1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 39 * 40 * 41 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42 * All rights reserved. 43 * 44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45 * 46 * Permission to use, copy, modify and distribute this software and 47 * its documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 * 66 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $ 67 * $DragonFly: src/sys/vm/vm_map.c,v 1.56 2007/04/29 18:25:41 dillon Exp $ 68 */ 69 70 /* 71 * Virtual memory mapping module. 72 */ 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/kernel.h> 77 #include <sys/proc.h> 78 #include <sys/serialize.h> 79 #include <sys/lock.h> 80 #include <sys/vmmeter.h> 81 #include <sys/mman.h> 82 #include <sys/vnode.h> 83 #include <sys/resourcevar.h> 84 #include <sys/shm.h> 85 #include <sys/tree.h> 86 #include <sys/malloc.h> 87 88 #include <vm/vm.h> 89 #include <vm/vm_param.h> 90 #include <vm/pmap.h> 91 #include <vm/vm_map.h> 92 #include <vm/vm_page.h> 93 #include <vm/vm_object.h> 94 #include <vm/vm_pager.h> 95 #include <vm/vm_kern.h> 96 #include <vm/vm_extern.h> 97 #include <vm/swap_pager.h> 98 #include <vm/vm_zone.h> 99 100 #include <sys/thread2.h> 101 #include <sys/sysref2.h> 102 #include <sys/random.h> 103 #include <sys/sysctl.h> 104 105 /* 106 * Virtual memory maps provide for the mapping, protection, and sharing 107 * of virtual memory objects. In addition, this module provides for an 108 * efficient virtual copy of memory from one map to another. 109 * 110 * Synchronization is required prior to most operations. 111 * 112 * Maps consist of an ordered doubly-linked list of simple entries. 113 * A hint and a RB tree is used to speed-up lookups. 114 * 115 * Callers looking to modify maps specify start/end addresses which cause 116 * the related map entry to be clipped if necessary, and then later 117 * recombined if the pieces remained compatible. 118 * 119 * Virtual copy operations are performed by copying VM object references 120 * from one map to another, and then marking both regions as copy-on-write. 121 */ 122 static void vmspace_terminate(struct vmspace *vm); 123 static void vmspace_lock(struct vmspace *vm); 124 static void vmspace_unlock(struct vmspace *vm); 125 static void vmspace_dtor(void *obj, void *private); 126 127 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore"); 128 129 struct sysref_class vmspace_sysref_class = { 130 .name = "vmspace", 131 .mtype = M_VMSPACE, 132 .proto = SYSREF_PROTO_VMSPACE, 133 .offset = offsetof(struct vmspace, vm_sysref), 134 .objsize = sizeof(struct vmspace), 135 .nom_cache = 32, 136 .flags = SRC_MANAGEDINIT, 137 .dtor = vmspace_dtor, 138 .ops = { 139 .terminate = (sysref_terminate_func_t)vmspace_terminate, 140 .lock = (sysref_lock_func_t)vmspace_lock, 141 .unlock = (sysref_lock_func_t)vmspace_unlock 142 } 143 }; 144 145 /* 146 * per-cpu page table cross mappings are initialized in early boot 147 * and might require a considerable number of vm_map_entry structures. 148 */ 149 #define VMEPERCPU (MAXCPU+1) 150 151 static struct vm_zone mapentzone_store, mapzone_store; 152 static vm_zone_t mapentzone, mapzone; 153 static struct vm_object mapentobj, mapobj; 154 155 static struct vm_map_entry map_entry_init[MAX_MAPENT]; 156 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU]; 157 static struct vm_map map_init[MAX_KMAP]; 158 159 static int randomize_mmap; 160 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0, 161 "Randomize mmap offsets"); 162 163 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref); 164 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *); 165 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); 166 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 167 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 168 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); 169 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); 170 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, 171 vm_map_entry_t); 172 static void vm_map_unclip_range (vm_map_t map, vm_map_entry_t start_entry, vm_offset_t start, vm_offset_t end, int *count, int flags); 173 174 /* 175 * Initialize the vm_map module. Must be called before any other vm_map 176 * routines. 177 * 178 * Map and entry structures are allocated from the general purpose 179 * memory pool with some exceptions: 180 * 181 * - The kernel map is allocated statically. 182 * - Initial kernel map entries are allocated out of a static pool. 183 * 184 * These restrictions are necessary since malloc() uses the 185 * maps and requires map entries. 186 * 187 * Called from the low level boot code only. 188 */ 189 void 190 vm_map_startup(void) 191 { 192 mapzone = &mapzone_store; 193 zbootinit(mapzone, "MAP", sizeof (struct vm_map), 194 map_init, MAX_KMAP); 195 mapentzone = &mapentzone_store; 196 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), 197 map_entry_init, MAX_MAPENT); 198 } 199 200 /* 201 * Called prior to any vmspace allocations. 202 * 203 * Called from the low level boot code only. 204 */ 205 void 206 vm_init2(void) 207 { 208 zinitna(mapentzone, &mapentobj, NULL, 0, 0, 209 ZONE_USE_RESERVE | ZONE_SPECIAL, 1); 210 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1); 211 pmap_init2(); 212 vm_object_init2(); 213 } 214 215 216 /* 217 * Red black tree functions 218 * 219 * The caller must hold the related map lock. 220 */ 221 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); 222 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); 223 224 /* a->start is address, and the only field has to be initialized */ 225 static int 226 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) 227 { 228 if (a->start < b->start) 229 return(-1); 230 else if (a->start > b->start) 231 return(1); 232 return(0); 233 } 234 235 /* 236 * Allocate a vmspace structure, including a vm_map and pmap. 237 * Initialize numerous fields. While the initial allocation is zerod, 238 * subsequence reuse from the objcache leaves elements of the structure 239 * intact (particularly the pmap), so portions must be zerod. 240 * 241 * The structure is not considered activated until we call sysref_activate(). 242 * 243 * No requirements. 244 */ 245 struct vmspace * 246 vmspace_alloc(vm_offset_t min, vm_offset_t max) 247 { 248 struct vmspace *vm; 249 250 vm = sysref_alloc(&vmspace_sysref_class); 251 bzero(&vm->vm_startcopy, 252 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy); 253 vm_map_init(&vm->vm_map, min, max, NULL); 254 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */ 255 lwkt_gettoken(&vm->vm_map.token); 256 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 257 vm->vm_shm = NULL; 258 vm->vm_exitingcnt = 0; 259 cpu_vmspace_alloc(vm); 260 sysref_activate(&vm->vm_sysref); 261 lwkt_reltoken(&vm->vm_map.token); 262 263 return (vm); 264 } 265 266 /* 267 * dtor function - Some elements of the pmap are retained in the 268 * free-cached vmspaces to improve performance. We have to clean them up 269 * here before returning the vmspace to the memory pool. 270 * 271 * No requirements. 272 */ 273 static void 274 vmspace_dtor(void *obj, void *private) 275 { 276 struct vmspace *vm = obj; 277 278 pmap_puninit(vmspace_pmap(vm)); 279 } 280 281 /* 282 * Called in two cases: 283 * 284 * (1) When the last sysref is dropped, but exitingcnt might still be 285 * non-zero. 286 * 287 * (2) When there are no sysrefs (i.e. refcnt is negative) left and the 288 * exitingcnt becomes zero 289 * 290 * sysref will not scrap the object until we call sysref_put() once more 291 * after the last ref has been dropped. 292 * 293 * Interlocked by the sysref API. 294 */ 295 static void 296 vmspace_terminate(struct vmspace *vm) 297 { 298 int count; 299 300 /* 301 * If exitingcnt is non-zero we can't get rid of the entire vmspace 302 * yet, but we can scrap user memory. 303 */ 304 lwkt_gettoken(&vm->vm_map.token); 305 if (vm->vm_exitingcnt) { 306 shmexit(vm); 307 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, 308 VM_MAX_USER_ADDRESS); 309 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, 310 VM_MAX_USER_ADDRESS); 311 lwkt_reltoken(&vm->vm_map.token); 312 return; 313 } 314 cpu_vmspace_free(vm); 315 316 /* 317 * Make sure any SysV shm is freed, it might not have in 318 * exit1() 319 */ 320 shmexit(vm); 321 322 KKASSERT(vm->vm_upcalls == NULL); 323 324 /* 325 * Lock the map, to wait out all other references to it. 326 * Delete all of the mappings and pages they hold, then call 327 * the pmap module to reclaim anything left. 328 */ 329 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 330 vm_map_lock(&vm->vm_map); 331 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 332 vm->vm_map.max_offset, &count); 333 vm_map_unlock(&vm->vm_map); 334 vm_map_entry_release(count); 335 336 lwkt_gettoken(&vmspace_pmap(vm)->pm_token); 337 pmap_release(vmspace_pmap(vm)); 338 lwkt_reltoken(&vmspace_pmap(vm)->pm_token); 339 lwkt_reltoken(&vm->vm_map.token); 340 sysref_put(&vm->vm_sysref); 341 } 342 343 /* 344 * vmspaces are not currently locked. 345 */ 346 static void 347 vmspace_lock(struct vmspace *vm __unused) 348 { 349 } 350 351 static void 352 vmspace_unlock(struct vmspace *vm __unused) 353 { 354 } 355 356 /* 357 * This is called during exit indicating that the vmspace is no 358 * longer in used by an exiting process, but the process has not yet 359 * been cleaned up. 360 * 361 * No requirements. 362 */ 363 void 364 vmspace_exitbump(struct vmspace *vm) 365 { 366 lwkt_gettoken(&vm->vm_map.token); 367 ++vm->vm_exitingcnt; 368 lwkt_reltoken(&vm->vm_map.token); 369 } 370 371 /* 372 * This is called in the wait*() handling code. The vmspace can be terminated 373 * after the last wait is finished using it. 374 * 375 * No requirements. 376 */ 377 void 378 vmspace_exitfree(struct proc *p) 379 { 380 struct vmspace *vm; 381 382 vm = p->p_vmspace; 383 lwkt_gettoken(&vm->vm_map.token); 384 p->p_vmspace = NULL; 385 386 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref)) { 387 lwkt_reltoken(&vm->vm_map.token); 388 vmspace_terminate(vm); 389 } else { 390 lwkt_reltoken(&vm->vm_map.token); 391 } 392 } 393 394 /* 395 * Swap useage is determined by taking the proportional swap used by 396 * VM objects backing the VM map. To make up for fractional losses, 397 * if the VM object has any swap use at all the associated map entries 398 * count for at least 1 swap page. 399 * 400 * No requirements. 401 */ 402 int 403 vmspace_swap_count(struct vmspace *vm) 404 { 405 vm_map_t map = &vm->vm_map; 406 vm_map_entry_t cur; 407 vm_object_t object; 408 int count = 0; 409 int n; 410 411 lwkt_gettoken(&vm->vm_map.token); 412 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 413 switch(cur->maptype) { 414 case VM_MAPTYPE_NORMAL: 415 case VM_MAPTYPE_VPAGETABLE: 416 if ((object = cur->object.vm_object) == NULL) 417 break; 418 if (object->swblock_count) { 419 n = (cur->end - cur->start) / PAGE_SIZE; 420 count += object->swblock_count * 421 SWAP_META_PAGES * n / object->size + 1; 422 } 423 break; 424 default: 425 break; 426 } 427 } 428 lwkt_reltoken(&vm->vm_map.token); 429 return(count); 430 } 431 432 /* 433 * Calculate the approximate number of anonymous pages in use by 434 * this vmspace. To make up for fractional losses, we count each 435 * VM object as having at least 1 anonymous page. 436 * 437 * No requirements. 438 */ 439 int 440 vmspace_anonymous_count(struct vmspace *vm) 441 { 442 vm_map_t map = &vm->vm_map; 443 vm_map_entry_t cur; 444 vm_object_t object; 445 int count = 0; 446 447 lwkt_gettoken(&vm->vm_map.token); 448 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 449 switch(cur->maptype) { 450 case VM_MAPTYPE_NORMAL: 451 case VM_MAPTYPE_VPAGETABLE: 452 if ((object = cur->object.vm_object) == NULL) 453 break; 454 if (object->type != OBJT_DEFAULT && 455 object->type != OBJT_SWAP) { 456 break; 457 } 458 count += object->resident_page_count; 459 break; 460 default: 461 break; 462 } 463 } 464 lwkt_reltoken(&vm->vm_map.token); 465 return(count); 466 } 467 468 /* 469 * Creates and returns a new empty VM map with the given physical map 470 * structure, and having the given lower and upper address bounds. 471 * 472 * No requirements. 473 */ 474 vm_map_t 475 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max) 476 { 477 if (result == NULL) 478 result = zalloc(mapzone); 479 vm_map_init(result, min, max, pmap); 480 return (result); 481 } 482 483 /* 484 * Initialize an existing vm_map structure such as that in the vmspace 485 * structure. The pmap is initialized elsewhere. 486 * 487 * No requirements. 488 */ 489 void 490 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap) 491 { 492 map->header.next = map->header.prev = &map->header; 493 RB_INIT(&map->rb_root); 494 map->nentries = 0; 495 map->size = 0; 496 map->system_map = 0; 497 map->min_offset = min; 498 map->max_offset = max; 499 map->pmap = pmap; 500 map->first_free = &map->header; 501 map->hint = &map->header; 502 map->timestamp = 0; 503 map->flags = 0; 504 lwkt_token_init(&map->token, "vm_map"); 505 lockinit(&map->lock, "thrd_sleep", (hz + 9) / 10, 0); 506 TUNABLE_INT("vm.cache_vmspaces", &vmspace_sysref_class.nom_cache); 507 } 508 509 /* 510 * Shadow the vm_map_entry's object. This typically needs to be done when 511 * a write fault is taken on an entry which had previously been cloned by 512 * fork(). The shared object (which might be NULL) must become private so 513 * we add a shadow layer above it. 514 * 515 * Object allocation for anonymous mappings is defered as long as possible. 516 * When creating a shadow, however, the underlying object must be instantiated 517 * so it can be shared. 518 * 519 * If the map segment is governed by a virtual page table then it is 520 * possible to address offsets beyond the mapped area. Just allocate 521 * a maximally sized object for this case. 522 * 523 * The vm_map must be exclusively locked. 524 * No other requirements. 525 */ 526 static 527 void 528 vm_map_entry_shadow(vm_map_entry_t entry, int addref) 529 { 530 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 531 vm_object_shadow(&entry->object.vm_object, &entry->offset, 532 0x7FFFFFFF, addref); /* XXX */ 533 } else { 534 vm_object_shadow(&entry->object.vm_object, &entry->offset, 535 atop(entry->end - entry->start), addref); 536 } 537 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 538 } 539 540 /* 541 * Allocate an object for a vm_map_entry. 542 * 543 * Object allocation for anonymous mappings is defered as long as possible. 544 * This function is called when we can defer no longer, generally when a map 545 * entry might be split or forked or takes a page fault. 546 * 547 * If the map segment is governed by a virtual page table then it is 548 * possible to address offsets beyond the mapped area. Just allocate 549 * a maximally sized object for this case. 550 * 551 * The vm_map must be exclusively locked. 