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 == end || !vm_map_range_valid(map, start, end)) 1620 return (KERN_INVALID_ADDRESS); 1621 1622 /* 1623 * Find the entry prior to the proposed starting address; if it's part 1624 * of an existing entry, this range is bogus. 1625 */ 1626 if (vm_map_lookup_entry(map, start, &prev_entry)) 1627 return (KERN_NO_SPACE); 1628 1629 /* 1630 * Assert that the next entry doesn't overlap the end point. 1631 */ 1632 next_entry = vm_map_entry_succ(prev_entry); 1633 if (next_entry->start < end) 1634 return (KERN_NO_SPACE); 1635 1636 if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL || 1637 max != VM_PROT_NONE)) 1638 return (KERN_INVALID_ARGUMENT); 1639 1640 protoeflags = 0; 1641 if (cow & MAP_COPY_ON_WRITE) 1642 protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY; 1643 if (cow & MAP_NOFAULT) 1644 protoeflags |= MAP_ENTRY_NOFAULT; 1645 if (cow & MAP_DISABLE_SYNCER) 1646 protoeflags |= MAP_ENTRY_NOSYNC; 1647 if (cow & MAP_DISABLE_COREDUMP) 1648 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1649 if (cow & MAP_STACK_GROWS_DOWN) 1650 protoeflags |= MAP_ENTRY_GROWS_DOWN; 1651 if (cow & MAP_STACK_GROWS_UP) 1652 protoeflags |= MAP_ENTRY_GROWS_UP; 1653 if (cow & MAP_WRITECOUNT) 1654 protoeflags |= MAP_ENTRY_WRITECNT; 1655 if (cow & MAP_VN_EXEC) 1656 protoeflags |= MAP_ENTRY_VN_EXEC; 1657 if ((cow & MAP_CREATE_GUARD) != 0) 1658 protoeflags |= MAP_ENTRY_GUARD; 1659 if ((cow & MAP_CREATE_STACK_GAP_DN) != 0) 1660 protoeflags |= MAP_ENTRY_STACK_GAP_DN; 1661 if ((cow & MAP_CREATE_STACK_GAP_UP) != 0) 1662 protoeflags |= MAP_ENTRY_STACK_GAP_UP; 1663 if (cow & MAP_INHERIT_SHARE) 1664 inheritance = VM_INHERIT_SHARE; 1665 else 1666 inheritance = VM_INHERIT_DEFAULT; 1667 1668 cred = NULL; 1669 if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0) 1670 goto charged; 1671 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1672 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1673 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1674 return (KERN_RESOURCE_SHORTAGE); 1675 KASSERT(object == NULL || 1676 (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 || 1677 object->cred == NULL, 1678 ("overcommit: vm_map_insert o %p", object)); 1679 cred = curthread->td_ucred; 1680 } 1681 1682 charged: 1683 /* Expand the kernel pmap, if necessary. */ 1684 if (map == kernel_map && end > kernel_vm_end) 1685 pmap_growkernel(end); 1686 if (object != NULL) { 1687 /* 1688 * OBJ_ONEMAPPING must be cleared unless this mapping 1689 * is trivially proven to be the only mapping for any 1690 * of the object's pages. (Object granularity 1691 * reference counting is insufficient to recognize 1692 * aliases with precision.) 1693 */ 1694 if ((object->flags & OBJ_ANON) != 0) { 1695 VM_OBJECT_WLOCK(object); 1696 if (object->ref_count > 1 || object->shadow_count != 0) 1697 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1698 VM_OBJECT_WUNLOCK(object); 1699 } 1700 } else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) == 1701 protoeflags && 1702 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP | 1703 MAP_VN_EXEC)) == 0 && 1704 prev_entry->end == start && (prev_entry->cred == cred || 1705 (prev_entry->object.vm_object != NULL && 1706 prev_entry->object.vm_object->cred == cred)) && 1707 vm_object_coalesce(prev_entry->object.vm_object, 1708 prev_entry->offset, 1709 (vm_size_t)(prev_entry->end - prev_entry->start), 1710 (vm_size_t)(end - prev_entry->end), cred != NULL && 1711 (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) { 1712 /* 1713 * We were able to extend the object. Determine if we 1714 * can extend the previous map entry to include the 1715 * new range as well. 1716 */ 1717 if (prev_entry->inheritance == inheritance && 1718 prev_entry->protection == prot && 1719 prev_entry->max_protection == max && 1720 prev_entry->wired_count == 0) { 1721 KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) == 1722 0, ("prev_entry %p has incoherent wiring", 1723 prev_entry)); 1724 if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0) 1725 map->size += end - prev_entry->end; 1726 vm_map_entry_resize(map, prev_entry, 1727 end - prev_entry->end); 1728 vm_map_try_merge_entries(map, prev_entry, next_entry); 1729 return (KERN_SUCCESS); 1730 } 1731 1732 /* 1733 * If we can extend the object but cannot extend the 1734 * map entry, we have to create a new map entry. We 1735 * must bump the ref count on the extended object to 1736 * account for it. object may be NULL. 1737 */ 1738 object = prev_entry->object.vm_object; 1739 offset = prev_entry->offset + 1740 (prev_entry->end - prev_entry->start); 1741 vm_object_reference(object); 1742 if (cred != NULL && object != NULL && object->cred != NULL && 1743 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1744 /* Object already accounts for this uid. */ 1745 cred = NULL; 1746 } 1747 } 1748 if (cred != NULL) 1749 crhold(cred); 1750 1751 /* 1752 * Create a new entry 1753 */ 1754 new_entry = vm_map_entry_create(map); 1755 new_entry->start = start; 1756 new_entry->end = end; 1757 new_entry->cred = NULL; 1758 1759 new_entry->eflags = protoeflags; 1760 new_entry->object.vm_object = object; 1761 new_entry->offset = offset; 1762 1763 new_entry->inheritance = inheritance; 1764 new_entry->protection = prot; 1765 new_entry->max_protection = max; 1766 new_entry->wired_count = 0; 1767 new_entry->wiring_thread = NULL; 1768 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1769 new_entry->next_read = start; 1770 1771 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1772 ("overcommit: vm_map_insert leaks vm_map %p", new_entry)); 1773 new_entry->cred = cred; 1774 1775 /* 1776 * Insert the new entry into the list 1777 */ 1778 vm_map_entry_link(map, new_entry); 1779 if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0) 1780 map->size += new_entry->end - new_entry->start; 1781 1782 /* 1783 * Try to coalesce the new entry with both the previous and next 1784 * entries in the list. Previously, we only attempted to coalesce 1785 * with the previous entry when object is NULL. Here, we handle the 1786 * other cases, which are less common. 1787 */ 1788 vm_map_try_merge_entries(map, prev_entry, new_entry); 1789 vm_map_try_merge_entries(map, new_entry, next_entry); 1790 1791 if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) { 1792 vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset), 1793 end - start, cow & MAP_PREFAULT_PARTIAL); 1794 } 1795 1796 return (KERN_SUCCESS); 1797 } 1798 1799 /* 1800 * vm_map_findspace: 1801 * 1802 * Find the first fit (lowest VM address) for "length" free bytes 1803 * beginning at address >= start in the given map. 1804 * 1805 * In a vm_map_entry, "max_free" is the maximum amount of 1806 * contiguous free space between an entry in its subtree and a 1807 * neighbor of that entry. This allows finding a free region in 1808 * one path down the tree, so O(log n) amortized with splay 1809 * trees. 1810 * 1811 * The map must be locked, and leaves it so. 1812 * 1813 * Returns: starting address if sufficient space, 1814 * vm_map_max(map)-length+1 if insufficient space. 1815 */ 1816 vm_offset_t 1817 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length) 1818 { 1819 vm_map_entry_t header, llist, rlist, root, y; 1820 vm_size_t left_length, max_free_left, max_free_right; 1821 vm_offset_t gap_end; 1822 1823 /* 1824 * Request must fit within min/max VM address and must avoid 1825 * address wrap. 1826 */ 1827 start = MAX(start, vm_map_min(map)); 1828 if (start >= vm_map_max(map) || length > vm_map_max(map) - start) 1829 return (vm_map_max(map) - length + 1); 1830 1831 /* Empty tree means wide open address space. */ 1832 if (map->root == NULL) 1833 return (start); 1834 1835 /* 1836 * After splay_split, if start is within an entry, push it to the start 1837 * of the following gap. If rlist is at the end of the gap containing 1838 * start, save the end of that gap in gap_end to see if the gap is big 1839 * enough; otherwise set gap_end to start skip gap-checking and move 1840 * directly to a search of the right subtree. 1841 */ 1842 header = &map->header; 1843 root = vm_map_splay_split(map, start, length, &llist, &rlist); 1844 gap_end = rlist->start; 1845 if (root != NULL) { 1846 start = root->end; 1847 if (root->right != rlist) 1848 gap_end = start; 1849 max_free_left = vm_map_splay_merge_left(header, root, llist); 1850 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1851 } else if (rlist != header) { 1852 root = rlist; 1853 rlist = root->left; 1854 max_free_left = vm_map_splay_merge_pred(header, root, llist); 1855 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1856 } else { 1857 root = llist; 1858 llist = root->right; 1859 max_free_left = vm_map_splay_merge_left(header, root, llist); 1860 max_free_right = vm_map_splay_merge_succ(header, root, rlist); 1861 } 1862 root->max_free = vm_size_max(max_free_left, max_free_right); 1863 map->root = root; 1864 VM_MAP_ASSERT_CONSISTENT(map); 1865 if (length <= gap_end - start) 1866 return (start); 1867 1868 /* With max_free, can immediately tell if no solution. */ 1869 if (root->right == header || length > root->right->max_free) 1870 return (vm_map_max(map) - length + 1); 1871 1872 /* 1873 * Splay for the least large-enough gap in the right subtree. 1874 */ 1875 llist = rlist = header; 1876 for (left_length = 0;; 1877 left_length = vm_map_entry_max_free_left(root, llist)) { 1878 if (length <= left_length) 1879 SPLAY_LEFT_STEP(root, y, llist, rlist, 1880 length <= vm_map_entry_max_free_left(y, llist)); 1881 else 1882 SPLAY_RIGHT_STEP(root, y, llist, rlist, 1883 length > vm_map_entry_max_free_left(y, root)); 1884 if (root == NULL) 1885 break; 1886 } 1887 root = llist; 1888 llist = root->right; 1889 max_free_left = vm_map_splay_merge_left(header, root, llist); 1890 if (rlist == header) { 1891 root->max_free = vm_size_max(max_free_left, 1892 vm_map_splay_merge_succ(header, root, rlist)); 1893 } else { 1894 y = rlist; 1895 rlist = y->left; 1896 y->max_free = vm_size_max( 1897 vm_map_splay_merge_pred(root, y, root), 1898 vm_map_splay_merge_right(header, y, rlist)); 1899 root->max_free = vm_size_max(max_free_left, y->max_free); 1900 } 1901 map->root = root; 1902 VM_MAP_ASSERT_CONSISTENT(map); 1903 return (root->end); 1904 } 1905 1906 int 1907 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1908 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1909 vm_prot_t max, int cow) 1910 { 1911 vm_offset_t end; 1912 int result; 1913 1914 end = start + length; 1915 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1916 object == NULL, 1917 ("vm_map_fixed: non-NULL backing object for stack")); 1918 vm_map_lock(map); 1919 VM_MAP_RANGE_CHECK(map, start, end); 1920 if ((cow & MAP_CHECK_EXCL) == 0) 1921 vm_map_delete(map, start, end); 1922 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1923 result = vm_map_stack_locked(map, start, length, sgrowsiz, 1924 prot, max, cow); 1925 } else { 1926 result = vm_map_insert(map, object, offset, start, end, 1927 prot, max, cow); 1928 } 1929 vm_map_unlock(map); 1930 return (result); 1931 } 1932 1933 static const int aslr_pages_rnd_64[2] = {0x1000, 0x10}; 1934 static const int aslr_pages_rnd_32[2] = {0x100, 0x4}; 1935 1936 static int cluster_anon = 1; 1937 SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW, 1938 &cluster_anon, 0, 1939 "Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always"); 1940 1941 static bool 1942 clustering_anon_allowed(vm_offset_t addr) 1943 { 1944 1945 switch (cluster_anon) { 1946 case 0: 1947 return (false); 1948 case 1: 1949 return (addr == 0); 1950 case 2: 1951 default: 1952 return (true); 1953 } 1954 } 1955 1956 static long aslr_restarts; 1957 SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD, 1958 &aslr_restarts, 0, 1959 "Number of aslr failures"); 1960 1961 #define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31) 1962 1963 /* 1964 * Searches for the specified amount of free space in the given map with the 1965 * specified alignment. Performs an address-ordered, first-fit search from 1966 * the given address "*addr", with an optional upper bound "max_addr". If the 1967 * parameter "alignment" is zero, then the alignment is computed from the 1968 * given (object, offset) pair so as to enable the greatest possible use of 1969 * superpage mappings. Returns KERN_SUCCESS and the address of the free space 1970 * in "*addr" if successful. Otherwise, returns KERN_NO_SPACE. 1971 * 1972 * The map must be locked. Initially, there must be at least "length" bytes 1973 * of free space at the given address. 1974 */ 1975 static int 1976 vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1977 vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr, 1978 vm_offset_t alignment) 1979 { 1980 vm_offset_t aligned_addr, free_addr; 1981 1982 VM_MAP_ASSERT_LOCKED(map); 1983 free_addr = *addr; 1984 KASSERT(free_addr == vm_map_findspace(map, free_addr, length), 1985 ("caller failed to provide space %#jx at address %p", 1986 (uintmax_t)length, (void *)free_addr)); 1987 for (;;) { 1988 /* 1989 * At the start of every iteration, the free space at address 1990 * "*addr" is at least "length" bytes. 1991 */ 1992 if (alignment == 0) 1993 pmap_align_superpage(object, offset, addr, length); 1994 else if ((*addr & (alignment - 1)) != 0) { 1995 *addr &= ~(alignment - 1); 1996 *addr += alignment; 1997 } 1998 aligned_addr = *addr; 1999 if (aligned_addr == free_addr) { 2000 /* 2001 * Alignment did not change "*addr", so "*addr" must 2002 * still provide sufficient free space. 2003 */ 2004 return (KERN_SUCCESS); 2005 } 2006 2007 /* 2008 * Test for address wrap on "*addr". A wrapped "*addr" could 2009 * be a valid address, in which case vm_map_findspace() cannot 2010 * be relied upon to fail. 2011 */ 2012 if (aligned_addr < free_addr) 2013 return (KERN_NO_SPACE); 2014 *addr = vm_map_findspace(map, aligned_addr, length); 2015 if (*addr + length > vm_map_max(map) || 2016 (max_addr != 0 && *addr + length > max_addr)) 2017 return (KERN_NO_SPACE); 2018 free_addr = *addr; 2019 if (free_addr == aligned_addr) { 2020 /* 2021 * If a successful call to vm_map_findspace() did not 2022 * change "*addr", then "*addr" must still be aligned 2023 * and provide sufficient free space. 