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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 35 * 36 * 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 * 62 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $ 63 */ 64 65 /* 66 * Virtual memory mapping module. 67 */ 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/kernel.h> 72 #include <sys/proc.h> 73 #include <sys/serialize.h> 74 #include <sys/lock.h> 75 #include <sys/vmmeter.h> 76 #include <sys/mman.h> 77 #include <sys/vnode.h> 78 #include <sys/resourcevar.h> 79 #include <sys/shm.h> 80 #include <sys/tree.h> 81 #include <sys/malloc.h> 82 #include <sys/objcache.h> 83 84 #include <vm/vm.h> 85 #include <vm/vm_param.h> 86 #include <vm/pmap.h> 87 #include <vm/vm_map.h> 88 #include <vm/vm_page.h> 89 #include <vm/vm_object.h> 90 #include <vm/vm_pager.h> 91 #include <vm/vm_kern.h> 92 #include <vm/vm_extern.h> 93 #include <vm/swap_pager.h> 94 #include <vm/vm_zone.h> 95 96 #include <sys/thread2.h> 97 #include <sys/random.h> 98 #include <sys/sysctl.h> 99 100 /* 101 * Virtual memory maps provide for the mapping, protection, and sharing 102 * of virtual memory objects. In addition, this module provides for an 103 * efficient virtual copy of memory from one map to another. 104 * 105 * Synchronization is required prior to most operations. 106 * 107 * Maps consist of an ordered doubly-linked list of simple entries. 108 * A hint and a RB tree is used to speed-up lookups. 109 * 110 * Callers looking to modify maps specify start/end addresses which cause 111 * the related map entry to be clipped if necessary, and then later 112 * recombined if the pieces remained compatible. 113 * 114 * Virtual copy operations are performed by copying VM object references 115 * from one map to another, and then marking both regions as copy-on-write. 116 */ 117 static __boolean_t vmspace_ctor(void *obj, void *privdata, int ocflags); 118 static void vmspace_dtor(void *obj, void *privdata); 119 static void vmspace_terminate(struct vmspace *vm, int final); 120 121 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore"); 122 static struct objcache *vmspace_cache; 123 124 /* 125 * per-cpu page table cross mappings are initialized in early boot 126 * and might require a considerable number of vm_map_entry structures. 127 */ 128 #define MAPENTRYBSP_CACHE (MAXCPU+1) 129 #define MAPENTRYAP_CACHE 8 130 131 static struct vm_zone mapentzone_store, mapzone_store; 132 static vm_zone_t mapentzone, mapzone; 133 static struct vm_object mapentobj, mapobj; 134 135 static struct vm_map_entry map_entry_init[MAX_MAPENT]; 136 static struct vm_map_entry cpu_map_entry_init_bsp[MAPENTRYBSP_CACHE]; 137 static struct vm_map_entry cpu_map_entry_init_ap[MAXCPU][MAPENTRYAP_CACHE]; 138 static struct vm_map map_init[MAX_KMAP]; 139 140 static int randomize_mmap; 141 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0, 142 "Randomize mmap offsets"); 143 static int vm_map_relock_enable = 1; 144 SYSCTL_INT(_vm, OID_AUTO, map_relock_enable, CTLFLAG_RW, 145 &vm_map_relock_enable, 0, "Randomize mmap offsets"); 146 147 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref); 148 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *); 149 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); 150 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 151 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 152 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); 153 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); 154 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, 155 vm_map_entry_t); 156 static void vm_map_unclip_range (vm_map_t map, vm_map_entry_t start_entry, vm_offset_t start, vm_offset_t end, int *count, int flags); 157 158 /* 159 * Initialize the vm_map module. Must be called before any other vm_map 160 * routines. 161 * 162 * Map and entry structures are allocated from the general purpose 163 * memory pool with some exceptions: 164 * 165 * - The kernel map is allocated statically. 166 * - Initial kernel map entries are allocated out of a static pool. 167 * - We must set ZONE_SPECIAL here or the early boot code can get 168 * stuck if there are >63 cores. 169 * 170 * These restrictions are necessary since malloc() uses the 171 * maps and requires map entries. 172 * 173 * Called from the low level boot code only. 174 */ 175 void 176 vm_map_startup(void) 177 { 178 mapzone = &mapzone_store; 179 zbootinit(mapzone, "MAP", sizeof (struct vm_map), 180 map_init, MAX_KMAP); 181 mapentzone = &mapentzone_store; 182 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), 183 map_entry_init, MAX_MAPENT); 184 mapentzone_store.zflags |= ZONE_SPECIAL; 185 } 186 187 /* 188 * Called prior to any vmspace allocations. 189 * 190 * Called from the low level boot code only. 191 */ 192 void 193 vm_init2(void) 194 { 195 vmspace_cache = objcache_create_mbacked(M_VMSPACE, 196 sizeof(struct vmspace), 197 0, ncpus * 4, 198 vmspace_ctor, vmspace_dtor, 199 NULL); 200 zinitna(mapentzone, &mapentobj, NULL, 0, 0, 201 ZONE_USE_RESERVE | ZONE_SPECIAL, 1); 202 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1); 203 pmap_init2(); 204 vm_object_init2(); 205 } 206 207 /* 208 * objcache support. We leave the pmap root cached as long as possible 209 * for performance reasons. 210 */ 211 static 212 __boolean_t 213 vmspace_ctor(void *obj, void *privdata, int ocflags) 214 { 215 struct vmspace *vm = obj; 216 217 bzero(vm, sizeof(*vm)); 218 vm->vm_refcnt = (u_int)-1; 219 220 return 1; 221 } 222 223 static 224 void 225 vmspace_dtor(void *obj, void *privdata) 226 { 227 struct vmspace *vm = obj; 228 229 KKASSERT(vm->vm_refcnt == (u_int)-1); 230 pmap_puninit(vmspace_pmap(vm)); 231 } 232 233 /* 234 * Red black tree functions 235 * 236 * The caller must hold the related map lock. 237 */ 238 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); 239 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); 240 241 /* a->start is address, and the only field has to be initialized */ 242 static int 243 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) 244 { 245 if (a->start < b->start) 246 return(-1); 247 else if (a->start > b->start) 248 return(1); 249 return(0); 250 } 251 252 /* 253 * Initialize vmspace ref/hold counts vmspace0. There is a holdcnt for 254 * every refcnt. 255 */ 256 void 257 vmspace_initrefs(struct vmspace *vm) 258 { 259 vm->vm_refcnt = 1; 260 vm->vm_holdcnt = 1; 261 } 262 263 /* 264 * Allocate a vmspace structure, including a vm_map and pmap. 265 * Initialize numerous fields. While the initial allocation is zerod, 266 * subsequence reuse from the objcache leaves elements of the structure 267 * intact (particularly the pmap), so portions must be zerod. 268 * 269 * Returns a referenced vmspace. 270 * 271 * No requirements. 272 */ 273 struct vmspace * 274 vmspace_alloc(vm_offset_t min, vm_offset_t max) 275 { 276 struct vmspace *vm; 277 278 vm = objcache_get(vmspace_cache, M_WAITOK); 279 280 bzero(&vm->vm_startcopy, 281 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy); 282 vm_map_init(&vm->vm_map, min, max, NULL); /* initializes token */ 283 284 /* 285 * NOTE: hold to acquires token for safety. 286 * 287 * On return vmspace is referenced (refs=1, hold=1). That is, 288 * each refcnt also has a holdcnt. There can be additional holds 289 * (holdcnt) above and beyond the refcnt. Finalization is handled in 290 * two stages, one on refs 1->0, and the the second on hold 1->0. 291 */ 292 KKASSERT(vm->vm_holdcnt == 0); 293 KKASSERT(vm->vm_refcnt == (u_int)-1); 294 vmspace_initrefs(vm); 295 vmspace_hold(vm); 296 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */ 297 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 298 vm->vm_shm = NULL; 299 vm->vm_flags = 0; 300 cpu_vmspace_alloc(vm); 301 vmspace_drop(vm); 302 303 return (vm); 304 } 305 306 /* 307 * NOTE: Can return -1 if the vmspace is exiting. 308 */ 309 int 310 vmspace_getrefs(struct vmspace *vm) 311 { 312 return ((int)vm->vm_refcnt); 313 } 314 315 /* 316 * A vmspace object must already have a non-zero hold to be able to gain 317 * further holds on it. 318 */ 319 static void 320 vmspace_hold_notoken(struct vmspace *vm) 321 { 322 KKASSERT(vm->vm_holdcnt != 0); 323 refcount_acquire(&vm->vm_holdcnt); 324 } 325 326 static void 327 vmspace_drop_notoken(struct vmspace *vm) 328 { 329 if (refcount_release(&vm->vm_holdcnt)) { 330 if (vm->vm_refcnt == (u_int)-1) { 331 vmspace_terminate(vm, 1); 332 } 333 } 334 } 335 336 void 337 vmspace_hold(struct vmspace *vm) 338 { 339 vmspace_hold_notoken(vm); 340 lwkt_gettoken(&vm->vm_map.token); 341 } 342 343 void 344 vmspace_drop(struct vmspace *vm) 345 { 346 lwkt_reltoken(&vm->vm_map.token); 347 vmspace_drop_notoken(vm); 348 } 349 350 /* 351 * A vmspace object must not be in a terminated state to be able to obtain 352 * additional refs on it. 353 * 354 * Ref'ing a vmspace object also increments its hold count. 355 */ 356 void 357 vmspace_ref(struct vmspace *vm) 358 { 359 KKASSERT((int)vm->vm_refcnt >= 0); 360 vmspace_hold_notoken(vm); 361 refcount_acquire(&vm->vm_refcnt); 362 } 363 364 /* 365 * Release a ref on the vmspace. On the 1->0 transition we do stage-1 366 * termination of the vmspace. Then, on the final drop of the hold we 367 * will do stage-2 final termination. 368 */ 369 void 370 vmspace_rel(struct vmspace *vm) 371 { 372 if (refcount_release(&vm->vm_refcnt)) { 373 vm->vm_refcnt = (u_int)-1; /* no other refs possible */ 374 vmspace_terminate(vm, 0); 375 } 376 vmspace_drop_notoken(vm); 377 } 378 379 /* 380 * This is called during exit indicating that the vmspace is no 381 * longer in used by an exiting process, but the process has not yet 382 * been reaped. 383 * 384 * We release the refcnt but not the associated holdcnt. 385 * 386 * No requirements. 387 */ 388 void 389 vmspace_relexit(struct vmspace *vm) 390 { 391 if (refcount_release(&vm->vm_refcnt)) { 392 vm->vm_refcnt = (u_int)-1; /* no other refs possible */ 393 vmspace_terminate(vm, 0); 394 } 395 } 396 397 /* 398 * Called during reap to disconnect the remainder of the vmspace from 399 * the process. On the hold drop the vmspace termination is finalized. 400 * 401 * No requirements. 402 */ 403 void 404 vmspace_exitfree(struct proc *p) 405 { 406 struct vmspace *vm; 407 408 vm = p->p_vmspace; 409 p->p_vmspace = NULL; 410 vmspace_drop_notoken(vm); 411 } 412 413 /* 414 * Called in two cases: 415 * 416 * (1) When the last refcnt is dropped and the vmspace becomes inactive, 417 * called with final == 0. refcnt will be (u_int)-1 at this point, 418 * and holdcnt will still be non-zero. 419 * 420 * (2) When holdcnt becomes 0, called with final == 1. There should no 421 * longer be anyone with access to the vmspace. 422 * 423 * VMSPACE_EXIT1 flags the primary deactivation 424 * VMSPACE_EXIT2 flags the last reap 425 */ 426 static void 427 vmspace_terminate(struct vmspace *vm, int final) 428 { 429 int count; 430 431 lwkt_gettoken(&vm->vm_map.token); 432 if (final == 0) { 433 KKASSERT((vm->vm_flags & VMSPACE_EXIT1) == 0); 434 435 /* 436 * Get rid of most of the resources. Leave the kernel pmap 437 * intact. 438 */ 439 vm->vm_flags |= VMSPACE_EXIT1; 440 shmexit(vm); 441 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, 442 VM_MAX_USER_ADDRESS); 443 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, 444 VM_MAX_USER_ADDRESS); 445 lwkt_reltoken(&vm->vm_map.token); 446 } else { 447 KKASSERT((vm->vm_flags & VMSPACE_EXIT1) != 0); 448 KKASSERT((vm->vm_flags & VMSPACE_EXIT2) == 0); 449 450 /* 451 * Get rid of remaining basic resources. 452 */ 453 vm->vm_flags |= VMSPACE_EXIT2; 454 cpu_vmspace_free(vm); 455 shmexit(vm); 456 457 /* 458 * Lock the map, to wait out all other references to it. 459 * Delete all of the mappings and pages they hold, then call 460 * the pmap module to reclaim anything left. 461 */ 462 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 463 vm_map_lock(&vm->vm_map); 464 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 465 vm->vm_map.max_offset, &count); 466 vm_map_unlock(&vm->vm_map); 467 vm_map_entry_release(count); 468 469 lwkt_gettoken(&vmspace_pmap(vm)->pm_token); 470 pmap_release(vmspace_pmap(vm)); 471 lwkt_reltoken(&vmspace_pmap(vm)->pm_token); 472 lwkt_reltoken(&vm->vm_map.token); 473 objcache_put(vmspace_cache, vm); 474 } 475 } 476 477 /* 478 * Swap useage is determined by taking the proportional swap used by 479 * VM objects backing the VM map. To make up for fractional losses, 480 * if the VM object has any swap use at all the associated map entries 481 * count for at least 1 swap page. 482 * 483 * No requirements. 484 */ 485 int 486 vmspace_swap_count(struct vmspace *vm) 487 { 488 vm_map_t map = &vm->vm_map; 489 vm_map_entry_t cur; 490 vm_object_t object; 491 int count = 0; 492 int n; 493 494 vmspace_hold(vm); 495 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 496 switch(cur->maptype) { 497 case VM_MAPTYPE_NORMAL: 498 case VM_MAPTYPE_VPAGETABLE: 499 if ((object = cur->object.vm_object) == NULL) 500 break; 501 if (object->swblock_count) { 502 n = (cur->end - cur->start) / PAGE_SIZE; 503 count += object->swblock_count * 504 SWAP_META_PAGES * n / object->size + 1; 505 } 506 break; 507 default: 508 break; 509 } 510 } 511 vmspace_drop(vm); 512 513 return(count); 514 } 515 516 /* 517 * Calculate the approximate number of anonymous pages in use by 518 * this vmspace. To make up for fractional losses, we count each 519 * VM object as having at least 1 anonymous page. 520 * 521 * No requirements. 522 */ 523 int 524 vmspace_anonymous_count(struct vmspace *vm) 525 { 526 vm_map_t map = &vm->vm_map; 527 vm_map_entry_t cur; 528 vm_object_t object; 529 int count = 0; 530 531 vmspace_hold(vm); 532 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 533 switch(cur->maptype) { 534 case VM_MAPTYPE_NORMAL: 535 case VM_MAPTYPE_VPAGETABLE: 536 if ((object = cur->object.vm_object) == NULL) 537 break; 538 if (object->type != OBJT_DEFAULT && 539 object->type != OBJT_SWAP) { 540 break; 541 } 542 count += object->resident_page_count; 543 break; 544 default: 545 break; 546 } 547 } 548 vmspace_drop(vm); 549 550 return(count); 551 } 552 553 /* 554 * Creates and returns a new empty VM map with the given physical map 555 * structure, and having the given lower and upper address bounds. 556 * 557 * No requirements. 558 */ 559 vm_map_t 560 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max) 561 { 562 if (result == NULL) 563 result = zalloc(mapzone); 564 vm_map_init(result, min, max, pmap); 565 return (result); 566 } 567 568 /* 569 * Initialize an existing vm_map structure such as that in the vmspace 570 * structure. The pmap is initialized elsewhere. 571 * 572 * No requirements. 573 */ 574 void 575 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap) 576 { 577 map->header.next = map->header.prev = &map->header; 578 RB_INIT(&map->rb_root); 579 map->nentries = 0; 580 map->size = 0; 581 map->system_map = 0; 582 map->min_offset = min; 583 map->max_offset = max; 584 map->pmap = pmap; 585 map->first_free = &map->header; 586 map->hint = &map->header; 587 map->timestamp = 0; 588 map->flags = 0; 589 lwkt_token_init(&map->token, "vm_map"); 590 lockinit(&map->lock, "vm_maplk", (hz + 9) / 10, 0); 591 } 592 593 /* 594 * Shadow the vm_map_entry's object. This typically needs to be done when 595 * a write fault is taken on an entry which had previously been cloned by 596 * fork(). The shared object (which might be NULL) must become private so 597 * we add a shadow layer above it. 598 * 599 * Object allocation for anonymous mappings is defered as long as possible. 600 * When creating a shadow, however, the underlying object must be instantiated 601 * so it can be shared. 