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 */ 68 69 /* 70 * Virtual memory mapping module. 71 */ 72 73 #include <sys/param.h> 74 #include <sys/systm.h> 75 #include <sys/kernel.h> 76 #include <sys/proc.h> 77 #include <sys/serialize.h> 78 #include <sys/lock.h> 79 #include <sys/vmmeter.h> 80 #include <sys/mman.h> 81 #include <sys/vnode.h> 82 #include <sys/resourcevar.h> 83 #include <sys/shm.h> 84 #include <sys/tree.h> 85 #include <sys/malloc.h> 86 87 #include <vm/vm.h> 88 #include <vm/vm_param.h> 89 #include <vm/pmap.h> 90 #include <vm/vm_map.h> 91 #include <vm/vm_page.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_pager.h> 94 #include <vm/vm_kern.h> 95 #include <vm/vm_extern.h> 96 #include <vm/swap_pager.h> 97 #include <vm/vm_zone.h> 98 99 #include <sys/thread2.h> 100 #include <sys/sysref2.h> 101 #include <sys/random.h> 102 #include <sys/sysctl.h> 103 104 /* 105 * Virtual memory maps provide for the mapping, protection, and sharing 106 * of virtual memory objects. In addition, this module provides for an 107 * efficient virtual copy of memory from one map to another. 108 * 109 * Synchronization is required prior to most operations. 110 * 111 * Maps consist of an ordered doubly-linked list of simple entries. 112 * A hint and a RB tree is used to speed-up lookups. 113 * 114 * Callers looking to modify maps specify start/end addresses which cause 115 * the related map entry to be clipped if necessary, and then later 116 * recombined if the pieces remained compatible. 117 * 118 * Virtual copy operations are performed by copying VM object references 119 * from one map to another, and then marking both regions as copy-on-write. 120 */ 121 static void vmspace_terminate(struct vmspace *vm); 122 static void vmspace_lock(struct vmspace *vm); 123 static void vmspace_unlock(struct vmspace *vm); 124 static void vmspace_dtor(void *obj, void *private); 125 126 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore"); 127 128 struct sysref_class vmspace_sysref_class = { 129 .name = "vmspace", 130 .mtype = M_VMSPACE, 131 .proto = SYSREF_PROTO_VMSPACE, 132 .offset = offsetof(struct vmspace, vm_sysref), 133 .objsize = sizeof(struct vmspace), 134 .nom_cache = 32, 135 .flags = SRC_MANAGEDINIT, 136 .dtor = vmspace_dtor, 137 .ops = { 138 .terminate = (sysref_terminate_func_t)vmspace_terminate, 139 .lock = (sysref_lock_func_t)vmspace_lock, 140 .unlock = (sysref_lock_func_t)vmspace_unlock 141 } 142 }; 143 144 /* 145 * per-cpu page table cross mappings are initialized in early boot 146 * and might require a considerable number of vm_map_entry structures. 147 */ 148 #define VMEPERCPU (MAXCPU+1) 149 150 static struct vm_zone mapentzone_store, mapzone_store; 151 static vm_zone_t mapentzone, mapzone; 152 static struct vm_object mapentobj, mapobj; 153 154 static struct vm_map_entry map_entry_init[MAX_MAPENT]; 155 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU]; 156 static struct vm_map map_init[MAX_KMAP]; 157 158 static int randomize_mmap; 159 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0, 160 "Randomize mmap offsets"); 161 162 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref); 163 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *); 164 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); 165 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 166 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 167 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); 168 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); 169 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, 170 vm_map_entry_t); 171 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); 172 173 /* 174 * Initialize the vm_map module. Must be called before any other vm_map 175 * routines. 176 * 177 * Map and entry structures are allocated from the general purpose 178 * memory pool with some exceptions: 179 * 180 * - The kernel map is allocated statically. 181 * - Initial kernel map entries are allocated out of a static pool. 182 * 183 * These restrictions are necessary since malloc() uses the 184 * maps and requires map entries. 185 * 186 * Called from the low level boot code only. 187 */ 188 void 189 vm_map_startup(void) 190 { 191 mapzone = &mapzone_store; 192 zbootinit(mapzone, "MAP", sizeof (struct vm_map), 193 map_init, MAX_KMAP); 194 mapentzone = &mapentzone_store; 195 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), 196 map_entry_init, MAX_MAPENT); 197 } 198 199 /* 200 * Called prior to any vmspace allocations. 201 * 202 * Called from the low level boot code only. 203 */ 204 void 205 vm_init2(void) 206 { 207 zinitna(mapentzone, &mapentobj, NULL, 0, 0, 208 ZONE_USE_RESERVE | ZONE_SPECIAL, 1); 209 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1); 210 pmap_init2(); 211 vm_object_init2(); 212 } 213 214 215 /* 216 * Red black tree functions 217 * 218 * The caller must hold the related map lock. 219 */ 220 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); 221 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); 222 223 /* a->start is address, and the only field has to be initialized */ 224 static int 225 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) 226 { 227 if (a->start < b->start) 228 return(-1); 229 else if (a->start > b->start) 230 return(1); 231 return(0); 232 } 233 234 /* 235 * Allocate a vmspace structure, including a vm_map and pmap. 236 * Initialize numerous fields. While the initial allocation is zerod, 237 * subsequence reuse from the objcache leaves elements of the structure 238 * intact (particularly the pmap), so portions must be zerod. 239 * 240 * The structure is not considered activated until we call sysref_activate(). 241 * 242 * No requirements. 243 */ 244 struct vmspace * 245 vmspace_alloc(vm_offset_t min, vm_offset_t max) 246 { 247 struct vmspace *vm; 248 249 vm = sysref_alloc(&vmspace_sysref_class); 250 bzero(&vm->vm_startcopy, 251 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy); 252 vm_map_init(&vm->vm_map, min, max, NULL); /* initializes token */ 253 254 /* 255 * Use a hold to prevent any additional racing hold from terminating 256 * the vmspace before we manage to activate it. This also acquires 257 * the token for safety. 258 */ 259 KKASSERT(vm->vm_holdcount == 0); 260 KKASSERT(vm->vm_exitingcnt == 0); 261 vmspace_hold(vm); 262 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */ 263 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 264 vm->vm_shm = NULL; 265 vm->vm_flags = 0; 266 cpu_vmspace_alloc(vm); 267 sysref_activate(&vm->vm_sysref); 268 vmspace_drop(vm); 269 270 return (vm); 271 } 272 273 /* 274 * Free a primary reference to a vmspace. This can trigger a 275 * stage-1 termination. 276 */ 277 void 278 vmspace_free(struct vmspace *vm) 279 { 280 /* 281 * We want all finalization to occur via vmspace_drop() so we 282 * need to hold the vm around the put. 283 */ 284 vmspace_hold(vm); 285 sysref_put(&vm->vm_sysref); 286 vmspace_drop(vm); 287 } 288 289 void 290 vmspace_ref(struct vmspace *vm) 291 { 292 sysref_get(&vm->vm_sysref); 293 } 294 295 void 296 vmspace_hold(struct vmspace *vm) 297 { 298 refcount_acquire(&vm->vm_holdcount); 299 lwkt_gettoken(&vm->vm_map.token); 300 } 301 302 void 303 vmspace_drop(struct vmspace *vm) 304 { 305 lwkt_reltoken(&vm->vm_map.token); 306 if (refcount_release(&vm->vm_holdcount)) { 307 if (vm->vm_exitingcnt == 0 && 308 sysref_isinactive(&vm->vm_sysref)) { 309 vmspace_terminate(vm); 310 } 311 } 312 } 313 314 /* 315 * dtor function - Some elements of the pmap are retained in the 316 * free-cached vmspaces to improve performance. We have to clean them up 317 * here before returning the vmspace to the memory pool. 318 * 319 * No requirements. 