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