vm_map.c revision 290362
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: releng/10.1/sys/vm/vm_map.c 290362 2015-11-04 11:27:21Z glebius $"); 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 2213 /* 2214 * Pre-populate paging structures in the 2215 * WILLNEED case. For wired entries, the 2216 * paging structures are already populated. 2217 */ 2218 if (behav == MADV_WILLNEED && 2219 current->wired_count == 0) { 2220 vm_map_pmap_enter(map, 2221 useStart, 2222 current->protection, 2223 current->object.vm_object, 2224 pstart, 2225 ptoa(pend - pstart), 2226 MAP_PREFAULT_MADVISE 2227 ); 2228 } 2229 } 2230 vm_map_unlock_read(map); 2231 } 2232 return (0); 2233} 2234 2235 2236/* 2237 * vm_map_inherit: 2238 * 2239 * Sets the inheritance of the specified address 2240 * range in the target map. Inheritance 2241 * affects how the map will be shared with 2242 * child maps at the time of vmspace_fork. 2243 */ 2244int 2245vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2246 vm_inherit_t new_inheritance) 2247{ 2248 vm_map_entry_t entry; 2249 vm_map_entry_t temp_entry; 2250 2251 switch (new_inheritance) { 2252 case VM_INHERIT_NONE: 2253 case VM_INHERIT_COPY: 2254 case VM_INHERIT_SHARE: 2255 break; 2256 default: 2257 return (KERN_INVALID_ARGUMENT); 2258 } 2259 if (start == end) 2260 return (KERN_SUCCESS); 2261 vm_map_lock(map); 2262 VM_MAP_RANGE_CHECK(map, start, end); 2263 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2264 entry = temp_entry; 2265 vm_map_clip_start(map, entry, start); 2266 } else 2267 entry = temp_entry->next; 2268 while ((entry != &map->header) && (entry->start < end)) { 2269 vm_map_clip_end(map, entry, end); 2270 entry->inheritance = new_inheritance; 2271 vm_map_simplify_entry(map, entry); 2272 entry = entry->next; 2273 } 2274 vm_map_unlock(map); 2275 return (KERN_SUCCESS); 2276} 2277 2278/* 2279 * vm_map_unwire: 2280 * 2281 * Implements both kernel and user unwiring. 2282 */ 2283int 2284vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2285 int flags) 2286{ 2287 vm_map_entry_t entry, first_entry, tmp_entry; 2288 vm_offset_t saved_start; 2289 unsigned int last_timestamp; 2290 int rv; 2291 boolean_t need_wakeup, result, user_unwire; 2292 2293 if (start == end) 2294 return (KERN_SUCCESS); 2295 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2296 vm_map_lock(map); 2297 VM_MAP_RANGE_CHECK(map, start, end); 2298 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2299 if (flags & VM_MAP_WIRE_HOLESOK) 2300 first_entry = first_entry->next; 2301 else { 2302 vm_map_unlock(map); 2303 return (KERN_INVALID_ADDRESS); 2304 } 2305 } 2306 last_timestamp = map->timestamp; 2307 entry = first_entry; 2308 while (entry != &map->header && entry->start < end) { 2309 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2310 /* 2311 * We have not yet clipped the entry. 2312 */ 2313 saved_start = (start >= entry->start) ? start : 2314 entry->start; 2315 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2316 if (vm_map_unlock_and_wait(map, 0)) { 2317 /* 2318 * Allow interruption of user unwiring? 2319 */ 2320 } 2321 vm_map_lock(map); 2322 if (last_timestamp+1 != map->timestamp) { 2323 /* 2324 * Look again for the entry because the map was 2325 * modified while it was unlocked. 2326 * Specifically, the entry may have been 2327 * clipped, merged, or deleted. 2328 */ 2329 if (!vm_map_lookup_entry(map, saved_start, 2330 &tmp_entry)) { 2331 if (flags & VM_MAP_WIRE_HOLESOK) 2332 tmp_entry = tmp_entry->next; 2333 else { 2334 if (saved_start == start) { 2335 /* 2336 * First_entry has been deleted. 2337 */ 2338 vm_map_unlock(map); 2339 return (KERN_INVALID_ADDRESS); 2340 } 2341 end = saved_start; 2342 rv = KERN_INVALID_ADDRESS; 2343 goto done; 2344 } 2345 } 2346 if (entry == first_entry) 2347 first_entry = tmp_entry; 2348 else 2349 first_entry = NULL; 2350 entry = tmp_entry; 2351 } 2352 last_timestamp = map->timestamp; 2353 continue; 2354 } 2355 vm_map_clip_start(map, entry, start); 2356 vm_map_clip_end(map, entry, end); 2357 /* 2358 * Mark the entry in case the map lock is released. (See 2359 * above.) 2360 */ 2361 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2362 entry->wiring_thread == NULL, 2363 ("owned map entry %p", entry)); 2364 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2365 entry->wiring_thread = curthread; 2366 /* 2367 * Check the map for holes in the specified region. 2368 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2369 */ 2370 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2371 (entry->end < end && (entry->next == &map->header || 2372 entry->next->start > entry->end))) { 2373 end = entry->end; 2374 rv = KERN_INVALID_ADDRESS; 2375 goto done; 2376 } 2377 /* 2378 * If system unwiring, require that the entry is system wired. 2379 */ 2380 if (!user_unwire && 2381 vm_map_entry_system_wired_count(entry) == 0) { 2382 end = entry->end; 2383 rv = KERN_INVALID_ARGUMENT; 2384 goto done; 2385 } 2386 entry = entry->next; 2387 } 2388 rv = KERN_SUCCESS; 2389done: 2390 need_wakeup = FALSE; 2391 if (first_entry == NULL) { 2392 result = vm_map_lookup_entry(map, start, &first_entry); 2393 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2394 first_entry = first_entry->next; 2395 else 2396 KASSERT(result, ("vm_map_unwire: lookup failed")); 2397 } 2398 for (entry = first_entry; entry != &map->header && entry->start < end; 2399 entry = entry->next) { 2400 /* 2401 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2402 * space in the unwired region could have been mapped 2403 * while the map lock was dropped for draining 2404 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 2405 * could be simultaneously wiring this new mapping 2406 * entry. Detect these cases and skip any entries 2407 * marked as in transition by us. 2408 */ 2409 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2410 entry->wiring_thread != curthread) { 2411 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2412 ("vm_map_unwire: !HOLESOK and new/changed entry")); 2413 continue; 2414 } 2415 2416 if (rv == KERN_SUCCESS && (!user_unwire || 2417 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 2418 if (user_unwire) 2419 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2420 if (entry->wired_count == 1) 2421 vm_map_entry_unwire(map, entry); 2422 else 2423 entry->wired_count--; 2424 } 2425 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2426 ("vm_map_unwire: in-transition flag missing %p", entry)); 2427 KASSERT(entry->wiring_thread == curthread, 2428 ("vm_map_unwire: alien wire %p", entry)); 2429 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 2430 entry->wiring_thread = NULL; 2431 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2432 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2433 need_wakeup = TRUE; 2434 } 2435 vm_map_simplify_entry(map, entry); 2436 } 2437 vm_map_unlock(map); 2438 if (need_wakeup) 2439 vm_map_wakeup(map); 2440 return (rv); 2441} 2442 2443/* 2444 * vm_map_wire_entry_failure: 2445 * 2446 * Handle a wiring failure on the given entry. 2447 * 2448 * The map should be locked. 2449 */ 2450static void 2451vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 2452 vm_offset_t failed_addr) 2453{ 2454 2455 VM_MAP_ASSERT_LOCKED(map); 2456 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 && 2457 entry->wired_count == 1, 2458 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry)); 2459 KASSERT(failed_addr < entry->end, 2460 ("vm_map_wire_entry_failure: entry %p was fully wired", entry)); 2461 2462 /* 2463 * If any pages at the start of this entry were successfully wired, 2464 * then unwire them. 2465 */ 2466 if (failed_addr > entry->start) { 2467 pmap_unwire(map->pmap, entry->start, failed_addr); 2468 vm_object_unwire(entry->object.vm_object, entry->offset, 2469 failed_addr - entry->start, PQ_ACTIVE); 2470 } 2471 2472 /* 2473 * Assign an out-of-range value to represent the failure to wire this 2474 * entry. 