vm_map.c revision 284665
1/*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61/* 62 * Virtual memory mapping module. 63 */ 64 65#include <sys/cdefs.h> 66__FBSDID("$FreeBSD: stable/10/sys/vm/vm_map.c 284665 2015-06-21 06:28:26Z trasz $"); 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} 300 301#ifdef RACCT 302static void 303vmspace_container_reset(struct proc *p) 304{ 305 306 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} 314#endif 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 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 346 "vmspace_free() called with non-sleepable lock held"); 347 348 if (vm->vm_refcnt == 0) 349 panic("vmspace_free: attempt to free already freed vmspace"); 350 351 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) 352 vmspace_dofree(vm); 353} 354 355void 356vmspace_exitfree(struct proc *p) 357{ 358 struct vmspace *vm; 359 360 PROC_VMSPACE_LOCK(p); 361 vm = p->p_vmspace; 362 p->p_vmspace = NULL; 363 PROC_VMSPACE_UNLOCK(p); 364 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 365 vmspace_free(vm); 366} 367 368void 369vmspace_exit(struct thread *td) 370{ 371 int refcnt; 372 struct vmspace *vm; 373 struct proc *p; 374 375 /* 376 * Release user portion of address space. 377 * This releases references to vnodes, 378 * which could cause I/O if the file has been unlinked. 379 * Need to do this early enough that we can still sleep. 380 * 381 * The last exiting process to reach this point releases as 382 * much of the environment as it can. vmspace_dofree() is the 383 * slower fallback in case another process had a temporary 384 * reference to the vmspace. 385 */ 386 387 p = td->td_proc; 388 vm = p->p_vmspace; 389 atomic_add_int(&vmspace0.vm_refcnt, 1); 390 do { 391 refcnt = vm->vm_refcnt; 392 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 393 /* Switch now since other proc might free vmspace */ 394 PROC_VMSPACE_LOCK(p); 395 p->p_vmspace = &vmspace0; 396 PROC_VMSPACE_UNLOCK(p); 397 pmap_activate(td); 398 } 399 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 400 if (refcnt == 1) { 401 if (p->p_vmspace != vm) { 402 /* vmspace not yet freed, switch back */ 403 PROC_VMSPACE_LOCK(p); 404 p->p_vmspace = vm; 405 PROC_VMSPACE_UNLOCK(p); 406 pmap_activate(td); 407 } 408 pmap_remove_pages(vmspace_pmap(vm)); 409 /* Switch now since this proc will free vmspace */ 410 PROC_VMSPACE_LOCK(p); 411 p->p_vmspace = &vmspace0; 412 PROC_VMSPACE_UNLOCK(p); 413 pmap_activate(td); 414 vmspace_dofree(vm); 415 } 416#ifdef RACCT 417 if (racct_enable) 418 vmspace_container_reset(p); 419#endif 420} 421 422/* Acquire reference to vmspace owned by another process. */ 423 424struct vmspace * 425vmspace_acquire_ref(struct proc *p) 426{ 427 struct vmspace *vm; 428 int refcnt; 429 430 PROC_VMSPACE_LOCK(p); 431 vm = p->p_vmspace; 432 if (vm == NULL) { 433 PROC_VMSPACE_UNLOCK(p); 434 return (NULL); 435 } 436 do { 437 refcnt = vm->vm_refcnt; 438 if (refcnt <= 0) { /* Avoid 0->1 transition */ 439 PROC_VMSPACE_UNLOCK(p); 440 return (NULL); 441 } 442 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1)); 443 if (vm != p->p_vmspace) { 444 PROC_VMSPACE_UNLOCK(p); 445 vmspace_free(vm); 446 return (NULL); 447 } 448 PROC_VMSPACE_UNLOCK(p); 449 return (vm); 450} 451 452void 453_vm_map_lock(vm_map_t map, const char *file, int line) 454{ 455 456 if (map->system_map) 457 mtx_lock_flags_(&map->system_mtx, 0, file, line); 458 else 459 sx_xlock_(&map->lock, file, line); 460 map->timestamp++; 461} 462 463static void 464vm_map_process_deferred(void) 465{ 466 struct thread *td; 467 vm_map_entry_t entry, next; 468 vm_object_t object; 469 470 td = curthread; 471 entry = td->td_map_def_user; 472 td->td_map_def_user = NULL; 473 while (entry != NULL) { 474 next = entry->next; 475 if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) { 476 /* 477 * Decrement the object's writemappings and 478 * possibly the vnode's v_writecount. 479 */ 480 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 481 ("Submap with writecount")); 482 object = entry->object.vm_object; 483 KASSERT(object != NULL, ("No object for writecount")); 484 vnode_pager_release_writecount(object, entry->start, 485 entry->end); 486 } 487 vm_map_entry_deallocate(entry, FALSE); 488 entry = next; 489 } 490} 491 492void 493_vm_map_unlock(vm_map_t map, const char *file, int line) 494{ 495 496 if (map->system_map) 497 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 498 else { 499 sx_xunlock_(&map->lock, file, line); 500 vm_map_process_deferred(); 501 } 502} 503 504void 505_vm_map_lock_read(vm_map_t map, const char *file, int line) 506{ 507 508 if (map->system_map) 509 mtx_lock_flags_(&map->system_mtx, 0, file, line); 510 else 511 sx_slock_(&map->lock, file, line); 512} 513 514void 515_vm_map_unlock_read(vm_map_t map, const char *file, int line) 516{ 517 518 if (map->system_map) 519 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 520 else { 521 sx_sunlock_(&map->lock, file, line); 522 vm_map_process_deferred(); 523 } 524} 525 526int 527_vm_map_trylock(vm_map_t map, const char *file, int line) 528{ 529 int error; 530 531 error = map->system_map ? 532 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 533 !sx_try_xlock_(&map->lock, file, line); 534 if (error == 0) 535 map->timestamp++; 536 return (error == 0); 537} 538 539int 540_vm_map_trylock_read(vm_map_t map, const char *file, int line) 541{ 542 int error; 543 544 error = map->system_map ? 545 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 546 !sx_try_slock_(&map->lock, file, line); 547 return (error == 0); 548} 549 550/* 551 * _vm_map_lock_upgrade: [ internal use only ] 552 * 553 * Tries to upgrade a read (shared) lock on the specified map to a write 554 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 555 * non-zero value if the upgrade fails. If the upgrade fails, the map is 556 * returned without a read or write lock held. 557 * 558 * Requires that the map be read locked. 559 */ 560int 561_vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 562{ 563 unsigned int last_timestamp; 564 565 if (map->system_map) { 566 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 567 } else { 568 if (!sx_try_upgrade_(&map->lock, file, line)) { 569 last_timestamp = map->timestamp; 570 sx_sunlock_(&map->lock, file, line); 571 vm_map_process_deferred(); 572 /* 573 * If the map's timestamp does not change while the 574 * map is unlocked, then the upgrade succeeds. 575 */ 576 sx_xlock_(&map->lock, file, line); 577 if (last_timestamp != map->timestamp) { 578 sx_xunlock_(&map->lock, file, line); 579 return (1); 580 } 581 } 582 } 583 map->timestamp++; 584 return (0); 585} 586 587void 588_vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 589{ 590 591 if (map->system_map) { 592 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 593 } else 594 sx_downgrade_(&map->lock, file, line); 595} 596 597/* 598 * vm_map_locked: 599 * 600 * Returns a non-zero value if the caller holds a write (exclusive) lock 601 * on the specified map and the value "0" otherwise. 602 */ 603int 604vm_map_locked(vm_map_t map) 605{ 606 607 if (map->system_map) 608 return (mtx_owned(&map->system_mtx)); 609 else 610 return (sx_xlocked(&map->lock)); 611} 612 613#ifdef INVARIANTS 614static void 615_vm_map_assert_locked(vm_map_t map, const char *file, int line) 616{ 617 618 if (map->system_map) 619 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 620 else 621 sx_assert_(&map->lock, SA_XLOCKED, file, line); 622} 623 624#define VM_MAP_ASSERT_LOCKED(map) \ 625 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 626#else 627#define VM_MAP_ASSERT_LOCKED(map) 628#endif 629 630/* 631 * _vm_map_unlock_and_wait: 632 * 633 * Atomically releases the lock on the specified map and puts the calling 634 * thread to sleep. The calling thread will remain asleep until either 635 * vm_map_wakeup() is performed on the map or the specified timeout is 636 * exceeded. 637 * 638 * WARNING! This function does not perform deferred deallocations of 639 * objects and map entries. Therefore, the calling thread is expected to 640 * reacquire the map lock after reawakening and later perform an ordinary 641 * unlock operation, such as vm_map_unlock(), before completing its 642 * operation on the map. 643 */ 644int 645_vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) 646{ 647 648 mtx_lock(&map_sleep_mtx); 649 if (map->system_map) 650 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 651 else 652 sx_xunlock_(&map->lock, file, line); 653 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 654 timo)); 655} 656 657/* 658 * vm_map_wakeup: 659 * 660 * Awaken any threads that have slept on the map using 661 * vm_map_unlock_and_wait(). 662 */ 663void 664vm_map_wakeup(vm_map_t map) 665{ 666 667 /* 668 * Acquire and release map_sleep_mtx to prevent a wakeup() 669 * from being performed (and lost) between the map unlock 670 * and the msleep() in _vm_map_unlock_and_wait(). 671 */ 672 mtx_lock(&map_sleep_mtx); 673 mtx_unlock(&map_sleep_mtx); 674 wakeup(&map->root); 675} 676 677void 678vm_map_busy(vm_map_t map) 679{ 680 681 VM_MAP_ASSERT_LOCKED(map); 682 map->busy++; 683} 684 685void 686vm_map_unbusy(vm_map_t map) 687{ 688 689 VM_MAP_ASSERT_LOCKED(map); 690 KASSERT(map->busy, ("vm_map_unbusy: not busy")); 691 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { 692 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); 693 wakeup(&map->busy); 694 } 695} 696 697void 698vm_map_wait_busy(vm_map_t map) 699{ 700 701 VM_MAP_ASSERT_LOCKED(map); 702 while (map->busy) { 703 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); 704 if (map->system_map) 705 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); 706 else 707 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); 708 } 709 map->timestamp++; 710} 711 712long 713vmspace_resident_count(struct vmspace *vmspace) 714{ 715 return pmap_resident_count(vmspace_pmap(vmspace)); 716} 717 718/* 719 * vm_map_create: 720 * 721 * Creates and returns a new empty VM map with 722 * the given physical map structure, and having 723 * the given lower and upper address bounds. 724 */ 725vm_map_t 726vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 727{ 728 vm_map_t result; 729 730 result = uma_zalloc(mapzone, M_WAITOK); 731 CTR1(KTR_VM, "vm_map_create: %p", result); 732 _vm_map_init(result, pmap, min, max); 733 return (result); 734} 735 736/* 737 * Initialize an existing vm_map structure 738 * such as that in the vmspace structure. 739 */ 740static void 741_vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 742{ 743 744 map->header.next = map->header.prev = &map->header; 745 map->needs_wakeup = FALSE; 746 map->system_map = 0; 747 map->pmap = pmap; 748 map->min_offset = min; 749 map->max_offset = max; 750 map->flags = 0; 751 map->root = NULL; 752 map->timestamp = 0; 753 map->busy = 0; 754} 755 756void 757vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 758{ 759 760 _vm_map_init(map, pmap, min, max); 761 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 762 sx_init(&map->lock, "user map"); 763} 764 765/* 766 * vm_map_entry_dispose: [ internal use only ] 767 * 768 * Inverse of vm_map_entry_create. 769 */ 770static void 771vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 772{ 773 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 774} 775 776/* 777 * vm_map_entry_create: [ internal use only ] 778 * 779 * Allocates a VM map entry for insertion. 780 * No entry fields are filled in. 781 */ 782static vm_map_entry_t 783vm_map_entry_create(vm_map_t map) 784{ 785 vm_map_entry_t new_entry; 786 787 if (map->system_map) 788 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 789 else 790 new_entry = uma_zalloc(mapentzone, M_WAITOK); 791 if (new_entry == NULL) 792 panic("vm_map_entry_create: kernel resources exhausted"); 793 return (new_entry); 794} 795 796/* 797 * vm_map_entry_set_behavior: 798 * 799 * Set the expected access behavior, either normal, random, or 800 * sequential. 801 */ 802static inline void 803vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 804{ 805 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 806 (behavior & MAP_ENTRY_BEHAV_MASK); 807} 808 809/* 810 * vm_map_entry_set_max_free: 811 * 812 * Set the max_free field in a vm_map_entry. 813 */ 814static inline void 815vm_map_entry_set_max_free(vm_map_entry_t entry) 816{ 817 818 entry->max_free = entry->adj_free; 819 if (entry->left != NULL && entry->left->max_free > entry->max_free) 820 entry->max_free = entry->left->max_free; 821 if (entry->right != NULL && entry->right->max_free > entry->max_free) 822 entry->max_free = entry->right->max_free; 823} 824 825/* 826 * vm_map_entry_splay: 827 * 828 * The Sleator and Tarjan top-down splay algorithm with the 829 * following variation. Max_free must be computed bottom-up, so 830 * on the downward pass, maintain the left and right spines in 831 * reverse order. Then, make a second pass up each side to fix 832 * the pointers and compute max_free. The time bound is O(log n) 833 * amortized. 834 * 835 * The new root is the vm_map_entry containing "addr", or else an 836 * adjacent entry (lower or higher) if addr is not in the tree. 837 * 838 * The map must be locked, and leaves it so. 839 * 840 * Returns: the new root. 841 */ 842static vm_map_entry_t 843vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root) 844{ 845 vm_map_entry_t llist, rlist; 846 vm_map_entry_t ltree, rtree; 847 vm_map_entry_t y; 848 849 /* Special case of empty tree. */ 850 if (root == NULL) 851 return (root); 852 853 /* 854 * Pass One: Splay down the tree until we find addr or a NULL 855 * pointer where addr would go. llist and rlist are the two 856 * sides in reverse order (bottom-up), with llist linked by 857 * the right pointer and rlist linked by the left pointer in 858 * the vm_map_entry. Wait until Pass Two to set max_free on 859 * the two spines. 860 */ 861 llist = NULL; 862 rlist = NULL; 863 for (;;) { 864 /* root is never NULL in here. */ 865 if (addr < root->start) { 866 y = root->left; 867 if (y == NULL) 868 break; 869 if (addr < y->start && y->left != NULL) { 870 /* Rotate right and put y on rlist. */ 871 root->left = y->right; 872 y->right = root; 873 vm_map_entry_set_max_free(root); 874 root = y->left; 875 y->left = rlist; 876 rlist = y; 877 } else { 878 /* Put root on rlist. */ 879 root->left = rlist; 880 rlist = root; 881 root = y; 882 } 883 } else if (addr >= root->end) { 884 y = root->right; 885 if (y == NULL) 886 break; 887 if (addr >= y->end && y->right != NULL) { 888 /* Rotate left and put y on llist. */ 889 root->right = y->left; 890 y->left = root; 891 vm_map_entry_set_max_free(root); 892 root = y->right; 893 y->right = llist; 894 llist = y; 895 } else { 896 /* Put root on llist. */ 897 root->right = llist; 898 llist = root; 899 root = y; 900 } 901 } else 902 break; 903 } 904 905 /* 906 * Pass Two: Walk back up the two spines, flip the pointers 907 * and set max_free. The subtrees of the root go at the 908 * bottom of llist and rlist. 