1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 39 * 40 * 41 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42 * All rights reserved. 43 * 44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45 * 46 * Permission to use, copy, modify and distribute this software and 47 * its documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 * 66 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $ 67 * $DragonFly: src/sys/vm/vm_map.c,v 1.56 2007/04/29 18:25:41 dillon Exp $ 68 */ 69 70 /* 71 * Virtual memory mapping module. 72 */ 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/kernel.h> 77 #include <sys/proc.h> 78 #include <sys/lock.h> 79 #include <sys/vmmeter.h> 80 #include <sys/mman.h> 81 #include <sys/vnode.h> 82 #include <sys/resourcevar.h> 83 #include <sys/shm.h> 84 #include <sys/tree.h> 85 #include <sys/malloc.h> 86 87 #include <vm/vm.h> 88 #include <vm/vm_param.h> 89 #include <vm/pmap.h> 90 #include <vm/vm_map.h> 91 #include <vm/vm_page.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_pager.h> 94 #include <vm/vm_kern.h> 95 #include <vm/vm_extern.h> 96 #include <vm/swap_pager.h> 97 #include <vm/vm_zone.h> 98 99 #include <sys/thread2.h> 100 #include <sys/sysref2.h> 101 102 /* 103 * Virtual memory maps provide for the mapping, protection, and sharing 104 * of virtual memory objects. In addition, this module provides for an 105 * efficient virtual copy of memory from one map to another. 106 * 107 * Synchronization is required prior to most operations. 108 * 109 * Maps consist of an ordered doubly-linked list of simple entries. 110 * A hint and a RB tree is used to speed-up lookups. 111 * 112 * Callers looking to modify maps specify start/end addresses which cause 113 * the related map entry to be clipped if necessary, and then later 114 * recombined if the pieces remained compatible. 115 * 116 * Virtual copy operations are performed by copying VM object references 117 * from one map to another, and then marking both regions as copy-on-write. 118 */ 119 static void vmspace_terminate(struct vmspace *vm); 120 static void vmspace_lock(struct vmspace *vm); 121 static void vmspace_unlock(struct vmspace *vm); 122 static void vmspace_dtor(void *obj, void *private); 123 124 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore"); 125 126 struct sysref_class vmspace_sysref_class = { 127 .name = "vmspace", 128 .mtype = M_VMSPACE, 129 .proto = SYSREF_PROTO_VMSPACE, 130 .offset = offsetof(struct vmspace, vm_sysref), 131 .objsize = sizeof(struct vmspace), 132 .mag_capacity = 32, 133 .flags = SRC_MANAGEDINIT, 134 .dtor = vmspace_dtor, 135 .ops = { 136 .terminate = (sysref_terminate_func_t)vmspace_terminate, 137 .lock = (sysref_lock_func_t)vmspace_lock, 138 .unlock = (sysref_lock_func_t)vmspace_unlock 139 } 140 }; 141 142 #define VMEPERCPU 2 143 144 static struct vm_zone mapentzone_store, mapzone_store; 145 static vm_zone_t mapentzone, mapzone; 146 static struct vm_object mapentobj, mapobj; 147 148 static struct vm_map_entry map_entry_init[MAX_MAPENT]; 149 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU]; 150 static struct vm_map map_init[MAX_KMAP]; 151 152 static void vm_map_entry_shadow(vm_map_entry_t entry); 153 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *); 154 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); 155 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 156 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 157 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); 158 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); 159 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, 160 vm_map_entry_t); 161 static void vm_map_split (vm_map_entry_t); 162 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); 163 164 /* 165 * Initialize the vm_map module. Must be called before any other vm_map 166 * routines. 167 * 168 * Map and entry structures are allocated from the general purpose 169 * memory pool with some exceptions: 170 * 171 * - The kernel map is allocated statically. 172 * - Initial kernel map entries are allocated out of a static pool. 173 * 174 * These restrictions are necessary since malloc() uses the 175 * maps and requires map entries. 176 * 177 * Called from the low level boot code only. 178 */ 179 void 180 vm_map_startup(void) 181 { 182 mapzone = &mapzone_store; 183 zbootinit(mapzone, "MAP", sizeof (struct vm_map), 184 map_init, MAX_KMAP); 185 mapentzone = &mapentzone_store; 186 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), 187 map_entry_init, MAX_MAPENT); 188 } 189 190 /* 191 * Called prior to any vmspace allocations. 192 * 193 * Called from the low level boot code only. 194 */ 195 void 196 vm_init2(void) 197 { 198 zinitna(mapentzone, &mapentobj, NULL, 0, 0, 199 ZONE_USE_RESERVE | ZONE_SPECIAL, 1); 200 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1); 201 pmap_init2(); 202 vm_object_init2(); 203 } 204 205 206 /* 207 * Red black tree functions 208 * 209 * The caller must hold the related map lock. 210 */ 211 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); 212 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); 213 214 /* a->start is address, and the only field has to be initialized */ 215 static int 216 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) 217 { 218 if (a->start < b->start) 219 return(-1); 220 else if (a->start > b->start) 221 return(1); 222 return(0); 223 } 224 225 /* 226 * Allocate a vmspace structure, including a vm_map and pmap. 227 * Initialize numerous fields. While the initial allocation is zerod, 228 * subsequence reuse from the objcache leaves elements of the structure 229 * intact (particularly the pmap), so portions must be zerod. 230 * 231 * The structure is not considered activated until we call sysref_activate(). 232 * 233 * No requirements. 234 */ 235 struct vmspace * 236 vmspace_alloc(vm_offset_t min, vm_offset_t max) 237 { 238 struct vmspace *vm; 239 240 lwkt_gettoken(&vmspace_token); 241 vm = sysref_alloc(&vmspace_sysref_class); 242 bzero(&vm->vm_startcopy, 243 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy); 244 vm_map_init(&vm->vm_map, min, max, NULL); 245 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */ 246 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 247 vm->vm_shm = NULL; 248 vm->vm_exitingcnt = 0; 249 cpu_vmspace_alloc(vm); 250 sysref_activate(&vm->vm_sysref); 251 lwkt_reltoken(&vmspace_token); 252 253 return (vm); 254 } 255 256 /* 257 * dtor function - Some elements of the pmap are retained in the 258 * free-cached vmspaces to improve performance. We have to clean them up 259 * here before returning the vmspace to the memory pool. 260 * 261 * No requirements. 262 */ 263 static void 264 vmspace_dtor(void *obj, void *private) 265 { 266 struct vmspace *vm = obj; 267 268 pmap_puninit(vmspace_pmap(vm)); 269 } 270 271 /* 272 * Called in two cases: 273 * 274 * (1) When the last sysref is dropped, but exitingcnt might still be 275 * non-zero. 276 * 277 * (2) When there are no sysrefs (i.e. refcnt is negative) left and the 278 * exitingcnt becomes zero 279 * 280 * sysref will not scrap the object until we call sysref_put() once more 281 * after the last ref has been dropped. 282 * 283 * Interlocked by the sysref API. 284 */ 285 static void 286 vmspace_terminate(struct vmspace *vm) 287 { 288 int count; 289 290 /* 291 * If exitingcnt is non-zero we can't get rid of the entire vmspace 292 * yet, but we can scrap user memory. 293 */ 294 lwkt_gettoken(&vmspace_token); 295 if (vm->vm_exitingcnt) { 296 shmexit(vm); 297 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, 298 VM_MAX_USER_ADDRESS); 299 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, 300 VM_MAX_USER_ADDRESS); 301 lwkt_reltoken(&vmspace_token); 302 return; 303 } 304 cpu_vmspace_free(vm); 305 306 /* 307 * Make sure any SysV shm is freed, it might not have in 308 * exit1() 309 */ 310 shmexit(vm); 311 312 KKASSERT(vm->vm_upcalls == NULL); 313 314 /* 315 * Lock the map, to wait out all other references to it. 316 * Delete all of the mappings and pages they hold, then call 317 * the pmap module to reclaim anything left. 318 */ 319 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 320 vm_map_lock(&vm->vm_map); 321 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 322 vm->vm_map.max_offset, &count); 323 vm_map_unlock(&vm->vm_map); 324 vm_map_entry_release(count); 325 326 pmap_release(vmspace_pmap(vm)); 327 sysref_put(&vm->vm_sysref); 328 lwkt_reltoken(&vmspace_token); 329 } 330 331 /* 332 * vmspaces are not currently locked. 333 */ 334 static void 335 vmspace_lock(struct vmspace *vm __unused) 336 { 337 } 338 339 static void 340 vmspace_unlock(struct vmspace *vm __unused) 341 { 342 } 343 344 /* 345 * This is called during exit indicating that the vmspace is no 346 * longer in used by an exiting process, but the process has not yet 347 * been cleaned up. 348 * 349 * No requirements. 350 */ 351 void 352 vmspace_exitbump(struct vmspace *vm) 353 { 354 lwkt_gettoken(&vmspace_token); 355 ++vm->vm_exitingcnt; 356 lwkt_reltoken(&vmspace_token); 357 } 358 359 /* 360 * This is called in the wait*() handling code. The vmspace can be terminated 361 * after the last wait is finished using it. 362 * 363 * No requirements. 364 */ 365 void 366 vmspace_exitfree(struct proc *p) 367 { 368 struct vmspace *vm; 369 370 lwkt_gettoken(&vmspace_token); 371 vm = p->p_vmspace; 372 p->p_vmspace = NULL; 373 374 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref)) 375 vmspace_terminate(vm); 376 lwkt_reltoken(&vmspace_token); 377 } 378 379 /* 380 * Swap useage is determined by taking the proportional swap used by 381 * VM objects backing the VM map. To make up for fractional losses, 382 * if the VM object has any swap use at all the associated map entries 383 * count for at least 1 swap page. 384 * 385 * No requirements. 386 */ 387 int 388 vmspace_swap_count(struct vmspace *vmspace) 389 { 390 vm_map_t map = &vmspace->vm_map; 391 vm_map_entry_t cur; 392 vm_object_t object; 393 int count = 0; 394 int n; 395 396 lwkt_gettoken(&vmspace_token); 397 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 398 switch(cur->maptype) { 399 case VM_MAPTYPE_NORMAL: 400 case VM_MAPTYPE_VPAGETABLE: 401 if ((object = cur->object.vm_object) == NULL) 402 break; 403 if (object->swblock_count) { 404 n = (cur->end - cur->start) / PAGE_SIZE; 405 count += object->swblock_count * 406 SWAP_META_PAGES * n / object->size + 1; 407 } 408 break; 409 default: 410 break; 411 } 412 } 413 lwkt_reltoken(&vmspace_token); 414 return(count); 415 } 416 417 /* 418 * Calculate the approximate number of anonymous pages in use by 419 * this vmspace. To make up for fractional losses, we count each 420 * VM object as having at least 1 anonymous page. 421 * 422 * No requirements. 423 */ 424 int 425 vmspace_anonymous_count(struct vmspace *vmspace) 426 { 427 vm_map_t map = &vmspace->vm_map; 428 vm_map_entry_t cur; 429 vm_object_t object; 430 int count = 0; 431 432 lwkt_gettoken(&vmspace_token); 433 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 434 switch(cur->maptype) { 435 case VM_MAPTYPE_NORMAL: 436 case VM_MAPTYPE_VPAGETABLE: 437 if ((object = cur->object.vm_object) == NULL) 438 break; 439 if (object->type != OBJT_DEFAULT && 440 object->type != OBJT_SWAP) { 441 break; 442 } 443 count += object->resident_page_count; 444 break; 445 default: 446 break; 447 } 448 } 449 lwkt_reltoken(&vmspace_token); 450 return(count); 451 } 452 453 /* 454 * Creates and returns a new empty VM map with the given physical map 455 * structure, and having the given lower and upper address bounds. 456 * 457 * No requirements. 458 */ 459 vm_map_t 460 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max) 461 { 462 if (result == NULL) 463 result = zalloc(mapzone); 464 vm_map_init(result, min, max, pmap); 465 return (result); 466 } 467 468 /* 469 * Initialize an existing vm_map structure such as that in the vmspace 470 * structure. The pmap is initialized elsewhere. 471 * 472 * No requirements. 473 */ 474 void 475 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap) 476 { 477 map->header.next = map->header.prev = &map->header; 478 RB_INIT(&map->rb_root); 479 map->nentries = 0; 480 map->size = 0; 481 map->system_map = 0; 482 map->infork = 0; 483 map->min_offset = min; 484 map->max_offset = max; 485 map->pmap = pmap; 486 map->first_free = &map->header; 487 map->hint = &map->header; 488 map->timestamp = 0; 489 lockinit(&map->lock, "thrd_sleep", 0, 0); 490 } 491 492 /* 493 * Shadow the vm_map_entry's object. This typically needs to be done when 494 * a write fault is taken on an entry which had previously been cloned by 495 * fork(). The shared object (which might be NULL) must become private so 496 * we add a shadow layer above it. 497 * 498 * Object allocation for anonymous mappings is defered as long as possible. 499 * When creating a shadow, however, the underlying object must be instantiated 500 * so it can be shared. 501 * 502 * If the map segment is governed by a virtual page table then it is 503 * possible to address offsets beyond the mapped area. Just allocate 504 * a maximally sized object for this case. 505 * 506 * The vm_map must be exclusively locked. 507 * No other requirements. 508 */ 509 static 510 void 511 vm_map_entry_shadow(vm_map_entry_t entry) 512 { 513 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 514 vm_object_shadow(&entry->object.vm_object, &entry->offset, 515 0x7FFFFFFF); /* XXX */ 516 } else { 517 vm_object_shadow(&entry->object.vm_object, &entry->offset, 518 atop(entry->end - entry->start)); 519 } 520 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 521 } 522 523 /* 524 * Allocate an object for a vm_map_entry. 525 * 526 * Object allocation for anonymous mappings is defered as long as possible. 