1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 35 * 36 * 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * Virtual memory mapping module. 65 */ 66 67 #include <sys/cdefs.h> 68 __FBSDID("$FreeBSD$"); 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/elf.h> 73 #include <sys/kernel.h> 74 #include <sys/ktr.h> 75 #include <sys/lock.h> 76 #include <sys/mutex.h> 77 #include <sys/proc.h> 78 #include <sys/vmmeter.h> 79 #include <sys/mman.h> 80 #include <sys/vnode.h> 81 #include <sys/racct.h> 82 #include <sys/resourcevar.h> 83 #include <sys/rwlock.h> 84 #include <sys/file.h> 85 #include <sys/sysctl.h> 86 #include <sys/sysent.h> 87 #include <sys/shm.h> 88 89 #include <vm/vm.h> 90 #include <vm/vm_param.h> 91 #include <vm/pmap.h> 92 #include <vm/vm_map.h> 93 #include <vm/vm_page.h> 94 #include <vm/vm_pageout.h> 95 #include <vm/vm_object.h> 96 #include <vm/vm_pager.h> 97 #include <vm/vm_kern.h> 98 #include <vm/vm_extern.h> 99 #include <vm/vnode_pager.h> 100 #include <vm/swap_pager.h> 101 #include <vm/uma.h> 102 103 /* 104 * Virtual memory maps provide for the mapping, protection, 105 * and sharing of virtual memory objects. In addition, 106 * this module provides for an efficient virtual copy of 107 * memory from one map to another. 108 * 109 * Synchronization is required prior to most operations. 110 * 111 * Maps consist of an ordered doubly-linked list of simple 112 * entries; a self-adjusting binary search tree of these 113 * entries is used to speed up lookups. 114 * 115 * Since portions of maps are specified by start/end addresses, 116 * which may not align with existing map entries, all 117 * routines merely "clip" entries to these start/end values. 118 * [That is, an entry is split into two, bordering at a 119 * start or end value.] Note that these clippings may not 120 * always be necessary (as the two resulting entries are then 121 * not changed); however, the clipping is done for convenience. 122 * 123 * As mentioned above, virtual copy operations are performed 124 * by copying VM object references from one map to 125 * another, and then marking both regions as copy-on-write. 126 */ 127 128 static struct mtx map_sleep_mtx; 129 static uma_zone_t mapentzone; 130 static uma_zone_t kmapentzone; 131 static uma_zone_t mapzone; 132 static uma_zone_t vmspace_zone; 133 static int vmspace_zinit(void *mem, int size, int flags); 134 static int vm_map_zinit(void *mem, int ize, int flags); 135 static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, 136 vm_offset_t max); 137 static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map); 138 static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry); 139 static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry); 140 static int vm_map_growstack(vm_map_t map, vm_offset_t addr, 141 vm_map_entry_t gap_entry); 142 static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 143 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags); 144 #ifdef INVARIANTS 145 static void vm_map_zdtor(void *mem, int size, void *arg); 146 static void vmspace_zdtor(void *mem, int size, void *arg); 147 #endif 148 static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, 149 vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max, 150 int cow); 151 static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 152 vm_offset_t failed_addr); 153 154 #define ENTRY_CHARGED(e) ((e)->cred != NULL || \ 155 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \ 156 !((e)->eflags & MAP_ENTRY_NEEDS_COPY))) 157 158 /* 159 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type 160 * stable. 161 */ 162 #define PROC_VMSPACE_LOCK(p) do { } while (0) 163 #define PROC_VMSPACE_UNLOCK(p) do { } while (0) 164 165 /* 166 * VM_MAP_RANGE_CHECK: [ internal use only ] 167 * 168 * Asserts that the starting and ending region 169 * addresses fall within the valid range of the map. 170 */ 171 #define VM_MAP_RANGE_CHECK(map, start, end) \ 172 { \ 173 if (start < vm_map_min(map)) \ 174 start = vm_map_min(map); \ 175 if (end > vm_map_max(map)) \ 176 end = vm_map_max(map); \ 177 if (start > end) \ 178 start = end; \ 179 } 180 181 /* 182 * vm_map_startup: 183 * 184 * Initialize the vm_map module. Must be called before 185 * any other vm_map routines. 186 * 187 * Map and entry structures are allocated from the general 188 * purpose memory pool with some exceptions: 189 * 190 * - The kernel map and kmem submap are allocated statically. 191 * - Kernel map entries are allocated out of a static pool. 192 * 193 * These restrictions are necessary since malloc() uses the 194 * maps and requires map entries. 195 */ 196 197 void 198 vm_map_startup(void) 199 { 200 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 201 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 202 #ifdef INVARIANTS 203 vm_map_zdtor, 204 #else 205 NULL, 206 #endif 207 vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 208 uma_prealloc(mapzone, MAX_KMAP); 209 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 210 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 211 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 212 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 213 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 214 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 215 #ifdef INVARIANTS 216 vmspace_zdtor, 217 #else 218 NULL, 219 #endif 220 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 221 } 222 223 static int 224 vmspace_zinit(void *mem, int size, int flags) 225 { 226 struct vmspace *vm; 227 228 vm = (struct vmspace *)mem; 229 230 vm->vm_map.pmap = NULL; 231 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); 232 PMAP_LOCK_INIT(vmspace_pmap(vm)); 233 return (0); 234 } 235 236 static int 237 vm_map_zinit(void *mem, int size, int flags) 238 { 239 vm_map_t map; 240 241 map = (vm_map_t)mem; 242 memset(map, 0, sizeof(*map)); 243 mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK); 244 sx_init(&map->lock, "vm map (user)"); 245 return (0); 246 } 247 248 #ifdef INVARIANTS 249 static void 250 vmspace_zdtor(void *mem, int size, void *arg) 251 { 252 struct vmspace *vm; 253 254 vm = (struct vmspace *)mem; 255 256 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 257 } 258 static void 259 vm_map_zdtor(void *mem, int size, void *arg) 260 { 261 vm_map_t map; 262 263 map = (vm_map_t)mem; 264 KASSERT(map->nentries == 0, 265 ("map %p nentries == %d on free.", 266 map, map->nentries)); 267 KASSERT(map->size == 0, 268 ("map %p size == %lu on free.", 269 map, (unsigned long)map->size)); 270 } 271 #endif /* INVARIANTS */ 272 273 /* 274 * Allocate a vmspace structure, including a vm_map and pmap, 275 * and initialize those structures. The refcnt is set to 1. 276 * 277 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit(). 278 */ 279 struct vmspace * 280 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit) 281 { 282 struct vmspace *vm; 283 284 vm = uma_zalloc(vmspace_zone, M_WAITOK); 285 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL")); 286 if (!pinit(vmspace_pmap(vm))) { 287 uma_zfree(vmspace_zone, vm); 288 return (NULL); 289 } 290 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 291 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max); 292 vm->vm_refcnt = 1; 293 vm->vm_shm = NULL; 294 vm->vm_swrss = 0; 295 vm->vm_tsize = 0; 296 vm->vm_dsize = 0; 297 vm->vm_ssize = 0; 298 vm->vm_taddr = 0; 299 vm->vm_daddr = 0; 300 vm->vm_maxsaddr = 0; 301 return (vm); 302 } 303 304 #ifdef RACCT 305 static void 306 vmspace_container_reset(struct proc *p) 307 { 308 309 PROC_LOCK(p); 310 racct_set(p, RACCT_DATA, 0); 311 racct_set(p, RACCT_STACK, 0); 312 racct_set(p, RACCT_RSS, 0); 313 racct_set(p, RACCT_MEMLOCK, 0); 314 racct_set(p, RACCT_VMEM, 0); 315 PROC_UNLOCK(p); 316 } 317 #endif 318 319 static inline void 320 vmspace_dofree(struct vmspace *vm) 321 { 322 323 CTR1(KTR_VM, "vmspace_free: %p", vm); 324 325 /* 326 * Make sure any SysV shm is freed, it might not have been in 327 * exit1(). 328 */ 329 shmexit(vm); 330 331 /* 332 * Lock the map, to wait out all other references to it. 333 * Delete all of the mappings and pages they hold, then call 334 * the pmap module to reclaim anything left. 335 */ 336 (void)vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 337 vm_map_max(&vm->vm_map)); 338 339 pmap_release(vmspace_pmap(vm)); 340 vm->vm_map.pmap = NULL; 341 uma_zfree(vmspace_zone, vm); 342 } 343 344 void 345 vmspace_free(struct vmspace *vm) 346 { 347 348 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 349 "vmspace_free() called"); 350 351 if (vm->vm_refcnt == 0) 352 panic("vmspace_free: attempt to free already freed vmspace"); 353 354 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) 355 vmspace_dofree(vm); 356 } 357 358 void 359 vmspace_exitfree(struct proc *p) 360 { 361 struct vmspace *vm; 362 363 PROC_VMSPACE_LOCK(p); 364 vm = p->p_vmspace; 365 p->p_vmspace = NULL; 366 PROC_VMSPACE_UNLOCK(p); 367 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 368 vmspace_free(vm); 369 } 370 371 void 372 vmspace_exit(struct thread *td) 373 { 374 int refcnt; 375 struct vmspace *vm; 376 struct proc *p; 377 378 /* 379 * Release user portion of address space. 380 * This releases references to vnodes, 381 * which could cause I/O if the file has been unlinked. 382 * Need to do this early enough that we can still sleep. 383 * 384 * The last exiting process to reach this point releases as 385 * much of the environment as it can. vmspace_dofree() is the 386 * slower fallback in case another process had a temporary 387 * reference to the vmspace. 388 */ 389 390 p = td->td_proc; 391 vm = p->p_vmspace; 392 atomic_add_int(&vmspace0.vm_refcnt, 1); 393 refcnt = vm->vm_refcnt; 394 do { 395 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 396 /* Switch now since other proc might free vmspace */ 397 PROC_VMSPACE_LOCK(p); 398 p->p_vmspace = &vmspace0; 399 PROC_VMSPACE_UNLOCK(p); 400 pmap_activate(td); 401 } 402 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt - 1)); 403 if (refcnt == 1) { 404 if (p->p_vmspace != vm) { 405 /* vmspace not yet freed, switch back */ 406 PROC_VMSPACE_LOCK(p); 407 p->p_vmspace = vm; 408 PROC_VMSPACE_UNLOCK(p); 409 pmap_activate(td); 410 } 411 pmap_remove_pages(vmspace_pmap(vm)); 412 /* Switch now since this proc will free vmspace */ 413 PROC_VMSPACE_LOCK(p); 414 p->p_vmspace = &vmspace0; 415 PROC_VMSPACE_UNLOCK(p); 416 pmap_activate(td); 417 vmspace_dofree(vm); 418 } 419 #ifdef RACCT 420 if (racct_enable) 421 vmspace_container_reset(p); 422 #endif 423 } 424 425 /* Acquire reference to vmspace owned by another process. */ 426 427 struct vmspace * 428 vmspace_acquire_ref(struct proc *p) 429 { 430 struct vmspace *vm; 431 int refcnt; 432 433 PROC_VMSPACE_LOCK(p); 434 vm = p->p_vmspace; 435 if (vm == NULL) { 436 PROC_VMSPACE_UNLOCK(p); 437 return (NULL); 438 } 439 refcnt = vm->vm_refcnt; 440 do { 441 if (refcnt <= 0) { /* Avoid 0->1 transition */ 442 PROC_VMSPACE_UNLOCK(p); 443 return (NULL); 444 } 445 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt + 1)); 446 if (vm != p->p_vmspace) { 447 PROC_VMSPACE_UNLOCK(p); 448 vmspace_free(vm); 449 return (NULL); 450 } 451 PROC_VMSPACE_UNLOCK(p); 452 return (vm); 453 } 454 455 /* 456 * Switch between vmspaces in an AIO kernel process. 457 * 458 * The new vmspace is either the vmspace of a user process obtained 459 * from an active AIO request or the initial vmspace of the AIO kernel 460 * process (when it is idling). Because user processes will block to 461 * drain any active AIO requests before proceeding in exit() or 462 * execve(), the reference count for vmspaces from AIO requests can 463 * never be 0. Similarly, AIO kernel processes hold an extra 464 * reference on their initial vmspace for the life of the process. As 465 * a result, the 'newvm' vmspace always has a non-zero reference 466 * count. This permits an additional reference on 'newvm' to be 467 * acquired via a simple atomic increment rather than the loop in 468 * vmspace_acquire_ref() above. 469 */ 470 void 471 vmspace_switch_aio(struct vmspace *newvm) 472 { 473 struct vmspace *oldvm; 474 475 /* XXX: Need some way to assert that this is an aio daemon. */ 476 477 KASSERT(newvm->vm_refcnt > 0, 478 ("vmspace_switch_aio: newvm unreferenced")); 479 480 oldvm = curproc->p_vmspace; 481 if (oldvm == newvm) 482 return; 483 484 /* 485 * Point to the new address space and refer to it. 486 */ 487 curproc->p_vmspace = newvm; 488 atomic_add_int(&newvm->vm_refcnt, 1); 489 490 /* Activate the new mapping. */ 491 pmap_activate(curthread); 492 493 vmspace_free(oldvm); 494 } 495 496 void 497 _vm_map_lock(vm_map_t map, const char *file, int line) 498 { 499 500 if (map->system_map) 501 mtx_lock_flags_(&map->system_mtx, 0, file, line); 502 else 503 sx_xlock_(&map->lock, file, line); 504 map->timestamp++; 505 } 506 507 void 508 vm_map_entry_set_vnode_text(vm_map_entry_t entry, bool add) 509 { 510 vm_object_t object; 511 struct vnode *vp; 512 bool vp_held; 513 514 if ((entry->eflags & MAP_ENTRY_VN_EXEC) == 0) 515 return; 516 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 517 ("Submap with execs")); 518 object = entry->object.vm_object; 519 KASSERT(object != NULL, ("No object for text, entry %p", entry)); 520 if ((object->flags & OBJ_ANON) != 0) 521 object = object->handle; 522 else 523 KASSERT(object->backing_object == NULL, 524 ("non-anon object %p shadows", object)); 525 KASSERT(object != NULL, ("No content object for text, entry %p obj %p", 526 entry, entry->object.vm_object)); 527 528 /* 529 * Mostly, we do not lock the backing object. It is 530 * referenced by the entry we are processing, so it cannot go 531 * away. 532 */ 533 vp = NULL; 534 vp_held = false; 535 if (object->type == OBJT_DEAD) { 536 /* 537 * For OBJT_DEAD objects, v_writecount was handled in 538 * vnode_pager_dealloc(). 539 */ 540 } else if (object->type == OBJT_VNODE) { 541 vp = object->handle; 542 } else if (object->type == OBJT_SWAP) { 543 KASSERT((object->flags & OBJ_TMPFS_NODE) != 0, 544 ("vm_map_entry_set_vnode_text: swap and !TMPFS " 545 "entry %p, object %p, add %d", entry, object, add)); 546 /* 547 * Tmpfs VREG node, which was reclaimed, has 548 * OBJ_TMPFS_NODE flag set, but not OBJ_TMPFS. In 549 * this case there is no v_writecount to adjust. 550 */ 551 VM_OBJECT_RLOCK(object); 552 if ((object->flags & OBJ_TMPFS) != 0) { 553 vp = object->un_pager.swp.swp_tmpfs; 554 if (vp != NULL) { 555 vhold(vp); 556 vp_held = true; 557 } 558 } 559 VM_OBJECT_RUNLOCK(object); 560 } else { 561 KASSERT(0, 562 ("vm_map_entry_set_vnode_text: wrong object type, " 563 "entry %p, object %p, add %d", entry, object, add)); 564 } 565 if (vp != NULL) { 566 if (add) { 567 VOP_SET_TEXT_CHECKED(vp); 568 } else { 569 vn_lock(vp, LK_SHARED | LK_RETRY); 570 VOP_UNSET_TEXT_CHECKED(vp); 571 VOP_UNLOCK(vp); 572 } 573 if (vp_held) 574 vdrop(vp); 575 } 576 } 577 578 /* 579 * Use a different name for this vm_map_entry field when it's use 580 * is not consistent with its use as part of an ordered search tree. 581 */ 582 #define defer_next right 583 584 static void 585 vm_map_process_deferred(void) 586 { 587 struct thread *td; 588 vm_map_entry_t entry, next; 589 vm_object_t object; 590 591 td = curthread; 592 entry = td->td_map_def_user; 593 td->td_map_def_user = NULL; 594 while (entry != NULL) { 595 next = entry->defer_next; 596 MPASS((entry->eflags & (MAP_ENTRY_WRITECNT | 597 MAP_ENTRY_VN_EXEC)) != (MAP_ENTRY_WRITECNT | 598 MAP_ENTRY_VN_EXEC)); 599 if ((entry->eflags & MAP_ENTRY_WRITECNT) != 0) { 600 /* 601 * Decrement the object's writemappings and 602 * possibly the vnode's v_writecount. 603 */ 604 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 605 ("Submap with writecount")); 606 object = entry->object.vm_object; 607 KASSERT(object != NULL, ("No object for writecount")); 608 vm_pager_release_writecount(object, entry->start, 609 entry->end); 610 } 611 vm_map_entry_set_vnode_text(entry, false); 612 vm_map_entry_deallocate(entry, FALSE); 613 entry = next; 614 } 615 } 616 617 #ifdef INVARIANTS 618 static void 619 _vm_map_assert_locked(vm_map_t map, const char *file, int line) 620 { 621 622 if (map->system_map) 623 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 624 else 625 sx_assert_(&map->lock, SA_XLOCKED, file, line); 626 } 627 628 #define VM_MAP_ASSERT_LOCKED(map) \ 629 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 630 631 enum { VMMAP_CHECK_NONE, VMMAP_CHECK_UNLOCK, VMMAP_CHECK_ALL }; 632 #ifdef DIAGNOSTIC 633 static int enable_vmmap_check = VMMAP_CHECK_UNLOCK; 634 #else 635 static int enable_vmmap_check = VMMAP_CHECK_NONE; 636 #endif 637 SYSCTL_INT(_debug, OID_AUTO, vmmap_check, CTLFLAG_RWTUN, 638 &enable_vmmap_check, 0, "Enable vm map consistency checking"); 639 640 static void _vm_map_assert_consistent(vm_map_t map, int check); 641 642 #define VM_MAP_ASSERT_CONSISTENT(map) \ 643 _vm_map_assert_consistent(map, VMMAP_CHECK_ALL) 644 #ifdef DIAGNOSTIC 645 #define VM_MAP_UNLOCK_CONSISTENT(map) do { \ 646 if (map->nupdates > map->nentries) { \ 647 _vm_map_assert_consistent(map, VMMAP_CHECK_UNLOCK); \ 648 map->nupdates = 0; \ 649 } \ 650 } while (0) 651 #else 652 #define VM_MAP_UNLOCK_CONSISTENT(map) 653 #endif 654 #else 655 #define VM_MAP_ASSERT_LOCKED(map) 656 #define VM_MAP_ASSERT_CONSISTENT(map) 657 #define VM_MAP_UNLOCK_CONSISTENT(map) 658 #endif /* INVARIANTS */ 659 660 void 661 _vm_map_unlock(vm_map_t map, const char *file, int line) 662 { 663 664 VM_MAP_UNLOCK_CONSISTENT(map); 665 if (map->system_map) 666 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 667 else { 668 sx_xunlock_(&map->lock, file, line); 669 vm_map_process_deferred(); 670 } 671 } 672 673 void 674 _vm_map_lock_read(vm_map_t map, const char *file, int line) 675 { 676 677 if (map->system_map) 678 mtx_lock_flags_(&map->system_mtx, 0, file, line); 679 else 680 sx_slock_(&map->lock, file, line); 681 } 682 683 void 684 _vm_map_unlock_read(vm_map_t map, const char *file, int line) 685 { 686 687 if (map->system_map) 688 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 689 else { 690 sx_sunlock_(&map->lock, file, line); 691 vm_map_process_deferred(); 692 } 693 } 694 695 int 696 _vm_map_trylock(vm_map_t map, const char *file, int line) 697 { 698 int error; 699 700 error = map->system_map ? 701 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 702 !sx_try_xlock_(&map->lock, file, line); 703 if (error == 0) 704 map->timestamp++; 705 return (error == 0); 706 } 707 708 int 709 _vm_map_trylock_read(vm_map_t map, const char *file, int line) 710 { 711 int error; 712 713 error = map->system_map ? 714 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 715 !sx_try_slock_(&map->lock, file, line); 716 return (error == 0); 717 } 718 719 /* 720 * _vm_map_lock_upgrade: [ internal use only ] 721 * 722 * Tries to upgrade a read (shared) lock on the specified map to a write 723 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 724 * non-zero value if the upgrade fails. If the upgrade fails, the map is 725 * returned without a read or write lock held. 726 * 727 * Requires that the map be read locked. 728 */ 729 int 730 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 731 { 732 unsigned int last_timestamp; 733 734 if (map->system_map) { 735 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 736 } else { 737 if (!sx_try_upgrade_(&map->lock, file, line)) { 738 last_timestamp = map->timestamp; 739 sx_sunlock_(&map->lock, file, line); 740 vm_map_process_deferred(); 741 /* 742 * If the map's timestamp does not change while the 743 * map is unlocked, then the upgrade succeeds. 