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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $ 65 * $DragonFly: src/sys/vm/vm_map.c,v 1.38 2005/02/07 20:39:01 dillon Exp $ 66 */ 67 68 /* 69 * Virtual memory mapping module. 70 */ 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/proc.h> 75 #include <sys/lock.h> 76 #include <sys/vmmeter.h> 77 #include <sys/mman.h> 78 #include <sys/vnode.h> 79 #include <sys/resourcevar.h> 80 #include <sys/shm.h> 81 #include <sys/tree.h> 82 83 #include <vm/vm.h> 84 #include <vm/vm_param.h> 85 #include <vm/pmap.h> 86 #include <vm/vm_map.h> 87 #include <vm/vm_page.h> 88 #include <vm/vm_object.h> 89 #include <vm/vm_pager.h> 90 #include <vm/vm_kern.h> 91 #include <vm/vm_extern.h> 92 #include <vm/swap_pager.h> 93 #include <vm/vm_zone.h> 94 95 #include <sys/thread2.h> 96 97 /* 98 * Virtual memory maps provide for the mapping, protection, 99 * and sharing of virtual memory objects. In addition, 100 * this module provides for an efficient virtual copy of 101 * memory from one map to another. 102 * 103 * Synchronization is required prior to most operations. 104 * 105 * Maps consist of an ordered doubly-linked list of simple 106 * entries; a single hint is used to speed up lookups. 107 * 108 * Since portions of maps are specified by start/end addresses, 109 * which may not align with existing map entries, all 110 * routines merely "clip" entries to these start/end values. 111 * [That is, an entry is split into two, bordering at a 112 * start or end value.] Note that these clippings may not 113 * always be necessary (as the two resulting entries are then 114 * not changed); however, the clipping is done for convenience. 115 * 116 * As mentioned above, virtual copy operations are performed 117 * by copying VM object references from one map to 118 * another, and then marking both regions as copy-on-write. 119 */ 120 121 /* 122 * vm_map_startup: 123 * 124 * Initialize the vm_map module. Must be called before 125 * any other vm_map routines. 126 * 127 * Map and entry structures are allocated from the general 128 * purpose memory pool with some exceptions: 129 * 130 * - The kernel map and kmem submap are allocated statically. 131 * - Kernel map entries are allocated out of a static pool. 132 * 133 * These restrictions are necessary since malloc() uses the 134 * maps and requires map entries. 135 */ 136 137 #define VMEPERCPU 2 138 139 static struct vm_zone mapentzone_store, mapzone_store; 140 static vm_zone_t mapentzone, mapzone, vmspace_zone; 141 static struct vm_object mapentobj, mapobj; 142 143 static struct vm_map_entry map_entry_init[MAX_MAPENT]; 144 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU]; 145 static struct vm_map map_init[MAX_KMAP]; 146 147 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *); 148 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); 149 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 150 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 151 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); 152 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); 153 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, 154 vm_map_entry_t); 155 static void vm_map_split (vm_map_entry_t); 156 static void vm_map_unclip_range (vm_map_t map, vm_map_entry_t start_entry, vm_offset_t start, vm_offset_t end, int *count, int flags); 157 158 void 159 vm_map_startup(void) 160 { 161 mapzone = &mapzone_store; 162 zbootinit(mapzone, "MAP", sizeof (struct vm_map), 163 map_init, MAX_KMAP); 164 mapentzone = &mapentzone_store; 165 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), 166 map_entry_init, MAX_MAPENT); 167 } 168 169 /* 170 * Red black tree functions 171 */ 172 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); 173 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); 174 175 /* a->start is address, and the only field has to be initialized */ 176 static int 177 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) 178 { 179 if (a->start < b->start) 180 return(-1); 181 else if (a->start > b->start) 182 return(1); 183 return(0); 184 } 185 186 /* 187 * Allocate a vmspace structure, including a vm_map and pmap, 188 * and initialize those structures. The refcnt is set to 1. 189 * The remaining fields must be initialized by the caller. 190 */ 191 struct vmspace * 192 vmspace_alloc(vm_offset_t min, vm_offset_t max) 193 { 194 struct vmspace *vm; 195 196 vm = zalloc(vmspace_zone); 197 vm_map_init(&vm->vm_map, min, max); 198 pmap_pinit(vmspace_pmap(vm)); 199 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 200 vm->vm_refcnt = 1; 201 vm->vm_shm = NULL; 202 vm->vm_exitingcnt = 0; 203 return (vm); 204 } 205 206 void 207 vm_init2(void) 208 { 209 zinitna(mapentzone, &mapentobj, NULL, 0, 0, 210 ZONE_USE_RESERVE | ZONE_SPECIAL, 1); 211 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1); 212 vmspace_zone = zinit("VMSPACE", sizeof (struct vmspace), 0, 0, 3); 213 pmap_init2(); 214 vm_object_init2(); 215 } 216 217 static __inline void 218 vmspace_dofree(struct vmspace *vm) 219 { 220 int count; 221 222 /* 223 * Make sure any SysV shm is freed, it might not have in 224 * exit1() 225 */ 226 shmexit(vm); 227 228 KKASSERT(vm->vm_upcalls == NULL); 229 230 /* 231 * Lock the map, to wait out all other references to it. 232 * Delete all of the mappings and pages they hold, then call 233 * the pmap module to reclaim anything left. 234 */ 235 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 236 vm_map_lock(&vm->vm_map); 237 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 238 vm->vm_map.max_offset, &count); 239 vm_map_unlock(&vm->vm_map); 240 vm_map_entry_release(count); 241 242 pmap_release(vmspace_pmap(vm)); 243 zfree(vmspace_zone, vm); 244 } 245 246 void 247 vmspace_free(struct vmspace *vm) 248 { 249 if (vm->vm_refcnt == 0) 250 panic("vmspace_free: attempt to free already freed vmspace"); 251 252 if (--vm->vm_refcnt == 0 && vm->vm_exitingcnt == 0) 253 vmspace_dofree(vm); 254 } 255 256 void 257 vmspace_exitfree(struct proc *p) 258 { 259 struct vmspace *vm; 260 261 vm = p->p_vmspace; 262 p->p_vmspace = NULL; 263 264 /* 265 * cleanup by parent process wait()ing on exiting child. vm_refcnt 266 * may not be 0 (e.g. fork() and child exits without exec()ing). 267 * exitingcnt may increment above 0 and drop back down to zero 268 * several times while vm_refcnt is held non-zero. vm_refcnt 269 * may also increment above 0 and drop back down to zero several 270 * times while vm_exitingcnt is held non-zero. 271 * 272 * The last wait on the exiting child's vmspace will clean up 273 * the remainder of the vmspace. 274 */ 275 if (--vm->vm_exitingcnt == 0 && vm->vm_refcnt == 0) 276 vmspace_dofree(vm); 277 } 278 279 /* 280 * vmspace_swap_count() - count the approximate swap useage in pages for a 281 * vmspace. 282 * 283 * Swap useage is determined by taking the proportional swap used by 284 * VM objects backing the VM map. To make up for fractional losses, 285 * if the VM object has any swap use at all the associated map entries 286 * count for at least 1 swap page. 287 */ 288 int 289 vmspace_swap_count(struct vmspace *vmspace) 290 { 291 vm_map_t map = &vmspace->vm_map; 292 vm_map_entry_t cur; 293 int count = 0; 294 295 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 296 vm_object_t object; 297 298 if ((cur->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 && 299 (object = cur->object.vm_object) != NULL && 300 object->type == OBJT_SWAP 301 ) { 302 int n = (cur->end - cur->start) / PAGE_SIZE; 303 304 if (object->un_pager.swp.swp_bcount) { 305 count += object->un_pager.swp.swp_bcount * 306 SWAP_META_PAGES * n / object->size + 1; 307 } 308 } 309 } 310 return(count); 311 } 312 313 314 /* 315 * vm_map_create: 316 * 317 * Creates and returns a new empty VM map with 318 * the given physical map structure, and having 319 * the given lower and upper address bounds. 320 */ 321 vm_map_t 322 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 323 { 324 vm_map_t result; 325 326 result = zalloc(mapzone); 327 vm_map_init(result, min, max); 328 result->pmap = pmap; 329 return (result); 330 } 331 332 /* 333 * Initialize an existing vm_map structure 334 * such as that in the vmspace structure. 335 * The pmap is set elsewhere. 336 */ 337 void 338 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max) 339 { 340 map->header.next = map->header.prev = &map->header; 341 RB_INIT(&map->rb_root); 342 map->nentries = 0; 343 map->size = 0; 344 map->system_map = 0; 345 map->infork = 0; 346 map->min_offset = min; 347 map->max_offset = max; 348 map->first_free = &map->header; 349 map->hint = &map->header; 350 map->timestamp = 0; 351 lockinit(&map->lock, 0, "thrd_sleep", 0, LK_NOPAUSE); 352 } 353 354 /* 355 * vm_map_entry_reserve_cpu_init: 356 * 357 * Set an initial negative count so the first attempt to reserve 358 * space preloads a bunch of vm_map_entry's for this cpu. Also 359 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to 360 * map a new page for vm_map_entry structures. SMP systems are 361 * particularly sensitive. 362 * 363 * This routine is called in early boot so we cannot just call 364 * vm_map_entry_reserve(). 365 * 366 * May be called for a gd other then mycpu, but may only be called 367 * during early boot. 368 */ 369 void 370 vm_map_entry_reserve_cpu_init(globaldata_t gd) 371 { 372 vm_map_entry_t entry; 373 int i; 374 375 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2; 376 entry = &cpu_map_entry_init[gd->gd_cpuid][0]; 377 for (i = 0; i < VMEPERCPU; ++i, ++entry) { 378 entry->next = gd->gd_vme_base; 379 gd->gd_vme_base = entry; 380 } 381 } 382 383 /* 384 * vm_map_entry_reserve: 385 * 386 * Reserves vm_map_entry structures so code later on can manipulate 387 * map_entry structures within a locked map without blocking trying 388 * to allocate a new vm_map_entry. 389 */ 390 int 391 vm_map_entry_reserve(int count) 392 { 393 struct globaldata *gd = mycpu; 394 vm_map_entry_t entry; 395 396 crit_enter(); 397 398 /* 399 * Make sure we have enough structures in gd_vme_base to handle 400 * the reservation request. 401 */ 402 while (gd->gd_vme_avail < count) { 403 entry = zalloc(mapentzone); 404 entry->next = gd->gd_vme_base; 405 gd->gd_vme_base = entry; 406 ++gd->gd_vme_avail; 407 } 408 gd->gd_vme_avail -= count; 409 crit_exit(); 410 return(count); 411 } 412 413 /* 414 * vm_map_entry_release: 415 * 416 * Releases previously reserved vm_map_entry structures that were not 417 * used. If we have too much junk in our per-cpu cache clean some of 418 * it out. 419 */ 420 void 421 vm_map_entry_release(int count) 422 { 423 struct globaldata *gd = mycpu; 424 vm_map_entry_t entry; 425 426 crit_enter(); 427 gd->gd_vme_avail += count; 428 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) { 429 entry = gd->gd_vme_base; 430 KKASSERT(entry != NULL); 431 gd->gd_vme_base = entry->next; 432 --gd->gd_vme_avail; 433 crit_exit(); 434 zfree(mapentzone, entry); 435 crit_enter(); 436 } 437 crit_exit(); 438 } 439 440 /* 441 * vm_map_entry_kreserve: 442 * 443 * Reserve map entry structures for use in kernel_map itself. These 444 * entries have *ALREADY* been reserved on a per-cpu basis when the map 445 * was inited. This function is used by zalloc() to avoid a recursion 446 * when zalloc() itself needs to allocate additional kernel memory. 447 * 448 * This function works like the normal reserve but does not load the 449 * vm_map_entry cache (because that would result in an infinite 450 * recursion). Note that gd_vme_avail may go negative. This is expected. 451 * 452 * Any caller of this function must be sure to renormalize after 453 * potentially eating entries to ensure that the reserve supply 454 * remains intact. 455 */ 456 int 457 vm_map_entry_kreserve(int count) 458 { 459 struct globaldata *gd = mycpu; 460 461 crit_enter(); 462 gd->gd_vme_avail -= count; 463 crit_exit(); 464 KASSERT(gd->gd_vme_base != NULL, ("no reserved entries left, gd_vme_avail = %d\n", gd->gd_vme_avail)); 465 return(count); 466 } 467 468 /* 469 * vm_map_entry_krelease: 470 * 471 * Release previously reserved map entries for kernel_map. We do not 472 * attempt to clean up like the normal release function as this would 473 * cause an unnecessary (but probably not fatal) deep procedure call. 474 */ 475 void 476 vm_map_entry_krelease(int count) 477 { 478 struct globaldata *gd = mycpu; 479 480 crit_enter(); 481 gd->gd_vme_avail += count; 482 crit_exit(); 483 } 484 485 /* 486 * vm_map_entry_create: [ internal use only ] 487 * 488 * Allocates a VM map entry for insertion. No entry fields are filled 489 * in. 490 * 491 * This routine may be called from an interrupt thread but not a FAST 492 * interrupt. This routine may recurse the map lock. 493 */ 494 static vm_map_entry_t 495 vm_map_entry_create(vm_map_t map, int *countp) 496 { 497 struct globaldata *gd = mycpu; 498 vm_map_entry_t entry; 499 500 KKASSERT(*countp > 0); 501 --*countp; 502 crit_enter(); 503 entry = gd->gd_vme_base; 504 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); 505 gd->gd_vme_base = entry->next; 506 crit_exit(); 507 return(entry); 508 } 509 510 /* 511 * vm_map_entry_dispose: [ internal use only ] 512 * 513 * Dispose of a vm_map_entry that is no longer being referenced. This 514 * function may be called from an interrupt. 