552 * No other requirements. 553 */ 554 void 555 vm_map_entry_allocate_object(vm_map_entry_t entry) 556 { 557 vm_object_t obj; 558 559 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 560 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */ 561 } else { 562 obj = vm_object_allocate(OBJT_DEFAULT, 563 atop(entry->end - entry->start)); 564 } 565 entry->object.vm_object = obj; 566 entry->offset = 0; 567 } 568 569 /* 570 * Set an initial negative count so the first attempt to reserve 571 * space preloads a bunch of vm_map_entry's for this cpu. Also 572 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to 573 * map a new page for vm_map_entry structures. SMP systems are 574 * particularly sensitive. 575 * 576 * This routine is called in early boot so we cannot just call 577 * vm_map_entry_reserve(). 578 * 579 * Called from the low level boot code only (for each cpu) 580 */ 581 void 582 vm_map_entry_reserve_cpu_init(globaldata_t gd) 583 { 584 vm_map_entry_t entry; 585 int i; 586 587 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2; 588 entry = &cpu_map_entry_init[gd->gd_cpuid][0]; 589 for (i = 0; i < VMEPERCPU; ++i, ++entry) { 590 entry->next = gd->gd_vme_base; 591 gd->gd_vme_base = entry; 592 } 593 } 594 595 /* 596 * Reserves vm_map_entry structures so code later on can manipulate 597 * map_entry structures within a locked map without blocking trying 598 * to allocate a new vm_map_entry. 599 * 600 * No requirements. 601 */ 602 int 603 vm_map_entry_reserve(int count) 604 { 605 struct globaldata *gd = mycpu; 606 vm_map_entry_t entry; 607 608 /* 609 * Make sure we have enough structures in gd_vme_base to handle 610 * the reservation request. 611 * 612 * The critical section protects access to the per-cpu gd. 613 */ 614 crit_enter(); 615 while (gd->gd_vme_avail < count) { 616 entry = zalloc(mapentzone); 617 entry->next = gd->gd_vme_base; 618 gd->gd_vme_base = entry; 619 ++gd->gd_vme_avail; 620 } 621 gd->gd_vme_avail -= count; 622 crit_exit(); 623 624 return(count); 625 } 626 627 /* 628 * Releases previously reserved vm_map_entry structures that were not 629 * used. If we have too much junk in our per-cpu cache clean some of 630 * it out. 631 * 632 * No requirements. 633 */ 634 void 635 vm_map_entry_release(int count) 636 { 637 struct globaldata *gd = mycpu; 638 vm_map_entry_t entry; 639 640 crit_enter(); 641 gd->gd_vme_avail += count; 642 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) { 643 entry = gd->gd_vme_base; 644 KKASSERT(entry != NULL); 645 gd->gd_vme_base = entry->next; 646 --gd->gd_vme_avail; 647 crit_exit(); 648 zfree(mapentzone, entry); 649 crit_enter(); 650 } 651 crit_exit(); 652 } 653 654 /* 655 * Reserve map entry structures for use in kernel_map itself. These 656 * entries have *ALREADY* been reserved on a per-cpu basis when the map 657 * was inited. This function is used by zalloc() to avoid a recursion 658 * when zalloc() itself needs to allocate additional kernel memory. 659 * 660 * This function works like the normal reserve but does not load the 661 * vm_map_entry cache (because that would result in an infinite 662 * recursion). Note that gd_vme_avail may go negative. This is expected. 663 * 664 * Any caller of this function must be sure to renormalize after 665 * potentially eating entries to ensure that the reserve supply 666 * remains intact. 667 * 668 * No requirements. 669 */ 670 int 671 vm_map_entry_kreserve(int count) 672 { 673 struct globaldata *gd = mycpu; 674 675 crit_enter(); 676 gd->gd_vme_avail -= count; 677 crit_exit(); 678 KASSERT(gd->gd_vme_base != NULL, 679 ("no reserved entries left, gd_vme_avail = %d\n", 680 gd->gd_vme_avail)); 681 return(count); 682 } 683 684 /* 685 * Release previously reserved map entries for kernel_map. We do not 686 * attempt to clean up like the normal release function as this would 687 * cause an unnecessary (but probably not fatal) deep procedure call. 688 * 689 * No requirements. 690 */ 691 void 692 vm_map_entry_krelease(int count) 693 { 694 struct globaldata *gd = mycpu; 695 696 crit_enter(); 697 gd->gd_vme_avail += count; 698 crit_exit(); 699 } 700 701 /* 702 * Allocates a VM map entry for insertion. No entry fields are filled in. 703 * 704 * The entries should have previously been reserved. The reservation count 705 * is tracked in (*countp). 706 * 707 * No requirements. 708 */ 709 static vm_map_entry_t 710 vm_map_entry_create(vm_map_t map, int *countp) 711 { 712 struct globaldata *gd = mycpu; 713 vm_map_entry_t entry; 714 715 KKASSERT(*countp > 0); 716 --*countp; 717 crit_enter(); 718 entry = gd->gd_vme_base; 719 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); 720 gd->gd_vme_base = entry->next; 721 crit_exit(); 722 723 return(entry); 724 } 725 726 /* 727 * Dispose of a vm_map_entry that is no longer being referenced. 728 * 729 * No requirements. 730 */ 731 static void 732 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) 733 { 734 struct globaldata *gd = mycpu; 735 736 KKASSERT(map->hint != entry); 737 KKASSERT(map->first_free != entry); 738 739 ++*countp; 740 crit_enter(); 741 entry->next = gd->gd_vme_base; 742 gd->gd_vme_base = entry; 743 crit_exit(); 744 } 745 746 747 /* 748 * Insert/remove entries from maps. 749 * 750 * The related map must be exclusively locked. 751 * The caller must hold map->token 752 * No other requirements. 753 */ 754 static __inline void 755 vm_map_entry_link(vm_map_t map, 756 vm_map_entry_t after_where, 757 vm_map_entry_t entry) 758 { 759 ASSERT_VM_MAP_LOCKED(map); 760 761 map->nentries++; 762 entry->prev = after_where; 763 entry->next = after_where->next; 764 entry->next->prev = entry; 765 after_where->next = entry; 766 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) 767 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); 768 } 769 770 static __inline void 771 vm_map_entry_unlink(vm_map_t map, 772 vm_map_entry_t entry) 773 { 774 vm_map_entry_t prev; 775 vm_map_entry_t next; 776 777 ASSERT_VM_MAP_LOCKED(map); 778 779 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 780 panic("vm_map_entry_unlink: attempt to mess with " 781 "locked entry! %p", entry); 782 } 783 prev = entry->prev; 784 next = entry->next; 785 next->prev = prev; 786 prev->next = next; 787 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); 788 map->nentries--; 789 } 790 791 /* 792 * Finds the map entry containing (or immediately preceding) the specified 793 * address in the given map. The entry is returned in (*entry). 794 * 795 * The boolean result indicates whether the address is actually contained 796 * in the map. 797 * 798 * The related map must be locked. 799 * No other requirements. 800 */ 801 boolean_t 802 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry) 803 { 804 vm_map_entry_t tmp; 805 vm_map_entry_t last; 806 807 ASSERT_VM_MAP_LOCKED(map); 808 #if 0 809 /* 810 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive 811 * the hint code with the red-black lookup meets with system crashes 812 * and lockups. We do not yet know why. 813 * 814 * It is possible that the problem is related to the setting 815 * of the hint during map_entry deletion, in the code specified 816 * at the GGG comment later on in this file. 817 */ 818 /* 819 * Quickly check the cached hint, there's a good chance of a match. 820 */ 821 if (map->hint != &map->header) { 822 tmp = map->hint; 823 if (address >= tmp->start && address < tmp->end) { 824 *entry = tmp; 825 return(TRUE); 826 } 827 } 828 #endif 829 830 /* 831 * Locate the record from the top of the tree. 'last' tracks the 832 * closest prior record and is returned if no match is found, which 833 * in binary tree terms means tracking the most recent right-branch 834 * taken. If there is no prior record, &map->header is returned. 835 */ 836 last = &map->header; 837 tmp = RB_ROOT(&map->rb_root); 838 839 while (tmp) { 840 if (address >= tmp->start) { 841 if (address < tmp->end) { 842 *entry = tmp; 843 map->hint = tmp; 844 return(TRUE); 845 } 846 last = tmp; 847 tmp = RB_RIGHT(tmp, rb_entry); 848 } else { 849 tmp = RB_LEFT(tmp, rb_entry); 850 } 851 } 852 *entry = last; 853 return (FALSE); 854 } 855 856 /* 857 * Inserts the given whole VM object into the target map at the specified 858 * address range. The object's size should match that of the address range. 859 * 860 * The map must be exclusively locked. 861 * The object must be held. 862 * The caller must have reserved sufficient vm_map_entry structures. 863 * 864 * If object is non-NULL, ref count must be bumped by caller prior to 865 * making call to account for the new entry. 866 */ 867 int 868 vm_map_insert(vm_map_t map, int *countp, 869 vm_object_t object, vm_ooffset_t offset, 870 vm_offset_t start, vm_offset_t end, 871 vm_maptype_t maptype, 872 vm_prot_t prot, vm_prot_t max, 873 int cow) 874 { 875 vm_map_entry_t new_entry; 876 vm_map_entry_t prev_entry; 877 vm_map_entry_t temp_entry; 878 vm_eflags_t protoeflags; 879 int must_drop = 0; 880 881 ASSERT_VM_MAP_LOCKED(map); 882 if (object) 883 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); 884 885 /* 886 * Check that the start and end points are not bogus. 887 */ 888 if ((start < map->min_offset) || (end > map->max_offset) || 889 (start >= end)) 890 return (KERN_INVALID_ADDRESS); 891 892 /* 893 * Find the entry prior to the proposed starting address; if it's part 894 * of an existing entry, this range is bogus. 895 */ 896 if (vm_map_lookup_entry(map, start, &temp_entry)) 897 return (KERN_NO_SPACE); 898 899 prev_entry = temp_entry; 900 901 /* 902 * Assert that the next entry doesn't overlap the end point. 903 */ 904 905 if ((prev_entry->next != &map->header) && 906 (prev_entry->next->start < end)) 907 return (KERN_NO_SPACE); 908 909 protoeflags = 0; 910 911 if (cow & MAP_COPY_ON_WRITE) 912 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 913 914 if (cow & MAP_NOFAULT) { 915 protoeflags |= MAP_ENTRY_NOFAULT; 916 917 KASSERT(object == NULL, 918 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 919 } 920 if (cow & MAP_DISABLE_SYNCER) 921 protoeflags |= MAP_ENTRY_NOSYNC; 922 if (cow & MAP_DISABLE_COREDUMP) 923 protoeflags |= MAP_ENTRY_NOCOREDUMP; 924 if (cow & MAP_IS_STACK) 925 protoeflags |= MAP_ENTRY_STACK; 926 if (cow & MAP_IS_KSTACK) 927 protoeflags |= MAP_ENTRY_KSTACK; 928 929 lwkt_gettoken(&map->token); 930 931 if (object) { 932 /* 933 * When object is non-NULL, it could be shared with another 934 * process. We have to set or clear OBJ_ONEMAPPING 935 * appropriately. 936 */ 937 if ((object->ref_count > 1) || (object->shadow_count != 0)) { 938 vm_object_clear_flag(object, OBJ_ONEMAPPING); 939 } 940 } 941 else if ((prev_entry != &map->header) && 942 (prev_entry->eflags == protoeflags) && 943 (prev_entry->end == start) && 944 (prev_entry->wired_count == 0) && 945 prev_entry->maptype == maptype && 946 ((prev_entry->object.vm_object == NULL) || 947 vm_object_coalesce(prev_entry->object.vm_object, 948 OFF_TO_IDX(prev_entry->offset), 949 (vm_size_t)(prev_entry->end - prev_entry->start), 950 (vm_size_t)(end - prev_entry->end)))) { 951 /* 952 * We were able to extend the object. Determine if we 953 * can extend the previous map entry to include the 954 * new range as well. 955 */ 956 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 957 (prev_entry->protection == prot) && 958 (prev_entry->max_protection == max)) { 959 map->size += (end - prev_entry->end); 960 prev_entry->end = end; 961 vm_map_simplify_entry(map, prev_entry, countp); 962 lwkt_reltoken(&map->token); 963 return (KERN_SUCCESS); 964 } 965 966 /* 967 * If we can extend the object but cannot extend the 968 * map entry, we have to create a new map entry. We 969 * must bump the ref count on the extended object to 970 * account for it. object may be NULL. 971 */ 972 object = prev_entry->object.vm_object; 973 offset = prev_entry->offset + 974 (prev_entry->end - prev_entry->start); 975 if (object) { 976 vm_object_hold(object); 977 vm_object_chain_wait(object); 978 vm_object_reference_locked(object); 979 must_drop = 1; 980 } 981 } 982 983 /* 984 * NOTE: if conditionals fail, object can be NULL here. This occurs 985 * in things like the buffer map where we manage kva but do not manage 986 * backing objects. 987 */ 988 989 /* 990 * Create a new entry 991 */ 992 993 new_entry = vm_map_entry_create(map, countp); 994 new_entry->start = start; 995 new_entry->end = end; 996 997 new_entry->maptype = maptype; 998 new_entry->eflags = protoeflags; 999 new_entry->object.vm_object = object; 1000 new_entry->offset = offset; 1001 new_entry->aux.master_pde = 0; 1002 1003 new_entry->inheritance = VM_INHERIT_DEFAULT; 1004 new_entry->protection = prot; 1005 new_entry->max_protection = max; 1006 new_entry->wired_count = 0; 1007 1008 /* 1009 * Insert the new entry into the list 1010 */ 1011 1012 vm_map_entry_link(map, prev_entry, new_entry); 1013 map->size += new_entry->end - new_entry->start; 1014 1015 /* 1016 * Update the free space hint. Entries cannot overlap. 1017 * An exact comparison is needed to avoid matching 1018 * against the map->header. 1019 */ 1020 if ((map->first_free == prev_entry) && 1021 (prev_entry->end == new_entry->start)) { 1022 map->first_free = new_entry; 1023 } 1024 1025 #if 0 1026 /* 1027 * Temporarily removed to avoid MAP_STACK panic, due to 1028 * MAP_STACK being a huge hack. Will be added back in 1029 * when MAP_STACK (and the user stack mapping) is fixed. 1030 */ 1031 /* 1032 * It may be possible to simplify the entry 1033 */ 1034 vm_map_simplify_entry(map, new_entry, countp); 1035 #endif 1036 1037 /* 1038 * Try to pre-populate the page table. Mappings governed by virtual 1039 * page tables cannot be prepopulated without a lot of work, so 1040 * don't try. 1041 */ 1042 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) && 1043 maptype != VM_MAPTYPE_VPAGETABLE) { 1044 pmap_object_init_pt(map->pmap, start, prot, 1045 object, OFF_TO_IDX(offset), end - start, 1046 cow & MAP_PREFAULT_PARTIAL); 1047 } 1048 if (must_drop) 1049 vm_object_drop(object); 1050 1051 lwkt_reltoken(&map->token); 1052 return (KERN_SUCCESS); 1053 } 1054 1055 /* 1056 * Find sufficient space for `length' bytes in the given map, starting at 1057 * `start'. Returns 0 on success, 1 on no space. 1058 * 1059 * This function will returned an arbitrarily aligned pointer. If no 1060 * particular alignment is required you should pass align as 1. Note that 1061 * the map may return PAGE_SIZE aligned pointers if all the lengths used in 1062 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align 1063 * argument. 1064 * 1065 * 'align' should be a power of 2 but is not required to be. 1066 * 1067 * The map must be exclusively locked. 1068 * No other requirements. 