vm_map.c revision 270920
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: stable/10/sys/vm/vm_map.c 270920 2014-09-01 07:58:15Z kib $"); 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 124static struct mtx map_sleep_mtx; 125static uma_zone_t mapentzone; 126static uma_zone_t kmapentzone; 127static uma_zone_t mapzone; 128static uma_zone_t vmspace_zone; 129static int vmspace_zinit(void *mem, int size, int flags); 130static int vm_map_zinit(void *mem, int ize, int flags); 131static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, 132 vm_offset_t max); 133static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map); 134static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry); 135static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry); 136#ifdef INVARIANTS 137static void vm_map_zdtor(void *mem, int size, void *arg); 138static void vmspace_zdtor(void *mem, int size, void *arg); 139#endif 140static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, 141 vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max, 142 int cow); 143static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 144 vm_offset_t failed_addr); 145 146#define ENTRY_CHARGED(e) ((e)->cred != NULL || \ 147 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \ 148 !((e)->eflags & MAP_ENTRY_NEEDS_COPY))) 149 150/* 151 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type 152 * stable. 153 */ 154#define PROC_VMSPACE_LOCK(p) do { } while (0) 155#define PROC_VMSPACE_UNLOCK(p) do { } while (0) 156 157/* 158 * VM_MAP_RANGE_CHECK: [ internal use only ] 159 * 160 * Asserts that the starting and ending region 161 * addresses fall within the valid range of the map. 162 */ 163#define VM_MAP_RANGE_CHECK(map, start, end) \ 164 { \ 165 if (start < vm_map_min(map)) \ 166 start = vm_map_min(map); \ 167 if (end > vm_map_max(map)) \ 168 end = vm_map_max(map); \ 169 if (start > end) \ 170 start = end; \ 171 } 172 173/* 174 * vm_map_startup: 175 * 176 * Initialize the vm_map module. Must be called before 177 * any other vm_map routines. 178 * 179 * Map and entry structures are allocated from the general 180 * purpose memory pool with some exceptions: 181 * 182 * - The kernel map and kmem submap are allocated statically. 183 * - Kernel map entries are allocated out of a static pool. 184 * 185 * These restrictions are necessary since malloc() uses the 186 * maps and requires map entries. 187 */ 188 189void 190vm_map_startup(void) 191{ 192 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 193 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 194#ifdef INVARIANTS 195 vm_map_zdtor, 196#else 197 NULL, 198#endif 199 vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 200 uma_prealloc(mapzone, MAX_KMAP); 201 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 202 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 203 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 204 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 205 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 206 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 207#ifdef INVARIANTS 208 vmspace_zdtor, 209#else 210 NULL, 211#endif 212 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 213} 214 215static int 216vmspace_zinit(void *mem, int size, int flags) 217{ 218 struct vmspace *vm; 219 220 vm = (struct vmspace *)mem; 221 222 vm->vm_map.pmap = NULL; 223 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); 224 PMAP_LOCK_INIT(vmspace_pmap(vm)); 225 return (0); 226} 227 228static int 229vm_map_zinit(void *mem, int size, int flags) 230{ 231 vm_map_t map; 232 233 map = (vm_map_t)mem; 234 memset(map, 0, sizeof(*map)); 235 mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK); 236 sx_init(&map->lock, "vm map (user)"); 237 return (0); 238} 239 240#ifdef INVARIANTS 241static void 242vmspace_zdtor(void *mem, int size, void *arg) 243{ 244 struct vmspace *vm; 245 246 vm = (struct vmspace *)mem; 247 248 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 249} 250static void 251vm_map_zdtor(void *mem, int size, void *arg) 252{ 253 vm_map_t map; 254 255 map = (vm_map_t)mem; 256 KASSERT(map->nentries == 0, 257 ("map %p nentries == %d on free.", 258 map, map->nentries)); 259 KASSERT(map->size == 0, 260 ("map %p size == %lu on free.", 261 map, (unsigned long)map->size)); 262} 263#endif /* INVARIANTS */ 264 265/* 266 * Allocate a vmspace structure, including a vm_map and pmap, 267 * and initialize those structures. The refcnt is set to 1. 268 * 269 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit(). 270 */ 271struct vmspace * 272vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit) 273{ 274 struct vmspace *vm; 275 276 vm = uma_zalloc(vmspace_zone, M_WAITOK); 277 278 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL")); 279 280 if (pinit == NULL) 281 pinit = &pmap_pinit; 282 283 if (!pinit(vmspace_pmap(vm))) { 284 uma_zfree(vmspace_zone, vm); 285 return (NULL); 286 } 287 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 288 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max); 289 vm->vm_refcnt = 1; 290 vm->vm_shm = NULL; 291 vm->vm_swrss = 0; 292 vm->vm_tsize = 0; 293 vm->vm_dsize = 0; 294 vm->vm_ssize = 0; 295 vm->vm_taddr = 0; 296 vm->vm_daddr = 0; 297 vm->vm_maxsaddr = 0; 298 return (vm); 299} 300 301static void 302vmspace_container_reset(struct proc *p) 303{ 304 305#ifdef RACCT 306 PROC_LOCK(p); 307 racct_set(p, RACCT_DATA, 0); 308 racct_set(p, RACCT_STACK, 0); 309 racct_set(p, RACCT_RSS, 0); 310 racct_set(p, RACCT_MEMLOCK, 0); 311 racct_set(p, RACCT_VMEM, 0); 312 PROC_UNLOCK(p); 313#endif 314} 315 316static inline void 317vmspace_dofree(struct vmspace *vm) 318{ 319 320 CTR1(KTR_VM, "vmspace_free: %p", vm); 321 322 /* 323 * Make sure any SysV shm is freed, it might not have been in 324 * exit1(). 325 */ 326 shmexit(vm); 327 328 /* 329 * Lock the map, to wait out all other references to it. 330 * Delete all of the mappings and pages they hold, then call 331 * the pmap module to reclaim anything left. 332 */ 333 (void)vm_map_remove(&vm->vm_map, vm->vm_map.min_offset, 334 vm->vm_map.max_offset); 335 336 pmap_release(vmspace_pmap(vm)); 337 vm->vm_map.pmap = NULL; 338 uma_zfree(vmspace_zone, vm); 339} 340 341void 342vmspace_free(struct vmspace *vm) 343{ 344 345 if (vm->vm_refcnt == 0) 346 panic("vmspace_free: attempt to free already freed vmspace"); 347 348 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) 349 vmspace_dofree(vm); 350} 351 352void 353vmspace_exitfree(struct proc *p) 354{ 355 struct vmspace *vm; 356 357 PROC_VMSPACE_LOCK(p); 358 vm = p->p_vmspace; 359 p->p_vmspace = NULL; 360 PROC_VMSPACE_UNLOCK(p); 361 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 362 vmspace_free(vm); 363} 364 365void 366vmspace_exit(struct thread *td) 367{ 368 int refcnt; 369 struct vmspace *vm; 370 struct proc *p; 371 372 /* 373 * Release user portion of address space. 374 * This releases references to vnodes, 375 * which could cause I/O if the file has been unlinked. 376 * Need to do this early enough that we can still sleep. 377 * 378 * The last exiting process to reach this point releases as 379 * much of the environment as it can. vmspace_dofree() is the 380 * slower fallback in case another process had a temporary 381 * reference to the vmspace. 382 */ 383 384 p = td->td_proc; 385 vm = p->p_vmspace; 386 atomic_add_int(&vmspace0.vm_refcnt, 1); 387 do { 388 refcnt = vm->vm_refcnt; 389 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 390 /* Switch now since other proc might free vmspace */ 391 PROC_VMSPACE_LOCK(p); 392 p->p_vmspace = &vmspace0; 393 PROC_VMSPACE_UNLOCK(p); 394 pmap_activate(td); 395 } 396 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 397 if (refcnt == 1) { 398 if (p->p_vmspace != vm) { 399 /* vmspace not yet freed, switch back */ 400 PROC_VMSPACE_LOCK(p); 401 p->p_vmspace = vm; 402 PROC_VMSPACE_UNLOCK(p); 403 pmap_activate(td); 404 } 405 pmap_remove_pages(vmspace_pmap(vm)); 406 /* Switch now since this proc will free vmspace */ 407 PROC_VMSPACE_LOCK(p); 408 p->p_vmspace = &vmspace0; 409 PROC_VMSPACE_UNLOCK(p); 410 pmap_activate(td); 411 vmspace_dofree(vm); 412 } 413 vmspace_container_reset(p); 414} 415 416/* Acquire reference to vmspace owned by another process. */ 417 418struct vmspace * 419vmspace_acquire_ref(struct proc *p) 420{ 421 struct vmspace *vm; 422 int refcnt; 423 424 PROC_VMSPACE_LOCK(p); 425 vm = p->p_vmspace; 426 if (vm == NULL) { 427 PROC_VMSPACE_UNLOCK(p); 428 return (NULL); 429 } 430 do { 431 refcnt = vm->vm_refcnt; 432 if (refcnt <= 0) { /* Avoid 0->1 transition */ 433 PROC_VMSPACE_UNLOCK(p); 434 return (NULL); 435 } 436 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1)); 437 if (vm != p->p_vmspace) { 438 PROC_VMSPACE_UNLOCK(p); 439 vmspace_free(vm); 440 return (NULL); 441 } 442 PROC_VMSPACE_UNLOCK(p); 443 return (vm); 444} 445 446void 447_vm_map_lock(vm_map_t map, const char *file, int line) 448{ 449 450 if (map->system_map) 451 mtx_lock_flags_(&map->system_mtx, 0, file, line); 452 else 453 sx_xlock_(&map->lock, file, line); 454 map->timestamp++; 455} 456 457static void 458vm_map_process_deferred(void) 459{ 460 struct thread *td; 461 vm_map_entry_t entry, next; 462 vm_object_t object; 463 464 td = curthread; 465 entry = td->td_map_def_user; 466 td->td_map_def_user = NULL; 467 while (entry != NULL) { 468 next = entry->next; 469 if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) { 470 /* 471 * Decrement the object's writemappings and 472 * possibly the vnode's v_writecount. 473 */ 474 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 475 ("Submap with writecount")); 476 object = entry->object.vm_object; 477 KASSERT(object != NULL, ("No object for writecount")); 478 vnode_pager_release_writecount(object, entry->start, 479 entry->end); 480 } 481 vm_map_entry_deallocate(entry, FALSE); 482 entry = next; 483 } 484} 485 486void 487_vm_map_unlock(vm_map_t map, const char *file, int line) 488{ 489 490 if (map->system_map) 491 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 492 else { 493 sx_xunlock_(&map->lock, file, line); 494 vm_map_process_deferred(); 495 } 496} 497 498void 499_vm_map_lock_read(vm_map_t map, const char *file, int line) 500{ 501 502 if (map->system_map) 503 mtx_lock_flags_(&map->system_mtx, 0, file, line); 504 else 505 sx_slock_(&map->lock, file, line); 506} 507 508void 509_vm_map_unlock_read(vm_map_t map, const char *file, int line) 510{ 511 512 if (map->system_map) 513 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 514 else { 515 sx_sunlock_(&map->lock, file, line); 516 vm_map_process_deferred(); 517 } 518} 519 520int 521_vm_map_trylock(vm_map_t map, const char *file, int line) 522{ 523 int error; 524 525 error = map->system_map ? 526 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 527 !sx_try_xlock_(&map->lock, file, line); 528 if (error == 0) 529 map->timestamp++; 530 return (error == 0); 531} 532 533int 534_vm_map_trylock_read(vm_map_t map, const char *file, int line) 535{ 536 int error; 537 538 error = map->system_map ? 539 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 540 !sx_try_slock_(&map->lock, file, line); 541 return (error == 0); 542} 543 544/* 545 * _vm_map_lock_upgrade: [ internal use only ] 546 * 547 * Tries to upgrade a read (shared) lock on the specified map to a write 548 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 549 * non-zero value if the upgrade fails. If the upgrade fails, the map is 550 * returned without a read or write lock held. 551 * 552 * Requires that the map be read locked. 553 */ 554int 555_vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 556{ 557 unsigned int last_timestamp; 558 559 if (map->system_map) { 560 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 561 } else { 562 if (!sx_try_upgrade_(&map->lock, file, line)) { 563 last_timestamp = map->timestamp; 564 sx_sunlock_(&map->lock, file, line); 565 vm_map_process_deferred(); 566 /* 567 * If the map's timestamp does not change while the 568 * map is unlocked, then the upgrade succeeds. 569 */ 570 sx_xlock_(&map->lock, file, line); 571 if (last_timestamp != map->timestamp) { 572 sx_xunlock_(&map->lock, file, line); 573 return (1); 574 } 575 } 576 } 577 map->timestamp++; 578 return (0); 579} 580 581void 582_vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 583{ 584 585 if (map->system_map) { 586 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 587 } else 588 sx_downgrade_(&map->lock, file, line); 589} 590 591/* 592 * vm_map_locked: 593 * 594 * Returns a non-zero value if the caller holds a write (exclusive) lock 595 * on the specified map and the value "0" otherwise. 596 */ 597int 598vm_map_locked(vm_map_t map) 599{ 600 601 if (map->system_map) 602 return (mtx_owned(&map->system_mtx)); 603 else 604 return (sx_xlocked(&map->lock)); 605} 606 607#ifdef INVARIANTS 608static void 609_vm_map_assert_locked(vm_map_t map, const char *file, int line) 610{ 611 612 if (map->system_map) 613 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 614 else 615 sx_assert_(&map->lock, SA_XLOCKED, file, line); 616} 617 618#define VM_MAP_ASSERT_LOCKED(map) \ 619 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 620#else 621#define VM_MAP_ASSERT_LOCKED(map) 622#endif 623 624/* 625 * _vm_map_unlock_and_wait: 626 * 627 * Atomically releases the lock on the specified map and puts the calling 628 * thread to sleep. The calling thread will remain asleep until either 629 * vm_map_wakeup() is performed on the map or the specified timeout is 630 * exceeded. 631 * 632 * WARNING! This function does not perform deferred deallocations of 633 * objects and map entries. Therefore, the calling thread is expected to 634 * reacquire the map lock after reawakening and later perform an ordinary 635 * unlock operation, such as vm_map_unlock(), before completing its 636 * operation on the map. 637 */ 638int 639_vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) 640{ 641 642 mtx_lock(&map_sleep_mtx); 643 if (map->system_map) 644 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 645 else 646 sx_xunlock_(&map->lock, file, line); 647 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 648 timo)); 649} 650 651/* 652 * vm_map_wakeup: 653 * 654 * Awaken any threads that have slept on the map using 655 * vm_map_unlock_and_wait(). 656 */ 657void 658vm_map_wakeup(vm_map_t map) 659{ 660 661 /* 662 * Acquire and release map_sleep_mtx to prevent a wakeup() 663 * from being performed (and lost) between the map unlock 664 * and the msleep() in _vm_map_unlock_and_wait(). 665 */ 666 mtx_lock(&map_sleep_mtx); 667 mtx_unlock(&map_sleep_mtx); 668 wakeup(&map->root); 669} 670 671void 672vm_map_busy(vm_map_t map) 673{ 674 675 VM_MAP_ASSERT_LOCKED(map); 676 map->busy++; 677} 678 679void 680vm_map_unbusy(vm_map_t map) 681{ 682 683 VM_MAP_ASSERT_LOCKED(map); 684 KASSERT(map->busy, ("vm_map_unbusy: not busy")); 685 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { 686 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); 687 wakeup(&map->busy); 688 } 689} 690 691void 692vm_map_wait_busy(vm_map_t map) 693{ 694 695 VM_MAP_ASSERT_LOCKED(map); 696 while (map->busy) { 697 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); 698 if (map->system_map) 699 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); 700 else 701 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); 702 } 703 map->timestamp++; 704} 705 706long 707vmspace_resident_count(struct vmspace *vmspace) 708{ 709 return pmap_resident_count(vmspace_pmap(vmspace)); 710} 711 712/* 713 * vm_map_create: 714 * 715 * Creates and returns a new empty VM map with 716 * the given physical map structure, and having 717 * the given lower and upper address bounds. 