320 */ 321 static void 322 vmspace_dtor(void *obj, void *private) 323 { 324 struct vmspace *vm = obj; 325 326 pmap_puninit(vmspace_pmap(vm)); 327 } 328 329 /* 330 * Called in three cases: 331 * 332 * (1) When the last sysref is dropped and the vmspace becomes inactive. 333 * (holdcount will not be 0 because the vmspace is held through the op) 334 * 335 * (2) When exitingcount becomes 0 on the last reap 336 * (holdcount will not be 0 because the vmspace is held through the op) 337 * 338 * (3) When the holdcount becomes 0 in addition to the above two 339 * 340 * sysref will not scrap the object until we call sysref_put() once more 341 * after the last ref has been dropped. 342 * 343 * VMSPACE_EXIT1 flags the primary deactivation 344 * VMSPACE_EXIT2 flags the last reap 345 */ 346 static void 347 vmspace_terminate(struct vmspace *vm) 348 { 349 int count; 350 351 /* 352 * 353 */ 354 lwkt_gettoken(&vm->vm_map.token); 355 if ((vm->vm_flags & VMSPACE_EXIT1) == 0) { 356 vm->vm_flags |= VMSPACE_EXIT1; 357 shmexit(vm); 358 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, 359 VM_MAX_USER_ADDRESS); 360 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, 361 VM_MAX_USER_ADDRESS); 362 } 363 if ((vm->vm_flags & VMSPACE_EXIT2) == 0 && vm->vm_exitingcnt == 0) { 364 vm->vm_flags |= VMSPACE_EXIT2; 365 cpu_vmspace_free(vm); 366 shmexit(vm); 367 368 /* 369 * Lock the map, to wait out all other references to it. 370 * Delete all of the mappings and pages they hold, then call 371 * the pmap module to reclaim anything left. 372 */ 373 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 374 vm_map_lock(&vm->vm_map); 375 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 376 vm->vm_map.max_offset, &count); 377 vm_map_unlock(&vm->vm_map); 378 vm_map_entry_release(count); 379 380 lwkt_gettoken(&vmspace_pmap(vm)->pm_token); 381 pmap_release(vmspace_pmap(vm)); 382 lwkt_reltoken(&vmspace_pmap(vm)->pm_token); 383 } 384 385 lwkt_reltoken(&vm->vm_map.token); 386 if (vm->vm_exitingcnt == 0 && vm->vm_holdcount == 0) { 387 KKASSERT(vm->vm_flags & VMSPACE_EXIT1); 388 KKASSERT(vm->vm_flags & VMSPACE_EXIT2); 389 sysref_put(&vm->vm_sysref); 390 } 391 } 392 393 /* 394 * vmspaces are not currently locked. 395 */ 396 static void 397 vmspace_lock(struct vmspace *vm __unused) 398 { 399 } 400 401 static void 402 vmspace_unlock(struct vmspace *vm __unused) 403 { 404 } 405 406 /* 407 * This is called during exit indicating that the vmspace is no 408 * longer in used by an exiting process, but the process has not yet 409 * been reaped. 410 * 411 * No requirements. 412 */ 413 void 414 vmspace_exitbump(struct vmspace *vm) 415 { 416 vmspace_hold(vm); 417 ++vm->vm_exitingcnt; 418 vmspace_drop(vm); /* handles termination sequencing */ 419 } 420 421 /* 422 * Decrement the exitingcnt and issue the stage-2 termination if it becomes 423 * zero and the stage1 termination has already occured. 424 * 425 * No requirements. 426 */ 427 void 428 vmspace_exitfree(struct proc *p) 429 { 430 struct vmspace *vm; 431 432 vm = p->p_vmspace; 433 p->p_vmspace = NULL; 434 vmspace_hold(vm); 435 KKASSERT(vm->vm_exitingcnt > 0); 436 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref)) 437 vmspace_terminate(vm); 438 vmspace_drop(vm); /* handles termination sequencing */ 439 } 440 441 /* 442 * Swap useage is determined by taking the proportional swap used by 443 * VM objects backing the VM map. To make up for fractional losses, 444 * if the VM object has any swap use at all the associated map entries 445 * count for at least 1 swap page. 446 * 447 * No requirements. 448 */ 449 int 450 vmspace_swap_count(struct vmspace *vm) 451 { 452 vm_map_t map = &vm->vm_map; 453 vm_map_entry_t cur; 454 vm_object_t object; 455 int count = 0; 456 int n; 457 458 vmspace_hold(vm); 459 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 460 switch(cur->maptype) { 461 case VM_MAPTYPE_NORMAL: 462 case VM_MAPTYPE_VPAGETABLE: 463 if ((object = cur->object.vm_object) == NULL) 464 break; 465 if (object->swblock_count) { 466 n = (cur->end - cur->start) / PAGE_SIZE; 467 count += object->swblock_count * 468 SWAP_META_PAGES * n / object->size + 1; 469 } 470 break; 471 default: 472 break; 473 } 474 } 475 vmspace_drop(vm); 476 477 return(count); 478 } 479 480 /* 481 * Calculate the approximate number of anonymous pages in use by 482 * this vmspace. To make up for fractional losses, we count each 483 * VM object as having at least 1 anonymous page. 484 * 485 * No requirements. 486 */ 487 int 488 vmspace_anonymous_count(struct vmspace *vm) 489 { 490 vm_map_t map = &vm->vm_map; 491 vm_map_entry_t cur; 492 vm_object_t object; 493 int count = 0; 494 495 vmspace_hold(vm); 496 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 497 switch(cur->maptype) { 498 case VM_MAPTYPE_NORMAL: 499 case VM_MAPTYPE_VPAGETABLE: 500 if ((object = cur->object.vm_object) == NULL) 501 break; 502 if (object->type != OBJT_DEFAULT && 503 object->type != OBJT_SWAP) { 504 break; 505 } 506 count += object->resident_page_count; 507 break; 508 default: 509 break; 510 } 511 } 512 vmspace_drop(vm); 513 514 return(count); 515 } 516 517 /* 518 * Creates and returns a new empty VM map with the given physical map 519 * structure, and having the given lower and upper address bounds. 520 * 521 * No requirements. 522 */ 523 vm_map_t 524 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max) 525 { 526 if (result == NULL) 527 result = zalloc(mapzone); 528 vm_map_init(result, min, max, pmap); 529 return (result); 530 } 531 532 /* 533 * Initialize an existing vm_map structure such as that in the vmspace 534 * structure. The pmap is initialized elsewhere. 535 * 536 * No requirements. 537 */ 538 void 539 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap) 540 { 541 map->header.next = map->header.prev = &map->header; 542 RB_INIT(&map->rb_root); 543 map->nentries = 0; 544 map->size = 0; 545 map->system_map = 0; 546 map->min_offset = min; 547 map->max_offset = max; 548 map->pmap = pmap; 549 map->first_free = &map->header; 550 map->hint = &map->header; 551 map->timestamp = 0; 552 map->flags = 0; 553 lwkt_token_init(&map->token, "vm_map"); 554 lockinit(&map->lock, "thrd_sleep", (hz + 9) / 10, 0); 555 TUNABLE_INT("vm.cache_vmspaces", &vmspace_sysref_class.nom_cache); 556 } 557 558 /* 559 * Shadow the vm_map_entry's object. This typically needs to be done when 560 * a write fault is taken on an entry which had previously been cloned by 561 * fork(). The shared object (which might be NULL) must become private so 562 * we add a shadow layer above it. 563 * 564 * Object allocation for anonymous mappings is defered as long as possible. 565 * When creating a shadow, however, the underlying object must be instantiated 566 * so it can be shared. 567 * 568 * If the map segment is governed by a virtual page table then it is 569 * possible to address offsets beyond the mapped area. Just allocate 570 * a maximally sized object for this case. 571 * 572 * The vm_map must be exclusively locked. 573 * No other requirements. 