602 * 603 * If the map segment is governed by a virtual page table then it is 604 * possible to address offsets beyond the mapped area. Just allocate 605 * a maximally sized object for this case. 606 * 607 * The vm_map must be exclusively locked. 608 * No other requirements. 609 */ 610 static 611 void 612 vm_map_entry_shadow(vm_map_entry_t entry, int addref) 613 { 614 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 615 vm_object_shadow(&entry->object.vm_object, &entry->offset, 616 0x7FFFFFFF, addref); /* XXX */ 617 } else { 618 vm_object_shadow(&entry->object.vm_object, &entry->offset, 619 atop(entry->end - entry->start), addref); 620 } 621 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 622 } 623 624 /* 625 * Allocate an object for a vm_map_entry. 626 * 627 * Object allocation for anonymous mappings is defered as long as possible. 628 * This function is called when we can defer no longer, generally when a map 629 * entry might be split or forked or takes a page fault. 630 * 631 * If the map segment is governed by a virtual page table then it is 632 * possible to address offsets beyond the mapped area. Just allocate 633 * a maximally sized object for this case. 634 * 635 * The vm_map must be exclusively locked. 636 * No other requirements. 637 */ 638 void 639 vm_map_entry_allocate_object(vm_map_entry_t entry) 640 { 641 vm_object_t obj; 642 643 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 644 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */ 645 } else { 646 obj = vm_object_allocate(OBJT_DEFAULT, 647 atop(entry->end - entry->start)); 648 } 649 entry->object.vm_object = obj; 650 entry->offset = 0; 651 } 652 653 /* 654 * Set an initial negative count so the first attempt to reserve 655 * space preloads a bunch of vm_map_entry's for this cpu. Also 656 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to 657 * map a new page for vm_map_entry structures. SMP systems are 658 * particularly sensitive. 659 * 660 * This routine is called in early boot so we cannot just call 661 * vm_map_entry_reserve(). 662 * 663 * Called from the low level boot code only (for each cpu) 664 * 665 * WARNING! Take care not to have too-big a static/BSS structure here 666 * as MAXCPU can be 256+, otherwise the loader's 64MB heap 667 * can get blown out by the kernel plus the initrd image. 668 */ 669 void 670 vm_map_entry_reserve_cpu_init(globaldata_t gd) 671 { 672 vm_map_entry_t entry; 673 int count; 674 int i; 675 676 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2; 677 if (gd->gd_cpuid == 0) { 678 entry = &cpu_map_entry_init_bsp[0]; 679 count = MAPENTRYBSP_CACHE; 680 } else { 681 entry = &cpu_map_entry_init_ap[gd->gd_cpuid][0]; 682 count = MAPENTRYAP_CACHE; 683 } 684 for (i = 0; i < count; ++i, ++entry) { 685 entry->next = gd->gd_vme_base; 686 gd->gd_vme_base = entry; 687 } 688 } 689 690 /* 691 * Reserves vm_map_entry structures so code later on can manipulate 692 * map_entry structures within a locked map without blocking trying 693 * to allocate a new vm_map_entry. 694 * 695 * No requirements. 696 */ 697 int 698 vm_map_entry_reserve(int count) 699 { 700 struct globaldata *gd = mycpu; 701 vm_map_entry_t entry; 702 703 /* 704 * Make sure we have enough structures in gd_vme_base to handle 705 * the reservation request. 706 * 707 * The critical section protects access to the per-cpu gd. 708 */ 709 crit_enter(); 710 while (gd->gd_vme_avail < count) { 711 entry = zalloc(mapentzone); 712 entry->next = gd->gd_vme_base; 713 gd->gd_vme_base = entry; 714 ++gd->gd_vme_avail; 715 } 716 gd->gd_vme_avail -= count; 717 crit_exit(); 718 719 return(count); 720 } 721 722 /* 723 * Releases previously reserved vm_map_entry structures that were not 724 * used. If we have too much junk in our per-cpu cache clean some of 725 * it out. 726 * 727 * No requirements. 728 */ 729 void 730 vm_map_entry_release(int count) 731 { 732 struct globaldata *gd = mycpu; 733 vm_map_entry_t entry; 734 735 crit_enter(); 736 gd->gd_vme_avail += count; 737 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) { 738 entry = gd->gd_vme_base; 739 KKASSERT(entry != NULL); 740 gd->gd_vme_base = entry->next; 741 --gd->gd_vme_avail; 742 crit_exit(); 743 zfree(mapentzone, entry); 744 crit_enter(); 745 } 746 crit_exit(); 747 } 748 749 /* 750 * Reserve map entry structures for use in kernel_map itself. These 751 * entries have *ALREADY* been reserved on a per-cpu basis when the map 752 * was inited. This function is used by zalloc() to avoid a recursion 753 * when zalloc() itself needs to allocate additional kernel memory. 754 * 755 * This function works like the normal reserve but does not load the 756 * vm_map_entry cache (because that would result in an infinite 757 * recursion). Note that gd_vme_avail may go negative. This is expected. 758 * 759 * Any caller of this function must be sure to renormalize after 760 * potentially eating entries to ensure that the reserve supply 761 * remains intact. 762 * 763 * No requirements. 764 */ 765 int 766 vm_map_entry_kreserve(int count) 767 { 768 struct globaldata *gd = mycpu; 769 770 crit_enter(); 771 gd->gd_vme_avail -= count; 772 crit_exit(); 773 KASSERT(gd->gd_vme_base != NULL, 774 ("no reserved entries left, gd_vme_avail = %d", 775 gd->gd_vme_avail)); 776 return(count); 777 } 778 779 /* 780 * Release previously reserved map entries for kernel_map. We do not 781 * attempt to clean up like the normal release function as this would 782 * cause an unnecessary (but probably not fatal) deep procedure call. 783 * 784 * No requirements. 785 */ 786 void 787 vm_map_entry_krelease(int count) 788 { 789 struct globaldata *gd = mycpu; 790 791 crit_enter(); 792 gd->gd_vme_avail += count; 793 crit_exit(); 794 } 795 796 /* 797 * Allocates a VM map entry for insertion. No entry fields are filled in. 798 * 799 * The entries should have previously been reserved. The reservation count 800 * is tracked in (*countp). 801 * 802 * No requirements. 803 */ 804 static vm_map_entry_t 805 vm_map_entry_create(vm_map_t map, int *countp) 806 { 807 struct globaldata *gd = mycpu; 808 vm_map_entry_t entry; 809 810 KKASSERT(*countp > 0); 811 --*countp; 812 crit_enter(); 813 entry = gd->gd_vme_base; 814 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); 815 gd->gd_vme_base = entry->next; 816 crit_exit(); 817 818 return(entry); 819 } 820 821 /* 822 * Dispose of a vm_map_entry that is no longer being referenced. 823 * 824 * No requirements. 825 */ 826 static void 827 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) 828 { 829 struct globaldata *gd = mycpu; 830 831 KKASSERT(map->hint != entry); 832 KKASSERT(map->first_free != entry); 833 834 ++*countp; 835 crit_enter(); 836 entry->next = gd->gd_vme_base; 837 gd->gd_vme_base = entry; 838 crit_exit(); 839 } 840 841 842 /* 843 * Insert/remove entries from maps. 844 * 845 * The related map must be exclusively locked. 846 * The caller must hold map->token 847 * No other requirements. 848 */ 849 static __inline void 850 vm_map_entry_link(vm_map_t map, 851 vm_map_entry_t after_where, 852 vm_map_entry_t entry) 853 { 854 ASSERT_VM_MAP_LOCKED(map); 855 856 map->nentries++; 857 entry->prev = after_where; 858 entry->next = after_where->next; 859 entry->next->prev = entry; 860 after_where->next = entry; 861 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) 862 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); 863 } 864 865 static __inline void 866 vm_map_entry_unlink(vm_map_t map, 867 vm_map_entry_t entry) 868 { 869 vm_map_entry_t prev; 870 vm_map_entry_t next; 871 872 ASSERT_VM_MAP_LOCKED(map); 873 874 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 875 panic("vm_map_entry_unlink: attempt to mess with " 876 "locked entry! %p", entry); 877 } 878 prev = entry->prev; 879 next = entry->next; 880 next->prev = prev; 881 prev->next = next; 882 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); 883 map->nentries--; 884 } 885 886 /* 887 * Finds the map entry containing (or immediately preceding) the specified 888 * address in the given map. The entry is returned in (*entry). 889 * 890 * The boolean result indicates whether the address is actually contained 891 * in the map. 892 * 893 * The related map must be locked. 894 * No other requirements. 895 */ 896 boolean_t 897 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry) 898 { 899 vm_map_entry_t tmp; 900 vm_map_entry_t last; 901 902 ASSERT_VM_MAP_LOCKED(map); 903 #if 0 904 /* 905 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive 906 * the hint code with the red-black lookup meets with system crashes 907 * and lockups. We do not yet know why. 908 * 909 * It is possible that the problem is related to the setting 910 * of the hint during map_entry deletion, in the code specified 911 * at the GGG comment later on in this file. 912 * 913 * YYY More likely it's because this function can be called with 914 * a shared lock on the map, resulting in map->hint updates possibly 915 * racing. Fixed now but untested. 916 */ 917 /* 918 * Quickly check the cached hint, there's a good chance of a match. 919 */ 920 tmp = map->hint; 921 cpu_ccfence(); 922 if (tmp != &map->header) { 923 if (address >= tmp->start && address < tmp->end) { 924 *entry = tmp; 925 return(TRUE); 926 } 927 } 928 #endif 929 930 /* 931 * Locate the record from the top of the tree. 'last' tracks the 932 * closest prior record and is returned if no match is found, which 933 * in binary tree terms means tracking the most recent right-branch 934 * taken. If there is no prior record, &map->header is returned. 935 */ 936 last = &map->header; 937 tmp = RB_ROOT(&map->rb_root); 938 939 while (tmp) { 940 if (address >= tmp->start) { 941 if (address < tmp->end) { 942 *entry = tmp; 943 map->hint = tmp; 944 return(TRUE); 945 } 946 last = tmp; 947 tmp = RB_RIGHT(tmp, rb_entry); 948 } else { 949 tmp = RB_LEFT(tmp, rb_entry); 950 } 951 } 952 *entry = last; 953 return (FALSE); 954 } 955 956 /* 957 * Inserts the given whole VM object into the target map at the specified 958 * address range. The object's size should match that of the address range. 959 * 960 * The map must be exclusively locked. 961 * The object must be held. 962 * The caller must have reserved sufficient vm_map_entry structures. 963 * 964 * If object is non-NULL, ref count must be bumped by caller prior to 965 * making call to account for the new entry. 966 */ 967 int 968 vm_map_insert(vm_map_t map, int *countp, void *map_object, void *map_aux, 969 vm_ooffset_t offset, vm_offset_t start, vm_offset_t end, 970 vm_maptype_t maptype, 971 vm_prot_t prot, vm_prot_t max, int cow) 972 { 973 vm_map_entry_t new_entry; 974 vm_map_entry_t prev_entry; 975 vm_map_entry_t temp_entry; 976 vm_eflags_t protoeflags; 977 int must_drop = 0; 978 vm_object_t object; 979 980 if (maptype == VM_MAPTYPE_UKSMAP) 981 object = NULL; 982 else 983 object = map_object; 984 985 ASSERT_VM_MAP_LOCKED(map); 986 if (object) 987 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 988 989 /* 990 * Check that the start and end points are not bogus. 991 */ 992 if ((start < map->min_offset) || (end > map->max_offset) || 993 (start >= end)) 994 return (KERN_INVALID_ADDRESS); 995 996 /* 997 * Find the entry prior to the proposed starting address; if it's part 998 * of an existing entry, this range is bogus. 999 */ 1000 if (vm_map_lookup_entry(map, start, &temp_entry)) 1001 return (KERN_NO_SPACE); 1002 1003 prev_entry = temp_entry; 1004 1005 /* 1006 * Assert that the next entry doesn't overlap the end point. 1007 */ 1008 1009 if ((prev_entry->next != &map->header) && 1010 (prev_entry->next->start < end)) 1011 return (KERN_NO_SPACE); 1012 1013 protoeflags = 0; 1014 1015 if (cow & MAP_COPY_ON_WRITE) 1016 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 1017 1018 if (cow & MAP_NOFAULT) { 1019 protoeflags |= MAP_ENTRY_NOFAULT; 1020 1021 KASSERT(object == NULL, 1022 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1023 } 1024 if (cow & MAP_DISABLE_SYNCER) 1025 protoeflags |= MAP_ENTRY_NOSYNC; 1026 if (cow & MAP_DISABLE_COREDUMP) 1027 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1028 if (cow & MAP_IS_STACK) 1029 protoeflags |= MAP_ENTRY_STACK; 1030 if (cow & MAP_IS_KSTACK) 1031 protoeflags |= MAP_ENTRY_KSTACK; 1032 1033 lwkt_gettoken(&map->token); 1034 1035 if (object) { 1036 /* 1037 * When object is non-NULL, it could be shared with another 1038 * process. We have to set or clear OBJ_ONEMAPPING 1039 * appropriately. 1040 * 1041 * NOTE: This flag is only applicable to DEFAULT and SWAP 1042 * objects and will already be clear in other types 1043 * of objects, so a shared object lock is ok for 1044 * VNODE objects. 1045 */ 1046 if ((object->ref_count > 1) || (object->shadow_count != 0)) { 1047 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1048 } 1049 } 1050 else if ((prev_entry != &map->header) && 1051 (prev_entry->eflags == protoeflags) && 1052 (prev_entry->end == start) && 1053 (prev_entry->wired_count == 0) && 1054 prev_entry->maptype == maptype && 1055 maptype == VM_MAPTYPE_NORMAL && 1056 ((prev_entry->object.vm_object == NULL) || 1057 vm_object_coalesce(prev_entry->object.vm_object, 1058 OFF_TO_IDX(prev_entry->offset), 1059 (vm_size_t)(prev_entry->end - prev_entry->start), 1060 (vm_size_t)(end - prev_entry->end)))) { 1061 /* 1062 * We were able to extend the object. Determine if we 1063 * can extend the previous map entry to include the 1064 * new range as well. 1065 */ 1066 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 1067 (prev_entry->protection == prot) && 1068 (prev_entry->max_protection == max)) { 1069 map->size += (end - prev_entry->end); 1070 prev_entry->end = end; 1071 vm_map_simplify_entry(map, prev_entry, countp); 1072 lwkt_reltoken(&map->token); 1073 return (KERN_SUCCESS); 1074 } 1075 1076 /* 1077 * If we can extend the object but cannot extend the 1078 * map entry, we have to create a new map entry. We 1079 * must bump the ref count on the extended object to 1080 * account for it. object may be NULL. 1081 */ 1082 object = prev_entry->object.vm_object; 1083 offset = prev_entry->offset + 1084 (prev_entry->end - prev_entry->start); 1085 if (object) { 1086 vm_object_hold(object); 1087 vm_object_chain_wait(object, 0); 1088 vm_object_reference_locked(object); 1089 must_drop = 1; 1090 } 1091 } 1092 1093 /* 1094 * NOTE: if conditionals fail, object can be NULL here. This occurs 1095 * in things like the buffer map where we manage kva but do not manage 1096 * backing objects. 1097 */ 1098 1099 /* 1100 * Create a new entry 1101 */ 1102 1103 new_entry = vm_map_entry_create(map, countp); 1104 new_entry->start = start; 1105 new_entry->end = end; 1106 1107 new_entry->maptype = maptype; 1108 new_entry->eflags = protoeflags; 1109 new_entry->object.map_object = map_object; 1110 new_entry->aux.master_pde = 0; /* in case size is different */ 1111 new_entry->aux.map_aux = map_aux; 1112 new_entry->offset = offset; 1113 1114 new_entry->inheritance = VM_INHERIT_DEFAULT; 1115 new_entry->protection = prot; 1116 new_entry->max_protection = max; 1117 new_entry->wired_count = 0; 1118 1119 /* 1120 * Insert the new entry into the list 1121 */ 1122 1123 vm_map_entry_link(map, prev_entry, new_entry); 1124 map->size += new_entry->end - new_entry->start; 1125 1126 /* 1127 * Update the free space hint. Entries cannot overlap. 1128 * An exact comparison is needed to avoid matching 1129 * against the map->header. 1130 */ 1131 if ((map->first_free == prev_entry) && 1132 (prev_entry->end == new_entry->start)) { 1133 map->first_free = new_entry; 1134 } 1135 1136 #if 0 1137 /* 1138 * Temporarily removed to avoid MAP_STACK panic, due to 1139 * MAP_STACK being a huge hack. Will be added back in 1140 * when MAP_STACK (and the user stack mapping) is fixed. 