vm_map.c revision 267017
1/*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61/* 62 * Virtual memory mapping module. 63 */ 64 65#include <sys/cdefs.h> 66__FBSDID("$FreeBSD: releng/10.0/sys/vm/vm_map.c 267017 2014-06-03 19:02:52Z delphij $"); 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); 135#ifdef INVARIANTS 136static void vm_map_zdtor(void *mem, int size, void *arg); 137static void vmspace_zdtor(void *mem, int size, void *arg); 138#endif 139 140#define ENTRY_CHARGED(e) ((e)->cred != NULL || \ 141 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \ 142 !((e)->eflags & MAP_ENTRY_NEEDS_COPY))) 143 144/* 145 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type 146 * stable. 147 */ 148#define PROC_VMSPACE_LOCK(p) do { } while (0) 149#define PROC_VMSPACE_UNLOCK(p) do { } while (0) 150 151/* 152 * VM_MAP_RANGE_CHECK: [ internal use only ] 153 * 154 * Asserts that the starting and ending region 155 * addresses fall within the valid range of the map. 156 */ 157#define VM_MAP_RANGE_CHECK(map, start, end) \ 158 { \ 159 if (start < vm_map_min(map)) \ 160 start = vm_map_min(map); \ 161 if (end > vm_map_max(map)) \ 162 end = vm_map_max(map); \ 163 if (start > end) \ 164 start = end; \ 165 } 166 167/* 168 * vm_map_startup: 169 * 170 * Initialize the vm_map module. Must be called before 171 * any other vm_map routines. 172 * 173 * Map and entry structures are allocated from the general 174 * purpose memory pool with some exceptions: 175 * 176 * - The kernel map and kmem submap are allocated statically. 177 * - Kernel map entries are allocated out of a static pool. 178 * 179 * These restrictions are necessary since malloc() uses the 180 * maps and requires map entries. 181 */ 182 183void 184vm_map_startup(void) 185{ 186 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 187 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 188#ifdef INVARIANTS 189 vm_map_zdtor, 190#else 191 NULL, 192#endif 193 vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 194 uma_prealloc(mapzone, MAX_KMAP); 195 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 196 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 197 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 198 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 199 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 200 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 201#ifdef INVARIANTS 202 vmspace_zdtor, 203#else 204 NULL, 205#endif 206 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 207} 208 209static int 210vmspace_zinit(void *mem, int size, int flags) 211{ 212 struct vmspace *vm; 213 214 vm = (struct vmspace *)mem; 215 216 vm->vm_map.pmap = NULL; 217 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); 218 PMAP_LOCK_INIT(vmspace_pmap(vm)); 219 return (0); 220} 221 222static int 223vm_map_zinit(void *mem, int size, int flags) 224{ 225 vm_map_t map; 226 227 map = (vm_map_t)mem; 228 memset(map, 0, sizeof(*map)); 229 mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK); 230 sx_init(&map->lock, "vm map (user)"); 231 return (0); 232} 233 234#ifdef INVARIANTS 235static void 236vmspace_zdtor(void *mem, int size, void *arg) 237{ 238 struct vmspace *vm; 239 240 vm = (struct vmspace *)mem; 241 242 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 243} 244static void 245vm_map_zdtor(void *mem, int size, void *arg) 246{ 247 vm_map_t map; 248 249 map = (vm_map_t)mem; 250 KASSERT(map->nentries == 0, 251 ("map %p nentries == %d on free.", 252 map, map->nentries)); 253 KASSERT(map->size == 0, 254 ("map %p size == %lu on free.", 255 map, (unsigned long)map->size)); 256} 257#endif /* INVARIANTS */ 258 259/* 260 * Allocate a vmspace structure, including a vm_map and pmap, 261 * and initialize those structures. The refcnt is set to 1. 262 * 263 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit(). 264 */ 265struct vmspace * 266vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit) 267{ 268 struct vmspace *vm; 269 270 vm = uma_zalloc(vmspace_zone, M_WAITOK); 271 272 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL")); 273 274 if (pinit == NULL) 275 pinit = &pmap_pinit; 276 277 if (!pinit(vmspace_pmap(vm))) { 278 uma_zfree(vmspace_zone, vm); 279 return (NULL); 280 } 281 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 282 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max); 283 vm->vm_refcnt = 1; 284 vm->vm_shm = NULL; 285 vm->vm_swrss = 0; 286 vm->vm_tsize = 0; 287 vm->vm_dsize = 0; 288 vm->vm_ssize = 0; 289 vm->vm_taddr = 0; 290 vm->vm_daddr = 0; 291 vm->vm_maxsaddr = 0; 292 return (vm); 293} 294 295static void 296vmspace_container_reset(struct proc *p) 297{ 298 299#ifdef RACCT 300 PROC_LOCK(p); 301 racct_set(p, RACCT_DATA, 0); 302 racct_set(p, RACCT_STACK, 0); 303 racct_set(p, RACCT_RSS, 0); 304 racct_set(p, RACCT_MEMLOCK, 0); 305 racct_set(p, RACCT_VMEM, 0); 306 PROC_UNLOCK(p); 307#endif 308} 309 310static inline void 311vmspace_dofree(struct vmspace *vm) 312{ 313 314 CTR1(KTR_VM, "vmspace_free: %p", vm); 315 316 /* 317 * Make sure any SysV shm is freed, it might not have been in 318 * exit1(). 319 */ 320 shmexit(vm); 321 322 /* 323 * Lock the map, to wait out all other references to it. 324 * Delete all of the mappings and pages they hold, then call 325 * the pmap module to reclaim anything left. 326 */ 327 (void)vm_map_remove(&vm->vm_map, vm->vm_map.min_offset, 328 vm->vm_map.max_offset); 329 330 pmap_release(vmspace_pmap(vm)); 331 vm->vm_map.pmap = NULL; 332 uma_zfree(vmspace_zone, vm); 333} 334 335void 336vmspace_free(struct vmspace *vm) 337{ 338 339 if (vm->vm_refcnt == 0) 340 panic("vmspace_free: attempt to free already freed vmspace"); 341 342 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) 343 vmspace_dofree(vm); 344} 345 346void 347vmspace_exitfree(struct proc *p) 348{ 349 struct vmspace *vm; 350 351 PROC_VMSPACE_LOCK(p); 352 vm = p->p_vmspace; 353 p->p_vmspace = NULL; 354 PROC_VMSPACE_UNLOCK(p); 355 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 356 vmspace_free(vm); 357} 358 359void 360vmspace_exit(struct thread *td) 361{ 362 int refcnt; 363 struct vmspace *vm; 364 struct proc *p; 365 366 /* 367 * Release user portion of address space. 368 * This releases references to vnodes, 369 * which could cause I/O if the file has been unlinked. 370 * Need to do this early enough that we can still sleep. 371 * 372 * The last exiting process to reach this point releases as 373 * much of the environment as it can. vmspace_dofree() is the 374 * slower fallback in case another process had a temporary 375 * reference to the vmspace. 376 */ 377 378 p = td->td_proc; 379 vm = p->p_vmspace; 380 atomic_add_int(&vmspace0.vm_refcnt, 1); 381 do { 382 refcnt = vm->vm_refcnt; 383 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 384 /* Switch now since other proc might free vmspace */ 385 PROC_VMSPACE_LOCK(p); 386 p->p_vmspace = &vmspace0; 387 PROC_VMSPACE_UNLOCK(p); 388 pmap_activate(td); 389 } 390 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 391 if (refcnt == 1) { 392 if (p->p_vmspace != vm) { 393 /* vmspace not yet freed, switch back */ 394 PROC_VMSPACE_LOCK(p); 395 p->p_vmspace = vm; 396 PROC_VMSPACE_UNLOCK(p); 397 pmap_activate(td); 398 } 399 pmap_remove_pages(vmspace_pmap(vm)); 400 /* Switch now since this proc will free vmspace */ 401 PROC_VMSPACE_LOCK(p); 402 p->p_vmspace = &vmspace0; 403 PROC_VMSPACE_UNLOCK(p); 404 pmap_activate(td); 405 vmspace_dofree(vm); 406 } 407 vmspace_container_reset(p); 408} 409 410/* Acquire reference to vmspace owned by another process. */ 411 412struct vmspace * 413vmspace_acquire_ref(struct proc *p) 414{ 415 struct vmspace *vm; 416 int refcnt; 417 418 PROC_VMSPACE_LOCK(p); 419 vm = p->p_vmspace; 420 if (vm == NULL) { 421 PROC_VMSPACE_UNLOCK(p); 422 return (NULL); 423 } 424 do { 425 refcnt = vm->vm_refcnt; 426 if (refcnt <= 0) { /* Avoid 0->1 transition */ 427 PROC_VMSPACE_UNLOCK(p); 428 return (NULL); 429 } 430 } while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1)); 431 if (vm != p->p_vmspace) { 432 PROC_VMSPACE_UNLOCK(p); 433 vmspace_free(vm); 434 return (NULL); 435 } 436 PROC_VMSPACE_UNLOCK(p); 437 return (vm); 438} 439 440void 441_vm_map_lock(vm_map_t map, const char *file, int line) 442{ 443 444 if (map->system_map) 445 mtx_lock_flags_(&map->system_mtx, 0, file, line); 446 else 447 sx_xlock_(&map->lock, file, line); 448 map->timestamp++; 449} 450 451static void 452vm_map_process_deferred(void) 453{ 454 struct thread *td; 455 vm_map_entry_t entry, next; 456 vm_object_t object; 457 458 td = curthread; 459 entry = td->td_map_def_user; 460 td->td_map_def_user = NULL; 461 while (entry != NULL) { 462 next = entry->next; 463 if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) { 464 /* 465 * Decrement the object's writemappings and 466 * possibly the vnode's v_writecount. 467 */ 468 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 469 ("Submap with writecount")); 470 object = entry->object.vm_object; 471 KASSERT(object != NULL, ("No object for writecount")); 472 vnode_pager_release_writecount(object, entry->start, 473 entry->end); 474 } 475 vm_map_entry_deallocate(entry, FALSE); 476 entry = next; 477 } 478} 479 480void 481_vm_map_unlock(vm_map_t map, const char *file, int line) 482{ 483 484 if (map->system_map) 485 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 486 else { 487 sx_xunlock_(&map->lock, file, line); 488 vm_map_process_deferred(); 489 } 490} 491 492void 493_vm_map_lock_read(vm_map_t map, const char *file, int line) 494{ 495 496 if (map->system_map) 497 mtx_lock_flags_(&map->system_mtx, 0, file, line); 498 else 499 sx_slock_(&map->lock, file, line); 500} 501 502void 503_vm_map_unlock_read(vm_map_t map, const char *file, int line) 504{ 505 506 if (map->system_map) 507 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 508 else { 509 sx_sunlock_(&map->lock, file, line); 510 vm_map_process_deferred(); 511 } 512} 513 514int 515_vm_map_trylock(vm_map_t map, const char *file, int line) 516{ 517 int error; 518 519 error = map->system_map ? 520 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 521 !sx_try_xlock_(&map->lock, file, line); 522 if (error == 0) 523 map->timestamp++; 524 return (error == 0); 525} 526 527int 528_vm_map_trylock_read(vm_map_t map, const char *file, int line) 529{ 530 int error; 531 532 error = map->system_map ? 533 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 534 !sx_try_slock_(&map->lock, file, line); 535 return (error == 0); 536} 537 538/* 539 * _vm_map_lock_upgrade: [ internal use only ] 540 * 541 * Tries to upgrade a read (shared) lock on the specified map to a write 542 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 543 * non-zero value if the upgrade fails. If the upgrade fails, the map is 544 * returned without a read or write lock held. 545 * 546 * Requires that the map be read locked. 547 */ 548int 549_vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 550{ 551 unsigned int last_timestamp; 552 553 if (map->system_map) { 554 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 555 } else { 556 if (!sx_try_upgrade_(&map->lock, file, line)) { 557 last_timestamp = map->timestamp; 558 sx_sunlock_(&map->lock, file, line); 559 vm_map_process_deferred(); 560 /* 561 * If the map's timestamp does not change while the 562 * map is unlocked, then the upgrade succeeds. 563 */ 564 sx_xlock_(&map->lock, file, line); 565 if (last_timestamp != map->timestamp) { 566 sx_xunlock_(&map->lock, file, line); 567 return (1); 568 } 569 } 570 } 571 map->timestamp++; 572 return (0); 573} 574 575void 576_vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 577{ 578 579 if (map->system_map) { 580 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 581 } else 582 sx_downgrade_(&map->lock, file, line); 583} 584 585/* 586 * vm_map_locked: 587 * 588 * Returns a non-zero value if the caller holds a write (exclusive) lock 589 * on the specified map and the value "0" otherwise. 590 */ 591int 592vm_map_locked(vm_map_t map) 593{ 594 595 if (map->system_map) 596 return (mtx_owned(&map->system_mtx)); 597 else 598 return (sx_xlocked(&map->lock)); 599} 600 601#ifdef INVARIANTS 602static void 603_vm_map_assert_locked(vm_map_t map, const char *file, int line) 604{ 605 606 if (map->system_map) 607 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 608 else 609 sx_assert_(&map->lock, SA_XLOCKED, file, line); 610} 611 612#define VM_MAP_ASSERT_LOCKED(map) \ 613 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 614#else 615#define VM_MAP_ASSERT_LOCKED(map) 616#endif 617 618/* 619 * _vm_map_unlock_and_wait: 620 * 621 * Atomically releases the lock on the specified map and puts the calling 622 * thread to sleep. The calling thread will remain asleep until either 623 * vm_map_wakeup() is performed on the map or the specified timeout is 624 * exceeded. 625 * 626 * WARNING! This function does not perform deferred deallocations of 627 * objects and map entries. Therefore, the calling thread is expected to 628 * reacquire the map lock after reawakening and later perform an ordinary 629 * unlock operation, such as vm_map_unlock(), before completing its 630 * operation on the map. 631 */ 632int 633_vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) 634{ 635 636 mtx_lock(&map_sleep_mtx); 637 if (map->system_map) 638 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 639 else 640 sx_xunlock_(&map->lock, file, line); 641 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 642 timo)); 643} 644 645/* 646 * vm_map_wakeup: 647 * 648 * Awaken any threads that have slept on the map using 649 * vm_map_unlock_and_wait(). 650 */ 651void 652vm_map_wakeup(vm_map_t map) 653{ 654 655 /* 656 * Acquire and release map_sleep_mtx to prevent a wakeup() 657 * from being performed (and lost) between the map unlock 658 * and the msleep() in _vm_map_unlock_and_wait(). 659 */ 660 mtx_lock(&map_sleep_mtx); 661 mtx_unlock(&map_sleep_mtx); 662 wakeup(&map->root); 663} 664 665void 666vm_map_busy(vm_map_t map) 667{ 668 669 VM_MAP_ASSERT_LOCKED(map); 670 map->busy++; 671} 672 673void 674vm_map_unbusy(vm_map_t map) 675{ 676 677 VM_MAP_ASSERT_LOCKED(map); 678 KASSERT(map->busy, ("vm_map_unbusy: not busy")); 679 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { 680 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); 681 wakeup(&map->busy); 682 } 683} 684 685void 686vm_map_wait_busy(vm_map_t map) 687{ 688 689 VM_MAP_ASSERT_LOCKED(map); 690 while (map->busy) { 691 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); 692 if (map->system_map) 693 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); 694 else 695 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); 696 } 697 map->timestamp++; 698} 699 700long 701vmspace_resident_count(struct vmspace *vmspace) 702{ 703 return pmap_resident_count(vmspace_pmap(vmspace)); 704} 705 706/* 707 * vm_map_create: 708 * 709 * Creates and returns a new empty VM map with 710 * the given physical map structure, and having 711 * the given lower and upper address bounds. 