515 */ 516 static void 517 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) 518 { 519 struct globaldata *gd = mycpu; 520 521 KKASSERT(map->hint != entry); 522 KKASSERT(map->first_free != entry); 523 524 ++*countp; 525 crit_enter(); 526 entry->next = gd->gd_vme_base; 527 gd->gd_vme_base = entry; 528 crit_exit(); 529 } 530 531 532 /* 533 * vm_map_entry_{un,}link: 534 * 535 * Insert/remove entries from maps. 536 */ 537 static __inline void 538 vm_map_entry_link(vm_map_t map, 539 vm_map_entry_t after_where, 540 vm_map_entry_t entry) 541 { 542 map->nentries++; 543 entry->prev = after_where; 544 entry->next = after_where->next; 545 entry->next->prev = entry; 546 after_where->next = entry; 547 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) 548 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); 549 } 550 551 static __inline void 552 vm_map_entry_unlink(vm_map_t map, 553 vm_map_entry_t entry) 554 { 555 vm_map_entry_t prev; 556 vm_map_entry_t next; 557 558 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) 559 panic("vm_map_entry_unlink: attempt to mess with locked entry! %p", entry); 560 prev = entry->prev; 561 next = entry->next; 562 next->prev = prev; 563 prev->next = next; 564 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); 565 map->nentries--; 566 } 567 568 /* 569 * vm_map_lookup_entry: [ internal use only ] 570 * 571 * Finds the map entry containing (or 572 * immediately preceding) the specified address 573 * in the given map; the entry is returned 574 * in the "entry" parameter. The boolean 575 * result indicates whether the address is 576 * actually contained in the map. 577 */ 578 boolean_t 579 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, 580 vm_map_entry_t *entry /* OUT */) 581 { 582 vm_map_entry_t tmp; 583 vm_map_entry_t last; 584 585 #if 0 586 /* 587 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive 588 * the hint code with the red-black lookup meets with system crashes 589 * and lockups. We do not yet know why. 590 * 591 * It is possible that the problem is related to the setting 592 * of the hint during map_entry deletion, in the code specified 593 * at the GGG comment later on in this file. 594 */ 595 /* 596 * Quickly check the cached hint, there's a good chance of a match. 597 */ 598 if (map->hint != &map->header) { 599 tmp = map->hint; 600 if (address >= tmp->start && address < tmp->end) { 601 *entry = tmp; 602 return(TRUE); 603 } 604 } 605 #endif 606 607 /* 608 * Locate the record from the top of the tree. 'last' tracks the 609 * closest prior record and is returned if no match is found, which 610 * in binary tree terms means tracking the most recent right-branch 611 * taken. If there is no prior record, &map->header is returned. 612 */ 613 last = &map->header; 614 tmp = RB_ROOT(&map->rb_root); 615 616 while (tmp) { 617 if (address >= tmp->start) { 618 if (address < tmp->end) { 619 *entry = tmp; 620 map->hint = tmp; 621 return(TRUE); 622 } 623 last = tmp; 624 tmp = RB_RIGHT(tmp, rb_entry); 625 } else { 626 tmp = RB_LEFT(tmp, rb_entry); 627 } 628 *entry = last; 629 } 630 *entry = last; 631 return (FALSE); 632 } 633 634 /* 635 * vm_map_insert: 636 * 637 * Inserts the given whole VM object into the target 638 * map at the specified address range. The object's 639 * size should match that of the address range. 640 * 641 * Requires that the map be locked, and leaves it so. Requires that 642 * sufficient vm_map_entry structures have been reserved and tracks 643 * the use via countp. 644 * 645 * If object is non-NULL, ref count must be bumped by caller 646 * prior to making call to account for the new entry. 647 */ 648 int 649 vm_map_insert(vm_map_t map, int *countp, 650 vm_object_t object, vm_ooffset_t offset, 651 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, 652 int cow) 653 { 654 vm_map_entry_t new_entry; 655 vm_map_entry_t prev_entry; 656 vm_map_entry_t temp_entry; 657 vm_eflags_t protoeflags; 658 659 /* 660 * Check that the start and end points are not bogus. 661 */ 662 663 if ((start < map->min_offset) || (end > map->max_offset) || 664 (start >= end)) 665 return (KERN_INVALID_ADDRESS); 666 667 /* 668 * Find the entry prior to the proposed starting address; if it's part 669 * of an existing entry, this range is bogus. 670 */ 671 672 if (vm_map_lookup_entry(map, start, &temp_entry)) 673 return (KERN_NO_SPACE); 674 675 prev_entry = temp_entry; 676 677 /* 678 * Assert that the next entry doesn't overlap the end point. 679 */ 680 681 if ((prev_entry->next != &map->header) && 682 (prev_entry->next->start < end)) 683 return (KERN_NO_SPACE); 684 685 protoeflags = 0; 686 687 if (cow & MAP_COPY_ON_WRITE) 688 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 689 690 if (cow & MAP_NOFAULT) { 691 protoeflags |= MAP_ENTRY_NOFAULT; 692 693 KASSERT(object == NULL, 694 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 695 } 696 if (cow & MAP_DISABLE_SYNCER) 697 protoeflags |= MAP_ENTRY_NOSYNC; 698 if (cow & MAP_DISABLE_COREDUMP) 699 protoeflags |= MAP_ENTRY_NOCOREDUMP; 700 701 if (object) { 702 /* 703 * When object is non-NULL, it could be shared with another 704 * process. We have to set or clear OBJ_ONEMAPPING 705 * appropriately. 706 */ 707 if ((object->ref_count > 1) || (object->shadow_count != 0)) { 708 vm_object_clear_flag(object, OBJ_ONEMAPPING); 709 } 710 } 711 else if ((prev_entry != &map->header) && 712 (prev_entry->eflags == protoeflags) && 713 (prev_entry->end == start) && 714 (prev_entry->wired_count == 0) && 715 ((prev_entry->object.vm_object == NULL) || 716 vm_object_coalesce(prev_entry->object.vm_object, 717 OFF_TO_IDX(prev_entry->offset), 718 (vm_size_t)(prev_entry->end - prev_entry->start), 719 (vm_size_t)(end - prev_entry->end)))) { 720 /* 721 * We were able to extend the object. Determine if we 722 * can extend the previous map entry to include the 723 * new range as well. 724 */ 725 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 726 (prev_entry->protection == prot) && 727 (prev_entry->max_protection == max)) { 728 map->size += (end - prev_entry->end); 729 prev_entry->end = end; 730 vm_map_simplify_entry(map, prev_entry, countp); 731 return (KERN_SUCCESS); 732 } 733 734 /* 735 * If we can extend the object but cannot extend the 736 * map entry, we have to create a new map entry. We 737 * must bump the ref count on the extended object to 738 * account for it. object may be NULL. 739 */ 740 object = prev_entry->object.vm_object; 741 offset = prev_entry->offset + 742 (prev_entry->end - prev_entry->start); 743 vm_object_reference(object); 744 } 745 746 /* 747 * NOTE: if conditionals fail, object can be NULL here. This occurs 748 * in things like the buffer map where we manage kva but do not manage 749 * backing objects. 750 */ 751 752 /* 753 * Create a new entry 754 */ 755 756 new_entry = vm_map_entry_create(map, countp); 757 new_entry->start = start; 758 new_entry->end = end; 759 760 new_entry->eflags = protoeflags; 761 new_entry->object.vm_object = object; 762 new_entry->offset = offset; 763 new_entry->avail_ssize = 0; 764 765 new_entry->inheritance = VM_INHERIT_DEFAULT; 766 new_entry->protection = prot; 767 new_entry->max_protection = max; 768 new_entry->wired_count = 0; 769 770 /* 771 * Insert the new entry into the list 772 */ 773 774 vm_map_entry_link(map, prev_entry, new_entry); 775 map->size += new_entry->end - new_entry->start; 776 777 /* 778 * Update the free space hint 779 */ 780 if ((map->first_free == prev_entry) && 781 (prev_entry->end >= new_entry->start)) { 782 map->first_free = new_entry; 783 } 784 785 #if 0 786 /* 787 * Temporarily removed to avoid MAP_STACK panic, due to 788 * MAP_STACK being a huge hack. Will be added back in 789 * when MAP_STACK (and the user stack mapping) is fixed. 790 */ 791 /* 792 * It may be possible to simplify the entry 793 */ 794 vm_map_simplify_entry(map, new_entry, countp); 795 #endif 796 797 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) { 798 pmap_object_init_pt(map->pmap, start, prot, 799 object, OFF_TO_IDX(offset), end - start, 800 cow & MAP_PREFAULT_PARTIAL); 801 } 802 803 return (KERN_SUCCESS); 804 } 805 806 /* 807 * Find sufficient space for `length' bytes in the given map, starting at 808 * `start'. The map must be locked. Returns 0 on success, 1 on no space. 809 * 810 * This function will returned an arbitrarily aligned pointer. If no 811 * particular alignment is required you should pass align as 1. Note that 812 * the map may return PAGE_SIZE aligned pointers if all the lengths used in 813 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align 814 * argument. 815 * 816 * 'align' should be a power of 2 but is not required to be. 817 */ 818 int 819 vm_map_findspace( 820 vm_map_t map, 821 vm_offset_t start, 822 vm_size_t length, 823 vm_offset_t align, 824 vm_offset_t *addr) 825 { 826 vm_map_entry_t entry, next; 827 vm_offset_t end; 828 vm_offset_t align_mask; 829 830 if (start < map->min_offset) 831 start = map->min_offset; 832 if (start > map->max_offset) 833 return (1); 834 835 /* 836 * If the alignment is not a power of 2 we will have to use 837 * a mod/division, set align_mask to a special value. 838 */ 839 if ((align | (align - 1)) + 1 != (align << 1)) 840 align_mask = (vm_offset_t)-1; 841 else 842 align_mask = align - 1; 843 844 retry: 845 /* 846 * Look for the first possible address; if there's already something 847 * at this address, we have to start after it. 848 */ 849 if (start == map->min_offset) { 850 if ((entry = map->first_free) != &map->header) 851 start = entry->end; 852 } else { 853 vm_map_entry_t tmp; 854 855 if (vm_map_lookup_entry(map, start, &tmp)) 856 start = tmp->end; 857 entry = tmp; 858 } 859 860 /* 861 * Look through the rest of the map, trying to fit a new region in the 862 * gap between existing regions, or after the very last region. 863 */ 864 for (;; start = (entry = next)->end) { 865 /* 866 * Adjust the proposed start by the requested alignment, 867 * be sure that we didn't wrap the address. 868 */ 869 if (align_mask == (vm_offset_t)-1) 870 end = ((start + align - 1) / align) * align; 871 else 872 end = (start + align_mask) & ~align_mask; 873 if (end < start) 874 return (1); 875 start = end; 876 /* 877 * Find the end of the proposed new region. Be sure we didn't 878 * go beyond the end of the map, or wrap around the address. 879 * Then check to see if this is the last entry or if the 880 * proposed end fits in the gap between this and the next 881 * entry. 882 */ 883 end = start + length; 884 if (end > map->max_offset || end < start) 885 return (1); 886 next = entry->next; 887 if (next == &map->header || next->start >= end) 888 break; 889 } 890 map->hint = entry; 891 if (map == kernel_map) { 892 vm_offset_t ksize; 893 if ((ksize = round_page(start + length)) > kernel_vm_end) { 894 pmap_growkernel(ksize); 895 goto retry; 896 } 897 } 898 *addr = start; 899 return (0); 900 } 901 902 /* 903 * vm_map_find finds an unallocated region in the target address 904 * map with the given length. The search is defined to be 905 * first-fit from the specified address; the region found is 906 * returned in the same parameter. 907 * 908 * If object is non-NULL, ref count must be bumped by caller 909 * prior to making call to account for the new entry. 910 */ 911 int 912 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 913 vm_offset_t *addr, /* IN/OUT */ 914 vm_size_t length, boolean_t find_space, vm_prot_t prot, 915 vm_prot_t max, int cow) 916 { 917 vm_offset_t start; 918 int result; 919 int count; 920 921 start = *addr; 922 923 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 924 vm_map_lock(map); 925 if (find_space) { 926 if (vm_map_findspace(map, start, length, 1, addr)) { 927 vm_map_unlock(map); 928 vm_map_entry_release(count); 929 return (KERN_NO_SPACE); 930 } 931 start = *addr; 932 } 933 result = vm_map_insert(map, &count, object, offset, 934 start, start + length, prot, max, cow); 935 vm_map_unlock(map); 936 vm_map_entry_release(count); 937 938 return (result); 939 } 940 941 /* 942 * vm_map_simplify_entry: 943 * 944 * Simplify the given map entry by merging with either neighbor. This 945 * routine also has the ability to merge with both neighbors. 