1069 */ 1070 int 1071 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 1072 vm_size_t align, int flags, vm_offset_t *addr) 1073 { 1074 vm_map_entry_t entry, next; 1075 vm_offset_t end; 1076 vm_offset_t align_mask; 1077 1078 if (start < map->min_offset) 1079 start = map->min_offset; 1080 if (start > map->max_offset) 1081 return (1); 1082 1083 /* 1084 * If the alignment is not a power of 2 we will have to use 1085 * a mod/division, set align_mask to a special value. 1086 */ 1087 if ((align | (align - 1)) + 1 != (align << 1)) 1088 align_mask = (vm_offset_t)-1; 1089 else 1090 align_mask = align - 1; 1091 1092 /* 1093 * Look for the first possible address; if there's already something 1094 * at this address, we have to start after it. 1095 */ 1096 if (start == map->min_offset) { 1097 if ((entry = map->first_free) != &map->header) 1098 start = entry->end; 1099 } else { 1100 vm_map_entry_t tmp; 1101 1102 if (vm_map_lookup_entry(map, start, &tmp)) 1103 start = tmp->end; 1104 entry = tmp; 1105 } 1106 1107 /* 1108 * Look through the rest of the map, trying to fit a new region in the 1109 * gap between existing regions, or after the very last region. 1110 */ 1111 for (;; start = (entry = next)->end) { 1112 /* 1113 * Adjust the proposed start by the requested alignment, 1114 * be sure that we didn't wrap the address. 1115 */ 1116 if (align_mask == (vm_offset_t)-1) 1117 end = ((start + align - 1) / align) * align; 1118 else 1119 end = (start + align_mask) & ~align_mask; 1120 if (end < start) 1121 return (1); 1122 start = end; 1123 /* 1124 * Find the end of the proposed new region. Be sure we didn't 1125 * go beyond the end of the map, or wrap around the address. 1126 * Then check to see if this is the last entry or if the 1127 * proposed end fits in the gap between this and the next 1128 * entry. 1129 */ 1130 end = start + length; 1131 if (end > map->max_offset || end < start) 1132 return (1); 1133 next = entry->next; 1134 1135 /* 1136 * If the next entry's start address is beyond the desired 1137 * end address we may have found a good entry. 1138 * 1139 * If the next entry is a stack mapping we do not map into 1140 * the stack's reserved space. 1141 * 1142 * XXX continue to allow mapping into the stack's reserved 1143 * space if doing a MAP_STACK mapping inside a MAP_STACK 1144 * mapping, for backwards compatibility. But the caller 1145 * really should use MAP_STACK | MAP_TRYFIXED if they 1146 * want to do that. 1147 */ 1148 if (next == &map->header) 1149 break; 1150 if (next->start >= end) { 1151 if ((next->eflags & MAP_ENTRY_STACK) == 0) 1152 break; 1153 if (flags & MAP_STACK) 1154 break; 1155 if (next->start - next->aux.avail_ssize >= end) 1156 break; 1157 } 1158 } 1159 map->hint = entry; 1160 1161 /* 1162 * Grow the kernel_map if necessary. pmap_growkernel() will panic 1163 * if it fails. The kernel_map is locked and nothing can steal 1164 * our address space if pmap_growkernel() blocks. 1165 * 1166 * NOTE: This may be unconditionally called for kldload areas on 1167 * x86_64 because these do not bump kernel_vm_end (which would 1168 * fill 128G worth of page tables!). Therefore we must not 1169 * retry. 1170 */ 1171 if (map == &kernel_map) { 1172 vm_offset_t kstop; 1173 1174 kstop = round_page(start + length); 1175 if (kstop > kernel_vm_end) 1176 pmap_growkernel(start, kstop); 1177 } 1178 *addr = start; 1179 return (0); 1180 } 1181 1182 /* 1183 * vm_map_find finds an unallocated region in the target address map with 1184 * the given length and allocates it. The search is defined to be first-fit 1185 * from the specified address; the region found is returned in the same 1186 * parameter. 1187 * 1188 * If object is non-NULL, ref count must be bumped by caller 1189 * prior to making call to account for the new entry. 1190 * 1191 * No requirements. This function will lock the map temporarily. 1192 */ 1193 int 1194 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1195 vm_offset_t *addr, vm_size_t length, vm_size_t align, 1196 boolean_t fitit, 1197 vm_maptype_t maptype, 1198 vm_prot_t prot, vm_prot_t max, 1199 int cow) 1200 { 1201 vm_offset_t start; 1202 int result; 1203 int count; 1204 1205 start = *addr; 1206 1207 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1208 vm_map_lock(map); 1209 if (object) 1210 vm_object_hold(object); 1211 if (fitit) { 1212 if (vm_map_findspace(map, start, length, align, 0, addr)) { 1213 vm_map_unlock(map); 1214 vm_map_entry_release(count); 1215 return (KERN_NO_SPACE); 1216 } 1217 start = *addr; 1218 } 1219 result = vm_map_insert(map, &count, object, offset, 1220 start, start + length, 1221 maptype, 1222 prot, max, 1223 cow); 1224 if (object) 1225 vm_object_drop(object); 1226 vm_map_unlock(map); 1227 vm_map_entry_release(count); 1228 1229 return (result); 1230 } 1231 1232 /* 1233 * Simplify the given map entry by merging with either neighbor. This 1234 * routine also has the ability to merge with both neighbors. 1235 * 1236 * This routine guarentees that the passed entry remains valid (though 1237 * possibly extended). When merging, this routine may delete one or 1238 * both neighbors. No action is taken on entries which have their 1239 * in-transition flag set. 1240 * 1241 * The map must be exclusively locked. 1242 */ 1243 void 1244 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp) 1245 { 1246 vm_map_entry_t next, prev; 1247 vm_size_t prevsize, esize; 1248 1249 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1250 ++mycpu->gd_cnt.v_intrans_coll; 1251 return; 1252 } 1253 1254 if (entry->maptype == VM_MAPTYPE_SUBMAP) 1255 return; 1256 1257 prev = entry->prev; 1258 if (prev != &map->header) { 1259 prevsize = prev->end - prev->start; 1260 if ( (prev->end == entry->start) && 1261 (prev->maptype == entry->maptype) && 1262 (prev->object.vm_object == entry->object.vm_object) && 1263 (!prev->object.vm_object || 1264 (prev->offset + prevsize == entry->offset)) && 1265 (prev->eflags == entry->eflags) && 1266 (prev->protection == entry->protection) && 1267 (prev->max_protection == entry->max_protection) && 1268 (prev->inheritance == entry->inheritance) && 1269 (prev->wired_count == entry->wired_count)) { 1270 if (map->first_free == prev) 1271 map->first_free = entry; 1272 if (map->hint == prev) 1273 map->hint = entry; 1274 vm_map_entry_unlink(map, prev); 1275 entry->start = prev->start; 1276 entry->offset = prev->offset; 1277 if (prev->object.vm_object) 1278 vm_object_deallocate(prev->object.vm_object); 1279 vm_map_entry_dispose(map, prev, countp); 1280 } 1281 } 1282 1283 next = entry->next; 1284 if (next != &map->header) { 1285 esize = entry->end - entry->start; 1286 if ((entry->end == next->start) && 1287 (next->maptype == entry->maptype) && 1288 (next->object.vm_object == entry->object.vm_object) && 1289 (!entry->object.vm_object || 1290 (entry->offset + esize == next->offset)) && 1291 (next->eflags == entry->eflags) && 1292 (next->protection == entry->protection) && 1293 (next->max_protection == entry->max_protection) && 1294 (next->inheritance == entry->inheritance) && 1295 (next->wired_count == entry->wired_count)) { 1296 if (map->first_free == next) 1297 map->first_free = entry; 1298 if (map->hint == next) 1299 map->hint = entry; 1300 vm_map_entry_unlink(map, next); 1301 entry->end = next->end; 1302 if (next->object.vm_object) 1303 vm_object_deallocate(next->object.vm_object); 1304 vm_map_entry_dispose(map, next, countp); 1305 } 1306 } 1307 } 1308 1309 /* 1310 * Asserts that the given entry begins at or after the specified address. 1311 * If necessary, it splits the entry into two. 1312 */ 1313 #define vm_map_clip_start(map, entry, startaddr, countp) \ 1314 { \ 1315 if (startaddr > entry->start) \ 1316 _vm_map_clip_start(map, entry, startaddr, countp); \ 1317 } 1318 1319 /* 1320 * This routine is called only when it is known that the entry must be split. 1321 * 1322 * The map must be exclusively locked. 1323 */ 1324 static void 1325 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start, 1326 int *countp) 1327 { 1328 vm_map_entry_t new_entry; 1329 1330 /* 1331 * Split off the front portion -- note that we must insert the new 1332 * entry BEFORE this one, so that this entry has the specified 1333 * starting address. 1334 */ 1335 1336 vm_map_simplify_entry(map, entry, countp); 1337 1338 /* 1339 * If there is no object backing this entry, we might as well create 1340 * one now. If we defer it, an object can get created after the map 1341 * is clipped, and individual objects will be created for the split-up 1342 * map. This is a bit of a hack, but is also about the best place to 1343 * put this improvement. 1344 */ 1345 if (entry->object.vm_object == NULL && !map->system_map) { 1346 vm_map_entry_allocate_object(entry); 1347 } 1348 1349 new_entry = vm_map_entry_create(map, countp); 1350 *new_entry = *entry; 1351 1352 new_entry->end = start; 1353 entry->offset += (start - entry->start); 1354 entry->start = start; 1355 1356 vm_map_entry_link(map, entry->prev, new_entry); 1357 1358 switch(entry->maptype) { 1359 case VM_MAPTYPE_NORMAL: 1360 case VM_MAPTYPE_VPAGETABLE: 1361 if (new_entry->object.vm_object) { 1362 vm_object_hold(new_entry->object.vm_object); 1363 vm_object_chain_wait(new_entry->object.vm_object); 1364 vm_object_reference_locked(new_entry->object.vm_object); 1365 vm_object_drop(new_entry->object.vm_object); 1366 } 1367 break; 1368 default: 1369 break; 1370 } 1371 } 1372 1373 /* 1374 * Asserts that the given entry ends at or before the specified address. 1375 * If necessary, it splits the entry into two. 1376 * 1377 * The map must be exclusively locked. 1378 */ 1379 #define vm_map_clip_end(map, entry, endaddr, countp) \ 1380 { \ 1381 if (endaddr < entry->end) \ 1382 _vm_map_clip_end(map, entry, endaddr, countp); \ 1383 } 1384 1385 /* 1386 * This routine is called only when it is known that the entry must be split. 1387 * 1388 * The map must be exclusively locked. 1389 */ 1390 static void 1391 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end, 1392 int *countp) 1393 { 1394 vm_map_entry_t new_entry; 1395 1396 /* 1397 * If there is no object backing this entry, we might as well create 1398 * one now. If we defer it, an object can get created after the map 1399 * is clipped, and individual objects will be created for the split-up 1400 * map. This is a bit of a hack, but is also about the best place to 1401 * put this improvement. 1402 */ 1403 1404 if (entry->object.vm_object == NULL && !map->system_map) { 1405 vm_map_entry_allocate_object(entry); 1406 } 1407 1408 /* 1409 * Create a new entry and insert it AFTER the specified entry 1410 */ 1411 1412 new_entry = vm_map_entry_create(map, countp); 1413 *new_entry = *entry; 1414 1415 new_entry->start = entry->end = end; 1416 new_entry->offset += (end - entry->start); 1417 1418 vm_map_entry_link(map, entry, new_entry); 1419 1420 switch(entry->maptype) { 1421 case VM_MAPTYPE_NORMAL: 1422 case VM_MAPTYPE_VPAGETABLE: 1423 if (new_entry->object.vm_object) { 1424 vm_object_hold(new_entry->object.vm_object); 1425 vm_object_chain_wait(new_entry->object.vm_object); 1426 vm_object_reference_locked(new_entry->object.vm_object); 1427 vm_object_drop(new_entry->object.vm_object); 1428 } 1429 break; 1430 default: 1431 break; 1432 } 1433 } 1434 1435 /* 1436 * Asserts that the starting and ending region addresses fall within the 1437 * valid range for the map. 1438 */ 1439 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1440 { \ 1441 if (start < vm_map_min(map)) \ 1442 start = vm_map_min(map); \ 1443 if (end > vm_map_max(map)) \ 1444 end = vm_map_max(map); \ 1445 if (start > end) \ 1446 start = end; \ 1447 } 1448 1449 /* 1450 * Used to block when an in-transition collison occurs. The map 1451 * is unlocked for the sleep and relocked before the return. 1452 */ 1453 void 1454 vm_map_transition_wait(vm_map_t map) 1455 { 1456 tsleep_interlock(map, 0); 1457 vm_map_unlock(map); 1458 tsleep(map, PINTERLOCKED, "vment", 0); 1459 vm_map_lock(map); 1460 } 1461 1462 /* 1463 * When we do blocking operations with the map lock held it is 1464 * possible that a clip might have occured on our in-transit entry, 1465 * requiring an adjustment to the entry in our loop. These macros 1466 * help the pageable and clip_range code deal with the case. The 1467 * conditional costs virtually nothing if no clipping has occured. 1468 */ 1469 1470 #define CLIP_CHECK_BACK(entry, save_start) \ 1471 do { \ 1472 while (entry->start != save_start) { \ 1473 entry = entry->prev; \ 1474 KASSERT(entry != &map->header, ("bad entry clip")); \ 1475 } \ 1476 } while(0) 1477 1478 #define CLIP_CHECK_FWD(entry, save_end) \ 1479 do { \ 1480 while (entry->end != save_end) { \ 1481 entry = entry->next; \ 1482 KASSERT(entry != &map->header, ("bad entry clip")); \ 1483 } \ 1484 } while(0) 1485 1486 1487 /* 1488 * Clip the specified range and return the base entry. The 1489 * range may cover several entries starting at the returned base 1490 * and the first and last entry in the covering sequence will be 1491 * properly clipped to the requested start and end address. 1492 * 1493 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES 1494 * flag. 1495 * 1496 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries 1497 * covered by the requested range. 1498 * 1499 * The map must be exclusively locked on entry and will remain locked 1500 * on return. If no range exists or the range contains holes and you 1501 * specified that no holes were allowed, NULL will be returned. This 1502 * routine may temporarily unlock the map in order avoid a deadlock when 1503 * sleeping. 1504 */ 1505 static 1506 vm_map_entry_t 1507 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, 1508 int *countp, int flags) 1509 { 1510 vm_map_entry_t start_entry; 1511 vm_map_entry_t entry; 1512 1513 /* 1514 * Locate the entry and effect initial clipping. The in-transition 1515 * case does not occur very often so do not try to optimize it. 1516 */ 1517 again: 1518 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) 1519 return (NULL); 1520 entry = start_entry; 1521 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1522 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1523 ++mycpu->gd_cnt.v_intrans_coll; 1524 ++mycpu->gd_cnt.v_intrans_wait; 1525 vm_map_transition_wait(map); 1526 /* 1527 * entry and/or start_entry may have been clipped while 1528 * we slept, or may have gone away entirely. We have 1529 * to restart from the lookup. 1530 */ 1531 goto again; 1532 } 1533 1534 /* 1535 * Since we hold an exclusive map lock we do not have to restart 1536 * after clipping, even though clipping may block in zalloc. 