1141 */ 1142 /* 1143 * It may be possible to simplify the entry 1144 */ 1145 vm_map_simplify_entry(map, new_entry, countp); 1146 #endif 1147 1148 /* 1149 * Try to pre-populate the page table. Mappings governed by virtual 1150 * page tables cannot be prepopulated without a lot of work, so 1151 * don't try. 1152 */ 1153 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) && 1154 maptype != VM_MAPTYPE_VPAGETABLE && 1155 maptype != VM_MAPTYPE_UKSMAP) { 1156 int dorelock = 0; 1157 if (vm_map_relock_enable && (cow & MAP_PREFAULT_RELOCK)) { 1158 dorelock = 1; 1159 vm_object_lock_swap(); 1160 vm_object_drop(object); 1161 } 1162 pmap_object_init_pt(map->pmap, start, prot, 1163 object, OFF_TO_IDX(offset), end - start, 1164 cow & MAP_PREFAULT_PARTIAL); 1165 if (dorelock) { 1166 vm_object_hold(object); 1167 vm_object_lock_swap(); 1168 } 1169 } 1170 if (must_drop) 1171 vm_object_drop(object); 1172 1173 lwkt_reltoken(&map->token); 1174 return (KERN_SUCCESS); 1175 } 1176 1177 /* 1178 * Find sufficient space for `length' bytes in the given map, starting at 1179 * `start'. Returns 0 on success, 1 on no space. 1180 * 1181 * This function will returned an arbitrarily aligned pointer. If no 1182 * particular alignment is required you should pass align as 1. Note that 1183 * the map may return PAGE_SIZE aligned pointers if all the lengths used in 1184 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align 1185 * argument. 1186 * 1187 * 'align' should be a power of 2 but is not required to be. 1188 * 1189 * The map must be exclusively locked. 1190 * No other requirements. 1191 */ 1192 int 1193 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1194 vm_size_t align, int flags, vm_offset_t *addr) 1195 { 1196 vm_map_entry_t entry, next; 1197 vm_offset_t end; 1198 vm_offset_t align_mask; 1199 1200 if (start < map->min_offset) 1201 start = map->min_offset; 1202 if (start > map->max_offset) 1203 return (1); 1204 1205 /* 1206 * If the alignment is not a power of 2 we will have to use 1207 * a mod/division, set align_mask to a special value. 1208 */ 1209 if ((align | (align - 1)) + 1 != (align << 1)) 1210 align_mask = (vm_offset_t)-1; 1211 else 1212 align_mask = align - 1; 1213 1214 /* 1215 * Look for the first possible address; if there's already something 1216 * at this address, we have to start after it. 1217 */ 1218 if (start == map->min_offset) { 1219 if ((entry = map->first_free) != &map->header) 1220 start = entry->end; 1221 } else { 1222 vm_map_entry_t tmp; 1223 1224 if (vm_map_lookup_entry(map, start, &tmp)) 1225 start = tmp->end; 1226 entry = tmp; 1227 } 1228 1229 /* 1230 * Look through the rest of the map, trying to fit a new region in the 1231 * gap between existing regions, or after the very last region. 1232 */ 1233 for (;; start = (entry = next)->end) { 1234 /* 1235 * Adjust the proposed start by the requested alignment, 1236 * be sure that we didn't wrap the address. 1237 */ 1238 if (align_mask == (vm_offset_t)-1) 1239 end = ((start + align - 1) / align) * align; 1240 else 1241 end = (start + align_mask) & ~align_mask; 1242 if (end < start) 1243 return (1); 1244 start = end; 1245 /* 1246 * Find the end of the proposed new region. Be sure we didn't 1247 * go beyond the end of the map, or wrap around the address. 1248 * Then check to see if this is the last entry or if the 1249 * proposed end fits in the gap between this and the next 1250 * entry. 1251 */ 1252 end = start + length; 1253 if (end > map->max_offset || end < start) 1254 return (1); 1255 next = entry->next; 1256 1257 /* 1258 * If the next entry's start address is beyond the desired 1259 * end address we may have found a good entry. 1260 * 1261 * If the next entry is a stack mapping we do not map into 1262 * the stack's reserved space. 1263 * 1264 * XXX continue to allow mapping into the stack's reserved 1265 * space if doing a MAP_STACK mapping inside a MAP_STACK 1266 * mapping, for backwards compatibility. But the caller 1267 * really should use MAP_STACK | MAP_TRYFIXED if they 1268 * want to do that. 1269 */ 1270 if (next == &map->header) 1271 break; 1272 if (next->start >= end) { 1273 if ((next->eflags & MAP_ENTRY_STACK) == 0) 1274 break; 1275 if (flags & MAP_STACK) 1276 break; 1277 if (next->start - next->aux.avail_ssize >= end) 1278 break; 1279 } 1280 } 1281 map->hint = entry; 1282 1283 /* 1284 * Grow the kernel_map if necessary. pmap_growkernel() will panic 1285 * if it fails. The kernel_map is locked and nothing can steal 1286 * our address space if pmap_growkernel() blocks. 1287 * 1288 * NOTE: This may be unconditionally called for kldload areas on 1289 * x86_64 because these do not bump kernel_vm_end (which would 1290 * fill 128G worth of page tables!). Therefore we must not 1291 * retry. 1292 */ 1293 if (map == &kernel_map) { 1294 vm_offset_t kstop; 1295 1296 kstop = round_page(start + length); 1297 if (kstop > kernel_vm_end) 1298 pmap_growkernel(start, kstop); 1299 } 1300 *addr = start; 1301 return (0); 1302 } 1303 1304 /* 1305 * vm_map_find finds an unallocated region in the target address map with 1306 * the given length and allocates it. The search is defined to be first-fit 1307 * from the specified address; the region found is returned in the same 1308 * parameter. 1309 * 1310 * If object is non-NULL, ref count must be bumped by caller 1311 * prior to making call to account for the new entry. 1312 * 1313 * No requirements. This function will lock the map temporarily. 1314 */ 1315 int 1316 vm_map_find(vm_map_t map, void *map_object, void *map_aux, 1317 vm_ooffset_t offset, vm_offset_t *addr, 1318 vm_size_t length, vm_size_t align, 1319 boolean_t fitit, 1320 vm_maptype_t maptype, 1321 vm_prot_t prot, vm_prot_t max, 1322 int cow) 1323 { 1324 vm_offset_t start; 1325 vm_object_t object; 1326 int result; 1327 int count; 1328 1329 if (maptype == VM_MAPTYPE_UKSMAP) 1330 object = NULL; 1331 else 1332 object = map_object; 1333 1334 start = *addr; 1335 1336 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1337 vm_map_lock(map); 1338 if (object) 1339 vm_object_hold_shared(object); 1340 if (fitit) { 1341 if (vm_map_findspace(map, start, length, align, 0, addr)) { 1342 if (object) 1343 vm_object_drop(object); 1344 vm_map_unlock(map); 1345 vm_map_entry_release(count); 1346 return (KERN_NO_SPACE); 1347 } 1348 start = *addr; 1349 } 1350 result = vm_map_insert(map, &count, map_object, map_aux, 1351 offset, start, start + length, 1352 maptype, prot, max, cow); 1353 if (object) 1354 vm_object_drop(object); 1355 vm_map_unlock(map); 1356 vm_map_entry_release(count); 1357 1358 return (result); 1359 } 1360 1361 /* 1362 * Simplify the given map entry by merging with either neighbor. This 1363 * routine also has the ability to merge with both neighbors. 1364 * 1365 * This routine guarentees that the passed entry remains valid (though 1366 * possibly extended). When merging, this routine may delete one or 1367 * both neighbors. No action is taken on entries which have their 1368 * in-transition flag set. 1369 * 1370 * The map must be exclusively locked. 1371 */ 1372 void 1373 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp) 1374 { 1375 vm_map_entry_t next, prev; 1376 vm_size_t prevsize, esize; 1377 1378 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1379 ++mycpu->gd_cnt.v_intrans_coll; 1380 return; 1381 } 1382 1383 if (entry->maptype == VM_MAPTYPE_SUBMAP) 1384 return; 1385 if (entry->maptype == VM_MAPTYPE_UKSMAP) 1386 return; 1387 1388 prev = entry->prev; 1389 if (prev != &map->header) { 1390 prevsize = prev->end - prev->start; 1391 if ( (prev->end == entry->start) && 1392 (prev->maptype == entry->maptype) && 1393 (prev->object.vm_object == entry->object.vm_object) && 1394 (!prev->object.vm_object || 1395 (prev->offset + prevsize == entry->offset)) && 1396 (prev->eflags == entry->eflags) && 1397 (prev->protection == entry->protection) && 1398 (prev->max_protection == entry->max_protection) && 1399 (prev->inheritance == entry->inheritance) && 1400 (prev->wired_count == entry->wired_count)) { 1401 if (map->first_free == prev) 1402 map->first_free = entry; 1403 if (map->hint == prev) 1404 map->hint = entry; 1405 vm_map_entry_unlink(map, prev); 1406 entry->start = prev->start; 1407 entry->offset = prev->offset; 1408 if (prev->object.vm_object) 1409 vm_object_deallocate(prev->object.vm_object); 1410 vm_map_entry_dispose(map, prev, countp); 1411 } 1412 } 1413 1414 next = entry->next; 1415 if (next != &map->header) { 1416 esize = entry->end - entry->start; 1417 if ((entry->end == next->start) && 1418 (next->maptype == entry->maptype) && 1419 (next->object.vm_object == entry->object.vm_object) && 1420 (!entry->object.vm_object || 1421 (entry->offset + esize == next->offset)) && 1422 (next->eflags == entry->eflags) && 1423 (next->protection == entry->protection) && 1424 (next->max_protection == entry->max_protection) && 1425 (next->inheritance == entry->inheritance) && 1426 (next->wired_count == entry->wired_count)) { 1427 if (map->first_free == next) 1428 map->first_free = entry; 1429 if (map->hint == next) 1430 map->hint = entry; 1431 vm_map_entry_unlink(map, next); 1432 entry->end = next->end; 1433 if (next->object.vm_object) 1434 vm_object_deallocate(next->object.vm_object); 1435 vm_map_entry_dispose(map, next, countp); 1436 } 1437 } 1438 } 1439 1440 /* 1441 * Asserts that the given entry begins at or after the specified address. 1442 * If necessary, it splits the entry into two. 1443 */ 1444 #define vm_map_clip_start(map, entry, startaddr, countp) \ 1445 { \ 1446 if (startaddr > entry->start) \ 1447 _vm_map_clip_start(map, entry, startaddr, countp); \ 1448 } 1449 1450 /* 1451 * This routine is called only when it is known that the entry must be split. 1452 * 1453 * The map must be exclusively locked. 1454 */ 1455 static void 1456 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start, 1457 int *countp) 1458 { 1459 vm_map_entry_t new_entry; 1460 1461 /* 1462 * Split off the front portion -- note that we must insert the new 1463 * entry BEFORE this one, so that this entry has the specified 1464 * starting address. 1465 */ 1466 1467 vm_map_simplify_entry(map, entry, countp); 1468 1469 /* 1470 * If there is no object backing this entry, we might as well create 1471 * one now. If we defer it, an object can get created after the map 1472 * is clipped, and individual objects will be created for the split-up 1473 * map. This is a bit of a hack, but is also about the best place to 1474 * put this improvement. 1475 */ 1476 if (entry->object.vm_object == NULL && !map->system_map) { 1477 vm_map_entry_allocate_object(entry); 1478 } 1479 1480 new_entry = vm_map_entry_create(map, countp); 1481 *new_entry = *entry; 1482 1483 new_entry->end = start; 1484 entry->offset += (start - entry->start); 1485 entry->start = start; 1486 1487 vm_map_entry_link(map, entry->prev, new_entry); 1488 1489 switch(entry->maptype) { 1490 case VM_MAPTYPE_NORMAL: 1491 case VM_MAPTYPE_VPAGETABLE: 1492 if (new_entry->object.vm_object) { 1493 vm_object_hold(new_entry->object.vm_object); 1494 vm_object_chain_wait(new_entry->object.vm_object, 0); 1495 vm_object_reference_locked(new_entry->object.vm_object); 1496 vm_object_drop(new_entry->object.vm_object); 1497 } 1498 break; 1499 default: 1500 break; 1501 } 1502 } 1503 1504 /* 1505 * Asserts that the given entry ends at or before the specified address. 1506 * If necessary, it splits the entry into two. 1507 * 1508 * The map must be exclusively locked. 1509 */ 1510 #define vm_map_clip_end(map, entry, endaddr, countp) \ 1511 { \ 1512 if (endaddr < entry->end) \ 1513 _vm_map_clip_end(map, entry, endaddr, countp); \ 1514 } 1515 1516 /* 1517 * This routine is called only when it is known that the entry must be split. 1518 * 1519 * The map must be exclusively locked. 1520 */ 1521 static void 1522 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end, 1523 int *countp) 1524 { 1525 vm_map_entry_t new_entry; 1526 1527 /* 1528 * If there is no object backing this entry, we might as well create 1529 * one now. If we defer it, an object can get created after the map 1530 * is clipped, and individual objects will be created for the split-up 1531 * map. This is a bit of a hack, but is also about the best place to 1532 * put this improvement. 1533 */ 1534 1535 if (entry->object.vm_object == NULL && !map->system_map) { 1536 vm_map_entry_allocate_object(entry); 1537 } 1538 1539 /* 1540 * Create a new entry and insert it AFTER the specified entry 1541 */ 1542 1543 new_entry = vm_map_entry_create(map, countp); 1544 *new_entry = *entry; 1545 1546 new_entry->start = entry->end = end; 1547 new_entry->offset += (end - entry->start); 1548 1549 vm_map_entry_link(map, entry, new_entry); 1550 1551 switch(entry->maptype) { 1552 case VM_MAPTYPE_NORMAL: 1553 case VM_MAPTYPE_VPAGETABLE: 1554 if (new_entry->object.vm_object) { 1555 vm_object_hold(new_entry->object.vm_object); 1556 vm_object_chain_wait(new_entry->object.vm_object, 0); 1557 vm_object_reference_locked(new_entry->object.vm_object); 1558 vm_object_drop(new_entry->object.vm_object); 1559 } 1560 break; 1561 default: 1562 break; 1563 } 1564 } 1565 1566 /* 1567 * Asserts that the starting and ending region addresses fall within the 1568 * valid range for the map. 1569 */ 1570 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1571 { \ 1572 if (start < vm_map_min(map)) \ 1573 start = vm_map_min(map); \ 1574 if (end > vm_map_max(map)) \ 1575 end = vm_map_max(map); \ 1576 if (start > end) \ 1577 start = end; \ 1578 } 1579 1580 /* 1581 * Used to block when an in-transition collison occurs. The map 1582 * is unlocked for the sleep and relocked before the return. 1583 */ 1584 void 1585 vm_map_transition_wait(vm_map_t map) 1586 { 1587 tsleep_interlock(map, 0); 1588 vm_map_unlock(map); 1589 tsleep(map, PINTERLOCKED, "vment", 0); 1590 vm_map_lock(map); 1591 } 1592 1593 /* 1594 * When we do blocking operations with the map lock held it is 1595 * possible that a clip might have occured on our in-transit entry, 1596 * requiring an adjustment to the entry in our loop. These macros 1597 * help the pageable and clip_range code deal with the case. The 1598 * conditional costs virtually nothing if no clipping has occured. 1599 */ 1600 1601 #define CLIP_CHECK_BACK(entry, save_start) \ 1602 do { \ 1603 while (entry->start != save_start) { \ 1604 entry = entry->prev; \ 1605 KASSERT(entry != &map->header, ("bad entry clip")); \ 1606 } \ 1607 } while(0) 1608 1609 #define CLIP_CHECK_FWD(entry, save_end) \ 1610 do { \ 1611 while (entry->end != save_end) { \ 1612 entry = entry->next; \ 1613 KASSERT(entry != &map->header, ("bad entry clip")); \ 1614 } \ 1615 } while(0) 1616 1617 1618 /* 1619 * Clip the specified range and return the base entry. The 1620 * range may cover several entries starting at the returned base 1621 * and the first and last entry in the covering sequence will be 1622 * properly clipped to the requested start and end address. 1623 * 1624 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES 1625 * flag. 1626 * 1627 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries 1628 * covered by the requested range. 1629 * 1630 * The map must be exclusively locked on entry and will remain locked 1631 * on return. If no range exists or the range contains holes and you 1632 * specified that no holes were allowed, NULL will be returned. This 1633 * routine may temporarily unlock the map in order avoid a deadlock when 1634 * sleeping. 