2024 */ 2025 return (KERN_SUCCESS); 2026 } 2027 } 2028 } 2029 2030 /* 2031 * vm_map_find finds an unallocated region in the target address 2032 * map with the given length. The search is defined to be 2033 * first-fit from the specified address; the region found is 2034 * returned in the same parameter. 2035 * 2036 * If object is non-NULL, ref count must be bumped by caller 2037 * prior to making call to account for the new entry. 2038 */ 2039 int 2040 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 2041 vm_offset_t *addr, /* IN/OUT */ 2042 vm_size_t length, vm_offset_t max_addr, int find_space, 2043 vm_prot_t prot, vm_prot_t max, int cow) 2044 { 2045 vm_offset_t alignment, curr_min_addr, min_addr; 2046 int gap, pidx, rv, try; 2047 bool cluster, en_aslr, update_anon; 2048 2049 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 2050 object == NULL, 2051 ("vm_map_find: non-NULL backing object for stack")); 2052 MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE && 2053 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0)); 2054 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 2055 (object->flags & OBJ_COLORED) == 0)) 2056 find_space = VMFS_ANY_SPACE; 2057 if (find_space >> 8 != 0) { 2058 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 2059 alignment = (vm_offset_t)1 << (find_space >> 8); 2060 } else 2061 alignment = 0; 2062 en_aslr = (map->flags & MAP_ASLR) != 0; 2063 update_anon = cluster = clustering_anon_allowed(*addr) && 2064 (map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 && 2065 find_space != VMFS_NO_SPACE && object == NULL && 2066 (cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP | 2067 MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE; 2068 curr_min_addr = min_addr = *addr; 2069 if (en_aslr && min_addr == 0 && !cluster && 2070 find_space != VMFS_NO_SPACE && 2071 (map->flags & MAP_ASLR_IGNSTART) != 0) 2072 curr_min_addr = min_addr = vm_map_min(map); 2073 try = 0; 2074 vm_map_lock(map); 2075 if (cluster) { 2076 curr_min_addr = map->anon_loc; 2077 if (curr_min_addr == 0) 2078 cluster = false; 2079 } 2080 if (find_space != VMFS_NO_SPACE) { 2081 KASSERT(find_space == VMFS_ANY_SPACE || 2082 find_space == VMFS_OPTIMAL_SPACE || 2083 find_space == VMFS_SUPER_SPACE || 2084 alignment != 0, ("unexpected VMFS flag")); 2085 again: 2086 /* 2087 * When creating an anonymous mapping, try clustering 2088 * with an existing anonymous mapping first. 2089 * 2090 * We make up to two attempts to find address space 2091 * for a given find_space value. The first attempt may 2092 * apply randomization or may cluster with an existing 2093 * anonymous mapping. If this first attempt fails, 2094 * perform a first-fit search of the available address 2095 * space. 2096 * 2097 * If all tries failed, and find_space is 2098 * VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE. 2099 * Again enable clustering and randomization. 2100 */ 2101 try++; 2102 MPASS(try <= 2); 2103 2104 if (try == 2) { 2105 /* 2106 * Second try: we failed either to find a 2107 * suitable region for randomizing the 2108 * allocation, or to cluster with an existing 2109 * mapping. Retry with free run. 2110 */ 2111 curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ? 2112 vm_map_min(map) : min_addr; 2113 atomic_add_long(&aslr_restarts, 1); 2114 } 2115 2116 if (try == 1 && en_aslr && !cluster) { 2117 /* 2118 * Find space for allocation, including 2119 * gap needed for later randomization. 2120 */ 2121 pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 && 2122 (find_space == VMFS_SUPER_SPACE || find_space == 2123 VMFS_OPTIMAL_SPACE) ? 1 : 0; 2124 gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR && 2125 (max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ? 2126 aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx]; 2127 *addr = vm_map_findspace(map, curr_min_addr, 2128 length + gap * pagesizes[pidx]); 2129 if (*addr + length + gap * pagesizes[pidx] > 2130 vm_map_max(map)) 2131 goto again; 2132 /* And randomize the start address. */ 2133 *addr += (arc4random() % gap) * pagesizes[pidx]; 2134 if (max_addr != 0 && *addr + length > max_addr) 2135 goto again; 2136 } else { 2137 *addr = vm_map_findspace(map, curr_min_addr, length); 2138 if (*addr + length > vm_map_max(map) || 2139 (max_addr != 0 && *addr + length > max_addr)) { 2140 if (cluster) { 2141 cluster = false; 2142 MPASS(try == 1); 2143 goto again; 2144 } 2145 rv = KERN_NO_SPACE; 2146 goto done; 2147 } 2148 } 2149 2150 if (find_space != VMFS_ANY_SPACE && 2151 (rv = vm_map_alignspace(map, object, offset, addr, length, 2152 max_addr, alignment)) != KERN_SUCCESS) { 2153 if (find_space == VMFS_OPTIMAL_SPACE) { 2154 find_space = VMFS_ANY_SPACE; 2155 curr_min_addr = min_addr; 2156 cluster = update_anon; 2157 try = 0; 2158 goto again; 2159 } 2160 goto done; 2161 } 2162 } else if ((cow & MAP_REMAP) != 0) { 2163 if (!vm_map_range_valid(map, *addr, *addr + length)) { 2164 rv = KERN_INVALID_ADDRESS; 2165 goto done; 2166 } 2167 vm_map_delete(map, *addr, *addr + length); 2168 } 2169 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 2170 rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot, 2171 max, cow); 2172 } else { 2173 rv = vm_map_insert(map, object, offset, *addr, *addr + length, 2174 prot, max, cow); 2175 } 2176 if (rv == KERN_SUCCESS && update_anon) 2177 map->anon_loc = *addr + length; 2178 done: 2179 vm_map_unlock(map); 2180 return (rv); 2181 } 2182 2183 /* 2184 * vm_map_find_min() is a variant of vm_map_find() that takes an 2185 * additional parameter (min_addr) and treats the given address 2186 * (*addr) differently. Specifically, it treats *addr as a hint 2187 * and not as the minimum address where the mapping is created. 2188 * 2189 * This function works in two phases. First, it tries to 2190 * allocate above the hint. If that fails and the hint is 2191 * greater than min_addr, it performs a second pass, replacing 2192 * the hint with min_addr as the minimum address for the 2193 * allocation. 2194 */ 2195 int 2196 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 2197 vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr, 2198 vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max, 2199 int cow) 2200 { 2201 vm_offset_t hint; 2202 int rv; 2203 2204 hint = *addr; 2205 for (;;) { 2206 rv = vm_map_find(map, object, offset, addr, length, max_addr, 2207 find_space, prot, max, cow); 2208 if (rv == KERN_SUCCESS || min_addr >= hint) 2209 return (rv); 2210 *addr = hint = min_addr; 2211 } 2212 } 2213 2214 /* 2215 * A map entry with any of the following flags set must not be merged with 2216 * another entry. 2217 */ 2218 #define MAP_ENTRY_NOMERGE_MASK (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \ 2219 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_VN_EXEC) 2220 2221 static bool 2222 vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry) 2223 { 2224 2225 KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 || 2226 (entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0, 2227 ("vm_map_mergeable_neighbors: neither %p nor %p are mergeable", 2228 prev, entry)); 2229 return (prev->end == entry->start && 2230 prev->object.vm_object == entry->object.vm_object && 2231 (prev->object.vm_object == NULL || 2232 prev->offset + (prev->end - prev->start) == entry->offset) && 2233 prev->eflags == entry->eflags && 2234 prev->protection == entry->protection && 2235 prev->max_protection == entry->max_protection && 2236 prev->inheritance == entry->inheritance && 2237 prev->wired_count == entry->wired_count && 2238 prev->cred == entry->cred); 2239 } 2240 2241 static void 2242 vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry) 2243 { 2244 2245 /* 2246 * If the backing object is a vnode object, vm_object_deallocate() 2247 * calls vrele(). However, vrele() does not lock the vnode because 2248 * the vnode has additional references. Thus, the map lock can be 2249 * kept without causing a lock-order reversal with the vnode lock. 2250 * 2251 * Since we count the number of virtual page mappings in 2252 * object->un_pager.vnp.writemappings, the writemappings value 2253 * should not be adjusted when the entry is disposed of. 2254 */ 2255 if (entry->object.vm_object != NULL) 2256 vm_object_deallocate(entry->object.vm_object); 2257 if (entry->cred != NULL) 2258 crfree(entry->cred); 2259 vm_map_entry_dispose(map, entry); 2260 } 2261 2262 /* 2263 * vm_map_try_merge_entries: 2264 * 2265 * Compare the given map entry to its predecessor, and merge its precessor 2266 * into it if possible. The entry remains valid, and may be extended. 2267 * The predecessor may be deleted. 2268 * 2269 * The map must be locked. 2270 */ 2271 void 2272 vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev_entry, 2273 vm_map_entry_t entry) 2274 { 2275 2276 VM_MAP_ASSERT_LOCKED(map); 2277 if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 && 2278 vm_map_mergeable_neighbors(prev_entry, entry)) { 2279 vm_map_entry_unlink(map, prev_entry, UNLINK_MERGE_NEXT); 2280 vm_map_merged_neighbor_dispose(map, prev_entry); 2281 } 2282 } 2283 2284 /* 2285 * vm_map_entry_back: 2286 * 2287 * Allocate an object to back a map entry. 2288 */ 2289 static inline void 2290 vm_map_entry_back(vm_map_entry_t entry) 2291 { 2292 vm_object_t object; 2293 2294 KASSERT(entry->object.vm_object == NULL, 2295 ("map entry %p has backing object", entry)); 2296 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 2297 ("map entry %p is a submap", entry)); 2298 object = vm_object_allocate_anon(atop(entry->end - entry->start), NULL, 2299 entry->cred, entry->end - entry->start); 2300 entry->object.vm_object = object; 2301 entry->offset = 0; 2302 entry->cred = NULL; 2303 } 2304 2305 /* 2306 * vm_map_entry_charge_object 2307 * 2308 * If there is no object backing this entry, create one. Otherwise, if 2309 * the entry has cred, give it to the backing object. 2310 */ 2311 static inline void 2312 vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry) 2313 { 2314 2315 VM_MAP_ASSERT_LOCKED(map); 2316 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 2317 ("map entry %p is a submap", entry)); 2318 if (entry->object.vm_object == NULL && !map->system_map && 2319 (entry->eflags & MAP_ENTRY_GUARD) == 0) 2320 vm_map_entry_back(entry); 2321 else if (entry->object.vm_object != NULL && 2322 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 2323 entry->cred != NULL) { 2324 VM_OBJECT_WLOCK(entry->object.vm_object); 2325 KASSERT(entry->object.vm_object->cred == NULL, 2326 ("OVERCOMMIT: %s: both cred e %p", __func__, entry)); 2327 entry->object.vm_object->cred = entry->cred; 2328 entry->object.vm_object->charge = entry->end - entry->start; 2329 VM_OBJECT_WUNLOCK(entry->object.vm_object); 2330 entry->cred = NULL; 2331 } 2332 } 2333 2334 /* 2335 * vm_map_entry_clone 2336 * 2337 * Create a duplicate map entry for clipping. 2338 */ 2339 static vm_map_entry_t 2340 vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry) 2341 { 2342 vm_map_entry_t new_entry; 2343 2344 VM_MAP_ASSERT_LOCKED(map); 2345 2346 /* 2347 * Create a backing object now, if none exists, so that more individual 2348 * objects won't be created after the map entry is split. 2349 */ 2350 vm_map_entry_charge_object(map, entry); 2351 2352 /* Clone the entry. */ 2353 new_entry = vm_map_entry_create(map); 2354 *new_entry = *entry; 2355 if (new_entry->cred != NULL) 2356 crhold(entry->cred); 2357 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 2358 vm_object_reference(new_entry->object.vm_object); 2359 vm_map_entry_set_vnode_text(new_entry, true); 2360 /* 2361 * The object->un_pager.vnp.writemappings for the object of 2362 * MAP_ENTRY_WRITECNT type entry shall be kept as is here. The 2363 * virtual pages are re-distributed among the clipped entries, 2364 * so the sum is left the same. 2365 */ 2366 } 2367 return (new_entry); 2368 } 2369 2370 /* 2371 * vm_map_clip_start: [ internal use only ] 2372 * 2373 * Asserts that the given entry begins at or after 2374 * the specified address; if necessary, 2375 * it splits the entry into two. 2376 */ 2377 static inline void 2378 vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 2379 { 2380 vm_map_entry_t new_entry; 2381 2382 if (!map->system_map) 2383 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 2384 "%s: map %p entry %p start 0x%jx", __func__, map, entry, 2385 (uintmax_t)start); 2386 2387 if (start <= entry->start) 2388 return; 2389 2390 VM_MAP_ASSERT_LOCKED(map); 2391 KASSERT(entry->end > start && entry->start < start, 2392 ("%s: invalid clip of entry %p", __func__, entry)); 2393 2394 new_entry = vm_map_entry_clone(map, entry); 2395 2396 /* 2397 * Split off the front portion. Insert the new entry BEFORE this one, 2398 * so that this entry has the specified starting address. 2399 */ 2400 new_entry->end = start; 2401 vm_map_entry_link(map, new_entry); 2402 } 2403 2404 /* 2405 * vm_map_lookup_clip_start: 2406 * 2407 * Find the entry at or just after 'start', and clip it if 'start' is in 2408 * the interior of the entry. Return entry after 'start', and in 2409 * prev_entry set the entry before 'start'. 