1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 39 * 40 * 41 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42 * All rights reserved. 43 * 44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45 * 46 * Permission to use, copy, modify and distribute this software and 47 * its documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 * 66 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $ 67 * $DragonFly: src/sys/vm/vm_map.c,v 1.56 2007/04/29 18:25:41 dillon Exp $ 68 */ 69 70 /* 71 * Virtual memory mapping module. 72 */ 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/kernel.h> 77 #include <sys/proc.h> 78 #include <sys/serialize.h> 79 #include <sys/lock.h> 80 #include <sys/vmmeter.h> 81 #include <sys/mman.h> 82 #include <sys/vnode.h> 83 #include <sys/resourcevar.h> 84 #include <sys/shm.h> 85 #include <sys/tree.h> 86 #include <sys/malloc.h> 87 88 #include <vm/vm.h> 89 #include <vm/vm_param.h> 90 #include <vm/pmap.h> 91 #include <vm/vm_map.h> 92 #include <vm/vm_page.h> 93 #include <vm/vm_object.h> 94 #include <vm/vm_pager.h> 95 #include <vm/vm_kern.h> 96 #include <vm/vm_extern.h> 97 #include <vm/swap_pager.h> 98 #include <vm/vm_zone.h> 99 100 #include <sys/thread2.h> 101 #include <sys/sysref2.h> 102 #include <sys/random.h> 103 #include <sys/sysctl.h> 104 105 /* 106 * Virtual memory maps provide for the mapping, protection, and sharing 107 * of virtual memory objects. In addition, this module provides for an 108 * efficient virtual copy of memory from one map to another. 109 * 110 * Synchronization is required prior to most operations. 111 * 112 * Maps consist of an ordered doubly-linked list of simple entries. 113 * A hint and a RB tree is used to speed-up lookups. 114 * 115 * Callers looking to modify maps specify start/end addresses which cause 116 * the related map entry to be clipped if necessary, and then later 117 * recombined if the pieces remained compatible. 118 * 119 * Virtual copy operations are performed by copying VM object references 120 * from one map to another, and then marking both regions as copy-on-write. 121 */ 122 static void vmspace_terminate(struct vmspace *vm); 123 static void vmspace_lock(struct vmspace *vm); 124 static void vmspace_unlock(struct vmspace *vm); 125 static void vmspace_dtor(void *obj, void *private); 126 127 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore"); 128 129 struct sysref_class vmspace_sysref_class = { 130 .name = "vmspace", 131 .mtype = M_VMSPACE, 132 .proto = SYSREF_PROTO_VMSPACE, 133 .offset = offsetof(struct vmspace, vm_sysref), 134 .objsize = sizeof(struct vmspace), 135 .nom_cache = 32, 136 .flags = SRC_MANAGEDINIT, 137 .dtor = vmspace_dtor, 138 .ops = { 139 .terminate = (sysref_terminate_func_t)vmspace_terminate, 140 .lock = (sysref_lock_func_t)vmspace_lock, 141 .unlock = (sysref_lock_func_t)vmspace_unlock 142 } 143 }; 144 145 /* 146 * per-cpu page table cross mappings are initialized in early boot 147 * and might require a considerable number of vm_map_entry structures. 148 */ 149 #define VMEPERCPU (MAXCPU+1) 150 151 static struct vm_zone mapentzone_store, mapzone_store; 152 static vm_zone_t mapentzone, mapzone; 153 static struct vm_object mapentobj, mapobj; 154 155 static struct vm_map_entry map_entry_init[MAX_MAPENT]; 156 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU]; 157 static struct vm_map map_init[MAX_KMAP]; 158 159 static int randomize_mmap; 160 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0, 161 "Randomize mmap offsets"); 162 163 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref); 164 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *); 165 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); 166 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 167 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 168 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); 169 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); 170 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, 171 vm_map_entry_t); 172 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); 173 174 /* 175 * Initialize the vm_map module. Must be called before any other vm_map 176 * routines. 177 * 178 * Map and entry structures are allocated from the general purpose 179 * memory pool with some exceptions: 180 * 181 * - The kernel map is allocated statically. 182 * - Initial kernel map entries are allocated out of a static pool. 183 * 184 * These restrictions are necessary since malloc() uses the 185 * maps and requires map entries. 186 * 187 * Called from the low level boot code only. 188 */ 189 void 190 vm_map_startup(void) 191 { 192 mapzone = &mapzone_store; 193 zbootinit(mapzone, "MAP", sizeof (struct vm_map), 194 map_init, MAX_KMAP); 195 mapentzone = &mapentzone_store; 196 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), 197 map_entry_init, MAX_MAPENT); 198 } 199 200 /* 201 * Called prior to any vmspace allocations. 202 * 203 * Called from the low level boot code only. 204 */ 205 void 206 vm_init2(void) 207 { 208 zinitna(mapentzone, &mapentobj, NULL, 0, 0, 209 ZONE_USE_RESERVE | ZONE_SPECIAL, 1); 210 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1); 211 pmap_init2(); 212 vm_object_init2(); 213 } 214 215 216 /* 217 * Red black tree functions 218 * 219 * The caller must hold the related map lock. 220 */ 221 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); 222 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); 223 224 /* a->start is address, and the only field has to be initialized */ 225 static int 226 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) 227 { 228 if (a->start < b->start) 229 return(-1); 230 else if (a->start > b->start) 231 return(1); 232 return(0); 233 } 234 235 /* 236 * Allocate a vmspace structure, including a vm_map and pmap. 237 * Initialize numerous fields. While the initial allocation is zerod, 238 * subsequence reuse from the objcache leaves elements of the structure 239 * intact (particularly the pmap), so portions must be zerod. 240 * 241 * The structure is not considered activated until we call sysref_activate(). 242 * 243 * No requirements. 244 */ 245 struct vmspace * 246 vmspace_alloc(vm_offset_t min, vm_offset_t max) 247 { 248 struct vmspace *vm; 249 250 vm = sysref_alloc(&vmspace_sysref_class); 251 bzero(&vm->vm_startcopy, 252 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy); 253 vm_map_init(&vm->vm_map, min, max, NULL); /* initializes token */ 254 255 /* 256 * Use a hold to prevent any additional racing hold from terminating 257 * the vmspace before we manage to activate it. This also acquires 258 * the token for safety. 259 */ 260 KKASSERT(vm->vm_holdcount == 0); 261 KKASSERT(vm->vm_exitingcnt == 0); 262 vmspace_hold(vm); 263 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */ 264 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 265 vm->vm_shm = NULL; 266 vm->vm_flags = 0; 267 cpu_vmspace_alloc(vm); 268 sysref_activate(&vm->vm_sysref); 269 vmspace_drop(vm); 270 271 return (vm); 272 } 273 274 /* 275 * Free a primary reference to a vmspace. This can trigger a 276 * stage-1 termination. 277 */ 278 void 279 vmspace_free(struct vmspace *vm) 280 { 281 /* 282 * We want all finalization to occur via vmspace_drop() so we 283 * need to hold the vm around the put. 284 */ 285 vmspace_hold(vm); 286 sysref_put(&vm->vm_sysref); 287 vmspace_drop(vm); 288 } 289 290 void 291 vmspace_ref(struct vmspace *vm) 292 { 293 sysref_get(&vm->vm_sysref); 294 } 295 296 void 297 vmspace_hold(struct vmspace *vm) 298 { 299 refcount_acquire(&vm->vm_holdcount); 300 lwkt_gettoken(&vm->vm_map.token); 301 } 302 303 void 304 vmspace_drop(struct vmspace *vm) 305 { 306 lwkt_reltoken(&vm->vm_map.token); 307 if (refcount_release(&vm->vm_holdcount)) { 308 if (vm->vm_exitingcnt == 0 && 309 sysref_isinactive(&vm->vm_sysref)) { 310 vmspace_terminate(vm); 311 } 312 } 313 } 314 315 /* 316 * dtor function - Some elements of the pmap are retained in the 317 * free-cached vmspaces to improve performance. We have to clean them up 318 * here before returning the vmspace to the memory pool. 319 * 320 * No requirements. 321 */ 322 static void 323 vmspace_dtor(void *obj, void *private) 324 { 325 struct vmspace *vm = obj; 326 327 pmap_puninit(vmspace_pmap(vm)); 328 } 329 330 /* 331 * Called in three cases: 332 * 333 * (1) When the last sysref is dropped and the vmspace becomes inactive. 334 * (holdcount will not be 0 because the vmspace is held through the op) 335 * 336 * (2) When exitingcount becomes 0 on the last reap 337 * (holdcount will not be 0 because the vmspace is held through the op) 338 * 339 * (3) When the holdcount becomes 0 in addition to the above two 340 * 341 * sysref will not scrap the object until we call sysref_put() once more 342 * after the last ref has been dropped. 343 * 344 * VMSPACE_EXIT1 flags the primary deactivation 345 * VMSPACE_EXIT2 flags the last reap 346 */ 347 static void 348 vmspace_terminate(struct vmspace *vm) 349 { 350 int count; 351 352 /* 353 * 354 */ 355 lwkt_gettoken(&vm->vm_map.token); 356 if ((vm->vm_flags & VMSPACE_EXIT1) == 0) { 357 vm->vm_flags |= VMSPACE_EXIT1; 358 shmexit(vm); 359 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, 360 VM_MAX_USER_ADDRESS); 361 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, 362 VM_MAX_USER_ADDRESS); 363 } 364 if ((vm->vm_flags & VMSPACE_EXIT2) == 0 && vm->vm_exitingcnt == 0) { 365 vm->vm_flags |= VMSPACE_EXIT2; 366 cpu_vmspace_free(vm); 367 shmexit(vm); 368 KKASSERT(vm->vm_upcalls == NULL); 369 370 /* 371 * Lock the map, to wait out all other references to it. 372 * Delete all of the mappings and pages they hold, then call 373 * the pmap module to reclaim anything left. 374 */ 375 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 376 vm_map_lock(&vm->vm_map); 377 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 378 vm->vm_map.max_offset, &count); 379 vm_map_unlock(&vm->vm_map); 380 vm_map_entry_release(count); 381 382 lwkt_gettoken(&vmspace_pmap(vm)->pm_token); 383 pmap_release(vmspace_pmap(vm)); 384 lwkt_reltoken(&vmspace_pmap(vm)->pm_token); 385 } 386 387 lwkt_reltoken(&vm->vm_map.token); 388 if (vm->vm_exitingcnt == 0 && vm->vm_holdcount == 0) { 389 KKASSERT(vm->vm_flags & VMSPACE_EXIT1); 390 KKASSERT(vm->vm_flags & VMSPACE_EXIT2); 391 sysref_put(&vm->vm_sysref); 392 } 393 } 394 395 /* 396 * vmspaces are not currently locked. 397 */ 398 static void 399 vmspace_lock(struct vmspace *vm __unused) 400 { 401 } 402 403 static void 404 vmspace_unlock(struct vmspace *vm __unused) 405 { 406 } 407 408 /* 409 * This is called during exit indicating that the vmspace is no 410 * longer in used by an exiting process, but the process has not yet 411 * been reaped. 412 * 413 * No requirements. 414 */ 415 void 416 vmspace_exitbump(struct vmspace *vm) 417 { 418 vmspace_hold(vm); 419 ++vm->vm_exitingcnt; 420 vmspace_drop(vm); /* handles termination sequencing */ 421 } 422 423 /* 424 * Decrement the exitingcnt and issue the stage-2 termination if it becomes 425 * zero and the stage1 termination has already occured. 426 * 427 * No requirements. 428 */ 429 void 430 vmspace_exitfree(struct proc *p) 431 { 432 struct vmspace *vm; 433 434 vm = p->p_vmspace; 435 p->p_vmspace = NULL; 436 vmspace_hold(vm); 437 KKASSERT(vm->vm_exitingcnt > 0); 438 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref)) 439 vmspace_terminate(vm); 440 vmspace_drop(vm); /* handles termination sequencing */ 441 } 442 443 /* 444 * Swap useage is determined by taking the proportional swap used by 445 * VM objects backing the VM map. To make up for fractional losses, 446 * if the VM object has any swap use at all the associated map entries 447 * count for at least 1 swap page. 448 * 449 * No requirements. 450 */ 451 int 452 vmspace_swap_count(struct vmspace *vm) 453 { 454 vm_map_t map = &vm->vm_map; 455 vm_map_entry_t cur; 456 vm_object_t object; 457 int count = 0; 458 int n; 459 460 vmspace_hold(vm); 461 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 462 switch(cur->maptype) { 463 case VM_MAPTYPE_NORMAL: 464 case VM_MAPTYPE_VPAGETABLE: 465 if ((object = cur->object.vm_object) == NULL) 466 break; 467 if (object->swblock_count) { 468 n = (cur->end - cur->start) / PAGE_SIZE; 469 count += object->swblock_count * 470 SWAP_META_PAGES * n / object->size + 1; 471 } 472 break; 473 default: 474 break; 475 } 476 } 477 vmspace_drop(vm); 478 479 return(count); 480 } 481 482 /* 483 * Calculate the approximate number of anonymous pages in use by 484 * this vmspace. To make up for fractional losses, we count each 485 * VM object as having at least 1 anonymous page. 486 * 487 * No requirements. 488 */ 489 int 490 vmspace_anonymous_count(struct vmspace *vm) 491 { 492 vm_map_t map = &vm->vm_map; 493 vm_map_entry_t cur; 494 vm_object_t object; 495 int count = 0; 496 497 vmspace_hold(vm); 498 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 499 switch(cur->maptype) { 500 case VM_MAPTYPE_NORMAL: 501 case VM_MAPTYPE_VPAGETABLE: 502 if ((object = cur->object.vm_object) == NULL) 503 break; 504 if (object->type != OBJT_DEFAULT && 505 object->type != OBJT_SWAP) { 506 break; 507 } 508 count += object->resident_page_count; 509 break; 510 default: 511 break; 512 } 513 } 514 vmspace_drop(vm); 515 516 return(count); 517 } 518 519 /* 520 * Creates and returns a new empty VM map with the given physical map 521 * structure, and having the given lower and upper address bounds. 522 * 523 * No requirements. 524 */ 525 vm_map_t 526 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max) 527 { 528 if (result == NULL) 529 result = zalloc(mapzone); 530 vm_map_init(result, min, max, pmap); 531 return (result); 532 } 533 534 /* 535 * Initialize an existing vm_map structure such as that in the vmspace 536 * structure. The pmap is initialized elsewhere. 537 * 538 * No requirements. 539 */ 540 void 541 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap) 542 { 543 map->header.next = map->header.prev = &map->header; 544 RB_INIT(&map->rb_root); 545 map->nentries = 0; 546 map->size = 0; 547 map->system_map = 0; 548 map->min_offset = min; 549 map->max_offset = max; 550 map->pmap = pmap; 551 map->first_free = &map->header; 552 map->hint = &map->header; 553 map->timestamp = 0; 554 map->flags = 0; 555 lwkt_token_init(&map->token, "vm_map"); 556 lockinit(&map->lock, "thrd_sleep", (hz + 9) / 10, 0); 557 TUNABLE_INT("vm.cache_vmspaces", &vmspace_sysref_class.nom_cache); 558 } 559 560 /* 561 * Shadow the vm_map_entry's object. This typically needs to be done when 562 * a write fault is taken on an entry which had previously been cloned by 563 * fork(). The shared object (which might be NULL) must become private so 564 * we add a shadow layer above it. 565 * 566 * Object allocation for anonymous mappings is defered as long as possible. 567 * When creating a shadow, however, the underlying object must be instantiated 568 * so it can be shared. 