712 */ 713vm_map_t 714vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 715{ 716 vm_map_t result; 717 718 result = uma_zalloc(mapzone, M_WAITOK); 719 CTR1(KTR_VM, "vm_map_create: %p", result); 720 _vm_map_init(result, pmap, min, max); 721 return (result); 722} 723 724/* 725 * Initialize an existing vm_map structure 726 * such as that in the vmspace structure. 727 */ 728static void 729_vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 730{ 731 732 map->header.next = map->header.prev = &map->header; 733 map->needs_wakeup = FALSE; 734 map->system_map = 0; 735 map->pmap = pmap; 736 map->min_offset = min; 737 map->max_offset = max; 738 map->flags = 0; 739 map->root = NULL; 740 map->timestamp = 0; 741 map->busy = 0; 742} 743 744void 745vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 746{ 747 748 _vm_map_init(map, pmap, min, max); 749 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 750 sx_init(&map->lock, "user map"); 751} 752 753/* 754 * vm_map_entry_dispose: [ internal use only ] 755 * 756 * Inverse of vm_map_entry_create. 757 */ 758static void 759vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 760{ 761 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 762} 763 764/* 765 * vm_map_entry_create: [ internal use only ] 766 * 767 * Allocates a VM map entry for insertion. 768 * No entry fields are filled in. 769 */ 770static vm_map_entry_t 771vm_map_entry_create(vm_map_t map) 772{ 773 vm_map_entry_t new_entry; 774 775 if (map->system_map) 776 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 777 else 778 new_entry = uma_zalloc(mapentzone, M_WAITOK); 779 if (new_entry == NULL) 780 panic("vm_map_entry_create: kernel resources exhausted"); 781 return (new_entry); 782} 783 784/* 785 * vm_map_entry_set_behavior: 786 * 787 * Set the expected access behavior, either normal, random, or 788 * sequential. 789 */ 790static inline void 791vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 792{ 793 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 794 (behavior & MAP_ENTRY_BEHAV_MASK); 795} 796 797/* 798 * vm_map_entry_set_max_free: 799 * 800 * Set the max_free field in a vm_map_entry. 801 */ 802static inline void 803vm_map_entry_set_max_free(vm_map_entry_t entry) 804{ 805 806 entry->max_free = entry->adj_free; 807 if (entry->left != NULL && entry->left->max_free > entry->max_free) 808 entry->max_free = entry->left->max_free; 809 if (entry->right != NULL && entry->right->max_free > entry->max_free) 810 entry->max_free = entry->right->max_free; 811} 812 813/* 814 * vm_map_entry_splay: 815 * 816 * The Sleator and Tarjan top-down splay algorithm with the 817 * following variation. Max_free must be computed bottom-up, so 818 * on the downward pass, maintain the left and right spines in 819 * reverse order. Then, make a second pass up each side to fix 820 * the pointers and compute max_free. The time bound is O(log n) 821 * amortized. 822 * 823 * The new root is the vm_map_entry containing "addr", or else an 824 * adjacent entry (lower or higher) if addr is not in the tree. 825 * 826 * The map must be locked, and leaves it so. 827 * 828 * Returns: the new root. 829 */ 830static vm_map_entry_t 831vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root) 832{ 833 vm_map_entry_t llist, rlist; 834 vm_map_entry_t ltree, rtree; 835 vm_map_entry_t y; 836 837 /* Special case of empty tree. */ 838 if (root == NULL) 839 return (root); 840 841 /* 842 * Pass One: Splay down the tree until we find addr or a NULL 843 * pointer where addr would go. llist and rlist are the two 844 * sides in reverse order (bottom-up), with llist linked by 845 * the right pointer and rlist linked by the left pointer in 846 * the vm_map_entry. Wait until Pass Two to set max_free on 847 * the two spines. 848 */ 849 llist = NULL; 850 rlist = NULL; 851 for (;;) { 852 /* root is never NULL in here. */ 853 if (addr < root->start) { 854 y = root->left; 855 if (y == NULL) 856 break; 857 if (addr < y->start && y->left != NULL) { 858 /* Rotate right and put y on rlist. */ 859 root->left = y->right; 860 y->right = root; 861 vm_map_entry_set_max_free(root); 862 root = y->left; 863 y->left = rlist; 864 rlist = y; 865 } else { 866 /* Put root on rlist. */ 867 root->left = rlist; 868 rlist = root; 869 root = y; 870 } 871 } else if (addr >= root->end) { 872 y = root->right; 873 if (y == NULL) 874 break; 875 if (addr >= y->end && y->right != NULL) { 876 /* Rotate left and put y on llist. */ 877 root->right = y->left; 878 y->left = root; 879 vm_map_entry_set_max_free(root); 880 root = y->right; 881 y->right = llist; 882 llist = y; 883 } else { 884 /* Put root on llist. */ 885 root->right = llist; 886 llist = root; 887 root = y; 888 } 889 } else 890 break; 891 } 892 893 /* 894 * Pass Two: Walk back up the two spines, flip the pointers 895 * and set max_free. The subtrees of the root go at the 896 * bottom of llist and rlist. 897 */ 898 ltree = root->left; 899 while (llist != NULL) { 900 y = llist->right; 901 llist->right = ltree; 902 vm_map_entry_set_max_free(llist); 903 ltree = llist; 904 llist = y; 905 } 906 rtree = root->right; 907 while (rlist != NULL) { 908 y = rlist->left; 909 rlist->left = rtree; 910 vm_map_entry_set_max_free(rlist); 911 rtree = rlist; 912 rlist = y; 913 } 914 915 /* 916 * Final assembly: add ltree and rtree as subtrees of root. 917 */ 918 root->left = ltree; 919 root->right = rtree; 920 vm_map_entry_set_max_free(root); 921 922 return (root); 923} 924 925/* 926 * vm_map_entry_{un,}link: 927 * 928 * Insert/remove entries from maps. 929 */ 930static void 931vm_map_entry_link(vm_map_t map, 932 vm_map_entry_t after_where, 933 vm_map_entry_t entry) 934{ 935 936 CTR4(KTR_VM, 937 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map, 938 map->nentries, entry, after_where); 939 VM_MAP_ASSERT_LOCKED(map); 940 map->nentries++; 941 entry->prev = after_where; 942 entry->next = after_where->next; 943 entry->next->prev = entry; 944 after_where->next = entry; 945 946 if (after_where != &map->header) { 947 if (after_where != map->root) 948 vm_map_entry_splay(after_where->start, map->root); 949 entry->right = after_where->right; 950 entry->left = after_where; 951 after_where->right = NULL; 952 after_where->adj_free = entry->start - after_where->end; 953 vm_map_entry_set_max_free(after_where); 954 } else { 955 entry->right = map->root; 956 entry->left = NULL; 957 } 958 entry->adj_free = (entry->next == &map->header ? map->max_offset : 959 entry->next->start) - entry->end; 960 vm_map_entry_set_max_free(entry); 961 map->root = entry; 962} 963 964static void 965vm_map_entry_unlink(vm_map_t map, 966 vm_map_entry_t entry) 967{ 968 vm_map_entry_t next, prev, root; 969 970 VM_MAP_ASSERT_LOCKED(map); 971 if (entry != map->root) 972 vm_map_entry_splay(entry->start, map->root); 973 if (entry->left == NULL) 974 root = entry->right; 975 else { 976 root = vm_map_entry_splay(entry->start, entry->left); 977 root->right = entry->right; 978 root->adj_free = (entry->next == &map->header ? map->max_offset : 979 entry->next->start) - root->end; 980 vm_map_entry_set_max_free(root); 981 } 982 map->root = root; 983 984 prev = entry->prev; 985 next = entry->next; 986 next->prev = prev; 987 prev->next = next; 988 map->nentries--; 989 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 990 map->nentries, entry); 991} 992 993/* 994 * vm_map_entry_resize_free: 995 * 996 * Recompute the amount of free space following a vm_map_entry 997 * and propagate that value up the tree. Call this function after 998 * resizing a map entry in-place, that is, without a call to 999 * vm_map_entry_link() or _unlink(). 1000 * 1001 * The map must be locked, and leaves it so. 1002 */ 1003static void 1004vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry) 1005{ 1006 1007 /* 1008 * Using splay trees without parent pointers, propagating 1009 * max_free up the tree is done by moving the entry to the 1010 * root and making the change there. 1011 */ 1012 if (entry != map->root) 1013 map->root = vm_map_entry_splay(entry->start, map->root); 1014 1015 entry->adj_free = (entry->next == &map->header ? map->max_offset : 1016 entry->next->start) - entry->end; 1017 vm_map_entry_set_max_free(entry); 1018} 1019 1020/* 1021 * vm_map_lookup_entry: [ internal use only ] 1022 * 1023 * Finds the map entry containing (or 1024 * immediately preceding) the specified address 1025 * in the given map; the entry is returned 1026 * in the "entry" parameter. The boolean 1027 * result indicates whether the address is 1028 * actually contained in the map. 1029 */ 1030boolean_t 1031vm_map_lookup_entry( 1032 vm_map_t map, 1033 vm_offset_t address, 1034 vm_map_entry_t *entry) /* OUT */ 1035{ 1036 vm_map_entry_t cur; 1037 boolean_t locked; 1038 1039 /* 1040 * If the map is empty, then the map entry immediately preceding 1041 * "address" is the map's header. 1042 */ 1043 cur = map->root; 1044 if (cur == NULL) 1045 *entry = &map->header; 1046 else if (address >= cur->start && cur->end > address) { 1047 *entry = cur; 1048 return (TRUE); 1049 } else if ((locked = vm_map_locked(map)) || 1050 sx_try_upgrade(&map->lock)) { 1051 /* 1052 * Splay requires a write lock on the map. However, it only 1053 * restructures the binary search tree; it does not otherwise 1054 * change the map. Thus, the map's timestamp need not change 1055 * on a temporary upgrade. 1056 */ 1057 map->root = cur = vm_map_entry_splay(address, cur); 1058 if (!locked) 1059 sx_downgrade(&map->lock); 1060 1061 /* 1062 * If "address" is contained within a map entry, the new root 1063 * is that map entry. Otherwise, the new root is a map entry 1064 * immediately before or after "address". 1065 */ 1066 if (address >= cur->start) { 1067 *entry = cur; 1068 if (cur->end > address) 1069 return (TRUE); 1070 } else 1071 *entry = cur->prev; 1072 } else 1073 /* 1074 * Since the map is only locked for read access, perform a 1075 * standard binary search tree lookup for "address". 1076 */ 1077 for (;;) { 1078 if (address < cur->start) { 1079 if (cur->left == NULL) { 1080 *entry = cur->prev; 1081 break; 1082 } 1083 cur = cur->left; 1084 } else if (cur->end > address) { 1085 *entry = cur; 1086 return (TRUE); 1087 } else { 1088 if (cur->right == NULL) { 1089 *entry = cur; 1090 break; 1091 } 1092 cur = cur->right; 1093 } 1094 } 1095 return (FALSE); 1096} 1097 1098/* 1099 * vm_map_insert: 1100 * 1101 * Inserts the given whole VM object into the target 1102 * map at the specified address range. The object's 1103 * size should match that of the address range. 1104 * 1105 * Requires that the map be locked, and leaves it so. 1106 * 1107 * If object is non-NULL, ref count must be bumped by caller 1108 * prior to making call to account for the new entry. 1109 */ 1110int 1111vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1112 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 1113 int cow) 1114{ 1115 vm_map_entry_t new_entry; 1116 vm_map_entry_t prev_entry; 1117 vm_map_entry_t temp_entry; 1118 vm_eflags_t protoeflags; 1119 struct ucred *cred; 1120 vm_inherit_t inheritance; 1121 boolean_t charge_prev_obj; 1122 1123 VM_MAP_ASSERT_LOCKED(map); 1124 1125 /* 1126 * Check that the start and end points are not bogus. 1127 */ 1128 if ((start < map->min_offset) || (end > map->max_offset) || 1129 (start >= end)) 1130 return (KERN_INVALID_ADDRESS); 1131 1132 /* 1133 * Find the entry prior to the proposed starting address; if it's part 1134 * of an existing entry, this range is bogus. 1135 */ 1136 if (vm_map_lookup_entry(map, start, &temp_entry)) 1137 return (KERN_NO_SPACE); 1138 1139 prev_entry = temp_entry; 1140 1141 /* 1142 * Assert that the next entry doesn't overlap the end point. 1143 */ 1144 if ((prev_entry->next != &map->header) && 1145 (prev_entry->next->start < end)) 1146 return (KERN_NO_SPACE); 1147 1148 protoeflags = 0; 1149 charge_prev_obj = FALSE; 1150 1151 if (cow & MAP_COPY_ON_WRITE) 1152 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 1153 1154 if (cow & MAP_NOFAULT) { 1155 protoeflags |= MAP_ENTRY_NOFAULT; 1156 1157 KASSERT(object == NULL, 1158 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1159 } 1160 if (cow & MAP_DISABLE_SYNCER) 1161 protoeflags |= MAP_ENTRY_NOSYNC; 1162 if (cow & MAP_DISABLE_COREDUMP) 1163 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1164 if (cow & MAP_VN_WRITECOUNT) 1165 protoeflags |= MAP_ENTRY_VN_WRITECNT; 1166 if (cow & MAP_INHERIT_SHARE) 1167 inheritance = VM_INHERIT_SHARE; 1168 else 1169 inheritance = VM_INHERIT_DEFAULT; 1170 1171 cred = NULL; 1172 KASSERT((object != kmem_object && object != kernel_object) || 1173 ((object == kmem_object || object == kernel_object) && 1174 !(protoeflags & MAP_ENTRY_NEEDS_COPY)), 1175 ("kmem or kernel object and cow")); 1176 if (cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT)) 1177 goto charged; 1178 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1179 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1180 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1181 return (KERN_RESOURCE_SHORTAGE); 1182 KASSERT(object == NULL || (protoeflags & MAP_ENTRY_NEEDS_COPY) || 1183 object->cred == NULL, 1184 ("OVERCOMMIT: vm_map_insert o %p", object)); 1185 cred = curthread->td_ucred; 1186 crhold(cred); 1187 if (object == NULL && !(protoeflags & MAP_ENTRY_NEEDS_COPY)) 1188 charge_prev_obj = TRUE; 1189 } 1190 1191charged: 1192 /* Expand the kernel pmap, if necessary. */ 1193 if (map == kernel_map && end > kernel_vm_end) 1194 pmap_growkernel(end); 1195 if (object != NULL) { 1196 /* 1197 * OBJ_ONEMAPPING must be cleared unless this mapping 1198 * is trivially proven to be the only mapping for any 1199 * of the object's pages. (Object granularity 1200 * reference counting is insufficient to recognize 1201 * aliases with precision.) 