909 */ 910 ltree = root->left; 911 while (llist != NULL) { 912 y = llist->right; 913 llist->right = ltree; 914 vm_map_entry_set_max_free(llist); 915 ltree = llist; 916 llist = y; 917 } 918 rtree = root->right; 919 while (rlist != NULL) { 920 y = rlist->left; 921 rlist->left = rtree; 922 vm_map_entry_set_max_free(rlist); 923 rtree = rlist; 924 rlist = y; 925 } 926 927 /* 928 * Final assembly: add ltree and rtree as subtrees of root. 929 */ 930 root->left = ltree; 931 root->right = rtree; 932 vm_map_entry_set_max_free(root); 933 934 return (root); 935} 936 937/* 938 * vm_map_entry_{un,}link: 939 * 940 * Insert/remove entries from maps. 941 */ 942static void 943vm_map_entry_link(vm_map_t map, 944 vm_map_entry_t after_where, 945 vm_map_entry_t entry) 946{ 947 948 CTR4(KTR_VM, 949 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 950 map->nentries, entry, after_where); 951 VM_MAP_ASSERT_LOCKED(map); 952 KASSERT(after_where == &map->header || 953 after_where->end <= entry->start, 954 ("vm_map_entry_link: prev end %jx new start %jx overlap", 955 (uintmax_t)after_where->end, (uintmax_t)entry->start)); 956 KASSERT(after_where->next == &map->header || 957 entry->end <= after_where->next->start, 958 ("vm_map_entry_link: new end %jx next start %jx overlap", 959 (uintmax_t)entry->end, (uintmax_t)after_where->next->start)); 960 961 map->nentries++; 962 entry->prev = after_where; 963 entry->next = after_where->next; 964 entry->next->prev = entry; 965 after_where->next = entry; 966 967 if (after_where != &map->header) { 968 if (after_where != map->root) 969 vm_map_entry_splay(after_where->start, map->root); 970 entry->right = after_where->right; 971 entry->left = after_where; 972 after_where->right = NULL; 973 after_where->adj_free = entry->start - after_where->end; 974 vm_map_entry_set_max_free(after_where); 975 } else { 976 entry->right = map->root; 977 entry->left = NULL; 978 } 979 entry->adj_free = (entry->next == &map->header ? map->max_offset : 980 entry->next->start) - entry->end; 981 vm_map_entry_set_max_free(entry); 982 map->root = entry; 983} 984 985static void 986vm_map_entry_unlink(vm_map_t map, 987 vm_map_entry_t entry) 988{ 989 vm_map_entry_t next, prev, root; 990 991 VM_MAP_ASSERT_LOCKED(map); 992 if (entry != map->root) 993 vm_map_entry_splay(entry->start, map->root); 994 if (entry->left == NULL) 995 root = entry->right; 996 else { 997 root = vm_map_entry_splay(entry->start, entry->left); 998 root->right = entry->right; 999 root->adj_free = (entry->next == &map->header ? map->max_offset : 1000 entry->next->start) - root->end; 1001 vm_map_entry_set_max_free(root); 1002 } 1003 map->root = root; 1004 1005 prev = entry->prev; 1006 next = entry->next; 1007 next->prev = prev; 1008 prev->next = next; 1009 map->nentries--; 1010 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 1011 map->nentries, entry); 1012} 1013 1014/* 1015 * vm_map_entry_resize_free: 1016 * 1017 * Recompute the amount of free space following a vm_map_entry 1018 * and propagate that value up the tree. Call this function after 1019 * resizing a map entry in-place, that is, without a call to 1020 * vm_map_entry_link() or _unlink(). 1021 * 1022 * The map must be locked, and leaves it so. 1023 */ 1024static void 1025vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry) 1026{ 1027 1028 /* 1029 * Using splay trees without parent pointers, propagating 1030 * max_free up the tree is done by moving the entry to the 1031 * root and making the change there. 1032 */ 1033 if (entry != map->root) 1034 map->root = vm_map_entry_splay(entry->start, map->root); 1035 1036 entry->adj_free = (entry->next == &map->header ? map->max_offset : 1037 entry->next->start) - entry->end; 1038 vm_map_entry_set_max_free(entry); 1039} 1040 1041/* 1042 * vm_map_lookup_entry: [ internal use only ] 1043 * 1044 * Finds the map entry containing (or 1045 * immediately preceding) the specified address 1046 * in the given map; the entry is returned 1047 * in the "entry" parameter. The boolean 1048 * result indicates whether the address is 1049 * actually contained in the map. 1050 */ 1051boolean_t 1052vm_map_lookup_entry( 1053 vm_map_t map, 1054 vm_offset_t address, 1055 vm_map_entry_t *entry) /* OUT */ 1056{ 1057 vm_map_entry_t cur; 1058 boolean_t locked; 1059 1060 /* 1061 * If the map is empty, then the map entry immediately preceding 1062 * "address" is the map's header. 1063 */ 1064 cur = map->root; 1065 if (cur == NULL) 1066 *entry = &map->header; 1067 else if (address >= cur->start && cur->end > address) { 1068 *entry = cur; 1069 return (TRUE); 1070 } else if ((locked = vm_map_locked(map)) || 1071 sx_try_upgrade(&map->lock)) { 1072 /* 1073 * Splay requires a write lock on the map. However, it only 1074 * restructures the binary search tree; it does not otherwise 1075 * change the map. Thus, the map's timestamp need not change 1076 * on a temporary upgrade. 1077 */ 1078 map->root = cur = vm_map_entry_splay(address, cur); 1079 if (!locked) 1080 sx_downgrade(&map->lock); 1081 1082 /* 1083 * If "address" is contained within a map entry, the new root 1084 * is that map entry. Otherwise, the new root is a map entry 1085 * immediately before or after "address". 1086 */ 1087 if (address >= cur->start) { 1088 *entry = cur; 1089 if (cur->end > address) 1090 return (TRUE); 1091 } else 1092 *entry = cur->prev; 1093 } else 1094 /* 1095 * Since the map is only locked for read access, perform a 1096 * standard binary search tree lookup for "address". 1097 */ 1098 for (;;) { 1099 if (address < cur->start) { 1100 if (cur->left == NULL) { 1101 *entry = cur->prev; 1102 break; 1103 } 1104 cur = cur->left; 1105 } else if (cur->end > address) { 1106 *entry = cur; 1107 return (TRUE); 1108 } else { 1109 if (cur->right == NULL) { 1110 *entry = cur; 1111 break; 1112 } 1113 cur = cur->right; 1114 } 1115 } 1116 return (FALSE); 1117} 1118 1119/* 1120 * vm_map_insert: 1121 * 1122 * Inserts the given whole VM object into the target 1123 * map at the specified address range. The object's 1124 * size should match that of the address range. 1125 * 1126 * Requires that the map be locked, and leaves it so. 1127 * 1128 * If object is non-NULL, ref count must be bumped by caller 1129 * prior to making call to account for the new entry. 1130 */ 1131int 1132vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1133 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 1134 int cow) 1135{ 1136 vm_map_entry_t new_entry; 1137 vm_map_entry_t prev_entry; 1138 vm_map_entry_t temp_entry; 1139 vm_eflags_t protoeflags; 1140 struct ucred *cred; 1141 vm_inherit_t inheritance; 1142 boolean_t charge_prev_obj; 1143 1144 VM_MAP_ASSERT_LOCKED(map); 1145 1146 /* 1147 * Check that the start and end points are not bogus. 1148 */ 1149 if ((start < map->min_offset) || (end > map->max_offset) || 1150 (start >= end)) 1151 return (KERN_INVALID_ADDRESS); 1152 1153 /* 1154 * Find the entry prior to the proposed starting address; if it's part 1155 * of an existing entry, this range is bogus. 1156 */ 1157 if (vm_map_lookup_entry(map, start, &temp_entry)) 1158 return (KERN_NO_SPACE); 1159 1160 prev_entry = temp_entry; 1161 1162 /* 1163 * Assert that the next entry doesn't overlap the end point. 1164 */ 1165 if ((prev_entry->next != &map->header) && 1166 (prev_entry->next->start < end)) 1167 return (KERN_NO_SPACE); 1168 1169 protoeflags = 0; 1170 charge_prev_obj = FALSE; 1171 1172 if (cow & MAP_COPY_ON_WRITE) 1173 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 1174 1175 if (cow & MAP_NOFAULT) { 1176 protoeflags |= MAP_ENTRY_NOFAULT; 1177 1178 KASSERT(object == NULL, 1179 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1180 } 1181 if (cow & MAP_DISABLE_SYNCER) 1182 protoeflags |= MAP_ENTRY_NOSYNC; 1183 if (cow & MAP_DISABLE_COREDUMP) 1184 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1185 if (cow & MAP_VN_WRITECOUNT) 1186 protoeflags |= MAP_ENTRY_VN_WRITECNT; 1187 if (cow & MAP_INHERIT_SHARE) 1188 inheritance = VM_INHERIT_SHARE; 1189 else 1190 inheritance = VM_INHERIT_DEFAULT; 1191 1192 cred = NULL; 1193 KASSERT((object != kmem_object && object != kernel_object) || 1194 ((object == kmem_object || object == kernel_object) && 1195 !(protoeflags & MAP_ENTRY_NEEDS_COPY)), 1196 ("kmem or kernel object and cow")); 1197 if (cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT)) 1198 goto charged; 1199 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1200 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1201 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1202 return (KERN_RESOURCE_SHORTAGE); 1203 KASSERT(object == NULL || (protoeflags & MAP_ENTRY_NEEDS_COPY) || 1204 object->cred == NULL, 1205 ("OVERCOMMIT: vm_map_insert o %p", object)); 1206 cred = curthread->td_ucred; 1207 crhold(cred); 1208 if (object == NULL && !(protoeflags & MAP_ENTRY_NEEDS_COPY)) 1209 charge_prev_obj = TRUE; 1210 } 1211 1212charged: 1213 /* Expand the kernel pmap, if necessary. */ 1214 if (map == kernel_map && end > kernel_vm_end) 1215 pmap_growkernel(end); 1216 if (object != NULL) { 1217 /* 1218 * OBJ_ONEMAPPING must be cleared unless this mapping 1219 * is trivially proven to be the only mapping for any 1220 * of the object's pages. (Object granularity 1221 * reference counting is insufficient to recognize 1222 * aliases with precision.) 1223 */ 1224 VM_OBJECT_WLOCK(object); 1225 if (object->ref_count > 1 || object->shadow_count != 0) 1226 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1227 VM_OBJECT_WUNLOCK(object); 1228 } 1229 else if ((prev_entry != &map->header) && 1230 (prev_entry->eflags == protoeflags) && 1231 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 && 1232 (prev_entry->end == start) && 1233 (prev_entry->wired_count == 0) && 1234 (prev_entry->cred == cred || 1235 (prev_entry->object.vm_object != NULL && 1236 (prev_entry->object.vm_object->cred == cred))) && 1237 vm_object_coalesce(prev_entry->object.vm_object, 1238 prev_entry->offset, 1239 (vm_size_t)(prev_entry->end - prev_entry->start), 1240 (vm_size_t)(end - prev_entry->end), charge_prev_obj)) { 1241 /* 1242 * We were able to extend the object. Determine if we 1243 * can extend the previous map entry to include the 1244 * new range as well. 1245 */ 1246 if ((prev_entry->inheritance == inheritance) && 1247 (prev_entry->protection == prot) && 1248 (prev_entry->max_protection == max)) { 1249 map->size += (end - prev_entry->end); 1250 prev_entry->end = end; 1251 vm_map_entry_resize_free(map, prev_entry); 1252 vm_map_simplify_entry(map, prev_entry); 1253 if (cred != NULL) 1254 crfree(cred); 1255 return (KERN_SUCCESS); 1256 } 1257 1258 /* 1259 * If we can extend the object but cannot extend the 1260 * map entry, we have to create a new map entry. We 1261 * must bump the ref count on the extended object to 1262 * account for it. object may be NULL. 1263 */ 1264 object = prev_entry->object.vm_object; 1265 offset = prev_entry->offset + 1266 (prev_entry->end - prev_entry->start); 1267 vm_object_reference(object); 1268 if (cred != NULL && object != NULL && object->cred != NULL && 1269 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1270 /* Object already accounts for this uid. */ 1271 crfree(cred); 1272 cred = NULL; 1273 } 1274 } 1275 1276 /* 1277 * NOTE: if conditionals fail, object can be NULL here. This occurs 1278 * in things like the buffer map where we manage kva but do not manage 1279 * backing objects. 1280 */ 1281 1282 /* 1283 * Create a new entry 1284 */ 1285 new_entry = vm_map_entry_create(map); 1286 new_entry->start = start; 1287 new_entry->end = end; 1288 new_entry->cred = NULL; 1289 1290 new_entry->eflags = protoeflags; 1291 new_entry->object.vm_object = object; 1292 new_entry->offset = offset; 1293 new_entry->avail_ssize = 0; 1294 1295 new_entry->inheritance = inheritance; 1296 new_entry->protection = prot; 1297 new_entry->max_protection = max; 1298 new_entry->wired_count = 0; 1299 new_entry->wiring_thread = NULL; 1300 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1301 new_entry->next_read = OFF_TO_IDX(offset); 1302 1303 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1304 ("OVERCOMMIT: vm_map_insert leaks vm_map %p", new_entry)); 1305 new_entry->cred = cred; 1306 1307 /* 1308 * Insert the new entry into the list 1309 */ 1310 vm_map_entry_link(map, prev_entry, new_entry); 1311 map->size += new_entry->end - new_entry->start; 1312 1313 /* 1314 * It may be possible to merge the new entry with the next and/or 1315 * previous entries. However, due to MAP_STACK_* being a hack, a 1316 * panic can result from merging such entries. 1317 */ 1318 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0) 1319 vm_map_simplify_entry(map, new_entry); 1320 1321 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 1322 vm_map_pmap_enter(map, start, prot, 1323 object, OFF_TO_IDX(offset), end - start, 1324 cow & MAP_PREFAULT_PARTIAL); 1325 } 1326 1327 return (KERN_SUCCESS); 1328} 1329 1330/* 1331 * vm_map_findspace: 1332 * 1333 * Find the first fit (lowest VM address) for "length" free bytes 1334 * beginning at address >= start in the given map. 1335 * 1336 * In a vm_map_entry, "adj_free" is the amount of free space 1337 * adjacent (higher address) to this entry, and "max_free" is the 1338 * maximum amount of contiguous free space in its subtree. This 1339 * allows finding a free region in one path down the tree, so 1340 * O(log n) amortized with splay trees. 1341 * 1342 * The map must be locked, and leaves it so. 1343 * 1344 * Returns: 0 on success, and starting address in *addr, 1345 * 1 if insufficient space. 1346 */ 1347int 1348vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1349 vm_offset_t *addr) /* OUT */ 1350{ 1351 vm_map_entry_t entry; 1352 vm_offset_t st; 1353 1354 /* 1355 * Request must fit within min/max VM address and must avoid 1356 * address wrap. 1357 */ 1358 if (start < map->min_offset) 1359 start = map->min_offset; 1360 if (start + length > map->max_offset || start + length < start) 1361 return (1); 1362 1363 /* Empty tree means wide open address space. */ 1364 if (map->root == NULL) { 1365 *addr = start; 1366 return (0); 1367 } 1368 1369 /* 1370 * After splay, if start comes before root node, then there 1371 * must be a gap from start to the root. 1372 */ 1373 map->root = vm_map_entry_splay(start, map->root); 1374 if (start + length <= map->root->start) { 1375 *addr = start; 1376 return (0); 1377 } 1378 1379 /* 1380 * Root is the last node that might begin its gap before 1381 * start, and this is the last comparison where address 1382 * wrap might be a problem. 