1537 */ 1538 vm_map_clip_start(map, entry, start, countp); 1539 vm_map_clip_end(map, entry, end, countp); 1540 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1541 1542 /* 1543 * Scan entries covered by the range. When working on the next 1544 * entry a restart need only re-loop on the current entry which 1545 * we have already locked, since 'next' may have changed. Also, 1546 * even though entry is safe, it may have been clipped so we 1547 * have to iterate forwards through the clip after sleeping. 1548 */ 1549 while (entry->next != &map->header && entry->next->start < end) { 1550 vm_map_entry_t next = entry->next; 1551 1552 if (flags & MAP_CLIP_NO_HOLES) { 1553 if (next->start > entry->end) { 1554 vm_map_unclip_range(map, start_entry, 1555 start, entry->end, countp, flags); 1556 return(NULL); 1557 } 1558 } 1559 1560 if (next->eflags & MAP_ENTRY_IN_TRANSITION) { 1561 vm_offset_t save_end = entry->end; 1562 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1563 ++mycpu->gd_cnt.v_intrans_coll; 1564 ++mycpu->gd_cnt.v_intrans_wait; 1565 vm_map_transition_wait(map); 1566 1567 /* 1568 * clips might have occured while we blocked. 1569 */ 1570 CLIP_CHECK_FWD(entry, save_end); 1571 CLIP_CHECK_BACK(start_entry, start); 1572 continue; 1573 } 1574 /* 1575 * No restart necessary even though clip_end may block, we 1576 * are holding the map lock. 1577 */ 1578 vm_map_clip_end(map, next, end, countp); 1579 next->eflags |= MAP_ENTRY_IN_TRANSITION; 1580 entry = next; 1581 } 1582 if (flags & MAP_CLIP_NO_HOLES) { 1583 if (entry->end != end) { 1584 vm_map_unclip_range(map, start_entry, 1585 start, entry->end, countp, flags); 1586 return(NULL); 1587 } 1588 } 1589 return(start_entry); 1590 } 1591 1592 /* 1593 * Undo the effect of vm_map_clip_range(). You should pass the same 1594 * flags and the same range that you passed to vm_map_clip_range(). 1595 * This code will clear the in-transition flag on the entries and 1596 * wake up anyone waiting. This code will also simplify the sequence 1597 * and attempt to merge it with entries before and after the sequence. 1598 * 1599 * The map must be locked on entry and will remain locked on return. 1600 * 1601 * Note that you should also pass the start_entry returned by 1602 * vm_map_clip_range(). However, if you block between the two calls 1603 * with the map unlocked please be aware that the start_entry may 1604 * have been clipped and you may need to scan it backwards to find 1605 * the entry corresponding with the original start address. You are 1606 * responsible for this, vm_map_unclip_range() expects the correct 1607 * start_entry to be passed to it and will KASSERT otherwise. 1608 */ 1609 static 1610 void 1611 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry, 1612 vm_offset_t start, vm_offset_t end, 1613 int *countp, int flags) 1614 { 1615 vm_map_entry_t entry; 1616 1617 entry = start_entry; 1618 1619 KASSERT(entry->start == start, ("unclip_range: illegal base entry")); 1620 while (entry != &map->header && entry->start < end) { 1621 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, 1622 ("in-transition flag not set during unclip on: %p", 1623 entry)); 1624 KASSERT(entry->end <= end, 1625 ("unclip_range: tail wasn't clipped")); 1626 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1627 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1628 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1629 wakeup(map); 1630 } 1631 entry = entry->next; 1632 } 1633 1634 /* 1635 * Simplification does not block so there is no restart case. 1636 */ 1637 entry = start_entry; 1638 while (entry != &map->header && entry->start < end) { 1639 vm_map_simplify_entry(map, entry, countp); 1640 entry = entry->next; 1641 } 1642 } 1643 1644 /* 1645 * Mark the given range as handled by a subordinate map. 1646 * 1647 * This range must have been created with vm_map_find(), and no other 1648 * operations may have been performed on this range prior to calling 1649 * vm_map_submap(). 1650 * 1651 * Submappings cannot be removed. 1652 * 1653 * No requirements. 1654 */ 1655 int 1656 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) 1657 { 1658 vm_map_entry_t entry; 1659 int result = KERN_INVALID_ARGUMENT; 1660 int count; 1661 1662 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1663 vm_map_lock(map); 1664 1665 VM_MAP_RANGE_CHECK(map, start, end); 1666 1667 if (vm_map_lookup_entry(map, start, &entry)) { 1668 vm_map_clip_start(map, entry, start, &count); 1669 } else { 1670 entry = entry->next; 1671 } 1672 1673 vm_map_clip_end(map, entry, end, &count); 1674 1675 if ((entry->start == start) && (entry->end == end) && 1676 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1677 (entry->object.vm_object == NULL)) { 1678 entry->object.sub_map = submap; 1679 entry->maptype = VM_MAPTYPE_SUBMAP; 1680 result = KERN_SUCCESS; 1681 } 1682 vm_map_unlock(map); 1683 vm_map_entry_release(count); 1684 1685 return (result); 1686 } 1687 1688 /* 1689 * Sets the protection of the specified address region in the target map. 1690 * If "set_max" is specified, the maximum protection is to be set; 1691 * otherwise, only the current protection is affected. 1692 * 1693 * The protection is not applicable to submaps, but is applicable to normal 1694 * maps and maps governed by virtual page tables. For example, when operating 1695 * on a virtual page table our protection basically controls how COW occurs 1696 * on the backing object, whereas the virtual page table abstraction itself 1697 * is an abstraction for userland. 1698 * 1699 * No requirements. 1700 */ 1701 int 1702 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1703 vm_prot_t new_prot, boolean_t set_max) 1704 { 1705 vm_map_entry_t current; 1706 vm_map_entry_t entry; 1707 int count; 1708 1709 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1710 vm_map_lock(map); 1711 1712 VM_MAP_RANGE_CHECK(map, start, end); 1713 1714 if (vm_map_lookup_entry(map, start, &entry)) { 1715 vm_map_clip_start(map, entry, start, &count); 1716 } else { 1717 entry = entry->next; 1718 } 1719 1720 /* 1721 * Make a first pass to check for protection violations. 1722 */ 1723 current = entry; 1724 while ((current != &map->header) && (current->start < end)) { 1725 if (current->maptype == VM_MAPTYPE_SUBMAP) { 1726 vm_map_unlock(map); 1727 vm_map_entry_release(count); 1728 return (KERN_INVALID_ARGUMENT); 1729 } 1730 if ((new_prot & current->max_protection) != new_prot) { 1731 vm_map_unlock(map); 1732 vm_map_entry_release(count); 1733 return (KERN_PROTECTION_FAILURE); 1734 } 1735 current = current->next; 1736 } 1737 1738 /* 1739 * Go back and fix up protections. [Note that clipping is not 1740 * necessary the second time.] 1741 */ 1742 current = entry; 1743 1744 while ((current != &map->header) && (current->start < end)) { 1745 vm_prot_t old_prot; 1746 1747 vm_map_clip_end(map, current, end, &count); 1748 1749 old_prot = current->protection; 1750 if (set_max) { 1751 current->protection = 1752 (current->max_protection = new_prot) & 1753 old_prot; 1754 } else { 1755 current->protection = new_prot; 1756 } 1757 1758 /* 1759 * Update physical map if necessary. Worry about copy-on-write 1760 * here -- CHECK THIS XXX 1761 */ 1762 1763 if (current->protection != old_prot) { 1764 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1765 VM_PROT_ALL) 1766 1767 pmap_protect(map->pmap, current->start, 1768 current->end, 1769 current->protection & MASK(current)); 1770 #undef MASK 1771 } 1772 1773 vm_map_simplify_entry(map, current, &count); 1774 1775 current = current->next; 1776 } 1777 1778 vm_map_unlock(map); 1779 vm_map_entry_release(count); 1780 return (KERN_SUCCESS); 1781 } 1782 1783 /* 1784 * This routine traverses a processes map handling the madvise 1785 * system call. Advisories are classified as either those effecting 1786 * the vm_map_entry structure, or those effecting the underlying 1787 * objects. 1788 * 1789 * The <value> argument is used for extended madvise calls. 1790 * 1791 * No requirements. 1792 */ 1793 int 1794 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end, 1795 int behav, off_t value) 1796 { 1797 vm_map_entry_t current, entry; 1798 int modify_map = 0; 1799 int error = 0; 1800 int count; 1801 1802 /* 1803 * Some madvise calls directly modify the vm_map_entry, in which case 1804 * we need to use an exclusive lock on the map and we need to perform 1805 * various clipping operations. Otherwise we only need a read-lock 1806 * on the map. 1807 */ 1808 1809 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1810 1811 switch(behav) { 1812 case MADV_NORMAL: 1813 case MADV_SEQUENTIAL: 1814 case MADV_RANDOM: 1815 case MADV_NOSYNC: 1816 case MADV_AUTOSYNC: 1817 case MADV_NOCORE: 1818 case MADV_CORE: 1819 case MADV_SETMAP: 1820 case MADV_INVAL: 1821 modify_map = 1; 1822 vm_map_lock(map); 1823 break; 1824 case MADV_WILLNEED: 1825 case MADV_DONTNEED: 1826 case MADV_FREE: 1827 vm_map_lock_read(map); 1828 break; 1829 default: 1830 vm_map_entry_release(count); 1831 return (EINVAL); 1832 } 1833 1834 /* 1835 * Locate starting entry and clip if necessary. 1836 */ 1837 1838 VM_MAP_RANGE_CHECK(map, start, end); 1839 1840 if (vm_map_lookup_entry(map, start, &entry)) { 1841 if (modify_map) 1842 vm_map_clip_start(map, entry, start, &count); 1843 } else { 1844 entry = entry->next; 1845 } 1846 1847 if (modify_map) { 1848 /* 1849 * madvise behaviors that are implemented in the vm_map_entry. 1850 * 1851 * We clip the vm_map_entry so that behavioral changes are 1852 * limited to the specified address range. 1853 */ 1854 for (current = entry; 1855 (current != &map->header) && (current->start < end); 1856 current = current->next 1857 ) { 1858 if (current->maptype == VM_MAPTYPE_SUBMAP) 1859 continue; 1860 1861 vm_map_clip_end(map, current, end, &count); 1862 1863 switch (behav) { 1864 case MADV_NORMAL: 1865 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1866 break; 1867 case MADV_SEQUENTIAL: 1868 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1869 break; 1870 case MADV_RANDOM: 1871 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1872 break; 1873 case MADV_NOSYNC: 1874 current->eflags |= MAP_ENTRY_NOSYNC; 1875 break; 1876 case MADV_AUTOSYNC: 1877 current->eflags &= ~MAP_ENTRY_NOSYNC; 1878 break; 1879 case MADV_NOCORE: 1880 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1881 break; 1882 case MADV_CORE: 1883 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1884 break; 1885 case MADV_INVAL: 1886 /* 1887 * Invalidate the related pmap entries, used 1888 * to flush portions of the real kernel's 1889 * pmap when the caller has removed or 1890 * modified existing mappings in a virtual 1891 * page table. 1892 */ 1893 pmap_remove(map->pmap, 1894 current->start, current->end); 1895 break; 1896 case MADV_SETMAP: 1897 /* 1898 * Set the page directory page for a map 1899 * governed by a virtual page table. Mark 1900 * the entry as being governed by a virtual 1901 * page table if it is not. 1902 * 1903 * XXX the page directory page is stored 1904 * in the avail_ssize field if the map_entry. 1905 * 1906 * XXX the map simplification code does not 1907 * compare this field so weird things may 1908 * happen if you do not apply this function 1909 * to the entire mapping governed by the 1910 * virtual page table. 1911 */ 1912 if (current->maptype != VM_MAPTYPE_VPAGETABLE) { 1913 error = EINVAL; 1914 break; 1915 } 1916 current->aux.master_pde = value; 1917 pmap_remove(map->pmap, 1918 current->start, current->end); 1919 break; 1920 default: 1921 error = EINVAL; 1922 break; 1923 } 1924 vm_map_simplify_entry(map, current, &count); 1925 } 1926 vm_map_unlock(map); 1927 } else { 1928 vm_pindex_t pindex; 1929 int count; 1930 1931 /* 1932 * madvise behaviors that are implemented in the underlying 1933 * vm_object. 1934 * 1935 * Since we don't clip the vm_map_entry, we have to clip 1936 * the vm_object pindex and count. 1937 * 1938 * NOTE! We currently do not support these functions on 1939 * virtual page tables. 1940 */ 1941 for (current = entry; 1942 (current != &map->header) && (current->start < end); 1943 current = current->next 1944 ) { 1945 vm_offset_t useStart; 1946 1947 if (current->maptype != VM_MAPTYPE_NORMAL) 1948 continue; 1949 1950 pindex = OFF_TO_IDX(current->offset); 1951 count = atop(current->end - current->start); 1952 useStart = current->start; 1953 1954 if (current->start < start) { 1955 pindex += atop(start - current->start); 1956 count -= atop(start - current->start); 1957 useStart = start; 1958 } 1959 if (current->end > end) 1960 count -= atop(current->end - end); 1961 1962 if (count <= 0) 1963 continue; 1964 1965 vm_object_madvise(current->object.vm_object, 1966 pindex, count, behav); 1967 1968 /* 1969 * Try to populate the page table. Mappings governed 1970 * by virtual page tables cannot be pre-populated 1971 * without a lot of work so don't try. 1972 */ 1973 if (behav == MADV_WILLNEED && 1974 current->maptype != VM_MAPTYPE_VPAGETABLE) { 1975 pmap_object_init_pt( 1976 map->pmap, 1977 useStart, 1978 current->protection, 1979 current->object.vm_object, 1980 pindex, 1981 (count << PAGE_SHIFT), 1982 MAP_PREFAULT_MADVISE 1983 ); 1984 } 1985 } 1986 vm_map_unlock_read(map); 1987 } 1988 vm_map_entry_release(count); 1989 return(error); 1990 } 1991 1992 1993 /* 1994 * Sets the inheritance of the specified address range in the target map. 1995 * Inheritance affects how the map will be shared with child maps at the 1996 * time of vm_map_fork. 1997 */ 1998 int 1999 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2000 vm_inherit_t new_inheritance) 2001 { 2002 vm_map_entry_t entry; 2003 vm_map_entry_t temp_entry; 2004 int count; 2005 2006 switch (new_inheritance) { 2007 case VM_INHERIT_NONE: 2008 case VM_INHERIT_COPY: 2009 case VM_INHERIT_SHARE: 2010 break; 2011 default: 2012 return (KERN_INVALID_ARGUMENT); 2013 } 2014 2015 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2016 vm_map_lock(map); 2017 2018 VM_MAP_RANGE_CHECK(map, start, end); 2019 2020 if (vm_map_lookup_entry(map, start, &temp_entry)) { 2021 entry = temp_entry; 2022 vm_map_clip_start(map, entry, start, &count); 2023 } else 2024 entry = temp_entry->next; 2025 2026 while ((entry != &map->header) && (entry->start < end)) { 2027 vm_map_clip_end(map, entry, end, &count); 2028 2029 entry->inheritance = new_inheritance; 2030 2031 vm_map_simplify_entry(map, entry, &count); 2032 2033 entry = entry->next; 2034 } 2035 vm_map_unlock(map); 2036 vm_map_entry_release(count); 2037 return (KERN_SUCCESS); 2038 } 2039 2040 /* 2041 * Implement the semantics of mlock 2042 */ 2043 int 2044 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, 2045 boolean_t new_pageable) 2046 { 2047 vm_map_entry_t entry; 2048 vm_map_entry_t start_entry; 2049 vm_offset_t end; 2050 int rv = KERN_SUCCESS; 2051 int count; 2052 2053 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2054 vm_map_lock(map); 2055 VM_MAP_RANGE_CHECK(map, start, real_end); 2056 end = real_end; 2057 2058 start_entry = vm_map_clip_range(map, start, end, &count, 2059 MAP_CLIP_NO_HOLES); 2060 if (start_entry == NULL) { 2061 vm_map_unlock(map); 2062 vm_map_entry_release(count); 2063 return (KERN_INVALID_ADDRESS); 2064 } 2065 2066 if (new_pageable == 0) { 2067 entry = start_entry; 2068 while ((entry != &map->header) && (entry->start < end)) { 2069 vm_offset_t save_start; 2070 vm_offset_t save_end; 2071 2072 /* 2073 * Already user wired or hard wired (trivial cases) 2074 */ 2075 if (entry->eflags & MAP_ENTRY_USER_WIRED) { 2076 entry = entry->next; 2077 continue; 2078 } 2079 if (entry->wired_count != 0) { 2080 entry->wired_count++; 2081 entry->eflags |= MAP_ENTRY_USER_WIRED; 2082 entry = entry->next; 2083 continue; 2084 } 2085 2086 /* 2087 * A new wiring requires instantiation of appropriate 2088 * management structures and the faulting in of the 2089 * page. 2090 */ 2091 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 2092 int copyflag = entry->eflags & 2093 MAP_ENTRY_NEEDS_COPY; 2094 if (copyflag && ((entry->protection & 2095 VM_PROT_WRITE) != 0)) { 2096 vm_map_entry_shadow(entry, 0); 2097 } else if (entry->object.vm_object == NULL && 2098 !map->system_map) { 2099 vm_map_entry_allocate_object(entry); 2100 } 2101 } 2102 entry->wired_count++; 2103 entry->eflags |= MAP_ENTRY_USER_WIRED; 2104 2105 /* 2106 * Now fault in the area. Note that vm_fault_wire() 2107 * may release the map lock temporarily, it will be 2108 * relocked on return. The in-transition 2109 * flag protects the entries. 