2475 */ 2476 entry->wired_count = -1; 2477} 2478 2479/* 2480 * vm_map_wire: 2481 * 2482 * Implements both kernel and user wiring. 2483 */ 2484int 2485vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2486 int flags) 2487{ 2488 vm_map_entry_t entry, first_entry, tmp_entry; 2489 vm_offset_t faddr, saved_end, saved_start; 2490 unsigned int last_timestamp; 2491 int rv; 2492 boolean_t need_wakeup, result, user_wire; 2493 vm_prot_t prot; 2494 2495 if (start == end) 2496 return (KERN_SUCCESS); 2497 prot = 0; 2498 if (flags & VM_MAP_WIRE_WRITE) 2499 prot |= VM_PROT_WRITE; 2500 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2501 vm_map_lock(map); 2502 VM_MAP_RANGE_CHECK(map, start, end); 2503 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2504 if (flags & VM_MAP_WIRE_HOLESOK) 2505 first_entry = first_entry->next; 2506 else { 2507 vm_map_unlock(map); 2508 return (KERN_INVALID_ADDRESS); 2509 } 2510 } 2511 last_timestamp = map->timestamp; 2512 entry = first_entry; 2513 while (entry != &map->header && entry->start < end) { 2514 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2515 /* 2516 * We have not yet clipped the entry. 2517 */ 2518 saved_start = (start >= entry->start) ? start : 2519 entry->start; 2520 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2521 if (vm_map_unlock_and_wait(map, 0)) { 2522 /* 2523 * Allow interruption of user wiring? 2524 */ 2525 } 2526 vm_map_lock(map); 2527 if (last_timestamp + 1 != map->timestamp) { 2528 /* 2529 * Look again for the entry because the map was 2530 * modified while it was unlocked. 2531 * Specifically, the entry may have been 2532 * clipped, merged, or deleted. 2533 */ 2534 if (!vm_map_lookup_entry(map, saved_start, 2535 &tmp_entry)) { 2536 if (flags & VM_MAP_WIRE_HOLESOK) 2537 tmp_entry = tmp_entry->next; 2538 else { 2539 if (saved_start == start) { 2540 /* 2541 * first_entry has been deleted. 2542 */ 2543 vm_map_unlock(map); 2544 return (KERN_INVALID_ADDRESS); 2545 } 2546 end = saved_start; 2547 rv = KERN_INVALID_ADDRESS; 2548 goto done; 2549 } 2550 } 2551 if (entry == first_entry) 2552 first_entry = tmp_entry; 2553 else 2554 first_entry = NULL; 2555 entry = tmp_entry; 2556 } 2557 last_timestamp = map->timestamp; 2558 continue; 2559 } 2560 vm_map_clip_start(map, entry, start); 2561 vm_map_clip_end(map, entry, end); 2562 /* 2563 * Mark the entry in case the map lock is released. (See 2564 * above.) 2565 */ 2566 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2567 entry->wiring_thread == NULL, 2568 ("owned map entry %p", entry)); 2569 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2570 entry->wiring_thread = curthread; 2571 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 2572 || (entry->protection & prot) != prot) { 2573 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 2574 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { 2575 end = entry->end; 2576 rv = KERN_INVALID_ADDRESS; 2577 goto done; 2578 } 2579 goto next_entry; 2580 } 2581 if (entry->wired_count == 0) { 2582 entry->wired_count++; 2583 saved_start = entry->start; 2584 saved_end = entry->end; 2585 2586 /* 2587 * Release the map lock, relying on the in-transition 2588 * mark. Mark the map busy for fork. 2589 */ 2590 vm_map_busy(map); 2591 vm_map_unlock(map); 2592 2593 faddr = saved_start; 2594 do { 2595 /* 2596 * Simulate a fault to get the page and enter 2597 * it into the physical map. 2598 */ 2599 if ((rv = vm_fault(map, faddr, VM_PROT_NONE, 2600 VM_FAULT_CHANGE_WIRING)) != KERN_SUCCESS) 2601 break; 2602 } while ((faddr += PAGE_SIZE) < saved_end); 2603 vm_map_lock(map); 2604 vm_map_unbusy(map); 2605 if (last_timestamp + 1 != map->timestamp) { 2606 /* 2607 * Look again for the entry because the map was 2608 * modified while it was unlocked. The entry 2609 * may have been clipped, but NOT merged or 2610 * deleted. 2611 */ 2612 result = vm_map_lookup_entry(map, saved_start, 2613 &tmp_entry); 2614 KASSERT(result, ("vm_map_wire: lookup failed")); 2615 if (entry == first_entry) 2616 first_entry = tmp_entry; 2617 else 2618 first_entry = NULL; 2619 entry = tmp_entry; 2620 while (entry->end < saved_end) { 2621 /* 2622 * In case of failure, handle entries 2623 * that were not fully wired here; 2624 * fully wired entries are handled 2625 * later. 2626 */ 2627 if (rv != KERN_SUCCESS && 2628 faddr < entry->end) 2629 vm_map_wire_entry_failure(map, 2630 entry, faddr); 2631 entry = entry->next; 2632 } 2633 } 2634 last_timestamp = map->timestamp; 2635 if (rv != KERN_SUCCESS) { 2636 vm_map_wire_entry_failure(map, entry, faddr); 2637 end = entry->end; 2638 goto done; 2639 } 2640 } else if (!user_wire || 2641 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2642 entry->wired_count++; 2643 } 2644 /* 2645 * Check the map for holes in the specified region. 2646 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2647 */ 2648 next_entry: 2649 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2650 (entry->end < end && (entry->next == &map->header || 2651 entry->next->start > entry->end))) { 2652 end = entry->end; 2653 rv = KERN_INVALID_ADDRESS; 2654 goto done; 2655 } 2656 entry = entry->next; 2657 } 2658 rv = KERN_SUCCESS; 2659done: 2660 need_wakeup = FALSE; 2661 if (first_entry == NULL) { 2662 result = vm_map_lookup_entry(map, start, &first_entry); 2663 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2664 first_entry = first_entry->next; 2665 else 2666 KASSERT(result, ("vm_map_wire: lookup failed")); 2667 } 2668 for (entry = first_entry; entry != &map->header && entry->start < end; 2669 entry = entry->next) { 2670 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) 2671 goto next_entry_done; 2672 2673 /* 2674 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2675 * space in the unwired region could have been mapped 2676 * while the map lock was dropped for faulting in the 2677 * pages or draining MAP_ENTRY_IN_TRANSITION. 2678 * Moreover, another thread could be simultaneously 2679 * wiring this new mapping entry. Detect these cases 2680 * and skip any entries marked as in transition by us. 2681 */ 2682 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2683 entry->wiring_thread != curthread) { 2684 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2685 ("vm_map_wire: !HOLESOK and new/changed entry")); 2686 continue; 2687 } 2688 2689 if (rv == KERN_SUCCESS) { 2690 if (user_wire) 2691 entry->eflags |= MAP_ENTRY_USER_WIRED; 2692 } else if (entry->wired_count == -1) { 2693 /* 2694 * Wiring failed on this entry. Thus, unwiring is 2695 * unnecessary. 2696 */ 2697 entry->wired_count = 0; 2698 } else if (!user_wire || 2699 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2700 /* 2701 * Undo the wiring. Wiring succeeded on this entry 2702 * but failed on a later entry. 2703 */ 2704 if (entry->wired_count == 1) 2705 vm_map_entry_unwire(map, entry); 2706 else 2707 entry->wired_count--; 2708 } 2709 next_entry_done: 2710 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2711 ("vm_map_wire: in-transition flag missing %p", entry)); 2712 KASSERT(entry->wiring_thread == curthread, 2713 ("vm_map_wire: alien wire %p", entry)); 2714 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 2715 MAP_ENTRY_WIRE_SKIPPED); 2716 entry->wiring_thread = NULL; 2717 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2718 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2719 need_wakeup = TRUE; 2720 } 2721 vm_map_simplify_entry(map, entry); 2722 } 2723 vm_map_unlock(map); 2724 if (need_wakeup) 2725 vm_map_wakeup(map); 2726 return (rv); 2727} 2728 2729/* 2730 * vm_map_sync 2731 * 2732 * Push any dirty cached pages in the address range to their pager. 2733 * If syncio is TRUE, dirty pages are written synchronously. 