1383 */ 1384 st = (start > map->root->end) ? start : map->root->end; 1385 if (length <= map->root->end + map->root->adj_free - st) { 1386 *addr = st; 1387 return (0); 1388 } 1389 1390 /* With max_free, can immediately tell if no solution. */ 1391 entry = map->root->right; 1392 if (entry == NULL || length > entry->max_free) 1393 return (1); 1394 1395 /* 1396 * Search the right subtree in the order: left subtree, root, 1397 * right subtree (first fit). The previous splay implies that 1398 * all regions in the right subtree have addresses > start. 1399 */ 1400 while (entry != NULL) { 1401 if (entry->left != NULL && entry->left->max_free >= length) 1402 entry = entry->left; 1403 else if (entry->adj_free >= length) { 1404 *addr = entry->end; 1405 return (0); 1406 } else 1407 entry = entry->right; 1408 } 1409 1410 /* Can't get here, so panic if we do. */ 1411 panic("vm_map_findspace: max_free corrupt"); 1412} 1413 1414int 1415vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1416 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1417 vm_prot_t max, int cow) 1418{ 1419 vm_offset_t end; 1420 int result; 1421 1422 end = start + length; 1423 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1424 object == NULL, 1425 ("vm_map_fixed: non-NULL backing object for stack")); 1426 vm_map_lock(map); 1427 VM_MAP_RANGE_CHECK(map, start, end); 1428 if ((cow & MAP_CHECK_EXCL) == 0) 1429 vm_map_delete(map, start, end); 1430 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1431 result = vm_map_stack_locked(map, start, length, sgrowsiz, 1432 prot, max, cow); 1433 } else { 1434 result = vm_map_insert(map, object, offset, start, end, 1435 prot, max, cow); 1436 } 1437 vm_map_unlock(map); 1438 return (result); 1439} 1440 1441/* 1442 * vm_map_find finds an unallocated region in the target address 1443 * map with the given length. The search is defined to be 1444 * first-fit from the specified address; the region found is 1445 * returned in the same parameter. 1446 * 1447 * If object is non-NULL, ref count must be bumped by caller 1448 * prior to making call to account for the new entry. 1449 */ 1450int 1451vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1452 vm_offset_t *addr, /* IN/OUT */ 1453 vm_size_t length, vm_offset_t max_addr, int find_space, 1454 vm_prot_t prot, vm_prot_t max, int cow) 1455{ 1456 vm_offset_t alignment, initial_addr, start; 1457 int result; 1458 1459 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1460 object == NULL, 1461 ("vm_map_find: non-NULL backing object for stack")); 1462 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 1463 (object->flags & OBJ_COLORED) == 0)) 1464 find_space = VMFS_ANY_SPACE; 1465 if (find_space >> 8 != 0) { 1466 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 1467 alignment = (vm_offset_t)1 << (find_space >> 8); 1468 } else 1469 alignment = 0; 1470 initial_addr = *addr; 1471again: 1472 start = initial_addr; 1473 vm_map_lock(map); 1474 do { 1475 if (find_space != VMFS_NO_SPACE) { 1476 if (vm_map_findspace(map, start, length, addr) || 1477 (max_addr != 0 && *addr + length > max_addr)) { 1478 vm_map_unlock(map); 1479 if (find_space == VMFS_OPTIMAL_SPACE) { 1480 find_space = VMFS_ANY_SPACE; 1481 goto again; 1482 } 1483 return (KERN_NO_SPACE); 1484 } 1485 switch (find_space) { 1486 case VMFS_SUPER_SPACE: 1487 case VMFS_OPTIMAL_SPACE: 1488 pmap_align_superpage(object, offset, addr, 1489 length); 1490 break; 1491 case VMFS_ANY_SPACE: 1492 break; 1493 default: 1494 if ((*addr & (alignment - 1)) != 0) { 1495 *addr &= ~(alignment - 1); 1496 *addr += alignment; 1497 } 1498 break; 1499 } 1500 1501 start = *addr; 1502 } 1503 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1504 result = vm_map_stack_locked(map, start, length, 1505 sgrowsiz, prot, max, cow); 1506 } else { 1507 result = vm_map_insert(map, object, offset, start, 1508 start + length, prot, max, cow); 1509 } 1510 } while (result == KERN_NO_SPACE && find_space != VMFS_NO_SPACE && 1511 find_space != VMFS_ANY_SPACE); 1512 vm_map_unlock(map); 1513 return (result); 1514} 1515 1516/* 1517 * vm_map_simplify_entry: 1518 * 1519 * Simplify the given map entry by merging with either neighbor. This 1520 * routine also has the ability to merge with both neighbors. 1521 * 1522 * The map must be locked. 1523 * 1524 * This routine guarentees that the passed entry remains valid (though 1525 * possibly extended). When merging, this routine may delete one or 1526 * both neighbors. 1527 */ 1528void 1529vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1530{ 1531 vm_map_entry_t next, prev; 1532 vm_size_t prevsize, esize; 1533 1534 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) 1535 return; 1536 1537 prev = entry->prev; 1538 if (prev != &map->header) { 1539 prevsize = prev->end - prev->start; 1540 if ( (prev->end == entry->start) && 1541 (prev->object.vm_object == entry->object.vm_object) && 1542 (!prev->object.vm_object || 1543 (prev->offset + prevsize == entry->offset)) && 1544 (prev->eflags == entry->eflags) && 1545 (prev->protection == entry->protection) && 1546 (prev->max_protection == entry->max_protection) && 1547 (prev->inheritance == entry->inheritance) && 1548 (prev->wired_count == entry->wired_count) && 1549 (prev->cred == entry->cred)) { 1550 vm_map_entry_unlink(map, prev); 1551 entry->start = prev->start; 1552 entry->offset = prev->offset; 1553 if (entry->prev != &map->header) 1554 vm_map_entry_resize_free(map, entry->prev); 1555 1556 /* 1557 * If the backing object is a vnode object, 1558 * vm_object_deallocate() calls vrele(). 1559 * However, vrele() does not lock the vnode 1560 * because the vnode has additional 1561 * references. Thus, the map lock can be kept 1562 * without causing a lock-order reversal with 1563 * the vnode lock. 1564 * 1565 * Since we count the number of virtual page 1566 * mappings in object->un_pager.vnp.writemappings, 1567 * the writemappings value should not be adjusted 1568 * when the entry is disposed of. 1569 */ 1570 if (prev->object.vm_object) 1571 vm_object_deallocate(prev->object.vm_object); 1572 if (prev->cred != NULL) 1573 crfree(prev->cred); 1574 vm_map_entry_dispose(map, prev); 1575 } 1576 } 1577 1578 next = entry->next; 1579 if (next != &map->header) { 1580 esize = entry->end - entry->start; 1581 if ((entry->end == next->start) && 1582 (next->object.vm_object == entry->object.vm_object) && 1583 (!entry->object.vm_object || 1584 (entry->offset + esize == next->offset)) && 1585 (next->eflags == entry->eflags) && 1586 (next->protection == entry->protection) && 1587 (next->max_protection == entry->max_protection) && 1588 (next->inheritance == entry->inheritance) && 1589 (next->wired_count == entry->wired_count) && 1590 (next->cred == entry->cred)) { 1591 vm_map_entry_unlink(map, next); 1592 entry->end = next->end; 1593 vm_map_entry_resize_free(map, entry); 1594 1595 /* 1596 * See comment above. 1597 */ 1598 if (next->object.vm_object) 1599 vm_object_deallocate(next->object.vm_object); 1600 if (next->cred != NULL) 1601 crfree(next->cred); 1602 vm_map_entry_dispose(map, next); 1603 } 1604 } 1605} 1606/* 1607 * vm_map_clip_start: [ internal use only ] 1608 * 1609 * Asserts that the given entry begins at or after 1610 * the specified address; if necessary, 1611 * it splits the entry into two. 1612 */ 1613#define vm_map_clip_start(map, entry, startaddr) \ 1614{ \ 1615 if (startaddr > entry->start) \ 1616 _vm_map_clip_start(map, entry, startaddr); \ 1617} 1618 1619/* 1620 * This routine is called only when it is known that 1621 * the entry must be split. 1622 */ 1623static void 1624_vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1625{ 1626 vm_map_entry_t new_entry; 1627 1628 VM_MAP_ASSERT_LOCKED(map); 1629 1630 /* 1631 * Split off the front portion -- note that we must insert the new 1632 * entry BEFORE this one, so that this entry has the specified 1633 * starting address. 1634 */ 1635 vm_map_simplify_entry(map, entry); 1636 1637 /* 1638 * If there is no object backing this entry, we might as well create 1639 * one now. If we defer it, an object can get created after the map 1640 * is clipped, and individual objects will be created for the split-up 1641 * map. This is a bit of a hack, but is also about the best place to 1642 * put this improvement. 1643 */ 1644 if (entry->object.vm_object == NULL && !map->system_map) { 1645 vm_object_t object; 1646 object = vm_object_allocate(OBJT_DEFAULT, 1647 atop(entry->end - entry->start)); 1648 entry->object.vm_object = object; 1649 entry->offset = 0; 1650 if (entry->cred != NULL) { 1651 object->cred = entry->cred; 1652 object->charge = entry->end - entry->start; 1653 entry->cred = NULL; 1654 } 1655 } else if (entry->object.vm_object != NULL && 1656 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1657 entry->cred != NULL) { 1658 VM_OBJECT_WLOCK(entry->object.vm_object); 1659 KASSERT(entry->object.vm_object->cred == NULL, 1660 ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry)); 1661 entry->object.vm_object->cred = entry->cred; 1662 entry->object.vm_object->charge = entry->end - entry->start; 1663 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1664 entry->cred = NULL; 1665 } 1666 1667 new_entry = vm_map_entry_create(map); 1668 *new_entry = *entry; 1669 1670 new_entry->end = start; 1671 entry->offset += (start - entry->start); 1672 entry->start = start; 1673 if (new_entry->cred != NULL) 1674 crhold(entry->cred); 1675 1676 vm_map_entry_link(map, entry->prev, new_entry); 1677 1678 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1679 vm_object_reference(new_entry->object.vm_object); 1680 /* 1681 * The object->un_pager.vnp.writemappings for the 1682 * object of MAP_ENTRY_VN_WRITECNT type entry shall be 1683 * kept as is here. The virtual pages are 1684 * re-distributed among the clipped entries, so the sum is 1685 * left the same. 1686 */ 1687 } 1688} 1689 1690/* 1691 * vm_map_clip_end: [ internal use only ] 1692 * 1693 * Asserts that the given entry ends at or before 1694 * the specified address; if necessary, 1695 * it splits the entry into two. 1696 */ 1697#define vm_map_clip_end(map, entry, endaddr) \ 1698{ \ 1699 if ((endaddr) < (entry->end)) \ 1700 _vm_map_clip_end((map), (entry), (endaddr)); \ 1701} 1702 1703/* 1704 * This routine is called only when it is known that 1705 * the entry must be split. 1706 */ 1707static void 1708_vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1709{ 1710 vm_map_entry_t new_entry; 1711 1712 VM_MAP_ASSERT_LOCKED(map); 1713 1714 /* 1715 * If there is no object backing this entry, we might as well create 1716 * one now. If we defer it, an object can get created after the map 1717 * is clipped, and individual objects will be created for the split-up 1718 * map. This is a bit of a hack, but is also about the best place to 1719 * put this improvement. 1720 */ 1721 if (entry->object.vm_object == NULL && !map->system_map) { 1722 vm_object_t object; 1723 object = vm_object_allocate(OBJT_DEFAULT, 1724 atop(entry->end - entry->start)); 1725 entry->object.vm_object = object; 1726 entry->offset = 0; 1727 if (entry->cred != NULL) { 1728 object->cred = entry->cred; 1729 object->charge = entry->end - entry->start; 1730 entry->cred = NULL; 1731 } 1732 } else if (entry->object.vm_object != NULL && 1733 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1734 entry->cred != NULL) { 1735 VM_OBJECT_WLOCK(entry->object.vm_object); 1736 KASSERT(entry->object.vm_object->cred == NULL, 1737 ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry)); 1738 entry->object.vm_object->cred = entry->cred; 1739 entry->object.vm_object->charge = entry->end - entry->start; 1740 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1741 entry->cred = NULL; 1742 } 1743 1744 /* 1745 * Create a new entry and insert it AFTER the specified entry 1746 */ 1747 new_entry = vm_map_entry_create(map); 1748 *new_entry = *entry; 1749 1750 new_entry->start = entry->end = end; 1751 new_entry->offset += (end - entry->start); 1752 if (new_entry->cred != NULL) 1753 crhold(entry->cred); 1754 1755 vm_map_entry_link(map, entry, new_entry); 1756 1757 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1758 vm_object_reference(new_entry->object.vm_object); 1759 } 1760} 1761 1762/* 1763 * vm_map_submap: [ kernel use only ] 1764 * 1765 * Mark the given range as handled by a subordinate map. 1766 * 1767 * This range must have been created with vm_map_find, 1768 * and no other operations may have been performed on this 1769 * range prior to calling vm_map_submap. 1770 * 1771 * Only a limited number of operations can be performed 1772 * within this rage after calling vm_map_submap: 1773 * vm_fault 1774 * [Don't try vm_map_copy!] 1775 * 1776 * To remove a submapping, one must first remove the 1777 * range from the superior map, and then destroy the 1778 * submap (if desired). [Better yet, don't try it.] 1779 */ 1780int 1781vm_map_submap( 1782 vm_map_t map, 1783 vm_offset_t start, 1784 vm_offset_t end, 1785 vm_map_t submap) 1786{ 1787 vm_map_entry_t entry; 1788 int result = KERN_INVALID_ARGUMENT; 1789 1790 vm_map_lock(map); 1791 1792 VM_MAP_RANGE_CHECK(map, start, end); 1793 1794 if (vm_map_lookup_entry(map, start, &entry)) { 1795 vm_map_clip_start(map, entry, start); 1796 } else 1797 entry = entry->next; 1798 1799 vm_map_clip_end(map, entry, end); 1800 1801 if ((entry->start == start) && (entry->end == end) && 1802 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1803 (entry->object.vm_object == NULL)) { 1804 entry->object.sub_map = submap; 1805 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1806 result = KERN_SUCCESS; 1807 } 1808 vm_map_unlock(map); 1809 1810 return (result); 1811} 1812 1813/* 1814 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified 1815 */ 1816#define MAX_INIT_PT 96 1817 1818/* 1819 * vm_map_pmap_enter: 1820 * 1821 * Preload the specified map's pmap with mappings to the specified 1822 * object's memory-resident pages. No further physical pages are 1823 * allocated, and no further virtual pages are retrieved from secondary 1824 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a 1825 * limited number of page mappings are created at the low-end of the 1826 * specified address range. (For this purpose, a superpage mapping 1827 * counts as one page mapping.) Otherwise, all resident pages within 1828 * the specified address range are mapped. Because these mappings are 1829 * being created speculatively, cached pages are not reactivated and 1830 * mapped. 