744 */ 745 sx_xlock_(&map->lock, file, line); 746 if (last_timestamp != map->timestamp) { 747 sx_xunlock_(&map->lock, file, line); 748 return (1); 749 } 750 } 751 } 752 map->timestamp++; 753 return (0); 754 } 755 756 void 757 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 758 { 759 760 if (map->system_map) { 761 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 762 } else { 763 VM_MAP_UNLOCK_CONSISTENT(map); 764 sx_downgrade_(&map->lock, file, line); 765 } 766 } 767 768 /* 769 * vm_map_locked: 770 * 771 * Returns a non-zero value if the caller holds a write (exclusive) lock 772 * on the specified map and the value "0" otherwise. 773 */ 774 int 775 vm_map_locked(vm_map_t map) 776 { 777 778 if (map->system_map) 779 return (mtx_owned(&map->system_mtx)); 780 else 781 return (sx_xlocked(&map->lock)); 782 } 783 784 /* 785 * _vm_map_unlock_and_wait: 786 * 787 * Atomically releases the lock on the specified map and puts the calling 788 * thread to sleep. The calling thread will remain asleep until either 789 * vm_map_wakeup() is performed on the map or the specified timeout is 790 * exceeded. 791 * 792 * WARNING! This function does not perform deferred deallocations of 793 * objects and map entries. Therefore, the calling thread is expected to 794 * reacquire the map lock after reawakening and later perform an ordinary 795 * unlock operation, such as vm_map_unlock(), before completing its 796 * operation on the map. 797 */ 798 int 799 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) 800 { 801 802 VM_MAP_UNLOCK_CONSISTENT(map); 803 mtx_lock(&map_sleep_mtx); 804 if (map->system_map) 805 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 806 else 807 sx_xunlock_(&map->lock, file, line); 808 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 809 timo)); 810 } 811 812 /* 813 * vm_map_wakeup: 814 * 815 * Awaken any threads that have slept on the map using 816 * vm_map_unlock_and_wait(). 817 */ 818 void 819 vm_map_wakeup(vm_map_t map) 820 { 821 822 /* 823 * Acquire and release map_sleep_mtx to prevent a wakeup() 824 * from being performed (and lost) between the map unlock 825 * and the msleep() in _vm_map_unlock_and_wait(). 826 */ 827 mtx_lock(&map_sleep_mtx); 828 mtx_unlock(&map_sleep_mtx); 829 wakeup(&map->root); 830 } 831 832 void 833 vm_map_busy(vm_map_t map) 834 { 835 836 VM_MAP_ASSERT_LOCKED(map); 837 map->busy++; 838 } 839 840 void 841 vm_map_unbusy(vm_map_t map) 842 { 843 844 VM_MAP_ASSERT_LOCKED(map); 845 KASSERT(map->busy, ("vm_map_unbusy: not busy")); 846 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { 847 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); 848 wakeup(&map->busy); 849 } 850 } 851 852 void 853 vm_map_wait_busy(vm_map_t map) 854 { 855 856 VM_MAP_ASSERT_LOCKED(map); 857 while (map->busy) { 858 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); 859 if (map->system_map) 860 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); 861 else 862 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); 863 } 864 map->timestamp++; 865 } 866 867 long 868 vmspace_resident_count(struct vmspace *vmspace) 869 { 870 return pmap_resident_count(vmspace_pmap(vmspace)); 871 } 872 873 /* 874 * vm_map_create: 875 * 876 * Creates and returns a new empty VM map with 877 * the given physical map structure, and having 878 * the given lower and upper address bounds. 879 */ 880 vm_map_t 881 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 882 { 883 vm_map_t result; 884 885 result = uma_zalloc(mapzone, M_WAITOK); 886 CTR1(KTR_VM, "vm_map_create: %p", result); 887 _vm_map_init(result, pmap, min, max); 888 return (result); 889 } 890 891 /* 892 * Initialize an existing vm_map structure 893 * such as that in the vmspace structure. 894 */ 895 static void 896 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 897 { 898 899 map->header.eflags = MAP_ENTRY_HEADER; 900 map->needs_wakeup = FALSE; 901 map->system_map = 0; 902 map->pmap = pmap; 903 map->header.end = min; 904 map->header.start = max; 905 map->flags = 0; 906 map->header.left = map->header.right = &map->header; 907 map->root = NULL; 908 map->timestamp = 0; 909 map->busy = 0; 910 map->anon_loc = 0; 911 #ifdef DIAGNOSTIC 912 map->nupdates = 0; 913 #endif 914 } 915 916 void 917 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 918 { 919 920 _vm_map_init(map, pmap, min, max); 921 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 922 sx_init(&map->lock, "user map"); 923 } 924 925 /* 926 * vm_map_entry_dispose: [ internal use only ] 927 * 928 * Inverse of vm_map_entry_create. 929 */ 930 static void 931 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 932 { 933 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 934 } 935 936 /* 937 * vm_map_entry_create: [ internal use only ] 938 * 939 * Allocates a VM map entry for insertion. 940 * No entry fields are filled in. 941 */ 942 static vm_map_entry_t 943 vm_map_entry_create(vm_map_t map) 944 { 945 vm_map_entry_t new_entry; 946 947 if (map->system_map) 948 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 949 else 950 new_entry = uma_zalloc(mapentzone, M_WAITOK); 951 if (new_entry == NULL) 952 panic("vm_map_entry_create: kernel resources exhausted"); 953 return (new_entry); 954 } 955 956 /* 957 * vm_map_entry_set_behavior: 958 * 959 * Set the expected access behavior, either normal, random, or 960 * sequential. 961 */ 962 static inline void 963 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 964 { 965 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 966 (behavior & MAP_ENTRY_BEHAV_MASK); 967 } 968 969 /* 970 * vm_map_entry_max_free_{left,right}: 971 * 972 * Compute the size of the largest free gap between two entries, 973 * one the root of a tree and the other the ancestor of that root 974 * that is the least or greatest ancestor found on the search path. 975 */ 976 static inline vm_size_t 977 vm_map_entry_max_free_left(vm_map_entry_t root, vm_map_entry_t left_ancestor) 978 { 979 980 return (root->left != left_ancestor ? 981 root->left->max_free : root->start - left_ancestor->end); 982 } 983 984 static inline vm_size_t 985 vm_map_entry_max_free_right(vm_map_entry_t root, vm_map_entry_t right_ancestor) 986 { 987 988 return (root->right != right_ancestor ? 989 root->right->max_free : right_ancestor->start - root->end); 990 } 991 992 /* 993 * vm_map_entry_{pred,succ}: 994 * 995 * Find the {predecessor, successor} of the entry by taking one step 996 * in the appropriate direction and backtracking as much as necessary. 997 * vm_map_entry_succ is defined in vm_map.h. 998 */ 999 static inline vm_map_entry_t 1000 vm_map_entry_pred(vm_map_entry_t entry) 1001 { 1002 vm_map_entry_t prior; 1003 1004 prior = entry->left; 1005 if (prior->right->start < entry->start) { 1006 do 1007 prior = prior->right; 1008 while (prior->right != entry); 1009 } 1010 return (prior); 1011 } 1012 1013 static inline vm_size_t 1014 vm_size_max(vm_size_t a, vm_size_t b) 1015 { 1016 1017 return (a > b ? a : b); 1018 } 1019 1020 #define SPLAY_LEFT_STEP(root, y, llist, rlist, test) do { \ 1021 vm_map_entry_t z; \ 1022 vm_size_t max_free; \ 1023 \ 1024 /* \ 1025 * Infer root->right->max_free == root->max_free when \ 1026 * y->max_free < root->max_free || root->max_free == 0. \ 1027 * Otherwise, look right to find it. \ 1028 */ \ 1029 y = root->left; \ 1030 max_free = root->max_free; \ 1031 KASSERT(max_free == vm_size_max( \ 1032 vm_map_entry_max_free_left(root, llist), \ 1033 vm_map_entry_max_free_right(root, rlist)), \ 1034 ("%s: max_free invariant fails", __func__)); \ 1035 if (max_free - 1 < vm_map_entry_max_free_left(root, llist)) \ 1036 max_free = vm_map_entry_max_free_right(root, rlist); \ 1037 if (y != llist && (test)) { \ 1038 /* Rotate right and make y root. */ \ 1039 z = y->right; \ 1040 if (z != root) { \ 1041 root->left = z; \ 1042 y->right = root; \ 1043 if (max_free < y->max_free) \ 1044 root->max_free = max_free = \ 1045 vm_size_max(max_free, z->max_free); \ 1046 } else if (max_free < y->max_free) \ 1047 root->max_free = max_free = \ 1048 vm_size_max(max_free, root->start - y->end);\ 1049 root = y; \ 1050 y = root->left; \ 1051 } \ 1052 /* Copy right->max_free. Put root on rlist. */ \ 1053 root->max_free = max_free; \ 1054 KASSERT(max_free == vm_map_entry_max_free_right(root, rlist), \ 1055 ("%s: max_free not copied from right", __func__)); \ 1056 root->left = rlist; \ 1057 rlist = root; \ 1058 root = y != llist ? y : NULL; \ 1059 } while (0) 1060 1061 #define SPLAY_RIGHT_STEP(root, y, llist, rlist, test) do { \ 1062 vm_map_entry_t z; \ 1063 vm_size_t max_free; \ 1064 \ 1065 /* \ 1066 * Infer root->left->max_free == root->max_free when \ 1067 * y->max_free < root->max_free || root->max_free == 0. \ 1068 * Otherwise, look left to find it. \ 1069 */ \ 1070 y = root->right; \ 1071 max_free = root->max_free; \ 1072 KASSERT(max_free == vm_size_max( \ 1073 vm_map_entry_max_free_left(root, llist), \ 1074 vm_map_entry_max_free_right(root, rlist)), \ 1075 ("%s: max_free invariant fails", __func__)); \ 1076 if (max_free - 1 < vm_map_entry_max_free_right(root, rlist)) \ 1077 max_free = vm_map_entry_max_free_left(root, llist); \ 1078 if (y != rlist && (test)) { \ 1079 /* Rotate left and make y root. */ \ 1080 z = y->left; \ 1081 if (z != root) { \ 1082 root->right = z; \ 1083 y->left = root; \ 1084 if (max_free < y->max_free) \ 1085 root->max_free = max_free = \ 1086 vm_size_max(max_free, z->max_free); \ 1087 } else if (max_free < y->max_free) \ 1088 root->max_free = max_free = \ 1089 vm_size_max(max_free, y->start - root->end);\ 1090 root = y; \ 1091 y = root->right; \ 1092 } \ 1093 /* Copy left->max_free. Put root on llist. */ \ 1094 root->max_free = max_free; \ 1095 KASSERT(max_free == vm_map_entry_max_free_left(root, llist), \ 1096 ("%s: max_free not copied from left", __func__)); \ 1097 root->right = llist; \ 1098 llist = root; \ 1099 root = y != rlist ? y : NULL; \ 1100 } while (0) 1101 1102 /* 1103 * Walk down the tree until we find addr or a gap where addr would go, breaking 1104 * off left and right subtrees of nodes less than, or greater than addr. Treat 1105 * subtrees with root->max_free < length as empty trees. llist and rlist are 1106 * the two sides in reverse order (bottom-up), with llist linked by the right 1107 * pointer and rlist linked by the left pointer in the vm_map_entry, and both 1108 * lists terminated by &map->header. This function, and the subsequent call to 1109 * vm_map_splay_merge_{left,right,pred,succ}, rely on the start and end address 1110 * values in &map->header. 1111 */ 1112 static __always_inline vm_map_entry_t 1113 vm_map_splay_split(vm_map_t map, vm_offset_t addr, vm_size_t length, 1114 vm_map_entry_t *llist, vm_map_entry_t *rlist) 1115 { 1116 vm_map_entry_t left, right, root, y; 1117 1118 left = right = &map->header; 1119 root = map->root; 1120 while (root != NULL && root->max_free >= length) { 1121 KASSERT(left->end <= root->start && 1122 root->end <= right->start, 1123 ("%s: root not within tree bounds", __func__)); 1124 if (addr < root->start) { 1125 SPLAY_LEFT_STEP(root, y, left, right, 1126 y->max_free >= length && addr < y->start); 1127 } else if (addr >= root->end) { 1128 SPLAY_RIGHT_STEP(root, y, left, right, 1129 y->max_free >= length && addr >= y->end); 1130 } else 1131 break; 1132 } 1133 *llist = left; 1134 *rlist = right; 1135 return (root); 1136 } 1137 1138 static __always_inline void 1139 vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *rlist) 1140 { 1141 vm_map_entry_t hi, right, y; 1142 1143 right = *rlist; 1144 hi = root->right == right ? NULL : root->right; 1145 if (hi == NULL) 1146 return; 1147 do 1148 SPLAY_LEFT_STEP(hi, y, root, right, true); 1149 while (hi != NULL); 1150 *rlist = right; 1151 } 1152 1153 static __always_inline void 1154 vm_map_splay_findprev(vm_map_entry_t root, vm_map_entry_t *llist) 1155 { 1156 vm_map_entry_t left, lo, y; 1157 1158 left = *llist; 1159 lo = root->left == left ? NULL : root->left; 1160 if (lo == NULL) 1161 return; 1162 do 1163 SPLAY_RIGHT_STEP(lo, y, left, root, true); 1164 while (lo != NULL); 1165 *llist = left; 1166 } 1167 1168 static inline void 1169 vm_map_entry_swap(vm_map_entry_t *a, vm_map_entry_t *b) 1170 { 1171 vm_map_entry_t tmp; 1172 1173 tmp = *b; 1174 *b = *a; 1175 *a = tmp; 1176 } 1177 1178 /* 1179 * Walk back up the two spines, flip the pointers and set max_free. The 1180 * subtrees of the root go at the bottom of llist and rlist. 1181 */ 1182 static vm_size_t 1183 vm_map_splay_merge_left_walk(vm_map_entry_t header, vm_map_entry_t root, 1184 vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t llist) 1185 { 1186 do { 1187 /* 1188 * The max_free values of the children of llist are in 1189 * llist->max_free and max_free. Update with the 1190 * max value. 1191 */ 1192 llist->max_free = max_free = 1193 vm_size_max(llist->max_free, max_free); 1194 vm_map_entry_swap(&llist->right, &tail); 1195 vm_map_entry_swap(&tail, &llist); 1196 } while (llist != header); 1197 root->left = tail; 1198 return (max_free); 1199 } 1200 1201 /* 1202 * When llist is known to be the predecessor of root. 1203 */ 1204 static inline vm_size_t 1205 vm_map_splay_merge_pred(vm_map_entry_t header, vm_map_entry_t root, 1206 vm_map_entry_t llist) 1207 { 1208 vm_size_t max_free; 1209 1210 max_free = root->start - llist->end; 1211 if (llist != header) { 1212 max_free = vm_map_splay_merge_left_walk(header, root, 1213 root, max_free, llist); 1214 } else { 1215 root->left = header; 1216 header->right = root; 1217 } 1218 return (max_free); 1219 } 1220 1221 /* 1222 * When llist may or may not be the predecessor of root. 1223 */ 1224 static inline vm_size_t 1225 vm_map_splay_merge_left(vm_map_entry_t header, vm_map_entry_t root, 1226 vm_map_entry_t llist) 1227 { 1228 vm_size_t max_free; 1229 1230 max_free = vm_map_entry_max_free_left(root, llist); 1231 if (llist != header) { 1232 max_free = vm_map_splay_merge_left_walk(header, root, 1233 root->left == llist ? root : root->left, 1234 max_free, llist); 1235 } 1236 return (max_free); 1237 } 1238 1239 static vm_size_t 1240 vm_map_splay_merge_right_walk(vm_map_entry_t header, vm_map_entry_t root, 1241 vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t rlist) 1242 { 1243 do { 1244 /* 1245 * The max_free values of the children of rlist are in 1246 * rlist->max_free and max_free. Update with the 1247 * max value. 1248 */ 1249 rlist->max_free = max_free = 1250 vm_size_max(rlist->max_free, max_free); 1251 vm_map_entry_swap(&rlist->left, &tail); 1252 vm_map_entry_swap(&tail, &rlist); 1253 } while (rlist != header); 1254 root->right = tail; 1255 return (max_free); 1256 } 1257 1258 /* 1259 * When rlist is known to be the succecessor of root. 1260 */ 1261 static inline vm_size_t 1262 vm_map_splay_merge_succ(vm_map_entry_t header, vm_map_entry_t root, 1263 vm_map_entry_t rlist) 1264 { 1265 vm_size_t max_free; 1266 1267 max_free = rlist->start - root->end; 1268 if (rlist != header) { 1269 max_free = vm_map_splay_merge_right_walk(header, root, 1270 root, max_free, rlist); 1271 } else { 1272 root->right = header; 1273 header->left = root; 1274 } 1275 return (max_free); 1276 } 1277 1278 /* 1279 * When rlist may or may not be the succecessor of root. 1280 */ 1281 static inline vm_size_t 1282 vm_map_splay_merge_right(vm_map_entry_t header, vm_map_entry_t root, 1283 vm_map_entry_t rlist) 1284 { 1285 vm_size_t max_free; 1286 1287 max_free = vm_map_entry_max_free_right(root, rlist); 1288 if (rlist != header) { 1289 max_free = vm_map_splay_merge_right_walk(header, root, 1290 root->right == rlist ? root : root->right, 1291 max_free, rlist); 1292 } 1293 return (max_free); 1294 } 1295 1296 /* 1297 * vm_map_splay: 1298 * 1299 * The Sleator and Tarjan top-down splay algorithm with the 1300 * following variation. Max_free must be computed bottom-up, so 1301 * on the downward pass, maintain the left and right spines in 1302 * reverse order. Then, make a second pass up each side to fix 1303 * the pointers and compute max_free. The time bound is O(log n) 1304 * amortized. 1305 * 1306 * The tree is threaded, which means that there are no null pointers. 1307 * When a node has no left child, its left pointer points to its 1308 * predecessor, which the last ancestor on the search path from the root 1309 * where the search branched right. Likewise, when a node has no right 1310 * child, its right pointer points to its successor. The map header node 1311 * is the predecessor of the first map entry, and the successor of the 1312 * last. 1313 * 1314 * The new root is the vm_map_entry containing "addr", or else an 1315 * adjacent entry (lower if possible) if addr is not in the tree. 1316 * 1317 * The map must be locked, and leaves it so. 1318 * 1319 * Returns: the new root. 1320 */ 1321 static vm_map_entry_t 1322 vm_map_splay(vm_map_t map, vm_offset_t addr) 1323 { 1324 vm_map_entry_t header, llist, rlist, root; 1325 vm_size_t max_free_left, max_free_right; 1326 1327 header = &map->header; 1328 root = vm_map_splay_split(map, addr, 0, &llist, &rlist); 1329 if (root != NULL) { 1330 max_free_left = vm_map_splay_merge_left(header, root, llist); 1331 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1332 } else if (llist != header) { 1333 /* 1334 * Recover the greatest node in the left 1335 * subtree and make it the root. 1336 */ 1337 root = llist; 1338 llist = root->right; 1339 max_free_left = vm_map_splay_merge_left(header, root, llist); 1340 max_free_right = vm_map_splay_merge_succ(header, root, rlist); 1341 } else if (rlist != header) { 1342 /* 1343 * Recover the least node in the right 1344 * subtree and make it the root. 1345 */ 1346 root = rlist; 1347 rlist = root->left; 1348 max_free_left = vm_map_splay_merge_pred(header, root, llist); 1349 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1350 } else { 1351 /* There is no root. */ 1352 return (NULL); 1353 } 1354 root->max_free = vm_size_max(max_free_left, max_free_right); 1355 map->root = root; 1356 VM_MAP_ASSERT_CONSISTENT(map); 1357 return (root); 1358 } 1359 1360 /* 1361 * vm_map_entry_{un,}link: 1362 * 1363 * Insert/remove entries from maps. On linking, if new entry clips 1364 * existing entry, trim existing entry to avoid overlap, and manage 1365 * offsets. On unlinking, merge disappearing entry with neighbor, if 1366 * called for, and manage offsets. Callers should not modify fields in 1367 * entries already mapped. 