946 * 947 * The map must be locked. 948 * 949 * This routine guarentees that the passed entry remains valid (though 950 * possibly extended). When merging, this routine may delete one or 951 * both neighbors. No action is taken on entries which have their 952 * in-transition flag set. 953 */ 954 void 955 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp) 956 { 957 vm_map_entry_t next, prev; 958 vm_size_t prevsize, esize; 959 960 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) { 961 ++mycpu->gd_cnt.v_intrans_coll; 962 return; 963 } 964 965 prev = entry->prev; 966 if (prev != &map->header) { 967 prevsize = prev->end - prev->start; 968 if ( (prev->end == entry->start) && 969 (prev->object.vm_object == entry->object.vm_object) && 970 (!prev->object.vm_object || 971 (prev->offset + prevsize == entry->offset)) && 972 (prev->eflags == entry->eflags) && 973 (prev->protection == entry->protection) && 974 (prev->max_protection == entry->max_protection) && 975 (prev->inheritance == entry->inheritance) && 976 (prev->wired_count == entry->wired_count)) { 977 if (map->first_free == prev) 978 map->first_free = entry; 979 if (map->hint == prev) 980 map->hint = entry; 981 vm_map_entry_unlink(map, prev); 982 entry->start = prev->start; 983 entry->offset = prev->offset; 984 if (prev->object.vm_object) 985 vm_object_deallocate(prev->object.vm_object); 986 vm_map_entry_dispose(map, prev, countp); 987 } 988 } 989 990 next = entry->next; 991 if (next != &map->header) { 992 esize = entry->end - entry->start; 993 if ((entry->end == next->start) && 994 (next->object.vm_object == entry->object.vm_object) && 995 (!entry->object.vm_object || 996 (entry->offset + esize == next->offset)) && 997 (next->eflags == entry->eflags) && 998 (next->protection == entry->protection) && 999 (next->max_protection == entry->max_protection) && 1000 (next->inheritance == entry->inheritance) && 1001 (next->wired_count == entry->wired_count)) { 1002 if (map->first_free == next) 1003 map->first_free = entry; 1004 if (map->hint == next) 1005 map->hint = entry; 1006 vm_map_entry_unlink(map, next); 1007 entry->end = next->end; 1008 if (next->object.vm_object) 1009 vm_object_deallocate(next->object.vm_object); 1010 vm_map_entry_dispose(map, next, countp); 1011 } 1012 } 1013 } 1014 /* 1015 * vm_map_clip_start: [ internal use only ] 1016 * 1017 * Asserts that the given entry begins at or after 1018 * the specified address; if necessary, 1019 * it splits the entry into two. 1020 */ 1021 #define vm_map_clip_start(map, entry, startaddr, countp) \ 1022 { \ 1023 if (startaddr > entry->start) \ 1024 _vm_map_clip_start(map, entry, startaddr, countp); \ 1025 } 1026 1027 /* 1028 * This routine is called only when it is known that 1029 * the entry must be split. 1030 */ 1031 static void 1032 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start, int *countp) 1033 { 1034 vm_map_entry_t new_entry; 1035 1036 /* 1037 * Split off the front portion -- note that we must insert the new 1038 * entry BEFORE this one, so that this entry has the specified 1039 * starting address. 1040 */ 1041 1042 vm_map_simplify_entry(map, entry, countp); 1043 1044 /* 1045 * If there is no object backing this entry, we might as well create 1046 * one now. If we defer it, an object can get created after the map 1047 * is clipped, and individual objects will be created for the split-up 1048 * map. This is a bit of a hack, but is also about the best place to 1049 * put this improvement. 1050 */ 1051 1052 if (entry->object.vm_object == NULL && !map->system_map) { 1053 vm_object_t object; 1054 object = vm_object_allocate(OBJT_DEFAULT, 1055 atop(entry->end - entry->start)); 1056 entry->object.vm_object = object; 1057 entry->offset = 0; 1058 } 1059 1060 new_entry = vm_map_entry_create(map, countp); 1061 *new_entry = *entry; 1062 1063 new_entry->end = start; 1064 entry->offset += (start - entry->start); 1065 entry->start = start; 1066 1067 vm_map_entry_link(map, entry->prev, new_entry); 1068 1069 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1070 vm_object_reference(new_entry->object.vm_object); 1071 } 1072 } 1073 1074 /* 1075 * vm_map_clip_end: [ internal use only ] 1076 * 1077 * Asserts that the given entry ends at or before 1078 * the specified address; if necessary, 1079 * it splits the entry into two. 1080 */ 1081 1082 #define vm_map_clip_end(map, entry, endaddr, countp) \ 1083 { \ 1084 if (endaddr < entry->end) \ 1085 _vm_map_clip_end(map, entry, endaddr, countp); \ 1086 } 1087 1088 /* 1089 * This routine is called only when it is known that 1090 * the entry must be split. 1091 */ 1092 static void 1093 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end, int *countp) 1094 { 1095 vm_map_entry_t new_entry; 1096 1097 /* 1098 * If there is no object backing this entry, we might as well create 1099 * one now. If we defer it, an object can get created after the map 1100 * is clipped, and individual objects will be created for the split-up 1101 * map. This is a bit of a hack, but is also about the best place to 1102 * put this improvement. 1103 */ 1104 1105 if (entry->object.vm_object == NULL && !map->system_map) { 1106 vm_object_t object; 1107 object = vm_object_allocate(OBJT_DEFAULT, 1108 atop(entry->end - entry->start)); 1109 entry->object.vm_object = object; 1110 entry->offset = 0; 1111 } 1112 1113 /* 1114 * Create a new entry and insert it AFTER the specified entry 1115 */ 1116 1117 new_entry = vm_map_entry_create(map, countp); 1118 *new_entry = *entry; 1119 1120 new_entry->start = entry->end = end; 1121 new_entry->offset += (end - entry->start); 1122 1123 vm_map_entry_link(map, entry, new_entry); 1124 1125 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1126 vm_object_reference(new_entry->object.vm_object); 1127 } 1128 } 1129 1130 /* 1131 * VM_MAP_RANGE_CHECK: [ internal use only ] 1132 * 1133 * Asserts that the starting and ending region 1134 * addresses fall within the valid range of the map. 1135 */ 1136 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1137 { \ 1138 if (start < vm_map_min(map)) \ 1139 start = vm_map_min(map); \ 1140 if (end > vm_map_max(map)) \ 1141 end = vm_map_max(map); \ 1142 if (start > end) \ 1143 start = end; \ 1144 } 1145 1146 /* 1147 * vm_map_transition_wait: [ kernel use only ] 1148 * 1149 * Used to block when an in-transition collison occurs. The map 1150 * is unlocked for the sleep and relocked before the return. 1151 */ 1152 static 1153 void 1154 vm_map_transition_wait(vm_map_t map) 1155 { 1156 vm_map_unlock(map); 1157 tsleep(map, 0, "vment", 0); 1158 vm_map_lock(map); 1159 } 1160 1161 /* 1162 * CLIP_CHECK_BACK 1163 * CLIP_CHECK_FWD 1164 * 1165 * When we do blocking operations with the map lock held it is 1166 * possible that a clip might have occured on our in-transit entry, 1167 * requiring an adjustment to the entry in our loop. These macros 1168 * help the pageable and clip_range code deal with the case. The 1169 * conditional costs virtually nothing if no clipping has occured. 1170 */ 1171 1172 #define CLIP_CHECK_BACK(entry, save_start) \ 1173 do { \ 1174 while (entry->start != save_start) { \ 1175 entry = entry->prev; \ 1176 KASSERT(entry != &map->header, ("bad entry clip")); \ 1177 } \ 1178 } while(0) 1179 1180 #define CLIP_CHECK_FWD(entry, save_end) \ 1181 do { \ 1182 while (entry->end != save_end) { \ 1183 entry = entry->next; \ 1184 KASSERT(entry != &map->header, ("bad entry clip")); \ 1185 } \ 1186 } while(0) 1187 1188 1189 /* 1190 * vm_map_clip_range: [ kernel use only ] 1191 * 1192 * Clip the specified range and return the base entry. The 1193 * range may cover several entries starting at the returned base 1194 * and the first and last entry in the covering sequence will be 1195 * properly clipped to the requested start and end address. 1196 * 1197 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES 1198 * flag. 1199 * 1200 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries 1201 * covered by the requested range. 1202 * 1203 * The map must be exclusively locked on entry and will remain locked 1204 * on return. If no range exists or the range contains holes and you 1205 * specified that no holes were allowed, NULL will be returned. This 1206 * routine may temporarily unlock the map in order avoid a deadlock when 1207 * sleeping. 1208 */ 1209 static 1210 vm_map_entry_t 1211 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, 1212 int *countp, int flags) 1213 { 1214 vm_map_entry_t start_entry; 1215 vm_map_entry_t entry; 1216 1217 /* 1218 * Locate the entry and effect initial clipping. The in-transition 1219 * case does not occur very often so do not try to optimize it. 1220 */ 1221 again: 1222 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) 1223 return (NULL); 1224 entry = start_entry; 1225 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1226 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1227 ++mycpu->gd_cnt.v_intrans_coll; 1228 ++mycpu->gd_cnt.v_intrans_wait; 1229 vm_map_transition_wait(map); 1230 /* 1231 * entry and/or start_entry may have been clipped while 1232 * we slept, or may have gone away entirely. We have 1233 * to restart from the lookup. 1234 */ 1235 goto again; 1236 } 1237 /* 1238 * Since we hold an exclusive map lock we do not have to restart 1239 * after clipping, even though clipping may block in zalloc. 1240 */ 1241 vm_map_clip_start(map, entry, start, countp); 1242 vm_map_clip_end(map, entry, end, countp); 1243 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1244 1245 /* 1246 * Scan entries covered by the range. When working on the next 1247 * entry a restart need only re-loop on the current entry which 1248 * we have already locked, since 'next' may have changed. Also, 1249 * even though entry is safe, it may have been clipped so we 1250 * have to iterate forwards through the clip after sleeping. 1251 */ 1252 while (entry->next != &map->header && entry->next->start < end) { 1253 vm_map_entry_t next = entry->next; 1254 1255 if (flags & MAP_CLIP_NO_HOLES) { 1256 if (next->start > entry->end) { 1257 vm_map_unclip_range(map, start_entry, 1258 start, entry->end, countp, flags); 1259 return(NULL); 1260 } 1261 } 1262 1263 if (next->eflags & MAP_ENTRY_IN_TRANSITION) { 1264 vm_offset_t save_end = entry->end; 1265 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1266 ++mycpu->gd_cnt.v_intrans_coll; 1267 ++mycpu->gd_cnt.v_intrans_wait; 1268 vm_map_transition_wait(map); 1269 1270 /* 1271 * clips might have occured while we blocked. 1272 */ 1273 CLIP_CHECK_FWD(entry, save_end); 1274 CLIP_CHECK_BACK(start_entry, start); 1275 continue; 1276 } 1277 /* 1278 * No restart necessary even though clip_end may block, we 1279 * are holding the map lock. 1280 */ 1281 vm_map_clip_end(map, next, end, countp); 1282 next->eflags |= MAP_ENTRY_IN_TRANSITION; 1283 entry = next; 1284 } 1285 if (flags & MAP_CLIP_NO_HOLES) { 1286 if (entry->end != end) { 1287 vm_map_unclip_range(map, start_entry, 1288 start, entry->end, countp, flags); 1289 return(NULL); 1290 } 1291 } 1292 return(start_entry); 1293 } 1294 1295 /* 1296 * vm_map_unclip_range: [ kernel use only ] 1297 * 1298 * Undo the effect of vm_map_clip_range(). You should pass the same 1299 * flags and the same range that you passed to vm_map_clip_range(). 1300 * This code will clear the in-transition flag on the entries and 1301 * wake up anyone waiting. This code will also simplify the sequence 1302 * and attempt to merge it with entries before and after the sequence. 1303 * 1304 * The map must be locked on entry and will remain locked on return. 1305 * 1306 * Note that you should also pass the start_entry returned by 1307 * vm_map_clip_range(). However, if you block between the two calls 1308 * with the map unlocked please be aware that the start_entry may 1309 * have been clipped and you may need to scan it backwards to find 1310 * the entry corresponding with the original start address. You are 1311 * responsible for this, vm_map_unclip_range() expects the correct 1312 * start_entry to be passed to it and will KASSERT otherwise. 