2734 * If invalidate is TRUE, any cached pages are freed as well. 2735 * 2736 * If the size of the region from start to end is zero, we are 2737 * supposed to flush all modified pages within the region containing 2738 * start. Unfortunately, a region can be split or coalesced with 2739 * neighboring regions, making it difficult to determine what the 2740 * original region was. Therefore, we approximate this requirement by 2741 * flushing the current region containing start. 2742 * 2743 * Returns an error if any part of the specified range is not mapped. 2744 */ 2745int 2746vm_map_sync( 2747 vm_map_t map, 2748 vm_offset_t start, 2749 vm_offset_t end, 2750 boolean_t syncio, 2751 boolean_t invalidate) 2752{ 2753 vm_map_entry_t current; 2754 vm_map_entry_t entry; 2755 vm_size_t size; 2756 vm_object_t object; 2757 vm_ooffset_t offset; 2758 unsigned int last_timestamp; 2759 boolean_t failed; 2760 2761 vm_map_lock_read(map); 2762 VM_MAP_RANGE_CHECK(map, start, end); 2763 if (!vm_map_lookup_entry(map, start, &entry)) { 2764 vm_map_unlock_read(map); 2765 return (KERN_INVALID_ADDRESS); 2766 } else if (start == end) { 2767 start = entry->start; 2768 end = entry->end; 2769 } 2770 /* 2771 * Make a first pass to check for user-wired memory and holes. 2772 */ 2773 for (current = entry; current != &map->header && current->start < end; 2774 current = current->next) { 2775 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 2776 vm_map_unlock_read(map); 2777 return (KERN_INVALID_ARGUMENT); 2778 } 2779 if (end > current->end && 2780 (current->next == &map->header || 2781 current->end != current->next->start)) { 2782 vm_map_unlock_read(map); 2783 return (KERN_INVALID_ADDRESS); 2784 } 2785 } 2786 2787 if (invalidate) 2788 pmap_remove(map->pmap, start, end); 2789 failed = FALSE; 2790 2791 /* 2792 * Make a second pass, cleaning/uncaching pages from the indicated 2793 * objects as we go. 2794 */ 2795 for (current = entry; current != &map->header && current->start < end;) { 2796 offset = current->offset + (start - current->start); 2797 size = (end <= current->end ? end : current->end) - start; 2798 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2799 vm_map_t smap; 2800 vm_map_entry_t tentry; 2801 vm_size_t tsize; 2802 2803 smap = current->object.sub_map; 2804 vm_map_lock_read(smap); 2805 (void) vm_map_lookup_entry(smap, offset, &tentry); 2806 tsize = tentry->end - offset; 2807 if (tsize < size) 2808 size = tsize; 2809 object = tentry->object.vm_object; 2810 offset = tentry->offset + (offset - tentry->start); 2811 vm_map_unlock_read(smap); 2812 } else { 2813 object = current->object.vm_object; 2814 } 2815 vm_object_reference(object); 2816 last_timestamp = map->timestamp; 2817 vm_map_unlock_read(map); 2818 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 2819 failed = TRUE; 2820 start += size; 2821 vm_object_deallocate(object); 2822 vm_map_lock_read(map); 2823 if (last_timestamp == map->timestamp || 2824 !vm_map_lookup_entry(map, start, ¤t)) 2825 current = current->next; 2826 } 2827 2828 vm_map_unlock_read(map); 2829 return (failed ? KERN_FAILURE : KERN_SUCCESS); 2830} 2831 2832/* 2833 * vm_map_entry_unwire: [ internal use only ] 2834 * 2835 * Make the region specified by this entry pageable. 2836 * 2837 * The map in question should be locked. 2838 * [This is the reason for this routine's existence.] 2839 */ 2840static void 2841vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2842{ 2843 2844 VM_MAP_ASSERT_LOCKED(map); 2845 KASSERT(entry->wired_count > 0, 2846 ("vm_map_entry_unwire: entry %p isn't wired", entry)); 2847 pmap_unwire(map->pmap, entry->start, entry->end); 2848 vm_object_unwire(entry->object.vm_object, entry->offset, entry->end - 2849 entry->start, PQ_ACTIVE); 2850 entry->wired_count = 0; 2851} 2852 2853static void 2854vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 2855{ 2856 2857 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 2858 vm_object_deallocate(entry->object.vm_object); 2859 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 2860} 2861 2862/* 2863 * vm_map_entry_delete: [ internal use only ] 2864 * 2865 * Deallocate the given entry from the target map. 2866 */ 2867static void 2868vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2869{ 2870 vm_object_t object; 2871 vm_pindex_t offidxstart, offidxend, count, size1; 2872 vm_ooffset_t size; 2873 2874 vm_map_entry_unlink(map, entry); 2875 object = entry->object.vm_object; 2876 size = entry->end - entry->start; 2877 map->size -= size; 2878 2879 if (entry->cred != NULL) { 2880 swap_release_by_cred(size, entry->cred); 2881 crfree(entry->cred); 2882 } 2883 2884 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2885 (object != NULL)) { 2886 KASSERT(entry->cred == NULL || object->cred == NULL || 2887 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 2888 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 2889 count = OFF_TO_IDX(size); 2890 offidxstart = OFF_TO_IDX(entry->offset); 2891 offidxend = offidxstart + count; 2892 VM_OBJECT_WLOCK(object); 2893 if (object->ref_count != 1 && 2894 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2895 object == kernel_object || object == kmem_object)) { 2896 vm_object_collapse(object); 2897 2898 /* 2899 * The option OBJPR_NOTMAPPED can be passed here 2900 * because vm_map_delete() already performed 2901 * pmap_remove() on the only mapping to this range 2902 * of pages. 2903 */ 2904 vm_object_page_remove(object, offidxstart, offidxend, 2905 OBJPR_NOTMAPPED); 2906 if (object->type == OBJT_SWAP) 2907 swap_pager_freespace(object, offidxstart, count); 2908 if (offidxend >= object->size && 2909 offidxstart < object->size) { 2910 size1 = object->size; 2911 object->size = offidxstart; 2912 if (object->cred != NULL) { 2913 size1 -= object->size; 2914 KASSERT(object->charge >= ptoa(size1), 2915 ("vm_map_entry_delete: object->charge < 0")); 2916 swap_release_by_cred(ptoa(size1), object->cred); 2917 object->charge -= ptoa(size1); 2918 } 2919 } 2920 } 2921 VM_OBJECT_WUNLOCK(object); 2922 } else 2923 entry->object.vm_object = NULL; 2924 if (map->system_map) 2925 vm_map_entry_deallocate(entry, TRUE); 2926 else { 2927 entry->next = curthread->td_map_def_user; 2928 curthread->td_map_def_user = entry; 2929 } 2930} 2931 2932/* 2933 * vm_map_delete: [ internal use only ] 2934 * 2935 * Deallocates the given address range from the target 2936 * map. 2937 */ 2938int 2939vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2940{ 2941 vm_map_entry_t entry; 2942 vm_map_entry_t first_entry; 2943 2944 VM_MAP_ASSERT_LOCKED(map); 2945 if (start == end) 2946 return (KERN_SUCCESS); 2947 2948 /* 2949 * Find the start of the region, and clip it 2950 */ 2951 if (!vm_map_lookup_entry(map, start, &first_entry)) 2952 entry = first_entry->next; 2953 else { 2954 entry = first_entry; 2955 vm_map_clip_start(map, entry, start); 2956 } 2957 2958 /* 2959 * Step through all entries in this region 2960 */ 2961 while ((entry != &map->header) && (entry->start < end)) { 2962 vm_map_entry_t next; 2963 2964 /* 2965 * Wait for wiring or unwiring of an entry to complete. 2966 * Also wait for any system wirings to disappear on 2967 * user maps. 2968 */ 2969 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 2970 (vm_map_pmap(map) != kernel_pmap && 2971 vm_map_entry_system_wired_count(entry) != 0)) { 2972 unsigned int last_timestamp; 2973 vm_offset_t saved_start; 2974 vm_map_entry_t tmp_entry; 2975 2976 saved_start = entry->start; 2977 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2978 last_timestamp = map->timestamp; 2979 (void) vm_map_unlock_and_wait(map, 0); 2980 vm_map_lock(map); 2981 if (last_timestamp + 1 != map->timestamp) { 2982 /* 2983 * Look again for the entry because the map was 2984 * modified while it was unlocked. 2985 * Specifically, the entry may have been 2986 * clipped, merged, or deleted. 