1368 */ 1369 static void 1370 vm_map_entry_link(vm_map_t map, vm_map_entry_t entry) 1371 { 1372 vm_map_entry_t header, llist, rlist, root; 1373 vm_size_t max_free_left, max_free_right; 1374 1375 CTR3(KTR_VM, 1376 "vm_map_entry_link: map %p, nentries %d, entry %p", map, 1377 map->nentries, entry); 1378 VM_MAP_ASSERT_LOCKED(map); 1379 map->nentries++; 1380 header = &map->header; 1381 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist); 1382 if (root == NULL) { 1383 /* 1384 * The new entry does not overlap any existing entry in the 1385 * map, so it becomes the new root of the map tree. 1386 */ 1387 max_free_left = vm_map_splay_merge_pred(header, entry, llist); 1388 max_free_right = vm_map_splay_merge_succ(header, entry, rlist); 1389 } else if (entry->start == root->start) { 1390 /* 1391 * The new entry is a clone of root, with only the end field 1392 * changed. The root entry will be shrunk to abut the new 1393 * entry, and will be the right child of the new root entry in 1394 * the modified map. 1395 */ 1396 KASSERT(entry->end < root->end, 1397 ("%s: clip_start not within entry", __func__)); 1398 vm_map_splay_findprev(root, &llist); 1399 root->offset += entry->end - root->start; 1400 root->start = entry->end; 1401 max_free_left = vm_map_splay_merge_pred(header, entry, llist); 1402 max_free_right = root->max_free = vm_size_max( 1403 vm_map_splay_merge_pred(entry, root, entry), 1404 vm_map_splay_merge_right(header, root, rlist)); 1405 } else { 1406 /* 1407 * The new entry is a clone of root, with only the start field 1408 * changed. The root entry will be shrunk to abut the new 1409 * entry, and will be the left child of the new root entry in 1410 * the modified map. 1411 */ 1412 KASSERT(entry->end == root->end, 1413 ("%s: clip_start not within entry", __func__)); 1414 vm_map_splay_findnext(root, &rlist); 1415 entry->offset += entry->start - root->start; 1416 root->end = entry->start; 1417 max_free_left = root->max_free = vm_size_max( 1418 vm_map_splay_merge_left(header, root, llist), 1419 vm_map_splay_merge_succ(entry, root, entry)); 1420 max_free_right = vm_map_splay_merge_succ(header, entry, rlist); 1421 } 1422 entry->max_free = vm_size_max(max_free_left, max_free_right); 1423 map->root = entry; 1424 VM_MAP_ASSERT_CONSISTENT(map); 1425 } 1426 1427 enum unlink_merge_type { 1428 UNLINK_MERGE_NONE, 1429 UNLINK_MERGE_NEXT 1430 }; 1431 1432 static void 1433 vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry, 1434 enum unlink_merge_type op) 1435 { 1436 vm_map_entry_t header, llist, rlist, root; 1437 vm_size_t max_free_left, max_free_right; 1438 1439 VM_MAP_ASSERT_LOCKED(map); 1440 header = &map->header; 1441 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist); 1442 KASSERT(root != NULL, 1443 ("vm_map_entry_unlink: unlink object not mapped")); 1444 1445 vm_map_splay_findprev(root, &llist); 1446 vm_map_splay_findnext(root, &rlist); 1447 if (op == UNLINK_MERGE_NEXT) { 1448 rlist->start = root->start; 1449 rlist->offset = root->offset; 1450 } 1451 if (llist != header) { 1452 root = llist; 1453 llist = root->right; 1454 max_free_left = vm_map_splay_merge_left(header, root, llist); 1455 max_free_right = vm_map_splay_merge_succ(header, root, rlist); 1456 } else if (rlist != header) { 1457 root = rlist; 1458 rlist = root->left; 1459 max_free_left = vm_map_splay_merge_pred(header, root, llist); 1460 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1461 } else { 1462 header->left = header->right = header; 1463 root = NULL; 1464 } 1465 if (root != NULL) 1466 root->max_free = vm_size_max(max_free_left, max_free_right); 1467 map->root = root; 1468 VM_MAP_ASSERT_CONSISTENT(map); 1469 map->nentries--; 1470 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 1471 map->nentries, entry); 1472 } 1473 1474 /* 1475 * vm_map_entry_resize: 1476 * 1477 * Resize a vm_map_entry, recompute the amount of free space that 1478 * follows it and propagate that value up the tree. 1479 * 1480 * The map must be locked, and leaves it so. 1481 */ 1482 static void 1483 vm_map_entry_resize(vm_map_t map, vm_map_entry_t entry, vm_size_t grow_amount) 1484 { 1485 vm_map_entry_t header, llist, rlist, root; 1486 1487 VM_MAP_ASSERT_LOCKED(map); 1488 header = &map->header; 1489 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist); 1490 KASSERT(root != NULL, ("%s: resize object not mapped", __func__)); 1491 vm_map_splay_findnext(root, &rlist); 1492 entry->end += grow_amount; 1493 root->max_free = vm_size_max( 1494 vm_map_splay_merge_left(header, root, llist), 1495 vm_map_splay_merge_succ(header, root, rlist)); 1496 map->root = root; 1497 VM_MAP_ASSERT_CONSISTENT(map); 1498 CTR4(KTR_VM, "%s: map %p, nentries %d, entry %p", 1499 __func__, map, map->nentries, entry); 1500 } 1501 1502 /* 1503 * vm_map_lookup_entry: [ internal use only ] 1504 * 1505 * Finds the map entry containing (or 1506 * immediately preceding) the specified address 1507 * in the given map; the entry is returned 1508 * in the "entry" parameter. The boolean 1509 * result indicates whether the address is 1510 * actually contained in the map. 1511 */ 1512 boolean_t 1513 vm_map_lookup_entry( 1514 vm_map_t map, 1515 vm_offset_t address, 1516 vm_map_entry_t *entry) /* OUT */ 1517 { 1518 vm_map_entry_t cur, header, lbound, ubound; 1519 boolean_t locked; 1520 1521 /* 1522 * If the map is empty, then the map entry immediately preceding 1523 * "address" is the map's header. 1524 */ 1525 header = &map->header; 1526 cur = map->root; 1527 if (cur == NULL) { 1528 *entry = header; 1529 return (FALSE); 1530 } 1531 if (address >= cur->start && cur->end > address) { 1532 *entry = cur; 1533 return (TRUE); 1534 } 1535 if ((locked = vm_map_locked(map)) || 1536 sx_try_upgrade(&map->lock)) { 1537 /* 1538 * Splay requires a write lock on the map. However, it only 1539 * restructures the binary search tree; it does not otherwise 1540 * change the map. Thus, the map's timestamp need not change 1541 * on a temporary upgrade. 1542 */ 1543 cur = vm_map_splay(map, address); 1544 if (!locked) { 1545 VM_MAP_UNLOCK_CONSISTENT(map); 1546 sx_downgrade(&map->lock); 1547 } 1548 1549 /* 1550 * If "address" is contained within a map entry, the new root 1551 * is that map entry. Otherwise, the new root is a map entry 1552 * immediately before or after "address". 1553 */ 1554 if (address < cur->start) { 1555 *entry = header; 1556 return (FALSE); 1557 } 1558 *entry = cur; 1559 return (address < cur->end); 1560 } 1561 /* 1562 * Since the map is only locked for read access, perform a 1563 * standard binary search tree lookup for "address". 1564 */ 1565 lbound = ubound = header; 1566 for (;;) { 1567 if (address < cur->start) { 1568 ubound = cur; 1569 cur = cur->left; 1570 if (cur == lbound) 1571 break; 1572 } else if (cur->end <= address) { 1573 lbound = cur; 1574 cur = cur->right; 1575 if (cur == ubound) 1576 break; 1577 } else { 1578 *entry = cur; 1579 return (TRUE); 1580 } 1581 } 1582 *entry = lbound; 1583 return (FALSE); 1584 } 1585 1586 /* 1587 * vm_map_insert: 1588 * 1589 * Inserts the given whole VM object into the target 1590 * map at the specified address range. The object's 1591 * size should match that of the address range. 1592 * 1593 * Requires that the map be locked, and leaves it so. 1594 * 1595 * If object is non-NULL, ref count must be bumped by caller 1596 * prior to making call to account for the new entry. 1597 */ 1598 int 1599 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1600 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow) 1601 { 1602 vm_map_entry_t new_entry, next_entry, prev_entry; 1603 struct ucred *cred; 1604 vm_eflags_t protoeflags; 1605 vm_inherit_t inheritance; 1606 1607 VM_MAP_ASSERT_LOCKED(map); 1608 KASSERT(object != kernel_object || 1609 (cow & MAP_COPY_ON_WRITE) == 0, 1610 ("vm_map_insert: kernel object and COW")); 1611 KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0, 1612 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1613 KASSERT((prot & ~max) == 0, 1614 ("prot %#x is not subset of max_prot %#x", prot, max)); 1615 1616 /* 1617 * Check that the start and end points are not bogus. 1618 */ 1619 if (start < vm_map_min(map) || end > vm_map_max(map) || 1620 start >= end) 1621 return (KERN_INVALID_ADDRESS); 1622 1623 /* 1624 * Find the entry prior to the proposed starting address; if it's part 1625 * of an existing entry, this range is bogus. 1626 */ 1627 if (vm_map_lookup_entry(map, start, &prev_entry)) 1628 return (KERN_NO_SPACE); 1629 1630 /* 1631 * Assert that the next entry doesn't overlap the end point. 1632 */ 1633 next_entry = vm_map_entry_succ(prev_entry); 1634 if (next_entry->start < end) 1635 return (KERN_NO_SPACE); 1636 1637 if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL || 1638 max != VM_PROT_NONE)) 1639 return (KERN_INVALID_ARGUMENT); 1640 1641 protoeflags = 0; 1642 if (cow & MAP_COPY_ON_WRITE) 1643 protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY; 1644 if (cow & MAP_NOFAULT) 1645 protoeflags |= MAP_ENTRY_NOFAULT; 1646 if (cow & MAP_DISABLE_SYNCER) 1647 protoeflags |= MAP_ENTRY_NOSYNC; 1648 if (cow & MAP_DISABLE_COREDUMP) 1649 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1650 if (cow & MAP_STACK_GROWS_DOWN) 1651 protoeflags |= MAP_ENTRY_GROWS_DOWN; 1652 if (cow & MAP_STACK_GROWS_UP) 1653 protoeflags |= MAP_ENTRY_GROWS_UP; 1654 if (cow & MAP_WRITECOUNT) 1655 protoeflags |= MAP_ENTRY_WRITECNT; 1656 if (cow & MAP_VN_EXEC) 1657 protoeflags |= MAP_ENTRY_VN_EXEC; 1658 if ((cow & MAP_CREATE_GUARD) != 0) 1659 protoeflags |= MAP_ENTRY_GUARD; 1660 if ((cow & MAP_CREATE_STACK_GAP_DN) != 0) 1661 protoeflags |= MAP_ENTRY_STACK_GAP_DN; 1662 if ((cow & MAP_CREATE_STACK_GAP_UP) != 0) 1663 protoeflags |= MAP_ENTRY_STACK_GAP_UP; 1664 if (cow & MAP_INHERIT_SHARE) 1665 inheritance = VM_INHERIT_SHARE; 1666 else 1667 inheritance = VM_INHERIT_DEFAULT; 1668 1669 cred = NULL; 1670 if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0) 1671 goto charged; 1672 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1673 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1674 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1675 return (KERN_RESOURCE_SHORTAGE); 1676 KASSERT(object == NULL || 1677 (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 || 1678 object->cred == NULL, 1679 ("overcommit: vm_map_insert o %p", object)); 1680 cred = curthread->td_ucred; 1681 } 1682 1683 charged: 1684 /* Expand the kernel pmap, if necessary. */ 1685 if (map == kernel_map && end > kernel_vm_end) 1686 pmap_growkernel(end); 1687 if (object != NULL) { 1688 /* 1689 * OBJ_ONEMAPPING must be cleared unless this mapping 1690 * is trivially proven to be the only mapping for any 1691 * of the object's pages. (Object granularity 1692 * reference counting is insufficient to recognize 1693 * aliases with precision.) 1694 */ 1695 if ((object->flags & OBJ_ANON) != 0) { 1696 VM_OBJECT_WLOCK(object); 1697 if (object->ref_count > 1 || object->shadow_count != 0) 1698 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1699 VM_OBJECT_WUNLOCK(object); 1700 } 1701 } else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) == 1702 protoeflags && 1703 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP | 1704 MAP_VN_EXEC)) == 0 && 1705 prev_entry->end == start && (prev_entry->cred == cred || 1706 (prev_entry->object.vm_object != NULL && 1707 prev_entry->object.vm_object->cred == cred)) && 1708 vm_object_coalesce(prev_entry->object.vm_object, 1709 prev_entry->offset, 1710 (vm_size_t)(prev_entry->end - prev_entry->start), 1711 (vm_size_t)(end - prev_entry->end), cred != NULL && 1712 (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) { 1713 /* 1714 * We were able to extend the object. Determine if we 1715 * can extend the previous map entry to include the 1716 * new range as well. 1717 */ 1718 if (prev_entry->inheritance == inheritance && 1719 prev_entry->protection == prot && 1720 prev_entry->max_protection == max && 1721 prev_entry->wired_count == 0) { 1722 KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) == 1723 0, ("prev_entry %p has incoherent wiring", 1724 prev_entry)); 1725 if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0) 1726 map->size += end - prev_entry->end; 1727 vm_map_entry_resize(map, prev_entry, 1728 end - prev_entry->end); 1729 vm_map_try_merge_entries(map, prev_entry, next_entry); 1730 return (KERN_SUCCESS); 1731 } 1732 1733 /* 1734 * If we can extend the object but cannot extend the 1735 * map entry, we have to create a new map entry. We 1736 * must bump the ref count on the extended object to 1737 * account for it. object may be NULL. 1738 */ 1739 object = prev_entry->object.vm_object; 1740 offset = prev_entry->offset + 1741 (prev_entry->end - prev_entry->start); 1742 vm_object_reference(object); 1743 if (cred != NULL && object != NULL && object->cred != NULL && 1744 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1745 /* Object already accounts for this uid. */ 1746 cred = NULL; 1747 } 1748 } 1749 if (cred != NULL) 1750 crhold(cred); 1751 1752 /* 1753 * Create a new entry 1754 */ 1755 new_entry = vm_map_entry_create(map); 1756 new_entry->start = start; 1757 new_entry->end = end; 1758 new_entry->cred = NULL; 1759 1760 new_entry->eflags = protoeflags; 1761 new_entry->object.vm_object = object; 1762 new_entry->offset = offset; 1763 1764 new_entry->inheritance = inheritance; 1765 new_entry->protection = prot; 1766 new_entry->max_protection = max; 1767 new_entry->wired_count = 0; 1768 new_entry->wiring_thread = NULL; 1769 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1770 new_entry->next_read = start; 1771 1772 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1773 ("overcommit: vm_map_insert leaks vm_map %p", new_entry)); 1774 new_entry->cred = cred; 1775 1776 /* 1777 * Insert the new entry into the list 1778 */ 1779 vm_map_entry_link(map, new_entry); 1780 if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0) 1781 map->size += new_entry->end - new_entry->start; 1782 1783 /* 1784 * Try to coalesce the new entry with both the previous and next 1785 * entries in the list. Previously, we only attempted to coalesce 1786 * with the previous entry when object is NULL. Here, we handle the 1787 * other cases, which are less common. 1788 */ 1789 vm_map_try_merge_entries(map, prev_entry, new_entry); 1790 vm_map_try_merge_entries(map, new_entry, next_entry); 1791 1792 if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) { 1793 vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset), 1794 end - start, cow & MAP_PREFAULT_PARTIAL); 1795 } 1796 1797 return (KERN_SUCCESS); 1798 } 1799 1800 /* 1801 * vm_map_findspace: 1802 * 1803 * Find the first fit (lowest VM address) for "length" free bytes 1804 * beginning at address >= start in the given map. 1805 * 1806 * In a vm_map_entry, "max_free" is the maximum amount of 1807 * contiguous free space between an entry in its subtree and a 1808 * neighbor of that entry. This allows finding a free region in 1809 * one path down the tree, so O(log n) amortized with splay 1810 * trees. 1811 * 1812 * The map must be locked, and leaves it so. 1813 * 1814 * Returns: starting address if sufficient space, 1815 * vm_map_max(map)-length+1 if insufficient space. 1816 */ 1817 vm_offset_t 1818 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length) 1819 { 1820 vm_map_entry_t header, llist, rlist, root, y; 1821 vm_size_t left_length, max_free_left, max_free_right; 1822 vm_offset_t gap_end; 1823 1824 /* 1825 * Request must fit within min/max VM address and must avoid 1826 * address wrap. 1827 */ 1828 start = MAX(start, vm_map_min(map)); 1829 if (start >= vm_map_max(map) || length > vm_map_max(map) - start) 1830 return (vm_map_max(map) - length + 1); 1831 1832 /* Empty tree means wide open address space. */ 1833 if (map->root == NULL) 1834 return (start); 1835 1836 /* 1837 * After splay_split, if start is within an entry, push it to the start 1838 * of the following gap. If rlist is at the end of the gap containing 1839 * start, save the end of that gap in gap_end to see if the gap is big 1840 * enough; otherwise set gap_end to start skip gap-checking and move 1841 * directly to a search of the right subtree. 1842 */ 1843 header = &map->header; 1844 root = vm_map_splay_split(map, start, length, &llist, &rlist); 1845 gap_end = rlist->start; 1846 if (root != NULL) { 1847 start = root->end; 1848 if (root->right != rlist) 1849 gap_end = start; 1850 max_free_left = vm_map_splay_merge_left(header, root, llist); 1851 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1852 } else if (rlist != header) { 1853 root = rlist; 1854 rlist = root->left; 1855 max_free_left = vm_map_splay_merge_pred(header, root, llist); 1856 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1857 } else { 1858 root = llist; 1859 llist = root->right; 1860 max_free_left = vm_map_splay_merge_left(header, root, llist); 1861 max_free_right = vm_map_splay_merge_succ(header, root, rlist); 1862 } 1863 root->max_free = vm_size_max(max_free_left, max_free_right); 1864 map->root = root; 1865 VM_MAP_ASSERT_CONSISTENT(map); 1866 if (length <= gap_end - start) 1867 return (start); 1868 1869 /* With max_free, can immediately tell if no solution. */ 1870 if (root->right == header || length > root->right->max_free) 1871 return (vm_map_max(map) - length + 1); 1872 1873 /* 1874 * Splay for the least large-enough gap in the right subtree. 1875 */ 1876 llist = rlist = header; 1877 for (left_length = 0;; 1878 left_length = vm_map_entry_max_free_left(root, llist)) { 1879 if (length <= left_length) 1880 SPLAY_LEFT_STEP(root, y, llist, rlist, 1881 length <= vm_map_entry_max_free_left(y, llist)); 1882 else 1883 SPLAY_RIGHT_STEP(root, y, llist, rlist, 1884 length > vm_map_entry_max_free_left(y, root)); 1885 if (root == NULL) 1886 break; 1887 } 1888 root = llist; 1889 llist = root->right; 1890 max_free_left = vm_map_splay_merge_left(header, root, llist); 1891 if (rlist == header) { 1892 root->max_free = vm_size_max(max_free_left, 1893 vm_map_splay_merge_succ(header, root, rlist)); 1894 } else { 1895 y = rlist; 1896 rlist = y->left; 1897 y->max_free = vm_size_max( 1898 vm_map_splay_merge_pred(root, y, root), 1899 vm_map_splay_merge_right(header, y, rlist)); 1900 root->max_free = vm_size_max(max_free_left, y->max_free); 1901 } 1902 map->root = root; 1903 VM_MAP_ASSERT_CONSISTENT(map); 1904 return (root->end); 1905 } 1906 1907 int 1908 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1909 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1910 vm_prot_t max, int cow) 1911 { 1912 vm_offset_t end; 1913 int result; 1914 1915 end = start + length; 1916 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1917 object == NULL, 1918 ("vm_map_fixed: non-NULL backing object for stack")); 1919 vm_map_lock(map); 1920 VM_MAP_RANGE_CHECK(map, start, end); 1921 if ((cow & MAP_CHECK_EXCL) == 0) 1922 vm_map_delete(map, start, end); 1923 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1924 result = vm_map_stack_locked(map, start, length, sgrowsiz, 1925 prot, max, cow); 1926 } else { 1927 result = vm_map_insert(map, object, offset, start, end, 1928 prot, max, cow); 1929 } 1930 vm_map_unlock(map); 1931 return (result); 1932 } 1933 1934 static const int aslr_pages_rnd_64[2] = {0x1000, 0x10}; 1935 static const int aslr_pages_rnd_32[2] = {0x100, 0x4}; 1936 1937 static int cluster_anon = 1; 1938 SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW, 1939 &cluster_anon, 0, 1940 "Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always"); 1941 1942 static bool 1943 clustering_anon_allowed(vm_offset_t addr) 1944 { 1945 1946 switch (cluster_anon) { 1947 case 0: 1948 return (false); 1949 case 1: 1950 return (addr == 0); 1951 case 2: 1952 default: 1953 return (true); 1954 } 1955 } 1956 1957 static long aslr_restarts; 1958 SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD, 1959 &aslr_restarts, 0, 1960 "Number of aslr failures"); 1961 1962 #define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31) 1963 1964 /* 1965 * Searches for the specified amount of free space in the given map with the 1966 * specified alignment. Performs an address-ordered, first-fit search from 1967 * the given address "*addr", with an optional upper bound "max_addr". If the 1968 * parameter "alignment" is zero, then the alignment is computed from the 1969 * given (object, offset) pair so as to enable the greatest possible use of 1970 * superpage mappings. Returns KERN_SUCCESS and the address of the free space 1971 * in "*addr" if successful. Otherwise, returns KERN_NO_SPACE. 1972 * 1973 * The map must be locked. Initially, there must be at least "length" bytes 1974 * of free space at the given address. 1975 */ 1976 static int 1977 vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1978 vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr, 1979 vm_offset_t alignment) 1980 { 1981 vm_offset_t aligned_addr, free_addr; 1982 1983 VM_MAP_ASSERT_LOCKED(map); 1984 free_addr = *addr; 1985 KASSERT(free_addr == vm_map_findspace(map, free_addr, length), 1986 ("caller failed to provide space %#jx at address %p", 1987 (uintmax_t)length, (void *)free_addr)); 1988 for (;;) { 1989 /* 1990 * At the start of every iteration, the free space at address 1991 * "*addr" is at least "length" bytes. 