718 */ 719vm_map_t 720vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 721{ 722 vm_map_t result; 723 724 result = uma_zalloc(mapzone, M_WAITOK); 725 CTR1(KTR_VM, "vm_map_create: %p", result); 726 _vm_map_init(result, pmap, min, max); 727 return (result); 728} 729 730/* 731 * Initialize an existing vm_map structure 732 * such as that in the vmspace structure. 733 */ 734static void 735_vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 736{ 737 738 map->header.next = map->header.prev = &map->header; 739 map->needs_wakeup = FALSE; 740 map->system_map = 0; 741 map->pmap = pmap; 742 map->min_offset = min; 743 map->max_offset = max; 744 map->flags = 0; 745 map->root = NULL; 746 map->timestamp = 0; 747 map->busy = 0; 748} 749 750void 751vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 752{ 753 754 _vm_map_init(map, pmap, min, max); 755 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 756 sx_init(&map->lock, "user map"); 757} 758 759/* 760 * vm_map_entry_dispose: [ internal use only ] 761 * 762 * Inverse of vm_map_entry_create. 763 */ 764static void 765vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 766{ 767 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 768} 769 770/* 771 * vm_map_entry_create: [ internal use only ] 772 * 773 * Allocates a VM map entry for insertion. 774 * No entry fields are filled in. 775 */ 776static vm_map_entry_t 777vm_map_entry_create(vm_map_t map) 778{ 779 vm_map_entry_t new_entry; 780 781 if (map->system_map) 782 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 783 else 784 new_entry = uma_zalloc(mapentzone, M_WAITOK); 785 if (new_entry == NULL) 786 panic("vm_map_entry_create: kernel resources exhausted"); 787 return (new_entry); 788} 789 790/* 791 * vm_map_entry_set_behavior: 792 * 793 * Set the expected access behavior, either normal, random, or 794 * sequential. 795 */ 796static inline void 797vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 798{ 799 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 800 (behavior & MAP_ENTRY_BEHAV_MASK); 801} 802 803/* 804 * vm_map_entry_set_max_free: 805 * 806 * Set the max_free field in a vm_map_entry. 807 */ 808static inline void 809vm_map_entry_set_max_free(vm_map_entry_t entry) 810{ 811 812 entry->max_free = entry->adj_free; 813 if (entry->left != NULL && entry->left->max_free > entry->max_free) 814 entry->max_free = entry->left->max_free; 815 if (entry->right != NULL && entry->right->max_free > entry->max_free) 816 entry->max_free = entry->right->max_free; 817} 818 819/* 820 * vm_map_entry_splay: 821 * 822 * The Sleator and Tarjan top-down splay algorithm with the 823 * following variation. Max_free must be computed bottom-up, so 824 * on the downward pass, maintain the left and right spines in 825 * reverse order. Then, make a second pass up each side to fix 826 * the pointers and compute max_free. The time bound is O(log n) 827 * amortized. 828 * 829 * The new root is the vm_map_entry containing "addr", or else an 830 * adjacent entry (lower or higher) if addr is not in the tree. 831 * 832 * The map must be locked, and leaves it so. 833 * 834 * Returns: the new root. 835 */ 836static vm_map_entry_t 837vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root) 838{ 839 vm_map_entry_t llist, rlist; 840 vm_map_entry_t ltree, rtree; 841 vm_map_entry_t y; 842 843 /* Special case of empty tree. */ 844 if (root == NULL) 845 return (root); 846 847 /* 848 * Pass One: Splay down the tree until we find addr or a NULL 849 * pointer where addr would go. llist and rlist are the two 850 * sides in reverse order (bottom-up), with llist linked by 851 * the right pointer and rlist linked by the left pointer in 852 * the vm_map_entry. Wait until Pass Two to set max_free on 853 * the two spines. 854 */ 855 llist = NULL; 856 rlist = NULL; 857 for (;;) { 858 /* root is never NULL in here. */ 859 if (addr < root->start) { 860 y = root->left; 861 if (y == NULL) 862 break; 863 if (addr < y->start && y->left != NULL) { 864 /* Rotate right and put y on rlist. */ 865 root->left = y->right; 866 y->right = root; 867 vm_map_entry_set_max_free(root); 868 root = y->left; 869 y->left = rlist; 870 rlist = y; 871 } else { 872 /* Put root on rlist. */ 873 root->left = rlist; 874 rlist = root; 875 root = y; 876 } 877 } else if (addr >= root->end) { 878 y = root->right; 879 if (y == NULL) 880 break; 881 if (addr >= y->end && y->right != NULL) { 882 /* Rotate left and put y on llist. */ 883 root->right = y->left; 884 y->left = root; 885 vm_map_entry_set_max_free(root); 886 root = y->right; 887 y->right = llist; 888 llist = y; 889 } else { 890 /* Put root on llist. */ 891 root->right = llist; 892 llist = root; 893 root = y; 894 } 895 } else 896 break; 897 } 898 899 /* 900 * Pass Two: Walk back up the two spines, flip the pointers 901 * and set max_free. The subtrees of the root go at the 902 * bottom of llist and rlist. 903 */ 904 ltree = root->left; 905 while (llist != NULL) { 906 y = llist->right; 907 llist->right = ltree; 908 vm_map_entry_set_max_free(llist); 909 ltree = llist; 910 llist = y; 911 } 912 rtree = root->right; 913 while (rlist != NULL) { 914 y = rlist->left; 915 rlist->left = rtree; 916 vm_map_entry_set_max_free(rlist); 917 rtree = rlist; 918 rlist = y; 919 } 920 921 /* 922 * Final assembly: add ltree and rtree as subtrees of root. 923 */ 924 root->left = ltree; 925 root->right = rtree; 926 vm_map_entry_set_max_free(root); 927 928 return (root); 929} 930 931/* 932 * vm_map_entry_{un,}link: 933 * 934 * Insert/remove entries from maps. 935 */ 936static void 937vm_map_entry_link(vm_map_t map, 938 vm_map_entry_t after_where, 939 vm_map_entry_t entry) 940{ 941 942 CTR4(KTR_VM, 943 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 944 map->nentries, entry, after_where); 945 VM_MAP_ASSERT_LOCKED(map); 946 KASSERT(after_where == &map->header || 947 after_where->end <= entry->start, 948 ("vm_map_entry_link: prev end %jx new start %jx overlap", 949 (uintmax_t)after_where->end, (uintmax_t)entry->start)); 950 KASSERT(after_where->next == &map->header || 951 entry->end <= after_where->next->start, 952 ("vm_map_entry_link: new end %jx next start %jx overlap", 953 (uintmax_t)entry->end, (uintmax_t)after_where->next->start)); 954 955 map->nentries++; 956 entry->prev = after_where; 957 entry->next = after_where->next; 958 entry->next->prev = entry; 959 after_where->next = entry; 960 961 if (after_where != &map->header) { 962 if (after_where != map->root) 963 vm_map_entry_splay(after_where->start, map->root); 964 entry->right = after_where->right; 965 entry->left = after_where; 966 after_where->right = NULL; 967 after_where->adj_free = entry->start - after_where->end; 968 vm_map_entry_set_max_free(after_where); 969 } else { 970 entry->right = map->root; 971 entry->left = NULL; 972 } 973 entry->adj_free = (entry->next == &map->header ? map->max_offset : 974 entry->next->start) - entry->end; 975 vm_map_entry_set_max_free(entry); 976 map->root = entry; 977} 978 979static void 980vm_map_entry_unlink(vm_map_t map, 981 vm_map_entry_t entry) 982{ 983 vm_map_entry_t next, prev, root; 984 985 VM_MAP_ASSERT_LOCKED(map); 986 if (entry != map->root) 987 vm_map_entry_splay(entry->start, map->root); 988 if (entry->left == NULL) 989 root = entry->right; 990 else { 991 root = vm_map_entry_splay(entry->start, entry->left); 992 root->right = entry->right; 993 root->adj_free = (entry->next == &map->header ? map->max_offset : 994 entry->next->start) - root->end; 995 vm_map_entry_set_max_free(root); 996 } 997 map->root = root; 998 999 prev = entry->prev; 1000 next = entry->next; 1001 next->prev = prev; 1002 prev->next = next; 1003 map->nentries--; 1004 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 1005 map->nentries, entry); 1006} 1007 1008/* 1009 * vm_map_entry_resize_free: 1010 * 1011 * Recompute the amount of free space following a vm_map_entry 1012 * and propagate that value up the tree. Call this function after 1013 * resizing a map entry in-place, that is, without a call to 1014 * vm_map_entry_link() or _unlink(). 1015 * 1016 * The map must be locked, and leaves it so. 1017 */ 1018static void 1019vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry) 1020{ 1021 1022 /* 1023 * Using splay trees without parent pointers, propagating 1024 * max_free up the tree is done by moving the entry to the 1025 * root and making the change there. 1026 */ 1027 if (entry != map->root) 1028 map->root = vm_map_entry_splay(entry->start, map->root); 1029 1030 entry->adj_free = (entry->next == &map->header ? map->max_offset : 1031 entry->next->start) - entry->end; 1032 vm_map_entry_set_max_free(entry); 1033} 1034 1035/* 1036 * vm_map_lookup_entry: [ internal use only ] 1037 * 1038 * Finds the map entry containing (or 1039 * immediately preceding) the specified address 1040 * in the given map; the entry is returned 1041 * in the "entry" parameter. The boolean 1042 * result indicates whether the address is 1043 * actually contained in the map. 1044 */ 1045boolean_t 1046vm_map_lookup_entry( 1047 vm_map_t map, 1048 vm_offset_t address, 1049 vm_map_entry_t *entry) /* OUT */ 1050{ 1051 vm_map_entry_t cur; 1052 boolean_t locked; 1053 1054 /* 1055 * If the map is empty, then the map entry immediately preceding 1056 * "address" is the map's header. 1057 */ 1058 cur = map->root; 1059 if (cur == NULL) 1060 *entry = &map->header; 1061 else if (address >= cur->start && cur->end > address) { 1062 *entry = cur; 1063 return (TRUE); 1064 } else if ((locked = vm_map_locked(map)) || 1065 sx_try_upgrade(&map->lock)) { 1066 /* 1067 * Splay requires a write lock on the map. However, it only 1068 * restructures the binary search tree; it does not otherwise 1069 * change the map. Thus, the map's timestamp need not change 1070 * on a temporary upgrade. 1071 */ 1072 map->root = cur = vm_map_entry_splay(address, cur); 1073 if (!locked) 1074 sx_downgrade(&map->lock); 1075 1076 /* 1077 * If "address" is contained within a map entry, the new root 1078 * is that map entry. Otherwise, the new root is a map entry 1079 * immediately before or after "address". 1080 */ 1081 if (address >= cur->start) { 1082 *entry = cur; 1083 if (cur->end > address) 1084 return (TRUE); 1085 } else 1086 *entry = cur->prev; 1087 } else 1088 /* 1089 * Since the map is only locked for read access, perform a 1090 * standard binary search tree lookup for "address". 1091 */ 1092 for (;;) { 1093 if (address < cur->start) { 1094 if (cur->left == NULL) { 1095 *entry = cur->prev; 1096 break; 1097 } 1098 cur = cur->left; 1099 } else if (cur->end > address) { 1100 *entry = cur; 1101 return (TRUE); 1102 } else { 1103 if (cur->right == NULL) { 1104 *entry = cur; 1105 break; 1106 } 1107 cur = cur->right; 1108 } 1109 } 1110 return (FALSE); 1111} 1112 1113/* 1114 * vm_map_insert: 1115 * 1116 * Inserts the given whole VM object into the target 1117 * map at the specified address range. The object's 1118 * size should match that of the address range. 1119 * 1120 * Requires that the map be locked, and leaves it so. 1121 * 1122 * If object is non-NULL, ref count must be bumped by caller 1123 * prior to making call to account for the new entry. 1124 */ 1125int 1126vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1127 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 1128 int cow) 1129{ 1130 vm_map_entry_t new_entry; 1131 vm_map_entry_t prev_entry; 1132 vm_map_entry_t temp_entry; 1133 vm_eflags_t protoeflags; 1134 struct ucred *cred; 1135 vm_inherit_t inheritance; 1136 boolean_t charge_prev_obj; 1137 1138 VM_MAP_ASSERT_LOCKED(map); 1139 1140 /* 1141 * Check that the start and end points are not bogus. 1142 */ 1143 if ((start < map->min_offset) || (end > map->max_offset) || 1144 (start >= end)) 1145 return (KERN_INVALID_ADDRESS); 1146 1147 /* 1148 * Find the entry prior to the proposed starting address; if it's part 1149 * of an existing entry, this range is bogus. 1150 */ 1151 if (vm_map_lookup_entry(map, start, &temp_entry)) 1152 return (KERN_NO_SPACE); 1153 1154 prev_entry = temp_entry; 1155 1156 /* 1157 * Assert that the next entry doesn't overlap the end point. 1158 */ 1159 if ((prev_entry->next != &map->header) && 1160 (prev_entry->next->start < end)) 1161 return (KERN_NO_SPACE); 1162 1163 protoeflags = 0; 1164 charge_prev_obj = FALSE; 1165 1166 if (cow & MAP_COPY_ON_WRITE) 1167 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 1168 1169 if (cow & MAP_NOFAULT) { 1170 protoeflags |= MAP_ENTRY_NOFAULT; 1171 1172 KASSERT(object == NULL, 1173 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1174 } 1175 if (cow & MAP_DISABLE_SYNCER) 1176 protoeflags |= MAP_ENTRY_NOSYNC; 1177 if (cow & MAP_DISABLE_COREDUMP) 1178 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1179 if (cow & MAP_VN_WRITECOUNT) 1180 protoeflags |= MAP_ENTRY_VN_WRITECNT; 1181 if (cow & MAP_INHERIT_SHARE) 1182 inheritance = VM_INHERIT_SHARE; 1183 else 1184 inheritance = VM_INHERIT_DEFAULT; 1185 1186 cred = NULL; 1187 KASSERT((object != kmem_object && object != kernel_object) || 1188 ((object == kmem_object || object == kernel_object) && 1189 !(protoeflags & MAP_ENTRY_NEEDS_COPY)), 1190 ("kmem or kernel object and cow")); 1191 if (cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT)) 1192 goto charged; 1193 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1194 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1195 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1196 return (KERN_RESOURCE_SHORTAGE); 1197 KASSERT(object == NULL || (protoeflags & MAP_ENTRY_NEEDS_COPY) || 1198 object->cred == NULL, 1199 ("OVERCOMMIT: vm_map_insert o %p", object)); 1200 cred = curthread->td_ucred; 1201 crhold(cred); 1202 if (object == NULL && !(protoeflags & MAP_ENTRY_NEEDS_COPY)) 1203 charge_prev_obj = TRUE; 1204 } 1205 1206charged: 1207 /* Expand the kernel pmap, if necessary. */ 1208 if (map == kernel_map && end > kernel_vm_end) 1209 pmap_growkernel(end); 1210 if (object != NULL) { 1211 /* 1212 * OBJ_ONEMAPPING must be cleared unless this mapping 1213 * is trivially proven to be the only mapping for any 1214 * of the object's pages. (Object granularity 1215 * reference counting is insufficient to recognize 1216 * aliases with precision.) 