1831 */ 1832void 1833vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 1834 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1835{ 1836 vm_offset_t start; 1837 vm_page_t p, p_start; 1838 vm_pindex_t mask, psize, threshold, tmpidx; 1839 1840 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 1841 return; 1842 VM_OBJECT_RLOCK(object); 1843 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1844 VM_OBJECT_RUNLOCK(object); 1845 VM_OBJECT_WLOCK(object); 1846 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1847 pmap_object_init_pt(map->pmap, addr, object, pindex, 1848 size); 1849 VM_OBJECT_WUNLOCK(object); 1850 return; 1851 } 1852 VM_OBJECT_LOCK_DOWNGRADE(object); 1853 } 1854 1855 psize = atop(size); 1856 if (psize + pindex > object->size) { 1857 if (object->size < pindex) { 1858 VM_OBJECT_RUNLOCK(object); 1859 return; 1860 } 1861 psize = object->size - pindex; 1862 } 1863 1864 start = 0; 1865 p_start = NULL; 1866 threshold = MAX_INIT_PT; 1867 1868 p = vm_page_find_least(object, pindex); 1869 /* 1870 * Assert: the variable p is either (1) the page with the 1871 * least pindex greater than or equal to the parameter pindex 1872 * or (2) NULL. 1873 */ 1874 for (; 1875 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1876 p = TAILQ_NEXT(p, listq)) { 1877 /* 1878 * don't allow an madvise to blow away our really 1879 * free pages allocating pv entries. 1880 */ 1881 if (((flags & MAP_PREFAULT_MADVISE) != 0 && 1882 cnt.v_free_count < cnt.v_free_reserved) || 1883 ((flags & MAP_PREFAULT_PARTIAL) != 0 && 1884 tmpidx >= threshold)) { 1885 psize = tmpidx; 1886 break; 1887 } 1888 if (p->valid == VM_PAGE_BITS_ALL) { 1889 if (p_start == NULL) { 1890 start = addr + ptoa(tmpidx); 1891 p_start = p; 1892 } 1893 /* Jump ahead if a superpage mapping is possible. */ 1894 if (p->psind > 0 && ((addr + ptoa(tmpidx)) & 1895 (pagesizes[p->psind] - 1)) == 0) { 1896 mask = atop(pagesizes[p->psind]) - 1; 1897 if (tmpidx + mask < psize && 1898 vm_page_ps_is_valid(p)) { 1899 p += mask; 1900 threshold += mask; 1901 } 1902 } 1903 } else if (p_start != NULL) { 1904 pmap_enter_object(map->pmap, start, addr + 1905 ptoa(tmpidx), p_start, prot); 1906 p_start = NULL; 1907 } 1908 } 1909 if (p_start != NULL) 1910 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 1911 p_start, prot); 1912 VM_OBJECT_RUNLOCK(object); 1913} 1914 1915/* 1916 * vm_map_protect: 1917 * 1918 * Sets the protection of the specified address 1919 * region in the target map. If "set_max" is 1920 * specified, the maximum protection is to be set; 1921 * otherwise, only the current protection is affected. 1922 */ 1923int 1924vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1925 vm_prot_t new_prot, boolean_t set_max) 1926{ 1927 vm_map_entry_t current, entry; 1928 vm_object_t obj; 1929 struct ucred *cred; 1930 vm_prot_t old_prot; 1931 1932 if (start == end) 1933 return (KERN_SUCCESS); 1934 1935 vm_map_lock(map); 1936 1937 VM_MAP_RANGE_CHECK(map, start, end); 1938 1939 if (vm_map_lookup_entry(map, start, &entry)) { 1940 vm_map_clip_start(map, entry, start); 1941 } else { 1942 entry = entry->next; 1943 } 1944 1945 /* 1946 * Make a first pass to check for protection violations. 1947 */ 1948 current = entry; 1949 while ((current != &map->header) && (current->start < end)) { 1950 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1951 vm_map_unlock(map); 1952 return (KERN_INVALID_ARGUMENT); 1953 } 1954 if ((new_prot & current->max_protection) != new_prot) { 1955 vm_map_unlock(map); 1956 return (KERN_PROTECTION_FAILURE); 1957 } 1958 current = current->next; 1959 } 1960 1961 1962 /* 1963 * Do an accounting pass for private read-only mappings that 1964 * now will do cow due to allowed write (e.g. debugger sets 1965 * breakpoint on text segment) 1966 */ 1967 for (current = entry; (current != &map->header) && 1968 (current->start < end); current = current->next) { 1969 1970 vm_map_clip_end(map, current, end); 1971 1972 if (set_max || 1973 ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 || 1974 ENTRY_CHARGED(current)) { 1975 continue; 1976 } 1977 1978 cred = curthread->td_ucred; 1979 obj = current->object.vm_object; 1980 1981 if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) { 1982 if (!swap_reserve(current->end - current->start)) { 1983 vm_map_unlock(map); 1984 return (KERN_RESOURCE_SHORTAGE); 1985 } 1986 crhold(cred); 1987 current->cred = cred; 1988 continue; 1989 } 1990 1991 VM_OBJECT_WLOCK(obj); 1992 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 1993 VM_OBJECT_WUNLOCK(obj); 1994 continue; 1995 } 1996 1997 /* 1998 * Charge for the whole object allocation now, since 1999 * we cannot distinguish between non-charged and 2000 * charged clipped mapping of the same object later. 2001 */ 2002 KASSERT(obj->charge == 0, 2003 ("vm_map_protect: object %p overcharged (entry %p)", 2004 obj, current)); 2005 if (!swap_reserve(ptoa(obj->size))) { 2006 VM_OBJECT_WUNLOCK(obj); 2007 vm_map_unlock(map); 2008 return (KERN_RESOURCE_SHORTAGE); 2009 } 2010 2011 crhold(cred); 2012 obj->cred = cred; 2013 obj->charge = ptoa(obj->size); 2014 VM_OBJECT_WUNLOCK(obj); 2015 } 2016 2017 /* 2018 * Go back and fix up protections. [Note that clipping is not 2019 * necessary the second time.] 2020 */ 2021 current = entry; 2022 while ((current != &map->header) && (current->start < end)) { 2023 old_prot = current->protection; 2024 2025 if (set_max) 2026 current->protection = 2027 (current->max_protection = new_prot) & 2028 old_prot; 2029 else 2030 current->protection = new_prot; 2031 2032 /* 2033 * For user wired map entries, the normal lazy evaluation of 2034 * write access upgrades through soft page faults is 2035 * undesirable. Instead, immediately copy any pages that are 2036 * copy-on-write and enable write access in the physical map. 2037 */ 2038 if ((current->eflags & MAP_ENTRY_USER_WIRED) != 0 && 2039 (current->protection & VM_PROT_WRITE) != 0 && 2040 (old_prot & VM_PROT_WRITE) == 0) 2041 vm_fault_copy_entry(map, map, current, current, NULL); 2042 2043 /* 2044 * When restricting access, update the physical map. Worry 2045 * about copy-on-write here. 2046 */ 2047 if ((old_prot & ~current->protection) != 0) { 2048#define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 2049 VM_PROT_ALL) 2050 pmap_protect(map->pmap, current->start, 2051 current->end, 2052 current->protection & MASK(current)); 2053#undef MASK 2054 } 2055 vm_map_simplify_entry(map, current); 2056 current = current->next; 2057 } 2058 vm_map_unlock(map); 2059 return (KERN_SUCCESS); 2060} 2061 2062/* 2063 * vm_map_madvise: 2064 * 2065 * This routine traverses a processes map handling the madvise 2066 * system call. Advisories are classified as either those effecting 2067 * the vm_map_entry structure, or those effecting the underlying 2068 * objects. 2069 */ 2070int 2071vm_map_madvise( 2072 vm_map_t map, 2073 vm_offset_t start, 2074 vm_offset_t end, 2075 int behav) 2076{ 2077 vm_map_entry_t current, entry; 2078 int modify_map = 0; 2079 2080 /* 2081 * Some madvise calls directly modify the vm_map_entry, in which case 2082 * we need to use an exclusive lock on the map and we need to perform 2083 * various clipping operations. Otherwise we only need a read-lock 2084 * on the map. 2085 */ 2086 switch(behav) { 2087 case MADV_NORMAL: 2088 case MADV_SEQUENTIAL: 2089 case MADV_RANDOM: 2090 case MADV_NOSYNC: 2091 case MADV_AUTOSYNC: 2092 case MADV_NOCORE: 2093 case MADV_CORE: 2094 if (start == end) 2095 return (KERN_SUCCESS); 2096 modify_map = 1; 2097 vm_map_lock(map); 2098 break; 2099 case MADV_WILLNEED: 2100 case MADV_DONTNEED: 2101 case MADV_FREE: 2102 if (start == end) 2103 return (KERN_SUCCESS); 2104 vm_map_lock_read(map); 2105 break; 2106 default: 2107 return (KERN_INVALID_ARGUMENT); 2108 } 2109 2110 /* 2111 * Locate starting entry and clip if necessary. 2112 */ 2113 VM_MAP_RANGE_CHECK(map, start, end); 2114 2115 if (vm_map_lookup_entry(map, start, &entry)) { 2116 if (modify_map) 2117 vm_map_clip_start(map, entry, start); 2118 } else { 2119 entry = entry->next; 2120 } 2121 2122 if (modify_map) { 2123 /* 2124 * madvise behaviors that are implemented in the vm_map_entry. 2125 * 2126 * We clip the vm_map_entry so that behavioral changes are 2127 * limited to the specified address range. 2128 */ 2129 for (current = entry; 2130 (current != &map->header) && (current->start < end); 2131 current = current->next 2132 ) { 2133 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2134 continue; 2135 2136 vm_map_clip_end(map, current, end); 2137 2138 switch (behav) { 2139 case MADV_NORMAL: 2140 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 2141 break; 2142 case MADV_SEQUENTIAL: 2143 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 2144 break; 2145 case MADV_RANDOM: 2146 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 2147 break; 2148 case MADV_NOSYNC: 2149 current->eflags |= MAP_ENTRY_NOSYNC; 2150 break; 2151 case MADV_AUTOSYNC: 2152 current->eflags &= ~MAP_ENTRY_NOSYNC; 2153 break; 2154 case MADV_NOCORE: 2155 current->eflags |= MAP_ENTRY_NOCOREDUMP; 2156 break; 2157 case MADV_CORE: 2158 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2159 break; 2160 default: 2161 break; 2162 } 2163 vm_map_simplify_entry(map, current); 2164 } 2165 vm_map_unlock(map); 2166 } else { 2167 vm_pindex_t pstart, pend; 2168 2169 /* 2170 * madvise behaviors that are implemented in the underlying 2171 * vm_object. 2172 * 2173 * Since we don't clip the vm_map_entry, we have to clip 2174 * the vm_object pindex and count. 2175 */ 2176 for (current = entry; 2177 (current != &map->header) && (current->start < end); 2178 current = current->next 2179 ) { 2180 vm_offset_t useEnd, useStart; 2181 2182 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2183 continue; 2184 2185 pstart = OFF_TO_IDX(current->offset); 2186 pend = pstart + atop(current->end - current->start); 2187 useStart = current->start; 2188 useEnd = current->end; 2189 2190 if (current->start < start) { 2191 pstart += atop(start - current->start); 2192 useStart = start; 2193 } 2194 if (current->end > end) { 2195 pend -= atop(current->end - end); 2196 useEnd = end; 2197 } 2198 2199 if (pstart >= pend) 2200 continue; 2201 2202 /* 2203 * Perform the pmap_advise() before clearing 2204 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2205 * concurrent pmap operation, such as pmap_remove(), 2206 * could clear a reference in the pmap and set 2207 * PGA_REFERENCED on the page before the pmap_advise() 2208 * had completed. Consequently, the page would appear 2209 * referenced based upon an old reference that 2210 * occurred before this pmap_advise() ran. 2211 */ 2212 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2213 pmap_advise(map->pmap, useStart, useEnd, 2214 behav); 2215 2216 vm_object_madvise(current->object.vm_object, pstart, 2217 pend, behav); 2218 2219 /* 2220 * Pre-populate paging structures in the 2221 * WILLNEED case. For wired entries, the 2222 * paging structures are already populated. 2223 */ 2224 if (behav == MADV_WILLNEED && 2225 current->wired_count == 0) { 2226 vm_map_pmap_enter(map, 2227 useStart, 2228 current->protection, 2229 current->object.vm_object, 2230 pstart, 2231 ptoa(pend - pstart), 2232 MAP_PREFAULT_MADVISE 2233 ); 2234 } 2235 } 2236 vm_map_unlock_read(map); 2237 } 2238 return (0); 2239} 2240 2241 2242/* 2243 * vm_map_inherit: 2244 * 2245 * Sets the inheritance of the specified address 2246 * range in the target map. Inheritance 2247 * affects how the map will be shared with 2248 * child maps at the time of vmspace_fork. 2249 */ 2250int 2251vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2252 vm_inherit_t new_inheritance) 2253{ 2254 vm_map_entry_t entry; 2255 vm_map_entry_t temp_entry; 2256 2257 switch (new_inheritance) { 2258 case VM_INHERIT_NONE: 2259 case VM_INHERIT_COPY: 2260 case VM_INHERIT_SHARE: 2261 break; 2262 default: 2263 return (KERN_INVALID_ARGUMENT); 2264 } 2265 if (start == end) 2266 return (KERN_SUCCESS); 2267 vm_map_lock(map); 2268 VM_MAP_RANGE_CHECK(map, start, end); 2269 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2270 entry = temp_entry; 2271 vm_map_clip_start(map, entry, start); 2272 } else 2273 entry = temp_entry->next; 2274 while ((entry != &map->header) && (entry->start < end)) { 2275 vm_map_clip_end(map, entry, end); 2276 entry->inheritance = new_inheritance; 2277 vm_map_simplify_entry(map, entry); 2278 entry = entry->next; 2279 } 2280 vm_map_unlock(map); 2281 return (KERN_SUCCESS); 2282} 2283 2284/* 2285 * vm_map_unwire: 2286 * 2287 * Implements both kernel and user unwiring. 2288 */ 2289int 2290vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2291 int flags) 2292{ 2293 vm_map_entry_t entry, first_entry, tmp_entry; 2294 vm_offset_t saved_start; 2295 unsigned int last_timestamp; 2296 int rv; 2297 boolean_t need_wakeup, result, user_unwire; 2298 2299 if (start == end) 2300 return (KERN_SUCCESS); 2301 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2302 vm_map_lock(map); 2303 VM_MAP_RANGE_CHECK(map, start, end); 2304 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2305 if (flags & VM_MAP_WIRE_HOLESOK) 2306 first_entry = first_entry->next; 2307 else { 2308 vm_map_unlock(map); 2309 return (KERN_INVALID_ADDRESS); 2310 } 2311 } 2312 last_timestamp = map->timestamp; 2313 entry = first_entry; 2314 while (entry != &map->header && entry->start < end) { 2315 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2316 /* 2317 * We have not yet clipped the entry. 2318 */ 2319 saved_start = (start >= entry->start) ? start : 2320 entry->start; 2321 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2322 if (vm_map_unlock_and_wait(map, 0)) { 2323 /* 2324 * Allow interruption of user unwiring? 2325 */ 2326 } 2327 vm_map_lock(map); 2328 if (last_timestamp+1 != map->timestamp) { 2329 /* 2330 * Look again for the entry because the map was 2331 * modified while it was unlocked. 2332 * Specifically, the entry may have been 2333 * clipped, merged, or deleted. 2334 */ 2335 if (!vm_map_lookup_entry(map, saved_start, 2336 &tmp_entry)) { 2337 if (flags & VM_MAP_WIRE_HOLESOK) 2338 tmp_entry = tmp_entry->next; 2339 else { 2340 if (saved_start == start) { 2341 /* 2342 * First_entry has been deleted. 2343 */ 2344 vm_map_unlock(map); 2345 return (KERN_INVALID_ADDRESS); 2346 } 2347 end = saved_start; 2348 rv = KERN_INVALID_ADDRESS; 2349 goto done; 2350 } 2351 } 2352 if (entry == first_entry) 2353 first_entry = tmp_entry; 2354 else 2355 first_entry = NULL; 2356 entry = tmp_entry; 2357 } 2358 last_timestamp = map->timestamp; 2359 continue; 2360 } 2361 vm_map_clip_start(map, entry, start); 2362 vm_map_clip_end(map, entry, end); 2363 /* 2364 * Mark the entry in case the map lock is released. (See 2365 * above.) 2366 */ 2367 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2368 entry->wiring_thread == NULL, 2369 ("owned map entry %p", entry)); 2370 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2371 entry->wiring_thread = curthread; 2372 /* 2373 * Check the map for holes in the specified region. 