1202 */ 1203 VM_OBJECT_WLOCK(object); 1204 if (object->ref_count > 1 || object->shadow_count != 0) 1205 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1206 VM_OBJECT_WUNLOCK(object); 1207 } 1208 else if ((prev_entry != &map->header) && 1209 (prev_entry->eflags == protoeflags) && 1210 (cow & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) == 0 && 1211 (prev_entry->end == start) && 1212 (prev_entry->wired_count == 0) && 1213 (prev_entry->cred == cred || 1214 (prev_entry->object.vm_object != NULL && 1215 (prev_entry->object.vm_object->cred == cred))) && 1216 vm_object_coalesce(prev_entry->object.vm_object, 1217 prev_entry->offset, 1218 (vm_size_t)(prev_entry->end - prev_entry->start), 1219 (vm_size_t)(end - prev_entry->end), charge_prev_obj)) { 1220 /* 1221 * We were able to extend the object. Determine if we 1222 * can extend the previous map entry to include the 1223 * new range as well. 1224 */ 1225 if ((prev_entry->inheritance == inheritance) && 1226 (prev_entry->protection == prot) && 1227 (prev_entry->max_protection == max)) { 1228 map->size += (end - prev_entry->end); 1229 prev_entry->end = end; 1230 vm_map_entry_resize_free(map, prev_entry); 1231 vm_map_simplify_entry(map, prev_entry); 1232 if (cred != NULL) 1233 crfree(cred); 1234 return (KERN_SUCCESS); 1235 } 1236 1237 /* 1238 * If we can extend the object but cannot extend the 1239 * map entry, we have to create a new map entry. We 1240 * must bump the ref count on the extended object to 1241 * account for it. object may be NULL. 1242 */ 1243 object = prev_entry->object.vm_object; 1244 offset = prev_entry->offset + 1245 (prev_entry->end - prev_entry->start); 1246 vm_object_reference(object); 1247 if (cred != NULL && object != NULL && object->cred != NULL && 1248 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1249 /* Object already accounts for this uid. */ 1250 crfree(cred); 1251 cred = NULL; 1252 } 1253 } 1254 1255 /* 1256 * NOTE: if conditionals fail, object can be NULL here. This occurs 1257 * in things like the buffer map where we manage kva but do not manage 1258 * backing objects. 1259 */ 1260 1261 /* 1262 * Create a new entry 1263 */ 1264 new_entry = vm_map_entry_create(map); 1265 new_entry->start = start; 1266 new_entry->end = end; 1267 new_entry->cred = NULL; 1268 1269 new_entry->eflags = protoeflags; 1270 new_entry->object.vm_object = object; 1271 new_entry->offset = offset; 1272 new_entry->avail_ssize = 0; 1273 1274 new_entry->inheritance = inheritance; 1275 new_entry->protection = prot; 1276 new_entry->max_protection = max; 1277 new_entry->wired_count = 0; 1278 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1279 new_entry->next_read = OFF_TO_IDX(offset); 1280 1281 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1282 ("OVERCOMMIT: vm_map_insert leaks vm_map %p", new_entry)); 1283 new_entry->cred = cred; 1284 1285 /* 1286 * Insert the new entry into the list 1287 */ 1288 vm_map_entry_link(map, prev_entry, new_entry); 1289 map->size += new_entry->end - new_entry->start; 1290 1291 /* 1292 * It may be possible to merge the new entry with the next and/or 1293 * previous entries. However, due to MAP_STACK_* being a hack, a 1294 * panic can result from merging such entries. 1295 */ 1296 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0) 1297 vm_map_simplify_entry(map, new_entry); 1298 1299 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 1300 vm_map_pmap_enter(map, start, prot, 1301 object, OFF_TO_IDX(offset), end - start, 1302 cow & MAP_PREFAULT_PARTIAL); 1303 } 1304 1305 return (KERN_SUCCESS); 1306} 1307 1308/* 1309 * vm_map_findspace: 1310 * 1311 * Find the first fit (lowest VM address) for "length" free bytes 1312 * beginning at address >= start in the given map. 1313 * 1314 * In a vm_map_entry, "adj_free" is the amount of free space 1315 * adjacent (higher address) to this entry, and "max_free" is the 1316 * maximum amount of contiguous free space in its subtree. This 1317 * allows finding a free region in one path down the tree, so 1318 * O(log n) amortized with splay trees. 1319 * 1320 * The map must be locked, and leaves it so. 1321 * 1322 * Returns: 0 on success, and starting address in *addr, 1323 * 1 if insufficient space. 1324 */ 1325int 1326vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1327 vm_offset_t *addr) /* OUT */ 1328{ 1329 vm_map_entry_t entry; 1330 vm_offset_t st; 1331 1332 /* 1333 * Request must fit within min/max VM address and must avoid 1334 * address wrap. 1335 */ 1336 if (start < map->min_offset) 1337 start = map->min_offset; 1338 if (start + length > map->max_offset || start + length < start) 1339 return (1); 1340 1341 /* Empty tree means wide open address space. */ 1342 if (map->root == NULL) { 1343 *addr = start; 1344 return (0); 1345 } 1346 1347 /* 1348 * After splay, if start comes before root node, then there 1349 * must be a gap from start to the root. 1350 */ 1351 map->root = vm_map_entry_splay(start, map->root); 1352 if (start + length <= map->root->start) { 1353 *addr = start; 1354 return (0); 1355 } 1356 1357 /* 1358 * Root is the last node that might begin its gap before 1359 * start, and this is the last comparison where address 1360 * wrap might be a problem. 1361 */ 1362 st = (start > map->root->end) ? start : map->root->end; 1363 if (length <= map->root->end + map->root->adj_free - st) { 1364 *addr = st; 1365 return (0); 1366 } 1367 1368 /* With max_free, can immediately tell if no solution. */ 1369 entry = map->root->right; 1370 if (entry == NULL || length > entry->max_free) 1371 return (1); 1372 1373 /* 1374 * Search the right subtree in the order: left subtree, root, 1375 * right subtree (first fit). The previous splay implies that 1376 * all regions in the right subtree have addresses > start. 1377 */ 1378 while (entry != NULL) { 1379 if (entry->left != NULL && entry->left->max_free >= length) 1380 entry = entry->left; 1381 else if (entry->adj_free >= length) { 1382 *addr = entry->end; 1383 return (0); 1384 } else 1385 entry = entry->right; 1386 } 1387 1388 /* Can't get here, so panic if we do. */ 1389 panic("vm_map_findspace: max_free corrupt"); 1390} 1391 1392int 1393vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1394 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1395 vm_prot_t max, int cow) 1396{ 1397 vm_offset_t end; 1398 int result; 1399 1400 end = start + length; 1401 vm_map_lock(map); 1402 VM_MAP_RANGE_CHECK(map, start, end); 1403 (void) vm_map_delete(map, start, end); 1404 result = vm_map_insert(map, object, offset, start, end, prot, 1405 max, cow); 1406 vm_map_unlock(map); 1407 return (result); 1408} 1409 1410/* 1411 * vm_map_find finds an unallocated region in the target address 1412 * map with the given length. The search is defined to be 1413 * first-fit from the specified address; the region found is 1414 * returned in the same parameter. 1415 * 1416 * If object is non-NULL, ref count must be bumped by caller 1417 * prior to making call to account for the new entry. 1418 */ 1419int 1420vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1421 vm_offset_t *addr, /* IN/OUT */ 1422 vm_size_t length, vm_offset_t max_addr, int find_space, 1423 vm_prot_t prot, vm_prot_t max, int cow) 1424{ 1425 vm_offset_t alignment, initial_addr, start; 1426 int result; 1427 1428 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 1429 (object->flags & OBJ_COLORED) == 0)) 1430 find_space = VMFS_ANY_SPACE; 1431 if (find_space >> 8 != 0) { 1432 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 1433 alignment = (vm_offset_t)1 << (find_space >> 8); 1434 } else 1435 alignment = 0; 1436 initial_addr = *addr; 1437again: 1438 start = initial_addr; 1439 vm_map_lock(map); 1440 do { 1441 if (find_space != VMFS_NO_SPACE) { 1442 if (vm_map_findspace(map, start, length, addr) || 1443 (max_addr != 0 && *addr + length > max_addr)) { 1444 vm_map_unlock(map); 1445 if (find_space == VMFS_OPTIMAL_SPACE) { 1446 find_space = VMFS_ANY_SPACE; 1447 goto again; 1448 } 1449 return (KERN_NO_SPACE); 1450 } 1451 switch (find_space) { 1452 case VMFS_SUPER_SPACE: 1453 case VMFS_OPTIMAL_SPACE: 1454 pmap_align_superpage(object, offset, addr, 1455 length); 1456 break; 1457 case VMFS_ANY_SPACE: 1458 break; 1459 default: 1460 if ((*addr & (alignment - 1)) != 0) { 1461 *addr &= ~(alignment - 1); 1462 *addr += alignment; 1463 } 1464 break; 1465 } 1466 1467 start = *addr; 1468 } 1469 result = vm_map_insert(map, object, offset, start, start + 1470 length, prot, max, cow); 1471 } while (result == KERN_NO_SPACE && find_space != VMFS_NO_SPACE && 1472 find_space != VMFS_ANY_SPACE); 1473 vm_map_unlock(map); 1474 return (result); 1475} 1476 1477/* 1478 * vm_map_simplify_entry: 1479 * 1480 * Simplify the given map entry by merging with either neighbor. This 1481 * routine also has the ability to merge with both neighbors. 1482 * 1483 * The map must be locked. 1484 * 1485 * This routine guarentees that the passed entry remains valid (though 1486 * possibly extended). When merging, this routine may delete one or 1487 * both neighbors. 1488 */ 1489void 1490vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry) 1491{ 1492 vm_map_entry_t next, prev; 1493 vm_size_t prevsize, esize; 1494 1495 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) 1496 return; 1497 1498 prev = entry->prev; 1499 if (prev != &map->header) { 1500 prevsize = prev->end - prev->start; 1501 if ( (prev->end == entry->start) && 1502 (prev->object.vm_object == entry->object.vm_object) && 1503 (!prev->object.vm_object || 1504 (prev->offset + prevsize == entry->offset)) && 1505 (prev->eflags == entry->eflags) && 1506 (prev->protection == entry->protection) && 1507 (prev->max_protection == entry->max_protection) && 1508 (prev->inheritance == entry->inheritance) && 1509 (prev->wired_count == entry->wired_count) && 1510 (prev->cred == entry->cred)) { 1511 vm_map_entry_unlink(map, prev); 1512 entry->start = prev->start; 1513 entry->offset = prev->offset; 1514 if (entry->prev != &map->header) 1515 vm_map_entry_resize_free(map, entry->prev); 1516 1517 /* 1518 * If the backing object is a vnode object, 1519 * vm_object_deallocate() calls vrele(). 1520 * However, vrele() does not lock the vnode 1521 * because the vnode has additional 1522 * references. Thus, the map lock can be kept 1523 * without causing a lock-order reversal with 1524 * the vnode lock. 1525 * 1526 * Since we count the number of virtual page 1527 * mappings in object->un_pager.vnp.writemappings, 1528 * the writemappings value should not be adjusted 1529 * when the entry is disposed of. 1530 */ 1531 if (prev->object.vm_object) 1532 vm_object_deallocate(prev->object.vm_object); 1533 if (prev->cred != NULL) 1534 crfree(prev->cred); 1535 vm_map_entry_dispose(map, prev); 1536 } 1537 } 1538 1539 next = entry->next; 1540 if (next != &map->header) { 1541 esize = entry->end - entry->start; 1542 if ((entry->end == next->start) && 1543 (next->object.vm_object == entry->object.vm_object) && 1544 (!entry->object.vm_object || 1545 (entry->offset + esize == next->offset)) && 1546 (next->eflags == entry->eflags) && 1547 (next->protection == entry->protection) && 1548 (next->max_protection == entry->max_protection) && 1549 (next->inheritance == entry->inheritance) && 1550 (next->wired_count == entry->wired_count) && 1551 (next->cred == entry->cred)) { 1552 vm_map_entry_unlink(map, next); 1553 entry->end = next->end; 1554 vm_map_entry_resize_free(map, entry); 1555 1556 /* 1557 * See comment above. 1558 */ 1559 if (next->object.vm_object) 1560 vm_object_deallocate(next->object.vm_object); 1561 if (next->cred != NULL) 1562 crfree(next->cred); 1563 vm_map_entry_dispose(map, next); 1564 } 1565 } 1566} 1567/* 1568 * vm_map_clip_start: [ internal use only ] 1569 * 1570 * Asserts that the given entry begins at or after 1571 * the specified address; if necessary, 1572 * it splits the entry into two. 1573 */ 1574#define vm_map_clip_start(map, entry, startaddr) \ 1575{ \ 1576 if (startaddr > entry->start) \ 1577 _vm_map_clip_start(map, entry, startaddr); \ 1578} 1579 1580/* 1581 * This routine is called only when it is known that 1582 * the entry must be split. 1583 */ 1584static void 1585_vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 1586{ 1587 vm_map_entry_t new_entry; 1588 1589 VM_MAP_ASSERT_LOCKED(map); 1590 1591 /* 1592 * Split off the front portion -- note that we must insert the new 1593 * entry BEFORE this one, so that this entry has the specified 1594 * starting address. 1595 */ 1596 vm_map_simplify_entry(map, entry); 1597 1598 /* 1599 * If there is no object backing this entry, we might as well create 1600 * one now. If we defer it, an object can get created after the map 1601 * is clipped, and individual objects will be created for the split-up 1602 * map. This is a bit of a hack, but is also about the best place to 1603 * put this improvement. 1604 */ 1605 if (entry->object.vm_object == NULL && !map->system_map) { 1606 vm_object_t object; 1607 object = vm_object_allocate(OBJT_DEFAULT, 1608 atop(entry->end - entry->start)); 1609 entry->object.vm_object = object; 1610 entry->offset = 0; 1611 if (entry->cred != NULL) { 1612 object->cred = entry->cred; 1613 object->charge = entry->end - entry->start; 1614 entry->cred = NULL; 1615 } 1616 } else if (entry->object.vm_object != NULL && 1617 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1618 entry->cred != NULL) { 1619 VM_OBJECT_WLOCK(entry->object.vm_object); 1620 KASSERT(entry->object.vm_object->cred == NULL, 1621 ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry)); 1622 entry->object.vm_object->cred = entry->cred; 1623 entry->object.vm_object->charge = entry->end - entry->start; 1624 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1625 entry->cred = NULL; 1626 } 1627 1628 new_entry = vm_map_entry_create(map); 1629 *new_entry = *entry; 1630 1631 new_entry->end = start; 1632 entry->offset += (start - entry->start); 1633 entry->start = start; 1634 if (new_entry->cred != NULL) 1635 crhold(entry->cred); 1636 1637 vm_map_entry_link(map, entry->prev, new_entry); 1638 1639 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1640 vm_object_reference(new_entry->object.vm_object); 1641 /* 1642 * The object->un_pager.vnp.writemappings for the 1643 * object of MAP_ENTRY_VN_WRITECNT type entry shall be 1644 * kept as is here. The virtual pages are 1645 * re-distributed among the clipped entries, so the sum is 1646 * left the same. 1647 */ 1648 } 1649} 1650 1651/* 1652 * vm_map_clip_end: [ internal use only ] 1653 * 1654 * Asserts that the given entry ends at or before 1655 * the specified address; if necessary, 1656 * it splits the entry into two. 1657 */ 1658#define vm_map_clip_end(map, entry, endaddr) \ 1659{ \ 1660 if ((endaddr) < (entry->end)) \ 1661 _vm_map_clip_end((map), (entry), (endaddr)); \ 1662} 1663 1664/* 1665 * This routine is called only when it is known that 1666 * the entry must be split. 1667 */ 1668static void 1669_vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 1670{ 1671 vm_map_entry_t new_entry; 1672 1673 VM_MAP_ASSERT_LOCKED(map); 1674 1675 /* 1676 * If there is no object backing this entry, we might as well create 1677 * one now. If we defer it, an object can get created after the map 1678 * is clipped, and individual objects will be created for the split-up 1679 * map. This is a bit of a hack, but is also about the best place to 1680 * put this improvement. 