527 * This function is called when we can defer no longer, generally when a map 528 * entry might be split or forked or takes a page fault. 529 * 530 * If the map segment is governed by a virtual page table then it is 531 * possible to address offsets beyond the mapped area. Just allocate 532 * a maximally sized object for this case. 533 * 534 * The vm_map must be exclusively locked. 535 * No other requirements. 536 */ 537 void 538 vm_map_entry_allocate_object(vm_map_entry_t entry) 539 { 540 vm_object_t obj; 541 542 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 543 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */ 544 } else { 545 obj = vm_object_allocate(OBJT_DEFAULT, 546 atop(entry->end - entry->start)); 547 } 548 entry->object.vm_object = obj; 549 entry->offset = 0; 550 } 551 552 /* 553 * Set an initial negative count so the first attempt to reserve 554 * space preloads a bunch of vm_map_entry's for this cpu. Also 555 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to 556 * map a new page for vm_map_entry structures. SMP systems are 557 * particularly sensitive. 558 * 559 * This routine is called in early boot so we cannot just call 560 * vm_map_entry_reserve(). 561 * 562 * Called from the low level boot code only (for each cpu) 563 */ 564 void 565 vm_map_entry_reserve_cpu_init(globaldata_t gd) 566 { 567 vm_map_entry_t entry; 568 int i; 569 570 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2; 571 entry = &cpu_map_entry_init[gd->gd_cpuid][0]; 572 for (i = 0; i < VMEPERCPU; ++i, ++entry) { 573 entry->next = gd->gd_vme_base; 574 gd->gd_vme_base = entry; 575 } 576 } 577 578 /* 579 * Reserves vm_map_entry structures so code later on can manipulate 580 * map_entry structures within a locked map without blocking trying 581 * to allocate a new vm_map_entry. 582 * 583 * No requirements. 584 */ 585 int 586 vm_map_entry_reserve(int count) 587 { 588 struct globaldata *gd = mycpu; 589 vm_map_entry_t entry; 590 591 /* 592 * Make sure we have enough structures in gd_vme_base to handle 593 * the reservation request. 594 */ 595 crit_enter(); 596 while (gd->gd_vme_avail < count) { 597 entry = zalloc(mapentzone); 598 entry->next = gd->gd_vme_base; 599 gd->gd_vme_base = entry; 600 ++gd->gd_vme_avail; 601 } 602 gd->gd_vme_avail -= count; 603 crit_exit(); 604 605 return(count); 606 } 607 608 /* 609 * Releases previously reserved vm_map_entry structures that were not 610 * used. If we have too much junk in our per-cpu cache clean some of 611 * it out. 612 * 613 * No requirements. 614 */ 615 void 616 vm_map_entry_release(int count) 617 { 618 struct globaldata *gd = mycpu; 619 vm_map_entry_t entry; 620 621 crit_enter(); 622 gd->gd_vme_avail += count; 623 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) { 624 entry = gd->gd_vme_base; 625 KKASSERT(entry != NULL); 626 gd->gd_vme_base = entry->next; 627 --gd->gd_vme_avail; 628 crit_exit(); 629 zfree(mapentzone, entry); 630 crit_enter(); 631 } 632 crit_exit(); 633 } 634 635 /* 636 * Reserve map entry structures for use in kernel_map itself. These 637 * entries have *ALREADY* been reserved on a per-cpu basis when the map 638 * was inited. This function is used by zalloc() to avoid a recursion 639 * when zalloc() itself needs to allocate additional kernel memory. 640 * 641 * This function works like the normal reserve but does not load the 642 * vm_map_entry cache (because that would result in an infinite 643 * recursion). Note that gd_vme_avail may go negative. This is expected. 644 * 645 * Any caller of this function must be sure to renormalize after 646 * potentially eating entries to ensure that the reserve supply 647 * remains intact. 648 * 649 * No requirements. 650 */ 651 int 652 vm_map_entry_kreserve(int count) 653 { 654 struct globaldata *gd = mycpu; 655 656 crit_enter(); 657 gd->gd_vme_avail -= count; 658 crit_exit(); 659 KASSERT(gd->gd_vme_base != NULL, 660 ("no reserved entries left, gd_vme_avail = %d\n", 661 gd->gd_vme_avail)); 662 return(count); 663 } 664 665 /* 666 * Release previously reserved map entries for kernel_map. We do not 667 * attempt to clean up like the normal release function as this would 668 * cause an unnecessary (but probably not fatal) deep procedure call. 669 * 670 * No requirements. 671 */ 672 void 673 vm_map_entry_krelease(int count) 674 { 675 struct globaldata *gd = mycpu; 676 677 crit_enter(); 678 gd->gd_vme_avail += count; 679 crit_exit(); 680 } 681 682 /* 683 * Allocates a VM map entry for insertion. No entry fields are filled in. 684 * 685 * The entries should have previously been reserved. The reservation count 686 * is tracked in (*countp). 687 * 688 * No requirements. 689 */ 690 static vm_map_entry_t 691 vm_map_entry_create(vm_map_t map, int *countp) 692 { 693 struct globaldata *gd = mycpu; 694 vm_map_entry_t entry; 695 696 KKASSERT(*countp > 0); 697 --*countp; 698 crit_enter(); 699 entry = gd->gd_vme_base; 700 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); 701 gd->gd_vme_base = entry->next; 702 crit_exit(); 703 704 return(entry); 705 } 706 707 /* 708 * Dispose of a vm_map_entry that is no longer being referenced. 709 * 710 * No requirements. 711 */ 712 static void 713 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) 714 { 715 struct globaldata *gd = mycpu; 716 717 KKASSERT(map->hint != entry); 718 KKASSERT(map->first_free != entry); 719 720 ++*countp; 721 crit_enter(); 722 entry->next = gd->gd_vme_base; 723 gd->gd_vme_base = entry; 724 crit_exit(); 725 } 726 727 728 /* 729 * Insert/remove entries from maps. 730 * 731 * The related map must be exclusively locked. 732 * No other requirements. 733 * 734 * NOTE! We currently acquire the vmspace_token only to avoid races 735 * against the pageout daemon's calls to vmspace_*_count(), which 736 * are unable to safely lock the vm_map without potentially 737 * deadlocking. 738 */ 739 static __inline void 740 vm_map_entry_link(vm_map_t map, 741 vm_map_entry_t after_where, 742 vm_map_entry_t entry) 743 { 744 ASSERT_VM_MAP_LOCKED(map); 745 746 lwkt_gettoken(&vmspace_token); 747 map->nentries++; 748 entry->prev = after_where; 749 entry->next = after_where->next; 750 entry->next->prev = entry; 751 after_where->next = entry; 752 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) 753 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); 754 lwkt_reltoken(&vmspace_token); 755 } 756 757 static __inline void 758 vm_map_entry_unlink(vm_map_t map, 759 vm_map_entry_t entry) 760 { 761 vm_map_entry_t prev; 762 vm_map_entry_t next; 763 764 ASSERT_VM_MAP_LOCKED(map); 765 766 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 767 panic("vm_map_entry_unlink: attempt to mess with " 768 "locked entry! %p", entry); 769 } 770 lwkt_gettoken(&vmspace_token); 771 prev = entry->prev; 772 next = entry->next; 773 next->prev = prev; 774 prev->next = next; 775 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); 776 map->nentries--; 777 lwkt_reltoken(&vmspace_token); 778 } 779 780 /* 781 * Finds the map entry containing (or immediately preceding) the specified 782 * address in the given map. The entry is returned in (*entry). 783 * 784 * The boolean result indicates whether the address is actually contained 785 * in the map. 786 * 787 * The related map must be locked. 788 * No other requirements. 789 */ 790 boolean_t 791 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry) 792 { 793 vm_map_entry_t tmp; 794 vm_map_entry_t last; 795 796 ASSERT_VM_MAP_LOCKED(map); 797 #if 0 798 /* 799 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive 800 * the hint code with the red-black lookup meets with system crashes 801 * and lockups. We do not yet know why. 802 * 803 * It is possible that the problem is related to the setting 804 * of the hint during map_entry deletion, in the code specified 805 * at the GGG comment later on in this file. 806 */ 807 /* 808 * Quickly check the cached hint, there's a good chance of a match. 809 */ 810 if (map->hint != &map->header) { 811 tmp = map->hint; 812 if (address >= tmp->start && address < tmp->end) { 813 *entry = tmp; 814 return(TRUE); 815 } 816 } 817 #endif 818 819 /* 820 * Locate the record from the top of the tree. 'last' tracks the 821 * closest prior record and is returned if no match is found, which 822 * in binary tree terms means tracking the most recent right-branch 823 * taken. If there is no prior record, &map->header is returned. 824 */ 825 last = &map->header; 826 tmp = RB_ROOT(&map->rb_root); 827 828 while (tmp) { 829 if (address >= tmp->start) { 830 if (address < tmp->end) { 831 *entry = tmp; 832 map->hint = tmp; 833 return(TRUE); 834 } 835 last = tmp; 836 tmp = RB_RIGHT(tmp, rb_entry); 837 } else { 838 tmp = RB_LEFT(tmp, rb_entry); 839 } 840 } 841 *entry = last; 842 return (FALSE); 843 } 844 845 /* 846 * Inserts the given whole VM object into the target map at the specified 847 * address range. The object's size should match that of the address range. 848 * 849 * The map must be exclusively locked. 850 * The caller must have reserved sufficient vm_map_entry structures. 851 * 852 * If object is non-NULL, ref count must be bumped by caller 853 * prior to making call to account for the new entry. 854 */ 855 int 856 vm_map_insert(vm_map_t map, int *countp, 857 vm_object_t object, vm_ooffset_t offset, 858 vm_offset_t start, vm_offset_t end, 859 vm_maptype_t maptype, 860 vm_prot_t prot, vm_prot_t max, 861 int cow) 862 { 863 vm_map_entry_t new_entry; 864 vm_map_entry_t prev_entry; 865 vm_map_entry_t temp_entry; 866 vm_eflags_t protoeflags; 867 868 ASSERT_VM_MAP_LOCKED(map); 869 870 /* 871 * Check that the start and end points are not bogus. 872 */ 873 if ((start < map->min_offset) || (end > map->max_offset) || 874 (start >= end)) 875 return (KERN_INVALID_ADDRESS); 876 877 /* 878 * Find the entry prior to the proposed starting address; if it's part 879 * of an existing entry, this range is bogus. 880 */ 881 if (vm_map_lookup_entry(map, start, &temp_entry)) 882 return (KERN_NO_SPACE); 883 884 prev_entry = temp_entry; 885 886 /* 887 * Assert that the next entry doesn't overlap the end point. 888 */ 889 890 if ((prev_entry->next != &map->header) && 891 (prev_entry->next->start < end)) 892 return (KERN_NO_SPACE); 893 894 protoeflags = 0; 895 896 if (cow & MAP_COPY_ON_WRITE) 897 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 898 899 if (cow & MAP_NOFAULT) { 900 protoeflags |= MAP_ENTRY_NOFAULT; 901 902 KASSERT(object == NULL, 903 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 904 } 905 if (cow & MAP_DISABLE_SYNCER) 906 protoeflags |= MAP_ENTRY_NOSYNC; 907 if (cow & MAP_DISABLE_COREDUMP) 908 protoeflags |= MAP_ENTRY_NOCOREDUMP; 909 if (cow & MAP_IS_STACK) 910 protoeflags |= MAP_ENTRY_STACK; 911 912 lwkt_gettoken(&vm_token); 913 lwkt_gettoken(&vmobj_token); 914 915 if (object) { 916 /* 917 * When object is non-NULL, it could be shared with another 918 * process. We have to set or clear OBJ_ONEMAPPING 919 * appropriately. 920 */ 921 if ((object->ref_count > 1) || (object->shadow_count != 0)) { 922 vm_object_clear_flag(object, OBJ_ONEMAPPING); 923 } 924 } 925 else if ((prev_entry != &map->header) && 926 (prev_entry->eflags == protoeflags) && 927 (prev_entry->end == start) && 928 (prev_entry->wired_count == 0) && 929 prev_entry->maptype == maptype && 930 ((prev_entry->object.vm_object == NULL) || 931 vm_object_coalesce(prev_entry->object.vm_object, 932 OFF_TO_IDX(prev_entry->offset), 933 (vm_size_t)(prev_entry->end - prev_entry->start), 934 (vm_size_t)(end - prev_entry->end)))) { 935 /* 936 * We were able to extend the object. Determine if we 937 * can extend the previous map entry to include the 938 * new range as well. 939 */ 940 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 941 (prev_entry->protection == prot) && 942 (prev_entry->max_protection == max)) { 943 lwkt_reltoken(&vmobj_token); 944 lwkt_reltoken(&vm_token); 945 map->size += (end - prev_entry->end); 946 prev_entry->end = end; 947 vm_map_simplify_entry(map, prev_entry, countp); 948 return (KERN_SUCCESS); 949 } 950 951 /* 952 * If we can extend the object but cannot extend the 953 * map entry, we have to create a new map entry. We 954 * must bump the ref count on the extended object to 955 * account for it. object may be NULL. 956 */ 957 object = prev_entry->object.vm_object; 958 offset = prev_entry->offset + 959 (prev_entry->end - prev_entry->start); 960 vm_object_reference_locked(object); 961 } 962 963 lwkt_reltoken(&vmobj_token); 964 lwkt_reltoken(&vm_token); 965 966 /* 967 * NOTE: if conditionals fail, object can be NULL here. This occurs 968 * in things like the buffer map where we manage kva but do not manage 969 * backing objects. 970 */ 971 972 /* 973 * Create a new entry 974 */ 975 976 new_entry = vm_map_entry_create(map, countp); 977 new_entry->start = start; 978 new_entry->end = end; 979 980 new_entry->maptype = maptype; 981 new_entry->eflags = protoeflags; 982 new_entry->object.vm_object = object; 983 new_entry->offset = offset; 984 new_entry->aux.master_pde = 0; 985 986 new_entry->inheritance = VM_INHERIT_DEFAULT; 987 new_entry->protection = prot; 988 new_entry->max_protection = max; 989 new_entry->wired_count = 0; 990 991 /* 992 * Insert the new entry into the list 993 */ 994 995 vm_map_entry_link(map, prev_entry, new_entry); 996 map->size += new_entry->end - new_entry->start; 997 998 /* 999 * Update the free space hint. Entries cannot overlap. 1000 * An exact comparison is needed to avoid matching 1001 * against the map->header. 1002 */ 1003 if ((map->first_free == prev_entry) && 1004 (prev_entry->end == new_entry->start)) { 1005 map->first_free = new_entry; 1006 } 1007 1008 #if 0 1009 /* 1010 * Temporarily removed to avoid MAP_STACK panic, due to 1011 * MAP_STACK being a huge hack. Will be added back in 1012 * when MAP_STACK (and the user stack mapping) is fixed. 