785 vm_map_unlock(map); 1786 1787 return (result); 1788 } 1789 1790 /* 1791 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified 1792 */ 1793 #define MAX_INIT_PT 96 1794 1795 /* 1796 * vm_map_pmap_enter: 1797 * 1798 * Preload the specified map's pmap with mappings to the specified 1799 * object's memory-resident pages. No further physical pages are 1800 * allocated, and no further virtual pages are retrieved from secondary 1801 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a 1802 * limited number of page mappings are created at the low-end of the 1803 * specified address range. (For this purpose, a superpage mapping 1804 * counts as one page mapping.) Otherwise, all resident pages within 1805 * the specified address range are mapped. Because these mappings are 1806 * being created speculatively, cached pages are not reactivated and 1807 * mapped. 1808 */ 1809 void 1810 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 1811 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1812 { 1813 vm_offset_t start; 1814 vm_page_t p, p_start; 1815 vm_pindex_t mask, psize, threshold, tmpidx; 1816 1817 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 1818 return; 1819 VM_OBJECT_RLOCK(object); 1820 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1821 VM_OBJECT_RUNLOCK(object); 1822 VM_OBJECT_WLOCK(object); 1823 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1824 pmap_object_init_pt(map->pmap, addr, object, pindex, 1825 size); 1826 VM_OBJECT_WUNLOCK(object); 1827 return; 1828 } 1829 VM_OBJECT_LOCK_DOWNGRADE(object); 1830 } 1831 1832 psize = atop(size); 1833 if (psize + pindex > object->size) { 1834 if (object->size < pindex) { 1835 VM_OBJECT_RUNLOCK(object); 1836 return; 1837 } 1838 psize = object->size - pindex; 1839 } 1840 1841 start = 0; 1842 p_start = NULL; 1843 threshold = MAX_INIT_PT; 1844 1845 p = vm_page_find_least(object, pindex); 1846 /* 1847 * Assert: the variable p is either (1) the page with the 1848 * least pindex greater than or equal to the parameter pindex 1849 * or (2) NULL. 1850 */ 1851 for (; 1852 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1853 p = TAILQ_NEXT(p, listq)) { 1854 /* 1855 * don't allow an madvise to blow away our really 1856 * free pages allocating pv entries. 1857 */ 1858 if (((flags & MAP_PREFAULT_MADVISE) != 0 && 1859 vm_cnt.v_free_count < vm_cnt.v_free_reserved) || 1860 ((flags & MAP_PREFAULT_PARTIAL) != 0 && 1861 tmpidx >= threshold)) { 1862 psize = tmpidx; 1863 break; 1864 } 1865 if (p->valid == VM_PAGE_BITS_ALL) { 1866 if (p_start == NULL) { 1867 start = addr + ptoa(tmpidx); 1868 p_start = p; 1869 } 1870 /* Jump ahead if a superpage mapping is possible. */ 1871 if (p->psind > 0 && ((addr + ptoa(tmpidx)) & 1872 (pagesizes[p->psind] - 1)) == 0) { 1873 mask = atop(pagesizes[p->psind]) - 1; 1874 if (tmpidx + mask < psize && 1875 vm_page_ps_is_valid(p)) { 1876 p += mask; 1877 threshold += mask; 1878 } 1879 } 1880 } else if (p_start != NULL) { 1881 pmap_enter_object(map->pmap, start, addr + 1882 ptoa(tmpidx), p_start, prot); 1883 p_start = NULL; 1884 } 1885 } 1886 if (p_start != NULL) 1887 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 1888 p_start, prot); 1889 VM_OBJECT_RUNLOCK(object); 1890 } 1891 1892 /* 1893 * vm_map_protect: 1894 * 1895 * Sets the protection of the specified address 1896 * region in the target map. If "set_max" is 1897 * specified, the maximum protection is to be set; 1898 * otherwise, only the current protection is affected. 1899 */ 1900 int 1901 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1902 vm_prot_t new_prot, boolean_t set_max) 1903 { 1904 vm_map_entry_t current, entry; 1905 vm_object_t obj; 1906 struct ucred *cred; 1907 vm_prot_t old_prot; 1908 1909 if (start == end) 1910 return (KERN_SUCCESS); 1911 1912 vm_map_lock(map); 1913 1914 VM_MAP_RANGE_CHECK(map, start, end); 1915 1916 if (vm_map_lookup_entry(map, start, &entry)) { 1917 vm_map_clip_start(map, entry, start); 1918 } else { 1919 entry = entry->next; 1920 } 1921 1922 /* 1923 * Make a first pass to check for protection violations. 1924 */ 1925 current = entry; 1926 while ((current != &map->header) && (current->start < end)) { 1927 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1928 vm_map_unlock(map); 1929 return (KERN_INVALID_ARGUMENT); 1930 } 1931 if ((new_prot & current->max_protection) != new_prot) { 1932 vm_map_unlock(map); 1933 return (KERN_PROTECTION_FAILURE); 1934 } 1935 current = current->next; 1936 } 1937 1938 1939 /* 1940 * Do an accounting pass for private read-only mappings that 1941 * now will do cow due to allowed write (e.g. debugger sets 1942 * breakpoint on text segment) 1943 */ 1944 for (current = entry; (current != &map->header) && 1945 (current->start < end); current = current->next) { 1946 1947 vm_map_clip_end(map, current, end); 1948 1949 if (set_max || 1950 ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 || 1951 ENTRY_CHARGED(current)) { 1952 continue; 1953 } 1954 1955 cred = curthread->td_ucred; 1956 obj = current->object.vm_object; 1957 1958 if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) { 1959 if (!swap_reserve(current->end - current->start)) { 1960 vm_map_unlock(map); 1961 return (KERN_RESOURCE_SHORTAGE); 1962 } 1963 crhold(cred); 1964 current->cred = cred; 1965 continue; 1966 } 1967 1968 VM_OBJECT_WLOCK(obj); 1969 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 1970 VM_OBJECT_WUNLOCK(obj); 1971 continue; 1972 } 1973 1974 /* 1975 * Charge for the whole object allocation now, since 1976 * we cannot distinguish between non-charged and 1977 * charged clipped mapping of the same object later. 1978 */ 1979 KASSERT(obj->charge == 0, 1980 ("vm_map_protect: object %p overcharged (entry %p)", 1981 obj, current)); 1982 if (!swap_reserve(ptoa(obj->size))) { 1983 VM_OBJECT_WUNLOCK(obj); 1984 vm_map_unlock(map); 1985 return (KERN_RESOURCE_SHORTAGE); 1986 } 1987 1988 crhold(cred); 1989 obj->cred = cred; 1990 obj->charge = ptoa(obj->size); 1991 VM_OBJECT_WUNLOCK(obj); 1992 } 1993 1994 /* 1995 * Go back and fix up protections. [Note that clipping is not 1996 * necessary the second time.] 1997 */ 1998 current = entry; 1999 while ((current != &map->header) && (current->start < end)) { 2000 old_prot = current->protection; 2001 2002 if (set_max) 2003 current->protection = 2004 (current->max_protection = new_prot) & 2005 old_prot; 2006 else 2007 current->protection = new_prot; 2008 2009 /* 2010 * For user wired map entries, the normal lazy evaluation of 2011 * write access upgrades through soft page faults is 2012 * undesirable. Instead, immediately copy any pages that are 2013 * copy-on-write and enable write access in the physical map. 2014 */ 2015 if ((current->eflags & MAP_ENTRY_USER_WIRED) != 0 && 2016 (current->protection & VM_PROT_WRITE) != 0 && 2017 (old_prot & VM_PROT_WRITE) == 0) 2018 vm_fault_copy_entry(map, map, current, current, NULL); 2019 2020 /* 2021 * When restricting access, update the physical map. Worry 2022 * about copy-on-write here. 2023 */ 2024 if ((old_prot & ~current->protection) != 0) { 2025 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 2026 VM_PROT_ALL) 2027 pmap_protect(map->pmap, current->start, 2028 current->end, 2029 current->protection & MASK(current)); 2030 #undef MASK 2031 } 2032 vm_map_simplify_entry(map, current); 2033 current = current->next; 2034 } 2035 vm_map_unlock(map); 2036 return (KERN_SUCCESS); 2037 } 2038 2039 /* 2040 * vm_map_madvise: 2041 * 2042 * This routine traverses a processes map handling the madvise 2043 * system call. Advisories are classified as either those effecting 2044 * the vm_map_entry structure, or those effecting the underlying 2045 * objects. 2046 */ 2047 int 2048 vm_map_madvise( 2049 vm_map_t map, 2050 vm_offset_t start, 2051 vm_offset_t end, 2052 int behav) 2053 { 2054 vm_map_entry_t current, entry; 2055 int modify_map = 0; 2056 2057 /* 2058 * Some madvise calls directly modify the vm_map_entry, in which case 2059 * we need to use an exclusive lock on the map and we need to perform 2060 * various clipping operations. Otherwise we only need a read-lock 2061 * on the map. 2062 */ 2063 switch(behav) { 2064 case MADV_NORMAL: 2065 case MADV_SEQUENTIAL: 2066 case MADV_RANDOM: 2067 case MADV_NOSYNC: 2068 case MADV_AUTOSYNC: 2069 case MADV_NOCORE: 2070 case MADV_CORE: 2071 if (start == end) 2072 return (KERN_SUCCESS); 2073 modify_map = 1; 2074 vm_map_lock(map); 2075 break; 2076 case MADV_WILLNEED: 2077 case MADV_DONTNEED: 2078 case MADV_FREE: 2079 if (start == end) 2080 return (KERN_SUCCESS); 2081 vm_map_lock_read(map); 2082 break; 2083 default: 2084 return (KERN_INVALID_ARGUMENT); 2085 } 2086 2087 /* 2088 * Locate starting entry and clip if necessary. 2089 */ 2090 VM_MAP_RANGE_CHECK(map, start, end); 2091 2092 if (vm_map_lookup_entry(map, start, &entry)) { 2093 if (modify_map) 2094 vm_map_clip_start(map, entry, start); 2095 } else { 2096 entry = entry->next; 2097 } 2098 2099 if (modify_map) { 2100 /* 2101 * madvise behaviors that are implemented in the vm_map_entry. 2102 * 2103 * We clip the vm_map_entry so that behavioral changes are 2104 * limited to the specified address range. 