569 * 570 * If the map segment is governed by a virtual page table then it is 571 * possible to address offsets beyond the mapped area. Just allocate 572 * a maximally sized object for this case. 573 * 574 * The vm_map must be exclusively locked. 575 * No other requirements. 576 */ 577 static 578 void 579 vm_map_entry_shadow(vm_map_entry_t entry, int addref) 580 { 581 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 582 vm_object_shadow(&entry->object.vm_object, &entry->offset, 583 0x7FFFFFFF, addref); /* XXX */ 584 } else { 585 vm_object_shadow(&entry->object.vm_object, &entry->offset, 586 atop(entry->end - entry->start), addref); 587 } 588 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 589 } 590 591 /* 592 * Allocate an object for a vm_map_entry. 593 * 594 * Object allocation for anonymous mappings is defered as long as possible. 595 * This function is called when we can defer no longer, generally when a map 596 * entry might be split or forked or takes a page fault. 597 * 598 * If the map segment is governed by a virtual page table then it is 599 * possible to address offsets beyond the mapped area. Just allocate 600 * a maximally sized object for this case. 601 * 602 * The vm_map must be exclusively locked. 603 * No other requirements. 604 */ 605 void 606 vm_map_entry_allocate_object(vm_map_entry_t entry) 607 { 608 vm_object_t obj; 609 610 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 611 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */ 612 } else { 613 obj = vm_object_allocate(OBJT_DEFAULT, 614 atop(entry->end - entry->start)); 615 } 616 entry->object.vm_object = obj; 617 entry->offset = 0; 618 } 619 620 /* 621 * Set an initial negative count so the first attempt to reserve 622 * space preloads a bunch of vm_map_entry's for this cpu. Also 623 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to 624 * map a new page for vm_map_entry structures. SMP systems are 625 * particularly sensitive. 626 * 627 * This routine is called in early boot so we cannot just call 628 * vm_map_entry_reserve(). 629 * 630 * Called from the low level boot code only (for each cpu) 631 */ 632 void 633 vm_map_entry_reserve_cpu_init(globaldata_t gd) 634 { 635 vm_map_entry_t entry; 636 int i; 637 638 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2; 639 entry = &cpu_map_entry_init[gd->gd_cpuid][0]; 640 for (i = 0; i < VMEPERCPU; ++i, ++entry) { 641 entry->next = gd->gd_vme_base; 642 gd->gd_vme_base = entry; 643 } 644 } 645 646 /* 647 * Reserves vm_map_entry structures so code later on can manipulate 648 * map_entry structures within a locked map without blocking trying 649 * to allocate a new vm_map_entry. 650 * 651 * No requirements. 652 */ 653 int 654 vm_map_entry_reserve(int count) 655 { 656 struct globaldata *gd = mycpu; 657 vm_map_entry_t entry; 658 659 /* 660 * Make sure we have enough structures in gd_vme_base to handle 661 * the reservation request. 662 * 663 * The critical section protects access to the per-cpu gd. 664 */ 665 crit_enter(); 666 while (gd->gd_vme_avail < count) { 667 entry = zalloc(mapentzone); 668 entry->next = gd->gd_vme_base; 669 gd->gd_vme_base = entry; 670 ++gd->gd_vme_avail; 671 } 672 gd->gd_vme_avail -= count; 673 crit_exit(); 674 675 return(count); 676 } 677 678 /* 679 * Releases previously reserved vm_map_entry structures that were not 680 * used. If we have too much junk in our per-cpu cache clean some of 681 * it out. 682 * 683 * No requirements. 684 */ 685 void 686 vm_map_entry_release(int count) 687 { 688 struct globaldata *gd = mycpu; 689 vm_map_entry_t entry; 690 691 crit_enter(); 692 gd->gd_vme_avail += count; 693 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) { 694 entry = gd->gd_vme_base; 695 KKASSERT(entry != NULL); 696 gd->gd_vme_base = entry->next; 697 --gd->gd_vme_avail; 698 crit_exit(); 699 zfree(mapentzone, entry); 700 crit_enter(); 701 } 702 crit_exit(); 703 } 704 705 /* 706 * Reserve map entry structures for use in kernel_map itself. These 707 * entries have *ALREADY* been reserved on a per-cpu basis when the map 708 * was inited. This function is used by zalloc() to avoid a recursion 709 * when zalloc() itself needs to allocate additional kernel memory. 710 * 711 * This function works like the normal reserve but does not load the 712 * vm_map_entry cache (because that would result in an infinite 713 * recursion). Note that gd_vme_avail may go negative. This is expected. 714 * 715 * Any caller of this function must be sure to renormalize after 716 * potentially eating entries to ensure that the reserve supply 717 * remains intact. 718 * 719 * No requirements. 720 */ 721 int 722 vm_map_entry_kreserve(int count) 723 { 724 struct globaldata *gd = mycpu; 725 726 crit_enter(); 727 gd->gd_vme_avail -= count; 728 crit_exit(); 729 KASSERT(gd->gd_vme_base != NULL, 730 ("no reserved entries left, gd_vme_avail = %d\n", 731 gd->gd_vme_avail)); 732 return(count); 733 } 734 735 /* 736 * Release previously reserved map entries for kernel_map. We do not 737 * attempt to clean up like the normal release function as this would 738 * cause an unnecessary (but probably not fatal) deep procedure call. 739 * 740 * No requirements. 741 */ 742 void 743 vm_map_entry_krelease(int count) 744 { 745 struct globaldata *gd = mycpu; 746 747 crit_enter(); 748 gd->gd_vme_avail += count; 749 crit_exit(); 750 } 751 752 /* 753 * Allocates a VM map entry for insertion. No entry fields are filled in. 754 * 755 * The entries should have previously been reserved. The reservation count 756 * is tracked in (*countp). 757 * 758 * No requirements. 759 */ 760 static vm_map_entry_t 761 vm_map_entry_create(vm_map_t map, int *countp) 762 { 763 struct globaldata *gd = mycpu; 764 vm_map_entry_t entry; 765 766 KKASSERT(*countp > 0); 767 --*countp; 768 crit_enter(); 769 entry = gd->gd_vme_base; 770 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); 771 gd->gd_vme_base = entry->next; 772 crit_exit(); 773 774 return(entry); 775 } 776 777 /* 778 * Dispose of a vm_map_entry that is no longer being referenced. 779 * 780 * No requirements. 781 */ 782 static void 783 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) 784 { 785 struct globaldata *gd = mycpu; 786 787 KKASSERT(map->hint != entry); 788 KKASSERT(map->first_free != entry); 789 790 ++*countp; 791 crit_enter(); 792 entry->next = gd->gd_vme_base; 793 gd->gd_vme_base = entry; 794 crit_exit(); 795 } 796 797 798 /* 799 * Insert/remove entries from maps. 800 * 801 * The related map must be exclusively locked. 802 * The caller must hold map->token 803 * No other requirements. 804 */ 805 static __inline void 806 vm_map_entry_link(vm_map_t map, 807 vm_map_entry_t after_where, 808 vm_map_entry_t entry) 809 { 810 ASSERT_VM_MAP_LOCKED(map); 811 812 map->nentries++; 813 entry->prev = after_where; 814 entry->next = after_where->next; 815 entry->next->prev = entry; 816 after_where->next = entry; 817 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) 818 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); 819 } 820 821 static __inline void 822 vm_map_entry_unlink(vm_map_t map, 823 vm_map_entry_t entry) 824 { 825 vm_map_entry_t prev; 826 vm_map_entry_t next; 827 828 ASSERT_VM_MAP_LOCKED(map); 829 830 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 831 panic("vm_map_entry_unlink: attempt to mess with " 832 "locked entry! %p", entry); 833 } 834 prev = entry->prev; 835 next = entry->next; 836 next->prev = prev; 837 prev->next = next; 838 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); 839 map->nentries--; 840 } 841 842 /* 843 * Finds the map entry containing (or immediately preceding) the specified 844 * address in the given map. The entry is returned in (*entry). 845 * 846 * The boolean result indicates whether the address is actually contained 847 * in the map. 848 * 849 * The related map must be locked. 850 * No other requirements. 851 */ 852 boolean_t 853 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry) 854 { 855 vm_map_entry_t tmp; 856 vm_map_entry_t last; 857 858 ASSERT_VM_MAP_LOCKED(map); 859 #if 0 860 /* 861 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive 862 * the hint code with the red-black lookup meets with system crashes 863 * and lockups. We do not yet know why. 864 * 865 * It is possible that the problem is related to the setting 866 * of the hint during map_entry deletion, in the code specified 867 * at the GGG comment later on in this file. 868 * 869 * YYY More likely it's because this function can be called with 870 * a shared lock on the map, resulting in map->hint updates possibly 871 * racing. Fixed now but untested. 872 */ 873 /* 874 * Quickly check the cached hint, there's a good chance of a match. 875 */ 876 tmp = map->hint; 877 cpu_ccfence(); 878 if (tmp != &map->header) { 879 if (address >= tmp->start && address < tmp->end) { 880 *entry = tmp; 881 return(TRUE); 882 } 883 } 884 #endif 885 886 /* 887 * Locate the record from the top of the tree. 'last' tracks the 888 * closest prior record and is returned if no match is found, which 889 * in binary tree terms means tracking the most recent right-branch 890 * taken. If there is no prior record, &map->header is returned. 891 */ 892 last = &map->header; 893 tmp = RB_ROOT(&map->rb_root); 894 895 while (tmp) { 896 if (address >= tmp->start) { 897 if (address < tmp->end) { 898 *entry = tmp; 899 map->hint = tmp; 900 return(TRUE); 901 } 902 last = tmp; 903 tmp = RB_RIGHT(tmp, rb_entry); 904 } else { 905 tmp = RB_LEFT(tmp, rb_entry); 906 } 907 } 908 *entry = last; 909 return (FALSE); 910 } 911 912 /* 913 * Inserts the given whole VM object into the target map at the specified 914 * address range. The object's size should match that of the address range. 915 * 916 * The map must be exclusively locked. 917 * The object must be held. 918 * The caller must have reserved sufficient vm_map_entry structures. 919 * 920 * If object is non-NULL, ref count must be bumped by caller prior to 921 * making call to account for the new entry. 922 */ 923 int 924 vm_map_insert(vm_map_t map, int *countp, 925 vm_object_t object, vm_ooffset_t offset, 926 vm_offset_t start, vm_offset_t end, 927 vm_maptype_t maptype, 928 vm_prot_t prot, vm_prot_t max, 929 int cow) 930 { 931 vm_map_entry_t new_entry; 932 vm_map_entry_t prev_entry; 933 vm_map_entry_t temp_entry; 934 vm_eflags_t protoeflags; 935 int must_drop = 0; 936 937 ASSERT_VM_MAP_LOCKED(map); 938 if (object) 939 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 940 941 /* 942 * Check that the start and end points are not bogus. 943 */ 944 if ((start < map->min_offset) || (end > map->max_offset) || 945 (start >= end)) 946 return (KERN_INVALID_ADDRESS); 947 948 /* 949 * Find the entry prior to the proposed starting address; if it's part 950 * of an existing entry, this range is bogus. 951 */ 952 if (vm_map_lookup_entry(map, start, &temp_entry)) 953 return (KERN_NO_SPACE); 954 955 prev_entry = temp_entry; 956 957 /* 958 * Assert that the next entry doesn't overlap the end point. 959 */ 960 961 if ((prev_entry->next != &map->header) && 962 (prev_entry->next->start < end)) 963 return (KERN_NO_SPACE); 964 965 protoeflags = 0; 966 967 if (cow & MAP_COPY_ON_WRITE) 968 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 969 970 if (cow & MAP_NOFAULT) { 971 protoeflags |= MAP_ENTRY_NOFAULT; 972 973 KASSERT(object == NULL, 974 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 975 } 976 if (cow & MAP_DISABLE_SYNCER) 977 protoeflags |= MAP_ENTRY_NOSYNC; 978 if (cow & MAP_DISABLE_COREDUMP) 979 protoeflags |= MAP_ENTRY_NOCOREDUMP; 980 if (cow & MAP_IS_STACK) 981 protoeflags |= MAP_ENTRY_STACK; 982 if (cow & MAP_IS_KSTACK) 983 protoeflags |= MAP_ENTRY_KSTACK; 984 985 lwkt_gettoken(&map->token); 986 987 if (object) { 988 /* 989 * When object is non-NULL, it could be shared with another 990 * process. We have to set or clear OBJ_ONEMAPPING 991 * appropriately. 992 */ 993 if ((object->ref_count > 1) || (object->shadow_count != 0)) { 994 vm_object_clear_flag(object, OBJ_ONEMAPPING); 995 } 996 } 997 else if ((prev_entry != &map->header) && 998 (prev_entry->eflags == protoeflags) && 999 (prev_entry->end == start) && 1000 (prev_entry->wired_count == 0) && 1001 prev_entry->maptype == maptype && 1002 ((prev_entry->object.vm_object == NULL) || 1003 vm_object_coalesce(prev_entry->object.vm_object, 1004 OFF_TO_IDX(prev_entry->offset), 1005 (vm_size_t)(prev_entry->end - prev_entry->start), 1006 (vm_size_t)(end - prev_entry->end)))) { 1007 /* 1008 * We were able to extend the object. Determine if we 1009 * can extend the previous map entry to include the 1010 * new range as well. 1011 */ 1012 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 1013 (prev_entry->protection == prot) && 1014 (prev_entry->max_protection == max)) { 1015 map->size += (end - prev_entry->end); 1016 prev_entry->end = end; 1017 vm_map_simplify_entry(map, prev_entry, countp); 1018 lwkt_reltoken(&map->token); 1019 return (KERN_SUCCESS); 1020 } 1021 1022 /* 1023 * If we can extend the object but cannot extend the 1024 * map entry, we have to create a new map entry. We 1025 * must bump the ref count on the extended object to 1026 * account for it. object may be NULL. 1027 */ 1028 object = prev_entry->object.vm_object; 1029 offset = prev_entry->offset + 1030 (prev_entry->end - prev_entry->start); 1031 if (object) { 1032 vm_object_hold(object); 1033 vm_object_chain_wait(object); 1034 vm_object_reference_locked(object); 1035 must_drop = 1; 1036 } 1037 } 1038 1039 /* 1040 * NOTE: if conditionals fail, object can be NULL here. This occurs 1041 * in things like the buffer map where we manage kva but do not manage 1042 * backing objects. 1043 */ 1044 1045 /* 1046 * Create a new entry 1047 */ 1048 1049 new_entry = vm_map_entry_create(map, countp); 1050 new_entry->start = start; 1051 new_entry->end = end; 1052 1053 new_entry->maptype = maptype; 1054 new_entry->eflags = protoeflags; 1055 new_entry->object.vm_object = object; 1056 new_entry->offset = offset; 1057 new_entry->aux.master_pde = 0; 1058 1059 new_entry->inheritance = VM_INHERIT_DEFAULT; 1060 new_entry->protection = prot; 1061 new_entry->max_protection = max; 1062 new_entry->wired_count = 0; 1063 1064 /* 1065 * Insert the new entry into the list 1066 */ 1067 1068 vm_map_entry_link(map, prev_entry, new_entry); 1069 map->size += new_entry->end - new_entry->start; 1070 1071 /* 1072 * Update the free space hint. Entries cannot overlap. 1073 * An exact comparison is needed to avoid matching 1074 * against the map->header. 1075 */ 1076 if ((map->first_free == prev_entry) && 1077 (prev_entry->end == new_entry->start)) { 1078 map->first_free = new_entry; 1079 } 1080 1081 #if 0 1082 /* 1083 * Temporarily removed to avoid MAP_STACK panic, due to 1084 * MAP_STACK being a huge hack. Will be added back in 1085 * when MAP_STACK (and the user stack mapping) is fixed. 