2410 */ 2411 static inline vm_map_entry_t 2412 vm_map_lookup_clip_start(vm_map_t map, vm_offset_t start, 2413 vm_map_entry_t *prev_entry) 2414 { 2415 vm_map_entry_t entry; 2416 2417 if (!map->system_map) 2418 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 2419 "%s: map %p start 0x%jx prev %p", __func__, map, 2420 (uintmax_t)start, prev_entry); 2421 2422 if (vm_map_lookup_entry(map, start, prev_entry)) { 2423 entry = *prev_entry; 2424 vm_map_clip_start(map, entry, start); 2425 *prev_entry = vm_map_entry_pred(entry); 2426 } else 2427 entry = vm_map_entry_succ(*prev_entry); 2428 return (entry); 2429 } 2430 2431 /* 2432 * vm_map_clip_end: [ internal use only ] 2433 * 2434 * Asserts that the given entry ends at or before 2435 * the specified address; if necessary, 2436 * it splits the entry into two. 2437 */ 2438 static inline void 2439 vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 2440 { 2441 vm_map_entry_t new_entry; 2442 2443 if (!map->system_map) 2444 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 2445 "%s: map %p entry %p end 0x%jx", __func__, map, entry, 2446 (uintmax_t)end); 2447 2448 if (end >= entry->end) 2449 return; 2450 2451 VM_MAP_ASSERT_LOCKED(map); 2452 KASSERT(entry->start < end && entry->end > end, 2453 ("%s: invalid clip of entry %p", __func__, entry)); 2454 2455 new_entry = vm_map_entry_clone(map, entry); 2456 2457 /* 2458 * Split off the back portion. Insert the new entry AFTER this one, 2459 * so that this entry has the specified ending address. 2460 */ 2461 new_entry->start = end; 2462 vm_map_entry_link(map, new_entry); 2463 } 2464 2465 /* 2466 * vm_map_submap: [ kernel use only ] 2467 * 2468 * Mark the given range as handled by a subordinate map. 2469 * 2470 * This range must have been created with vm_map_find, 2471 * and no other operations may have been performed on this 2472 * range prior to calling vm_map_submap. 2473 * 2474 * Only a limited number of operations can be performed 2475 * within this rage after calling vm_map_submap: 2476 * vm_fault 2477 * [Don't try vm_map_copy!] 2478 * 2479 * To remove a submapping, one must first remove the 2480 * range from the superior map, and then destroy the 2481 * submap (if desired). [Better yet, don't try it.] 2482 */ 2483 int 2484 vm_map_submap( 2485 vm_map_t map, 2486 vm_offset_t start, 2487 vm_offset_t end, 2488 vm_map_t submap) 2489 { 2490 vm_map_entry_t entry; 2491 int result; 2492 2493 result = KERN_INVALID_ARGUMENT; 2494 2495 vm_map_lock(submap); 2496 submap->flags |= MAP_IS_SUB_MAP; 2497 vm_map_unlock(submap); 2498 2499 vm_map_lock(map); 2500 VM_MAP_RANGE_CHECK(map, start, end); 2501 if (vm_map_lookup_entry(map, start, &entry) && entry->end >= end && 2502 (entry->eflags & MAP_ENTRY_COW) == 0 && 2503 entry->object.vm_object == NULL) { 2504 vm_map_clip_start(map, entry, start); 2505 vm_map_clip_end(map, entry, end); 2506 entry->object.sub_map = submap; 2507 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 2508 result = KERN_SUCCESS; 2509 } 2510 vm_map_unlock(map); 2511 2512 if (result != KERN_SUCCESS) { 2513 vm_map_lock(submap); 2514 submap->flags &= ~MAP_IS_SUB_MAP; 2515 vm_map_unlock(submap); 2516 } 2517 return (result); 2518 } 2519 2520 /* 2521 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified 2522 */ 2523 #define MAX_INIT_PT 96 2524 2525 /* 2526 * vm_map_pmap_enter: 2527 * 2528 * Preload the specified map's pmap with mappings to the specified 2529 * object's memory-resident pages. No further physical pages are 2530 * allocated, and no further virtual pages are retrieved from secondary 2531 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a 2532 * limited number of page mappings are created at the low-end of the 2533 * specified address range. (For this purpose, a superpage mapping 2534 * counts as one page mapping.) Otherwise, all resident pages within 2535 * the specified address range are mapped. 2536 */ 2537 static void 2538 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 2539 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 2540 { 2541 vm_offset_t start; 2542 vm_page_t p, p_start; 2543 vm_pindex_t mask, psize, threshold, tmpidx; 2544 2545 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 2546 return; 2547 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 2548 VM_OBJECT_WLOCK(object); 2549 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 2550 pmap_object_init_pt(map->pmap, addr, object, pindex, 2551 size); 2552 VM_OBJECT_WUNLOCK(object); 2553 return; 2554 } 2555 VM_OBJECT_LOCK_DOWNGRADE(object); 2556 } else 2557 VM_OBJECT_RLOCK(object); 2558 2559 psize = atop(size); 2560 if (psize + pindex > object->size) { 2561 if (pindex >= object->size) { 2562 VM_OBJECT_RUNLOCK(object); 2563 return; 2564 } 2565 psize = object->size - pindex; 2566 } 2567 2568 start = 0; 2569 p_start = NULL; 2570 threshold = MAX_INIT_PT; 2571 2572 p = vm_page_find_least(object, pindex); 2573 /* 2574 * Assert: the variable p is either (1) the page with the 2575 * least pindex greater than or equal to the parameter pindex 2576 * or (2) NULL. 2577 */ 2578 for (; 2579 p != NULL && (tmpidx = p->pindex - pindex) < psize; 2580 p = TAILQ_NEXT(p, listq)) { 2581 /* 2582 * don't allow an madvise to blow away our really 2583 * free pages allocating pv entries. 2584 */ 2585 if (((flags & MAP_PREFAULT_MADVISE) != 0 && 2586 vm_page_count_severe()) || 2587 ((flags & MAP_PREFAULT_PARTIAL) != 0 && 2588 tmpidx >= threshold)) { 2589 psize = tmpidx; 2590 break; 2591 } 2592 if (vm_page_all_valid(p)) { 2593 if (p_start == NULL) { 2594 start = addr + ptoa(tmpidx); 2595 p_start = p; 2596 } 2597 /* Jump ahead if a superpage mapping is possible. */ 2598 if (p->psind > 0 && ((addr + ptoa(tmpidx)) & 2599 (pagesizes[p->psind] - 1)) == 0) { 2600 mask = atop(pagesizes[p->psind]) - 1; 2601 if (tmpidx + mask < psize && 2602 vm_page_ps_test(p, PS_ALL_VALID, NULL)) { 2603 p += mask; 2604 threshold += mask; 2605 } 2606 } 2607 } else if (p_start != NULL) { 2608 pmap_enter_object(map->pmap, start, addr + 2609 ptoa(tmpidx), p_start, prot); 2610 p_start = NULL; 2611 } 2612 } 2613 if (p_start != NULL) 2614 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 2615 p_start, prot); 2616 VM_OBJECT_RUNLOCK(object); 2617 } 2618 2619 /* 2620 * vm_map_protect: 2621 * 2622 * Sets the protection of the specified address 2623 * region in the target map. If "set_max" is 2624 * specified, the maximum protection is to be set; 2625 * otherwise, only the current protection is affected. 2626 */ 2627 int 2628 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 2629 vm_prot_t new_prot, boolean_t set_max) 2630 { 2631 vm_map_entry_t entry, first_entry, in_tran, prev_entry; 2632 vm_object_t obj; 2633 struct ucred *cred; 2634 vm_prot_t old_prot; 2635 int rv; 2636 2637 if (start == end) 2638 return (KERN_SUCCESS); 2639 2640 again: 2641 in_tran = NULL; 2642 vm_map_lock(map); 2643 2644 /* 2645 * Ensure that we are not concurrently wiring pages. vm_map_wire() may 2646 * need to fault pages into the map and will drop the map lock while 2647 * doing so, and the VM object may end up in an inconsistent state if we 2648 * update the protection on the map entry in between faults. 2649 */ 2650 vm_map_wait_busy(map); 2651 2652 VM_MAP_RANGE_CHECK(map, start, end); 2653 2654 if (!vm_map_lookup_entry(map, start, &first_entry)) 2655 first_entry = vm_map_entry_succ(first_entry); 2656 2657 /* 2658 * Make a first pass to check for protection violations. 2659 */ 2660 for (entry = first_entry; entry->start < end; 2661 entry = vm_map_entry_succ(entry)) { 2662 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) 2663 continue; 2664 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 2665 vm_map_unlock(map); 2666 return (KERN_INVALID_ARGUMENT); 2667 } 2668 if ((new_prot & entry->max_protection) != new_prot) { 2669 vm_map_unlock(map); 2670 return (KERN_PROTECTION_FAILURE); 2671 } 2672 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0) 2673 in_tran = entry; 2674 } 2675 2676 /* 2677 * Postpone the operation until all in-transition map entries have 2678 * stabilized. An in-transition entry might already have its pages 2679 * wired and wired_count incremented, but not yet have its 2680 * MAP_ENTRY_USER_WIRED flag set. In which case, we would fail to call 2681 * vm_fault_copy_entry() in the final loop below. 2682 */ 2683 if (in_tran != NULL) { 2684 in_tran->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2685 vm_map_unlock_and_wait(map, 0); 2686 goto again; 2687 } 2688 2689 /* 2690 * Before changing the protections, try to reserve swap space for any 2691 * private (i.e., copy-on-write) mappings that are transitioning from 2692 * read-only to read/write access. If a reservation fails, break out 2693 * of this loop early and let the next loop simplify the entries, since 2694 * some may now be mergeable. 2695 */ 2696 rv = KERN_SUCCESS; 2697 vm_map_clip_start(map, first_entry, start); 2698 for (entry = first_entry; entry->start < end; 2699 entry = vm_map_entry_succ(entry)) { 2700 vm_map_clip_end(map, entry, end); 2701 2702 if (set_max || 2703 ((new_prot & ~entry->protection) & VM_PROT_WRITE) == 0 || 2704 ENTRY_CHARGED(entry) || 2705 (entry->eflags & MAP_ENTRY_GUARD) != 0) { 2706 continue; 2707 } 2708 2709 cred = curthread->td_ucred; 2710 obj = entry->object.vm_object; 2711 2712 if (obj == NULL || 2713 (entry->eflags & MAP_ENTRY_NEEDS_COPY) != 0) { 2714 if (!swap_reserve(entry->end - entry->start)) { 2715 rv = KERN_RESOURCE_SHORTAGE; 2716 end = entry->end; 2717 break; 2718 } 2719 crhold(cred); 2720 entry->cred = cred; 2721 continue; 2722 } 2723 2724 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) 2725 continue; 2726 VM_OBJECT_WLOCK(obj); 2727 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 2728 VM_OBJECT_WUNLOCK(obj); 2729 continue; 2730 } 2731 2732 /* 2733 * Charge for the whole object allocation now, since 2734 * we cannot distinguish between non-charged and 2735 * charged clipped mapping of the same object later. 2736 */ 2737 KASSERT(obj->charge == 0, 2738 ("vm_map_protect: object %p overcharged (entry %p)", 2739 obj, entry)); 2740 if (!swap_reserve(ptoa(obj->size))) { 2741 VM_OBJECT_WUNLOCK(obj); 2742 rv = KERN_RESOURCE_SHORTAGE; 2743 end = entry->end; 2744 break; 2745 } 2746 2747 crhold(cred); 2748 obj->cred = cred; 2749 obj->charge = ptoa(obj->size); 2750 VM_OBJECT_WUNLOCK(obj); 2751 } 2752 2753 /* 2754 * If enough swap space was available, go back and fix up protections. 2755 * Otherwise, just simplify entries, since some may have been modified. 2756 * [Note that clipping is not necessary the second time.] 2757 */ 2758 for (prev_entry = vm_map_entry_pred(first_entry), entry = first_entry; 2759 entry->start < end; 2760 vm_map_try_merge_entries(map, prev_entry, entry), 2761 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 2762 if (rv != KERN_SUCCESS || 2763 (entry->eflags & MAP_ENTRY_GUARD) != 0) 2764 continue; 2765 2766 old_prot = entry->protection; 2767 2768 if (set_max) 2769 entry->protection = 2770 (entry->max_protection = new_prot) & 2771 old_prot; 2772 else 2773 entry->protection = new_prot; 2774 2775 /* 2776 * For user wired map entries, the normal lazy evaluation of 2777 * write access upgrades through soft page faults is 2778 * undesirable. Instead, immediately copy any pages that are 2779 * copy-on-write and enable write access in the physical map. 2780 */ 2781 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0 && 2782 (entry->protection & VM_PROT_WRITE) != 0 && 2783 (old_prot & VM_PROT_WRITE) == 0) 2784 vm_fault_copy_entry(map, map, entry, entry, NULL); 2785 2786 /* 2787 * When restricting access, update the physical map. Worry 2788 * about copy-on-write here. 2789 */ 2790 if ((old_prot & ~entry->protection) != 0) { 2791 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 2792 VM_PROT_ALL) 2793 pmap_protect(map->pmap, entry->start, 2794 entry->end, 2795 entry->protection & MASK(entry)); 2796 #undef MASK 2797 } 2798 } 2799 vm_map_try_merge_entries(map, prev_entry, entry); 2800 vm_map_unlock(map); 2801 return (rv); 2802 } 2803 2804 /* 2805 * vm_map_madvise: 2806 * 2807 * This routine traverses a processes map handling the madvise 2808 * system call. Advisories are classified as either those effecting 2809 * the vm_map_entry structure, or those effecting the underlying 2810 * objects. 2811 */ 2812 int 2813 vm_map_madvise( 2814 vm_map_t map, 2815 vm_offset_t start, 2816 vm_offset_t end, 2817 int behav) 2818 { 2819 vm_map_entry_t entry, prev_entry; 2820 bool modify_map; 2821 2822 /* 2823 * Some madvise calls directly modify the vm_map_entry, in which case 2824 * we need to use an exclusive lock on the map and we need to perform 2825 * various clipping operations. Otherwise we only need a read-lock 2826 * on the map. 2827 */ 2828 switch(behav) { 2829 case MADV_NORMAL: 2830 case MADV_SEQUENTIAL: 2831 case MADV_RANDOM: 2832 case MADV_NOSYNC: 2833 case MADV_AUTOSYNC: 2834 case MADV_NOCORE: 2835 case MADV_CORE: 2836 if (start == end) 2837 return (0); 2838 modify_map = true; 2839 vm_map_lock(map); 2840 break; 2841 case MADV_WILLNEED: 2842 case MADV_DONTNEED: 2843 case MADV_FREE: 2844 if (start == end) 2845 return (0); 2846 modify_map = false; 2847 vm_map_lock_read(map); 2848 break; 2849 default: 2850 return (EINVAL); 2851 } 2852 2853 /* 2854 * Locate starting entry and clip if necessary. 2855 */ 2856 VM_MAP_RANGE_CHECK(map, start, end); 2857 2858 if (modify_map) { 2859 /* 2860 * madvise behaviors that are implemented in the vm_map_entry. 2861 * 2862 * We clip the vm_map_entry so that behavioral changes are 2863 * limited to the specified address range. 2864 */ 2865 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry); 2866 entry->start < end; 2867 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 2868 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 2869 continue; 2870 2871 vm_map_clip_end(map, entry, end); 2872 2873 switch (behav) { 2874 case MADV_NORMAL: 2875 vm_map_entry_set_behavior(entry, 2876 MAP_ENTRY_BEHAV_NORMAL); 2877 break; 2878 case MADV_SEQUENTIAL: 2879 vm_map_entry_set_behavior(entry, 2880 MAP_ENTRY_BEHAV_SEQUENTIAL); 2881 break; 2882 case MADV_RANDOM: 2883 vm_map_entry_set_behavior(entry, 2884 MAP_ENTRY_BEHAV_RANDOM); 2885 break; 2886 case MADV_NOSYNC: 2887 entry->eflags |= MAP_ENTRY_NOSYNC; 2888 break; 2889 case MADV_AUTOSYNC: 2890 entry->eflags &= ~MAP_ENTRY_NOSYNC; 2891 break; 2892 case MADV_NOCORE: 2893 entry->eflags |= MAP_ENTRY_NOCOREDUMP; 2894 break; 2895 case MADV_CORE: 2896 entry->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2897 break; 2898 default: 2899 break; 2900 } 2901 vm_map_try_merge_entries(map, prev_entry, entry); 2902 } 2903 vm_map_try_merge_entries(map, prev_entry, entry); 2904 vm_map_unlock(map); 2905 } else { 2906 vm_pindex_t pstart, pend; 2907 2908 /* 2909 * madvise behaviors that are implemented in the underlying 2910 * vm_object. 