1992 */ 1993 if (alignment == 0) 1994 pmap_align_superpage(object, offset, addr, length); 1995 else if ((*addr & (alignment - 1)) != 0) { 1996 *addr &= ~(alignment - 1); 1997 *addr += alignment; 1998 } 1999 aligned_addr = *addr; 2000 if (aligned_addr == free_addr) { 2001 /* 2002 * Alignment did not change "*addr", so "*addr" must 2003 * still provide sufficient free space. 2004 */ 2005 return (KERN_SUCCESS); 2006 } 2007 2008 /* 2009 * Test for address wrap on "*addr". A wrapped "*addr" could 2010 * be a valid address, in which case vm_map_findspace() cannot 2011 * be relied upon to fail. 2012 */ 2013 if (aligned_addr < free_addr) 2014 return (KERN_NO_SPACE); 2015 *addr = vm_map_findspace(map, aligned_addr, length); 2016 if (*addr + length > vm_map_max(map) || 2017 (max_addr != 0 && *addr + length > max_addr)) 2018 return (KERN_NO_SPACE); 2019 free_addr = *addr; 2020 if (free_addr == aligned_addr) { 2021 /* 2022 * If a successful call to vm_map_findspace() did not 2023 * change "*addr", then "*addr" must still be aligned 2024 * and provide sufficient free space. 2025 */ 2026 return (KERN_SUCCESS); 2027 } 2028 } 2029 } 2030 2031 /* 2032 * vm_map_find finds an unallocated region in the target address 2033 * map with the given length. The search is defined to be 2034 * first-fit from the specified address; the region found is 2035 * returned in the same parameter. 2036 * 2037 * If object is non-NULL, ref count must be bumped by caller 2038 * prior to making call to account for the new entry. 2039 */ 2040 int 2041 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 2042 vm_offset_t *addr, /* IN/OUT */ 2043 vm_size_t length, vm_offset_t max_addr, int find_space, 2044 vm_prot_t prot, vm_prot_t max, int cow) 2045 { 2046 vm_offset_t alignment, curr_min_addr, min_addr; 2047 int gap, pidx, rv, try; 2048 bool cluster, en_aslr, update_anon; 2049 2050 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 2051 object == NULL, 2052 ("vm_map_find: non-NULL backing object for stack")); 2053 MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE && 2054 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0)); 2055 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 2056 (object->flags & OBJ_COLORED) == 0)) 2057 find_space = VMFS_ANY_SPACE; 2058 if (find_space >> 8 != 0) { 2059 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 2060 alignment = (vm_offset_t)1 << (find_space >> 8); 2061 } else 2062 alignment = 0; 2063 en_aslr = (map->flags & MAP_ASLR) != 0; 2064 update_anon = cluster = clustering_anon_allowed(*addr) && 2065 (map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 && 2066 find_space != VMFS_NO_SPACE && object == NULL && 2067 (cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP | 2068 MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE; 2069 curr_min_addr = min_addr = *addr; 2070 if (en_aslr && min_addr == 0 && !cluster && 2071 find_space != VMFS_NO_SPACE && 2072 (map->flags & MAP_ASLR_IGNSTART) != 0) 2073 curr_min_addr = min_addr = vm_map_min(map); 2074 try = 0; 2075 vm_map_lock(map); 2076 if (cluster) { 2077 curr_min_addr = map->anon_loc; 2078 if (curr_min_addr == 0) 2079 cluster = false; 2080 } 2081 if (find_space != VMFS_NO_SPACE) { 2082 KASSERT(find_space == VMFS_ANY_SPACE || 2083 find_space == VMFS_OPTIMAL_SPACE || 2084 find_space == VMFS_SUPER_SPACE || 2085 alignment != 0, ("unexpected VMFS flag")); 2086 again: 2087 /* 2088 * When creating an anonymous mapping, try clustering 2089 * with an existing anonymous mapping first. 2090 * 2091 * We make up to two attempts to find address space 2092 * for a given find_space value. The first attempt may 2093 * apply randomization or may cluster with an existing 2094 * anonymous mapping. If this first attempt fails, 2095 * perform a first-fit search of the available address 2096 * space. 2097 * 2098 * If all tries failed, and find_space is 2099 * VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE. 2100 * Again enable clustering and randomization. 2101 */ 2102 try++; 2103 MPASS(try <= 2); 2104 2105 if (try == 2) { 2106 /* 2107 * Second try: we failed either to find a 2108 * suitable region for randomizing the 2109 * allocation, or to cluster with an existing 2110 * mapping. Retry with free run. 2111 */ 2112 curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ? 2113 vm_map_min(map) : min_addr; 2114 atomic_add_long(&aslr_restarts, 1); 2115 } 2116 2117 if (try == 1 && en_aslr && !cluster) { 2118 /* 2119 * Find space for allocation, including 2120 * gap needed for later randomization. 2121 */ 2122 pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 && 2123 (find_space == VMFS_SUPER_SPACE || find_space == 2124 VMFS_OPTIMAL_SPACE) ? 1 : 0; 2125 gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR && 2126 (max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ? 2127 aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx]; 2128 *addr = vm_map_findspace(map, curr_min_addr, 2129 length + gap * pagesizes[pidx]); 2130 if (*addr + length + gap * pagesizes[pidx] > 2131 vm_map_max(map)) 2132 goto again; 2133 /* And randomize the start address. */ 2134 *addr += (arc4random() % gap) * pagesizes[pidx]; 2135 if (max_addr != 0 && *addr + length > max_addr) 2136 goto again; 2137 } else { 2138 *addr = vm_map_findspace(map, curr_min_addr, length); 2139 if (*addr + length > vm_map_max(map) || 2140 (max_addr != 0 && *addr + length > max_addr)) { 2141 if (cluster) { 2142 cluster = false; 2143 MPASS(try == 1); 2144 goto again; 2145 } 2146 rv = KERN_NO_SPACE; 2147 goto done; 2148 } 2149 } 2150 2151 if (find_space != VMFS_ANY_SPACE && 2152 (rv = vm_map_alignspace(map, object, offset, addr, length, 2153 max_addr, alignment)) != KERN_SUCCESS) { 2154 if (find_space == VMFS_OPTIMAL_SPACE) { 2155 find_space = VMFS_ANY_SPACE; 2156 curr_min_addr = min_addr; 2157 cluster = update_anon; 2158 try = 0; 2159 goto again; 2160 } 2161 goto done; 2162 } 2163 } else if ((cow & MAP_REMAP) != 0) { 2164 if (*addr < vm_map_min(map) || 2165 *addr + length > vm_map_max(map) || 2166 *addr + length <= length) { 2167 rv = KERN_INVALID_ADDRESS; 2168 goto done; 2169 } 2170 vm_map_delete(map, *addr, *addr + length); 2171 } 2172 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 2173 rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot, 2174 max, cow); 2175 } else { 2176 rv = vm_map_insert(map, object, offset, *addr, *addr + length, 2177 prot, max, cow); 2178 } 2179 if (rv == KERN_SUCCESS && update_anon) 2180 map->anon_loc = *addr + length; 2181 done: 2182 vm_map_unlock(map); 2183 return (rv); 2184 } 2185 2186 /* 2187 * vm_map_find_min() is a variant of vm_map_find() that takes an 2188 * additional parameter (min_addr) and treats the given address 2189 * (*addr) differently. Specifically, it treats *addr as a hint 2190 * and not as the minimum address where the mapping is created. 2191 * 2192 * This function works in two phases. First, it tries to 2193 * allocate above the hint. If that fails and the hint is 2194 * greater than min_addr, it performs a second pass, replacing 2195 * the hint with min_addr as the minimum address for the 2196 * allocation. 2197 */ 2198 int 2199 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 2200 vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr, 2201 vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max, 2202 int cow) 2203 { 2204 vm_offset_t hint; 2205 int rv; 2206 2207 hint = *addr; 2208 for (;;) { 2209 rv = vm_map_find(map, object, offset, addr, length, max_addr, 2210 find_space, prot, max, cow); 2211 if (rv == KERN_SUCCESS || min_addr >= hint) 2212 return (rv); 2213 *addr = hint = min_addr; 2214 } 2215 } 2216 2217 /* 2218 * A map entry with any of the following flags set must not be merged with 2219 * another entry. 2220 */ 2221 #define MAP_ENTRY_NOMERGE_MASK (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \ 2222 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_VN_EXEC) 2223 2224 static bool 2225 vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry) 2226 { 2227 2228 KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 || 2229 (entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0, 2230 ("vm_map_mergeable_neighbors: neither %p nor %p are mergeable", 2231 prev, entry)); 2232 return (prev->end == entry->start && 2233 prev->object.vm_object == entry->object.vm_object && 2234 (prev->object.vm_object == NULL || 2235 prev->offset + (prev->end - prev->start) == entry->offset) && 2236 prev->eflags == entry->eflags && 2237 prev->protection == entry->protection && 2238 prev->max_protection == entry->max_protection && 2239 prev->inheritance == entry->inheritance && 2240 prev->wired_count == entry->wired_count && 2241 prev->cred == entry->cred); 2242 } 2243 2244 static void 2245 vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry) 2246 { 2247 2248 /* 2249 * If the backing object is a vnode object, vm_object_deallocate() 2250 * calls vrele(). However, vrele() does not lock the vnode because 2251 * the vnode has additional references. Thus, the map lock can be 2252 * kept without causing a lock-order reversal with the vnode lock. 2253 * 2254 * Since we count the number of virtual page mappings in 2255 * object->un_pager.vnp.writemappings, the writemappings value 2256 * should not be adjusted when the entry is disposed of. 2257 */ 2258 if (entry->object.vm_object != NULL) 2259 vm_object_deallocate(entry->object.vm_object); 2260 if (entry->cred != NULL) 2261 crfree(entry->cred); 2262 vm_map_entry_dispose(map, entry); 2263 } 2264 2265 /* 2266 * vm_map_try_merge_entries: 2267 * 2268 * Compare the given map entry to its predecessor, and merge its precessor 2269 * into it if possible. The entry remains valid, and may be extended. 2270 * The predecessor may be deleted. 2271 * 2272 * The map must be locked. 2273 */ 2274 void 2275 vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev_entry, 2276 vm_map_entry_t entry) 2277 { 2278 2279 VM_MAP_ASSERT_LOCKED(map); 2280 if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 && 2281 vm_map_mergeable_neighbors(prev_entry, entry)) { 2282 vm_map_entry_unlink(map, prev_entry, UNLINK_MERGE_NEXT); 2283 vm_map_merged_neighbor_dispose(map, prev_entry); 2284 } 2285 } 2286 2287 /* 2288 * vm_map_entry_back: 2289 * 2290 * Allocate an object to back a map entry. 2291 */ 2292 static inline void 2293 vm_map_entry_back(vm_map_entry_t entry) 2294 { 2295 vm_object_t object; 2296 2297 KASSERT(entry->object.vm_object == NULL, 2298 ("map entry %p has backing object", entry)); 2299 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 2300 ("map entry %p is a submap", entry)); 2301 object = vm_object_allocate_anon(atop(entry->end - entry->start), NULL, 2302 entry->cred, entry->end - entry->start); 2303 entry->object.vm_object = object; 2304 entry->offset = 0; 2305 entry->cred = NULL; 2306 } 2307 2308 /* 2309 * vm_map_entry_charge_object 2310 * 2311 * If there is no object backing this entry, create one. Otherwise, if 2312 * the entry has cred, give it to the backing object. 2313 */ 2314 static inline void 2315 vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry) 2316 { 2317 2318 VM_MAP_ASSERT_LOCKED(map); 2319 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 2320 ("map entry %p is a submap", entry)); 2321 if (entry->object.vm_object == NULL && !map->system_map && 2322 (entry->eflags & MAP_ENTRY_GUARD) == 0) 2323 vm_map_entry_back(entry); 2324 else if (entry->object.vm_object != NULL && 2325 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 2326 entry->cred != NULL) { 2327 VM_OBJECT_WLOCK(entry->object.vm_object); 2328 KASSERT(entry->object.vm_object->cred == NULL, 2329 ("OVERCOMMIT: %s: both cred e %p", __func__, entry)); 2330 entry->object.vm_object->cred = entry->cred; 2331 entry->object.vm_object->charge = entry->end - entry->start; 2332 VM_OBJECT_WUNLOCK(entry->object.vm_object); 2333 entry->cred = NULL; 2334 } 2335 } 2336 2337 /* 2338 * vm_map_entry_clone 2339 * 2340 * Create a duplicate map entry for clipping. 2341 */ 2342 static vm_map_entry_t 2343 vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry) 2344 { 2345 vm_map_entry_t new_entry; 2346 2347 VM_MAP_ASSERT_LOCKED(map); 2348 2349 /* 2350 * Create a backing object now, if none exists, so that more individual 2351 * objects won't be created after the map entry is split. 2352 */ 2353 vm_map_entry_charge_object(map, entry); 2354 2355 /* Clone the entry. */ 2356 new_entry = vm_map_entry_create(map); 2357 *new_entry = *entry; 2358 if (new_entry->cred != NULL) 2359 crhold(entry->cred); 2360 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 2361 vm_object_reference(new_entry->object.vm_object); 2362 vm_map_entry_set_vnode_text(new_entry, true); 2363 /* 2364 * The object->un_pager.vnp.writemappings for the object of 2365 * MAP_ENTRY_WRITECNT type entry shall be kept as is here. The 2366 * virtual pages are re-distributed among the clipped entries, 2367 * so the sum is left the same. 2368 */ 2369 } 2370 return (new_entry); 2371 } 2372 2373 /* 2374 * vm_map_clip_start: [ internal use only ] 2375 * 2376 * Asserts that the given entry begins at or after 2377 * the specified address; if necessary, 2378 * it splits the entry into two. 2379 */ 2380 static inline void 2381 vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 2382 { 2383 vm_map_entry_t new_entry; 2384 2385 if (start <= entry->start) 2386 return; 2387 2388 VM_MAP_ASSERT_LOCKED(map); 2389 KASSERT(entry->end > start && entry->start < start, 2390 ("%s: invalid clip of entry %p", __func__, entry)); 2391 2392 new_entry = vm_map_entry_clone(map, entry); 2393 2394 /* 2395 * Split off the front portion. Insert the new entry BEFORE this one, 2396 * so that this entry has the specified starting address. 2397 */ 2398 new_entry->end = start; 2399 vm_map_entry_link(map, new_entry); 2400 } 2401 2402 /* 2403 * vm_map_lookup_clip_start: 2404 * 2405 * Find the entry at or just after 'start', and clip it if 'start' is in 2406 * the interior of the entry. Return entry after 'start', and in 2407 * prev_entry set the entry before 'start'. 2408 */ 2409 static inline vm_map_entry_t 2410 vm_map_lookup_clip_start(vm_map_t map, vm_offset_t start, 2411 vm_map_entry_t *prev_entry) 2412 { 2413 vm_map_entry_t entry; 2414 2415 if (vm_map_lookup_entry(map, start, prev_entry)) { 2416 entry = *prev_entry; 2417 vm_map_clip_start(map, entry, start); 2418 *prev_entry = vm_map_entry_pred(entry); 2419 } else 2420 entry = vm_map_entry_succ(*prev_entry); 2421 return (entry); 2422 } 2423 2424 /* 2425 * vm_map_clip_end: [ internal use only ] 2426 * 2427 * Asserts that the given entry ends at or before 2428 * the specified address; if necessary, 2429 * it splits the entry into two. 2430 */ 2431 static inline void 2432 vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 2433 { 2434 vm_map_entry_t new_entry; 2435 2436 if (end >= entry->end) 2437 return; 2438 2439 VM_MAP_ASSERT_LOCKED(map); 2440 KASSERT(entry->start < end && entry->end > end, 2441 ("%s: invalid clip of entry %p", __func__, entry)); 2442 2443 new_entry = vm_map_entry_clone(map, entry); 2444 2445 /* 2446 * Split off the back portion. Insert the new entry AFTER this one, 2447 * so that this entry has the specified ending address. 2448 */ 2449 new_entry->start = end; 2450 vm_map_entry_link(map, new_entry); 2451 } 2452 2453 /* 2454 * vm_map_submap: [ kernel use only ] 2455 * 2456 * Mark the given range as handled by a subordinate map. 2457 * 2458 * This range must have been created with vm_map_find, 2459 * and no other operations may have been performed on this 2460 * range prior to calling vm_map_submap. 2461 * 2462 * Only a limited number of operations can be performed 2463 * within this rage after calling vm_map_submap: 2464 * vm_fault 2465 * [Don't try vm_map_copy!] 2466 * 2467 * To remove a submapping, one must first remove the 2468 * range from the superior map, and then destroy the 2469 * submap (if desired). [Better yet, don't try it.] 2470 */ 2471 int 2472 vm_map_submap( 2473 vm_map_t map, 2474 vm_offset_t start, 2475 vm_offset_t end, 2476 vm_map_t submap) 2477 { 2478 vm_map_entry_t entry; 2479 int result; 2480 2481 result = KERN_INVALID_ARGUMENT; 2482 2483 vm_map_lock(submap); 2484 submap->flags |= MAP_IS_SUB_MAP; 2485 vm_map_unlock(submap); 2486 2487 vm_map_lock(map); 2488 VM_MAP_RANGE_CHECK(map, start, end); 2489 if (vm_map_lookup_entry(map, start, &entry) && entry->end >= end && 2490 (entry->eflags & MAP_ENTRY_COW) == 0 && 2491 entry->object.vm_object == NULL) { 2492 vm_map_clip_start(map, entry, start); 2493 vm_map_clip_end(map, entry, end); 2494 entry->object.sub_map = submap; 2495 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 2496 result = KERN_SUCCESS; 2497 } 2498 vm_map_unlock(map); 2499 2500 if (result != KERN_SUCCESS) { 2501 vm_map_lock(submap); 2502 submap->flags &= ~MAP_IS_SUB_MAP; 2503 vm_map_unlock(submap); 2504 } 2505 return (result); 2506 } 2507 2508 /* 2509 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified 2510 */ 2511 #define MAX_INIT_PT 96 2512 2513 /* 2514 * vm_map_pmap_enter: 2515 * 2516 * Preload the specified map's pmap with mappings to the specified 2517 * object's memory-resident pages. No further physical pages are 2518 * allocated, and no further virtual pages are retrieved from secondary 2519 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a 2520 * limited number of page mappings are created at the low-end of the 2521 * specified address range. (For this purpose, a superpage mapping 2522 * counts as one page mapping.) Otherwise, all resident pages within 2523 * the specified address range are mapped. 2524 */ 2525 static void 2526 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 2527 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 2528 { 2529 vm_offset_t start; 2530 vm_page_t p, p_start; 2531 vm_pindex_t mask, psize, threshold, tmpidx; 2532 2533 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 2534 return; 2535 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 2536 VM_OBJECT_WLOCK(object); 2537 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 2538 pmap_object_init_pt(map->pmap, addr, object, pindex, 2539 size); 2540 VM_OBJECT_WUNLOCK(object); 2541 return; 2542 } 2543 VM_OBJECT_LOCK_DOWNGRADE(object); 2544 } else 2545 VM_OBJECT_RLOCK(object); 2546 2547 psize = atop(size); 2548 if (psize + pindex > object->size) { 2549 if (pindex >= object->size) { 2550 VM_OBJECT_RUNLOCK(object); 2551 return; 2552 } 2553 psize = object->size - pindex; 2554 } 2555 2556 start = 0; 2557 p_start = NULL; 2558 threshold = MAX_INIT_PT; 2559 2560 p = vm_page_find_least(object, pindex); 2561 /* 2562 * Assert: the variable p is either (1) the page with the 2563 * least pindex greater than or equal to the parameter pindex 2564 * or (2) NULL. 2565 */ 2566 for (; 2567 p != NULL && (tmpidx = p->pindex - pindex) < psize; 2568 p = TAILQ_NEXT(p, listq)) { 2569 /* 2570 * don't allow an madvise to blow away our really 2571 * free pages allocating pv entries. 