1086 */ 1087 /* 1088 * It may be possible to simplify the entry 1089 */ 1090 vm_map_simplify_entry(map, new_entry, countp); 1091 #endif 1092 1093 /* 1094 * Try to pre-populate the page table. Mappings governed by virtual 1095 * page tables cannot be prepopulated without a lot of work, so 1096 * don't try. 1097 */ 1098 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) && 1099 maptype != VM_MAPTYPE_VPAGETABLE) { 1100 pmap_object_init_pt(map->pmap, start, prot, 1101 object, OFF_TO_IDX(offset), end - start, 1102 cow & MAP_PREFAULT_PARTIAL); 1103 } 1104 if (must_drop) 1105 vm_object_drop(object); 1106 1107 lwkt_reltoken(&map->token); 1108 return (KERN_SUCCESS); 1109 } 1110 1111 /* 1112 * Find sufficient space for `length' bytes in the given map, starting at 1113 * `start'. Returns 0 on success, 1 on no space. 1114 * 1115 * This function will returned an arbitrarily aligned pointer. If no 1116 * particular alignment is required you should pass align as 1. Note that 1117 * the map may return PAGE_SIZE aligned pointers if all the lengths used in 1118 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align 1119 * argument. 1120 * 1121 * 'align' should be a power of 2 but is not required to be. 1122 * 1123 * The map must be exclusively locked. 1124 * No other requirements. 1125 */ 1126 int 1127 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1128 vm_size_t align, int flags, vm_offset_t *addr) 1129 { 1130 vm_map_entry_t entry, next; 1131 vm_offset_t end; 1132 vm_offset_t align_mask; 1133 1134 if (start < map->min_offset) 1135 start = map->min_offset; 1136 if (start > map->max_offset) 1137 return (1); 1138 1139 /* 1140 * If the alignment is not a power of 2 we will have to use 1141 * a mod/division, set align_mask to a special value. 1142 */ 1143 if ((align | (align - 1)) + 1 != (align << 1)) 1144 align_mask = (vm_offset_t)-1; 1145 else 1146 align_mask = align - 1; 1147 1148 /* 1149 * Look for the first possible address; if there's already something 1150 * at this address, we have to start after it. 1151 */ 1152 if (start == map->min_offset) { 1153 if ((entry = map->first_free) != &map->header) 1154 start = entry->end; 1155 } else { 1156 vm_map_entry_t tmp; 1157 1158 if (vm_map_lookup_entry(map, start, &tmp)) 1159 start = tmp->end; 1160 entry = tmp; 1161 } 1162 1163 /* 1164 * Look through the rest of the map, trying to fit a new region in the 1165 * gap between existing regions, or after the very last region. 1166 */ 1167 for (;; start = (entry = next)->end) { 1168 /* 1169 * Adjust the proposed start by the requested alignment, 1170 * be sure that we didn't wrap the address. 1171 */ 1172 if (align_mask == (vm_offset_t)-1) 1173 end = ((start + align - 1) / align) * align; 1174 else 1175 end = (start + align_mask) & ~align_mask; 1176 if (end < start) 1177 return (1); 1178 start = end; 1179 /* 1180 * Find the end of the proposed new region. Be sure we didn't 1181 * go beyond the end of the map, or wrap around the address. 1182 * Then check to see if this is the last entry or if the 1183 * proposed end fits in the gap between this and the next 1184 * entry. 1185 */ 1186 end = start + length; 1187 if (end > map->max_offset || end < start) 1188 return (1); 1189 next = entry->next; 1190 1191 /* 1192 * If the next entry's start address is beyond the desired 1193 * end address we may have found a good entry. 1194 * 1195 * If the next entry is a stack mapping we do not map into 1196 * the stack's reserved space. 1197 * 1198 * XXX continue to allow mapping into the stack's reserved 1199 * space if doing a MAP_STACK mapping inside a MAP_STACK 1200 * mapping, for backwards compatibility. But the caller 1201 * really should use MAP_STACK | MAP_TRYFIXED if they 1202 * want to do that. 1203 */ 1204 if (next == &map->header) 1205 break; 1206 if (next->start >= end) { 1207 if ((next->eflags & MAP_ENTRY_STACK) == 0) 1208 break; 1209 if (flags & MAP_STACK) 1210 break; 1211 if (next->start - next->aux.avail_ssize >= end) 1212 break; 1213 } 1214 } 1215 map->hint = entry; 1216 1217 /* 1218 * Grow the kernel_map if necessary. pmap_growkernel() will panic 1219 * if it fails. The kernel_map is locked and nothing can steal 1220 * our address space if pmap_growkernel() blocks. 1221 * 1222 * NOTE: This may be unconditionally called for kldload areas on 1223 * x86_64 because these do not bump kernel_vm_end (which would 1224 * fill 128G worth of page tables!). Therefore we must not 1225 * retry. 1226 */ 1227 if (map == &kernel_map) { 1228 vm_offset_t kstop; 1229 1230 kstop = round_page(start + length); 1231 if (kstop > kernel_vm_end) 1232 pmap_growkernel(start, kstop); 1233 } 1234 *addr = start; 1235 return (0); 1236 } 1237 1238 /* 1239 * vm_map_find finds an unallocated region in the target address map with 1240 * the given length and allocates it. The search is defined to be first-fit 1241 * from the specified address; the region found is returned in the same 1242 * parameter. 1243 * 1244 * If object is non-NULL, ref count must be bumped by caller 1245 * prior to making call to account for the new entry. 1246 * 1247 * No requirements. This function will lock the map temporarily. 1248 */ 1249 int 1250 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1251 vm_offset_t *addr, vm_size_t length, vm_size_t align, 1252 boolean_t fitit, 1253 vm_maptype_t maptype, 1254 vm_prot_t prot, vm_prot_t max, 1255 int cow) 1256 { 1257 vm_offset_t start; 1258 int result; 1259 int count; 1260 1261 start = *addr; 1262 1263 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1264 vm_map_lock(map); 1265 if (object) 1266 vm_object_hold(object); 1267 if (fitit) { 1268 if (vm_map_findspace(map, start, length, align, 0, addr)) { 1269 vm_map_unlock(map); 1270 vm_map_entry_release(count); 1271 return (KERN_NO_SPACE); 1272 } 1273 start = *addr; 1274 } 1275 result = vm_map_insert(map, &count, object, offset, 1276 start, start + length, 1277 maptype, 1278 prot, max, 1279 cow); 1280 if (object) 1281 vm_object_drop(object); 1282 vm_map_unlock(map); 1283 vm_map_entry_release(count); 1284 1285 return (result); 1286 } 1287 1288 /* 1289 * Simplify the given map entry by merging with either neighbor. This 1290 * routine also has the ability to merge with both neighbors. 1291 * 1292 * This routine guarentees that the passed entry remains valid (though 1293 * possibly extended). When merging, this routine may delete one or 1294 * both neighbors. No action is taken on entries which have their 1295 * in-transition flag set. 1296 * 1297 * The map must be exclusively locked. 1298 */ 1299 void 1300 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp) 1301 { 1302 vm_map_entry_t next, prev; 1303 vm_size_t prevsize, esize; 1304 1305 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1306 ++mycpu->gd_cnt.v_intrans_coll; 1307 return; 1308 } 1309 1310 if (entry->maptype == VM_MAPTYPE_SUBMAP) 1311 return; 1312 1313 prev = entry->prev; 1314 if (prev != &map->header) { 1315 prevsize = prev->end - prev->start; 1316 if ( (prev->end == entry->start) && 1317 (prev->maptype == entry->maptype) && 1318 (prev->object.vm_object == entry->object.vm_object) && 1319 (!prev->object.vm_object || 1320 (prev->offset + prevsize == entry->offset)) && 1321 (prev->eflags == entry->eflags) && 1322 (prev->protection == entry->protection) && 1323 (prev->max_protection == entry->max_protection) && 1324 (prev->inheritance == entry->inheritance) && 1325 (prev->wired_count == entry->wired_count)) { 1326 if (map->first_free == prev) 1327 map->first_free = entry; 1328 if (map->hint == prev) 1329 map->hint = entry; 1330 vm_map_entry_unlink(map, prev); 1331 entry->start = prev->start; 1332 entry->offset = prev->offset; 1333 if (prev->object.vm_object) 1334 vm_object_deallocate(prev->object.vm_object); 1335 vm_map_entry_dispose(map, prev, countp); 1336 } 1337 } 1338 1339 next = entry->next; 1340 if (next != &map->header) { 1341 esize = entry->end - entry->start; 1342 if ((entry->end == next->start) && 1343 (next->maptype == entry->maptype) && 1344 (next->object.vm_object == entry->object.vm_object) && 1345 (!entry->object.vm_object || 1346 (entry->offset + esize == next->offset)) && 1347 (next->eflags == entry->eflags) && 1348 (next->protection == entry->protection) && 1349 (next->max_protection == entry->max_protection) && 1350 (next->inheritance == entry->inheritance) && 1351 (next->wired_count == entry->wired_count)) { 1352 if (map->first_free == next) 1353 map->first_free = entry; 1354 if (map->hint == next) 1355 map->hint = entry; 1356 vm_map_entry_unlink(map, next); 1357 entry->end = next->end; 1358 if (next->object.vm_object) 1359 vm_object_deallocate(next->object.vm_object); 1360 vm_map_entry_dispose(map, next, countp); 1361 } 1362 } 1363 } 1364 1365 /* 1366 * Asserts that the given entry begins at or after the specified address. 1367 * If necessary, it splits the entry into two. 1368 */ 1369 #define vm_map_clip_start(map, entry, startaddr, countp) \ 1370 { \ 1371 if (startaddr > entry->start) \ 1372 _vm_map_clip_start(map, entry, startaddr, countp); \ 1373 } 1374 1375 /* 1376 * This routine is called only when it is known that the entry must be split. 1377 * 1378 * The map must be exclusively locked. 1379 */ 1380 static void 1381 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start, 1382 int *countp) 1383 { 1384 vm_map_entry_t new_entry; 1385 1386 /* 1387 * Split off the front portion -- note that we must insert the new 1388 * entry BEFORE this one, so that this entry has the specified 1389 * starting address. 1390 */ 1391 1392 vm_map_simplify_entry(map, entry, countp); 1393 1394 /* 1395 * If there is no object backing this entry, we might as well create 1396 * one now. If we defer it, an object can get created after the map 1397 * is clipped, and individual objects will be created for the split-up 1398 * map. This is a bit of a hack, but is also about the best place to 1399 * put this improvement. 1400 */ 1401 if (entry->object.vm_object == NULL && !map->system_map) { 1402 vm_map_entry_allocate_object(entry); 1403 } 1404 1405 new_entry = vm_map_entry_create(map, countp); 1406 *new_entry = *entry; 1407 1408 new_entry->end = start; 1409 entry->offset += (start - entry->start); 1410 entry->start = start; 1411 1412 vm_map_entry_link(map, entry->prev, new_entry); 1413 1414 switch(entry->maptype) { 1415 case VM_MAPTYPE_NORMAL: 1416 case VM_MAPTYPE_VPAGETABLE: 1417 if (new_entry->object.vm_object) { 1418 vm_object_hold(new_entry->object.vm_object); 1419 vm_object_chain_wait(new_entry->object.vm_object); 1420 vm_object_reference_locked(new_entry->object.vm_object); 1421 vm_object_drop(new_entry->object.vm_object); 1422 } 1423 break; 1424 default: 1425 break; 1426 } 1427 } 1428 1429 /* 1430 * Asserts that the given entry ends at or before the specified address. 1431 * If necessary, it splits the entry into two. 1432 * 1433 * The map must be exclusively locked. 1434 */ 1435 #define vm_map_clip_end(map, entry, endaddr, countp) \ 1436 { \ 1437 if (endaddr < entry->end) \ 1438 _vm_map_clip_end(map, entry, endaddr, countp); \ 1439 } 1440 1441 /* 1442 * This routine is called only when it is known that the entry must be split. 1443 * 1444 * The map must be exclusively locked. 1445 */ 1446 static void 1447 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end, 1448 int *countp) 1449 { 1450 vm_map_entry_t new_entry; 1451 1452 /* 1453 * If there is no object backing this entry, we might as well create 1454 * one now. If we defer it, an object can get created after the map 1455 * is clipped, and individual objects will be created for the split-up 1456 * map. This is a bit of a hack, but is also about the best place to 1457 * put this improvement. 1458 */ 1459 1460 if (entry->object.vm_object == NULL && !map->system_map) { 1461 vm_map_entry_allocate_object(entry); 1462 } 1463 1464 /* 1465 * Create a new entry and insert it AFTER the specified entry 1466 */ 1467 1468 new_entry = vm_map_entry_create(map, countp); 1469 *new_entry = *entry; 1470 1471 new_entry->start = entry->end = end; 1472 new_entry->offset += (end - entry->start); 1473 1474 vm_map_entry_link(map, entry, new_entry); 1475 1476 switch(entry->maptype) { 1477 case VM_MAPTYPE_NORMAL: 1478 case VM_MAPTYPE_VPAGETABLE: 1479 if (new_entry->object.vm_object) { 1480 vm_object_hold(new_entry->object.vm_object); 1481 vm_object_chain_wait(new_entry->object.vm_object); 1482 vm_object_reference_locked(new_entry->object.vm_object); 1483 vm_object_drop(new_entry->object.vm_object); 1484 } 1485 break; 1486 default: 1487 break; 1488 } 1489 } 1490 1491 /* 1492 * Asserts that the starting and ending region addresses fall within the 1493 * valid range for the map. 1494 */ 1495 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1496 { \ 1497 if (start < vm_map_min(map)) \ 1498 start = vm_map_min(map); \ 1499 if (end > vm_map_max(map)) \ 1500 end = vm_map_max(map); \ 1501 if (start > end) \ 1502 start = end; \ 1503 } 1504 1505 /* 1506 * Used to block when an in-transition collison occurs. The map 1507 * is unlocked for the sleep and relocked before the return. 1508 */ 1509 void 1510 vm_map_transition_wait(vm_map_t map) 1511 { 1512 tsleep_interlock(map, 0); 1513 vm_map_unlock(map); 1514 tsleep(map, PINTERLOCKED, "vment", 0); 1515 vm_map_lock(map); 1516 } 1517 1518 /* 1519 * When we do blocking operations with the map lock held it is 1520 * possible that a clip might have occured on our in-transit entry, 1521 * requiring an adjustment to the entry in our loop. These macros 1522 * help the pageable and clip_range code deal with the case. The 1523 * conditional costs virtually nothing if no clipping has occured. 1524 */ 1525 1526 #define CLIP_CHECK_BACK(entry, save_start) \ 1527 do { \ 1528 while (entry->start != save_start) { \ 1529 entry = entry->prev; \ 1530 KASSERT(entry != &map->header, ("bad entry clip")); \ 1531 } \ 1532 } while(0) 1533 1534 #define CLIP_CHECK_FWD(entry, save_end) \ 1535 do { \ 1536 while (entry->end != save_end) { \ 1537 entry = entry->next; \ 1538 KASSERT(entry != &map->header, ("bad entry clip")); \ 1539 } \ 1540 } while(0) 1541 1542 1543 /* 1544 * Clip the specified range and return the base entry. The 1545 * range may cover several entries starting at the returned base 1546 * and the first and last entry in the covering sequence will be 1547 * properly clipped to the requested start and end address. 1548 * 1549 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES 1550 * flag. 1551 * 1552 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries 1553 * covered by the requested range. 1554 * 1555 * The map must be exclusively locked on entry and will remain locked 1556 * on return. If no range exists or the range contains holes and you 1557 * specified that no holes were allowed, NULL will be returned. This 1558 * routine may temporarily unlock the map in order avoid a deadlock when 1559 * sleeping. 