2105 */ 2106 for (current = entry; 2107 (current != &map->header) && (current->start < end); 2108 current = current->next 2109 ) { 2110 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2111 continue; 2112 2113 vm_map_clip_end(map, current, end); 2114 2115 switch (behav) { 2116 case MADV_NORMAL: 2117 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 2118 break; 2119 case MADV_SEQUENTIAL: 2120 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 2121 break; 2122 case MADV_RANDOM: 2123 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 2124 break; 2125 case MADV_NOSYNC: 2126 current->eflags |= MAP_ENTRY_NOSYNC; 2127 break; 2128 case MADV_AUTOSYNC: 2129 current->eflags &= ~MAP_ENTRY_NOSYNC; 2130 break; 2131 case MADV_NOCORE: 2132 current->eflags |= MAP_ENTRY_NOCOREDUMP; 2133 break; 2134 case MADV_CORE: 2135 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2136 break; 2137 default: 2138 break; 2139 } 2140 vm_map_simplify_entry(map, current); 2141 } 2142 vm_map_unlock(map); 2143 } else { 2144 vm_pindex_t pstart, pend; 2145 2146 /* 2147 * madvise behaviors that are implemented in the underlying 2148 * vm_object. 2149 * 2150 * Since we don't clip the vm_map_entry, we have to clip 2151 * the vm_object pindex and count. 2152 */ 2153 for (current = entry; 2154 (current != &map->header) && (current->start < end); 2155 current = current->next 2156 ) { 2157 vm_offset_t useEnd, useStart; 2158 2159 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2160 continue; 2161 2162 pstart = OFF_TO_IDX(current->offset); 2163 pend = pstart + atop(current->end - current->start); 2164 useStart = current->start; 2165 useEnd = current->end; 2166 2167 if (current->start < start) { 2168 pstart += atop(start - current->start); 2169 useStart = start; 2170 } 2171 if (current->end > end) { 2172 pend -= atop(current->end - end); 2173 useEnd = end; 2174 } 2175 2176 if (pstart >= pend) 2177 continue; 2178 2179 /* 2180 * Perform the pmap_advise() before clearing 2181 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2182 * concurrent pmap operation, such as pmap_remove(), 2183 * could clear a reference in the pmap and set 2184 * PGA_REFERENCED on the page before the pmap_advise() 2185 * had completed. Consequently, the page would appear 2186 * referenced based upon an old reference that 2187 * occurred before this pmap_advise() ran. 2188 */ 2189 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2190 pmap_advise(map->pmap, useStart, useEnd, 2191 behav); 2192 2193 vm_object_madvise(current->object.vm_object, pstart, 2194 pend, behav); 2195 if (behav == MADV_WILLNEED) { 2196 vm_map_pmap_enter(map, 2197 useStart, 2198 current->protection, 2199 current->object.vm_object, 2200 pstart, 2201 ptoa(pend - pstart), 2202 MAP_PREFAULT_MADVISE 2203 ); 2204 } 2205 } 2206 vm_map_unlock_read(map); 2207 } 2208 return (0); 2209 } 2210 2211 2212 /* 2213 * vm_map_inherit: 2214 * 2215 * Sets the inheritance of the specified address 2216 * range in the target map. Inheritance 2217 * affects how the map will be shared with 2218 * child maps at the time of vmspace_fork. 2219 */ 2220 int 2221 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2222 vm_inherit_t new_inheritance) 2223 { 2224 vm_map_entry_t entry; 2225 vm_map_entry_t temp_entry; 2226 2227 switch (new_inheritance) { 2228 case VM_INHERIT_NONE: 2229 case VM_INHERIT_COPY: 2230 case VM_INHERIT_SHARE: 2231 break; 2232 default: 2233 return (KERN_INVALID_ARGUMENT); 2234 } 2235 if (start == end) 2236 return (KERN_SUCCESS); 2237 vm_map_lock(map); 2238 VM_MAP_RANGE_CHECK(map, start, end); 2239 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2240 entry = temp_entry; 2241 vm_map_clip_start(map, entry, start); 2242 } else 2243 entry = temp_entry->next; 2244 while ((entry != &map->header) && (entry->start < end)) { 2245 vm_map_clip_end(map, entry, end); 2246 entry->inheritance = new_inheritance; 2247 vm_map_simplify_entry(map, entry); 2248 entry = entry->next; 2249 } 2250 vm_map_unlock(map); 2251 return (KERN_SUCCESS); 2252 } 2253 2254 /* 2255 * vm_map_unwire: 2256 * 2257 * Implements both kernel and user unwiring. 2258 */ 2259 int 2260 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2261 int flags) 2262 { 2263 vm_map_entry_t entry, first_entry, tmp_entry; 2264 vm_offset_t saved_start; 2265 unsigned int last_timestamp; 2266 int rv; 2267 boolean_t need_wakeup, result, user_unwire; 2268 2269 if (start == end) 2270 return (KERN_SUCCESS); 2271 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2272 vm_map_lock(map); 2273 VM_MAP_RANGE_CHECK(map, start, end); 2274 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2275 if (flags & VM_MAP_WIRE_HOLESOK) 2276 first_entry = first_entry->next; 2277 else { 2278 vm_map_unlock(map); 2279 return (KERN_INVALID_ADDRESS); 2280 } 2281 } 2282 last_timestamp = map->timestamp; 2283 entry = first_entry; 2284 while (entry != &map->header && entry->start < end) { 2285 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2286 /* 2287 * We have not yet clipped the entry. 2288 */ 2289 saved_start = (start >= entry->start) ? start : 2290 entry->start; 2291 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2292 if (vm_map_unlock_and_wait(map, 0)) { 2293 /* 2294 * Allow interruption of user unwiring? 2295 */ 2296 } 2297 vm_map_lock(map); 2298 if (last_timestamp+1 != map->timestamp) { 2299 /* 2300 * Look again for the entry because the map was 2301 * modified while it was unlocked. 2302 * Specifically, the entry may have been 2303 * clipped, merged, or deleted. 2304 */ 2305 if (!vm_map_lookup_entry(map, saved_start, 2306 &tmp_entry)) { 2307 if (flags & VM_MAP_WIRE_HOLESOK) 2308 tmp_entry = tmp_entry->next; 2309 else { 2310 if (saved_start == start) { 2311 /* 2312 * First_entry has been deleted. 2313 */ 2314 vm_map_unlock(map); 2315 return (KERN_INVALID_ADDRESS); 2316 } 2317 end = saved_start; 2318 rv = KERN_INVALID_ADDRESS; 2319 goto done; 2320 } 2321 } 2322 if (entry == first_entry) 2323 first_entry = tmp_entry; 2324 else 2325 first_entry = NULL; 2326 entry = tmp_entry; 2327 } 2328 last_timestamp = map->timestamp; 2329 continue; 2330 } 2331 vm_map_clip_start(map, entry, start); 2332 vm_map_clip_end(map, entry, end); 2333 /* 2334 * Mark the entry in case the map lock is released. (See 2335 * above.) 2336 */ 2337 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2338 entry->wiring_thread == NULL, 2339 ("owned map entry %p", entry)); 2340 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2341 entry->wiring_thread = curthread; 2342 /* 2343 * Check the map for holes in the specified region. 2344 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2345 */ 2346 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2347 (entry->end < end && (entry->next == &map->header || 2348 entry->next->start > entry->end))) { 2349 end = entry->end; 2350 rv = KERN_INVALID_ADDRESS; 2351 goto done; 2352 } 2353 /* 2354 * If system unwiring, require that the entry is system wired. 2355 */ 2356 if (!user_unwire && 2357 vm_map_entry_system_wired_count(entry) == 0) { 2358 end = entry->end; 2359 rv = KERN_INVALID_ARGUMENT; 2360 goto done; 2361 } 2362 entry = entry->next; 2363 } 2364 rv = KERN_SUCCESS; 2365 done: 2366 need_wakeup = FALSE; 2367 if (first_entry == NULL) { 2368 result = vm_map_lookup_entry(map, start, &first_entry); 2369 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2370 first_entry = first_entry->next; 2371 else 2372 KASSERT(result, ("vm_map_unwire: lookup failed")); 2373 } 2374 for (entry = first_entry; entry != &map->header && entry->start < end; 2375 entry = entry->next) { 2376 /* 2377 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2378 * space in the unwired region could have been mapped 2379 * while the map lock was dropped for draining 2380 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 2381 * could be simultaneously wiring this new mapping 2382 * entry. Detect these cases and skip any entries 2383 * marked as in transition by us. 2384 */ 2385 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2386 entry->wiring_thread != curthread) { 2387 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2388 ("vm_map_unwire: !HOLESOK and new/changed entry")); 2389 continue; 2390 } 2391 2392 if (rv == KERN_SUCCESS && (!user_unwire || 2393 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 2394 if (user_unwire) 2395 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2396 entry->wired_count--; 2397 if (entry->wired_count == 0) { 2398 /* 2399 * Retain the map lock. 2400 */ 2401 vm_fault_unwire(map, entry->start, entry->end, 2402 entry->object.vm_object != NULL && 2403 (entry->object.vm_object->flags & 2404 OBJ_FICTITIOUS) != 0); 2405 } 2406 } 2407 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2408 ("vm_map_unwire: in-transition flag missing %p", entry)); 2409 KASSERT(entry->wiring_thread == curthread, 2410 ("vm_map_unwire: alien wire %p", entry)); 2411 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 2412 entry->wiring_thread = NULL; 2413 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2414 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2415 need_wakeup = TRUE; 2416 } 2417 vm_map_simplify_entry(map, entry); 2418 } 2419 vm_map_unlock(map); 2420 if (need_wakeup) 2421 vm_map_wakeup(map); 2422 return (rv); 2423 } 2424 2425 /* 2426 * vm_map_wire: 2427 * 2428 * Implements both kernel and user wiring. 