2374 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2375 */ 2376 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2377 (entry->end < end && (entry->next == &map->header || 2378 entry->next->start > entry->end))) { 2379 end = entry->end; 2380 rv = KERN_INVALID_ADDRESS; 2381 goto done; 2382 } 2383 /* 2384 * If system unwiring, require that the entry is system wired. 2385 */ 2386 if (!user_unwire && 2387 vm_map_entry_system_wired_count(entry) == 0) { 2388 end = entry->end; 2389 rv = KERN_INVALID_ARGUMENT; 2390 goto done; 2391 } 2392 entry = entry->next; 2393 } 2394 rv = KERN_SUCCESS; 2395done: 2396 need_wakeup = FALSE; 2397 if (first_entry == NULL) { 2398 result = vm_map_lookup_entry(map, start, &first_entry); 2399 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2400 first_entry = first_entry->next; 2401 else 2402 KASSERT(result, ("vm_map_unwire: lookup failed")); 2403 } 2404 for (entry = first_entry; entry != &map->header && entry->start < end; 2405 entry = entry->next) { 2406 /* 2407 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2408 * space in the unwired region could have been mapped 2409 * while the map lock was dropped for draining 2410 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 2411 * could be simultaneously wiring this new mapping 2412 * entry. Detect these cases and skip any entries 2413 * marked as in transition by us. 2414 */ 2415 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2416 entry->wiring_thread != curthread) { 2417 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2418 ("vm_map_unwire: !HOLESOK and new/changed entry")); 2419 continue; 2420 } 2421 2422 if (rv == KERN_SUCCESS && (!user_unwire || 2423 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 2424 if (user_unwire) 2425 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2426 if (entry->wired_count == 1) 2427 vm_map_entry_unwire(map, entry); 2428 else 2429 entry->wired_count--; 2430 } 2431 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2432 ("vm_map_unwire: in-transition flag missing %p", entry)); 2433 KASSERT(entry->wiring_thread == curthread, 2434 ("vm_map_unwire: alien wire %p", entry)); 2435 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 2436 entry->wiring_thread = NULL; 2437 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2438 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2439 need_wakeup = TRUE; 2440 } 2441 vm_map_simplify_entry(map, entry); 2442 } 2443 vm_map_unlock(map); 2444 if (need_wakeup) 2445 vm_map_wakeup(map); 2446 return (rv); 2447} 2448 2449/* 2450 * vm_map_wire_entry_failure: 2451 * 2452 * Handle a wiring failure on the given entry. 2453 * 2454 * The map should be locked. 2455 */ 2456static void 2457vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 2458 vm_offset_t failed_addr) 2459{ 2460 2461 VM_MAP_ASSERT_LOCKED(map); 2462 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 && 2463 entry->wired_count == 1, 2464 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry)); 2465 KASSERT(failed_addr < entry->end, 2466 ("vm_map_wire_entry_failure: entry %p was fully wired", entry)); 2467 2468 /* 2469 * If any pages at the start of this entry were successfully wired, 2470 * then unwire them. 2471 */ 2472 if (failed_addr > entry->start) { 2473 pmap_unwire(map->pmap, entry->start, failed_addr); 2474 vm_object_unwire(entry->object.vm_object, entry->offset, 2475 failed_addr - entry->start, PQ_ACTIVE); 2476 } 2477 2478 /* 2479 * Assign an out-of-range value to represent the failure to wire this 2480 * entry. 2481 */ 2482 entry->wired_count = -1; 2483} 2484 2485/* 2486 * vm_map_wire: 2487 * 2488 * Implements both kernel and user wiring. 2489 */ 2490int 2491vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2492 int flags) 2493{ 2494 vm_map_entry_t entry, first_entry, tmp_entry; 2495 vm_offset_t faddr, saved_end, saved_start; 2496 unsigned int last_timestamp; 2497 int rv; 2498 boolean_t need_wakeup, result, user_wire; 2499 vm_prot_t prot; 2500 2501 if (start == end) 2502 return (KERN_SUCCESS); 2503 prot = 0; 2504 if (flags & VM_MAP_WIRE_WRITE) 2505 prot |= VM_PROT_WRITE; 2506 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2507 vm_map_lock(map); 2508 VM_MAP_RANGE_CHECK(map, start, end); 2509 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2510 if (flags & VM_MAP_WIRE_HOLESOK) 2511 first_entry = first_entry->next; 2512 else { 2513 vm_map_unlock(map); 2514 return (KERN_INVALID_ADDRESS); 2515 } 2516 } 2517 last_timestamp = map->timestamp; 2518 entry = first_entry; 2519 while (entry != &map->header && entry->start < end) { 2520 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2521 /* 2522 * We have not yet clipped the entry. 2523 */ 2524 saved_start = (start >= entry->start) ? start : 2525 entry->start; 2526 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2527 if (vm_map_unlock_and_wait(map, 0)) { 2528 /* 2529 * Allow interruption of user wiring? 2530 */ 2531 } 2532 vm_map_lock(map); 2533 if (last_timestamp + 1 != map->timestamp) { 2534 /* 2535 * Look again for the entry because the map was 2536 * modified while it was unlocked. 2537 * Specifically, the entry may have been 2538 * clipped, merged, or deleted. 2539 */ 2540 if (!vm_map_lookup_entry(map, saved_start, 2541 &tmp_entry)) { 2542 if (flags & VM_MAP_WIRE_HOLESOK) 2543 tmp_entry = tmp_entry->next; 2544 else { 2545 if (saved_start == start) { 2546 /* 2547 * first_entry has been deleted. 2548 */ 2549 vm_map_unlock(map); 2550 return (KERN_INVALID_ADDRESS); 2551 } 2552 end = saved_start; 2553 rv = KERN_INVALID_ADDRESS; 2554 goto done; 2555 } 2556 } 2557 if (entry == first_entry) 2558 first_entry = tmp_entry; 2559 else 2560 first_entry = NULL; 2561 entry = tmp_entry; 2562 } 2563 last_timestamp = map->timestamp; 2564 continue; 2565 } 2566 vm_map_clip_start(map, entry, start); 2567 vm_map_clip_end(map, entry, end); 2568 /* 2569 * Mark the entry in case the map lock is released. (See 2570 * above.) 2571 */ 2572 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 2573 entry->wiring_thread == NULL, 2574 ("owned map entry %p", entry)); 2575 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2576 entry->wiring_thread = curthread; 2577 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 2578 || (entry->protection & prot) != prot) { 2579 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 2580 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { 2581 end = entry->end; 2582 rv = KERN_INVALID_ADDRESS; 2583 goto done; 2584 } 2585 goto next_entry; 2586 } 2587 if (entry->wired_count == 0) { 2588 entry->wired_count++; 2589 saved_start = entry->start; 2590 saved_end = entry->end; 2591 2592 /* 2593 * Release the map lock, relying on the in-transition 2594 * mark. Mark the map busy for fork. 2595 */ 2596 vm_map_busy(map); 2597 vm_map_unlock(map); 2598 2599 faddr = saved_start; 2600 do { 2601 /* 2602 * Simulate a fault to get the page and enter 2603 * it into the physical map. 2604 */ 2605 if ((rv = vm_fault(map, faddr, VM_PROT_NONE, 2606 VM_FAULT_CHANGE_WIRING)) != KERN_SUCCESS) 2607 break; 2608 } while ((faddr += PAGE_SIZE) < saved_end); 2609 vm_map_lock(map); 2610 vm_map_unbusy(map); 2611 if (last_timestamp + 1 != map->timestamp) { 2612 /* 2613 * Look again for the entry because the map was 2614 * modified while it was unlocked. The entry 2615 * may have been clipped, but NOT merged or 2616 * deleted. 2617 */ 2618 result = vm_map_lookup_entry(map, saved_start, 2619 &tmp_entry); 2620 KASSERT(result, ("vm_map_wire: lookup failed")); 2621 if (entry == first_entry) 2622 first_entry = tmp_entry; 2623 else 2624 first_entry = NULL; 2625 entry = tmp_entry; 2626 while (entry->end < saved_end) { 2627 /* 2628 * In case of failure, handle entries 2629 * that were not fully wired here; 2630 * fully wired entries are handled 2631 * later. 2632 */ 2633 if (rv != KERN_SUCCESS && 2634 faddr < entry->end) 2635 vm_map_wire_entry_failure(map, 2636 entry, faddr); 2637 entry = entry->next; 2638 } 2639 } 2640 last_timestamp = map->timestamp; 2641 if (rv != KERN_SUCCESS) { 2642 vm_map_wire_entry_failure(map, entry, faddr); 2643 end = entry->end; 2644 goto done; 2645 } 2646 } else if (!user_wire || 2647 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2648 entry->wired_count++; 2649 } 2650 /* 2651 * Check the map for holes in the specified region. 2652 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2653 */ 2654 next_entry: 2655 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2656 (entry->end < end && (entry->next == &map->header || 2657 entry->next->start > entry->end))) { 2658 end = entry->end; 2659 rv = KERN_INVALID_ADDRESS; 2660 goto done; 2661 } 2662 entry = entry->next; 2663 } 2664 rv = KERN_SUCCESS; 2665done: 2666 need_wakeup = FALSE; 2667 if (first_entry == NULL) { 2668 result = vm_map_lookup_entry(map, start, &first_entry); 2669 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2670 first_entry = first_entry->next; 2671 else 2672 KASSERT(result, ("vm_map_wire: lookup failed")); 2673 } 2674 for (entry = first_entry; entry != &map->header && entry->start < end; 2675 entry = entry->next) { 2676 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) 2677 goto next_entry_done; 2678 2679 /* 2680 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2681 * space in the unwired region could have been mapped 2682 * while the map lock was dropped for faulting in the 2683 * pages or draining MAP_ENTRY_IN_TRANSITION. 2684 * Moreover, another thread could be simultaneously 2685 * wiring this new mapping entry. Detect these cases 2686 * and skip any entries marked as in transition by us. 2687 */ 2688 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2689 entry->wiring_thread != curthread) { 2690 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2691 ("vm_map_wire: !HOLESOK and new/changed entry")); 2692 continue; 2693 } 2694 2695 if (rv == KERN_SUCCESS) { 2696 if (user_wire) 2697 entry->eflags |= MAP_ENTRY_USER_WIRED; 2698 } else if (entry->wired_count == -1) { 2699 /* 2700 * Wiring failed on this entry. Thus, unwiring is 2701 * unnecessary. 2702 */ 2703 entry->wired_count = 0; 2704 } else if (!user_wire || 2705 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2706 /* 2707 * Undo the wiring. Wiring succeeded on this entry 2708 * but failed on a later entry. 2709 */ 2710 if (entry->wired_count == 1) 2711 vm_map_entry_unwire(map, entry); 2712 else 2713 entry->wired_count--; 2714 } 2715 next_entry_done: 2716 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2717 ("vm_map_wire: in-transition flag missing %p", entry)); 2718 KASSERT(entry->wiring_thread == curthread, 2719 ("vm_map_wire: alien wire %p", entry)); 2720 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 2721 MAP_ENTRY_WIRE_SKIPPED); 2722 entry->wiring_thread = NULL; 2723 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2724 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2725 need_wakeup = TRUE; 2726 } 2727 vm_map_simplify_entry(map, entry); 2728 } 2729 vm_map_unlock(map); 2730 if (need_wakeup) 2731 vm_map_wakeup(map); 2732 return (rv); 2733} 2734 2735/* 2736 * vm_map_sync 2737 * 2738 * Push any dirty cached pages in the address range to their pager. 2739 * If syncio is TRUE, dirty pages are written synchronously. 2740 * If invalidate is TRUE, any cached pages are freed as well. 2741 * 2742 * If the size of the region from start to end is zero, we are 2743 * supposed to flush all modified pages within the region containing 2744 * start. Unfortunately, a region can be split or coalesced with 2745 * neighboring regions, making it difficult to determine what the 2746 * original region was. Therefore, we approximate this requirement by 2747 * flushing the current region containing start. 2748 * 2749 * Returns an error if any part of the specified range is not mapped. 2750 */ 2751int 2752vm_map_sync( 2753 vm_map_t map, 2754 vm_offset_t start, 2755 vm_offset_t end, 2756 boolean_t syncio, 2757 boolean_t invalidate) 2758{ 2759 vm_map_entry_t current; 2760 vm_map_entry_t entry; 2761 vm_size_t size; 2762 vm_object_t object; 2763 vm_ooffset_t offset; 2764 unsigned int last_timestamp; 2765 boolean_t failed; 2766 2767 vm_map_lock_read(map); 2768 VM_MAP_RANGE_CHECK(map, start, end); 2769 if (!vm_map_lookup_entry(map, start, &entry)) { 2770 vm_map_unlock_read(map); 2771 return (KERN_INVALID_ADDRESS); 2772 } else if (start == end) { 2773 start = entry->start; 2774 end = entry->end; 2775 } 2776 /* 2777 * Make a first pass to check for user-wired memory and holes. 2778 */ 2779 for (current = entry; current != &map->header && current->start < end; 2780 current = current->next) { 2781 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 2782 vm_map_unlock_read(map); 2783 return (KERN_INVALID_ARGUMENT); 2784 } 2785 if (end > current->end && 2786 (current->next == &map->header || 2787 current->end != current->next->start)) { 2788 vm_map_unlock_read(map); 2789 return (KERN_INVALID_ADDRESS); 2790 } 2791 } 2792 2793 if (invalidate) 2794 pmap_remove(map->pmap, start, end); 2795 failed = FALSE; 2796 2797 /* 2798 * Make a second pass, cleaning/uncaching pages from the indicated 2799 * objects as we go. 2800 */ 2801 for (current = entry; current != &map->header && current->start < end;) { 2802 offset = current->offset + (start - current->start); 2803 size = (end <= current->end ? end : current->end) - start; 2804 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2805 vm_map_t smap; 2806 vm_map_entry_t tentry; 2807 vm_size_t tsize; 2808 2809 smap = current->object.sub_map; 2810 vm_map_lock_read(smap); 2811 (void) vm_map_lookup_entry(smap, offset, &tentry); 2812 tsize = tentry->end - offset; 2813 if (tsize < size) 2814 size = tsize; 2815 object = tentry->object.vm_object; 2816 offset = tentry->offset + (offset - tentry->start); 2817 vm_map_unlock_read(smap); 2818 } else { 2819 object = current->object.vm_object; 2820 } 2821 vm_object_reference(object); 2822 last_timestamp = map->timestamp; 2823 vm_map_unlock_read(map); 2824 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 2825 failed = TRUE; 2826 start += size; 2827 vm_object_deallocate(object); 2828 vm_map_lock_read(map); 2829 if (last_timestamp == map->timestamp || 2830 !vm_map_lookup_entry(map, start, ¤t)) 2831 current = current->next; 2832 } 2833 2834 vm_map_unlock_read(map); 2835 return (failed ? KERN_FAILURE : KERN_SUCCESS); 2836} 2837 2838/* 2839 * vm_map_entry_unwire: [ internal use only ] 2840 * 2841 * Make the region specified by this entry pageable. 2842 * 2843 * The map in question should be locked. 2844 * [This is the reason for this routine's existence.] 