574 */ 575 static 576 void 577 vm_map_entry_shadow(vm_map_entry_t entry, int addref) 578 { 579 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 580 vm_object_shadow(&entry->object.vm_object, &entry->offset, 581 0x7FFFFFFF, addref); /* XXX */ 582 } else { 583 vm_object_shadow(&entry->object.vm_object, &entry->offset, 584 atop(entry->end - entry->start), addref); 585 } 586 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 587 } 588 589 /* 590 * Allocate an object for a vm_map_entry. 591 * 592 * Object allocation for anonymous mappings is defered as long as possible. 593 * This function is called when we can defer no longer, generally when a map 594 * entry might be split or forked or takes a page fault. 595 * 596 * If the map segment is governed by a virtual page table then it is 597 * possible to address offsets beyond the mapped area. Just allocate 598 * a maximally sized object for this case. 599 * 600 * The vm_map must be exclusively locked. 601 * No other requirements. 602 */ 603 void 604 vm_map_entry_allocate_object(vm_map_entry_t entry) 605 { 606 vm_object_t obj; 607 608 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 609 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */ 610 } else { 611 obj = vm_object_allocate(OBJT_DEFAULT, 612 atop(entry->end - entry->start)); 613 } 614 entry->object.vm_object = obj; 615 entry->offset = 0; 616 } 617 618 /* 619 * Set an initial negative count so the first attempt to reserve 620 * space preloads a bunch of vm_map_entry's for this cpu. Also 621 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to 622 * map a new page for vm_map_entry structures. SMP systems are 623 * particularly sensitive. 624 * 625 * This routine is called in early boot so we cannot just call 626 * vm_map_entry_reserve(). 627 * 628 * Called from the low level boot code only (for each cpu) 629 */ 630 void 631 vm_map_entry_reserve_cpu_init(globaldata_t gd) 632 { 633 vm_map_entry_t entry; 634 int i; 635 636 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2; 637 entry = &cpu_map_entry_init[gd->gd_cpuid][0]; 638 for (i = 0; i < VMEPERCPU; ++i, ++entry) { 639 entry->next = gd->gd_vme_base; 640 gd->gd_vme_base = entry; 641 } 642 } 643 644 /* 645 * Reserves vm_map_entry structures so code later on can manipulate 646 * map_entry structures within a locked map without blocking trying 647 * to allocate a new vm_map_entry. 648 * 649 * No requirements. 650 */ 651 int 652 vm_map_entry_reserve(int count) 653 { 654 struct globaldata *gd = mycpu; 655 vm_map_entry_t entry; 656 657 /* 658 * Make sure we have enough structures in gd_vme_base to handle 659 * the reservation request. 660 * 661 * The critical section protects access to the per-cpu gd. 662 */ 663 crit_enter(); 664 while (gd->gd_vme_avail < count) { 665 entry = zalloc(mapentzone); 666 entry->next = gd->gd_vme_base; 667 gd->gd_vme_base = entry; 668 ++gd->gd_vme_avail; 669 } 670 gd->gd_vme_avail -= count; 671 crit_exit(); 672 673 return(count); 674 } 675 676 /* 677 * Releases previously reserved vm_map_entry structures that were not 678 * used. If we have too much junk in our per-cpu cache clean some of 679 * it out. 680 * 681 * No requirements. 682 */ 683 void 684 vm_map_entry_release(int count) 685 { 686 struct globaldata *gd = mycpu; 687 vm_map_entry_t entry; 688 689 crit_enter(); 690 gd->gd_vme_avail += count; 691 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) { 692 entry = gd->gd_vme_base; 693 KKASSERT(entry != NULL); 694 gd->gd_vme_base = entry->next; 695 --gd->gd_vme_avail; 696 crit_exit(); 697 zfree(mapentzone, entry); 698 crit_enter(); 699 } 700 crit_exit(); 701 } 702 703 /* 704 * Reserve map entry structures for use in kernel_map itself. These 705 * entries have *ALREADY* been reserved on a per-cpu basis when the map 706 * was inited. This function is used by zalloc() to avoid a recursion 707 * when zalloc() itself needs to allocate additional kernel memory. 708 * 709 * This function works like the normal reserve but does not load the 710 * vm_map_entry cache (because that would result in an infinite 711 * recursion). Note that gd_vme_avail may go negative. This is expected. 712 * 713 * Any caller of this function must be sure to renormalize after 714 * potentially eating entries to ensure that the reserve supply 715 * remains intact. 716 * 717 * No requirements. 718 */ 719 int 720 vm_map_entry_kreserve(int count) 721 { 722 struct globaldata *gd = mycpu; 723 724 crit_enter(); 725 gd->gd_vme_avail -= count; 726 crit_exit(); 727 KASSERT(gd->gd_vme_base != NULL, 728 ("no reserved entries left, gd_vme_avail = %d", 729 gd->gd_vme_avail)); 730 return(count); 731 } 732 733 /* 734 * Release previously reserved map entries for kernel_map. We do not 735 * attempt to clean up like the normal release function as this would 736 * cause an unnecessary (but probably not fatal) deep procedure call. 737 * 738 * No requirements. 739 */ 740 void 741 vm_map_entry_krelease(int count) 742 { 743 struct globaldata *gd = mycpu; 744 745 crit_enter(); 746 gd->gd_vme_avail += count; 747 crit_exit(); 748 } 749 750 /* 751 * Allocates a VM map entry for insertion. No entry fields are filled in. 752 * 753 * The entries should have previously been reserved. The reservation count 754 * is tracked in (*countp). 755 * 756 * No requirements. 757 */ 758 static vm_map_entry_t 759 vm_map_entry_create(vm_map_t map, int *countp) 760 { 761 struct globaldata *gd = mycpu; 762 vm_map_entry_t entry; 763 764 KKASSERT(*countp > 0); 765 --*countp; 766 crit_enter(); 767 entry = gd->gd_vme_base; 768 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); 769 gd->gd_vme_base = entry->next; 770 crit_exit(); 771 772 return(entry); 773 } 774 775 /* 776 * Dispose of a vm_map_entry that is no longer being referenced. 777 * 778 * No requirements. 779 */ 780 static void 781 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) 782 { 783 struct globaldata *gd = mycpu; 784 785 KKASSERT(map->hint != entry); 786 KKASSERT(map->first_free != entry); 787 788 ++*countp; 789 crit_enter(); 790 entry->next = gd->gd_vme_base; 791 gd->gd_vme_base = entry; 792 crit_exit(); 793 } 794 795 796 /* 797 * Insert/remove entries from maps. 798 * 799 * The related map must be exclusively locked. 800 * The caller must hold map->token 801 * No other requirements. 802 */ 803 static __inline void 804 vm_map_entry_link(vm_map_t map, 805 vm_map_entry_t after_where, 806 vm_map_entry_t entry) 807 { 808 ASSERT_VM_MAP_LOCKED(map); 809 810 map->nentries++; 811 entry->prev = after_where; 812 entry->next = after_where->next; 813 entry->next->prev = entry; 814 after_where->next = entry; 815 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) 816 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); 817 } 818 819 static __inline void 820 vm_map_entry_unlink(vm_map_t map, 821 vm_map_entry_t entry) 822 { 823 vm_map_entry_t prev; 824 vm_map_entry_t next; 825 826 ASSERT_VM_MAP_LOCKED(map); 827 828 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 829 panic("vm_map_entry_unlink: attempt to mess with " 830 "locked entry! %p", entry); 831 } 832 prev = entry->prev; 833 next = entry->next; 834 next->prev = prev; 835 prev->next = next; 836 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); 837 map->nentries--; 838 } 839 840 /* 841 * Finds the map entry containing (or immediately preceding) the specified 842 * address in the given map. The entry is returned in (*entry). 843 * 844 * The boolean result indicates whether the address is actually contained 845 * in the map. 846 * 847 * The related map must be locked. 