1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 35 * 36 * 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * Virtual memory mapping module. 65 */ 66 67 #include <sys/cdefs.h> 68 __FBSDID("$FreeBSD$"); 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/elf.h> 73 #include <sys/kernel.h> 74 #include <sys/ktr.h> 75 #include <sys/lock.h> 76 #include <sys/mutex.h> 77 #include <sys/proc.h> 78 #include <sys/vmmeter.h> 79 #include <sys/mman.h> 80 #include <sys/vnode.h> 81 #include <sys/racct.h> 82 #include <sys/resourcevar.h> 83 #include <sys/rwlock.h> 84 #include <sys/file.h> 85 #include <sys/sysctl.h> 86 #include <sys/sysent.h> 87 #include <sys/shm.h> 88 89 #include <vm/vm.h> 90 #include <vm/vm_param.h> 91 #include <vm/pmap.h> 92 #include <vm/vm_map.h> 93 #include <vm/vm_page.h> 94 #include <vm/vm_pageout.h> 95 #include <vm/vm_object.h> 96 #include <vm/vm_pager.h> 97 #include <vm/vm_kern.h> 98 #include <vm/vm_extern.h> 99 #include <vm/vnode_pager.h> 100 #include <vm/swap_pager.h> 101 #include <vm/uma.h> 102 103 /* 104 * Virtual memory maps provide for the mapping, protection, 105 * and sharing of virtual memory objects. In addition, 106 * this module provides for an efficient virtual copy of 107 * memory from one map to another. 108 * 109 * Synchronization is required prior to most operations. 110 * 111 * Maps consist of an ordered doubly-linked list of simple 112 * entries; a self-adjusting binary search tree of these 113 * entries is used to speed up lookups. 114 * 115 * Since portions of maps are specified by start/end addresses, 116 * which may not align with existing map entries, all 117 * routines merely "clip" entries to these start/end values. 118 * [That is, an entry is split into two, bordering at a 119 * start or end value.] Note that these clippings may not 120 * always be necessary (as the two resulting entries are then 121 * not changed); however, the clipping is done for convenience. 122 * 123 * As mentioned above, virtual copy operations are performed 124 * by copying VM object references from one map to 125 * another, and then marking both regions as copy-on-write. 126 */ 127 128 static struct mtx map_sleep_mtx; 129 static uma_zone_t mapentzone; 130 static uma_zone_t kmapentzone; 131 static uma_zone_t mapzone; 132 static uma_zone_t vmspace_zone; 133 static int vmspace_zinit(void *mem, int size, int flags); 134 static int vm_map_zinit(void *mem, int ize, int flags); 135 static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, 136 vm_offset_t max); 137 static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map); 138 static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry); 139 static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry); 140 static int vm_map_growstack(vm_map_t map, vm_offset_t addr, 141 vm_map_entry_t gap_entry); 142 static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 143 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags); 144 #ifdef INVARIANTS 145 static void vm_map_zdtor(void *mem, int size, void *arg); 146 static void vmspace_zdtor(void *mem, int size, void *arg); 147 #endif 148 static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, 149 vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max, 150 int cow); 151 static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 152 vm_offset_t failed_addr); 153 154 #define ENTRY_CHARGED(e) ((e)->cred != NULL || \ 155 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \ 156 !((e)->eflags & MAP_ENTRY_NEEDS_COPY))) 157 158 /* 159 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type 160 * stable. 