1313 */ 1314 static 1315 void 1316 vm_map_unclip_range( 1317 vm_map_t map, 1318 vm_map_entry_t start_entry, 1319 vm_offset_t start, 1320 vm_offset_t end, 1321 int *countp, 1322 int flags) 1323 { 1324 vm_map_entry_t entry; 1325 1326 entry = start_entry; 1327 1328 KASSERT(entry->start == start, ("unclip_range: illegal base entry")); 1329 while (entry != &map->header && entry->start < end) { 1330 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, ("in-transition flag not set during unclip on: %p", entry)); 1331 KASSERT(entry->end <= end, ("unclip_range: tail wasn't clipped")); 1332 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1333 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1334 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1335 wakeup(map); 1336 } 1337 entry = entry->next; 1338 } 1339 1340 /* 1341 * Simplification does not block so there is no restart case. 1342 */ 1343 entry = start_entry; 1344 while (entry != &map->header && entry->start < end) { 1345 vm_map_simplify_entry(map, entry, countp); 1346 entry = entry->next; 1347 } 1348 } 1349 1350 /* 1351 * vm_map_submap: [ kernel use only ] 1352 * 1353 * Mark the given range as handled by a subordinate map. 1354 * 1355 * This range must have been created with vm_map_find, 1356 * and no other operations may have been performed on this 1357 * range prior to calling vm_map_submap. 1358 * 1359 * Only a limited number of operations can be performed 1360 * within this rage after calling vm_map_submap: 1361 * vm_fault 1362 * [Don't try vm_map_copy!] 1363 * 1364 * To remove a submapping, one must first remove the 1365 * range from the superior map, and then destroy the 1366 * submap (if desired). [Better yet, don't try it.] 1367 */ 1368 int 1369 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) 1370 { 1371 vm_map_entry_t entry; 1372 int result = KERN_INVALID_ARGUMENT; 1373 int count; 1374 1375 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1376 vm_map_lock(map); 1377 1378 VM_MAP_RANGE_CHECK(map, start, end); 1379 1380 if (vm_map_lookup_entry(map, start, &entry)) { 1381 vm_map_clip_start(map, entry, start, &count); 1382 } else { 1383 entry = entry->next; 1384 } 1385 1386 vm_map_clip_end(map, entry, end, &count); 1387 1388 if ((entry->start == start) && (entry->end == end) && 1389 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1390 (entry->object.vm_object == NULL)) { 1391 entry->object.sub_map = submap; 1392 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 1393 result = KERN_SUCCESS; 1394 } 1395 vm_map_unlock(map); 1396 vm_map_entry_release(count); 1397 1398 return (result); 1399 } 1400 1401 /* 1402 * vm_map_protect: 1403 * 1404 * Sets the protection of the specified address 1405 * region in the target map. If "set_max" is 1406 * specified, the maximum protection is to be set; 1407 * otherwise, only the current protection is affected. 1408 */ 1409 int 1410 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1411 vm_prot_t new_prot, boolean_t set_max) 1412 { 1413 vm_map_entry_t current; 1414 vm_map_entry_t entry; 1415 int count; 1416 1417 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1418 vm_map_lock(map); 1419 1420 VM_MAP_RANGE_CHECK(map, start, end); 1421 1422 if (vm_map_lookup_entry(map, start, &entry)) { 1423 vm_map_clip_start(map, entry, start, &count); 1424 } else { 1425 entry = entry->next; 1426 } 1427 1428 /* 1429 * Make a first pass to check for protection violations. 1430 */ 1431 1432 current = entry; 1433 while ((current != &map->header) && (current->start < end)) { 1434 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 1435 vm_map_unlock(map); 1436 vm_map_entry_release(count); 1437 return (KERN_INVALID_ARGUMENT); 1438 } 1439 if ((new_prot & current->max_protection) != new_prot) { 1440 vm_map_unlock(map); 1441 vm_map_entry_release(count); 1442 return (KERN_PROTECTION_FAILURE); 1443 } 1444 current = current->next; 1445 } 1446 1447 /* 1448 * Go back and fix up protections. [Note that clipping is not 1449 * necessary the second time.] 1450 */ 1451 current = entry; 1452 1453 while ((current != &map->header) && (current->start < end)) { 1454 vm_prot_t old_prot; 1455 1456 vm_map_clip_end(map, current, end, &count); 1457 1458 old_prot = current->protection; 1459 if (set_max) 1460 current->protection = 1461 (current->max_protection = new_prot) & 1462 old_prot; 1463 else 1464 current->protection = new_prot; 1465 1466 /* 1467 * Update physical map if necessary. Worry about copy-on-write 1468 * here -- CHECK THIS XXX 1469 */ 1470 1471 if (current->protection != old_prot) { 1472 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1473 VM_PROT_ALL) 1474 1475 pmap_protect(map->pmap, current->start, 1476 current->end, 1477 current->protection & MASK(current)); 1478 #undef MASK 1479 } 1480 1481 vm_map_simplify_entry(map, current, &count); 1482 1483 current = current->next; 1484 } 1485 1486 vm_map_unlock(map); 1487 vm_map_entry_release(count); 1488 return (KERN_SUCCESS); 1489 } 1490 1491 /* 1492 * vm_map_madvise: 1493 * 1494 * This routine traverses a processes map handling the madvise 1495 * system call. Advisories are classified as either those effecting 1496 * the vm_map_entry structure, or those effecting the underlying 1497 * objects. 1498 */ 1499 1500 int 1501 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end, int behav) 1502 { 1503 vm_map_entry_t current, entry; 1504 int modify_map = 0; 1505 int count; 1506 1507 /* 1508 * Some madvise calls directly modify the vm_map_entry, in which case 1509 * we need to use an exclusive lock on the map and we need to perform 1510 * various clipping operations. Otherwise we only need a read-lock 1511 * on the map. 1512 */ 1513 1514 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1515 1516 switch(behav) { 1517 case MADV_NORMAL: 1518 case MADV_SEQUENTIAL: 1519 case MADV_RANDOM: 1520 case MADV_NOSYNC: 1521 case MADV_AUTOSYNC: 1522 case MADV_NOCORE: 1523 case MADV_CORE: 1524 modify_map = 1; 1525 vm_map_lock(map); 1526 break; 1527 case MADV_WILLNEED: 1528 case MADV_DONTNEED: 1529 case MADV_FREE: 1530 vm_map_lock_read(map); 1531 break; 1532 default: 1533 vm_map_entry_release(count); 1534 return (KERN_INVALID_ARGUMENT); 1535 } 1536 1537 /* 1538 * Locate starting entry and clip if necessary. 1539 */ 1540 1541 VM_MAP_RANGE_CHECK(map, start, end); 1542 1543 if (vm_map_lookup_entry(map, start, &entry)) { 1544 if (modify_map) 1545 vm_map_clip_start(map, entry, start, &count); 1546 } else { 1547 entry = entry->next; 1548 } 1549 1550 if (modify_map) { 1551 /* 1552 * madvise behaviors that are implemented in the vm_map_entry. 1553 * 1554 * We clip the vm_map_entry so that behavioral changes are 1555 * limited to the specified address range. 1556 */ 1557 for (current = entry; 1558 (current != &map->header) && (current->start < end); 1559 current = current->next 1560 ) { 1561 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1562 continue; 1563 1564 vm_map_clip_end(map, current, end, &count); 1565 1566 switch (behav) { 1567 case MADV_NORMAL: 1568 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1569 break; 1570 case MADV_SEQUENTIAL: 1571 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1572 break; 1573 case MADV_RANDOM: 1574 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1575 break; 1576 case MADV_NOSYNC: 1577 current->eflags |= MAP_ENTRY_NOSYNC; 1578 break; 1579 case MADV_AUTOSYNC: 1580 current->eflags &= ~MAP_ENTRY_NOSYNC; 1581 break; 1582 case MADV_NOCORE: 1583 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1584 break; 1585 case MADV_CORE: 1586 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1587 break; 1588 default: 1589 break; 1590 } 1591 vm_map_simplify_entry(map, current, &count); 1592 } 1593 vm_map_unlock(map); 1594 } else { 1595 vm_pindex_t pindex; 1596 int count; 1597 1598 /* 1599 * madvise behaviors that are implemented in the underlying 1600 * vm_object. 1601 * 1602 * Since we don't clip the vm_map_entry, we have to clip 1603 * the vm_object pindex and count. 1604 */ 1605 for (current = entry; 1606 (current != &map->header) && (current->start < end); 1607 current = current->next 1608 ) { 1609 vm_offset_t useStart; 1610 1611 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) 1612 continue; 1613 1614 pindex = OFF_TO_IDX(current->offset); 1615 count = atop(current->end - current->start); 1616 useStart = current->start; 1617 1618 if (current->start < start) { 1619 pindex += atop(start - current->start); 1620 count -= atop(start - current->start); 1621 useStart = start; 1622 } 1623 if (current->end > end) 1624 count -= atop(current->end - end); 1625 1626 if (count <= 0) 1627 continue; 1628 1629 vm_object_madvise(current->object.vm_object, 1630 pindex, count, behav); 1631 if (behav == MADV_WILLNEED) { 1632 pmap_object_init_pt( 1633 map->pmap, 1634 useStart, 1635 current->protection, 1636 current->object.vm_object, 1637 pindex, 1638 (count << PAGE_SHIFT), 1639 MAP_PREFAULT_MADVISE 1640 ); 1641 } 1642 } 1643 vm_map_unlock_read(map); 1644 } 1645 vm_map_entry_release(count); 1646 return(0); 1647 } 1648 1649 1650 /* 1651 * vm_map_inherit: 1652 * 1653 * Sets the inheritance of the specified address 1654 * range in the target map. Inheritance 1655 * affects how the map will be shared with 1656 * child maps at the time of vm_map_fork. 1657 */ 1658 int 1659 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 1660 vm_inherit_t new_inheritance) 1661 { 1662 vm_map_entry_t entry; 1663 vm_map_entry_t temp_entry; 1664 int count; 1665 1666 switch (new_inheritance) { 1667 case VM_INHERIT_NONE: 1668 case VM_INHERIT_COPY: 1669 case VM_INHERIT_SHARE: 1670 break; 1671 default: 1672 return (KERN_INVALID_ARGUMENT); 1673 } 1674 1675 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1676 vm_map_lock(map); 1677 1678 VM_MAP_RANGE_CHECK(map, start, end); 1679 1680 if (vm_map_lookup_entry(map, start, &temp_entry)) { 1681 entry = temp_entry; 1682 vm_map_clip_start(map, entry, start, &count); 1683 } else 1684 entry = temp_entry->next; 1685 1686 while ((entry != &map->header) && (entry->start < end)) { 1687 vm_map_clip_end(map, entry, end, &count); 1688 1689 entry->inheritance = new_inheritance; 1690 1691 vm_map_simplify_entry(map, entry, &count); 1692 1693 entry = entry->next; 1694 } 1695 vm_map_unlock(map); 1696 vm_map_entry_release(count); 1697 return (KERN_SUCCESS); 1698 } 1699 1700 /* 1701 * Implement the semantics of mlock 1702 */ 1703 int 1704 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, 1705 boolean_t new_pageable) 1706 { 1707 vm_map_entry_t entry; 1708 vm_map_entry_t start_entry; 1709 vm_offset_t end; 1710 int rv = KERN_SUCCESS; 1711 int count; 1712 1713 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1714 vm_map_lock(map); 1715 VM_MAP_RANGE_CHECK(map, start, real_end); 1716 end = real_end; 1717 1718 start_entry = vm_map_clip_range(map, start, end, &count, MAP_CLIP_NO_HOLES); 1719 if (start_entry == NULL) { 1720 vm_map_unlock(map); 1721 vm_map_entry_release(count); 1722 return (KERN_INVALID_ADDRESS); 1723 } 1724 1725 if (new_pageable == 0) { 1726 entry = start_entry; 1727 while ((entry != &map->header) && (entry->start < end)) { 1728 vm_offset_t save_start; 1729 vm_offset_t save_end; 1730 1731 /* 1732 * Already user wired or hard wired (trivial cases) 1733 */ 1734 if (entry->eflags & MAP_ENTRY_USER_WIRED) { 1735 entry = entry->next; 1736 continue; 1737 } 1738 if (entry->wired_count != 0) { 1739 entry->wired_count++; 1740 entry->eflags |= MAP_ENTRY_USER_WIRED; 1741 entry = entry->next; 1742 continue; 1743 } 1744 1745 /* 1746 * A new wiring requires instantiation of appropriate 1747 * management structures and the faulting in of the 1748 * page. 1749 */ 1750 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1751 int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY; 1752 if (copyflag && ((entry->protection & VM_PROT_WRITE) != 0)) { 1753 1754 vm_object_shadow(&entry->object.vm_object, 1755 &entry->offset, 1756 atop(entry->end - entry->start)); 1757 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 1758 1759 } else if (entry->object.vm_object == NULL && 1760 !map->system_map) { 1761 1762 entry->object.vm_object = 1763 vm_object_allocate(OBJT_DEFAULT, 1764 atop(entry->end - entry->start)); 1765 entry->offset = (vm_offset_t) 0; 1766 1767 } 1768 } 1769 entry->wired_count++; 1770 entry->eflags |= MAP_ENTRY_USER_WIRED; 1771 1772 /* 1773 * Now fault in the area. Note that vm_fault_wire() 1774 * may release the map lock temporarily, it will be 1775 * relocked on return. The in-transition 1776 * flag protects the entries. 