1635 */ 1636 static 1637 vm_map_entry_t 1638 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, 1639 int *countp, int flags) 1640 { 1641 vm_map_entry_t start_entry; 1642 vm_map_entry_t entry; 1643 1644 /* 1645 * Locate the entry and effect initial clipping. The in-transition 1646 * case does not occur very often so do not try to optimize it. 1647 */ 1648 again: 1649 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) 1650 return (NULL); 1651 entry = start_entry; 1652 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1653 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1654 ++mycpu->gd_cnt.v_intrans_coll; 1655 ++mycpu->gd_cnt.v_intrans_wait; 1656 vm_map_transition_wait(map); 1657 /* 1658 * entry and/or start_entry may have been clipped while 1659 * we slept, or may have gone away entirely. We have 1660 * to restart from the lookup. 1661 */ 1662 goto again; 1663 } 1664 1665 /* 1666 * Since we hold an exclusive map lock we do not have to restart 1667 * after clipping, even though clipping may block in zalloc. 1668 */ 1669 vm_map_clip_start(map, entry, start, countp); 1670 vm_map_clip_end(map, entry, end, countp); 1671 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1672 1673 /* 1674 * Scan entries covered by the range. When working on the next 1675 * entry a restart need only re-loop on the current entry which 1676 * we have already locked, since 'next' may have changed. Also, 1677 * even though entry is safe, it may have been clipped so we 1678 * have to iterate forwards through the clip after sleeping. 1679 */ 1680 while (entry->next != &map->header && entry->next->start < end) { 1681 vm_map_entry_t next = entry->next; 1682 1683 if (flags & MAP_CLIP_NO_HOLES) { 1684 if (next->start > entry->end) { 1685 vm_map_unclip_range(map, start_entry, 1686 start, entry->end, countp, flags); 1687 return(NULL); 1688 } 1689 } 1690 1691 if (next->eflags & MAP_ENTRY_IN_TRANSITION) { 1692 vm_offset_t save_end = entry->end; 1693 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1694 ++mycpu->gd_cnt.v_intrans_coll; 1695 ++mycpu->gd_cnt.v_intrans_wait; 1696 vm_map_transition_wait(map); 1697 1698 /* 1699 * clips might have occured while we blocked. 1700 */ 1701 CLIP_CHECK_FWD(entry, save_end); 1702 CLIP_CHECK_BACK(start_entry, start); 1703 continue; 1704 } 1705 /* 1706 * No restart necessary even though clip_end may block, we 1707 * are holding the map lock. 1708 */ 1709 vm_map_clip_end(map, next, end, countp); 1710 next->eflags |= MAP_ENTRY_IN_TRANSITION; 1711 entry = next; 1712 } 1713 if (flags & MAP_CLIP_NO_HOLES) { 1714 if (entry->end != end) { 1715 vm_map_unclip_range(map, start_entry, 1716 start, entry->end, countp, flags); 1717 return(NULL); 1718 } 1719 } 1720 return(start_entry); 1721 } 1722 1723 /* 1724 * Undo the effect of vm_map_clip_range(). You should pass the same 1725 * flags and the same range that you passed to vm_map_clip_range(). 1726 * This code will clear the in-transition flag on the entries and 1727 * wake up anyone waiting. This code will also simplify the sequence 1728 * and attempt to merge it with entries before and after the sequence. 1729 * 1730 * The map must be locked on entry and will remain locked on return. 1731 * 1732 * Note that you should also pass the start_entry returned by 1733 * vm_map_clip_range(). However, if you block between the two calls 1734 * with the map unlocked please be aware that the start_entry may 1735 * have been clipped and you may need to scan it backwards to find 1736 * the entry corresponding with the original start address. You are 1737 * responsible for this, vm_map_unclip_range() expects the correct 1738 * start_entry to be passed to it and will KASSERT otherwise. 1739 */ 1740 static 1741 void 1742 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry, 1743 vm_offset_t start, vm_offset_t end, 1744 int *countp, int flags) 1745 { 1746 vm_map_entry_t entry; 1747 1748 entry = start_entry; 1749 1750 KASSERT(entry->start == start, ("unclip_range: illegal base entry")); 1751 while (entry != &map->header && entry->start < end) { 1752 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1753 ("in-transition flag not set during unclip on: %p", 1754 entry)); 1755 KASSERT(entry->end <= end, 1756 ("unclip_range: tail wasn't clipped")); 1757 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1758 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1759 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1760 wakeup(map); 1761 } 1762 entry = entry->next; 1763 } 1764 1765 /* 1766 * Simplification does not block so there is no restart case. 1767 */ 1768 entry = start_entry; 1769 while (entry != &map->header && entry->start < end) { 1770 vm_map_simplify_entry(map, entry, countp); 1771 entry = entry->next; 1772 } 1773 } 1774 1775 /* 1776 * Mark the given range as handled by a subordinate map. 1777 * 1778 * This range must have been created with vm_map_find(), and no other 1779 * operations may have been performed on this range prior to calling 1780 * vm_map_submap(). 1781 * 1782 * Submappings cannot be removed. 1783 * 1784 * No requirements. 1785 */ 1786 int 1787 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) 1788 { 1789 vm_map_entry_t entry; 1790 int result = KERN_INVALID_ARGUMENT; 1791 int count; 1792 1793 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1794 vm_map_lock(map); 1795 1796 VM_MAP_RANGE_CHECK(map, start, end); 1797 1798 if (vm_map_lookup_entry(map, start, &entry)) { 1799 vm_map_clip_start(map, entry, start, &count); 1800 } else { 1801 entry = entry->next; 1802 } 1803 1804 vm_map_clip_end(map, entry, end, &count); 1805 1806 if ((entry->start == start) && (entry->end == end) && 1807 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1808 (entry->object.vm_object == NULL)) { 1809 entry->object.sub_map = submap; 1810 entry->maptype = VM_MAPTYPE_SUBMAP; 1811 result = KERN_SUCCESS; 1812 } 1813 vm_map_unlock(map); 1814 vm_map_entry_release(count); 1815 1816 return (result); 1817 } 1818 1819 /* 1820 * Sets the protection of the specified address region in the target map. 1821 * If "set_max" is specified, the maximum protection is to be set; 1822 * otherwise, only the current protection is affected. 1823 * 1824 * The protection is not applicable to submaps, but is applicable to normal 1825 * maps and maps governed by virtual page tables. For example, when operating 1826 * on a virtual page table our protection basically controls how COW occurs 1827 * on the backing object, whereas the virtual page table abstraction itself 1828 * is an abstraction for userland. 1829 * 1830 * No requirements. 1831 */ 1832 int 1833 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1834 vm_prot_t new_prot, boolean_t set_max) 1835 { 1836 vm_map_entry_t current; 1837 vm_map_entry_t entry; 1838 int count; 1839 1840 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1841 vm_map_lock(map); 1842 1843 VM_MAP_RANGE_CHECK(map, start, end); 1844 1845 if (vm_map_lookup_entry(map, start, &entry)) { 1846 vm_map_clip_start(map, entry, start, &count); 1847 } else { 1848 entry = entry->next; 1849 } 1850 1851 /* 1852 * Make a first pass to check for protection violations. 1853 */ 1854 current = entry; 1855 while ((current != &map->header) && (current->start < end)) { 1856 if (current->maptype == VM_MAPTYPE_SUBMAP) { 1857 vm_map_unlock(map); 1858 vm_map_entry_release(count); 1859 return (KERN_INVALID_ARGUMENT); 1860 } 1861 if ((new_prot & current->max_protection) != new_prot) { 1862 vm_map_unlock(map); 1863 vm_map_entry_release(count); 1864 return (KERN_PROTECTION_FAILURE); 1865 } 1866 current = current->next; 1867 } 1868 1869 /* 1870 * Go back and fix up protections. [Note that clipping is not 1871 * necessary the second time.] 1872 */ 1873 current = entry; 1874 1875 while ((current != &map->header) && (current->start < end)) { 1876 vm_prot_t old_prot; 1877 1878 vm_map_clip_end(map, current, end, &count); 1879 1880 old_prot = current->protection; 1881 if (set_max) { 1882 current->protection = 1883 (current->max_protection = new_prot) & 1884 old_prot; 1885 } else { 1886 current->protection = new_prot; 1887 } 1888 1889 /* 1890 * Update physical map if necessary. Worry about copy-on-write 1891 * here -- CHECK THIS XXX 1892 */ 1893 1894 if (current->protection != old_prot) { 1895 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1896 VM_PROT_ALL) 1897 1898 pmap_protect(map->pmap, current->start, 1899 current->end, 1900 current->protection & MASK(current)); 1901 #undef MASK 1902 } 1903 1904 vm_map_simplify_entry(map, current, &count); 1905 1906 current = current->next; 1907 } 1908 1909 vm_map_unlock(map); 1910 vm_map_entry_release(count); 1911 return (KERN_SUCCESS); 1912 } 1913 1914 /* 1915 * This routine traverses a processes map handling the madvise 1916 * system call. Advisories are classified as either those effecting 1917 * the vm_map_entry structure, or those effecting the underlying 1918 * objects. 1919 * 1920 * The <value> argument is used for extended madvise calls. 1921 * 1922 * No requirements. 1923 */ 1924 int 1925 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end, 1926 int behav, off_t value) 1927 { 1928 vm_map_entry_t current, entry; 1929 int modify_map = 0; 1930 int error = 0; 1931 int count; 1932 1933 /* 1934 * Some madvise calls directly modify the vm_map_entry, in which case 1935 * we need to use an exclusive lock on the map and we need to perform 1936 * various clipping operations. Otherwise we only need a read-lock 1937 * on the map. 1938 */ 1939 1940 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1941 1942 switch(behav) { 1943 case MADV_NORMAL: 1944 case MADV_SEQUENTIAL: 1945 case MADV_RANDOM: 1946 case MADV_NOSYNC: 1947 case MADV_AUTOSYNC: 1948 case MADV_NOCORE: 1949 case MADV_CORE: 1950 case MADV_SETMAP: 1951 case MADV_INVAL: 1952 modify_map = 1; 1953 vm_map_lock(map); 1954 break; 1955 case MADV_WILLNEED: 1956 case MADV_DONTNEED: 1957 case MADV_FREE: 1958 vm_map_lock_read(map); 1959 break; 1960 default: 1961 vm_map_entry_release(count); 1962 return (EINVAL); 1963 } 1964 1965 /* 1966 * Locate starting entry and clip if necessary. 1967 */ 1968 1969 VM_MAP_RANGE_CHECK(map, start, end); 1970 1971 if (vm_map_lookup_entry(map, start, &entry)) { 1972 if (modify_map) 1973 vm_map_clip_start(map, entry, start, &count); 1974 } else { 1975 entry = entry->next; 1976 } 1977 1978 if (modify_map) { 1979 /* 1980 * madvise behaviors that are implemented in the vm_map_entry. 1981 * 1982 * We clip the vm_map_entry so that behavioral changes are 1983 * limited to the specified address range. 1984 */ 1985 for (current = entry; 1986 (current != &map->header) && (current->start < end); 1987 current = current->next 1988 ) { 1989 if (current->maptype == VM_MAPTYPE_SUBMAP) 1990 continue; 1991 1992 vm_map_clip_end(map, current, end, &count); 1993 1994 switch (behav) { 1995 case MADV_NORMAL: 1996 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1997 break; 1998 case MADV_SEQUENTIAL: 1999 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 2000 break; 2001 case MADV_RANDOM: 2002 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 2003 break; 2004 case MADV_NOSYNC: 2005 current->eflags |= MAP_ENTRY_NOSYNC; 2006 break; 2007 case MADV_AUTOSYNC: 2008 current->eflags &= ~MAP_ENTRY_NOSYNC; 2009 break; 2010 case MADV_NOCORE: 2011 current->eflags |= MAP_ENTRY_NOCOREDUMP; 2012 break; 2013 case MADV_CORE: 2014 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2015 break; 2016 case MADV_INVAL: 2017 /* 2018 * Invalidate the related pmap entries, used 2019 * to flush portions of the real kernel's 2020 * pmap when the caller has removed or 2021 * modified existing mappings in a virtual 2022 * page table. 2023 */ 2024 pmap_remove(map->pmap, 2025 current->start, current->end); 2026 break; 2027 case MADV_SETMAP: 2028 /* 2029 * Set the page directory page for a map 2030 * governed by a virtual page table. Mark 2031 * the entry as being governed by a virtual 2032 * page table if it is not. 2033 * 2034 * XXX the page directory page is stored 2035 * in the avail_ssize field if the map_entry. 2036 * 2037 * XXX the map simplification code does not 2038 * compare this field so weird things may 2039 * happen if you do not apply this function 2040 * to the entire mapping governed by the 2041 * virtual page table. 2042 */ 2043 if (current->maptype != VM_MAPTYPE_VPAGETABLE) { 2044 error = EINVAL; 2045 break; 2046 } 2047 current->aux.master_pde = value; 2048 pmap_remove(map->pmap, 2049 current->start, current->end); 2050 break; 2051 default: 2052 error = EINVAL; 2053 break; 2054 } 2055 vm_map_simplify_entry(map, current, &count); 2056 } 2057 vm_map_unlock(map); 2058 } else { 2059 vm_pindex_t pindex; 2060 int count; 2061 2062 /* 2063 * madvise behaviors that are implemented in the underlying 2064 * vm_object. 2065 * 2066 * Since we don't clip the vm_map_entry, we have to clip 2067 * the vm_object pindex and count. 2068 * 2069 * NOTE! We currently do not support these functions on 2070 * virtual page tables. 2071 */ 2072 for (current = entry; 2073 (current != &map->header) && (current->start < end); 2074 current = current->next 2075 ) { 2076 vm_offset_t useStart; 2077 2078 if (current->maptype != VM_MAPTYPE_NORMAL) 2079 continue; 2080 2081 pindex = OFF_TO_IDX(current->offset); 2082 count = atop(current->end - current->start); 2083 useStart = current->start; 2084 2085 if (current->start < start) { 2086 pindex += atop(start - current->start); 2087 count -= atop(start - current->start); 2088 useStart = start; 2089 } 2090 if (current->end > end) 2091 count -= atop(current->end - end); 2092 2093 if (count <= 0) 2094 continue; 2095 2096 vm_object_madvise(current->object.vm_object, 2097 pindex, count, behav); 2098 2099 /* 2100 * Try to populate the page table. Mappings governed 2101 * by virtual page tables cannot be pre-populated 2102 * without a lot of work so don't try. 2103 */ 2104 if (behav == MADV_WILLNEED && 2105 current->maptype != VM_MAPTYPE_VPAGETABLE) { 2106 pmap_object_init_pt( 2107 map->pmap, 2108 useStart, 2109 current->protection, 2110 current->object.vm_object, 2111 pindex, 2112 (count << PAGE_SHIFT), 2113 MAP_PREFAULT_MADVISE 2114 ); 2115 } 2116 } 2117 vm_map_unlock_read(map); 2118 } 2119 vm_map_entry_release(count); 2120 return(error); 2121 } 2122 2123 2124 /* 2125 * Sets the inheritance of the specified address range in the target map. 2126 * Inheritance affects how the map will be shared with child maps at the 2127 * time of vm_map_fork. 2128 */ 2129 int 2130 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2131 vm_inherit_t new_inheritance) 2132 { 2133 vm_map_entry_t entry; 2134 vm_map_entry_t temp_entry; 2135 int count; 2136 2137 switch (new_inheritance) { 2138 case VM_INHERIT_NONE: 2139 case VM_INHERIT_COPY: 2140 case VM_INHERIT_SHARE: 2141 break; 2142 default: 2143 return (KERN_INVALID_ARGUMENT); 2144 } 2145 2146 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2147 vm_map_lock(map); 2148 2149 VM_MAP_RANGE_CHECK(map, start, end); 2150 2151 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2152 entry = temp_entry; 2153 vm_map_clip_start(map, entry, start, &count); 2154 } else 2155 entry = temp_entry->next; 2156 2157 while ((entry != &map->header) && (entry->start < end)) { 2158 vm_map_clip_end(map, entry, end, &count); 2159 2160 entry->inheritance = new_inheritance; 2161 2162 vm_map_simplify_entry(map, entry, &count); 2163 2164 entry = entry->next; 2165 } 2166 vm_map_unlock(map); 2167 vm_map_entry_release(count); 2168 return (KERN_SUCCESS); 2169 } 2170 2171 /* 2172 * Implement the semantics of mlock 2173 */ 2174 int 2175 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, 2176 boolean_t new_pageable) 2177 { 2178 vm_map_entry_t entry; 2179 vm_map_entry_t start_entry; 2180 vm_offset_t end; 2181 int rv = KERN_SUCCESS; 2182 int count; 2183 2184 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2185 vm_map_lock(map); 2186 VM_MAP_RANGE_CHECK(map, start, real_end); 2187 end = real_end; 2188 2189 start_entry = vm_map_clip_range(map, start, end, &count, 2190 MAP_CLIP_NO_HOLES); 2191 if (start_entry == NULL) { 2192 vm_map_unlock(map); 2193 vm_map_entry_release(count); 2194 return (KERN_INVALID_ADDRESS); 2195 } 2196 2197 if (new_pageable == 0) { 2198 entry = start_entry; 2199 while ((entry != &map->header) && (entry->start < end)) { 2200 vm_offset_t save_start; 2201 vm_offset_t save_end; 2202 2203 /* 2204 * Already user wired or hard wired (trivial cases) 2205 */ 2206 if (entry->eflags & MAP_ENTRY_USER_WIRED) { 2207 entry = entry->next; 2208 continue; 2209 } 2210 if (entry->wired_count != 0) { 2211 entry->wired_count++; 2212 entry->eflags |= MAP_ENTRY_USER_WIRED; 2213 entry = entry->next; 2214 continue; 2215 } 2216 2217 /* 2218 * A new wiring requires instantiation of appropriate 2219 * management structures and the faulting in of the 2220 * page. 2221 */ 2222 if (entry->maptype == VM_MAPTYPE_NORMAL || 2223 entry->maptype == VM_MAPTYPE_VPAGETABLE) { 2224 int copyflag = entry->eflags & 2225 MAP_ENTRY_NEEDS_COPY; 2226 if (copyflag && ((entry->protection & 2227 VM_PROT_WRITE) != 0)) { 2228 vm_map_entry_shadow(entry, 0); 2229 } else if (entry->object.vm_object == NULL && 2230 !map->system_map) { 2231 vm_map_entry_allocate_object(entry); 2232 } 2233 } 2234 entry->wired_count++; 2235 entry->eflags |= MAP_ENTRY_USER_WIRED; 2236 2237 /* 2238 * Now fault in the area. Note that vm_fault_wire() 2239 * may release the map lock temporarily, it will be 2240 * relocked on return. The in-transition 2241 * flag protects the entries. 