2572 */ 2573 if (((flags & MAP_PREFAULT_MADVISE) != 0 && 2574 vm_page_count_severe()) || 2575 ((flags & MAP_PREFAULT_PARTIAL) != 0 && 2576 tmpidx >= threshold)) { 2577 psize = tmpidx; 2578 break; 2579 } 2580 if (vm_page_all_valid(p)) { 2581 if (p_start == NULL) { 2582 start = addr + ptoa(tmpidx); 2583 p_start = p; 2584 } 2585 /* Jump ahead if a superpage mapping is possible. */ 2586 if (p->psind > 0 && ((addr + ptoa(tmpidx)) & 2587 (pagesizes[p->psind] - 1)) == 0) { 2588 mask = atop(pagesizes[p->psind]) - 1; 2589 if (tmpidx + mask < psize && 2590 vm_page_ps_test(p, PS_ALL_VALID, NULL)) { 2591 p += mask; 2592 threshold += mask; 2593 } 2594 } 2595 } else if (p_start != NULL) { 2596 pmap_enter_object(map->pmap, start, addr + 2597 ptoa(tmpidx), p_start, prot); 2598 p_start = NULL; 2599 } 2600 } 2601 if (p_start != NULL) 2602 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 2603 p_start, prot); 2604 VM_OBJECT_RUNLOCK(object); 2605 } 2606 2607 /* 2608 * vm_map_protect: 2609 * 2610 * Sets the protection of the specified address 2611 * region in the target map. If "set_max" is 2612 * specified, the maximum protection is to be set; 2613 * otherwise, only the current protection is affected. 2614 */ 2615 int 2616 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 2617 vm_prot_t new_prot, boolean_t set_max) 2618 { 2619 vm_map_entry_t entry, first_entry, in_tran, prev_entry; 2620 vm_object_t obj; 2621 struct ucred *cred; 2622 vm_prot_t old_prot; 2623 int rv; 2624 2625 if (start == end) 2626 return (KERN_SUCCESS); 2627 2628 again: 2629 in_tran = NULL; 2630 vm_map_lock(map); 2631 2632 /* 2633 * Ensure that we are not concurrently wiring pages. vm_map_wire() may 2634 * need to fault pages into the map and will drop the map lock while 2635 * doing so, and the VM object may end up in an inconsistent state if we 2636 * update the protection on the map entry in between faults. 2637 */ 2638 vm_map_wait_busy(map); 2639 2640 VM_MAP_RANGE_CHECK(map, start, end); 2641 2642 if (!vm_map_lookup_entry(map, start, &first_entry)) 2643 first_entry = vm_map_entry_succ(first_entry); 2644 2645 /* 2646 * Make a first pass to check for protection violations. 2647 */ 2648 for (entry = first_entry; entry->start < end; 2649 entry = vm_map_entry_succ(entry)) { 2650 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) 2651 continue; 2652 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 2653 vm_map_unlock(map); 2654 return (KERN_INVALID_ARGUMENT); 2655 } 2656 if ((new_prot & entry->max_protection) != new_prot) { 2657 vm_map_unlock(map); 2658 return (KERN_PROTECTION_FAILURE); 2659 } 2660 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0) 2661 in_tran = entry; 2662 } 2663 2664 /* 2665 * Postpone the operation until all in-transition map entries have 2666 * stabilized. An in-transition entry might already have its pages 2667 * wired and wired_count incremented, but not yet have its 2668 * MAP_ENTRY_USER_WIRED flag set. In which case, we would fail to call 2669 * vm_fault_copy_entry() in the final loop below. 2670 */ 2671 if (in_tran != NULL) { 2672 in_tran->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2673 vm_map_unlock_and_wait(map, 0); 2674 goto again; 2675 } 2676 2677 /* 2678 * Before changing the protections, try to reserve swap space for any 2679 * private (i.e., copy-on-write) mappings that are transitioning from 2680 * read-only to read/write access. If a reservation fails, break out 2681 * of this loop early and let the next loop simplify the entries, since 2682 * some may now be mergeable. 2683 */ 2684 rv = KERN_SUCCESS; 2685 vm_map_clip_start(map, first_entry, start); 2686 for (entry = first_entry; entry->start < end; 2687 entry = vm_map_entry_succ(entry)) { 2688 vm_map_clip_end(map, entry, end); 2689 2690 if (set_max || 2691 ((new_prot & ~entry->protection) & VM_PROT_WRITE) == 0 || 2692 ENTRY_CHARGED(entry) || 2693 (entry->eflags & MAP_ENTRY_GUARD) != 0) { 2694 continue; 2695 } 2696 2697 cred = curthread->td_ucred; 2698 obj = entry->object.vm_object; 2699 2700 if (obj == NULL || 2701 (entry->eflags & MAP_ENTRY_NEEDS_COPY) != 0) { 2702 if (!swap_reserve(entry->end - entry->start)) { 2703 rv = KERN_RESOURCE_SHORTAGE; 2704 end = entry->end; 2705 break; 2706 } 2707 crhold(cred); 2708 entry->cred = cred; 2709 continue; 2710 } 2711 2712 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) 2713 continue; 2714 VM_OBJECT_WLOCK(obj); 2715 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 2716 VM_OBJECT_WUNLOCK(obj); 2717 continue; 2718 } 2719 2720 /* 2721 * Charge for the whole object allocation now, since 2722 * we cannot distinguish between non-charged and 2723 * charged clipped mapping of the same object later. 2724 */ 2725 KASSERT(obj->charge == 0, 2726 ("vm_map_protect: object %p overcharged (entry %p)", 2727 obj, entry)); 2728 if (!swap_reserve(ptoa(obj->size))) { 2729 VM_OBJECT_WUNLOCK(obj); 2730 rv = KERN_RESOURCE_SHORTAGE; 2731 end = entry->end; 2732 break; 2733 } 2734 2735 crhold(cred); 2736 obj->cred = cred; 2737 obj->charge = ptoa(obj->size); 2738 VM_OBJECT_WUNLOCK(obj); 2739 } 2740 2741 /* 2742 * If enough swap space was available, go back and fix up protections. 2743 * Otherwise, just simplify entries, since some may have been modified. 2744 * [Note that clipping is not necessary the second time.] 2745 */ 2746 for (prev_entry = vm_map_entry_pred(first_entry), entry = first_entry; 2747 entry->start < end; 2748 vm_map_try_merge_entries(map, prev_entry, entry), 2749 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 2750 if (rv != KERN_SUCCESS || 2751 (entry->eflags & MAP_ENTRY_GUARD) != 0) 2752 continue; 2753 2754 old_prot = entry->protection; 2755 2756 if (set_max) 2757 entry->protection = 2758 (entry->max_protection = new_prot) & 2759 old_prot; 2760 else 2761 entry->protection = new_prot; 2762 2763 /* 2764 * For user wired map entries, the normal lazy evaluation of 2765 * write access upgrades through soft page faults is 2766 * undesirable. Instead, immediately copy any pages that are 2767 * copy-on-write and enable write access in the physical map. 2768 */ 2769 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0 && 2770 (entry->protection & VM_PROT_WRITE) != 0 && 2771 (old_prot & VM_PROT_WRITE) == 0) 2772 vm_fault_copy_entry(map, map, entry, entry, NULL); 2773 2774 /* 2775 * When restricting access, update the physical map. Worry 2776 * about copy-on-write here. 2777 */ 2778 if ((old_prot & ~entry->protection) != 0) { 2779 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 2780 VM_PROT_ALL) 2781 pmap_protect(map->pmap, entry->start, 2782 entry->end, 2783 entry->protection & MASK(entry)); 2784 #undef MASK 2785 } 2786 } 2787 vm_map_try_merge_entries(map, prev_entry, entry); 2788 vm_map_unlock(map); 2789 return (rv); 2790 } 2791 2792 /* 2793 * vm_map_madvise: 2794 * 2795 * This routine traverses a processes map handling the madvise 2796 * system call. Advisories are classified as either those effecting 2797 * the vm_map_entry structure, or those effecting the underlying 2798 * objects. 2799 */ 2800 int 2801 vm_map_madvise( 2802 vm_map_t map, 2803 vm_offset_t start, 2804 vm_offset_t end, 2805 int behav) 2806 { 2807 vm_map_entry_t entry, prev_entry; 2808 bool modify_map; 2809 2810 /* 2811 * Some madvise calls directly modify the vm_map_entry, in which case 2812 * we need to use an exclusive lock on the map and we need to perform 2813 * various clipping operations. Otherwise we only need a read-lock 2814 * on the map. 2815 */ 2816 switch(behav) { 2817 case MADV_NORMAL: 2818 case MADV_SEQUENTIAL: 2819 case MADV_RANDOM: 2820 case MADV_NOSYNC: 2821 case MADV_AUTOSYNC: 2822 case MADV_NOCORE: 2823 case MADV_CORE: 2824 if (start == end) 2825 return (0); 2826 modify_map = true; 2827 vm_map_lock(map); 2828 break; 2829 case MADV_WILLNEED: 2830 case MADV_DONTNEED: 2831 case MADV_FREE: 2832 if (start == end) 2833 return (0); 2834 modify_map = false; 2835 vm_map_lock_read(map); 2836 break; 2837 default: 2838 return (EINVAL); 2839 } 2840 2841 /* 2842 * Locate starting entry and clip if necessary. 2843 */ 2844 VM_MAP_RANGE_CHECK(map, start, end); 2845 2846 if (modify_map) { 2847 /* 2848 * madvise behaviors that are implemented in the vm_map_entry. 2849 * 2850 * We clip the vm_map_entry so that behavioral changes are 2851 * limited to the specified address range. 2852 */ 2853 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry); 2854 entry->start < end; 2855 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 2856 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 2857 continue; 2858 2859 vm_map_clip_end(map, entry, end); 2860 2861 switch (behav) { 2862 case MADV_NORMAL: 2863 vm_map_entry_set_behavior(entry, 2864 MAP_ENTRY_BEHAV_NORMAL); 2865 break; 2866 case MADV_SEQUENTIAL: 2867 vm_map_entry_set_behavior(entry, 2868 MAP_ENTRY_BEHAV_SEQUENTIAL); 2869 break; 2870 case MADV_RANDOM: 2871 vm_map_entry_set_behavior(entry, 2872 MAP_ENTRY_BEHAV_RANDOM); 2873 break; 2874 case MADV_NOSYNC: 2875 entry->eflags |= MAP_ENTRY_NOSYNC; 2876 break; 2877 case MADV_AUTOSYNC: 2878 entry->eflags &= ~MAP_ENTRY_NOSYNC; 2879 break; 2880 case MADV_NOCORE: 2881 entry->eflags |= MAP_ENTRY_NOCOREDUMP; 2882 break; 2883 case MADV_CORE: 2884 entry->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2885 break; 2886 default: 2887 break; 2888 } 2889 vm_map_try_merge_entries(map, prev_entry, entry); 2890 } 2891 vm_map_try_merge_entries(map, prev_entry, entry); 2892 vm_map_unlock(map); 2893 } else { 2894 vm_pindex_t pstart, pend; 2895 2896 /* 2897 * madvise behaviors that are implemented in the underlying 2898 * vm_object. 2899 * 2900 * Since we don't clip the vm_map_entry, we have to clip 2901 * the vm_object pindex and count. 2902 */ 2903 if (!vm_map_lookup_entry(map, start, &entry)) 2904 entry = vm_map_entry_succ(entry); 2905 for (; entry->start < end; 2906 entry = vm_map_entry_succ(entry)) { 2907 vm_offset_t useEnd, useStart; 2908 2909 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 2910 continue; 2911 2912 /* 2913 * MADV_FREE would otherwise rewind time to 2914 * the creation of the shadow object. Because 2915 * we hold the VM map read-locked, neither the 2916 * entry's object nor the presence of a 2917 * backing object can change. 2918 */ 2919 if (behav == MADV_FREE && 2920 entry->object.vm_object != NULL && 2921 entry->object.vm_object->backing_object != NULL) 2922 continue; 2923 2924 pstart = OFF_TO_IDX(entry->offset); 2925 pend = pstart + atop(entry->end - entry->start); 2926 useStart = entry->start; 2927 useEnd = entry->end; 2928 2929 if (entry->start < start) { 2930 pstart += atop(start - entry->start); 2931 useStart = start; 2932 } 2933 if (entry->end > end) { 2934 pend -= atop(entry->end - end); 2935 useEnd = end; 2936 } 2937 2938 if (pstart >= pend) 2939 continue; 2940 2941 /* 2942 * Perform the pmap_advise() before clearing 2943 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2944 * concurrent pmap operation, such as pmap_remove(), 2945 * could clear a reference in the pmap and set 2946 * PGA_REFERENCED on the page before the pmap_advise() 2947 * had completed. Consequently, the page would appear 2948 * referenced based upon an old reference that 2949 * occurred before this pmap_advise() ran. 2950 */ 2951 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2952 pmap_advise(map->pmap, useStart, useEnd, 2953 behav); 2954 2955 vm_object_madvise(entry->object.vm_object, pstart, 2956 pend, behav); 2957 2958 /* 2959 * Pre-populate paging structures in the 2960 * WILLNEED case. For wired entries, the 2961 * paging structures are already populated. 2962 */ 2963 if (behav == MADV_WILLNEED && 2964 entry->wired_count == 0) { 2965 vm_map_pmap_enter(map, 2966 useStart, 2967 entry->protection, 2968 entry->object.vm_object, 2969 pstart, 2970 ptoa(pend - pstart), 2971 MAP_PREFAULT_MADVISE 2972 ); 2973 } 2974 } 2975 vm_map_unlock_read(map); 2976 } 2977 return (0); 2978 } 2979 2980 2981 /* 2982 * vm_map_inherit: 2983 * 2984 * Sets the inheritance of the specified address 2985 * range in the target map. Inheritance 2986 * affects how the map will be shared with 2987 * child maps at the time of vmspace_fork. 2988 */ 2989 int 2990 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 2991 vm_inherit_t new_inheritance) 2992 { 2993 vm_map_entry_t entry, prev_entry; 2994 2995 switch (new_inheritance) { 2996 case VM_INHERIT_NONE: 2997 case VM_INHERIT_COPY: 2998 case VM_INHERIT_SHARE: 2999 case VM_INHERIT_ZERO: 3000 break; 3001 default: 3002 return (KERN_INVALID_ARGUMENT); 3003 } 3004 if (start == end) 3005 return (KERN_SUCCESS); 3006 vm_map_lock(map); 3007 VM_MAP_RANGE_CHECK(map, start, end); 3008 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry); 3009 entry->start < end; 3010 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3011 vm_map_clip_end(map, entry, end); 3012 if ((entry->eflags & MAP_ENTRY_GUARD) == 0 || 3013 new_inheritance != VM_INHERIT_ZERO) 3014 entry->inheritance = new_inheritance; 3015 vm_map_try_merge_entries(map, prev_entry, entry); 3016 } 3017 vm_map_try_merge_entries(map, prev_entry, entry); 3018 vm_map_unlock(map); 3019 return (KERN_SUCCESS); 3020 } 3021 3022 /* 3023 * vm_map_entry_in_transition: 3024 * 3025 * Release the map lock, and sleep until the entry is no longer in 3026 * transition. Awake and acquire the map lock. If the map changed while 3027 * another held the lock, lookup a possibly-changed entry at or after the 3028 * 'start' position of the old entry. 3029 */ 3030 static vm_map_entry_t 3031 vm_map_entry_in_transition(vm_map_t map, vm_offset_t in_start, 3032 vm_offset_t *io_end, bool holes_ok, vm_map_entry_t in_entry) 3033 { 3034 vm_map_entry_t entry; 3035 vm_offset_t start; 3036 u_int last_timestamp; 3037 3038 VM_MAP_ASSERT_LOCKED(map); 3039 KASSERT((in_entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3040 ("not in-tranition map entry %p", in_entry)); 3041 /* 3042 * We have not yet clipped the entry. 3043 */ 3044 start = MAX(in_start, in_entry->start); 3045 in_entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 3046 last_timestamp = map->timestamp; 3047 if (vm_map_unlock_and_wait(map, 0)) { 3048 /* 3049 * Allow interruption of user wiring/unwiring? 3050 */ 3051 } 3052 vm_map_lock(map); 3053 if (last_timestamp + 1 == map->timestamp) 3054 return (in_entry); 3055 3056 /* 3057 * Look again for the entry because the map was modified while it was 3058 * unlocked. Specifically, the entry may have been clipped, merged, or 3059 * deleted. 3060 */ 3061 if (!vm_map_lookup_entry(map, start, &entry)) { 3062 if (!holes_ok) { 3063 *io_end = start; 3064 return (NULL); 3065 } 3066 entry = vm_map_entry_succ(entry); 3067 } 3068 return (entry); 3069 } 3070 3071 /* 3072 * vm_map_unwire: 3073 * 3074 * Implements both kernel and user unwiring. 3075 */ 3076 int 3077 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 3078 int flags) 3079 { 3080 vm_map_entry_t entry, first_entry, next_entry, prev_entry; 3081 int rv; 3082 bool holes_ok, need_wakeup, user_unwire; 3083 3084 if (start == end) 3085 return (KERN_SUCCESS); 3086 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0; 3087 user_unwire = (flags & VM_MAP_WIRE_USER) != 0; 3088 vm_map_lock(map); 3089 VM_MAP_RANGE_CHECK(map, start, end); 3090 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3091 if (holes_ok) 3092 first_entry = vm_map_entry_succ(first_entry); 3093 else { 3094 vm_map_unlock(map); 3095 return (KERN_INVALID_ADDRESS); 3096 } 3097 } 3098 rv = KERN_SUCCESS; 3099 for (entry = first_entry; entry->start < end; entry = next_entry) { 3100 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 3101 /* 3102 * We have not yet clipped the entry. 3103 */ 3104 next_entry = vm_map_entry_in_transition(map, start, 3105 &end, holes_ok, entry); 3106 if (next_entry == NULL) { 3107 if (entry == first_entry) { 3108 vm_map_unlock(map); 3109 return (KERN_INVALID_ADDRESS); 3110 } 3111 rv = KERN_INVALID_ADDRESS; 3112 break; 3113 } 3114 first_entry = (entry == first_entry) ? 3115 next_entry : NULL; 3116 continue; 3117 } 3118 vm_map_clip_start(map, entry, start); 3119 vm_map_clip_end(map, entry, end); 3120 /* 3121 * Mark the entry in case the map lock is released. (See 3122 * above.) 3123 */ 3124 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 3125 entry->wiring_thread == NULL, 3126 ("owned map entry %p", entry)); 3127 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 3128 entry->wiring_thread = curthread; 3129 next_entry = vm_map_entry_succ(entry); 3130 /* 3131 * Check the map for holes in the specified region. 3132 * If holes_ok, skip this check. 3133 */ 3134 if (!holes_ok && 3135 entry->end < end && next_entry->start > entry->end) { 3136 end = entry->end; 3137 rv = KERN_INVALID_ADDRESS; 3138 break; 3139 } 3140 /* 3141 * If system unwiring, require that the entry is system wired. 3142 */ 3143 if (!user_unwire && 3144 vm_map_entry_system_wired_count(entry) == 0) { 3145 end = entry->end; 3146 rv = KERN_INVALID_ARGUMENT; 3147 break; 3148 } 3149 } 3150 need_wakeup = false; 3151 if (first_entry == NULL && 3152 !vm_map_lookup_entry(map, start, &first_entry)) { 3153 KASSERT(holes_ok, ("vm_map_unwire: lookup failed")); 3154 prev_entry = first_entry; 3155 entry = vm_map_entry_succ(first_entry); 3156 } else { 3157 prev_entry = vm_map_entry_pred(first_entry); 3158 entry = first_entry; 3159 } 3160 for (; entry->start < end; 3161 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3162 /* 3163 * If holes_ok was specified, an empty 3164 * space in the unwired region could have been mapped 3165 * while the map lock was dropped for draining 3166 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 3167 * could be simultaneously wiring this new mapping 3168 * entry. Detect these cases and skip any entries 3169 * marked as in transition by us. 3170 */ 3171 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 3172 entry->wiring_thread != curthread) { 3173 KASSERT(holes_ok, 3174 ("vm_map_unwire: !HOLESOK and new/changed entry")); 3175 continue; 3176 } 3177 3178 if (rv == KERN_SUCCESS && (!user_unwire || 3179 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 3180 if (entry->wired_count == 1) 3181 vm_map_entry_unwire(map, entry); 3182 else 3183 entry->wired_count--; 3184 if (user_unwire) 3185 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3186 } 3187 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3188 ("vm_map_unwire: in-transition flag missing %p", entry)); 3189 KASSERT(entry->wiring_thread == curthread, 3190 ("vm_map_unwire: alien wire %p", entry)); 3191 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 3192 entry->wiring_thread = NULL; 3193 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 3194 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 3195 need_wakeup = true; 3196 } 3197 vm_map_try_merge_entries(map, prev_entry, entry); 3198 } 3199 vm_map_try_merge_entries(map, prev_entry, entry); 3200 vm_map_unlock(map); 3201 if (need_wakeup) 3202 vm_map_wakeup(map); 3203 return (rv); 3204 } 3205 3206 static void 3207 vm_map_wire_user_count_sub(u_long npages) 3208 { 3209 3210 atomic_subtract_long(&vm_user_wire_count, npages); 3211 } 3212 3213 static bool 3214 vm_map_wire_user_count_add(u_long npages) 3215 { 3216 u_long wired; 3217 3218 wired = vm_user_wire_count; 3219 do { 3220 if (npages + wired > vm_page_max_user_wired) 3221 return (false); 3222 } while (!atomic_fcmpset_long(&vm_user_wire_count, &wired, 3223 npages + wired)); 3224 3225 return (true); 3226 } 3227 3228 /* 3229 * vm_map_wire_entry_failure: 3230 * 3231 * Handle a wiring failure on the given entry. 3232 * 3233 * The map should be locked. 3234 */ 3235 static void 3236 vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 3237 vm_offset_t failed_addr) 3238 { 3239 3240 VM_MAP_ASSERT_LOCKED(map); 3241 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 && 3242 entry->wired_count == 1, 3243 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry)); 3244 KASSERT(failed_addr < entry->end, 3245 ("vm_map_wire_entry_failure: entry %p was fully wired", entry)); 3246 3247 /* 3248 * If any pages at the start of this entry were successfully wired, 3249 * then unwire them. 3250 */ 3251 if (failed_addr > entry->start) { 3252 pmap_unwire(map->pmap, entry->start, failed_addr); 3253 vm_object_unwire(entry->object.vm_object, entry->offset, 3254 failed_addr - entry->start, PQ_ACTIVE); 3255 } 3256 3257 /* 3258 * Assign an out-of-range value to represent the failure to wire this 3259 * entry. 