2110 */ 2111 save_start = entry->start; 2112 save_end = entry->end; 2113 rv = vm_fault_wire(map, entry, TRUE); 2114 if (rv) { 2115 CLIP_CHECK_BACK(entry, save_start); 2116 for (;;) { 2117 KASSERT(entry->wired_count == 1, ("bad wired_count on entry")); 2118 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2119 entry->wired_count = 0; 2120 if (entry->end == save_end) 2121 break; 2122 entry = entry->next; 2123 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2124 } 2125 end = save_start; /* unwire the rest */ 2126 break; 2127 } 2128 /* 2129 * note that even though the entry might have been 2130 * clipped, the USER_WIRED flag we set prevents 2131 * duplication so we do not have to do a 2132 * clip check. 2133 */ 2134 entry = entry->next; 2135 } 2136 2137 /* 2138 * If we failed fall through to the unwiring section to 2139 * unwire what we had wired so far. 'end' has already 2140 * been adjusted. 2141 */ 2142 if (rv) 2143 new_pageable = 1; 2144 2145 /* 2146 * start_entry might have been clipped if we unlocked the 2147 * map and blocked. No matter how clipped it has gotten 2148 * there should be a fragment that is on our start boundary. 2149 */ 2150 CLIP_CHECK_BACK(start_entry, start); 2151 } 2152 2153 /* 2154 * Deal with the unwiring case. 2155 */ 2156 if (new_pageable) { 2157 /* 2158 * This is the unwiring case. We must first ensure that the 2159 * range to be unwired is really wired down. We know there 2160 * are no holes. 2161 */ 2162 entry = start_entry; 2163 while ((entry != &map->header) && (entry->start < end)) { 2164 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2165 rv = KERN_INVALID_ARGUMENT; 2166 goto done; 2167 } 2168 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry)); 2169 entry = entry->next; 2170 } 2171 2172 /* 2173 * Now decrement the wiring count for each region. If a region 2174 * becomes completely unwired, unwire its physical pages and 2175 * mappings. 2176 */ 2177 /* 2178 * The map entries are processed in a loop, checking to 2179 * make sure the entry is wired and asserting it has a wired 2180 * count. However, another loop was inserted more-or-less in 2181 * the middle of the unwiring path. This loop picks up the 2182 * "entry" loop variable from the first loop without first 2183 * setting it to start_entry. Naturally, the secound loop 2184 * is never entered and the pages backing the entries are 2185 * never unwired. This can lead to a leak of wired pages. 2186 */ 2187 entry = start_entry; 2188 while ((entry != &map->header) && (entry->start < end)) { 2189 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, 2190 ("expected USER_WIRED on entry %p", entry)); 2191 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2192 entry->wired_count--; 2193 if (entry->wired_count == 0) 2194 vm_fault_unwire(map, entry); 2195 entry = entry->next; 2196 } 2197 } 2198 done: 2199 vm_map_unclip_range(map, start_entry, start, real_end, &count, 2200 MAP_CLIP_NO_HOLES); 2201 map->timestamp++; 2202 vm_map_unlock(map); 2203 vm_map_entry_release(count); 2204 return (rv); 2205 } 2206 2207 /* 2208 * Sets the pageability of the specified address range in the target map. 2209 * Regions specified as not pageable require locked-down physical 2210 * memory and physical page maps. 2211 * 2212 * The map must not be locked, but a reference must remain to the map 2213 * throughout the call. 2214 * 2215 * This function may be called via the zalloc path and must properly 2216 * reserve map entries for kernel_map. 2217 * 2218 * No requirements. 2219 */ 2220 int 2221 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags) 2222 { 2223 vm_map_entry_t entry; 2224 vm_map_entry_t start_entry; 2225 vm_offset_t end; 2226 int rv = KERN_SUCCESS; 2227 int count; 2228 2229 if (kmflags & KM_KRESERVE) 2230 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT); 2231 else 2232 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2233 vm_map_lock(map); 2234 VM_MAP_RANGE_CHECK(map, start, real_end); 2235 end = real_end; 2236 2237 start_entry = vm_map_clip_range(map, start, end, &count, 2238 MAP_CLIP_NO_HOLES); 2239 if (start_entry == NULL) { 2240 vm_map_unlock(map); 2241 rv = KERN_INVALID_ADDRESS; 2242 goto failure; 2243 } 2244 if ((kmflags & KM_PAGEABLE) == 0) { 2245 /* 2246 * Wiring. 2247 * 2248 * 1. Holding the write lock, we create any shadow or zero-fill 2249 * objects that need to be created. Then we clip each map 2250 * entry to the region to be wired and increment its wiring 2251 * count. We create objects before clipping the map entries 2252 * to avoid object proliferation. 2253 * 2254 * 2. We downgrade to a read lock, and call vm_fault_wire to 2255 * fault in the pages for any newly wired area (wired_count is 2256 * 1). 2257 * 2258 * Downgrading to a read lock for vm_fault_wire avoids a 2259 * possible deadlock with another process that may have faulted 2260 * on one of the pages to be wired (it would mark the page busy, 2261 * blocking us, then in turn block on the map lock that we 2262 * hold). Because of problems in the recursive lock package, 2263 * we cannot upgrade to a write lock in vm_map_lookup. Thus, 2264 * any actions that require the write lock must be done 2265 * beforehand. Because we keep the read lock on the map, the 2266 * copy-on-write status of the entries we modify here cannot 2267 * change. 2268 */ 2269 entry = start_entry; 2270 while ((entry != &map->header) && (entry->start < end)) { 2271 /* 2272 * Trivial case if the entry is already wired 2273 */ 2274 if (entry->wired_count) { 2275 entry->wired_count++; 2276 entry = entry->next; 2277 continue; 2278 } 2279 2280 /* 2281 * The entry is being newly wired, we have to setup 2282 * appropriate management structures. A shadow 2283 * object is required for a copy-on-write region, 2284 * or a normal object for a zero-fill region. We 2285 * do not have to do this for entries that point to sub 2286 * maps because we won't hold the lock on the sub map. 2287 */ 2288 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 2289 int copyflag = entry->eflags & 2290 MAP_ENTRY_NEEDS_COPY; 2291 if (copyflag && ((entry->protection & 2292 VM_PROT_WRITE) != 0)) { 2293 vm_map_entry_shadow(entry, 0); 2294 } else if (entry->object.vm_object == NULL && 2295 !map->system_map) { 2296 vm_map_entry_allocate_object(entry); 2297 } 2298 } 2299 2300 entry->wired_count++; 2301 entry = entry->next; 2302 } 2303 2304 /* 2305 * Pass 2. 2306 */ 2307 2308 /* 2309 * HACK HACK HACK HACK 2310 * 2311 * vm_fault_wire() temporarily unlocks the map to avoid 2312 * deadlocks. The in-transition flag from vm_map_clip_range 2313 * call should protect us from changes while the map is 2314 * unlocked. T 2315 * 2316 * NOTE: Previously this comment stated that clipping might 2317 * still occur while the entry is unlocked, but from 2318 * what I can tell it actually cannot. 2319 * 2320 * It is unclear whether the CLIP_CHECK_*() calls 2321 * are still needed but we keep them in anyway. 2322 * 2323 * HACK HACK HACK HACK 2324 */ 2325 2326 entry = start_entry; 2327 while (entry != &map->header && entry->start < end) { 2328 /* 2329 * If vm_fault_wire fails for any page we need to undo 2330 * what has been done. We decrement the wiring count 2331 * for those pages which have not yet been wired (now) 2332 * and unwire those that have (later). 2333 */ 2334 vm_offset_t save_start = entry->start; 2335 vm_offset_t save_end = entry->end; 2336 2337 if (entry->wired_count == 1) 2338 rv = vm_fault_wire(map, entry, FALSE); 2339 if (rv) { 2340 CLIP_CHECK_BACK(entry, save_start); 2341 for (;;) { 2342 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly")); 2343 entry->wired_count = 0; 2344 if (entry->end == save_end) 2345 break; 2346 entry = entry->next; 2347 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2348 } 2349 end = save_start; 2350 break; 2351 } 2352 CLIP_CHECK_FWD(entry, save_end); 2353 entry = entry->next; 2354 } 2355 2356 /* 2357 * If a failure occured undo everything by falling through 2358 * to the unwiring code. 'end' has already been adjusted 2359 * appropriately. 2360 */ 2361 if (rv) 2362 kmflags |= KM_PAGEABLE; 2363 2364 /* 2365 * start_entry is still IN_TRANSITION but may have been 2366 * clipped since vm_fault_wire() unlocks and relocks the 2367 * map. No matter how clipped it has gotten there should 2368 * be a fragment that is on our start boundary. 2369 */ 2370 CLIP_CHECK_BACK(start_entry, start); 2371 } 2372 2373 if (kmflags & KM_PAGEABLE) { 2374 /* 2375 * This is the unwiring case. We must first ensure that the 2376 * range to be unwired is really wired down. We know there 2377 * are no holes. 2378 */ 2379 entry = start_entry; 2380 while ((entry != &map->header) && (entry->start < end)) { 2381 if (entry->wired_count == 0) { 2382 rv = KERN_INVALID_ARGUMENT; 2383 goto done; 2384 } 2385 entry = entry->next; 2386 } 2387 2388 /* 2389 * Now decrement the wiring count for each region. If a region 2390 * becomes completely unwired, unwire its physical pages and 2391 * mappings. 2392 */ 2393 entry = start_entry; 2394 while ((entry != &map->header) && (entry->start < end)) { 2395 entry->wired_count--; 2396 if (entry->wired_count == 0) 2397 vm_fault_unwire(map, entry); 2398 entry = entry->next; 2399 } 2400 } 2401 done: 2402 vm_map_unclip_range(map, start_entry, start, real_end, 2403 &count, MAP_CLIP_NO_HOLES); 2404 map->timestamp++; 2405 vm_map_unlock(map); 2406 failure: 2407 if (kmflags & KM_KRESERVE) 2408 vm_map_entry_krelease(count); 2409 else 2410 vm_map_entry_release(count); 2411 return (rv); 2412 } 2413 2414 /* 2415 * Mark a newly allocated address range as wired but do not fault in 2416 * the pages. The caller is expected to load the pages into the object. 2417 * 2418 * The map must be locked on entry and will remain locked on return. 2419 * No other requirements. 2420 */ 2421 void 2422 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size, 2423 int *countp) 2424 { 2425 vm_map_entry_t scan; 2426 vm_map_entry_t entry; 2427 2428 entry = vm_map_clip_range(map, addr, addr + size, 2429 countp, MAP_CLIP_NO_HOLES); 2430 for (scan = entry; 2431 scan != &map->header && scan->start < addr + size; 2432 scan = scan->next) { 2433 KKASSERT(entry->wired_count == 0); 2434 entry->wired_count = 1; 2435 } 2436 vm_map_unclip_range(map, entry, addr, addr + size, 2437 countp, MAP_CLIP_NO_HOLES); 2438 } 2439 2440 /* 2441 * Push any dirty cached pages in the address range to their pager. 2442 * If syncio is TRUE, dirty pages are written synchronously. 2443 * If invalidate is TRUE, any cached pages are freed as well. 2444 * 2445 * This routine is called by sys_msync() 2446 * 2447 * Returns an error if any part of the specified range is not mapped. 2448 * 2449 * No requirements. 2450 */ 2451 int 2452 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end, 2453 boolean_t syncio, boolean_t invalidate) 2454 { 2455 vm_map_entry_t current; 2456 vm_map_entry_t entry; 2457 vm_size_t size; 2458 vm_object_t object; 2459 vm_object_t tobj; 2460 vm_ooffset_t offset; 2461 2462 vm_map_lock_read(map); 2463 VM_MAP_RANGE_CHECK(map, start, end); 2464 if (!vm_map_lookup_entry(map, start, &entry)) { 2465 vm_map_unlock_read(map); 2466 return (KERN_INVALID_ADDRESS); 2467 } 2468 lwkt_gettoken(&map->token); 2469 2470 /* 2471 * Make a first pass to check for holes. 2472 */ 2473 for (current = entry; current->start < end; current = current->next) { 2474 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2475 lwkt_reltoken(&map->token); 2476 vm_map_unlock_read(map); 2477 return (KERN_INVALID_ARGUMENT); 2478 } 2479 if (end > current->end && 2480 (current->next == &map->header || 2481 current->end != current->next->start)) { 2482 lwkt_reltoken(&map->token); 2483 vm_map_unlock_read(map); 2484 return (KERN_INVALID_ADDRESS); 2485 } 2486 } 2487 2488 if (invalidate) 2489 pmap_remove(vm_map_pmap(map), start, end); 2490 2491 /* 2492 * Make a second pass, cleaning/uncaching pages from the indicated 2493 * objects as we go. 2494 */ 2495 for (current = entry; current->start < end; current = current->next) { 2496 offset = current->offset + (start - current->start); 2497 size = (end <= current->end ? end : current->end) - start; 2498 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2499 vm_map_t smap; 2500 vm_map_entry_t tentry; 2501 vm_size_t tsize; 2502 2503 smap = current->object.sub_map; 2504 vm_map_lock_read(smap); 2505 vm_map_lookup_entry(smap, offset, &tentry); 2506 tsize = tentry->end - offset; 2507 if (tsize < size) 2508 size = tsize; 2509 object = tentry->object.vm_object; 2510 offset = tentry->offset + (offset - tentry->start); 2511 vm_map_unlock_read(smap); 2512 } else { 2513 object = current->object.vm_object; 2514 } 2515 2516 if (object) 2517 vm_object_hold(object); 2518 2519 /* 2520 * Note that there is absolutely no sense in writing out 2521 * anonymous objects, so we track down the vnode object 2522 * to write out. 2523 * We invalidate (remove) all pages from the address space 2524 * anyway, for semantic correctness. 2525 * 2526 * note: certain anonymous maps, such as MAP_NOSYNC maps, 2527 * may start out with a NULL object. 