1013 */ 1014 /* 1015 * It may be possible to simplify the entry 1016 */ 1017 vm_map_simplify_entry(map, new_entry, countp); 1018 #endif 1019 1020 /* 1021 * Try to pre-populate the page table. Mappings governed by virtual 1022 * page tables cannot be prepopulated without a lot of work, so 1023 * don't try. 1024 */ 1025 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) && 1026 maptype != VM_MAPTYPE_VPAGETABLE) { 1027 pmap_object_init_pt(map->pmap, start, prot, 1028 object, OFF_TO_IDX(offset), end - start, 1029 cow & MAP_PREFAULT_PARTIAL); 1030 } 1031 1032 return (KERN_SUCCESS); 1033 } 1034 1035 /* 1036 * Find sufficient space for `length' bytes in the given map, starting at 1037 * `start'. Returns 0 on success, 1 on no space. 1038 * 1039 * This function will returned an arbitrarily aligned pointer. If no 1040 * particular alignment is required you should pass align as 1. Note that 1041 * the map may return PAGE_SIZE aligned pointers if all the lengths used in 1042 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align 1043 * argument. 1044 * 1045 * 'align' should be a power of 2 but is not required to be. 1046 * 1047 * The map must be exclusively locked. 1048 * No other requirements. 1049 */ 1050 int 1051 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1052 vm_size_t align, int flags, vm_offset_t *addr) 1053 { 1054 vm_map_entry_t entry, next; 1055 vm_offset_t end; 1056 vm_offset_t align_mask; 1057 1058 if (start < map->min_offset) 1059 start = map->min_offset; 1060 if (start > map->max_offset) 1061 return (1); 1062 1063 /* 1064 * If the alignment is not a power of 2 we will have to use 1065 * a mod/division, set align_mask to a special value. 1066 */ 1067 if ((align | (align - 1)) + 1 != (align << 1)) 1068 align_mask = (vm_offset_t)-1; 1069 else 1070 align_mask = align - 1; 1071 1072 /* 1073 * Look for the first possible address; if there's already something 1074 * at this address, we have to start after it. 1075 */ 1076 if (start == map->min_offset) { 1077 if ((entry = map->first_free) != &map->header) 1078 start = entry->end; 1079 } else { 1080 vm_map_entry_t tmp; 1081 1082 if (vm_map_lookup_entry(map, start, &tmp)) 1083 start = tmp->end; 1084 entry = tmp; 1085 } 1086 1087 /* 1088 * Look through the rest of the map, trying to fit a new region in the 1089 * gap between existing regions, or after the very last region. 1090 */ 1091 for (;; start = (entry = next)->end) { 1092 /* 1093 * Adjust the proposed start by the requested alignment, 1094 * be sure that we didn't wrap the address. 1095 */ 1096 if (align_mask == (vm_offset_t)-1) 1097 end = ((start + align - 1) / align) * align; 1098 else 1099 end = (start + align_mask) & ~align_mask; 1100 if (end < start) 1101 return (1); 1102 start = end; 1103 /* 1104 * Find the end of the proposed new region. Be sure we didn't 1105 * go beyond the end of the map, or wrap around the address. 1106 * Then check to see if this is the last entry or if the 1107 * proposed end fits in the gap between this and the next 1108 * entry. 1109 */ 1110 end = start + length; 1111 if (end > map->max_offset || end < start) 1112 return (1); 1113 next = entry->next; 1114 1115 /* 1116 * If the next entry's start address is beyond the desired 1117 * end address we may have found a good entry. 1118 * 1119 * If the next entry is a stack mapping we do not map into 1120 * the stack's reserved space. 1121 * 1122 * XXX continue to allow mapping into the stack's reserved 1123 * space if doing a MAP_STACK mapping inside a MAP_STACK 1124 * mapping, for backwards compatibility. But the caller 1125 * really should use MAP_STACK | MAP_TRYFIXED if they 1126 * want to do that. 1127 */ 1128 if (next == &map->header) 1129 break; 1130 if (next->start >= end) { 1131 if ((next->eflags & MAP_ENTRY_STACK) == 0) 1132 break; 1133 if (flags & MAP_STACK) 1134 break; 1135 if (next->start - next->aux.avail_ssize >= end) 1136 break; 1137 } 1138 } 1139 map->hint = entry; 1140 1141 /* 1142 * Grow the kernel_map if necessary. pmap_growkernel() will panic 1143 * if it fails. The kernel_map is locked and nothing can steal 1144 * our address space if pmap_growkernel() blocks. 1145 * 1146 * NOTE: This may be unconditionally called for kldload areas on 1147 * x86_64 because these do not bump kernel_vm_end (which would 1148 * fill 128G worth of page tables!). Therefore we must not 1149 * retry. 1150 */ 1151 if (map == &kernel_map) { 1152 vm_offset_t kstop; 1153 1154 kstop = round_page(start + length); 1155 if (kstop > kernel_vm_end) 1156 pmap_growkernel(start, kstop); 1157 } 1158 *addr = start; 1159 return (0); 1160 } 1161 1162 /* 1163 * vm_map_find finds an unallocated region in the target address map with 1164 * the given length. The search is defined to be first-fit from the 1165 * specified address; the region found is returned in the same parameter. 1166 * 1167 * If object is non-NULL, ref count must be bumped by caller 1168 * prior to making call to account for the new entry. 1169 * 1170 * No requirements. This function will lock the map temporarily. 1171 */ 1172 int 1173 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1174 vm_offset_t *addr, vm_size_t length, vm_size_t align, 1175 boolean_t fitit, 1176 vm_maptype_t maptype, 1177 vm_prot_t prot, vm_prot_t max, 1178 int cow) 1179 { 1180 vm_offset_t start; 1181 int result; 1182 int count; 1183 1184 start = *addr; 1185 1186 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1187 vm_map_lock(map); 1188 if (fitit) { 1189 if (vm_map_findspace(map, start, length, align, 0, addr)) { 1190 vm_map_unlock(map); 1191 vm_map_entry_release(count); 1192 return (KERN_NO_SPACE); 1193 } 1194 start = *addr; 1195 } 1196 result = vm_map_insert(map, &count, object, offset, 1197 start, start + length, 1198 maptype, 1199 prot, max, 1200 cow); 1201 vm_map_unlock(map); 1202 vm_map_entry_release(count); 1203 1204 return (result); 1205 } 1206 1207 /* 1208 * Simplify the given map entry by merging with either neighbor. This 1209 * routine also has the ability to merge with both neighbors. 1210 * 1211 * This routine guarentees that the passed entry remains valid (though 1212 * possibly extended). When merging, this routine may delete one or 1213 * both neighbors. No action is taken on entries which have their 1214 * in-transition flag set. 1215 * 1216 * The map must be exclusively locked. 1217 */ 1218 void 1219 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp) 1220 { 1221 vm_map_entry_t next, prev; 1222 vm_size_t prevsize, esize; 1223 1224 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1225 ++mycpu->gd_cnt.v_intrans_coll; 1226 return; 1227 } 1228 1229 if (entry->maptype == VM_MAPTYPE_SUBMAP) 1230 return; 1231 1232 prev = entry->prev; 1233 if (prev != &map->header) { 1234 prevsize = prev->end - prev->start; 1235 if ( (prev->end == entry->start) && 1236 (prev->maptype == entry->maptype) && 1237 (prev->object.vm_object == entry->object.vm_object) && 1238 (!prev->object.vm_object || 1239 (prev->offset + prevsize == entry->offset)) && 1240 (prev->eflags == entry->eflags) && 1241 (prev->protection == entry->protection) && 1242 (prev->max_protection == entry->max_protection) && 1243 (prev->inheritance == entry->inheritance) && 1244 (prev->wired_count == entry->wired_count)) { 1245 if (map->first_free == prev) 1246 map->first_free = entry; 1247 if (map->hint == prev) 1248 map->hint = entry; 1249 vm_map_entry_unlink(map, prev); 1250 entry->start = prev->start; 1251 entry->offset = prev->offset; 1252 if (prev->object.vm_object) 1253 vm_object_deallocate(prev->object.vm_object); 1254 vm_map_entry_dispose(map, prev, countp); 1255 } 1256 } 1257 1258 next = entry->next; 1259 if (next != &map->header) { 1260 esize = entry->end - entry->start; 1261 if ((entry->end == next->start) && 1262 (next->maptype == entry->maptype) && 1263 (next->object.vm_object == entry->object.vm_object) && 1264 (!entry->object.vm_object || 1265 (entry->offset + esize == next->offset)) && 1266 (next->eflags == entry->eflags) && 1267 (next->protection == entry->protection) && 1268 (next->max_protection == entry->max_protection) && 1269 (next->inheritance == entry->inheritance) && 1270 (next->wired_count == entry->wired_count)) { 1271 if (map->first_free == next) 1272 map->first_free = entry; 1273 if (map->hint == next) 1274 map->hint = entry; 1275 vm_map_entry_unlink(map, next); 1276 entry->end = next->end; 1277 if (next->object.vm_object) 1278 vm_object_deallocate(next->object.vm_object); 1279 vm_map_entry_dispose(map, next, countp); 1280 } 1281 } 1282 } 1283 1284 /* 1285 * Asserts that the given entry begins at or after the specified address. 1286 * If necessary, it splits the entry into two. 1287 */ 1288 #define vm_map_clip_start(map, entry, startaddr, countp) \ 1289 { \ 1290 if (startaddr > entry->start) \ 1291 _vm_map_clip_start(map, entry, startaddr, countp); \ 1292 } 1293 1294 /* 1295 * This routine is called only when it is known that the entry must be split. 1296 * 1297 * The map must be exclusively locked. 1298 */ 1299 static void 1300 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start, 1301 int *countp) 1302 { 1303 vm_map_entry_t new_entry; 1304 1305 /* 1306 * Split off the front portion -- note that we must insert the new 1307 * entry BEFORE this one, so that this entry has the specified 1308 * starting address. 1309 */ 1310 1311 vm_map_simplify_entry(map, entry, countp); 1312 1313 /* 1314 * If there is no object backing this entry, we might as well create 1315 * one now. If we defer it, an object can get created after the map 1316 * is clipped, and individual objects will be created for the split-up 1317 * map. This is a bit of a hack, but is also about the best place to 1318 * put this improvement. 1319 */ 1320 if (entry->object.vm_object == NULL && !map->system_map) { 1321 vm_map_entry_allocate_object(entry); 1322 } 1323 1324 new_entry = vm_map_entry_create(map, countp); 1325 *new_entry = *entry; 1326 1327 new_entry->end = start; 1328 entry->offset += (start - entry->start); 1329 entry->start = start; 1330 1331 vm_map_entry_link(map, entry->prev, new_entry); 1332 1333 switch(entry->maptype) { 1334 case VM_MAPTYPE_NORMAL: 1335 case VM_MAPTYPE_VPAGETABLE: 1336 vm_object_reference(new_entry->object.vm_object); 1337 break; 1338 default: 1339 break; 1340 } 1341 } 1342 1343 /* 1344 * Asserts that the given entry ends at or before the specified address. 1345 * If necessary, it splits the entry into two. 1346 * 1347 * The map must be exclusively locked. 1348 */ 1349 #define vm_map_clip_end(map, entry, endaddr, countp) \ 1350 { \ 1351 if (endaddr < entry->end) \ 1352 _vm_map_clip_end(map, entry, endaddr, countp); \ 1353 } 1354 1355 /* 1356 * This routine is called only when it is known that the entry must be split. 1357 * 1358 * The map must be exclusively locked. 1359 */ 1360 static void 1361 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end, 1362 int *countp) 1363 { 1364 vm_map_entry_t new_entry; 1365 1366 /* 1367 * If there is no object backing this entry, we might as well create 1368 * one now. If we defer it, an object can get created after the map 1369 * is clipped, and individual objects will be created for the split-up 1370 * map. This is a bit of a hack, but is also about the best place to 1371 * put this improvement. 1372 */ 1373 1374 if (entry->object.vm_object == NULL && !map->system_map) { 1375 vm_map_entry_allocate_object(entry); 1376 } 1377 1378 /* 1379 * Create a new entry and insert it AFTER the specified entry 1380 */ 1381 1382 new_entry = vm_map_entry_create(map, countp); 1383 *new_entry = *entry; 1384 1385 new_entry->start = entry->end = end; 1386 new_entry->offset += (end - entry->start); 1387 1388 vm_map_entry_link(map, entry, new_entry); 1389 1390 switch(entry->maptype) { 1391 case VM_MAPTYPE_NORMAL: 1392 case VM_MAPTYPE_VPAGETABLE: 1393 vm_object_reference(new_entry->object.vm_object); 1394 break; 1395 default: 1396 break; 1397 } 1398 } 1399 1400 /* 1401 * Asserts that the starting and ending region addresses fall within the 1402 * valid range for the map. 1403 */ 1404 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1405 { \ 1406 if (start < vm_map_min(map)) \ 1407 start = vm_map_min(map); \ 1408 if (end > vm_map_max(map)) \ 1409 end = vm_map_max(map); \ 1410 if (start > end) \ 1411 start = end; \ 1412 } 1413 1414 /* 1415 * Used to block when an in-transition collison occurs. The map 1416 * is unlocked for the sleep and relocked before the return. 1417 */ 1418 static 1419 void 1420 vm_map_transition_wait(vm_map_t map) 1421 { 1422 vm_map_unlock(map); 1423 tsleep(map, 0, "vment", 0); 1424 vm_map_lock(map); 1425 } 1426 1427 /* 1428 * When we do blocking operations with the map lock held it is 1429 * possible that a clip might have occured on our in-transit entry, 1430 * requiring an adjustment to the entry in our loop. These macros 1431 * help the pageable and clip_range code deal with the case. The 1432 * conditional costs virtually nothing if no clipping has occured. 1433 */ 1434 1435 #define CLIP_CHECK_BACK(entry, save_start) \ 1436 do { \ 1437 while (entry->start != save_start) { \ 1438 entry = entry->prev; \ 1439 KASSERT(entry != &map->header, ("bad entry clip")); \ 1440 } \ 1441 } while(0) 1442 1443 #define CLIP_CHECK_FWD(entry, save_end) \ 1444 do { \ 1445 while (entry->end != save_end) { \ 1446 entry = entry->next; \ 1447 KASSERT(entry != &map->header, ("bad entry clip")); \ 1448 } \ 1449 } while(0) 1450 1451 1452 /* 1453 * Clip the specified range and return the base entry. The 1454 * range may cover several entries starting at the returned base 1455 * and the first and last entry in the covering sequence will be 1456 * properly clipped to the requested start and end address. 