2911 * 2912 * Since we don't clip the vm_map_entry, we have to clip 2913 * the vm_object pindex and count. 2914 */ 2915 if (!vm_map_lookup_entry(map, start, &entry)) 2916 entry = vm_map_entry_succ(entry); 2917 for (; entry->start < end; 2918 entry = vm_map_entry_succ(entry)) { 2919 vm_offset_t useEnd, useStart; 2920 2921 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 2922 continue; 2923 2924 /* 2925 * MADV_FREE would otherwise rewind time to 2926 * the creation of the shadow object. Because 2927 * we hold the VM map read-locked, neither the 2928 * entry's object nor the presence of a 2929 * backing object can change. 2930 */ 2931 if (behav == MADV_FREE && 2932 entry->object.vm_object != NULL && 2933 entry->object.vm_object->backing_object != NULL) 2934 continue; 2935 2936 pstart = OFF_TO_IDX(entry->offset); 2937 pend = pstart + atop(entry->end - entry->start); 2938 useStart = entry->start; 2939 useEnd = entry->end; 2940 2941 if (entry->start < start) { 2942 pstart += atop(start - entry->start); 2943 useStart = start; 2944 } 2945 if (entry->end > end) { 2946 pend -= atop(entry->end - end); 2947 useEnd = end; 2948 } 2949 2950 if (pstart >= pend) 2951 continue; 2952 2953 /* 2954 * Perform the pmap_advise() before clearing 2955 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2956 * concurrent pmap operation, such as pmap_remove(), 2957 * could clear a reference in the pmap and set 2958 * PGA_REFERENCED on the page before the pmap_advise() 2959 * had completed. Consequently, the page would appear 2960 * referenced based upon an old reference that 2961 * occurred before this pmap_advise() ran. 2962 */ 2963 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2964 pmap_advise(map->pmap, useStart, useEnd, 2965 behav); 2966 2967 vm_object_madvise(entry->object.vm_object, pstart, 2968 pend, behav); 2969 2970 /* 2971 * Pre-populate paging structures in the 2972 * WILLNEED case. For wired entries, the 2973 * paging structures are already populated. 2974 */ 2975 if (behav == MADV_WILLNEED && 2976 entry->wired_count == 0) { 2977 vm_map_pmap_enter(map, 2978 useStart, 2979 entry->protection, 2980 entry->object.vm_object, 2981 pstart, 2982 ptoa(pend - pstart), 2983 MAP_PREFAULT_MADVISE 2984 ); 2985 } 2986 } 2987 vm_map_unlock_read(map); 2988 } 2989 return (0); 2990 } 2991 2992 2993 /* 2994 * vm_map_inherit: 2995 * 2996 * Sets the inheritance of the specified address 2997 * range in the target map. Inheritance 2998 * affects how the map will be shared with 2999 * child maps at the time of vmspace_fork. 3000 */ 3001 int 3002 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 3003 vm_inherit_t new_inheritance) 3004 { 3005 vm_map_entry_t entry, prev_entry; 3006 3007 switch (new_inheritance) { 3008 case VM_INHERIT_NONE: 3009 case VM_INHERIT_COPY: 3010 case VM_INHERIT_SHARE: 3011 case VM_INHERIT_ZERO: 3012 break; 3013 default: 3014 return (KERN_INVALID_ARGUMENT); 3015 } 3016 if (start == end) 3017 return (KERN_SUCCESS); 3018 vm_map_lock(map); 3019 VM_MAP_RANGE_CHECK(map, start, end); 3020 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry); 3021 entry->start < end; 3022 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3023 vm_map_clip_end(map, entry, end); 3024 if ((entry->eflags & MAP_ENTRY_GUARD) == 0 || 3025 new_inheritance != VM_INHERIT_ZERO) 3026 entry->inheritance = new_inheritance; 3027 vm_map_try_merge_entries(map, prev_entry, entry); 3028 } 3029 vm_map_try_merge_entries(map, prev_entry, entry); 3030 vm_map_unlock(map); 3031 return (KERN_SUCCESS); 3032 } 3033 3034 /* 3035 * vm_map_entry_in_transition: 3036 * 3037 * Release the map lock, and sleep until the entry is no longer in 3038 * transition. Awake and acquire the map lock. If the map changed while 3039 * another held the lock, lookup a possibly-changed entry at or after the 3040 * 'start' position of the old entry. 3041 */ 3042 static vm_map_entry_t 3043 vm_map_entry_in_transition(vm_map_t map, vm_offset_t in_start, 3044 vm_offset_t *io_end, bool holes_ok, vm_map_entry_t in_entry) 3045 { 3046 vm_map_entry_t entry; 3047 vm_offset_t start; 3048 u_int last_timestamp; 3049 3050 VM_MAP_ASSERT_LOCKED(map); 3051 KASSERT((in_entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3052 ("not in-tranition map entry %p", in_entry)); 3053 /* 3054 * We have not yet clipped the entry. 3055 */ 3056 start = MAX(in_start, in_entry->start); 3057 in_entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 3058 last_timestamp = map->timestamp; 3059 if (vm_map_unlock_and_wait(map, 0)) { 3060 /* 3061 * Allow interruption of user wiring/unwiring? 3062 */ 3063 } 3064 vm_map_lock(map); 3065 if (last_timestamp + 1 == map->timestamp) 3066 return (in_entry); 3067 3068 /* 3069 * Look again for the entry because the map was modified while it was 3070 * unlocked. Specifically, the entry may have been clipped, merged, or 3071 * deleted. 3072 */ 3073 if (!vm_map_lookup_entry(map, start, &entry)) { 3074 if (!holes_ok) { 3075 *io_end = start; 3076 return (NULL); 3077 } 3078 entry = vm_map_entry_succ(entry); 3079 } 3080 return (entry); 3081 } 3082 3083 /* 3084 * vm_map_unwire: 3085 * 3086 * Implements both kernel and user unwiring. 3087 */ 3088 int 3089 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 3090 int flags) 3091 { 3092 vm_map_entry_t entry, first_entry, next_entry, prev_entry; 3093 int rv; 3094 bool holes_ok, need_wakeup, user_unwire; 3095 3096 if (start == end) 3097 return (KERN_SUCCESS); 3098 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0; 3099 user_unwire = (flags & VM_MAP_WIRE_USER) != 0; 3100 vm_map_lock(map); 3101 VM_MAP_RANGE_CHECK(map, start, end); 3102 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3103 if (holes_ok) 3104 first_entry = vm_map_entry_succ(first_entry); 3105 else { 3106 vm_map_unlock(map); 3107 return (KERN_INVALID_ADDRESS); 3108 } 3109 } 3110 rv = KERN_SUCCESS; 3111 for (entry = first_entry; entry->start < end; entry = next_entry) { 3112 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 3113 /* 3114 * We have not yet clipped the entry. 3115 */ 3116 next_entry = vm_map_entry_in_transition(map, start, 3117 &end, holes_ok, entry); 3118 if (next_entry == NULL) { 3119 if (entry == first_entry) { 3120 vm_map_unlock(map); 3121 return (KERN_INVALID_ADDRESS); 3122 } 3123 rv = KERN_INVALID_ADDRESS; 3124 break; 3125 } 3126 first_entry = (entry == first_entry) ? 3127 next_entry : NULL; 3128 continue; 3129 } 3130 vm_map_clip_start(map, entry, start); 3131 vm_map_clip_end(map, entry, end); 3132 /* 3133 * Mark the entry in case the map lock is released. (See 3134 * above.) 3135 */ 3136 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 3137 entry->wiring_thread == NULL, 3138 ("owned map entry %p", entry)); 3139 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 3140 entry->wiring_thread = curthread; 3141 next_entry = vm_map_entry_succ(entry); 3142 /* 3143 * Check the map for holes in the specified region. 3144 * If holes_ok, skip this check. 3145 */ 3146 if (!holes_ok && 3147 entry->end < end && next_entry->start > entry->end) { 3148 end = entry->end; 3149 rv = KERN_INVALID_ADDRESS; 3150 break; 3151 } 3152 /* 3153 * If system unwiring, require that the entry is system wired. 3154 */ 3155 if (!user_unwire && 3156 vm_map_entry_system_wired_count(entry) == 0) { 3157 end = entry->end; 3158 rv = KERN_INVALID_ARGUMENT; 3159 break; 3160 } 3161 } 3162 need_wakeup = false; 3163 if (first_entry == NULL && 3164 !vm_map_lookup_entry(map, start, &first_entry)) { 3165 KASSERT(holes_ok, ("vm_map_unwire: lookup failed")); 3166 prev_entry = first_entry; 3167 entry = vm_map_entry_succ(first_entry); 3168 } else { 3169 prev_entry = vm_map_entry_pred(first_entry); 3170 entry = first_entry; 3171 } 3172 for (; entry->start < end; 3173 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3174 /* 3175 * If holes_ok was specified, an empty 3176 * space in the unwired region could have been mapped 3177 * while the map lock was dropped for draining 3178 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 3179 * could be simultaneously wiring this new mapping 3180 * entry. Detect these cases and skip any entries 3181 * marked as in transition by us. 3182 */ 3183 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 3184 entry->wiring_thread != curthread) { 3185 KASSERT(holes_ok, 3186 ("vm_map_unwire: !HOLESOK and new/changed entry")); 3187 continue; 3188 } 3189 3190 if (rv == KERN_SUCCESS && (!user_unwire || 3191 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 3192 if (entry->wired_count == 1) 3193 vm_map_entry_unwire(map, entry); 3194 else 3195 entry->wired_count--; 3196 if (user_unwire) 3197 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3198 } 3199 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3200 ("vm_map_unwire: in-transition flag missing %p", entry)); 3201 KASSERT(entry->wiring_thread == curthread, 3202 ("vm_map_unwire: alien wire %p", entry)); 3203 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 3204 entry->wiring_thread = NULL; 3205 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 3206 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 3207 need_wakeup = true; 3208 } 3209 vm_map_try_merge_entries(map, prev_entry, entry); 3210 } 3211 vm_map_try_merge_entries(map, prev_entry, entry); 3212 vm_map_unlock(map); 3213 if (need_wakeup) 3214 vm_map_wakeup(map); 3215 return (rv); 3216 } 3217 3218 static void 3219 vm_map_wire_user_count_sub(u_long npages) 3220 { 3221 3222 atomic_subtract_long(&vm_user_wire_count, npages); 3223 } 3224 3225 static bool 3226 vm_map_wire_user_count_add(u_long npages) 3227 { 3228 u_long wired; 3229 3230 wired = vm_user_wire_count; 3231 do { 3232 if (npages + wired > vm_page_max_user_wired) 3233 return (false); 3234 } while (!atomic_fcmpset_long(&vm_user_wire_count, &wired, 3235 npages + wired)); 3236 3237 return (true); 3238 } 3239 3240 /* 3241 * vm_map_wire_entry_failure: 3242 * 3243 * Handle a wiring failure on the given entry. 3244 * 3245 * The map should be locked. 3246 */ 3247 static void 3248 vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 3249 vm_offset_t failed_addr) 3250 { 3251 3252 VM_MAP_ASSERT_LOCKED(map); 3253 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 && 3254 entry->wired_count == 1, 3255 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry)); 3256 KASSERT(failed_addr < entry->end, 3257 ("vm_map_wire_entry_failure: entry %p was fully wired", entry)); 3258 3259 /* 3260 * If any pages at the start of this entry were successfully wired, 3261 * then unwire them. 3262 */ 3263 if (failed_addr > entry->start) { 3264 pmap_unwire(map->pmap, entry->start, failed_addr); 3265 vm_object_unwire(entry->object.vm_object, entry->offset, 3266 failed_addr - entry->start, PQ_ACTIVE); 3267 } 3268 3269 /* 3270 * Assign an out-of-range value to represent the failure to wire this 3271 * entry. 3272 */ 3273 entry->wired_count = -1; 3274 } 3275 3276 int 3277 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) 3278 { 3279 int rv; 3280 3281 vm_map_lock(map); 3282 rv = vm_map_wire_locked(map, start, end, flags); 3283 vm_map_unlock(map); 3284 return (rv); 3285 } 3286 3287 3288 /* 3289 * vm_map_wire_locked: 3290 * 3291 * Implements both kernel and user wiring. Returns with the map locked, 3292 * the map lock may be dropped. 3293 */ 3294 int 3295 vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) 3296 { 3297 vm_map_entry_t entry, first_entry, next_entry, prev_entry; 3298 vm_offset_t faddr, saved_end, saved_start; 3299 u_long npages; 3300 u_int last_timestamp; 3301 int rv; 3302 bool holes_ok, need_wakeup, user_wire; 3303 vm_prot_t prot; 3304 3305 VM_MAP_ASSERT_LOCKED(map); 3306 3307 if (start == end) 3308 return (KERN_SUCCESS); 3309 prot = 0; 3310 if (flags & VM_MAP_WIRE_WRITE) 3311 prot |= VM_PROT_WRITE; 3312 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0; 3313 user_wire = (flags & VM_MAP_WIRE_USER) != 0; 3314 VM_MAP_RANGE_CHECK(map, start, end); 3315 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3316 if (holes_ok) 3317 first_entry = vm_map_entry_succ(first_entry); 3318 else 3319 return (KERN_INVALID_ADDRESS); 3320 } 3321 for (entry = first_entry; entry->start < end; entry = next_entry) { 3322 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 3323 /* 3324 * We have not yet clipped the entry. 3325 */ 3326 next_entry = vm_map_entry_in_transition(map, start, 3327 &end, holes_ok, entry); 3328 if (next_entry == NULL) { 3329 if (entry == first_entry) 3330 return (KERN_INVALID_ADDRESS); 3331 rv = KERN_INVALID_ADDRESS; 3332 goto done; 3333 } 3334 first_entry = (entry == first_entry) ? 3335 next_entry : NULL; 3336 continue; 3337 } 3338 vm_map_clip_start(map, entry, start); 3339 vm_map_clip_end(map, entry, end); 3340 /* 3341 * Mark the entry in case the map lock is released. (See 3342 * above.) 