1777 */ 1778 save_start = entry->start; 1779 save_end = entry->end; 1780 rv = vm_fault_wire(map, entry, TRUE); 1781 if (rv) { 1782 CLIP_CHECK_BACK(entry, save_start); 1783 for (;;) { 1784 KASSERT(entry->wired_count == 1, ("bad wired_count on entry")); 1785 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 1786 entry->wired_count = 0; 1787 if (entry->end == save_end) 1788 break; 1789 entry = entry->next; 1790 KASSERT(entry != &map->header, ("bad entry clip during backout")); 1791 } 1792 end = save_start; /* unwire the rest */ 1793 break; 1794 } 1795 /* 1796 * note that even though the entry might have been 1797 * clipped, the USER_WIRED flag we set prevents 1798 * duplication so we do not have to do a 1799 * clip check. 1800 */ 1801 entry = entry->next; 1802 } 1803 1804 /* 1805 * If we failed fall through to the unwiring section to 1806 * unwire what we had wired so far. 'end' has already 1807 * been adjusted. 1808 */ 1809 if (rv) 1810 new_pageable = 1; 1811 1812 /* 1813 * start_entry might have been clipped if we unlocked the 1814 * map and blocked. No matter how clipped it has gotten 1815 * there should be a fragment that is on our start boundary. 1816 */ 1817 CLIP_CHECK_BACK(start_entry, start); 1818 } 1819 1820 /* 1821 * Deal with the unwiring case. 1822 */ 1823 if (new_pageable) { 1824 /* 1825 * This is the unwiring case. We must first ensure that the 1826 * range to be unwired is really wired down. We know there 1827 * are no holes. 1828 */ 1829 entry = start_entry; 1830 while ((entry != &map->header) && (entry->start < end)) { 1831 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 1832 rv = KERN_INVALID_ARGUMENT; 1833 goto done; 1834 } 1835 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry)); 1836 entry = entry->next; 1837 } 1838 1839 /* 1840 * Now decrement the wiring count for each region. If a region 1841 * becomes completely unwired, unwire its physical pages and 1842 * mappings. 1843 */ 1844 /* 1845 * The map entries are processed in a loop, checking to 1846 * make sure the entry is wired and asserting it has a wired 1847 * count. However, another loop was inserted more-or-less in 1848 * the middle of the unwiring path. This loop picks up the 1849 * "entry" loop variable from the first loop without first 1850 * setting it to start_entry. Naturally, the secound loop 1851 * is never entered and the pages backing the entries are 1852 * never unwired. This can lead to a leak of wired pages. 1853 */ 1854 entry = start_entry; 1855 while ((entry != &map->header) && (entry->start < end)) { 1856 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, 1857 ("expected USER_WIRED on entry %p", entry)); 1858 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 1859 entry->wired_count--; 1860 if (entry->wired_count == 0) 1861 vm_fault_unwire(map, entry); 1862 entry = entry->next; 1863 } 1864 } 1865 done: 1866 vm_map_unclip_range(map, start_entry, start, real_end, &count, 1867 MAP_CLIP_NO_HOLES); 1868 map->timestamp++; 1869 vm_map_unlock(map); 1870 vm_map_entry_release(count); 1871 return (rv); 1872 } 1873 1874 /* 1875 * vm_map_wire: 1876 * 1877 * Sets the pageability of the specified address 1878 * range in the target map. Regions specified 1879 * as not pageable require locked-down physical 1880 * memory and physical page maps. 1881 * 1882 * The map must not be locked, but a reference 1883 * must remain to the map throughout the call. 1884 * 1885 * This function may be called via the zalloc path and must properly 1886 * reserve map entries for kernel_map. 1887 */ 1888 int 1889 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags) 1890 { 1891 vm_map_entry_t entry; 1892 vm_map_entry_t start_entry; 1893 vm_offset_t end; 1894 int rv = KERN_SUCCESS; 1895 int count; 1896 1897 if (kmflags & KM_KRESERVE) 1898 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT); 1899 else 1900 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1901 vm_map_lock(map); 1902 VM_MAP_RANGE_CHECK(map, start, real_end); 1903 end = real_end; 1904 1905 start_entry = vm_map_clip_range(map, start, end, &count, MAP_CLIP_NO_HOLES); 1906 if (start_entry == NULL) { 1907 vm_map_unlock(map); 1908 rv = KERN_INVALID_ADDRESS; 1909 goto failure; 1910 } 1911 if ((kmflags & KM_PAGEABLE) == 0) { 1912 /* 1913 * Wiring. 1914 * 1915 * 1. Holding the write lock, we create any shadow or zero-fill 1916 * objects that need to be created. Then we clip each map 1917 * entry to the region to be wired and increment its wiring 1918 * count. We create objects before clipping the map entries 1919 * to avoid object proliferation. 1920 * 1921 * 2. We downgrade to a read lock, and call vm_fault_wire to 1922 * fault in the pages for any newly wired area (wired_count is 1923 * 1). 1924 * 1925 * Downgrading to a read lock for vm_fault_wire avoids a 1926 * possible deadlock with another process that may have faulted 1927 * on one of the pages to be wired (it would mark the page busy, 1928 * blocking us, then in turn block on the map lock that we 1929 * hold). Because of problems in the recursive lock package, 1930 * we cannot upgrade to a write lock in vm_map_lookup. Thus, 1931 * any actions that require the write lock must be done 1932 * beforehand. Because we keep the read lock on the map, the 1933 * copy-on-write status of the entries we modify here cannot 1934 * change. 1935 */ 1936 1937 entry = start_entry; 1938 while ((entry != &map->header) && (entry->start < end)) { 1939 /* 1940 * Trivial case if the entry is already wired 1941 */ 1942 if (entry->wired_count) { 1943 entry->wired_count++; 1944 entry = entry->next; 1945 continue; 1946 } 1947 1948 /* 1949 * The entry is being newly wired, we have to setup 1950 * appropriate management structures. A shadow 1951 * object is required for a copy-on-write region, 1952 * or a normal object for a zero-fill region. We 1953 * do not have to do this for entries that point to sub 1954 * maps because we won't hold the lock on the sub map. 1955 */ 1956 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 1957 int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY; 1958 if (copyflag && 1959 ((entry->protection & VM_PROT_WRITE) != 0)) { 1960 1961 vm_object_shadow(&entry->object.vm_object, 1962 &entry->offset, 1963 atop(entry->end - entry->start)); 1964 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 1965 } else if (entry->object.vm_object == NULL && 1966 !map->system_map) { 1967 entry->object.vm_object = 1968 vm_object_allocate(OBJT_DEFAULT, 1969 atop(entry->end - entry->start)); 1970 entry->offset = (vm_offset_t) 0; 1971 } 1972 } 1973 1974 entry->wired_count++; 1975 entry = entry->next; 1976 } 1977 1978 /* 1979 * Pass 2. 1980 */ 1981 1982 /* 1983 * HACK HACK HACK HACK 1984 * 1985 * Unlock the map to avoid deadlocks. The in-transit flag 1986 * protects us from most changes but note that 1987 * clipping may still occur. To prevent clipping from 1988 * occuring after the unlock, except for when we are 1989 * blocking in vm_fault_wire, we must run in a critical 1990 * section, otherwise our accesses to entry->start and 1991 * entry->end could be corrupted. We have to enter the 1992 * critical section prior to unlocking so start_entry does 1993 * not change out from under us at the very beginning of the 1994 * loop. 1995 * 1996 * HACK HACK HACK HACK 1997 */ 1998 1999 crit_enter(); 2000 2001 entry = start_entry; 2002 while (entry != &map->header && entry->start < end) { 2003 /* 2004 * If vm_fault_wire fails for any page we need to undo 2005 * what has been done. We decrement the wiring count 2006 * for those pages which have not yet been wired (now) 2007 * and unwire those that have (later). 2008 */ 2009 vm_offset_t save_start = entry->start; 2010 vm_offset_t save_end = entry->end; 2011 2012 if (entry->wired_count == 1) 2013 rv = vm_fault_wire(map, entry, FALSE); 2014 if (rv) { 2015 CLIP_CHECK_BACK(entry, save_start); 2016 for (;;) { 2017 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly")); 2018 entry->wired_count = 0; 2019 if (entry->end == save_end) 2020 break; 2021 entry = entry->next; 2022 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2023 } 2024 end = save_start; 2025 break; 2026 } 2027 CLIP_CHECK_FWD(entry, save_end); 2028 entry = entry->next; 2029 } 2030 crit_exit(); 2031 2032 /* 2033 * If a failure occured undo everything by falling through 2034 * to the unwiring code. 'end' has already been adjusted 2035 * appropriately. 2036 */ 2037 if (rv) 2038 kmflags |= KM_PAGEABLE; 2039 2040 /* 2041 * start_entry is still IN_TRANSITION but may have been 2042 * clipped since vm_fault_wire() unlocks and relocks the 2043 * map. No matter how clipped it has gotten there should 2044 * be a fragment that is on our start boundary. 2045 */ 2046 CLIP_CHECK_BACK(start_entry, start); 2047 } 2048 2049 if (kmflags & KM_PAGEABLE) { 2050 /* 2051 * This is the unwiring case. We must first ensure that the 2052 * range to be unwired is really wired down. We know there 2053 * are no holes. 2054 */ 2055 entry = start_entry; 2056 while ((entry != &map->header) && (entry->start < end)) { 2057 if (entry->wired_count == 0) { 2058 rv = KERN_INVALID_ARGUMENT; 2059 goto done; 2060 } 2061 entry = entry->next; 2062 } 2063 2064 /* 2065 * Now decrement the wiring count for each region. If a region 2066 * becomes completely unwired, unwire its physical pages and 2067 * mappings. 2068 */ 2069 entry = start_entry; 2070 while ((entry != &map->header) && (entry->start < end)) { 2071 entry->wired_count--; 2072 if (entry->wired_count == 0) 2073 vm_fault_unwire(map, entry); 2074 entry = entry->next; 2075 } 2076 } 2077 done: 2078 vm_map_unclip_range(map, start_entry, start, real_end, &count, 2079 MAP_CLIP_NO_HOLES); 2080 map->timestamp++; 2081 vm_map_unlock(map); 2082 failure: 2083 if (kmflags & KM_KRESERVE) 2084 vm_map_entry_krelease(count); 2085 else 2086 vm_map_entry_release(count); 2087 return (rv); 2088 } 2089 2090 /* 2091 * vm_map_set_wired_quick() 2092 * 2093 * Mark a newly allocated address range as wired but do not fault in 2094 * the pages. The caller is expected to load the pages into the object. 2095 * 2096 * The map must be locked on entry and will remain locked on return. 2097 */ 2098 void 2099 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size, int *countp) 2100 { 2101 vm_map_entry_t scan; 2102 vm_map_entry_t entry; 2103 2104 entry = vm_map_clip_range(map, addr, addr + size, countp, MAP_CLIP_NO_HOLES); 2105 for (scan = entry; scan != &map->header && scan->start < addr + size; scan = scan->next) { 2106 KKASSERT(entry->wired_count == 0); 2107 entry->wired_count = 1; 2108 } 2109 vm_map_unclip_range(map, entry, addr, addr + size, countp, MAP_CLIP_NO_HOLES); 2110 } 2111 2112 /* 2113 * vm_map_clean 2114 * 2115 * Push any dirty cached pages in the address range to their pager. 2116 * If syncio is TRUE, dirty pages are written synchronously. 2117 * If invalidate is TRUE, any cached pages are freed as well. 2118 * 2119 * Returns an error if any part of the specified range is not mapped. 2120 */ 2121 int 2122 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end, boolean_t syncio, 2123 boolean_t invalidate) 2124 { 2125 vm_map_entry_t current; 2126 vm_map_entry_t entry; 2127 vm_size_t size; 2128 vm_object_t object; 2129 vm_ooffset_t offset; 2130 2131 vm_map_lock_read(map); 2132 VM_MAP_RANGE_CHECK(map, start, end); 2133 if (!vm_map_lookup_entry(map, start, &entry)) { 2134 vm_map_unlock_read(map); 2135 return (KERN_INVALID_ADDRESS); 2136 } 2137 /* 2138 * Make a first pass to check for holes. 2139 */ 2140 for (current = entry; current->start < end; current = current->next) { 2141 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2142 vm_map_unlock_read(map); 2143 return (KERN_INVALID_ARGUMENT); 2144 } 2145 if (end > current->end && 2146 (current->next == &map->header || 2147 current->end != current->next->start)) { 2148 vm_map_unlock_read(map); 2149 return (KERN_INVALID_ADDRESS); 2150 } 2151 } 2152 2153 if (invalidate) 2154 pmap_remove(vm_map_pmap(map), start, end); 2155 /* 2156 * Make a second pass, cleaning/uncaching pages from the indicated 2157 * objects as we go. 2158 */ 2159 for (current = entry; current->start < end; current = current->next) { 2160 offset = current->offset + (start - current->start); 2161 size = (end <= current->end ? end : current->end) - start; 2162 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) { 2163 vm_map_t smap; 2164 vm_map_entry_t tentry; 2165 vm_size_t tsize; 2166 2167 smap = current->object.sub_map; 2168 vm_map_lock_read(smap); 2169 (void) vm_map_lookup_entry(smap, offset, &tentry); 2170 tsize = tentry->end - offset; 2171 if (tsize < size) 2172 size = tsize; 2173 object = tentry->object.vm_object; 2174 offset = tentry->offset + (offset - tentry->start); 2175 vm_map_unlock_read(smap); 2176 } else { 2177 object = current->object.vm_object; 2178 } 2179 /* 2180 * Note that there is absolutely no sense in writing out 2181 * anonymous objects, so we track down the vnode object 2182 * to write out. 2183 * We invalidate (remove) all pages from the address space 2184 * anyway, for semantic correctness. 