161 */ 162 #define PROC_VMSPACE_LOCK(p) do { } while (0) 163 #define PROC_VMSPACE_UNLOCK(p) do { } while (0) 164 165 /* 166 * VM_MAP_RANGE_CHECK: [ internal use only ] 167 * 168 * Asserts that the starting and ending region 169 * addresses fall within the valid range of the map. 170 */ 171 #define VM_MAP_RANGE_CHECK(map, start, end) \ 172 { \ 173 if (start < vm_map_min(map)) \ 174 start = vm_map_min(map); \ 175 if (end > vm_map_max(map)) \ 176 end = vm_map_max(map); \ 177 if (start > end) \ 178 start = end; \ 179 } 180 181 /* 182 * vm_map_startup: 183 * 184 * Initialize the vm_map module. Must be called before 185 * any other vm_map routines. 186 * 187 * Map and entry structures are allocated from the general 188 * purpose memory pool with some exceptions: 189 * 190 * - The kernel map and kmem submap are allocated statically. 191 * - Kernel map entries are allocated out of a static pool. 192 * 193 * These restrictions are necessary since malloc() uses the 194 * maps and requires map entries. 195 */ 196 197 void 198 vm_map_startup(void) 199 { 200 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF); 201 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL, 202 #ifdef INVARIANTS 203 vm_map_zdtor, 204 #else 205 NULL, 206 #endif 207 vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 208 uma_prealloc(mapzone, MAX_KMAP); 209 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry), 210 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 211 UMA_ZONE_MTXCLASS | UMA_ZONE_VM); 212 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry), 213 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 214 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL, 215 #ifdef INVARIANTS 216 vmspace_zdtor, 217 #else 218 NULL, 219 #endif 220 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 221 } 222 223 static int 224 vmspace_zinit(void *mem, int size, int flags) 225 { 226 struct vmspace *vm; 227 228 vm = (struct vmspace *)mem; 229 230 vm->vm_map.pmap = NULL; 231 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags); 232 PMAP_LOCK_INIT(vmspace_pmap(vm)); 233 return (0); 234 } 235 236 static int 237 vm_map_zinit(void *mem, int size, int flags) 238 { 239 vm_map_t map; 240 241 map = (vm_map_t)mem; 242 memset(map, 0, sizeof(*map)); 243 mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK); 244 sx_init(&map->lock, "vm map (user)"); 245 return (0); 246 } 247 248 #ifdef INVARIANTS 249 static void 250 vmspace_zdtor(void *mem, int size, void *arg) 251 { 252 struct vmspace *vm; 253 254 vm = (struct vmspace *)mem; 255 256 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg); 257 } 258 static void 259 vm_map_zdtor(void *mem, int size, void *arg) 260 { 261 vm_map_t map; 262 263 map = (vm_map_t)mem; 264 KASSERT(map->nentries == 0, 265 ("map %p nentries == %d on free.", 266 map, map->nentries)); 267 KASSERT(map->size == 0, 268 ("map %p size == %lu on free.", 269 map, (unsigned long)map->size)); 270 } 271 #endif /* INVARIANTS */ 272 273 /* 274 * Allocate a vmspace structure, including a vm_map and pmap, 275 * and initialize those structures. The refcnt is set to 1. 276 * 277 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit(). 278 */ 279 struct vmspace * 280 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit) 281 { 282 struct vmspace *vm; 283 284 vm = uma_zalloc(vmspace_zone, M_WAITOK); 285 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL")); 286 if (!pinit(vmspace_pmap(vm))) { 287 uma_zfree(vmspace_zone, vm); 288 return (NULL); 289 } 290 CTR1(KTR_VM, "vmspace_alloc: %p", vm); 291 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max); 292 vm->vm_refcnt = 1; 293 vm->vm_shm = NULL; 294 vm->vm_swrss = 0; 295 vm->vm_tsize = 0; 296 vm->vm_dsize = 0; 297 vm->vm_ssize = 0; 298 vm->vm_taddr = 0; 299 vm->vm_daddr = 0; 300 vm->vm_maxsaddr = 0; 301 return (vm); 302 } 303 304 #ifdef RACCT 305 static void 306 vmspace_container_reset(struct proc *p) 307 { 308 309 PROC_LOCK(p); 310 racct_set(p, RACCT_DATA, 0); 311 racct_set(p, RACCT_STACK, 0); 312 racct_set(p, RACCT_RSS, 0); 313 racct_set(p, RACCT_MEMLOCK, 0); 314 racct_set(p, RACCT_VMEM, 0); 315 PROC_UNLOCK(p); 316 } 317 #endif 318 319 static inline void 320 vmspace_dofree(struct vmspace *vm) 321 { 322 323 CTR1(KTR_VM, "vmspace_free: %p", vm); 324 325 /* 326 * Make sure any SysV shm is freed, it might not have been in 327 * exit1(). 