1217 */ 1218 VM_OBJECT_WLOCK(object); 1219 if (object->ref_count > 1 || object->shadow_count != 0) 1220 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1221 VM_OBJECT_WUNLOCK(object); 1222 } 1223 else if ((prev_entry != &map->header) && 1224 (prev_entry->eflags == protoeflags) && 1225 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 && 1226 (prev_entry->end == start) && 1227 (prev_entry->wired_count == 0) && 1228 (prev_entry->cred == cred || 1229 (prev_entry->object.vm_object != NULL && 1230 (prev_entry->object.vm_object->cred == cred))) && 1231 vm_object_coalesce(prev_entry->object.vm_object, 1232 prev_entry->offset, 1233 (vm_size_t)(prev_entry->end - prev_entry->start), 1234 (vm_size_t)(end - prev_entry->end), charge_prev_obj)) { 1235 /* 1236 * We were able to extend the object. Determine if we 1237 * can extend the previous map entry to include the 1238 * new range as well. 1239 */ 1240 if ((prev_entry->inheritance == inheritance) && 1241 (prev_entry->protection == prot) && 1242 (prev_entry->max_protection == max)) { 1243 map->size += (end - prev_entry->end); 1244 prev_entry->end = end; 1245 vm_map_entry_resize_free(map, prev_entry); 1246 vm_map_simplify_entry(map, prev_entry); 1247 if (cred != NULL) 1248 crfree(cred); 1249 return (KERN_SUCCESS); 1250 } 1251 1252 /* 1253 * If we can extend the object but cannot extend the 1254 * map entry, we have to create a new map entry. We 1255 * must bump the ref count on the extended object to 1256 * account for it. object may be NULL. 1257 */ 1258 object = prev_entry->object.vm_object; 1259 offset = prev_entry->offset + 1260 (prev_entry->end - prev_entry->start); 1261 vm_object_reference(object); 1262 if (cred != NULL && object != NULL && object->cred != NULL && 1263 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1264 /* Object already accounts for this uid. */ 1265 crfree(cred); 1266 cred = NULL; 1267 } 1268 } 1269 1270 /* 1271 * NOTE: if conditionals fail, object can be NULL here. This occurs 1272 * in things like the buffer map where we manage kva but do not manage 1273 * backing objects. 1274 */ 1275 1276 /* 1277 * Create a new entry 1278 */ 1279 new_entry = vm_map_entry_create(map); 1280 new_entry->start = start; 1281 new_entry->end = end; 1282 new_entry->cred = NULL; 1283 1284 new_entry->eflags = protoeflags; 1285 new_entry->object.vm_object = object; 1286 new_entry->offset = offset; 1287 new_entry->avail_ssize = 0; 1288 1289 new_entry->inheritance = inheritance; 1290 new_entry->protection = prot; 1291 new_entry->max_protection = max; 1292 new_entry->wired_count = 0; 1293 new_entry->wiring_thread = NULL; 1294 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1295 new_entry->next_read = OFF_TO_IDX(offset); 1296 1297 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1298 ("OVERCOMMIT: vm_map_insert leaks vm_map %p", new_entry)); 1299 new_entry->cred = cred; 1300 1301 /* 1302 * Insert the new entry into the list 1303 */ 1304 vm_map_entry_link(map, prev_entry, new_entry); 1305 map->size += new_entry->end - new_entry->start; 1306 1307 /* 1308 * It may be possible to merge the new entry with the next and/or 1309 * previous entries. However, due to MAP_STACK_* being a hack, a 1310 * panic can result from merging such entries. 1311 */ 1312 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0) 1313 vm_map_simplify_entry(map, new_entry); 1314 1315 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 1316 vm_map_pmap_enter(map, start, prot, 1317 object, OFF_TO_IDX(offset), end - start, 1318 cow & MAP_PREFAULT_PARTIAL); 1319 } 1320 1321 return (KERN_SUCCESS); 1322} 1323 1324/* 1325 * vm_map_findspace: 1326 * 1327 * Find the first fit (lowest VM address) for "length" free bytes 1328 * beginning at address >= start in the given map. 1329 * 1330 * In a vm_map_entry, "adj_free" is the amount of free space 1331 * adjacent (higher address) to this entry, and "max_free" is the 1332 * maximum amount of contiguous free space in its subtree. This 1333 * allows finding a free region in one path down the tree, so 1334 * O(log n) amortized with splay trees. 1335 * 1336 * The map must be locked, and leaves it so. 1337 * 1338 * Returns: 0 on success, and starting address in *addr, 1339 * 1 if insufficient space. 1340 */ 1341int 1342vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1343 vm_offset_t *addr) /* OUT */ 1344{ 1345 vm_map_entry_t entry; 1346 vm_offset_t st; 1347 1348 /* 1349 * Request must fit within min/max VM address and must avoid 1350 * address wrap. 1351 */ 1352 if (start < map->min_offset) 1353 start = map->min_offset; 1354 if (start + length > map->max_offset || start + length < start) 1355 return (1); 1356 1357 /* Empty tree means wide open address space. */ 1358 if (map->root == NULL) { 1359 *addr = start; 1360 return (0); 1361 } 1362 1363 /* 1364 * After splay, if start comes before root node, then there 1365 * must be a gap from start to the root. 1366 */ 1367 map->root = vm_map_entry_splay(start, map->root); 1368 if (start + length <= map->root->start) { 1369 *addr = start; 1370 return (0); 1371 } 1372 1373 /* 1374 * Root is the last node that might begin its gap before 1375 * start, and this is the last comparison where address 1376 * wrap might be a problem. 1377 */ 1378 st = (start > map->root->end) ? start : map->root->end; 1379 if (length <= map->root->end + map->root->adj_free - st) { 1380 *addr = st; 1381 return (0); 1382 } 1383 1384 /* With max_free, can immediately tell if no solution. */ 1385 entry = map->root->right; 1386 if (entry == NULL || length > entry->max_free) 1387 return (1); 1388 1389 /* 1390 * Search the right subtree in the order: left subtree, root, 1391 * right subtree (first fit). The previous splay implies that 1392 * all regions in the right subtree have addresses > start. 1393 */ 1394 while (entry != NULL) { 1395 if (entry->left != NULL && entry->left->max_free >= length) 1396 entry = entry->left; 1397 else if (entry->adj_free >= length) { 1398 *addr = entry->end; 1399 return (0); 1400 } else 1401 entry = entry->right; 1402 } 1403 1404 /* Can't get here, so panic if we do. */ 1405 panic("vm_map_findspace: max_free corrupt"); 1406} 1407 1408int 1409vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1410 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1411 vm_prot_t max, int cow) 1412{ 1413 vm_offset_t end; 1414 int result; 1415 1416 end = start + length; 1417 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1418 object == NULL, 1419 ("vm_map_fixed: non-NULL backing object for stack")); 1420 vm_map_lock(map); 1421 VM_MAP_RANGE_CHECK(map, start, end); 1422 if ((cow & MAP_CHECK_EXCL) == 0) 1423 vm_map_delete(map, start, end); 1424 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1425 result = vm_map_stack_locked(map, start, length, sgrowsiz, 1426 prot, max, cow); 1427 } else { 1428 result = vm_map_insert(map, object, offset, start, end, 1429 prot, max, cow); 1430 } 1431 vm_map_unlock(map); 1432 return (result); 1433} 1434 1435/* 1436 * vm_map_find finds an unallocated region in the target address 1437 * map with the given length. The search is defined to be 1438 * first-fit from the specified address; the region found is 1439 * returned in the same parameter. 1440 * 1441 * If object is non-NULL, ref count must be bumped by caller 1442 * prior to making call to account for the new entry. 1443 */ 1444int 1445vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1446 vm_offset_t *addr, /* IN/OUT */ 1447 vm_size_t length, vm_offset_t max_addr, int find_space, 1448 vm_prot_t prot, vm_prot_t max, int cow) 1449{ 1450 vm_offset_t alignment, initial_addr, start; 1451 int result; 1452 1453 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1454 object == NULL, 1455 ("vm_map_find: non-NULL backing object for stack")); 1456 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 1457 (object->flags & OBJ_COLORED) == 0)) 1458 find_space = VMFS_ANY_SPACE; 1459 if (find_space >> 8 != 0) { 1460 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 1461 alignment = (vm_offset_t)1 << (find_space >> 8); 1462 } else 1463 alignment = 0; 1464 initial_addr = *addr; 1465again: 1466 start = initial_addr; 1467 vm_map_lock(map); 1468 do { 1469 if (find_space != VMFS_NO_SPACE) { 1470 if (vm_map_findspace(map, start, length, addr) || 1471 (max_addr != 0 && *addr + length > max_addr)) { 1472 vm_map_unlock(map); 1473 if (find_space == VMFS_OPTIMAL_SPACE) { 1474 find_space = VMFS_ANY_SPACE; 1475 goto again; 1476 } 1477 return (KERN_NO_SPACE); 1478 } 1479 switch (find_space) { 1480 case VMFS_SUPER_SPACE: 1481 case VMFS_OPTIMAL_SPACE: 1482 pmap_align_superpage(object, offset, addr, 1483 length); 1484 break; 1485 case VMFS_ANY_SPACE: 1486 break; 1487 default: 1488 if ((*addr & (alignment - 1)) != 0) { 1489 *addr &= ~(alignment - 1); 1490 *addr += alignment; 1491 } 1492 break; 1493 } 1494 1495 start = *addr; 1496 } 1497 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1498 result = vm_map_stack_locked(map, start, length, 1499 sgrowsiz, prot, max, cow); 1500 } else { 1501 result = vm_map_insert(map, object, offset, start, 1502 start + length, prot, max, cow); 1503 } 1504 } while (result == KERN_NO_SPACE && find_space != VMFS_NO_SPACE && 1505 find_space != VMFS_ANY_SPACE); 1506 vm_map_unlock(map); 1507 return (result); 1508} 1509 1510/* 1511 * vm_map_simplify_entry: 1512 * 1513 * Simplify the given map entry by merging with either neighbor. This 1514 * routine also has the ability to merge with both neighbors. 1515 * 1516 * The map must be locked. 1517 * 1518 * This routine guarentees that the passed entry remains valid (though 1519 * possibly extended). When merging, this routine may delete one or 1520 * both neighbors. 1521 */ 1522void 1523vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1524{ 1525 vm_map_entry_t next, prev; 1526 vm_size_t prevsize, esize; 1527 1528 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) 1529 return; 1530 1531 prev = entry->prev; 1532 if (prev != &map->header) { 1533 prevsize = prev->end - prev->start; 1534 if ( (prev->end == entry->start) && 1535 (prev->object.vm_object == entry->object.vm_object) && 1536 (!prev->object.vm_object || 1537 (prev->offset + prevsize == entry->offset)) && 1538 (prev->eflags == entry->eflags) && 1539 (prev->protection == entry->protection) && 1540 (prev->max_protection == entry->max_protection) && 1541 (prev->inheritance == entry->inheritance) && 1542 (prev->wired_count == entry->wired_count) && 1543 (prev->cred == entry->cred)) { 1544 vm_map_entry_unlink(map, prev); 1545 entry->start = prev->start; 1546 entry->offset = prev->offset; 1547 if (entry->prev != &map->header) 1548 vm_map_entry_resize_free(map, entry->prev); 1549 1550 /* 1551 * If the backing object is a vnode object, 1552 * vm_object_deallocate() calls vrele(). 1553 * However, vrele() does not lock the vnode 1554 * because the vnode has additional 1555 * references. Thus, the map lock can be kept 1556 * without causing a lock-order reversal with 1557 * the vnode lock. 1558 * 1559 * Since we count the number of virtual page 1560 * mappings in object->un_pager.vnp.writemappings, 1561 * the writemappings value should not be adjusted 1562 * when the entry is disposed of. 1563 */ 1564 if (prev->object.vm_object) 1565 vm_object_deallocate(prev->object.vm_object); 1566 if (prev->cred != NULL) 1567 crfree(prev->cred); 1568 vm_map_entry_dispose(map, prev); 1569 } 1570 } 1571 1572 next = entry->next; 1573 if (next != &map->header) { 1574 esize = entry->end - entry->start; 1575 if ((entry->end == next->start) && 1576 (next->object.vm_object == entry->object.vm_object) && 1577 (!entry->object.vm_object || 1578 (entry->offset + esize == next->offset)) && 1579 (next->eflags == entry->eflags) && 1580 (next->protection == entry->protection) && 1581 (next->max_protection == entry->max_protection) && 1582 (next->inheritance == entry->inheritance) && 1583 (next->wired_count == entry->wired_count) && 1584 (next->cred == entry->cred)) { 1585 vm_map_entry_unlink(map, next); 1586 entry->end = next->end; 1587 vm_map_entry_resize_free(map, entry); 1588 1589 /* 1590 * See comment above. 1591 */ 1592 if (next->object.vm_object) 1593 vm_object_deallocate(next->object.vm_object); 1594 if (next->cred != NULL) 1595 crfree(next->cred); 1596 vm_map_entry_dispose(map, next); 1597 } 1598 } 1599} 1600/* 1601 * vm_map_clip_start: [ internal use only ] 1602 * 1603 * Asserts that the given entry begins at or after 1604 * the specified address; if necessary, 1605 * it splits the entry into two. 1606 */ 1607#define vm_map_clip_start(map, entry, startaddr) \ 1608{ \ 1609 if (startaddr > entry->start) \ 1610 _vm_map_clip_start(map, entry, startaddr); \ 1611} 1612 1613/* 1614 * This routine is called only when it is known that 1615 * the entry must be split. 1616 */ 1617static void 1618_vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1619{ 1620 vm_map_entry_t new_entry; 1621 1622 VM_MAP_ASSERT_LOCKED(map); 1623 1624 /* 1625 * Split off the front portion -- note that we must insert the new 1626 * entry BEFORE this one, so that this entry has the specified 1627 * starting address. 1628 */ 1629 vm_map_simplify_entry(map, entry); 1630 1631 /* 1632 * If there is no object backing this entry, we might as well create 1633 * one now. If we defer it, an object can get created after the map 1634 * is clipped, and individual objects will be created for the split-up 1635 * map. This is a bit of a hack, but is also about the best place to 1636 * put this improvement. 1637 */ 1638 if (entry->object.vm_object == NULL && !map->system_map) { 1639 vm_object_t object; 1640 object = vm_object_allocate(OBJT_DEFAULT, 1641 atop(entry->end - entry->start)); 1642 entry->object.vm_object = object; 1643 entry->offset = 0; 1644 if (entry->cred != NULL) { 1645 object->cred = entry->cred; 1646 object->charge = entry->end - entry->start; 1647 entry->cred = NULL; 1648 } 1649 } else if (entry->object.vm_object != NULL && 1650 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1651 entry->cred != NULL) { 1652 VM_OBJECT_WLOCK(entry->object.vm_object); 1653 KASSERT(entry->object.vm_object->cred == NULL, 1654 ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry)); 1655 entry->object.vm_object->cred = entry->cred; 1656 entry->object.vm_object->charge = entry->end - entry->start; 1657 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1658 entry->cred = NULL; 1659 } 1660 1661 new_entry = vm_map_entry_create(map); 1662 *new_entry = *entry; 1663 1664 new_entry->end = start; 1665 entry->offset += (start - entry->start); 1666 entry->start = start; 1667 if (new_entry->cred != NULL) 1668 crhold(entry->cred); 1669 1670 vm_map_entry_link(map, entry->prev, new_entry); 1671 1672 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1673 vm_object_reference(new_entry->object.vm_object); 1674 /* 1675 * The object->un_pager.vnp.writemappings for the 1676 * object of MAP_ENTRY_VN_WRITECNT type entry shall be 1677 * kept as is here. The virtual pages are 1678 * re-distributed among the clipped entries, so the sum is 1679 * left the same. 1680 */ 1681 } 1682} 1683 1684/* 1685 * vm_map_clip_end: [ internal use only ] 1686 * 1687 * Asserts that the given entry ends at or before 1688 * the specified address; if necessary, 1689 * it splits the entry into two. 1690 */ 1691#define vm_map_clip_end(map, entry, endaddr) \ 1692{ \ 1693 if ((endaddr) < (entry->end)) \ 1694 _vm_map_clip_end((map), (entry), (endaddr)); \ 1695} 1696 1697/* 1698 * This routine is called only when it is known that 1699 * the entry must be split. 1700 */ 1701static void 1702_vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1703{ 1704 vm_map_entry_t new_entry; 1705 1706 VM_MAP_ASSERT_LOCKED(map); 1707 1708 /* 1709 * If there is no object backing this entry, we might as well create 1710 * one now. If we defer it, an object can get created after the map 1711 * is clipped, and individual objects will be created for the split-up 1712 * map. This is a bit of a hack, but is also about the best place to 1713 * put this improvement. 