2185 * 2186 * note: certain anonymous maps, such as MAP_NOSYNC maps, 2187 * may start out with a NULL object. 2188 */ 2189 while (object && object->backing_object) { 2190 offset += object->backing_object_offset; 2191 object = object->backing_object; 2192 if (object->size < OFF_TO_IDX( offset + size)) 2193 size = IDX_TO_OFF(object->size) - offset; 2194 } 2195 if (object && (object->type == OBJT_VNODE) && 2196 (current->protection & VM_PROT_WRITE)) { 2197 /* 2198 * Flush pages if writing is allowed, invalidate them 2199 * if invalidation requested. Pages undergoing I/O 2200 * will be ignored by vm_object_page_remove(). 2201 * 2202 * We cannot lock the vnode and then wait for paging 2203 * to complete without deadlocking against vm_fault. 2204 * Instead we simply call vm_object_page_remove() and 2205 * allow it to block internally on a page-by-page 2206 * basis when it encounters pages undergoing async 2207 * I/O. 2208 */ 2209 int flags; 2210 2211 vm_object_reference(object); 2212 vn_lock(object->handle, 2213 LK_EXCLUSIVE | LK_RETRY, curthread); 2214 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 2215 flags |= invalidate ? OBJPC_INVAL : 0; 2216 vm_object_page_clean(object, 2217 OFF_TO_IDX(offset), 2218 OFF_TO_IDX(offset + size + PAGE_MASK), 2219 flags); 2220 VOP_UNLOCK(((struct vnode *)object->handle), 2221 0, curthread); 2222 vm_object_deallocate(object); 2223 } 2224 if (object && invalidate && 2225 ((object->type == OBJT_VNODE) || 2226 (object->type == OBJT_DEVICE))) { 2227 int clean_only = 2228 (object->type == OBJT_DEVICE) ? FALSE : TRUE; 2229 vm_object_reference(object); 2230 vm_object_page_remove(object, 2231 OFF_TO_IDX(offset), 2232 OFF_TO_IDX(offset + size + PAGE_MASK), 2233 clean_only); 2234 vm_object_deallocate(object); 2235 } 2236 start += size; 2237 } 2238 2239 vm_map_unlock_read(map); 2240 return (KERN_SUCCESS); 2241 } 2242 2243 /* 2244 * vm_map_entry_unwire: [ internal use only ] 2245 * 2246 * Make the region specified by this entry pageable. 2247 * 2248 * The map in question should be locked. 2249 * [This is the reason for this routine's existence.] 2250 */ 2251 static void 2252 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2253 { 2254 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2255 entry->wired_count = 0; 2256 vm_fault_unwire(map, entry); 2257 } 2258 2259 /* 2260 * vm_map_entry_delete: [ internal use only ] 2261 * 2262 * Deallocate the given entry from the target map. 2263 */ 2264 static void 2265 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp) 2266 { 2267 vm_map_entry_unlink(map, entry); 2268 map->size -= entry->end - entry->start; 2269 2270 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 2271 vm_object_deallocate(entry->object.vm_object); 2272 } 2273 2274 vm_map_entry_dispose(map, entry, countp); 2275 } 2276 2277 /* 2278 * vm_map_delete: [ internal use only ] 2279 * 2280 * Deallocates the given address range from the target 2281 * map. 2282 */ 2283 int 2284 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp) 2285 { 2286 vm_object_t object; 2287 vm_map_entry_t entry; 2288 vm_map_entry_t first_entry; 2289 2290 again: 2291 /* 2292 * Find the start of the region, and clip it. Set entry to point 2293 * at the first record containing the requested address or, if no 2294 * such record exists, the next record with a greater address. The 2295 * loop will run from this point until a record beyond the termination 2296 * address is encountered. 2297 * 2298 * map->hint must be adjusted to not point to anything we delete, 2299 * so set it to the entry prior to the one being deleted. 2300 * 2301 * GGG see other GGG comment. 2302 */ 2303 if (vm_map_lookup_entry(map, start, &first_entry)) { 2304 entry = first_entry; 2305 vm_map_clip_start(map, entry, start, countp); 2306 map->hint = entry->prev; /* possible problem XXX */ 2307 } else { 2308 map->hint = first_entry; /* possible problem XXX */ 2309 entry = first_entry->next; 2310 } 2311 2312 /* 2313 * If a hole opens up prior to the current first_free then 2314 * adjust first_free. As with map->hint, map->first_free 2315 * cannot be left set to anything we might delete. 2316 */ 2317 if (entry == &map->header) { 2318 map->first_free = &map->header; 2319 } else if (map->first_free->start >= start) { 2320 map->first_free = entry->prev; 2321 } 2322 2323 /* 2324 * Step through all entries in this region 2325 */ 2326 2327 while ((entry != &map->header) && (entry->start < end)) { 2328 vm_map_entry_t next; 2329 vm_offset_t s, e; 2330 vm_pindex_t offidxstart, offidxend, count; 2331 2332 /* 2333 * If we hit an in-transition entry we have to sleep and 2334 * retry. It's easier (and not really slower) to just retry 2335 * since this case occurs so rarely and the hint is already 2336 * pointing at the right place. We have to reset the 2337 * start offset so as not to accidently delete an entry 2338 * another process just created in vacated space. 2339 */ 2340 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2341 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2342 start = entry->start; 2343 ++mycpu->gd_cnt.v_intrans_coll; 2344 ++mycpu->gd_cnt.v_intrans_wait; 2345 vm_map_transition_wait(map); 2346 goto again; 2347 } 2348 vm_map_clip_end(map, entry, end, countp); 2349 2350 s = entry->start; 2351 e = entry->end; 2352 next = entry->next; 2353 2354 offidxstart = OFF_TO_IDX(entry->offset); 2355 count = OFF_TO_IDX(e - s); 2356 object = entry->object.vm_object; 2357 2358 /* 2359 * Unwire before removing addresses from the pmap; otherwise, 2360 * unwiring will put the entries back in the pmap. 2361 */ 2362 if (entry->wired_count != 0) 2363 vm_map_entry_unwire(map, entry); 2364 2365 offidxend = offidxstart + count; 2366 2367 if ((object == kernel_object) || (object == kmem_object)) { 2368 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2369 } else { 2370 pmap_remove(map->pmap, s, e); 2371 if (object != NULL && 2372 object->ref_count != 1 && 2373 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING && 2374 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2375 vm_object_collapse(object); 2376 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2377 if (object->type == OBJT_SWAP) { 2378 swap_pager_freespace(object, offidxstart, count); 2379 } 2380 if (offidxend >= object->size && 2381 offidxstart < object->size) { 2382 object->size = offidxstart; 2383 } 2384 } 2385 } 2386 2387 /* 2388 * Delete the entry (which may delete the object) only after 2389 * removing all pmap entries pointing to its pages. 2390 * (Otherwise, its page frames may be reallocated, and any 2391 * modify bits will be set in the wrong object!) 2392 */ 2393 vm_map_entry_delete(map, entry, countp); 2394 entry = next; 2395 } 2396 return (KERN_SUCCESS); 2397 } 2398 2399 /* 2400 * vm_map_remove: 2401 * 2402 * Remove the given address range from the target map. 2403 * This is the exported form of vm_map_delete. 2404 */ 2405 int 2406 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2407 { 2408 int result; 2409 int count; 2410 2411 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2412 vm_map_lock(map); 2413 VM_MAP_RANGE_CHECK(map, start, end); 2414 result = vm_map_delete(map, start, end, &count); 2415 vm_map_unlock(map); 2416 vm_map_entry_release(count); 2417 2418 return (result); 2419 } 2420 2421 /* 2422 * vm_map_check_protection: 2423 * 2424 * Assert that the target map allows the specified 2425 * privilege on the entire address region given. 2426 * The entire region must be allocated. 2427 */ 2428 boolean_t 2429 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2430 vm_prot_t protection) 2431 { 2432 vm_map_entry_t entry; 2433 vm_map_entry_t tmp_entry; 2434 2435 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 2436 return (FALSE); 2437 } 2438 entry = tmp_entry; 2439 2440 while (start < end) { 2441 if (entry == &map->header) { 2442 return (FALSE); 2443 } 2444 /* 2445 * No holes allowed! 2446 */ 2447 2448 if (start < entry->start) { 2449 return (FALSE); 2450 } 2451 /* 2452 * Check protection associated with entry. 2453 */ 2454 2455 if ((entry->protection & protection) != protection) { 2456 return (FALSE); 2457 } 2458 /* go to next entry */ 2459 2460 start = entry->end; 2461 entry = entry->next; 2462 } 2463 return (TRUE); 2464 } 2465 2466 /* 2467 * Split the pages in a map entry into a new object. This affords 2468 * easier removal of unused pages, and keeps object inheritance from 2469 * being a negative impact on memory usage. 2470 */ 2471 static void 2472 vm_map_split(vm_map_entry_t entry) 2473 { 2474 vm_page_t m; 2475 vm_object_t orig_object, new_object, source; 2476 vm_offset_t s, e; 2477 vm_pindex_t offidxstart, offidxend, idx; 2478 vm_size_t size; 2479 vm_ooffset_t offset; 2480 2481 orig_object = entry->object.vm_object; 2482 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 2483 return; 2484 if (orig_object->ref_count <= 1) 2485 return; 2486 2487 offset = entry->offset; 2488 s = entry->start; 2489 e = entry->end; 2490 2491 offidxstart = OFF_TO_IDX(offset); 2492 offidxend = offidxstart + OFF_TO_IDX(e - s); 2493 size = offidxend - offidxstart; 2494 2495 new_object = vm_pager_allocate(orig_object->type, 2496 NULL, IDX_TO_OFF(size), VM_PROT_ALL, 0LL); 2497 if (new_object == NULL) 2498 return; 2499 2500 source = orig_object->backing_object; 2501 if (source != NULL) { 2502 vm_object_reference(source); /* Referenced by new_object */ 2503 LIST_INSERT_HEAD(&source->shadow_head, 2504 new_object, shadow_list); 2505 vm_object_clear_flag(source, OBJ_ONEMAPPING); 2506 new_object->backing_object_offset = 2507 orig_object->backing_object_offset + IDX_TO_OFF(offidxstart); 2508 new_object->backing_object = source; 2509 source->shadow_count++; 2510 source->generation++; 2511 } 2512 2513 for (idx = 0; idx < size; idx++) { 2514 vm_page_t m; 2515 2516 /* 2517 * A critical section is required to avoid a race between 2518 * the lookup and an interrupt/unbusy/free and our busy 2519 * check. 2520 */ 2521 crit_enter(); 2522 retry: 2523 m = vm_page_lookup(orig_object, offidxstart + idx); 2524 if (m == NULL) { 2525 crit_exit(); 2526 continue; 2527 } 2528 2529 /* 2530 * We must wait for pending I/O to complete before we can 2531 * rename the page. 2532 * 2533 * We do not have to VM_PROT_NONE the page as mappings should 2534 * not be changed by this operation. 2535 */ 2536 if (vm_page_sleep_busy(m, TRUE, "spltwt")) 2537 goto retry; 2538 vm_page_busy(m); 2539 vm_page_rename(m, new_object, idx); 2540 /* page automatically made dirty by rename and cache handled */ 2541 vm_page_busy(m); 2542 crit_exit(); 2543 } 2544 2545 if (orig_object->type == OBJT_SWAP) { 2546 vm_object_pip_add(orig_object, 1); 2547 /* 2548 * copy orig_object pages into new_object 2549 * and destroy unneeded pages in 2550 * shadow object. 2551 */ 2552 swap_pager_copy(orig_object, new_object, offidxstart, 0); 2553 vm_object_pip_wakeup(orig_object); 2554 } 2555 2556 /* 2557 * Wakeup the pages we played with. No spl protection is needed 2558 * for a simple wakeup. 2559 */ 2560 for (idx = 0; idx < size; idx++) { 2561 m = vm_page_lookup(new_object, idx); 2562 if (m) 2563 vm_page_wakeup(m); 2564 } 2565 2566 entry->object.vm_object = new_object; 2567 entry->offset = 0LL; 2568 vm_object_deallocate(orig_object); 2569 } 2570 2571 /* 2572 * vm_map_copy_entry: 2573 * 2574 * Copies the contents of the source entry to the destination 2575 * entry. The entries *must* be aligned properly. 2576 */ 2577 static void 2578 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map, 2579 vm_map_entry_t src_entry, vm_map_entry_t dst_entry) 2580 { 2581 vm_object_t src_object; 2582 2583 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 2584 return; 2585 2586 if (src_entry->wired_count == 0) { 2587 2588 /* 2589 * If the source entry is marked needs_copy, it is already 2590 * write-protected. 2591 */ 2592 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 2593 pmap_protect(src_map->pmap, 2594 src_entry->start, 2595 src_entry->end, 2596 src_entry->protection & ~VM_PROT_WRITE); 2597 } 2598 2599 /* 2600 * Make a copy of the object. 