1681 */ 1682 if (entry->object.vm_object == NULL && !map->system_map) { 1683 vm_object_t object; 1684 object = vm_object_allocate(OBJT_DEFAULT, 1685 atop(entry->end - entry->start)); 1686 entry->object.vm_object = object; 1687 entry->offset = 0; 1688 if (entry->cred != NULL) { 1689 object->cred = entry->cred; 1690 object->charge = entry->end - entry->start; 1691 entry->cred = NULL; 1692 } 1693 } else if (entry->object.vm_object != NULL && 1694 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 1695 entry->cred != NULL) { 1696 VM_OBJECT_WLOCK(entry->object.vm_object); 1697 KASSERT(entry->object.vm_object->cred == NULL, 1698 ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry)); 1699 entry->object.vm_object->cred = entry->cred; 1700 entry->object.vm_object->charge = entry->end - entry->start; 1701 VM_OBJECT_WUNLOCK(entry->object.vm_object); 1702 entry->cred = NULL; 1703 } 1704 1705 /* 1706 * Create a new entry and insert it AFTER the specified entry 1707 */ 1708 new_entry = vm_map_entry_create(map); 1709 *new_entry = *entry; 1710 1711 new_entry->start = entry->end = end; 1712 new_entry->offset += (end - entry->start); 1713 if (new_entry->cred != NULL) 1714 crhold(entry->cred); 1715 1716 vm_map_entry_link(map, entry, new_entry); 1717 1718 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1719 vm_object_reference(new_entry->object.vm_object); 1720 } 1721} 1722 1723/* 1724 * vm_map_submap: [ kernel use only ] 1725 * 1726 * Mark the given range as handled by a subordinate map. 1727 * 1728 * This range must have been created with vm_map_find, 1729 * and no other operations may have been performed on this 1730 * range prior to calling vm_map_submap. 1731 * 1732 * Only a limited number of operations can be performed 1733 * within this rage after calling vm_map_submap: 1734 * vm_fault 1735 * [Don't try vm_map_copy!] 1736 * 1737 * To remove a submapping, one must first remove the 1738 * range from the superior map, and then destroy the 1739 * submap (if desired). [Better yet, don't try it.] 1740 */ 1741int 1742vm_map_submap( 1743 vm_map_t map, 1744 vm_offset_t start, 1745 vm_offset_t end, 1746 vm_map_t submap) 1747{ 1748 vm_map_entry_t entry; 1749 int result = KERN_INVALID_ARGUMENT; 1750 1751 vm_map_lock(map); 1752 1753 VM_MAP_RANGE_CHECK(map, start, end); 1754 1755 if (vm_map_lookup_entry(map, start, &entry)) { 1756 vm_map_clip_start(map, entry, start); 1757 } else 1758 entry = entry->next; 1759 1760 vm_map_clip_end(map, entry, end); 1761 1762 if ((entry->start == start) && (entry->end == end) && 1763 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1764 (entry->object.vm_object == NULL)) { 1765 entry->object.sub_map = submap; 1766 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1767 result = KERN_SUCCESS; 1768 } 1769 vm_map_unlock(map); 1770 1771 return (result); 1772} 1773 1774/* 1775 * The maximum number of pages to map 1776 */ 1777#define MAX_INIT_PT 96 1778 1779/* 1780 * vm_map_pmap_enter: 1781 * 1782 * Preload read-only mappings for the specified object's resident pages 1783 * into the target map. If "flags" is MAP_PREFAULT_PARTIAL, then only 1784 * the resident pages within the address range [addr, addr + ulmin(size, 1785 * ptoa(MAX_INIT_PT))) are mapped. Otherwise, all resident pages within 1786 * the specified address range are mapped. This eliminates many soft 1787 * faults on process startup and immediately after an mmap(2). Because 1788 * these are speculative mappings, cached pages are not reactivated and 1789 * mapped. 1790 */ 1791void 1792vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 1793 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 1794{ 1795 vm_offset_t start; 1796 vm_page_t p, p_start; 1797 vm_pindex_t psize, tmpidx; 1798 1799 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 1800 return; 1801 VM_OBJECT_RLOCK(object); 1802 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1803 VM_OBJECT_RUNLOCK(object); 1804 VM_OBJECT_WLOCK(object); 1805 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 1806 pmap_object_init_pt(map->pmap, addr, object, pindex, 1807 size); 1808 VM_OBJECT_WUNLOCK(object); 1809 return; 1810 } 1811 VM_OBJECT_LOCK_DOWNGRADE(object); 1812 } 1813 1814 psize = atop(size); 1815 if (psize > MAX_INIT_PT && (flags & MAP_PREFAULT_PARTIAL) != 0) 1816 psize = MAX_INIT_PT; 1817 if (psize + pindex > object->size) { 1818 if (object->size < pindex) { 1819 VM_OBJECT_RUNLOCK(object); 1820 return; 1821 } 1822 psize = object->size - pindex; 1823 } 1824 1825 start = 0; 1826 p_start = NULL; 1827 1828 p = vm_page_find_least(object, pindex); 1829 /* 1830 * Assert: the variable p is either (1) the page with the 1831 * least pindex greater than or equal to the parameter pindex 1832 * or (2) NULL. 1833 */ 1834 for (; 1835 p != NULL && (tmpidx = p->pindex - pindex) < psize; 1836 p = TAILQ_NEXT(p, listq)) { 1837 /* 1838 * don't allow an madvise to blow away our really 1839 * free pages allocating pv entries. 1840 */ 1841 if ((flags & MAP_PREFAULT_MADVISE) && 1842 cnt.v_free_count < cnt.v_free_reserved) { 1843 psize = tmpidx; 1844 break; 1845 } 1846 if (p->valid == VM_PAGE_BITS_ALL) { 1847 if (p_start == NULL) { 1848 start = addr + ptoa(tmpidx); 1849 p_start = p; 1850 } 1851 } else if (p_start != NULL) { 1852 pmap_enter_object(map->pmap, start, addr + 1853 ptoa(tmpidx), p_start, prot); 1854 p_start = NULL; 1855 } 1856 } 1857 if (p_start != NULL) 1858 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 1859 p_start, prot); 1860 VM_OBJECT_RUNLOCK(object); 1861} 1862 1863/* 1864 * vm_map_protect: 1865 * 1866 * Sets the protection of the specified address 1867 * region in the target map. If "set_max" is 1868 * specified, the maximum protection is to be set; 1869 * otherwise, only the current protection is affected. 1870 */ 1871int 1872vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1873 vm_prot_t new_prot, boolean_t set_max) 1874{ 1875 vm_map_entry_t current, entry; 1876 vm_object_t obj; 1877 struct ucred *cred; 1878 vm_prot_t old_prot; 1879 1880 vm_map_lock(map); 1881 1882 VM_MAP_RANGE_CHECK(map, start, end); 1883 1884 if (vm_map_lookup_entry(map, start, &entry)) { 1885 vm_map_clip_start(map, entry, start); 1886 } else { 1887 entry = entry->next; 1888 } 1889 1890 /* 1891 * Make a first pass to check for protection violations. 1892 */ 1893 current = entry; 1894 while ((current != &map->header) && (current->start < end)) { 1895 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1896 vm_map_unlock(map); 1897 return (KERN_INVALID_ARGUMENT); 1898 } 1899 if ((new_prot & current->max_protection) != new_prot) { 1900 vm_map_unlock(map); 1901 return (KERN_PROTECTION_FAILURE); 1902 } 1903 current = current->next; 1904 } 1905 1906 1907 /* 1908 * Do an accounting pass for private read-only mappings that 1909 * now will do cow due to allowed write (e.g. debugger sets 1910 * breakpoint on text segment) 1911 */ 1912 for (current = entry; (current != &map->header) && 1913 (current->start < end); current = current->next) { 1914 1915 vm_map_clip_end(map, current, end); 1916 1917 if (set_max || 1918 ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 || 1919 ENTRY_CHARGED(current)) { 1920 continue; 1921 } 1922 1923 cred = curthread->td_ucred; 1924 obj = current->object.vm_object; 1925 1926 if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) { 1927 if (!swap_reserve(current->end - current->start)) { 1928 vm_map_unlock(map); 1929 return (KERN_RESOURCE_SHORTAGE); 1930 } 1931 crhold(cred); 1932 current->cred = cred; 1933 continue; 1934 } 1935 1936 VM_OBJECT_WLOCK(obj); 1937 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 1938 VM_OBJECT_WUNLOCK(obj); 1939 continue; 1940 } 1941 1942 /* 1943 * Charge for the whole object allocation now, since 1944 * we cannot distinguish between non-charged and 1945 * charged clipped mapping of the same object later. 1946 */ 1947 KASSERT(obj->charge == 0, 1948 ("vm_map_protect: object %p overcharged\n", obj)); 1949 if (!swap_reserve(ptoa(obj->size))) { 1950 VM_OBJECT_WUNLOCK(obj); 1951 vm_map_unlock(map); 1952 return (KERN_RESOURCE_SHORTAGE); 1953 } 1954 1955 crhold(cred); 1956 obj->cred = cred; 1957 obj->charge = ptoa(obj->size); 1958 VM_OBJECT_WUNLOCK(obj); 1959 } 1960 1961 /* 1962 * Go back and fix up protections. [Note that clipping is not 1963 * necessary the second time.] 1964 */ 1965 current = entry; 1966 while ((current != &map->header) && (current->start < end)) { 1967 old_prot = current->protection; 1968 1969 if (set_max) 1970 current->protection = 1971 (current->max_protection = new_prot) & 1972 old_prot; 1973 else 1974 current->protection = new_prot; 1975 1976 if ((current->eflags & (MAP_ENTRY_COW | MAP_ENTRY_USER_WIRED)) 1977 == (MAP_ENTRY_COW | MAP_ENTRY_USER_WIRED) && 1978 (current->protection & VM_PROT_WRITE) != 0 && 1979 (old_prot & VM_PROT_WRITE) == 0) { 1980 vm_fault_copy_entry(map, map, current, current, NULL); 1981 } 1982 1983 /* 1984 * When restricting access, update the physical map. Worry 1985 * about copy-on-write here. 1986 */ 1987 if ((old_prot & ~current->protection) != 0) { 1988#define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1989 VM_PROT_ALL) 1990 pmap_protect(map->pmap, current->start, 1991 current->end, 1992 current->protection & MASK(current)); 1993#undef MASK 1994 } 1995 vm_map_simplify_entry(map, current); 1996 current = current->next; 1997 } 1998 vm_map_unlock(map); 1999 return (KERN_SUCCESS); 2000} 2001 2002/* 2003 * vm_map_madvise: 2004 * 2005 * This routine traverses a processes map handling the madvise 2006 * system call. Advisories are classified as either those effecting 2007 * the vm_map_entry structure, or those effecting the underlying 2008 * objects. 2009 */ 2010int 2011vm_map_madvise( 2012 vm_map_t map, 2013 vm_offset_t start, 2014 vm_offset_t end, 2015 int behav) 2016{ 2017 vm_map_entry_t current, entry; 2018 int modify_map = 0; 2019 2020 /* 2021 * Some madvise calls directly modify the vm_map_entry, in which case 2022 * we need to use an exclusive lock on the map and we need to perform 2023 * various clipping operations. Otherwise we only need a read-lock 2024 * on the map. 2025 */ 2026 switch(behav) { 2027 case MADV_NORMAL: 2028 case MADV_SEQUENTIAL: 2029 case MADV_RANDOM: 2030 case MADV_NOSYNC: 2031 case MADV_AUTOSYNC: 2032 case MADV_NOCORE: 2033 case MADV_CORE: 2034 modify_map = 1; 2035 vm_map_lock(map); 2036 break; 2037 case MADV_WILLNEED: 2038 case MADV_DONTNEED: 2039 case MADV_FREE: 2040 vm_map_lock_read(map); 2041 break; 2042 default: 2043 return (KERN_INVALID_ARGUMENT); 2044 } 2045 2046 /* 2047 * Locate starting entry and clip if necessary. 2048 */ 2049 VM_MAP_RANGE_CHECK(map, start, end); 2050 2051 if (vm_map_lookup_entry(map, start, &entry)) { 2052 if (modify_map) 2053 vm_map_clip_start(map, entry, start); 2054 } else { 2055 entry = entry->next; 2056 } 2057 2058 if (modify_map) { 2059 /* 2060 * madvise behaviors that are implemented in the vm_map_entry. 2061 * 2062 * We clip the vm_map_entry so that behavioral changes are 2063 * limited to the specified address range. 2064 */ 2065 for (current = entry; 2066 (current != &map->header) && (current->start < end); 2067 current = current->next 2068 ) { 2069 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2070 continue; 2071 2072 vm_map_clip_end(map, current, end); 2073 2074 switch (behav) { 2075 case MADV_NORMAL: 2076 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 2077 break; 2078 case MADV_SEQUENTIAL: 2079 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 2080 break; 2081 case MADV_RANDOM: 2082 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 2083 break; 2084 case MADV_NOSYNC: 2085 current->eflags |= MAP_ENTRY_NOSYNC; 2086 break; 2087 case MADV_AUTOSYNC: 2088 current->eflags &= ~MAP_ENTRY_NOSYNC; 2089 break; 2090 case MADV_NOCORE: 2091 current->eflags |= MAP_ENTRY_NOCOREDUMP; 2092 break; 2093 case MADV_CORE: 2094 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2095 break; 2096 default: 2097 break; 2098 } 2099 vm_map_simplify_entry(map, current); 2100 } 2101 vm_map_unlock(map); 2102 } else { 2103 vm_pindex_t pstart, pend; 2104 2105 /* 2106 * madvise behaviors that are implemented in the underlying 2107 * vm_object. 2108 * 2109 * Since we don't clip the vm_map_entry, we have to clip 2110 * the vm_object pindex and count. 2111 */ 2112 for (current = entry; 2113 (current != &map->header) && (current->start < end); 2114 current = current->next 2115 ) { 2116 vm_offset_t useEnd, useStart; 2117 2118 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 2119 continue; 2120 2121 pstart = OFF_TO_IDX(current->offset); 2122 pend = pstart + atop(current->end - current->start); 2123 useStart = current->start; 2124 useEnd = current->end; 2125 2126 if (current->start < start) { 2127 pstart += atop(start - current->start); 2128 useStart = start; 2129 } 2130 if (current->end > end) { 2131 pend -= atop(current->end - end); 2132 useEnd = end; 2133 } 2134 2135 if (pstart >= pend) 2136 continue; 2137 2138 /* 2139 * Perform the pmap_advise() before clearing 2140 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2141 * concurrent pmap operation, such as pmap_remove(), 2142 * could clear a reference in the pmap and set 2143 * PGA_REFERENCED on the page before the pmap_advise() 2144 * had completed. Consequently, the page would appear 2145 * referenced based upon an old reference that 2146 * occurred before this pmap_advise() ran. 2147 */ 2148 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2149 pmap_advise(map->pmap, useStart, useEnd, 2150 behav); 2151 2152 vm_object_madvise(current->object.vm_object, pstart, 2153 pend, behav); 2154 if (behav == MADV_WILLNEED) { 2155 vm_map_pmap_enter(map, 2156 useStart, 2157 current->protection, 2158 current->object.vm_object, 2159 pstart, 2160 ptoa(pend - pstart), 2161 MAP_PREFAULT_MADVISE 2162 ); 2163 } 2164 } 2165 vm_map_unlock_read(map); 2166 } 2167 return (0); 2168} 2169 2170 2171/* 2172 * vm_map_inherit: 2173 * 2174 * Sets the inheritance of the specified address 2175 * range in the target map. Inheritance 2176 * affects how the map will be shared with 2177 * child maps at the time of vmspace_fork. 2178 */ 2179int 2180vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2181 vm_inherit_t new_inheritance) 2182{ 2183 vm_map_entry_t entry; 2184 vm_map_entry_t temp_entry; 2185 2186 switch (new_inheritance) { 2187 case VM_INHERIT_NONE: 2188 case VM_INHERIT_COPY: 2189 case VM_INHERIT_SHARE: 2190 break; 2191 default: 2192 return (KERN_INVALID_ARGUMENT); 2193 } 2194 vm_map_lock(map); 2195 VM_MAP_RANGE_CHECK(map, start, end); 2196 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2197 entry = temp_entry; 2198 vm_map_clip_start(map, entry, start); 2199 } else 2200 entry = temp_entry->next; 2201 while ((entry != &map->header) && (entry->start < end)) { 2202 vm_map_clip_end(map, entry, end); 2203 entry->inheritance = new_inheritance; 2204 vm_map_simplify_entry(map, entry); 2205 entry = entry->next; 2206 } 2207 vm_map_unlock(map); 2208 return (KERN_SUCCESS); 2209} 2210 2211/* 2212 * vm_map_unwire: 2213 * 2214 * Implements both kernel and user unwiring. 