848 * No other requirements. 849 */ 850 boolean_t 851 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry) 852 { 853 vm_map_entry_t tmp; 854 vm_map_entry_t last; 855 856 ASSERT_VM_MAP_LOCKED(map); 857 #if 0 858 /* 859 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive 860 * the hint code with the red-black lookup meets with system crashes 861 * and lockups. We do not yet know why. 862 * 863 * It is possible that the problem is related to the setting 864 * of the hint during map_entry deletion, in the code specified 865 * at the GGG comment later on in this file. 866 * 867 * YYY More likely it's because this function can be called with 868 * a shared lock on the map, resulting in map->hint updates possibly 869 * racing. Fixed now but untested. 870 */ 871 /* 872 * Quickly check the cached hint, there's a good chance of a match. 873 */ 874 tmp = map->hint; 875 cpu_ccfence(); 876 if (tmp != &map->header) { 877 if (address >= tmp->start && address < tmp->end) { 878 *entry = tmp; 879 return(TRUE); 880 } 881 } 882 #endif 883 884 /* 885 * Locate the record from the top of the tree. 'last' tracks the 886 * closest prior record and is returned if no match is found, which 887 * in binary tree terms means tracking the most recent right-branch 888 * taken. If there is no prior record, &map->header is returned. 889 */ 890 last = &map->header; 891 tmp = RB_ROOT(&map->rb_root); 892 893 while (tmp) { 894 if (address >= tmp->start) { 895 if (address < tmp->end) { 896 *entry = tmp; 897 map->hint = tmp; 898 return(TRUE); 899 } 900 last = tmp; 901 tmp = RB_RIGHT(tmp, rb_entry); 902 } else { 903 tmp = RB_LEFT(tmp, rb_entry); 904 } 905 } 906 *entry = last; 907 return (FALSE); 908 } 909 910 /* 911 * Inserts the given whole VM object into the target map at the specified 912 * address range. The object's size should match that of the address range. 913 * 914 * The map must be exclusively locked. 915 * The object must be held. 916 * The caller must have reserved sufficient vm_map_entry structures. 917 * 918 * If object is non-NULL, ref count must be bumped by caller prior to 919 * making call to account for the new entry. 920 */ 921 int 922 vm_map_insert(vm_map_t map, int *countp, 923 vm_object_t object, vm_ooffset_t offset, 924 vm_offset_t start, vm_offset_t end, 925 vm_maptype_t maptype, 926 vm_prot_t prot, vm_prot_t max, 927 int cow) 928 { 929 vm_map_entry_t new_entry; 930 vm_map_entry_t prev_entry; 931 vm_map_entry_t temp_entry; 932 vm_eflags_t protoeflags; 933 int must_drop = 0; 934 935 ASSERT_VM_MAP_LOCKED(map); 936 if (object) 937 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 938 939 /* 940 * Check that the start and end points are not bogus. 941 */ 942 if ((start < map->min_offset) || (end > map->max_offset) || 943 (start >= end)) 944 return (KERN_INVALID_ADDRESS); 945 946 /* 947 * Find the entry prior to the proposed starting address; if it's part 948 * of an existing entry, this range is bogus. 949 */ 950 if (vm_map_lookup_entry(map, start, &temp_entry)) 951 return (KERN_NO_SPACE); 952 953 prev_entry = temp_entry; 954 955 /* 956 * Assert that the next entry doesn't overlap the end point. 957 */ 958 959 if ((prev_entry->next != &map->header) && 960 (prev_entry->next->start < end)) 961 return (KERN_NO_SPACE); 962 963 protoeflags = 0; 964 965 if (cow & MAP_COPY_ON_WRITE) 966 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 967 968 if (cow & MAP_NOFAULT) { 969 protoeflags |= MAP_ENTRY_NOFAULT; 970 971 KASSERT(object == NULL, 972 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 973 } 974 if (cow & MAP_DISABLE_SYNCER) 975 protoeflags |= MAP_ENTRY_NOSYNC; 976 if (cow & MAP_DISABLE_COREDUMP) 977 protoeflags |= MAP_ENTRY_NOCOREDUMP; 978 if (cow & MAP_IS_STACK) 979 protoeflags |= MAP_ENTRY_STACK; 980 if (cow & MAP_IS_KSTACK) 981 protoeflags |= MAP_ENTRY_KSTACK; 982 983 lwkt_gettoken(&map->token); 984 985 if (object) { 986 /* 987 * When object is non-NULL, it could be shared with another 988 * process. We have to set or clear OBJ_ONEMAPPING 989 * appropriately. 990 */ 991 if ((object->ref_count > 1) || (object->shadow_count != 0)) { 992 vm_object_clear_flag(object, OBJ_ONEMAPPING); 993 } 994 } 995 else if ((prev_entry != &map->header) && 996 (prev_entry->eflags == protoeflags) && 997 (prev_entry->end == start) && 998 (prev_entry->wired_count == 0) && 999 prev_entry->maptype == maptype && 1000 ((prev_entry->object.vm_object == NULL) || 1001 vm_object_coalesce(prev_entry->object.vm_object, 1002 OFF_TO_IDX(prev_entry->offset), 1003 (vm_size_t)(prev_entry->end - prev_entry->start), 1004 (vm_size_t)(end - prev_entry->end)))) { 1005 /* 1006 * We were able to extend the object. Determine if we 1007 * can extend the previous map entry to include the 1008 * new range as well. 1009 */ 1010 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 1011 (prev_entry->protection == prot) && 1012 (prev_entry->max_protection == max)) { 1013 map->size += (end - prev_entry->end); 1014 prev_entry->end = end; 1015 vm_map_simplify_entry(map, prev_entry, countp); 1016 lwkt_reltoken(&map->token); 1017 return (KERN_SUCCESS); 1018 } 1019 1020 /* 1021 * If we can extend the object but cannot extend the 1022 * map entry, we have to create a new map entry. We 1023 * must bump the ref count on the extended object to 1024 * account for it. object may be NULL. 1025 */ 1026 object = prev_entry->object.vm_object; 1027 offset = prev_entry->offset + 1028 (prev_entry->end - prev_entry->start); 1029 if (object) { 1030 vm_object_hold(object); 1031 vm_object_chain_wait(object); 1032 vm_object_reference_locked(object); 1033 must_drop = 1; 1034 } 1035 } 1036 1037 /* 1038 * NOTE: if conditionals fail, object can be NULL here. This occurs 1039 * in things like the buffer map where we manage kva but do not manage 1040 * backing objects. 1041 */ 1042 1043 /* 1044 * Create a new entry 1045 */ 1046 1047 new_entry = vm_map_entry_create(map, countp); 1048 new_entry->start = start; 1049 new_entry->end = end; 1050 1051 new_entry->maptype = maptype; 1052 new_entry->eflags = protoeflags; 1053 new_entry->object.vm_object = object; 1054 new_entry->offset = offset; 1055 new_entry->aux.master_pde = 0; 1056 1057 new_entry->inheritance = VM_INHERIT_DEFAULT; 1058 new_entry->protection = prot; 1059 new_entry->max_protection = max; 1060 new_entry->wired_count = 0; 1061 1062 /* 1063 * Insert the new entry into the list 1064 */ 1065 1066 vm_map_entry_link(map, prev_entry, new_entry); 1067 map->size += new_entry->end - new_entry->start; 1068 1069 /* 1070 * Update the free space hint. Entries cannot overlap. 1071 * An exact comparison is needed to avoid matching 1072 * against the map->header. 1073 */ 1074 if ((map->first_free == prev_entry) && 1075 (prev_entry->end == new_entry->start)) { 1076 map->first_free = new_entry; 1077 } 1078 1079 #if 0 1080 /* 1081 * Temporarily removed to avoid MAP_STACK panic, due to 1082 * MAP_STACK being a huge hack. Will be added back in 1083 * when MAP_STACK (and the user stack mapping) is fixed. 