2429 */ 2430 int 2431 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2432 int flags) 2433 { 2434 vm_map_entry_t entry, first_entry, tmp_entry; 2435 vm_offset_t saved_end, saved_start; 2436 unsigned int last_timestamp; 2437 int rv; 2438 boolean_t fictitious, need_wakeup, result, user_wire; 2439 vm_prot_t prot; 2440 2441 if (start == end) 2442 return (KERN_SUCCESS); 2443 prot = 0; 2444 if (flags & VM_MAP_WIRE_WRITE) 2445 prot |= VM_PROT_WRITE; 2446 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2447 vm_map_lock(map); 2448 VM_MAP_RANGE_CHECK(map, start, end); 2449 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2450 if (flags & VM_MAP_WIRE_HOLESOK) 2451 first_entry = first_entry->next; 2452 else { 2453 vm_map_unlock(map); 2454 return (KERN_INVALID_ADDRESS); 2455 } 2456 } 2457 last_timestamp = map->timestamp; 2458 entry = first_entry; 2459 while (entry != &map->header && entry->start < end) { 2460 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2461 /* 2462 * We have not yet clipped the entry. 2463 */ 2464 saved_start = (start >= entry->start) ? start : 2465 entry->start; 2466 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2467 if (vm_map_unlock_and_wait(map, 0)) { 2468 /* 2469 * Allow interruption of user wiring? 2470 */ 2471 } 2472 vm_map_lock(map); 2473 if (last_timestamp + 1 != map->timestamp) { 2474 /* 2475 * Look again for the entry because the map was 2476 * modified while it was unlocked. 2477 * Specifically, the entry may have been 2478 * clipped, merged, or deleted. 2479 */ 2480 if (!vm_map_lookup_entry(map, saved_start, 2481 &tmp_entry)) { 2482 if (flags & VM_MAP_WIRE_HOLESOK) 2483 tmp_entry = tmp_entry->next; 2484 else { 2485 if (saved_start == start) { 2486 /* 2487 * first_entry has been deleted. 2488 */ 2489 vm_map_unlock(map); 2490 return (KERN_INVALID_ADDRESS); 2491 } 2492 end = saved_start; 2493 rv = KERN_INVALID_ADDRESS; 2494 goto done; 2495 } 2496 } 2497 if (entry == first_entry) 2498 first_entry = tmp_entry; 2499 else 2500 first_entry = NULL; 2501 entry = tmp_entry; 2502 } 2503 last_timestamp = map->timestamp; 2504 continue; 2505 } 2506 vm_map_clip_start(map, entry, start); 2507 vm_map_clip_end(map, entry, end); 2508 /* 2509 * Mark the entry in case the map lock is released. (See 2510 * above.) 2511 */ 2512 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2513 entry->wiring_thread == NULL, 2514 ("owned map entry %p", entry)); 2515 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2516 entry->wiring_thread = curthread; 2517 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 2518 || (entry->protection & prot) != prot) { 2519 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 2520 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { 2521 end = entry->end; 2522 rv = KERN_INVALID_ADDRESS; 2523 goto done; 2524 } 2525 goto next_entry; 2526 } 2527 if (entry->wired_count == 0) { 2528 entry->wired_count++; 2529 saved_start = entry->start; 2530 saved_end = entry->end; 2531 fictitious = entry->object.vm_object != NULL && 2532 (entry->object.vm_object->flags & 2533 OBJ_FICTITIOUS) != 0; 2534 /* 2535 * Release the map lock, relying on the in-transition 2536 * mark. Mark the map busy for fork. 2537 */ 2538 vm_map_busy(map); 2539 vm_map_unlock(map); 2540 rv = vm_fault_wire(map, saved_start, saved_end, 2541 fictitious); 2542 vm_map_lock(map); 2543 vm_map_unbusy(map); 2544 if (last_timestamp + 1 != map->timestamp) { 2545 /* 2546 * Look again for the entry because the map was 2547 * modified while it was unlocked. The entry 2548 * may have been clipped, but NOT merged or 2549 * deleted. 2550 */ 2551 result = vm_map_lookup_entry(map, saved_start, 2552 &tmp_entry); 2553 KASSERT(result, ("vm_map_wire: lookup failed")); 2554 if (entry == first_entry) 2555 first_entry = tmp_entry; 2556 else 2557 first_entry = NULL; 2558 entry = tmp_entry; 2559 while (entry->end < saved_end) { 2560 if (rv != KERN_SUCCESS) { 2561 KASSERT(entry->wired_count == 1, 2562 ("vm_map_wire: bad count")); 2563 entry->wired_count = -1; 2564 } 2565 entry = entry->next; 2566 } 2567 } 2568 last_timestamp = map->timestamp; 2569 if (rv != KERN_SUCCESS) { 2570 KASSERT(entry->wired_count == 1, 2571 ("vm_map_wire: bad count")); 2572 /* 2573 * Assign an out-of-range value to represent 2574 * the failure to wire this entry. 2575 */ 2576 entry->wired_count = -1; 2577 end = entry->end; 2578 goto done; 2579 } 2580 } else if (!user_wire || 2581 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2582 entry->wired_count++; 2583 } 2584 /* 2585 * Check the map for holes in the specified region. 2586 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2587 */ 2588 next_entry: 2589 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2590 (entry->end < end && (entry->next == &map->header || 2591 entry->next->start > entry->end))) { 2592 end = entry->end; 2593 rv = KERN_INVALID_ADDRESS; 2594 goto done; 2595 } 2596 entry = entry->next; 2597 } 2598 rv = KERN_SUCCESS; 2599 done: 2600 need_wakeup = FALSE; 2601 if (first_entry == NULL) { 2602 result = vm_map_lookup_entry(map, start, &first_entry); 2603 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2604 first_entry = first_entry->next; 2605 else 2606 KASSERT(result, ("vm_map_wire: lookup failed")); 2607 } 2608 for (entry = first_entry; entry != &map->header && entry->start < end; 2609 entry = entry->next) { 2610 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) 2611 goto next_entry_done; 2612 2613 /* 2614 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2615 * space in the unwired region could have been mapped 2616 * while the map lock was dropped for faulting in the 2617 * pages or draining MAP_ENTRY_IN_TRANSITION. 2618 * Moreover, another thread could be simultaneously 2619 * wiring this new mapping entry. Detect these cases 2620 * and skip any entries marked as in transition by us. 2621 */ 2622 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2623 entry->wiring_thread != curthread) { 2624 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2625 ("vm_map_wire: !HOLESOK and new/changed entry")); 2626 continue; 2627 } 2628 2629 if (rv == KERN_SUCCESS) { 2630 if (user_wire) 2631 entry->eflags |= MAP_ENTRY_USER_WIRED; 2632 } else if (entry->wired_count == -1) { 2633 /* 2634 * Wiring failed on this entry. Thus, unwiring is 2635 * unnecessary. 2636 */ 2637 entry->wired_count = 0; 2638 } else { 2639 if (!user_wire || 2640 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) 2641 entry->wired_count--; 2642 if (entry->wired_count == 0) { 2643 /* 2644 * Retain the map lock. 2645 */ 2646 vm_fault_unwire(map, entry->start, entry->end, 2647 entry->object.vm_object != NULL && 2648 (entry->object.vm_object->flags & 2649 OBJ_FICTITIOUS) != 0); 2650 } 2651 } 2652 next_entry_done: 2653 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2654 ("vm_map_wire: in-transition flag missing %p", entry)); 2655 KASSERT(entry->wiring_thread == curthread, 2656 ("vm_map_wire: alien wire %p", entry)); 2657 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 2658 MAP_ENTRY_WIRE_SKIPPED); 2659 entry->wiring_thread = NULL; 2660 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2661 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2662 need_wakeup = TRUE; 2663 } 2664 vm_map_simplify_entry(map, entry); 2665 } 2666 vm_map_unlock(map); 2667 if (need_wakeup) 2668 vm_map_wakeup(map); 2669 return (rv); 2670 } 2671 2672 /* 2673 * vm_map_sync 2674 * 2675 * Push any dirty cached pages in the address range to their pager. 2676 * If syncio is TRUE, dirty pages are written synchronously. 2677 * If invalidate is TRUE, any cached pages are freed as well. 2678 * 2679 * If the size of the region from start to end is zero, we are 2680 * supposed to flush all modified pages within the region containing 2681 * start. Unfortunately, a region can be split or coalesced with 2682 * neighboring regions, making it difficult to determine what the 2683 * original region was. Therefore, we approximate this requirement by 2684 * flushing the current region containing start. 2685 * 2686 * Returns an error if any part of the specified range is not mapped. 2687 */ 2688 int 2689 vm_map_sync( 2690 vm_map_t map, 2691 vm_offset_t start, 2692 vm_offset_t end, 2693 boolean_t syncio, 2694 boolean_t invalidate) 2695 { 2696 vm_map_entry_t current; 2697 vm_map_entry_t entry; 2698 vm_size_t size; 2699 vm_object_t object; 2700 vm_ooffset_t offset; 2701 unsigned int last_timestamp; 2702 boolean_t failed; 2703 2704 vm_map_lock_read(map); 2705 VM_MAP_RANGE_CHECK(map, start, end); 2706 if (!vm_map_lookup_entry(map, start, &entry)) { 2707 vm_map_unlock_read(map); 2708 return (KERN_INVALID_ADDRESS); 2709 } else if (start == end) { 2710 start = entry->start; 2711 end = entry->end; 2712 } 2713 /* 2714 * Make a first pass to check for user-wired memory and holes. 