2215 */ 2216int 2217vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2218 int flags) 2219{ 2220 vm_map_entry_t entry, first_entry, tmp_entry; 2221 vm_offset_t saved_start; 2222 unsigned int last_timestamp; 2223 int rv; 2224 boolean_t need_wakeup, result, user_unwire; 2225 2226 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2227 vm_map_lock(map); 2228 VM_MAP_RANGE_CHECK(map, start, end); 2229 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2230 if (flags & VM_MAP_WIRE_HOLESOK) 2231 first_entry = first_entry->next; 2232 else { 2233 vm_map_unlock(map); 2234 return (KERN_INVALID_ADDRESS); 2235 } 2236 } 2237 last_timestamp = map->timestamp; 2238 entry = first_entry; 2239 while (entry != &map->header && entry->start < end) { 2240 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2241 /* 2242 * We have not yet clipped the entry. 2243 */ 2244 saved_start = (start >= entry->start) ? start : 2245 entry->start; 2246 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2247 if (vm_map_unlock_and_wait(map, 0)) { 2248 /* 2249 * Allow interruption of user unwiring? 2250 */ 2251 } 2252 vm_map_lock(map); 2253 if (last_timestamp+1 != map->timestamp) { 2254 /* 2255 * Look again for the entry because the map was 2256 * modified while it was unlocked. 2257 * Specifically, the entry may have been 2258 * clipped, merged, or deleted. 2259 */ 2260 if (!vm_map_lookup_entry(map, saved_start, 2261 &tmp_entry)) { 2262 if (flags & VM_MAP_WIRE_HOLESOK) 2263 tmp_entry = tmp_entry->next; 2264 else { 2265 if (saved_start == start) { 2266 /* 2267 * First_entry has been deleted. 2268 */ 2269 vm_map_unlock(map); 2270 return (KERN_INVALID_ADDRESS); 2271 } 2272 end = saved_start; 2273 rv = KERN_INVALID_ADDRESS; 2274 goto done; 2275 } 2276 } 2277 if (entry == first_entry) 2278 first_entry = tmp_entry; 2279 else 2280 first_entry = NULL; 2281 entry = tmp_entry; 2282 } 2283 last_timestamp = map->timestamp; 2284 continue; 2285 } 2286 vm_map_clip_start(map, entry, start); 2287 vm_map_clip_end(map, entry, end); 2288 /* 2289 * Mark the entry in case the map lock is released. (See 2290 * above.) 2291 */ 2292 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2293 entry->wiring_thread = curthread; 2294 /* 2295 * Check the map for holes in the specified region. 2296 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2297 */ 2298 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2299 (entry->end < end && (entry->next == &map->header || 2300 entry->next->start > entry->end))) { 2301 end = entry->end; 2302 rv = KERN_INVALID_ADDRESS; 2303 goto done; 2304 } 2305 /* 2306 * If system unwiring, require that the entry is system wired. 2307 */ 2308 if (!user_unwire && 2309 vm_map_entry_system_wired_count(entry) == 0) { 2310 end = entry->end; 2311 rv = KERN_INVALID_ARGUMENT; 2312 goto done; 2313 } 2314 entry = entry->next; 2315 } 2316 rv = KERN_SUCCESS; 2317done: 2318 need_wakeup = FALSE; 2319 if (first_entry == NULL) { 2320 result = vm_map_lookup_entry(map, start, &first_entry); 2321 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2322 first_entry = first_entry->next; 2323 else 2324 KASSERT(result, ("vm_map_unwire: lookup failed")); 2325 } 2326 for (entry = first_entry; entry != &map->header && entry->start < end; 2327 entry = entry->next) { 2328 /* 2329 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2330 * space in the unwired region could have been mapped 2331 * while the map lock was dropped for draining 2332 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 2333 * could be simultaneously wiring this new mapping 2334 * entry. Detect these cases and skip any entries 2335 * marked as in transition by us. 2336 */ 2337 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2338 entry->wiring_thread != curthread) { 2339 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2340 ("vm_map_unwire: !HOLESOK and new/changed entry")); 2341 continue; 2342 } 2343 2344 if (rv == KERN_SUCCESS && (!user_unwire || 2345 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 2346 if (user_unwire) 2347 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2348 entry->wired_count--; 2349 if (entry->wired_count == 0) { 2350 /* 2351 * Retain the map lock. 2352 */ 2353 vm_fault_unwire(map, entry->start, entry->end, 2354 entry->object.vm_object != NULL && 2355 (entry->object.vm_object->flags & 2356 OBJ_FICTITIOUS) != 0); 2357 } 2358 } 2359 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2360 ("vm_map_unwire: in-transition flag missing")); 2361 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 2362 entry->wiring_thread = NULL; 2363 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2364 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2365 need_wakeup = TRUE; 2366 } 2367 vm_map_simplify_entry(map, entry); 2368 } 2369 vm_map_unlock(map); 2370 if (need_wakeup) 2371 vm_map_wakeup(map); 2372 return (rv); 2373} 2374 2375/* 2376 * vm_map_wire: 2377 * 2378 * Implements both kernel and user wiring. 2379 */ 2380int 2381vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, 2382 int flags) 2383{ 2384 vm_map_entry_t entry, first_entry, tmp_entry; 2385 vm_offset_t saved_end, saved_start; 2386 unsigned int last_timestamp; 2387 int rv; 2388 boolean_t fictitious, need_wakeup, result, user_wire; 2389 vm_prot_t prot; 2390 2391 prot = 0; 2392 if (flags & VM_MAP_WIRE_WRITE) 2393 prot |= VM_PROT_WRITE; 2394 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE; 2395 vm_map_lock(map); 2396 VM_MAP_RANGE_CHECK(map, start, end); 2397 if (!vm_map_lookup_entry(map, start, &first_entry)) { 2398 if (flags & VM_MAP_WIRE_HOLESOK) 2399 first_entry = first_entry->next; 2400 else { 2401 vm_map_unlock(map); 2402 return (KERN_INVALID_ADDRESS); 2403 } 2404 } 2405 last_timestamp = map->timestamp; 2406 entry = first_entry; 2407 while (entry != &map->header && entry->start < end) { 2408 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2409 /* 2410 * We have not yet clipped the entry. 2411 */ 2412 saved_start = (start >= entry->start) ? start : 2413 entry->start; 2414 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2415 if (vm_map_unlock_and_wait(map, 0)) { 2416 /* 2417 * Allow interruption of user wiring? 2418 */ 2419 } 2420 vm_map_lock(map); 2421 if (last_timestamp + 1 != map->timestamp) { 2422 /* 2423 * Look again for the entry because the map was 2424 * modified while it was unlocked. 2425 * Specifically, the entry may have been 2426 * clipped, merged, or deleted. 2427 */ 2428 if (!vm_map_lookup_entry(map, saved_start, 2429 &tmp_entry)) { 2430 if (flags & VM_MAP_WIRE_HOLESOK) 2431 tmp_entry = tmp_entry->next; 2432 else { 2433 if (saved_start == start) { 2434 /* 2435 * first_entry has been deleted. 2436 */ 2437 vm_map_unlock(map); 2438 return (KERN_INVALID_ADDRESS); 2439 } 2440 end = saved_start; 2441 rv = KERN_INVALID_ADDRESS; 2442 goto done; 2443 } 2444 } 2445 if (entry == first_entry) 2446 first_entry = tmp_entry; 2447 else 2448 first_entry = NULL; 2449 entry = tmp_entry; 2450 } 2451 last_timestamp = map->timestamp; 2452 continue; 2453 } 2454 vm_map_clip_start(map, entry, start); 2455 vm_map_clip_end(map, entry, end); 2456 /* 2457 * Mark the entry in case the map lock is released. (See 2458 * above.) 2459 */ 2460 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 2461 entry->wiring_thread = curthread; 2462 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 2463 || (entry->protection & prot) != prot) { 2464 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 2465 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) { 2466 end = entry->end; 2467 rv = KERN_INVALID_ADDRESS; 2468 goto done; 2469 } 2470 goto next_entry; 2471 } 2472 if (entry->wired_count == 0) { 2473 entry->wired_count++; 2474 saved_start = entry->start; 2475 saved_end = entry->end; 2476 fictitious = entry->object.vm_object != NULL && 2477 (entry->object.vm_object->flags & 2478 OBJ_FICTITIOUS) != 0; 2479 /* 2480 * Release the map lock, relying on the in-transition 2481 * mark. Mark the map busy for fork. 2482 */ 2483 vm_map_busy(map); 2484 vm_map_unlock(map); 2485 rv = vm_fault_wire(map, saved_start, saved_end, 2486 fictitious); 2487 vm_map_lock(map); 2488 vm_map_unbusy(map); 2489 if (last_timestamp + 1 != map->timestamp) { 2490 /* 2491 * Look again for the entry because the map was 2492 * modified while it was unlocked. The entry 2493 * may have been clipped, but NOT merged or 2494 * deleted. 2495 */ 2496 result = vm_map_lookup_entry(map, saved_start, 2497 &tmp_entry); 2498 KASSERT(result, ("vm_map_wire: lookup failed")); 2499 if (entry == first_entry) 2500 first_entry = tmp_entry; 2501 else 2502 first_entry = NULL; 2503 entry = tmp_entry; 2504 while (entry->end < saved_end) { 2505 if (rv != KERN_SUCCESS) { 2506 KASSERT(entry->wired_count == 1, 2507 ("vm_map_wire: bad count")); 2508 entry->wired_count = -1; 2509 } 2510 entry = entry->next; 2511 } 2512 } 2513 last_timestamp = map->timestamp; 2514 if (rv != KERN_SUCCESS) { 2515 KASSERT(entry->wired_count == 1, 2516 ("vm_map_wire: bad count")); 2517 /* 2518 * Assign an out-of-range value to represent 2519 * the failure to wire this entry. 2520 */ 2521 entry->wired_count = -1; 2522 end = entry->end; 2523 goto done; 2524 } 2525 } else if (!user_wire || 2526 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2527 entry->wired_count++; 2528 } 2529 /* 2530 * Check the map for holes in the specified region. 2531 * If VM_MAP_WIRE_HOLESOK was specified, skip this check. 2532 */ 2533 next_entry: 2534 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) && 2535 (entry->end < end && (entry->next == &map->header || 2536 entry->next->start > entry->end))) { 2537 end = entry->end; 2538 rv = KERN_INVALID_ADDRESS; 2539 goto done; 2540 } 2541 entry = entry->next; 2542 } 2543 rv = KERN_SUCCESS; 2544done: 2545 need_wakeup = FALSE; 2546 if (first_entry == NULL) { 2547 result = vm_map_lookup_entry(map, start, &first_entry); 2548 if (!result && (flags & VM_MAP_WIRE_HOLESOK)) 2549 first_entry = first_entry->next; 2550 else 2551 KASSERT(result, ("vm_map_wire: lookup failed")); 2552 } 2553 for (entry = first_entry; entry != &map->header && entry->start < end; 2554 entry = entry->next) { 2555 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) 2556 goto next_entry_done; 2557 2558 /* 2559 * If VM_MAP_WIRE_HOLESOK was specified, an empty 2560 * space in the unwired region could have been mapped 2561 * while the map lock was dropped for faulting in the 2562 * pages or draining MAP_ENTRY_IN_TRANSITION. 2563 * Moreover, another thread could be simultaneously 2564 * wiring this new mapping entry. Detect these cases 2565 * and skip any entries marked as in transition by us. 2566 */ 2567 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 2568 entry->wiring_thread != curthread) { 2569 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0, 2570 ("vm_map_wire: !HOLESOK and new/changed entry")); 2571 continue; 2572 } 2573 2574 if (rv == KERN_SUCCESS) { 2575 if (user_wire) 2576 entry->eflags |= MAP_ENTRY_USER_WIRED; 2577 } else if (entry->wired_count == -1) { 2578 /* 2579 * Wiring failed on this entry. Thus, unwiring is 2580 * unnecessary. 2581 */ 2582 entry->wired_count = 0; 2583 } else { 2584 if (!user_wire || 2585 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) 2586 entry->wired_count--; 2587 if (entry->wired_count == 0) { 2588 /* 2589 * Retain the map lock. 2590 */ 2591 vm_fault_unwire(map, entry->start, entry->end, 2592 entry->object.vm_object != NULL && 2593 (entry->object.vm_object->flags & 2594 OBJ_FICTITIOUS) != 0); 2595 } 2596 } 2597 next_entry_done: 2598 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 2599 ("vm_map_wire: in-transition flag missing %p", entry)); 2600 KASSERT(entry->wiring_thread == curthread, 2601 ("vm_map_wire: alien wire %p", entry)); 2602 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 2603 MAP_ENTRY_WIRE_SKIPPED); 2604 entry->wiring_thread = NULL; 2605 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 2606 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 2607 need_wakeup = TRUE; 2608 } 2609 vm_map_simplify_entry(map, entry); 2610 } 2611 vm_map_unlock(map); 2612 if (need_wakeup) 2613 vm_map_wakeup(map); 2614 return (rv); 2615} 2616 2617/* 2618 * vm_map_sync 2619 * 2620 * Push any dirty cached pages in the address range to their pager. 2621 * If syncio is TRUE, dirty pages are written synchronously. 2622 * If invalidate is TRUE, any cached pages are freed as well. 2623 * 2624 * If the size of the region from start to end is zero, we are 2625 * supposed to flush all modified pages within the region containing 2626 * start. Unfortunately, a region can be split or coalesced with 2627 * neighboring regions, making it difficult to determine what the 2628 * original region was. Therefore, we approximate this requirement by 2629 * flushing the current region containing start. 2630 * 2631 * Returns an error if any part of the specified range is not mapped. 2632 */ 2633int 2634vm_map_sync( 2635 vm_map_t map, 2636 vm_offset_t start, 2637 vm_offset_t end, 2638 boolean_t syncio, 2639 boolean_t invalidate) 2640{ 2641 vm_map_entry_t current; 2642 vm_map_entry_t entry; 2643 vm_size_t size; 2644 vm_object_t object; 2645 vm_ooffset_t offset; 2646 unsigned int last_timestamp; 2647 boolean_t failed; 2648 2649 vm_map_lock_read(map); 2650 VM_MAP_RANGE_CHECK(map, start, end); 2651 if (!vm_map_lookup_entry(map, start, &entry)) { 2652 vm_map_unlock_read(map); 2653 return (KERN_INVALID_ADDRESS); 2654 } else if (start == end) { 2655 start = entry->start; 2656 end = entry->end; 2657 } 2658 /* 2659 * Make a first pass to check for user-wired memory and holes. 2660 */ 2661 for (current = entry; current != &map->header && current->start < end; 2662 current = current->next) { 2663 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) { 2664 vm_map_unlock_read(map); 2665 return (KERN_INVALID_ARGUMENT); 2666 } 2667 if (end > current->end && 2668 (current->next == &map->header || 2669 current->end != current->next->start)) { 2670 vm_map_unlock_read(map); 2671 return (KERN_INVALID_ADDRESS); 2672 } 2673 } 2674 2675 if (invalidate) 2676 pmap_remove(map->pmap, start, end); 2677 failed = FALSE; 2678 2679 /* 2680 * Make a second pass, cleaning/uncaching pages from the indicated 2681 * objects as we go. 2682 */ 2683 for (current = entry; current != &map->header && current->start < end;) { 2684 offset = current->offset + (start - current->start); 2685 size = (end <= current->end ? end : current->end) - start; 2686 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2687 vm_map_t smap; 2688 vm_map_entry_t tentry; 2689 vm_size_t tsize; 2690 2691 smap = current->object.sub_map; 2692 vm_map_lock_read(smap); 2693 (void) vm_map_lookup_entry(smap, offset, &tentry); 2694 tsize = tentry->end - offset; 2695 if (tsize < size) 2696 size = tsize; 2697 object = tentry->object.vm_object; 2698 offset = tentry->offset + (offset - tentry->start); 2699 vm_map_unlock_read(smap); 2700 } else { 2701 object = current->object.vm_object; 2702 } 2703 vm_object_reference(object); 2704 last_timestamp = map->timestamp; 2705 vm_map_unlock_read(map); 2706 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 2707 failed = TRUE; 2708 start += size; 2709 vm_object_deallocate(object); 2710 vm_map_lock_read(map); 2711 if (last_timestamp == map->timestamp || 2712 !vm_map_lookup_entry(map, start, ¤t)) 2713 current = current->next; 2714 } 2715 2716 vm_map_unlock_read(map); 2717 return (failed ? KERN_FAILURE : KERN_SUCCESS); 2718} 2719 2720/* 2721 * vm_map_entry_unwire: [ internal use only ] 2722 * 2723 * Make the region specified by this entry pageable. 