1084 */ 1085 /* 1086 * It may be possible to simplify the entry 1087 */ 1088 vm_map_simplify_entry(map, new_entry, countp); 1089 #endif 1090 1091 /* 1092 * Try to pre-populate the page table. Mappings governed by virtual 1093 * page tables cannot be prepopulated without a lot of work, so 1094 * don't try. 1095 */ 1096 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) && 1097 maptype != VM_MAPTYPE_VPAGETABLE) { 1098 pmap_object_init_pt(map->pmap, start, prot, 1099 object, OFF_TO_IDX(offset), end - start, 1100 cow & MAP_PREFAULT_PARTIAL); 1101 } 1102 if (must_drop) 1103 vm_object_drop(object); 1104 1105 lwkt_reltoken(&map->token); 1106 return (KERN_SUCCESS); 1107 } 1108 1109 /* 1110 * Find sufficient space for `length' bytes in the given map, starting at 1111 * `start'. Returns 0 on success, 1 on no space. 1112 * 1113 * This function will returned an arbitrarily aligned pointer. If no 1114 * particular alignment is required you should pass align as 1. Note that 1115 * the map may return PAGE_SIZE aligned pointers if all the lengths used in 1116 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align 1117 * argument. 1118 * 1119 * 'align' should be a power of 2 but is not required to be. 1120 * 1121 * The map must be exclusively locked. 1122 * No other requirements. 1123 */ 1124 int 1125 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1126 vm_size_t align, int flags, vm_offset_t *addr) 1127 { 1128 vm_map_entry_t entry, next; 1129 vm_offset_t end; 1130 vm_offset_t align_mask; 1131 1132 if (start < map->min_offset) 1133 start = map->min_offset; 1134 if (start > map->max_offset) 1135 return (1); 1136 1137 /* 1138 * If the alignment is not a power of 2 we will have to use 1139 * a mod/division, set align_mask to a special value. 1140 */ 1141 if ((align | (align - 1)) + 1 != (align << 1)) 1142 align_mask = (vm_offset_t)-1; 1143 else 1144 align_mask = align - 1; 1145 1146 /* 1147 * Look for the first possible address; if there's already something 1148 * at this address, we have to start after it. 1149 */ 1150 if (start == map->min_offset) { 1151 if ((entry = map->first_free) != &map->header) 1152 start = entry->end; 1153 } else { 1154 vm_map_entry_t tmp; 1155 1156 if (vm_map_lookup_entry(map, start, &tmp)) 1157 start = tmp->end; 1158 entry = tmp; 1159 } 1160 1161 /* 1162 * Look through the rest of the map, trying to fit a new region in the 1163 * gap between existing regions, or after the very last region. 1164 */ 1165 for (;; start = (entry = next)->end) { 1166 /* 1167 * Adjust the proposed start by the requested alignment, 1168 * be sure that we didn't wrap the address. 1169 */ 1170 if (align_mask == (vm_offset_t)-1) 1171 end = ((start + align - 1) / align) * align; 1172 else 1173 end = (start + align_mask) & ~align_mask; 1174 if (end < start) 1175 return (1); 1176 start = end; 1177 /* 1178 * Find the end of the proposed new region. Be sure we didn't 1179 * go beyond the end of the map, or wrap around the address. 1180 * Then check to see if this is the last entry or if the 1181 * proposed end fits in the gap between this and the next 1182 * entry. 1183 */ 1184 end = start + length; 1185 if (end > map->max_offset || end < start) 1186 return (1); 1187 next = entry->next; 1188 1189 /* 1190 * If the next entry's start address is beyond the desired 1191 * end address we may have found a good entry. 1192 * 1193 * If the next entry is a stack mapping we do not map into 1194 * the stack's reserved space. 1195 * 1196 * XXX continue to allow mapping into the stack's reserved 1197 * space if doing a MAP_STACK mapping inside a MAP_STACK 1198 * mapping, for backwards compatibility. But the caller 1199 * really should use MAP_STACK | MAP_TRYFIXED if they 1200 * want to do that. 1201 */ 1202 if (next == &map->header) 1203 break; 1204 if (next->start >= end) { 1205 if ((next->eflags & MAP_ENTRY_STACK) == 0) 1206 break; 1207 if (flags & MAP_STACK) 1208 break; 1209 if (next->start - next->aux.avail_ssize >= end) 1210 break; 1211 } 1212 } 1213 map->hint = entry; 1214 1215 /* 1216 * Grow the kernel_map if necessary. pmap_growkernel() will panic 1217 * if it fails. The kernel_map is locked and nothing can steal 1218 * our address space if pmap_growkernel() blocks. 1219 * 1220 * NOTE: This may be unconditionally called for kldload areas on 1221 * x86_64 because these do not bump kernel_vm_end (which would 1222 * fill 128G worth of page tables!). Therefore we must not 1223 * retry. 1224 */ 1225 if (map == &kernel_map) { 1226 vm_offset_t kstop; 1227 1228 kstop = round_page(start + length); 1229 if (kstop > kernel_vm_end) 1230 pmap_growkernel(start, kstop); 1231 } 1232 *addr = start; 1233 return (0); 1234 } 1235 1236 /* 1237 * vm_map_find finds an unallocated region in the target address map with 1238 * the given length and allocates it. The search is defined to be first-fit 1239 * from the specified address; the region found is returned in the same 1240 * parameter. 1241 * 1242 * If object is non-NULL, ref count must be bumped by caller 1243 * prior to making call to account for the new entry. 1244 * 1245 * No requirements. This function will lock the map temporarily. 1246 */ 1247 int 1248 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1249 vm_offset_t *addr, vm_size_t length, vm_size_t align, 1250 boolean_t fitit, 1251 vm_maptype_t maptype, 1252 vm_prot_t prot, vm_prot_t max, 1253 int cow) 1254 { 1255 vm_offset_t start; 1256 int result; 1257 int count; 1258 1259 start = *addr; 1260 1261 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1262 vm_map_lock(map); 1263 if (object) 1264 vm_object_hold(object); 1265 if (fitit) { 1266 if (vm_map_findspace(map, start, length, align, 0, addr)) { 1267 if (object) 1268 vm_object_drop(object); 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(scan->wired_count == 0); 2490 scan->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 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 3267 lwkt_gettoken(&vm2->vm_map.token); 3268 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 3269 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); 3270 new_map = &vm2->vm_map; /* XXX */ 3271 new_map->timestamp = 1; 3272 3273 vm_map_lock(new_map); 3274 3275 count = 0; 3276 old_entry = old_map->header.next; 3277 while (old_entry != &old_map->header) { 3278 ++count; 3279 old_entry = old_entry->next; 3280 } 3281 3282 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); 3283 3284 old_entry = old_map->header.next; 3285 while (old_entry != &old_map->header) { 3286 if (old_entry->maptype == VM_MAPTYPE_SUBMAP) 3287 panic("vm_map_fork: encountered a submap"); 3288 3289 switch (old_entry->inheritance) { 3290 case VM_INHERIT_NONE: 3291 break; 3292 case VM_INHERIT_SHARE: 3293 /* 3294 * Clone the entry, creating the shared object if 3295 * necessary. 3296 */ 3297 if (old_entry->object.vm_object == NULL) 3298 vm_map_entry_allocate_object(old_entry); 3299 3300 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3301 /* 3302 * Shadow a map_entry which needs a copy, 3303 * replacing its object with a new object 3304 * that points to the old one. Ask the 3305 * shadow code to automatically add an 3306 * additional ref. We can't do it afterwords 3307 * because we might race a collapse. The call 3308 * to vm_map_entry_shadow() will also clear 3309 * OBJ_ONEMAPPING. 3310 */ 3311 vm_map_entry_shadow(old_entry, 1); 3312 } else { 3313 /* 3314 * We will make a shared copy of the object, 3315 * and must clear OBJ_ONEMAPPING. 3316 * 3317 * XXX assert that object.vm_object != NULL 3318 * since we allocate it above. 3319 */ 3320 if (old_entry->object.vm_object) { 3321 object = old_entry->object.vm_object; 3322 vm_object_hold(object); 3323 vm_object_chain_wait(object); 3324 vm_object_reference_locked(object); 3325 vm_object_clear_flag(object, 3326 OBJ_ONEMAPPING); 3327 vm_object_drop(object); 3328 } 3329 } 3330 3331 /* 3332 * Clone the entry. We've already bumped the ref on 3333 * any vm_object. 