2242 */ 2243 save_start = entry->start; 2244 save_end = entry->end; 2245 rv = vm_fault_wire(map, entry, TRUE, 0); 2246 if (rv) { 2247 CLIP_CHECK_BACK(entry, save_start); 2248 for (;;) { 2249 KASSERT(entry->wired_count == 1, ("bad wired_count on entry")); 2250 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2251 entry->wired_count = 0; 2252 if (entry->end == save_end) 2253 break; 2254 entry = entry->next; 2255 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2256 } 2257 end = save_start; /* unwire the rest */ 2258 break; 2259 } 2260 /* 2261 * note that even though the entry might have been 2262 * clipped, the USER_WIRED flag we set prevents 2263 * duplication so we do not have to do a 2264 * clip check. 2265 */ 2266 entry = entry->next; 2267 } 2268 2269 /* 2270 * If we failed fall through to the unwiring section to 2271 * unwire what we had wired so far. 'end' has already 2272 * been adjusted. 2273 */ 2274 if (rv) 2275 new_pageable = 1; 2276 2277 /* 2278 * start_entry might have been clipped if we unlocked the 2279 * map and blocked. No matter how clipped it has gotten 2280 * there should be a fragment that is on our start boundary. 2281 */ 2282 CLIP_CHECK_BACK(start_entry, start); 2283 } 2284 2285 /* 2286 * Deal with the unwiring case. 2287 */ 2288 if (new_pageable) { 2289 /* 2290 * This is the unwiring case. We must first ensure that the 2291 * range to be unwired is really wired down. We know there 2292 * are no holes. 2293 */ 2294 entry = start_entry; 2295 while ((entry != &map->header) && (entry->start < end)) { 2296 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2297 rv = KERN_INVALID_ARGUMENT; 2298 goto done; 2299 } 2300 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry)); 2301 entry = entry->next; 2302 } 2303 2304 /* 2305 * Now decrement the wiring count for each region. If a region 2306 * becomes completely unwired, unwire its physical pages and 2307 * mappings. 2308 */ 2309 /* 2310 * The map entries are processed in a loop, checking to 2311 * make sure the entry is wired and asserting it has a wired 2312 * count. However, another loop was inserted more-or-less in 2313 * the middle of the unwiring path. This loop picks up the 2314 * "entry" loop variable from the first loop without first 2315 * setting it to start_entry. Naturally, the secound loop 2316 * is never entered and the pages backing the entries are 2317 * never unwired. This can lead to a leak of wired pages. 2318 */ 2319 entry = start_entry; 2320 while ((entry != &map->header) && (entry->start < end)) { 2321 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, 2322 ("expected USER_WIRED on entry %p", entry)); 2323 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2324 entry->wired_count--; 2325 if (entry->wired_count == 0) 2326 vm_fault_unwire(map, entry); 2327 entry = entry->next; 2328 } 2329 } 2330 done: 2331 vm_map_unclip_range(map, start_entry, start, real_end, &count, 2332 MAP_CLIP_NO_HOLES); 2333 map->timestamp++; 2334 vm_map_unlock(map); 2335 vm_map_entry_release(count); 2336 return (rv); 2337 } 2338 2339 /* 2340 * Sets the pageability of the specified address range in the target map. 2341 * Regions specified as not pageable require locked-down physical 2342 * memory and physical page maps. 2343 * 2344 * The map must not be locked, but a reference must remain to the map 2345 * throughout the call. 2346 * 2347 * This function may be called via the zalloc path and must properly 2348 * reserve map entries for kernel_map. 2349 * 2350 * No requirements. 2351 */ 2352 int 2353 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags) 2354 { 2355 vm_map_entry_t entry; 2356 vm_map_entry_t start_entry; 2357 vm_offset_t end; 2358 int rv = KERN_SUCCESS; 2359 int count; 2360 2361 if (kmflags & KM_KRESERVE) 2362 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT); 2363 else 2364 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2365 vm_map_lock(map); 2366 VM_MAP_RANGE_CHECK(map, start, real_end); 2367 end = real_end; 2368 2369 start_entry = vm_map_clip_range(map, start, end, &count, 2370 MAP_CLIP_NO_HOLES); 2371 if (start_entry == NULL) { 2372 vm_map_unlock(map); 2373 rv = KERN_INVALID_ADDRESS; 2374 goto failure; 2375 } 2376 if ((kmflags & KM_PAGEABLE) == 0) { 2377 /* 2378 * Wiring. 2379 * 2380 * 1. Holding the write lock, we create any shadow or zero-fill 2381 * objects that need to be created. Then we clip each map 2382 * entry to the region to be wired and increment its wiring 2383 * count. We create objects before clipping the map entries 2384 * to avoid object proliferation. 2385 * 2386 * 2. We downgrade to a read lock, and call vm_fault_wire to 2387 * fault in the pages for any newly wired area (wired_count is 2388 * 1). 2389 * 2390 * Downgrading to a read lock for vm_fault_wire avoids a 2391 * possible deadlock with another process that may have faulted 2392 * on one of the pages to be wired (it would mark the page busy, 2393 * blocking us, then in turn block on the map lock that we 2394 * hold). Because of problems in the recursive lock package, 2395 * we cannot upgrade to a write lock in vm_map_lookup. Thus, 2396 * any actions that require the write lock must be done 2397 * beforehand. Because we keep the read lock on the map, the 2398 * copy-on-write status of the entries we modify here cannot 2399 * change. 2400 */ 2401 entry = start_entry; 2402 while ((entry != &map->header) && (entry->start < end)) { 2403 /* 2404 * Trivial case if the entry is already wired 2405 */ 2406 if (entry->wired_count) { 2407 entry->wired_count++; 2408 entry = entry->next; 2409 continue; 2410 } 2411 2412 /* 2413 * The entry is being newly wired, we have to setup 2414 * appropriate management structures. A shadow 2415 * object is required for a copy-on-write region, 2416 * or a normal object for a zero-fill region. We 2417 * do not have to do this for entries that point to sub 2418 * maps because we won't hold the lock on the sub map. 2419 */ 2420 if (entry->maptype == VM_MAPTYPE_NORMAL || 2421 entry->maptype == VM_MAPTYPE_VPAGETABLE) { 2422 int copyflag = entry->eflags & 2423 MAP_ENTRY_NEEDS_COPY; 2424 if (copyflag && ((entry->protection & 2425 VM_PROT_WRITE) != 0)) { 2426 vm_map_entry_shadow(entry, 0); 2427 } else if (entry->object.vm_object == NULL && 2428 !map->system_map) { 2429 vm_map_entry_allocate_object(entry); 2430 } 2431 } 2432 2433 entry->wired_count++; 2434 entry = entry->next; 2435 } 2436 2437 /* 2438 * Pass 2. 2439 */ 2440 2441 /* 2442 * HACK HACK HACK HACK 2443 * 2444 * vm_fault_wire() temporarily unlocks the map to avoid 2445 * deadlocks. The in-transition flag from vm_map_clip_range 2446 * call should protect us from changes while the map is 2447 * unlocked. T 2448 * 2449 * NOTE: Previously this comment stated that clipping might 2450 * still occur while the entry is unlocked, but from 2451 * what I can tell it actually cannot. 2452 * 2453 * It is unclear whether the CLIP_CHECK_*() calls 2454 * are still needed but we keep them in anyway. 2455 * 2456 * HACK HACK HACK HACK 2457 */ 2458 2459 entry = start_entry; 2460 while (entry != &map->header && entry->start < end) { 2461 /* 2462 * If vm_fault_wire fails for any page we need to undo 2463 * what has been done. We decrement the wiring count 2464 * for those pages which have not yet been wired (now) 2465 * and unwire those that have (later). 2466 */ 2467 vm_offset_t save_start = entry->start; 2468 vm_offset_t save_end = entry->end; 2469 2470 if (entry->wired_count == 1) 2471 rv = vm_fault_wire(map, entry, FALSE, kmflags); 2472 if (rv) { 2473 CLIP_CHECK_BACK(entry, save_start); 2474 for (;;) { 2475 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly")); 2476 entry->wired_count = 0; 2477 if (entry->end == save_end) 2478 break; 2479 entry = entry->next; 2480 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2481 } 2482 end = save_start; 2483 break; 2484 } 2485 CLIP_CHECK_FWD(entry, save_end); 2486 entry = entry->next; 2487 } 2488 2489 /* 2490 * If a failure occured undo everything by falling through 2491 * to the unwiring code. 'end' has already been adjusted 2492 * appropriately. 2493 */ 2494 if (rv) 2495 kmflags |= KM_PAGEABLE; 2496 2497 /* 2498 * start_entry is still IN_TRANSITION but may have been 2499 * clipped since vm_fault_wire() unlocks and relocks the 2500 * map. No matter how clipped it has gotten there should 2501 * be a fragment that is on our start boundary. 2502 */ 2503 CLIP_CHECK_BACK(start_entry, start); 2504 } 2505 2506 if (kmflags & KM_PAGEABLE) { 2507 /* 2508 * This is the unwiring case. We must first ensure that the 2509 * range to be unwired is really wired down. We know there 2510 * are no holes. 2511 */ 2512 entry = start_entry; 2513 while ((entry != &map->header) && (entry->start < end)) { 2514 if (entry->wired_count == 0) { 2515 rv = KERN_INVALID_ARGUMENT; 2516 goto done; 2517 } 2518 entry = entry->next; 2519 } 2520 2521 /* 2522 * Now decrement the wiring count for each region. If a region 2523 * becomes completely unwired, unwire its physical pages and 2524 * mappings. 2525 */ 2526 entry = start_entry; 2527 while ((entry != &map->header) && (entry->start < end)) { 2528 entry->wired_count--; 2529 if (entry->wired_count == 0) 2530 vm_fault_unwire(map, entry); 2531 entry = entry->next; 2532 } 2533 } 2534 done: 2535 vm_map_unclip_range(map, start_entry, start, real_end, 2536 &count, MAP_CLIP_NO_HOLES); 2537 map->timestamp++; 2538 vm_map_unlock(map); 2539 failure: 2540 if (kmflags & KM_KRESERVE) 2541 vm_map_entry_krelease(count); 2542 else 2543 vm_map_entry_release(count); 2544 return (rv); 2545 } 2546 2547 /* 2548 * Mark a newly allocated address range as wired but do not fault in 2549 * the pages. The caller is expected to load the pages into the object. 2550 * 2551 * The map must be locked on entry and will remain locked on return. 2552 * No other requirements. 2553 */ 2554 void 2555 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size, 2556 int *countp) 2557 { 2558 vm_map_entry_t scan; 2559 vm_map_entry_t entry; 2560 2561 entry = vm_map_clip_range(map, addr, addr + size, 2562 countp, MAP_CLIP_NO_HOLES); 2563 for (scan = entry; 2564 scan != &map->header && scan->start < addr + size; 2565 scan = scan->next) { 2566 KKASSERT(scan->wired_count == 0); 2567 scan->wired_count = 1; 2568 } 2569 vm_map_unclip_range(map, entry, addr, addr + size, 2570 countp, MAP_CLIP_NO_HOLES); 2571 } 2572 2573 /* 2574 * Push any dirty cached pages in the address range to their pager. 2575 * If syncio is TRUE, dirty pages are written synchronously. 2576 * If invalidate is TRUE, any cached pages are freed as well. 2577 * 2578 * This routine is called by sys_msync() 2579 * 2580 * Returns an error if any part of the specified range is not mapped. 2581 * 2582 * No requirements. 2583 */ 2584 int 2585 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end, 2586 boolean_t syncio, boolean_t invalidate) 2587 { 2588 vm_map_entry_t current; 2589 vm_map_entry_t entry; 2590 vm_size_t size; 2591 vm_object_t object; 2592 vm_object_t tobj; 2593 vm_ooffset_t offset; 2594 2595 vm_map_lock_read(map); 2596 VM_MAP_RANGE_CHECK(map, start, end); 2597 if (!vm_map_lookup_entry(map, start, &entry)) { 2598 vm_map_unlock_read(map); 2599 return (KERN_INVALID_ADDRESS); 2600 } 2601 lwkt_gettoken(&map->token); 2602 2603 /* 2604 * Make a first pass to check for holes. 2605 */ 2606 for (current = entry; current->start < end; current = current->next) { 2607 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2608 lwkt_reltoken(&map->token); 2609 vm_map_unlock_read(map); 2610 return (KERN_INVALID_ARGUMENT); 2611 } 2612 if (end > current->end && 2613 (current->next == &map->header || 2614 current->end != current->next->start)) { 2615 lwkt_reltoken(&map->token); 2616 vm_map_unlock_read(map); 2617 return (KERN_INVALID_ADDRESS); 2618 } 2619 } 2620 2621 if (invalidate) 2622 pmap_remove(vm_map_pmap(map), start, end); 2623 2624 /* 2625 * Make a second pass, cleaning/uncaching pages from the indicated 2626 * objects as we go. 2627 */ 2628 for (current = entry; current->start < end; current = current->next) { 2629 offset = current->offset + (start - current->start); 2630 size = (end <= current->end ? end : current->end) - start; 2631 2632 switch(current->maptype) { 2633 case VM_MAPTYPE_SUBMAP: 2634 { 2635 vm_map_t smap; 2636 vm_map_entry_t tentry; 2637 vm_size_t tsize; 2638 2639 smap = current->object.sub_map; 2640 vm_map_lock_read(smap); 2641 vm_map_lookup_entry(smap, offset, &tentry); 2642 tsize = tentry->end - offset; 2643 if (tsize < size) 2644 size = tsize; 2645 object = tentry->object.vm_object; 2646 offset = tentry->offset + (offset - tentry->start); 2647 vm_map_unlock_read(smap); 2648 break; 2649 } 2650 case VM_MAPTYPE_NORMAL: 2651 case VM_MAPTYPE_VPAGETABLE: 2652 object = current->object.vm_object; 2653 break; 2654 default: 2655 object = NULL; 2656 break; 2657 } 2658 2659 if (object) 2660 vm_object_hold(object); 2661 2662 /* 2663 * Note that there is absolutely no sense in writing out 2664 * anonymous objects, so we track down the vnode object 2665 * to write out. 2666 * We invalidate (remove) all pages from the address space 2667 * anyway, for semantic correctness. 2668 * 2669 * note: certain anonymous maps, such as MAP_NOSYNC maps, 2670 * may start out with a NULL object. 2671 */ 2672 while (object && (tobj = object->backing_object) != NULL) { 2673 vm_object_hold(tobj); 2674 if (tobj == object->backing_object) { 2675 vm_object_lock_swap(); 2676 offset += object->backing_object_offset; 2677 vm_object_drop(object); 2678 object = tobj; 2679 if (object->size < OFF_TO_IDX(offset + size)) 2680 size = IDX_TO_OFF(object->size) - 2681 offset; 2682 break; 2683 } 2684 vm_object_drop(tobj); 2685 } 2686 if (object && (object->type == OBJT_VNODE) && 2687 (current->protection & VM_PROT_WRITE) && 2688 (object->flags & OBJ_NOMSYNC) == 0) { 2689 /* 2690 * Flush pages if writing is allowed, invalidate them 2691 * if invalidation requested. Pages undergoing I/O 2692 * will be ignored by vm_object_page_remove(). 2693 * 2694 * We cannot lock the vnode and then wait for paging 2695 * to complete without deadlocking against vm_fault. 