1560 */ 1561 static 1562 vm_map_entry_t 1563 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, 1564 int *countp, int flags) 1565 { 1566 vm_map_entry_t start_entry; 1567 vm_map_entry_t entry; 1568 1569 /* 1570 * Locate the entry and effect initial clipping. The in-transition 1571 * case does not occur very often so do not try to optimize it. 1572 */ 1573 again: 1574 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) 1575 return (NULL); 1576 entry = start_entry; 1577 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1578 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1579 ++mycpu->gd_cnt.v_intrans_coll; 1580 ++mycpu->gd_cnt.v_intrans_wait; 1581 vm_map_transition_wait(map); 1582 /* 1583 * entry and/or start_entry may have been clipped while 1584 * we slept, or may have gone away entirely. We have 1585 * to restart from the lookup. 1586 */ 1587 goto again; 1588 } 1589 1590 /* 1591 * Since we hold an exclusive map lock we do not have to restart 1592 * after clipping, even though clipping may block in zalloc. 1593 */ 1594 vm_map_clip_start(map, entry, start, countp); 1595 vm_map_clip_end(map, entry, end, countp); 1596 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1597 1598 /* 1599 * Scan entries covered by the range. When working on the next 1600 * entry a restart need only re-loop on the current entry which 1601 * we have already locked, since 'next' may have changed. Also, 1602 * even though entry is safe, it may have been clipped so we 1603 * have to iterate forwards through the clip after sleeping. 1604 */ 1605 while (entry->next != &map->header && entry->next->start < end) { 1606 vm_map_entry_t next = entry->next; 1607 1608 if (flags & MAP_CLIP_NO_HOLES) { 1609 if (next->start > entry->end) { 1610 vm_map_unclip_range(map, start_entry, 1611 start, entry->end, countp, flags); 1612 return(NULL); 1613 } 1614 } 1615 1616 if (next->eflags & MAP_ENTRY_IN_TRANSITION) { 1617 vm_offset_t save_end = entry->end; 1618 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1619 ++mycpu->gd_cnt.v_intrans_coll; 1620 ++mycpu->gd_cnt.v_intrans_wait; 1621 vm_map_transition_wait(map); 1622 1623 /* 1624 * clips might have occured while we blocked. 1625 */ 1626 CLIP_CHECK_FWD(entry, save_end); 1627 CLIP_CHECK_BACK(start_entry, start); 1628 continue; 1629 } 1630 /* 1631 * No restart necessary even though clip_end may block, we 1632 * are holding the map lock. 1633 */ 1634 vm_map_clip_end(map, next, end, countp); 1635 next->eflags |= MAP_ENTRY_IN_TRANSITION; 1636 entry = next; 1637 } 1638 if (flags & MAP_CLIP_NO_HOLES) { 1639 if (entry->end != end) { 1640 vm_map_unclip_range(map, start_entry, 1641 start, entry->end, countp, flags); 1642 return(NULL); 1643 } 1644 } 1645 return(start_entry); 1646 } 1647 1648 /* 1649 * Undo the effect of vm_map_clip_range(). You should pass the same 1650 * flags and the same range that you passed to vm_map_clip_range(). 1651 * This code will clear the in-transition flag on the entries and 1652 * wake up anyone waiting. This code will also simplify the sequence 1653 * and attempt to merge it with entries before and after the sequence. 1654 * 1655 * The map must be locked on entry and will remain locked on return. 1656 * 1657 * Note that you should also pass the start_entry returned by 1658 * vm_map_clip_range(). However, if you block between the two calls 1659 * with the map unlocked please be aware that the start_entry may 1660 * have been clipped and you may need to scan it backwards to find 1661 * the entry corresponding with the original start address. You are 1662 * responsible for this, vm_map_unclip_range() expects the correct 1663 * start_entry to be passed to it and will KASSERT otherwise. 1664 */ 1665 static 1666 void 1667 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry, 1668 vm_offset_t start, vm_offset_t end, 1669 int *countp, int flags) 1670 { 1671 vm_map_entry_t entry; 1672 1673 entry = start_entry; 1674 1675 KASSERT(entry->start == start, ("unclip_range: illegal base entry")); 1676 while (entry != &map->header && entry->start < end) { 1677 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1678 ("in-transition flag not set during unclip on: %p", 1679 entry)); 1680 KASSERT(entry->end <= end, 1681 ("unclip_range: tail wasn't clipped")); 1682 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1683 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1684 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1685 wakeup(map); 1686 } 1687 entry = entry->next; 1688 } 1689 1690 /* 1691 * Simplification does not block so there is no restart case. 1692 */ 1693 entry = start_entry; 1694 while (entry != &map->header && entry->start < end) { 1695 vm_map_simplify_entry(map, entry, countp); 1696 entry = entry->next; 1697 } 1698 } 1699 1700 /* 1701 * Mark the given range as handled by a subordinate map. 1702 * 1703 * This range must have been created with vm_map_find(), and no other 1704 * operations may have been performed on this range prior to calling 1705 * vm_map_submap(). 1706 * 1707 * Submappings cannot be removed. 1708 * 1709 * No requirements. 1710 */ 1711 int 1712 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) 1713 { 1714 vm_map_entry_t entry; 1715 int result = KERN_INVALID_ARGUMENT; 1716 int count; 1717 1718 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1719 vm_map_lock(map); 1720 1721 VM_MAP_RANGE_CHECK(map, start, end); 1722 1723 if (vm_map_lookup_entry(map, start, &entry)) { 1724 vm_map_clip_start(map, entry, start, &count); 1725 } else { 1726 entry = entry->next; 1727 } 1728 1729 vm_map_clip_end(map, entry, end, &count); 1730 1731 if ((entry->start == start) && (entry->end == end) && 1732 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1733 (entry->object.vm_object == NULL)) { 1734 entry->object.sub_map = submap; 1735 entry->maptype = VM_MAPTYPE_SUBMAP; 1736 result = KERN_SUCCESS; 1737 } 1738 vm_map_unlock(map); 1739 vm_map_entry_release(count); 1740 1741 return (result); 1742 } 1743 1744 /* 1745 * Sets the protection of the specified address region in the target map. 1746 * If "set_max" is specified, the maximum protection is to be set; 1747 * otherwise, only the current protection is affected. 1748 * 1749 * The protection is not applicable to submaps, but is applicable to normal 1750 * maps and maps governed by virtual page tables. For example, when operating 1751 * on a virtual page table our protection basically controls how COW occurs 1752 * on the backing object, whereas the virtual page table abstraction itself 1753 * is an abstraction for userland. 1754 * 1755 * No requirements. 1756 */ 1757 int 1758 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1759 vm_prot_t new_prot, boolean_t set_max) 1760 { 1761 vm_map_entry_t current; 1762 vm_map_entry_t entry; 1763 int count; 1764 1765 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1766 vm_map_lock(map); 1767 1768 VM_MAP_RANGE_CHECK(map, start, end); 1769 1770 if (vm_map_lookup_entry(map, start, &entry)) { 1771 vm_map_clip_start(map, entry, start, &count); 1772 } else { 1773 entry = entry->next; 1774 } 1775 1776 /* 1777 * Make a first pass to check for protection violations. 1778 */ 1779 current = entry; 1780 while ((current != &map->header) && (current->start < end)) { 1781 if (current->maptype == VM_MAPTYPE_SUBMAP) { 1782 vm_map_unlock(map); 1783 vm_map_entry_release(count); 1784 return (KERN_INVALID_ARGUMENT); 1785 } 1786 if ((new_prot & current->max_protection) != new_prot) { 1787 vm_map_unlock(map); 1788 vm_map_entry_release(count); 1789 return (KERN_PROTECTION_FAILURE); 1790 } 1791 current = current->next; 1792 } 1793 1794 /* 1795 * Go back and fix up protections. [Note that clipping is not 1796 * necessary the second time.] 1797 */ 1798 current = entry; 1799 1800 while ((current != &map->header) && (current->start < end)) { 1801 vm_prot_t old_prot; 1802 1803 vm_map_clip_end(map, current, end, &count); 1804 1805 old_prot = current->protection; 1806 if (set_max) { 1807 current->protection = 1808 (current->max_protection = new_prot) & 1809 old_prot; 1810 } else { 1811 current->protection = new_prot; 1812 } 1813 1814 /* 1815 * Update physical map if necessary. Worry about copy-on-write 1816 * here -- CHECK THIS XXX 1817 */ 1818 1819 if (current->protection != old_prot) { 1820 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1821 VM_PROT_ALL) 1822 1823 pmap_protect(map->pmap, current->start, 1824 current->end, 1825 current->protection & MASK(current)); 1826 #undef MASK 1827 } 1828 1829 vm_map_simplify_entry(map, current, &count); 1830 1831 current = current->next; 1832 } 1833 1834 vm_map_unlock(map); 1835 vm_map_entry_release(count); 1836 return (KERN_SUCCESS); 1837 } 1838 1839 /* 1840 * This routine traverses a processes map handling the madvise 1841 * system call. Advisories are classified as either those effecting 1842 * the vm_map_entry structure, or those effecting the underlying 1843 * objects. 1844 * 1845 * The <value> argument is used for extended madvise calls. 1846 * 1847 * No requirements. 1848 */ 1849 int 1850 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end, 1851 int behav, off_t value) 1852 { 1853 vm_map_entry_t current, entry; 1854 int modify_map = 0; 1855 int error = 0; 1856 int count; 1857 1858 /* 1859 * Some madvise calls directly modify the vm_map_entry, in which case 1860 * we need to use an exclusive lock on the map and we need to perform 1861 * various clipping operations. Otherwise we only need a read-lock 1862 * on the map. 1863 */ 1864 1865 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1866 1867 switch(behav) { 1868 case MADV_NORMAL: 1869 case MADV_SEQUENTIAL: 1870 case MADV_RANDOM: 1871 case MADV_NOSYNC: 1872 case MADV_AUTOSYNC: 1873 case MADV_NOCORE: 1874 case MADV_CORE: 1875 case MADV_SETMAP: 1876 case MADV_INVAL: 1877 modify_map = 1; 1878 vm_map_lock(map); 1879 break; 1880 case MADV_WILLNEED: 1881 case MADV_DONTNEED: 1882 case MADV_FREE: 1883 vm_map_lock_read(map); 1884 break; 1885 default: 1886 vm_map_entry_release(count); 1887 return (EINVAL); 1888 } 1889 1890 /* 1891 * Locate starting entry and clip if necessary. 1892 */ 1893 1894 VM_MAP_RANGE_CHECK(map, start, end); 1895 1896 if (vm_map_lookup_entry(map, start, &entry)) { 1897 if (modify_map) 1898 vm_map_clip_start(map, entry, start, &count); 1899 } else { 1900 entry = entry->next; 1901 } 1902 1903 if (modify_map) { 1904 /* 1905 * madvise behaviors that are implemented in the vm_map_entry. 1906 * 1907 * We clip the vm_map_entry so that behavioral changes are 1908 * limited to the specified address range. 1909 */ 1910 for (current = entry; 1911 (current != &map->header) && (current->start < end); 1912 current = current->next 1913 ) { 1914 if (current->maptype == VM_MAPTYPE_SUBMAP) 1915 continue; 1916 1917 vm_map_clip_end(map, current, end, &count); 1918 1919 switch (behav) { 1920 case MADV_NORMAL: 1921 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1922 break; 1923 case MADV_SEQUENTIAL: 1924 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1925 break; 1926 case MADV_RANDOM: 1927 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1928 break; 1929 case MADV_NOSYNC: 1930 current->eflags |= MAP_ENTRY_NOSYNC; 1931 break; 1932 case MADV_AUTOSYNC: 1933 current->eflags &= ~MAP_ENTRY_NOSYNC; 1934 break; 1935 case MADV_NOCORE: 1936 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1937 break; 1938 case MADV_CORE: 1939 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1940 break; 1941 case MADV_INVAL: 1942 /* 1943 * Invalidate the related pmap entries, used 1944 * to flush portions of the real kernel's 1945 * pmap when the caller has removed or 1946 * modified existing mappings in a virtual 1947 * page table. 1948 */ 1949 pmap_remove(map->pmap, 1950 current->start, current->end); 1951 break; 1952 case MADV_SETMAP: 1953 /* 1954 * Set the page directory page for a map 1955 * governed by a virtual page table. Mark 1956 * the entry as being governed by a virtual 1957 * page table if it is not. 1958 * 1959 * XXX the page directory page is stored 1960 * in the avail_ssize field if the map_entry. 1961 * 1962 * XXX the map simplification code does not 1963 * compare this field so weird things may 1964 * happen if you do not apply this function 1965 * to the entire mapping governed by the 1966 * virtual page table. 1967 */ 1968 if (current->maptype != VM_MAPTYPE_VPAGETABLE) { 1969 error = EINVAL; 1970 break; 1971 } 1972 current->aux.master_pde = value; 1973 pmap_remove(map->pmap, 1974 current->start, current->end); 1975 break; 1976 default: 1977 error = EINVAL; 1978 break; 1979 } 1980 vm_map_simplify_entry(map, current, &count); 1981 } 1982 vm_map_unlock(map); 1983 } else { 1984 vm_pindex_t pindex; 1985 int count; 1986 1987 /* 1988 * madvise behaviors that are implemented in the underlying 1989 * vm_object. 1990 * 1991 * Since we don't clip the vm_map_entry, we have to clip 1992 * the vm_object pindex and count. 1993 * 1994 * NOTE! We currently do not support these functions on 1995 * virtual page tables. 1996 */ 1997 for (current = entry; 1998 (current != &map->header) && (current->start < end); 1999 current = current->next 2000 ) { 2001 vm_offset_t useStart; 2002 2003 if (current->maptype != VM_MAPTYPE_NORMAL) 2004 continue; 2005 2006 pindex = OFF_TO_IDX(current->offset); 2007 count = atop(current->end - current->start); 2008 useStart = current->start; 2009 2010 if (current->start < start) { 2011 pindex += atop(start - current->start); 2012 count -= atop(start - current->start); 2013 useStart = start; 2014 } 2015 if (current->end > end) 2016 count -= atop(current->end - end); 2017 2018 if (count <= 0) 2019 continue; 2020 2021 vm_object_madvise(current->object.vm_object, 2022 pindex, count, behav); 2023 2024 /* 2025 * Try to populate the page table. Mappings governed 2026 * by virtual page tables cannot be pre-populated 2027 * without a lot of work so don't try. 2028 */ 2029 if (behav == MADV_WILLNEED && 2030 current->maptype != VM_MAPTYPE_VPAGETABLE) { 2031 pmap_object_init_pt( 2032 map->pmap, 2033 useStart, 2034 current->protection, 2035 current->object.vm_object, 2036 pindex, 2037 (count << PAGE_SHIFT), 2038 MAP_PREFAULT_MADVISE 2039 ); 2040 } 2041 } 2042 vm_map_unlock_read(map); 2043 } 2044 vm_map_entry_release(count); 2045 return(error); 2046 } 2047 2048 2049 /* 2050 * Sets the inheritance of the specified address range in the target map. 2051 * Inheritance affects how the map will be shared with child maps at the 2052 * time of vm_map_fork. 2053 */ 2054 int 2055 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2056 vm_inherit_t new_inheritance) 2057 { 2058 vm_map_entry_t entry; 2059 vm_map_entry_t temp_entry; 2060 int count; 2061 2062 switch (new_inheritance) { 2063 case VM_INHERIT_NONE: 2064 case VM_INHERIT_COPY: 2065 case VM_INHERIT_SHARE: 2066 break; 2067 default: 2068 return (KERN_INVALID_ARGUMENT); 2069 } 2070 2071 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2072 vm_map_lock(map); 2073 2074 VM_MAP_RANGE_CHECK(map, start, end); 2075 2076 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2077 entry = temp_entry; 2078 vm_map_clip_start(map, entry, start, &count); 2079 } else 2080 entry = temp_entry->next; 2081 2082 while ((entry != &map->header) && (entry->start < end)) { 2083 vm_map_clip_end(map, entry, end, &count); 2084 2085 entry->inheritance = new_inheritance; 2086 2087 vm_map_simplify_entry(map, entry, &count); 2088 2089 entry = entry->next; 2090 } 2091 vm_map_unlock(map); 2092 vm_map_entry_release(count); 2093 return (KERN_SUCCESS); 2094 } 2095 2096 /* 2097 * Implement the semantics of mlock 2098 */ 2099 int 2100 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, 2101 boolean_t new_pageable) 2102 { 2103 vm_map_entry_t entry; 2104 vm_map_entry_t start_entry; 2105 vm_offset_t end; 2106 int rv = KERN_SUCCESS; 2107 int count; 2108 2109 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2110 vm_map_lock(map); 2111 VM_MAP_RANGE_CHECK(map, start, real_end); 2112 end = real_end; 2113 2114 start_entry = vm_map_clip_range(map, start, end, &count, 2115 MAP_CLIP_NO_HOLES); 2116 if (start_entry == NULL) { 2117 vm_map_unlock(map); 2118 vm_map_entry_release(count); 2119 return (KERN_INVALID_ADDRESS); 2120 } 2121 2122 if (new_pageable == 0) { 2123 entry = start_entry; 2124 while ((entry != &map->header) && (entry->start < end)) { 2125 vm_offset_t save_start; 2126 vm_offset_t save_end; 2127 2128 /* 2129 * Already user wired or hard wired (trivial cases) 2130 */ 2131 if (entry->eflags & MAP_ENTRY_USER_WIRED) { 2132 entry = entry->next; 2133 continue; 2134 } 2135 if (entry->wired_count != 0) { 2136 entry->wired_count++; 2137 entry->eflags |= MAP_ENTRY_USER_WIRED; 2138 entry = entry->next; 2139 continue; 2140 } 2141 2142 /* 2143 * A new wiring requires instantiation of appropriate 2144 * management structures and the faulting in of the 2145 * page. 2146 */ 2147 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 2148 int copyflag = entry->eflags & 2149 MAP_ENTRY_NEEDS_COPY; 2150 if (copyflag && ((entry->protection & 2151 VM_PROT_WRITE) != 0)) { 2152 vm_map_entry_shadow(entry, 0); 2153 } else if (entry->object.vm_object == NULL && 2154 !map->system_map) { 2155 vm_map_entry_allocate_object(entry); 2156 } 2157 } 2158 entry->wired_count++; 2159 entry->eflags |= MAP_ENTRY_USER_WIRED; 2160 2161 /* 2162 * Now fault in the area. Note that vm_fault_wire() 2163 * may release the map lock temporarily, it will be 2164 * relocked on return. The in-transition 2165 * flag protects the entries. 