2724 * 2725 * The map in question should be locked. 2726 * [This is the reason for this routine's existence.] 2727 */ 2728static void 2729vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2730{ 2731 vm_fault_unwire(map, entry->start, entry->end, 2732 entry->object.vm_object != NULL && 2733 (entry->object.vm_object->flags & OBJ_FICTITIOUS) != 0); 2734 entry->wired_count = 0; 2735} 2736 2737static void 2738vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 2739{ 2740 2741 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 2742 vm_object_deallocate(entry->object.vm_object); 2743 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 2744} 2745 2746/* 2747 * vm_map_entry_delete: [ internal use only ] 2748 * 2749 * Deallocate the given entry from the target map. 2750 */ 2751static void 2752vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 2753{ 2754 vm_object_t object; 2755 vm_pindex_t offidxstart, offidxend, count, size1; 2756 vm_ooffset_t size; 2757 2758 vm_map_entry_unlink(map, entry); 2759 object = entry->object.vm_object; 2760 size = entry->end - entry->start; 2761 map->size -= size; 2762 2763 if (entry->cred != NULL) { 2764 swap_release_by_cred(size, entry->cred); 2765 crfree(entry->cred); 2766 } 2767 2768 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 2769 (object != NULL)) { 2770 KASSERT(entry->cred == NULL || object->cred == NULL || 2771 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 2772 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 2773 count = OFF_TO_IDX(size); 2774 offidxstart = OFF_TO_IDX(entry->offset); 2775 offidxend = offidxstart + count; 2776 VM_OBJECT_WLOCK(object); 2777 if (object->ref_count != 1 && 2778 ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING || 2779 object == kernel_object || object == kmem_object)) { 2780 vm_object_collapse(object); 2781 2782 /* 2783 * The option OBJPR_NOTMAPPED can be passed here 2784 * because vm_map_delete() already performed 2785 * pmap_remove() on the only mapping to this range 2786 * of pages. 2787 */ 2788 vm_object_page_remove(object, offidxstart, offidxend, 2789 OBJPR_NOTMAPPED); 2790 if (object->type == OBJT_SWAP) 2791 swap_pager_freespace(object, offidxstart, count); 2792 if (offidxend >= object->size && 2793 offidxstart < object->size) { 2794 size1 = object->size; 2795 object->size = offidxstart; 2796 if (object->cred != NULL) { 2797 size1 -= object->size; 2798 KASSERT(object->charge >= ptoa(size1), 2799 ("vm_map_entry_delete: object->charge < 0")); 2800 swap_release_by_cred(ptoa(size1), object->cred); 2801 object->charge -= ptoa(size1); 2802 } 2803 } 2804 } 2805 VM_OBJECT_WUNLOCK(object); 2806 } else 2807 entry->object.vm_object = NULL; 2808 if (map->system_map) 2809 vm_map_entry_deallocate(entry, TRUE); 2810 else { 2811 entry->next = curthread->td_map_def_user; 2812 curthread->td_map_def_user = entry; 2813 } 2814} 2815 2816/* 2817 * vm_map_delete: [ internal use only ] 2818 * 2819 * Deallocates the given address range from the target 2820 * map. 2821 */ 2822int 2823vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 2824{ 2825 vm_map_entry_t entry; 2826 vm_map_entry_t first_entry; 2827 2828 VM_MAP_ASSERT_LOCKED(map); 2829 2830 /* 2831 * Find the start of the region, and clip it 2832 */ 2833 if (!vm_map_lookup_entry(map, start, &first_entry)) 2834 entry = first_entry->next; 2835 else { 2836 entry = first_entry; 2837 vm_map_clip_start(map, entry, start); 2838 } 2839 2840 /* 2841 * Step through all entries in this region 2842 */ 2843 while ((entry != &map->header) && (entry->start < end)) { 2844 vm_map_entry_t next; 2845 2846 /* 2847 * Wait for wiring or unwiring of an entry to complete. 2848 * Also wait for any system wirings to disappear on 2849 * user maps. 2850 */ 2851 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 2852 (vm_map_pmap(map) != kernel_pmap && 2853 vm_map_entry_system_wired_count(entry) != 0)) { 2854 unsigned int last_timestamp; 2855 vm_offset_t saved_start; 2856 vm_map_entry_t tmp_entry; 2857 2858 saved_start = entry->start; 2859 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2860 last_timestamp = map->timestamp; 2861 (void) vm_map_unlock_and_wait(map, 0); 2862 vm_map_lock(map); 2863 if (last_timestamp + 1 != map->timestamp) { 2864 /* 2865 * Look again for the entry because the map was 2866 * modified while it was unlocked. 2867 * Specifically, the entry may have been 2868 * clipped, merged, or deleted. 2869 */ 2870 if (!vm_map_lookup_entry(map, saved_start, 2871 &tmp_entry)) 2872 entry = tmp_entry->next; 2873 else { 2874 entry = tmp_entry; 2875 vm_map_clip_start(map, entry, 2876 saved_start); 2877 } 2878 } 2879 continue; 2880 } 2881 vm_map_clip_end(map, entry, end); 2882 2883 next = entry->next; 2884 2885 /* 2886 * Unwire before removing addresses from the pmap; otherwise, 2887 * unwiring will put the entries back in the pmap. 2888 */ 2889 if (entry->wired_count != 0) { 2890 vm_map_entry_unwire(map, entry); 2891 } 2892 2893 pmap_remove(map->pmap, entry->start, entry->end); 2894 2895 /* 2896 * Delete the entry only after removing all pmap 2897 * entries pointing to its pages. (Otherwise, its 2898 * page frames may be reallocated, and any modify bits 2899 * will be set in the wrong object!) 2900 */ 2901 vm_map_entry_delete(map, entry); 2902 entry = next; 2903 } 2904 return (KERN_SUCCESS); 2905} 2906 2907/* 2908 * vm_map_remove: 2909 * 2910 * Remove the given address range from the target map. 2911 * This is the exported form of vm_map_delete. 2912 */ 2913int 2914vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2915{ 2916 int result; 2917 2918 vm_map_lock(map); 2919 VM_MAP_RANGE_CHECK(map, start, end); 2920 result = vm_map_delete(map, start, end); 2921 vm_map_unlock(map); 2922 return (result); 2923} 2924 2925/* 2926 * vm_map_check_protection: 2927 * 2928 * Assert that the target map allows the specified privilege on the 2929 * entire address region given. The entire region must be allocated. 2930 * 2931 * WARNING! This code does not and should not check whether the 2932 * contents of the region is accessible. For example a smaller file 2933 * might be mapped into a larger address space. 2934 * 2935 * NOTE! This code is also called by munmap(). 2936 * 2937 * The map must be locked. A read lock is sufficient. 2938 */ 2939boolean_t 2940vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2941 vm_prot_t protection) 2942{ 2943 vm_map_entry_t entry; 2944 vm_map_entry_t tmp_entry; 2945 2946 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 2947 return (FALSE); 2948 entry = tmp_entry; 2949 2950 while (start < end) { 2951 if (entry == &map->header) 2952 return (FALSE); 2953 /* 2954 * No holes allowed! 2955 */ 2956 if (start < entry->start) 2957 return (FALSE); 2958 /* 2959 * Check protection associated with entry. 2960 */ 2961 if ((entry->protection & protection) != protection) 2962 return (FALSE); 2963 /* go to next entry */ 2964 start = entry->end; 2965 entry = entry->next; 2966 } 2967 return (TRUE); 2968} 2969 2970/* 2971 * vm_map_copy_entry: 2972 * 2973 * Copies the contents of the source entry to the destination 2974 * entry. The entries *must* be aligned properly. 2975 */ 2976static void 2977vm_map_copy_entry( 2978 vm_map_t src_map, 2979 vm_map_t dst_map, 2980 vm_map_entry_t src_entry, 2981 vm_map_entry_t dst_entry, 2982 vm_ooffset_t *fork_charge) 2983{ 2984 vm_object_t src_object; 2985 vm_map_entry_t fake_entry; 2986 vm_offset_t size; 2987 struct ucred *cred; 2988 int charged; 2989 2990 VM_MAP_ASSERT_LOCKED(dst_map); 2991 2992 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 2993 return; 2994 2995 if (src_entry->wired_count == 0) { 2996 2997 /* 2998 * If the source entry is marked needs_copy, it is already 2999 * write-protected. 3000 */ 3001 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 3002 pmap_protect(src_map->pmap, 3003 src_entry->start, 3004 src_entry->end, 3005 src_entry->protection & ~VM_PROT_WRITE); 3006 } 3007 3008 /* 3009 * Make a copy of the object. 3010 */ 3011 size = src_entry->end - src_entry->start; 3012 if ((src_object = src_entry->object.vm_object) != NULL) { 3013 VM_OBJECT_WLOCK(src_object); 3014 charged = ENTRY_CHARGED(src_entry); 3015 if ((src_object->handle == NULL) && 3016 (src_object->type == OBJT_DEFAULT || 3017 src_object->type == OBJT_SWAP)) { 3018 vm_object_collapse(src_object); 3019 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 3020 vm_object_split(src_entry); 3021 src_object = src_entry->object.vm_object; 3022 } 3023 } 3024 vm_object_reference_locked(src_object); 3025 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3026 if (src_entry->cred != NULL && 3027 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3028 KASSERT(src_object->cred == NULL, 3029 ("OVERCOMMIT: vm_map_copy_entry: cred %p", 3030 src_object)); 3031 src_object->cred = src_entry->cred; 3032 src_object->charge = size; 3033 } 3034 VM_OBJECT_WUNLOCK(src_object); 3035 dst_entry->object.vm_object = src_object; 3036 if (charged) { 3037 cred = curthread->td_ucred; 3038 crhold(cred); 3039 dst_entry->cred = cred; 3040 *fork_charge += size; 3041 if (!(src_entry->eflags & 3042 MAP_ENTRY_NEEDS_COPY)) { 3043 crhold(cred); 3044 src_entry->cred = cred; 3045 *fork_charge += size; 3046 } 3047 } 3048 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3049 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 3050 dst_entry->offset = src_entry->offset; 3051 if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3052 /* 3053 * MAP_ENTRY_VN_WRITECNT cannot 3054 * indicate write reference from 3055 * src_entry, since the entry is 3056 * marked as needs copy. Allocate a 3057 * fake entry that is used to 3058 * decrement object->un_pager.vnp.writecount 3059 * at the appropriate time. Attach 3060 * fake_entry to the deferred list. 3061 */ 3062 fake_entry = vm_map_entry_create(dst_map); 3063 fake_entry->eflags = MAP_ENTRY_VN_WRITECNT; 3064 src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT; 3065 vm_object_reference(src_object); 3066 fake_entry->object.vm_object = src_object; 3067 fake_entry->start = src_entry->start; 3068 fake_entry->end = src_entry->end; 3069 fake_entry->next = curthread->td_map_def_user; 3070 curthread->td_map_def_user = fake_entry; 3071 } 3072 } else { 3073 dst_entry->object.vm_object = NULL; 3074 dst_entry->offset = 0; 3075 if (src_entry->cred != NULL) { 3076 dst_entry->cred = curthread->td_ucred; 3077 crhold(dst_entry->cred); 3078 *fork_charge += size; 3079 } 3080 } 3081 3082 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3083 dst_entry->end - dst_entry->start, src_entry->start); 3084 } else { 3085 /* 3086 * Of course, wired down pages can't be set copy-on-write. 3087 * Cause wired pages to be copied into the new map by 3088 * simulating faults (the new pages are pageable) 3089 */ 3090 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 3091 fork_charge); 3092 } 3093} 3094 3095/* 3096 * vmspace_map_entry_forked: 3097 * Update the newly-forked vmspace each time a map entry is inherited 3098 * or copied. The values for vm_dsize and vm_tsize are approximate 3099 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 3100 */ 3101static void 3102vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 3103 vm_map_entry_t entry) 3104{ 3105 vm_size_t entrysize; 3106 vm_offset_t newend; 3107 3108 entrysize = entry->end - entry->start; 3109 vm2->vm_map.size += entrysize; 3110 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 3111 vm2->vm_ssize += btoc(entrysize); 3112 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 3113 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 3114 newend = MIN(entry->end, 3115 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 3116 vm2->vm_dsize += btoc(newend - entry->start); 3117 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 3118 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 3119 newend = MIN(entry->end, 3120 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 3121 vm2->vm_tsize += btoc(newend - entry->start); 3122 } 3123} 3124 3125/* 3126 * vmspace_fork: 3127 * Create a new process vmspace structure and vm_map 3128 * based on those of an existing process. The new map 3129 * is based on the old map, according to the inheritance 3130 * values on the regions in that map. 3131 * 3132 * XXX It might be worth coalescing the entries added to the new vmspace. 3133 * 3134 * The source map must not be locked. 3135 */ 3136struct vmspace * 3137vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 3138{ 3139 struct vmspace *vm2; 3140 vm_map_t new_map, old_map; 3141 vm_map_entry_t new_entry, old_entry; 3142 vm_object_t object; 3143 int locked; 3144 3145 old_map = &vm1->vm_map; 3146 /* Copy immutable fields of vm1 to vm2. */ 3147 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL); 3148 if (vm2 == NULL) 3149 return (NULL); 3150 vm2->vm_taddr = vm1->vm_taddr; 3151 vm2->vm_daddr = vm1->vm_daddr; 3152 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 3153 vm_map_lock(old_map); 3154 if (old_map->busy) 3155 vm_map_wait_busy(old_map); 3156 new_map = &vm2->vm_map; 3157 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 3158 KASSERT(locked, ("vmspace_fork: lock failed")); 3159 3160 old_entry = old_map->header.next; 3161 3162 while (old_entry != &old_map->header) { 3163 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 3164 panic("vm_map_fork: encountered a submap"); 3165 3166 switch (old_entry->inheritance) { 3167 case VM_INHERIT_NONE: 3168 break; 3169 3170 case VM_INHERIT_SHARE: 3171 /* 3172 * Clone the entry, creating the shared object if necessary. 3173 */ 3174 object = old_entry->object.vm_object; 3175 if (object == NULL) { 3176 object = vm_object_allocate(OBJT_DEFAULT, 3177 atop(old_entry->end - old_entry->start)); 3178 old_entry->object.vm_object = object; 3179 old_entry->offset = 0; 3180 if (old_entry->cred != NULL) { 3181 object->cred = old_entry->cred; 3182 object->charge = old_entry->end - 3183 old_entry->start; 3184 old_entry->cred = NULL; 3185 } 3186 } 3187 3188 /* 3189 * Add the reference before calling vm_object_shadow 3190 * to insure that a shadow object is created. 