3334 */ 3335 new_entry = vm_map_entry_create(new_map, &count); 3336 *new_entry = *old_entry; 3337 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3338 new_entry->wired_count = 0; 3339 3340 /* 3341 * Insert the entry into the new map -- we know we're 3342 * inserting at the end of the new map. 3343 */ 3344 3345 vm_map_entry_link(new_map, new_map->header.prev, 3346 new_entry); 3347 3348 /* 3349 * Update the physical map 3350 */ 3351 pmap_copy(new_map->pmap, old_map->pmap, 3352 new_entry->start, 3353 (old_entry->end - old_entry->start), 3354 old_entry->start); 3355 break; 3356 case VM_INHERIT_COPY: 3357 /* 3358 * Clone the entry and link into the map. 3359 */ 3360 new_entry = vm_map_entry_create(new_map, &count); 3361 *new_entry = *old_entry; 3362 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3363 new_entry->wired_count = 0; 3364 new_entry->object.vm_object = NULL; 3365 vm_map_entry_link(new_map, new_map->header.prev, 3366 new_entry); 3367 vm_map_copy_entry(old_map, new_map, old_entry, 3368 new_entry); 3369 break; 3370 } 3371 old_entry = old_entry->next; 3372 } 3373 3374 new_map->size = old_map->size; 3375 vm_map_unlock(old_map); 3376 vm_map_unlock(new_map); 3377 vm_map_entry_release(count); 3378 3379 lwkt_reltoken(&vm2->vm_map.token); 3380 lwkt_reltoken(&vm1->vm_map.token); 3381 3382 return (vm2); 3383 } 3384 3385 /* 3386 * Create an auto-grow stack entry 3387 * 3388 * No requirements. 3389 */ 3390 int 3391 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3392 int flags, vm_prot_t prot, vm_prot_t max, int cow) 3393 { 3394 vm_map_entry_t prev_entry; 3395 vm_map_entry_t new_stack_entry; 3396 vm_size_t init_ssize; 3397 int rv; 3398 int count; 3399 vm_offset_t tmpaddr; 3400 3401 cow |= MAP_IS_STACK; 3402 3403 if (max_ssize < sgrowsiz) 3404 init_ssize = max_ssize; 3405 else 3406 init_ssize = sgrowsiz; 3407 3408 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3409 vm_map_lock(map); 3410 3411 /* 3412 * Find space for the mapping 3413 */ 3414 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) { 3415 if (vm_map_findspace(map, addrbos, max_ssize, 1, 3416 flags, &tmpaddr)) { 3417 vm_map_unlock(map); 3418 vm_map_entry_release(count); 3419 return (KERN_NO_SPACE); 3420 } 3421 addrbos = tmpaddr; 3422 } 3423 3424 /* If addr is already mapped, no go */ 3425 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3426 vm_map_unlock(map); 3427 vm_map_entry_release(count); 3428 return (KERN_NO_SPACE); 3429 } 3430 3431 #if 0 3432 /* XXX already handled by kern_mmap() */ 3433 /* If we would blow our VMEM resource limit, no go */ 3434 if (map->size + init_ssize > 3435 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3436 vm_map_unlock(map); 3437 vm_map_entry_release(count); 3438 return (KERN_NO_SPACE); 3439 } 3440 #endif 3441 3442 /* 3443 * If we can't accomodate max_ssize in the current mapping, 3444 * no go. However, we need to be aware that subsequent user 3445 * mappings might map into the space we have reserved for 3446 * stack, and currently this space is not protected. 3447 * 3448 * Hopefully we will at least detect this condition 3449 * when we try to grow the stack. 3450 */ 3451 if ((prev_entry->next != &map->header) && 3452 (prev_entry->next->start < addrbos + max_ssize)) { 3453 vm_map_unlock(map); 3454 vm_map_entry_release(count); 3455 return (KERN_NO_SPACE); 3456 } 3457 3458 /* 3459 * We initially map a stack of only init_ssize. We will 3460 * grow as needed later. Since this is to be a grow 3461 * down stack, we map at the top of the range. 3462 * 3463 * Note: we would normally expect prot and max to be 3464 * VM_PROT_ALL, and cow to be 0. Possibly we should 3465 * eliminate these as input parameters, and just 3466 * pass these values here in the insert call. 3467 */ 3468 rv = vm_map_insert(map, &count, 3469 NULL, 0, addrbos + max_ssize - init_ssize, 3470 addrbos + max_ssize, 3471 VM_MAPTYPE_NORMAL, 3472 prot, max, 3473 cow); 3474 3475 /* Now set the avail_ssize amount */ 3476 if (rv == KERN_SUCCESS) { 3477 if (prev_entry != &map->header) 3478 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count); 3479 new_stack_entry = prev_entry->next; 3480 if (new_stack_entry->end != addrbos + max_ssize || 3481 new_stack_entry->start != addrbos + max_ssize - init_ssize) 3482 panic ("Bad entry start/end for new stack entry"); 3483 else 3484 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize; 3485 } 3486 3487 vm_map_unlock(map); 3488 vm_map_entry_release(count); 3489 return (rv); 3490 } 3491 3492 /* 3493 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3494 * desired address is already mapped, or if we successfully grow 3495 * the stack. Also returns KERN_SUCCESS if addr is outside the 3496 * stack range (this is strange, but preserves compatibility with 3497 * the grow function in vm_machdep.c). 3498 * 3499 * No requirements. 3500 */ 3501 int 3502 vm_map_growstack (struct proc *p, vm_offset_t addr) 3503 { 3504 vm_map_entry_t prev_entry; 3505 vm_map_entry_t stack_entry; 3506 vm_map_entry_t new_stack_entry; 3507 struct vmspace *vm = p->p_vmspace; 3508 vm_map_t map = &vm->vm_map; 3509 vm_offset_t end; 3510 int grow_amount; 3511 int rv = KERN_SUCCESS; 3512 int is_procstack; 3513 int use_read_lock = 1; 3514 int count; 3515 3516 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3517 Retry: 3518 if (use_read_lock) 3519 vm_map_lock_read(map); 3520 else 3521 vm_map_lock(map); 3522 3523 /* If addr is already in the entry range, no need to grow.*/ 3524 if (vm_map_lookup_entry(map, addr, &prev_entry)) 3525 goto done; 3526 3527 if ((stack_entry = prev_entry->next) == &map->header) 3528 goto done; 3529 if (prev_entry == &map->header) 3530 end = stack_entry->start - stack_entry->aux.avail_ssize; 3531 else 3532 end = prev_entry->end; 3533 3534 /* 3535 * This next test mimics the old grow function in vm_machdep.c. 3536 * It really doesn't quite make sense, but we do it anyway 3537 * for compatibility. 3538 * 3539 * If not growable stack, return success. This signals the 3540 * caller to proceed as he would normally with normal vm. 3541 */ 3542 if (stack_entry->aux.avail_ssize < 1 || 3543 addr >= stack_entry->start || 3544 addr < stack_entry->start - stack_entry->aux.avail_ssize) { 3545 goto done; 3546 } 3547 3548 /* Find the minimum grow amount */ 3549 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE); 3550 if (grow_amount > stack_entry->aux.avail_ssize) { 3551 rv = KERN_NO_SPACE; 3552 goto done; 3553 } 3554 3555 /* 3556 * If there is no longer enough space between the entries 3557 * nogo, and adjust the available space. Note: this 3558 * should only happen if the user has mapped into the 3559 * stack area after the stack was created, and is 3560 * probably an error. 3561 * 3562 * This also effectively destroys any guard page the user 3563 * might have intended by limiting the stack size. 3564 */ 3565 if (grow_amount > stack_entry->start - end) { 3566 if (use_read_lock && vm_map_lock_upgrade(map)) { 3567 /* lost lock */ 3568 use_read_lock = 0; 3569 goto Retry; 3570 } 3571 use_read_lock = 0; 3572 stack_entry->aux.avail_ssize = stack_entry->start - end; 3573 rv = KERN_NO_SPACE; 3574 goto done; 3575 } 3576 3577 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; 3578 3579 /* If this is the main process stack, see if we're over the 3580 * stack limit. 