2845 */ 2846static void 2847vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2848{ 2849 2850 VM_MAP_ASSERT_LOCKED(map); 2851 KASSERT(entry->wired_count > 0, 2852 ("vm_map_entry_unwire: entry %p isn't wired", entry)); 2853 pmap_unwire(map->pmap, entry->start, entry->end); 2854 vm_object_unwire(entry->object.vm_object, entry->offset, entry->end - 2855 entry->start, PQ_ACTIVE); 2856 entry->wired_count = 0; 2857} 2858 2859static void 2860vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 2861{ 2862 2863 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 2864 vm_object_deallocate(entry->object.vm_object); 2865 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 2866} 2867 2868/* 2869 * vm_map_entry_delete: [ internal use only ] 2870 * 2871 * Deallocate the given entry from the target map. 2872 */ 2873static void 2874vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2875{ 2876 vm_object_t object; 2877 vm_pindex_t offidxstart, offidxend, count, size1; 2878 vm_ooffset_t size; 2879 2880 vm_map_entry_unlink(map, entry); 2881 object = entry->object.vm_object; 2882 size = entry->end - entry->start; 2883 map->size -= size; 2884 2885 if (entry->cred != NULL) { 2886 swap_release_by_cred(size, entry->cred); 2887 crfree(entry->cred); 2888 } 2889 2890 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2891 (object != NULL)) { 2892 KASSERT(entry->cred == NULL || object->cred == NULL || 2893 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 2894 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 2895 count = OFF_TO_IDX(size); 2896 offidxstart = OFF_TO_IDX(entry->offset); 2897 offidxend = offidxstart + count; 2898 VM_OBJECT_WLOCK(object); 2899 if (object->ref_count != 1 && 2900 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2901 object == kernel_object || object == kmem_object)) { 2902 vm_object_collapse(object); 2903 2904 /* 2905 * The option OBJPR_NOTMAPPED can be passed here 2906 * because vm_map_delete() already performed 2907 * pmap_remove() on the only mapping to this range 2908 * of pages. 2909 */ 2910 vm_object_page_remove(object, offidxstart, offidxend, 2911 OBJPR_NOTMAPPED); 2912 if (object->type == OBJT_SWAP) 2913 swap_pager_freespace(object, offidxstart, count); 2914 if (offidxend >= object->size && 2915 offidxstart < object->size) { 2916 size1 = object->size; 2917 object->size = offidxstart; 2918 if (object->cred != NULL) { 2919 size1 -= object->size; 2920 KASSERT(object->charge >= ptoa(size1), 2921 ("vm_map_entry_delete: object->charge < 0")); 2922 swap_release_by_cred(ptoa(size1), object->cred); 2923 object->charge -= ptoa(size1); 2924 } 2925 } 2926 } 2927 VM_OBJECT_WUNLOCK(object); 2928 } else 2929 entry->object.vm_object = NULL; 2930 if (map->system_map) 2931 vm_map_entry_deallocate(entry, TRUE); 2932 else { 2933 entry->next = curthread->td_map_def_user; 2934 curthread->td_map_def_user = entry; 2935 } 2936} 2937 2938/* 2939 * vm_map_delete: [ internal use only ] 2940 * 2941 * Deallocates the given address range from the target 2942 * map. 2943 */ 2944int 2945vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2946{ 2947 vm_map_entry_t entry; 2948 vm_map_entry_t first_entry; 2949 2950 VM_MAP_ASSERT_LOCKED(map); 2951 if (start == end) 2952 return (KERN_SUCCESS); 2953 2954 /* 2955 * Find the start of the region, and clip it 2956 */ 2957 if (!vm_map_lookup_entry(map, start, &first_entry)) 2958 entry = first_entry->next; 2959 else { 2960 entry = first_entry; 2961 vm_map_clip_start(map, entry, start); 2962 } 2963 2964 /* 2965 * Step through all entries in this region 2966 */ 2967 while ((entry != &map->header) && (entry->start < end)) { 2968 vm_map_entry_t next; 2969 2970 /* 2971 * Wait for wiring or unwiring of an entry to complete. 2972 * Also wait for any system wirings to disappear on 2973 * user maps. 2974 */ 2975 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 2976 (vm_map_pmap(map) != kernel_pmap && 2977 vm_map_entry_system_wired_count(entry) != 0)) { 2978 unsigned int last_timestamp; 2979 vm_offset_t saved_start; 2980 vm_map_entry_t tmp_entry; 2981 2982 saved_start = entry->start; 2983 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2984 last_timestamp = map->timestamp; 2985 (void) vm_map_unlock_and_wait(map, 0); 2986 vm_map_lock(map); 2987 if (last_timestamp + 1 != map->timestamp) { 2988 /* 2989 * Look again for the entry because the map was 2990 * modified while it was unlocked. 2991 * Specifically, the entry may have been 2992 * clipped, merged, or deleted. 2993 */ 2994 if (!vm_map_lookup_entry(map, saved_start, 2995 &tmp_entry)) 2996 entry = tmp_entry->next; 2997 else { 2998 entry = tmp_entry; 2999 vm_map_clip_start(map, entry, 3000 saved_start); 3001 } 3002 } 3003 continue; 3004 } 3005 vm_map_clip_end(map, entry, end); 3006 3007 next = entry->next; 3008 3009 /* 3010 * Unwire before removing addresses from the pmap; otherwise, 3011 * unwiring will put the entries back in the pmap. 3012 */ 3013 if (entry->wired_count != 0) { 3014 vm_map_entry_unwire(map, entry); 3015 } 3016 3017 pmap_remove(map->pmap, entry->start, entry->end); 3018 3019 /* 3020 * Delete the entry only after removing all pmap 3021 * entries pointing to its pages. (Otherwise, its 3022 * page frames may be reallocated, and any modify bits 3023 * will be set in the wrong object!) 3024 */ 3025 vm_map_entry_delete(map, entry); 3026 entry = next; 3027 } 3028 return (KERN_SUCCESS); 3029} 3030 3031/* 3032 * vm_map_remove: 3033 * 3034 * Remove the given address range from the target map. 3035 * This is the exported form of vm_map_delete. 3036 */ 3037int 3038vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 3039{ 3040 int result; 3041 3042 vm_map_lock(map); 3043 VM_MAP_RANGE_CHECK(map, start, end); 3044 result = vm_map_delete(map, start, end); 3045 vm_map_unlock(map); 3046 return (result); 3047} 3048 3049/* 3050 * vm_map_check_protection: 3051 * 3052 * Assert that the target map allows the specified privilege on the 3053 * entire address region given. The entire region must be allocated. 3054 * 3055 * WARNING! This code does not and should not check whether the 3056 * contents of the region is accessible. For example a smaller file 3057 * might be mapped into a larger address space. 3058 * 3059 * NOTE! This code is also called by munmap(). 3060 * 3061 * The map must be locked. A read lock is sufficient. 3062 */ 3063boolean_t 3064vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 3065 vm_prot_t protection) 3066{ 3067 vm_map_entry_t entry; 3068 vm_map_entry_t tmp_entry; 3069 3070 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 3071 return (FALSE); 3072 entry = tmp_entry; 3073 3074 while (start < end) { 3075 if (entry == &map->header) 3076 return (FALSE); 3077 /* 3078 * No holes allowed! 3079 */ 3080 if (start < entry->start) 3081 return (FALSE); 3082 /* 3083 * Check protection associated with entry. 3084 */ 3085 if ((entry->protection & protection) != protection) 3086 return (FALSE); 3087 /* go to next entry */ 3088 start = entry->end; 3089 entry = entry->next; 3090 } 3091 return (TRUE); 3092} 3093 3094/* 3095 * vm_map_copy_entry: 3096 * 3097 * Copies the contents of the source entry to the destination 3098 * entry. The entries *must* be aligned properly. 3099 */ 3100static void 3101vm_map_copy_entry( 3102 vm_map_t src_map, 3103 vm_map_t dst_map, 3104 vm_map_entry_t src_entry, 3105 vm_map_entry_t dst_entry, 3106 vm_ooffset_t *fork_charge) 3107{ 3108 vm_object_t src_object; 3109 vm_map_entry_t fake_entry; 3110 vm_offset_t size; 3111 struct ucred *cred; 3112 int charged; 3113 3114 VM_MAP_ASSERT_LOCKED(dst_map); 3115 3116 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3117 return; 3118 3119 if (src_entry->wired_count == 0 || 3120 (src_entry->protection & VM_PROT_WRITE) == 0) { 3121 /* 3122 * If the source entry is marked needs_copy, it is already 3123 * write-protected. 3124 */ 3125 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && 3126 (src_entry->protection & VM_PROT_WRITE) != 0) { 3127 pmap_protect(src_map->pmap, 3128 src_entry->start, 3129 src_entry->end, 3130 src_entry->protection & ~VM_PROT_WRITE); 3131 } 3132 3133 /* 3134 * Make a copy of the object. 3135 */ 3136 size = src_entry->end - src_entry->start; 3137 if ((src_object = src_entry->object.vm_object) != NULL) { 3138 VM_OBJECT_WLOCK(src_object); 3139 charged = ENTRY_CHARGED(src_entry); 3140 if ((src_object->handle == NULL) && 3141 (src_object->type == OBJT_DEFAULT || 3142 src_object->type == OBJT_SWAP)) { 3143 vm_object_collapse(src_object); 3144 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 3145 vm_object_split(src_entry); 3146 src_object = src_entry->object.vm_object; 3147 } 3148 } 3149 vm_object_reference_locked(src_object); 3150 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3151 if (src_entry->cred != NULL && 3152 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3153 KASSERT(src_object->cred == NULL, 3154 ("OVERCOMMIT: vm_map_copy_entry: cred %p", 3155 src_object)); 3156 src_object->cred = src_entry->cred; 3157 src_object->charge = size; 3158 } 3159 VM_OBJECT_WUNLOCK(src_object); 3160 dst_entry->object.vm_object = src_object; 3161 if (charged) { 3162 cred = curthread->td_ucred; 3163 crhold(cred); 3164 dst_entry->cred = cred; 3165 *fork_charge += size; 3166 if (!(src_entry->eflags & 3167 MAP_ENTRY_NEEDS_COPY)) { 3168 crhold(cred); 3169 src_entry->cred = cred; 3170 *fork_charge += size; 3171 } 3172 } 3173 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3174 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3175 dst_entry->offset = src_entry->offset; 3176 if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3177 /* 3178 * MAP_ENTRY_VN_WRITECNT cannot 3179 * indicate write reference from 3180 * src_entry, since the entry is 3181 * marked as needs copy. Allocate a 3182 * fake entry that is used to 3183 * decrement object->un_pager.vnp.writecount 3184 * at the appropriate time. Attach 3185 * fake_entry to the deferred list. 3186 */ 3187 fake_entry = vm_map_entry_create(dst_map); 3188 fake_entry->eflags = MAP_ENTRY_VN_WRITECNT; 3189 src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT; 3190 vm_object_reference(src_object); 3191 fake_entry->object.vm_object = src_object; 3192 fake_entry->start = src_entry->start; 3193 fake_entry->end = src_entry->end; 3194 fake_entry->next = curthread->td_map_def_user; 3195 curthread->td_map_def_user = fake_entry; 3196 } 3197 } else { 3198 dst_entry->object.vm_object = NULL; 3199 dst_entry->offset = 0; 3200 if (src_entry->cred != NULL) { 3201 dst_entry->cred = curthread->td_ucred; 3202 crhold(dst_entry->cred); 3203 *fork_charge += size; 3204 } 3205 } 3206 3207 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3208 dst_entry->end - dst_entry->start, src_entry->start); 3209 } else { 3210 /* 3211 * We don't want to make writeable wired pages copy-on-write. 3212 * Immediately copy these pages into the new map by simulating 3213 * page faults. The new pages are pageable. 3214 */ 3215 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 3216 fork_charge); 3217 } 3218} 3219 3220/* 3221 * vmspace_map_entry_forked: 3222 * Update the newly-forked vmspace each time a map entry is inherited 3223 * or copied. The values for vm_dsize and vm_tsize are approximate 3224 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 3225 */ 3226static void 3227vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 3228 vm_map_entry_t entry) 3229{ 3230 vm_size_t entrysize; 3231 vm_offset_t newend; 3232 3233 entrysize = entry->end - entry->start; 3234 vm2->vm_map.size += entrysize; 3235 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 3236 vm2->vm_ssize += btoc(entrysize); 3237 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 3238 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 3239 newend = MIN(entry->end, 3240 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 3241 vm2->vm_dsize += btoc(newend - entry->start); 3242 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 3243 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 3244 newend = MIN(entry->end, 3245 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 3246 vm2->vm_tsize += btoc(newend - entry->start); 3247 } 3248} 3249 3250/* 3251 * vmspace_fork: 3252 * Create a new process vmspace structure and vm_map 3253 * based on those of an existing process. The new map 3254 * is based on the old map, according to the inheritance 3255 * values on the regions in that map. 3256 * 3257 * XXX It might be worth coalescing the entries added to the new vmspace. 3258 * 3259 * The source map must not be locked. 3260 */ 3261struct vmspace * 3262vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 3263{ 3264 struct vmspace *vm2; 3265 vm_map_t new_map, old_map; 3266 vm_map_entry_t new_entry, old_entry; 3267 vm_object_t object; 3268 int locked; 3269 3270 old_map = &vm1->vm_map; 3271 /* Copy immutable fields of vm1 to vm2. */ 3272 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL); 3273 if (vm2 == NULL) 3274 return (NULL); 3275 vm2->vm_taddr = vm1->vm_taddr; 3276 vm2->vm_daddr = vm1->vm_daddr; 3277 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 3278 vm_map_lock(old_map); 3279 if (old_map->busy) 3280 vm_map_wait_busy(old_map); 3281 new_map = &vm2->vm_map; 3282 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 3283 KASSERT(locked, ("vmspace_fork: lock failed")); 3284 3285 old_entry = old_map->header.next; 3286 3287 while (old_entry != &old_map->header) { 3288 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 3289 panic("vm_map_fork: encountered a submap"); 3290 3291 switch (old_entry->inheritance) { 3292 case VM_INHERIT_NONE: 3293 break; 3294 3295 case VM_INHERIT_SHARE: 3296 /* 3297 * Clone the entry, creating the shared object if necessary. 3298 */ 3299 object = old_entry->object.vm_object; 3300 if (object == NULL) { 3301 object = vm_object_allocate(OBJT_DEFAULT, 3302 atop(old_entry->end - old_entry->start)); 3303 old_entry->object.vm_object = object; 3304 old_entry->offset = 0; 3305 if (old_entry->cred != NULL) { 3306 object->cred = old_entry->cred; 3307 object->charge = old_entry->end - 3308 old_entry->start; 3309 old_entry->cred = NULL; 3310 } 3311 } 3312 3313 /* 3314 * Add the reference before calling vm_object_shadow 3315 * to insure that a shadow object is created. 3316 */ 3317 vm_object_reference(object); 3318 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3319 vm_object_shadow(&old_entry->object.vm_object, 3320 &old_entry->offset, 3321 old_entry->end - old_entry->start); 3322 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3323 /* Transfer the second reference too. */ 3324 vm_object_reference( 3325 old_entry->object.vm_object); 3326 3327 /* 3328 * As in vm_map_simplify_entry(), the 3329 * vnode lock will not be acquired in 3330 * this call to vm_object_deallocate(). 