2715 */ 2716 for (current = entry; current != &map->header && current->start < end; 2717 current = current->next) { 2718 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 2719 vm_map_unlock_read(map); 2720 return (KERN_INVALID_ARGUMENT); 2721 } 2722 if (end > current->end && 2723 (current->next == &map->header || 2724 current->end != current->next->start)) { 2725 vm_map_unlock_read(map); 2726 return (KERN_INVALID_ADDRESS); 2727 } 2728 } 2729 2730 if (invalidate) 2731 pmap_remove(map->pmap, start, end); 2732 failed = FALSE; 2733 2734 /* 2735 * Make a second pass, cleaning/uncaching pages from the indicated 2736 * objects as we go. 2737 */ 2738 for (current = entry; current != &map->header && current->start < end;) { 2739 offset = current->offset + (start - current->start); 2740 size = (end <= current->end ? end : current->end) - start; 2741 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2742 vm_map_t smap; 2743 vm_map_entry_t tentry; 2744 vm_size_t tsize; 2745 2746 smap = current->object.sub_map; 2747 vm_map_lock_read(smap); 2748 (void) vm_map_lookup_entry(smap, offset, &tentry); 2749 tsize = tentry->end - offset; 2750 if (tsize < size) 2751 size = tsize; 2752 object = tentry->object.vm_object; 2753 offset = tentry->offset + (offset - tentry->start); 2754 vm_map_unlock_read(smap); 2755 } else { 2756 object = current->object.vm_object; 2757 } 2758 vm_object_reference(object); 2759 last_timestamp = map->timestamp; 2760 vm_map_unlock_read(map); 2761 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 2762 failed = TRUE; 2763 start += size; 2764 vm_object_deallocate(object); 2765 vm_map_lock_read(map); 2766 if (last_timestamp == map->timestamp || 2767 !vm_map_lookup_entry(map, start, ¤t)) 2768 current = current->next; 2769 } 2770 2771 vm_map_unlock_read(map); 2772 return (failed ? KERN_FAILURE : KERN_SUCCESS); 2773 } 2774 2775 /* 2776 * vm_map_entry_unwire: [ internal use only ] 2777 * 2778 * Make the region specified by this entry pageable. 2779 * 2780 * The map in question should be locked. 2781 * [This is the reason for this routine's existence.] 2782 */ 2783 static void 2784 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2785 { 2786 vm_fault_unwire(map, entry->start, entry->end, 2787 entry->object.vm_object != NULL && 2788 (entry->object.vm_object->flags & OBJ_FICTITIOUS) != 0); 2789 entry->wired_count = 0; 2790 } 2791 2792 static void 2793 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 2794 { 2795 2796 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 2797 vm_object_deallocate(entry->object.vm_object); 2798 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 2799 } 2800 2801 /* 2802 * vm_map_entry_delete: [ internal use only ] 2803 * 2804 * Deallocate the given entry from the target map. 2805 */ 2806 static void 2807 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2808 { 2809 vm_object_t object; 2810 vm_pindex_t offidxstart, offidxend, count, size1; 2811 vm_ooffset_t size; 2812 2813 vm_map_entry_unlink(map, entry); 2814 object = entry->object.vm_object; 2815 size = entry->end - entry->start; 2816 map->size -= size; 2817 2818 if (entry->cred != NULL) { 2819 swap_release_by_cred(size, entry->cred); 2820 crfree(entry->cred); 2821 } 2822 2823 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2824 (object != NULL)) { 2825 KASSERT(entry->cred == NULL || object->cred == NULL || 2826 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 2827 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 2828 count = OFF_TO_IDX(size); 2829 offidxstart = OFF_TO_IDX(entry->offset); 2830 offidxend = offidxstart + count; 2831 VM_OBJECT_WLOCK(object); 2832 if (object->ref_count != 1 && 2833 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2834 object == kernel_object || object == kmem_object)) { 2835 vm_object_collapse(object); 2836 2837 /* 2838 * The option OBJPR_NOTMAPPED can be passed here 2839 * because vm_map_delete() already performed 2840 * pmap_remove() on the only mapping to this range 2841 * of pages. 2842 */ 2843 vm_object_page_remove(object, offidxstart, offidxend, 2844 OBJPR_NOTMAPPED); 2845 if (object->type == OBJT_SWAP) 2846 swap_pager_freespace(object, offidxstart, count); 2847 if (offidxend >= object->size && 2848 offidxstart < object->size) { 2849 size1 = object->size; 2850 object->size = offidxstart; 2851 if (object->cred != NULL) { 2852 size1 -= object->size; 2853 KASSERT(object->charge >= ptoa(size1), 2854 ("vm_map_entry_delete: object->charge < 0")); 2855 swap_release_by_cred(ptoa(size1), object->cred); 2856 object->charge -= ptoa(size1); 2857 } 2858 } 2859 } 2860 VM_OBJECT_WUNLOCK(object); 2861 } else 2862 entry->object.vm_object = NULL; 2863 if (map->system_map) 2864 vm_map_entry_deallocate(entry, TRUE); 2865 else { 2866 entry->next = curthread->td_map_def_user; 2867 curthread->td_map_def_user = entry; 2868 } 2869 } 2870 2871 /* 2872 * vm_map_delete: [ internal use only ] 2873 * 2874 * Deallocates the given address range from the target 2875 * map. 2876 */ 2877 int 2878 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2879 { 2880 vm_map_entry_t entry; 2881 vm_map_entry_t first_entry; 2882 2883 VM_MAP_ASSERT_LOCKED(map); 2884 if (start == end) 2885 return (KERN_SUCCESS); 2886 2887 /* 2888 * Find the start of the region, and clip it 2889 */ 2890 if (!vm_map_lookup_entry(map, start, &first_entry)) 2891 entry = first_entry->next; 2892 else { 2893 entry = first_entry; 2894 vm_map_clip_start(map, entry, start); 2895 } 2896 2897 /* 2898 * Step through all entries in this region 2899 */ 2900 while ((entry != &map->header) && (entry->start < end)) { 2901 vm_map_entry_t next; 2902 2903 /* 2904 * Wait for wiring or unwiring of an entry to complete. 2905 * Also wait for any system wirings to disappear on 2906 * user maps. 2907 */ 2908 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 2909 (vm_map_pmap(map) != kernel_pmap && 2910 vm_map_entry_system_wired_count(entry) != 0)) { 2911 unsigned int last_timestamp; 2912 vm_offset_t saved_start; 2913 vm_map_entry_t tmp_entry; 2914 2915 saved_start = entry->start; 2916 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2917 last_timestamp = map->timestamp; 2918 (void) vm_map_unlock_and_wait(map, 0); 2919 vm_map_lock(map); 2920 if (last_timestamp + 1 != map->timestamp) { 2921 /* 2922 * Look again for the entry because the map was 2923 * modified while it was unlocked. 2924 * Specifically, the entry may have been 2925 * clipped, merged, or deleted. 2926 */ 2927 if (!vm_map_lookup_entry(map, saved_start, 2928 &tmp_entry)) 2929 entry = tmp_entry->next; 2930 else { 2931 entry = tmp_entry; 2932 vm_map_clip_start(map, entry, 2933 saved_start); 2934 } 2935 } 2936 continue; 2937 } 2938 vm_map_clip_end(map, entry, end); 2939 2940 next = entry->next; 2941 2942 /* 2943 * Unwire before removing addresses from the pmap; otherwise, 2944 * unwiring will put the entries back in the pmap. 2945 */ 2946 if (entry->wired_count != 0) { 2947 vm_map_entry_unwire(map, entry); 2948 } 2949 2950 pmap_remove(map->pmap, entry->start, entry->end); 2951 2952 /* 2953 * Delete the entry only after removing all pmap 2954 * entries pointing to its pages. (Otherwise, its 2955 * page frames may be reallocated, and any modify bits 2956 * will be set in the wrong object!) 2957 */ 2958 vm_map_entry_delete(map, entry); 2959 entry = next; 2960 } 2961 return (KERN_SUCCESS); 2962 } 2963 2964 /* 2965 * vm_map_remove: 2966 * 2967 * Remove the given address range from the target map. 2968 * This is the exported form of vm_map_delete. 2969 */ 2970 int 2971 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2972 { 2973 int result; 2974 2975 vm_map_lock(map); 2976 VM_MAP_RANGE_CHECK(map, start, end); 2977 result = vm_map_delete(map, start, end); 2978 vm_map_unlock(map); 2979 return (result); 2980 } 2981 2982 /* 2983 * vm_map_check_protection: 2984 * 2985 * Assert that the target map allows the specified privilege on the 2986 * entire address region given. The entire region must be allocated. 2987 * 2988 * WARNING! This code does not and should not check whether the 2989 * contents of the region is accessible. For example a smaller file 2990 * might be mapped into a larger address space. 2991 * 2992 * NOTE! This code is also called by munmap(). 2993 * 2994 * The map must be locked. A read lock is sufficient. 2995 */ 2996 boolean_t 2997 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2998 vm_prot_t protection) 2999 { 3000 vm_map_entry_t entry; 3001 vm_map_entry_t tmp_entry; 3002 3003 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 3004 return (FALSE); 3005 entry = tmp_entry; 3006 3007 while (start < end) { 3008 if (entry == &map->header) 3009 return (FALSE); 3010 /* 3011 * No holes allowed! 3012 */ 3013 if (start < entry->start) 3014 return (FALSE); 3015 /* 3016 * Check protection associated with entry. 3017 */ 3018 if ((entry->protection & protection) != protection) 3019 return (FALSE); 3020 /* go to next entry */ 3021 start = entry->end; 3022 entry = entry->next; 3023 } 3024 return (TRUE); 3025 } 3026 3027 /* 3028 * vm_map_copy_entry: 3029 * 3030 * Copies the contents of the source entry to the destination 3031 * entry. The entries *must* be aligned properly. 