2696 * Instead we simply call vm_object_page_remove() and 2697 * allow it to block internally on a page-by-page 2698 * basis when it encounters pages undergoing async 2699 * I/O. 2700 */ 2701 int flags; 2702 2703 /* no chain wait needed for vnode objects */ 2704 vm_object_reference_locked(object); 2705 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY); 2706 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 2707 flags |= invalidate ? OBJPC_INVAL : 0; 2708 2709 /* 2710 * When operating on a virtual page table just 2711 * flush the whole object. XXX we probably ought 2712 * to 2713 */ 2714 switch(current->maptype) { 2715 case VM_MAPTYPE_NORMAL: 2716 vm_object_page_clean(object, 2717 OFF_TO_IDX(offset), 2718 OFF_TO_IDX(offset + size + PAGE_MASK), 2719 flags); 2720 break; 2721 case VM_MAPTYPE_VPAGETABLE: 2722 vm_object_page_clean(object, 0, 0, flags); 2723 break; 2724 } 2725 vn_unlock(((struct vnode *)object->handle)); 2726 vm_object_deallocate_locked(object); 2727 } 2728 if (object && invalidate && 2729 ((object->type == OBJT_VNODE) || 2730 (object->type == OBJT_DEVICE) || 2731 (object->type == OBJT_MGTDEVICE))) { 2732 int clean_only = 2733 ((object->type == OBJT_DEVICE) || 2734 (object->type == OBJT_MGTDEVICE)) ? FALSE : TRUE; 2735 /* no chain wait needed for vnode/device objects */ 2736 vm_object_reference_locked(object); 2737 switch(current->maptype) { 2738 case VM_MAPTYPE_NORMAL: 2739 vm_object_page_remove(object, 2740 OFF_TO_IDX(offset), 2741 OFF_TO_IDX(offset + size + PAGE_MASK), 2742 clean_only); 2743 break; 2744 case VM_MAPTYPE_VPAGETABLE: 2745 vm_object_page_remove(object, 0, 0, clean_only); 2746 break; 2747 } 2748 vm_object_deallocate_locked(object); 2749 } 2750 start += size; 2751 if (object) 2752 vm_object_drop(object); 2753 } 2754 2755 lwkt_reltoken(&map->token); 2756 vm_map_unlock_read(map); 2757 2758 return (KERN_SUCCESS); 2759 } 2760 2761 /* 2762 * Make the region specified by this entry pageable. 2763 * 2764 * The vm_map must be exclusively locked. 2765 */ 2766 static void 2767 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2768 { 2769 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2770 entry->wired_count = 0; 2771 vm_fault_unwire(map, entry); 2772 } 2773 2774 /* 2775 * Deallocate the given entry from the target map. 2776 * 2777 * The vm_map must be exclusively locked. 2778 */ 2779 static void 2780 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp) 2781 { 2782 vm_map_entry_unlink(map, entry); 2783 map->size -= entry->end - entry->start; 2784 2785 switch(entry->maptype) { 2786 case VM_MAPTYPE_NORMAL: 2787 case VM_MAPTYPE_VPAGETABLE: 2788 case VM_MAPTYPE_SUBMAP: 2789 vm_object_deallocate(entry->object.vm_object); 2790 break; 2791 case VM_MAPTYPE_UKSMAP: 2792 /* XXX TODO */ 2793 break; 2794 default: 2795 break; 2796 } 2797 2798 vm_map_entry_dispose(map, entry, countp); 2799 } 2800 2801 /* 2802 * Deallocates the given address range from the target map. 2803 * 2804 * The vm_map must be exclusively locked. 2805 */ 2806 int 2807 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp) 2808 { 2809 vm_object_t object; 2810 vm_map_entry_t entry; 2811 vm_map_entry_t first_entry; 2812 2813 ASSERT_VM_MAP_LOCKED(map); 2814 lwkt_gettoken(&map->token); 2815 again: 2816 /* 2817 * Find the start of the region, and clip it. Set entry to point 2818 * at the first record containing the requested address or, if no 2819 * such record exists, the next record with a greater address. The 2820 * loop will run from this point until a record beyond the termination 2821 * address is encountered. 2822 * 2823 * map->hint must be adjusted to not point to anything we delete, 2824 * so set it to the entry prior to the one being deleted. 2825 * 2826 * GGG see other GGG comment. 2827 */ 2828 if (vm_map_lookup_entry(map, start, &first_entry)) { 2829 entry = first_entry; 2830 vm_map_clip_start(map, entry, start, countp); 2831 map->hint = entry->prev; /* possible problem XXX */ 2832 } else { 2833 map->hint = first_entry; /* possible problem XXX */ 2834 entry = first_entry->next; 2835 } 2836 2837 /* 2838 * If a hole opens up prior to the current first_free then 2839 * adjust first_free. As with map->hint, map->first_free 2840 * cannot be left set to anything we might delete. 2841 */ 2842 if (entry == &map->header) { 2843 map->first_free = &map->header; 2844 } else if (map->first_free->start >= start) { 2845 map->first_free = entry->prev; 2846 } 2847 2848 /* 2849 * Step through all entries in this region 2850 */ 2851 while ((entry != &map->header) && (entry->start < end)) { 2852 vm_map_entry_t next; 2853 vm_offset_t s, e; 2854 vm_pindex_t offidxstart, offidxend, count; 2855 2856 /* 2857 * If we hit an in-transition entry we have to sleep and 2858 * retry. It's easier (and not really slower) to just retry 2859 * since this case occurs so rarely and the hint is already 2860 * pointing at the right place. We have to reset the 2861 * start offset so as not to accidently delete an entry 2862 * another process just created in vacated space. 2863 */ 2864 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2865 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2866 start = entry->start; 2867 ++mycpu->gd_cnt.v_intrans_coll; 2868 ++mycpu->gd_cnt.v_intrans_wait; 2869 vm_map_transition_wait(map); 2870 goto again; 2871 } 2872 vm_map_clip_end(map, entry, end, countp); 2873 2874 s = entry->start; 2875 e = entry->end; 2876 next = entry->next; 2877 2878 offidxstart = OFF_TO_IDX(entry->offset); 2879 count = OFF_TO_IDX(e - s); 2880 2881 switch(entry->maptype) { 2882 case VM_MAPTYPE_NORMAL: 2883 case VM_MAPTYPE_VPAGETABLE: 2884 case VM_MAPTYPE_SUBMAP: 2885 object = entry->object.vm_object; 2886 break; 2887 default: 2888 object = NULL; 2889 break; 2890 } 2891 2892 /* 2893 * Unwire before removing addresses from the pmap; otherwise, 2894 * unwiring will put the entries back in the pmap. 2895 */ 2896 if (entry->wired_count != 0) 2897 vm_map_entry_unwire(map, entry); 2898 2899 offidxend = offidxstart + count; 2900 2901 if (object == &kernel_object) { 2902 vm_object_hold(object); 2903 vm_object_page_remove(object, offidxstart, 2904 offidxend, FALSE); 2905 vm_object_drop(object); 2906 } else if (object && object->type != OBJT_DEFAULT && 2907 object->type != OBJT_SWAP) { 2908 /* 2909 * vnode object routines cannot be chain-locked, 2910 * but since we aren't removing pages from the 2911 * object here we can use a shared hold. 2912 */ 2913 vm_object_hold_shared(object); 2914 pmap_remove(map->pmap, s, e); 2915 vm_object_drop(object); 2916 } else if (object) { 2917 vm_object_hold(object); 2918 vm_object_chain_acquire(object, 0); 2919 pmap_remove(map->pmap, s, e); 2920 2921 if (object != NULL && 2922 object->ref_count != 1 && 2923 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == 2924 OBJ_ONEMAPPING && 2925 (object->type == OBJT_DEFAULT || 2926 object->type == OBJT_SWAP)) { 2927 vm_object_collapse(object, NULL); 2928 vm_object_page_remove(object, offidxstart, 2929 offidxend, FALSE); 2930 if (object->type == OBJT_SWAP) { 2931 swap_pager_freespace(object, 2932 offidxstart, 2933 count); 2934 } 2935 if (offidxend >= object->size && 2936 offidxstart < object->size) { 2937 object->size = offidxstart; 2938 } 2939 } 2940 vm_object_chain_release(object); 2941 vm_object_drop(object); 2942 } else if (entry->maptype == VM_MAPTYPE_UKSMAP) { 2943 pmap_remove(map->pmap, s, e); 2944 } 2945 2946 /* 2947 * Delete the entry (which may delete the object) only after 2948 * removing all pmap entries pointing to its pages. 2949 * (Otherwise, its page frames may be reallocated, and any 2950 * modify bits will be set in the wrong object!) 2951 */ 2952 vm_map_entry_delete(map, entry, countp); 2953 entry = next; 2954 } 2955 lwkt_reltoken(&map->token); 2956 return (KERN_SUCCESS); 2957 } 2958 2959 /* 2960 * Remove the given address range from the target map. 2961 * This is the exported form of vm_map_delete. 2962 * 2963 * No requirements. 2964 */ 2965 int 2966 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2967 { 2968 int result; 2969 int count; 2970 2971 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2972 vm_map_lock(map); 2973 VM_MAP_RANGE_CHECK(map, start, end); 2974 result = vm_map_delete(map, start, end, &count); 2975 vm_map_unlock(map); 2976 vm_map_entry_release(count); 2977 2978 return (result); 2979 } 2980 2981 /* 2982 * Assert that the target map allows the specified privilege on the 2983 * entire address region given. The entire region must be allocated. 2984 * 2985 * The caller must specify whether the vm_map is already locked or not. 2986 */ 2987 boolean_t 2988 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2989 vm_prot_t protection, boolean_t have_lock) 2990 { 2991 vm_map_entry_t entry; 2992 vm_map_entry_t tmp_entry; 2993 boolean_t result; 2994 2995 if (have_lock == FALSE) 2996 vm_map_lock_read(map); 2997 2998 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 2999 if (have_lock == FALSE) 3000 vm_map_unlock_read(map); 3001 return (FALSE); 3002 } 3003 entry = tmp_entry; 3004 3005 result = TRUE; 3006 while (start < end) { 3007 if (entry == &map->header) { 3008 result = FALSE; 3009 break; 3010 } 3011 /* 3012 * No holes allowed! 3013 */ 3014 3015 if (start < entry->start) { 3016 result = FALSE; 3017 break; 3018 } 3019 /* 3020 * Check protection associated with entry. 3021 */ 3022 3023 if ((entry->protection & protection) != protection) { 3024 result = FALSE; 3025 break; 3026 } 3027 /* go to next entry */ 3028 3029 start = entry->end; 3030 entry = entry->next; 3031 } 3032 if (have_lock == FALSE) 3033 vm_map_unlock_read(map); 3034 return (result); 3035 } 3036 3037 /* 3038 * If appropriate this function shadows the original object with a new object 3039 * and moves the VM pages from the original object to the new object. 3040 * The original object will also be collapsed, if possible. 3041 * 3042 * We can only do this for normal memory objects with a single mapping, and 3043 * it only makes sense to do it if there are 2 or more refs on the original 3044 * object. i.e. typically a memory object that has been extended into 3045 * multiple vm_map_entry's with non-overlapping ranges. 3046 * 3047 * This makes it easier to remove unused pages and keeps object inheritance 3048 * from being a negative impact on memory usage. 3049 * 3050 * On return the (possibly new) entry->object.vm_object will have an 3051 * additional ref on it for the caller to dispose of (usually by cloning 3052 * the vm_map_entry). The additional ref had to be done in this routine 3053 * to avoid racing a collapse. The object's ONEMAPPING flag will also be 3054 * cleared. 3055 * 3056 * The vm_map must be locked and its token held. 3057 */ 3058 static void 3059 vm_map_split(vm_map_entry_t entry) 3060 { 3061 /* OPTIMIZED */ 3062 vm_object_t oobject, nobject, bobject; 3063 vm_offset_t s, e; 3064 vm_page_t m; 3065 vm_pindex_t offidxstart, offidxend, idx; 3066 vm_size_t size; 3067 vm_ooffset_t offset; 3068 int useshadowlist; 3069 3070 /* 3071 * Optimize away object locks for vnode objects. Important exit/exec 3072 * critical path. 3073 * 3074 * OBJ_ONEMAPPING doesn't apply to vnode objects but clear the flag 3075 * anyway. 3076 */ 3077 oobject = entry->object.vm_object; 3078 if (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) { 3079 vm_object_reference_quick(oobject); 3080 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 3081 return; 3082 } 3083 3084 /* 3085 * Setup. Chain lock the original object throughout the entire 3086 * routine to prevent new page faults from occuring. 3087 * 3088 * XXX can madvise WILLNEED interfere with us too? 3089 */ 3090 vm_object_hold(oobject); 3091 vm_object_chain_acquire(oobject, 0); 3092 3093 /* 3094 * Original object cannot be split? Might have also changed state. 3095 */ 3096 if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT && 3097 oobject->type != OBJT_SWAP)) { 3098 vm_object_chain_release(oobject); 3099 vm_object_reference_locked(oobject); 3100 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 3101 vm_object_drop(oobject); 3102 return; 3103 } 3104 3105 /* 3106 * Collapse original object with its backing store as an 3107 * optimization to reduce chain lengths when possible. 3108 * 3109 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's 3110 * for oobject, so there's no point collapsing it. 3111 * 3112 * Then re-check whether the object can be split. 3113 */ 3114 vm_object_collapse(oobject, NULL); 3115 3116 if (oobject->ref_count <= 1 || 3117 (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) || 3118 (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) { 3119 vm_object_chain_release(oobject); 3120 vm_object_reference_locked(oobject); 3121 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 3122 vm_object_drop(oobject); 3123 return; 3124 } 3125 3126 /* 3127 * Acquire the chain lock on the backing object. 3128 * 3129 * Give bobject an additional ref count for when it will be shadowed 3130 * by nobject. 3131 */ 3132 useshadowlist = 0; 3133 if ((bobject = oobject->backing_object) != NULL) { 3134 if (bobject->type != OBJT_VNODE) { 3135 useshadowlist = 1; 3136 vm_object_hold(bobject); 3137 vm_object_chain_wait(bobject, 0); 3138 vm_object_reference_locked(bobject); 3139 vm_object_chain_acquire(bobject, 0); 3140 KKASSERT(bobject->backing_object == bobject); 3141 KKASSERT((bobject->flags & OBJ_DEAD) == 0); 3142 } else { 3143 vm_object_reference_quick(bobject); 3144 } 3145 } 3146 3147 /* 3148 * Calculate the object page range and allocate the new object. 3149 */ 3150 offset = entry->offset; 3151 s = entry->start; 3152 e = entry->end; 3153 3154 offidxstart = OFF_TO_IDX(offset); 3155 offidxend = offidxstart + OFF_TO_IDX(e - s); 3156 size = offidxend - offidxstart; 3157 3158 switch(oobject->type) { 3159 case OBJT_DEFAULT: 3160 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size), 3161 VM_PROT_ALL, 0); 3162 break; 3163 case OBJT_SWAP: 3164 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size), 3165 VM_PROT_ALL, 0); 3166 break; 3167 default: 3168 /* not reached */ 3169 nobject = NULL; 3170 KKASSERT(0); 3171 } 3172 3173 if (nobject == NULL) { 3174 if (bobject) { 3175 if (useshadowlist) { 3176 vm_object_chain_release(bobject); 3177 vm_object_deallocate(bobject); 3178 vm_object_drop(bobject); 3179 } else { 3180 vm_object_deallocate(bobject); 3181 } 3182 } 3183 vm_object_chain_release(oobject); 3184 vm_object_reference_locked(oobject); 3185 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 3186 vm_object_drop(oobject); 3187 return; 3188 } 3189 3190 /* 3191 * The new object will replace entry->object.vm_object so it needs 3192 * a second reference (the caller expects an additional ref). 3193 */ 3194 vm_object_hold(nobject); 3195 vm_object_reference_locked(nobject); 3196 vm_object_chain_acquire(nobject, 0); 3197 3198 /* 3199 * nobject shadows bobject (oobject already shadows bobject). 3200 */ 3201 if (bobject) { 3202 nobject->backing_object_offset = 3203 oobject->backing_object_offset + IDX_TO_OFF(offidxstart); 3204 nobject->backing_object = bobject; 3205 if (useshadowlist) { 3206 bobject->shadow_count++; 3207 bobject->generation++; 3208 LIST_INSERT_HEAD(&bobject->shadow_head, 3209 nobject, shadow_list); 3210 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /*XXX*/ 3211 vm_object_chain_release(bobject); 3212 vm_object_drop(bobject); 3213 vm_object_set_flag(nobject, OBJ_ONSHADOW); 3214 } 3215 } 3216 3217 /* 3218 * Move the VM pages from oobject to nobject 3219 */ 3220 for (idx = 0; idx < size; idx++) { 3221 vm_page_t m; 3222 3223 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx, 3224 TRUE, "vmpg"); 3225 if (m == NULL) 3226 continue; 3227 3228 /* 3229 * We must wait for pending I/O to complete before we can 3230 * rename the page. 3231 * 3232 * We do not have to VM_PROT_NONE the page as mappings should 3233 * not be changed by this operation. 3234 * 3235 * NOTE: The act of renaming a page updates chaingen for both 3236 * objects. 