3260 */ 3261 entry->wired_count = -1; 3262 } 3263 3264 int 3265 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) 3266 { 3267 int rv; 3268 3269 vm_map_lock(map); 3270 rv = vm_map_wire_locked(map, start, end, flags); 3271 vm_map_unlock(map); 3272 return (rv); 3273 } 3274 3275 3276 /* 3277 * vm_map_wire_locked: 3278 * 3279 * Implements both kernel and user wiring. Returns with the map locked, 3280 * the map lock may be dropped. 3281 */ 3282 int 3283 vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) 3284 { 3285 vm_map_entry_t entry, first_entry, next_entry, prev_entry; 3286 vm_offset_t faddr, saved_end, saved_start; 3287 u_long npages; 3288 u_int last_timestamp; 3289 int rv; 3290 bool holes_ok, need_wakeup, user_wire; 3291 vm_prot_t prot; 3292 3293 VM_MAP_ASSERT_LOCKED(map); 3294 3295 if (start == end) 3296 return (KERN_SUCCESS); 3297 prot = 0; 3298 if (flags & VM_MAP_WIRE_WRITE) 3299 prot |= VM_PROT_WRITE; 3300 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0; 3301 user_wire = (flags & VM_MAP_WIRE_USER) != 0; 3302 VM_MAP_RANGE_CHECK(map, start, end); 3303 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3304 if (holes_ok) 3305 first_entry = vm_map_entry_succ(first_entry); 3306 else 3307 return (KERN_INVALID_ADDRESS); 3308 } 3309 for (entry = first_entry; entry->start < end; entry = next_entry) { 3310 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 3311 /* 3312 * We have not yet clipped the entry. 3313 */ 3314 next_entry = vm_map_entry_in_transition(map, start, 3315 &end, holes_ok, entry); 3316 if (next_entry == NULL) { 3317 if (entry == first_entry) 3318 return (KERN_INVALID_ADDRESS); 3319 rv = KERN_INVALID_ADDRESS; 3320 goto done; 3321 } 3322 first_entry = (entry == first_entry) ? 3323 next_entry : NULL; 3324 continue; 3325 } 3326 vm_map_clip_start(map, entry, start); 3327 vm_map_clip_end(map, entry, end); 3328 /* 3329 * Mark the entry in case the map lock is released. (See 3330 * above.) 3331 */ 3332 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 3333 entry->wiring_thread == NULL, 3334 ("owned map entry %p", entry)); 3335 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 3336 entry->wiring_thread = curthread; 3337 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 3338 || (entry->protection & prot) != prot) { 3339 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 3340 if (!holes_ok) { 3341 end = entry->end; 3342 rv = KERN_INVALID_ADDRESS; 3343 goto done; 3344 } 3345 } else if (entry->wired_count == 0) { 3346 entry->wired_count++; 3347 3348 npages = atop(entry->end - entry->start); 3349 if (user_wire && !vm_map_wire_user_count_add(npages)) { 3350 vm_map_wire_entry_failure(map, entry, 3351 entry->start); 3352 end = entry->end; 3353 rv = KERN_RESOURCE_SHORTAGE; 3354 goto done; 3355 } 3356 3357 /* 3358 * Release the map lock, relying on the in-transition 3359 * mark. Mark the map busy for fork. 3360 */ 3361 saved_start = entry->start; 3362 saved_end = entry->end; 3363 last_timestamp = map->timestamp; 3364 vm_map_busy(map); 3365 vm_map_unlock(map); 3366 3367 faddr = saved_start; 3368 do { 3369 /* 3370 * Simulate a fault to get the page and enter 3371 * it into the physical map. 3372 */ 3373 if ((rv = vm_fault(map, faddr, 3374 VM_PROT_NONE, VM_FAULT_WIRE, NULL)) != 3375 KERN_SUCCESS) 3376 break; 3377 } while ((faddr += PAGE_SIZE) < saved_end); 3378 vm_map_lock(map); 3379 vm_map_unbusy(map); 3380 if (last_timestamp + 1 != map->timestamp) { 3381 /* 3382 * Look again for the entry because the map was 3383 * modified while it was unlocked. The entry 3384 * may have been clipped, but NOT merged or 3385 * deleted. 3386 */ 3387 if (!vm_map_lookup_entry(map, saved_start, 3388 &next_entry)) 3389 KASSERT(false, 3390 ("vm_map_wire: lookup failed")); 3391 first_entry = (entry == first_entry) ? 3392 next_entry : NULL; 3393 for (entry = next_entry; entry->end < saved_end; 3394 entry = vm_map_entry_succ(entry)) { 3395 /* 3396 * In case of failure, handle entries 3397 * that were not fully wired here; 3398 * fully wired entries are handled 3399 * later. 3400 */ 3401 if (rv != KERN_SUCCESS && 3402 faddr < entry->end) 3403 vm_map_wire_entry_failure(map, 3404 entry, faddr); 3405 } 3406 } 3407 if (rv != KERN_SUCCESS) { 3408 vm_map_wire_entry_failure(map, entry, faddr); 3409 if (user_wire) 3410 vm_map_wire_user_count_sub(npages); 3411 end = entry->end; 3412 goto done; 3413 } 3414 } else if (!user_wire || 3415 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 3416 entry->wired_count++; 3417 } 3418 /* 3419 * Check the map for holes in the specified region. 3420 * If holes_ok was specified, skip this check. 3421 */ 3422 next_entry = vm_map_entry_succ(entry); 3423 if (!holes_ok && 3424 entry->end < end && next_entry->start > entry->end) { 3425 end = entry->end; 3426 rv = KERN_INVALID_ADDRESS; 3427 goto done; 3428 } 3429 } 3430 rv = KERN_SUCCESS; 3431 done: 3432 need_wakeup = false; 3433 if (first_entry == NULL && 3434 !vm_map_lookup_entry(map, start, &first_entry)) { 3435 KASSERT(holes_ok, ("vm_map_wire: lookup failed")); 3436 prev_entry = first_entry; 3437 entry = vm_map_entry_succ(first_entry); 3438 } else { 3439 prev_entry = vm_map_entry_pred(first_entry); 3440 entry = first_entry; 3441 } 3442 for (; entry->start < end; 3443 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3444 /* 3445 * If holes_ok was specified, an empty 3446 * space in the unwired region could have been mapped 3447 * while the map lock was dropped for faulting in the 3448 * pages or draining MAP_ENTRY_IN_TRANSITION. 3449 * Moreover, another thread could be simultaneously 3450 * wiring this new mapping entry. Detect these cases 3451 * and skip any entries marked as in transition not by us. 3452 */ 3453 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 3454 entry->wiring_thread != curthread) { 3455 KASSERT(holes_ok, 3456 ("vm_map_wire: !HOLESOK and new/changed entry")); 3457 continue; 3458 } 3459 3460 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) { 3461 /* do nothing */ 3462 } else if (rv == KERN_SUCCESS) { 3463 if (user_wire) 3464 entry->eflags |= MAP_ENTRY_USER_WIRED; 3465 } else if (entry->wired_count == -1) { 3466 /* 3467 * Wiring failed on this entry. Thus, unwiring is 3468 * unnecessary. 3469 */ 3470 entry->wired_count = 0; 3471 } else if (!user_wire || 3472 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 3473 /* 3474 * Undo the wiring. Wiring succeeded on this entry 3475 * but failed on a later entry. 3476 */ 3477 if (entry->wired_count == 1) { 3478 vm_map_entry_unwire(map, entry); 3479 if (user_wire) 3480 vm_map_wire_user_count_sub( 3481 atop(entry->end - entry->start)); 3482 } else 3483 entry->wired_count--; 3484 } 3485 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3486 ("vm_map_wire: in-transition flag missing %p", entry)); 3487 KASSERT(entry->wiring_thread == curthread, 3488 ("vm_map_wire: alien wire %p", entry)); 3489 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 3490 MAP_ENTRY_WIRE_SKIPPED); 3491 entry->wiring_thread = NULL; 3492 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 3493 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 3494 need_wakeup = true; 3495 } 3496 vm_map_try_merge_entries(map, prev_entry, entry); 3497 } 3498 vm_map_try_merge_entries(map, prev_entry, entry); 3499 if (need_wakeup) 3500 vm_map_wakeup(map); 3501 return (rv); 3502 } 3503 3504 /* 3505 * vm_map_sync 3506 * 3507 * Push any dirty cached pages in the address range to their pager. 3508 * If syncio is TRUE, dirty pages are written synchronously. 3509 * If invalidate is TRUE, any cached pages are freed as well. 3510 * 3511 * If the size of the region from start to end is zero, we are 3512 * supposed to flush all modified pages within the region containing 3513 * start. Unfortunately, a region can be split or coalesced with 3514 * neighboring regions, making it difficult to determine what the 3515 * original region was. Therefore, we approximate this requirement by 3516 * flushing the current region containing start. 3517 * 3518 * Returns an error if any part of the specified range is not mapped. 3519 */ 3520 int 3521 vm_map_sync( 3522 vm_map_t map, 3523 vm_offset_t start, 3524 vm_offset_t end, 3525 boolean_t syncio, 3526 boolean_t invalidate) 3527 { 3528 vm_map_entry_t entry, first_entry, next_entry; 3529 vm_size_t size; 3530 vm_object_t object; 3531 vm_ooffset_t offset; 3532 unsigned int last_timestamp; 3533 boolean_t failed; 3534 3535 vm_map_lock_read(map); 3536 VM_MAP_RANGE_CHECK(map, start, end); 3537 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3538 vm_map_unlock_read(map); 3539 return (KERN_INVALID_ADDRESS); 3540 } else if (start == end) { 3541 start = first_entry->start; 3542 end = first_entry->end; 3543 } 3544 /* 3545 * Make a first pass to check for user-wired memory and holes. 3546 */ 3547 for (entry = first_entry; entry->start < end; entry = next_entry) { 3548 if (invalidate && 3549 (entry->eflags & MAP_ENTRY_USER_WIRED) != 0) { 3550 vm_map_unlock_read(map); 3551 return (KERN_INVALID_ARGUMENT); 3552 } 3553 next_entry = vm_map_entry_succ(entry); 3554 if (end > entry->end && 3555 entry->end != next_entry->start) { 3556 vm_map_unlock_read(map); 3557 return (KERN_INVALID_ADDRESS); 3558 } 3559 } 3560 3561 if (invalidate) 3562 pmap_remove(map->pmap, start, end); 3563 failed = FALSE; 3564 3565 /* 3566 * Make a second pass, cleaning/uncaching pages from the indicated 3567 * objects as we go. 3568 */ 3569 for (entry = first_entry; entry->start < end;) { 3570 offset = entry->offset + (start - entry->start); 3571 size = (end <= entry->end ? end : entry->end) - start; 3572 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 3573 vm_map_t smap; 3574 vm_map_entry_t tentry; 3575 vm_size_t tsize; 3576 3577 smap = entry->object.sub_map; 3578 vm_map_lock_read(smap); 3579 (void) vm_map_lookup_entry(smap, offset, &tentry); 3580 tsize = tentry->end - offset; 3581 if (tsize < size) 3582 size = tsize; 3583 object = tentry->object.vm_object; 3584 offset = tentry->offset + (offset - tentry->start); 3585 vm_map_unlock_read(smap); 3586 } else { 3587 object = entry->object.vm_object; 3588 } 3589 vm_object_reference(object); 3590 last_timestamp = map->timestamp; 3591 vm_map_unlock_read(map); 3592 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 3593 failed = TRUE; 3594 start += size; 3595 vm_object_deallocate(object); 3596 vm_map_lock_read(map); 3597 if (last_timestamp == map->timestamp || 3598 !vm_map_lookup_entry(map, start, &entry)) 3599 entry = vm_map_entry_succ(entry); 3600 } 3601 3602 vm_map_unlock_read(map); 3603 return (failed ? KERN_FAILURE : KERN_SUCCESS); 3604 } 3605 3606 /* 3607 * vm_map_entry_unwire: [ internal use only ] 3608 * 3609 * Make the region specified by this entry pageable. 3610 * 3611 * The map in question should be locked. 3612 * [This is the reason for this routine's existence.] 3613 */ 3614 static void 3615 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 3616 { 3617 vm_size_t size; 3618 3619 VM_MAP_ASSERT_LOCKED(map); 3620 KASSERT(entry->wired_count > 0, 3621 ("vm_map_entry_unwire: entry %p isn't wired", entry)); 3622 3623 size = entry->end - entry->start; 3624 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0) 3625 vm_map_wire_user_count_sub(atop(size)); 3626 pmap_unwire(map->pmap, entry->start, entry->end); 3627 vm_object_unwire(entry->object.vm_object, entry->offset, size, 3628 PQ_ACTIVE); 3629 entry->wired_count = 0; 3630 } 3631 3632 static void 3633 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 3634 { 3635 3636 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 3637 vm_object_deallocate(entry->object.vm_object); 3638 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 3639 } 3640 3641 /* 3642 * vm_map_entry_delete: [ internal use only ] 3643 * 3644 * Deallocate the given entry from the target map. 3645 */ 3646 static void 3647 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 3648 { 3649 vm_object_t object; 3650 vm_pindex_t offidxstart, offidxend, count, size1; 3651 vm_size_t size; 3652 3653 vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE); 3654 object = entry->object.vm_object; 3655 3656 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) { 3657 MPASS(entry->cred == NULL); 3658 MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0); 3659 MPASS(object == NULL); 3660 vm_map_entry_deallocate(entry, map->system_map); 3661 return; 3662 } 3663 3664 size = entry->end - entry->start; 3665 map->size -= size; 3666 3667 if (entry->cred != NULL) { 3668 swap_release_by_cred(size, entry->cred); 3669 crfree(entry->cred); 3670 } 3671 3672 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) { 3673 entry->object.vm_object = NULL; 3674 } else if ((object->flags & OBJ_ANON) != 0 || 3675 object == kernel_object) { 3676 KASSERT(entry->cred == NULL || object->cred == NULL || 3677 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 3678 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 3679 count = atop(size); 3680 offidxstart = OFF_TO_IDX(entry->offset); 3681 offidxend = offidxstart + count; 3682 VM_OBJECT_WLOCK(object); 3683 if (object->ref_count != 1 && 3684 ((object->flags & OBJ_ONEMAPPING) != 0 || 3685 object == kernel_object)) { 3686 vm_object_collapse(object); 3687 3688 /* 3689 * The option OBJPR_NOTMAPPED can be passed here 3690 * because vm_map_delete() already performed 3691 * pmap_remove() on the only mapping to this range 3692 * of pages. 3693 */ 3694 vm_object_page_remove(object, offidxstart, offidxend, 3695 OBJPR_NOTMAPPED); 3696 if (object->type == OBJT_SWAP) 3697 swap_pager_freespace(object, offidxstart, 3698 count); 3699 if (offidxend >= object->size && 3700 offidxstart < object->size) { 3701 size1 = object->size; 3702 object->size = offidxstart; 3703 if (object->cred != NULL) { 3704 size1 -= object->size; 3705 KASSERT(object->charge >= ptoa(size1), 3706 ("object %p charge < 0", object)); 3707 swap_release_by_cred(ptoa(size1), 3708 object->cred); 3709 object->charge -= ptoa(size1); 3710 } 3711 } 3712 } 3713 VM_OBJECT_WUNLOCK(object); 3714 } 3715 if (map->system_map) 3716 vm_map_entry_deallocate(entry, TRUE); 3717 else { 3718 entry->defer_next = curthread->td_map_def_user; 3719 curthread->td_map_def_user = entry; 3720 } 3721 } 3722 3723 /* 3724 * vm_map_delete: [ internal use only ] 3725 * 3726 * Deallocates the given address range from the target 3727 * map. 3728 */ 3729 int 3730 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 3731 { 3732 vm_map_entry_t entry, next_entry; 3733 3734 VM_MAP_ASSERT_LOCKED(map); 3735 if (start == end) 3736 return (KERN_SUCCESS); 3737 3738 /* 3739 * Find the start of the region, and clip it. 3740 * Step through all entries in this region. 3741 */ 3742 for (entry = vm_map_lookup_clip_start(map, start, &entry); 3743 entry->start < end; entry = next_entry) { 3744 /* 3745 * Wait for wiring or unwiring of an entry to complete. 3746 * Also wait for any system wirings to disappear on 3747 * user maps. 3748 */ 3749 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 3750 (vm_map_pmap(map) != kernel_pmap && 3751 vm_map_entry_system_wired_count(entry) != 0)) { 3752 unsigned int last_timestamp; 3753 vm_offset_t saved_start; 3754 3755 saved_start = entry->start; 3756 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 3757 last_timestamp = map->timestamp; 3758 (void) vm_map_unlock_and_wait(map, 0); 3759 vm_map_lock(map); 3760 if (last_timestamp + 1 != map->timestamp) { 3761 /* 3762 * Look again for the entry because the map was 3763 * modified while it was unlocked. 3764 * Specifically, the entry may have been 3765 * clipped, merged, or deleted. 3766 */ 3767 next_entry = vm_map_lookup_clip_start(map, 3768 saved_start, &next_entry); 3769 } else 3770 next_entry = entry; 3771 continue; 3772 } 3773 vm_map_clip_end(map, entry, end); 3774 next_entry = vm_map_entry_succ(entry); 3775 3776 /* 3777 * Unwire before removing addresses from the pmap; otherwise, 3778 * unwiring will put the entries back in the pmap. 3779 */ 3780 if (entry->wired_count != 0) 3781 vm_map_entry_unwire(map, entry); 3782 3783 /* 3784 * Remove mappings for the pages, but only if the 3785 * mappings could exist. For instance, it does not 3786 * make sense to call pmap_remove() for guard entries. 3787 */ 3788 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || 3789 entry->object.vm_object != NULL) 3790 pmap_remove(map->pmap, entry->start, entry->end); 3791 3792 if (entry->end == map->anon_loc) 3793 map->anon_loc = entry->start; 3794 3795 /* 3796 * Delete the entry only after removing all pmap 3797 * entries pointing to its pages. (Otherwise, its 3798 * page frames may be reallocated, and any modify bits 3799 * will be set in the wrong object!) 3800 */ 3801 vm_map_entry_delete(map, entry); 3802 } 3803 return (KERN_SUCCESS); 3804 } 3805 3806 /* 3807 * vm_map_remove: 3808 * 3809 * Remove the given address range from the target map. 3810 * This is the exported form of vm_map_delete. 3811 */ 3812 int 3813 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 3814 { 3815 int result; 3816 3817 vm_map_lock(map); 3818 VM_MAP_RANGE_CHECK(map, start, end); 3819 result = vm_map_delete(map, start, end); 3820 vm_map_unlock(map); 3821 return (result); 3822 } 3823 3824 /* 3825 * vm_map_check_protection: 3826 * 3827 * Assert that the target map allows the specified privilege on the 3828 * entire address region given. The entire region must be allocated. 3829 * 3830 * WARNING! This code does not and should not check whether the 3831 * contents of the region is accessible. For example a smaller file 3832 * might be mapped into a larger address space. 3833 * 3834 * NOTE! This code is also called by munmap(). 3835 * 3836 * The map must be locked. A read lock is sufficient. 3837 */ 3838 boolean_t 3839 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 3840 vm_prot_t protection) 3841 { 3842 vm_map_entry_t entry; 3843 vm_map_entry_t tmp_entry; 3844 3845 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 3846 return (FALSE); 3847 entry = tmp_entry; 3848 3849 while (start < end) { 3850 /* 3851 * No holes allowed! 3852 */ 3853 if (start < entry->start) 3854 return (FALSE); 3855 /* 3856 * Check protection associated with entry. 3857 */ 3858 if ((entry->protection & protection) != protection) 3859 return (FALSE); 3860 /* go to next entry */ 3861 start = entry->end; 3862 entry = vm_map_entry_succ(entry); 3863 } 3864 return (TRUE); 3865 } 3866 3867 3868 /* 3869 * 3870 * vm_map_copy_swap_object: 3871 * 3872 * Copies a swap-backed object from an existing map entry to a 3873 * new one. Carries forward the swap charge. May change the 3874 * src object on return. 