3581 */ 3582 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3583 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3584 rv = KERN_NO_SPACE; 3585 goto done; 3586 } 3587 3588 /* Round up the grow amount modulo SGROWSIZ */ 3589 grow_amount = roundup (grow_amount, sgrowsiz); 3590 if (grow_amount > stack_entry->aux.avail_ssize) { 3591 grow_amount = stack_entry->aux.avail_ssize; 3592 } 3593 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3594 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3595 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 3596 ctob(vm->vm_ssize); 3597 } 3598 3599 /* If we would blow our VMEM resource limit, no go */ 3600 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3601 rv = KERN_NO_SPACE; 3602 goto done; 3603 } 3604 3605 if (use_read_lock && vm_map_lock_upgrade(map)) { 3606 /* lost lock */ 3607 use_read_lock = 0; 3608 goto Retry; 3609 } 3610 use_read_lock = 0; 3611 3612 /* Get the preliminary new entry start value */ 3613 addr = stack_entry->start - grow_amount; 3614 3615 /* If this puts us into the previous entry, cut back our growth 3616 * to the available space. Also, see the note above. 3617 */ 3618 if (addr < end) { 3619 stack_entry->aux.avail_ssize = stack_entry->start - end; 3620 addr = end; 3621 } 3622 3623 rv = vm_map_insert(map, &count, 3624 NULL, 0, addr, stack_entry->start, 3625 VM_MAPTYPE_NORMAL, 3626 VM_PROT_ALL, VM_PROT_ALL, 3627 0); 3628 3629 /* Adjust the available stack space by the amount we grew. */ 3630 if (rv == KERN_SUCCESS) { 3631 if (prev_entry != &map->header) 3632 vm_map_clip_end(map, prev_entry, addr, &count); 3633 new_stack_entry = prev_entry->next; 3634 if (new_stack_entry->end != stack_entry->start || 3635 new_stack_entry->start != addr) 3636 panic ("Bad stack grow start/end in new stack entry"); 3637 else { 3638 new_stack_entry->aux.avail_ssize = 3639 stack_entry->aux.avail_ssize - 3640 (new_stack_entry->end - new_stack_entry->start); 3641 if (is_procstack) 3642 vm->vm_ssize += btoc(new_stack_entry->end - 3643 new_stack_entry->start); 3644 } 3645 3646 if (map->flags & MAP_WIREFUTURE) 3647 vm_map_unwire(map, new_stack_entry->start, 3648 new_stack_entry->end, FALSE); 3649 } 3650 3651 done: 3652 if (use_read_lock) 3653 vm_map_unlock_read(map); 3654 else 3655 vm_map_unlock(map); 3656 vm_map_entry_release(count); 3657 return (rv); 3658 } 3659 3660 /* 3661 * Unshare the specified VM space for exec. If other processes are 3662 * mapped to it, then create a new one. The new vmspace is null. 3663 * 3664 * No requirements. 3665 */ 3666 void 3667 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 3668 { 3669 struct vmspace *oldvmspace = p->p_vmspace; 3670 struct vmspace *newvmspace; 3671 vm_map_t map = &p->p_vmspace->vm_map; 3672 3673 /* 3674 * If we are execing a resident vmspace we fork it, otherwise 3675 * we create a new vmspace. Note that exitingcnt is not 3676 * copied to the new vmspace. 3677 */ 3678 lwkt_gettoken(&oldvmspace->vm_map.token); 3679 if (vmcopy) { 3680 newvmspace = vmspace_fork(vmcopy); 3681 lwkt_gettoken(&newvmspace->vm_map.token); 3682 } else { 3683 newvmspace = vmspace_alloc(map->min_offset, map->max_offset); 3684 lwkt_gettoken(&newvmspace->vm_map.token); 3685 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 3686 (caddr_t)&oldvmspace->vm_endcopy - 3687 (caddr_t)&oldvmspace->vm_startcopy); 3688 } 3689 3690 /* 3691 * Finish initializing the vmspace before assigning it 3692 * to the process. The vmspace will become the current vmspace 3693 * if p == curproc. 3694 */ 3695 pmap_pinit2(vmspace_pmap(newvmspace)); 3696 pmap_replacevm(p, newvmspace, 0); 3697 lwkt_reltoken(&newvmspace->vm_map.token); 3698 lwkt_reltoken(&oldvmspace->vm_map.token); 3699 vmspace_free(oldvmspace); 3700 } 3701 3702 /* 3703 * Unshare the specified VM space for forcing COW. This 3704 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3705 */ 3706 void 3707 vmspace_unshare(struct proc *p) 3708 { 3709 struct vmspace *oldvmspace = p->p_vmspace; 3710 struct vmspace *newvmspace; 3711 3712 lwkt_gettoken(&oldvmspace->vm_map.token); 3713 if (oldvmspace->vm_sysref.refcnt == 1) { 3714 lwkt_reltoken(&oldvmspace->vm_map.token); 3715 return; 3716 } 3717 newvmspace = vmspace_fork(oldvmspace); 3718 lwkt_gettoken(&newvmspace->vm_map.token); 3719 pmap_pinit2(vmspace_pmap(newvmspace)); 3720 pmap_replacevm(p, newvmspace, 0); 3721 lwkt_reltoken(&newvmspace->vm_map.token); 3722 lwkt_reltoken(&oldvmspace->vm_map.token); 3723 vmspace_free(oldvmspace); 3724 } 3725 3726 /* 3727 * vm_map_hint: return the beginning of the best area suitable for 3728 * creating a new mapping with "prot" protection. 3729 * 3730 * No requirements. 3731 */ 3732 vm_offset_t 3733 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot) 3734 { 3735 struct vmspace *vms = p->p_vmspace; 3736 3737 if (!randomize_mmap) { 3738 /* 3739 * Set a reasonable start point for the hint if it was 3740 * not specified or if it falls within the heap space. 3741 * Hinted mmap()s do not allocate out of the heap space. 3742 */ 3743 if (addr == 0 || 3744 (addr >= round_page((vm_offset_t)vms->vm_taddr) && 3745 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) { 3746 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); 3747 } 3748 3749 return addr; 3750 } 3751 3752 if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr) 3753 return addr; 3754 3755 #ifdef notyet 3756 #ifdef __i386__ 3757 /* 3758 * If executable skip first two pages, otherwise start 3759 * after data + heap region. 3760 */ 3761 if ((prot & VM_PROT_EXECUTE) && 3762 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) { 3763 addr = (PAGE_SIZE * 2) + 3764 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1)); 3765 return (round_page(addr)); 3766 } 3767 #endif /* __i386__ */ 3768 #endif /* notyet */ 3769 3770 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ; 3771 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1); 3772 3773 return (round_page(addr)); 3774 } 3775 3776 /* 3777 * Finds the VM object, offset, and protection for a given virtual address 3778 * in the specified map, assuming a page fault of the type specified. 3779 * 3780 * Leaves the map in question locked for read; return values are guaranteed 3781 * until a vm_map_lookup_done call is performed. Note that the map argument 3782 * is in/out; the returned map must be used in the call to vm_map_lookup_done. 3783 * 3784 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make 3785 * that fast. 3786 * 3787 * If a lookup is requested with "write protection" specified, the map may 3788 * be changed to perform virtual copying operations, although the data 3789 * referenced will remain the same. 3790 * 3791 * No requirements. 3792 */ 3793 int 3794 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3795 vm_offset_t vaddr, 3796 vm_prot_t fault_typea, 3797 vm_map_entry_t *out_entry, /* OUT */ 3798 vm_object_t *object, /* OUT */ 3799 vm_pindex_t *pindex, /* OUT */ 3800 vm_prot_t *out_prot, /* OUT */ 3801 boolean_t *wired) /* OUT */ 3802 { 3803 vm_map_entry_t entry; 3804 vm_map_t map = *var_map; 3805 vm_prot_t prot; 3806 vm_prot_t fault_type = fault_typea; 3807 int use_read_lock = 1; 3808 int rv = KERN_SUCCESS; 3809 3810 RetryLookup: 3811 if (use_read_lock) 3812 vm_map_lock_read(map); 3813 else 3814 vm_map_lock(map); 3815 3816 /* 3817 * If the map has an interesting hint, try it before calling full 3818 * blown lookup routine. 