1714 */ 1715 if (entry->object.vm_object == NULL && !map->system_map) { 1716 vm_object_t object; 1717 object = vm_object_allocate(OBJT_DEFAULT, 1718 atop(entry->end - entry->start)); 1719 entry->object.vm_object = object; 1720 entry->offset = 0; 1721 if (entry->cred != NULL) { 1722 object->cred = entry->cred; 1723 object->charge = entry->end - entry->start; 1724 entry->cred = NULL; 1725 } 1726 } else if (entry->object.vm_object != NULL && 1727 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1728 entry->cred != NULL) { 1729 VM_OBJECT_WLOCK(entry->object.vm_object); 1730 KASSERT(entry->object.vm_object->cred == NULL, 1731 ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry)); 1732 entry->object.vm_object->cred = entry->cred; 1733 entry->object.vm_object->charge = entry->end - entry->start; 1734 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1735 entry->cred = NULL; 1736 } 1737 1738 /* 1739 * Create a new entry and insert it AFTER the specified entry 1740 */ 1741 new_entry = vm_map_entry_create(map); 1742 *new_entry = *entry; 1743 1744 new_entry->start = entry->end = end; 1745 new_entry->offset += (end - entry->start); 1746 if (new_entry->cred != NULL) 1747 crhold(entry->cred); 1748 1749 vm_map_entry_link(map, entry, new_entry); 1750 1751 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1752 vm_object_reference(new_entry->object.vm_object); 1753 } 1754} 1755 1756/* 1757 * vm_map_submap: [ kernel use only ] 1758 * 1759 * Mark the given range as handled by a subordinate map. 1760 * 1761 * This range must have been created with vm_map_find, 1762 * and no other operations may have been performed on this 1763 * range prior to calling vm_map_submap. 1764 * 1765 * Only a limited number of operations can be performed 1766 * within this rage after calling vm_map_submap: 1767 * vm_fault 1768 * [Don't try vm_map_copy!] 1769 * 1770 * To remove a submapping, one must first remove the 1771 * range from the superior map, and then destroy the 1772 * submap (if desired). [Better yet, don't try it.] 1773 */ 1774int 1775vm_map_submap( 1776 vm_map_t map, 1777 vm_offset_t start, 1778 vm_offset_t end, 1779 vm_map_t submap) 1780{ 1781 vm_map_entry_t entry; 1782 int result = KERN_INVALID_ARGUMENT; 1783 1784 vm_map_lock(map); 1785 1786 VM_MAP_RANGE_CHECK(map, start, end); 1787 1788 if (vm_map_lookup_entry(map, start, &entry)) { 1789 vm_map_clip_start(map, entry, start); 1790 } else 1791 entry = entry->next; 1792 1793 vm_map_clip_end(map, entry, end); 1794 1795 if ((entry->start == start) && (entry->end == end) && 1796 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1797 (entry->object.vm_object == NULL)) { 1798 entry->object.sub_map = submap; 1799 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1800 result = KERN_SUCCESS; 1801 } 1802 vm_map_unlock(map); 1803 1804 return (result); 1805} 1806 1807/* 1808 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified 1809 */ 1810#define MAX_INIT_PT 96 1811 1812/* 1813 * vm_map_pmap_enter: 1814 * 1815 * Preload the specified map's pmap with mappings to the specified 1816 * object's memory-resident pages. No further physical pages are 1817 * allocated, and no further virtual pages are retrieved from secondary 1818 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a 1819 * limited number of page mappings are created at the low-end of the 1820 * specified address range. (For this purpose, a superpage mapping 1821 * counts as one page mapping.) Otherwise, all resident pages within 1822 * the specified address range are mapped. Because these mappings are 1823 * being created speculatively, cached pages are not reactivated and 1824 * mapped. 1825 */ 1826void 1827vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 1828 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1829{ 1830 vm_offset_t start; 1831 vm_page_t p, p_start; 1832 vm_pindex_t mask, psize, threshold, tmpidx; 1833 1834 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 1835 return; 1836 VM_OBJECT_RLOCK(object); 1837 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1838 VM_OBJECT_RUNLOCK(object); 1839 VM_OBJECT_WLOCK(object); 1840 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1841 pmap_object_init_pt(map->pmap, addr, object, pindex, 1842 size); 1843 VM_OBJECT_WUNLOCK(object); 1844 return; 1845 } 1846 VM_OBJECT_LOCK_DOWNGRADE(object); 1847 } 1848 1849 psize = atop(size); 1850 if (psize + pindex > object->size) { 1851 if (object->size < pindex) { 1852 VM_OBJECT_RUNLOCK(object); 1853 return; 1854 } 1855 psize = object->size - pindex; 1856 } 1857 1858 start = 0; 1859 p_start = NULL; 1860 threshold = MAX_INIT_PT; 1861 1862 p = vm_page_find_least(object, pindex); 1863 /* 1864 * Assert: the variable p is either (1) the page with the 1865 * least pindex greater than or equal to the parameter pindex 1866 * or (2) NULL. 1867 */ 1868 for (; 1869 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1870 p = TAILQ_NEXT(p, listq)) { 1871 /* 1872 * don't allow an madvise to blow away our really 1873 * free pages allocating pv entries. 1874 */ 1875 if (((flags & MAP_PREFAULT_MADVISE) != 0 && 1876 cnt.v_free_count < cnt.v_free_reserved) || 1877 ((flags & MAP_PREFAULT_PARTIAL) != 0 && 1878 tmpidx >= threshold)) { 1879 psize = tmpidx; 1880 break; 1881 } 1882 if (p->valid == VM_PAGE_BITS_ALL) { 1883 if (p_start == NULL) { 1884 start = addr + ptoa(tmpidx); 1885 p_start = p; 1886 } 1887 /* Jump ahead if a superpage mapping is possible. */ 1888 if (p->psind > 0 && ((addr + ptoa(tmpidx)) & 1889 (pagesizes[p->psind] - 1)) == 0) { 1890 mask = atop(pagesizes[p->psind]) - 1; 1891 if (tmpidx + mask < psize && 1892 vm_page_ps_is_valid(p)) { 1893 p += mask; 1894 threshold += mask; 1895 } 1896 } 1897 } else if (p_start != NULL) { 1898 pmap_enter_object(map->pmap, start, addr + 1899 ptoa(tmpidx), p_start, prot); 1900 p_start = NULL; 1901 } 1902 } 1903 if (p_start != NULL) 1904 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 1905 p_start, prot); 1906 VM_OBJECT_RUNLOCK(object); 1907} 1908 1909/* 1910 * vm_map_protect: 1911 * 1912 * Sets the protection of the specified address 1913 * region in the target map. If "set_max" is 1914 * specified, the maximum protection is to be set; 1915 * otherwise, only the current protection is affected. 1916 */ 1917int 1918vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1919 vm_prot_t new_prot, boolean_t set_max) 1920{ 1921 vm_map_entry_t current, entry; 1922 vm_object_t obj; 1923 struct ucred *cred; 1924 vm_prot_t old_prot; 1925 1926 if (start == end) 1927 return (KERN_SUCCESS); 1928 1929 vm_map_lock(map); 1930 1931 VM_MAP_RANGE_CHECK(map, start, end); 1932 1933 if (vm_map_lookup_entry(map, start, &entry)) { 1934 vm_map_clip_start(map, entry, start); 1935 } else { 1936 entry = entry->next; 1937 } 1938 1939 /* 1940 * Make a first pass to check for protection violations. 1941 */ 1942 current = entry; 1943 while ((current != &map->header) && (current->start < end)) { 1944 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1945 vm_map_unlock(map); 1946 return (KERN_INVALID_ARGUMENT); 1947 } 1948 if ((new_prot & current->max_protection) != new_prot) { 1949 vm_map_unlock(map); 1950 return (KERN_PROTECTION_FAILURE); 1951 } 1952 current = current->next; 1953 } 1954 1955 1956 /* 1957 * Do an accounting pass for private read-only mappings that 1958 * now will do cow due to allowed write (e.g. debugger sets 1959 * breakpoint on text segment) 1960 */ 1961 for (current = entry; (current != &map->header) && 1962 (current->start < end); current = current->next) { 1963 1964 vm_map_clip_end(map, current, end); 1965 1966 if (set_max || 1967 ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 || 1968 ENTRY_CHARGED(current)) { 1969 continue; 1970 } 1971 1972 cred = curthread->td_ucred; 1973 obj = current->object.vm_object; 1974 1975 if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) { 1976 if (!swap_reserve(current->end - current->start)) { 1977 vm_map_unlock(map); 1978 return (KERN_RESOURCE_SHORTAGE); 1979 } 1980 crhold(cred); 1981 current->cred = cred; 1982 continue; 1983 } 1984 1985 VM_OBJECT_WLOCK(obj); 1986 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 1987 VM_OBJECT_WUNLOCK(obj); 1988 continue; 1989 } 1990 1991 /* 1992 * Charge for the whole object allocation now, since 1993 * we cannot distinguish between non-charged and 1994 * charged clipped mapping of the same object later. 1995 */ 1996 KASSERT(obj->charge == 0, 1997 ("vm_map_protect: object %p overcharged (entry %p)", 1998 obj, current)); 1999 if (!swap_reserve(ptoa(obj->size))) { 2000 VM_OBJECT_WUNLOCK(obj); 2001 vm_map_unlock(map); 2002 return (KERN_RESOURCE_SHORTAGE); 2003 } 2004 2005 crhold(cred); 2006 obj->cred = cred; 2007 obj->charge = ptoa(obj->size); 2008 VM_OBJECT_WUNLOCK(obj); 2009 } 2010 2011 /* 2012 * Go back and fix up protections. [Note that clipping is not 2013 * necessary the second time.] 2014 */ 2015 current = entry; 2016 while ((current != &map->header) && (current->start < end)) { 2017 old_prot = current->protection; 2018 2019 if (set_max) 2020 current->protection = 2021 (current->max_protection = new_prot) & 2022 old_prot; 2023 else 2024 current->protection = new_prot; 2025 2026 /* 2027 * For user wired map entries, the normal lazy evaluation of 2028 * write access upgrades through soft page faults is 2029 * undesirable. Instead, immediately copy any pages that are 2030 * copy-on-write and enable write access in the physical map. 2031 */ 2032 if ((current->eflags & MAP_ENTRY_USER_WIRED) != 0 && 2033 (current->protection & VM_PROT_WRITE) != 0 && 2034 (old_prot & VM_PROT_WRITE) == 0) 2035 vm_fault_copy_entry(map, map, current, current, NULL); 2036 2037 /* 2038 * When restricting access, update the physical map. Worry 2039 * about copy-on-write here. 2040 */ 2041 if ((old_prot & ~current->protection) != 0) { 2042#define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 2043 VM_PROT_ALL) 2044 pmap_protect(map->pmap, current->start, 2045 current->end, 2046 current->protection & MASK(current)); 2047#undef MASK 2048 } 2049 vm_map_simplify_entry(map, current); 2050 current = current->next; 2051 } 2052 vm_map_unlock(map); 2053 return (KERN_SUCCESS); 2054} 2055 2056/* 2057 * vm_map_madvise: 2058 * 2059 * This routine traverses a processes map handling the madvise 2060 * system call. Advisories are classified as either those effecting 2061 * the vm_map_entry structure, or those effecting the underlying 2062 * objects. 2063 */ 2064int 2065vm_map_madvise( 2066 vm_map_t map, 2067 vm_offset_t start, 2068 vm_offset_t end, 2069 int behav) 2070{ 2071 vm_map_entry_t current, entry; 2072 int modify_map = 0; 2073 2074 /* 2075 * Some madvise calls directly modify the vm_map_entry, in which case 2076 * we need to use an exclusive lock on the map and we need to perform 2077 * various clipping operations. Otherwise we only need a read-lock 2078 * on the map. 2079 */ 2080 switch(behav) { 2081 case MADV_NORMAL: 2082 case MADV_SEQUENTIAL: 2083 case MADV_RANDOM: 2084 case MADV_NOSYNC: 2085 case MADV_AUTOSYNC: 2086 case MADV_NOCORE: 2087 case MADV_CORE: 2088 if (start == end) 2089 return (KERN_SUCCESS); 2090 modify_map = 1; 2091 vm_map_lock(map); 2092 break; 2093 case MADV_WILLNEED: 2094 case MADV_DONTNEED: 2095 case MADV_FREE: 2096 if (start == end) 2097 return (KERN_SUCCESS); 2098 vm_map_lock_read(map); 2099 break; 2100 default: 2101 return (KERN_INVALID_ARGUMENT); 2102 } 2103 2104 /* 2105 * Locate starting entry and clip if necessary. 2106 */ 2107 VM_MAP_RANGE_CHECK(map, start, end); 2108 2109 if (vm_map_lookup_entry(map, start, &entry)) { 2110 if (modify_map) 2111 vm_map_clip_start(map, entry, start); 2112 } else { 2113 entry = entry->next; 2114 } 2115 2116 if (modify_map) { 2117 /* 2118 * madvise behaviors that are implemented in the vm_map_entry. 2119 * 2120 * We clip the vm_map_entry so that behavioral changes are 2121 * limited to the specified address range. 2122 */ 2123 for (current = entry; 2124 (current != &map->header) && (current->start < end); 2125 current = current->next 2126 ) { 2127 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2128 continue; 2129 2130 vm_map_clip_end(map, current, end); 2131 2132 switch (behav) { 2133 case MADV_NORMAL: 2134 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 2135 break; 2136 case MADV_SEQUENTIAL: 2137 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 2138 break; 2139 case MADV_RANDOM: 2140 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 2141 break; 2142 case MADV_NOSYNC: 2143 current->eflags |= MAP_ENTRY_NOSYNC; 2144 break; 2145 case MADV_AUTOSYNC: 2146 current->eflags &= ~MAP_ENTRY_NOSYNC; 2147 break; 2148 case MADV_NOCORE: 2149 current->eflags |= MAP_ENTRY_NOCOREDUMP; 2150 break; 2151 case MADV_CORE: 2152 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2153 break; 2154 default: 2155 break; 2156 } 2157 vm_map_simplify_entry(map, current); 2158 } 2159 vm_map_unlock(map); 2160 } else { 2161 vm_pindex_t pstart, pend; 2162 2163 /* 2164 * madvise behaviors that are implemented in the underlying 2165 * vm_object. 2166 * 2167 * Since we don't clip the vm_map_entry, we have to clip 2168 * the vm_object pindex and count. 2169 */ 2170 for (current = entry; 2171 (current != &map->header) && (current->start < end); 2172 current = current->next 2173 ) { 2174 vm_offset_t useEnd, useStart; 2175 2176 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2177 continue; 2178 2179 pstart = OFF_TO_IDX(current->offset); 2180 pend = pstart + atop(current->end - current->start); 2181 useStart = current->start; 2182 useEnd = current->end; 2183 2184 if (current->start < start) { 2185 pstart += atop(start - current->start); 2186 useStart = start; 2187 } 2188 if (current->end > end) { 2189 pend -= atop(current->end - end); 2190 useEnd = end; 2191 } 2192 2193 if (pstart >= pend) 2194 continue; 2195 2196 /* 2197 * Perform the pmap_advise() before clearing 2198 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2199 * concurrent pmap operation, such as pmap_remove(), 2200 * could clear a reference in the pmap and set 2201 * PGA_REFERENCED on the page before the pmap_advise() 2202 * had completed. Consequently, the page would appear 2203 * referenced based upon an old reference that 2204 * occurred before this pmap_advise() ran. 2205 */ 2206 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2207 pmap_advise(map->pmap, useStart, useEnd, 2208 behav); 2209 2210 vm_object_madvise(current->object.vm_object, pstart, 2211 pend, behav); 2212 if (behav == MADV_WILLNEED) { 2213 vm_map_pmap_enter(map, 2214 useStart, 2215 current->protection, 2216 current->object.vm_object, 2217 pstart, 2218 ptoa(pend - pstart), 2219 MAP_PREFAULT_MADVISE 2220 ); 2221 } 2222 } 2223 vm_map_unlock_read(map); 2224 } 2225 return (0); 2226} 2227 2228 2229/* 2230 * vm_map_inherit: 2231 * 2232 * Sets the inheritance of the specified address 2233 * range in the target map. Inheritance 2234 * affects how the map will be shared with 2235 * child maps at the time of vmspace_fork. 2236 */ 2237int 2238vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2239 vm_inherit_t new_inheritance) 2240{ 2241 vm_map_entry_t entry; 2242 vm_map_entry_t temp_entry; 2243 2244 switch (new_inheritance) { 2245 case VM_INHERIT_NONE: 2246 case VM_INHERIT_COPY: 2247 case VM_INHERIT_SHARE: 2248 break; 2249 default: 2250 return (KERN_INVALID_ARGUMENT); 2251 } 2252 if (start == end) 2253 return (KERN_SUCCESS); 2254 vm_map_lock(map); 2255 VM_MAP_RANGE_CHECK(map, start, end); 2256 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2257 entry = temp_entry; 2258 vm_map_clip_start(map, entry, start); 2259 } else 2260 entry = temp_entry->next; 2261 while ((entry != &map->header) && (entry->start < end)) { 2262 vm_map_clip_end(map, entry, end); 2263 entry->inheritance = new_inheritance; 2264 vm_map_simplify_entry(map, entry); 2265 entry = entry->next; 2266 } 2267 vm_map_unlock(map); 2268 return (KERN_SUCCESS); 2269} 2270 2271/* 2272 * vm_map_unwire: 2273 * 2274 * Implements both kernel and user unwiring. 