2601 */ 2602 if ((src_object = src_entry->object.vm_object) != NULL) { 2603 2604 if ((src_object->handle == NULL) && 2605 (src_object->type == OBJT_DEFAULT || 2606 src_object->type == OBJT_SWAP)) { 2607 vm_object_collapse(src_object); 2608 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 2609 vm_map_split(src_entry); 2610 src_object = src_entry->object.vm_object; 2611 } 2612 } 2613 2614 vm_object_reference(src_object); 2615 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 2616 dst_entry->object.vm_object = src_object; 2617 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2618 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2619 dst_entry->offset = src_entry->offset; 2620 } else { 2621 dst_entry->object.vm_object = NULL; 2622 dst_entry->offset = 0; 2623 } 2624 2625 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 2626 dst_entry->end - dst_entry->start, src_entry->start); 2627 } else { 2628 /* 2629 * Of course, wired down pages can't be set copy-on-write. 2630 * Cause wired pages to be copied into the new map by 2631 * simulating faults (the new pages are pageable) 2632 */ 2633 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 2634 } 2635 } 2636 2637 /* 2638 * vmspace_fork: 2639 * Create a new process vmspace structure and vm_map 2640 * based on those of an existing process. The new map 2641 * is based on the old map, according to the inheritance 2642 * values on the regions in that map. 2643 * 2644 * The source map must not be locked. 2645 */ 2646 struct vmspace * 2647 vmspace_fork(struct vmspace *vm1) 2648 { 2649 struct vmspace *vm2; 2650 vm_map_t old_map = &vm1->vm_map; 2651 vm_map_t new_map; 2652 vm_map_entry_t old_entry; 2653 vm_map_entry_t new_entry; 2654 vm_object_t object; 2655 int count; 2656 2657 vm_map_lock(old_map); 2658 old_map->infork = 1; 2659 2660 /* 2661 * XXX Note: upcalls are not copied. 2662 */ 2663 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 2664 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 2665 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); 2666 new_map = &vm2->vm_map; /* XXX */ 2667 new_map->timestamp = 1; 2668 2669 count = 0; 2670 old_entry = old_map->header.next; 2671 while (old_entry != &old_map->header) { 2672 ++count; 2673 old_entry = old_entry->next; 2674 } 2675 2676 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); 2677 2678 old_entry = old_map->header.next; 2679 while (old_entry != &old_map->header) { 2680 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) 2681 panic("vm_map_fork: encountered a submap"); 2682 2683 switch (old_entry->inheritance) { 2684 case VM_INHERIT_NONE: 2685 break; 2686 2687 case VM_INHERIT_SHARE: 2688 /* 2689 * Clone the entry, creating the shared object if necessary. 2690 */ 2691 object = old_entry->object.vm_object; 2692 if (object == NULL) { 2693 object = vm_object_allocate(OBJT_DEFAULT, 2694 atop(old_entry->end - old_entry->start)); 2695 old_entry->object.vm_object = object; 2696 old_entry->offset = (vm_offset_t) 0; 2697 } 2698 2699 /* 2700 * Add the reference before calling vm_object_shadow 2701 * to insure that a shadow object is created. 2702 */ 2703 vm_object_reference(object); 2704 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 2705 vm_object_shadow(&old_entry->object.vm_object, 2706 &old_entry->offset, 2707 atop(old_entry->end - old_entry->start)); 2708 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 2709 /* Transfer the second reference too. */ 2710 vm_object_reference( 2711 old_entry->object.vm_object); 2712 vm_object_deallocate(object); 2713 object = old_entry->object.vm_object; 2714 } 2715 vm_object_clear_flag(object, OBJ_ONEMAPPING); 2716 2717 /* 2718 * Clone the entry, referencing the shared object. 2719 */ 2720 new_entry = vm_map_entry_create(new_map, &count); 2721 *new_entry = *old_entry; 2722 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2723 new_entry->wired_count = 0; 2724 2725 /* 2726 * Insert the entry into the new map -- we know we're 2727 * inserting at the end of the new map. 2728 */ 2729 2730 vm_map_entry_link(new_map, new_map->header.prev, 2731 new_entry); 2732 2733 /* 2734 * Update the physical map 2735 */ 2736 2737 pmap_copy(new_map->pmap, old_map->pmap, 2738 new_entry->start, 2739 (old_entry->end - old_entry->start), 2740 old_entry->start); 2741 break; 2742 2743 case VM_INHERIT_COPY: 2744 /* 2745 * Clone the entry and link into the map. 2746 */ 2747 new_entry = vm_map_entry_create(new_map, &count); 2748 *new_entry = *old_entry; 2749 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2750 new_entry->wired_count = 0; 2751 new_entry->object.vm_object = NULL; 2752 vm_map_entry_link(new_map, new_map->header.prev, 2753 new_entry); 2754 vm_map_copy_entry(old_map, new_map, old_entry, 2755 new_entry); 2756 break; 2757 } 2758 old_entry = old_entry->next; 2759 } 2760 2761 new_map->size = old_map->size; 2762 old_map->infork = 0; 2763 vm_map_unlock(old_map); 2764 vm_map_entry_release(count); 2765 2766 return (vm2); 2767 } 2768 2769 int 2770 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 2771 vm_prot_t prot, vm_prot_t max, int cow) 2772 { 2773 vm_map_entry_t prev_entry; 2774 vm_map_entry_t new_stack_entry; 2775 vm_size_t init_ssize; 2776 int rv; 2777 int count; 2778 2779 if (VM_MIN_ADDRESS > 0 && addrbos < VM_MIN_ADDRESS) 2780 return (KERN_NO_SPACE); 2781 2782 if (max_ssize < sgrowsiz) 2783 init_ssize = max_ssize; 2784 else 2785 init_ssize = sgrowsiz; 2786 2787 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2788 vm_map_lock(map); 2789 2790 /* If addr is already mapped, no go */ 2791 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 2792 vm_map_unlock(map); 2793 vm_map_entry_release(count); 2794 return (KERN_NO_SPACE); 2795 } 2796 2797 /* If we would blow our VMEM resource limit, no go */ 2798 if (map->size + init_ssize > 2799 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 2800 vm_map_unlock(map); 2801 vm_map_entry_release(count); 2802 return (KERN_NO_SPACE); 2803 } 2804 2805 /* If we can't accomodate max_ssize in the current mapping, 2806 * no go. However, we need to be aware that subsequent user 2807 * mappings might map into the space we have reserved for 2808 * stack, and currently this space is not protected. 2809 * 2810 * Hopefully we will at least detect this condition 2811 * when we try to grow the stack. 2812 */ 2813 if ((prev_entry->next != &map->header) && 2814 (prev_entry->next->start < addrbos + max_ssize)) { 2815 vm_map_unlock(map); 2816 vm_map_entry_release(count); 2817 return (KERN_NO_SPACE); 2818 } 2819 2820 /* We initially map a stack of only init_ssize. We will 2821 * grow as needed later. Since this is to be a grow 2822 * down stack, we map at the top of the range. 2823 * 2824 * Note: we would normally expect prot and max to be 2825 * VM_PROT_ALL, and cow to be 0. Possibly we should 2826 * eliminate these as input parameters, and just 2827 * pass these values here in the insert call. 2828 */ 2829 rv = vm_map_insert(map, &count, 2830 NULL, 0, addrbos + max_ssize - init_ssize, 2831 addrbos + max_ssize, prot, max, cow); 2832 2833 /* Now set the avail_ssize amount */ 2834 if (rv == KERN_SUCCESS) { 2835 if (prev_entry != &map->header) 2836 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count); 2837 new_stack_entry = prev_entry->next; 2838 if (new_stack_entry->end != addrbos + max_ssize || 2839 new_stack_entry->start != addrbos + max_ssize - init_ssize) 2840 panic ("Bad entry start/end for new stack entry"); 2841 else 2842 new_stack_entry->avail_ssize = max_ssize - init_ssize; 2843 } 2844 2845 vm_map_unlock(map); 2846 vm_map_entry_release(count); 2847 return (rv); 2848 } 2849 2850 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 2851 * desired address is already mapped, or if we successfully grow 2852 * the stack. Also returns KERN_SUCCESS if addr is outside the 2853 * stack range (this is strange, but preserves compatibility with 2854 * the grow function in vm_machdep.c). 2855 */ 2856 int 2857 vm_map_growstack (struct proc *p, vm_offset_t addr) 2858 { 2859 vm_map_entry_t prev_entry; 2860 vm_map_entry_t stack_entry; 2861 vm_map_entry_t new_stack_entry; 2862 struct vmspace *vm = p->p_vmspace; 2863 vm_map_t map = &vm->vm_map; 2864 vm_offset_t end; 2865 int grow_amount; 2866 int rv = KERN_SUCCESS; 2867 int is_procstack; 2868 int use_read_lock = 1; 2869 int count; 2870 2871 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2872 Retry: 2873 if (use_read_lock) 2874 vm_map_lock_read(map); 2875 else 2876 vm_map_lock(map); 2877 2878 /* If addr is already in the entry range, no need to grow.*/ 2879 if (vm_map_lookup_entry(map, addr, &prev_entry)) 2880 goto done; 2881 2882 if ((stack_entry = prev_entry->next) == &map->header) 2883 goto done; 2884 if (prev_entry == &map->header) 2885 end = stack_entry->start - stack_entry->avail_ssize; 2886 else 2887 end = prev_entry->end; 2888 2889 /* This next test mimics the old grow function in vm_machdep.c. 2890 * It really doesn't quite make sense, but we do it anyway 2891 * for compatibility. 2892 * 2893 * If not growable stack, return success. This signals the 2894 * caller to proceed as he would normally with normal vm. 2895 */ 2896 if (stack_entry->avail_ssize < 1 || 2897 addr >= stack_entry->start || 2898 addr < stack_entry->start - stack_entry->avail_ssize) { 2899 goto done; 2900 } 2901 2902 /* Find the minimum grow amount */ 2903 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE); 2904 if (grow_amount > stack_entry->avail_ssize) { 2905 rv = KERN_NO_SPACE; 2906 goto done; 2907 } 2908 2909 /* If there is no longer enough space between the entries 2910 * nogo, and adjust the available space. Note: this 2911 * should only happen if the user has mapped into the 2912 * stack area after the stack was created, and is 2913 * probably an error. 2914 * 2915 * This also effectively destroys any guard page the user 2916 * might have intended by limiting the stack size. 2917 */ 2918 if (grow_amount > stack_entry->start - end) { 2919 if (use_read_lock && vm_map_lock_upgrade(map)) { 2920 use_read_lock = 0; 2921 goto Retry; 2922 } 2923 use_read_lock = 0; 2924 stack_entry->avail_ssize = stack_entry->start - end; 2925 rv = KERN_NO_SPACE; 2926 goto done; 2927 } 2928 2929 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; 2930 2931 /* If this is the main process stack, see if we're over the 2932 * stack limit. 2933 */ 2934 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 2935 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 2936 rv = KERN_NO_SPACE; 2937 goto done; 2938 } 2939 2940 /* Round up the grow amount modulo SGROWSIZ */ 2941 grow_amount = roundup (grow_amount, sgrowsiz); 2942 if (grow_amount > stack_entry->avail_ssize) { 2943 grow_amount = stack_entry->avail_ssize; 2944 } 2945 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 2946 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 2947 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 2948 ctob(vm->vm_ssize); 2949 } 2950 2951 /* If we would blow our VMEM resource limit, no go */ 2952 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 2953 rv = KERN_NO_SPACE; 2954 goto done; 2955 } 2956 2957 if (use_read_lock && vm_map_lock_upgrade(map)) { 2958 use_read_lock = 0; 2959 goto Retry; 2960 } 2961 use_read_lock = 0; 2962 2963 /* Get the preliminary new entry start value */ 2964 addr = stack_entry->start - grow_amount; 2965 2966 /* If this puts us into the previous entry, cut back our growth 2967 * to the available space. Also, see the note above. 2968 */ 2969 if (addr < end) { 2970 stack_entry->avail_ssize = stack_entry->start - end; 2971 addr = end; 2972 } 2973 2974 rv = vm_map_insert(map, &count, 2975 NULL, 0, addr, stack_entry->start, 2976 VM_PROT_ALL, 2977 VM_PROT_ALL, 2978 0); 2979 2980 /* Adjust the available stack space by the amount we grew. */ 2981 if (rv == KERN_SUCCESS) { 2982 if (prev_entry != &map->header) 2983 vm_map_clip_end(map, prev_entry, addr, &count); 2984 new_stack_entry = prev_entry->next; 2985 if (new_stack_entry->end != stack_entry->start || 2986 new_stack_entry->start != addr) 2987 panic ("Bad stack grow start/end in new stack entry"); 2988 else { 2989 new_stack_entry->avail_ssize = stack_entry->avail_ssize - 2990 (new_stack_entry->end - 2991 new_stack_entry->start); 2992 if (is_procstack) 2993 vm->vm_ssize += btoc(new_stack_entry->end - 2994 new_stack_entry->start); 2995 } 2996 } 2997 2998 done: 2999 if (use_read_lock) 3000 vm_map_unlock_read(map); 3001 else 3002 vm_map_unlock(map); 3003 vm_map_entry_release(count); 3004 return (rv); 3005 } 3006 3007 /* 3008 * Unshare the specified VM space for exec. If other processes are 3009 * mapped to it, then create a new one. The new vmspace is null. 3010 */ 3011 3012 void 3013 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 3014 { 3015 struct vmspace *oldvmspace = p->p_vmspace; 3016 struct vmspace *newvmspace; 3017 vm_map_t map = &p->p_vmspace->vm_map; 3018 3019 /* 3020 * If we are execing a resident vmspace we fork it, otherwise 3021 * we create a new vmspace. Note that exitingcnt and upcalls 3022 * are not copied to the new vmspace. 