3875 */ 3876 static void 3877 vm_map_copy_swap_object(vm_map_entry_t src_entry, vm_map_entry_t dst_entry, 3878 vm_offset_t size, vm_ooffset_t *fork_charge) 3879 { 3880 vm_object_t src_object; 3881 struct ucred *cred; 3882 int charged; 3883 3884 src_object = src_entry->object.vm_object; 3885 charged = ENTRY_CHARGED(src_entry); 3886 if ((src_object->flags & OBJ_ANON) != 0) { 3887 VM_OBJECT_WLOCK(src_object); 3888 vm_object_collapse(src_object); 3889 if ((src_object->flags & OBJ_ONEMAPPING) != 0) { 3890 vm_object_split(src_entry); 3891 src_object = src_entry->object.vm_object; 3892 } 3893 vm_object_reference_locked(src_object); 3894 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3895 VM_OBJECT_WUNLOCK(src_object); 3896 } else 3897 vm_object_reference(src_object); 3898 if (src_entry->cred != NULL && 3899 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3900 KASSERT(src_object->cred == NULL, 3901 ("OVERCOMMIT: vm_map_copy_anon_entry: cred %p", 3902 src_object)); 3903 src_object->cred = src_entry->cred; 3904 src_object->charge = size; 3905 } 3906 dst_entry->object.vm_object = src_object; 3907 if (charged) { 3908 cred = curthread->td_ucred; 3909 crhold(cred); 3910 dst_entry->cred = cred; 3911 *fork_charge += size; 3912 if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3913 crhold(cred); 3914 src_entry->cred = cred; 3915 *fork_charge += size; 3916 } 3917 } 3918 } 3919 3920 /* 3921 * vm_map_copy_entry: 3922 * 3923 * Copies the contents of the source entry to the destination 3924 * entry. The entries *must* be aligned properly. 3925 */ 3926 static void 3927 vm_map_copy_entry( 3928 vm_map_t src_map, 3929 vm_map_t dst_map, 3930 vm_map_entry_t src_entry, 3931 vm_map_entry_t dst_entry, 3932 vm_ooffset_t *fork_charge) 3933 { 3934 vm_object_t src_object; 3935 vm_map_entry_t fake_entry; 3936 vm_offset_t size; 3937 3938 VM_MAP_ASSERT_LOCKED(dst_map); 3939 3940 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3941 return; 3942 3943 if (src_entry->wired_count == 0 || 3944 (src_entry->protection & VM_PROT_WRITE) == 0) { 3945 /* 3946 * If the source entry is marked needs_copy, it is already 3947 * write-protected. 3948 */ 3949 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && 3950 (src_entry->protection & VM_PROT_WRITE) != 0) { 3951 pmap_protect(src_map->pmap, 3952 src_entry->start, 3953 src_entry->end, 3954 src_entry->protection & ~VM_PROT_WRITE); 3955 } 3956 3957 /* 3958 * Make a copy of the object. 3959 */ 3960 size = src_entry->end - src_entry->start; 3961 if ((src_object = src_entry->object.vm_object) != NULL) { 3962 if (src_object->type == OBJT_DEFAULT || 3963 src_object->type == OBJT_SWAP) { 3964 vm_map_copy_swap_object(src_entry, dst_entry, 3965 size, fork_charge); 3966 /* May have split/collapsed, reload obj. */ 3967 src_object = src_entry->object.vm_object; 3968 } else { 3969 vm_object_reference(src_object); 3970 dst_entry->object.vm_object = src_object; 3971 } 3972 src_entry->eflags |= MAP_ENTRY_COW | 3973 MAP_ENTRY_NEEDS_COPY; 3974 dst_entry->eflags |= MAP_ENTRY_COW | 3975 MAP_ENTRY_NEEDS_COPY; 3976 dst_entry->offset = src_entry->offset; 3977 if (src_entry->eflags & MAP_ENTRY_WRITECNT) { 3978 /* 3979 * MAP_ENTRY_WRITECNT cannot 3980 * indicate write reference from 3981 * src_entry, since the entry is 3982 * marked as needs copy. Allocate a 3983 * fake entry that is used to 3984 * decrement object->un_pager writecount 3985 * at the appropriate time. Attach 3986 * fake_entry to the deferred list. 3987 */ 3988 fake_entry = vm_map_entry_create(dst_map); 3989 fake_entry->eflags = MAP_ENTRY_WRITECNT; 3990 src_entry->eflags &= ~MAP_ENTRY_WRITECNT; 3991 vm_object_reference(src_object); 3992 fake_entry->object.vm_object = src_object; 3993 fake_entry->start = src_entry->start; 3994 fake_entry->end = src_entry->end; 3995 fake_entry->defer_next = 3996 curthread->td_map_def_user; 3997 curthread->td_map_def_user = fake_entry; 3998 } 3999 4000 pmap_copy(dst_map->pmap, src_map->pmap, 4001 dst_entry->start, dst_entry->end - dst_entry->start, 4002 src_entry->start); 4003 } else { 4004 dst_entry->object.vm_object = NULL; 4005 dst_entry->offset = 0; 4006 if (src_entry->cred != NULL) { 4007 dst_entry->cred = curthread->td_ucred; 4008 crhold(dst_entry->cred); 4009 *fork_charge += size; 4010 } 4011 } 4012 } else { 4013 /* 4014 * We don't want to make writeable wired pages copy-on-write. 4015 * Immediately copy these pages into the new map by simulating 4016 * page faults. The new pages are pageable. 4017 */ 4018 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 4019 fork_charge); 4020 } 4021 } 4022 4023 /* 4024 * vmspace_map_entry_forked: 4025 * Update the newly-forked vmspace each time a map entry is inherited 4026 * or copied. The values for vm_dsize and vm_tsize are approximate 4027 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 4028 */ 4029 static void 4030 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 4031 vm_map_entry_t entry) 4032 { 4033 vm_size_t entrysize; 4034 vm_offset_t newend; 4035 4036 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) 4037 return; 4038 entrysize = entry->end - entry->start; 4039 vm2->vm_map.size += entrysize; 4040 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 4041 vm2->vm_ssize += btoc(entrysize); 4042 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 4043 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 4044 newend = MIN(entry->end, 4045 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 4046 vm2->vm_dsize += btoc(newend - entry->start); 4047 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 4048 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 4049 newend = MIN(entry->end, 4050 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 4051 vm2->vm_tsize += btoc(newend - entry->start); 4052 } 4053 } 4054 4055 /* 4056 * vmspace_fork: 4057 * Create a new process vmspace structure and vm_map 4058 * based on those of an existing process. The new map 4059 * is based on the old map, according to the inheritance 4060 * values on the regions in that map. 4061 * 4062 * XXX It might be worth coalescing the entries added to the new vmspace. 4063 * 4064 * The source map must not be locked. 4065 */ 4066 struct vmspace * 4067 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 4068 { 4069 struct vmspace *vm2; 4070 vm_map_t new_map, old_map; 4071 vm_map_entry_t new_entry, old_entry; 4072 vm_object_t object; 4073 int error, locked; 4074 vm_inherit_t inh; 4075 4076 old_map = &vm1->vm_map; 4077 /* Copy immutable fields of vm1 to vm2. */ 4078 vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map), 4079 pmap_pinit); 4080 if (vm2 == NULL) 4081 return (NULL); 4082 4083 vm2->vm_taddr = vm1->vm_taddr; 4084 vm2->vm_daddr = vm1->vm_daddr; 4085 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 4086 vm_map_lock(old_map); 4087 if (old_map->busy) 4088 vm_map_wait_busy(old_map); 4089 new_map = &vm2->vm_map; 4090 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 4091 KASSERT(locked, ("vmspace_fork: lock failed")); 4092 4093 error = pmap_vmspace_copy(new_map->pmap, old_map->pmap); 4094 if (error != 0) { 4095 sx_xunlock(&old_map->lock); 4096 sx_xunlock(&new_map->lock); 4097 vm_map_process_deferred(); 4098 vmspace_free(vm2); 4099 return (NULL); 4100 } 4101 4102 new_map->anon_loc = old_map->anon_loc; 4103 4104 VM_MAP_ENTRY_FOREACH(old_entry, old_map) { 4105 if ((old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 4106 panic("vm_map_fork: encountered a submap"); 4107 4108 inh = old_entry->inheritance; 4109 if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 && 4110 inh != VM_INHERIT_NONE) 4111 inh = VM_INHERIT_COPY; 4112 4113 switch (inh) { 4114 case VM_INHERIT_NONE: 4115 break; 4116 4117 case VM_INHERIT_SHARE: 4118 /* 4119 * Clone the entry, creating the shared object if 4120 * necessary. 4121 */ 4122 object = old_entry->object.vm_object; 4123 if (object == NULL) { 4124 vm_map_entry_back(old_entry); 4125 object = old_entry->object.vm_object; 4126 } 4127 4128 /* 4129 * Add the reference before calling vm_object_shadow 4130 * to insure that a shadow object is created. 4131 */ 4132 vm_object_reference(object); 4133 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4134 vm_object_shadow(&old_entry->object.vm_object, 4135 &old_entry->offset, 4136 old_entry->end - old_entry->start, 4137 old_entry->cred, 4138 /* Transfer the second reference too. */ 4139 true); 4140 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4141 old_entry->cred = NULL; 4142 4143 /* 4144 * As in vm_map_merged_neighbor_dispose(), 4145 * the vnode lock will not be acquired in 4146 * this call to vm_object_deallocate(). 4147 */ 4148 vm_object_deallocate(object); 4149 object = old_entry->object.vm_object; 4150 } else { 4151 VM_OBJECT_WLOCK(object); 4152 vm_object_clear_flag(object, OBJ_ONEMAPPING); 4153 if (old_entry->cred != NULL) { 4154 KASSERT(object->cred == NULL, 4155 ("vmspace_fork both cred")); 4156 object->cred = old_entry->cred; 4157 object->charge = old_entry->end - 4158 old_entry->start; 4159 old_entry->cred = NULL; 4160 } 4161 4162 /* 4163 * Assert the correct state of the vnode 4164 * v_writecount while the object is locked, to 4165 * not relock it later for the assertion 4166 * correctness. 4167 */ 4168 if (old_entry->eflags & MAP_ENTRY_WRITECNT && 4169 object->type == OBJT_VNODE) { 4170 KASSERT(((struct vnode *)object-> 4171 handle)->v_writecount > 0, 4172 ("vmspace_fork: v_writecount %p", 4173 object)); 4174 KASSERT(object->un_pager.vnp. 4175 writemappings > 0, 4176 ("vmspace_fork: vnp.writecount %p", 4177 object)); 4178 } 4179 VM_OBJECT_WUNLOCK(object); 4180 } 4181 4182 /* 4183 * Clone the entry, referencing the shared object. 4184 */ 4185 new_entry = vm_map_entry_create(new_map); 4186 *new_entry = *old_entry; 4187 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 4188 MAP_ENTRY_IN_TRANSITION); 4189 new_entry->wiring_thread = NULL; 4190 new_entry->wired_count = 0; 4191 if (new_entry->eflags & MAP_ENTRY_WRITECNT) { 4192 vm_pager_update_writecount(object, 4193 new_entry->start, new_entry->end); 4194 } 4195 vm_map_entry_set_vnode_text(new_entry, true); 4196 4197 /* 4198 * Insert the entry into the new map -- we know we're 4199 * inserting at the end of the new map. 4200 */ 4201 vm_map_entry_link(new_map, new_entry); 4202 vmspace_map_entry_forked(vm1, vm2, new_entry); 4203 4204 /* 4205 * Update the physical map 4206 */ 4207 pmap_copy(new_map->pmap, old_map->pmap, 4208 new_entry->start, 4209 (old_entry->end - old_entry->start), 4210 old_entry->start); 4211 break; 4212 4213 case VM_INHERIT_COPY: 4214 /* 4215 * Clone the entry and link into the map. 4216 */ 4217 new_entry = vm_map_entry_create(new_map); 4218 *new_entry = *old_entry; 4219 /* 4220 * Copied entry is COW over the old object. 4221 */ 4222 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 4223 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WRITECNT); 4224 new_entry->wiring_thread = NULL; 4225 new_entry->wired_count = 0; 4226 new_entry->object.vm_object = NULL; 4227 new_entry->cred = NULL; 4228 vm_map_entry_link(new_map, new_entry); 4229 vmspace_map_entry_forked(vm1, vm2, new_entry); 4230 vm_map_copy_entry(old_map, new_map, old_entry, 4231 new_entry, fork_charge); 4232 vm_map_entry_set_vnode_text(new_entry, true); 4233 break; 4234 4235 case VM_INHERIT_ZERO: 4236 /* 4237 * Create a new anonymous mapping entry modelled from 4238 * the old one. 4239 */ 4240 new_entry = vm_map_entry_create(new_map); 4241 memset(new_entry, 0, sizeof(*new_entry)); 4242 4243 new_entry->start = old_entry->start; 4244 new_entry->end = old_entry->end; 4245 new_entry->eflags = old_entry->eflags & 4246 ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION | 4247 MAP_ENTRY_WRITECNT | MAP_ENTRY_VN_EXEC); 4248 new_entry->protection = old_entry->protection; 4249 new_entry->max_protection = old_entry->max_protection; 4250 new_entry->inheritance = VM_INHERIT_ZERO; 4251 4252 vm_map_entry_link(new_map, new_entry); 4253 vmspace_map_entry_forked(vm1, vm2, new_entry); 4254 4255 new_entry->cred = curthread->td_ucred; 4256 crhold(new_entry->cred); 4257 *fork_charge += (new_entry->end - new_entry->start); 4258 4259 break; 4260 } 4261 } 4262 /* 4263 * Use inlined vm_map_unlock() to postpone handling the deferred 4264 * map entries, which cannot be done until both old_map and 4265 * new_map locks are released. 4266 */ 4267 sx_xunlock(&old_map->lock); 4268 sx_xunlock(&new_map->lock); 4269 vm_map_process_deferred(); 4270 4271 return (vm2); 4272 } 4273 4274 /* 4275 * Create a process's stack for exec_new_vmspace(). This function is never 4276 * asked to wire the newly created stack. 4277 */ 4278 int 4279 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 4280 vm_prot_t prot, vm_prot_t max, int cow) 4281 { 4282 vm_size_t growsize, init_ssize; 4283 rlim_t vmemlim; 4284 int rv; 4285 4286 MPASS((map->flags & MAP_WIREFUTURE) == 0); 4287 growsize = sgrowsiz; 4288 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 4289 vm_map_lock(map); 4290 vmemlim = lim_cur(curthread, RLIMIT_VMEM); 4291 /* If we would blow our VMEM resource limit, no go */ 4292 if (map->size + init_ssize > vmemlim) { 4293 rv = KERN_NO_SPACE; 4294 goto out; 4295 } 4296 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, 4297 max, cow); 4298 out: 4299 vm_map_unlock(map); 4300 return (rv); 4301 } 4302 4303 static int stack_guard_page = 1; 4304 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN, 4305 &stack_guard_page, 0, 4306 "Specifies the number of guard pages for a stack that grows"); 4307 4308 static int 4309 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 4310 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) 4311 { 4312 vm_map_entry_t new_entry, prev_entry; 4313 vm_offset_t bot, gap_bot, gap_top, top; 4314 vm_size_t init_ssize, sgp; 4315 int orient, rv; 4316 4317 /* 4318 * The stack orientation is piggybacked with the cow argument. 4319 * Extract it into orient and mask the cow argument so that we 4320 * don't pass it around further. 4321 */ 4322 orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP); 4323 KASSERT(orient != 0, ("No stack grow direction")); 4324 KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP), 4325 ("bi-dir stack")); 4326 4327 if (addrbos < vm_map_min(map) || 4328 addrbos + max_ssize > vm_map_max(map) || 4329 addrbos + max_ssize <= addrbos) 4330 return (KERN_INVALID_ADDRESS); 4331 sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 || 4332 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 : 4333 (vm_size_t)stack_guard_page * PAGE_SIZE; 4334 if (sgp >= max_ssize) 4335 return (KERN_INVALID_ARGUMENT); 4336 4337 init_ssize = growsize; 4338 if (max_ssize < init_ssize + sgp) 4339 init_ssize = max_ssize - sgp; 4340 4341 /* If addr is already mapped, no go */ 4342 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) 4343 return (KERN_NO_SPACE); 4344 4345 /* 4346 * If we can't accommodate max_ssize in the current mapping, no go. 4347 */ 4348 if (vm_map_entry_succ(prev_entry)->start < addrbos + max_ssize) 4349 return (KERN_NO_SPACE); 4350 4351 /* 4352 * We initially map a stack of only init_ssize. We will grow as 4353 * needed later. Depending on the orientation of the stack (i.e. 4354 * the grow direction) we either map at the top of the range, the 4355 * bottom of the range or in the middle. 4356 * 4357 * Note: we would normally expect prot and max to be VM_PROT_ALL, 4358 * and cow to be 0. Possibly we should eliminate these as input 4359 * parameters, and just pass these values here in the insert call. 4360 */ 4361 if (orient == MAP_STACK_GROWS_DOWN) { 4362 bot = addrbos + max_ssize - init_ssize; 4363 top = bot + init_ssize; 4364 gap_bot = addrbos; 4365 gap_top = bot; 4366 } else /* if (orient == MAP_STACK_GROWS_UP) */ { 4367 bot = addrbos; 4368 top = bot + init_ssize; 4369 gap_bot = top; 4370 gap_top = addrbos + max_ssize; 4371 } 4372 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 4373 if (rv != KERN_SUCCESS) 4374 return (rv); 4375 new_entry = vm_map_entry_succ(prev_entry); 4376 KASSERT(new_entry->end == top || new_entry->start == bot, 4377 ("Bad entry start/end for new stack entry")); 4378 KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 || 4379 (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0, 4380 ("new entry lacks MAP_ENTRY_GROWS_DOWN")); 4381 KASSERT((orient & MAP_STACK_GROWS_UP) == 0 || 4382 (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0, 4383 ("new entry lacks MAP_ENTRY_GROWS_UP")); 4384 if (gap_bot == gap_top) 4385 return (KERN_SUCCESS); 4386 rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE, 4387 VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ? 4388 MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP)); 4389 if (rv == KERN_SUCCESS) { 4390 /* 4391 * Gap can never successfully handle a fault, so 4392 * read-ahead logic is never used for it. Re-use 4393 * next_read of the gap entry to store 4394 * stack_guard_page for vm_map_growstack(). 4395 */ 4396 if (orient == MAP_STACK_GROWS_DOWN) 4397 vm_map_entry_pred(new_entry)->next_read = sgp; 4398 else 4399 vm_map_entry_succ(new_entry)->next_read = sgp; 4400 } else { 4401 (void)vm_map_delete(map, bot, top); 4402 } 4403 return (rv); 4404 } 4405 4406 /* 4407 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we 4408 * successfully grow the stack. 4409 */ 4410 static int 4411 vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry) 4412 { 4413 vm_map_entry_t stack_entry; 4414 struct proc *p; 4415 struct vmspace *vm; 4416 struct ucred *cred; 4417 vm_offset_t gap_end, gap_start, grow_start; 4418 vm_size_t grow_amount, guard, max_grow; 4419 rlim_t lmemlim, stacklim, vmemlim; 4420 int rv, rv1; 4421 bool gap_deleted, grow_down, is_procstack; 4422 #ifdef notyet 4423 uint64_t limit; 4424 #endif 4425 #ifdef RACCT 4426 int error; 4427 #endif 4428 4429 p = curproc; 4430 vm = p->p_vmspace; 4431 4432 /* 4433 * Disallow stack growth when the access is performed by a 4434 * debugger or AIO daemon. The reason is that the wrong 4435 * resource limits are applied. 4436 */ 4437 if (p != initproc && (map != &p->p_vmspace->vm_map || 4438 p->p_textvp == NULL)) 4439 return (KERN_FAILURE); 4440 4441 MPASS(!map->system_map); 4442 4443 lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK); 4444 stacklim = lim_cur(curthread, RLIMIT_STACK); 4445 vmemlim = lim_cur(curthread, RLIMIT_VMEM); 4446 retry: 4447 /* If addr is not in a hole for a stack grow area, no need to grow. */ 4448 if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry)) 4449 return (KERN_FAILURE); 4450 if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0) 4451 return (KERN_SUCCESS); 4452 if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) { 4453 stack_entry = vm_map_entry_succ(gap_entry); 4454 if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 || 4455 stack_entry->start != gap_entry->end) 4456 return (KERN_FAILURE); 4457 grow_amount = round_page(stack_entry->start - addr); 4458 grow_down = true; 4459 } else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) { 4460 stack_entry = vm_map_entry_pred(gap_entry); 4461 if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 || 4462 stack_entry->end != gap_entry->start) 4463 return (KERN_FAILURE); 4464 grow_amount = round_page(addr + 1 - stack_entry->end); 4465 grow_down = false; 4466 } else { 4467 return (KERN_FAILURE); 4468 } 4469 guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 || 4470 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 : 4471 gap_entry->next_read; 4472 max_grow = gap_entry->end - gap_entry->start; 4473 if (guard > max_grow) 4474 return (KERN_NO_SPACE); 4475 max_grow -= guard; 4476 if (grow_amount > max_grow) 4477 return (KERN_NO_SPACE); 4478 4479 /* 4480 * If this is the main process stack, see if we're over the stack 4481 * limit. 