2528 */ 2529 while (object && (tobj = object->backing_object) != NULL) { 2530 vm_object_hold(tobj); 2531 if (tobj == object->backing_object) { 2532 vm_object_lock_swap(); 2533 offset += object->backing_object_offset; 2534 vm_object_drop(object); 2535 object = tobj; 2536 if (object->size < OFF_TO_IDX(offset + size)) 2537 size = IDX_TO_OFF(object->size) - 2538 offset; 2539 break; 2540 } 2541 vm_object_drop(tobj); 2542 } 2543 if (object && (object->type == OBJT_VNODE) && 2544 (current->protection & VM_PROT_WRITE) && 2545 (object->flags & OBJ_NOMSYNC) == 0) { 2546 /* 2547 * Flush pages if writing is allowed, invalidate them 2548 * if invalidation requested. Pages undergoing I/O 2549 * will be ignored by vm_object_page_remove(). 2550 * 2551 * We cannot lock the vnode and then wait for paging 2552 * to complete without deadlocking against vm_fault. 2553 * Instead we simply call vm_object_page_remove() and 2554 * allow it to block internally on a page-by-page 2555 * basis when it encounters pages undergoing async 2556 * I/O. 2557 */ 2558 int flags; 2559 2560 /* no chain wait needed for vnode objects */ 2561 vm_object_reference_locked(object); 2562 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY); 2563 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 2564 flags |= invalidate ? OBJPC_INVAL : 0; 2565 2566 /* 2567 * When operating on a virtual page table just 2568 * flush the whole object. XXX we probably ought 2569 * to 2570 */ 2571 switch(current->maptype) { 2572 case VM_MAPTYPE_NORMAL: 2573 vm_object_page_clean(object, 2574 OFF_TO_IDX(offset), 2575 OFF_TO_IDX(offset + size + PAGE_MASK), 2576 flags); 2577 break; 2578 case VM_MAPTYPE_VPAGETABLE: 2579 vm_object_page_clean(object, 0, 0, flags); 2580 break; 2581 } 2582 vn_unlock(((struct vnode *)object->handle)); 2583 vm_object_deallocate_locked(object); 2584 } 2585 if (object && invalidate && 2586 ((object->type == OBJT_VNODE) || 2587 (object->type == OBJT_DEVICE))) { 2588 int clean_only = 2589 (object->type == OBJT_DEVICE) ? FALSE : TRUE; 2590 /* no chain wait needed for vnode/device objects */ 2591 vm_object_reference_locked(object); 2592 switch(current->maptype) { 2593 case VM_MAPTYPE_NORMAL: 2594 vm_object_page_remove(object, 2595 OFF_TO_IDX(offset), 2596 OFF_TO_IDX(offset + size + PAGE_MASK), 2597 clean_only); 2598 break; 2599 case VM_MAPTYPE_VPAGETABLE: 2600 vm_object_page_remove(object, 0, 0, clean_only); 2601 break; 2602 } 2603 vm_object_deallocate_locked(object); 2604 } 2605 start += size; 2606 if (object) 2607 vm_object_drop(object); 2608 } 2609 2610 lwkt_reltoken(&map->token); 2611 vm_map_unlock_read(map); 2612 2613 return (KERN_SUCCESS); 2614 } 2615 2616 /* 2617 * Make the region specified by this entry pageable. 2618 * 2619 * The vm_map must be exclusively locked. 2620 */ 2621 static void 2622 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2623 { 2624 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2625 entry->wired_count = 0; 2626 vm_fault_unwire(map, entry); 2627 } 2628 2629 /* 2630 * Deallocate the given entry from the target map. 2631 * 2632 * The vm_map must be exclusively locked. 2633 */ 2634 static void 2635 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp) 2636 { 2637 vm_map_entry_unlink(map, entry); 2638 map->size -= entry->end - entry->start; 2639 2640 switch(entry->maptype) { 2641 case VM_MAPTYPE_NORMAL: 2642 case VM_MAPTYPE_VPAGETABLE: 2643 vm_object_deallocate(entry->object.vm_object); 2644 break; 2645 default: 2646 break; 2647 } 2648 2649 vm_map_entry_dispose(map, entry, countp); 2650 } 2651 2652 /* 2653 * Deallocates the given address range from the target map. 2654 * 2655 * The vm_map must be exclusively locked. 2656 */ 2657 int 2658 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp) 2659 { 2660 vm_object_t object; 2661 vm_map_entry_t entry; 2662 vm_map_entry_t first_entry; 2663 2664 ASSERT_VM_MAP_LOCKED(map); 2665 lwkt_gettoken(&map->token); 2666 again: 2667 /* 2668 * Find the start of the region, and clip it. Set entry to point 2669 * at the first record containing the requested address or, if no 2670 * such record exists, the next record with a greater address. The 2671 * loop will run from this point until a record beyond the termination 2672 * address is encountered. 2673 * 2674 * map->hint must be adjusted to not point to anything we delete, 2675 * so set it to the entry prior to the one being deleted. 2676 * 2677 * GGG see other GGG comment. 2678 */ 2679 if (vm_map_lookup_entry(map, start, &first_entry)) { 2680 entry = first_entry; 2681 vm_map_clip_start(map, entry, start, countp); 2682 map->hint = entry->prev; /* possible problem XXX */ 2683 } else { 2684 map->hint = first_entry; /* possible problem XXX */ 2685 entry = first_entry->next; 2686 } 2687 2688 /* 2689 * If a hole opens up prior to the current first_free then 2690 * adjust first_free. As with map->hint, map->first_free 2691 * cannot be left set to anything we might delete. 2692 */ 2693 if (entry == &map->header) { 2694 map->first_free = &map->header; 2695 } else if (map->first_free->start >= start) { 2696 map->first_free = entry->prev; 2697 } 2698 2699 /* 2700 * Step through all entries in this region 2701 */ 2702 while ((entry != &map->header) && (entry->start < end)) { 2703 vm_map_entry_t next; 2704 vm_offset_t s, e; 2705 vm_pindex_t offidxstart, offidxend, count; 2706 2707 /* 2708 * If we hit an in-transition entry we have to sleep and 2709 * retry. It's easier (and not really slower) to just retry 2710 * since this case occurs so rarely and the hint is already 2711 * pointing at the right place. We have to reset the 2712 * start offset so as not to accidently delete an entry 2713 * another process just created in vacated space. 2714 */ 2715 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2716 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2717 start = entry->start; 2718 ++mycpu->gd_cnt.v_intrans_coll; 2719 ++mycpu->gd_cnt.v_intrans_wait; 2720 vm_map_transition_wait(map); 2721 goto again; 2722 } 2723 vm_map_clip_end(map, entry, end, countp); 2724 2725 s = entry->start; 2726 e = entry->end; 2727 next = entry->next; 2728 2729 offidxstart = OFF_TO_IDX(entry->offset); 2730 count = OFF_TO_IDX(e - s); 2731 object = entry->object.vm_object; 2732 2733 /* 2734 * Unwire before removing addresses from the pmap; otherwise, 2735 * unwiring will put the entries back in the pmap. 2736 */ 2737 if (entry->wired_count != 0) 2738 vm_map_entry_unwire(map, entry); 2739 2740 offidxend = offidxstart + count; 2741 2742 if (object == &kernel_object) { 2743 vm_object_hold(object); 2744 vm_object_page_remove(object, offidxstart, 2745 offidxend, FALSE); 2746 vm_object_drop(object); 2747 } else if (object && object->type != OBJT_DEFAULT && 2748 object->type != OBJT_SWAP) { 2749 /* 2750 * vnode object routines cannot be chain-locked 2751 */ 2752 vm_object_hold(object); 2753 pmap_remove(map->pmap, s, e); 2754 vm_object_drop(object); 2755 } else if (object) { 2756 vm_object_hold(object); 2757 vm_object_chain_acquire(object); 2758 pmap_remove(map->pmap, s, e); 2759 2760 if (object != NULL && 2761 object->ref_count != 1 && 2762 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == 2763 OBJ_ONEMAPPING && 2764 (object->type == OBJT_DEFAULT || 2765 object->type == OBJT_SWAP)) { 2766 vm_object_collapse(object, NULL); 2767 vm_object_page_remove(object, offidxstart, 2768 offidxend, FALSE); 2769 if (object->type == OBJT_SWAP) { 2770 swap_pager_freespace(object, 2771 offidxstart, 2772 count); 2773 } 2774 if (offidxend >= object->size && 2775 offidxstart < object->size) { 2776 object->size = offidxstart; 2777 } 2778 } 2779 vm_object_chain_release(object); 2780 vm_object_drop(object); 2781 } 2782 2783 /* 2784 * Delete the entry (which may delete the object) only after 2785 * removing all pmap entries pointing to its pages. 2786 * (Otherwise, its page frames may be reallocated, and any 2787 * modify bits will be set in the wrong object!) 2788 */ 2789 vm_map_entry_delete(map, entry, countp); 2790 entry = next; 2791 } 2792 lwkt_reltoken(&map->token); 2793 return (KERN_SUCCESS); 2794 } 2795 2796 /* 2797 * Remove the given address range from the target map. 2798 * This is the exported form of vm_map_delete. 2799 * 2800 * No requirements. 2801 */ 2802 int 2803 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2804 { 2805 int result; 2806 int count; 2807 2808 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2809 vm_map_lock(map); 2810 VM_MAP_RANGE_CHECK(map, start, end); 2811 result = vm_map_delete(map, start, end, &count); 2812 vm_map_unlock(map); 2813 vm_map_entry_release(count); 2814 2815 return (result); 2816 } 2817 2818 /* 2819 * Assert that the target map allows the specified privilege on the 2820 * entire address region given. The entire region must be allocated. 2821 * 2822 * The caller must specify whether the vm_map is already locked or not. 2823 */ 2824 boolean_t 2825 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2826 vm_prot_t protection, boolean_t have_lock) 2827 { 2828 vm_map_entry_t entry; 2829 vm_map_entry_t tmp_entry; 2830 boolean_t result; 2831 2832 if (have_lock == FALSE) 2833 vm_map_lock_read(map); 2834 2835 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 2836 if (have_lock == FALSE) 2837 vm_map_unlock_read(map); 2838 return (FALSE); 2839 } 2840 entry = tmp_entry; 2841 2842 result = TRUE; 2843 while (start < end) { 2844 if (entry == &map->header) { 2845 result = FALSE; 2846 break; 2847 } 2848 /* 2849 * No holes allowed! 2850 */ 2851 2852 if (start < entry->start) { 2853 result = FALSE; 2854 break; 2855 } 2856 /* 2857 * Check protection associated with entry. 2858 */ 2859 2860 if ((entry->protection & protection) != protection) { 2861 result = FALSE; 2862 break; 2863 } 2864 /* go to next entry */ 2865 2866 start = entry->end; 2867 entry = entry->next; 2868 } 2869 if (have_lock == FALSE) 2870 vm_map_unlock_read(map); 2871 return (result); 2872 } 2873 2874 /* 2875 * If appropriate this function shadows the original object with a new object 2876 * and moves the VM pages from the original object to the new object. 2877 * The original object will also be collapsed, if possible. 2878 * 2879 * We can only do this for normal memory objects with a single mapping, and 2880 * it only makes sense to do it if there are 2 or more refs on the original 2881 * object. i.e. typically a memory object that has been extended into 2882 * multiple vm_map_entry's with non-overlapping ranges. 2883 * 2884 * This makes it easier to remove unused pages and keeps object inheritance 2885 * from being a negative impact on memory usage. 2886 * 2887 * On return the (possibly new) entry->object.vm_object will have an 2888 * additional ref on it for the caller to dispose of (usually by cloning 2889 * the vm_map_entry). The additional ref had to be done in this routine 2890 * to avoid racing a collapse. The object's ONEMAPPING flag will also be 2891 * cleared. 2892 * 2893 * The vm_map must be locked and its token held. 2894 */ 2895 static void 2896 vm_map_split(vm_map_entry_t entry) 2897 { 2898 #if 0 2899 /* UNOPTIMIZED */ 2900 vm_object_t oobject; 2901 2902 oobject = entry->object.vm_object; 2903 vm_object_hold(oobject); 2904 vm_object_chain_wait(oobject); 2905 vm_object_reference_locked(oobject); 2906 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 2907 vm_object_drop(oobject); 2908 #else 2909 /* OPTIMIZED */ 2910 vm_object_t oobject, nobject, bobject; 2911 vm_offset_t s, e; 2912 vm_page_t m; 2913 vm_pindex_t offidxstart, offidxend, idx; 2914 vm_size_t size; 2915 vm_ooffset_t offset; 2916 2917 /* 2918 * Setup. Chain lock the original object throughout the entire 2919 * routine to prevent new page faults from occuring. 2920 * 2921 * XXX can madvise WILLNEED interfere with us too? 2922 */ 2923 oobject = entry->object.vm_object; 2924 vm_object_hold(oobject); 2925 vm_object_chain_acquire(oobject); 2926 2927 /* 2928 * Original object cannot be split? 2929 */ 2930 if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT && 2931 oobject->type != OBJT_SWAP)) { 2932 vm_object_chain_release(oobject); 2933 vm_object_reference_locked(oobject); 2934 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 2935 vm_object_drop(oobject); 2936 return; 2937 } 2938 2939 /* 2940 * Collapse original object with its backing store as an 2941 * optimization to reduce chain lengths when possible. 2942 * 2943 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's 2944 * for oobject, so there's no point collapsing it. 2945 * 2946 * Then re-check whether the object can be split. 2947 */ 2948 vm_object_collapse(oobject, NULL); 2949 2950 if (oobject->ref_count <= 1 || 2951 (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) || 2952 (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) { 2953 vm_object_chain_release(oobject); 2954 vm_object_reference_locked(oobject); 2955 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 2956 vm_object_drop(oobject); 2957 return; 2958 } 2959 2960 /* 2961 * Acquire the chain lock on the backing object. 2962 * 2963 * Give bobject an additional ref count for when it will be shadowed 2964 * by nobject. 2965 */ 2966 if ((bobject = oobject->backing_object) != NULL) { 2967 vm_object_hold(bobject); 2968 vm_object_chain_wait(bobject); 2969 vm_object_reference_locked(bobject); 2970 vm_object_chain_acquire(bobject); 2971 KKASSERT(bobject->backing_object == bobject); 2972 KKASSERT((bobject->flags & OBJ_DEAD) == 0); 2973 } 2974 2975 /* 2976 * Calculate the object page range and allocate the new object. 2977 */ 2978 offset = entry->offset; 2979 s = entry->start; 2980 e = entry->end; 2981 2982 offidxstart = OFF_TO_IDX(offset); 2983 offidxend = offidxstart + OFF_TO_IDX(e - s); 2984 size = offidxend - offidxstart; 2985 2986 switch(oobject->type) { 2987 case OBJT_DEFAULT: 2988 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size), 2989 VM_PROT_ALL, 0); 2990 break; 2991 case OBJT_SWAP: 2992 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size), 2993 VM_PROT_ALL, 0); 2994 break; 2995 default: 2996 /* not reached */ 2997 nobject = NULL; 2998 KKASSERT(0); 2999 } 3000 3001 if (nobject == NULL) { 3002 if (bobject) { 3003 vm_object_chain_release(bobject); 3004 vm_object_deallocate(bobject); 3005 vm_object_drop(bobject); 3006 } 3007 vm_object_chain_release(oobject); 3008 vm_object_reference_locked(oobject); 3009 vm_object_clear_flag(oobject, OBJ_ONEMAPPING); 3010 vm_object_drop(oobject); 3011 return; 3012 } 3013 3014 /* 3015 * The new object will replace entry->object.vm_object so it needs 3016 * a second reference (the caller expects an additional ref). 3017 */ 3018 vm_object_hold(nobject); 3019 vm_object_reference_locked(nobject); 3020 vm_object_chain_acquire(nobject); 3021 3022 /* 3023 * nobject shadows bobject (oobject already shadows bobject). 