2275 */ 2276int 2277vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2278 int flags) 2279{ 2280 vm_map_entry_t entry, first_entry, tmp_entry; 2281 vm_offset_t saved_start; 2282 unsigned int last_timestamp; 2283 int rv; 2284 boolean_t need_wakeup, result, user_unwire; 2285 2286 if (start == end) 2287 return (KERN_SUCCESS); 2288 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2289 vm_map_lock(map); 2290 VM_MAP_RANGE_CHECK(map, start, end); 2291 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2292 if (flags & VM_MAP_WIRE_HOLESOK) 2293 first_entry = first_entry->next; 2294 else { 2295 vm_map_unlock(map); 2296 return (KERN_INVALID_ADDRESS); 2297 } 2298 } 2299 last_timestamp = map->timestamp; 2300 entry = first_entry; 2301 while (entry != &map->header && entry->start < end) { 2302 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2303 /* 2304 * We have not yet clipped the entry. 2305 */ 2306 saved_start = (start >= entry->start) ? start : 2307 entry->start; 2308 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2309 if (vm_map_unlock_and_wait(map, 0)) { 2310 /* 2311 * Allow interruption of user unwiring? 2312 */ 2313 } 2314 vm_map_lock(map); 2315 if (last_timestamp+1 != map->timestamp) { 2316 /* 2317 * Look again for the entry because the map was 2318 * modified while it was unlocked. 2319 * Specifically, the entry may have been 2320 * clipped, merged, or deleted. 2321 */ 2322 if (!vm_map_lookup_entry(map, saved_start, 2323 &tmp_entry)) { 2324 if (flags & VM_MAP_WIRE_HOLESOK) 2325 tmp_entry = tmp_entry->next; 2326 else { 2327 if (saved_start == start) { 2328 /* 2329 * First_entry has been deleted. 2330 */ 2331 vm_map_unlock(map); 2332 return (KERN_INVALID_ADDRESS); 2333 } 2334 end = saved_start; 2335 rv = KERN_INVALID_ADDRESS; 2336 goto done; 2337 } 2338 } 2339 if (entry == first_entry) 2340 first_entry = tmp_entry; 2341 else 2342 first_entry = NULL; 2343 entry = tmp_entry; 2344 } 2345 last_timestamp = map->timestamp; 2346 continue; 2347 } 2348 vm_map_clip_start(map, entry, start); 2349 vm_map_clip_end(map, entry, end); 2350 /* 2351 * Mark the entry in case the map lock is released. (See 2352 * above.) 2353 */ 2354 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2355 entry->wiring_thread == NULL, 2356 ("owned map entry %p", entry)); 2357 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2358 entry->wiring_thread = curthread; 2359 /* 2360 * Check the map for holes in the specified region. 2361 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2362 */ 2363 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2364 (entry->end < end && (entry->next == &map->header || 2365 entry->next->start > entry->end))) { 2366 end = entry->end; 2367 rv = KERN_INVALID_ADDRESS; 2368 goto done; 2369 } 2370 /* 2371 * If system unwiring, require that the entry is system wired. 2372 */ 2373 if (!user_unwire && 2374 vm_map_entry_system_wired_count(entry) == 0) { 2375 end = entry->end; 2376 rv = KERN_INVALID_ARGUMENT; 2377 goto done; 2378 } 2379 entry = entry->next; 2380 } 2381 rv = KERN_SUCCESS; 2382done: 2383 need_wakeup = FALSE; 2384 if (first_entry == NULL) { 2385 result = vm_map_lookup_entry(map, start, &first_entry); 2386 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2387 first_entry = first_entry->next; 2388 else 2389 KASSERT(result, ("vm_map_unwire: lookup failed")); 2390 } 2391 for (entry = first_entry; entry != &map->header && entry->start < end; 2392 entry = entry->next) { 2393 /* 2394 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2395 * space in the unwired region could have been mapped 2396 * while the map lock was dropped for draining 2397 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 2398 * could be simultaneously wiring this new mapping 2399 * entry. Detect these cases and skip any entries 2400 * marked as in transition by us. 2401 */ 2402 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2403 entry->wiring_thread != curthread) { 2404 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2405 ("vm_map_unwire: !HOLESOK and new/changed entry")); 2406 continue; 2407 } 2408 2409 if (rv == KERN_SUCCESS && (!user_unwire || 2410 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 2411 if (user_unwire) 2412 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2413 if (entry->wired_count == 1) 2414 vm_map_entry_unwire(map, entry); 2415 else 2416 entry->wired_count--; 2417 } 2418 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2419 ("vm_map_unwire: in-transition flag missing %p", entry)); 2420 KASSERT(entry->wiring_thread == curthread, 2421 ("vm_map_unwire: alien wire %p", entry)); 2422 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 2423 entry->wiring_thread = NULL; 2424 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2425 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2426 need_wakeup = TRUE; 2427 } 2428 vm_map_simplify_entry(map, entry); 2429 } 2430 vm_map_unlock(map); 2431 if (need_wakeup) 2432 vm_map_wakeup(map); 2433 return (rv); 2434} 2435 2436/* 2437 * vm_map_wire_entry_failure: 2438 * 2439 * Handle a wiring failure on the given entry. 2440 * 2441 * The map should be locked. 2442 */ 2443static void 2444vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 2445 vm_offset_t failed_addr) 2446{ 2447 2448 VM_MAP_ASSERT_LOCKED(map); 2449 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 && 2450 entry->wired_count == 1, 2451 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry)); 2452 KASSERT(failed_addr < entry->end, 2453 ("vm_map_wire_entry_failure: entry %p was fully wired", entry)); 2454 2455 /* 2456 * If any pages at the start of this entry were successfully wired, 2457 * then unwire them. 2458 */ 2459 if (failed_addr > entry->start) { 2460 pmap_unwire(map->pmap, entry->start, failed_addr); 2461 vm_object_unwire(entry->object.vm_object, entry->offset, 2462 failed_addr - entry->start, PQ_ACTIVE); 2463 } 2464 2465 /* 2466 * Assign an out-of-range value to represent the failure to wire this 2467 * entry. 2468 */ 2469 entry->wired_count = -1; 2470} 2471 2472/* 2473 * vm_map_wire: 2474 * 2475 * Implements both kernel and user wiring. 2476 */ 2477int 2478vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2479 int flags) 2480{ 2481 vm_map_entry_t entry, first_entry, tmp_entry; 2482 vm_offset_t faddr, saved_end, saved_start; 2483 unsigned int last_timestamp; 2484 int rv; 2485 boolean_t need_wakeup, result, user_wire; 2486 vm_prot_t prot; 2487 2488 if (start == end) 2489 return (KERN_SUCCESS); 2490 prot = 0; 2491 if (flags & VM_MAP_WIRE_WRITE) 2492 prot |= VM_PROT_WRITE; 2493 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2494 vm_map_lock(map); 2495 VM_MAP_RANGE_CHECK(map, start, end); 2496 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2497 if (flags & VM_MAP_WIRE_HOLESOK) 2498 first_entry = first_entry->next; 2499 else { 2500 vm_map_unlock(map); 2501 return (KERN_INVALID_ADDRESS); 2502 } 2503 } 2504 last_timestamp = map->timestamp; 2505 entry = first_entry; 2506 while (entry != &map->header && entry->start < end) { 2507 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2508 /* 2509 * We have not yet clipped the entry. 2510 */ 2511 saved_start = (start >= entry->start) ? start : 2512 entry->start; 2513 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2514 if (vm_map_unlock_and_wait(map, 0)) { 2515 /* 2516 * Allow interruption of user wiring? 2517 */ 2518 } 2519 vm_map_lock(map); 2520 if (last_timestamp + 1 != map->timestamp) { 2521 /* 2522 * Look again for the entry because the map was 2523 * modified while it was unlocked. 2524 * Specifically, the entry may have been 2525 * clipped, merged, or deleted. 2526 */ 2527 if (!vm_map_lookup_entry(map, saved_start, 2528 &tmp_entry)) { 2529 if (flags & VM_MAP_WIRE_HOLESOK) 2530 tmp_entry = tmp_entry->next; 2531 else { 2532 if (saved_start == start) { 2533 /* 2534 * first_entry has been deleted. 2535 */ 2536 vm_map_unlock(map); 2537 return (KERN_INVALID_ADDRESS); 2538 } 2539 end = saved_start; 2540 rv = KERN_INVALID_ADDRESS; 2541 goto done; 2542 } 2543 } 2544 if (entry == first_entry) 2545 first_entry = tmp_entry; 2546 else 2547 first_entry = NULL; 2548 entry = tmp_entry; 2549 } 2550 last_timestamp = map->timestamp; 2551 continue; 2552 } 2553 vm_map_clip_start(map, entry, start); 2554 vm_map_clip_end(map, entry, end); 2555 /* 2556 * Mark the entry in case the map lock is released. (See 2557 * above.) 2558 */ 2559 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2560 entry->wiring_thread == NULL, 2561 ("owned map entry %p", entry)); 2562 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2563 entry->wiring_thread = curthread; 2564 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 2565 || (entry->protection & prot) != prot) { 2566 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 2567 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { 2568 end = entry->end; 2569 rv = KERN_INVALID_ADDRESS; 2570 goto done; 2571 } 2572 goto next_entry; 2573 } 2574 if (entry->wired_count == 0) { 2575 entry->wired_count++; 2576 saved_start = entry->start; 2577 saved_end = entry->end; 2578 2579 /* 2580 * Release the map lock, relying on the in-transition 2581 * mark. Mark the map busy for fork. 2582 */ 2583 vm_map_busy(map); 2584 vm_map_unlock(map); 2585 2586 faddr = saved_start; 2587 do { 2588 /* 2589 * Simulate a fault to get the page and enter 2590 * it into the physical map. 2591 */ 2592 if ((rv = vm_fault(map, faddr, VM_PROT_NONE, 2593 VM_FAULT_CHANGE_WIRING)) != KERN_SUCCESS) 2594 break; 2595 } while ((faddr += PAGE_SIZE) < saved_end); 2596 vm_map_lock(map); 2597 vm_map_unbusy(map); 2598 if (last_timestamp + 1 != map->timestamp) { 2599 /* 2600 * Look again for the entry because the map was 2601 * modified while it was unlocked. The entry 2602 * may have been clipped, but NOT merged or 2603 * deleted. 2604 */ 2605 result = vm_map_lookup_entry(map, saved_start, 2606 &tmp_entry); 2607 KASSERT(result, ("vm_map_wire: lookup failed")); 2608 if (entry == first_entry) 2609 first_entry = tmp_entry; 2610 else 2611 first_entry = NULL; 2612 entry = tmp_entry; 2613 while (entry->end < saved_end) { 2614 /* 2615 * In case of failure, handle entries 2616 * that were not fully wired here; 2617 * fully wired entries are handled 2618 * later. 2619 */ 2620 if (rv != KERN_SUCCESS && 2621 faddr < entry->end) 2622 vm_map_wire_entry_failure(map, 2623 entry, faddr); 2624 entry = entry->next; 2625 } 2626 } 2627 last_timestamp = map->timestamp; 2628 if (rv != KERN_SUCCESS) { 2629 vm_map_wire_entry_failure(map, entry, faddr); 2630 end = entry->end; 2631 goto done; 2632 } 2633 } else if (!user_wire || 2634 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2635 entry->wired_count++; 2636 } 2637 /* 2638 * Check the map for holes in the specified region. 2639 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2640 */ 2641 next_entry: 2642 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2643 (entry->end < end && (entry->next == &map->header || 2644 entry->next->start > entry->end))) { 2645 end = entry->end; 2646 rv = KERN_INVALID_ADDRESS; 2647 goto done; 2648 } 2649 entry = entry->next; 2650 } 2651 rv = KERN_SUCCESS; 2652done: 2653 need_wakeup = FALSE; 2654 if (first_entry == NULL) { 2655 result = vm_map_lookup_entry(map, start, &first_entry); 2656 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2657 first_entry = first_entry->next; 2658 else 2659 KASSERT(result, ("vm_map_wire: lookup failed")); 2660 } 2661 for (entry = first_entry; entry != &map->header && entry->start < end; 2662 entry = entry->next) { 2663 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) 2664 goto next_entry_done; 2665 2666 /* 2667 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2668 * space in the unwired region could have been mapped 2669 * while the map lock was dropped for faulting in the 2670 * pages or draining MAP_ENTRY_IN_TRANSITION. 2671 * Moreover, another thread could be simultaneously 2672 * wiring this new mapping entry. Detect these cases 2673 * and skip any entries marked as in transition by us. 2674 */ 2675 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2676 entry->wiring_thread != curthread) { 2677 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2678 ("vm_map_wire: !HOLESOK and new/changed entry")); 2679 continue; 2680 } 2681 2682 if (rv == KERN_SUCCESS) { 2683 if (user_wire) 2684 entry->eflags |= MAP_ENTRY_USER_WIRED; 2685 } else if (entry->wired_count == -1) { 2686 /* 2687 * Wiring failed on this entry. Thus, unwiring is 2688 * unnecessary. 2689 */ 2690 entry->wired_count = 0; 2691 } else if (!user_wire || 2692 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2693 /* 2694 * Undo the wiring. Wiring succeeded on this entry 2695 * but failed on a later entry. 2696 */ 2697 if (entry->wired_count == 1) 2698 vm_map_entry_unwire(map, entry); 2699 else 2700 entry->wired_count--; 2701 } 2702 next_entry_done: 2703 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2704 ("vm_map_wire: in-transition flag missing %p", entry)); 2705 KASSERT(entry->wiring_thread == curthread, 2706 ("vm_map_wire: alien wire %p", entry)); 2707 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 2708 MAP_ENTRY_WIRE_SKIPPED); 2709 entry->wiring_thread = NULL; 2710 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2711 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2712 need_wakeup = TRUE; 2713 } 2714 vm_map_simplify_entry(map, entry); 2715 } 2716 vm_map_unlock(map); 2717 if (need_wakeup) 2718 vm_map_wakeup(map); 2719 return (rv); 2720} 2721 2722/* 2723 * vm_map_sync 2724 * 2725 * Push any dirty cached pages in the address range to their pager. 2726 * If syncio is TRUE, dirty pages are written synchronously. 2727 * If invalidate is TRUE, any cached pages are freed as well. 2728 * 2729 * If the size of the region from start to end is zero, we are 2730 * supposed to flush all modified pages within the region containing 2731 * start. Unfortunately, a region can be split or coalesced with 2732 * neighboring regions, making it difficult to determine what the 2733 * original region was. Therefore, we approximate this requirement by 2734 * flushing the current region containing start. 2735 * 2736 * Returns an error if any part of the specified range is not mapped. 2737 */ 2738int 2739vm_map_sync( 2740 vm_map_t map, 2741 vm_offset_t start, 2742 vm_offset_t end, 2743 boolean_t syncio, 2744 boolean_t invalidate) 2745{ 2746 vm_map_entry_t current; 2747 vm_map_entry_t entry; 2748 vm_size_t size; 2749 vm_object_t object; 2750 vm_ooffset_t offset; 2751 unsigned int last_timestamp; 2752 boolean_t failed; 2753 2754 vm_map_lock_read(map); 2755 VM_MAP_RANGE_CHECK(map, start, end); 2756 if (!vm_map_lookup_entry(map, start, &entry)) { 2757 vm_map_unlock_read(map); 2758 return (KERN_INVALID_ADDRESS); 2759 } else if (start == end) { 2760 start = entry->start; 2761 end = entry->end; 2762 } 2763 /* 2764 * Make a first pass to check for user-wired memory and holes. 