2166 */ 2167 save_start = entry->start; 2168 save_end = entry->end; 2169 rv = vm_fault_wire(map, entry, TRUE); 2170 if (rv) { 2171 CLIP_CHECK_BACK(entry, save_start); 2172 for (;;) { 2173 KASSERT(entry->wired_count == 1, ("bad wired_count on entry")); 2174 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2175 entry->wired_count = 0; 2176 if (entry->end == save_end) 2177 break; 2178 entry = entry->next; 2179 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2180 } 2181 end = save_start; /* unwire the rest */ 2182 break; 2183 } 2184 /* 2185 * note that even though the entry might have been 2186 * clipped, the USER_WIRED flag we set prevents 2187 * duplication so we do not have to do a 2188 * clip check. 2189 */ 2190 entry = entry->next; 2191 } 2192 2193 /* 2194 * If we failed fall through to the unwiring section to 2195 * unwire what we had wired so far. 'end' has already 2196 * been adjusted. 2197 */ 2198 if (rv) 2199 new_pageable = 1; 2200 2201 /* 2202 * start_entry might have been clipped if we unlocked the 2203 * map and blocked. No matter how clipped it has gotten 2204 * there should be a fragment that is on our start boundary. 2205 */ 2206 CLIP_CHECK_BACK(start_entry, start); 2207 } 2208 2209 /* 2210 * Deal with the unwiring case. 2211 */ 2212 if (new_pageable) { 2213 /* 2214 * This is the unwiring case. We must first ensure that the 2215 * range to be unwired is really wired down. We know there 2216 * are no holes. 2217 */ 2218 entry = start_entry; 2219 while ((entry != &map->header) && (entry->start < end)) { 2220 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2221 rv = KERN_INVALID_ARGUMENT; 2222 goto done; 2223 } 2224 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry)); 2225 entry = entry->next; 2226 } 2227 2228 /* 2229 * Now decrement the wiring count for each region. If a region 2230 * becomes completely unwired, unwire its physical pages and 2231 * mappings. 2232 */ 2233 /* 2234 * The map entries are processed in a loop, checking to 2235 * make sure the entry is wired and asserting it has a wired 2236 * count. However, another loop was inserted more-or-less in 2237 * the middle of the unwiring path. This loop picks up the 2238 * "entry" loop variable from the first loop without first 2239 * setting it to start_entry. Naturally, the secound loop 2240 * is never entered and the pages backing the entries are 2241 * never unwired. This can lead to a leak of wired pages. 2242 */ 2243 entry = start_entry; 2244 while ((entry != &map->header) && (entry->start < end)) { 2245 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, 2246 ("expected USER_WIRED on entry %p", entry)); 2247 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2248 entry->wired_count--; 2249 if (entry->wired_count == 0) 2250 vm_fault_unwire(map, entry); 2251 entry = entry->next; 2252 } 2253 } 2254 done: 2255 vm_map_unclip_range(map, start_entry, start, real_end, &count, 2256 MAP_CLIP_NO_HOLES); 2257 map->timestamp++; 2258 vm_map_unlock(map); 2259 vm_map_entry_release(count); 2260 return (rv); 2261 } 2262 2263 /* 2264 * Sets the pageability of the specified address range in the target map. 2265 * Regions specified as not pageable require locked-down physical 2266 * memory and physical page maps. 2267 * 2268 * The map must not be locked, but a reference must remain to the map 2269 * throughout the call. 2270 * 2271 * This function may be called via the zalloc path and must properly 2272 * reserve map entries for kernel_map. 2273 * 2274 * No requirements. 2275 */ 2276 int 2277 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags) 2278 { 2279 vm_map_entry_t entry; 2280 vm_map_entry_t start_entry; 2281 vm_offset_t end; 2282 int rv = KERN_SUCCESS; 2283 int count; 2284 2285 if (kmflags & KM_KRESERVE) 2286 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT); 2287 else 2288 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2289 vm_map_lock(map); 2290 VM_MAP_RANGE_CHECK(map, start, real_end); 2291 end = real_end; 2292 2293 start_entry = vm_map_clip_range(map, start, end, &count, 2294 MAP_CLIP_NO_HOLES); 2295 if (start_entry == NULL) { 2296 vm_map_unlock(map); 2297 rv = KERN_INVALID_ADDRESS; 2298 goto failure; 2299 } 2300 if ((kmflags & KM_PAGEABLE) == 0) { 2301 /* 2302 * Wiring. 2303 * 2304 * 1. Holding the write lock, we create any shadow or zero-fill 2305 * objects that need to be created. Then we clip each map 2306 * entry to the region to be wired and increment its wiring 2307 * count. We create objects before clipping the map entries 2308 * to avoid object proliferation. 2309 * 2310 * 2. We downgrade to a read lock, and call vm_fault_wire to 2311 * fault in the pages for any newly wired area (wired_count is 2312 * 1). 2313 * 2314 * Downgrading to a read lock for vm_fault_wire avoids a 2315 * possible deadlock with another process that may have faulted 2316 * on one of the pages to be wired (it would mark the page busy, 2317 * blocking us, then in turn block on the map lock that we 2318 * hold). Because of problems in the recursive lock package, 2319 * we cannot upgrade to a write lock in vm_map_lookup. Thus, 2320 * any actions that require the write lock must be done 2321 * beforehand. Because we keep the read lock on the map, the 2322 * copy-on-write status of the entries we modify here cannot 2323 * change. 2324 */ 2325 entry = start_entry; 2326 while ((entry != &map->header) && (entry->start < end)) { 2327 /* 2328 * Trivial case if the entry is already wired 2329 */ 2330 if (entry->wired_count) { 2331 entry->wired_count++; 2332 entry = entry->next; 2333 continue; 2334 } 2335 2336 /* 2337 * The entry is being newly wired, we have to setup 2338 * appropriate management structures. A shadow 2339 * object is required for a copy-on-write region, 2340 * or a normal object for a zero-fill region. We 2341 * do not have to do this for entries that point to sub 2342 * maps because we won't hold the lock on the sub map. 2343 */ 2344 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 2345 int copyflag = entry->eflags & 2346 MAP_ENTRY_NEEDS_COPY; 2347 if (copyflag && ((entry->protection & 2348 VM_PROT_WRITE) != 0)) { 2349 vm_map_entry_shadow(entry, 0); 2350 } else if (entry->object.vm_object == NULL && 2351 !map->system_map) { 2352 vm_map_entry_allocate_object(entry); 2353 } 2354 } 2355 2356 entry->wired_count++; 2357 entry = entry->next; 2358 } 2359 2360 /* 2361 * Pass 2. 2362 */ 2363 2364 /* 2365 * HACK HACK HACK HACK 2366 * 2367 * vm_fault_wire() temporarily unlocks the map to avoid 2368 * deadlocks. The in-transition flag from vm_map_clip_range 2369 * call should protect us from changes while the map is 2370 * unlocked. T 2371 * 2372 * NOTE: Previously this comment stated that clipping might 2373 * still occur while the entry is unlocked, but from 2374 * what I can tell it actually cannot. 2375 * 2376 * It is unclear whether the CLIP_CHECK_*() calls 2377 * are still needed but we keep them in anyway. 2378 * 2379 * HACK HACK HACK HACK 2380 */ 2381 2382 entry = start_entry; 2383 while (entry != &map->header && entry->start < end) { 2384 /* 2385 * If vm_fault_wire fails for any page we need to undo 2386 * what has been done. We decrement the wiring count 2387 * for those pages which have not yet been wired (now) 2388 * and unwire those that have (later). 2389 */ 2390 vm_offset_t save_start = entry->start; 2391 vm_offset_t save_end = entry->end; 2392 2393 if (entry->wired_count == 1) 2394 rv = vm_fault_wire(map, entry, FALSE); 2395 if (rv) { 2396 CLIP_CHECK_BACK(entry, save_start); 2397 for (;;) { 2398 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly")); 2399 entry->wired_count = 0; 2400 if (entry->end == save_end) 2401 break; 2402 entry = entry->next; 2403 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2404 } 2405 end = save_start; 2406 break; 2407 } 2408 CLIP_CHECK_FWD(entry, save_end); 2409 entry = entry->next; 2410 } 2411 2412 /* 2413 * If a failure occured undo everything by falling through 2414 * to the unwiring code. 'end' has already been adjusted 2415 * appropriately. 2416 */ 2417 if (rv) 2418 kmflags |= KM_PAGEABLE; 2419 2420 /* 2421 * start_entry is still IN_TRANSITION but may have been 2422 * clipped since vm_fault_wire() unlocks and relocks the 2423 * map. No matter how clipped it has gotten there should 2424 * be a fragment that is on our start boundary. 2425 */ 2426 CLIP_CHECK_BACK(start_entry, start); 2427 } 2428 2429 if (kmflags & KM_PAGEABLE) { 2430 /* 2431 * This is the unwiring case. We must first ensure that the 2432 * range to be unwired is really wired down. We know there 2433 * are no holes. 2434 */ 2435 entry = start_entry; 2436 while ((entry != &map->header) && (entry->start < end)) { 2437 if (entry->wired_count == 0) { 2438 rv = KERN_INVALID_ARGUMENT; 2439 goto done; 2440 } 2441 entry = entry->next; 2442 } 2443 2444 /* 2445 * Now decrement the wiring count for each region. If a region 2446 * becomes completely unwired, unwire its physical pages and 2447 * mappings. 2448 */ 2449 entry = start_entry; 2450 while ((entry != &map->header) && (entry->start < end)) { 2451 entry->wired_count--; 2452 if (entry->wired_count == 0) 2453 vm_fault_unwire(map, entry); 2454 entry = entry->next; 2455 } 2456 } 2457 done: 2458 vm_map_unclip_range(map, start_entry, start, real_end, 2459 &count, MAP_CLIP_NO_HOLES); 2460 map->timestamp++; 2461 vm_map_unlock(map); 2462 failure: 2463 if (kmflags & KM_KRESERVE) 2464 vm_map_entry_krelease(count); 2465 else 2466 vm_map_entry_release(count); 2467 return (rv); 2468 } 2469 2470 /* 2471 * Mark a newly allocated address range as wired but do not fault in 2472 * the pages. The caller is expected to load the pages into the object. 2473 * 2474 * The map must be locked on entry and will remain locked on return. 2475 * No other requirements. 2476 */ 2477 void 2478 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size, 2479 int *countp) 2480 { 2481 vm_map_entry_t scan; 2482 vm_map_entry_t entry; 2483 2484 entry = vm_map_clip_range(map, addr, addr + size, 2485 countp, MAP_CLIP_NO_HOLES); 2486 for (scan = entry; 2487 scan != &map->header && scan->start < addr + size; 2488 scan = scan->next) { 2489 KKASSERT(entry->wired_count == 0); 2490 entry->wired_count = 1; 2491 } 2492 vm_map_unclip_range(map, entry, addr, addr + size, 2493 countp, MAP_CLIP_NO_HOLES); 2494 } 2495 2496 /* 2497 * Push any dirty cached pages in the address range to their pager. 2498 * If syncio is TRUE, dirty pages are written synchronously. 2499 * If invalidate is TRUE, any cached pages are freed as well. 2500 * 2501 * This routine is called by sys_msync() 2502 * 2503 * Returns an error if any part of the specified range is not mapped. 2504 * 2505 * No requirements. 2506 */ 2507 int 2508 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end, 2509 boolean_t syncio, boolean_t invalidate) 2510 { 2511 vm_map_entry_t current; 2512 vm_map_entry_t entry; 2513 vm_size_t size; 2514 vm_object_t object; 2515 vm_object_t tobj; 2516 vm_ooffset_t offset; 2517 2518 vm_map_lock_read(map); 2519 VM_MAP_RANGE_CHECK(map, start, end); 2520 if (!vm_map_lookup_entry(map, start, &entry)) { 2521 vm_map_unlock_read(map); 2522 return (KERN_INVALID_ADDRESS); 2523 } 2524 lwkt_gettoken(&map->token); 2525 2526 /* 2527 * Make a first pass to check for holes. 2528 */ 2529 for (current = entry; current->start < end; current = current->next) { 2530 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2531 lwkt_reltoken(&map->token); 2532 vm_map_unlock_read(map); 2533 return (KERN_INVALID_ARGUMENT); 2534 } 2535 if (end > current->end && 2536 (current->next == &map->header || 2537 current->end != current->next->start)) { 2538 lwkt_reltoken(&map->token); 2539 vm_map_unlock_read(map); 2540 return (KERN_INVALID_ADDRESS); 2541 } 2542 } 2543 2544 if (invalidate) 2545 pmap_remove(vm_map_pmap(map), start, end); 2546 2547 /* 2548 * Make a second pass, cleaning/uncaching pages from the indicated 2549 * objects as we go. 2550 */ 2551 for (current = entry; current->start < end; current = current->next) { 2552 offset = current->offset + (start - current->start); 2553 size = (end <= current->end ? end : current->end) - start; 2554 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2555 vm_map_t smap; 2556 vm_map_entry_t tentry; 2557 vm_size_t tsize; 2558 2559 smap = current->object.sub_map; 2560 vm_map_lock_read(smap); 2561 vm_map_lookup_entry(smap, offset, &tentry); 2562 tsize = tentry->end - offset; 2563 if (tsize < size) 2564 size = tsize; 2565 object = tentry->object.vm_object; 2566 offset = tentry->offset + (offset - tentry->start); 2567 vm_map_unlock_read(smap); 2568 } else { 2569 object = current->object.vm_object; 2570 } 2571 2572 if (object) 2573 vm_object_hold(object); 2574 2575 /* 2576 * Note that there is absolutely no sense in writing out 2577 * anonymous objects, so we track down the vnode object 2578 * to write out. 2579 * We invalidate (remove) all pages from the address space 2580 * anyway, for semantic correctness. 