3237 */ 3238 vm_page_rename(m, nobject, idx); 3239 /* page automatically made dirty by rename and cache handled */ 3240 /* page remains busy */ 3241 } 3242 3243 if (oobject->type == OBJT_SWAP) { 3244 vm_object_pip_add(oobject, 1); 3245 /* 3246 * copy oobject pages into nobject and destroy unneeded 3247 * pages in shadow object. 3248 */ 3249 swap_pager_copy(oobject, nobject, offidxstart, 0); 3250 vm_object_pip_wakeup(oobject); 3251 } 3252 3253 /* 3254 * Wakeup the pages we played with. No spl protection is needed 3255 * for a simple wakeup. 3256 */ 3257 for (idx = 0; idx < size; idx++) { 3258 m = vm_page_lookup(nobject, idx); 3259 if (m) { 3260 KKASSERT(m->flags & PG_BUSY); 3261 vm_page_wakeup(m); 3262 } 3263 } 3264 entry->object.vm_object = nobject; 3265 entry->offset = 0LL; 3266 3267 /* 3268 * Cleanup 3269 * 3270 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the 3271 * related pages were moved and are no longer applicable to the 3272 * original object. 3273 * 3274 * NOTE: Deallocate oobject (due to its entry->object.vm_object being 3275 * replaced by nobject). 3276 */ 3277 vm_object_chain_release(nobject); 3278 vm_object_drop(nobject); 3279 if (bobject && useshadowlist) { 3280 vm_object_chain_release(bobject); 3281 vm_object_drop(bobject); 3282 } 3283 vm_object_chain_release(oobject); 3284 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/ 3285 vm_object_deallocate_locked(oobject); 3286 vm_object_drop(oobject); 3287 } 3288 3289 /* 3290 * Copies the contents of the source entry to the destination 3291 * entry. The entries *must* be aligned properly. 3292 * 3293 * The vm_maps must be exclusively locked. 3294 * The vm_map's token must be held. 3295 * 3296 * Because the maps are locked no faults can be in progress during the 3297 * operation. 3298 */ 3299 static void 3300 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map, 3301 vm_map_entry_t src_entry, vm_map_entry_t dst_entry) 3302 { 3303 vm_object_t src_object; 3304 3305 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP || 3306 dst_entry->maptype == VM_MAPTYPE_UKSMAP) 3307 return; 3308 if (src_entry->maptype == VM_MAPTYPE_SUBMAP || 3309 src_entry->maptype == VM_MAPTYPE_UKSMAP) 3310 return; 3311 3312 if (src_entry->wired_count == 0) { 3313 /* 3314 * If the source entry is marked needs_copy, it is already 3315 * write-protected. 3316 */ 3317 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 3318 pmap_protect(src_map->pmap, 3319 src_entry->start, 3320 src_entry->end, 3321 src_entry->protection & ~VM_PROT_WRITE); 3322 } 3323 3324 /* 3325 * Make a copy of the object. 3326 * 3327 * The object must be locked prior to checking the object type 3328 * and for the call to vm_object_collapse() and vm_map_split(). 3329 * We cannot use *_hold() here because the split code will 3330 * probably try to destroy the object. The lock is a pool 3331 * token and doesn't care. 3332 * 3333 * We must bump src_map->timestamp when setting 3334 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault 3335 * to retry, otherwise the concurrent fault might improperly 3336 * install a RW pte when its supposed to be a RO(COW) pte. 3337 * This race can occur because a vnode-backed fault may have 3338 * to temporarily release the map lock. 3339 */ 3340 if (src_entry->object.vm_object != NULL) { 3341 vm_map_split(src_entry); 3342 src_object = src_entry->object.vm_object; 3343 dst_entry->object.vm_object = src_object; 3344 src_entry->eflags |= (MAP_ENTRY_COW | 3345 MAP_ENTRY_NEEDS_COPY); 3346 dst_entry->eflags |= (MAP_ENTRY_COW | 3347 MAP_ENTRY_NEEDS_COPY); 3348 dst_entry->offset = src_entry->offset; 3349 ++src_map->timestamp; 3350 } else { 3351 dst_entry->object.vm_object = NULL; 3352 dst_entry->offset = 0; 3353 } 3354 3355 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3356 dst_entry->end - dst_entry->start, src_entry->start); 3357 } else { 3358 /* 3359 * Of course, wired down pages can't be set copy-on-write. 3360 * Cause wired pages to be copied into the new map by 3361 * simulating faults (the new pages are pageable) 3362 */ 3363 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 3364 } 3365 } 3366 3367 /* 3368 * vmspace_fork: 3369 * Create a new process vmspace structure and vm_map 3370 * based on those of an existing process. The new map 3371 * is based on the old map, according to the inheritance 3372 * values on the regions in that map. 3373 * 3374 * The source map must not be locked. 3375 * No requirements. 3376 */ 3377 static void vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map, 3378 vm_map_entry_t old_entry, int *countp); 3379 static void vmspace_fork_uksmap_entry(vm_map_t old_map, vm_map_t new_map, 3380 vm_map_entry_t old_entry, int *countp); 3381 3382 struct vmspace * 3383 vmspace_fork(struct vmspace *vm1) 3384 { 3385 struct vmspace *vm2; 3386 vm_map_t old_map = &vm1->vm_map; 3387 vm_map_t new_map; 3388 vm_map_entry_t old_entry; 3389 int count; 3390 3391 lwkt_gettoken(&vm1->vm_map.token); 3392 vm_map_lock(old_map); 3393 3394 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 3395 lwkt_gettoken(&vm2->vm_map.token); 3396 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 3397 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); 3398 new_map = &vm2->vm_map; /* XXX */ 3399 new_map->timestamp = 1; 3400 3401 vm_map_lock(new_map); 3402 3403 count = 0; 3404 old_entry = old_map->header.next; 3405 while (old_entry != &old_map->header) { 3406 ++count; 3407 old_entry = old_entry->next; 3408 } 3409 3410 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); 3411 3412 old_entry = old_map->header.next; 3413 while (old_entry != &old_map->header) { 3414 switch(old_entry->maptype) { 3415 case VM_MAPTYPE_SUBMAP: 3416 panic("vm_map_fork: encountered a submap"); 3417 break; 3418 case VM_MAPTYPE_UKSMAP: 3419 vmspace_fork_uksmap_entry(old_map, new_map, 3420 old_entry, &count); 3421 break; 3422 case VM_MAPTYPE_NORMAL: 3423 case VM_MAPTYPE_VPAGETABLE: 3424 vmspace_fork_normal_entry(old_map, new_map, 3425 old_entry, &count); 3426 break; 3427 } 3428 old_entry = old_entry->next; 3429 } 3430 3431 new_map->size = old_map->size; 3432 vm_map_unlock(old_map); 3433 vm_map_unlock(new_map); 3434 vm_map_entry_release(count); 3435 3436 lwkt_reltoken(&vm2->vm_map.token); 3437 lwkt_reltoken(&vm1->vm_map.token); 3438 3439 return (vm2); 3440 } 3441 3442 static 3443 void 3444 vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map, 3445 vm_map_entry_t old_entry, int *countp) 3446 { 3447 vm_map_entry_t new_entry; 3448 vm_object_t object; 3449 3450 switch (old_entry->inheritance) { 3451 case VM_INHERIT_NONE: 3452 break; 3453 case VM_INHERIT_SHARE: 3454 /* 3455 * Clone the entry, creating the shared object if 3456 * necessary. 3457 */ 3458 if (old_entry->object.vm_object == NULL) 3459 vm_map_entry_allocate_object(old_entry); 3460 3461 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3462 /* 3463 * Shadow a map_entry which needs a copy, 3464 * replacing its object with a new object 3465 * that points to the old one. Ask the 3466 * shadow code to automatically add an 3467 * additional ref. We can't do it afterwords 3468 * because we might race a collapse. The call 3469 * to vm_map_entry_shadow() will also clear 3470 * OBJ_ONEMAPPING. 3471 */ 3472 vm_map_entry_shadow(old_entry, 1); 3473 } else if (old_entry->object.vm_object) { 3474 /* 3475 * We will make a shared copy of the object, 3476 * and must clear OBJ_ONEMAPPING. 3477 * 3478 * Optimize vnode objects. OBJ_ONEMAPPING 3479 * is non-applicable but clear it anyway, 3480 * and its terminal so we don'th ave to deal 3481 * with chains. Reduces SMP conflicts. 3482 * 3483 * XXX assert that object.vm_object != NULL 3484 * since we allocate it above. 3485 */ 3486 object = old_entry->object.vm_object; 3487 if (object->type == OBJT_VNODE) { 3488 vm_object_reference_quick(object); 3489 vm_object_clear_flag(object, 3490 OBJ_ONEMAPPING); 3491 } else { 3492 vm_object_hold(object); 3493 vm_object_chain_wait(object, 0); 3494 vm_object_reference_locked(object); 3495 vm_object_clear_flag(object, 3496 OBJ_ONEMAPPING); 3497 vm_object_drop(object); 3498 } 3499 } 3500 3501 /* 3502 * Clone the entry. We've already bumped the ref on 3503 * any vm_object. 3504 */ 3505 new_entry = vm_map_entry_create(new_map, countp); 3506 *new_entry = *old_entry; 3507 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3508 new_entry->wired_count = 0; 3509 3510 /* 3511 * Insert the entry into the new map -- we know we're 3512 * inserting at the end of the new map. 3513 */ 3514 3515 vm_map_entry_link(new_map, new_map->header.prev, 3516 new_entry); 3517 3518 /* 3519 * Update the physical map 3520 */ 3521 pmap_copy(new_map->pmap, old_map->pmap, 3522 new_entry->start, 3523 (old_entry->end - old_entry->start), 3524 old_entry->start); 3525 break; 3526 case VM_INHERIT_COPY: 3527 /* 3528 * Clone the entry and link into the map. 3529 */ 3530 new_entry = vm_map_entry_create(new_map, countp); 3531 *new_entry = *old_entry; 3532 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3533 new_entry->wired_count = 0; 3534 new_entry->object.vm_object = NULL; 3535 vm_map_entry_link(new_map, new_map->header.prev, 3536 new_entry); 3537 vm_map_copy_entry(old_map, new_map, old_entry, 3538 new_entry); 3539 break; 3540 } 3541 } 3542 3543 /* 3544 * When forking user-kernel shared maps, the map might change in the 3545 * child so do not try to copy the underlying pmap entries. 3546 */ 3547 static 3548 void 3549 vmspace_fork_uksmap_entry(vm_map_t old_map, vm_map_t new_map, 3550 vm_map_entry_t old_entry, int *countp) 3551 { 3552 vm_map_entry_t new_entry; 3553 3554 new_entry = vm_map_entry_create(new_map, countp); 3555 *new_entry = *old_entry; 3556 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3557 new_entry->wired_count = 0; 3558 vm_map_entry_link(new_map, new_map->header.prev, 3559 new_entry); 3560 } 3561 3562 /* 3563 * Create an auto-grow stack entry 3564 * 3565 * No requirements. 3566 */ 3567 int 3568 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3569 int flags, vm_prot_t prot, vm_prot_t max, int cow) 3570 { 3571 vm_map_entry_t prev_entry; 3572 vm_map_entry_t new_stack_entry; 3573 vm_size_t init_ssize; 3574 int rv; 3575 int count; 3576 vm_offset_t tmpaddr; 3577 3578 cow |= MAP_IS_STACK; 3579 3580 if (max_ssize < sgrowsiz) 3581 init_ssize = max_ssize; 3582 else 3583 init_ssize = sgrowsiz; 3584 3585 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3586 vm_map_lock(map); 3587 3588 /* 3589 * Find space for the mapping 3590 */ 3591 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) { 3592 if (vm_map_findspace(map, addrbos, max_ssize, 1, 3593 flags, &tmpaddr)) { 3594 vm_map_unlock(map); 3595 vm_map_entry_release(count); 3596 return (KERN_NO_SPACE); 3597 } 3598 addrbos = tmpaddr; 3599 } 3600 3601 /* If addr is already mapped, no go */ 3602 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3603 vm_map_unlock(map); 3604 vm_map_entry_release(count); 3605 return (KERN_NO_SPACE); 3606 } 3607 3608 #if 0 3609 /* XXX already handled by kern_mmap() */ 3610 /* If we would blow our VMEM resource limit, no go */ 3611 if (map->size + init_ssize > 3612 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3613 vm_map_unlock(map); 3614 vm_map_entry_release(count); 3615 return (KERN_NO_SPACE); 3616 } 3617 #endif 3618 3619 /* 3620 * If we can't accomodate max_ssize in the current mapping, 3621 * no go. However, we need to be aware that subsequent user 3622 * mappings might map into the space we have reserved for 3623 * stack, and currently this space is not protected. 3624 * 3625 * Hopefully we will at least detect this condition 3626 * when we try to grow the stack. 3627 */ 3628 if ((prev_entry->next != &map->header) && 3629 (prev_entry->next->start < addrbos + max_ssize)) { 3630 vm_map_unlock(map); 3631 vm_map_entry_release(count); 3632 return (KERN_NO_SPACE); 3633 } 3634 3635 /* 3636 * We initially map a stack of only init_ssize. We will 3637 * grow as needed later. Since this is to be a grow 3638 * down stack, we map at the top of the range. 3639 * 3640 * Note: we would normally expect prot and max to be 3641 * VM_PROT_ALL, and cow to be 0. Possibly we should 3642 * eliminate these as input parameters, and just 3643 * pass these values here in the insert call. 3644 */ 3645 rv = vm_map_insert(map, &count, NULL, NULL, 3646 0, addrbos + max_ssize - init_ssize, 3647 addrbos + max_ssize, 3648 VM_MAPTYPE_NORMAL, 3649 prot, max, cow); 3650 3651 /* Now set the avail_ssize amount */ 3652 if (rv == KERN_SUCCESS) { 3653 if (prev_entry != &map->header) 3654 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count); 3655 new_stack_entry = prev_entry->next; 3656 if (new_stack_entry->end != addrbos + max_ssize || 3657 new_stack_entry->start != addrbos + max_ssize - init_ssize) 3658 panic ("Bad entry start/end for new stack entry"); 3659 else 3660 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize; 3661 } 3662 3663 vm_map_unlock(map); 3664 vm_map_entry_release(count); 3665 return (rv); 3666 } 3667 3668 /* 3669 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3670 * desired address is already mapped, or if we successfully grow 3671 * the stack. Also returns KERN_SUCCESS if addr is outside the 3672 * stack range (this is strange, but preserves compatibility with 3673 * the grow function in vm_machdep.c). 3674 * 3675 * No requirements. 3676 */ 3677 int 3678 vm_map_growstack (struct proc *p, vm_offset_t addr) 3679 { 3680 vm_map_entry_t prev_entry; 3681 vm_map_entry_t stack_entry; 3682 vm_map_entry_t new_stack_entry; 3683 struct vmspace *vm = p->p_vmspace; 3684 vm_map_t map = &vm->vm_map; 3685 vm_offset_t end; 3686 int grow_amount; 3687 int rv = KERN_SUCCESS; 3688 int is_procstack; 3689 int use_read_lock = 1; 3690 int count; 3691 3692 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3693 Retry: 3694 if (use_read_lock) 3695 vm_map_lock_read(map); 3696 else 3697 vm_map_lock(map); 3698 3699 /* If addr is already in the entry range, no need to grow.*/ 3700 if (vm_map_lookup_entry(map, addr, &prev_entry)) 3701 goto done; 3702 3703 if ((stack_entry = prev_entry->next) == &map->header) 3704 goto done; 3705 if (prev_entry == &map->header) 3706 end = stack_entry->start - stack_entry->aux.avail_ssize; 3707 else 3708 end = prev_entry->end; 3709 3710 /* 3711 * This next test mimics the old grow function in vm_machdep.c. 3712 * It really doesn't quite make sense, but we do it anyway 3713 * for compatibility. 3714 * 3715 * If not growable stack, return success. This signals the 3716 * caller to proceed as he would normally with normal vm. 3717 */ 3718 if (stack_entry->aux.avail_ssize < 1 || 3719 addr >= stack_entry->start || 3720 addr < stack_entry->start - stack_entry->aux.avail_ssize) { 3721 goto done; 3722 } 3723 3724 /* Find the minimum grow amount */ 3725 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE); 3726 if (grow_amount > stack_entry->aux.avail_ssize) { 3727 rv = KERN_NO_SPACE; 3728 goto done; 3729 } 3730 3731 /* 3732 * If there is no longer enough space between the entries 3733 * nogo, and adjust the available space. Note: this 3734 * should only happen if the user has mapped into the 3735 * stack area after the stack was created, and is 3736 * probably an error. 3737 * 3738 * This also effectively destroys any guard page the user 3739 * might have intended by limiting the stack size. 3740 */ 3741 if (grow_amount > stack_entry->start - end) { 3742 if (use_read_lock && vm_map_lock_upgrade(map)) { 3743 /* lost lock */ 3744 use_read_lock = 0; 3745 goto Retry; 3746 } 3747 use_read_lock = 0; 3748 stack_entry->aux.avail_ssize = stack_entry->start - end; 3749 rv = KERN_NO_SPACE; 3750 goto done; 3751 } 3752 3753 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; 3754 3755 /* If this is the main process stack, see if we're over the 3756 * stack limit. 