328 */ 329 shmexit(vm); 330 331 /* 332 * Lock the map, to wait out all other references to it. 333 * Delete all of the mappings and pages they hold, then call 334 * the pmap module to reclaim anything left. 335 */ 336 (void)vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 337 vm_map_max(&vm->vm_map)); 338 339 pmap_release(vmspace_pmap(vm)); 340 vm->vm_map.pmap = NULL; 341 uma_zfree(vmspace_zone, vm); 342 } 343 344 void 345 vmspace_free(struct vmspace *vm) 346 { 347 348 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 349 "vmspace_free() called"); 350 351 if (vm->vm_refcnt == 0) 352 panic("vmspace_free: attempt to free already freed vmspace"); 353 354 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1) 355 vmspace_dofree(vm); 356 } 357 358 void 359 vmspace_exitfree(struct proc *p) 360 { 361 struct vmspace *vm; 362 363 PROC_VMSPACE_LOCK(p); 364 vm = p->p_vmspace; 365 p->p_vmspace = NULL; 366 PROC_VMSPACE_UNLOCK(p); 367 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace")); 368 vmspace_free(vm); 369 } 370 371 void 372 vmspace_exit(struct thread *td) 373 { 374 int refcnt; 375 struct vmspace *vm; 376 struct proc *p; 377 378 /* 379 * Release user portion of address space. 380 * This releases references to vnodes, 381 * which could cause I/O if the file has been unlinked. 382 * Need to do this early enough that we can still sleep. 383 * 384 * The last exiting process to reach this point releases as 385 * much of the environment as it can. vmspace_dofree() is the 386 * slower fallback in case another process had a temporary 387 * reference to the vmspace. 388 */ 389 390 p = td->td_proc; 391 vm = p->p_vmspace; 392 atomic_add_int(&vmspace0.vm_refcnt, 1); 393 refcnt = vm->vm_refcnt; 394 do { 395 if (refcnt > 1 && p->p_vmspace != &vmspace0) { 396 /* Switch now since other proc might free vmspace */ 397 PROC_VMSPACE_LOCK(p); 398 p->p_vmspace = &vmspace0; 399 PROC_VMSPACE_UNLOCK(p); 400 pmap_activate(td); 401 } 402 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt - 1)); 403 if (refcnt == 1) { 404 if (p->p_vmspace != vm) { 405 /* vmspace not yet freed, switch back */ 406 PROC_VMSPACE_LOCK(p); 407 p->p_vmspace = vm; 408 PROC_VMSPACE_UNLOCK(p); 409 pmap_activate(td); 410 } 411 pmap_remove_pages(vmspace_pmap(vm)); 412 /* Switch now since this proc will free vmspace */ 413 PROC_VMSPACE_LOCK(p); 414 p->p_vmspace = &vmspace0; 415 PROC_VMSPACE_UNLOCK(p); 416 pmap_activate(td); 417 vmspace_dofree(vm); 418 } 419 #ifdef RACCT 420 if (racct_enable) 421 vmspace_container_reset(p); 422 #endif 423 } 424 425 /* Acquire reference to vmspace owned by another process. */ 426 427 struct vmspace * 428 vmspace_acquire_ref(struct proc *p) 429 { 430 struct vmspace *vm; 431 int refcnt; 432 433 PROC_VMSPACE_LOCK(p); 434 vm = p->p_vmspace; 435 if (vm == NULL) { 436 PROC_VMSPACE_UNLOCK(p); 437 return (NULL); 438 } 439 refcnt = vm->vm_refcnt; 440 do { 441 if (refcnt <= 0) { /* Avoid 0->1 transition */ 442 PROC_VMSPACE_UNLOCK(p); 443 return (NULL); 444 } 445 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt + 1)); 446 if (vm != p->p_vmspace) { 447 PROC_VMSPACE_UNLOCK(p); 448 vmspace_free(vm); 449 return (NULL); 450 } 451 PROC_VMSPACE_UNLOCK(p); 452 return (vm); 453 } 454 455 /* 456 * Switch between vmspaces in an AIO kernel process. 