3032 */ 3033 static void 3034 vm_map_copy_entry( 3035 vm_map_t src_map, 3036 vm_map_t dst_map, 3037 vm_map_entry_t src_entry, 3038 vm_map_entry_t dst_entry, 3039 vm_ooffset_t *fork_charge) 3040 { 3041 vm_object_t src_object; 3042 vm_map_entry_t fake_entry; 3043 vm_offset_t size; 3044 struct ucred *cred; 3045 int charged; 3046 3047 VM_MAP_ASSERT_LOCKED(dst_map); 3048 3049 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3050 return; 3051 3052 if (src_entry->wired_count == 0 || 3053 (src_entry->protection & VM_PROT_WRITE) == 0) { 3054 /* 3055 * If the source entry is marked needs_copy, it is already 3056 * write-protected. 3057 */ 3058 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && 3059 (src_entry->protection & VM_PROT_WRITE) != 0) { 3060 pmap_protect(src_map->pmap, 3061 src_entry->start, 3062 src_entry->end, 3063 src_entry->protection & ~VM_PROT_WRITE); 3064 } 3065 3066 /* 3067 * Make a copy of the object. 3068 */ 3069 size = src_entry->end - src_entry->start; 3070 if ((src_object = src_entry->object.vm_object) != NULL) { 3071 VM_OBJECT_WLOCK(src_object); 3072 charged = ENTRY_CHARGED(src_entry); 3073 if ((src_object->handle == NULL) && 3074 (src_object->type == OBJT_DEFAULT || 3075 src_object->type == OBJT_SWAP)) { 3076 vm_object_collapse(src_object); 3077 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 3078 vm_object_split(src_entry); 3079 src_object = src_entry->object.vm_object; 3080 } 3081 } 3082 vm_object_reference_locked(src_object); 3083 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3084 if (src_entry->cred != NULL && 3085 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3086 KASSERT(src_object->cred == NULL, 3087 ("OVERCOMMIT: vm_map_copy_entry: cred %p", 3088 src_object)); 3089 src_object->cred = src_entry->cred; 3090 src_object->charge = size; 3091 } 3092 VM_OBJECT_WUNLOCK(src_object); 3093 dst_entry->object.vm_object = src_object; 3094 if (charged) { 3095 cred = curthread->td_ucred; 3096 crhold(cred); 3097 dst_entry->cred = cred; 3098 *fork_charge += size; 3099 if (!(src_entry->eflags & 3100 MAP_ENTRY_NEEDS_COPY)) { 3101 crhold(cred); 3102 src_entry->cred = cred; 3103 *fork_charge += size; 3104 } 3105 } 3106 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3107 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3108 dst_entry->offset = src_entry->offset; 3109 if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3110 /* 3111 * MAP_ENTRY_VN_WRITECNT cannot 3112 * indicate write reference from 3113 * src_entry, since the entry is 3114 * marked as needs copy. Allocate a 3115 * fake entry that is used to 3116 * decrement object->un_pager.vnp.writecount 3117 * at the appropriate time. Attach 3118 * fake_entry to the deferred list. 3119 */ 3120 fake_entry = vm_map_entry_create(dst_map); 3121 fake_entry->eflags = MAP_ENTRY_VN_WRITECNT; 3122 src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT; 3123 vm_object_reference(src_object); 3124 fake_entry->object.vm_object = src_object; 3125 fake_entry->start = src_entry->start; 3126 fake_entry->end = src_entry->end; 3127 fake_entry->next = curthread->td_map_def_user; 3128 curthread->td_map_def_user = fake_entry; 3129 } 3130 } else { 3131 dst_entry->object.vm_object = NULL; 3132 dst_entry->offset = 0; 3133 if (src_entry->cred != NULL) { 3134 dst_entry->cred = curthread->td_ucred; 3135 crhold(dst_entry->cred); 3136 *fork_charge += size; 3137 } 3138 } 3139 3140 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3141 dst_entry->end - dst_entry->start, src_entry->start); 3142 } else { 3143 /* 3144 * We don't want to make writeable wired pages copy-on-write. 3145 * Immediately copy these pages into the new map by simulating 3146 * page faults. The new pages are pageable. 3147 */ 3148 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 3149 fork_charge); 3150 } 3151 } 3152 3153 /* 3154 * vmspace_map_entry_forked: 3155 * Update the newly-forked vmspace each time a map entry is inherited 3156 * or copied. The values for vm_dsize and vm_tsize are approximate 3157 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 3158 */ 3159 static void 3160 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 3161 vm_map_entry_t entry) 3162 { 3163 vm_size_t entrysize; 3164 vm_offset_t newend; 3165 3166 entrysize = entry->end - entry->start; 3167 vm2->vm_map.size += entrysize; 3168 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 3169 vm2->vm_ssize += btoc(entrysize); 3170 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 3171 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 3172 newend = MIN(entry->end, 3173 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 3174 vm2->vm_dsize += btoc(newend - entry->start); 3175 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 3176 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 3177 newend = MIN(entry->end, 3178 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 3179 vm2->vm_tsize += btoc(newend - entry->start); 3180 } 3181 } 3182 3183 /* 3184 * vmspace_fork: 3185 * Create a new process vmspace structure and vm_map 3186 * based on those of an existing process. The new map 3187 * is based on the old map, according to the inheritance 3188 * values on the regions in that map. 3189 * 3190 * XXX It might be worth coalescing the entries added to the new vmspace. 3191 * 3192 * The source map must not be locked. 3193 */ 3194 struct vmspace * 3195 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 3196 { 3197 struct vmspace *vm2; 3198 vm_map_t new_map, old_map; 3199 vm_map_entry_t new_entry, old_entry; 3200 vm_object_t object; 3201 int locked; 3202 3203 old_map = &vm1->vm_map; 3204 /* Copy immutable fields of vm1 to vm2. */ 3205 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL); 3206 if (vm2 == NULL) 3207 return (NULL); 3208 vm2->vm_taddr = vm1->vm_taddr; 3209 vm2->vm_daddr = vm1->vm_daddr; 3210 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 3211 vm_map_lock(old_map); 3212 if (old_map->busy) 3213 vm_map_wait_busy(old_map); 3214 new_map = &vm2->vm_map; 3215 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 3216 KASSERT(locked, ("vmspace_fork: lock failed")); 3217 3218 old_entry = old_map->header.next; 3219 3220 while (old_entry != &old_map->header) { 3221 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 3222 panic("vm_map_fork: encountered a submap"); 3223 3224 switch (old_entry->inheritance) { 3225 case VM_INHERIT_NONE: 3226 break; 3227 3228 case VM_INHERIT_SHARE: 3229 /* 3230 * Clone the entry, creating the shared object if necessary. 3231 */ 3232 object = old_entry->object.vm_object; 3233 if (object == NULL) { 3234 object = vm_object_allocate(OBJT_DEFAULT, 3235 atop(old_entry->end - old_entry->start)); 3236 old_entry->object.vm_object = object; 3237 old_entry->offset = 0; 3238 if (old_entry->cred != NULL) { 3239 object->cred = old_entry->cred; 3240 object->charge = old_entry->end - 3241 old_entry->start; 3242 old_entry->cred = NULL; 3243 } 3244 } 3245 3246 /* 3247 * Add the reference before calling vm_object_shadow 3248 * to insure that a shadow object is created. 3249 */ 3250 vm_object_reference(object); 3251 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3252 vm_object_shadow(&old_entry->object.vm_object, 3253 &old_entry->offset, 3254 old_entry->end - old_entry->start); 3255 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3256 /* Transfer the second reference too. */ 3257 vm_object_reference( 3258 old_entry->object.vm_object); 3259 3260 /* 3261 * As in vm_map_simplify_entry(), the 3262 * vnode lock will not be acquired in 3263 * this call to vm_object_deallocate(). 3264 */ 3265 vm_object_deallocate(object); 3266 object = old_entry->object.vm_object; 3267 } 3268 VM_OBJECT_WLOCK(object); 3269 vm_object_clear_flag(object, OBJ_ONEMAPPING); 3270 if (old_entry->cred != NULL) { 3271 KASSERT(object->cred == NULL, ("vmspace_fork both cred")); 3272 object->cred = old_entry->cred; 3273 object->charge = old_entry->end - old_entry->start; 3274 old_entry->cred = NULL; 3275 } 3276 3277 /* 3278 * Assert the correct state of the vnode 3279 * v_writecount while the object is locked, to 3280 * not relock it later for the assertion 3281 * correctness. 3282 */ 3283 if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT && 3284 object->type == OBJT_VNODE) { 3285 KASSERT(((struct vnode *)object->handle)-> 3286 v_writecount > 0, 3287 ("vmspace_fork: v_writecount %p", object)); 3288 KASSERT(object->un_pager.vnp.writemappings > 0, 3289 ("vmspace_fork: vnp.writecount %p", 3290 object)); 3291 } 3292 VM_OBJECT_WUNLOCK(object); 3293 3294 /* 3295 * Clone the entry, referencing the shared object. 3296 */ 3297 new_entry = vm_map_entry_create(new_map); 3298 *new_entry = *old_entry; 3299 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3300 MAP_ENTRY_IN_TRANSITION); 3301 new_entry->wiring_thread = NULL; 3302 new_entry->wired_count = 0; 3303 if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3304 vnode_pager_update_writecount(object, 3305 new_entry->start, new_entry->end); 3306 } 3307 3308 /* 3309 * Insert the entry into the new map -- we know we're 3310 * inserting at the end of the new map. 3311 */ 3312 vm_map_entry_link(new_map, new_map->header.prev, 3313 new_entry); 3314 vmspace_map_entry_forked(vm1, vm2, new_entry); 3315 3316 /* 3317 * Update the physical map 3318 */ 3319 pmap_copy(new_map->pmap, old_map->pmap, 3320 new_entry->start, 3321 (old_entry->end - old_entry->start), 3322 old_entry->start); 3323 break; 3324 3325 case VM_INHERIT_COPY: 3326 /* 3327 * Clone the entry and link into the map. 3328 */ 3329 new_entry = vm_map_entry_create(new_map); 3330 *new_entry = *old_entry; 3331 /* 3332 * Copied entry is COW over the old object. 