2987 */ 2988 if (!vm_map_lookup_entry(map, saved_start, 2989 &tmp_entry)) 2990 entry = tmp_entry->next; 2991 else { 2992 entry = tmp_entry; 2993 vm_map_clip_start(map, entry, 2994 saved_start); 2995 } 2996 } 2997 continue; 2998 } 2999 vm_map_clip_end(map, entry, end); 3000 3001 next = entry->next; 3002 3003 /* 3004 * Unwire before removing addresses from the pmap; otherwise, 3005 * unwiring will put the entries back in the pmap. 3006 */ 3007 if (entry->wired_count != 0) { 3008 vm_map_entry_unwire(map, entry); 3009 } 3010 3011 pmap_remove(map->pmap, entry->start, entry->end); 3012 3013 /* 3014 * Delete the entry only after removing all pmap 3015 * entries pointing to its pages. (Otherwise, its 3016 * page frames may be reallocated, and any modify bits 3017 * will be set in the wrong object!) 3018 */ 3019 vm_map_entry_delete(map, entry); 3020 entry = next; 3021 } 3022 return (KERN_SUCCESS); 3023} 3024 3025/* 3026 * vm_map_remove: 3027 * 3028 * Remove the given address range from the target map. 3029 * This is the exported form of vm_map_delete. 3030 */ 3031int 3032vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 3033{ 3034 int result; 3035 3036 vm_map_lock(map); 3037 VM_MAP_RANGE_CHECK(map, start, end); 3038 result = vm_map_delete(map, start, end); 3039 vm_map_unlock(map); 3040 return (result); 3041} 3042 3043/* 3044 * vm_map_check_protection: 3045 * 3046 * Assert that the target map allows the specified privilege on the 3047 * entire address region given. The entire region must be allocated. 3048 * 3049 * WARNING! This code does not and should not check whether the 3050 * contents of the region is accessible. For example a smaller file 3051 * might be mapped into a larger address space. 3052 * 3053 * NOTE! This code is also called by munmap(). 3054 * 3055 * The map must be locked. A read lock is sufficient. 3056 */ 3057boolean_t 3058vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 3059 vm_prot_t protection) 3060{ 3061 vm_map_entry_t entry; 3062 vm_map_entry_t tmp_entry; 3063 3064 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 3065 return (FALSE); 3066 entry = tmp_entry; 3067 3068 while (start < end) { 3069 if (entry == &map->header) 3070 return (FALSE); 3071 /* 3072 * No holes allowed! 3073 */ 3074 if (start < entry->start) 3075 return (FALSE); 3076 /* 3077 * Check protection associated with entry. 3078 */ 3079 if ((entry->protection & protection) != protection) 3080 return (FALSE); 3081 /* go to next entry */ 3082 start = entry->end; 3083 entry = entry->next; 3084 } 3085 return (TRUE); 3086} 3087 3088/* 3089 * vm_map_copy_entry: 3090 * 3091 * Copies the contents of the source entry to the destination 3092 * entry. The entries *must* be aligned properly. 3093 */ 3094static void 3095vm_map_copy_entry( 3096 vm_map_t src_map, 3097 vm_map_t dst_map, 3098 vm_map_entry_t src_entry, 3099 vm_map_entry_t dst_entry, 3100 vm_ooffset_t *fork_charge) 3101{ 3102 vm_object_t src_object; 3103 vm_map_entry_t fake_entry; 3104 vm_offset_t size; 3105 struct ucred *cred; 3106 int charged; 3107 3108 VM_MAP_ASSERT_LOCKED(dst_map); 3109 3110 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3111 return; 3112 3113 if (src_entry->wired_count == 0 || 3114 (src_entry->protection & VM_PROT_WRITE) == 0) { 3115 /* 3116 * If the source entry is marked needs_copy, it is already 3117 * write-protected. 3118 */ 3119 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && 3120 (src_entry->protection & VM_PROT_WRITE) != 0) { 3121 pmap_protect(src_map->pmap, 3122 src_entry->start, 3123 src_entry->end, 3124 src_entry->protection & ~VM_PROT_WRITE); 3125 } 3126 3127 /* 3128 * Make a copy of the object. 3129 */ 3130 size = src_entry->end - src_entry->start; 3131 if ((src_object = src_entry->object.vm_object) != NULL) { 3132 VM_OBJECT_WLOCK(src_object); 3133 charged = ENTRY_CHARGED(src_entry); 3134 if ((src_object->handle == NULL) && 3135 (src_object->type == OBJT_DEFAULT || 3136 src_object->type == OBJT_SWAP)) { 3137 vm_object_collapse(src_object); 3138 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 3139 vm_object_split(src_entry); 3140 src_object = src_entry->object.vm_object; 3141 } 3142 } 3143 vm_object_reference_locked(src_object); 3144 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3145 if (src_entry->cred != NULL && 3146 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3147 KASSERT(src_object->cred == NULL, 3148 ("OVERCOMMIT: vm_map_copy_entry: cred %p", 3149 src_object)); 3150 src_object->cred = src_entry->cred; 3151 src_object->charge = size; 3152 } 3153 VM_OBJECT_WUNLOCK(src_object); 3154 dst_entry->object.vm_object = src_object; 3155 if (charged) { 3156 cred = curthread->td_ucred; 3157 crhold(cred); 3158 dst_entry->cred = cred; 3159 *fork_charge += size; 3160 if (!(src_entry->eflags & 3161 MAP_ENTRY_NEEDS_COPY)) { 3162 crhold(cred); 3163 src_entry->cred = cred; 3164 *fork_charge += size; 3165 } 3166 } 3167 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3168 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3169 dst_entry->offset = src_entry->offset; 3170 if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3171 /* 3172 * MAP_ENTRY_VN_WRITECNT cannot 3173 * indicate write reference from 3174 * src_entry, since the entry is 3175 * marked as needs copy. Allocate a 3176 * fake entry that is used to 3177 * decrement object->un_pager.vnp.writecount 3178 * at the appropriate time. Attach 3179 * fake_entry to the deferred list. 3180 */ 3181 fake_entry = vm_map_entry_create(dst_map); 3182 fake_entry->eflags = MAP_ENTRY_VN_WRITECNT; 3183 src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT; 3184 vm_object_reference(src_object); 3185 fake_entry->object.vm_object = src_object; 3186 fake_entry->start = src_entry->start; 3187 fake_entry->end = src_entry->end; 3188 fake_entry->next = curthread->td_map_def_user; 3189 curthread->td_map_def_user = fake_entry; 3190 } 3191 } else { 3192 dst_entry->object.vm_object = NULL; 3193 dst_entry->offset = 0; 3194 if (src_entry->cred != NULL) { 3195 dst_entry->cred = curthread->td_ucred; 3196 crhold(dst_entry->cred); 3197 *fork_charge += size; 3198 } 3199 } 3200 3201 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3202 dst_entry->end - dst_entry->start, src_entry->start); 3203 } else { 3204 /* 3205 * We don't want to make writeable wired pages copy-on-write. 3206 * Immediately copy these pages into the new map by simulating 3207 * page faults. The new pages are pageable. 3208 */ 3209 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 3210 fork_charge); 3211 } 3212} 3213 3214/* 3215 * vmspace_map_entry_forked: 3216 * Update the newly-forked vmspace each time a map entry is inherited 3217 * or copied. The values for vm_dsize and vm_tsize are approximate 3218 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 3219 */ 3220static void 3221vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 3222 vm_map_entry_t entry) 3223{ 3224 vm_size_t entrysize; 3225 vm_offset_t newend; 3226 3227 entrysize = entry->end - entry->start; 3228 vm2->vm_map.size += entrysize; 3229 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 3230 vm2->vm_ssize += btoc(entrysize); 3231 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 3232 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 3233 newend = MIN(entry->end, 3234 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 3235 vm2->vm_dsize += btoc(newend - entry->start); 3236 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 3237 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 3238 newend = MIN(entry->end, 3239 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 3240 vm2->vm_tsize += btoc(newend - entry->start); 3241 } 3242} 3243 3244/* 3245 * vmspace_fork: 3246 * Create a new process vmspace structure and vm_map 3247 * based on those of an existing process. The new map 3248 * is based on the old map, according to the inheritance 3249 * values on the regions in that map. 3250 * 3251 * XXX It might be worth coalescing the entries added to the new vmspace. 3252 * 3253 * The source map must not be locked. 