3343 */ 3344 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 3345 entry->wiring_thread == NULL, 3346 ("owned map entry %p", entry)); 3347 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 3348 entry->wiring_thread = curthread; 3349 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 3350 || (entry->protection & prot) != prot) { 3351 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 3352 if (!holes_ok) { 3353 end = entry->end; 3354 rv = KERN_INVALID_ADDRESS; 3355 goto done; 3356 } 3357 } else if (entry->wired_count == 0) { 3358 entry->wired_count++; 3359 3360 npages = atop(entry->end - entry->start); 3361 if (user_wire && !vm_map_wire_user_count_add(npages)) { 3362 vm_map_wire_entry_failure(map, entry, 3363 entry->start); 3364 end = entry->end; 3365 rv = KERN_RESOURCE_SHORTAGE; 3366 goto done; 3367 } 3368 3369 /* 3370 * Release the map lock, relying on the in-transition 3371 * mark. Mark the map busy for fork. 3372 */ 3373 saved_start = entry->start; 3374 saved_end = entry->end; 3375 last_timestamp = map->timestamp; 3376 vm_map_busy(map); 3377 vm_map_unlock(map); 3378 3379 faddr = saved_start; 3380 do { 3381 /* 3382 * Simulate a fault to get the page and enter 3383 * it into the physical map. 3384 */ 3385 if ((rv = vm_fault(map, faddr, 3386 VM_PROT_NONE, VM_FAULT_WIRE, NULL)) != 3387 KERN_SUCCESS) 3388 break; 3389 } while ((faddr += PAGE_SIZE) < saved_end); 3390 vm_map_lock(map); 3391 vm_map_unbusy(map); 3392 if (last_timestamp + 1 != map->timestamp) { 3393 /* 3394 * Look again for the entry because the map was 3395 * modified while it was unlocked. The entry 3396 * may have been clipped, but NOT merged or 3397 * deleted. 3398 */ 3399 if (!vm_map_lookup_entry(map, saved_start, 3400 &next_entry)) 3401 KASSERT(false, 3402 ("vm_map_wire: lookup failed")); 3403 first_entry = (entry == first_entry) ? 3404 next_entry : NULL; 3405 for (entry = next_entry; entry->end < saved_end; 3406 entry = vm_map_entry_succ(entry)) { 3407 /* 3408 * In case of failure, handle entries 3409 * that were not fully wired here; 3410 * fully wired entries are handled 3411 * later. 3412 */ 3413 if (rv != KERN_SUCCESS && 3414 faddr < entry->end) 3415 vm_map_wire_entry_failure(map, 3416 entry, faddr); 3417 } 3418 } 3419 if (rv != KERN_SUCCESS) { 3420 vm_map_wire_entry_failure(map, entry, faddr); 3421 if (user_wire) 3422 vm_map_wire_user_count_sub(npages); 3423 end = entry->end; 3424 goto done; 3425 } 3426 } else if (!user_wire || 3427 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 3428 entry->wired_count++; 3429 } 3430 /* 3431 * Check the map for holes in the specified region. 3432 * If holes_ok was specified, skip this check. 3433 */ 3434 next_entry = vm_map_entry_succ(entry); 3435 if (!holes_ok && 3436 entry->end < end && next_entry->start > entry->end) { 3437 end = entry->end; 3438 rv = KERN_INVALID_ADDRESS; 3439 goto done; 3440 } 3441 } 3442 rv = KERN_SUCCESS; 3443 done: 3444 need_wakeup = false; 3445 if (first_entry == NULL && 3446 !vm_map_lookup_entry(map, start, &first_entry)) { 3447 KASSERT(holes_ok, ("vm_map_wire: lookup failed")); 3448 prev_entry = first_entry; 3449 entry = vm_map_entry_succ(first_entry); 3450 } else { 3451 prev_entry = vm_map_entry_pred(first_entry); 3452 entry = first_entry; 3453 } 3454 for (; entry->start < end; 3455 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3456 /* 3457 * If holes_ok was specified, an empty 3458 * space in the unwired region could have been mapped 3459 * while the map lock was dropped for faulting in the 3460 * pages or draining MAP_ENTRY_IN_TRANSITION. 3461 * Moreover, another thread could be simultaneously 3462 * wiring this new mapping entry. Detect these cases 3463 * and skip any entries marked as in transition not by us. 3464 */ 3465 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 3466 entry->wiring_thread != curthread) { 3467 KASSERT(holes_ok, 3468 ("vm_map_wire: !HOLESOK and new/changed entry")); 3469 continue; 3470 } 3471 3472 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) { 3473 /* do nothing */ 3474 } else if (rv == KERN_SUCCESS) { 3475 if (user_wire) 3476 entry->eflags |= MAP_ENTRY_USER_WIRED; 3477 } else if (entry->wired_count == -1) { 3478 /* 3479 * Wiring failed on this entry. Thus, unwiring is 3480 * unnecessary. 3481 */ 3482 entry->wired_count = 0; 3483 } else if (!user_wire || 3484 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 3485 /* 3486 * Undo the wiring. Wiring succeeded on this entry 3487 * but failed on a later entry. 3488 */ 3489 if (entry->wired_count == 1) { 3490 vm_map_entry_unwire(map, entry); 3491 if (user_wire) 3492 vm_map_wire_user_count_sub( 3493 atop(entry->end - entry->start)); 3494 } else 3495 entry->wired_count--; 3496 } 3497 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3498 ("vm_map_wire: in-transition flag missing %p", entry)); 3499 KASSERT(entry->wiring_thread == curthread, 3500 ("vm_map_wire: alien wire %p", entry)); 3501 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 3502 MAP_ENTRY_WIRE_SKIPPED); 3503 entry->wiring_thread = NULL; 3504 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 3505 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 3506 need_wakeup = true; 3507 } 3508 vm_map_try_merge_entries(map, prev_entry, entry); 3509 } 3510 vm_map_try_merge_entries(map, prev_entry, entry); 3511 if (need_wakeup) 3512 vm_map_wakeup(map); 3513 return (rv); 3514 } 3515 3516 /* 3517 * vm_map_sync 3518 * 3519 * Push any dirty cached pages in the address range to their pager. 3520 * If syncio is TRUE, dirty pages are written synchronously. 3521 * If invalidate is TRUE, any cached pages are freed as well. 3522 * 3523 * If the size of the region from start to end is zero, we are 3524 * supposed to flush all modified pages within the region containing 3525 * start. Unfortunately, a region can be split or coalesced with 3526 * neighboring regions, making it difficult to determine what the 3527 * original region was. Therefore, we approximate this requirement by 3528 * flushing the current region containing start. 3529 * 3530 * Returns an error if any part of the specified range is not mapped. 3531 */ 3532 int 3533 vm_map_sync( 3534 vm_map_t map, 3535 vm_offset_t start, 3536 vm_offset_t end, 3537 boolean_t syncio, 3538 boolean_t invalidate) 3539 { 3540 vm_map_entry_t entry, first_entry, next_entry; 3541 vm_size_t size; 3542 vm_object_t object; 3543 vm_ooffset_t offset; 3544 unsigned int last_timestamp; 3545 boolean_t failed; 3546 3547 vm_map_lock_read(map); 3548 VM_MAP_RANGE_CHECK(map, start, end); 3549 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3550 vm_map_unlock_read(map); 3551 return (KERN_INVALID_ADDRESS); 3552 } else if (start == end) { 3553 start = first_entry->start; 3554 end = first_entry->end; 3555 } 3556 /* 3557 * Make a first pass to check for user-wired memory and holes. 3558 */ 3559 for (entry = first_entry; entry->start < end; entry = next_entry) { 3560 if (invalidate && 3561 (entry->eflags & MAP_ENTRY_USER_WIRED) != 0) { 3562 vm_map_unlock_read(map); 3563 return (KERN_INVALID_ARGUMENT); 3564 } 3565 next_entry = vm_map_entry_succ(entry); 3566 if (end > entry->end && 3567 entry->end != next_entry->start) { 3568 vm_map_unlock_read(map); 3569 return (KERN_INVALID_ADDRESS); 3570 } 3571 } 3572 3573 if (invalidate) 3574 pmap_remove(map->pmap, start, end); 3575 failed = FALSE; 3576 3577 /* 3578 * Make a second pass, cleaning/uncaching pages from the indicated 3579 * objects as we go. 3580 */ 3581 for (entry = first_entry; entry->start < end;) { 3582 offset = entry->offset + (start - entry->start); 3583 size = (end <= entry->end ? end : entry->end) - start; 3584 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 3585 vm_map_t smap; 3586 vm_map_entry_t tentry; 3587 vm_size_t tsize; 3588 3589 smap = entry->object.sub_map; 3590 vm_map_lock_read(smap); 3591 (void) vm_map_lookup_entry(smap, offset, &tentry); 3592 tsize = tentry->end - offset; 3593 if (tsize < size) 3594 size = tsize; 3595 object = tentry->object.vm_object; 3596 offset = tentry->offset + (offset - tentry->start); 3597 vm_map_unlock_read(smap); 3598 } else { 3599 object = entry->object.vm_object; 3600 } 3601 vm_object_reference(object); 3602 last_timestamp = map->timestamp; 3603 vm_map_unlock_read(map); 3604 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 3605 failed = TRUE; 3606 start += size; 3607 vm_object_deallocate(object); 3608 vm_map_lock_read(map); 3609 if (last_timestamp == map->timestamp || 3610 !vm_map_lookup_entry(map, start, &entry)) 3611 entry = vm_map_entry_succ(entry); 3612 } 3613 3614 vm_map_unlock_read(map); 3615 return (failed ? KERN_FAILURE : KERN_SUCCESS); 3616 } 3617 3618 /* 3619 * vm_map_entry_unwire: [ internal use only ] 3620 * 3621 * Make the region specified by this entry pageable. 3622 * 3623 * The map in question should be locked. 3624 * [This is the reason for this routine's existence.] 3625 */ 3626 static void 3627 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 3628 { 3629 vm_size_t size; 3630 3631 VM_MAP_ASSERT_LOCKED(map); 3632 KASSERT(entry->wired_count > 0, 3633 ("vm_map_entry_unwire: entry %p isn't wired", entry)); 3634 3635 size = entry->end - entry->start; 3636 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0) 3637 vm_map_wire_user_count_sub(atop(size)); 3638 pmap_unwire(map->pmap, entry->start, entry->end); 3639 vm_object_unwire(entry->object.vm_object, entry->offset, size, 3640 PQ_ACTIVE); 3641 entry->wired_count = 0; 3642 } 3643 3644 static void 3645 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 3646 { 3647 3648 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 3649 vm_object_deallocate(entry->object.vm_object); 3650 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 3651 } 3652 3653 /* 3654 * vm_map_entry_delete: [ internal use only ] 3655 * 3656 * Deallocate the given entry from the target map. 3657 */ 3658 static void 3659 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 3660 { 3661 vm_object_t object; 3662 vm_pindex_t offidxstart, offidxend, size1; 3663 vm_size_t size; 3664 3665 vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE); 3666 object = entry->object.vm_object; 3667 3668 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) { 3669 MPASS(entry->cred == NULL); 3670 MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0); 3671 MPASS(object == NULL); 3672 vm_map_entry_deallocate(entry, map->system_map); 3673 return; 3674 } 3675 3676 size = entry->end - entry->start; 3677 map->size -= size; 3678 3679 if (entry->cred != NULL) { 3680 swap_release_by_cred(size, entry->cred); 3681 crfree(entry->cred); 3682 } 3683 3684 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) { 3685 entry->object.vm_object = NULL; 3686 } else if ((object->flags & OBJ_ANON) != 0 || 3687 object == kernel_object) { 3688 KASSERT(entry->cred == NULL || object->cred == NULL || 3689 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 3690 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 3691 offidxstart = OFF_TO_IDX(entry->offset); 3692 offidxend = offidxstart + atop(size); 3693 VM_OBJECT_WLOCK(object); 3694 if (object->ref_count != 1 && 3695 ((object->flags & OBJ_ONEMAPPING) != 0 || 3696 object == kernel_object)) { 3697 vm_object_collapse(object); 3698 3699 /* 3700 * The option OBJPR_NOTMAPPED can be passed here 3701 * because vm_map_delete() already performed 3702 * pmap_remove() on the only mapping to this range 3703 * of pages. 3704 */ 3705 vm_object_page_remove(object, offidxstart, offidxend, 3706 OBJPR_NOTMAPPED); 3707 if (offidxend >= object->size && 3708 offidxstart < object->size) { 3709 size1 = object->size; 3710 object->size = offidxstart; 3711 if (object->cred != NULL) { 3712 size1 -= object->size; 3713 KASSERT(object->charge >= ptoa(size1), 3714 ("object %p charge < 0", object)); 3715 swap_release_by_cred(ptoa(size1), 3716 object->cred); 3717 object->charge -= ptoa(size1); 3718 } 3719 } 3720 } 3721 VM_OBJECT_WUNLOCK(object); 3722 } 3723 if (map->system_map) 3724 vm_map_entry_deallocate(entry, TRUE); 3725 else { 3726 entry->defer_next = curthread->td_map_def_user; 3727 curthread->td_map_def_user = entry; 3728 } 3729 } 3730 3731 /* 3732 * vm_map_delete: [ internal use only ] 3733 * 3734 * Deallocates the given address range from the target 3735 * map. 3736 */ 3737 int 3738 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 3739 { 3740 vm_map_entry_t entry, next_entry; 3741 3742 VM_MAP_ASSERT_LOCKED(map); 3743 3744 if (start == end) 3745 return (KERN_SUCCESS); 3746 3747 /* 3748 * Find the start of the region, and clip it. 3749 * Step through all entries in this region. 3750 */ 3751 for (entry = vm_map_lookup_clip_start(map, start, &entry); 3752 entry->start < end; entry = next_entry) { 3753 /* 3754 * Wait for wiring or unwiring of an entry to complete. 3755 * Also wait for any system wirings to disappear on 3756 * user maps. 3757 */ 3758 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 3759 (vm_map_pmap(map) != kernel_pmap && 3760 vm_map_entry_system_wired_count(entry) != 0)) { 3761 unsigned int last_timestamp; 3762 vm_offset_t saved_start; 3763 3764 saved_start = entry->start; 3765 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 3766 last_timestamp = map->timestamp; 3767 (void) vm_map_unlock_and_wait(map, 0); 3768 vm_map_lock(map); 3769 if (last_timestamp + 1 != map->timestamp) { 3770 /* 3771 * Look again for the entry because the map was 3772 * modified while it was unlocked. 3773 * Specifically, the entry may have been 3774 * clipped, merged, or deleted. 3775 */ 3776 next_entry = vm_map_lookup_clip_start(map, 3777 saved_start, &next_entry); 3778 } else 3779 next_entry = entry; 3780 continue; 3781 } 3782 vm_map_clip_end(map, entry, end); 3783 next_entry = vm_map_entry_succ(entry); 3784 3785 /* 3786 * Unwire before removing addresses from the pmap; otherwise, 3787 * unwiring will put the entries back in the pmap. 3788 */ 3789 if (entry->wired_count != 0) 3790 vm_map_entry_unwire(map, entry); 3791 3792 /* 3793 * Remove mappings for the pages, but only if the 3794 * mappings could exist. For instance, it does not 3795 * make sense to call pmap_remove() for guard entries. 3796 */ 3797 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || 3798 entry->object.vm_object != NULL) 3799 pmap_remove(map->pmap, entry->start, entry->end); 3800 3801 if (entry->end == map->anon_loc) 3802 map->anon_loc = entry->start; 3803 3804 /* 3805 * Delete the entry only after removing all pmap 3806 * entries pointing to its pages. (Otherwise, its 3807 * page frames may be reallocated, and any modify bits 3808 * will be set in the wrong object!) 