3333 */ 3334 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3335 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT); 3336 new_entry->wiring_thread = NULL; 3337 new_entry->wired_count = 0; 3338 new_entry->object.vm_object = NULL; 3339 new_entry->cred = NULL; 3340 vm_map_entry_link(new_map, new_map->header.prev, 3341 new_entry); 3342 vmspace_map_entry_forked(vm1, vm2, new_entry); 3343 vm_map_copy_entry(old_map, new_map, old_entry, 3344 new_entry, fork_charge); 3345 break; 3346 } 3347 old_entry = old_entry->next; 3348 } 3349 /* 3350 * Use inlined vm_map_unlock() to postpone handling the deferred 3351 * map entries, which cannot be done until both old_map and 3352 * new_map locks are released. 3353 */ 3354 sx_xunlock(&old_map->lock); 3355 sx_xunlock(&new_map->lock); 3356 vm_map_process_deferred(); 3357 3358 return (vm2); 3359 } 3360 3361 int 3362 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3363 vm_prot_t prot, vm_prot_t max, int cow) 3364 { 3365 vm_size_t growsize, init_ssize; 3366 rlim_t lmemlim, vmemlim; 3367 int rv; 3368 3369 growsize = sgrowsiz; 3370 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3371 vm_map_lock(map); 3372 PROC_LOCK(curproc); 3373 lmemlim = lim_cur(curproc, RLIMIT_MEMLOCK); 3374 vmemlim = lim_cur(curproc, RLIMIT_VMEM); 3375 PROC_UNLOCK(curproc); 3376 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3377 if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) { 3378 rv = KERN_NO_SPACE; 3379 goto out; 3380 } 3381 } 3382 /* If we would blow our VMEM resource limit, no go */ 3383 if (map->size + init_ssize > vmemlim) { 3384 rv = KERN_NO_SPACE; 3385 goto out; 3386 } 3387 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, 3388 max, cow); 3389 out: 3390 vm_map_unlock(map); 3391 return (rv); 3392 } 3393 3394 static int 3395 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3396 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) 3397 { 3398 vm_map_entry_t new_entry, prev_entry; 3399 vm_offset_t bot, top; 3400 vm_size_t init_ssize; 3401 int orient, rv; 3402 3403 /* 3404 * The stack orientation is piggybacked with the cow argument. 3405 * Extract it into orient and mask the cow argument so that we 3406 * don't pass it around further. 3407 * NOTE: We explicitly allow bi-directional stacks. 3408 */ 3409 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 3410 KASSERT(orient != 0, ("No stack grow direction")); 3411 3412 if (addrbos < vm_map_min(map) || 3413 addrbos > vm_map_max(map) || 3414 addrbos + max_ssize < addrbos) 3415 return (KERN_NO_SPACE); 3416 3417 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3418 3419 /* If addr is already mapped, no go */ 3420 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) 3421 return (KERN_NO_SPACE); 3422 3423 /* 3424 * If we can't accomodate max_ssize in the current mapping, no go. 3425 * However, we need to be aware that subsequent user mappings might 3426 * map into the space we have reserved for stack, and currently this 3427 * space is not protected. 3428 * 3429 * Hopefully we will at least detect this condition when we try to 3430 * grow the stack. 3431 */ 3432 if ((prev_entry->next != &map->header) && 3433 (prev_entry->next->start < addrbos + max_ssize)) 3434 return (KERN_NO_SPACE); 3435 3436 /* 3437 * We initially map a stack of only init_ssize. We will grow as 3438 * needed later. Depending on the orientation of the stack (i.e. 3439 * the grow direction) we either map at the top of the range, the 3440 * bottom of the range or in the middle. 3441 * 3442 * Note: we would normally expect prot and max to be VM_PROT_ALL, 3443 * and cow to be 0. Possibly we should eliminate these as input 3444 * parameters, and just pass these values here in the insert call. 3445 */ 3446 if (orient == MAP_STACK_GROWS_DOWN) 3447 bot = addrbos + max_ssize - init_ssize; 3448 else if (orient == MAP_STACK_GROWS_UP) 3449 bot = addrbos; 3450 else 3451 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 3452 top = bot + init_ssize; 3453 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 3454 3455 /* Now set the avail_ssize amount. */ 3456 if (rv == KERN_SUCCESS) { 3457 new_entry = prev_entry->next; 3458 if (new_entry->end != top || new_entry->start != bot) 3459 panic("Bad entry start/end for new stack entry"); 3460 3461 new_entry->avail_ssize = max_ssize - init_ssize; 3462 KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 || 3463 (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0, 3464 ("new entry lacks MAP_ENTRY_GROWS_DOWN")); 3465 KASSERT((orient & MAP_STACK_GROWS_UP) == 0 || 3466 (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0, 3467 ("new entry lacks MAP_ENTRY_GROWS_UP")); 3468 } 3469 3470 return (rv); 3471 } 3472 3473 static int stack_guard_page = 0; 3474 TUNABLE_INT("security.bsd.stack_guard_page", &stack_guard_page); 3475 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RW, 3476 &stack_guard_page, 0, 3477 "Insert stack guard page ahead of the growable segments."); 3478 3479 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3480 * desired address is already mapped, or if we successfully grow 3481 * the stack. Also returns KERN_SUCCESS if addr is outside the 3482 * stack range (this is strange, but preserves compatibility with 3483 * the grow function in vm_machdep.c). 3484 */ 3485 int 3486 vm_map_growstack(struct proc *p, vm_offset_t addr) 3487 { 3488 vm_map_entry_t next_entry, prev_entry; 3489 vm_map_entry_t new_entry, stack_entry; 3490 struct vmspace *vm = p->p_vmspace; 3491 vm_map_t map = &vm->vm_map; 3492 vm_offset_t end; 3493 vm_size_t growsize; 3494 size_t grow_amount, max_grow; 3495 rlim_t lmemlim, stacklim, vmemlim; 3496 int is_procstack, rv; 3497 struct ucred *cred; 3498 #ifdef notyet 3499 uint64_t limit; 3500 #endif 3501 #ifdef RACCT 3502 int error; 3503 #endif 3504 3505 Retry: 3506 PROC_LOCK(p); 3507 lmemlim = lim_cur(p, RLIMIT_MEMLOCK); 3508 stacklim = lim_cur(p, RLIMIT_STACK); 3509 vmemlim = lim_cur(p, RLIMIT_VMEM); 3510 PROC_UNLOCK(p); 3511 3512 vm_map_lock_read(map); 3513 3514 /* If addr is already in the entry range, no need to grow.*/ 3515 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 3516 vm_map_unlock_read(map); 3517 return (KERN_SUCCESS); 3518 } 3519 3520 next_entry = prev_entry->next; 3521 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 3522 /* 3523 * This entry does not grow upwards. Since the address lies 3524 * beyond this entry, the next entry (if one exists) has to 3525 * be a downward growable entry. The entry list header is 3526 * never a growable entry, so it suffices to check the flags. 3527 */ 3528 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 3529 vm_map_unlock_read(map); 3530 return (KERN_SUCCESS); 3531 } 3532 stack_entry = next_entry; 3533 } else { 3534 /* 3535 * This entry grows upward. If the next entry does not at 3536 * least grow downwards, this is the entry we need to grow. 3537 * otherwise we have two possible choices and we have to 3538 * select one. 3539 */ 3540 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 3541 /* 3542 * We have two choices; grow the entry closest to 3543 * the address to minimize the amount of growth. 3544 */ 3545 if (addr - prev_entry->end <= next_entry->start - addr) 3546 stack_entry = prev_entry; 3547 else 3548 stack_entry = next_entry; 3549 } else 3550 stack_entry = prev_entry; 3551 } 3552 3553 if (stack_entry == next_entry) { 3554 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 3555 KASSERT(addr < stack_entry->start, ("foo")); 3556 end = (prev_entry != &map->header) ? prev_entry->end : 3557 stack_entry->start - stack_entry->avail_ssize; 3558 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 3559 max_grow = stack_entry->start - end; 3560 } else { 3561 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 3562 KASSERT(addr >= stack_entry->end, ("foo")); 3563 end = (next_entry != &map->header) ? next_entry->start : 3564 stack_entry->end + stack_entry->avail_ssize; 3565 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 3566 max_grow = end - stack_entry->end; 3567 } 3568 3569 if (grow_amount > stack_entry->avail_ssize) { 3570 vm_map_unlock_read(map); 3571 return (KERN_NO_SPACE); 3572 } 3573 3574 /* 3575 * If there is no longer enough space between the entries nogo, and 3576 * adjust the available space. Note: this should only happen if the 3577 * user has mapped into the stack area after the stack was created, 3578 * and is probably an error. 3579 * 3580 * This also effectively destroys any guard page the user might have 3581 * intended by limiting the stack size. 3582 */ 3583 if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) { 3584 if (vm_map_lock_upgrade(map)) 3585 goto Retry; 3586 3587 stack_entry->avail_ssize = max_grow; 3588 3589 vm_map_unlock(map); 3590 return (KERN_NO_SPACE); 3591 } 3592 3593 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 3594 3595 /* 3596 * If this is the main process stack, see if we're over the stack 3597 * limit. 