3254 */ 3255struct vmspace * 3256vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 3257{ 3258 struct vmspace *vm2; 3259 vm_map_t new_map, old_map; 3260 vm_map_entry_t new_entry, old_entry; 3261 vm_object_t object; 3262 int locked; 3263 3264 old_map = &vm1->vm_map; 3265 /* Copy immutable fields of vm1 to vm2. */ 3266 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL); 3267 if (vm2 == NULL) 3268 return (NULL); 3269 vm2->vm_taddr = vm1->vm_taddr; 3270 vm2->vm_daddr = vm1->vm_daddr; 3271 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 3272 vm_map_lock(old_map); 3273 if (old_map->busy) 3274 vm_map_wait_busy(old_map); 3275 new_map = &vm2->vm_map; 3276 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 3277 KASSERT(locked, ("vmspace_fork: lock failed")); 3278 3279 old_entry = old_map->header.next; 3280 3281 while (old_entry != &old_map->header) { 3282 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 3283 panic("vm_map_fork: encountered a submap"); 3284 3285 switch (old_entry->inheritance) { 3286 case VM_INHERIT_NONE: 3287 break; 3288 3289 case VM_INHERIT_SHARE: 3290 /* 3291 * Clone the entry, creating the shared object if necessary. 3292 */ 3293 object = old_entry->object.vm_object; 3294 if (object == NULL) { 3295 object = vm_object_allocate(OBJT_DEFAULT, 3296 atop(old_entry->end - old_entry->start)); 3297 old_entry->object.vm_object = object; 3298 old_entry->offset = 0; 3299 if (old_entry->cred != NULL) { 3300 object->cred = old_entry->cred; 3301 object->charge = old_entry->end - 3302 old_entry->start; 3303 old_entry->cred = NULL; 3304 } 3305 } 3306 3307 /* 3308 * Add the reference before calling vm_object_shadow 3309 * to insure that a shadow object is created. 3310 */ 3311 vm_object_reference(object); 3312 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3313 vm_object_shadow(&old_entry->object.vm_object, 3314 &old_entry->offset, 3315 old_entry->end - old_entry->start); 3316 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3317 /* Transfer the second reference too. */ 3318 vm_object_reference( 3319 old_entry->object.vm_object); 3320 3321 /* 3322 * As in vm_map_simplify_entry(), the 3323 * vnode lock will not be acquired in 3324 * this call to vm_object_deallocate(). 3325 */ 3326 vm_object_deallocate(object); 3327 object = old_entry->object.vm_object; 3328 } 3329 VM_OBJECT_WLOCK(object); 3330 vm_object_clear_flag(object, OBJ_ONEMAPPING); 3331 if (old_entry->cred != NULL) { 3332 KASSERT(object->cred == NULL, ("vmspace_fork both cred")); 3333 object->cred = old_entry->cred; 3334 object->charge = old_entry->end - old_entry->start; 3335 old_entry->cred = NULL; 3336 } 3337 3338 /* 3339 * Assert the correct state of the vnode 3340 * v_writecount while the object is locked, to 3341 * not relock it later for the assertion 3342 * correctness. 3343 */ 3344 if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT && 3345 object->type == OBJT_VNODE) { 3346 KASSERT(((struct vnode *)object->handle)-> 3347 v_writecount > 0, 3348 ("vmspace_fork: v_writecount %p", object)); 3349 KASSERT(object->un_pager.vnp.writemappings > 0, 3350 ("vmspace_fork: vnp.writecount %p", 3351 object)); 3352 } 3353 VM_OBJECT_WUNLOCK(object); 3354 3355 /* 3356 * Clone the entry, referencing the shared object. 3357 */ 3358 new_entry = vm_map_entry_create(new_map); 3359 *new_entry = *old_entry; 3360 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3361 MAP_ENTRY_IN_TRANSITION); 3362 new_entry->wiring_thread = NULL; 3363 new_entry->wired_count = 0; 3364 if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3365 vnode_pager_update_writecount(object, 3366 new_entry->start, new_entry->end); 3367 } 3368 3369 /* 3370 * Insert the entry into the new map -- we know we're 3371 * inserting at the end of the new map. 3372 */ 3373 vm_map_entry_link(new_map, new_map->header.prev, 3374 new_entry); 3375 vmspace_map_entry_forked(vm1, vm2, new_entry); 3376 3377 /* 3378 * Update the physical map 3379 */ 3380 pmap_copy(new_map->pmap, old_map->pmap, 3381 new_entry->start, 3382 (old_entry->end - old_entry->start), 3383 old_entry->start); 3384 break; 3385 3386 case VM_INHERIT_COPY: 3387 /* 3388 * Clone the entry and link into the map. 3389 */ 3390 new_entry = vm_map_entry_create(new_map); 3391 *new_entry = *old_entry; 3392 /* 3393 * Copied entry is COW over the old object. 3394 */ 3395 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3396 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT); 3397 new_entry->wiring_thread = NULL; 3398 new_entry->wired_count = 0; 3399 new_entry->object.vm_object = NULL; 3400 new_entry->cred = NULL; 3401 vm_map_entry_link(new_map, new_map->header.prev, 3402 new_entry); 3403 vmspace_map_entry_forked(vm1, vm2, new_entry); 3404 vm_map_copy_entry(old_map, new_map, old_entry, 3405 new_entry, fork_charge); 3406 break; 3407 } 3408 old_entry = old_entry->next; 3409 } 3410 /* 3411 * Use inlined vm_map_unlock() to postpone handling the deferred 3412 * map entries, which cannot be done until both old_map and 3413 * new_map locks are released. 3414 */ 3415 sx_xunlock(&old_map->lock); 3416 sx_xunlock(&new_map->lock); 3417 vm_map_process_deferred(); 3418 3419 return (vm2); 3420} 3421 3422int 3423vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3424 vm_prot_t prot, vm_prot_t max, int cow) 3425{ 3426 vm_size_t growsize, init_ssize; 3427 rlim_t lmemlim, vmemlim; 3428 int rv; 3429 3430 growsize = sgrowsiz; 3431 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3432 vm_map_lock(map); 3433 PROC_LOCK(curproc); 3434 lmemlim = lim_cur(curproc, RLIMIT_MEMLOCK); 3435 vmemlim = lim_cur(curproc, RLIMIT_VMEM); 3436 PROC_UNLOCK(curproc); 3437 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3438 if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) { 3439 rv = KERN_NO_SPACE; 3440 goto out; 3441 } 3442 } 3443 /* If we would blow our VMEM resource limit, no go */ 3444 if (map->size + init_ssize > vmemlim) { 3445 rv = KERN_NO_SPACE; 3446 goto out; 3447 } 3448 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, 3449 max, cow); 3450out: 3451 vm_map_unlock(map); 3452 return (rv); 3453} 3454 3455static int 3456vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3457 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) 3458{ 3459 vm_map_entry_t new_entry, prev_entry; 3460 vm_offset_t bot, top; 3461 vm_size_t init_ssize; 3462 int orient, rv; 3463 3464 /* 3465 * The stack orientation is piggybacked with the cow argument. 3466 * Extract it into orient and mask the cow argument so that we 3467 * don't pass it around further. 3468 * NOTE: We explicitly allow bi-directional stacks. 3469 */ 3470 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 3471 KASSERT(orient != 0, ("No stack grow direction")); 3472 3473 if (addrbos < vm_map_min(map) || 3474 addrbos > vm_map_max(map) || 3475 addrbos + max_ssize < addrbos) 3476 return (KERN_NO_SPACE); 3477 3478 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3479 3480 /* If addr is already mapped, no go */ 3481 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) 3482 return (KERN_NO_SPACE); 3483 3484 /* 3485 * If we can't accomodate max_ssize in the current mapping, no go. 3486 * However, we need to be aware that subsequent user mappings might 3487 * map into the space we have reserved for stack, and currently this 3488 * space is not protected. 3489 * 3490 * Hopefully we will at least detect this condition when we try to 3491 * grow the stack. 3492 */ 3493 if ((prev_entry->next != &map->header) && 3494 (prev_entry->next->start < addrbos + max_ssize)) 3495 return (KERN_NO_SPACE); 3496 3497 /* 3498 * We initially map a stack of only init_ssize. We will grow as 3499 * needed later. Depending on the orientation of the stack (i.e. 3500 * the grow direction) we either map at the top of the range, the 3501 * bottom of the range or in the middle. 