457 * 458 * The new vmspace is either the vmspace of a user process obtained 459 * from an active AIO request or the initial vmspace of the AIO kernel 460 * process (when it is idling). Because user processes will block to 461 * drain any active AIO requests before proceeding in exit() or 462 * execve(), the reference count for vmspaces from AIO requests can 463 * never be 0. Similarly, AIO kernel processes hold an extra 464 * reference on their initial vmspace for the life of the process. As 465 * a result, the 'newvm' vmspace always has a non-zero reference 466 * count. This permits an additional reference on 'newvm' to be 467 * acquired via a simple atomic increment rather than the loop in 468 * vmspace_acquire_ref() above. 469 */ 470 void 471 vmspace_switch_aio(struct vmspace *newvm) 472 { 473 struct vmspace *oldvm; 474 475 /* XXX: Need some way to assert that this is an aio daemon. */ 476 477 KASSERT(newvm->vm_refcnt > 0, 478 ("vmspace_switch_aio: newvm unreferenced")); 479 480 oldvm = curproc->p_vmspace; 481 if (oldvm == newvm) 482 return; 483 484 /* 485 * Point to the new address space and refer to it. 486 */ 487 curproc->p_vmspace = newvm; 488 atomic_add_int(&newvm->vm_refcnt, 1); 489 490 /* Activate the new mapping. */ 491 pmap_activate(curthread); 492 493 vmspace_free(oldvm); 494 } 495 496 void 497 _vm_map_lock(vm_map_t map, const char *file, int line) 498 { 499 500 if (map->system_map) 501 mtx_lock_flags_(&map->system_mtx, 0, file, line); 502 else 503 sx_xlock_(&map->lock, file, line); 504 map->timestamp++; 505 } 506 507 void 508 vm_map_entry_set_vnode_text(vm_map_entry_t entry, bool add) 509 { 510 vm_object_t object; 511 struct vnode *vp; 512 bool vp_held; 513 514 if ((entry->eflags & MAP_ENTRY_VN_EXEC) == 0) 515 return; 516 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 517 ("Submap with execs")); 518 object = entry->object.vm_object; 519 KASSERT(object != NULL, ("No object for text, entry %p", entry)); 520 if ((object->flags & OBJ_ANON) != 0) 521 object = object->handle; 522 else 523 KASSERT(object->backing_object == NULL, 524 ("non-anon object %p shadows", object)); 525 KASSERT(object != NULL, ("No content object for text, entry %p obj %p", 526 entry, entry->object.vm_object)); 527 528 /* 529 * Mostly, we do not lock the backing object. It is 530 * referenced by the entry we are processing, so it cannot go 531 * away. 532 */ 533 vp = NULL; 534 vp_held = false; 535 if (object->type == OBJT_DEAD) { 536 /* 537 * For OBJT_DEAD objects, v_writecount was handled in 538 * vnode_pager_dealloc(). 539 */ 540 } else if (object->type == OBJT_VNODE) { 541 vp = object->handle; 542 } else if (object->type == OBJT_SWAP) { 543 KASSERT((object->flags & OBJ_TMPFS_NODE) != 0, 544 ("vm_map_entry_set_vnode_text: swap and !TMPFS " 545 "entry %p, object %p, add %d", entry, object, add)); 546 /* 547 * Tmpfs VREG node, which was reclaimed, has 548 * OBJ_TMPFS_NODE flag set, but not OBJ_TMPFS. In 549 * this case there is no v_writecount to adjust. 550 */ 551 VM_OBJECT_RLOCK(object); 552 if ((object->flags & OBJ_TMPFS) != 0) { 553 vp = object->un_pager.swp.swp_tmpfs; 554 if (vp != NULL) { 555 vhold(vp); 556 vp_held = true; 557 } 558 } 559 VM_OBJECT_RUNLOCK(object); 560 } else { 561 KASSERT(0, 562 ("vm_map_entry_set_vnode_text: wrong object type, " 563 "entry %p, object %p, add %d", entry, object, add)); 564 } 565 if (vp != NULL) { 566 if (add) { 567 VOP_SET_TEXT_CHECKED(vp); 568 } else { 569 vn_lock(vp, LK_SHARED | LK_RETRY); 570 VOP_UNSET_TEXT_CHECKED(vp); 571 VOP_UNLOCK(vp); 572 } 573 if (vp_held) 574 vdrop(vp); 575 } 576 } 577 578 /* 579 * Use a different name for this vm_map_entry field when it's use 580 * is not consistent with its use as part of an ordered search tree. 581 */ 582 #define defer_next right 583 584 static void 585 vm_map_process_deferred(void) 586 { 587 struct thread *td; 588 vm_map_entry_t entry, next; 589 vm_object_t object; 590 591 td = curthread; 592 entry = td->td_map_def_user; 593 td->td_map_def_user = NULL; 594 while (entry != NULL) { 595 next = entry->defer_next; 596 MPASS((entry->eflags & (MAP_ENTRY_WRITECNT | 597 MAP_ENTRY_VN_EXEC)) != (MAP_ENTRY_WRITECNT | 598 MAP_ENTRY_VN_EXEC)); 599 if ((entry->eflags & MAP_ENTRY_WRITECNT) != 0) { 600 /* 601 * Decrement the object's writemappings and 602 * possibly the vnode's v_writecount. 