3809 */ 3810 vm_map_entry_delete(map, entry); 3811 } 3812 return (KERN_SUCCESS); 3813 } 3814 3815 /* 3816 * vm_map_remove: 3817 * 3818 * Remove the given address range from the target map. 3819 * This is the exported form of vm_map_delete. 3820 */ 3821 int 3822 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 3823 { 3824 int result; 3825 3826 vm_map_lock(map); 3827 VM_MAP_RANGE_CHECK(map, start, end); 3828 result = vm_map_delete(map, start, end); 3829 vm_map_unlock(map); 3830 return (result); 3831 } 3832 3833 /* 3834 * vm_map_check_protection: 3835 * 3836 * Assert that the target map allows the specified privilege on the 3837 * entire address region given. The entire region must be allocated. 3838 * 3839 * WARNING! This code does not and should not check whether the 3840 * contents of the region is accessible. For example a smaller file 3841 * might be mapped into a larger address space. 3842 * 3843 * NOTE! This code is also called by munmap(). 3844 * 3845 * The map must be locked. A read lock is sufficient. 3846 */ 3847 boolean_t 3848 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 3849 vm_prot_t protection) 3850 { 3851 vm_map_entry_t entry; 3852 vm_map_entry_t tmp_entry; 3853 3854 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 3855 return (FALSE); 3856 entry = tmp_entry; 3857 3858 while (start < end) { 3859 /* 3860 * No holes allowed! 3861 */ 3862 if (start < entry->start) 3863 return (FALSE); 3864 /* 3865 * Check protection associated with entry. 3866 */ 3867 if ((entry->protection & protection) != protection) 3868 return (FALSE); 3869 /* go to next entry */ 3870 start = entry->end; 3871 entry = vm_map_entry_succ(entry); 3872 } 3873 return (TRUE); 3874 } 3875 3876 3877 /* 3878 * 3879 * vm_map_copy_swap_object: 3880 * 3881 * Copies a swap-backed object from an existing map entry to a 3882 * new one. Carries forward the swap charge. May change the 3883 * src object on return. 3884 */ 3885 static void 3886 vm_map_copy_swap_object(vm_map_entry_t src_entry, vm_map_entry_t dst_entry, 3887 vm_offset_t size, vm_ooffset_t *fork_charge) 3888 { 3889 vm_object_t src_object; 3890 struct ucred *cred; 3891 int charged; 3892 3893 src_object = src_entry->object.vm_object; 3894 charged = ENTRY_CHARGED(src_entry); 3895 if ((src_object->flags & OBJ_ANON) != 0) { 3896 VM_OBJECT_WLOCK(src_object); 3897 vm_object_collapse(src_object); 3898 if ((src_object->flags & OBJ_ONEMAPPING) != 0) { 3899 vm_object_split(src_entry); 3900 src_object = src_entry->object.vm_object; 3901 } 3902 vm_object_reference_locked(src_object); 3903 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3904 VM_OBJECT_WUNLOCK(src_object); 3905 } else 3906 vm_object_reference(src_object); 3907 if (src_entry->cred != NULL && 3908 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3909 KASSERT(src_object->cred == NULL, 3910 ("OVERCOMMIT: vm_map_copy_anon_entry: cred %p", 3911 src_object)); 3912 src_object->cred = src_entry->cred; 3913 src_object->charge = size; 3914 } 3915 dst_entry->object.vm_object = src_object; 3916 if (charged) { 3917 cred = curthread->td_ucred; 3918 crhold(cred); 3919 dst_entry->cred = cred; 3920 *fork_charge += size; 3921 if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3922 crhold(cred); 3923 src_entry->cred = cred; 3924 *fork_charge += size; 3925 } 3926 } 3927 } 3928 3929 /* 3930 * vm_map_copy_entry: 3931 * 3932 * Copies the contents of the source entry to the destination 3933 * entry. The entries *must* be aligned properly. 3934 */ 3935 static void 3936 vm_map_copy_entry( 3937 vm_map_t src_map, 3938 vm_map_t dst_map, 3939 vm_map_entry_t src_entry, 3940 vm_map_entry_t dst_entry, 3941 vm_ooffset_t *fork_charge) 3942 { 3943 vm_object_t src_object; 3944 vm_map_entry_t fake_entry; 3945 vm_offset_t size; 3946 3947 VM_MAP_ASSERT_LOCKED(dst_map); 3948 3949 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3950 return; 3951 3952 if (src_entry->wired_count == 0 || 3953 (src_entry->protection & VM_PROT_WRITE) == 0) { 3954 /* 3955 * If the source entry is marked needs_copy, it is already 3956 * write-protected. 3957 */ 3958 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && 3959 (src_entry->protection & VM_PROT_WRITE) != 0) { 3960 pmap_protect(src_map->pmap, 3961 src_entry->start, 3962 src_entry->end, 3963 src_entry->protection & ~VM_PROT_WRITE); 3964 } 3965 3966 /* 3967 * Make a copy of the object. 3968 */ 3969 size = src_entry->end - src_entry->start; 3970 if ((src_object = src_entry->object.vm_object) != NULL) { 3971 if (src_object->type == OBJT_DEFAULT || 3972 src_object->type == OBJT_SWAP) { 3973 vm_map_copy_swap_object(src_entry, dst_entry, 3974 size, fork_charge); 3975 /* May have split/collapsed, reload obj. */ 3976 src_object = src_entry->object.vm_object; 3977 } else { 3978 vm_object_reference(src_object); 3979 dst_entry->object.vm_object = src_object; 3980 } 3981 src_entry->eflags |= MAP_ENTRY_COW | 3982 MAP_ENTRY_NEEDS_COPY; 3983 dst_entry->eflags |= MAP_ENTRY_COW | 3984 MAP_ENTRY_NEEDS_COPY; 3985 dst_entry->offset = src_entry->offset; 3986 if (src_entry->eflags & MAP_ENTRY_WRITECNT) { 3987 /* 3988 * MAP_ENTRY_WRITECNT cannot 3989 * indicate write reference from 3990 * src_entry, since the entry is 3991 * marked as needs copy. Allocate a 3992 * fake entry that is used to 3993 * decrement object->un_pager writecount 3994 * at the appropriate time. Attach 3995 * fake_entry to the deferred list. 3996 */ 3997 fake_entry = vm_map_entry_create(dst_map); 3998 fake_entry->eflags = MAP_ENTRY_WRITECNT; 3999 src_entry->eflags &= ~MAP_ENTRY_WRITECNT; 4000 vm_object_reference(src_object); 4001 fake_entry->object.vm_object = src_object; 4002 fake_entry->start = src_entry->start; 4003 fake_entry->end = src_entry->end; 4004 fake_entry->defer_next = 4005 curthread->td_map_def_user; 4006 curthread->td_map_def_user = fake_entry; 4007 } 4008 4009 pmap_copy(dst_map->pmap, src_map->pmap, 4010 dst_entry->start, dst_entry->end - dst_entry->start, 4011 src_entry->start); 4012 } else { 4013 dst_entry->object.vm_object = NULL; 4014 dst_entry->offset = 0; 4015 if (src_entry->cred != NULL) { 4016 dst_entry->cred = curthread->td_ucred; 4017 crhold(dst_entry->cred); 4018 *fork_charge += size; 4019 } 4020 } 4021 } else { 4022 /* 4023 * We don't want to make writeable wired pages copy-on-write. 4024 * Immediately copy these pages into the new map by simulating 4025 * page faults. The new pages are pageable. 4026 */ 4027 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 4028 fork_charge); 4029 } 4030 } 4031 4032 /* 4033 * vmspace_map_entry_forked: 4034 * Update the newly-forked vmspace each time a map entry is inherited 4035 * or copied. The values for vm_dsize and vm_tsize are approximate 4036 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 4037 */ 4038 static void 4039 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 4040 vm_map_entry_t entry) 4041 { 4042 vm_size_t entrysize; 4043 vm_offset_t newend; 4044 4045 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) 4046 return; 4047 entrysize = entry->end - entry->start; 4048 vm2->vm_map.size += entrysize; 4049 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 4050 vm2->vm_ssize += btoc(entrysize); 4051 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 4052 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 4053 newend = MIN(entry->end, 4054 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 4055 vm2->vm_dsize += btoc(newend - entry->start); 4056 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 4057 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 4058 newend = MIN(entry->end, 4059 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 4060 vm2->vm_tsize += btoc(newend - entry->start); 4061 } 4062 } 4063 4064 /* 4065 * vmspace_fork: 4066 * Create a new process vmspace structure and vm_map 4067 * based on those of an existing process. The new map 4068 * is based on the old map, according to the inheritance 4069 * values on the regions in that map. 4070 * 4071 * XXX It might be worth coalescing the entries added to the new vmspace. 4072 * 4073 * The source map must not be locked. 4074 */ 4075 struct vmspace * 4076 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 4077 { 4078 struct vmspace *vm2; 4079 vm_map_t new_map, old_map; 4080 vm_map_entry_t new_entry, old_entry; 4081 vm_object_t object; 4082 int error, locked; 4083 vm_inherit_t inh; 4084 4085 old_map = &vm1->vm_map; 4086 /* Copy immutable fields of vm1 to vm2. */ 4087 vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map), 4088 pmap_pinit); 4089 if (vm2 == NULL) 4090 return (NULL); 4091 4092 vm2->vm_taddr = vm1->vm_taddr; 4093 vm2->vm_daddr = vm1->vm_daddr; 4094 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 4095 vm_map_lock(old_map); 4096 if (old_map->busy) 4097 vm_map_wait_busy(old_map); 4098 new_map = &vm2->vm_map; 4099 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 4100 KASSERT(locked, ("vmspace_fork: lock failed")); 4101 4102 error = pmap_vmspace_copy(new_map->pmap, old_map->pmap); 4103 if (error != 0) { 4104 sx_xunlock(&old_map->lock); 4105 sx_xunlock(&new_map->lock); 4106 vm_map_process_deferred(); 4107 vmspace_free(vm2); 4108 return (NULL); 4109 } 4110 4111 new_map->anon_loc = old_map->anon_loc; 4112 4113 VM_MAP_ENTRY_FOREACH(old_entry, old_map) { 4114 if ((old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 4115 panic("vm_map_fork: encountered a submap"); 4116 4117 inh = old_entry->inheritance; 4118 if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 && 4119 inh != VM_INHERIT_NONE) 4120 inh = VM_INHERIT_COPY; 4121 4122 switch (inh) { 4123 case VM_INHERIT_NONE: 4124 break; 4125 4126 case VM_INHERIT_SHARE: 4127 /* 4128 * Clone the entry, creating the shared object if 4129 * necessary. 4130 */ 4131 object = old_entry->object.vm_object; 4132 if (object == NULL) { 4133 vm_map_entry_back(old_entry); 4134 object = old_entry->object.vm_object; 4135 } 4136 4137 /* 4138 * Add the reference before calling vm_object_shadow 4139 * to insure that a shadow object is created. 4140 */ 4141 vm_object_reference(object); 4142 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4143 vm_object_shadow(&old_entry->object.vm_object, 4144 &old_entry->offset, 4145 old_entry->end - old_entry->start, 4146 old_entry->cred, 4147 /* Transfer the second reference too. */ 4148 true); 4149 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4150 old_entry->cred = NULL; 4151 4152 /* 4153 * As in vm_map_merged_neighbor_dispose(), 4154 * the vnode lock will not be acquired in 4155 * this call to vm_object_deallocate(). 4156 */ 4157 vm_object_deallocate(object); 4158 object = old_entry->object.vm_object; 4159 } else { 4160 VM_OBJECT_WLOCK(object); 4161 vm_object_clear_flag(object, OBJ_ONEMAPPING); 4162 if (old_entry->cred != NULL) { 4163 KASSERT(object->cred == NULL, 4164 ("vmspace_fork both cred")); 4165 object->cred = old_entry->cred; 4166 object->charge = old_entry->end - 4167 old_entry->start; 4168 old_entry->cred = NULL; 4169 } 4170 4171 /* 4172 * Assert the correct state of the vnode 4173 * v_writecount while the object is locked, to 4174 * not relock it later for the assertion 4175 * correctness. 4176 */ 4177 if (old_entry->eflags & MAP_ENTRY_WRITECNT && 4178 object->type == OBJT_VNODE) { 4179 KASSERT(((struct vnode *)object-> 4180 handle)->v_writecount > 0, 4181 ("vmspace_fork: v_writecount %p", 4182 object)); 4183 KASSERT(object->un_pager.vnp. 4184 writemappings > 0, 4185 ("vmspace_fork: vnp.writecount %p", 4186 object)); 4187 } 4188 VM_OBJECT_WUNLOCK(object); 4189 } 4190 4191 /* 4192 * Clone the entry, referencing the shared object. 4193 */ 4194 new_entry = vm_map_entry_create(new_map); 4195 *new_entry = *old_entry; 4196 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 4197 MAP_ENTRY_IN_TRANSITION); 4198 new_entry->wiring_thread = NULL; 4199 new_entry->wired_count = 0; 4200 if (new_entry->eflags & MAP_ENTRY_WRITECNT) { 4201 vm_pager_update_writecount(object, 4202 new_entry->start, new_entry->end); 4203 } 4204 vm_map_entry_set_vnode_text(new_entry, true); 4205 4206 /* 4207 * Insert the entry into the new map -- we know we're 4208 * inserting at the end of the new map. 4209 */ 4210 vm_map_entry_link(new_map, new_entry); 4211 vmspace_map_entry_forked(vm1, vm2, new_entry); 4212 4213 /* 4214 * Update the physical map 4215 */ 4216 pmap_copy(new_map->pmap, old_map->pmap, 4217 new_entry->start, 4218 (old_entry->end - old_entry->start), 4219 old_entry->start); 4220 break; 4221 4222 case VM_INHERIT_COPY: 4223 /* 4224 * Clone the entry and link into the map. 4225 */ 4226 new_entry = vm_map_entry_create(new_map); 4227 *new_entry = *old_entry; 4228 /* 4229 * Copied entry is COW over the old object. 4230 */ 4231 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 4232 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WRITECNT); 4233 new_entry->wiring_thread = NULL; 4234 new_entry->wired_count = 0; 4235 new_entry->object.vm_object = NULL; 4236 new_entry->cred = NULL; 4237 vm_map_entry_link(new_map, new_entry); 4238 vmspace_map_entry_forked(vm1, vm2, new_entry); 4239 vm_map_copy_entry(old_map, new_map, old_entry, 4240 new_entry, fork_charge); 4241 vm_map_entry_set_vnode_text(new_entry, true); 4242 break; 4243 4244 case VM_INHERIT_ZERO: 4245 /* 4246 * Create a new anonymous mapping entry modelled from 4247 * the old one. 4248 */ 4249 new_entry = vm_map_entry_create(new_map); 4250 memset(new_entry, 0, sizeof(*new_entry)); 4251 4252 new_entry->start = old_entry->start; 4253 new_entry->end = old_entry->end; 4254 new_entry->eflags = old_entry->eflags & 4255 ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION | 4256 MAP_ENTRY_WRITECNT | MAP_ENTRY_VN_EXEC); 4257 new_entry->protection = old_entry->protection; 4258 new_entry->max_protection = old_entry->max_protection; 4259 new_entry->inheritance = VM_INHERIT_ZERO; 4260 4261 vm_map_entry_link(new_map, new_entry); 4262 vmspace_map_entry_forked(vm1, vm2, new_entry); 4263 4264 new_entry->cred = curthread->td_ucred; 4265 crhold(new_entry->cred); 4266 *fork_charge += (new_entry->end - new_entry->start); 4267 4268 break; 4269 } 4270 } 4271 /* 4272 * Use inlined vm_map_unlock() to postpone handling the deferred 4273 * map entries, which cannot be done until both old_map and 4274 * new_map locks are released. 