2581 * 2582 * note: certain anonymous maps, such as MAP_NOSYNC maps, 2583 * may start out with a NULL object. 2584 */ 2585 while (object && (tobj = object->backing_object) != NULL) { 2586 vm_object_hold(tobj); 2587 if (tobj == object->backing_object) { 2588 vm_object_lock_swap(); 2589 offset += object->backing_object_offset; 2590 vm_object_drop(object); 2591 object = tobj; 2592 if (object->size < OFF_TO_IDX(offset + size)) 2593 size = IDX_TO_OFF(object->size) - 2594 offset; 2595 break; 2596 } 2597 vm_object_drop(tobj); 2598 } 2599 if (object && (object->type == OBJT_VNODE) && 2600 (current->protection & VM_PROT_WRITE) && 2601 (object->flags & OBJ_NOMSYNC) == 0) { 2602 /* 2603 * Flush pages if writing is allowed, invalidate them 2604 * if invalidation requested. Pages undergoing I/O 2605 * will be ignored by vm_object_page_remove(). 2606 * 2607 * We cannot lock the vnode and then wait for paging 2608 * to complete without deadlocking against vm_fault. 2609 * Instead we simply call vm_object_page_remove() and 2610 * allow it to block internally on a page-by-page 2611 * basis when it encounters pages undergoing async 2612 * I/O. 2613 */ 2614 int flags; 2615 2616 /* no chain wait needed for vnode objects */ 2617 vm_object_reference_locked(object); 2618 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY); 2619 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 2620 flags |= invalidate ? OBJPC_INVAL : 0; 2621 2622 /* 2623 * When operating on a virtual page table just 2624 * flush the whole object. XXX we probably ought 2625 * to 2626 */ 2627 switch(current->maptype) { 2628 case VM_MAPTYPE_NORMAL: 2629 vm_object_page_clean(object, 2630 OFF_TO_IDX(offset), 2631 OFF_TO_IDX(offset + size + PAGE_MASK), 2632 flags); 2633 break; 2634 case VM_MAPTYPE_VPAGETABLE: 2635 vm_object_page_clean(object, 0, 0, flags); 2636 break; 2637 } 2638 vn_unlock(((struct vnode *)object->handle)); 2639 vm_object_deallocate_locked(object); 2640 } 2641 if (object && invalidate && 2642 ((object->type == OBJT_VNODE) || 2643 (object->type == OBJT_DEVICE))) { 2644 int clean_only = 2645 (object->type == OBJT_DEVICE) ? FALSE : TRUE; 2646 /* no chain wait needed for vnode/device objects */ 2647 vm_object_reference_locked(object); 2648 switch(current->maptype) { 2649 case VM_MAPTYPE_NORMAL: 2650 vm_object_page_remove(object, 2651 OFF_TO_IDX(offset), 2652 OFF_TO_IDX(offset + size + PAGE_MASK), 2653 clean_only); 2654 break; 2655 case VM_MAPTYPE_VPAGETABLE: 2656 vm_object_page_remove(object, 0, 0, clean_only); 2657 break; 2658 } 2659 vm_object_deallocate_locked(object); 2660 } 2661 start += size; 2662 if (object) 2663 vm_object_drop(object); 2664 } 2665 2666 lwkt_reltoken(&map->token); 2667 vm_map_unlock_read(map); 2668 2669 return (KERN_SUCCESS); 2670 } 2671 2672 /* 2673 * Make the region specified by this entry pageable. 2674 * 2675 * The vm_map must be exclusively locked. 2676 */ 2677 static void 2678 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2679 { 2680 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2681 entry->wired_count = 0; 2682 vm_fault_unwire(map, entry); 2683 } 2684 2685 /* 2686 * Deallocate the given entry from the target map. 2687 * 2688 * The vm_map must be exclusively locked. 2689 */ 2690 static void 2691 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp) 2692 { 2693 vm_map_entry_unlink(map, entry); 2694 map->size -= entry->end - entry->start; 2695 2696 switch(entry->maptype) { 2697 case VM_MAPTYPE_NORMAL: 2698 case VM_MAPTYPE_VPAGETABLE: 2699 vm_object_deallocate(entry->object.vm_object); 2700 break; 2701 default: 2702 break; 2703 } 2704 2705 vm_map_entry_dispose(map, entry, countp); 2706 } 2707 2708 /* 2709 * Deallocates the given address range from the target map. 2710 * 2711 * The vm_map must be exclusively locked. 2712 */ 2713 int 2714 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp) 2715 { 2716 vm_object_t object; 2717 vm_map_entry_t entry; 2718 vm_map_entry_t first_entry; 2719 2720 ASSERT_VM_MAP_LOCKED(map); 2721 lwkt_gettoken(&map->token); 2722 again: 2723 /* 2724 * Find the start of the region, and clip it. Set entry to point 2725 * at the first record containing the requested address or, if no 2726 * such record exists, the next record with a greater address. The 2727 * loop will run from this point until a record beyond the termination 2728 * address is encountered. 2729 * 2730 * map->hint must be adjusted to not point to anything we delete, 2731 * so set it to the entry prior to the one being deleted. 2732 * 2733 * GGG see other GGG comment. 2734 */ 2735 if (vm_map_lookup_entry(map, start, &first_entry)) { 2736 entry = first_entry; 2737 vm_map_clip_start(map, entry, start, countp); 2738 map->hint = entry->prev; /* possible problem XXX */ 2739 } else { 2740 map->hint = first_entry; /* possible problem XXX */ 2741 entry = first_entry->next; 2742 } 2743 2744 /* 2745 * If a hole opens up prior to the current first_free then 2746 * adjust first_free. As with map->hint, map->first_free 2747 * cannot be left set to anything we might delete. 2748 */ 2749 if (entry == &map->header) { 2750 map->first_free = &map->header; 2751 } else if (map->first_free->start >= start) { 2752 map->first_free = entry->prev; 2753 } 2754 2755 /* 2756 * Step through all entries in this region 2757 */ 2758 while ((entry != &map->header) && (entry->start < end)) { 2759 vm_map_entry_t next; 2760 vm_offset_t s, e; 2761 vm_pindex_t offidxstart, offidxend, count; 2762 2763 /* 2764 * If we hit an in-transition entry we have to sleep and 2765 * retry. It's easier (and not really slower) to just retry 2766 * since this case occurs so rarely and the hint is already 2767 * pointing at the right place. We have to reset the 2768 * start offset so as not to accidently delete an entry 2769 * another process just created in vacated space. 2770 */ 2771 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2772 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2773 start = entry->start; 2774 ++mycpu->gd_cnt.v_intrans_coll; 2775 ++mycpu->gd_cnt.v_intrans_wait; 2776 vm_map_transition_wait(map); 2777 goto again; 2778 } 2779 vm_map_clip_end(map, entry, end, countp); 2780 2781 s = entry->start; 2782 e = entry->end; 2783 next = entry->next; 2784 2785 offidxstart = OFF_TO_IDX(entry->offset); 2786 count = OFF_TO_IDX(e - s); 2787 object = entry->object.vm_object; 2788 2789 /* 2790 * Unwire before removing addresses from the pmap; otherwise, 2791 * unwiring will put the entries back in the pmap. 2792 */ 2793 if (entry->wired_count != 0) 2794 vm_map_entry_unwire(map, entry); 2795 2796 offidxend = offidxstart + count; 2797 2798 if (object == &kernel_object) { 2799 vm_object_hold(object); 2800 vm_object_page_remove(object, offidxstart, 2801 offidxend, FALSE); 2802 vm_object_drop(object); 2803 } else if (object && object->type != OBJT_DEFAULT && 2804 object->type != OBJT_SWAP) { 2805 /* 2806 * vnode object routines cannot be chain-locked 2807 */ 2808 vm_object_hold(object); 2809 pmap_remove(map->pmap, s, e); 2810 vm_object_drop(object); 2811 } else if (object) { 2812 vm_object_hold(object); 2813 vm_object_chain_acquire(object); 2814 pmap_remove(map->pmap, s, e); 2815 2816 if (object != NULL && 2817 object->ref_count != 1 && 2818 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == 2819 OBJ_ONEMAPPING && 2820 (object->type == OBJT_DEFAULT || 2821 object->type == OBJT_SWAP)) { 2822 vm_object_collapse(object, NULL); 2823 vm_object_page_remove(object, offidxstart, 2824 offidxend, FALSE); 2825 if (object->type == OBJT_SWAP) { 2826 swap_pager_freespace(object, 2827 offidxstart, 2828 count); 2829 } 2830 if (offidxend >= object->size && 2831 offidxstart < object->size) { 2832 object->size = offidxstart; 2833 } 2834 } 2835 vm_object_chain_release(object); 2836 vm_object_drop(object); 2837 } 2838 2839 /* 2840 * Delete the entry (which may delete the object) only after 2841 * removing all pmap entries pointing to its pages. 2842 * (Otherwise, its page frames may be reallocated, and any 2843 * modify bits will be set in the wrong object!) 2844 */ 2845 vm_map_entry_delete(map, entry, countp); 2846 entry = next; 2847 } 2848 lwkt_reltoken(&map->token); 2849 return (KERN_SUCCESS); 2850 } 2851 2852 /* 2853 * Remove the given address range from the target map. 2854 * This is the exported form of vm_map_delete. 2855 * 2856 * No requirements. 2857 */ 2858 int 2859 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2860 { 2861 int result; 2862 int count; 2863 2864 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2865 vm_map_lock(map); 2866 VM_MAP_RANGE_CHECK(map, start, end); 2867 result = vm_map_delete(map, start, end, &count); 2868 vm_map_unlock(map); 2869 vm_map_entry_release(count); 2870 2871 return (result); 2872 } 2873 2874 /* 2875 * Assert that the target map allows the specified privilege on the 2876 * entire address region given. The entire region must be allocated. 2877 * 2878 * The caller must specify whether the vm_map is already locked or not. 2879 */ 2880 boolean_t 2881 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2882 vm_prot_t protection, boolean_t have_lock) 2883 { 2884 vm_map_entry_t entry; 2885 vm_map_entry_t tmp_entry; 2886 boolean_t result; 2887 2888 if (have_lock == FALSE) 2889 vm_map_lock_read(map); 2890 2891 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 2892 if (have_lock == FALSE) 2893 vm_map_unlock_read(map); 2894 return (FALSE); 2895 } 2896 entry = tmp_entry; 2897 2898 result = TRUE; 2899 while (start < end) { 2900 if (entry == &map->header) { 2901 result = FALSE; 2902 break; 2903 } 2904 /* 2905 * No holes allowed! 2906 */ 2907 2908 if (start < entry->start) { 2909 result = FALSE; 2910 break; 2911 } 2912 /* 2913 * Check protection associated with entry. 2914 */ 2915 2916 if ((entry->protection & protection) != protection) { 2917 result = FALSE; 2918 break; 2919 } 2920 /* go to next entry */ 2921 2922 start = entry->end; 2923 entry = entry->next; 2924 } 2925 if (have_lock == FALSE) 2926 vm_map_unlock_read(map); 2927 return (result); 2928 } 2929 2930 /* 2931 * If appropriate this function shadows the original object with a new object 2932 * and moves the VM pages from the original object to the new object. 2933 * The original object will also be collapsed, if possible. 2934 * 2935 * We can only do this for normal memory objects with a single mapping, and 2936 * it only makes sense to do it if there are 2 or more refs on the original 2937 * object. i.e. typically a memory object that has been extended into 2938 * multiple vm_map_entry's with non-overlapping ranges. 2939 * 2940 * This makes it easier to remove unused pages and keeps object inheritance 2941 * from being a negative impact on memory usage. 2942 * 2943 * On return the (possibly new) entry->object.vm_object will have an 2944 * additional ref on it for the caller to dispose of (usually by cloning 2945 * the vm_map_entry). The additional ref had to be done in this routine 2946 * to avoid racing a collapse. The object's ONEMAPPING flag will also be 2947 * cleared. 2948 * 2949 * The vm_map must be locked and its token held. 2950 */ 2951 static void 2952 vm_map_split(vm_map_entry_t entry) 2953 { 2954 #if 0 2955 /* UNOPTIMIZED */ 2956 vm_object_t oobject; 2957 2958 oobject = entry->object.vm_object; 2959 vm_object_hold(oobject); 2960 vm_object_chain_wait(oobject); 2961 vm_object_reference_locked(oobject); 2962 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 2963 vm_object_drop(oobject); 2964 #else 2965 /* OPTIMIZED */ 2966 vm_object_t oobject, nobject, bobject; 2967 vm_offset_t s, e; 2968 vm_page_t m; 2969 vm_pindex_t offidxstart, offidxend, idx; 2970 vm_size_t size; 2971 vm_ooffset_t offset; 2972 2973 /* 2974 * Setup. Chain lock the original object throughout the entire 2975 * routine to prevent new page faults from occuring. 2976 * 2977 * XXX can madvise WILLNEED interfere with us too? 2978 */ 2979 oobject = entry->object.vm_object; 2980 vm_object_hold(oobject); 2981 vm_object_chain_acquire(oobject); 2982 2983 /* 2984 * Original object cannot be split? 2985 */ 2986 if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT && 2987 oobject->type != OBJT_SWAP)) { 2988 vm_object_chain_release(oobject); 2989 vm_object_reference_locked(oobject); 2990 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 2991 vm_object_drop(oobject); 2992 return; 2993 } 2994 2995 /* 2996 * Collapse original object with its backing store as an 2997 * optimization to reduce chain lengths when possible. 2998 * 2999 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's 3000 * for oobject, so there's no point collapsing it. 3001 * 3002 * Then re-check whether the object can be split. 3003 */ 3004 vm_object_collapse(oobject, NULL); 3005 3006 if (oobject->ref_count <= 1 || 3007 (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) || 3008 (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) { 3009 vm_object_chain_release(oobject); 3010 vm_object_reference_locked(oobject); 3011 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 3012 vm_object_drop(oobject); 3013 return; 3014 } 3015 3016 /* 3017 * Acquire the chain lock on the backing object. 3018 * 3019 * Give bobject an additional ref count for when it will be shadowed 3020 * by nobject. 3021 */ 3022 if ((bobject = oobject->backing_object) != NULL) { 3023 vm_object_hold(bobject); 3024 vm_object_chain_wait(bobject); 3025 vm_object_reference_locked(bobject); 3026 vm_object_chain_acquire(bobject); 3027 KKASSERT(bobject->backing_object == bobject); 3028 KKASSERT((bobject->flags & OBJ_DEAD) == 0); 3029 } 3030 3031 /* 3032 * Calculate the object page range and allocate the new object. 3033 */ 3034 offset = entry->offset; 3035 s = entry->start; 3036 e = entry->end; 3037 3038 offidxstart = OFF_TO_IDX(offset); 3039 offidxend = offidxstart + OFF_TO_IDX(e - s); 3040 size = offidxend - offidxstart; 3041 3042 switch(oobject->type) { 3043 case OBJT_DEFAULT: 3044 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size), 3045 VM_PROT_ALL, 0); 3046 break; 3047 case OBJT_SWAP: 3048 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size), 3049 VM_PROT_ALL, 0); 3050 break; 3051 default: 3052 /* not reached */ 3053 nobject = NULL; 3054 KKASSERT(0); 3055 } 3056 3057 if (nobject == NULL) { 3058 if (bobject) { 3059 vm_object_chain_release(bobject); 3060 vm_object_deallocate(bobject); 3061 vm_object_drop(bobject); 3062 } 3063 vm_object_chain_release(oobject); 3064 vm_object_reference_locked(oobject); 3065 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 3066 vm_object_drop(oobject); 3067 return; 3068 } 3069 3070 /* 3071 * The new object will replace entry->object.vm_object so it needs 3072 * a second reference (the caller expects an additional ref). 3073 */ 3074 vm_object_hold(nobject); 3075 vm_object_reference_locked(nobject); 3076 vm_object_chain_acquire(nobject); 3077 3078 /* 3079 * nobject shadows bobject (oobject already shadows bobject). 