1457 * 1458 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES 1459 * flag. 1460 * 1461 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries 1462 * covered by the requested range. 1463 * 1464 * The map must be exclusively locked on entry and will remain locked 1465 * on return. If no range exists or the range contains holes and you 1466 * specified that no holes were allowed, NULL will be returned. This 1467 * routine may temporarily unlock the map in order avoid a deadlock when 1468 * sleeping. 1469 */ 1470 static 1471 vm_map_entry_t 1472 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, 1473 int *countp, int flags) 1474 { 1475 vm_map_entry_t start_entry; 1476 vm_map_entry_t entry; 1477 1478 /* 1479 * Locate the entry and effect initial clipping. The in-transition 1480 * case does not occur very often so do not try to optimize it. 1481 */ 1482 again: 1483 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) 1484 return (NULL); 1485 entry = start_entry; 1486 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1487 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1488 ++mycpu->gd_cnt.v_intrans_coll; 1489 ++mycpu->gd_cnt.v_intrans_wait; 1490 vm_map_transition_wait(map); 1491 /* 1492 * entry and/or start_entry may have been clipped while 1493 * we slept, or may have gone away entirely. We have 1494 * to restart from the lookup. 1495 */ 1496 goto again; 1497 } 1498 1499 /* 1500 * Since we hold an exclusive map lock we do not have to restart 1501 * after clipping, even though clipping may block in zalloc. 1502 */ 1503 vm_map_clip_start(map, entry, start, countp); 1504 vm_map_clip_end(map, entry, end, countp); 1505 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1506 1507 /* 1508 * Scan entries covered by the range. When working on the next 1509 * entry a restart need only re-loop on the current entry which 1510 * we have already locked, since 'next' may have changed. Also, 1511 * even though entry is safe, it may have been clipped so we 1512 * have to iterate forwards through the clip after sleeping. 1513 */ 1514 while (entry->next != &map->header && entry->next->start < end) { 1515 vm_map_entry_t next = entry->next; 1516 1517 if (flags & MAP_CLIP_NO_HOLES) { 1518 if (next->start > entry->end) { 1519 vm_map_unclip_range(map, start_entry, 1520 start, entry->end, countp, flags); 1521 return(NULL); 1522 } 1523 } 1524 1525 if (next->eflags & MAP_ENTRY_IN_TRANSITION) { 1526 vm_offset_t save_end = entry->end; 1527 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1528 ++mycpu->gd_cnt.v_intrans_coll; 1529 ++mycpu->gd_cnt.v_intrans_wait; 1530 vm_map_transition_wait(map); 1531 1532 /* 1533 * clips might have occured while we blocked. 1534 */ 1535 CLIP_CHECK_FWD(entry, save_end); 1536 CLIP_CHECK_BACK(start_entry, start); 1537 continue; 1538 } 1539 /* 1540 * No restart necessary even though clip_end may block, we 1541 * are holding the map lock. 1542 */ 1543 vm_map_clip_end(map, next, end, countp); 1544 next->eflags |= MAP_ENTRY_IN_TRANSITION; 1545 entry = next; 1546 } 1547 if (flags & MAP_CLIP_NO_HOLES) { 1548 if (entry->end != end) { 1549 vm_map_unclip_range(map, start_entry, 1550 start, entry->end, countp, flags); 1551 return(NULL); 1552 } 1553 } 1554 return(start_entry); 1555 } 1556 1557 /* 1558 * Undo the effect of vm_map_clip_range(). You should pass the same 1559 * flags and the same range that you passed to vm_map_clip_range(). 1560 * This code will clear the in-transition flag on the entries and 1561 * wake up anyone waiting. This code will also simplify the sequence 1562 * and attempt to merge it with entries before and after the sequence. 1563 * 1564 * The map must be locked on entry and will remain locked on return. 1565 * 1566 * Note that you should also pass the start_entry returned by 1567 * vm_map_clip_range(). However, if you block between the two calls 1568 * with the map unlocked please be aware that the start_entry may 1569 * have been clipped and you may need to scan it backwards to find 1570 * the entry corresponding with the original start address. You are 1571 * responsible for this, vm_map_unclip_range() expects the correct 1572 * start_entry to be passed to it and will KASSERT otherwise. 1573 */ 1574 static 1575 void 1576 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry, 1577 vm_offset_t start, vm_offset_t end, 1578 int *countp, int flags) 1579 { 1580 vm_map_entry_t entry; 1581 1582 entry = start_entry; 1583 1584 KASSERT(entry->start == start, ("unclip_range: illegal base entry")); 1585 while (entry != &map->header && entry->start < end) { 1586 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1587 ("in-transition flag not set during unclip on: %p", 1588 entry)); 1589 KASSERT(entry->end <= end, 1590 ("unclip_range: tail wasn't clipped")); 1591 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1592 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1593 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1594 wakeup(map); 1595 } 1596 entry = entry->next; 1597 } 1598 1599 /* 1600 * Simplification does not block so there is no restart case. 1601 */ 1602 entry = start_entry; 1603 while (entry != &map->header && entry->start < end) { 1604 vm_map_simplify_entry(map, entry, countp); 1605 entry = entry->next; 1606 } 1607 } 1608 1609 /* 1610 * Mark the given range as handled by a subordinate map. 1611 * 1612 * This range must have been created with vm_map_find(), and no other 1613 * operations may have been performed on this range prior to calling 1614 * vm_map_submap(). 1615 * 1616 * Submappings cannot be removed. 1617 * 1618 * No requirements. 1619 */ 1620 int 1621 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) 1622 { 1623 vm_map_entry_t entry; 1624 int result = KERN_INVALID_ARGUMENT; 1625 int count; 1626 1627 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1628 vm_map_lock(map); 1629 1630 VM_MAP_RANGE_CHECK(map, start, end); 1631 1632 if (vm_map_lookup_entry(map, start, &entry)) { 1633 vm_map_clip_start(map, entry, start, &count); 1634 } else { 1635 entry = entry->next; 1636 } 1637 1638 vm_map_clip_end(map, entry, end, &count); 1639 1640 if ((entry->start == start) && (entry->end == end) && 1641 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1642 (entry->object.vm_object == NULL)) { 1643 entry->object.sub_map = submap; 1644 entry->maptype = VM_MAPTYPE_SUBMAP; 1645 result = KERN_SUCCESS; 1646 } 1647 vm_map_unlock(map); 1648 vm_map_entry_release(count); 1649 1650 return (result); 1651 } 1652 1653 /* 1654 * Sets the protection of the specified address region in the target map. 1655 * If "set_max" is specified, the maximum protection is to be set; 1656 * otherwise, only the current protection is affected. 1657 * 1658 * The protection is not applicable to submaps, but is applicable to normal 1659 * maps and maps governed by virtual page tables. For example, when operating 1660 * on a virtual page table our protection basically controls how COW occurs 1661 * on the backing object, whereas the virtual page table abstraction itself 1662 * is an abstraction for userland. 1663 * 1664 * No requirements. 1665 */ 1666 int 1667 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1668 vm_prot_t new_prot, boolean_t set_max) 1669 { 1670 vm_map_entry_t current; 1671 vm_map_entry_t entry; 1672 int count; 1673 1674 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1675 vm_map_lock(map); 1676 1677 VM_MAP_RANGE_CHECK(map, start, end); 1678 1679 if (vm_map_lookup_entry(map, start, &entry)) { 1680 vm_map_clip_start(map, entry, start, &count); 1681 } else { 1682 entry = entry->next; 1683 } 1684 1685 /* 1686 * Make a first pass to check for protection violations. 1687 */ 1688 current = entry; 1689 while ((current != &map->header) && (current->start < end)) { 1690 if (current->maptype == VM_MAPTYPE_SUBMAP) { 1691 vm_map_unlock(map); 1692 vm_map_entry_release(count); 1693 return (KERN_INVALID_ARGUMENT); 1694 } 1695 if ((new_prot & current->max_protection) != new_prot) { 1696 vm_map_unlock(map); 1697 vm_map_entry_release(count); 1698 return (KERN_PROTECTION_FAILURE); 1699 } 1700 current = current->next; 1701 } 1702 1703 /* 1704 * Go back and fix up protections. [Note that clipping is not 1705 * necessary the second time.] 1706 */ 1707 current = entry; 1708 1709 while ((current != &map->header) && (current->start < end)) { 1710 vm_prot_t old_prot; 1711 1712 vm_map_clip_end(map, current, end, &count); 1713 1714 old_prot = current->protection; 1715 if (set_max) { 1716 current->protection = 1717 (current->max_protection = new_prot) & 1718 old_prot; 1719 } else { 1720 current->protection = new_prot; 1721 } 1722 1723 /* 1724 * Update physical map if necessary. Worry about copy-on-write 1725 * here -- CHECK THIS XXX 1726 */ 1727 1728 if (current->protection != old_prot) { 1729 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1730 VM_PROT_ALL) 1731 1732 pmap_protect(map->pmap, current->start, 1733 current->end, 1734 current->protection & MASK(current)); 1735 #undef MASK 1736 } 1737 1738 vm_map_simplify_entry(map, current, &count); 1739 1740 current = current->next; 1741 } 1742 1743 vm_map_unlock(map); 1744 vm_map_entry_release(count); 1745 return (KERN_SUCCESS); 1746 } 1747 1748 /* 1749 * This routine traverses a processes map handling the madvise 1750 * system call. Advisories are classified as either those effecting 1751 * the vm_map_entry structure, or those effecting the underlying 1752 * objects. 1753 * 1754 * The <value> argument is used for extended madvise calls. 1755 * 1756 * No requirements. 1757 */ 1758 int 1759 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end, 1760 int behav, off_t value) 1761 { 1762 vm_map_entry_t current, entry; 1763 int modify_map = 0; 1764 int error = 0; 1765 int count; 1766 1767 /* 1768 * Some madvise calls directly modify the vm_map_entry, in which case 1769 * we need to use an exclusive lock on the map and we need to perform 1770 * various clipping operations. Otherwise we only need a read-lock 1771 * on the map. 1772 */ 1773 1774 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1775 1776 switch(behav) { 1777 case MADV_NORMAL: 1778 case MADV_SEQUENTIAL: 1779 case MADV_RANDOM: 1780 case MADV_NOSYNC: 1781 case MADV_AUTOSYNC: 1782 case MADV_NOCORE: 1783 case MADV_CORE: 1784 case MADV_SETMAP: 1785 case MADV_INVAL: 1786 modify_map = 1; 1787 vm_map_lock(map); 1788 break; 1789 case MADV_WILLNEED: 1790 case MADV_DONTNEED: 1791 case MADV_FREE: 1792 vm_map_lock_read(map); 1793 break; 1794 default: 1795 vm_map_entry_release(count); 1796 return (EINVAL); 1797 } 1798 1799 /* 1800 * Locate starting entry and clip if necessary. 1801 */ 1802 1803 VM_MAP_RANGE_CHECK(map, start, end); 1804 1805 if (vm_map_lookup_entry(map, start, &entry)) { 1806 if (modify_map) 1807 vm_map_clip_start(map, entry, start, &count); 1808 } else { 1809 entry = entry->next; 1810 } 1811 1812 if (modify_map) { 1813 /* 1814 * madvise behaviors that are implemented in the vm_map_entry. 1815 * 1816 * We clip the vm_map_entry so that behavioral changes are 1817 * limited to the specified address range. 1818 */ 1819 for (current = entry; 1820 (current != &map->header) && (current->start < end); 1821 current = current->next 1822 ) { 1823 if (current->maptype == VM_MAPTYPE_SUBMAP) 1824 continue; 1825 1826 vm_map_clip_end(map, current, end, &count); 1827 1828 switch (behav) { 1829 case MADV_NORMAL: 1830 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1831 break; 1832 case MADV_SEQUENTIAL: 1833 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1834 break; 1835 case MADV_RANDOM: 1836 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1837 break; 1838 case MADV_NOSYNC: 1839 current->eflags |= MAP_ENTRY_NOSYNC; 1840 break; 1841 case MADV_AUTOSYNC: 1842 current->eflags &= ~MAP_ENTRY_NOSYNC; 1843 break; 1844 case MADV_NOCORE: 1845 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1846 break; 1847 case MADV_CORE: 1848 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1849 break; 1850 case MADV_INVAL: 1851 /* 1852 * Invalidate the related pmap entries, used 1853 * to flush portions of the real kernel's 1854 * pmap when the caller has removed or 1855 * modified existing mappings in a virtual 1856 * page table. 1857 */ 1858 pmap_remove(map->pmap, 1859 current->start, current->end); 1860 break; 1861 case MADV_SETMAP: 1862 /* 1863 * Set the page directory page for a map 1864 * governed by a virtual page table. Mark 1865 * the entry as being governed by a virtual 1866 * page table if it is not. 1867 * 1868 * XXX the page directory page is stored 1869 * in the avail_ssize field if the map_entry. 1870 * 1871 * XXX the map simplification code does not 1872 * compare this field so weird things may 1873 * happen if you do not apply this function 1874 * to the entire mapping governed by the 1875 * virtual page table. 1876 */ 1877 if (current->maptype != VM_MAPTYPE_VPAGETABLE) { 1878 error = EINVAL; 1879 break; 1880 } 1881 current->aux.master_pde = value; 1882 pmap_remove(map->pmap, 1883 current->start, current->end); 1884 break; 1885 default: 1886 error = EINVAL; 1887 break; 1888 } 1889 vm_map_simplify_entry(map, current, &count); 1890 } 1891 vm_map_unlock(map); 1892 } else { 1893 vm_pindex_t pindex; 1894 int count; 1895 1896 /* 1897 * madvise behaviors that are implemented in the underlying 1898 * vm_object. 1899 * 1900 * Since we don't clip the vm_map_entry, we have to clip 1901 * the vm_object pindex and count. 1902 * 1903 * NOTE! We currently do not support these functions on 1904 * virtual page tables. 