603 */ 604 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 605 ("Submap with writecount")); 606 object = entry->object.vm_object; 607 KASSERT(object != NULL, ("No object for writecount")); 608 vm_pager_release_writecount(object, entry->start, 609 entry->end); 610 } 611 vm_map_entry_set_vnode_text(entry, false); 612 vm_map_entry_deallocate(entry, FALSE); 613 entry = next; 614 } 615 } 616 617 #ifdef INVARIANTS 618 static void 619 _vm_map_assert_locked(vm_map_t map, const char *file, int line) 620 { 621 622 if (map->system_map) 623 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 624 else 625 sx_assert_(&map->lock, SA_XLOCKED, file, line); 626 } 627 628 #define VM_MAP_ASSERT_LOCKED(map) \ 629 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE) 630 631 enum { VMMAP_CHECK_NONE, VMMAP_CHECK_UNLOCK, VMMAP_CHECK_ALL }; 632 #ifdef DIAGNOSTIC 633 static int enable_vmmap_check = VMMAP_CHECK_UNLOCK; 634 #else 635 static int enable_vmmap_check = VMMAP_CHECK_NONE; 636 #endif 637 SYSCTL_INT(_debug, OID_AUTO, vmmap_check, CTLFLAG_RWTUN, 638 &enable_vmmap_check, 0, "Enable vm map consistency checking"); 639 640 static void _vm_map_assert_consistent(vm_map_t map, int check); 641 642 #define VM_MAP_ASSERT_CONSISTENT(map) \ 643 _vm_map_assert_consistent(map, VMMAP_CHECK_ALL) 644 #ifdef DIAGNOSTIC 645 #define VM_MAP_UNLOCK_CONSISTENT(map) do { \ 646 if (map->nupdates > map->nentries) { \ 647 _vm_map_assert_consistent(map, VMMAP_CHECK_UNLOCK); \ 648 map->nupdates = 0; \ 649 } \ 650 } while (0) 651 #else 652 #define VM_MAP_UNLOCK_CONSISTENT(map) 653 #endif 654 #else 655 #define VM_MAP_ASSERT_LOCKED(map) 656 #define VM_MAP_ASSERT_CONSISTENT(map) 657 #define VM_MAP_UNLOCK_CONSISTENT(map) 658 #endif /* INVARIANTS */ 659 660 void 661 _vm_map_unlock(vm_map_t map, const char *file, int line) 662 { 663 664 VM_MAP_UNLOCK_CONSISTENT(map); 665 if (map->system_map) 666 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 667 else { 668 sx_xunlock_(&map->lock, file, line); 669 vm_map_process_deferred(); 670 } 671 } 672 673 void 674 _vm_map_lock_read(vm_map_t map, const char *file, int line) 675 { 676 677 if (map->system_map) 678 mtx_lock_flags_(&map->system_mtx, 0, file, line); 679 else 680 sx_slock_(&map->lock, file, line); 681 } 682 683 void 684 _vm_map_unlock_read(vm_map_t map, const char *file, int line) 685 { 686 687 if (map->system_map) 688 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 689 else { 690 sx_sunlock_(&map->lock, file, line); 691 vm_map_process_deferred(); 692 } 693 } 694 695 int 696 _vm_map_trylock(vm_map_t map, const char *file, int line) 697 { 698 int error; 699 700 error = map->system_map ? 701 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 702 !sx_try_xlock_(&map->lock, file, line); 703 if (error == 0) 704 map->timestamp++; 705 return (error == 0); 706 } 707 708 int 709 _vm_map_trylock_read(vm_map_t map, const char *file, int line) 710 { 711 int error; 712 713 error = map->system_map ? 714 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) : 715 !sx_try_slock_(&map->lock, file, line); 716 return (error == 0); 717 } 718 719 /* 720 * _vm_map_lock_upgrade: [ internal use only ] 721 * 722 * Tries to upgrade a read (shared) lock on the specified map to a write 723 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a 724 * non-zero value if the upgrade fails. If the upgrade fails, the map is 725 * returned without a read or write lock held. 726 * 727 * Requires that the map be read locked. 