3502 * 3503 * Note: we would normally expect prot and max to be VM_PROT_ALL, 3504 * and cow to be 0. Possibly we should eliminate these as input 3505 * parameters, and just pass these values here in the insert call. 3506 */ 3507 if (orient == MAP_STACK_GROWS_DOWN) 3508 bot = addrbos + max_ssize - init_ssize; 3509 else if (orient == MAP_STACK_GROWS_UP) 3510 bot = addrbos; 3511 else 3512 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 3513 top = bot + init_ssize; 3514 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 3515 3516 /* Now set the avail_ssize amount. */ 3517 if (rv == KERN_SUCCESS) { 3518 if (prev_entry != &map->header) 3519 vm_map_clip_end(map, prev_entry, bot); 3520 new_entry = prev_entry->next; 3521 if (new_entry->end != top || new_entry->start != bot) 3522 panic("Bad entry start/end for new stack entry"); 3523 3524 new_entry->avail_ssize = max_ssize - init_ssize; 3525 if (orient & MAP_STACK_GROWS_DOWN) 3526 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3527 if (orient & MAP_STACK_GROWS_UP) 3528 new_entry->eflags |= MAP_ENTRY_GROWS_UP; 3529 } 3530 3531 return (rv); 3532} 3533 3534static int stack_guard_page = 0; 3535TUNABLE_INT("security.bsd.stack_guard_page", &stack_guard_page); 3536SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RW, 3537 &stack_guard_page, 0, 3538 "Insert stack guard page ahead of the growable segments."); 3539 3540/* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3541 * desired address is already mapped, or if we successfully grow 3542 * the stack. Also returns KERN_SUCCESS if addr is outside the 3543 * stack range (this is strange, but preserves compatibility with 3544 * the grow function in vm_machdep.c). 3545 */ 3546int 3547vm_map_growstack(struct proc *p, vm_offset_t addr) 3548{ 3549 vm_map_entry_t next_entry, prev_entry; 3550 vm_map_entry_t new_entry, stack_entry; 3551 struct vmspace *vm = p->p_vmspace; 3552 vm_map_t map = &vm->vm_map; 3553 vm_offset_t end; 3554 vm_size_t growsize; 3555 size_t grow_amount, max_grow; 3556 rlim_t lmemlim, stacklim, vmemlim; 3557 int is_procstack, rv; 3558 struct ucred *cred; 3559#ifdef notyet 3560 uint64_t limit; 3561#endif 3562#ifdef RACCT 3563 int error; 3564#endif 3565 3566Retry: 3567 PROC_LOCK(p); 3568 lmemlim = lim_cur(p, RLIMIT_MEMLOCK); 3569 stacklim = lim_cur(p, RLIMIT_STACK); 3570 vmemlim = lim_cur(p, RLIMIT_VMEM); 3571 PROC_UNLOCK(p); 3572 3573 vm_map_lock_read(map); 3574 3575 /* If addr is already in the entry range, no need to grow.*/ 3576 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 3577 vm_map_unlock_read(map); 3578 return (KERN_SUCCESS); 3579 } 3580 3581 next_entry = prev_entry->next; 3582 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 3583 /* 3584 * This entry does not grow upwards. Since the address lies 3585 * beyond this entry, the next entry (if one exists) has to 3586 * be a downward growable entry. The entry list header is 3587 * never a growable entry, so it suffices to check the flags. 3588 */ 3589 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 3590 vm_map_unlock_read(map); 3591 return (KERN_SUCCESS); 3592 } 3593 stack_entry = next_entry; 3594 } else { 3595 /* 3596 * This entry grows upward. If the next entry does not at 3597 * least grow downwards, this is the entry we need to grow. 3598 * otherwise we have two possible choices and we have to 3599 * select one. 3600 */ 3601 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 3602 /* 3603 * We have two choices; grow the entry closest to 3604 * the address to minimize the amount of growth. 3605 */ 3606 if (addr - prev_entry->end <= next_entry->start - addr) 3607 stack_entry = prev_entry; 3608 else 3609 stack_entry = next_entry; 3610 } else 3611 stack_entry = prev_entry; 3612 } 3613 3614 if (stack_entry == next_entry) { 3615 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 3616 KASSERT(addr < stack_entry->start, ("foo")); 3617 end = (prev_entry != &map->header) ? prev_entry->end : 3618 stack_entry->start - stack_entry->avail_ssize; 3619 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 3620 max_grow = stack_entry->start - end; 3621 } else { 3622 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 3623 KASSERT(addr >= stack_entry->end, ("foo")); 3624 end = (next_entry != &map->header) ? next_entry->start : 3625 stack_entry->end + stack_entry->avail_ssize; 3626 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 3627 max_grow = end - stack_entry->end; 3628 } 3629 3630 if (grow_amount > stack_entry->avail_ssize) { 3631 vm_map_unlock_read(map); 3632 return (KERN_NO_SPACE); 3633 } 3634 3635 /* 3636 * If there is no longer enough space between the entries nogo, and 3637 * adjust the available space. Note: this should only happen if the 3638 * user has mapped into the stack area after the stack was created, 3639 * and is probably an error. 3640 * 3641 * This also effectively destroys any guard page the user might have 3642 * intended by limiting the stack size. 3643 */ 3644 if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) { 3645 if (vm_map_lock_upgrade(map)) 3646 goto Retry; 3647 3648 stack_entry->avail_ssize = max_grow; 3649 3650 vm_map_unlock(map); 3651 return (KERN_NO_SPACE); 3652 } 3653 3654 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 3655 3656 /* 3657 * If this is the main process stack, see if we're over the stack 3658 * limit. 3659 */ 3660 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3661 vm_map_unlock_read(map); 3662 return (KERN_NO_SPACE); 3663 } 3664#ifdef RACCT 3665 PROC_LOCK(p); 3666 if (is_procstack && 3667 racct_set(p, RACCT_STACK, ctob(vm->vm_ssize) + grow_amount)) { 3668 PROC_UNLOCK(p); 3669 vm_map_unlock_read(map); 3670 return (KERN_NO_SPACE); 3671 } 3672 PROC_UNLOCK(p); 3673#endif 3674 3675 /* Round up the grow amount modulo sgrowsiz */ 3676 growsize = sgrowsiz; 3677 grow_amount = roundup(grow_amount, growsize); 3678 if (grow_amount > stack_entry->avail_ssize) 3679 grow_amount = stack_entry->avail_ssize; 3680 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3681 grow_amount = trunc_page((vm_size_t)stacklim) - 3682 ctob(vm->vm_ssize); 3683 } 3684#ifdef notyet 3685 PROC_LOCK(p); 3686 limit = racct_get_available(p, RACCT_STACK); 3687 PROC_UNLOCK(p); 3688 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 3689 grow_amount = limit - ctob(vm->vm_ssize); 3690#endif 3691 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3692 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 3693 vm_map_unlock_read(map); 3694 rv = KERN_NO_SPACE; 3695 goto out; 3696 } 3697#ifdef RACCT 3698 PROC_LOCK(p); 3699 if (racct_set(p, RACCT_MEMLOCK, 3700 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 3701 PROC_UNLOCK(p); 3702 vm_map_unlock_read(map); 3703 rv = KERN_NO_SPACE; 3704 goto out; 3705 } 3706 PROC_UNLOCK(p); 3707#endif 3708 } 3709 /* If we would blow our VMEM resource limit, no go */ 3710 if (map->size + grow_amount > vmemlim) { 3711 vm_map_unlock_read(map); 3712 rv = KERN_NO_SPACE; 3713 goto out; 3714 } 3715#ifdef RACCT 3716 PROC_LOCK(p); 3717 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 3718 PROC_UNLOCK(p); 3719 vm_map_unlock_read(map); 3720 rv = KERN_NO_SPACE; 3721 goto out; 3722 } 3723 PROC_UNLOCK(p); 3724#endif 3725 3726 if (vm_map_lock_upgrade(map)) 3727 goto Retry; 3728 3729 if (stack_entry == next_entry) { 3730 /* 3731 * Growing downward. 3732 */ 3733 /* Get the preliminary new entry start value */ 3734 addr = stack_entry->start - grow_amount; 3735 3736 /* 3737 * If this puts us into the previous entry, cut back our 3738 * growth to the available space. Also, see the note above. 