3598 */ 3599 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3600 vm_map_unlock_read(map); 3601 return (KERN_NO_SPACE); 3602 } 3603 #ifdef RACCT 3604 PROC_LOCK(p); 3605 if (is_procstack && 3606 racct_set(p, RACCT_STACK, ctob(vm->vm_ssize) + grow_amount)) { 3607 PROC_UNLOCK(p); 3608 vm_map_unlock_read(map); 3609 return (KERN_NO_SPACE); 3610 } 3611 PROC_UNLOCK(p); 3612 #endif 3613 3614 /* Round up the grow amount modulo sgrowsiz */ 3615 growsize = sgrowsiz; 3616 grow_amount = roundup(grow_amount, growsize); 3617 if (grow_amount > stack_entry->avail_ssize) 3618 grow_amount = stack_entry->avail_ssize; 3619 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3620 grow_amount = trunc_page((vm_size_t)stacklim) - 3621 ctob(vm->vm_ssize); 3622 } 3623 #ifdef notyet 3624 PROC_LOCK(p); 3625 limit = racct_get_available(p, RACCT_STACK); 3626 PROC_UNLOCK(p); 3627 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 3628 grow_amount = limit - ctob(vm->vm_ssize); 3629 #endif 3630 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3631 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 3632 vm_map_unlock_read(map); 3633 rv = KERN_NO_SPACE; 3634 goto out; 3635 } 3636 #ifdef RACCT 3637 PROC_LOCK(p); 3638 if (racct_set(p, RACCT_MEMLOCK, 3639 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 3640 PROC_UNLOCK(p); 3641 vm_map_unlock_read(map); 3642 rv = KERN_NO_SPACE; 3643 goto out; 3644 } 3645 PROC_UNLOCK(p); 3646 #endif 3647 } 3648 /* If we would blow our VMEM resource limit, no go */ 3649 if (map->size + grow_amount > vmemlim) { 3650 vm_map_unlock_read(map); 3651 rv = KERN_NO_SPACE; 3652 goto out; 3653 } 3654 #ifdef RACCT 3655 PROC_LOCK(p); 3656 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 3657 PROC_UNLOCK(p); 3658 vm_map_unlock_read(map); 3659 rv = KERN_NO_SPACE; 3660 goto out; 3661 } 3662 PROC_UNLOCK(p); 3663 #endif 3664 3665 if (vm_map_lock_upgrade(map)) 3666 goto Retry; 3667 3668 if (stack_entry == next_entry) { 3669 /* 3670 * Growing downward. 3671 */ 3672 /* Get the preliminary new entry start value */ 3673 addr = stack_entry->start - grow_amount; 3674 3675 /* 3676 * If this puts us into the previous entry, cut back our 3677 * growth to the available space. Also, see the note above. 3678 */ 3679 if (addr < end) { 3680 stack_entry->avail_ssize = max_grow; 3681 addr = end; 3682 if (stack_guard_page) 3683 addr += PAGE_SIZE; 3684 } 3685 3686 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 3687 next_entry->protection, next_entry->max_protection, 3688 MAP_STACK_GROWS_DOWN); 3689 3690 /* Adjust the available stack space by the amount we grew. */ 3691 if (rv == KERN_SUCCESS) { 3692 new_entry = prev_entry->next; 3693 KASSERT(new_entry == stack_entry->prev, ("foo")); 3694 KASSERT(new_entry->end == stack_entry->start, ("foo")); 3695 KASSERT(new_entry->start == addr, ("foo")); 3696 KASSERT((new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 3697 0, ("new entry lacks MAP_ENTRY_GROWS_DOWN")); 3698 grow_amount = new_entry->end - new_entry->start; 3699 new_entry->avail_ssize = stack_entry->avail_ssize - 3700 grow_amount; 3701 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 3702 } 3703 } else { 3704 /* 3705 * Growing upward. 3706 */ 3707 addr = stack_entry->end + grow_amount; 3708 3709 /* 3710 * If this puts us into the next entry, cut back our growth 3711 * to the available space. Also, see the note above. 3712 */ 3713 if (addr > end) { 3714 stack_entry->avail_ssize = end - stack_entry->end; 3715 addr = end; 3716 if (stack_guard_page) 3717 addr -= PAGE_SIZE; 3718 } 3719 3720 grow_amount = addr - stack_entry->end; 3721 cred = stack_entry->cred; 3722 if (cred == NULL && stack_entry->object.vm_object != NULL) 3723 cred = stack_entry->object.vm_object->cred; 3724 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 3725 rv = KERN_NO_SPACE; 3726 /* Grow the underlying object if applicable. */ 3727 else if (stack_entry->object.vm_object == NULL || 3728 vm_object_coalesce(stack_entry->object.vm_object, 3729 stack_entry->offset, 3730 (vm_size_t)(stack_entry->end - stack_entry->start), 3731 (vm_size_t)grow_amount, cred != NULL)) { 3732 map->size += (addr - stack_entry->end); 3733 /* Update the current entry. */ 3734 stack_entry->end = addr; 3735 stack_entry->avail_ssize -= grow_amount; 3736 vm_map_entry_resize_free(map, stack_entry); 3737 rv = KERN_SUCCESS; 3738 } else 3739 rv = KERN_FAILURE; 3740 } 3741 3742 if (rv == KERN_SUCCESS && is_procstack) 3743 vm->vm_ssize += btoc(grow_amount); 3744 3745 vm_map_unlock(map); 3746 3747 /* 3748 * Heed the MAP_WIREFUTURE flag if it was set for this process. 3749 */ 3750 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 3751 vm_map_wire(map, 3752 (stack_entry == next_entry) ? addr : addr - grow_amount, 3753 (stack_entry == next_entry) ? stack_entry->start : addr, 3754 (p->p_flag & P_SYSTEM) 3755 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 3756 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 3757 } 3758 3759 out: 3760 #ifdef RACCT 3761 if (rv != KERN_SUCCESS) { 3762 PROC_LOCK(p); 3763 error = racct_set(p, RACCT_VMEM, map->size); 3764 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 3765 if (!old_mlock) { 3766 error = racct_set(p, RACCT_MEMLOCK, 3767 ptoa(pmap_wired_count(map->pmap))); 3768 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 3769 } 3770 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 3771 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 3772 PROC_UNLOCK(p); 3773 } 3774 #endif 3775 3776 return (rv); 3777 } 3778 3779 /* 3780 * Unshare the specified VM space for exec. If other processes are 3781 * mapped to it, then create a new one. The new vmspace is null. 3782 */ 3783 int 3784 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 3785 { 3786 struct vmspace *oldvmspace = p->p_vmspace; 3787 struct vmspace *newvmspace; 3788 3789 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 3790 ("vmspace_exec recursed")); 3791 newvmspace = vmspace_alloc(minuser, maxuser, NULL); 3792 if (newvmspace == NULL) 3793 return (ENOMEM); 3794 newvmspace->vm_swrss = oldvmspace->vm_swrss; 3795 /* 3796 * This code is written like this for prototype purposes. The 3797 * goal is to avoid running down the vmspace here, but let the 3798 * other process's that are still using the vmspace to finally 3799 * run it down. Even though there is little or no chance of blocking 3800 * here, it is a good idea to keep this form for future mods. 3801 */ 3802 PROC_VMSPACE_LOCK(p); 3803 p->p_vmspace = newvmspace; 3804 PROC_VMSPACE_UNLOCK(p); 3805 if (p == curthread->td_proc) 3806 pmap_activate(curthread); 3807 curthread->td_pflags |= TDP_EXECVMSPC; 3808 return (0); 3809 } 3810 3811 /* 3812 * Unshare the specified VM space for forcing COW. This 3813 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3814 */ 3815 int 3816 vmspace_unshare(struct proc *p) 3817 { 3818 struct vmspace *oldvmspace = p->p_vmspace; 3819 struct vmspace *newvmspace; 3820 vm_ooffset_t fork_charge; 3821 3822 if (oldvmspace->vm_refcnt == 1) 3823 return (0); 3824 fork_charge = 0; 3825 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 3826 if (newvmspace == NULL) 3827 return (ENOMEM); 3828 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 3829 vmspace_free(newvmspace); 3830 return (ENOMEM); 3831 } 3832 PROC_VMSPACE_LOCK(p); 3833 p->p_vmspace = newvmspace; 3834 PROC_VMSPACE_UNLOCK(p); 3835 if (p == curthread->td_proc) 3836 pmap_activate(curthread); 3837 vmspace_free(oldvmspace); 3838 return (0); 3839 } 3840 3841 /* 3842 * vm_map_lookup: 3843 * 3844 * Finds the VM object, offset, and 3845 * protection for a given virtual address in the 3846 * specified map, assuming a page fault of the 3847 * type specified. 3848 * 3849 * Leaves the map in question locked for read; return 3850 * values are guaranteed until a vm_map_lookup_done 3851 * call is performed. Note that the map argument 3852 * is in/out; the returned map must be used in 3853 * the call to vm_map_lookup_done. 3854 * 3855 * A handle (out_entry) is returned for use in 3856 * vm_map_lookup_done, to make that fast. 3857 * 3858 * If a lookup is requested with "write protection" 3859 * specified, the map may be changed to perform virtual 3860 * copying operations, although the data referenced will 3861 * remain the same. 3862 */ 3863 int 3864 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3865 vm_offset_t vaddr, 3866 vm_prot_t fault_typea, 3867 vm_map_entry_t *out_entry, /* OUT */ 3868 vm_object_t *object, /* OUT */ 3869 vm_pindex_t *pindex, /* OUT */ 3870 vm_prot_t *out_prot, /* OUT */ 3871 boolean_t *wired) /* OUT */ 3872 { 3873 vm_map_entry_t entry; 3874 vm_map_t map = *var_map; 3875 vm_prot_t prot; 3876 vm_prot_t fault_type = fault_typea; 3877 vm_object_t eobject; 3878 vm_size_t size; 3879 struct ucred *cred; 3880 3881 RetryLookup:; 3882 3883 vm_map_lock_read(map); 3884 3885 /* 3886 * Lookup the faulting address. 3887 */ 3888 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 3889 vm_map_unlock_read(map); 3890 return (KERN_INVALID_ADDRESS); 3891 } 3892 3893 entry = *out_entry; 3894 3895 /* 3896 * Handle submaps. 