2765 */ 2766 for (current = entry; current != &map->header && current->start < end; 2767 current = current->next) { 2768 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 2769 vm_map_unlock_read(map); 2770 return (KERN_INVALID_ARGUMENT); 2771 } 2772 if (end > current->end && 2773 (current->next == &map->header || 2774 current->end != current->next->start)) { 2775 vm_map_unlock_read(map); 2776 return (KERN_INVALID_ADDRESS); 2777 } 2778 } 2779 2780 if (invalidate) 2781 pmap_remove(map->pmap, start, end); 2782 failed = FALSE; 2783 2784 /* 2785 * Make a second pass, cleaning/uncaching pages from the indicated 2786 * objects as we go. 2787 */ 2788 for (current = entry; current != &map->header && current->start < end;) { 2789 offset = current->offset + (start - current->start); 2790 size = (end <= current->end ? end : current->end) - start; 2791 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2792 vm_map_t smap; 2793 vm_map_entry_t tentry; 2794 vm_size_t tsize; 2795 2796 smap = current->object.sub_map; 2797 vm_map_lock_read(smap); 2798 (void) vm_map_lookup_entry(smap, offset, &tentry); 2799 tsize = tentry->end - offset; 2800 if (tsize < size) 2801 size = tsize; 2802 object = tentry->object.vm_object; 2803 offset = tentry->offset + (offset - tentry->start); 2804 vm_map_unlock_read(smap); 2805 } else { 2806 object = current->object.vm_object; 2807 } 2808 vm_object_reference(object); 2809 last_timestamp = map->timestamp; 2810 vm_map_unlock_read(map); 2811 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 2812 failed = TRUE; 2813 start += size; 2814 vm_object_deallocate(object); 2815 vm_map_lock_read(map); 2816 if (last_timestamp == map->timestamp || 2817 !vm_map_lookup_entry(map, start, ¤t)) 2818 current = current->next; 2819 } 2820 2821 vm_map_unlock_read(map); 2822 return (failed ? KERN_FAILURE : KERN_SUCCESS); 2823} 2824 2825/* 2826 * vm_map_entry_unwire: [ internal use only ] 2827 * 2828 * Make the region specified by this entry pageable. 2829 * 2830 * The map in question should be locked. 2831 * [This is the reason for this routine's existence.] 2832 */ 2833static void 2834vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2835{ 2836 2837 VM_MAP_ASSERT_LOCKED(map); 2838 KASSERT(entry->wired_count > 0, 2839 ("vm_map_entry_unwire: entry %p isn't wired", entry)); 2840 pmap_unwire(map->pmap, entry->start, entry->end); 2841 vm_object_unwire(entry->object.vm_object, entry->offset, entry->end - 2842 entry->start, PQ_ACTIVE); 2843 entry->wired_count = 0; 2844} 2845 2846static void 2847vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 2848{ 2849 2850 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 2851 vm_object_deallocate(entry->object.vm_object); 2852 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 2853} 2854 2855/* 2856 * vm_map_entry_delete: [ internal use only ] 2857 * 2858 * Deallocate the given entry from the target map. 2859 */ 2860static void 2861vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2862{ 2863 vm_object_t object; 2864 vm_pindex_t offidxstart, offidxend, count, size1; 2865 vm_ooffset_t size; 2866 2867 vm_map_entry_unlink(map, entry); 2868 object = entry->object.vm_object; 2869 size = entry->end - entry->start; 2870 map->size -= size; 2871 2872 if (entry->cred != NULL) { 2873 swap_release_by_cred(size, entry->cred); 2874 crfree(entry->cred); 2875 } 2876 2877 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2878 (object != NULL)) { 2879 KASSERT(entry->cred == NULL || object->cred == NULL || 2880 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 2881 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 2882 count = OFF_TO_IDX(size); 2883 offidxstart = OFF_TO_IDX(entry->offset); 2884 offidxend = offidxstart + count; 2885 VM_OBJECT_WLOCK(object); 2886 if (object->ref_count != 1 && 2887 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2888 object == kernel_object || object == kmem_object)) { 2889 vm_object_collapse(object); 2890 2891 /* 2892 * The option OBJPR_NOTMAPPED can be passed here 2893 * because vm_map_delete() already performed 2894 * pmap_remove() on the only mapping to this range 2895 * of pages. 2896 */ 2897 vm_object_page_remove(object, offidxstart, offidxend, 2898 OBJPR_NOTMAPPED); 2899 if (object->type == OBJT_SWAP) 2900 swap_pager_freespace(object, offidxstart, count); 2901 if (offidxend >= object->size && 2902 offidxstart < object->size) { 2903 size1 = object->size; 2904 object->size = offidxstart; 2905 if (object->cred != NULL) { 2906 size1 -= object->size; 2907 KASSERT(object->charge >= ptoa(size1), 2908 ("vm_map_entry_delete: object->charge < 0")); 2909 swap_release_by_cred(ptoa(size1), object->cred); 2910 object->charge -= ptoa(size1); 2911 } 2912 } 2913 } 2914 VM_OBJECT_WUNLOCK(object); 2915 } else 2916 entry->object.vm_object = NULL; 2917 if (map->system_map) 2918 vm_map_entry_deallocate(entry, TRUE); 2919 else { 2920 entry->next = curthread->td_map_def_user; 2921 curthread->td_map_def_user = entry; 2922 } 2923} 2924 2925/* 2926 * vm_map_delete: [ internal use only ] 2927 * 2928 * Deallocates the given address range from the target 2929 * map. 2930 */ 2931int 2932vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2933{ 2934 vm_map_entry_t entry; 2935 vm_map_entry_t first_entry; 2936 2937 VM_MAP_ASSERT_LOCKED(map); 2938 if (start == end) 2939 return (KERN_SUCCESS); 2940 2941 /* 2942 * Find the start of the region, and clip it 2943 */ 2944 if (!vm_map_lookup_entry(map, start, &first_entry)) 2945 entry = first_entry->next; 2946 else { 2947 entry = first_entry; 2948 vm_map_clip_start(map, entry, start); 2949 } 2950 2951 /* 2952 * Step through all entries in this region 2953 */ 2954 while ((entry != &map->header) && (entry->start < end)) { 2955 vm_map_entry_t next; 2956 2957 /* 2958 * Wait for wiring or unwiring of an entry to complete. 2959 * Also wait for any system wirings to disappear on 2960 * user maps. 2961 */ 2962 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 2963 (vm_map_pmap(map) != kernel_pmap && 2964 vm_map_entry_system_wired_count(entry) != 0)) { 2965 unsigned int last_timestamp; 2966 vm_offset_t saved_start; 2967 vm_map_entry_t tmp_entry; 2968 2969 saved_start = entry->start; 2970 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2971 last_timestamp = map->timestamp; 2972 (void) vm_map_unlock_and_wait(map, 0); 2973 vm_map_lock(map); 2974 if (last_timestamp + 1 != map->timestamp) { 2975 /* 2976 * Look again for the entry because the map was 2977 * modified while it was unlocked. 2978 * Specifically, the entry may have been 2979 * clipped, merged, or deleted. 2980 */ 2981 if (!vm_map_lookup_entry(map, saved_start, 2982 &tmp_entry)) 2983 entry = tmp_entry->next; 2984 else { 2985 entry = tmp_entry; 2986 vm_map_clip_start(map, entry, 2987 saved_start); 2988 } 2989 } 2990 continue; 2991 } 2992 vm_map_clip_end(map, entry, end); 2993 2994 next = entry->next; 2995 2996 /* 2997 * Unwire before removing addresses from the pmap; otherwise, 2998 * unwiring will put the entries back in the pmap. 2999 */ 3000 if (entry->wired_count != 0) { 3001 vm_map_entry_unwire(map, entry); 3002 } 3003 3004 pmap_remove(map->pmap, entry->start, entry->end); 3005 3006 /* 3007 * Delete the entry only after removing all pmap 3008 * entries pointing to its pages. (Otherwise, its 3009 * page frames may be reallocated, and any modify bits 3010 * will be set in the wrong object!) 3011 */ 3012 vm_map_entry_delete(map, entry); 3013 entry = next; 3014 } 3015 return (KERN_SUCCESS); 3016} 3017 3018/* 3019 * vm_map_remove: 3020 * 3021 * Remove the given address range from the target map. 3022 * This is the exported form of vm_map_delete. 3023 */ 3024int 3025vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 3026{ 3027 int result; 3028 3029 vm_map_lock(map); 3030 VM_MAP_RANGE_CHECK(map, start, end); 3031 result = vm_map_delete(map, start, end); 3032 vm_map_unlock(map); 3033 return (result); 3034} 3035 3036/* 3037 * vm_map_check_protection: 3038 * 3039 * Assert that the target map allows the specified privilege on the 3040 * entire address region given. The entire region must be allocated. 3041 * 3042 * WARNING! This code does not and should not check whether the 3043 * contents of the region is accessible. For example a smaller file 3044 * might be mapped into a larger address space. 3045 * 3046 * NOTE! This code is also called by munmap(). 3047 * 3048 * The map must be locked. A read lock is sufficient. 3049 */ 3050boolean_t 3051vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 3052 vm_prot_t protection) 3053{ 3054 vm_map_entry_t entry; 3055 vm_map_entry_t tmp_entry; 3056 3057 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 3058 return (FALSE); 3059 entry = tmp_entry; 3060 3061 while (start < end) { 3062 if (entry == &map->header) 3063 return (FALSE); 3064 /* 3065 * No holes allowed! 3066 */ 3067 if (start < entry->start) 3068 return (FALSE); 3069 /* 3070 * Check protection associated with entry. 3071 */ 3072 if ((entry->protection & protection) != protection) 3073 return (FALSE); 3074 /* go to next entry */ 3075 start = entry->end; 3076 entry = entry->next; 3077 } 3078 return (TRUE); 3079} 3080 3081/* 3082 * vm_map_copy_entry: 3083 * 3084 * Copies the contents of the source entry to the destination 3085 * entry. The entries *must* be aligned properly. 3086 */ 3087static void 3088vm_map_copy_entry( 3089 vm_map_t src_map, 3090 vm_map_t dst_map, 3091 vm_map_entry_t src_entry, 3092 vm_map_entry_t dst_entry, 3093 vm_ooffset_t *fork_charge) 3094{ 3095 vm_object_t src_object; 3096 vm_map_entry_t fake_entry; 3097 vm_offset_t size; 3098 struct ucred *cred; 3099 int charged; 3100 3101 VM_MAP_ASSERT_LOCKED(dst_map); 3102 3103 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3104 return; 3105 3106 if (src_entry->wired_count == 0 || 3107 (src_entry->protection & VM_PROT_WRITE) == 0) { 3108 /* 3109 * If the source entry is marked needs_copy, it is already 3110 * write-protected. 3111 */ 3112 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && 3113 (src_entry->protection & VM_PROT_WRITE) != 0) { 3114 pmap_protect(src_map->pmap, 3115 src_entry->start, 3116 src_entry->end, 3117 src_entry->protection & ~VM_PROT_WRITE); 3118 } 3119 3120 /* 3121 * Make a copy of the object. 3122 */ 3123 size = src_entry->end - src_entry->start; 3124 if ((src_object = src_entry->object.vm_object) != NULL) { 3125 VM_OBJECT_WLOCK(src_object); 3126 charged = ENTRY_CHARGED(src_entry); 3127 if ((src_object->handle == NULL) && 3128 (src_object->type == OBJT_DEFAULT || 3129 src_object->type == OBJT_SWAP)) { 3130 vm_object_collapse(src_object); 3131 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 3132 vm_object_split(src_entry); 3133 src_object = src_entry->object.vm_object; 3134 } 3135 } 3136 vm_object_reference_locked(src_object); 3137 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3138 if (src_entry->cred != NULL && 3139 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3140 KASSERT(src_object->cred == NULL, 3141 ("OVERCOMMIT: vm_map_copy_entry: cred %p", 3142 src_object)); 3143 src_object->cred = src_entry->cred; 3144 src_object->charge = size; 3145 } 3146 VM_OBJECT_WUNLOCK(src_object); 3147 dst_entry->object.vm_object = src_object; 3148 if (charged) { 3149 cred = curthread->td_ucred; 3150 crhold(cred); 3151 dst_entry->cred = cred; 3152 *fork_charge += size; 3153 if (!(src_entry->eflags & 3154 MAP_ENTRY_NEEDS_COPY)) { 3155 crhold(cred); 3156 src_entry->cred = cred; 3157 *fork_charge += size; 3158 } 3159 } 3160 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3161 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3162 dst_entry->offset = src_entry->offset; 3163 if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3164 /* 3165 * MAP_ENTRY_VN_WRITECNT cannot 3166 * indicate write reference from 3167 * src_entry, since the entry is 3168 * marked as needs copy. Allocate a 3169 * fake entry that is used to 3170 * decrement object->un_pager.vnp.writecount 3171 * at the appropriate time. Attach 3172 * fake_entry to the deferred list. 3173 */ 3174 fake_entry = vm_map_entry_create(dst_map); 3175 fake_entry->eflags = MAP_ENTRY_VN_WRITECNT; 3176 src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT; 3177 vm_object_reference(src_object); 3178 fake_entry->object.vm_object = src_object; 3179 fake_entry->start = src_entry->start; 3180 fake_entry->end = src_entry->end; 3181 fake_entry->next = curthread->td_map_def_user; 3182 curthread->td_map_def_user = fake_entry; 3183 } 3184 } else { 3185 dst_entry->object.vm_object = NULL; 3186 dst_entry->offset = 0; 3187 if (src_entry->cred != NULL) { 3188 dst_entry->cred = curthread->td_ucred; 3189 crhold(dst_entry->cred); 3190 *fork_charge += size; 3191 } 3192 } 3193 3194 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3195 dst_entry->end - dst_entry->start, src_entry->start); 3196 } else { 3197 /* 3198 * We don't want to make writeable wired pages copy-on-write. 3199 * Immediately copy these pages into the new map by simulating 3200 * page faults. The new pages are pageable. 3201 */ 3202 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 3203 fork_charge); 3204 } 3205} 3206 3207/* 3208 * vmspace_map_entry_forked: 3209 * Update the newly-forked vmspace each time a map entry is inherited 3210 * or copied. The values for vm_dsize and vm_tsize are approximate 3211 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 3212 */ 3213static void 3214vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 3215 vm_map_entry_t entry) 3216{ 3217 vm_size_t entrysize; 3218 vm_offset_t newend; 3219 3220 entrysize = entry->end - entry->start; 3221 vm2->vm_map.size += entrysize; 3222 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 3223 vm2->vm_ssize += btoc(entrysize); 3224 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 3225 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 3226 newend = MIN(entry->end, 3227 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 3228 vm2->vm_dsize += btoc(newend - entry->start); 3229 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 3230 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 3231 newend = MIN(entry->end, 3232 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 3233 vm2->vm_tsize += btoc(newend - entry->start); 3234 } 3235} 3236 3237/* 3238 * vmspace_fork: 3239 * Create a new process vmspace structure and vm_map 3240 * based on those of an existing process. The new map 3241 * is based on the old map, according to the inheritance 3242 * values on the regions in that map. 3243 * 3244 * XXX It might be worth coalescing the entries added to the new vmspace. 3245 * 3246 * The source map must not be locked. 3247 */ 3248struct vmspace * 3249vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 3250{ 3251 struct vmspace *vm2; 3252 vm_map_t new_map, old_map; 3253 vm_map_entry_t new_entry, old_entry; 3254 vm_object_t object; 3255 int locked; 3256 3257 old_map = &vm1->vm_map; 3258 /* Copy immutable fields of vm1 to vm2. */ 3259 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL); 3260 if (vm2 == NULL) 3261 return (NULL); 3262 vm2->vm_taddr = vm1->vm_taddr; 3263 vm2->vm_daddr = vm1->vm_daddr; 3264 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 3265 vm_map_lock(old_map); 3266 if (old_map->busy) 3267 vm_map_wait_busy(old_map); 3268 new_map = &vm2->vm_map; 3269 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 3270 KASSERT(locked, ("vmspace_fork: lock failed")); 3271 3272 old_entry = old_map->header.next; 3273 3274 while (old_entry != &old_map->header) { 3275 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 3276 panic("vm_map_fork: encountered a submap"); 3277 3278 switch (old_entry->inheritance) { 3279 case VM_INHERIT_NONE: 3280 break; 3281 3282 case VM_INHERIT_SHARE: 3283 /* 3284 * Clone the entry, creating the shared object if necessary. 