3757 */ 3758 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3759 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3760 rv = KERN_NO_SPACE; 3761 goto done; 3762 } 3763 3764 /* Round up the grow amount modulo SGROWSIZ */ 3765 grow_amount = roundup (grow_amount, sgrowsiz); 3766 if (grow_amount > stack_entry->aux.avail_ssize) { 3767 grow_amount = stack_entry->aux.avail_ssize; 3768 } 3769 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3770 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3771 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 3772 ctob(vm->vm_ssize); 3773 } 3774 3775 /* If we would blow our VMEM resource limit, no go */ 3776 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3777 rv = KERN_NO_SPACE; 3778 goto done; 3779 } 3780 3781 if (use_read_lock && vm_map_lock_upgrade(map)) { 3782 /* lost lock */ 3783 use_read_lock = 0; 3784 goto Retry; 3785 } 3786 use_read_lock = 0; 3787 3788 /* Get the preliminary new entry start value */ 3789 addr = stack_entry->start - grow_amount; 3790 3791 /* If this puts us into the previous entry, cut back our growth 3792 * to the available space. Also, see the note above. 3793 */ 3794 if (addr < end) { 3795 stack_entry->aux.avail_ssize = stack_entry->start - end; 3796 addr = end; 3797 } 3798 3799 rv = vm_map_insert(map, &count, NULL, NULL, 3800 0, addr, stack_entry->start, 3801 VM_MAPTYPE_NORMAL, 3802 VM_PROT_ALL, VM_PROT_ALL, 0); 3803 3804 /* Adjust the available stack space by the amount we grew. */ 3805 if (rv == KERN_SUCCESS) { 3806 if (prev_entry != &map->header) 3807 vm_map_clip_end(map, prev_entry, addr, &count); 3808 new_stack_entry = prev_entry->next; 3809 if (new_stack_entry->end != stack_entry->start || 3810 new_stack_entry->start != addr) 3811 panic ("Bad stack grow start/end in new stack entry"); 3812 else { 3813 new_stack_entry->aux.avail_ssize = 3814 stack_entry->aux.avail_ssize - 3815 (new_stack_entry->end - new_stack_entry->start); 3816 if (is_procstack) 3817 vm->vm_ssize += btoc(new_stack_entry->end - 3818 new_stack_entry->start); 3819 } 3820 3821 if (map->flags & MAP_WIREFUTURE) 3822 vm_map_unwire(map, new_stack_entry->start, 3823 new_stack_entry->end, FALSE); 3824 } 3825 3826 done: 3827 if (use_read_lock) 3828 vm_map_unlock_read(map); 3829 else 3830 vm_map_unlock(map); 3831 vm_map_entry_release(count); 3832 return (rv); 3833 } 3834 3835 /* 3836 * Unshare the specified VM space for exec. If other processes are 3837 * mapped to it, then create a new one. The new vmspace is null. 3838 * 3839 * No requirements. 3840 */ 3841 void 3842 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 3843 { 3844 struct vmspace *oldvmspace = p->p_vmspace; 3845 struct vmspace *newvmspace; 3846 vm_map_t map = &p->p_vmspace->vm_map; 3847 3848 /* 3849 * If we are execing a resident vmspace we fork it, otherwise 3850 * we create a new vmspace. Note that exitingcnt is not 3851 * copied to the new vmspace. 3852 */ 3853 lwkt_gettoken(&oldvmspace->vm_map.token); 3854 if (vmcopy) { 3855 newvmspace = vmspace_fork(vmcopy); 3856 lwkt_gettoken(&newvmspace->vm_map.token); 3857 } else { 3858 newvmspace = vmspace_alloc(map->min_offset, map->max_offset); 3859 lwkt_gettoken(&newvmspace->vm_map.token); 3860 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 3861 (caddr_t)&oldvmspace->vm_endcopy - 3862 (caddr_t)&oldvmspace->vm_startcopy); 3863 } 3864 3865 /* 3866 * Finish initializing the vmspace before assigning it 3867 * to the process. The vmspace will become the current vmspace 3868 * if p == curproc. 3869 */ 3870 pmap_pinit2(vmspace_pmap(newvmspace)); 3871 pmap_replacevm(p, newvmspace, 0); 3872 lwkt_reltoken(&newvmspace->vm_map.token); 3873 lwkt_reltoken(&oldvmspace->vm_map.token); 3874 vmspace_rel(oldvmspace); 3875 } 3876 3877 /* 3878 * Unshare the specified VM space for forcing COW. This 3879 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3880 */ 3881 void 3882 vmspace_unshare(struct proc *p) 3883 { 3884 struct vmspace *oldvmspace = p->p_vmspace; 3885 struct vmspace *newvmspace; 3886 3887 lwkt_gettoken(&oldvmspace->vm_map.token); 3888 if (vmspace_getrefs(oldvmspace) == 1) { 3889 lwkt_reltoken(&oldvmspace->vm_map.token); 3890 return; 3891 } 3892 newvmspace = vmspace_fork(oldvmspace); 3893 lwkt_gettoken(&newvmspace->vm_map.token); 3894 pmap_pinit2(vmspace_pmap(newvmspace)); 3895 pmap_replacevm(p, newvmspace, 0); 3896 lwkt_reltoken(&newvmspace->vm_map.token); 3897 lwkt_reltoken(&oldvmspace->vm_map.token); 3898 vmspace_rel(oldvmspace); 3899 } 3900 3901 /* 3902 * vm_map_hint: return the beginning of the best area suitable for 3903 * creating a new mapping with "prot" protection. 3904 * 3905 * No requirements. 3906 */ 3907 vm_offset_t 3908 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot) 3909 { 3910 struct vmspace *vms = p->p_vmspace; 3911 3912 if (!randomize_mmap || addr != 0) { 3913 /* 3914 * Set a reasonable start point for the hint if it was 3915 * not specified or if it falls within the heap space. 3916 * Hinted mmap()s do not allocate out of the heap space. 3917 */ 3918 if (addr == 0 || 3919 (addr >= round_page((vm_offset_t)vms->vm_taddr) && 3920 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) { 3921 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); 3922 } 3923 3924 return addr; 3925 } 3926 3927 #ifdef notyet 3928 #ifdef __i386__ 3929 /* 3930 * If executable skip first two pages, otherwise start 3931 * after data + heap region. 3932 */ 3933 if ((prot & VM_PROT_EXECUTE) && 3934 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) { 3935 addr = (PAGE_SIZE * 2) + 3936 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1)); 3937 return (round_page(addr)); 3938 } 3939 #endif /* __i386__ */ 3940 #endif /* notyet */ 3941 3942 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ; 3943 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1); 3944 3945 return (round_page(addr)); 3946 } 3947 3948 /* 3949 * Finds the VM object, offset, and protection for a given virtual address 3950 * in the specified map, assuming a page fault of the type specified. 3951 * 3952 * Leaves the map in question locked for read; return values are guaranteed 3953 * until a vm_map_lookup_done call is performed. Note that the map argument 3954 * is in/out; the returned map must be used in the call to vm_map_lookup_done. 3955 * 3956 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make 3957 * that fast. 3958 * 3959 * If a lookup is requested with "write protection" specified, the map may 3960 * be changed to perform virtual copying operations, although the data 3961 * referenced will remain the same. 3962 * 3963 * No requirements. 3964 */ 3965 int 3966 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3967 vm_offset_t vaddr, 3968 vm_prot_t fault_typea, 3969 vm_map_entry_t *out_entry, /* OUT */ 3970 vm_object_t *object, /* OUT */ 3971 vm_pindex_t *pindex, /* OUT */ 3972 vm_prot_t *out_prot, /* OUT */ 3973 boolean_t *wired) /* OUT */ 3974 { 3975 vm_map_entry_t entry; 3976 vm_map_t map = *var_map; 3977 vm_prot_t prot; 3978 vm_prot_t fault_type = fault_typea; 3979 int use_read_lock = 1; 3980 int rv = KERN_SUCCESS; 3981 3982 RetryLookup: 3983 if (use_read_lock) 3984 vm_map_lock_read(map); 3985 else 3986 vm_map_lock(map); 3987 3988 /* 3989 * If the map has an interesting hint, try it before calling full 3990 * blown lookup routine. 3991 */ 3992 entry = map->hint; 3993 cpu_ccfence(); 3994 *out_entry = entry; 3995 *object = NULL; 3996 3997 if ((entry == &map->header) || 3998 (vaddr < entry->start) || (vaddr >= entry->end)) { 3999 vm_map_entry_t tmp_entry; 4000 4001 /* 4002 * Entry was either not a valid hint, or the vaddr was not 4003 * contained in the entry, so do a full lookup. 4004 */ 4005 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { 4006 rv = KERN_INVALID_ADDRESS; 4007 goto done; 4008 } 4009 4010 entry = tmp_entry; 4011 *out_entry = entry; 4012 } 4013 4014 /* 4015 * Handle submaps. 4016 */ 4017 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 4018 vm_map_t old_map = map; 4019 4020 *var_map = map = entry->object.sub_map; 4021 if (use_read_lock) 4022 vm_map_unlock_read(old_map); 4023 else 4024 vm_map_unlock(old_map); 4025 use_read_lock = 1; 4026 goto RetryLookup; 4027 } 4028 4029 /* 4030 * Check whether this task is allowed to have this page. 4031 * Note the special case for MAP_ENTRY_COW 4032 * pages with an override. This is to implement a forced 4033 * COW for debuggers. 4034 */ 4035 4036 if (fault_type & VM_PROT_OVERRIDE_WRITE) 4037 prot = entry->max_protection; 4038 else 4039 prot = entry->protection; 4040 4041 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 4042 if ((fault_type & prot) != fault_type) { 4043 rv = KERN_PROTECTION_FAILURE; 4044 goto done; 4045 } 4046 4047 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 4048 (entry->eflags & MAP_ENTRY_COW) && 4049 (fault_type & VM_PROT_WRITE) && 4050 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 4051 rv = KERN_PROTECTION_FAILURE; 4052 goto done; 4053 } 4054 4055 /* 4056 * If this page is not pageable, we have to get it for all possible 4057 * accesses. 4058 */ 4059 *wired = (entry->wired_count != 0); 4060 if (*wired) 4061 prot = fault_type = entry->protection; 4062 4063 /* 4064 * Virtual page tables may need to update the accessed (A) bit 4065 * in a page table entry. Upgrade the fault to a write fault for 4066 * that case if the map will support it. If the map does not support 4067 * it the page table entry simply will not be updated. 4068 */ 4069 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 4070 if (prot & VM_PROT_WRITE) 4071 fault_type |= VM_PROT_WRITE; 4072 } 4073 4074 if (curthread->td_lwp && curthread->td_lwp->lwp_vmspace && 4075 pmap_emulate_ad_bits(&curthread->td_lwp->lwp_vmspace->vm_pmap)) { 4076 if ((prot & VM_PROT_WRITE) == 0) 4077 fault_type |= VM_PROT_WRITE; 4078 } 4079 4080 /* 4081 * Only NORMAL and VPAGETABLE maps are object-based. UKSMAPs are not. 4082 */ 4083 if (entry->maptype != VM_MAPTYPE_NORMAL && 4084 entry->maptype != VM_MAPTYPE_VPAGETABLE) { 4085 *object = NULL; 4086 goto skip; 4087 } 4088 4089 /* 4090 * If the entry was copy-on-write, we either ... 4091 */ 4092 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4093 /* 4094 * If we want to write the page, we may as well handle that 4095 * now since we've got the map locked. 4096 * 4097 * If we don't need to write the page, we just demote the 4098 * permissions allowed. 4099 */ 4100 4101 if (fault_type & VM_PROT_WRITE) { 4102 /* 4103 * Make a new object, and place it in the object 4104 * chain. Note that no new references have appeared 4105 * -- one just moved from the map to the new 4106 * object. 4107 */ 4108 4109 if (use_read_lock && vm_map_lock_upgrade(map)) { 4110 /* lost lock */ 4111 use_read_lock = 0; 4112 goto RetryLookup; 4113 } 4114 use_read_lock = 0; 4115 4116 vm_map_entry_shadow(entry, 0); 4117 } else { 4118 /* 4119 * We're attempting to read a copy-on-write page -- 4120 * don't allow writes. 4121 */ 4122 4123 prot &= ~VM_PROT_WRITE; 4124 } 4125 } 4126 4127 /* 4128 * Create an object if necessary. 4129 */ 4130 if (entry->object.vm_object == NULL && !map->system_map) { 4131 if (use_read_lock && vm_map_lock_upgrade(map)) { 4132 /* lost lock */ 4133 use_read_lock = 0; 4134 goto RetryLookup; 4135 } 4136 use_read_lock = 0; 4137 vm_map_entry_allocate_object(entry); 4138 } 4139 4140 /* 4141 * Return the object/offset from this entry. If the entry was 4142 * copy-on-write or empty, it has been fixed up. 4143 */ 4144 *object = entry->object.vm_object; 4145 4146 skip: 4147 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4148 4149 /* 4150 * Return whether this is the only map sharing this data. On 4151 * success we return with a read lock held on the map. On failure 4152 * we return with the map unlocked. 4153 */ 4154 *out_prot = prot; 4155 done: 4156 if (rv == KERN_SUCCESS) { 4157 if (use_read_lock == 0) 4158 vm_map_lock_downgrade(map); 4159 } else if (use_read_lock) { 4160 vm_map_unlock_read(map); 4161 } else { 4162 vm_map_unlock(map); 4163 } 4164 return (rv); 4165 } 4166 4167 /* 4168 * Releases locks acquired by a vm_map_lookup() 4169 * (according to the handle returned by that lookup). 4170 * 4171 * No other requirements. 4172 */ 4173 void 4174 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) 4175 { 4176 /* 4177 * Unlock the main-level map 4178 */ 4179 vm_map_unlock_read(map); 4180 if (count) 4181 vm_map_entry_release(count); 4182 } 4183 4184 #include "opt_ddb.h" 4185 #ifdef DDB 4186 #include <sys/kernel.h> 4187 4188 #include <ddb/ddb.h> 4189 4190 /* 4191 * Debugging only 4192 */ 4193 DB_SHOW_COMMAND(map, vm_map_print) 4194 { 4195 static int nlines; 4196 /* XXX convert args. */ 4197 vm_map_t map = (vm_map_t)addr; 4198 boolean_t full = have_addr; 4199 4200 vm_map_entry_t entry; 4201 4202 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 4203 (void *)map, 4204 (void *)map->pmap, map->nentries, map->timestamp); 4205 nlines++; 4206 4207 if (!full && db_indent) 4208 return; 4209 4210 db_indent += 2; 4211 for (entry = map->header.next; entry != &map->header; 4212 entry = entry->next) { 4213 db_iprintf("map entry %p: start=%p, end=%p\n", 4214 (void *)entry, (void *)entry->start, (void *)entry->end); 4215 nlines++; 4216 { 4217 static char *inheritance_name[4] = 4218 {"share", "copy", "none", "donate_copy"}; 4219 4220 db_iprintf(" prot=%x/%x/%s", 4221 entry->protection, 4222 entry->max_protection, 4223 inheritance_name[(int)(unsigned char)entry->inheritance]); 4224 if (entry->wired_count != 0) 4225 db_printf(", wired"); 4226 } 4227 switch(entry->maptype) { 4228 case VM_MAPTYPE_SUBMAP: 4229 /* XXX no %qd in kernel. Truncate entry->offset. */ 4230 db_printf(", share=%p, offset=0x%lx\n", 4231 (void *)entry->object.sub_map, 4232 (long)entry->offset); 4233 nlines++; 4234 if ((entry->prev == &map->header) || 4235 (entry->prev->object.sub_map != 4236 entry->object.sub_map)) { 4237 db_indent += 2; 4238 vm_map_print((db_expr_t)(intptr_t) 4239 entry->object.sub_map, 4240 full, 0, NULL); 4241 db_indent -= 2; 4242 } 4243 break; 4244 case VM_MAPTYPE_NORMAL: 4245 case VM_MAPTYPE_VPAGETABLE: 4246 /* XXX no %qd in kernel. Truncate entry->offset. */ 4247 db_printf(", object=%p, offset=0x%lx", 4248 (void *)entry->object.vm_object, 4249 (long)entry->offset); 4250 if (entry->eflags & MAP_ENTRY_COW) 4251 db_printf(", copy (%s)", 4252 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4253 db_printf("\n"); 4254 nlines++; 4255 4256 if ((entry->prev == &map->header) || 4257 (entry->prev->object.vm_object != 4258 entry->object.vm_object)) { 4259 db_indent += 2; 4260 vm_object_print((db_expr_t)(intptr_t) 4261 entry->object.vm_object, 4262 full, 0, NULL); 4263 nlines += 4; 4264 db_indent -= 2; 4265 } 4266 break; 4267 case VM_MAPTYPE_UKSMAP: 4268 db_printf(", uksmap=%p, offset=0x%lx", 4269 (void *)entry->object.uksmap, 4270 (long)entry->offset); 4271 if (entry->eflags & MAP_ENTRY_COW) 4272 db_printf(", copy (%s)", 4273 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4274 db_printf("\n"); 4275 nlines++; 4276 break; 4277 default: 4278 break; 4279 } 4280 } 4281 db_indent -= 2; 4282 if (db_indent == 0) 4283 nlines = 0; 4284 } 4285 4286 /* 4287 * Debugging only 4288 */ 4289 DB_SHOW_COMMAND(procvm, procvm) 4290 { 4291 struct proc *p; 4292 4293 if (have_addr) { 4294 p = (struct proc *) addr; 4295 } else { 4296 p = curproc; 4297 } 4298 4299 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4300 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4301 (void *)vmspace_pmap(p->p_vmspace)); 4302 4303 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 4304 } 4305 4306 #endif /* DDB */ 4307