728 */ 729 int 730 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line) 731 { 732 unsigned int last_timestamp; 733 734 if (map->system_map) { 735 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 736 } else { 737 if (!sx_try_upgrade_(&map->lock, file, line)) { 738 last_timestamp = map->timestamp; 739 sx_sunlock_(&map->lock, file, line); 740 vm_map_process_deferred(); 741 /* 742 * If the map's timestamp does not change while the 743 * map is unlocked, then the upgrade succeeds. 744 */ 745 sx_xlock_(&map->lock, file, line); 746 if (last_timestamp != map->timestamp) { 747 sx_xunlock_(&map->lock, file, line); 748 return (1); 749 } 750 } 751 } 752 map->timestamp++; 753 return (0); 754 } 755 756 void 757 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line) 758 { 759 760 if (map->system_map) { 761 mtx_assert_(&map->system_mtx, MA_OWNED, file, line); 762 } else { 763 VM_MAP_UNLOCK_CONSISTENT(map); 764 sx_downgrade_(&map->lock, file, line); 765 } 766 } 767 768 /* 769 * vm_map_locked: 770 * 771 * Returns a non-zero value if the caller holds a write (exclusive) lock 772 * on the specified map and the value "0" otherwise. 773 */ 774 int 775 vm_map_locked(vm_map_t map) 776 { 777 778 if (map->system_map) 779 return (mtx_owned(&map->system_mtx)); 780 else 781 return (sx_xlocked(&map->lock)); 782 } 783 784 /* 785 * _vm_map_unlock_and_wait: 786 * 787 * Atomically releases the lock on the specified map and puts the calling 788 * thread to sleep. The calling thread will remain asleep until either 789 * vm_map_wakeup() is performed on the map or the specified timeout is 790 * exceeded. 791 * 792 * WARNING! This function does not perform deferred deallocations of 793 * objects and map entries. Therefore, the calling thread is expected to 794 * reacquire the map lock after reawakening and later perform an ordinary 795 * unlock operation, such as vm_map_unlock(), before completing its 796 * operation on the map. 797 */ 798 int 799 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line) 800 { 801 802 VM_MAP_UNLOCK_CONSISTENT(map); 803 mtx_lock(&map_sleep_mtx); 804 if (map->system_map) 805 mtx_unlock_flags_(&map->system_mtx, 0, file, line); 806 else 807 sx_xunlock_(&map->lock, file, line); 808 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 809 timo)); 810 } 811 812 /* 813 * vm_map_wakeup: 814 * 815 * Awaken any threads that have slept on the map using 816 * vm_map_unlock_and_wait(). 817 */ 818 void 819 vm_map_wakeup(vm_map_t map) 820 { 821 822 /* 823 * Acquire and release map_sleep_mtx to prevent a wakeup() 824 * from being performed (and lost) between the map unlock 825 * and the msleep() in _vm_map_unlock_and_wait(). 826 */ 827 mtx_lock(&map_sleep_mtx); 828 mtx_unlock(&map_sleep_mtx); 829 wakeup(&map->root); 830 } 831 832 void 833 vm_map_busy(vm_map_t map) 834 { 835 836 VM_MAP_ASSERT_LOCKED(map); 837 map->busy++; 838 } 839 840 void 841 vm_map_unbusy(vm_map_t map) 842 { 843 844 VM_MAP_ASSERT_LOCKED(map); 845 KASSERT(map->busy, ("vm_map_unbusy: not busy")); 846 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { 847 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); 848 wakeup(&map->busy); 849 } 850 } 851 852 void 853 vm_map_wait_busy(vm_map_t map) 854 { 855 856 VM_MAP_ASSERT_LOCKED(map); 857 while (map->busy) { 858 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); 859 if (map->system_map) 860 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); 861 else 862 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); 863 } 864 map->timestamp++; 865 } 866 867 long 868 vmspace_resident_count(struct vmspace *vmspace) 869 { 870 return pmap_resident_count(vmspace_pmap(vmspace)); 871 } 872 873 /* 874 * vm_map_create: 875 * 876 * Creates and returns a new empty VM map with 877 * the given physical map structure, and having 878 * the given lower and upper address bounds. 