3331 */ 3332 vm_object_deallocate(object); 3333 object = old_entry->object.vm_object; 3334 } 3335 VM_OBJECT_WLOCK(object); 3336 vm_object_clear_flag(object, OBJ_ONEMAPPING); 3337 if (old_entry->cred != NULL) { 3338 KASSERT(object->cred == NULL, ("vmspace_fork both cred")); 3339 object->cred = old_entry->cred; 3340 object->charge = old_entry->end - old_entry->start; 3341 old_entry->cred = NULL; 3342 } 3343 3344 /* 3345 * Assert the correct state of the vnode 3346 * v_writecount while the object is locked, to 3347 * not relock it later for the assertion 3348 * correctness. 3349 */ 3350 if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT && 3351 object->type == OBJT_VNODE) { 3352 KASSERT(((struct vnode *)object->handle)-> 3353 v_writecount > 0, 3354 ("vmspace_fork: v_writecount %p", object)); 3355 KASSERT(object->un_pager.vnp.writemappings > 0, 3356 ("vmspace_fork: vnp.writecount %p", 3357 object)); 3358 } 3359 VM_OBJECT_WUNLOCK(object); 3360 3361 /* 3362 * Clone the entry, referencing the shared object. 3363 */ 3364 new_entry = vm_map_entry_create(new_map); 3365 *new_entry = *old_entry; 3366 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3367 MAP_ENTRY_IN_TRANSITION); 3368 new_entry->wiring_thread = NULL; 3369 new_entry->wired_count = 0; 3370 if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3371 vnode_pager_update_writecount(object, 3372 new_entry->start, new_entry->end); 3373 } 3374 3375 /* 3376 * Insert the entry into the new map -- we know we're 3377 * inserting at the end of the new map. 3378 */ 3379 vm_map_entry_link(new_map, new_map->header.prev, 3380 new_entry); 3381 vmspace_map_entry_forked(vm1, vm2, new_entry); 3382 3383 /* 3384 * Update the physical map 3385 */ 3386 pmap_copy(new_map->pmap, old_map->pmap, 3387 new_entry->start, 3388 (old_entry->end - old_entry->start), 3389 old_entry->start); 3390 break; 3391 3392 case VM_INHERIT_COPY: 3393 /* 3394 * Clone the entry and link into the map. 3395 */ 3396 new_entry = vm_map_entry_create(new_map); 3397 *new_entry = *old_entry; 3398 /* 3399 * Copied entry is COW over the old object. 3400 */ 3401 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3402 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT); 3403 new_entry->wiring_thread = NULL; 3404 new_entry->wired_count = 0; 3405 new_entry->object.vm_object = NULL; 3406 new_entry->cred = NULL; 3407 vm_map_entry_link(new_map, new_map->header.prev, 3408 new_entry); 3409 vmspace_map_entry_forked(vm1, vm2, new_entry); 3410 vm_map_copy_entry(old_map, new_map, old_entry, 3411 new_entry, fork_charge); 3412 break; 3413 } 3414 old_entry = old_entry->next; 3415 } 3416 /* 3417 * Use inlined vm_map_unlock() to postpone handling the deferred 3418 * map entries, which cannot be done until both old_map and 3419 * new_map locks are released. 3420 */ 3421 sx_xunlock(&old_map->lock); 3422 sx_xunlock(&new_map->lock); 3423 vm_map_process_deferred(); 3424 3425 return (vm2); 3426} 3427 3428int 3429vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3430 vm_prot_t prot, vm_prot_t max, int cow) 3431{ 3432 vm_size_t growsize, init_ssize; 3433 rlim_t lmemlim, vmemlim; 3434 int rv; 3435 3436 growsize = sgrowsiz; 3437 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3438 vm_map_lock(map); 3439 PROC_LOCK(curproc); 3440 lmemlim = lim_cur(curproc, RLIMIT_MEMLOCK); 3441 vmemlim = lim_cur(curproc, RLIMIT_VMEM); 3442 PROC_UNLOCK(curproc); 3443 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3444 if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) { 3445 rv = KERN_NO_SPACE; 3446 goto out; 3447 } 3448 } 3449 /* If we would blow our VMEM resource limit, no go */ 3450 if (map->size + init_ssize > vmemlim) { 3451 rv = KERN_NO_SPACE; 3452 goto out; 3453 } 3454 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, 3455 max, cow); 3456out: 3457 vm_map_unlock(map); 3458 return (rv); 3459} 3460 3461static int 3462vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3463 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) 3464{ 3465 vm_map_entry_t new_entry, prev_entry; 3466 vm_offset_t bot, top; 3467 vm_size_t init_ssize; 3468 int orient, rv; 3469 3470 /* 3471 * The stack orientation is piggybacked with the cow argument. 3472 * Extract it into orient and mask the cow argument so that we 3473 * don't pass it around further. 3474 * NOTE: We explicitly allow bi-directional stacks. 3475 */ 3476 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 3477 KASSERT(orient != 0, ("No stack grow direction")); 3478 3479 if (addrbos < vm_map_min(map) || 3480 addrbos > vm_map_max(map) || 3481 addrbos + max_ssize < addrbos) 3482 return (KERN_NO_SPACE); 3483 3484 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3485 3486 /* If addr is already mapped, no go */ 3487 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) 3488 return (KERN_NO_SPACE); 3489 3490 /* 3491 * If we can't accomodate max_ssize in the current mapping, no go. 3492 * However, we need to be aware that subsequent user mappings might 3493 * map into the space we have reserved for stack, and currently this 3494 * space is not protected. 3495 * 3496 * Hopefully we will at least detect this condition when we try to 3497 * grow the stack. 3498 */ 3499 if ((prev_entry->next != &map->header) && 3500 (prev_entry->next->start < addrbos + max_ssize)) 3501 return (KERN_NO_SPACE); 3502 3503 /* 3504 * We initially map a stack of only init_ssize. We will grow as 3505 * needed later. Depending on the orientation of the stack (i.e. 3506 * the grow direction) we either map at the top of the range, the 3507 * bottom of the range or in the middle. 3508 * 3509 * Note: we would normally expect prot and max to be VM_PROT_ALL, 3510 * and cow to be 0. Possibly we should eliminate these as input 3511 * parameters, and just pass these values here in the insert call. 3512 */ 3513 if (orient == MAP_STACK_GROWS_DOWN) 3514 bot = addrbos + max_ssize - init_ssize; 3515 else if (orient == MAP_STACK_GROWS_UP) 3516 bot = addrbos; 3517 else 3518 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 3519 top = bot + init_ssize; 3520 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 3521 3522 /* Now set the avail_ssize amount. */ 3523 if (rv == KERN_SUCCESS) { 3524 if (prev_entry != &map->header) 3525 vm_map_clip_end(map, prev_entry, bot); 3526 new_entry = prev_entry->next; 3527 if (new_entry->end != top || new_entry->start != bot) 3528 panic("Bad entry start/end for new stack entry"); 3529 3530 new_entry->avail_ssize = max_ssize - init_ssize; 3531 if (orient & MAP_STACK_GROWS_DOWN) 3532 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3533 if (orient & MAP_STACK_GROWS_UP) 3534 new_entry->eflags |= MAP_ENTRY_GROWS_UP; 3535 } 3536 3537 return (rv); 3538} 3539 3540static int stack_guard_page = 0; 3541TUNABLE_INT("security.bsd.stack_guard_page", &stack_guard_page); 3542SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RW, 3543 &stack_guard_page, 0, 3544 "Insert stack guard page ahead of the growable segments."); 3545 3546/* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3547 * desired address is already mapped, or if we successfully grow 3548 * the stack. Also returns KERN_SUCCESS if addr is outside the 3549 * stack range (this is strange, but preserves compatibility with 3550 * the grow function in vm_machdep.c). 3551 */ 3552int 3553vm_map_growstack(struct proc *p, vm_offset_t addr) 3554{ 3555 vm_map_entry_t next_entry, prev_entry; 3556 vm_map_entry_t new_entry, stack_entry; 3557 struct vmspace *vm = p->p_vmspace; 3558 vm_map_t map = &vm->vm_map; 3559 vm_offset_t end; 3560 vm_size_t growsize; 3561 size_t grow_amount, max_grow; 3562 rlim_t lmemlim, stacklim, vmemlim; 3563 int is_procstack, rv; 3564 struct ucred *cred; 3565#ifdef notyet 3566 uint64_t limit; 3567#endif 3568#ifdef RACCT 3569 int error; 3570#endif 3571 3572Retry: 3573 PROC_LOCK(p); 3574 lmemlim = lim_cur(p, RLIMIT_MEMLOCK); 3575 stacklim = lim_cur(p, RLIMIT_STACK); 3576 vmemlim = lim_cur(p, RLIMIT_VMEM); 3577 PROC_UNLOCK(p); 3578 3579 vm_map_lock_read(map); 3580 3581 /* If addr is already in the entry range, no need to grow.*/ 3582 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 3583 vm_map_unlock_read(map); 3584 return (KERN_SUCCESS); 3585 } 3586 3587 next_entry = prev_entry->next; 3588 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 3589 /* 3590 * This entry does not grow upwards. Since the address lies 3591 * beyond this entry, the next entry (if one exists) has to 3592 * be a downward growable entry. The entry list header is 3593 * never a growable entry, so it suffices to check the flags. 3594 */ 3595 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 3596 vm_map_unlock_read(map); 3597 return (KERN_SUCCESS); 3598 } 3599 stack_entry = next_entry; 3600 } else { 3601 /* 3602 * This entry grows upward. If the next entry does not at 3603 * least grow downwards, this is the entry we need to grow. 3604 * otherwise we have two possible choices and we have to 3605 * select one. 3606 */ 3607 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 3608 /* 3609 * We have two choices; grow the entry closest to 3610 * the address to minimize the amount of growth. 3611 */ 3612 if (addr - prev_entry->end <= next_entry->start - addr) 3613 stack_entry = prev_entry; 3614 else 3615 stack_entry = next_entry; 3616 } else 3617 stack_entry = prev_entry; 3618 } 3619 3620 if (stack_entry == next_entry) { 3621 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 3622 KASSERT(addr < stack_entry->start, ("foo")); 3623 end = (prev_entry != &map->header) ? prev_entry->end : 3624 stack_entry->start - stack_entry->avail_ssize; 3625 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 3626 max_grow = stack_entry->start - end; 3627 } else { 3628 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 3629 KASSERT(addr >= stack_entry->end, ("foo")); 3630 end = (next_entry != &map->header) ? next_entry->start : 3631 stack_entry->end + stack_entry->avail_ssize; 3632 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 3633 max_grow = end - stack_entry->end; 3634 } 3635 3636 if (grow_amount > stack_entry->avail_ssize) { 3637 vm_map_unlock_read(map); 3638 return (KERN_NO_SPACE); 3639 } 3640 3641 /* 3642 * If there is no longer enough space between the entries nogo, and 3643 * adjust the available space. Note: this should only happen if the 3644 * user has mapped into the stack area after the stack was created, 3645 * and is probably an error. 3646 * 3647 * This also effectively destroys any guard page the user might have 3648 * intended by limiting the stack size. 3649 */ 3650 if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) { 3651 if (vm_map_lock_upgrade(map)) 3652 goto Retry; 3653 3654 stack_entry->avail_ssize = max_grow; 3655 3656 vm_map_unlock(map); 3657 return (KERN_NO_SPACE); 3658 } 3659 3660 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 3661 3662 /* 3663 * If this is the main process stack, see if we're over the stack 3664 * limit. 3665 */ 3666 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3667 vm_map_unlock_read(map); 3668 return (KERN_NO_SPACE); 3669 } 3670#ifdef RACCT 3671 if (racct_enable) { 3672 PROC_LOCK(p); 3673 if (is_procstack && racct_set(p, RACCT_STACK, 3674 ctob(vm->vm_ssize) + grow_amount)) { 3675 PROC_UNLOCK(p); 3676 vm_map_unlock_read(map); 3677 return (KERN_NO_SPACE); 3678 } 3679 PROC_UNLOCK(p); 3680 } 3681#endif 3682 3683 /* Round up the grow amount modulo sgrowsiz */ 3684 growsize = sgrowsiz; 3685 grow_amount = roundup(grow_amount, growsize); 3686 if (grow_amount > stack_entry->avail_ssize) 3687 grow_amount = stack_entry->avail_ssize; 3688 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3689 grow_amount = trunc_page((vm_size_t)stacklim) - 3690 ctob(vm->vm_ssize); 3691 } 3692#ifdef notyet 3693 PROC_LOCK(p); 3694 limit = racct_get_available(p, RACCT_STACK); 3695 PROC_UNLOCK(p); 3696 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 3697 grow_amount = limit - ctob(vm->vm_ssize); 3698#endif 3699 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3700 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 3701 vm_map_unlock_read(map); 3702 rv = KERN_NO_SPACE; 3703 goto out; 3704 } 3705#ifdef RACCT 3706 if (racct_enable) { 3707 PROC_LOCK(p); 3708 if (racct_set(p, RACCT_MEMLOCK, 3709 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 3710 PROC_UNLOCK(p); 3711 vm_map_unlock_read(map); 3712 rv = KERN_NO_SPACE; 3713 goto out; 3714 } 3715 PROC_UNLOCK(p); 3716 } 3717#endif 3718 } 3719 /* If we would blow our VMEM resource limit, no go */ 3720 if (map->size + grow_amount > vmemlim) { 3721 vm_map_unlock_read(map); 3722 rv = KERN_NO_SPACE; 3723 goto out; 3724 } 3725#ifdef RACCT 3726 if (racct_enable) { 3727 PROC_LOCK(p); 3728 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 3729 PROC_UNLOCK(p); 3730 vm_map_unlock_read(map); 3731 rv = KERN_NO_SPACE; 3732 goto out; 3733 } 3734 PROC_UNLOCK(p); 3735 } 3736#endif 3737 3738 if (vm_map_lock_upgrade(map)) 3739 goto Retry; 3740 3741 if (stack_entry == next_entry) { 3742 /* 3743 * Growing downward. 3744 */ 3745 /* Get the preliminary new entry start value */ 3746 addr = stack_entry->start - grow_amount; 3747 3748 /* 3749 * If this puts us into the previous entry, cut back our 3750 * growth to the available space. Also, see the note above. 3751 */ 3752 if (addr < end) { 3753 stack_entry->avail_ssize = max_grow; 3754 addr = end; 3755 if (stack_guard_page) 3756 addr += PAGE_SIZE; 3757 } 3758 3759 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 3760 next_entry->protection, next_entry->max_protection, 0); 3761 3762 /* Adjust the available stack space by the amount we grew. */ 3763 if (rv == KERN_SUCCESS) { 3764 if (prev_entry != &map->header) 3765 vm_map_clip_end(map, prev_entry, addr); 3766 new_entry = prev_entry->next; 3767 KASSERT(new_entry == stack_entry->prev, ("foo")); 3768 KASSERT(new_entry->end == stack_entry->start, ("foo")); 3769 KASSERT(new_entry->start == addr, ("foo")); 3770 grow_amount = new_entry->end - new_entry->start; 3771 new_entry->avail_ssize = stack_entry->avail_ssize - 3772 grow_amount; 3773 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 3774 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3775 } 3776 } else { 3777 /* 3778 * Growing upward. 3779 */ 3780 addr = stack_entry->end + grow_amount; 3781 3782 /* 3783 * If this puts us into the next entry, cut back our growth 3784 * to the available space. Also, see the note above. 