3897 */ 3898 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3899 vm_map_t old_map = map; 3900 3901 *var_map = map = entry->object.sub_map; 3902 vm_map_unlock_read(old_map); 3903 goto RetryLookup; 3904 } 3905 3906 /* 3907 * Check whether this task is allowed to have this page. 3908 */ 3909 prot = entry->protection; 3910 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3911 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 3912 vm_map_unlock_read(map); 3913 return (KERN_PROTECTION_FAILURE); 3914 } 3915 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3916 (entry->eflags & MAP_ENTRY_COW) && 3917 (fault_type & VM_PROT_WRITE)) { 3918 vm_map_unlock_read(map); 3919 return (KERN_PROTECTION_FAILURE); 3920 } 3921 if ((fault_typea & VM_PROT_COPY) != 0 && 3922 (entry->max_protection & VM_PROT_WRITE) == 0 && 3923 (entry->eflags & MAP_ENTRY_COW) == 0) { 3924 vm_map_unlock_read(map); 3925 return (KERN_PROTECTION_FAILURE); 3926 } 3927 3928 /* 3929 * If this page is not pageable, we have to get it for all possible 3930 * accesses. 3931 */ 3932 *wired = (entry->wired_count != 0); 3933 if (*wired) 3934 fault_type = entry->protection; 3935 size = entry->end - entry->start; 3936 /* 3937 * If the entry was copy-on-write, we either ... 3938 */ 3939 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3940 /* 3941 * If we want to write the page, we may as well handle that 3942 * now since we've got the map locked. 3943 * 3944 * If we don't need to write the page, we just demote the 3945 * permissions allowed. 3946 */ 3947 if ((fault_type & VM_PROT_WRITE) != 0 || 3948 (fault_typea & VM_PROT_COPY) != 0) { 3949 /* 3950 * Make a new object, and place it in the object 3951 * chain. Note that no new references have appeared 3952 * -- one just moved from the map to the new 3953 * object. 3954 */ 3955 if (vm_map_lock_upgrade(map)) 3956 goto RetryLookup; 3957 3958 if (entry->cred == NULL) { 3959 /* 3960 * The debugger owner is charged for 3961 * the memory. 3962 */ 3963 cred = curthread->td_ucred; 3964 crhold(cred); 3965 if (!swap_reserve_by_cred(size, cred)) { 3966 crfree(cred); 3967 vm_map_unlock(map); 3968 return (KERN_RESOURCE_SHORTAGE); 3969 } 3970 entry->cred = cred; 3971 } 3972 vm_object_shadow(&entry->object.vm_object, 3973 &entry->offset, size); 3974 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3975 eobject = entry->object.vm_object; 3976 if (eobject->cred != NULL) { 3977 /* 3978 * The object was not shadowed. 3979 */ 3980 swap_release_by_cred(size, entry->cred); 3981 crfree(entry->cred); 3982 entry->cred = NULL; 3983 } else if (entry->cred != NULL) { 3984 VM_OBJECT_WLOCK(eobject); 3985 eobject->cred = entry->cred; 3986 eobject->charge = size; 3987 VM_OBJECT_WUNLOCK(eobject); 3988 entry->cred = NULL; 3989 } 3990 3991 vm_map_lock_downgrade(map); 3992 } else { 3993 /* 3994 * We're attempting to read a copy-on-write page -- 3995 * don't allow writes. 3996 */ 3997 prot &= ~VM_PROT_WRITE; 3998 } 3999 } 4000 4001 /* 4002 * Create an object if necessary. 4003 */ 4004 if (entry->object.vm_object == NULL && 4005 !map->system_map) { 4006 if (vm_map_lock_upgrade(map)) 4007 goto RetryLookup; 4008 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 4009 atop(size)); 4010 entry->offset = 0; 4011 if (entry->cred != NULL) { 4012 VM_OBJECT_WLOCK(entry->object.vm_object); 4013 entry->object.vm_object->cred = entry->cred; 4014 entry->object.vm_object->charge = size; 4015 VM_OBJECT_WUNLOCK(entry->object.vm_object); 4016 entry->cred = NULL; 4017 } 4018 vm_map_lock_downgrade(map); 4019 } 4020 4021 /* 4022 * Return the object/offset from this entry. If the entry was 4023 * copy-on-write or empty, it has been fixed up. 4024 */ 4025 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4026 *object = entry->object.vm_object; 4027 4028 *out_prot = prot; 4029 return (KERN_SUCCESS); 4030 } 4031 4032 /* 4033 * vm_map_lookup_locked: 4034 * 4035 * Lookup the faulting address. A version of vm_map_lookup that returns 4036 * KERN_FAILURE instead of blocking on map lock or memory allocation. 4037 */ 4038 int 4039 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4040 vm_offset_t vaddr, 4041 vm_prot_t fault_typea, 4042 vm_map_entry_t *out_entry, /* OUT */ 4043 vm_object_t *object, /* OUT */ 4044 vm_pindex_t *pindex, /* OUT */ 4045 vm_prot_t *out_prot, /* OUT */ 4046 boolean_t *wired) /* OUT */ 4047 { 4048 vm_map_entry_t entry; 4049 vm_map_t map = *var_map; 4050 vm_prot_t prot; 4051 vm_prot_t fault_type = fault_typea; 4052 4053 /* 4054 * Lookup the faulting address. 4055 */ 4056 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4057 return (KERN_INVALID_ADDRESS); 4058 4059 entry = *out_entry; 4060 4061 /* 4062 * Fail if the entry refers to a submap. 4063 */ 4064 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4065 return (KERN_FAILURE); 4066 4067 /* 4068 * Check whether this task is allowed to have this page. 4069 */ 4070 prot = entry->protection; 4071 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4072 if ((fault_type & prot) != fault_type) 4073 return (KERN_PROTECTION_FAILURE); 4074 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 4075 (entry->eflags & MAP_ENTRY_COW) && 4076 (fault_type & VM_PROT_WRITE)) 4077 return (KERN_PROTECTION_FAILURE); 4078 4079 /* 4080 * If this page is not pageable, we have to get it for all possible 4081 * accesses. 4082 */ 4083 *wired = (entry->wired_count != 0); 4084 if (*wired) 4085 fault_type = entry->protection; 4086 4087 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4088 /* 4089 * Fail if the entry was copy-on-write for a write fault. 4090 */ 4091 if (fault_type & VM_PROT_WRITE) 4092 return (KERN_FAILURE); 4093 /* 4094 * We're attempting to read a copy-on-write page -- 4095 * don't allow writes. 4096 */ 4097 prot &= ~VM_PROT_WRITE; 4098 } 4099 4100 /* 4101 * Fail if an object should be created. 4102 */ 4103 if (entry->object.vm_object == NULL && !map->system_map) 4104 return (KERN_FAILURE); 4105 4106 /* 4107 * Return the object/offset from this entry. If the entry was 4108 * copy-on-write or empty, it has been fixed up. 4109 */ 4110 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4111 *object = entry->object.vm_object; 4112 4113 *out_prot = prot; 4114 return (KERN_SUCCESS); 4115 } 4116 4117 /* 4118 * vm_map_lookup_done: 4119 * 4120 * Releases locks acquired by a vm_map_lookup 4121 * (according to the handle returned by that lookup). 4122 */ 4123 void 4124 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4125 { 4126 /* 4127 * Unlock the main-level map 4128 */ 4129 vm_map_unlock_read(map); 4130 } 4131 4132 #include "opt_ddb.h" 4133 #ifdef DDB 4134 #include <sys/kernel.h> 4135 4136 #include <ddb/ddb.h> 4137 4138 static void 4139 vm_map_print(vm_map_t map) 4140 { 4141 vm_map_entry_t entry; 4142 4143 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4144 (void *)map, 4145 (void *)map->pmap, map->nentries, map->timestamp); 4146 4147 db_indent += 2; 4148 for (entry = map->header.next; entry != &map->header; 4149 entry = entry->next) { 4150 db_iprintf("map entry %p: start=%p, end=%p\n", 4151 (void *)entry, (void *)entry->start, (void *)entry->end); 4152 { 4153 static char *inheritance_name[4] = 4154 {"share", "copy", "none", "donate_copy"}; 4155 4156 db_iprintf(" prot=%x/%x/%s", 4157 entry->protection, 4158 entry->max_protection, 4159 inheritance_name[(int)(unsigned char)entry->inheritance]); 4160 if (entry->wired_count != 0) 4161 db_printf(", wired"); 4162 } 4163 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4164 db_printf(", share=%p, offset=0x%jx\n", 4165 (void *)entry->object.sub_map, 4166 (uintmax_t)entry->offset); 4167 if ((entry->prev == &map->header) || 4168 (entry->prev->object.sub_map != 4169 entry->object.sub_map)) { 4170 db_indent += 2; 4171 vm_map_print((vm_map_t)entry->object.sub_map); 4172 db_indent -= 2; 4173 } 4174 } else { 4175 if (entry->cred != NULL) 4176 db_printf(", ruid %d", entry->cred->cr_ruid); 4177 db_printf(", object=%p, offset=0x%jx", 4178 (void *)entry->object.vm_object, 4179 (uintmax_t)entry->offset); 4180 if (entry->object.vm_object && entry->object.vm_object->cred) 4181 db_printf(", obj ruid %d charge %jx", 4182 entry->object.vm_object->cred->cr_ruid, 4183 (uintmax_t)entry->object.vm_object->charge); 4184 if (entry->eflags & MAP_ENTRY_COW) 4185 db_printf(", copy (%s)", 4186 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4187 db_printf("\n"); 4188 4189 if ((entry->prev == &map->header) || 4190 (entry->prev->object.vm_object != 4191 entry->object.vm_object)) { 4192 db_indent += 2; 4193 vm_object_print((db_expr_t)(intptr_t) 4194 entry->object.vm_object, 4195 0, 0, (char *)0); 4196 db_indent -= 2; 4197 } 4198 } 4199 } 4200 db_indent -= 2; 4201 } 4202 4203 DB_SHOW_COMMAND(map, map) 4204 { 4205 4206 if (!have_addr) { 4207 db_printf("usage: show map <addr>\n"); 4208 return; 4209 } 4210 vm_map_print((vm_map_t)addr); 4211 } 4212 4213 DB_SHOW_COMMAND(procvm, procvm) 4214 { 4215 struct proc *p; 4216 4217 if (have_addr) { 4218 p = (struct proc *) addr; 4219 } else { 4220 p = curproc; 4221 } 4222 4223 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4224 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4225 (void *)vmspace_pmap(p->p_vmspace)); 4226 4227 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 4228 } 4229 4230 #endif /* DDB */ 4231