3024 */ 3025 if (bobject) { 3026 nobject->backing_object_offset = 3027 oobject->backing_object_offset + IDX_TO_OFF(offidxstart); 3028 nobject->backing_object = bobject; 3029 bobject->shadow_count++; 3030 bobject->generation++; 3031 LIST_INSERT_HEAD(&bobject->shadow_head, nobject, shadow_list); 3032 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /* XXX? */ 3033 vm_object_chain_release(bobject); 3034 vm_object_drop(bobject); 3035 } 3036 3037 /* 3038 * Move the VM pages from oobject to nobject 3039 */ 3040 for (idx = 0; idx < size; idx++) { 3041 vm_page_t m; 3042 3043 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx, 3044 TRUE, "vmpg"); 3045 if (m == NULL) 3046 continue; 3047 3048 /* 3049 * We must wait for pending I/O to complete before we can 3050 * rename the page. 3051 * 3052 * We do not have to VM_PROT_NONE the page as mappings should 3053 * not be changed by this operation. 3054 * 3055 * NOTE: The act of renaming a page updates chaingen for both 3056 * objects. 3057 */ 3058 vm_page_rename(m, nobject, idx); 3059 /* page automatically made dirty by rename and cache handled */ 3060 /* page remains busy */ 3061 } 3062 3063 if (oobject->type == OBJT_SWAP) { 3064 vm_object_pip_add(oobject, 1); 3065 /* 3066 * copy oobject pages into nobject and destroy unneeded 3067 * pages in shadow object. 3068 */ 3069 swap_pager_copy(oobject, nobject, offidxstart, 0); 3070 vm_object_pip_wakeup(oobject); 3071 } 3072 3073 /* 3074 * Wakeup the pages we played with. No spl protection is needed 3075 * for a simple wakeup. 3076 */ 3077 for (idx = 0; idx < size; idx++) { 3078 m = vm_page_lookup(nobject, idx); 3079 if (m) { 3080 KKASSERT(m->flags & PG_BUSY); 3081 vm_page_wakeup(m); 3082 } 3083 } 3084 entry->object.vm_object = nobject; 3085 entry->offset = 0LL; 3086 3087 /* 3088 * Cleanup 3089 * 3090 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the 3091 * related pages were moved and are no longer applicable to the 3092 * original object. 3093 * 3094 * NOTE: Deallocate oobject (due to its entry->object.vm_object being 3095 * replaced by nobject). 3096 */ 3097 vm_object_chain_release(nobject); 3098 vm_object_drop(nobject); 3099 if (bobject) { 3100 vm_object_chain_release(bobject); 3101 vm_object_drop(bobject); 3102 } 3103 vm_object_chain_release(oobject); 3104 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/ 3105 vm_object_deallocate_locked(oobject); 3106 vm_object_drop(oobject); 3107 #endif 3108 } 3109 3110 /* 3111 * Copies the contents of the source entry to the destination 3112 * entry. The entries *must* be aligned properly. 3113 * 3114 * The vm_maps must be exclusively locked. 3115 * The vm_map's token must be held. 3116 * 3117 * Because the maps are locked no faults can be in progress during the 3118 * operation. 3119 */ 3120 static void 3121 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map, 3122 vm_map_entry_t src_entry, vm_map_entry_t dst_entry) 3123 { 3124 vm_object_t src_object; 3125 3126 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP) 3127 return; 3128 if (src_entry->maptype == VM_MAPTYPE_SUBMAP) 3129 return; 3130 3131 if (src_entry->wired_count == 0) { 3132 /* 3133 * If the source entry is marked needs_copy, it is already 3134 * write-protected. 3135 */ 3136 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 3137 pmap_protect(src_map->pmap, 3138 src_entry->start, 3139 src_entry->end, 3140 src_entry->protection & ~VM_PROT_WRITE); 3141 } 3142 3143 /* 3144 * Make a copy of the object. 3145 * 3146 * The object must be locked prior to checking the object type 3147 * and for the call to vm_object_collapse() and vm_map_split(). 3148 * We cannot use *_hold() here because the split code will 3149 * probably try to destroy the object. The lock is a pool 3150 * token and doesn't care. 3151 */ 3152 if (src_entry->object.vm_object != NULL) { 3153 vm_map_split(src_entry); 3154 src_object = src_entry->object.vm_object; 3155 dst_entry->object.vm_object = src_object; 3156 src_entry->eflags |= (MAP_ENTRY_COW | 3157 MAP_ENTRY_NEEDS_COPY); 3158 dst_entry->eflags |= (MAP_ENTRY_COW | 3159 MAP_ENTRY_NEEDS_COPY); 3160 dst_entry->offset = src_entry->offset; 3161 } else { 3162 dst_entry->object.vm_object = NULL; 3163 dst_entry->offset = 0; 3164 } 3165 3166 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 3167 dst_entry->end - dst_entry->start, src_entry->start); 3168 } else { 3169 /* 3170 * Of course, wired down pages can't be set copy-on-write. 3171 * Cause wired pages to be copied into the new map by 3172 * simulating faults (the new pages are pageable) 3173 */ 3174 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 3175 } 3176 } 3177 3178 /* 3179 * vmspace_fork: 3180 * Create a new process vmspace structure and vm_map 3181 * based on those of an existing process. The new map 3182 * is based on the old map, according to the inheritance 3183 * values on the regions in that map. 3184 * 3185 * The source map must not be locked. 3186 * No requirements. 3187 */ 3188 struct vmspace * 3189 vmspace_fork(struct vmspace *vm1) 3190 { 3191 struct vmspace *vm2; 3192 vm_map_t old_map = &vm1->vm_map; 3193 vm_map_t new_map; 3194 vm_map_entry_t old_entry; 3195 vm_map_entry_t new_entry; 3196 vm_object_t object; 3197 int count; 3198 3199 lwkt_gettoken(&vm1->vm_map.token); 3200 vm_map_lock(old_map); 3201 3202 /* 3203 * XXX Note: upcalls are not copied. 3204 */ 3205 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 3206 lwkt_gettoken(&vm2->vm_map.token); 3207 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 3208 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); 3209 new_map = &vm2->vm_map; /* XXX */ 3210 new_map->timestamp = 1; 3211 3212 vm_map_lock(new_map); 3213 3214 count = 0; 3215 old_entry = old_map->header.next; 3216 while (old_entry != &old_map->header) { 3217 ++count; 3218 old_entry = old_entry->next; 3219 } 3220 3221 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); 3222 3223 old_entry = old_map->header.next; 3224 while (old_entry != &old_map->header) { 3225 if (old_entry->maptype == VM_MAPTYPE_SUBMAP) 3226 panic("vm_map_fork: encountered a submap"); 3227 3228 switch (old_entry->inheritance) { 3229 case VM_INHERIT_NONE: 3230 break; 3231 case VM_INHERIT_SHARE: 3232 /* 3233 * Clone the entry, creating the shared object if 3234 * necessary. 3235 */ 3236 if (old_entry->object.vm_object == NULL) 3237 vm_map_entry_allocate_object(old_entry); 3238 3239 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3240 /* 3241 * Shadow a map_entry which needs a copy, 3242 * replacing its object with a new object 3243 * that points to the old one. Ask the 3244 * shadow code to automatically add an 3245 * additional ref. We can't do it afterwords 3246 * because we might race a collapse. The call 3247 * to vm_map_entry_shadow() will also clear 3248 * OBJ_ONEMAPPING. 3249 */ 3250 vm_map_entry_shadow(old_entry, 1); 3251 } else { 3252 /* 3253 * We will make a shared copy of the object, 3254 * and must clear OBJ_ONEMAPPING. 3255 * 3256 * XXX assert that object.vm_object != NULL 3257 * since we allocate it above. 3258 */ 3259 if (old_entry->object.vm_object) { 3260 object = old_entry->object.vm_object; 3261 vm_object_hold(object); 3262 vm_object_chain_wait(object); 3263 vm_object_reference_locked(object); 3264 vm_object_clear_flag(object, 3265 OBJ_ONEMAPPING); 3266 vm_object_drop(object); 3267 } 3268 } 3269 3270 /* 3271 * Clone the entry. We've already bumped the ref on 3272 * any vm_object. 3273 */ 3274 new_entry = vm_map_entry_create(new_map, &count); 3275 *new_entry = *old_entry; 3276 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3277 new_entry->wired_count = 0; 3278 3279 /* 3280 * Insert the entry into the new map -- we know we're 3281 * inserting at the end of the new map. 3282 */ 3283 3284 vm_map_entry_link(new_map, new_map->header.prev, 3285 new_entry); 3286 3287 /* 3288 * Update the physical map 3289 */ 3290 pmap_copy(new_map->pmap, old_map->pmap, 3291 new_entry->start, 3292 (old_entry->end - old_entry->start), 3293 old_entry->start); 3294 break; 3295 case VM_INHERIT_COPY: 3296 /* 3297 * Clone the entry and link into the map. 3298 */ 3299 new_entry = vm_map_entry_create(new_map, &count); 3300 *new_entry = *old_entry; 3301 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3302 new_entry->wired_count = 0; 3303 new_entry->object.vm_object = NULL; 3304 vm_map_entry_link(new_map, new_map->header.prev, 3305 new_entry); 3306 vm_map_copy_entry(old_map, new_map, old_entry, 3307 new_entry); 3308 break; 3309 } 3310 old_entry = old_entry->next; 3311 } 3312 3313 new_map->size = old_map->size; 3314 vm_map_unlock(old_map); 3315 vm_map_unlock(new_map); 3316 vm_map_entry_release(count); 3317 3318 lwkt_reltoken(&vm2->vm_map.token); 3319 lwkt_reltoken(&vm1->vm_map.token); 3320 3321 return (vm2); 3322 } 3323 3324 /* 3325 * Create an auto-grow stack entry 3326 * 3327 * No requirements. 3328 */ 3329 int 3330 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3331 int flags, vm_prot_t prot, vm_prot_t max, int cow) 3332 { 3333 vm_map_entry_t prev_entry; 3334 vm_map_entry_t new_stack_entry; 3335 vm_size_t init_ssize; 3336 int rv; 3337 int count; 3338 vm_offset_t tmpaddr; 3339 3340 cow |= MAP_IS_STACK; 3341 3342 if (max_ssize < sgrowsiz) 3343 init_ssize = max_ssize; 3344 else 3345 init_ssize = sgrowsiz; 3346 3347 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3348 vm_map_lock(map); 3349 3350 /* 3351 * Find space for the mapping 3352 */ 3353 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) { 3354 if (vm_map_findspace(map, addrbos, max_ssize, 1, 3355 flags, &tmpaddr)) { 3356 vm_map_unlock(map); 3357 vm_map_entry_release(count); 3358 return (KERN_NO_SPACE); 3359 } 3360 addrbos = tmpaddr; 3361 } 3362 3363 /* If addr is already mapped, no go */ 3364 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3365 vm_map_unlock(map); 3366 vm_map_entry_release(count); 3367 return (KERN_NO_SPACE); 3368 } 3369 3370 #if 0 3371 /* XXX already handled by kern_mmap() */ 3372 /* If we would blow our VMEM resource limit, no go */ 3373 if (map->size + init_ssize > 3374 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3375 vm_map_unlock(map); 3376 vm_map_entry_release(count); 3377 return (KERN_NO_SPACE); 3378 } 3379 #endif 3380 3381 /* 3382 * If we can't accomodate max_ssize in the current mapping, 3383 * no go. However, we need to be aware that subsequent user 3384 * mappings might map into the space we have reserved for 3385 * stack, and currently this space is not protected. 3386 * 3387 * Hopefully we will at least detect this condition 3388 * when we try to grow the stack. 3389 */ 3390 if ((prev_entry->next != &map->header) && 3391 (prev_entry->next->start < addrbos + max_ssize)) { 3392 vm_map_unlock(map); 3393 vm_map_entry_release(count); 3394 return (KERN_NO_SPACE); 3395 } 3396 3397 /* 3398 * We initially map a stack of only init_ssize. We will 3399 * grow as needed later. Since this is to be a grow 3400 * down stack, we map at the top of the range. 3401 * 3402 * Note: we would normally expect prot and max to be 3403 * VM_PROT_ALL, and cow to be 0. Possibly we should 3404 * eliminate these as input parameters, and just 3405 * pass these values here in the insert call. 3406 */ 3407 rv = vm_map_insert(map, &count, 3408 NULL, 0, addrbos + max_ssize - init_ssize, 3409 addrbos + max_ssize, 3410 VM_MAPTYPE_NORMAL, 3411 prot, max, 3412 cow); 3413 3414 /* Now set the avail_ssize amount */ 3415 if (rv == KERN_SUCCESS) { 3416 if (prev_entry != &map->header) 3417 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count); 3418 new_stack_entry = prev_entry->next; 3419 if (new_stack_entry->end != addrbos + max_ssize || 3420 new_stack_entry->start != addrbos + max_ssize - init_ssize) 3421 panic ("Bad entry start/end for new stack entry"); 3422 else 3423 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize; 3424 } 3425 3426 vm_map_unlock(map); 3427 vm_map_entry_release(count); 3428 return (rv); 3429 } 3430 3431 /* 3432 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3433 * desired address is already mapped, or if we successfully grow 3434 * the stack. Also returns KERN_SUCCESS if addr is outside the 3435 * stack range (this is strange, but preserves compatibility with 3436 * the grow function in vm_machdep.c). 3437 * 3438 * No requirements. 3439 */ 3440 int 3441 vm_map_growstack (struct proc *p, vm_offset_t addr) 3442 { 3443 vm_map_entry_t prev_entry; 3444 vm_map_entry_t stack_entry; 3445 vm_map_entry_t new_stack_entry; 3446 struct vmspace *vm = p->p_vmspace; 3447 vm_map_t map = &vm->vm_map; 3448 vm_offset_t end; 3449 int grow_amount; 3450 int rv = KERN_SUCCESS; 3451 int is_procstack; 3452 int use_read_lock = 1; 3453 int count; 3454 3455 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3456 Retry: 3457 if (use_read_lock) 3458 vm_map_lock_read(map); 3459 else 3460 vm_map_lock(map); 3461 3462 /* If addr is already in the entry range, no need to grow.*/ 3463 if (vm_map_lookup_entry(map, addr, &prev_entry)) 3464 goto done; 3465 3466 if ((stack_entry = prev_entry->next) == &map->header) 3467 goto done; 3468 if (prev_entry == &map->header) 3469 end = stack_entry->start - stack_entry->aux.avail_ssize; 3470 else 3471 end = prev_entry->end; 3472 3473 /* 3474 * This next test mimics the old grow function in vm_machdep.c. 3475 * It really doesn't quite make sense, but we do it anyway 3476 * for compatibility. 3477 * 3478 * If not growable stack, return success. This signals the 3479 * caller to proceed as he would normally with normal vm. 3480 */ 3481 if (stack_entry->aux.avail_ssize < 1 || 3482 addr >= stack_entry->start || 3483 addr < stack_entry->start - stack_entry->aux.avail_ssize) { 3484 goto done; 3485 } 3486 3487 /* Find the minimum grow amount */ 3488 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE); 3489 if (grow_amount > stack_entry->aux.avail_ssize) { 3490 rv = KERN_NO_SPACE; 3491 goto done; 3492 } 3493 3494 /* 3495 * If there is no longer enough space between the entries 3496 * nogo, and adjust the available space. Note: this 3497 * should only happen if the user has mapped into the 3498 * stack area after the stack was created, and is 3499 * probably an error. 3500 * 3501 * This also effectively destroys any guard page the user 3502 * might have intended by limiting the stack size. 3503 */ 3504 if (grow_amount > stack_entry->start - end) { 3505 if (use_read_lock && vm_map_lock_upgrade(map)) { 3506 use_read_lock = 0; 3507 goto Retry; 3508 } 3509 use_read_lock = 0; 3510 stack_entry->aux.avail_ssize = stack_entry->start - end; 3511 rv = KERN_NO_SPACE; 3512 goto done; 3513 } 3514 3515 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; 3516 3517 /* If this is the main process stack, see if we're over the 3518 * stack limit. 