3080 */ 3081 if (bobject) { 3082 nobject->backing_object_offset = 3083 oobject->backing_object_offset + IDX_TO_OFF(offidxstart); 3084 nobject->backing_object = bobject; 3085 bobject->shadow_count++; 3086 bobject->generation++; 3087 LIST_INSERT_HEAD(&bobject->shadow_head, nobject, shadow_list); 3088 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /* XXX? */ 3089 vm_object_chain_release(bobject); 3090 vm_object_drop(bobject); 3091 } 3092 3093 /* 3094 * Move the VM pages from oobject to nobject 3095 */ 3096 for (idx = 0; idx < size; idx++) { 3097 vm_page_t m; 3098 3099 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx, 3100 TRUE, "vmpg"); 3101 if (m == NULL) 3102 continue; 3103 3104 /* 3105 * We must wait for pending I/O to complete before we can 3106 * rename the page. 3107 * 3108 * We do not have to VM_PROT_NONE the page as mappings should 3109 * not be changed by this operation. 3110 * 3111 * NOTE: The act of renaming a page updates chaingen for both 3112 * objects. 3113 */ 3114 vm_page_rename(m, nobject, idx); 3115 /* page automatically made dirty by rename and cache handled */ 3116 /* page remains busy */ 3117 } 3118 3119 if (oobject->type == OBJT_SWAP) { 3120 vm_object_pip_add(oobject, 1); 3121 /* 3122 * copy oobject pages into nobject and destroy unneeded 3123 * pages in shadow object. 3124 */ 3125 swap_pager_copy(oobject, nobject, offidxstart, 0); 3126 vm_object_pip_wakeup(oobject); 3127 } 3128 3129 /* 3130 * Wakeup the pages we played with. No spl protection is needed 3131 * for a simple wakeup. 3132 */ 3133 for (idx = 0; idx < size; idx++) { 3134 m = vm_page_lookup(nobject, idx); 3135 if (m) { 3136 KKASSERT(m->flags & PG_BUSY); 3137 vm_page_wakeup(m); 3138 } 3139 } 3140 entry->object.vm_object = nobject; 3141 entry->offset = 0LL; 3142 3143 /* 3144 * Cleanup 3145 * 3146 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the 3147 * related pages were moved and are no longer applicable to the 3148 * original object. 3149 * 3150 * NOTE: Deallocate oobject (due to its entry->object.vm_object being 3151 * replaced by nobject). 3152 */ 3153 vm_object_chain_release(nobject); 3154 vm_object_drop(nobject); 3155 if (bobject) { 3156 vm_object_chain_release(bobject); 3157 vm_object_drop(bobject); 3158 } 3159 vm_object_chain_release(oobject); 3160 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/ 3161 vm_object_deallocate_locked(oobject); 3162 vm_object_drop(oobject); 3163 #endif 3164 } 3165 3166 /* 3167 * Copies the contents of the source entry to the destination 3168 * entry. The entries *must* be aligned properly. 3169 * 3170 * The vm_maps must be exclusively locked. 3171 * The vm_map's token must be held. 3172 * 3173 * Because the maps are locked no faults can be in progress during the 3174 * operation. 3175 */ 3176 static void 3177 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map, 3178 vm_map_entry_t src_entry, vm_map_entry_t dst_entry) 3179 { 3180 vm_object_t src_object; 3181 3182 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP) 3183 return; 3184 if (src_entry->maptype == VM_MAPTYPE_SUBMAP) 3185 return; 3186 3187 if (src_entry->wired_count == 0) { 3188 /* 3189 * If the source entry is marked needs_copy, it is already 3190 * write-protected. 3191 */ 3192 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 3193 pmap_protect(src_map->pmap, 3194 src_entry->start, 3195 src_entry->end, 3196 src_entry->protection & ~VM_PROT_WRITE); 3197 } 3198 3199 /* 3200 * Make a copy of the object. 3201 * 3202 * The object must be locked prior to checking the object type 3203 * and for the call to vm_object_collapse() and vm_map_split(). 3204 * We cannot use *_hold() here because the split code will 3205 * probably try to destroy the object. The lock is a pool 3206 * token and doesn't care. 3207 * 3208 * We must bump src_map->timestamp when setting 3209 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault 3210 * to retry, otherwise the concurrent fault might improperly 3211 * install a RW pte when its supposed to be a RO(COW) pte. 3212 * This race can occur because a vnode-backed fault may have 3213 * to temporarily release the map lock. 3214 */ 3215 if (src_entry->object.vm_object != NULL) { 3216 vm_map_split(src_entry); 3217 src_object = src_entry->object.vm_object; 3218 dst_entry->object.vm_object = src_object; 3219 src_entry->eflags |= (MAP_ENTRY_COW | 3220 MAP_ENTRY_NEEDS_COPY); 3221 dst_entry->eflags |= (MAP_ENTRY_COW | 3222 MAP_ENTRY_NEEDS_COPY); 3223 dst_entry->offset = src_entry->offset; 3224 ++src_map->timestamp; 3225 } else { 3226 dst_entry->object.vm_object = NULL; 3227 dst_entry->offset = 0; 3228 } 3229 3230 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3231 dst_entry->end - dst_entry->start, src_entry->start); 3232 } else { 3233 /* 3234 * Of course, wired down pages can't be set copy-on-write. 3235 * Cause wired pages to be copied into the new map by 3236 * simulating faults (the new pages are pageable) 3237 */ 3238 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 3239 } 3240 } 3241 3242 /* 3243 * vmspace_fork: 3244 * Create a new process vmspace structure and vm_map 3245 * based on those of an existing process. The new map 3246 * is based on the old map, according to the inheritance 3247 * values on the regions in that map. 3248 * 3249 * The source map must not be locked. 3250 * No requirements. 3251 */ 3252 struct vmspace * 3253 vmspace_fork(struct vmspace *vm1) 3254 { 3255 struct vmspace *vm2; 3256 vm_map_t old_map = &vm1->vm_map; 3257 vm_map_t new_map; 3258 vm_map_entry_t old_entry; 3259 vm_map_entry_t new_entry; 3260 vm_object_t object; 3261 int count; 3262 3263 lwkt_gettoken(&vm1->vm_map.token); 3264 vm_map_lock(old_map); 3265 3266 /* 3267 * XXX Note: upcalls are not copied. 3268 */ 3269 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 3270 lwkt_gettoken(&vm2->vm_map.token); 3271 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 3272 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); 3273 new_map = &vm2->vm_map; /* XXX */ 3274 new_map->timestamp = 1; 3275 3276 vm_map_lock(new_map); 3277 3278 count = 0; 3279 old_entry = old_map->header.next; 3280 while (old_entry != &old_map->header) { 3281 ++count; 3282 old_entry = old_entry->next; 3283 } 3284 3285 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); 3286 3287 old_entry = old_map->header.next; 3288 while (old_entry != &old_map->header) { 3289 if (old_entry->maptype == VM_MAPTYPE_SUBMAP) 3290 panic("vm_map_fork: encountered a submap"); 3291 3292 switch (old_entry->inheritance) { 3293 case VM_INHERIT_NONE: 3294 break; 3295 case VM_INHERIT_SHARE: 3296 /* 3297 * Clone the entry, creating the shared object if 3298 * necessary. 3299 */ 3300 if (old_entry->object.vm_object == NULL) 3301 vm_map_entry_allocate_object(old_entry); 3302 3303 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3304 /* 3305 * Shadow a map_entry which needs a copy, 3306 * replacing its object with a new object 3307 * that points to the old one. Ask the 3308 * shadow code to automatically add an 3309 * additional ref. We can't do it afterwords 3310 * because we might race a collapse. The call 3311 * to vm_map_entry_shadow() will also clear 3312 * OBJ_ONEMAPPING. 3313 */ 3314 vm_map_entry_shadow(old_entry, 1); 3315 } else { 3316 /* 3317 * We will make a shared copy of the object, 3318 * and must clear OBJ_ONEMAPPING. 3319 * 3320 * XXX assert that object.vm_object != NULL 3321 * since we allocate it above. 3322 */ 3323 if (old_entry->object.vm_object) { 3324 object = old_entry->object.vm_object; 3325 vm_object_hold(object); 3326 vm_object_chain_wait(object); 3327 vm_object_reference_locked(object); 3328 vm_object_clear_flag(object, 3329 OBJ_ONEMAPPING); 3330 vm_object_drop(object); 3331 } 3332 } 3333 3334 /* 3335 * Clone the entry. We've already bumped the ref on 3336 * any vm_object. 3337 */ 3338 new_entry = vm_map_entry_create(new_map, &count); 3339 *new_entry = *old_entry; 3340 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3341 new_entry->wired_count = 0; 3342 3343 /* 3344 * Insert the entry into the new map -- we know we're 3345 * inserting at the end of the new map. 3346 */ 3347 3348 vm_map_entry_link(new_map, new_map->header.prev, 3349 new_entry); 3350 3351 /* 3352 * Update the physical map 3353 */ 3354 pmap_copy(new_map->pmap, old_map->pmap, 3355 new_entry->start, 3356 (old_entry->end - old_entry->start), 3357 old_entry->start); 3358 break; 3359 case VM_INHERIT_COPY: 3360 /* 3361 * Clone the entry and link into the map. 3362 */ 3363 new_entry = vm_map_entry_create(new_map, &count); 3364 *new_entry = *old_entry; 3365 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3366 new_entry->wired_count = 0; 3367 new_entry->object.vm_object = NULL; 3368 vm_map_entry_link(new_map, new_map->header.prev, 3369 new_entry); 3370 vm_map_copy_entry(old_map, new_map, old_entry, 3371 new_entry); 3372 break; 3373 } 3374 old_entry = old_entry->next; 3375 } 3376 3377 new_map->size = old_map->size; 3378 vm_map_unlock(old_map); 3379 vm_map_unlock(new_map); 3380 vm_map_entry_release(count); 3381 3382 lwkt_reltoken(&vm2->vm_map.token); 3383 lwkt_reltoken(&vm1->vm_map.token); 3384 3385 return (vm2); 3386 } 3387 3388 /* 3389 * Create an auto-grow stack entry 3390 * 3391 * No requirements. 3392 */ 3393 int 3394 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3395 int flags, vm_prot_t prot, vm_prot_t max, int cow) 3396 { 3397 vm_map_entry_t prev_entry; 3398 vm_map_entry_t new_stack_entry; 3399 vm_size_t init_ssize; 3400 int rv; 3401 int count; 3402 vm_offset_t tmpaddr; 3403 3404 cow |= MAP_IS_STACK; 3405 3406 if (max_ssize < sgrowsiz) 3407 init_ssize = max_ssize; 3408 else 3409 init_ssize = sgrowsiz; 3410 3411 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3412 vm_map_lock(map); 3413 3414 /* 3415 * Find space for the mapping 3416 */ 3417 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) { 3418 if (vm_map_findspace(map, addrbos, max_ssize, 1, 3419 flags, &tmpaddr)) { 3420 vm_map_unlock(map); 3421 vm_map_entry_release(count); 3422 return (KERN_NO_SPACE); 3423 } 3424 addrbos = tmpaddr; 3425 } 3426 3427 /* If addr is already mapped, no go */ 3428 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3429 vm_map_unlock(map); 3430 vm_map_entry_release(count); 3431 return (KERN_NO_SPACE); 3432 } 3433 3434 #if 0 3435 /* XXX already handled by kern_mmap() */ 3436 /* If we would blow our VMEM resource limit, no go */ 3437 if (map->size + init_ssize > 3438 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3439 vm_map_unlock(map); 3440 vm_map_entry_release(count); 3441 return (KERN_NO_SPACE); 3442 } 3443 #endif 3444 3445 /* 3446 * If we can't accomodate max_ssize in the current mapping, 3447 * no go. However, we need to be aware that subsequent user 3448 * mappings might map into the space we have reserved for 3449 * stack, and currently this space is not protected. 3450 * 3451 * Hopefully we will at least detect this condition 3452 * when we try to grow the stack. 3453 */ 3454 if ((prev_entry->next != &map->header) && 3455 (prev_entry->next->start < addrbos + max_ssize)) { 3456 vm_map_unlock(map); 3457 vm_map_entry_release(count); 3458 return (KERN_NO_SPACE); 3459 } 3460 3461 /* 3462 * We initially map a stack of only init_ssize. We will 3463 * grow as needed later. Since this is to be a grow 3464 * down stack, we map at the top of the range. 3465 * 3466 * Note: we would normally expect prot and max to be 3467 * VM_PROT_ALL, and cow to be 0. Possibly we should 3468 * eliminate these as input parameters, and just 3469 * pass these values here in the insert call. 3470 */ 3471 rv = vm_map_insert(map, &count, 3472 NULL, 0, addrbos + max_ssize - init_ssize, 3473 addrbos + max_ssize, 3474 VM_MAPTYPE_NORMAL, 3475 prot, max, 3476 cow); 3477 3478 /* Now set the avail_ssize amount */ 3479 if (rv == KERN_SUCCESS) { 3480 if (prev_entry != &map->header) 3481 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count); 3482 new_stack_entry = prev_entry->next; 3483 if (new_stack_entry->end != addrbos + max_ssize || 3484 new_stack_entry->start != addrbos + max_ssize - init_ssize) 3485 panic ("Bad entry start/end for new stack entry"); 3486 else 3487 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize; 3488 } 3489 3490 vm_map_unlock(map); 3491 vm_map_entry_release(count); 3492 return (rv); 3493 } 3494 3495 /* 3496 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3497 * desired address is already mapped, or if we successfully grow 3498 * the stack. Also returns KERN_SUCCESS if addr is outside the 3499 * stack range (this is strange, but preserves compatibility with 3500 * the grow function in vm_machdep.c). 3501 * 3502 * No requirements. 3503 */ 3504 int 3505 vm_map_growstack (struct proc *p, vm_offset_t addr) 3506 { 3507 vm_map_entry_t prev_entry; 3508 vm_map_entry_t stack_entry; 3509 vm_map_entry_t new_stack_entry; 3510 struct vmspace *vm = p->p_vmspace; 3511 vm_map_t map = &vm->vm_map; 3512 vm_offset_t end; 3513 int grow_amount; 3514 int rv = KERN_SUCCESS; 3515 int is_procstack; 3516 int use_read_lock = 1; 3517 int count; 3518 3519 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3520 Retry: 3521 if (use_read_lock) 3522 vm_map_lock_read(map); 3523 else 3524 vm_map_lock(map); 3525 3526 /* If addr is already in the entry range, no need to grow.*/ 3527 if (vm_map_lookup_entry(map, addr, &prev_entry)) 3528 goto done; 3529 3530 if ((stack_entry = prev_entry->next) == &map->header) 3531 goto done; 3532 if (prev_entry == &map->header) 3533 end = stack_entry->start - stack_entry->aux.avail_ssize; 3534 else 3535 end = prev_entry->end; 3536 3537 /* 3538 * This next test mimics the old grow function in vm_machdep.c. 3539 * It really doesn't quite make sense, but we do it anyway 3540 * for compatibility. 3541 * 3542 * If not growable stack, return success. This signals the 3543 * caller to proceed as he would normally with normal vm. 3544 */ 3545 if (stack_entry->aux.avail_ssize < 1 || 3546 addr >= stack_entry->start || 3547 addr < stack_entry->start - stack_entry->aux.avail_ssize) { 3548 goto done; 3549 } 3550 3551 /* Find the minimum grow amount */ 3552 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE); 3553 if (grow_amount > stack_entry->aux.avail_ssize) { 3554 rv = KERN_NO_SPACE; 3555 goto done; 3556 } 3557 3558 /* 3559 * If there is no longer enough space between the entries 3560 * nogo, and adjust the available space. Note: this 3561 * should only happen if the user has mapped into the 3562 * stack area after the stack was created, and is 3563 * probably an error. 3564 * 3565 * This also effectively destroys any guard page the user 3566 * might have intended by limiting the stack size. 3567 */ 3568 if (grow_amount > stack_entry->start - end) { 3569 if (use_read_lock && vm_map_lock_upgrade(map)) { 3570 /* lost lock */ 3571 use_read_lock = 0; 3572 goto Retry; 3573 } 3574 use_read_lock = 0; 3575 stack_entry->aux.avail_ssize = stack_entry->start - end; 3576 rv = KERN_NO_SPACE; 3577 goto done; 3578 } 3579 3580 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; 3581 3582 /* If this is the main process stack, see if we're over the 3583 * stack limit. 