1905 */ 1906 for (current = entry; 1907 (current != &map->header) && (current->start < end); 1908 current = current->next 1909 ) { 1910 vm_offset_t useStart; 1911 1912 if (current->maptype != VM_MAPTYPE_NORMAL) 1913 continue; 1914 1915 pindex = OFF_TO_IDX(current->offset); 1916 count = atop(current->end - current->start); 1917 useStart = current->start; 1918 1919 if (current->start < start) { 1920 pindex += atop(start - current->start); 1921 count -= atop(start - current->start); 1922 useStart = start; 1923 } 1924 if (current->end > end) 1925 count -= atop(current->end - end); 1926 1927 if (count <= 0) 1928 continue; 1929 1930 vm_object_madvise(current->object.vm_object, 1931 pindex, count, behav); 1932 1933 /* 1934 * Try to populate the page table. Mappings governed 1935 * by virtual page tables cannot be pre-populated 1936 * without a lot of work so don't try. 1937 */ 1938 if (behav == MADV_WILLNEED && 1939 current->maptype != VM_MAPTYPE_VPAGETABLE) { 1940 pmap_object_init_pt( 1941 map->pmap, 1942 useStart, 1943 current->protection, 1944 current->object.vm_object, 1945 pindex, 1946 (count << PAGE_SHIFT), 1947 MAP_PREFAULT_MADVISE 1948 ); 1949 } 1950 } 1951 vm_map_unlock_read(map); 1952 } 1953 vm_map_entry_release(count); 1954 return(error); 1955 } 1956 1957 1958 /* 1959 * Sets the inheritance of the specified address range in the target map. 1960 * Inheritance affects how the map will be shared with child maps at the 1961 * time of vm_map_fork. 1962 */ 1963 int 1964 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 1965 vm_inherit_t new_inheritance) 1966 { 1967 vm_map_entry_t entry; 1968 vm_map_entry_t temp_entry; 1969 int count; 1970 1971 switch (new_inheritance) { 1972 case VM_INHERIT_NONE: 1973 case VM_INHERIT_COPY: 1974 case VM_INHERIT_SHARE: 1975 break; 1976 default: 1977 return (KERN_INVALID_ARGUMENT); 1978 } 1979 1980 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1981 vm_map_lock(map); 1982 1983 VM_MAP_RANGE_CHECK(map, start, end); 1984 1985 if (vm_map_lookup_entry(map, start, &temp_entry)) { 1986 entry = temp_entry; 1987 vm_map_clip_start(map, entry, start, &count); 1988 } else 1989 entry = temp_entry->next; 1990 1991 while ((entry != &map->header) && (entry->start < end)) { 1992 vm_map_clip_end(map, entry, end, &count); 1993 1994 entry->inheritance = new_inheritance; 1995 1996 vm_map_simplify_entry(map, entry, &count); 1997 1998 entry = entry->next; 1999 } 2000 vm_map_unlock(map); 2001 vm_map_entry_release(count); 2002 return (KERN_SUCCESS); 2003 } 2004 2005 /* 2006 * Implement the semantics of mlock 2007 */ 2008 int 2009 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, 2010 boolean_t new_pageable) 2011 { 2012 vm_map_entry_t entry; 2013 vm_map_entry_t start_entry; 2014 vm_offset_t end; 2015 int rv = KERN_SUCCESS; 2016 int count; 2017 2018 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2019 vm_map_lock(map); 2020 VM_MAP_RANGE_CHECK(map, start, real_end); 2021 end = real_end; 2022 2023 start_entry = vm_map_clip_range(map, start, end, &count, 2024 MAP_CLIP_NO_HOLES); 2025 if (start_entry == NULL) { 2026 vm_map_unlock(map); 2027 vm_map_entry_release(count); 2028 return (KERN_INVALID_ADDRESS); 2029 } 2030 2031 if (new_pageable == 0) { 2032 entry = start_entry; 2033 while ((entry != &map->header) && (entry->start < end)) { 2034 vm_offset_t save_start; 2035 vm_offset_t save_end; 2036 2037 /* 2038 * Already user wired or hard wired (trivial cases) 2039 */ 2040 if (entry->eflags & MAP_ENTRY_USER_WIRED) { 2041 entry = entry->next; 2042 continue; 2043 } 2044 if (entry->wired_count != 0) { 2045 entry->wired_count++; 2046 entry->eflags |= MAP_ENTRY_USER_WIRED; 2047 entry = entry->next; 2048 continue; 2049 } 2050 2051 /* 2052 * A new wiring requires instantiation of appropriate 2053 * management structures and the faulting in of the 2054 * page. 2055 */ 2056 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 2057 int copyflag = entry->eflags & 2058 MAP_ENTRY_NEEDS_COPY; 2059 if (copyflag && ((entry->protection & 2060 VM_PROT_WRITE) != 0)) { 2061 vm_map_entry_shadow(entry); 2062 } else if (entry->object.vm_object == NULL && 2063 !map->system_map) { 2064 vm_map_entry_allocate_object(entry); 2065 } 2066 } 2067 entry->wired_count++; 2068 entry->eflags |= MAP_ENTRY_USER_WIRED; 2069 2070 /* 2071 * Now fault in the area. Note that vm_fault_wire() 2072 * may release the map lock temporarily, it will be 2073 * relocked on return. The in-transition 2074 * flag protects the entries. 2075 */ 2076 save_start = entry->start; 2077 save_end = entry->end; 2078 rv = vm_fault_wire(map, entry, TRUE); 2079 if (rv) { 2080 CLIP_CHECK_BACK(entry, save_start); 2081 for (;;) { 2082 KASSERT(entry->wired_count == 1, ("bad wired_count on entry")); 2083 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2084 entry->wired_count = 0; 2085 if (entry->end == save_end) 2086 break; 2087 entry = entry->next; 2088 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2089 } 2090 end = save_start; /* unwire the rest */ 2091 break; 2092 } 2093 /* 2094 * note that even though the entry might have been 2095 * clipped, the USER_WIRED flag we set prevents 2096 * duplication so we do not have to do a 2097 * clip check. 2098 */ 2099 entry = entry->next; 2100 } 2101 2102 /* 2103 * If we failed fall through to the unwiring section to 2104 * unwire what we had wired so far. 'end' has already 2105 * been adjusted. 2106 */ 2107 if (rv) 2108 new_pageable = 1; 2109 2110 /* 2111 * start_entry might have been clipped if we unlocked the 2112 * map and blocked. No matter how clipped it has gotten 2113 * there should be a fragment that is on our start boundary. 2114 */ 2115 CLIP_CHECK_BACK(start_entry, start); 2116 } 2117 2118 /* 2119 * Deal with the unwiring case. 2120 */ 2121 if (new_pageable) { 2122 /* 2123 * This is the unwiring case. We must first ensure that the 2124 * range to be unwired is really wired down. We know there 2125 * are no holes. 2126 */ 2127 entry = start_entry; 2128 while ((entry != &map->header) && (entry->start < end)) { 2129 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2130 rv = KERN_INVALID_ARGUMENT; 2131 goto done; 2132 } 2133 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry)); 2134 entry = entry->next; 2135 } 2136 2137 /* 2138 * Now decrement the wiring count for each region. If a region 2139 * becomes completely unwired, unwire its physical pages and 2140 * mappings. 2141 */ 2142 /* 2143 * The map entries are processed in a loop, checking to 2144 * make sure the entry is wired and asserting it has a wired 2145 * count. However, another loop was inserted more-or-less in 2146 * the middle of the unwiring path. This loop picks up the 2147 * "entry" loop variable from the first loop without first 2148 * setting it to start_entry. Naturally, the secound loop 2149 * is never entered and the pages backing the entries are 2150 * never unwired. This can lead to a leak of wired pages. 2151 */ 2152 entry = start_entry; 2153 while ((entry != &map->header) && (entry->start < end)) { 2154 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, 2155 ("expected USER_WIRED on entry %p", entry)); 2156 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2157 entry->wired_count--; 2158 if (entry->wired_count == 0) 2159 vm_fault_unwire(map, entry); 2160 entry = entry->next; 2161 } 2162 } 2163 done: 2164 vm_map_unclip_range(map, start_entry, start, real_end, &count, 2165 MAP_CLIP_NO_HOLES); 2166 map->timestamp++; 2167 vm_map_unlock(map); 2168 vm_map_entry_release(count); 2169 return (rv); 2170 } 2171 2172 /* 2173 * Sets the pageability of the specified address range in the target map. 2174 * Regions specified as not pageable require locked-down physical 2175 * memory and physical page maps. 2176 * 2177 * The map must not be locked, but a reference must remain to the map 2178 * throughout the call. 2179 * 2180 * This function may be called via the zalloc path and must properly 2181 * reserve map entries for kernel_map. 2182 * 2183 * No requirements. 2184 */ 2185 int 2186 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags) 2187 { 2188 vm_map_entry_t entry; 2189 vm_map_entry_t start_entry; 2190 vm_offset_t end; 2191 int rv = KERN_SUCCESS; 2192 int count; 2193 2194 if (kmflags & KM_KRESERVE) 2195 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT); 2196 else 2197 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2198 vm_map_lock(map); 2199 VM_MAP_RANGE_CHECK(map, start, real_end); 2200 end = real_end; 2201 2202 start_entry = vm_map_clip_range(map, start, end, &count, 2203 MAP_CLIP_NO_HOLES); 2204 if (start_entry == NULL) { 2205 vm_map_unlock(map); 2206 rv = KERN_INVALID_ADDRESS; 2207 goto failure; 2208 } 2209 if ((kmflags & KM_PAGEABLE) == 0) { 2210 /* 2211 * Wiring. 2212 * 2213 * 1. Holding the write lock, we create any shadow or zero-fill 2214 * objects that need to be created. Then we clip each map 2215 * entry to the region to be wired and increment its wiring 2216 * count. We create objects before clipping the map entries 2217 * to avoid object proliferation. 2218 * 2219 * 2. We downgrade to a read lock, and call vm_fault_wire to 2220 * fault in the pages for any newly wired area (wired_count is 2221 * 1). 2222 * 2223 * Downgrading to a read lock for vm_fault_wire avoids a 2224 * possible deadlock with another process that may have faulted 2225 * on one of the pages to be wired (it would mark the page busy, 2226 * blocking us, then in turn block on the map lock that we 2227 * hold). Because of problems in the recursive lock package, 2228 * we cannot upgrade to a write lock in vm_map_lookup. Thus, 2229 * any actions that require the write lock must be done 2230 * beforehand. Because we keep the read lock on the map, the 2231 * copy-on-write status of the entries we modify here cannot 2232 * change. 2233 */ 2234 entry = start_entry; 2235 while ((entry != &map->header) && (entry->start < end)) { 2236 /* 2237 * Trivial case if the entry is already wired 2238 */ 2239 if (entry->wired_count) { 2240 entry->wired_count++; 2241 entry = entry->next; 2242 continue; 2243 } 2244 2245 /* 2246 * The entry is being newly wired, we have to setup 2247 * appropriate management structures. A shadow 2248 * object is required for a copy-on-write region, 2249 * or a normal object for a zero-fill region. We 2250 * do not have to do this for entries that point to sub 2251 * maps because we won't hold the lock on the sub map. 2252 */ 2253 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 2254 int copyflag = entry->eflags & 2255 MAP_ENTRY_NEEDS_COPY; 2256 if (copyflag && ((entry->protection & 2257 VM_PROT_WRITE) != 0)) { 2258 vm_map_entry_shadow(entry); 2259 } else if (entry->object.vm_object == NULL && 2260 !map->system_map) { 2261 vm_map_entry_allocate_object(entry); 2262 } 2263 } 2264 2265 entry->wired_count++; 2266 entry = entry->next; 2267 } 2268 2269 /* 2270 * Pass 2. 2271 */ 2272 2273 /* 2274 * HACK HACK HACK HACK 2275 * 2276 * vm_fault_wire() temporarily unlocks the map to avoid 2277 * deadlocks. The in-transition flag from vm_map_clip_range 2278 * call should protect us from changes while the map is 2279 * unlocked. T 2280 * 2281 * NOTE: Previously this comment stated that clipping might 2282 * still occur while the entry is unlocked, but from 2283 * what I can tell it actually cannot. 2284 * 2285 * It is unclear whether the CLIP_CHECK_*() calls 2286 * are still needed but we keep them in anyway. 2287 * 2288 * HACK HACK HACK HACK 2289 */ 2290 2291 entry = start_entry; 2292 while (entry != &map->header && entry->start < end) { 2293 /* 2294 * If vm_fault_wire fails for any page we need to undo 2295 * what has been done. We decrement the wiring count 2296 * for those pages which have not yet been wired (now) 2297 * and unwire those that have (later). 2298 */ 2299 vm_offset_t save_start = entry->start; 2300 vm_offset_t save_end = entry->end; 2301 2302 if (entry->wired_count == 1) 2303 rv = vm_fault_wire(map, entry, FALSE); 2304 if (rv) { 2305 CLIP_CHECK_BACK(entry, save_start); 2306 for (;;) { 2307 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly")); 2308 entry->wired_count = 0; 2309 if (entry->end == save_end) 2310 break; 2311 entry = entry->next; 2312 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2313 } 2314 end = save_start; 2315 break; 2316 } 2317 CLIP_CHECK_FWD(entry, save_end); 2318 entry = entry->next; 2319 } 2320 2321 /* 2322 * If a failure occured undo everything by falling through 2323 * to the unwiring code. 'end' has already been adjusted 2324 * appropriately. 2325 */ 2326 if (rv) 2327 kmflags |= KM_PAGEABLE; 2328 2329 /* 2330 * start_entry is still IN_TRANSITION but may have been 2331 * clipped since vm_fault_wire() unlocks and relocks the 2332 * map. No matter how clipped it has gotten there should 2333 * be a fragment that is on our start boundary. 2334 */ 2335 CLIP_CHECK_BACK(start_entry, start); 2336 } 2337 2338 if (kmflags & KM_PAGEABLE) { 2339 /* 2340 * This is the unwiring case. We must first ensure that the 2341 * range to be unwired is really wired down. We know there 2342 * are no holes. 2343 */ 2344 entry = start_entry; 2345 while ((entry != &map->header) && (entry->start < end)) { 2346 if (entry->wired_count == 0) { 2347 rv = KERN_INVALID_ARGUMENT; 2348 goto done; 2349 } 2350 entry = entry->next; 2351 } 2352 2353 /* 2354 * Now decrement the wiring count for each region. If a region 2355 * becomes completely unwired, unwire its physical pages and 2356 * mappings. 2357 */ 2358 entry = start_entry; 2359 while ((entry != &map->header) && (entry->start < end)) { 2360 entry->wired_count--; 2361 if (entry->wired_count == 0) 2362 vm_fault_unwire(map, entry); 2363 entry = entry->next; 2364 } 2365 } 2366 done: 2367 vm_map_unclip_range(map, start_entry, start, real_end, 2368 &count, MAP_CLIP_NO_HOLES); 2369 map->timestamp++; 2370 vm_map_unlock(map); 2371 failure: 2372 if (kmflags & KM_KRESERVE) 2373 vm_map_entry_krelease(count); 2374 else 2375 vm_map_entry_release(count); 2376 return (rv); 2377 } 2378 2379 /* 2380 * Mark a newly allocated address range as wired but do not fault in 2381 * the pages. The caller is expected to load the pages into the object. 