3819 */ 3820 entry = map->hint; 3821 cpu_ccfence(); 3822 *out_entry = entry; 3823 *object = NULL; 3824 3825 if ((entry == &map->header) || 3826 (vaddr < entry->start) || (vaddr >= entry->end)) { 3827 vm_map_entry_t tmp_entry; 3828 3829 /* 3830 * Entry was either not a valid hint, or the vaddr was not 3831 * contained in the entry, so do a full lookup. 3832 */ 3833 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { 3834 rv = KERN_INVALID_ADDRESS; 3835 goto done; 3836 } 3837 3838 entry = tmp_entry; 3839 *out_entry = entry; 3840 } 3841 3842 /* 3843 * Handle submaps. 3844 */ 3845 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3846 vm_map_t old_map = map; 3847 3848 *var_map = map = entry->object.sub_map; 3849 if (use_read_lock) 3850 vm_map_unlock_read(old_map); 3851 else 3852 vm_map_unlock(old_map); 3853 use_read_lock = 1; 3854 goto RetryLookup; 3855 } 3856 3857 /* 3858 * Check whether this task is allowed to have this page. 3859 * Note the special case for MAP_ENTRY_COW 3860 * pages with an override. This is to implement a forced 3861 * COW for debuggers. 3862 */ 3863 3864 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3865 prot = entry->max_protection; 3866 else 3867 prot = entry->protection; 3868 3869 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3870 if ((fault_type & prot) != fault_type) { 3871 rv = KERN_PROTECTION_FAILURE; 3872 goto done; 3873 } 3874 3875 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3876 (entry->eflags & MAP_ENTRY_COW) && 3877 (fault_type & VM_PROT_WRITE) && 3878 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 3879 rv = KERN_PROTECTION_FAILURE; 3880 goto done; 3881 } 3882 3883 /* 3884 * If this page is not pageable, we have to get it for all possible 3885 * accesses. 3886 */ 3887 *wired = (entry->wired_count != 0); 3888 if (*wired) 3889 prot = fault_type = entry->protection; 3890 3891 /* 3892 * Virtual page tables may need to update the accessed (A) bit 3893 * in a page table entry. Upgrade the fault to a write fault for 3894 * that case if the map will support it. If the map does not support 3895 * it the page table entry simply will not be updated. 3896 */ 3897 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 3898 if (prot & VM_PROT_WRITE) 3899 fault_type |= VM_PROT_WRITE; 3900 } 3901 3902 /* 3903 * If the entry was copy-on-write, we either ... 3904 */ 3905 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3906 /* 3907 * If we want to write the page, we may as well handle that 3908 * now since we've got the map locked. 3909 * 3910 * If we don't need to write the page, we just demote the 3911 * permissions allowed. 3912 */ 3913 3914 if (fault_type & VM_PROT_WRITE) { 3915 /* 3916 * Make a new object, and place it in the object 3917 * chain. Note that no new references have appeared 3918 * -- one just moved from the map to the new 3919 * object. 3920 */ 3921 3922 if (use_read_lock && vm_map_lock_upgrade(map)) { 3923 /* lost lock */ 3924 use_read_lock = 0; 3925 goto RetryLookup; 3926 } 3927 use_read_lock = 0; 3928 3929 vm_map_entry_shadow(entry, 0); 3930 } else { 3931 /* 3932 * We're attempting to read a copy-on-write page -- 3933 * don't allow writes. 3934 */ 3935 3936 prot &= ~VM_PROT_WRITE; 3937 } 3938 } 3939 3940 /* 3941 * Create an object if necessary. 3942 */ 3943 if (entry->object.vm_object == NULL && !map->system_map) { 3944 if (use_read_lock && vm_map_lock_upgrade(map)) { 3945 /* lost lock */ 3946 use_read_lock = 0; 3947 goto RetryLookup; 3948 } 3949 use_read_lock = 0; 3950 vm_map_entry_allocate_object(entry); 3951 } 3952 3953 /* 3954 * Return the object/offset from this entry. If the entry was 3955 * copy-on-write or empty, it has been fixed up. 3956 */ 3957 3958 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3959 *object = entry->object.vm_object; 3960 3961 /* 3962 * Return whether this is the only map sharing this data. On 3963 * success we return with a read lock held on the map. On failure 3964 * we return with the map unlocked. 3965 */ 3966 *out_prot = prot; 3967 done: 3968 if (rv == KERN_SUCCESS) { 3969 if (use_read_lock == 0) 3970 vm_map_lock_downgrade(map); 3971 } else if (use_read_lock) { 3972 vm_map_unlock_read(map); 3973 } else { 3974 vm_map_unlock(map); 3975 } 3976 return (rv); 3977 } 3978 3979 /* 3980 * Releases locks acquired by a vm_map_lookup() 3981 * (according to the handle returned by that lookup). 3982 * 3983 * No other requirements. 3984 */ 3985 void 3986 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) 3987 { 3988 /* 3989 * Unlock the main-level map 3990 */ 3991 vm_map_unlock_read(map); 3992 if (count) 3993 vm_map_entry_release(count); 3994 } 3995 3996 #include "opt_ddb.h" 3997 #ifdef DDB 3998 #include <sys/kernel.h> 3999 4000 #include <ddb/ddb.h> 4001 4002 /* 4003 * Debugging only 4004 */ 4005 DB_SHOW_COMMAND(map, vm_map_print) 4006 { 4007 static int nlines; 4008 /* XXX convert args. */ 4009 vm_map_t map = (vm_map_t)addr; 4010 boolean_t full = have_addr; 4011 4012 vm_map_entry_t entry; 4013 4014 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4015 (void *)map, 4016 (void *)map->pmap, map->nentries, map->timestamp); 4017 nlines++; 4018 4019 if (!full && db_indent) 4020 return; 4021 4022 db_indent += 2; 4023 for (entry = map->header.next; entry != &map->header; 4024 entry = entry->next) { 4025 db_iprintf("map entry %p: start=%p, end=%p\n", 4026 (void *)entry, (void *)entry->start, (void *)entry->end); 4027 nlines++; 4028 { 4029 static char *inheritance_name[4] = 4030 {"share", "copy", "none", "donate_copy"}; 4031 4032 db_iprintf(" prot=%x/%x/%s", 4033 entry->protection, 4034 entry->max_protection, 4035 inheritance_name[(int)(unsigned char)entry->inheritance]); 4036 if (entry->wired_count != 0) 4037 db_printf(", wired"); 4038 } 4039 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 4040 /* XXX no %qd in kernel. Truncate entry->offset. */ 4041 db_printf(", share=%p, offset=0x%lx\n", 4042 (void *)entry->object.sub_map, 4043 (long)entry->offset); 4044 nlines++; 4045 if ((entry->prev == &map->header) || 4046 (entry->prev->object.sub_map != 4047 entry->object.sub_map)) { 4048 db_indent += 2; 4049 vm_map_print((db_expr_t)(intptr_t) 4050 entry->object.sub_map, 4051 full, 0, NULL); 4052 db_indent -= 2; 4053 } 4054 } else { 4055 /* XXX no %qd in kernel. Truncate entry->offset. */ 4056 db_printf(", object=%p, offset=0x%lx", 4057 (void *)entry->object.vm_object, 4058 (long)entry->offset); 4059 if (entry->eflags & MAP_ENTRY_COW) 4060 db_printf(", copy (%s)", 4061 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4062 db_printf("\n"); 4063 nlines++; 4064 4065 if ((entry->prev == &map->header) || 4066 (entry->prev->object.vm_object != 4067 entry->object.vm_object)) { 4068 db_indent += 2; 4069 vm_object_print((db_expr_t)(intptr_t) 4070 entry->object.vm_object, 4071 full, 0, NULL); 4072 nlines += 4; 4073 db_indent -= 2; 4074 } 4075 } 4076 } 4077 db_indent -= 2; 4078 if (db_indent == 0) 4079 nlines = 0; 4080 } 4081 4082 /* 4083 * Debugging only 4084 */ 4085 DB_SHOW_COMMAND(procvm, procvm) 4086 { 4087 struct proc *p; 4088 4089 if (have_addr) { 4090 p = (struct proc *) addr; 4091 } else { 4092 p = curproc; 4093 } 4094 4095 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4096 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4097 (void *)vmspace_pmap(p->p_vmspace)); 4098 4099 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 4100 } 4101 4102 #endif /* DDB */ 4103