3785 */ 3786 if (addr > end) { 3787 stack_entry->avail_ssize = end - stack_entry->end; 3788 addr = end; 3789 if (stack_guard_page) 3790 addr -= PAGE_SIZE; 3791 } 3792 3793 grow_amount = addr - stack_entry->end; 3794 cred = stack_entry->cred; 3795 if (cred == NULL && stack_entry->object.vm_object != NULL) 3796 cred = stack_entry->object.vm_object->cred; 3797 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 3798 rv = KERN_NO_SPACE; 3799 /* Grow the underlying object if applicable. */ 3800 else if (stack_entry->object.vm_object == NULL || 3801 vm_object_coalesce(stack_entry->object.vm_object, 3802 stack_entry->offset, 3803 (vm_size_t)(stack_entry->end - stack_entry->start), 3804 (vm_size_t)grow_amount, cred != NULL)) { 3805 map->size += (addr - stack_entry->end); 3806 /* Update the current entry. */ 3807 stack_entry->end = addr; 3808 stack_entry->avail_ssize -= grow_amount; 3809 vm_map_entry_resize_free(map, stack_entry); 3810 rv = KERN_SUCCESS; 3811 3812 if (next_entry != &map->header) 3813 vm_map_clip_start(map, next_entry, addr); 3814 } else 3815 rv = KERN_FAILURE; 3816 } 3817 3818 if (rv == KERN_SUCCESS && is_procstack) 3819 vm->vm_ssize += btoc(grow_amount); 3820 3821 vm_map_unlock(map); 3822 3823 /* 3824 * Heed the MAP_WIREFUTURE flag if it was set for this process. 3825 */ 3826 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 3827 vm_map_wire(map, 3828 (stack_entry == next_entry) ? addr : addr - grow_amount, 3829 (stack_entry == next_entry) ? stack_entry->start : addr, 3830 (p->p_flag & P_SYSTEM) 3831 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 3832 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 3833 } 3834 3835out: 3836#ifdef RACCT 3837 if (racct_enable && rv != KERN_SUCCESS) { 3838 PROC_LOCK(p); 3839 error = racct_set(p, RACCT_VMEM, map->size); 3840 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 3841 if (!old_mlock) { 3842 error = racct_set(p, RACCT_MEMLOCK, 3843 ptoa(pmap_wired_count(map->pmap))); 3844 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 3845 } 3846 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 3847 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 3848 PROC_UNLOCK(p); 3849 } 3850#endif 3851 3852 return (rv); 3853} 3854 3855/* 3856 * Unshare the specified VM space for exec. If other processes are 3857 * mapped to it, then create a new one. The new vmspace is null. 3858 */ 3859int 3860vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 3861{ 3862 struct vmspace *oldvmspace = p->p_vmspace; 3863 struct vmspace *newvmspace; 3864 3865 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 3866 ("vmspace_exec recursed")); 3867 newvmspace = vmspace_alloc(minuser, maxuser, NULL); 3868 if (newvmspace == NULL) 3869 return (ENOMEM); 3870 newvmspace->vm_swrss = oldvmspace->vm_swrss; 3871 /* 3872 * This code is written like this for prototype purposes. The 3873 * goal is to avoid running down the vmspace here, but let the 3874 * other process's that are still using the vmspace to finally 3875 * run it down. Even though there is little or no chance of blocking 3876 * here, it is a good idea to keep this form for future mods. 3877 */ 3878 PROC_VMSPACE_LOCK(p); 3879 p->p_vmspace = newvmspace; 3880 PROC_VMSPACE_UNLOCK(p); 3881 if (p == curthread->td_proc) 3882 pmap_activate(curthread); 3883 curthread->td_pflags |= TDP_EXECVMSPC; 3884 return (0); 3885} 3886 3887/* 3888 * Unshare the specified VM space for forcing COW. This 3889 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3890 */ 3891int 3892vmspace_unshare(struct proc *p) 3893{ 3894 struct vmspace *oldvmspace = p->p_vmspace; 3895 struct vmspace *newvmspace; 3896 vm_ooffset_t fork_charge; 3897 3898 if (oldvmspace->vm_refcnt == 1) 3899 return (0); 3900 fork_charge = 0; 3901 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 3902 if (newvmspace == NULL) 3903 return (ENOMEM); 3904 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 3905 vmspace_free(newvmspace); 3906 return (ENOMEM); 3907 } 3908 PROC_VMSPACE_LOCK(p); 3909 p->p_vmspace = newvmspace; 3910 PROC_VMSPACE_UNLOCK(p); 3911 if (p == curthread->td_proc) 3912 pmap_activate(curthread); 3913 vmspace_free(oldvmspace); 3914 return (0); 3915} 3916 3917/* 3918 * vm_map_lookup: 3919 * 3920 * Finds the VM object, offset, and 3921 * protection for a given virtual address in the 3922 * specified map, assuming a page fault of the 3923 * type specified. 3924 * 3925 * Leaves the map in question locked for read; return 3926 * values are guaranteed until a vm_map_lookup_done 3927 * call is performed. Note that the map argument 3928 * is in/out; the returned map must be used in 3929 * the call to vm_map_lookup_done. 3930 * 3931 * A handle (out_entry) is returned for use in 3932 * vm_map_lookup_done, to make that fast. 3933 * 3934 * If a lookup is requested with "write protection" 3935 * specified, the map may be changed to perform virtual 3936 * copying operations, although the data referenced will 3937 * remain the same. 3938 */ 3939int 3940vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3941 vm_offset_t vaddr, 3942 vm_prot_t fault_typea, 3943 vm_map_entry_t *out_entry, /* OUT */ 3944 vm_object_t *object, /* OUT */ 3945 vm_pindex_t *pindex, /* OUT */ 3946 vm_prot_t *out_prot, /* OUT */ 3947 boolean_t *wired) /* OUT */ 3948{ 3949 vm_map_entry_t entry; 3950 vm_map_t map = *var_map; 3951 vm_prot_t prot; 3952 vm_prot_t fault_type = fault_typea; 3953 vm_object_t eobject; 3954 vm_size_t size; 3955 struct ucred *cred; 3956 3957RetryLookup:; 3958 3959 vm_map_lock_read(map); 3960 3961 /* 3962 * Lookup the faulting address. 3963 */ 3964 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 3965 vm_map_unlock_read(map); 3966 return (KERN_INVALID_ADDRESS); 3967 } 3968 3969 entry = *out_entry; 3970 3971 /* 3972 * Handle submaps. 3973 */ 3974 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3975 vm_map_t old_map = map; 3976 3977 *var_map = map = entry->object.sub_map; 3978 vm_map_unlock_read(old_map); 3979 goto RetryLookup; 3980 } 3981 3982 /* 3983 * Check whether this task is allowed to have this page. 3984 */ 3985 prot = entry->protection; 3986 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3987 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 3988 vm_map_unlock_read(map); 3989 return (KERN_PROTECTION_FAILURE); 3990 } 3991 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3992 (entry->eflags & MAP_ENTRY_COW) && 3993 (fault_type & VM_PROT_WRITE)) { 3994 vm_map_unlock_read(map); 3995 return (KERN_PROTECTION_FAILURE); 3996 } 3997 if ((fault_typea & VM_PROT_COPY) != 0 && 3998 (entry->max_protection & VM_PROT_WRITE) == 0 && 3999 (entry->eflags & MAP_ENTRY_COW) == 0) { 4000 vm_map_unlock_read(map); 4001 return (KERN_PROTECTION_FAILURE); 4002 } 4003 4004 /* 4005 * If this page is not pageable, we have to get it for all possible 4006 * accesses. 4007 */ 4008 *wired = (entry->wired_count != 0); 4009 if (*wired) 4010 fault_type = entry->protection; 4011 size = entry->end - entry->start; 4012 /* 4013 * If the entry was copy-on-write, we either ... 4014 */ 4015 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4016 /* 4017 * If we want to write the page, we may as well handle that 4018 * now since we've got the map locked. 4019 * 4020 * If we don't need to write the page, we just demote the 4021 * permissions allowed. 4022 */ 4023 if ((fault_type & VM_PROT_WRITE) != 0 || 4024 (fault_typea & VM_PROT_COPY) != 0) { 4025 /* 4026 * Make a new object, and place it in the object 4027 * chain. Note that no new references have appeared 4028 * -- one just moved from the map to the new 4029 * object. 4030 */ 4031 if (vm_map_lock_upgrade(map)) 4032 goto RetryLookup; 4033 4034 if (entry->cred == NULL) { 4035 /* 4036 * The debugger owner is charged for 4037 * the memory. 4038 */ 4039 cred = curthread->td_ucred; 4040 crhold(cred); 4041 if (!swap_reserve_by_cred(size, cred)) { 4042 crfree(cred); 4043 vm_map_unlock(map); 4044 return (KERN_RESOURCE_SHORTAGE); 4045 } 4046 entry->cred = cred; 4047 } 4048 vm_object_shadow(&entry->object.vm_object, 4049 &entry->offset, size); 4050 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4051 eobject = entry->object.vm_object; 4052 if (eobject->cred != NULL) { 4053 /* 4054 * The object was not shadowed. 4055 */ 4056 swap_release_by_cred(size, entry->cred); 4057 crfree(entry->cred); 4058 entry->cred = NULL; 4059 } else if (entry->cred != NULL) { 4060 VM_OBJECT_WLOCK(eobject); 4061 eobject->cred = entry->cred; 4062 eobject->charge = size; 4063 VM_OBJECT_WUNLOCK(eobject); 4064 entry->cred = NULL; 4065 } 4066 4067 vm_map_lock_downgrade(map); 4068 } else { 4069 /* 4070 * We're attempting to read a copy-on-write page -- 4071 * don't allow writes. 4072 */ 4073 prot &= ~VM_PROT_WRITE; 4074 } 4075 } 4076 4077 /* 4078 * Create an object if necessary. 4079 */ 4080 if (entry->object.vm_object == NULL && 4081 !map->system_map) { 4082 if (vm_map_lock_upgrade(map)) 4083 goto RetryLookup; 4084 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 4085 atop(size)); 4086 entry->offset = 0; 4087 if (entry->cred != NULL) { 4088 VM_OBJECT_WLOCK(entry->object.vm_object); 4089 entry->object.vm_object->cred = entry->cred; 4090 entry->object.vm_object->charge = size; 4091 VM_OBJECT_WUNLOCK(entry->object.vm_object); 4092 entry->cred = NULL; 4093 } 4094 vm_map_lock_downgrade(map); 4095 } 4096 4097 /* 4098 * Return the object/offset from this entry. If the entry was 4099 * copy-on-write or empty, it has been fixed up. 4100 */ 4101 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4102 *object = entry->object.vm_object; 4103 4104 *out_prot = prot; 4105 return (KERN_SUCCESS); 4106} 4107 4108/* 4109 * vm_map_lookup_locked: 4110 * 4111 * Lookup the faulting address. A version of vm_map_lookup that returns 4112 * KERN_FAILURE instead of blocking on map lock or memory allocation. 4113 */ 4114int 4115vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4116 vm_offset_t vaddr, 4117 vm_prot_t fault_typea, 4118 vm_map_entry_t *out_entry, /* OUT */ 4119 vm_object_t *object, /* OUT */ 4120 vm_pindex_t *pindex, /* OUT */ 4121 vm_prot_t *out_prot, /* OUT */ 4122 boolean_t *wired) /* OUT */ 4123{ 4124 vm_map_entry_t entry; 4125 vm_map_t map = *var_map; 4126 vm_prot_t prot; 4127 vm_prot_t fault_type = fault_typea; 4128 4129 /* 4130 * Lookup the faulting address. 4131 */ 4132 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4133 return (KERN_INVALID_ADDRESS); 4134 4135 entry = *out_entry; 4136 4137 /* 4138 * Fail if the entry refers to a submap. 4139 */ 4140 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4141 return (KERN_FAILURE); 4142 4143 /* 4144 * Check whether this task is allowed to have this page. 4145 */ 4146 prot = entry->protection; 4147 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4148 if ((fault_type & prot) != fault_type) 4149 return (KERN_PROTECTION_FAILURE); 4150 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 4151 (entry->eflags & MAP_ENTRY_COW) && 4152 (fault_type & VM_PROT_WRITE)) 4153 return (KERN_PROTECTION_FAILURE); 4154 4155 /* 4156 * If this page is not pageable, we have to get it for all possible 4157 * accesses. 4158 */ 4159 *wired = (entry->wired_count != 0); 4160 if (*wired) 4161 fault_type = entry->protection; 4162 4163 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4164 /* 4165 * Fail if the entry was copy-on-write for a write fault. 4166 */ 4167 if (fault_type & VM_PROT_WRITE) 4168 return (KERN_FAILURE); 4169 /* 4170 * We're attempting to read a copy-on-write page -- 4171 * don't allow writes. 4172 */ 4173 prot &= ~VM_PROT_WRITE; 4174 } 4175 4176 /* 4177 * Fail if an object should be created. 4178 */ 4179 if (entry->object.vm_object == NULL && !map->system_map) 4180 return (KERN_FAILURE); 4181 4182 /* 4183 * Return the object/offset from this entry. If the entry was 4184 * copy-on-write or empty, it has been fixed up. 4185 */ 4186 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4187 *object = entry->object.vm_object; 4188 4189 *out_prot = prot; 4190 return (KERN_SUCCESS); 4191} 4192 4193/* 4194 * vm_map_lookup_done: 4195 * 4196 * Releases locks acquired by a vm_map_lookup 4197 * (according to the handle returned by that lookup). 4198 */ 4199void 4200vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4201{ 4202 /* 4203 * Unlock the main-level map 4204 */ 4205 vm_map_unlock_read(map); 4206} 4207 4208#include "opt_ddb.h" 4209#ifdef DDB 4210#include <sys/kernel.h> 4211 4212#include <ddb/ddb.h> 4213 4214static void 4215vm_map_print(vm_map_t map) 4216{ 4217 vm_map_entry_t entry; 4218 4219 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4220 (void *)map, 4221 (void *)map->pmap, map->nentries, map->timestamp); 4222 4223 db_indent += 2; 4224 for (entry = map->header.next; entry != &map->header; 4225 entry = entry->next) { 4226 db_iprintf("map entry %p: start=%p, end=%p\n", 4227 (void *)entry, (void *)entry->start, (void *)entry->end); 4228 { 4229 static char *inheritance_name[4] = 4230 {"share", "copy", "none", "donate_copy"}; 4231 4232 db_iprintf(" prot=%x/%x/%s", 4233 entry->protection, 4234 entry->max_protection, 4235 inheritance_name[(int)(unsigned char)entry->inheritance]); 4236 if (entry->wired_count != 0) 4237 db_printf(", wired"); 4238 } 4239 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4240 db_printf(", share=%p, offset=0x%jx\n", 4241 (void *)entry->object.sub_map, 4242 (uintmax_t)entry->offset); 4243 if ((entry->prev == &map->header) || 4244 (entry->prev->object.sub_map != 4245 entry->object.sub_map)) { 4246 db_indent += 2; 4247 vm_map_print((vm_map_t)entry->object.sub_map); 4248 db_indent -= 2; 4249 } 4250 } else { 4251 if (entry->cred != NULL) 4252 db_printf(", ruid %d", entry->cred->cr_ruid); 4253 db_printf(", object=%p, offset=0x%jx", 4254 (void *)entry->object.vm_object, 4255 (uintmax_t)entry->offset); 4256 if (entry->object.vm_object && entry->object.vm_object->cred) 4257 db_printf(", obj ruid %d charge %jx", 4258 entry->object.vm_object->cred->cr_ruid, 4259 (uintmax_t)entry->object.vm_object->charge); 4260 if (entry->eflags & MAP_ENTRY_COW) 4261 db_printf(", copy (%s)", 4262 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4263 db_printf("\n"); 4264 4265 if ((entry->prev == &map->header) || 4266 (entry->prev->object.vm_object != 4267 entry->object.vm_object)) { 4268 db_indent += 2; 4269 vm_object_print((db_expr_t)(intptr_t) 4270 entry->object.vm_object, 4271 0, 0, (char *)0); 4272 db_indent -= 2; 4273 } 4274 } 4275 } 4276 db_indent -= 2; 4277} 4278 4279DB_SHOW_COMMAND(map, map) 4280{ 4281 4282 if (!have_addr) { 4283 db_printf("usage: show map <addr>\n"); 4284 return; 4285 } 4286 vm_map_print((vm_map_t)addr); 4287} 4288 4289DB_SHOW_COMMAND(procvm, procvm) 4290{ 4291 struct proc *p; 4292 4293 if (have_addr) { 4294 p = (struct proc *) addr; 4295 } else { 4296 p = curproc; 4297 } 4298 4299 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4300 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4301 (void *)vmspace_pmap(p->p_vmspace)); 4302 4303 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 4304} 4305 4306#endif /* DDB */ 4307