3191 */ 3192 vm_object_reference(object); 3193 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3194 vm_object_shadow(&old_entry->object.vm_object, 3195 &old_entry->offset, 3196 old_entry->end - old_entry->start); 3197 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3198 /* Transfer the second reference too. */ 3199 vm_object_reference( 3200 old_entry->object.vm_object); 3201 3202 /* 3203 * As in vm_map_simplify_entry(), the 3204 * vnode lock will not be acquired in 3205 * this call to vm_object_deallocate(). 3206 */ 3207 vm_object_deallocate(object); 3208 object = old_entry->object.vm_object; 3209 } 3210 VM_OBJECT_WLOCK(object); 3211 vm_object_clear_flag(object, OBJ_ONEMAPPING); 3212 if (old_entry->cred != NULL) { 3213 KASSERT(object->cred == NULL, ("vmspace_fork both cred")); 3214 object->cred = old_entry->cred; 3215 object->charge = old_entry->end - old_entry->start; 3216 old_entry->cred = NULL; 3217 } 3218 3219 /* 3220 * Assert the correct state of the vnode 3221 * v_writecount while the object is locked, to 3222 * not relock it later for the assertion 3223 * correctness. 3224 */ 3225 if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT && 3226 object->type == OBJT_VNODE) { 3227 KASSERT(((struct vnode *)object->handle)-> 3228 v_writecount > 0, 3229 ("vmspace_fork: v_writecount %p", object)); 3230 KASSERT(object->un_pager.vnp.writemappings > 0, 3231 ("vmspace_fork: vnp.writecount %p", 3232 object)); 3233 } 3234 VM_OBJECT_WUNLOCK(object); 3235 3236 /* 3237 * Clone the entry, referencing the shared object. 3238 */ 3239 new_entry = vm_map_entry_create(new_map); 3240 *new_entry = *old_entry; 3241 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3242 MAP_ENTRY_IN_TRANSITION); 3243 new_entry->wiring_thread = NULL; 3244 new_entry->wired_count = 0; 3245 if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) { 3246 vnode_pager_update_writecount(object, 3247 new_entry->start, new_entry->end); 3248 } 3249 3250 /* 3251 * Insert the entry into the new map -- we know we're 3252 * inserting at the end of the new map. 3253 */ 3254 vm_map_entry_link(new_map, new_map->header.prev, 3255 new_entry); 3256 vmspace_map_entry_forked(vm1, vm2, new_entry); 3257 3258 /* 3259 * Update the physical map 3260 */ 3261 pmap_copy(new_map->pmap, old_map->pmap, 3262 new_entry->start, 3263 (old_entry->end - old_entry->start), 3264 old_entry->start); 3265 break; 3266 3267 case VM_INHERIT_COPY: 3268 /* 3269 * Clone the entry and link into the map. 3270 */ 3271 new_entry = vm_map_entry_create(new_map); 3272 *new_entry = *old_entry; 3273 /* 3274 * Copied entry is COW over the old object. 3275 */ 3276 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 3277 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT); 3278 new_entry->wiring_thread = NULL; 3279 new_entry->wired_count = 0; 3280 new_entry->object.vm_object = NULL; 3281 new_entry->cred = NULL; 3282 vm_map_entry_link(new_map, new_map->header.prev, 3283 new_entry); 3284 vmspace_map_entry_forked(vm1, vm2, new_entry); 3285 vm_map_copy_entry(old_map, new_map, old_entry, 3286 new_entry, fork_charge); 3287 break; 3288 } 3289 old_entry = old_entry->next; 3290 } 3291 /* 3292 * Use inlined vm_map_unlock() to postpone handling the deferred 3293 * map entries, which cannot be done until both old_map and 3294 * new_map locks are released. 3295 */ 3296 sx_xunlock(&old_map->lock); 3297 sx_xunlock(&new_map->lock); 3298 vm_map_process_deferred(); 3299 3300 return (vm2); 3301} 3302 3303int 3304vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3305 vm_prot_t prot, vm_prot_t max, int cow) 3306{ 3307 vm_map_entry_t new_entry, prev_entry; 3308 vm_offset_t bot, top; 3309 vm_size_t growsize, init_ssize; 3310 int orient, rv; 3311 rlim_t lmemlim, vmemlim; 3312 3313 /* 3314 * The stack orientation is piggybacked with the cow argument. 3315 * Extract it into orient and mask the cow argument so that we 3316 * don't pass it around further. 3317 * NOTE: We explicitly allow bi-directional stacks. 3318 */ 3319 orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); 3320 KASSERT(orient != 0, ("No stack grow direction")); 3321 3322 if (addrbos < vm_map_min(map) || 3323 addrbos > vm_map_max(map) || 3324 addrbos + max_ssize < addrbos) 3325 return (KERN_NO_SPACE); 3326 3327 growsize = sgrowsiz; 3328 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 3329 3330 PROC_LOCK(curproc); 3331 lmemlim = lim_cur(curproc, RLIMIT_MEMLOCK); 3332 vmemlim = lim_cur(curproc, RLIMIT_VMEM); 3333 PROC_UNLOCK(curproc); 3334 3335 vm_map_lock(map); 3336 3337 /* If addr is already mapped, no go */ 3338 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3339 vm_map_unlock(map); 3340 return (KERN_NO_SPACE); 3341 } 3342 3343 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3344 if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) { 3345 vm_map_unlock(map); 3346 return (KERN_NO_SPACE); 3347 } 3348 } 3349 3350 /* If we would blow our VMEM resource limit, no go */ 3351 if (map->size + init_ssize > vmemlim) { 3352 vm_map_unlock(map); 3353 return (KERN_NO_SPACE); 3354 } 3355 3356 /* 3357 * If we can't accomodate max_ssize in the current mapping, no go. 3358 * However, we need to be aware that subsequent user mappings might 3359 * map into the space we have reserved for stack, and currently this 3360 * space is not protected. 3361 * 3362 * Hopefully we will at least detect this condition when we try to 3363 * grow the stack. 3364 */ 3365 if ((prev_entry->next != &map->header) && 3366 (prev_entry->next->start < addrbos + max_ssize)) { 3367 vm_map_unlock(map); 3368 return (KERN_NO_SPACE); 3369 } 3370 3371 /* 3372 * We initially map a stack of only init_ssize. We will grow as 3373 * needed later. Depending on the orientation of the stack (i.e. 3374 * the grow direction) we either map at the top of the range, the 3375 * bottom of the range or in the middle. 3376 * 3377 * Note: we would normally expect prot and max to be VM_PROT_ALL, 3378 * and cow to be 0. Possibly we should eliminate these as input 3379 * parameters, and just pass these values here in the insert call. 3380 */ 3381 if (orient == MAP_STACK_GROWS_DOWN) 3382 bot = addrbos + max_ssize - init_ssize; 3383 else if (orient == MAP_STACK_GROWS_UP) 3384 bot = addrbos; 3385 else 3386 bot = round_page(addrbos + max_ssize/2 - init_ssize/2); 3387 top = bot + init_ssize; 3388 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 3389 3390 /* Now set the avail_ssize amount. */ 3391 if (rv == KERN_SUCCESS) { 3392 if (prev_entry != &map->header) 3393 vm_map_clip_end(map, prev_entry, bot); 3394 new_entry = prev_entry->next; 3395 if (new_entry->end != top || new_entry->start != bot) 3396 panic("Bad entry start/end for new stack entry"); 3397 3398 new_entry->avail_ssize = max_ssize - init_ssize; 3399 if (orient & MAP_STACK_GROWS_DOWN) 3400 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3401 if (orient & MAP_STACK_GROWS_UP) 3402 new_entry->eflags |= MAP_ENTRY_GROWS_UP; 3403 } 3404 3405 vm_map_unlock(map); 3406 return (rv); 3407} 3408 3409static int stack_guard_page = 0; 3410TUNABLE_INT("security.bsd.stack_guard_page", &stack_guard_page); 3411SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RW, 3412 &stack_guard_page, 0, 3413 "Insert stack guard page ahead of the growable segments."); 3414 3415/* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3416 * desired address is already mapped, or if we successfully grow 3417 * the stack. Also returns KERN_SUCCESS if addr is outside the 3418 * stack range (this is strange, but preserves compatibility with 3419 * the grow function in vm_machdep.c). 3420 */ 3421int 3422vm_map_growstack(struct proc *p, vm_offset_t addr) 3423{ 3424 vm_map_entry_t next_entry, prev_entry; 3425 vm_map_entry_t new_entry, stack_entry; 3426 struct vmspace *vm = p->p_vmspace; 3427 vm_map_t map = &vm->vm_map; 3428 vm_offset_t end; 3429 vm_size_t growsize; 3430 size_t grow_amount, max_grow; 3431 rlim_t lmemlim, stacklim, vmemlim; 3432 int is_procstack, rv; 3433 struct ucred *cred; 3434#ifdef notyet 3435 uint64_t limit; 3436#endif 3437#ifdef RACCT 3438 int error; 3439#endif 3440 3441Retry: 3442 PROC_LOCK(p); 3443 lmemlim = lim_cur(p, RLIMIT_MEMLOCK); 3444 stacklim = lim_cur(p, RLIMIT_STACK); 3445 vmemlim = lim_cur(p, RLIMIT_VMEM); 3446 PROC_UNLOCK(p); 3447 3448 vm_map_lock_read(map); 3449 3450 /* If addr is already in the entry range, no need to grow.*/ 3451 if (vm_map_lookup_entry(map, addr, &prev_entry)) { 3452 vm_map_unlock_read(map); 3453 return (KERN_SUCCESS); 3454 } 3455 3456 next_entry = prev_entry->next; 3457 if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) { 3458 /* 3459 * This entry does not grow upwards. Since the address lies 3460 * beyond this entry, the next entry (if one exists) has to 3461 * be a downward growable entry. The entry list header is 3462 * never a growable entry, so it suffices to check the flags. 3463 */ 3464 if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) { 3465 vm_map_unlock_read(map); 3466 return (KERN_SUCCESS); 3467 } 3468 stack_entry = next_entry; 3469 } else { 3470 /* 3471 * This entry grows upward. If the next entry does not at 3472 * least grow downwards, this is the entry we need to grow. 3473 * otherwise we have two possible choices and we have to 3474 * select one. 3475 */ 3476 if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) { 3477 /* 3478 * We have two choices; grow the entry closest to 3479 * the address to minimize the amount of growth. 3480 */ 3481 if (addr - prev_entry->end <= next_entry->start - addr) 3482 stack_entry = prev_entry; 3483 else 3484 stack_entry = next_entry; 3485 } else 3486 stack_entry = prev_entry; 3487 } 3488 3489 if (stack_entry == next_entry) { 3490 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo")); 3491 KASSERT(addr < stack_entry->start, ("foo")); 3492 end = (prev_entry != &map->header) ? prev_entry->end : 3493 stack_entry->start - stack_entry->avail_ssize; 3494 grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE); 3495 max_grow = stack_entry->start - end; 3496 } else { 3497 KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo")); 3498 KASSERT(addr >= stack_entry->end, ("foo")); 3499 end = (next_entry != &map->header) ? next_entry->start : 3500 stack_entry->end + stack_entry->avail_ssize; 3501 grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); 3502 max_grow = end - stack_entry->end; 3503 } 3504 3505 if (grow_amount > stack_entry->avail_ssize) { 3506 vm_map_unlock_read(map); 3507 return (KERN_NO_SPACE); 3508 } 3509 3510 /* 3511 * If there is no longer enough space between the entries nogo, and 3512 * adjust the available space. Note: this should only happen if the 3513 * user has mapped into the stack area after the stack was created, 3514 * and is probably an error. 3515 * 3516 * This also effectively destroys any guard page the user might have 3517 * intended by limiting the stack size. 3518 */ 3519 if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) { 3520 if (vm_map_lock_upgrade(map)) 3521 goto Retry; 3522 3523 stack_entry->avail_ssize = max_grow; 3524 3525 vm_map_unlock(map); 3526 return (KERN_NO_SPACE); 3527 } 3528 3529 is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0; 3530 3531 /* 3532 * If this is the main process stack, see if we're over the stack 3533 * limit. 3534 */ 3535 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3536 vm_map_unlock_read(map); 3537 return (KERN_NO_SPACE); 3538 } 3539#ifdef RACCT 3540 PROC_LOCK(p); 3541 if (is_procstack && 3542 racct_set(p, RACCT_STACK, ctob(vm->vm_ssize) + grow_amount)) { 3543 PROC_UNLOCK(p); 3544 vm_map_unlock_read(map); 3545 return (KERN_NO_SPACE); 3546 } 3547 PROC_UNLOCK(p); 3548#endif 3549 3550 /* Round up the grow amount modulo sgrowsiz */ 3551 growsize = sgrowsiz; 3552 grow_amount = roundup(grow_amount, growsize); 3553 if (grow_amount > stack_entry->avail_ssize) 3554 grow_amount = stack_entry->avail_ssize; 3555 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 3556 grow_amount = trunc_page((vm_size_t)stacklim) - 3557 ctob(vm->vm_ssize); 3558 } 3559#ifdef notyet 3560 PROC_LOCK(p); 3561 limit = racct_get_available(p, RACCT_STACK); 3562 PROC_UNLOCK(p); 3563 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 3564 grow_amount = limit - ctob(vm->vm_ssize); 3565#endif 3566 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 3567 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 3568 vm_map_unlock_read(map); 3569 rv = KERN_NO_SPACE; 3570 goto out; 3571 } 3572#ifdef RACCT 3573 PROC_LOCK(p); 3574 if (racct_set(p, RACCT_MEMLOCK, 3575 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 3576 PROC_UNLOCK(p); 3577 vm_map_unlock_read(map); 3578 rv = KERN_NO_SPACE; 3579 goto out; 3580 } 3581 PROC_UNLOCK(p); 3582#endif 3583 } 3584 /* If we would blow our VMEM resource limit, no go */ 3585 if (map->size + grow_amount > vmemlim) { 3586 vm_map_unlock_read(map); 3587 rv = KERN_NO_SPACE; 3588 goto out; 3589 } 3590#ifdef RACCT 3591 PROC_LOCK(p); 3592 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 3593 PROC_UNLOCK(p); 3594 vm_map_unlock_read(map); 3595 rv = KERN_NO_SPACE; 3596 goto out; 3597 } 3598 PROC_UNLOCK(p); 3599#endif 3600 3601 if (vm_map_lock_upgrade(map)) 3602 goto Retry; 3603 3604 if (stack_entry == next_entry) { 3605 /* 3606 * Growing downward. 3607 */ 3608 /* Get the preliminary new entry start value */ 3609 addr = stack_entry->start - grow_amount; 3610 3611 /* 3612 * If this puts us into the previous entry, cut back our 3613 * growth to the available space. Also, see the note above. 3614 */ 3615 if (addr < end) { 3616 stack_entry->avail_ssize = max_grow; 3617 addr = end; 3618 if (stack_guard_page) 3619 addr += PAGE_SIZE; 3620 } 3621 3622 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start, 3623 next_entry->protection, next_entry->max_protection, 0); 3624 3625 /* Adjust the available stack space by the amount we grew. */ 3626 if (rv == KERN_SUCCESS) { 3627 if (prev_entry != &map->header) 3628 vm_map_clip_end(map, prev_entry, addr); 3629 new_entry = prev_entry->next; 3630 KASSERT(new_entry == stack_entry->prev, ("foo")); 3631 KASSERT(new_entry->end == stack_entry->start, ("foo")); 3632 KASSERT(new_entry->start == addr, ("foo")); 3633 grow_amount = new_entry->end - new_entry->start; 3634 new_entry->avail_ssize = stack_entry->avail_ssize - 3635 grow_amount; 3636 stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN; 3637 new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; 3638 } 3639 } else { 3640 /* 3641 * Growing upward. 3642 */ 3643 addr = stack_entry->end + grow_amount; 3644 3645 /* 3646 * If this puts us into the next entry, cut back our growth 3647 * to the available space. Also, see the note above. 