4275 */ 4276 sx_xunlock(&old_map->lock); 4277 sx_xunlock(&new_map->lock); 4278 vm_map_process_deferred(); 4279 4280 return (vm2); 4281 } 4282 4283 /* 4284 * Create a process's stack for exec_new_vmspace(). This function is never 4285 * asked to wire the newly created stack. 4286 */ 4287 int 4288 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 4289 vm_prot_t prot, vm_prot_t max, int cow) 4290 { 4291 vm_size_t growsize, init_ssize; 4292 rlim_t vmemlim; 4293 int rv; 4294 4295 MPASS((map->flags & MAP_WIREFUTURE) == 0); 4296 growsize = sgrowsiz; 4297 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 4298 vm_map_lock(map); 4299 vmemlim = lim_cur(curthread, RLIMIT_VMEM); 4300 /* If we would blow our VMEM resource limit, no go */ 4301 if (map->size + init_ssize > vmemlim) { 4302 rv = KERN_NO_SPACE; 4303 goto out; 4304 } 4305 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, 4306 max, cow); 4307 out: 4308 vm_map_unlock(map); 4309 return (rv); 4310 } 4311 4312 static int stack_guard_page = 1; 4313 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN, 4314 &stack_guard_page, 0, 4315 "Specifies the number of guard pages for a stack that grows"); 4316 4317 static int 4318 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 4319 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) 4320 { 4321 vm_map_entry_t new_entry, prev_entry; 4322 vm_offset_t bot, gap_bot, gap_top, top; 4323 vm_size_t init_ssize, sgp; 4324 int orient, rv; 4325 4326 /* 4327 * The stack orientation is piggybacked with the cow argument. 4328 * Extract it into orient and mask the cow argument so that we 4329 * don't pass it around further. 4330 */ 4331 orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP); 4332 KASSERT(orient != 0, ("No stack grow direction")); 4333 KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP), 4334 ("bi-dir stack")); 4335 4336 if (max_ssize == 0 || 4337 !vm_map_range_valid(map, addrbos, addrbos + max_ssize)) 4338 return (KERN_INVALID_ADDRESS); 4339 sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 || 4340 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 : 4341 (vm_size_t)stack_guard_page * PAGE_SIZE; 4342 if (sgp >= max_ssize) 4343 return (KERN_INVALID_ARGUMENT); 4344 4345 init_ssize = growsize; 4346 if (max_ssize < init_ssize + sgp) 4347 init_ssize = max_ssize - sgp; 4348 4349 /* If addr is already mapped, no go */ 4350 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) 4351 return (KERN_NO_SPACE); 4352 4353 /* 4354 * If we can't accommodate max_ssize in the current mapping, no go. 4355 */ 4356 if (vm_map_entry_succ(prev_entry)->start < addrbos + max_ssize) 4357 return (KERN_NO_SPACE); 4358 4359 /* 4360 * We initially map a stack of only init_ssize. We will grow as 4361 * needed later. Depending on the orientation of the stack (i.e. 4362 * the grow direction) we either map at the top of the range, the 4363 * bottom of the range or in the middle. 4364 * 4365 * Note: we would normally expect prot and max to be VM_PROT_ALL, 4366 * and cow to be 0. Possibly we should eliminate these as input 4367 * parameters, and just pass these values here in the insert call. 4368 */ 4369 if (orient == MAP_STACK_GROWS_DOWN) { 4370 bot = addrbos + max_ssize - init_ssize; 4371 top = bot + init_ssize; 4372 gap_bot = addrbos; 4373 gap_top = bot; 4374 } else /* if (orient == MAP_STACK_GROWS_UP) */ { 4375 bot = addrbos; 4376 top = bot + init_ssize; 4377 gap_bot = top; 4378 gap_top = addrbos + max_ssize; 4379 } 4380 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 4381 if (rv != KERN_SUCCESS) 4382 return (rv); 4383 new_entry = vm_map_entry_succ(prev_entry); 4384 KASSERT(new_entry->end == top || new_entry->start == bot, 4385 ("Bad entry start/end for new stack entry")); 4386 KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 || 4387 (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0, 4388 ("new entry lacks MAP_ENTRY_GROWS_DOWN")); 4389 KASSERT((orient & MAP_STACK_GROWS_UP) == 0 || 4390 (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0, 4391 ("new entry lacks MAP_ENTRY_GROWS_UP")); 4392 if (gap_bot == gap_top) 4393 return (KERN_SUCCESS); 4394 rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE, 4395 VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ? 4396 MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP)); 4397 if (rv == KERN_SUCCESS) { 4398 /* 4399 * Gap can never successfully handle a fault, so 4400 * read-ahead logic is never used for it. Re-use 4401 * next_read of the gap entry to store 4402 * stack_guard_page for vm_map_growstack(). 4403 */ 4404 if (orient == MAP_STACK_GROWS_DOWN) 4405 vm_map_entry_pred(new_entry)->next_read = sgp; 4406 else 4407 vm_map_entry_succ(new_entry)->next_read = sgp; 4408 } else { 4409 (void)vm_map_delete(map, bot, top); 4410 } 4411 return (rv); 4412 } 4413 4414 /* 4415 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we 4416 * successfully grow the stack. 4417 */ 4418 static int 4419 vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry) 4420 { 4421 vm_map_entry_t stack_entry; 4422 struct proc *p; 4423 struct vmspace *vm; 4424 struct ucred *cred; 4425 vm_offset_t gap_end, gap_start, grow_start; 4426 vm_size_t grow_amount, guard, max_grow; 4427 rlim_t lmemlim, stacklim, vmemlim; 4428 int rv, rv1; 4429 bool gap_deleted, grow_down, is_procstack; 4430 #ifdef notyet 4431 uint64_t limit; 4432 #endif 4433 #ifdef RACCT 4434 int error; 4435 #endif 4436 4437 p = curproc; 4438 vm = p->p_vmspace; 4439 4440 /* 4441 * Disallow stack growth when the access is performed by a 4442 * debugger or AIO daemon. The reason is that the wrong 4443 * resource limits are applied. 4444 */ 4445 if (p != initproc && (map != &p->p_vmspace->vm_map || 4446 p->p_textvp == NULL)) 4447 return (KERN_FAILURE); 4448 4449 MPASS(!map->system_map); 4450 4451 lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK); 4452 stacklim = lim_cur(curthread, RLIMIT_STACK); 4453 vmemlim = lim_cur(curthread, RLIMIT_VMEM); 4454 retry: 4455 /* If addr is not in a hole for a stack grow area, no need to grow. */ 4456 if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry)) 4457 return (KERN_FAILURE); 4458 if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0) 4459 return (KERN_SUCCESS); 4460 if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) { 4461 stack_entry = vm_map_entry_succ(gap_entry); 4462 if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 || 4463 stack_entry->start != gap_entry->end) 4464 return (KERN_FAILURE); 4465 grow_amount = round_page(stack_entry->start - addr); 4466 grow_down = true; 4467 } else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) { 4468 stack_entry = vm_map_entry_pred(gap_entry); 4469 if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 || 4470 stack_entry->end != gap_entry->start) 4471 return (KERN_FAILURE); 4472 grow_amount = round_page(addr + 1 - stack_entry->end); 4473 grow_down = false; 4474 } else { 4475 return (KERN_FAILURE); 4476 } 4477 guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 || 4478 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 : 4479 gap_entry->next_read; 4480 max_grow = gap_entry->end - gap_entry->start; 4481 if (guard > max_grow) 4482 return (KERN_NO_SPACE); 4483 max_grow -= guard; 4484 if (grow_amount > max_grow) 4485 return (KERN_NO_SPACE); 4486 4487 /* 4488 * If this is the main process stack, see if we're over the stack 4489 * limit. 4490 */ 4491 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr && 4492 addr < (vm_offset_t)p->p_sysent->sv_usrstack; 4493 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) 4494 return (KERN_NO_SPACE); 4495 4496 #ifdef RACCT 4497 if (racct_enable) { 4498 PROC_LOCK(p); 4499 if (is_procstack && racct_set(p, RACCT_STACK, 4500 ctob(vm->vm_ssize) + grow_amount)) { 4501 PROC_UNLOCK(p); 4502 return (KERN_NO_SPACE); 4503 } 4504 PROC_UNLOCK(p); 4505 } 4506 #endif 4507 4508 grow_amount = roundup(grow_amount, sgrowsiz); 4509 if (grow_amount > max_grow) 4510 grow_amount = max_grow; 4511 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 4512 grow_amount = trunc_page((vm_size_t)stacklim) - 4513 ctob(vm->vm_ssize); 4514 } 4515 4516 #ifdef notyet 4517 PROC_LOCK(p); 4518 limit = racct_get_available(p, RACCT_STACK); 4519 PROC_UNLOCK(p); 4520 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 4521 grow_amount = limit - ctob(vm->vm_ssize); 4522 #endif 4523 4524 if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) { 4525 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 4526 rv = KERN_NO_SPACE; 4527 goto out; 4528 } 4529 #ifdef RACCT 4530 if (racct_enable) { 4531 PROC_LOCK(p); 4532 if (racct_set(p, RACCT_MEMLOCK, 4533 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 4534 PROC_UNLOCK(p); 4535 rv = KERN_NO_SPACE; 4536 goto out; 4537 } 4538 PROC_UNLOCK(p); 4539 } 4540 #endif 4541 } 4542 4543 /* If we would blow our VMEM resource limit, no go */ 4544 if (map->size + grow_amount > vmemlim) { 4545 rv = KERN_NO_SPACE; 4546 goto out; 4547 } 4548 #ifdef RACCT 4549 if (racct_enable) { 4550 PROC_LOCK(p); 4551 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 4552 PROC_UNLOCK(p); 4553 rv = KERN_NO_SPACE; 4554 goto out; 4555 } 4556 PROC_UNLOCK(p); 4557 } 4558 #endif 4559 4560 if (vm_map_lock_upgrade(map)) { 4561 gap_entry = NULL; 4562 vm_map_lock_read(map); 4563 goto retry; 4564 } 4565 4566 if (grow_down) { 4567 grow_start = gap_entry->end - grow_amount; 4568 if (gap_entry->start + grow_amount == gap_entry->end) { 4569 gap_start = gap_entry->start; 4570 gap_end = gap_entry->end; 4571 vm_map_entry_delete(map, gap_entry); 4572 gap_deleted = true; 4573 } else { 4574 MPASS(gap_entry->start < gap_entry->end - grow_amount); 4575 vm_map_entry_resize(map, gap_entry, -grow_amount); 4576 gap_deleted = false; 4577 } 4578 rv = vm_map_insert(map, NULL, 0, grow_start, 4579 grow_start + grow_amount, 4580 stack_entry->protection, stack_entry->max_protection, 4581 MAP_STACK_GROWS_DOWN); 4582 if (rv != KERN_SUCCESS) { 4583 if (gap_deleted) { 4584 rv1 = vm_map_insert(map, NULL, 0, gap_start, 4585 gap_end, VM_PROT_NONE, VM_PROT_NONE, 4586 MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN); 4587 MPASS(rv1 == KERN_SUCCESS); 4588 } else 4589 vm_map_entry_resize(map, gap_entry, 4590 grow_amount); 4591 } 4592 } else { 4593 grow_start = stack_entry->end; 4594 cred = stack_entry->cred; 4595 if (cred == NULL && stack_entry->object.vm_object != NULL) 4596 cred = stack_entry->object.vm_object->cred; 4597 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 4598 rv = KERN_NO_SPACE; 4599 /* Grow the underlying object if applicable. */ 4600 else if (stack_entry->object.vm_object == NULL || 4601 vm_object_coalesce(stack_entry->object.vm_object, 4602 stack_entry->offset, 4603 (vm_size_t)(stack_entry->end - stack_entry->start), 4604 grow_amount, cred != NULL)) { 4605 if (gap_entry->start + grow_amount == gap_entry->end) { 4606 vm_map_entry_delete(map, gap_entry); 4607 vm_map_entry_resize(map, stack_entry, 4608 grow_amount); 4609 } else { 4610 gap_entry->start += grow_amount; 4611 stack_entry->end += grow_amount; 4612 } 4613 map->size += grow_amount; 4614 rv = KERN_SUCCESS; 4615 } else 4616 rv = KERN_FAILURE; 4617 } 4618 if (rv == KERN_SUCCESS && is_procstack) 4619 vm->vm_ssize += btoc(grow_amount); 4620 4621 /* 4622 * Heed the MAP_WIREFUTURE flag if it was set for this process. 4623 */ 4624 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) { 4625 rv = vm_map_wire_locked(map, grow_start, 4626 grow_start + grow_amount, 4627 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES); 4628 } 4629 vm_map_lock_downgrade(map); 4630 4631 out: 4632 #ifdef RACCT 4633 if (racct_enable && rv != KERN_SUCCESS) { 4634 PROC_LOCK(p); 4635 error = racct_set(p, RACCT_VMEM, map->size); 4636 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 4637 if (!old_mlock) { 4638 error = racct_set(p, RACCT_MEMLOCK, 4639 ptoa(pmap_wired_count(map->pmap))); 4640 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 4641 } 4642 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 4643 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 4644 PROC_UNLOCK(p); 4645 } 4646 #endif 4647 4648 return (rv); 4649 } 4650 4651 /* 4652 * Unshare the specified VM space for exec. If other processes are 4653 * mapped to it, then create a new one. The new vmspace is null. 4654 */ 4655 int 4656 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 4657 { 4658 struct vmspace *oldvmspace = p->p_vmspace; 4659 struct vmspace *newvmspace; 4660 4661 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 4662 ("vmspace_exec recursed")); 4663 newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit); 4664 if (newvmspace == NULL) 4665 return (ENOMEM); 4666 newvmspace->vm_swrss = oldvmspace->vm_swrss; 4667 /* 4668 * This code is written like this for prototype purposes. The 4669 * goal is to avoid running down the vmspace here, but let the 4670 * other process's that are still using the vmspace to finally 4671 * run it down. Even though there is little or no chance of blocking 4672 * here, it is a good idea to keep this form for future mods. 4673 */ 4674 PROC_VMSPACE_LOCK(p); 4675 p->p_vmspace = newvmspace; 4676 PROC_VMSPACE_UNLOCK(p); 4677 if (p == curthread->td_proc) 4678 pmap_activate(curthread); 4679 curthread->td_pflags |= TDP_EXECVMSPC; 4680 return (0); 4681 } 4682 4683 /* 4684 * Unshare the specified VM space for forcing COW. This 4685 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 4686 */ 4687 int 4688 vmspace_unshare(struct proc *p) 4689 { 4690 struct vmspace *oldvmspace = p->p_vmspace; 4691 struct vmspace *newvmspace; 4692 vm_ooffset_t fork_charge; 4693 4694 if (oldvmspace->vm_refcnt == 1) 4695 return (0); 4696 fork_charge = 0; 4697 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 4698 if (newvmspace == NULL) 4699 return (ENOMEM); 4700 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 4701 vmspace_free(newvmspace); 4702 return (ENOMEM); 4703 } 4704 PROC_VMSPACE_LOCK(p); 4705 p->p_vmspace = newvmspace; 4706 PROC_VMSPACE_UNLOCK(p); 4707 if (p == curthread->td_proc) 4708 pmap_activate(curthread); 4709 vmspace_free(oldvmspace); 4710 return (0); 4711 } 4712 4713 /* 4714 * vm_map_lookup: 4715 * 4716 * Finds the VM object, offset, and 4717 * protection for a given virtual address in the 4718 * specified map, assuming a page fault of the 4719 * type specified. 