3285 */ 3286 object = old_entry->object.vm_object; 3287 if (object == NULL) { 3288 object = vm_object_allocate(OBJT_DEFAULT, 3289 atop(old_entry->end - old_entry->start)); 3290 old_entry->object.vm_object = object; 3291 old_entry->offset = 0; 3292 if (old_entry->cred != NULL) { 3293 object->cred = old_entry->cred; 3294 object->charge = old_entry->end - 3295 old_entry->start; 3296 old_entry->cred = NULL; 3297 } 3298 } 3299 3300 /* 3301 * Add the reference before calling vm_object_shadow 3302 * to insure that a shadow object is created. 3303 */ 3304 vm_object_reference(object); 3305 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3306 vm_object_shadow(&old_entry->object.vm_object, 3307 &old_entry->offset, 3308 old_entry->end - old_entry->start); 3309 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3310 /* Transfer the second reference too. */ 3311 vm_object_reference( 3312 old_entry->object.vm_object); 3313 3314 /* 3315 * As in vm_map_simplify_entry(), the 3316 * vnode lock will not be acquired in 3317 * this call to vm_object_deallocate(). 3318 */ 3319 vm_object_deallocate(object); 3320 object = old_entry->object.vm_object; 3321 } 3322 VM_OBJECT_WLOCK(object); 3323 vm_object_clear_flag(object, OBJ_ONEMAPPING); 3324 if (old_entry->cred != NULL) { 3325 KASSERT(object->cred == NULL, ("vmspace_fork both cred")); 3326 object->cred = old_entry->cred; 3327 object->charge = old_entry->end - old_entry->start; 3328 old_entry->cred = NULL; 3329 } 3330 3331 /* 3332 * Assert the correct state of the vnode 3333 * v_writecount while the object is locked, to 3334 * not relock it later for the assertion 3335 * correctness. 3336 */ 3337 if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT && 3338 object->type == OBJT_VNODE) { 3339 KASSERT(((struct vnode *)object->handle)-> 3340 v_writecount > 0, 3341 ("vmspace_fork: v_writecount %p", object)); 3342 KASSERT(object->un_pager.vnp.writemappings > 0, 3343 ("vmspace_fork: vnp.writecount %p", 3344 object)); 3345 } 3346 VM_OBJECT_WUNLOCK(object); 3347 3348 /* 3349 * Clone the entry, referencing the shared object. 3350 */ 3351 new_entry = vm_map_entry_create(new_map); 3352 *new_entry = *old_entry; 3353 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3354 MAP_ENTRY_IN_TRANSITION); 3355 new_entry->wiring_thread = NULL; 3356 new_entry->wired_count = 0; 3357 if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3358 vnode_pager_update_writecount(object, 3359 new_entry->start, new_entry->end); 3360 } 3361 3362 /* 3363 * Insert the entry into the new map -- we know we're 3364 * inserting at the end of the new map. 3365 */ 3366 vm_map_entry_link(new_map, new_map->header.prev, 3367 new_entry); 3368 vmspace_map_entry_forked(vm1, vm2, new_entry); 3369 3370 /* 3371 * Update the physical map 3372 */ 3373 pmap_copy(new_map->pmap, old_map->pmap, 3374 new_entry->start, 3375 (old_entry->end - old_entry->start), 3376 old_entry->start); 3377 break; 3378 3379 case VM_INHERIT_COPY: 3380 /* 3381 * Clone the entry and link into the map. 3382 */ 3383 new_entry = vm_map_entry_create(new_map); 3384 *new_entry = *old_entry; 3385 /* 3386 * Copied entry is COW over the old object. 3387 */ 3388 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3389 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT); 3390 new_entry->wiring_thread = NULL; 3391 new_entry->wired_count = 0; 3392 new_entry->object.vm_object = NULL; 3393 new_entry->cred = NULL; 3394 vm_map_entry_link(new_map, new_map->header.prev, 3395 new_entry); 3396 vmspace_map_entry_forked(vm1, vm2, new_entry); 3397 vm_map_copy_entry(old_map, new_map, old_entry, 3398 new_entry, fork_charge); 3399 break; 3400 } 3401 old_entry = old_entry->next; 3402 } 3403 /* 3404 * Use inlined vm_map_unlock() to postpone handling the deferred 3405 * map entries, which cannot be done until both old_map and 3406 * new_map locks are released. 3407 */ 3408 sx_xunlock(&old_map->lock); 3409 sx_xunlock(&new_map->lock); 3410 vm_map_process_deferred(); 3411 3412 return (vm2); 3413} 3414 3415int 3416vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3417 vm_prot_t prot, vm_prot_t max, int cow) 3418{ 3419 vm_size_t growsize, init_ssize; 3420 rlim_t lmemlim, vmemlim; 3421 int rv; 3422 3423 growsize = sgrowsiz; 3424 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3425 vm_map_lock(map); 3426 PROC_LOCK(curproc); 3427 lmemlim = lim_cur(curproc, RLIMIT_MEMLOCK); 3428 vmemlim = lim_cur(curproc, RLIMIT_VMEM); 3429 PROC_UNLOCK(curproc); 3430 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3431 if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) { 3432 rv = KERN_NO_SPACE; 3433 goto out; 3434 } 3435 } 3436 /* If we would blow our VMEM resource limit, no go */ 3437 if (map->size + init_ssize > vmemlim) { 3438 rv = KERN_NO_SPACE; 3439 goto out; 3440 } 3441 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, 3442 max, cow); 3443out: 3444 vm_map_unlock(map); 3445 return (rv); 3446} 3447 3448static int 3449vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3450 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) 3451{ 3452 vm_map_entry_t new_entry, prev_entry; 3453 vm_offset_t bot, top; 3454 vm_size_t init_ssize; 3455 int orient, rv; 3456 3457 /* 3458 * The stack orientation is piggybacked with the cow argument. 3459 * Extract it into orient and mask the cow argument so that we 3460 * don't pass it around further. 3461 * NOTE: We explicitly allow bi-directional stacks. 3462 */ 3463 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 3464 KASSERT(orient != 0, ("No stack grow direction")); 3465 3466 if (addrbos < vm_map_min(map) || 3467 addrbos > vm_map_max(map) || 3468 addrbos + max_ssize < addrbos) 3469 return (KERN_NO_SPACE); 3470 3471 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3472 3473 /* If addr is already mapped, no go */ 3474 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) 3475 return (KERN_NO_SPACE); 3476 3477 /* 3478 * If we can't accomodate max_ssize in the current mapping, no go. 3479 * However, we need to be aware that subsequent user mappings might 3480 * map into the space we have reserved for stack, and currently this 3481 * space is not protected. 3482 * 3483 * Hopefully we will at least detect this condition when we try to 3484 * grow the stack. 3485 */ 3486 if ((prev_entry->next != &map->header) && 3487 (prev_entry->next->start < addrbos + max_ssize)) 3488 return (KERN_NO_SPACE); 3489 3490 /* 3491 * We initially map a stack of only init_ssize. We will grow as 3492 * needed later. Depending on the orientation of the stack (i.e. 3493 * the grow direction) we either map at the top of the range, the 3494 * bottom of the range or in the middle. 3495 * 3496 * Note: we would normally expect prot and max to be VM_PROT_ALL, 3497 * and cow to be 0. Possibly we should eliminate these as input 3498 * parameters, and just pass these values here in the insert call. 3499 */ 3500 if (orient == MAP_STACK_GROWS_DOWN) 3501 bot = addrbos + max_ssize - init_ssize; 3502 else if (orient == MAP_STACK_GROWS_UP) 3503 bot = addrbos; 3504 else 3505 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 3506 top = bot + init_ssize; 3507 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 3508 3509 /* Now set the avail_ssize amount. */ 3510 if (rv == KERN_SUCCESS) { 3511 if (prev_entry != &map->header) 3512 vm_map_clip_end(map, prev_entry, bot); 3513 new_entry = prev_entry->next; 3514 if (new_entry->end != top || new_entry->start != bot) 3515 panic("Bad entry start/end for new stack entry"); 3516 3517 new_entry->avail_ssize = max_ssize - init_ssize; 3518 if (orient & MAP_STACK_GROWS_DOWN) 3519 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3520 if (orient & MAP_STACK_GROWS_UP) 3521 new_entry->eflags |= MAP_ENTRY_GROWS_UP; 3522 } 3523 3524 return (rv); 3525} 3526 3527static int stack_guard_page = 0; 3528TUNABLE_INT("security.bsd.stack_guard_page", &stack_guard_page); 3529SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RW, 3530 &stack_guard_page, 0, 3531 "Insert stack guard page ahead of the growable segments."); 3532 3533/* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3534 * desired address is already mapped, or if we successfully grow 3535 * the stack. Also returns KERN_SUCCESS if addr is outside the 3536 * stack range (this is strange, but preserves compatibility with 3537 * the grow function in vm_machdep.c). 3538 */ 3539int 3540vm_map_growstack(struct proc *p, vm_offset_t addr) 3541{ 3542 vm_map_entry_t next_entry, prev_entry; 3543 vm_map_entry_t new_entry, stack_entry; 3544 struct vmspace *vm = p->p_vmspace; 3545 vm_map_t map = &vm->vm_map; 3546 vm_offset_t end; 3547 vm_size_t growsize; 3548 size_t grow_amount, max_grow; 3549 rlim_t lmemlim, stacklim, vmemlim; 3550 int is_procstack, rv; 3551 struct ucred *cred; 3552#ifdef notyet 3553 uint64_t limit; 3554#endif 3555#ifdef RACCT 3556 int error; 3557#endif 3558 3559Retry: 3560 PROC_LOCK(p); 3561 lmemlim = lim_cur(p, RLIMIT_MEMLOCK); 3562 stacklim = lim_cur(p, RLIMIT_STACK); 3563 vmemlim = lim_cur(p, RLIMIT_VMEM); 3564 PROC_UNLOCK(p); 3565 3566 vm_map_lock_read(map); 3567 3568 /* If addr is already in the entry range, no need to grow.*/ 3569 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 3570 vm_map_unlock_read(map); 3571 return (KERN_SUCCESS); 3572 } 3573 3574 next_entry = prev_entry->next; 3575 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 3576 /* 3577 * This entry does not grow upwards. Since the address lies 3578 * beyond this entry, the next entry (if one exists) has to 3579 * be a downward growable entry. The entry list header is 3580 * never a growable entry, so it suffices to check the flags. 3581 */ 3582 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 3583 vm_map_unlock_read(map); 3584 return (KERN_SUCCESS); 3585 } 3586 stack_entry = next_entry; 3587 } else { 3588 /* 3589 * This entry grows upward. If the next entry does not at 3590 * least grow downwards, this is the entry we need to grow. 3591 * otherwise we have two possible choices and we have to 3592 * select one. 3593 */ 3594 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 3595 /* 3596 * We have two choices; grow the entry closest to 3597 * the address to minimize the amount of growth. 3598 */ 3599 if (addr - prev_entry->end <= next_entry->start - addr) 3600 stack_entry = prev_entry; 3601 else 3602 stack_entry = next_entry; 3603 } else 3604 stack_entry = prev_entry; 3605 } 3606 3607 if (stack_entry == next_entry) { 3608 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 3609 KASSERT(addr < stack_entry->start, ("foo")); 3610 end = (prev_entry != &map->header) ? prev_entry->end : 3611 stack_entry->start - stack_entry->avail_ssize; 3612 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 3613 max_grow = stack_entry->start - end; 3614 } else { 3615 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 3616 KASSERT(addr >= stack_entry->end, ("foo")); 3617 end = (next_entry != &map->header) ? next_entry->start : 3618 stack_entry->end + stack_entry->avail_ssize; 3619 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 3620 max_grow = end - stack_entry->end; 3621 } 3622 3623 if (grow_amount > stack_entry->avail_ssize) { 3624 vm_map_unlock_read(map); 3625 return (KERN_NO_SPACE); 3626 } 3627 3628 /* 3629 * If there is no longer enough space between the entries nogo, and 3630 * adjust the available space. Note: this should only happen if the 3631 * user has mapped into the stack area after the stack was created, 3632 * and is probably an error. 3633 * 3634 * This also effectively destroys any guard page the user might have 3635 * intended by limiting the stack size. 3636 */ 3637 if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) { 3638 if (vm_map_lock_upgrade(map)) 3639 goto Retry; 3640 3641 stack_entry->avail_ssize = max_grow; 3642 3643 vm_map_unlock(map); 3644 return (KERN_NO_SPACE); 3645 } 3646 3647 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 3648 3649 /* 3650 * If this is the main process stack, see if we're over the stack 3651 * limit. 3652 */ 3653 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3654 vm_map_unlock_read(map); 3655 return (KERN_NO_SPACE); 3656 } 3657#ifdef RACCT 3658 PROC_LOCK(p); 3659 if (is_procstack && 3660 racct_set(p, RACCT_STACK, ctob(vm->vm_ssize) + grow_amount)) { 3661 PROC_UNLOCK(p); 3662 vm_map_unlock_read(map); 3663 return (KERN_NO_SPACE); 3664 } 3665 PROC_UNLOCK(p); 3666#endif 3667 3668 /* Round up the grow amount modulo sgrowsiz */ 3669 growsize = sgrowsiz; 3670 grow_amount = roundup(grow_amount, growsize); 3671 if (grow_amount > stack_entry->avail_ssize) 3672 grow_amount = stack_entry->avail_ssize; 3673 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3674 grow_amount = trunc_page((vm_size_t)stacklim) - 3675 ctob(vm->vm_ssize); 3676 } 3677#ifdef notyet 3678 PROC_LOCK(p); 3679 limit = racct_get_available(p, RACCT_STACK); 3680 PROC_UNLOCK(p); 3681 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 3682 grow_amount = limit - ctob(vm->vm_ssize); 3683#endif 3684 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3685 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 3686 vm_map_unlock_read(map); 3687 rv = KERN_NO_SPACE; 3688 goto out; 3689 } 3690#ifdef RACCT 3691 PROC_LOCK(p); 3692 if (racct_set(p, RACCT_MEMLOCK, 3693 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 3694 PROC_UNLOCK(p); 3695 vm_map_unlock_read(map); 3696 rv = KERN_NO_SPACE; 3697 goto out; 3698 } 3699 PROC_UNLOCK(p); 3700#endif 3701 } 3702 /* If we would blow our VMEM resource limit, no go */ 3703 if (map->size + grow_amount > vmemlim) { 3704 vm_map_unlock_read(map); 3705 rv = KERN_NO_SPACE; 3706 goto out; 3707 } 3708#ifdef RACCT 3709 PROC_LOCK(p); 3710 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 3711 PROC_UNLOCK(p); 3712 vm_map_unlock_read(map); 3713 rv = KERN_NO_SPACE; 3714 goto out; 3715 } 3716 PROC_UNLOCK(p); 3717#endif 3718 3719 if (vm_map_lock_upgrade(map)) 3720 goto Retry; 3721 3722 if (stack_entry == next_entry) { 3723 /* 3724 * Growing downward. 3725 */ 3726 /* Get the preliminary new entry start value */ 3727 addr = stack_entry->start - grow_amount; 3728 3729 /* 3730 * If this puts us into the previous entry, cut back our 3731 * growth to the available space. Also, see the note above. 3732 */ 3733 if (addr < end) { 3734 stack_entry->avail_ssize = max_grow; 3735 addr = end; 3736 if (stack_guard_page) 3737 addr += PAGE_SIZE; 3738 } 3739 3740 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 3741 next_entry->protection, next_entry->max_protection, 0); 3742 3743 /* Adjust the available stack space by the amount we grew. */ 3744 if (rv == KERN_SUCCESS) { 3745 if (prev_entry != &map->header) 3746 vm_map_clip_end(map, prev_entry, addr); 3747 new_entry = prev_entry->next; 3748 KASSERT(new_entry == stack_entry->prev, ("foo")); 3749 KASSERT(new_entry->end == stack_entry->start, ("foo")); 3750 KASSERT(new_entry->start == addr, ("foo")); 3751 grow_amount = new_entry->end - new_entry->start; 3752 new_entry->avail_ssize = stack_entry->avail_ssize - 3753 grow_amount; 3754 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 3755 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3756 } 3757 } else { 3758 /* 3759 * Growing upward. 