3739 */ 3740 if (addr < end) { 3741 stack_entry->avail_ssize = max_grow; 3742 addr = end; 3743 if (stack_guard_page) 3744 addr += PAGE_SIZE; 3745 } 3746 3747 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 3748 next_entry->protection, next_entry->max_protection, 0); 3749 3750 /* Adjust the available stack space by the amount we grew. */ 3751 if (rv == KERN_SUCCESS) { 3752 if (prev_entry != &map->header) 3753 vm_map_clip_end(map, prev_entry, addr); 3754 new_entry = prev_entry->next; 3755 KASSERT(new_entry == stack_entry->prev, ("foo")); 3756 KASSERT(new_entry->end == stack_entry->start, ("foo")); 3757 KASSERT(new_entry->start == addr, ("foo")); 3758 grow_amount = new_entry->end - new_entry->start; 3759 new_entry->avail_ssize = stack_entry->avail_ssize - 3760 grow_amount; 3761 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 3762 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3763 } 3764 } else { 3765 /* 3766 * Growing upward. 3767 */ 3768 addr = stack_entry->end + grow_amount; 3769 3770 /* 3771 * If this puts us into the next entry, cut back our growth 3772 * to the available space. Also, see the note above. 3773 */ 3774 if (addr > end) { 3775 stack_entry->avail_ssize = end - stack_entry->end; 3776 addr = end; 3777 if (stack_guard_page) 3778 addr -= PAGE_SIZE; 3779 } 3780 3781 grow_amount = addr - stack_entry->end; 3782 cred = stack_entry->cred; 3783 if (cred == NULL && stack_entry->object.vm_object != NULL) 3784 cred = stack_entry->object.vm_object->cred; 3785 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 3786 rv = KERN_NO_SPACE; 3787 /* Grow the underlying object if applicable. */ 3788 else if (stack_entry->object.vm_object == NULL || 3789 vm_object_coalesce(stack_entry->object.vm_object, 3790 stack_entry->offset, 3791 (vm_size_t)(stack_entry->end - stack_entry->start), 3792 (vm_size_t)grow_amount, cred != NULL)) { 3793 map->size += (addr - stack_entry->end); 3794 /* Update the current entry. */ 3795 stack_entry->end = addr; 3796 stack_entry->avail_ssize -= grow_amount; 3797 vm_map_entry_resize_free(map, stack_entry); 3798 rv = KERN_SUCCESS; 3799 3800 if (next_entry != &map->header) 3801 vm_map_clip_start(map, next_entry, addr); 3802 } else 3803 rv = KERN_FAILURE; 3804 } 3805 3806 if (rv == KERN_SUCCESS && is_procstack) 3807 vm->vm_ssize += btoc(grow_amount); 3808 3809 vm_map_unlock(map); 3810 3811 /* 3812 * Heed the MAP_WIREFUTURE flag if it was set for this process. 3813 */ 3814 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 3815 vm_map_wire(map, 3816 (stack_entry == next_entry) ? addr : addr - grow_amount, 3817 (stack_entry == next_entry) ? stack_entry->start : addr, 3818 (p->p_flag & P_SYSTEM) 3819 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 3820 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 3821 } 3822 3823out: 3824#ifdef RACCT 3825 if (rv != KERN_SUCCESS) { 3826 PROC_LOCK(p); 3827 error = racct_set(p, RACCT_VMEM, map->size); 3828 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 3829 if (!old_mlock) { 3830 error = racct_set(p, RACCT_MEMLOCK, 3831 ptoa(pmap_wired_count(map->pmap))); 3832 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 3833 } 3834 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 3835 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 3836 PROC_UNLOCK(p); 3837 } 3838#endif 3839 3840 return (rv); 3841} 3842 3843/* 3844 * Unshare the specified VM space for exec. If other processes are 3845 * mapped to it, then create a new one. The new vmspace is null. 3846 */ 3847int 3848vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 3849{ 3850 struct vmspace *oldvmspace = p->p_vmspace; 3851 struct vmspace *newvmspace; 3852 3853 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 3854 ("vmspace_exec recursed")); 3855 newvmspace = vmspace_alloc(minuser, maxuser, NULL); 3856 if (newvmspace == NULL) 3857 return (ENOMEM); 3858 newvmspace->vm_swrss = oldvmspace->vm_swrss; 3859 /* 3860 * This code is written like this for prototype purposes. The 3861 * goal is to avoid running down the vmspace here, but let the 3862 * other process's that are still using the vmspace to finally 3863 * run it down. Even though there is little or no chance of blocking 3864 * here, it is a good idea to keep this form for future mods. 3865 */ 3866 PROC_VMSPACE_LOCK(p); 3867 p->p_vmspace = newvmspace; 3868 PROC_VMSPACE_UNLOCK(p); 3869 if (p == curthread->td_proc) 3870 pmap_activate(curthread); 3871 curthread->td_pflags |= TDP_EXECVMSPC; 3872 return (0); 3873} 3874 3875/* 3876 * Unshare the specified VM space for forcing COW. This 3877 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3878 */ 3879int 3880vmspace_unshare(struct proc *p) 3881{ 3882 struct vmspace *oldvmspace = p->p_vmspace; 3883 struct vmspace *newvmspace; 3884 vm_ooffset_t fork_charge; 3885 3886 if (oldvmspace->vm_refcnt == 1) 3887 return (0); 3888 fork_charge = 0; 3889 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 3890 if (newvmspace == NULL) 3891 return (ENOMEM); 3892 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 3893 vmspace_free(newvmspace); 3894 return (ENOMEM); 3895 } 3896 PROC_VMSPACE_LOCK(p); 3897 p->p_vmspace = newvmspace; 3898 PROC_VMSPACE_UNLOCK(p); 3899 if (p == curthread->td_proc) 3900 pmap_activate(curthread); 3901 vmspace_free(oldvmspace); 3902 return (0); 3903} 3904 3905/* 3906 * vm_map_lookup: 3907 * 3908 * Finds the VM object, offset, and 3909 * protection for a given virtual address in the 3910 * specified map, assuming a page fault of the 3911 * type specified. 3912 * 3913 * Leaves the map in question locked for read; return 3914 * values are guaranteed until a vm_map_lookup_done 3915 * call is performed. Note that the map argument 3916 * is in/out; the returned map must be used in 3917 * the call to vm_map_lookup_done. 3918 * 3919 * A handle (out_entry) is returned for use in 3920 * vm_map_lookup_done, to make that fast. 3921 * 3922 * If a lookup is requested with "write protection" 3923 * specified, the map may be changed to perform virtual 3924 * copying operations, although the data referenced will 3925 * remain the same. 3926 */ 3927int 3928vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3929 vm_offset_t vaddr, 3930 vm_prot_t fault_typea, 3931 vm_map_entry_t *out_entry, /* OUT */ 3932 vm_object_t *object, /* OUT */ 3933 vm_pindex_t *pindex, /* OUT */ 3934 vm_prot_t *out_prot, /* OUT */ 3935 boolean_t *wired) /* OUT */ 3936{ 3937 vm_map_entry_t entry; 3938 vm_map_t map = *var_map; 3939 vm_prot_t prot; 3940 vm_prot_t fault_type = fault_typea; 3941 vm_object_t eobject; 3942 vm_size_t size; 3943 struct ucred *cred; 3944 3945RetryLookup:; 3946 3947 vm_map_lock_read(map); 3948 3949 /* 3950 * Lookup the faulting address. 3951 */ 3952 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 3953 vm_map_unlock_read(map); 3954 return (KERN_INVALID_ADDRESS); 3955 } 3956 3957 entry = *out_entry; 3958 3959 /* 3960 * Handle submaps. 3961 */ 3962 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3963 vm_map_t old_map = map; 3964 3965 *var_map = map = entry->object.sub_map; 3966 vm_map_unlock_read(old_map); 3967 goto RetryLookup; 3968 } 3969 3970 /* 3971 * Check whether this task is allowed to have this page. 3972 */ 3973 prot = entry->protection; 3974 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3975 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 3976 vm_map_unlock_read(map); 3977 return (KERN_PROTECTION_FAILURE); 3978 } 3979 KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags & 3980 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) != 3981 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY), 3982 ("entry %p flags %x", entry, entry->eflags)); 3983 if ((fault_typea & VM_PROT_COPY) != 0 && 3984 (entry->max_protection & VM_PROT_WRITE) == 0 && 3985 (entry->eflags & MAP_ENTRY_COW) == 0) { 3986 vm_map_unlock_read(map); 3987 return (KERN_PROTECTION_FAILURE); 3988 } 3989 3990 /* 3991 * If this page is not pageable, we have to get it for all possible 3992 * accesses. 3993 */ 3994 *wired = (entry->wired_count != 0); 3995 if (*wired) 3996 fault_type = entry->protection; 3997 size = entry->end - entry->start; 3998 /* 3999 * If the entry was copy-on-write, we either ... 