2382 * 2383 * The map must be locked on entry and will remain locked on return. 2384 * No other requirements. 2385 */ 2386 void 2387 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size, 2388 int *countp) 2389 { 2390 vm_map_entry_t scan; 2391 vm_map_entry_t entry; 2392 2393 entry = vm_map_clip_range(map, addr, addr + size, 2394 countp, MAP_CLIP_NO_HOLES); 2395 for (scan = entry; 2396 scan != &map->header && scan->start < addr + size; 2397 scan = scan->next) { 2398 KKASSERT(entry->wired_count == 0); 2399 entry->wired_count = 1; 2400 } 2401 vm_map_unclip_range(map, entry, addr, addr + size, 2402 countp, MAP_CLIP_NO_HOLES); 2403 } 2404 2405 /* 2406 * Push any dirty cached pages in the address range to their pager. 2407 * If syncio is TRUE, dirty pages are written synchronously. 2408 * If invalidate is TRUE, any cached pages are freed as well. 2409 * 2410 * This routine is called by sys_msync() 2411 * 2412 * Returns an error if any part of the specified range is not mapped. 2413 * 2414 * No requirements. 2415 */ 2416 int 2417 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end, 2418 boolean_t syncio, boolean_t invalidate) 2419 { 2420 vm_map_entry_t current; 2421 vm_map_entry_t entry; 2422 vm_size_t size; 2423 vm_object_t object; 2424 vm_ooffset_t offset; 2425 2426 vm_map_lock_read(map); 2427 VM_MAP_RANGE_CHECK(map, start, end); 2428 if (!vm_map_lookup_entry(map, start, &entry)) { 2429 vm_map_unlock_read(map); 2430 return (KERN_INVALID_ADDRESS); 2431 } 2432 /* 2433 * Make a first pass to check for holes. 2434 */ 2435 for (current = entry; current->start < end; current = current->next) { 2436 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2437 vm_map_unlock_read(map); 2438 return (KERN_INVALID_ARGUMENT); 2439 } 2440 if (end > current->end && 2441 (current->next == &map->header || 2442 current->end != current->next->start)) { 2443 vm_map_unlock_read(map); 2444 return (KERN_INVALID_ADDRESS); 2445 } 2446 } 2447 2448 if (invalidate) 2449 pmap_remove(vm_map_pmap(map), start, end); 2450 2451 /* 2452 * Make a second pass, cleaning/uncaching pages from the indicated 2453 * objects as we go. 2454 * 2455 * Hold vm_token to avoid blocking in vm_object_reference() 2456 */ 2457 lwkt_gettoken(&vm_token); 2458 lwkt_gettoken(&vmobj_token); 2459 2460 for (current = entry; current->start < end; current = current->next) { 2461 offset = current->offset + (start - current->start); 2462 size = (end <= current->end ? end : current->end) - start; 2463 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2464 vm_map_t smap; 2465 vm_map_entry_t tentry; 2466 vm_size_t tsize; 2467 2468 smap = current->object.sub_map; 2469 vm_map_lock_read(smap); 2470 vm_map_lookup_entry(smap, offset, &tentry); 2471 tsize = tentry->end - offset; 2472 if (tsize < size) 2473 size = tsize; 2474 object = tentry->object.vm_object; 2475 offset = tentry->offset + (offset - tentry->start); 2476 vm_map_unlock_read(smap); 2477 } else { 2478 object = current->object.vm_object; 2479 } 2480 /* 2481 * Note that there is absolutely no sense in writing out 2482 * anonymous objects, so we track down the vnode object 2483 * to write out. 2484 * We invalidate (remove) all pages from the address space 2485 * anyway, for semantic correctness. 2486 * 2487 * note: certain anonymous maps, such as MAP_NOSYNC maps, 2488 * may start out with a NULL object. 2489 */ 2490 while (object && object->backing_object) { 2491 offset += object->backing_object_offset; 2492 object = object->backing_object; 2493 if (object->size < OFF_TO_IDX( offset + size)) 2494 size = IDX_TO_OFF(object->size) - offset; 2495 } 2496 if (object && (object->type == OBJT_VNODE) && 2497 (current->protection & VM_PROT_WRITE) && 2498 (object->flags & OBJ_NOMSYNC) == 0) { 2499 /* 2500 * Flush pages if writing is allowed, invalidate them 2501 * if invalidation requested. Pages undergoing I/O 2502 * will be ignored by vm_object_page_remove(). 2503 * 2504 * We cannot lock the vnode and then wait for paging 2505 * to complete without deadlocking against vm_fault. 2506 * Instead we simply call vm_object_page_remove() and 2507 * allow it to block internally on a page-by-page 2508 * basis when it encounters pages undergoing async 2509 * I/O. 2510 */ 2511 int flags; 2512 2513 vm_object_reference_locked(object); 2514 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY); 2515 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 2516 flags |= invalidate ? OBJPC_INVAL : 0; 2517 2518 /* 2519 * When operating on a virtual page table just 2520 * flush the whole object. XXX we probably ought 2521 * to 2522 */ 2523 switch(current->maptype) { 2524 case VM_MAPTYPE_NORMAL: 2525 vm_object_page_clean(object, 2526 OFF_TO_IDX(offset), 2527 OFF_TO_IDX(offset + size + PAGE_MASK), 2528 flags); 2529 break; 2530 case VM_MAPTYPE_VPAGETABLE: 2531 vm_object_page_clean(object, 0, 0, flags); 2532 break; 2533 } 2534 vn_unlock(((struct vnode *)object->handle)); 2535 vm_object_deallocate_locked(object); 2536 } 2537 if (object && invalidate && 2538 ((object->type == OBJT_VNODE) || 2539 (object->type == OBJT_DEVICE))) { 2540 int clean_only = 2541 (object->type == OBJT_DEVICE) ? FALSE : TRUE; 2542 vm_object_reference_locked(object); 2543 switch(current->maptype) { 2544 case VM_MAPTYPE_NORMAL: 2545 vm_object_page_remove(object, 2546 OFF_TO_IDX(offset), 2547 OFF_TO_IDX(offset + size + PAGE_MASK), 2548 clean_only); 2549 break; 2550 case VM_MAPTYPE_VPAGETABLE: 2551 vm_object_page_remove(object, 0, 0, clean_only); 2552 break; 2553 } 2554 vm_object_deallocate_locked(object); 2555 } 2556 start += size; 2557 } 2558 2559 lwkt_reltoken(&vmobj_token); 2560 lwkt_reltoken(&vm_token); 2561 vm_map_unlock_read(map); 2562 2563 return (KERN_SUCCESS); 2564 } 2565 2566 /* 2567 * Make the region specified by this entry pageable. 2568 * 2569 * The vm_map must be exclusively locked. 2570 */ 2571 static void 2572 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2573 { 2574 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2575 entry->wired_count = 0; 2576 vm_fault_unwire(map, entry); 2577 } 2578 2579 /* 2580 * Deallocate the given entry from the target map. 2581 * 2582 * The vm_map must be exclusively locked. 2583 */ 2584 static void 2585 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp) 2586 { 2587 vm_map_entry_unlink(map, entry); 2588 map->size -= entry->end - entry->start; 2589 2590 switch(entry->maptype) { 2591 case VM_MAPTYPE_NORMAL: 2592 case VM_MAPTYPE_VPAGETABLE: 2593 vm_object_deallocate(entry->object.vm_object); 2594 break; 2595 default: 2596 break; 2597 } 2598 2599 vm_map_entry_dispose(map, entry, countp); 2600 } 2601 2602 /* 2603 * Deallocates the given address range from the target map. 2604 * 2605 * The vm_map must be exclusively locked. 2606 */ 2607 int 2608 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp) 2609 { 2610 vm_object_t object; 2611 vm_map_entry_t entry; 2612 vm_map_entry_t first_entry; 2613 2614 ASSERT_VM_MAP_LOCKED(map); 2615 again: 2616 /* 2617 * Find the start of the region, and clip it. Set entry to point 2618 * at the first record containing the requested address or, if no 2619 * such record exists, the next record with a greater address. The 2620 * loop will run from this point until a record beyond the termination 2621 * address is encountered. 2622 * 2623 * map->hint must be adjusted to not point to anything we delete, 2624 * so set it to the entry prior to the one being deleted. 2625 * 2626 * GGG see other GGG comment. 2627 */ 2628 if (vm_map_lookup_entry(map, start, &first_entry)) { 2629 entry = first_entry; 2630 vm_map_clip_start(map, entry, start, countp); 2631 map->hint = entry->prev; /* possible problem XXX */ 2632 } else { 2633 map->hint = first_entry; /* possible problem XXX */ 2634 entry = first_entry->next; 2635 } 2636 2637 /* 2638 * If a hole opens up prior to the current first_free then 2639 * adjust first_free. As with map->hint, map->first_free 2640 * cannot be left set to anything we might delete. 2641 */ 2642 if (entry == &map->header) { 2643 map->first_free = &map->header; 2644 } else if (map->first_free->start >= start) { 2645 map->first_free = entry->prev; 2646 } 2647 2648 /* 2649 * Step through all entries in this region 2650 */ 2651 while ((entry != &map->header) && (entry->start < end)) { 2652 vm_map_entry_t next; 2653 vm_offset_t s, e; 2654 vm_pindex_t offidxstart, offidxend, count; 2655 2656 /* 2657 * If we hit an in-transition entry we have to sleep and 2658 * retry. It's easier (and not really slower) to just retry 2659 * since this case occurs so rarely and the hint is already 2660 * pointing at the right place. We have to reset the 2661 * start offset so as not to accidently delete an entry 2662 * another process just created in vacated space. 2663 */ 2664 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2665 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2666 start = entry->start; 2667 ++mycpu->gd_cnt.v_intrans_coll; 2668 ++mycpu->gd_cnt.v_intrans_wait; 2669 vm_map_transition_wait(map); 2670 goto again; 2671 } 2672 vm_map_clip_end(map, entry, end, countp); 2673 2674 s = entry->start; 2675 e = entry->end; 2676 next = entry->next; 2677 2678 offidxstart = OFF_TO_IDX(entry->offset); 2679 count = OFF_TO_IDX(e - s); 2680 object = entry->object.vm_object; 2681 2682 /* 2683 * Unwire before removing addresses from the pmap; otherwise, 2684 * unwiring will put the entries back in the pmap. 2685 */ 2686 if (entry->wired_count != 0) 2687 vm_map_entry_unwire(map, entry); 2688 2689 offidxend = offidxstart + count; 2690 2691 /* 2692 * Hold vm_token when manipulating vm_objects, 2693 * 2694 * Hold vmobj_token when potentially adding or removing 2695 * objects (collapse requires both). 2696 */ 2697 lwkt_gettoken(&vm_token); 2698 lwkt_gettoken(&vmobj_token); 2699 2700 if (object == &kernel_object) { 2701 vm_object_page_remove(object, offidxstart, 2702 offidxend, FALSE); 2703 } else { 2704 pmap_remove(map->pmap, s, e); 2705 2706 if (object != NULL && 2707 object->ref_count != 1 && 2708 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == 2709 OBJ_ONEMAPPING && 2710 (object->type == OBJT_DEFAULT || 2711 object->type == OBJT_SWAP)) { 2712 vm_object_collapse(object); 2713 vm_object_page_remove(object, offidxstart, 2714 offidxend, FALSE); 2715 if (object->type == OBJT_SWAP) { 2716 swap_pager_freespace(object, 2717 offidxstart, 2718 count); 2719 } 2720 if (offidxend >= object->size && 2721 offidxstart < object->size) { 2722 object->size = offidxstart; 2723 } 2724 } 2725 } 2726 lwkt_reltoken(&vmobj_token); 2727 lwkt_reltoken(&vm_token); 2728 2729 /* 2730 * Delete the entry (which may delete the object) only after 2731 * removing all pmap entries pointing to its pages. 2732 * (Otherwise, its page frames may be reallocated, and any 2733 * modify bits will be set in the wrong object!) 2734 */ 2735 vm_map_entry_delete(map, entry, countp); 2736 entry = next; 2737 } 2738 return (KERN_SUCCESS); 2739 } 2740 2741 /* 2742 * Remove the given address range from the target map. 2743 * This is the exported form of vm_map_delete. 2744 * 2745 * No requirements. 2746 */ 2747 int 2748 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2749 { 2750 int result; 2751 int count; 2752 2753 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2754 vm_map_lock(map); 2755 VM_MAP_RANGE_CHECK(map, start, end); 2756 result = vm_map_delete(map, start, end, &count); 2757 vm_map_unlock(map); 2758 vm_map_entry_release(count); 2759 2760 return (result); 2761 } 2762 2763 /* 2764 * Assert that the target map allows the specified privilege on the 2765 * entire address region given. The entire region must be allocated. 2766 * 2767 * The caller must specify whether the vm_map is already locked or not. 2768 */ 2769 boolean_t 2770 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2771 vm_prot_t protection, boolean_t have_lock) 2772 { 2773 vm_map_entry_t entry; 2774 vm_map_entry_t tmp_entry; 2775 boolean_t result; 2776 2777 if (have_lock == FALSE) 2778 vm_map_lock_read(map); 2779 2780 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 2781 if (have_lock == FALSE) 2782 vm_map_unlock_read(map); 2783 return (FALSE); 2784 } 2785 entry = tmp_entry; 2786 2787 result = TRUE; 2788 while (start < end) { 2789 if (entry == &map->header) { 2790 result = FALSE; 2791 break; 2792 } 2793 /* 2794 * No holes allowed! 2795 */ 2796 2797 if (start < entry->start) { 2798 result = FALSE; 2799 break; 2800 } 2801 /* 2802 * Check protection associated with entry. 2803 */ 2804 2805 if ((entry->protection & protection) != protection) { 2806 result = FALSE; 2807 break; 2808 } 2809 /* go to next entry */ 2810 2811 start = entry->end; 2812 entry = entry->next; 2813 } 2814 if (have_lock == FALSE) 2815 vm_map_unlock_read(map); 2816 return (result); 2817 } 2818 2819 /* 2820 * Split the pages in a map entry into a new object. This affords 2821 * easier removal of unused pages, and keeps object inheritance from 2822 * being a negative impact on memory usage. 2823 * 2824 * The vm_map must be exclusively locked. 2825 */ 2826 static void 2827 vm_map_split(vm_map_entry_t entry) 2828 { 2829 vm_page_t m; 2830 vm_object_t orig_object, new_object, source; 2831 vm_offset_t s, e; 2832 vm_pindex_t offidxstart, offidxend, idx; 2833 vm_size_t size; 2834 vm_ooffset_t offset; 2835 2836 orig_object = entry->object.vm_object; 2837 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 2838 return; 2839 if (orig_object->ref_count <= 1) 2840 return; 2841 2842 offset = entry->offset; 2843 s = entry->start; 2844 e = entry->end; 2845 2846 offidxstart = OFF_TO_IDX(offset); 2847 offidxend = offidxstart + OFF_TO_IDX(e - s); 2848 size = offidxend - offidxstart; 2849 2850 switch(orig_object->type) { 2851 case OBJT_DEFAULT: 2852 new_object = default_pager_alloc(NULL, IDX_TO_OFF(size), 2853 VM_PROT_ALL, 0); 2854 break; 2855 case OBJT_SWAP: 2856 new_object = swap_pager_alloc(NULL, IDX_TO_OFF(size), 2857 VM_PROT_ALL, 0); 2858 break; 2859 default: 2860 /* not reached */ 2861 new_object = NULL; 2862 KKASSERT(0); 2863 } 2864 if (new_object == NULL) 2865 return; 2866 2867 /* 2868 * vm_token required when manipulating vm_objects. 