3584 */ 3585 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3586 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3587 rv = KERN_NO_SPACE; 3588 goto done; 3589 } 3590 3591 /* Round up the grow amount modulo SGROWSIZ */ 3592 grow_amount = roundup (grow_amount, sgrowsiz); 3593 if (grow_amount > stack_entry->aux.avail_ssize) { 3594 grow_amount = stack_entry->aux.avail_ssize; 3595 } 3596 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3597 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3598 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 3599 ctob(vm->vm_ssize); 3600 } 3601 3602 /* If we would blow our VMEM resource limit, no go */ 3603 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3604 rv = KERN_NO_SPACE; 3605 goto done; 3606 } 3607 3608 if (use_read_lock && vm_map_lock_upgrade(map)) { 3609 /* lost lock */ 3610 use_read_lock = 0; 3611 goto Retry; 3612 } 3613 use_read_lock = 0; 3614 3615 /* Get the preliminary new entry start value */ 3616 addr = stack_entry->start - grow_amount; 3617 3618 /* If this puts us into the previous entry, cut back our growth 3619 * to the available space. Also, see the note above. 3620 */ 3621 if (addr < end) { 3622 stack_entry->aux.avail_ssize = stack_entry->start - end; 3623 addr = end; 3624 } 3625 3626 rv = vm_map_insert(map, &count, 3627 NULL, 0, addr, stack_entry->start, 3628 VM_MAPTYPE_NORMAL, 3629 VM_PROT_ALL, VM_PROT_ALL, 3630 0); 3631 3632 /* Adjust the available stack space by the amount we grew. */ 3633 if (rv == KERN_SUCCESS) { 3634 if (prev_entry != &map->header) 3635 vm_map_clip_end(map, prev_entry, addr, &count); 3636 new_stack_entry = prev_entry->next; 3637 if (new_stack_entry->end != stack_entry->start || 3638 new_stack_entry->start != addr) 3639 panic ("Bad stack grow start/end in new stack entry"); 3640 else { 3641 new_stack_entry->aux.avail_ssize = 3642 stack_entry->aux.avail_ssize - 3643 (new_stack_entry->end - new_stack_entry->start); 3644 if (is_procstack) 3645 vm->vm_ssize += btoc(new_stack_entry->end - 3646 new_stack_entry->start); 3647 } 3648 3649 if (map->flags & MAP_WIREFUTURE) 3650 vm_map_unwire(map, new_stack_entry->start, 3651 new_stack_entry->end, FALSE); 3652 } 3653 3654 done: 3655 if (use_read_lock) 3656 vm_map_unlock_read(map); 3657 else 3658 vm_map_unlock(map); 3659 vm_map_entry_release(count); 3660 return (rv); 3661 } 3662 3663 /* 3664 * Unshare the specified VM space for exec. If other processes are 3665 * mapped to it, then create a new one. The new vmspace is null. 3666 * 3667 * No requirements. 3668 */ 3669 void 3670 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 3671 { 3672 struct vmspace *oldvmspace = p->p_vmspace; 3673 struct vmspace *newvmspace; 3674 vm_map_t map = &p->p_vmspace->vm_map; 3675 3676 /* 3677 * If we are execing a resident vmspace we fork it, otherwise 3678 * we create a new vmspace. Note that exitingcnt and upcalls 3679 * are not copied to the new vmspace. 3680 */ 3681 lwkt_gettoken(&oldvmspace->vm_map.token); 3682 if (vmcopy) { 3683 newvmspace = vmspace_fork(vmcopy); 3684 lwkt_gettoken(&newvmspace->vm_map.token); 3685 } else { 3686 newvmspace = vmspace_alloc(map->min_offset, map->max_offset); 3687 lwkt_gettoken(&newvmspace->vm_map.token); 3688 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 3689 (caddr_t)&oldvmspace->vm_endcopy - 3690 (caddr_t)&oldvmspace->vm_startcopy); 3691 } 3692 3693 /* 3694 * Finish initializing the vmspace before assigning it 3695 * to the process. The vmspace will become the current vmspace 3696 * if p == curproc. 3697 */ 3698 pmap_pinit2(vmspace_pmap(newvmspace)); 3699 pmap_replacevm(p, newvmspace, 0); 3700 lwkt_reltoken(&newvmspace->vm_map.token); 3701 lwkt_reltoken(&oldvmspace->vm_map.token); 3702 vmspace_free(oldvmspace); 3703 } 3704 3705 /* 3706 * Unshare the specified VM space for forcing COW. This 3707 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3708 */ 3709 void 3710 vmspace_unshare(struct proc *p) 3711 { 3712 struct vmspace *oldvmspace = p->p_vmspace; 3713 struct vmspace *newvmspace; 3714 3715 lwkt_gettoken(&oldvmspace->vm_map.token); 3716 if (oldvmspace->vm_sysref.refcnt == 1) { 3717 lwkt_reltoken(&oldvmspace->vm_map.token); 3718 return; 3719 } 3720 newvmspace = vmspace_fork(oldvmspace); 3721 lwkt_gettoken(&newvmspace->vm_map.token); 3722 pmap_pinit2(vmspace_pmap(newvmspace)); 3723 pmap_replacevm(p, newvmspace, 0); 3724 lwkt_reltoken(&newvmspace->vm_map.token); 3725 lwkt_reltoken(&oldvmspace->vm_map.token); 3726 vmspace_free(oldvmspace); 3727 } 3728 3729 /* 3730 * vm_map_hint: return the beginning of the best area suitable for 3731 * creating a new mapping with "prot" protection. 3732 * 3733 * No requirements. 3734 */ 3735 vm_offset_t 3736 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot) 3737 { 3738 struct vmspace *vms = p->p_vmspace; 3739 3740 if (!randomize_mmap) { 3741 /* 3742 * Set a reasonable start point for the hint if it was 3743 * not specified or if it falls within the heap space. 3744 * Hinted mmap()s do not allocate out of the heap space. 3745 */ 3746 if (addr == 0 || 3747 (addr >= round_page((vm_offset_t)vms->vm_taddr) && 3748 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) { 3749 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); 3750 } 3751 3752 return addr; 3753 } 3754 3755 if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr) 3756 return addr; 3757 3758 #ifdef notyet 3759 #ifdef __i386__ 3760 /* 3761 * If executable skip first two pages, otherwise start 3762 * after data + heap region. 3763 */ 3764 if ((prot & VM_PROT_EXECUTE) && 3765 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) { 3766 addr = (PAGE_SIZE * 2) + 3767 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1)); 3768 return (round_page(addr)); 3769 } 3770 #endif /* __i386__ */ 3771 #endif /* notyet */ 3772 3773 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ; 3774 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1); 3775 3776 return (round_page(addr)); 3777 } 3778 3779 /* 3780 * Finds the VM object, offset, and protection for a given virtual address 3781 * in the specified map, assuming a page fault of the type specified. 3782 * 3783 * Leaves the map in question locked for read; return values are guaranteed 3784 * until a vm_map_lookup_done call is performed. Note that the map argument 3785 * is in/out; the returned map must be used in the call to vm_map_lookup_done. 3786 * 3787 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make 3788 * that fast. 3789 * 3790 * If a lookup is requested with "write protection" specified, the map may 3791 * be changed to perform virtual copying operations, although the data 3792 * referenced will remain the same. 3793 * 3794 * No requirements. 3795 */ 3796 int 3797 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3798 vm_offset_t vaddr, 3799 vm_prot_t fault_typea, 3800 vm_map_entry_t *out_entry, /* OUT */ 3801 vm_object_t *object, /* OUT */ 3802 vm_pindex_t *pindex, /* OUT */ 3803 vm_prot_t *out_prot, /* OUT */ 3804 boolean_t *wired) /* OUT */ 3805 { 3806 vm_map_entry_t entry; 3807 vm_map_t map = *var_map; 3808 vm_prot_t prot; 3809 vm_prot_t fault_type = fault_typea; 3810 int use_read_lock = 1; 3811 int rv = KERN_SUCCESS; 3812 3813 RetryLookup: 3814 if (use_read_lock) 3815 vm_map_lock_read(map); 3816 else 3817 vm_map_lock(map); 3818 3819 /* 3820 * If the map has an interesting hint, try it before calling full 3821 * blown lookup routine. 3822 */ 3823 entry = map->hint; 3824 cpu_ccfence(); 3825 *out_entry = entry; 3826 *object = NULL; 3827 3828 if ((entry == &map->header) || 3829 (vaddr < entry->start) || (vaddr >= entry->end)) { 3830 vm_map_entry_t tmp_entry; 3831 3832 /* 3833 * Entry was either not a valid hint, or the vaddr was not 3834 * contained in the entry, so do a full lookup. 3835 */ 3836 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { 3837 rv = KERN_INVALID_ADDRESS; 3838 goto done; 3839 } 3840 3841 entry = tmp_entry; 3842 *out_entry = entry; 3843 } 3844 3845 /* 3846 * Handle submaps. 3847 */ 3848 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3849 vm_map_t old_map = map; 3850 3851 *var_map = map = entry->object.sub_map; 3852 if (use_read_lock) 3853 vm_map_unlock_read(old_map); 3854 else 3855 vm_map_unlock(old_map); 3856 use_read_lock = 1; 3857 goto RetryLookup; 3858 } 3859 3860 /* 3861 * Check whether this task is allowed to have this page. 3862 * Note the special case for MAP_ENTRY_COW 3863 * pages with an override. This is to implement a forced 3864 * COW for debuggers. 3865 */ 3866 3867 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3868 prot = entry->max_protection; 3869 else 3870 prot = entry->protection; 3871 3872 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3873 if ((fault_type & prot) != fault_type) { 3874 rv = KERN_PROTECTION_FAILURE; 3875 goto done; 3876 } 3877 3878 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3879 (entry->eflags & MAP_ENTRY_COW) && 3880 (fault_type & VM_PROT_WRITE) && 3881 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 3882 rv = KERN_PROTECTION_FAILURE; 3883 goto done; 3884 } 3885 3886 /* 3887 * If this page is not pageable, we have to get it for all possible 3888 * accesses. 3889 */ 3890 *wired = (entry->wired_count != 0); 3891 if (*wired) 3892 prot = fault_type = entry->protection; 3893 3894 /* 3895 * Virtual page tables may need to update the accessed (A) bit 3896 * in a page table entry. Upgrade the fault to a write fault for 3897 * that case if the map will support it. If the map does not support 3898 * it the page table entry simply will not be updated. 3899 */ 3900 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 3901 if (prot & VM_PROT_WRITE) 3902 fault_type |= VM_PROT_WRITE; 3903 } 3904 3905 /* 3906 * If the entry was copy-on-write, we either ... 3907 */ 3908 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3909 /* 3910 * If we want to write the page, we may as well handle that 3911 * now since we've got the map locked. 3912 * 3913 * If we don't need to write the page, we just demote the 3914 * permissions allowed. 3915 */ 3916 3917 if (fault_type & VM_PROT_WRITE) { 3918 /* 3919 * Make a new object, and place it in the object 3920 * chain. Note that no new references have appeared 3921 * -- one just moved from the map to the new 3922 * object. 3923 */ 3924 3925 if (use_read_lock && vm_map_lock_upgrade(map)) { 3926 /* lost lock */ 3927 use_read_lock = 0; 3928 goto RetryLookup; 3929 } 3930 use_read_lock = 0; 3931 3932 vm_map_entry_shadow(entry, 0); 3933 } else { 3934 /* 3935 * We're attempting to read a copy-on-write page -- 3936 * don't allow writes. 3937 */ 3938 3939 prot &= ~VM_PROT_WRITE; 3940 } 3941 } 3942 3943 /* 3944 * Create an object if necessary. 3945 */ 3946 if (entry->object.vm_object == NULL && !map->system_map) { 3947 if (use_read_lock && vm_map_lock_upgrade(map)) { 3948 /* lost lock */ 3949 use_read_lock = 0; 3950 goto RetryLookup; 3951 } 3952 use_read_lock = 0; 3953 vm_map_entry_allocate_object(entry); 3954 } 3955 3956 /* 3957 * Return the object/offset from this entry. If the entry was 3958 * copy-on-write or empty, it has been fixed up. 3959 */ 3960 3961 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3962 *object = entry->object.vm_object; 3963 3964 /* 3965 * Return whether this is the only map sharing this data. On 3966 * success we return with a read lock held on the map. On failure 3967 * we return with the map unlocked. 3968 */ 3969 *out_prot = prot; 3970 done: 3971 if (rv == KERN_SUCCESS) { 3972 if (use_read_lock == 0) 3973 vm_map_lock_downgrade(map); 3974 } else if (use_read_lock) { 3975 vm_map_unlock_read(map); 3976 } else { 3977 vm_map_unlock(map); 3978 } 3979 return (rv); 3980 } 3981 3982 /* 3983 * Releases locks acquired by a vm_map_lookup() 3984 * (according to the handle returned by that lookup). 3985 * 3986 * No other requirements. 3987 */ 3988 void 3989 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) 3990 { 3991 /* 3992 * Unlock the main-level map 3993 */ 3994 vm_map_unlock_read(map); 3995 if (count) 3996 vm_map_entry_release(count); 3997 } 3998 3999 #include "opt_ddb.h" 4000 #ifdef DDB 4001 #include <sys/kernel.h> 4002 4003 #include <ddb/ddb.h> 4004 4005 /* 4006 * Debugging only 4007 */ 4008 DB_SHOW_COMMAND(map, vm_map_print) 4009 { 4010 static int nlines; 4011 /* XXX convert args. */ 4012 vm_map_t map = (vm_map_t)addr; 4013 boolean_t full = have_addr; 4014 4015 vm_map_entry_t entry; 4016 4017 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4018 (void *)map, 4019 (void *)map->pmap, map->nentries, map->timestamp); 4020 nlines++; 4021 4022 if (!full && db_indent) 4023 return; 4024 4025 db_indent += 2; 4026 for (entry = map->header.next; entry != &map->header; 4027 entry = entry->next) { 4028 db_iprintf("map entry %p: start=%p, end=%p\n", 4029 (void *)entry, (void *)entry->start, (void *)entry->end); 4030 nlines++; 4031 { 4032 static char *inheritance_name[4] = 4033 {"share", "copy", "none", "donate_copy"}; 4034 4035 db_iprintf(" prot=%x/%x/%s", 4036 entry->protection, 4037 entry->max_protection, 4038 inheritance_name[(int)(unsigned char)entry->inheritance]); 4039 if (entry->wired_count != 0) 4040 db_printf(", wired"); 4041 } 4042 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 4043 /* XXX no %qd in kernel. Truncate entry->offset. */ 4044 db_printf(", share=%p, offset=0x%lx\n", 4045 (void *)entry->object.sub_map, 4046 (long)entry->offset); 4047 nlines++; 4048 if ((entry->prev == &map->header) || 4049 (entry->prev->object.sub_map != 4050 entry->object.sub_map)) { 4051 db_indent += 2; 4052 vm_map_print((db_expr_t)(intptr_t) 4053 entry->object.sub_map, 4054 full, 0, NULL); 4055 db_indent -= 2; 4056 } 4057 } else { 4058 /* XXX no %qd in kernel. Truncate entry->offset. */ 4059 db_printf(", object=%p, offset=0x%lx", 4060 (void *)entry->object.vm_object, 4061 (long)entry->offset); 4062 if (entry->eflags & MAP_ENTRY_COW) 4063 db_printf(", copy (%s)", 4064 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4065 db_printf("\n"); 4066 nlines++; 4067 4068 if ((entry->prev == &map->header) || 4069 (entry->prev->object.vm_object != 4070 entry->object.vm_object)) { 4071 db_indent += 2; 4072 vm_object_print((db_expr_t)(intptr_t) 4073 entry->object.vm_object, 4074 full, 0, NULL); 4075 nlines += 4; 4076 db_indent -= 2; 4077 } 4078 } 4079 } 4080 db_indent -= 2; 4081 if (db_indent == 0) 4082 nlines = 0; 4083 } 4084 4085 /* 4086 * Debugging only 4087 */ 4088 DB_SHOW_COMMAND(procvm, procvm) 4089 { 4090 struct proc *p; 4091 4092 if (have_addr) { 4093 p = (struct proc *) addr; 4094 } else { 4095 p = curproc; 4096 } 4097 4098 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4099 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4100 (void *)vmspace_pmap(p->p_vmspace)); 4101 4102 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 4103 } 4104 4105 #endif /* DDB */ 4106