3760 */ 3761 addr = stack_entry->end + grow_amount; 3762 3763 /* 3764 * If this puts us into the next entry, cut back our growth 3765 * to the available space. Also, see the note above. 3766 */ 3767 if (addr > end) { 3768 stack_entry->avail_ssize = end - stack_entry->end; 3769 addr = end; 3770 if (stack_guard_page) 3771 addr -= PAGE_SIZE; 3772 } 3773 3774 grow_amount = addr - stack_entry->end; 3775 cred = stack_entry->cred; 3776 if (cred == NULL && stack_entry->object.vm_object != NULL) 3777 cred = stack_entry->object.vm_object->cred; 3778 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 3779 rv = KERN_NO_SPACE; 3780 /* Grow the underlying object if applicable. */ 3781 else if (stack_entry->object.vm_object == NULL || 3782 vm_object_coalesce(stack_entry->object.vm_object, 3783 stack_entry->offset, 3784 (vm_size_t)(stack_entry->end - stack_entry->start), 3785 (vm_size_t)grow_amount, cred != NULL)) { 3786 map->size += (addr - stack_entry->end); 3787 /* Update the current entry. */ 3788 stack_entry->end = addr; 3789 stack_entry->avail_ssize -= grow_amount; 3790 vm_map_entry_resize_free(map, stack_entry); 3791 rv = KERN_SUCCESS; 3792 3793 if (next_entry != &map->header) 3794 vm_map_clip_start(map, next_entry, addr); 3795 } else 3796 rv = KERN_FAILURE; 3797 } 3798 3799 if (rv == KERN_SUCCESS && is_procstack) 3800 vm->vm_ssize += btoc(grow_amount); 3801 3802 vm_map_unlock(map); 3803 3804 /* 3805 * Heed the MAP_WIREFUTURE flag if it was set for this process. 3806 */ 3807 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 3808 vm_map_wire(map, 3809 (stack_entry == next_entry) ? addr : addr - grow_amount, 3810 (stack_entry == next_entry) ? stack_entry->start : addr, 3811 (p->p_flag & P_SYSTEM) 3812 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 3813 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 3814 } 3815 3816out: 3817#ifdef RACCT 3818 if (rv != KERN_SUCCESS) { 3819 PROC_LOCK(p); 3820 error = racct_set(p, RACCT_VMEM, map->size); 3821 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 3822 if (!old_mlock) { 3823 error = racct_set(p, RACCT_MEMLOCK, 3824 ptoa(pmap_wired_count(map->pmap))); 3825 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 3826 } 3827 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 3828 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 3829 PROC_UNLOCK(p); 3830 } 3831#endif 3832 3833 return (rv); 3834} 3835 3836/* 3837 * Unshare the specified VM space for exec. If other processes are 3838 * mapped to it, then create a new one. The new vmspace is null. 3839 */ 3840int 3841vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 3842{ 3843 struct vmspace *oldvmspace = p->p_vmspace; 3844 struct vmspace *newvmspace; 3845 3846 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 3847 ("vmspace_exec recursed")); 3848 newvmspace = vmspace_alloc(minuser, maxuser, NULL); 3849 if (newvmspace == NULL) 3850 return (ENOMEM); 3851 newvmspace->vm_swrss = oldvmspace->vm_swrss; 3852 /* 3853 * This code is written like this for prototype purposes. The 3854 * goal is to avoid running down the vmspace here, but let the 3855 * other process's that are still using the vmspace to finally 3856 * run it down. Even though there is little or no chance of blocking 3857 * here, it is a good idea to keep this form for future mods. 3858 */ 3859 PROC_VMSPACE_LOCK(p); 3860 p->p_vmspace = newvmspace; 3861 PROC_VMSPACE_UNLOCK(p); 3862 if (p == curthread->td_proc) 3863 pmap_activate(curthread); 3864 curthread->td_pflags |= TDP_EXECVMSPC; 3865 return (0); 3866} 3867 3868/* 3869 * Unshare the specified VM space for forcing COW. This 3870 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3871 */ 3872int 3873vmspace_unshare(struct proc *p) 3874{ 3875 struct vmspace *oldvmspace = p->p_vmspace; 3876 struct vmspace *newvmspace; 3877 vm_ooffset_t fork_charge; 3878 3879 if (oldvmspace->vm_refcnt == 1) 3880 return (0); 3881 fork_charge = 0; 3882 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 3883 if (newvmspace == NULL) 3884 return (ENOMEM); 3885 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 3886 vmspace_free(newvmspace); 3887 return (ENOMEM); 3888 } 3889 PROC_VMSPACE_LOCK(p); 3890 p->p_vmspace = newvmspace; 3891 PROC_VMSPACE_UNLOCK(p); 3892 if (p == curthread->td_proc) 3893 pmap_activate(curthread); 3894 vmspace_free(oldvmspace); 3895 return (0); 3896} 3897 3898/* 3899 * vm_map_lookup: 3900 * 3901 * Finds the VM object, offset, and 3902 * protection for a given virtual address in the 3903 * specified map, assuming a page fault of the 3904 * type specified. 3905 * 3906 * Leaves the map in question locked for read; return 3907 * values are guaranteed until a vm_map_lookup_done 3908 * call is performed. Note that the map argument 3909 * is in/out; the returned map must be used in 3910 * the call to vm_map_lookup_done. 3911 * 3912 * A handle (out_entry) is returned for use in 3913 * vm_map_lookup_done, to make that fast. 3914 * 3915 * If a lookup is requested with "write protection" 3916 * specified, the map may be changed to perform virtual 3917 * copying operations, although the data referenced will 3918 * remain the same. 3919 */ 3920int 3921vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3922 vm_offset_t vaddr, 3923 vm_prot_t fault_typea, 3924 vm_map_entry_t *out_entry, /* OUT */ 3925 vm_object_t *object, /* OUT */ 3926 vm_pindex_t *pindex, /* OUT */ 3927 vm_prot_t *out_prot, /* OUT */ 3928 boolean_t *wired) /* OUT */ 3929{ 3930 vm_map_entry_t entry; 3931 vm_map_t map = *var_map; 3932 vm_prot_t prot; 3933 vm_prot_t fault_type = fault_typea; 3934 vm_object_t eobject; 3935 vm_size_t size; 3936 struct ucred *cred; 3937 3938RetryLookup:; 3939 3940 vm_map_lock_read(map); 3941 3942 /* 3943 * Lookup the faulting address. 3944 */ 3945 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 3946 vm_map_unlock_read(map); 3947 return (KERN_INVALID_ADDRESS); 3948 } 3949 3950 entry = *out_entry; 3951 3952 /* 3953 * Handle submaps. 3954 */ 3955 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3956 vm_map_t old_map = map; 3957 3958 *var_map = map = entry->object.sub_map; 3959 vm_map_unlock_read(old_map); 3960 goto RetryLookup; 3961 } 3962 3963 /* 3964 * Check whether this task is allowed to have this page. 3965 */ 3966 prot = entry->protection; 3967 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3968 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 3969 vm_map_unlock_read(map); 3970 return (KERN_PROTECTION_FAILURE); 3971 } 3972 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3973 (entry->eflags & MAP_ENTRY_COW) && 3974 (fault_type & VM_PROT_WRITE)) { 3975 vm_map_unlock_read(map); 3976 return (KERN_PROTECTION_FAILURE); 3977 } 3978 if ((fault_typea & VM_PROT_COPY) != 0 && 3979 (entry->max_protection & VM_PROT_WRITE) == 0 && 3980 (entry->eflags & MAP_ENTRY_COW) == 0) { 3981 vm_map_unlock_read(map); 3982 return (KERN_PROTECTION_FAILURE); 3983 } 3984 3985 /* 3986 * If this page is not pageable, we have to get it for all possible 3987 * accesses. 3988 */ 3989 *wired = (entry->wired_count != 0); 3990 if (*wired) 3991 fault_type = entry->protection; 3992 size = entry->end - entry->start; 3993 /* 3994 * If the entry was copy-on-write, we either ... 3995 */ 3996 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3997 /* 3998 * If we want to write the page, we may as well handle that 3999 * now since we've got the map locked. 4000 * 4001 * If we don't need to write the page, we just demote the 4002 * permissions allowed. 4003 */ 4004 if ((fault_type & VM_PROT_WRITE) != 0 || 4005 (fault_typea & VM_PROT_COPY) != 0) { 4006 /* 4007 * Make a new object, and place it in the object 4008 * chain. Note that no new references have appeared 4009 * -- one just moved from the map to the new 4010 * object. 4011 */ 4012 if (vm_map_lock_upgrade(map)) 4013 goto RetryLookup; 4014 4015 if (entry->cred == NULL) { 4016 /* 4017 * The debugger owner is charged for 4018 * the memory. 4019 */ 4020 cred = curthread->td_ucred; 4021 crhold(cred); 4022 if (!swap_reserve_by_cred(size, cred)) { 4023 crfree(cred); 4024 vm_map_unlock(map); 4025 return (KERN_RESOURCE_SHORTAGE); 4026 } 4027 entry->cred = cred; 4028 } 4029 vm_object_shadow(&entry->object.vm_object, 4030 &entry->offset, size); 4031 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4032 eobject = entry->object.vm_object; 4033 if (eobject->cred != NULL) { 4034 /* 4035 * The object was not shadowed. 4036 */ 4037 swap_release_by_cred(size, entry->cred); 4038 crfree(entry->cred); 4039 entry->cred = NULL; 4040 } else if (entry->cred != NULL) { 4041 VM_OBJECT_WLOCK(eobject); 4042 eobject->cred = entry->cred; 4043 eobject->charge = size; 4044 VM_OBJECT_WUNLOCK(eobject); 4045 entry->cred = NULL; 4046 } 4047 4048 vm_map_lock_downgrade(map); 4049 } else { 4050 /* 4051 * We're attempting to read a copy-on-write page -- 4052 * don't allow writes. 4053 */ 4054 prot &= ~VM_PROT_WRITE; 4055 } 4056 } 4057 4058 /* 4059 * Create an object if necessary. 4060 */ 4061 if (entry->object.vm_object == NULL && 4062 !map->system_map) { 4063 if (vm_map_lock_upgrade(map)) 4064 goto RetryLookup; 4065 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 4066 atop(size)); 4067 entry->offset = 0; 4068 if (entry->cred != NULL) { 4069 VM_OBJECT_WLOCK(entry->object.vm_object); 4070 entry->object.vm_object->cred = entry->cred; 4071 entry->object.vm_object->charge = size; 4072 VM_OBJECT_WUNLOCK(entry->object.vm_object); 4073 entry->cred = NULL; 4074 } 4075 vm_map_lock_downgrade(map); 4076 } 4077 4078 /* 4079 * Return the object/offset from this entry. If the entry was 4080 * copy-on-write or empty, it has been fixed up. 4081 */ 4082 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4083 *object = entry->object.vm_object; 4084 4085 *out_prot = prot; 4086 return (KERN_SUCCESS); 4087} 4088 4089/* 4090 * vm_map_lookup_locked: 4091 * 4092 * Lookup the faulting address. A version of vm_map_lookup that returns 4093 * KERN_FAILURE instead of blocking on map lock or memory allocation. 4094 */ 4095int 4096vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4097 vm_offset_t vaddr, 4098 vm_prot_t fault_typea, 4099 vm_map_entry_t *out_entry, /* OUT */ 4100 vm_object_t *object, /* OUT */ 4101 vm_pindex_t *pindex, /* OUT */ 4102 vm_prot_t *out_prot, /* OUT */ 4103 boolean_t *wired) /* OUT */ 4104{ 4105 vm_map_entry_t entry; 4106 vm_map_t map = *var_map; 4107 vm_prot_t prot; 4108 vm_prot_t fault_type = fault_typea; 4109 4110 /* 4111 * Lookup the faulting address. 4112 */ 4113 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4114 return (KERN_INVALID_ADDRESS); 4115 4116 entry = *out_entry; 4117 4118 /* 4119 * Fail if the entry refers to a submap. 4120 */ 4121 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4122 return (KERN_FAILURE); 4123 4124 /* 4125 * Check whether this task is allowed to have this page. 4126 */ 4127 prot = entry->protection; 4128 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4129 if ((fault_type & prot) != fault_type) 4130 return (KERN_PROTECTION_FAILURE); 4131 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 4132 (entry->eflags & MAP_ENTRY_COW) && 4133 (fault_type & VM_PROT_WRITE)) 4134 return (KERN_PROTECTION_FAILURE); 4135 4136 /* 4137 * If this page is not pageable, we have to get it for all possible 4138 * accesses. 4139 */ 4140 *wired = (entry->wired_count != 0); 4141 if (*wired) 4142 fault_type = entry->protection; 4143 4144 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4145 /* 4146 * Fail if the entry was copy-on-write for a write fault. 4147 */ 4148 if (fault_type & VM_PROT_WRITE) 4149 return (KERN_FAILURE); 4150 /* 4151 * We're attempting to read a copy-on-write page -- 4152 * don't allow writes. 4153 */ 4154 prot &= ~VM_PROT_WRITE; 4155 } 4156 4157 /* 4158 * Fail if an object should be created. 4159 */ 4160 if (entry->object.vm_object == NULL && !map->system_map) 4161 return (KERN_FAILURE); 4162 4163 /* 4164 * Return the object/offset from this entry. If the entry was 4165 * copy-on-write or empty, it has been fixed up. 4166 */ 4167 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4168 *object = entry->object.vm_object; 4169 4170 *out_prot = prot; 4171 return (KERN_SUCCESS); 4172} 4173 4174/* 4175 * vm_map_lookup_done: 4176 * 4177 * Releases locks acquired by a vm_map_lookup 4178 * (according to the handle returned by that lookup). 4179 */ 4180void 4181vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4182{ 4183 /* 4184 * Unlock the main-level map 4185 */ 4186 vm_map_unlock_read(map); 4187} 4188 4189#include "opt_ddb.h" 4190#ifdef DDB 4191#include <sys/kernel.h> 4192 4193#include <ddb/ddb.h> 4194 4195static void 4196vm_map_print(vm_map_t map) 4197{ 4198 vm_map_entry_t entry; 4199 4200 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4201 (void *)map, 4202 (void *)map->pmap, map->nentries, map->timestamp); 4203 4204 db_indent += 2; 4205 for (entry = map->header.next; entry != &map->header; 4206 entry = entry->next) { 4207 db_iprintf("map entry %p: start=%p, end=%p\n", 4208 (void *)entry, (void *)entry->start, (void *)entry->end); 4209 { 4210 static char *inheritance_name[4] = 4211 {"share", "copy", "none", "donate_copy"}; 4212 4213 db_iprintf(" prot=%x/%x/%s", 4214 entry->protection, 4215 entry->max_protection, 4216 inheritance_name[(int)(unsigned char)entry->inheritance]); 4217 if (entry->wired_count != 0) 4218 db_printf(", wired"); 4219 } 4220 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4221 db_printf(", share=%p, offset=0x%jx\n", 4222 (void *)entry->object.sub_map, 4223 (uintmax_t)entry->offset); 4224 if ((entry->prev == &map->header) || 4225 (entry->prev->object.sub_map != 4226 entry->object.sub_map)) { 4227 db_indent += 2; 4228 vm_map_print((vm_map_t)entry->object.sub_map); 4229 db_indent -= 2; 4230 } 4231 } else { 4232 if (entry->cred != NULL) 4233 db_printf(", ruid %d", entry->cred->cr_ruid); 4234 db_printf(", object=%p, offset=0x%jx", 4235 (void *)entry->object.vm_object, 4236 (uintmax_t)entry->offset); 4237 if (entry->object.vm_object && entry->object.vm_object->cred) 4238 db_printf(", obj ruid %d charge %jx", 4239 entry->object.vm_object->cred->cr_ruid, 4240 (uintmax_t)entry->object.vm_object->charge); 4241 if (entry->eflags & MAP_ENTRY_COW) 4242 db_printf(", copy (%s)", 4243 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4244 db_printf("\n"); 4245 4246 if ((entry->prev == &map->header) || 4247 (entry->prev->object.vm_object != 4248 entry->object.vm_object)) { 4249 db_indent += 2; 4250 vm_object_print((db_expr_t)(intptr_t) 4251 entry->object.vm_object, 4252 0, 0, (char *)0); 4253 db_indent -= 2; 4254 } 4255 } 4256 } 4257 db_indent -= 2; 4258} 4259 4260DB_SHOW_COMMAND(map, map) 4261{ 4262 4263 if (!have_addr) { 4264 db_printf("usage: show map <addr>\n"); 4265 return; 4266 } 4267 vm_map_print((vm_map_t)addr); 4268} 4269 4270DB_SHOW_COMMAND(procvm, procvm) 4271{ 4272 struct proc *p; 4273 4274 if (have_addr) { 4275 p = (struct proc *) addr; 4276 } else { 4277 p = curproc; 4278 } 4279 4280 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4281 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4282 (void *)vmspace_pmap(p->p_vmspace)); 4283 4284 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 4285} 4286 4287#endif /* DDB */ 4288