4720 * 4721 * Leaves the map in question locked for read; return 4722 * values are guaranteed until a vm_map_lookup_done 4723 * call is performed. Note that the map argument 4724 * is in/out; the returned map must be used in 4725 * the call to vm_map_lookup_done. 4726 * 4727 * A handle (out_entry) is returned for use in 4728 * vm_map_lookup_done, to make that fast. 4729 * 4730 * If a lookup is requested with "write protection" 4731 * specified, the map may be changed to perform virtual 4732 * copying operations, although the data referenced will 4733 * remain the same. 4734 */ 4735 int 4736 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 4737 vm_offset_t vaddr, 4738 vm_prot_t fault_typea, 4739 vm_map_entry_t *out_entry, /* OUT */ 4740 vm_object_t *object, /* OUT */ 4741 vm_pindex_t *pindex, /* OUT */ 4742 vm_prot_t *out_prot, /* OUT */ 4743 boolean_t *wired) /* OUT */ 4744 { 4745 vm_map_entry_t entry; 4746 vm_map_t map = *var_map; 4747 vm_prot_t prot; 4748 vm_prot_t fault_type; 4749 vm_object_t eobject; 4750 vm_size_t size; 4751 struct ucred *cred; 4752 4753 RetryLookup: 4754 4755 vm_map_lock_read(map); 4756 4757 RetryLookupLocked: 4758 /* 4759 * Lookup the faulting address. 4760 */ 4761 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 4762 vm_map_unlock_read(map); 4763 return (KERN_INVALID_ADDRESS); 4764 } 4765 4766 entry = *out_entry; 4767 4768 /* 4769 * Handle submaps. 4770 */ 4771 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4772 vm_map_t old_map = map; 4773 4774 *var_map = map = entry->object.sub_map; 4775 vm_map_unlock_read(old_map); 4776 goto RetryLookup; 4777 } 4778 4779 /* 4780 * Check whether this task is allowed to have this page. 4781 */ 4782 prot = entry->protection; 4783 if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) { 4784 fault_typea &= ~VM_PROT_FAULT_LOOKUP; 4785 if (prot == VM_PROT_NONE && map != kernel_map && 4786 (entry->eflags & MAP_ENTRY_GUARD) != 0 && 4787 (entry->eflags & (MAP_ENTRY_STACK_GAP_DN | 4788 MAP_ENTRY_STACK_GAP_UP)) != 0 && 4789 vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS) 4790 goto RetryLookupLocked; 4791 } 4792 fault_type = fault_typea & VM_PROT_ALL; 4793 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 4794 vm_map_unlock_read(map); 4795 return (KERN_PROTECTION_FAILURE); 4796 } 4797 KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags & 4798 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) != 4799 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY), 4800 ("entry %p flags %x", entry, entry->eflags)); 4801 if ((fault_typea & VM_PROT_COPY) != 0 && 4802 (entry->max_protection & VM_PROT_WRITE) == 0 && 4803 (entry->eflags & MAP_ENTRY_COW) == 0) { 4804 vm_map_unlock_read(map); 4805 return (KERN_PROTECTION_FAILURE); 4806 } 4807 4808 /* 4809 * If this page is not pageable, we have to get it for all possible 4810 * accesses. 4811 */ 4812 *wired = (entry->wired_count != 0); 4813 if (*wired) 4814 fault_type = entry->protection; 4815 size = entry->end - entry->start; 4816 4817 /* 4818 * If the entry was copy-on-write, we either ... 4819 */ 4820 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4821 /* 4822 * If we want to write the page, we may as well handle that 4823 * now since we've got the map locked. 4824 * 4825 * If we don't need to write the page, we just demote the 4826 * permissions allowed. 4827 */ 4828 if ((fault_type & VM_PROT_WRITE) != 0 || 4829 (fault_typea & VM_PROT_COPY) != 0) { 4830 /* 4831 * Make a new object, and place it in the object 4832 * chain. Note that no new references have appeared 4833 * -- one just moved from the map to the new 4834 * object. 4835 */ 4836 if (vm_map_lock_upgrade(map)) 4837 goto RetryLookup; 4838 4839 if (entry->cred == NULL) { 4840 /* 4841 * The debugger owner is charged for 4842 * the memory. 4843 */ 4844 cred = curthread->td_ucred; 4845 crhold(cred); 4846 if (!swap_reserve_by_cred(size, cred)) { 4847 crfree(cred); 4848 vm_map_unlock(map); 4849 return (KERN_RESOURCE_SHORTAGE); 4850 } 4851 entry->cred = cred; 4852 } 4853 eobject = entry->object.vm_object; 4854 vm_object_shadow(&entry->object.vm_object, 4855 &entry->offset, size, entry->cred, false); 4856 if (eobject == entry->object.vm_object) { 4857 /* 4858 * The object was not shadowed. 4859 */ 4860 swap_release_by_cred(size, entry->cred); 4861 crfree(entry->cred); 4862 } 4863 entry->cred = NULL; 4864 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4865 4866 vm_map_lock_downgrade(map); 4867 } else { 4868 /* 4869 * We're attempting to read a copy-on-write page -- 4870 * don't allow writes. 4871 */ 4872 prot &= ~VM_PROT_WRITE; 4873 } 4874 } 4875 4876 /* 4877 * Create an object if necessary. 4878 */ 4879 if (entry->object.vm_object == NULL && !map->system_map) { 4880 if (vm_map_lock_upgrade(map)) 4881 goto RetryLookup; 4882 entry->object.vm_object = vm_object_allocate_anon(atop(size), 4883 NULL, entry->cred, entry->cred != NULL ? size : 0); 4884 entry->offset = 0; 4885 entry->cred = NULL; 4886 vm_map_lock_downgrade(map); 4887 } 4888 4889 /* 4890 * Return the object/offset from this entry. If the entry was 4891 * copy-on-write or empty, it has been fixed up. 4892 */ 4893 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4894 *object = entry->object.vm_object; 4895 4896 *out_prot = prot; 4897 return (KERN_SUCCESS); 4898 } 4899 4900 /* 4901 * vm_map_lookup_locked: 4902 * 4903 * Lookup the faulting address. A version of vm_map_lookup that returns 4904 * KERN_FAILURE instead of blocking on map lock or memory allocation. 4905 */ 4906 int 4907 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4908 vm_offset_t vaddr, 4909 vm_prot_t fault_typea, 4910 vm_map_entry_t *out_entry, /* OUT */ 4911 vm_object_t *object, /* OUT */ 4912 vm_pindex_t *pindex, /* OUT */ 4913 vm_prot_t *out_prot, /* OUT */ 4914 boolean_t *wired) /* OUT */ 4915 { 4916 vm_map_entry_t entry; 4917 vm_map_t map = *var_map; 4918 vm_prot_t prot; 4919 vm_prot_t fault_type = fault_typea; 4920 4921 /* 4922 * Lookup the faulting address. 4923 */ 4924 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4925 return (KERN_INVALID_ADDRESS); 4926 4927 entry = *out_entry; 4928 4929 /* 4930 * Fail if the entry refers to a submap. 4931 */ 4932 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4933 return (KERN_FAILURE); 4934 4935 /* 4936 * Check whether this task is allowed to have this page. 4937 */ 4938 prot = entry->protection; 4939 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4940 if ((fault_type & prot) != fault_type) 4941 return (KERN_PROTECTION_FAILURE); 4942 4943 /* 4944 * If this page is not pageable, we have to get it for all possible 4945 * accesses. 4946 */ 4947 *wired = (entry->wired_count != 0); 4948 if (*wired) 4949 fault_type = entry->protection; 4950 4951 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4952 /* 4953 * Fail if the entry was copy-on-write for a write fault. 4954 */ 4955 if (fault_type & VM_PROT_WRITE) 4956 return (KERN_FAILURE); 4957 /* 4958 * We're attempting to read a copy-on-write page -- 4959 * don't allow writes. 4960 */ 4961 prot &= ~VM_PROT_WRITE; 4962 } 4963 4964 /* 4965 * Fail if an object should be created. 4966 */ 4967 if (entry->object.vm_object == NULL && !map->system_map) 4968 return (KERN_FAILURE); 4969 4970 /* 4971 * Return the object/offset from this entry. If the entry was 4972 * copy-on-write or empty, it has been fixed up. 4973 */ 4974 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4975 *object = entry->object.vm_object; 4976 4977 *out_prot = prot; 4978 return (KERN_SUCCESS); 4979 } 4980 4981 /* 4982 * vm_map_lookup_done: 4983 * 4984 * Releases locks acquired by a vm_map_lookup 4985 * (according to the handle returned by that lookup). 4986 */ 4987 void 4988 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4989 { 4990 /* 4991 * Unlock the main-level map 4992 */ 4993 vm_map_unlock_read(map); 4994 } 4995 4996 vm_offset_t 4997 vm_map_max_KBI(const struct vm_map *map) 4998 { 4999 5000 return (vm_map_max(map)); 5001 } 5002 5003 vm_offset_t 5004 vm_map_min_KBI(const struct vm_map *map) 5005 { 5006 5007 return (vm_map_min(map)); 5008 } 5009 5010 pmap_t 5011 vm_map_pmap_KBI(vm_map_t map) 5012 { 5013 5014 return (map->pmap); 5015 } 5016 5017 #ifdef INVARIANTS 5018 static void 5019 _vm_map_assert_consistent(vm_map_t map, int check) 5020 { 5021 vm_map_entry_t entry, prev; 5022 vm_map_entry_t cur, header, lbound, ubound; 5023 vm_size_t max_left, max_right; 5024 5025 #ifdef DIAGNOSTIC 5026 ++map->nupdates; 5027 #endif 5028 if (enable_vmmap_check != check) 5029 return; 5030 5031 header = prev = &map->header; 5032 VM_MAP_ENTRY_FOREACH(entry, map) { 5033 KASSERT(prev->end <= entry->start, 5034 ("map %p prev->end = %jx, start = %jx", map, 5035 (uintmax_t)prev->end, (uintmax_t)entry->start)); 5036 KASSERT(entry->start < entry->end, 5037 ("map %p start = %jx, end = %jx", map, 5038 (uintmax_t)entry->start, (uintmax_t)entry->end)); 5039 KASSERT(entry->left == header || 5040 entry->left->start < entry->start, 5041 ("map %p left->start = %jx, start = %jx", map, 5042 (uintmax_t)entry->left->start, (uintmax_t)entry->start)); 5043 KASSERT(entry->right == header || 5044 entry->start < entry->right->start, 5045 ("map %p start = %jx, right->start = %jx", map, 5046 (uintmax_t)entry->start, (uintmax_t)entry->right->start)); 5047 cur = map->root; 5048 lbound = ubound = header; 5049 for (;;) { 5050 if (entry->start < cur->start) { 5051 ubound = cur; 5052 cur = cur->left; 5053 KASSERT(cur != lbound, 5054 ("map %p cannot find %jx", 5055 map, (uintmax_t)entry->start)); 5056 } else if (cur->end <= entry->start) { 5057 lbound = cur; 5058 cur = cur->right; 5059 KASSERT(cur != ubound, 5060 ("map %p cannot find %jx", 5061 map, (uintmax_t)entry->start)); 5062 } else { 5063 KASSERT(cur == entry, 5064 ("map %p cannot find %jx", 5065 map, (uintmax_t)entry->start)); 5066 break; 5067 } 5068 } 5069 max_left = vm_map_entry_max_free_left(entry, lbound); 5070 max_right = vm_map_entry_max_free_right(entry, ubound); 5071 KASSERT(entry->max_free == vm_size_max(max_left, max_right), 5072 ("map %p max = %jx, max_left = %jx, max_right = %jx", map, 5073 (uintmax_t)entry->max_free, 5074 (uintmax_t)max_left, (uintmax_t)max_right)); 5075 prev = entry; 5076 } 5077 KASSERT(prev->end <= entry->start, 5078 ("map %p prev->end = %jx, start = %jx", map, 5079 (uintmax_t)prev->end, (uintmax_t)entry->start)); 5080 } 5081 #endif 5082 5083 #include "opt_ddb.h" 5084 #ifdef DDB 5085 #include <sys/kernel.h> 5086 5087 #include <ddb/ddb.h> 5088 5089 static void 5090 vm_map_print(vm_map_t map) 5091 { 5092 vm_map_entry_t entry, prev; 5093 5094 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 5095 (void *)map, 5096 (void *)map->pmap, map->nentries, map->timestamp); 5097 5098 db_indent += 2; 5099 prev = &map->header; 5100 VM_MAP_ENTRY_FOREACH(entry, map) { 5101 db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n", 5102 (void *)entry, (void *)entry->start, (void *)entry->end, 5103 entry->eflags); 5104 { 5105 static const char * const inheritance_name[4] = 5106 {"share", "copy", "none", "donate_copy"}; 5107 5108 db_iprintf(" prot=%x/%x/%s", 5109 entry->protection, 5110 entry->max_protection, 5111 inheritance_name[(int)(unsigned char) 5112 entry->inheritance]); 5113 if (entry->wired_count != 0) 5114 db_printf(", wired"); 5115 } 5116 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 5117 db_printf(", share=%p, offset=0x%jx\n", 5118 (void *)entry->object.sub_map, 5119 (uintmax_t)entry->offset); 5120 if (prev == &map->header || 5121 prev->object.sub_map != 5122 entry->object.sub_map) { 5123 db_indent += 2; 5124 vm_map_print((vm_map_t)entry->object.sub_map); 5125 db_indent -= 2; 5126 } 5127 } else { 5128 if (entry->cred != NULL) 5129 db_printf(", ruid %d", entry->cred->cr_ruid); 5130 db_printf(", object=%p, offset=0x%jx", 5131 (void *)entry->object.vm_object, 5132 (uintmax_t)entry->offset); 5133 if (entry->object.vm_object && entry->object.vm_object->cred) 5134 db_printf(", obj ruid %d charge %jx", 5135 entry->object.vm_object->cred->cr_ruid, 5136 (uintmax_t)entry->object.vm_object->charge); 5137 if (entry->eflags & MAP_ENTRY_COW) 5138 db_printf(", copy (%s)", 5139 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 5140 db_printf("\n"); 5141 5142 if (prev == &map->header || 5143 prev->object.vm_object != 5144 entry->object.vm_object) { 5145 db_indent += 2; 5146 vm_object_print((db_expr_t)(intptr_t) 5147 entry->object.vm_object, 5148 0, 0, (char *)0); 5149 db_indent -= 2; 5150 } 5151 } 5152 prev = entry; 5153 } 5154 db_indent -= 2; 5155 } 5156 5157 DB_SHOW_COMMAND(map, map) 5158 { 5159 5160 if (!have_addr) { 5161 db_printf("usage: show map <addr>\n"); 5162 return; 5163 } 5164 vm_map_print((vm_map_t)addr); 5165 } 5166 5167 DB_SHOW_COMMAND(procvm, procvm) 5168 { 5169 struct proc *p; 5170 5171 if (have_addr) { 5172 p = db_lookup_proc(addr); 5173 } else { 5174 p = curproc; 5175 } 5176 5177 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 5178 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 5179 (void *)vmspace_pmap(p->p_vmspace)); 5180 5181 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 5182 } 5183 5184 #endif /* DDB */ 5185