4000 */ 4001 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4002 /* 4003 * If we want to write the page, we may as well handle that 4004 * now since we've got the map locked. 4005 * 4006 * If we don't need to write the page, we just demote the 4007 * permissions allowed. 4008 */ 4009 if ((fault_type & VM_PROT_WRITE) != 0 || 4010 (fault_typea & VM_PROT_COPY) != 0) { 4011 /* 4012 * Make a new object, and place it in the object 4013 * chain. Note that no new references have appeared 4014 * -- one just moved from the map to the new 4015 * object. 4016 */ 4017 if (vm_map_lock_upgrade(map)) 4018 goto RetryLookup; 4019 4020 if (entry->cred == NULL) { 4021 /* 4022 * The debugger owner is charged for 4023 * the memory. 4024 */ 4025 cred = curthread->td_ucred; 4026 crhold(cred); 4027 if (!swap_reserve_by_cred(size, cred)) { 4028 crfree(cred); 4029 vm_map_unlock(map); 4030 return (KERN_RESOURCE_SHORTAGE); 4031 } 4032 entry->cred = cred; 4033 } 4034 vm_object_shadow(&entry->object.vm_object, 4035 &entry->offset, size); 4036 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4037 eobject = entry->object.vm_object; 4038 if (eobject->cred != NULL) { 4039 /* 4040 * The object was not shadowed. 4041 */ 4042 swap_release_by_cred(size, entry->cred); 4043 crfree(entry->cred); 4044 entry->cred = NULL; 4045 } else if (entry->cred != NULL) { 4046 VM_OBJECT_WLOCK(eobject); 4047 eobject->cred = entry->cred; 4048 eobject->charge = size; 4049 VM_OBJECT_WUNLOCK(eobject); 4050 entry->cred = NULL; 4051 } 4052 4053 vm_map_lock_downgrade(map); 4054 } else { 4055 /* 4056 * We're attempting to read a copy-on-write page -- 4057 * don't allow writes. 4058 */ 4059 prot &= ~VM_PROT_WRITE; 4060 } 4061 } 4062 4063 /* 4064 * Create an object if necessary. 4065 */ 4066 if (entry->object.vm_object == NULL && 4067 !map->system_map) { 4068 if (vm_map_lock_upgrade(map)) 4069 goto RetryLookup; 4070 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 4071 atop(size)); 4072 entry->offset = 0; 4073 if (entry->cred != NULL) { 4074 VM_OBJECT_WLOCK(entry->object.vm_object); 4075 entry->object.vm_object->cred = entry->cred; 4076 entry->object.vm_object->charge = size; 4077 VM_OBJECT_WUNLOCK(entry->object.vm_object); 4078 entry->cred = NULL; 4079 } 4080 vm_map_lock_downgrade(map); 4081 } 4082 4083 /* 4084 * Return the object/offset from this entry. If the entry was 4085 * copy-on-write or empty, it has been fixed up. 4086 */ 4087 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4088 *object = entry->object.vm_object; 4089 4090 *out_prot = prot; 4091 return (KERN_SUCCESS); 4092} 4093 4094/* 4095 * vm_map_lookup_locked: 4096 * 4097 * Lookup the faulting address. A version of vm_map_lookup that returns 4098 * KERN_FAILURE instead of blocking on map lock or memory allocation. 4099 */ 4100int 4101vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4102 vm_offset_t vaddr, 4103 vm_prot_t fault_typea, 4104 vm_map_entry_t *out_entry, /* OUT */ 4105 vm_object_t *object, /* OUT */ 4106 vm_pindex_t *pindex, /* OUT */ 4107 vm_prot_t *out_prot, /* OUT */ 4108 boolean_t *wired) /* OUT */ 4109{ 4110 vm_map_entry_t entry; 4111 vm_map_t map = *var_map; 4112 vm_prot_t prot; 4113 vm_prot_t fault_type = fault_typea; 4114 4115 /* 4116 * Lookup the faulting address. 4117 */ 4118 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4119 return (KERN_INVALID_ADDRESS); 4120 4121 entry = *out_entry; 4122 4123 /* 4124 * Fail if the entry refers to a submap. 4125 */ 4126 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4127 return (KERN_FAILURE); 4128 4129 /* 4130 * Check whether this task is allowed to have this page. 4131 */ 4132 prot = entry->protection; 4133 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4134 if ((fault_type & prot) != fault_type) 4135 return (KERN_PROTECTION_FAILURE); 4136 4137 /* 4138 * If this page is not pageable, we have to get it for all possible 4139 * accesses. 4140 */ 4141 *wired = (entry->wired_count != 0); 4142 if (*wired) 4143 fault_type = entry->protection; 4144 4145 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4146 /* 4147 * Fail if the entry was copy-on-write for a write fault. 4148 */ 4149 if (fault_type & VM_PROT_WRITE) 4150 return (KERN_FAILURE); 4151 /* 4152 * We're attempting to read a copy-on-write page -- 4153 * don't allow writes. 4154 */ 4155 prot &= ~VM_PROT_WRITE; 4156 } 4157 4158 /* 4159 * Fail if an object should be created. 4160 */ 4161 if (entry->object.vm_object == NULL && !map->system_map) 4162 return (KERN_FAILURE); 4163 4164 /* 4165 * Return the object/offset from this entry. If the entry was 4166 * copy-on-write or empty, it has been fixed up. 4167 */ 4168 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4169 *object = entry->object.vm_object; 4170 4171 *out_prot = prot; 4172 return (KERN_SUCCESS); 4173} 4174 4175/* 4176 * vm_map_lookup_done: 4177 * 4178 * Releases locks acquired by a vm_map_lookup 4179 * (according to the handle returned by that lookup). 4180 */ 4181void 4182vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4183{ 4184 /* 4185 * Unlock the main-level map 4186 */ 4187 vm_map_unlock_read(map); 4188} 4189 4190#include "opt_ddb.h" 4191#ifdef DDB 4192#include <sys/kernel.h> 4193 4194#include <ddb/ddb.h> 4195 4196static void 4197vm_map_print(vm_map_t map) 4198{ 4199 vm_map_entry_t entry; 4200 4201 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4202 (void *)map, 4203 (void *)map->pmap, map->nentries, map->timestamp); 4204 4205 db_indent += 2; 4206 for (entry = map->header.next; entry != &map->header; 4207 entry = entry->next) { 4208 db_iprintf("map entry %p: start=%p, end=%p\n", 4209 (void *)entry, (void *)entry->start, (void *)entry->end); 4210 { 4211 static char *inheritance_name[4] = 4212 {"share", "copy", "none", "donate_copy"}; 4213 4214 db_iprintf(" prot=%x/%x/%s", 4215 entry->protection, 4216 entry->max_protection, 4217 inheritance_name[(int)(unsigned char)entry->inheritance]); 4218 if (entry->wired_count != 0) 4219 db_printf(", wired"); 4220 } 4221 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4222 db_printf(", share=%p, offset=0x%jx\n", 4223 (void *)entry->object.sub_map, 4224 (uintmax_t)entry->offset); 4225 if ((entry->prev == &map->header) || 4226 (entry->prev->object.sub_map != 4227 entry->object.sub_map)) { 4228 db_indent += 2; 4229 vm_map_print((vm_map_t)entry->object.sub_map); 4230 db_indent -= 2; 4231 } 4232 } else { 4233 if (entry->cred != NULL) 4234 db_printf(", ruid %d", entry->cred->cr_ruid); 4235 db_printf(", object=%p, offset=0x%jx", 4236 (void *)entry->object.vm_object, 4237 (uintmax_t)entry->offset); 4238 if (entry->object.vm_object && entry->object.vm_object->cred) 4239 db_printf(", obj ruid %d charge %jx", 4240 entry->object.vm_object->cred->cr_ruid, 4241 (uintmax_t)entry->object.vm_object->charge); 4242 if (entry->eflags & MAP_ENTRY_COW) 4243 db_printf(", copy (%s)", 4244 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4245 db_printf("\n"); 4246 4247 if ((entry->prev == &map->header) || 4248 (entry->prev->object.vm_object != 4249 entry->object.vm_object)) { 4250 db_indent += 2; 4251 vm_object_print((db_expr_t)(intptr_t) 4252 entry->object.vm_object, 4253 0, 0, (char *)0); 4254 db_indent -= 2; 4255 } 4256 } 4257 } 4258 db_indent -= 2; 4259} 4260 4261DB_SHOW_COMMAND(map, map) 4262{ 4263 4264 if (!have_addr) { 4265 db_printf("usage: show map <addr>\n"); 4266 return; 4267 } 4268 vm_map_print((vm_map_t)addr); 4269} 4270 4271DB_SHOW_COMMAND(procvm, procvm) 4272{ 4273 struct proc *p; 4274 4275 if (have_addr) { 4276 p = (struct proc *) addr; 4277 } else { 4278 p = curproc; 4279 } 4280 4281 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4282 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4283 (void *)vmspace_pmap(p->p_vmspace)); 4284 4285 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 4286} 4287 4288#endif /* DDB */ 4289