3519 */ 3520 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3521 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3522 rv = KERN_NO_SPACE; 3523 goto done; 3524 } 3525 3526 /* Round up the grow amount modulo SGROWSIZ */ 3527 grow_amount = roundup (grow_amount, sgrowsiz); 3528 if (grow_amount > stack_entry->aux.avail_ssize) { 3529 grow_amount = stack_entry->aux.avail_ssize; 3530 } 3531 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3532 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3533 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 3534 ctob(vm->vm_ssize); 3535 } 3536 3537 /* If we would blow our VMEM resource limit, no go */ 3538 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3539 rv = KERN_NO_SPACE; 3540 goto done; 3541 } 3542 3543 if (use_read_lock && vm_map_lock_upgrade(map)) { 3544 use_read_lock = 0; 3545 goto Retry; 3546 } 3547 use_read_lock = 0; 3548 3549 /* Get the preliminary new entry start value */ 3550 addr = stack_entry->start - grow_amount; 3551 3552 /* If this puts us into the previous entry, cut back our growth 3553 * to the available space. Also, see the note above. 3554 */ 3555 if (addr < end) { 3556 stack_entry->aux.avail_ssize = stack_entry->start - end; 3557 addr = end; 3558 } 3559 3560 rv = vm_map_insert(map, &count, 3561 NULL, 0, addr, stack_entry->start, 3562 VM_MAPTYPE_NORMAL, 3563 VM_PROT_ALL, VM_PROT_ALL, 3564 0); 3565 3566 /* Adjust the available stack space by the amount we grew. */ 3567 if (rv == KERN_SUCCESS) { 3568 if (prev_entry != &map->header) 3569 vm_map_clip_end(map, prev_entry, addr, &count); 3570 new_stack_entry = prev_entry->next; 3571 if (new_stack_entry->end != stack_entry->start || 3572 new_stack_entry->start != addr) 3573 panic ("Bad stack grow start/end in new stack entry"); 3574 else { 3575 new_stack_entry->aux.avail_ssize = 3576 stack_entry->aux.avail_ssize - 3577 (new_stack_entry->end - new_stack_entry->start); 3578 if (is_procstack) 3579 vm->vm_ssize += btoc(new_stack_entry->end - 3580 new_stack_entry->start); 3581 } 3582 3583 if (map->flags & MAP_WIREFUTURE) 3584 vm_map_unwire(map, new_stack_entry->start, 3585 new_stack_entry->end, FALSE); 3586 } 3587 3588 done: 3589 if (use_read_lock) 3590 vm_map_unlock_read(map); 3591 else 3592 vm_map_unlock(map); 3593 vm_map_entry_release(count); 3594 return (rv); 3595 } 3596 3597 /* 3598 * Unshare the specified VM space for exec. If other processes are 3599 * mapped to it, then create a new one. The new vmspace is null. 3600 * 3601 * No requirements. 3602 */ 3603 void 3604 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 3605 { 3606 struct vmspace *oldvmspace = p->p_vmspace; 3607 struct vmspace *newvmspace; 3608 vm_map_t map = &p->p_vmspace->vm_map; 3609 3610 /* 3611 * If we are execing a resident vmspace we fork it, otherwise 3612 * we create a new vmspace. Note that exitingcnt and upcalls 3613 * are not copied to the new vmspace. 3614 */ 3615 lwkt_gettoken(&oldvmspace->vm_map.token); 3616 if (vmcopy) { 3617 newvmspace = vmspace_fork(vmcopy); 3618 lwkt_gettoken(&newvmspace->vm_map.token); 3619 } else { 3620 newvmspace = vmspace_alloc(map->min_offset, map->max_offset); 3621 lwkt_gettoken(&newvmspace->vm_map.token); 3622 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 3623 (caddr_t)&oldvmspace->vm_endcopy - 3624 (caddr_t)&oldvmspace->vm_startcopy); 3625 } 3626 3627 /* 3628 * Finish initializing the vmspace before assigning it 3629 * to the process. The vmspace will become the current vmspace 3630 * if p == curproc. 3631 */ 3632 pmap_pinit2(vmspace_pmap(newvmspace)); 3633 pmap_replacevm(p, newvmspace, 0); 3634 lwkt_reltoken(&newvmspace->vm_map.token); 3635 lwkt_reltoken(&oldvmspace->vm_map.token); 3636 sysref_put(&oldvmspace->vm_sysref); 3637 } 3638 3639 /* 3640 * Unshare the specified VM space for forcing COW. This 3641 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3642 * 3643 * The exitingcnt test is not strictly necessary but has been 3644 * included for code sanity (to make the code a bit more deterministic). 3645 */ 3646 void 3647 vmspace_unshare(struct proc *p) 3648 { 3649 struct vmspace *oldvmspace = p->p_vmspace; 3650 struct vmspace *newvmspace; 3651 3652 lwkt_gettoken(&oldvmspace->vm_map.token); 3653 if (oldvmspace->vm_sysref.refcnt == 1 && oldvmspace->vm_exitingcnt == 0) { 3654 lwkt_reltoken(&oldvmspace->vm_map.token); 3655 return; 3656 } 3657 newvmspace = vmspace_fork(oldvmspace); 3658 lwkt_gettoken(&newvmspace->vm_map.token); 3659 pmap_pinit2(vmspace_pmap(newvmspace)); 3660 pmap_replacevm(p, newvmspace, 0); 3661 lwkt_reltoken(&newvmspace->vm_map.token); 3662 lwkt_reltoken(&oldvmspace->vm_map.token); 3663 sysref_put(&oldvmspace->vm_sysref); 3664 } 3665 3666 /* 3667 * vm_map_hint: return the beginning of the best area suitable for 3668 * creating a new mapping with "prot" protection. 3669 * 3670 * No requirements. 3671 */ 3672 vm_offset_t 3673 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot) 3674 { 3675 struct vmspace *vms = p->p_vmspace; 3676 3677 if (!randomize_mmap) { 3678 /* 3679 * Set a reasonable start point for the hint if it was 3680 * not specified or if it falls within the heap space. 3681 * Hinted mmap()s do not allocate out of the heap space. 3682 */ 3683 if (addr == 0 || 3684 (addr >= round_page((vm_offset_t)vms->vm_taddr) && 3685 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) { 3686 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); 3687 } 3688 3689 return addr; 3690 } 3691 3692 if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr) 3693 return addr; 3694 3695 #ifdef notyet 3696 #ifdef __i386__ 3697 /* 3698 * If executable skip first two pages, otherwise start 3699 * after data + heap region. 3700 */ 3701 if ((prot & VM_PROT_EXECUTE) && 3702 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) { 3703 addr = (PAGE_SIZE * 2) + 3704 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1)); 3705 return (round_page(addr)); 3706 } 3707 #endif /* __i386__ */ 3708 #endif /* notyet */ 3709 3710 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ; 3711 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1); 3712 3713 return (round_page(addr)); 3714 } 3715 3716 /* 3717 * Finds the VM object, offset, and protection for a given virtual address 3718 * in the specified map, assuming a page fault of the type specified. 3719 * 3720 * Leaves the map in question locked for read; return values are guaranteed 3721 * until a vm_map_lookup_done call is performed. Note that the map argument 3722 * is in/out; the returned map must be used in the call to vm_map_lookup_done. 3723 * 3724 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make 3725 * that fast. 3726 * 3727 * If a lookup is requested with "write protection" specified, the map may 3728 * be changed to perform virtual copying operations, although the data 3729 * referenced will remain the same. 3730 * 3731 * No requirements. 3732 */ 3733 int 3734 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3735 vm_offset_t vaddr, 3736 vm_prot_t fault_typea, 3737 vm_map_entry_t *out_entry, /* OUT */ 3738 vm_object_t *object, /* OUT */ 3739 vm_pindex_t *pindex, /* OUT */ 3740 vm_prot_t *out_prot, /* OUT */ 3741 boolean_t *wired) /* OUT */ 3742 { 3743 vm_map_entry_t entry; 3744 vm_map_t map = *var_map; 3745 vm_prot_t prot; 3746 vm_prot_t fault_type = fault_typea; 3747 int use_read_lock = 1; 3748 int rv = KERN_SUCCESS; 3749 3750 RetryLookup: 3751 if (use_read_lock) 3752 vm_map_lock_read(map); 3753 else 3754 vm_map_lock(map); 3755 3756 /* 3757 * If the map has an interesting hint, try it before calling full 3758 * blown lookup routine. 3759 */ 3760 entry = map->hint; 3761 *out_entry = entry; 3762 *object = NULL; 3763 3764 if ((entry == &map->header) || 3765 (vaddr < entry->start) || (vaddr >= entry->end)) { 3766 vm_map_entry_t tmp_entry; 3767 3768 /* 3769 * Entry was either not a valid hint, or the vaddr was not 3770 * contained in the entry, so do a full lookup. 3771 */ 3772 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { 3773 rv = KERN_INVALID_ADDRESS; 3774 goto done; 3775 } 3776 3777 entry = tmp_entry; 3778 *out_entry = entry; 3779 } 3780 3781 /* 3782 * Handle submaps. 3783 */ 3784 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3785 vm_map_t old_map = map; 3786 3787 *var_map = map = entry->object.sub_map; 3788 if (use_read_lock) 3789 vm_map_unlock_read(old_map); 3790 else 3791 vm_map_unlock(old_map); 3792 use_read_lock = 1; 3793 goto RetryLookup; 3794 } 3795 3796 /* 3797 * Check whether this task is allowed to have this page. 3798 * Note the special case for MAP_ENTRY_COW 3799 * pages with an override. This is to implement a forced 3800 * COW for debuggers. 3801 */ 3802 3803 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3804 prot = entry->max_protection; 3805 else 3806 prot = entry->protection; 3807 3808 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3809 if ((fault_type & prot) != fault_type) { 3810 rv = KERN_PROTECTION_FAILURE; 3811 goto done; 3812 } 3813 3814 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3815 (entry->eflags & MAP_ENTRY_COW) && 3816 (fault_type & VM_PROT_WRITE) && 3817 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 3818 rv = KERN_PROTECTION_FAILURE; 3819 goto done; 3820 } 3821 3822 /* 3823 * If this page is not pageable, we have to get it for all possible 3824 * accesses. 3825 */ 3826 *wired = (entry->wired_count != 0); 3827 if (*wired) 3828 prot = fault_type = entry->protection; 3829 3830 /* 3831 * Virtual page tables may need to update the accessed (A) bit 3832 * in a page table entry. Upgrade the fault to a write fault for 3833 * that case if the map will support it. If the map does not support 3834 * it the page table entry simply will not be updated. 3835 */ 3836 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 3837 if (prot & VM_PROT_WRITE) 3838 fault_type |= VM_PROT_WRITE; 3839 } 3840 3841 /* 3842 * If the entry was copy-on-write, we either ... 3843 */ 3844 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3845 /* 3846 * If we want to write the page, we may as well handle that 3847 * now since we've got the map locked. 3848 * 3849 * If we don't need to write the page, we just demote the 3850 * permissions allowed. 3851 */ 3852 3853 if (fault_type & VM_PROT_WRITE) { 3854 /* 3855 * Make a new object, and place it in the object 3856 * chain. Note that no new references have appeared 3857 * -- one just moved from the map to the new 3858 * object. 3859 */ 3860 3861 if (use_read_lock && vm_map_lock_upgrade(map)) { 3862 use_read_lock = 0; 3863 goto RetryLookup; 3864 } 3865 use_read_lock = 0; 3866 3867 vm_map_entry_shadow(entry, 0); 3868 } else { 3869 /* 3870 * We're attempting to read a copy-on-write page -- 3871 * don't allow writes. 3872 */ 3873 3874 prot &= ~VM_PROT_WRITE; 3875 } 3876 } 3877 3878 /* 3879 * Create an object if necessary. 3880 */ 3881 if (entry->object.vm_object == NULL && 3882 !map->system_map) { 3883 if (use_read_lock && vm_map_lock_upgrade(map)) { 3884 use_read_lock = 0; 3885 goto RetryLookup; 3886 } 3887 use_read_lock = 0; 3888 vm_map_entry_allocate_object(entry); 3889 } 3890 3891 /* 3892 * Return the object/offset from this entry. If the entry was 3893 * copy-on-write or empty, it has been fixed up. 3894 */ 3895 3896 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3897 *object = entry->object.vm_object; 3898 3899 /* 3900 * Return whether this is the only map sharing this data. On 3901 * success we return with a read lock held on the map. On failure 3902 * we return with the map unlocked. 3903 */ 3904 *out_prot = prot; 3905 done: 3906 if (rv == KERN_SUCCESS) { 3907 if (use_read_lock == 0) 3908 vm_map_lock_downgrade(map); 3909 } else if (use_read_lock) { 3910 vm_map_unlock_read(map); 3911 } else { 3912 vm_map_unlock(map); 3913 } 3914 return (rv); 3915 } 3916 3917 /* 3918 * Releases locks acquired by a vm_map_lookup() 3919 * (according to the handle returned by that lookup). 3920 * 3921 * No other requirements. 3922 */ 3923 void 3924 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) 3925 { 3926 /* 3927 * Unlock the main-level map 3928 */ 3929 vm_map_unlock_read(map); 3930 if (count) 3931 vm_map_entry_release(count); 3932 } 3933 3934 #include "opt_ddb.h" 3935 #ifdef DDB 3936 #include <sys/kernel.h> 3937 3938 #include <ddb/ddb.h> 3939 3940 /* 3941 * Debugging only 3942 */ 3943 DB_SHOW_COMMAND(map, vm_map_print) 3944 { 3945 static int nlines; 3946 /* XXX convert args. */ 3947 vm_map_t map = (vm_map_t)addr; 3948 boolean_t full = have_addr; 3949 3950 vm_map_entry_t entry; 3951 3952 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 3953 (void *)map, 3954 (void *)map->pmap, map->nentries, map->timestamp); 3955 nlines++; 3956 3957 if (!full && db_indent) 3958 return; 3959 3960 db_indent += 2; 3961 for (entry = map->header.next; entry != &map->header; 3962 entry = entry->next) { 3963 db_iprintf("map entry %p: start=%p, end=%p\n", 3964 (void *)entry, (void *)entry->start, (void *)entry->end); 3965 nlines++; 3966 { 3967 static char *inheritance_name[4] = 3968 {"share", "copy", "none", "donate_copy"}; 3969 3970 db_iprintf(" prot=%x/%x/%s", 3971 entry->protection, 3972 entry->max_protection, 3973 inheritance_name[(int)(unsigned char)entry->inheritance]); 3974 if (entry->wired_count != 0) 3975 db_printf(", wired"); 3976 } 3977 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3978 /* XXX no %qd in kernel. Truncate entry->offset. */ 3979 db_printf(", share=%p, offset=0x%lx\n", 3980 (void *)entry->object.sub_map, 3981 (long)entry->offset); 3982 nlines++; 3983 if ((entry->prev == &map->header) || 3984 (entry->prev->object.sub_map != 3985 entry->object.sub_map)) { 3986 db_indent += 2; 3987 vm_map_print((db_expr_t)(intptr_t) 3988 entry->object.sub_map, 3989 full, 0, NULL); 3990 db_indent -= 2; 3991 } 3992 } else { 3993 /* XXX no %qd in kernel. Truncate entry->offset. */ 3994 db_printf(", object=%p, offset=0x%lx", 3995 (void *)entry->object.vm_object, 3996 (long)entry->offset); 3997 if (entry->eflags & MAP_ENTRY_COW) 3998 db_printf(", copy (%s)", 3999 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 4000 db_printf("\n"); 4001 nlines++; 4002 4003 if ((entry->prev == &map->header) || 4004 (entry->prev->object.vm_object != 4005 entry->object.vm_object)) { 4006 db_indent += 2; 4007 vm_object_print((db_expr_t)(intptr_t) 4008 entry->object.vm_object, 4009 full, 0, NULL); 4010 nlines += 4; 4011 db_indent -= 2; 4012 } 4013 } 4014 } 4015 db_indent -= 2; 4016 if (db_indent == 0) 4017 nlines = 0; 4018 } 4019 4020 /* 4021 * Debugging only 4022 */ 4023 DB_SHOW_COMMAND(procvm, procvm) 4024 { 4025 struct proc *p; 4026 4027 if (have_addr) { 4028 p = (struct proc *) addr; 4029 } else { 4030 p = curproc; 4031 } 4032 4033 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 4034 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 4035 (void *)vmspace_pmap(p->p_vmspace)); 4036 4037 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 4038 } 4039 4040 #endif /* DDB */ 4041