3648 */ 3649 if (addr > end) { 3650 stack_entry->avail_ssize = end - stack_entry->end; 3651 addr = end; 3652 if (stack_guard_page) 3653 addr -= PAGE_SIZE; 3654 } 3655 3656 grow_amount = addr - stack_entry->end; 3657 cred = stack_entry->cred; 3658 if (cred == NULL && stack_entry->object.vm_object != NULL) 3659 cred = stack_entry->object.vm_object->cred; 3660 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 3661 rv = KERN_NO_SPACE; 3662 /* Grow the underlying object if applicable. */ 3663 else if (stack_entry->object.vm_object == NULL || 3664 vm_object_coalesce(stack_entry->object.vm_object, 3665 stack_entry->offset, 3666 (vm_size_t)(stack_entry->end - stack_entry->start), 3667 (vm_size_t)grow_amount, cred != NULL)) { 3668 map->size += (addr - stack_entry->end); 3669 /* Update the current entry. */ 3670 stack_entry->end = addr; 3671 stack_entry->avail_ssize -= grow_amount; 3672 vm_map_entry_resize_free(map, stack_entry); 3673 rv = KERN_SUCCESS; 3674 3675 if (next_entry != &map->header) 3676 vm_map_clip_start(map, next_entry, addr); 3677 } else 3678 rv = KERN_FAILURE; 3679 } 3680 3681 if (rv == KERN_SUCCESS && is_procstack) 3682 vm->vm_ssize += btoc(grow_amount); 3683 3684 vm_map_unlock(map); 3685 3686 /* 3687 * Heed the MAP_WIREFUTURE flag if it was set for this process. 3688 */ 3689 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) { 3690 vm_map_wire(map, 3691 (stack_entry == next_entry) ? addr : addr - grow_amount, 3692 (stack_entry == next_entry) ? stack_entry->start : addr, 3693 (p->p_flag & P_SYSTEM) 3694 ? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES 3695 : VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 3696 } 3697 3698out: 3699#ifdef RACCT 3700 if (rv != KERN_SUCCESS) { 3701 PROC_LOCK(p); 3702 error = racct_set(p, RACCT_VMEM, map->size); 3703 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 3704 if (!old_mlock) { 3705 error = racct_set(p, RACCT_MEMLOCK, 3706 ptoa(pmap_wired_count(map->pmap))); 3707 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 3708 } 3709 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 3710 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 3711 PROC_UNLOCK(p); 3712 } 3713#endif 3714 3715 return (rv); 3716} 3717 3718/* 3719 * Unshare the specified VM space for exec. If other processes are 3720 * mapped to it, then create a new one. The new vmspace is null. 3721 */ 3722int 3723vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 3724{ 3725 struct vmspace *oldvmspace = p->p_vmspace; 3726 struct vmspace *newvmspace; 3727 3728 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 3729 ("vmspace_exec recursed")); 3730 newvmspace = vmspace_alloc(minuser, maxuser, NULL); 3731 if (newvmspace == NULL) 3732 return (ENOMEM); 3733 newvmspace->vm_swrss = oldvmspace->vm_swrss; 3734 /* 3735 * This code is written like this for prototype purposes. The 3736 * goal is to avoid running down the vmspace here, but let the 3737 * other process's that are still using the vmspace to finally 3738 * run it down. Even though there is little or no chance of blocking 3739 * here, it is a good idea to keep this form for future mods. 3740 */ 3741 PROC_VMSPACE_LOCK(p); 3742 p->p_vmspace = newvmspace; 3743 PROC_VMSPACE_UNLOCK(p); 3744 if (p == curthread->td_proc) 3745 pmap_activate(curthread); 3746 curthread->td_pflags |= TDP_EXECVMSPC; 3747 return (0); 3748} 3749 3750/* 3751 * Unshare the specified VM space for forcing COW. This 3752 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3753 */ 3754int 3755vmspace_unshare(struct proc *p) 3756{ 3757 struct vmspace *oldvmspace = p->p_vmspace; 3758 struct vmspace *newvmspace; 3759 vm_ooffset_t fork_charge; 3760 3761 if (oldvmspace->vm_refcnt == 1) 3762 return (0); 3763 fork_charge = 0; 3764 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 3765 if (newvmspace == NULL) 3766 return (ENOMEM); 3767 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 3768 vmspace_free(newvmspace); 3769 return (ENOMEM); 3770 } 3771 PROC_VMSPACE_LOCK(p); 3772 p->p_vmspace = newvmspace; 3773 PROC_VMSPACE_UNLOCK(p); 3774 if (p == curthread->td_proc) 3775 pmap_activate(curthread); 3776 vmspace_free(oldvmspace); 3777 return (0); 3778} 3779 3780/* 3781 * vm_map_lookup: 3782 * 3783 * Finds the VM object, offset, and 3784 * protection for a given virtual address in the 3785 * specified map, assuming a page fault of the 3786 * type specified. 3787 * 3788 * Leaves the map in question locked for read; return 3789 * values are guaranteed until a vm_map_lookup_done 3790 * call is performed. Note that the map argument 3791 * is in/out; the returned map must be used in 3792 * the call to vm_map_lookup_done. 3793 * 3794 * A handle (out_entry) is returned for use in 3795 * vm_map_lookup_done, to make that fast. 3796 * 3797 * If a lookup is requested with "write protection" 3798 * specified, the map may be changed to perform virtual 3799 * copying operations, although the data referenced will 3800 * remain the same. 3801 */ 3802int 3803vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3804 vm_offset_t vaddr, 3805 vm_prot_t fault_typea, 3806 vm_map_entry_t *out_entry, /* OUT */ 3807 vm_object_t *object, /* OUT */ 3808 vm_pindex_t *pindex, /* OUT */ 3809 vm_prot_t *out_prot, /* OUT */ 3810 boolean_t *wired) /* OUT */ 3811{ 3812 vm_map_entry_t entry; 3813 vm_map_t map = *var_map; 3814 vm_prot_t prot; 3815 vm_prot_t fault_type = fault_typea; 3816 vm_object_t eobject; 3817 vm_size_t size; 3818 struct ucred *cred; 3819 3820RetryLookup:; 3821 3822 vm_map_lock_read(map); 3823 3824 /* 3825 * Lookup the faulting address. 3826 */ 3827 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 3828 vm_map_unlock_read(map); 3829 return (KERN_INVALID_ADDRESS); 3830 } 3831 3832 entry = *out_entry; 3833 3834 /* 3835 * Handle submaps. 3836 */ 3837 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3838 vm_map_t old_map = map; 3839 3840 *var_map = map = entry->object.sub_map; 3841 vm_map_unlock_read(old_map); 3842 goto RetryLookup; 3843 } 3844 3845 /* 3846 * Check whether this task is allowed to have this page. 3847 */ 3848 prot = entry->protection; 3849 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3850 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 3851 vm_map_unlock_read(map); 3852 return (KERN_PROTECTION_FAILURE); 3853 } 3854 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3855 (entry->eflags & MAP_ENTRY_COW) && 3856 (fault_type & VM_PROT_WRITE)) { 3857 vm_map_unlock_read(map); 3858 return (KERN_PROTECTION_FAILURE); 3859 } 3860 if ((fault_typea & VM_PROT_COPY) != 0 && 3861 (entry->max_protection & VM_PROT_WRITE) == 0 && 3862 (entry->eflags & MAP_ENTRY_COW) == 0) { 3863 vm_map_unlock_read(map); 3864 return (KERN_PROTECTION_FAILURE); 3865 } 3866 3867 /* 3868 * If this page is not pageable, we have to get it for all possible 3869 * accesses. 3870 */ 3871 *wired = (entry->wired_count != 0); 3872 if (*wired) 3873 fault_type = entry->protection; 3874 size = entry->end - entry->start; 3875 /* 3876 * If the entry was copy-on-write, we either ... 3877 */ 3878 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3879 /* 3880 * If we want to write the page, we may as well handle that 3881 * now since we've got the map locked. 3882 * 3883 * If we don't need to write the page, we just demote the 3884 * permissions allowed. 3885 */ 3886 if ((fault_type & VM_PROT_WRITE) != 0 || 3887 (fault_typea & VM_PROT_COPY) != 0) { 3888 /* 3889 * Make a new object, and place it in the object 3890 * chain. Note that no new references have appeared 3891 * -- one just moved from the map to the new 3892 * object. 3893 */ 3894 if (vm_map_lock_upgrade(map)) 3895 goto RetryLookup; 3896 3897 if (entry->cred == NULL) { 3898 /* 3899 * The debugger owner is charged for 3900 * the memory. 3901 */ 3902 cred = curthread->td_ucred; 3903 crhold(cred); 3904 if (!swap_reserve_by_cred(size, cred)) { 3905 crfree(cred); 3906 vm_map_unlock(map); 3907 return (KERN_RESOURCE_SHORTAGE); 3908 } 3909 entry->cred = cred; 3910 } 3911 vm_object_shadow(&entry->object.vm_object, 3912 &entry->offset, size); 3913 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3914 eobject = entry->object.vm_object; 3915 if (eobject->cred != NULL) { 3916 /* 3917 * The object was not shadowed. 3918 */ 3919 swap_release_by_cred(size, entry->cred); 3920 crfree(entry->cred); 3921 entry->cred = NULL; 3922 } else if (entry->cred != NULL) { 3923 VM_OBJECT_WLOCK(eobject); 3924 eobject->cred = entry->cred; 3925 eobject->charge = size; 3926 VM_OBJECT_WUNLOCK(eobject); 3927 entry->cred = NULL; 3928 } 3929 3930 vm_map_lock_downgrade(map); 3931 } else { 3932 /* 3933 * We're attempting to read a copy-on-write page -- 3934 * don't allow writes. 3935 */ 3936 prot &= ~VM_PROT_WRITE; 3937 } 3938 } 3939 3940 /* 3941 * Create an object if necessary. 3942 */ 3943 if (entry->object.vm_object == NULL && 3944 !map->system_map) { 3945 if (vm_map_lock_upgrade(map)) 3946 goto RetryLookup; 3947 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 3948 atop(size)); 3949 entry->offset = 0; 3950 if (entry->cred != NULL) { 3951 VM_OBJECT_WLOCK(entry->object.vm_object); 3952 entry->object.vm_object->cred = entry->cred; 3953 entry->object.vm_object->charge = size; 3954 VM_OBJECT_WUNLOCK(entry->object.vm_object); 3955 entry->cred = NULL; 3956 } 3957 vm_map_lock_downgrade(map); 3958 } 3959 3960 /* 3961 * Return the object/offset from this entry. If the entry was 3962 * copy-on-write or empty, it has been fixed up. 3963 */ 3964 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3965 *object = entry->object.vm_object; 3966 3967 *out_prot = prot; 3968 return (KERN_SUCCESS); 3969} 3970 3971/* 3972 * vm_map_lookup_locked: 3973 * 3974 * Lookup the faulting address. A version of vm_map_lookup that returns 3975 * KERN_FAILURE instead of blocking on map lock or memory allocation. 3976 */ 3977int 3978vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 3979 vm_offset_t vaddr, 3980 vm_prot_t fault_typea, 3981 vm_map_entry_t *out_entry, /* OUT */ 3982 vm_object_t *object, /* OUT */ 3983 vm_pindex_t *pindex, /* OUT */ 3984 vm_prot_t *out_prot, /* OUT */ 3985 boolean_t *wired) /* OUT */ 3986{ 3987 vm_map_entry_t entry; 3988 vm_map_t map = *var_map; 3989 vm_prot_t prot; 3990 vm_prot_t fault_type = fault_typea; 3991 3992 /* 3993 * Lookup the faulting address. 3994 */ 3995 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 3996 return (KERN_INVALID_ADDRESS); 3997 3998 entry = *out_entry; 3999 4000 /* 4001 * Fail if the entry refers to a submap. 4002 */ 4003 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4004 return (KERN_FAILURE); 4005 4006 /* 4007 * Check whether this task is allowed to have this page. 4008 */ 4009 prot = entry->protection; 4010 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4011 if ((fault_type & prot) != fault_type) 4012 return (KERN_PROTECTION_FAILURE); 4013 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 4014 (entry->eflags & MAP_ENTRY_COW) && 4015 (fault_type & VM_PROT_WRITE)) 4016 return (KERN_PROTECTION_FAILURE); 4017 4018 /* 4019 * If this page is not pageable, we have to get it for all possible 4020 * accesses. 4021 */ 4022 *wired = (entry->wired_count != 0); 4023 if (*wired) 4024 fault_type = entry->protection; 4025 4026 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4027 /* 4028 * Fail if the entry was copy-on-write for a write fault. 4029 */ 4030 if (fault_type & VM_PROT_WRITE) 4031 return (KERN_FAILURE); 4032 /* 4033 * We're attempting to read a copy-on-write page -- 4034 * don't allow writes. 4035 */ 4036 prot &= ~VM_PROT_WRITE; 4037 } 4038 4039 /* 4040 * Fail if an object should be created. 4041 */ 4042 if (entry->object.vm_object == NULL && !map->system_map) 4043 return (KERN_FAILURE); 4044 4045 /* 4046 * Return the object/offset from this entry. If the entry was 4047 * copy-on-write or empty, it has been fixed up. 4048 */ 4049 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4050 *object = entry->object.vm_object; 4051 4052 *out_prot = prot; 4053 return (KERN_SUCCESS); 4054} 4055 4056/* 4057 * vm_map_lookup_done: 4058 * 4059 * Releases locks acquired by a vm_map_lookup 4060 * (according to the handle returned by that lookup). 4061 */ 4062void 4063vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4064{ 4065 /* 4066 * Unlock the main-level map 4067 */ 4068 vm_map_unlock_read(map); 4069} 4070 4071#include "opt_ddb.h" 4072#ifdef DDB 4073#include <sys/kernel.h> 4074 4075#include <ddb/ddb.h> 4076 4077static void 4078vm_map_print(vm_map_t map) 4079{ 4080 vm_map_entry_t entry; 4081 4082 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4083 (void *)map, 4084 (void *)map->pmap, map->nentries, map->timestamp); 4085 4086 db_indent += 2; 4087 for (entry = map->header.next; entry != &map->header; 4088 entry = entry->next) { 4089 db_iprintf("map entry %p: start=%p, end=%p\n", 4090 (void *)entry, (void *)entry->start, (void *)entry->end); 4091 { 4092 static char *inheritance_name[4] = 4093 {"share", "copy", "none", "donate_copy"}; 4094 4095 db_iprintf(" prot=%x/%x/%s", 4096 entry->protection, 4097 entry->max_protection, 4098 inheritance_name[(int)(unsigned char)entry->inheritance]); 4099 if (entry->wired_count != 0) 4100 db_printf(", wired"); 4101 } 4102 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4103 db_printf(", share=%p, offset=0x%jx\n", 4104 (void *)entry->object.sub_map, 4105 (uintmax_t)entry->offset); 4106 if ((entry->prev == &map->header) || 4107 (entry->prev->object.sub_map != 4108 entry->object.sub_map)) { 4109 db_indent += 2; 4110 vm_map_print((vm_map_t)entry->object.sub_map); 4111 db_indent -= 2; 4112 } 4113 } else { 4114 if (entry->cred != NULL) 4115 db_printf(", ruid %d", entry->cred->cr_ruid); 4116 db_printf(", object=%p, offset=0x%jx", 4117 (void *)entry->object.vm_object, 4118 (uintmax_t)entry->offset); 4119 if (entry->object.vm_object && entry->object.vm_object->cred) 4120 db_printf(", obj ruid %d charge %jx", 4121 entry->object.vm_object->cred->cr_ruid, 4122 (uintmax_t)entry->object.vm_object->charge); 4123 if (entry->eflags & MAP_ENTRY_COW) 4124 db_printf(", copy (%s)", 4125 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4126 db_printf("\n"); 4127 4128 if ((entry->prev == &map->header) || 4129 (entry->prev->object.vm_object != 4130 entry->object.vm_object)) { 4131 db_indent += 2; 4132 vm_object_print((db_expr_t)(intptr_t) 4133 entry->object.vm_object, 4134 1, 0, (char *)0); 4135 db_indent -= 2; 4136 } 4137 } 4138 } 4139 db_indent -= 2; 4140} 4141 4142DB_SHOW_COMMAND(map, map) 4143{ 4144 4145 if (!have_addr) { 4146 db_printf("usage: show map <addr>\n"); 4147 return; 4148 } 4149 vm_map_print((vm_map_t)addr); 4150} 4151 4152DB_SHOW_COMMAND(procvm, procvm) 4153{ 4154 struct proc *p; 4155 4156 if (have_addr) { 4157 p = (struct proc *) addr; 4158 } else { 4159 p = curproc; 4160 } 4161 4162 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4163 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4164 (void *)vmspace_pmap(p->p_vmspace)); 4165 4166 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 4167} 4168 4169#endif /* DDB */ 4170