3023 */ 3024 if (vmcopy) { 3025 newvmspace = vmspace_fork(vmcopy); 3026 } else { 3027 newvmspace = vmspace_alloc(map->min_offset, map->max_offset); 3028 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 3029 (caddr_t)&oldvmspace->vm_endcopy - 3030 (caddr_t)&oldvmspace->vm_startcopy); 3031 } 3032 3033 /* 3034 * This code is written like this for prototype purposes. The 3035 * goal is to avoid running down the vmspace here, but let the 3036 * other process's that are still using the vmspace to finally 3037 * run it down. Even though there is little or no chance of blocking 3038 * here, it is a good idea to keep this form for future mods. 3039 */ 3040 p->p_vmspace = newvmspace; 3041 pmap_pinit2(vmspace_pmap(newvmspace)); 3042 if (p == curproc) 3043 pmap_activate(p); 3044 vmspace_free(oldvmspace); 3045 } 3046 3047 /* 3048 * Unshare the specified VM space for forcing COW. This 3049 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3050 * 3051 * The exitingcnt test is not strictly necessary but has been 3052 * included for code sanity (to make the code a bit more deterministic). 3053 */ 3054 3055 void 3056 vmspace_unshare(struct proc *p) 3057 { 3058 struct vmspace *oldvmspace = p->p_vmspace; 3059 struct vmspace *newvmspace; 3060 3061 if (oldvmspace->vm_refcnt == 1 && oldvmspace->vm_exitingcnt == 0) 3062 return; 3063 newvmspace = vmspace_fork(oldvmspace); 3064 p->p_vmspace = newvmspace; 3065 pmap_pinit2(vmspace_pmap(newvmspace)); 3066 if (p == curproc) 3067 pmap_activate(p); 3068 vmspace_free(oldvmspace); 3069 } 3070 3071 /* 3072 * vm_map_lookup: 3073 * 3074 * Finds the VM object, offset, and 3075 * protection for a given virtual address in the 3076 * specified map, assuming a page fault of the 3077 * type specified. 3078 * 3079 * Leaves the map in question locked for read; return 3080 * values are guaranteed until a vm_map_lookup_done 3081 * call is performed. Note that the map argument 3082 * is in/out; the returned map must be used in 3083 * the call to vm_map_lookup_done. 3084 * 3085 * A handle (out_entry) is returned for use in 3086 * vm_map_lookup_done, to make that fast. 3087 * 3088 * If a lookup is requested with "write protection" 3089 * specified, the map may be changed to perform virtual 3090 * copying operations, although the data referenced will 3091 * remain the same. 3092 */ 3093 int 3094 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3095 vm_offset_t vaddr, 3096 vm_prot_t fault_typea, 3097 vm_map_entry_t *out_entry, /* OUT */ 3098 vm_object_t *object, /* OUT */ 3099 vm_pindex_t *pindex, /* OUT */ 3100 vm_prot_t *out_prot, /* OUT */ 3101 boolean_t *wired) /* OUT */ 3102 { 3103 vm_map_entry_t entry; 3104 vm_map_t map = *var_map; 3105 vm_prot_t prot; 3106 vm_prot_t fault_type = fault_typea; 3107 int use_read_lock = 1; 3108 int rv = KERN_SUCCESS; 3109 3110 RetryLookup: 3111 if (use_read_lock) 3112 vm_map_lock_read(map); 3113 else 3114 vm_map_lock(map); 3115 3116 /* 3117 * If the map has an interesting hint, try it before calling full 3118 * blown lookup routine. 3119 */ 3120 entry = map->hint; 3121 *out_entry = entry; 3122 3123 if ((entry == &map->header) || 3124 (vaddr < entry->start) || (vaddr >= entry->end)) { 3125 vm_map_entry_t tmp_entry; 3126 3127 /* 3128 * Entry was either not a valid hint, or the vaddr was not 3129 * contained in the entry, so do a full lookup. 3130 */ 3131 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { 3132 rv = KERN_INVALID_ADDRESS; 3133 goto done; 3134 } 3135 3136 entry = tmp_entry; 3137 *out_entry = entry; 3138 } 3139 3140 /* 3141 * Handle submaps. 3142 */ 3143 3144 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3145 vm_map_t old_map = map; 3146 3147 *var_map = map = entry->object.sub_map; 3148 if (use_read_lock) 3149 vm_map_unlock_read(old_map); 3150 else 3151 vm_map_unlock(old_map); 3152 use_read_lock = 1; 3153 goto RetryLookup; 3154 } 3155 3156 /* 3157 * Check whether this task is allowed to have this page. 3158 * Note the special case for MAP_ENTRY_COW 3159 * pages with an override. This is to implement a forced 3160 * COW for debuggers. 3161 */ 3162 3163 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3164 prot = entry->max_protection; 3165 else 3166 prot = entry->protection; 3167 3168 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3169 if ((fault_type & prot) != fault_type) { 3170 rv = KERN_PROTECTION_FAILURE; 3171 goto done; 3172 } 3173 3174 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3175 (entry->eflags & MAP_ENTRY_COW) && 3176 (fault_type & VM_PROT_WRITE) && 3177 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 3178 rv = KERN_PROTECTION_FAILURE; 3179 goto done; 3180 } 3181 3182 /* 3183 * If this page is not pageable, we have to get it for all possible 3184 * accesses. 3185 */ 3186 3187 *wired = (entry->wired_count != 0); 3188 if (*wired) 3189 prot = fault_type = entry->protection; 3190 3191 /* 3192 * If the entry was copy-on-write, we either ... 3193 */ 3194 3195 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3196 /* 3197 * If we want to write the page, we may as well handle that 3198 * now since we've got the map locked. 3199 * 3200 * If we don't need to write the page, we just demote the 3201 * permissions allowed. 3202 */ 3203 3204 if (fault_type & VM_PROT_WRITE) { 3205 /* 3206 * Make a new object, and place it in the object 3207 * chain. Note that no new references have appeared 3208 * -- one just moved from the map to the new 3209 * object. 3210 */ 3211 3212 if (use_read_lock && vm_map_lock_upgrade(map)) { 3213 use_read_lock = 0; 3214 goto RetryLookup; 3215 } 3216 use_read_lock = 0; 3217 3218 vm_object_shadow( 3219 &entry->object.vm_object, 3220 &entry->offset, 3221 atop(entry->end - entry->start)); 3222 3223 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 3224 } else { 3225 /* 3226 * We're attempting to read a copy-on-write page -- 3227 * don't allow writes. 3228 */ 3229 3230 prot &= ~VM_PROT_WRITE; 3231 } 3232 } 3233 3234 /* 3235 * Create an object if necessary. 3236 */ 3237 if (entry->object.vm_object == NULL && 3238 !map->system_map) { 3239 if (use_read_lock && vm_map_lock_upgrade(map)) { 3240 use_read_lock = 0; 3241 goto RetryLookup; 3242 } 3243 use_read_lock = 0; 3244 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT, 3245 atop(entry->end - entry->start)); 3246 entry->offset = 0; 3247 } 3248 3249 /* 3250 * Return the object/offset from this entry. If the entry was 3251 * copy-on-write or empty, it has been fixed up. 3252 */ 3253 3254 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3255 *object = entry->object.vm_object; 3256 3257 /* 3258 * Return whether this is the only map sharing this data. On 3259 * success we return with a read lock held on the map. On failure 3260 * we return with the map unlocked. 3261 */ 3262 *out_prot = prot; 3263 done: 3264 if (rv == KERN_SUCCESS) { 3265 if (use_read_lock == 0) 3266 vm_map_lock_downgrade(map); 3267 } else if (use_read_lock) { 3268 vm_map_unlock_read(map); 3269 } else { 3270 vm_map_unlock(map); 3271 } 3272 return (rv); 3273 } 3274 3275 /* 3276 * vm_map_lookup_done: 3277 * 3278 * Releases locks acquired by a vm_map_lookup 3279 * (according to the handle returned by that lookup). 3280 */ 3281 3282 void 3283 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) 3284 { 3285 /* 3286 * Unlock the main-level map 3287 */ 3288 vm_map_unlock_read(map); 3289 if (count) 3290 vm_map_entry_release(count); 3291 } 3292 3293 /* 3294 * Performs the copy_on_write operations necessary to allow the virtual copies 3295 * into user space to work. This has to be called for write(2) system calls 3296 * from other processes, file unlinking, and file size shrinkage. 3297 */ 3298 void 3299 vm_freeze_copyopts(vm_object_t object, vm_pindex_t froma, vm_pindex_t toa) 3300 { 3301 int rv; 3302 vm_object_t robject; 3303 vm_pindex_t idx; 3304 3305 if ((object == NULL) || 3306 ((object->flags & OBJ_OPT) == 0)) 3307 return; 3308 3309 if (object->shadow_count > object->ref_count) 3310 panic("vm_freeze_copyopts: sc > rc"); 3311 3312 while ((robject = LIST_FIRST(&object->shadow_head)) != NULL) { 3313 vm_pindex_t bo_pindex; 3314 vm_page_t m_in, m_out; 3315 3316 bo_pindex = OFF_TO_IDX(robject->backing_object_offset); 3317 3318 vm_object_reference(robject); 3319 3320 vm_object_pip_wait(robject, "objfrz"); 3321 3322 if (robject->ref_count == 1) { 3323 vm_object_deallocate(robject); 3324 continue; 3325 } 3326 3327 vm_object_pip_add(robject, 1); 3328 3329 for (idx = 0; idx < robject->size; idx++) { 3330 3331 m_out = vm_page_grab(robject, idx, 3332 VM_ALLOC_NORMAL | VM_ALLOC_RETRY); 3333 3334 if (m_out->valid == 0) { 3335 m_in = vm_page_grab(object, bo_pindex + idx, 3336 VM_ALLOC_NORMAL | VM_ALLOC_RETRY); 3337 if (m_in->valid == 0) { 3338 rv = vm_pager_get_pages(object, &m_in, 1, 0); 3339 if (rv != VM_PAGER_OK) { 3340 printf("vm_freeze_copyopts: cannot read page from file: %lx\n", (long)m_in->pindex); 3341 continue; 3342 } 3343 vm_page_deactivate(m_in); 3344 } 3345 3346 vm_page_protect(m_in, VM_PROT_NONE); 3347 pmap_copy_page(VM_PAGE_TO_PHYS(m_in), VM_PAGE_TO_PHYS(m_out)); 3348 m_out->valid = m_in->valid; 3349 vm_page_dirty(m_out); 3350 vm_page_activate(m_out); 3351 vm_page_wakeup(m_in); 3352 } 3353 vm_page_wakeup(m_out); 3354 } 3355 3356 object->shadow_count--; 3357 object->ref_count--; 3358 LIST_REMOVE(robject, shadow_list); 3359 robject->backing_object = NULL; 3360 robject->backing_object_offset = 0; 3361 3362 vm_object_pip_wakeup(robject); 3363 vm_object_deallocate(robject); 3364 } 3365 3366 vm_object_clear_flag(object, OBJ_OPT); 3367 } 3368 3369 #include "opt_ddb.h" 3370 #ifdef DDB 3371 #include <sys/kernel.h> 3372 3373 #include <ddb/ddb.h> 3374 3375 /* 3376 * vm_map_print: [ debug ] 3377 */ 3378 DB_SHOW_COMMAND(map, vm_map_print) 3379 { 3380 static int nlines; 3381 /* XXX convert args. */ 3382 vm_map_t map = (vm_map_t)addr; 3383 boolean_t full = have_addr; 3384 3385 vm_map_entry_t entry; 3386 3387 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 3388 (void *)map, 3389 (void *)map->pmap, map->nentries, map->timestamp); 3390 nlines++; 3391 3392 if (!full && db_indent) 3393 return; 3394 3395 db_indent += 2; 3396 for (entry = map->header.next; entry != &map->header; 3397 entry = entry->next) { 3398 db_iprintf("map entry %p: start=%p, end=%p\n", 3399 (void *)entry, (void *)entry->start, (void *)entry->end); 3400 nlines++; 3401 { 3402 static char *inheritance_name[4] = 3403 {"share", "copy", "none", "donate_copy"}; 3404 3405 db_iprintf(" prot=%x/%x/%s", 3406 entry->protection, 3407 entry->max_protection, 3408 inheritance_name[(int)(unsigned char)entry->inheritance]); 3409 if (entry->wired_count != 0) 3410 db_printf(", wired"); 3411 } 3412 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 3413 /* XXX no %qd in kernel. Truncate entry->offset. */ 3414 db_printf(", share=%p, offset=0x%lx\n", 3415 (void *)entry->object.sub_map, 3416 (long)entry->offset); 3417 nlines++; 3418 if ((entry->prev == &map->header) || 3419 (entry->prev->object.sub_map != 3420 entry->object.sub_map)) { 3421 db_indent += 2; 3422 vm_map_print((db_expr_t)(intptr_t) 3423 entry->object.sub_map, 3424 full, 0, (char *)0); 3425 db_indent -= 2; 3426 } 3427 } else { 3428 /* XXX no %qd in kernel. Truncate entry->offset. */ 3429 db_printf(", object=%p, offset=0x%lx", 3430 (void *)entry->object.vm_object, 3431 (long)entry->offset); 3432 if (entry->eflags & MAP_ENTRY_COW) 3433 db_printf(", copy (%s)", 3434 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 3435 db_printf("\n"); 3436 nlines++; 3437 3438 if ((entry->prev == &map->header) || 3439 (entry->prev->object.vm_object != 3440 entry->object.vm_object)) { 3441 db_indent += 2; 3442 vm_object_print((db_expr_t)(intptr_t) 3443 entry->object.vm_object, 3444 full, 0, (char *)0); 3445 nlines += 4; 3446 db_indent -= 2; 3447 } 3448 } 3449 } 3450 db_indent -= 2; 3451 if (db_indent == 0) 3452 nlines = 0; 3453 } 3454 3455 3456 DB_SHOW_COMMAND(procvm, procvm) 3457 { 3458 struct proc *p; 3459 3460 if (have_addr) { 3461 p = (struct proc *) addr; 3462 } else { 3463 p = curproc; 3464 } 3465 3466 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 3467 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 3468 (void *)vmspace_pmap(p->p_vmspace)); 3469 3470 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 3471 } 3472 3473 #endif /* DDB */ 3474