2869 */ 2870 lwkt_gettoken(&vm_token); 2871 lwkt_gettoken(&vmobj_token); 2872 2873 source = orig_object->backing_object; 2874 if (source != NULL) { 2875 /* Referenced by new_object */ 2876 vm_object_reference_locked(source); 2877 LIST_INSERT_HEAD(&source->shadow_head, 2878 new_object, shadow_list); 2879 vm_object_clear_flag(source, OBJ_ONEMAPPING); 2880 new_object->backing_object_offset = 2881 orig_object->backing_object_offset + 2882 IDX_TO_OFF(offidxstart); 2883 new_object->backing_object = source; 2884 source->shadow_count++; 2885 source->generation++; 2886 } 2887 2888 for (idx = 0; idx < size; idx++) { 2889 vm_page_t m; 2890 2891 retry: 2892 m = vm_page_lookup(orig_object, offidxstart + idx); 2893 if (m == NULL) 2894 continue; 2895 2896 /* 2897 * We must wait for pending I/O to complete before we can 2898 * rename the page. 2899 * 2900 * We do not have to VM_PROT_NONE the page as mappings should 2901 * not be changed by this operation. 2902 */ 2903 if (vm_page_sleep_busy(m, TRUE, "spltwt")) 2904 goto retry; 2905 vm_page_busy(m); 2906 vm_page_rename(m, new_object, idx); 2907 /* page automatically made dirty by rename and cache handled */ 2908 vm_page_busy(m); 2909 } 2910 2911 if (orig_object->type == OBJT_SWAP) { 2912 vm_object_pip_add(orig_object, 1); 2913 /* 2914 * copy orig_object pages into new_object 2915 * and destroy unneeded pages in 2916 * shadow object. 2917 */ 2918 swap_pager_copy(orig_object, new_object, offidxstart, 0); 2919 vm_object_pip_wakeup(orig_object); 2920 } 2921 2922 /* 2923 * Wakeup the pages we played with. No spl protection is needed 2924 * for a simple wakeup. 2925 */ 2926 for (idx = 0; idx < size; idx++) { 2927 m = vm_page_lookup(new_object, idx); 2928 if (m) 2929 vm_page_wakeup(m); 2930 } 2931 2932 entry->object.vm_object = new_object; 2933 entry->offset = 0LL; 2934 vm_object_deallocate_locked(orig_object); 2935 lwkt_reltoken(&vmobj_token); 2936 lwkt_reltoken(&vm_token); 2937 } 2938 2939 /* 2940 * Copies the contents of the source entry to the destination 2941 * entry. The entries *must* be aligned properly. 2942 * 2943 * The vm_map must be exclusively locked. 2944 * vm_token must be held 2945 */ 2946 static void 2947 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map, 2948 vm_map_entry_t src_entry, vm_map_entry_t dst_entry) 2949 { 2950 vm_object_t src_object; 2951 2952 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP) 2953 return; 2954 if (src_entry->maptype == VM_MAPTYPE_SUBMAP) 2955 return; 2956 2957 ASSERT_LWKT_TOKEN_HELD(&vm_token); 2958 lwkt_gettoken(&vmobj_token); /* required for collapse */ 2959 2960 if (src_entry->wired_count == 0) { 2961 /* 2962 * If the source entry is marked needs_copy, it is already 2963 * write-protected. 2964 */ 2965 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 2966 pmap_protect(src_map->pmap, 2967 src_entry->start, 2968 src_entry->end, 2969 src_entry->protection & ~VM_PROT_WRITE); 2970 } 2971 2972 /* 2973 * Make a copy of the object. 2974 */ 2975 if ((src_object = src_entry->object.vm_object) != NULL) { 2976 if ((src_object->handle == NULL) && 2977 (src_object->type == OBJT_DEFAULT || 2978 src_object->type == OBJT_SWAP)) { 2979 vm_object_collapse(src_object); 2980 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 2981 vm_map_split(src_entry); 2982 src_object = src_entry->object.vm_object; 2983 } 2984 } 2985 2986 vm_object_reference_locked(src_object); 2987 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 2988 dst_entry->object.vm_object = src_object; 2989 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2990 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2991 dst_entry->offset = src_entry->offset; 2992 } else { 2993 dst_entry->object.vm_object = NULL; 2994 dst_entry->offset = 0; 2995 } 2996 2997 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 2998 dst_entry->end - dst_entry->start, src_entry->start); 2999 } else { 3000 /* 3001 * Of course, wired down pages can't be set copy-on-write. 3002 * Cause wired pages to be copied into the new map by 3003 * simulating faults (the new pages are pageable) 3004 */ 3005 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 3006 } 3007 lwkt_reltoken(&vmobj_token); 3008 } 3009 3010 /* 3011 * vmspace_fork: 3012 * Create a new process vmspace structure and vm_map 3013 * based on those of an existing process. The new map 3014 * is based on the old map, according to the inheritance 3015 * values on the regions in that map. 3016 * 3017 * The source map must not be locked. 3018 * No requirements. 3019 */ 3020 struct vmspace * 3021 vmspace_fork(struct vmspace *vm1) 3022 { 3023 struct vmspace *vm2; 3024 vm_map_t old_map = &vm1->vm_map; 3025 vm_map_t new_map; 3026 vm_map_entry_t old_entry; 3027 vm_map_entry_t new_entry; 3028 vm_object_t object; 3029 int count; 3030 3031 lwkt_gettoken(&vm_token); 3032 lwkt_gettoken(&vmspace_token); 3033 lwkt_gettoken(&vmobj_token); 3034 vm_map_lock(old_map); 3035 old_map->infork = 1; 3036 3037 /* 3038 * XXX Note: upcalls are not copied. 3039 */ 3040 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 3041 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 3042 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); 3043 new_map = &vm2->vm_map; /* XXX */ 3044 new_map->timestamp = 1; 3045 3046 vm_map_lock(new_map); 3047 3048 count = 0; 3049 old_entry = old_map->header.next; 3050 while (old_entry != &old_map->header) { 3051 ++count; 3052 old_entry = old_entry->next; 3053 } 3054 3055 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); 3056 3057 old_entry = old_map->header.next; 3058 while (old_entry != &old_map->header) { 3059 if (old_entry->maptype == VM_MAPTYPE_SUBMAP) 3060 panic("vm_map_fork: encountered a submap"); 3061 3062 switch (old_entry->inheritance) { 3063 case VM_INHERIT_NONE: 3064 break; 3065 case VM_INHERIT_SHARE: 3066 /* 3067 * Clone the entry, creating the shared object if 3068 * necessary. 3069 */ 3070 object = old_entry->object.vm_object; 3071 if (object == NULL) { 3072 vm_map_entry_allocate_object(old_entry); 3073 object = old_entry->object.vm_object; 3074 } 3075 3076 /* 3077 * Add the reference before calling vm_map_entry_shadow 3078 * to insure that a shadow object is created. 3079 */ 3080 vm_object_reference_locked(object); 3081 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3082 vm_map_entry_shadow(old_entry); 3083 /* Transfer the second reference too. */ 3084 vm_object_reference_locked( 3085 old_entry->object.vm_object); 3086 vm_object_deallocate_locked(object); 3087 object = old_entry->object.vm_object; 3088 } 3089 vm_object_clear_flag(object, OBJ_ONEMAPPING); 3090 3091 /* 3092 * Clone the entry, referencing the shared object. 3093 */ 3094 new_entry = vm_map_entry_create(new_map, &count); 3095 *new_entry = *old_entry; 3096 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3097 new_entry->wired_count = 0; 3098 3099 /* 3100 * Insert the entry into the new map -- we know we're 3101 * inserting at the end of the new map. 3102 */ 3103 3104 vm_map_entry_link(new_map, new_map->header.prev, 3105 new_entry); 3106 3107 /* 3108 * Update the physical map 3109 */ 3110 pmap_copy(new_map->pmap, old_map->pmap, 3111 new_entry->start, 3112 (old_entry->end - old_entry->start), 3113 old_entry->start); 3114 break; 3115 case VM_INHERIT_COPY: 3116 /* 3117 * Clone the entry and link into the map. 3118 */ 3119 new_entry = vm_map_entry_create(new_map, &count); 3120 *new_entry = *old_entry; 3121 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3122 new_entry->wired_count = 0; 3123 new_entry->object.vm_object = NULL; 3124 vm_map_entry_link(new_map, new_map->header.prev, 3125 new_entry); 3126 vm_map_copy_entry(old_map, new_map, old_entry, 3127 new_entry); 3128 break; 3129 } 3130 old_entry = old_entry->next; 3131 } 3132 3133 new_map->size = old_map->size; 3134 old_map->infork = 0; 3135 vm_map_unlock(old_map); 3136 vm_map_unlock(new_map); 3137 vm_map_entry_release(count); 3138 3139 lwkt_reltoken(&vmobj_token); 3140 lwkt_reltoken(&vmspace_token); 3141 lwkt_reltoken(&vm_token); 3142 3143 return (vm2); 3144 } 3145 3146 /* 3147 * Create an auto-grow stack entry 3148 * 3149 * No requirements. 3150 */ 3151 int 3152 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3153 int flags, vm_prot_t prot, vm_prot_t max, int cow) 3154 { 3155 vm_map_entry_t prev_entry; 3156 vm_map_entry_t new_stack_entry; 3157 vm_size_t init_ssize; 3158 int rv; 3159 int count; 3160 vm_offset_t tmpaddr; 3161 3162 cow |= MAP_IS_STACK; 3163 3164 if (max_ssize < sgrowsiz) 3165 init_ssize = max_ssize; 3166 else 3167 init_ssize = sgrowsiz; 3168 3169 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3170 vm_map_lock(map); 3171 3172 /* 3173 * Find space for the mapping 3174 */ 3175 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) { 3176 if (vm_map_findspace(map, addrbos, max_ssize, 1, 3177 flags, &tmpaddr)) { 3178 vm_map_unlock(map); 3179 vm_map_entry_release(count); 3180 return (KERN_NO_SPACE); 3181 } 3182 addrbos = tmpaddr; 3183 } 3184 3185 /* If addr is already mapped, no go */ 3186 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3187 vm_map_unlock(map); 3188 vm_map_entry_release(count); 3189 return (KERN_NO_SPACE); 3190 } 3191 3192 #if 0 3193 /* XXX already handled by kern_mmap() */ 3194 /* If we would blow our VMEM resource limit, no go */ 3195 if (map->size + init_ssize > 3196 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3197 vm_map_unlock(map); 3198 vm_map_entry_release(count); 3199 return (KERN_NO_SPACE); 3200 } 3201 #endif 3202 3203 /* 3204 * If we can't accomodate max_ssize in the current mapping, 3205 * no go. However, we need to be aware that subsequent user 3206 * mappings might map into the space we have reserved for 3207 * stack, and currently this space is not protected. 3208 * 3209 * Hopefully we will at least detect this condition 3210 * when we try to grow the stack. 3211 */ 3212 if ((prev_entry->next != &map->header) && 3213 (prev_entry->next->start < addrbos + max_ssize)) { 3214 vm_map_unlock(map); 3215 vm_map_entry_release(count); 3216 return (KERN_NO_SPACE); 3217 } 3218 3219 /* 3220 * We initially map a stack of only init_ssize. We will 3221 * grow as needed later. Since this is to be a grow 3222 * down stack, we map at the top of the range. 3223 * 3224 * Note: we would normally expect prot and max to be 3225 * VM_PROT_ALL, and cow to be 0. Possibly we should 3226 * eliminate these as input parameters, and just 3227 * pass these values here in the insert call. 3228 */ 3229 rv = vm_map_insert(map, &count, 3230 NULL, 0, addrbos + max_ssize - init_ssize, 3231 addrbos + max_ssize, 3232 VM_MAPTYPE_NORMAL, 3233 prot, max, 3234 cow); 3235 3236 /* Now set the avail_ssize amount */ 3237 if (rv == KERN_SUCCESS) { 3238 if (prev_entry != &map->header) 3239 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count); 3240 new_stack_entry = prev_entry->next; 3241 if (new_stack_entry->end != addrbos + max_ssize || 3242 new_stack_entry->start != addrbos + max_ssize - init_ssize) 3243 panic ("Bad entry start/end for new stack entry"); 3244 else 3245 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize; 3246 } 3247 3248 vm_map_unlock(map); 3249 vm_map_entry_release(count); 3250 return (rv); 3251 } 3252 3253 /* 3254 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3255 * desired address is already mapped, or if we successfully grow 3256 * the stack. Also returns KERN_SUCCESS if addr is outside the 3257 * stack range (this is strange, but preserves compatibility with 3258 * the grow function in vm_machdep.c). 3259 * 3260 * No requirements. 3261 */ 3262 int 3263 vm_map_growstack (struct proc *p, vm_offset_t addr) 3264 { 3265 vm_map_entry_t prev_entry; 3266 vm_map_entry_t stack_entry; 3267 vm_map_entry_t new_stack_entry; 3268 struct vmspace *vm = p->p_vmspace; 3269 vm_map_t map = &vm->vm_map; 3270 vm_offset_t end; 3271 int grow_amount; 3272 int rv = KERN_SUCCESS; 3273 int is_procstack; 3274 int use_read_lock = 1; 3275 int count; 3276 3277 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3278 Retry: 3279 if (use_read_lock) 3280 vm_map_lock_read(map); 3281 else 3282 vm_map_lock(map); 3283 3284 /* If addr is already in the entry range, no need to grow.*/ 3285 if (vm_map_lookup_entry(map, addr, &prev_entry)) 3286 goto done; 3287 3288 if ((stack_entry = prev_entry->next) == &map->header) 3289 goto done; 3290 if (prev_entry == &map->header) 3291 end = stack_entry->start - stack_entry->aux.avail_ssize; 3292 else 3293 end = prev_entry->end; 3294 3295 /* 3296 * This next test mimics the old grow function in vm_machdep.c. 3297 * It really doesn't quite make sense, but we do it anyway 3298 * for compatibility. 3299 * 3300 * If not growable stack, return success. This signals the 3301 * caller to proceed as he would normally with normal vm. 3302 */ 3303 if (stack_entry->aux.avail_ssize < 1 || 3304 addr >= stack_entry->start || 3305 addr < stack_entry->start - stack_entry->aux.avail_ssize) { 3306 goto done; 3307 } 3308 3309 /* Find the minimum grow amount */ 3310 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE); 3311 if (grow_amount > stack_entry->aux.avail_ssize) { 3312 rv = KERN_NO_SPACE; 3313 goto done; 3314 } 3315 3316 /* 3317 * If there is no longer enough space between the entries 3318 * nogo, and adjust the available space. Note: this 3319 * should only happen if the user has mapped into the 3320 * stack area after the stack was created, and is 3321 * probably an error. 