4482 */ 4483 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr && 4484 addr < (vm_offset_t)p->p_sysent->sv_usrstack; 4485 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) 4486 return (KERN_NO_SPACE); 4487 4488 #ifdef RACCT 4489 if (racct_enable) { 4490 PROC_LOCK(p); 4491 if (is_procstack && racct_set(p, RACCT_STACK, 4492 ctob(vm->vm_ssize) + grow_amount)) { 4493 PROC_UNLOCK(p); 4494 return (KERN_NO_SPACE); 4495 } 4496 PROC_UNLOCK(p); 4497 } 4498 #endif 4499 4500 grow_amount = roundup(grow_amount, sgrowsiz); 4501 if (grow_amount > max_grow) 4502 grow_amount = max_grow; 4503 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 4504 grow_amount = trunc_page((vm_size_t)stacklim) - 4505 ctob(vm->vm_ssize); 4506 } 4507 4508 #ifdef notyet 4509 PROC_LOCK(p); 4510 limit = racct_get_available(p, RACCT_STACK); 4511 PROC_UNLOCK(p); 4512 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 4513 grow_amount = limit - ctob(vm->vm_ssize); 4514 #endif 4515 4516 if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) { 4517 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 4518 rv = KERN_NO_SPACE; 4519 goto out; 4520 } 4521 #ifdef RACCT 4522 if (racct_enable) { 4523 PROC_LOCK(p); 4524 if (racct_set(p, RACCT_MEMLOCK, 4525 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 4526 PROC_UNLOCK(p); 4527 rv = KERN_NO_SPACE; 4528 goto out; 4529 } 4530 PROC_UNLOCK(p); 4531 } 4532 #endif 4533 } 4534 4535 /* If we would blow our VMEM resource limit, no go */ 4536 if (map->size + grow_amount > vmemlim) { 4537 rv = KERN_NO_SPACE; 4538 goto out; 4539 } 4540 #ifdef RACCT 4541 if (racct_enable) { 4542 PROC_LOCK(p); 4543 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 4544 PROC_UNLOCK(p); 4545 rv = KERN_NO_SPACE; 4546 goto out; 4547 } 4548 PROC_UNLOCK(p); 4549 } 4550 #endif 4551 4552 if (vm_map_lock_upgrade(map)) { 4553 gap_entry = NULL; 4554 vm_map_lock_read(map); 4555 goto retry; 4556 } 4557 4558 if (grow_down) { 4559 grow_start = gap_entry->end - grow_amount; 4560 if (gap_entry->start + grow_amount == gap_entry->end) { 4561 gap_start = gap_entry->start; 4562 gap_end = gap_entry->end; 4563 vm_map_entry_delete(map, gap_entry); 4564 gap_deleted = true; 4565 } else { 4566 MPASS(gap_entry->start < gap_entry->end - grow_amount); 4567 vm_map_entry_resize(map, gap_entry, -grow_amount); 4568 gap_deleted = false; 4569 } 4570 rv = vm_map_insert(map, NULL, 0, grow_start, 4571 grow_start + grow_amount, 4572 stack_entry->protection, stack_entry->max_protection, 4573 MAP_STACK_GROWS_DOWN); 4574 if (rv != KERN_SUCCESS) { 4575 if (gap_deleted) { 4576 rv1 = vm_map_insert(map, NULL, 0, gap_start, 4577 gap_end, VM_PROT_NONE, VM_PROT_NONE, 4578 MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN); 4579 MPASS(rv1 == KERN_SUCCESS); 4580 } else 4581 vm_map_entry_resize(map, gap_entry, 4582 grow_amount); 4583 } 4584 } else { 4585 grow_start = stack_entry->end; 4586 cred = stack_entry->cred; 4587 if (cred == NULL && stack_entry->object.vm_object != NULL) 4588 cred = stack_entry->object.vm_object->cred; 4589 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 4590 rv = KERN_NO_SPACE; 4591 /* Grow the underlying object if applicable. */ 4592 else if (stack_entry->object.vm_object == NULL || 4593 vm_object_coalesce(stack_entry->object.vm_object, 4594 stack_entry->offset, 4595 (vm_size_t)(stack_entry->end - stack_entry->start), 4596 grow_amount, cred != NULL)) { 4597 if (gap_entry->start + grow_amount == gap_entry->end) { 4598 vm_map_entry_delete(map, gap_entry); 4599 vm_map_entry_resize(map, stack_entry, 4600 grow_amount); 4601 } else { 4602 gap_entry->start += grow_amount; 4603 stack_entry->end += grow_amount; 4604 } 4605 map->size += grow_amount; 4606 rv = KERN_SUCCESS; 4607 } else 4608 rv = KERN_FAILURE; 4609 } 4610 if (rv == KERN_SUCCESS && is_procstack) 4611 vm->vm_ssize += btoc(grow_amount); 4612 4613 /* 4614 * Heed the MAP_WIREFUTURE flag if it was set for this process. 4615 */ 4616 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) { 4617 rv = vm_map_wire_locked(map, grow_start, 4618 grow_start + grow_amount, 4619 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES); 4620 } 4621 vm_map_lock_downgrade(map); 4622 4623 out: 4624 #ifdef RACCT 4625 if (racct_enable && rv != KERN_SUCCESS) { 4626 PROC_LOCK(p); 4627 error = racct_set(p, RACCT_VMEM, map->size); 4628 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 4629 if (!old_mlock) { 4630 error = racct_set(p, RACCT_MEMLOCK, 4631 ptoa(pmap_wired_count(map->pmap))); 4632 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 4633 } 4634 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 4635 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 4636 PROC_UNLOCK(p); 4637 } 4638 #endif 4639 4640 return (rv); 4641 } 4642 4643 /* 4644 * Unshare the specified VM space for exec. If other processes are 4645 * mapped to it, then create a new one. The new vmspace is null. 4646 */ 4647 int 4648 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 4649 { 4650 struct vmspace *oldvmspace = p->p_vmspace; 4651 struct vmspace *newvmspace; 4652 4653 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 4654 ("vmspace_exec recursed")); 4655 newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit); 4656 if (newvmspace == NULL) 4657 return (ENOMEM); 4658 newvmspace->vm_swrss = oldvmspace->vm_swrss; 4659 /* 4660 * This code is written like this for prototype purposes. The 4661 * goal is to avoid running down the vmspace here, but let the 4662 * other process's that are still using the vmspace to finally 4663 * run it down. Even though there is little or no chance of blocking 4664 * here, it is a good idea to keep this form for future mods. 4665 */ 4666 PROC_VMSPACE_LOCK(p); 4667 p->p_vmspace = newvmspace; 4668 PROC_VMSPACE_UNLOCK(p); 4669 if (p == curthread->td_proc) 4670 pmap_activate(curthread); 4671 curthread->td_pflags |= TDP_EXECVMSPC; 4672 return (0); 4673 } 4674 4675 /* 4676 * Unshare the specified VM space for forcing COW. This 4677 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 4678 */ 4679 int 4680 vmspace_unshare(struct proc *p) 4681 { 4682 struct vmspace *oldvmspace = p->p_vmspace; 4683 struct vmspace *newvmspace; 4684 vm_ooffset_t fork_charge; 4685 4686 if (oldvmspace->vm_refcnt == 1) 4687 return (0); 4688 fork_charge = 0; 4689 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 4690 if (newvmspace == NULL) 4691 return (ENOMEM); 4692 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 4693 vmspace_free(newvmspace); 4694 return (ENOMEM); 4695 } 4696 PROC_VMSPACE_LOCK(p); 4697 p->p_vmspace = newvmspace; 4698 PROC_VMSPACE_UNLOCK(p); 4699 if (p == curthread->td_proc) 4700 pmap_activate(curthread); 4701 vmspace_free(oldvmspace); 4702 return (0); 4703 } 4704 4705 /* 4706 * vm_map_lookup: 4707 * 4708 * Finds the VM object, offset, and 4709 * protection for a given virtual address in the 4710 * specified map, assuming a page fault of the 4711 * type specified. 4712 * 4713 * Leaves the map in question locked for read; return 4714 * values are guaranteed until a vm_map_lookup_done 4715 * call is performed. Note that the map argument 4716 * is in/out; the returned map must be used in 4717 * the call to vm_map_lookup_done. 4718 * 4719 * A handle (out_entry) is returned for use in 4720 * vm_map_lookup_done, to make that fast. 4721 * 4722 * If a lookup is requested with "write protection" 4723 * specified, the map may be changed to perform virtual 4724 * copying operations, although the data referenced will 4725 * remain the same. 4726 */ 4727 int 4728 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 4729 vm_offset_t vaddr, 4730 vm_prot_t fault_typea, 4731 vm_map_entry_t *out_entry, /* OUT */ 4732 vm_object_t *object, /* OUT */ 4733 vm_pindex_t *pindex, /* OUT */ 4734 vm_prot_t *out_prot, /* OUT */ 4735 boolean_t *wired) /* OUT */ 4736 { 4737 vm_map_entry_t entry; 4738 vm_map_t map = *var_map; 4739 vm_prot_t prot; 4740 vm_prot_t fault_type; 4741 vm_object_t eobject; 4742 vm_size_t size; 4743 struct ucred *cred; 4744 4745 RetryLookup: 4746 4747 vm_map_lock_read(map); 4748 4749 RetryLookupLocked: 4750 /* 4751 * Lookup the faulting address. 4752 */ 4753 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 4754 vm_map_unlock_read(map); 4755 return (KERN_INVALID_ADDRESS); 4756 } 4757 4758 entry = *out_entry; 4759 4760 /* 4761 * Handle submaps. 4762 */ 4763 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4764 vm_map_t old_map = map; 4765 4766 *var_map = map = entry->object.sub_map; 4767 vm_map_unlock_read(old_map); 4768 goto RetryLookup; 4769 } 4770 4771 /* 4772 * Check whether this task is allowed to have this page. 4773 */ 4774 prot = entry->protection; 4775 if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) { 4776 fault_typea &= ~VM_PROT_FAULT_LOOKUP; 4777 if (prot == VM_PROT_NONE && map != kernel_map && 4778 (entry->eflags & MAP_ENTRY_GUARD) != 0 && 4779 (entry->eflags & (MAP_ENTRY_STACK_GAP_DN | 4780 MAP_ENTRY_STACK_GAP_UP)) != 0 && 4781 vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS) 4782 goto RetryLookupLocked; 4783 } 4784 fault_type = fault_typea & VM_PROT_ALL; 4785 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 4786 vm_map_unlock_read(map); 4787 return (KERN_PROTECTION_FAILURE); 4788 } 4789 KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags & 4790 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) != 4791 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY), 4792 ("entry %p flags %x", entry, entry->eflags)); 4793 if ((fault_typea & VM_PROT_COPY) != 0 && 4794 (entry->max_protection & VM_PROT_WRITE) == 0 && 4795 (entry->eflags & MAP_ENTRY_COW) == 0) { 4796 vm_map_unlock_read(map); 4797 return (KERN_PROTECTION_FAILURE); 4798 } 4799 4800 /* 4801 * If this page is not pageable, we have to get it for all possible 4802 * accesses. 4803 */ 4804 *wired = (entry->wired_count != 0); 4805 if (*wired) 4806 fault_type = entry->protection; 4807 size = entry->end - entry->start; 4808 4809 /* 4810 * If the entry was copy-on-write, we either ... 4811 */ 4812 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4813 /* 4814 * If we want to write the page, we may as well handle that 4815 * now since we've got the map locked. 4816 * 4817 * If we don't need to write the page, we just demote the 4818 * permissions allowed. 4819 */ 4820 if ((fault_type & VM_PROT_WRITE) != 0 || 4821 (fault_typea & VM_PROT_COPY) != 0) { 4822 /* 4823 * Make a new object, and place it in the object 4824 * chain. Note that no new references have appeared 4825 * -- one just moved from the map to the new 4826 * object. 4827 */ 4828 if (vm_map_lock_upgrade(map)) 4829 goto RetryLookup; 4830 4831 if (entry->cred == NULL) { 4832 /* 4833 * The debugger owner is charged for 4834 * the memory. 4835 */ 4836 cred = curthread->td_ucred; 4837 crhold(cred); 4838 if (!swap_reserve_by_cred(size, cred)) { 4839 crfree(cred); 4840 vm_map_unlock(map); 4841 return (KERN_RESOURCE_SHORTAGE); 4842 } 4843 entry->cred = cred; 4844 } 4845 eobject = entry->object.vm_object; 4846 vm_object_shadow(&entry->object.vm_object, 4847 &entry->offset, size, entry->cred, false); 4848 if (eobject == entry->object.vm_object) { 4849 /* 4850 * The object was not shadowed. 4851 */ 4852 swap_release_by_cred(size, entry->cred); 4853 crfree(entry->cred); 4854 } 4855 entry->cred = NULL; 4856 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4857 4858 vm_map_lock_downgrade(map); 4859 } else { 4860 /* 4861 * We're attempting to read a copy-on-write page -- 4862 * don't allow writes. 4863 */ 4864 prot &= ~VM_PROT_WRITE; 4865 } 4866 } 4867 4868 /* 4869 * Create an object if necessary. 4870 */ 4871 if (entry->object.vm_object == NULL && !map->system_map) { 4872 if (vm_map_lock_upgrade(map)) 4873 goto RetryLookup; 4874 entry->object.vm_object = vm_object_allocate_anon(atop(size), 4875 NULL, entry->cred, entry->cred != NULL ? size : 0); 4876 entry->offset = 0; 4877 entry->cred = NULL; 4878 vm_map_lock_downgrade(map); 4879 } 4880 4881 /* 4882 * Return the object/offset from this entry. If the entry was 4883 * copy-on-write or empty, it has been fixed up. 4884 */ 4885 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4886 *object = entry->object.vm_object; 4887 4888 *out_prot = prot; 4889 return (KERN_SUCCESS); 4890 } 4891 4892 /* 4893 * vm_map_lookup_locked: 4894 * 4895 * Lookup the faulting address. A version of vm_map_lookup that returns 4896 * KERN_FAILURE instead of blocking on map lock or memory allocation. 4897 */ 4898 int 4899 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4900 vm_offset_t vaddr, 4901 vm_prot_t fault_typea, 4902 vm_map_entry_t *out_entry, /* OUT */ 4903 vm_object_t *object, /* OUT */ 4904 vm_pindex_t *pindex, /* OUT */ 4905 vm_prot_t *out_prot, /* OUT */ 4906 boolean_t *wired) /* OUT */ 4907 { 4908 vm_map_entry_t entry; 4909 vm_map_t map = *var_map; 4910 vm_prot_t prot; 4911 vm_prot_t fault_type = fault_typea; 4912 4913 /* 4914 * Lookup the faulting address. 4915 */ 4916 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4917 return (KERN_INVALID_ADDRESS); 4918 4919 entry = *out_entry; 4920 4921 /* 4922 * Fail if the entry refers to a submap. 4923 */ 4924 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4925 return (KERN_FAILURE); 4926 4927 /* 4928 * Check whether this task is allowed to have this page. 4929 */ 4930 prot = entry->protection; 4931 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4932 if ((fault_type & prot) != fault_type) 4933 return (KERN_PROTECTION_FAILURE); 4934 4935 /* 4936 * If this page is not pageable, we have to get it for all possible 4937 * accesses. 4938 */ 4939 *wired = (entry->wired_count != 0); 4940 if (*wired) 4941 fault_type = entry->protection; 4942 4943 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4944 /* 4945 * Fail if the entry was copy-on-write for a write fault. 4946 */ 4947 if (fault_type & VM_PROT_WRITE) 4948 return (KERN_FAILURE); 4949 /* 4950 * We're attempting to read a copy-on-write page -- 4951 * don't allow writes. 4952 */ 4953 prot &= ~VM_PROT_WRITE; 4954 } 4955 4956 /* 4957 * Fail if an object should be created. 4958 */ 4959 if (entry->object.vm_object == NULL && !map->system_map) 4960 return (KERN_FAILURE); 4961 4962 /* 4963 * Return the object/offset from this entry. If the entry was 4964 * copy-on-write or empty, it has been fixed up. 4965 */ 4966 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4967 *object = entry->object.vm_object; 4968 4969 *out_prot = prot; 4970 return (KERN_SUCCESS); 4971 } 4972 4973 /* 4974 * vm_map_lookup_done: 4975 * 4976 * Releases locks acquired by a vm_map_lookup 4977 * (according to the handle returned by that lookup). 4978 */ 4979 void 4980 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4981 { 4982 /* 4983 * Unlock the main-level map 4984 */ 4985 vm_map_unlock_read(map); 4986 } 4987 4988 vm_offset_t 4989 vm_map_max_KBI(const struct vm_map *map) 4990 { 4991 4992 return (vm_map_max(map)); 4993 } 4994 4995 vm_offset_t 4996 vm_map_min_KBI(const struct vm_map *map) 4997 { 4998 4999 return (vm_map_min(map)); 5000 } 5001 5002 pmap_t 5003 vm_map_pmap_KBI(vm_map_t map) 5004 { 5005 5006 return (map->pmap); 5007 } 5008 5009 #ifdef INVARIANTS 5010 static void 5011 _vm_map_assert_consistent(vm_map_t map, int check) 5012 { 5013 vm_map_entry_t entry, prev; 5014 vm_map_entry_t cur, header, lbound, ubound; 5015 vm_size_t max_left, max_right; 5016 5017 #ifdef DIAGNOSTIC 5018 ++map->nupdates; 5019 #endif 5020 if (enable_vmmap_check != check) 5021 return; 5022 5023 header = prev = &map->header; 5024 VM_MAP_ENTRY_FOREACH(entry, map) { 5025 KASSERT(prev->end <= entry->start, 5026 ("map %p prev->end = %jx, start = %jx", map, 5027 (uintmax_t)prev->end, (uintmax_t)entry->start)); 5028 KASSERT(entry->start < entry->end, 5029 ("map %p start = %jx, end = %jx", map, 5030 (uintmax_t)entry->start, (uintmax_t)entry->end)); 5031 KASSERT(entry->left == header || 5032 entry->left->start < entry->start, 5033 ("map %p left->start = %jx, start = %jx", map, 5034 (uintmax_t)entry->left->start, (uintmax_t)entry->start)); 5035 KASSERT(entry->right == header || 5036 entry->start < entry->right->start, 5037 ("map %p start = %jx, right->start = %jx", map, 5038 (uintmax_t)entry->start, (uintmax_t)entry->right->start)); 5039 cur = map->root; 5040 lbound = ubound = header; 5041 for (;;) { 5042 if (entry->start < cur->start) { 5043 ubound = cur; 5044 cur = cur->left; 5045 KASSERT(cur != lbound, 5046 ("map %p cannot find %jx", 5047 map, (uintmax_t)entry->start)); 5048 } else if (cur->end <= entry->start) { 5049 lbound = cur; 5050 cur = cur->right; 5051 KASSERT(cur != ubound, 5052 ("map %p cannot find %jx", 5053 map, (uintmax_t)entry->start)); 5054 } else { 5055 KASSERT(cur == entry, 5056 ("map %p cannot find %jx", 5057 map, (uintmax_t)entry->start)); 5058 break; 5059 } 5060 } 5061 max_left = vm_map_entry_max_free_left(entry, lbound); 5062 max_right = vm_map_entry_max_free_right(entry, ubound); 5063 KASSERT(entry->max_free == vm_size_max(max_left, max_right), 5064 ("map %p max = %jx, max_left = %jx, max_right = %jx", map, 5065 (uintmax_t)entry->max_free, 5066 (uintmax_t)max_left, (uintmax_t)max_right)); 5067 prev = entry; 5068 } 5069 KASSERT(prev->end <= entry->start, 5070 ("map %p prev->end = %jx, start = %jx", map, 5071 (uintmax_t)prev->end, (uintmax_t)entry->start)); 5072 } 5073 #endif 5074 5075 #include "opt_ddb.h" 5076 #ifdef DDB 5077 #include <sys/kernel.h> 5078 5079 #include <ddb/ddb.h> 5080 5081 static void 5082 vm_map_print(vm_map_t map) 5083 { 5084 vm_map_entry_t entry, prev; 5085 5086 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 5087 (void *)map, 5088 (void *)map->pmap, map->nentries, map->timestamp); 5089 5090 db_indent += 2; 5091 prev = &map->header; 5092 VM_MAP_ENTRY_FOREACH(entry, map) { 5093 db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n", 5094 (void *)entry, (void *)entry->start, (void *)entry->end, 5095 entry->eflags); 5096 { 5097 static const char * const inheritance_name[4] = 5098 {"share", "copy", "none", "donate_copy"}; 5099 5100 db_iprintf(" prot=%x/%x/%s", 5101 entry->protection, 5102 entry->max_protection, 5103 inheritance_name[(int)(unsigned char) 5104 entry->inheritance]); 5105 if (entry->wired_count != 0) 5106 db_printf(", wired"); 5107 } 5108 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 5109 db_printf(", share=%p, offset=0x%jx\n", 5110 (void *)entry->object.sub_map, 5111 (uintmax_t)entry->offset); 5112 if (prev == &map->header || 5113 prev->object.sub_map != 5114 entry->object.sub_map) { 5115 db_indent += 2; 5116 vm_map_print((vm_map_t)entry->object.sub_map); 5117 db_indent -= 2; 5118 } 5119 } else { 5120 if (entry->cred != NULL) 5121 db_printf(", ruid %d", entry->cred->cr_ruid); 5122 db_printf(", object=%p, offset=0x%jx", 5123 (void *)entry->object.vm_object, 5124 (uintmax_t)entry->offset); 5125 if (entry->object.vm_object && entry->object.vm_object->cred) 5126 db_printf(", obj ruid %d charge %jx", 5127 entry->object.vm_object->cred->cr_ruid, 5128 (uintmax_t)entry->object.vm_object->charge); 5129 if (entry->eflags & MAP_ENTRY_COW) 5130 db_printf(", copy (%s)", 5131 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 5132 db_printf("\n"); 5133 5134 if (prev == &map->header || 5135 prev->object.vm_object != 5136 entry->object.vm_object) { 5137 db_indent += 2; 5138 vm_object_print((db_expr_t)(intptr_t) 5139 entry->object.vm_object, 5140 0, 0, (char *)0); 5141 db_indent -= 2; 5142 } 5143 } 5144 prev = entry; 5145 } 5146 db_indent -= 2; 5147 } 5148 5149 DB_SHOW_COMMAND(map, map) 5150 { 5151 5152 if (!have_addr) { 5153 db_printf("usage: show map <addr>\n"); 5154 return; 5155 } 5156 vm_map_print((vm_map_t)addr); 5157 } 5158 5159 DB_SHOW_COMMAND(procvm, procvm) 5160 { 5161 struct proc *p; 5162 5163 if (have_addr) { 5164 p = db_lookup_proc(addr); 5165 } else { 5166 p = curproc; 5167 } 5168 5169 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 5170 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 5171 (void *)vmspace_pmap(p->p_vmspace)); 5172 5173 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 5174 } 5175 5176 #endif /* DDB */ 5177