3322 * 3323 * This also effectively destroys any guard page the user 3324 * might have intended by limiting the stack size. 3325 */ 3326 if (grow_amount > stack_entry->start - end) { 3327 if (use_read_lock && vm_map_lock_upgrade(map)) { 3328 use_read_lock = 0; 3329 goto Retry; 3330 } 3331 use_read_lock = 0; 3332 stack_entry->aux.avail_ssize = stack_entry->start - end; 3333 rv = KERN_NO_SPACE; 3334 goto done; 3335 } 3336 3337 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; 3338 3339 /* If this is the main process stack, see if we're over the 3340 * stack limit. 3341 */ 3342 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3343 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3344 rv = KERN_NO_SPACE; 3345 goto done; 3346 } 3347 3348 /* Round up the grow amount modulo SGROWSIZ */ 3349 grow_amount = roundup (grow_amount, sgrowsiz); 3350 if (grow_amount > stack_entry->aux.avail_ssize) { 3351 grow_amount = stack_entry->aux.avail_ssize; 3352 } 3353 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3354 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3355 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 3356 ctob(vm->vm_ssize); 3357 } 3358 3359 /* If we would blow our VMEM resource limit, no go */ 3360 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3361 rv = KERN_NO_SPACE; 3362 goto done; 3363 } 3364 3365 if (use_read_lock && vm_map_lock_upgrade(map)) { 3366 use_read_lock = 0; 3367 goto Retry; 3368 } 3369 use_read_lock = 0; 3370 3371 /* Get the preliminary new entry start value */ 3372 addr = stack_entry->start - grow_amount; 3373 3374 /* If this puts us into the previous entry, cut back our growth 3375 * to the available space. Also, see the note above. 3376 */ 3377 if (addr < end) { 3378 stack_entry->aux.avail_ssize = stack_entry->start - end; 3379 addr = end; 3380 } 3381 3382 rv = vm_map_insert(map, &count, 3383 NULL, 0, addr, stack_entry->start, 3384 VM_MAPTYPE_NORMAL, 3385 VM_PROT_ALL, VM_PROT_ALL, 3386 0); 3387 3388 /* Adjust the available stack space by the amount we grew. */ 3389 if (rv == KERN_SUCCESS) { 3390 if (prev_entry != &map->header) 3391 vm_map_clip_end(map, prev_entry, addr, &count); 3392 new_stack_entry = prev_entry->next; 3393 if (new_stack_entry->end != stack_entry->start || 3394 new_stack_entry->start != addr) 3395 panic ("Bad stack grow start/end in new stack entry"); 3396 else { 3397 new_stack_entry->aux.avail_ssize = 3398 stack_entry->aux.avail_ssize - 3399 (new_stack_entry->end - new_stack_entry->start); 3400 if (is_procstack) 3401 vm->vm_ssize += btoc(new_stack_entry->end - 3402 new_stack_entry->start); 3403 } 3404 } 3405 3406 done: 3407 if (use_read_lock) 3408 vm_map_unlock_read(map); 3409 else 3410 vm_map_unlock(map); 3411 vm_map_entry_release(count); 3412 return (rv); 3413 } 3414 3415 /* 3416 * Unshare the specified VM space for exec. If other processes are 3417 * mapped to it, then create a new one. The new vmspace is null. 3418 * 3419 * No requirements. 3420 */ 3421 void 3422 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 3423 { 3424 struct vmspace *oldvmspace = p->p_vmspace; 3425 struct vmspace *newvmspace; 3426 vm_map_t map = &p->p_vmspace->vm_map; 3427 3428 /* 3429 * If we are execing a resident vmspace we fork it, otherwise 3430 * we create a new vmspace. Note that exitingcnt and upcalls 3431 * are not copied to the new vmspace. 3432 */ 3433 lwkt_gettoken(&vmspace_token); 3434 if (vmcopy) { 3435 newvmspace = vmspace_fork(vmcopy); 3436 } else { 3437 newvmspace = vmspace_alloc(map->min_offset, map->max_offset); 3438 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 3439 (caddr_t)&oldvmspace->vm_endcopy - 3440 (caddr_t)&oldvmspace->vm_startcopy); 3441 } 3442 3443 /* 3444 * Finish initializing the vmspace before assigning it 3445 * to the process. The vmspace will become the current vmspace 3446 * if p == curproc. 3447 */ 3448 pmap_pinit2(vmspace_pmap(newvmspace)); 3449 pmap_replacevm(p, newvmspace, 0); 3450 sysref_put(&oldvmspace->vm_sysref); 3451 lwkt_reltoken(&vmspace_token); 3452 } 3453 3454 /* 3455 * Unshare the specified VM space for forcing COW. This 3456 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3457 * 3458 * The exitingcnt test is not strictly necessary but has been 3459 * included for code sanity (to make the code a bit more deterministic). 3460 */ 3461 void 3462 vmspace_unshare(struct proc *p) 3463 { 3464 struct vmspace *oldvmspace = p->p_vmspace; 3465 struct vmspace *newvmspace; 3466 3467 lwkt_gettoken(&vmspace_token); 3468 if (oldvmspace->vm_sysref.refcnt == 1 && oldvmspace->vm_exitingcnt == 0) 3469 return; 3470 newvmspace = vmspace_fork(oldvmspace); 3471 pmap_pinit2(vmspace_pmap(newvmspace)); 3472 pmap_replacevm(p, newvmspace, 0); 3473 sysref_put(&oldvmspace->vm_sysref); 3474 lwkt_reltoken(&vmspace_token); 3475 } 3476 3477 /* 3478 * Finds the VM object, offset, and protection for a given virtual address 3479 * in the specified map, assuming a page fault of the type specified. 3480 * 3481 * Leaves the map in question locked for read; return values are guaranteed 3482 * until a vm_map_lookup_done call is performed. Note that the map argument 3483 * is in/out; the returned map must be used in the call to vm_map_lookup_done. 3484 * 3485 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make 3486 * that fast. 3487 * 3488 * If a lookup is requested with "write protection" specified, the map may 3489 * be changed to perform virtual copying operations, although the data 3490 * referenced will remain the same. 3491 * 3492 * No requirements. 3493 */ 3494 int 3495 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3496 vm_offset_t vaddr, 3497 vm_prot_t fault_typea, 3498 vm_map_entry_t *out_entry, /* OUT */ 3499 vm_object_t *object, /* OUT */ 3500 vm_pindex_t *pindex, /* OUT */ 3501 vm_prot_t *out_prot, /* OUT */ 3502 boolean_t *wired) /* OUT */ 3503 { 3504 vm_map_entry_t entry; 3505 vm_map_t map = *var_map; 3506 vm_prot_t prot; 3507 vm_prot_t fault_type = fault_typea; 3508 int use_read_lock = 1; 3509 int rv = KERN_SUCCESS; 3510 3511 RetryLookup: 3512 if (use_read_lock) 3513 vm_map_lock_read(map); 3514 else 3515 vm_map_lock(map); 3516 3517 /* 3518 * If the map has an interesting hint, try it before calling full 3519 * blown lookup routine. 3520 */ 3521 entry = map->hint; 3522 *out_entry = entry; 3523 3524 if ((entry == &map->header) || 3525 (vaddr < entry->start) || (vaddr >= entry->end)) { 3526 vm_map_entry_t tmp_entry; 3527 3528 /* 3529 * Entry was either not a valid hint, or the vaddr was not 3530 * contained in the entry, so do a full lookup. 3531 */ 3532 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { 3533 rv = KERN_INVALID_ADDRESS; 3534 goto done; 3535 } 3536 3537 entry = tmp_entry; 3538 *out_entry = entry; 3539 } 3540 3541 /* 3542 * Handle submaps. 3543 */ 3544 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3545 vm_map_t old_map = map; 3546 3547 *var_map = map = entry->object.sub_map; 3548 if (use_read_lock) 3549 vm_map_unlock_read(old_map); 3550 else 3551 vm_map_unlock(old_map); 3552 use_read_lock = 1; 3553 goto RetryLookup; 3554 } 3555 3556 /* 3557 * Check whether this task is allowed to have this page. 3558 * Note the special case for MAP_ENTRY_COW 3559 * pages with an override. This is to implement a forced 3560 * COW for debuggers. 3561 */ 3562 3563 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3564 prot = entry->max_protection; 3565 else 3566 prot = entry->protection; 3567 3568 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3569 if ((fault_type & prot) != fault_type) { 3570 rv = KERN_PROTECTION_FAILURE; 3571 goto done; 3572 } 3573 3574 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3575 (entry->eflags & MAP_ENTRY_COW) && 3576 (fault_type & VM_PROT_WRITE) && 3577 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 3578 rv = KERN_PROTECTION_FAILURE; 3579 goto done; 3580 } 3581 3582 /* 3583 * If this page is not pageable, we have to get it for all possible 3584 * accesses. 3585 */ 3586 *wired = (entry->wired_count != 0); 3587 if (*wired) 3588 prot = fault_type = entry->protection; 3589 3590 /* 3591 * Virtual page tables may need to update the accessed (A) bit 3592 * in a page table entry. Upgrade the fault to a write fault for 3593 * that case if the map will support it. If the map does not support 3594 * it the page table entry simply will not be updated. 3595 */ 3596 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 3597 if (prot & VM_PROT_WRITE) 3598 fault_type |= VM_PROT_WRITE; 3599 } 3600 3601 /* 3602 * If the entry was copy-on-write, we either ... 3603 */ 3604 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3605 /* 3606 * If we want to write the page, we may as well handle that 3607 * now since we've got the map locked. 3608 * 3609 * If we don't need to write the page, we just demote the 3610 * permissions allowed. 3611 */ 3612 3613 if (fault_type & VM_PROT_WRITE) { 3614 /* 3615 * Make a new object, and place it in the object 3616 * chain. Note that no new references have appeared 3617 * -- one just moved from the map to the new 3618 * object. 3619 */ 3620 3621 if (use_read_lock && vm_map_lock_upgrade(map)) { 3622 use_read_lock = 0; 3623 goto RetryLookup; 3624 } 3625 use_read_lock = 0; 3626 3627 vm_map_entry_shadow(entry); 3628 } else { 3629 /* 3630 * We're attempting to read a copy-on-write page -- 3631 * don't allow writes. 3632 */ 3633 3634 prot &= ~VM_PROT_WRITE; 3635 } 3636 } 3637 3638 /* 3639 * Create an object if necessary. 3640 */ 3641 if (entry->object.vm_object == NULL && 3642 !map->system_map) { 3643 if (use_read_lock && vm_map_lock_upgrade(map)) { 3644 use_read_lock = 0; 3645 goto RetryLookup; 3646 } 3647 use_read_lock = 0; 3648 vm_map_entry_allocate_object(entry); 3649 } 3650 3651 /* 3652 * Return the object/offset from this entry. If the entry was 3653 * copy-on-write or empty, it has been fixed up. 3654 */ 3655 3656 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3657 *object = entry->object.vm_object; 3658 3659 /* 3660 * Return whether this is the only map sharing this data. On 3661 * success we return with a read lock held on the map. On failure 3662 * we return with the map unlocked. 3663 */ 3664 *out_prot = prot; 3665 done: 3666 if (rv == KERN_SUCCESS) { 3667 if (use_read_lock == 0) 3668 vm_map_lock_downgrade(map); 3669 } else if (use_read_lock) { 3670 vm_map_unlock_read(map); 3671 } else { 3672 vm_map_unlock(map); 3673 } 3674 return (rv); 3675 } 3676 3677 /* 3678 * Releases locks acquired by a vm_map_lookup() 3679 * (according to the handle returned by that lookup). 3680 * 3681 * No other requirements. 3682 */ 3683 void 3684 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) 3685 { 3686 /* 3687 * Unlock the main-level map 3688 */ 3689 vm_map_unlock_read(map); 3690 if (count) 3691 vm_map_entry_release(count); 3692 } 3693 3694 #include "opt_ddb.h" 3695 #ifdef DDB 3696 #include <sys/kernel.h> 3697 3698 #include <ddb/ddb.h> 3699 3700 /* 3701 * Debugging only 3702 */ 3703 DB_SHOW_COMMAND(map, vm_map_print) 3704 { 3705 static int nlines; 3706 /* XXX convert args. */ 3707 vm_map_t map = (vm_map_t)addr; 3708 boolean_t full = have_addr; 3709 3710 vm_map_entry_t entry; 3711 3712 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 3713 (void *)map, 3714 (void *)map->pmap, map->nentries, map->timestamp); 3715 nlines++; 3716 3717 if (!full && db_indent) 3718 return; 3719 3720 db_indent += 2; 3721 for (entry = map->header.next; entry != &map->header; 3722 entry = entry->next) { 3723 db_iprintf("map entry %p: start=%p, end=%p\n", 3724 (void *)entry, (void *)entry->start, (void *)entry->end); 3725 nlines++; 3726 { 3727 static char *inheritance_name[4] = 3728 {"share", "copy", "none", "donate_copy"}; 3729 3730 db_iprintf(" prot=%x/%x/%s", 3731 entry->protection, 3732 entry->max_protection, 3733 inheritance_name[(int)(unsigned char)entry->inheritance]); 3734 if (entry->wired_count != 0) 3735 db_printf(", wired"); 3736 } 3737 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3738 /* XXX no %qd in kernel. Truncate entry->offset. */ 3739 db_printf(", share=%p, offset=0x%lx\n", 3740 (void *)entry->object.sub_map, 3741 (long)entry->offset); 3742 nlines++; 3743 if ((entry->prev == &map->header) || 3744 (entry->prev->object.sub_map != 3745 entry->object.sub_map)) { 3746 db_indent += 2; 3747 vm_map_print((db_expr_t)(intptr_t) 3748 entry->object.sub_map, 3749 full, 0, NULL); 3750 db_indent -= 2; 3751 } 3752 } else { 3753 /* XXX no %qd in kernel. Truncate entry->offset. */ 3754 db_printf(", object=%p, offset=0x%lx", 3755 (void *)entry->object.vm_object, 3756 (long)entry->offset); 3757 if (entry->eflags & MAP_ENTRY_COW) 3758 db_printf(", copy (%s)", 3759 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 3760 db_printf("\n"); 3761 nlines++; 3762 3763 if ((entry->prev == &map->header) || 3764 (entry->prev->object.vm_object != 3765 entry->object.vm_object)) { 3766 db_indent += 2; 3767 vm_object_print((db_expr_t)(intptr_t) 3768 entry->object.vm_object, 3769 full, 0, NULL); 3770 nlines += 4; 3771 db_indent -= 2; 3772 } 3773 } 3774 } 3775 db_indent -= 2; 3776 if (db_indent == 0) 3777 nlines = 0; 3778 } 3779 3780 /* 3781 * Debugging only 3782 */ 3783 DB_SHOW_COMMAND(procvm, procvm) 3784 { 3785 struct proc *p; 3786 3787 if (have_addr) { 3788 p = (struct proc *) addr; 3789 } else { 3790 p = curproc; 3791 } 3792 3793 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 3794 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 3795 (void *)vmspace_pmap(p->p_vmspace)); 3796 3797 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 3798 } 3799 3800 #endif /* DDB */ 3801