879 */ 880 vm_map_t 881 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max) 882 { 883 vm_map_t result; 884 885 result = uma_zalloc(mapzone, M_WAITOK); 886 CTR1(KTR_VM, "vm_map_create: %p", result); 887 _vm_map_init(result, pmap, min, max); 888 return (result); 889 } 890 891 /* 892 * Initialize an existing vm_map structure 893 * such as that in the vmspace structure. 894 */ 895 static void 896 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 897 { 898 899 map->header.eflags = MAP_ENTRY_HEADER; 900 map->needs_wakeup = FALSE; 901 map->system_map = 0; 902 map->pmap = pmap; 903 map->header.end = min; 904 map->header.start = max; 905 map->flags = 0; 906 map->header.left = map->header.right = &map->header; 907 map->root = NULL; 908 map->timestamp = 0; 909 map->busy = 0; 910 map->anon_loc = 0; 911 #ifdef DIAGNOSTIC 912 map->nupdates = 0; 913 #endif 914 } 915 916 void 917 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) 918 { 919 920 _vm_map_init(map, pmap, min, max); 921 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK); 922 sx_init(&map->lock, "user map"); 923 } 924 925 /* 926 * vm_map_entry_dispose: [ internal use only ] 927 * 928 * Inverse of vm_map_entry_create. 929 */ 930 static void 931 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry) 932 { 933 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry); 934 } 935 936 /* 937 * vm_map_entry_create: [ internal use only ] 938 * 939 * Allocates a VM map entry for insertion. 940 * No entry fields are filled in. 941 */ 942 static vm_map_entry_t 943 vm_map_entry_create(vm_map_t map) 944 { 945 vm_map_entry_t new_entry; 946 947 if (map->system_map) 948 new_entry = uma_zalloc(kmapentzone, M_NOWAIT); 949 else 950 new_entry = uma_zalloc(mapentzone, M_WAITOK); 951 if (new_entry == NULL) 952 panic("vm_map_entry_create: kernel resources exhausted"); 953 return (new_entry); 954 } 955 956 /* 957 * vm_map_entry_set_behavior: 958 * 959 * Set the expected access behavior, either normal, random, or 960 * sequential. 961 */ 962 static inline void 963 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior) 964 { 965 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) | 966 (behavior & MAP_ENTRY_BEHAV_MASK); 967 } 968 969 /* 970 * vm_map_entry_max_free_{left,right}: 971 * 972 * Compute the size of the largest free gap between two entries, 973 * one the root of a tree and the other the ancestor of that root 974 * that is the least or greatest ancestor found on the search path. 975 */ 976 static inline vm_size_t 977 vm_map_entry_max_free_left(vm_map_entry_t root, vm_map_entry_t left_ancestor) 978 { 979 980 return (root->left != left_ancestor ? 981 root->left->max_free : root->start - left_ancestor->end); 982 } 983 984 static inline vm_size_t 985 vm_map_entry_max_free_right(vm_map_entry_t root, vm_map_entry_t right_ancestor) 986 { 987 988 return (root->right != right_ancestor ? 989 root->right->max_free : right_ancestor->start - root->end); 990 } 991 992 /* 993 * vm_map_entry_{pred,succ}: 994 * 995 * Find the {predecessor, successor} of the entry by taking one step 996 * in the appropriate direction and backtracking as much as necessary. 997 * vm_map_entry_succ is defined in vm_map.h. 998 */ 999 static inline vm_map_entry_t 1000 vm_map_entry_pred(vm_map_entry_t entry) 1001 { 1002 vm_map_entry_t prior; 1003 1004 prior = entry->left; 1005 if (prior->right->start < entry->start) { 1006 do 1007 prior = prior->right; 1008 while (prior->right != entry); 1009 } 1010 return (prior); 1011 } 1012 1013 static inline vm_size_t 1014 vm_size_max(vm_size_t a, vm_size_t b) 1015 { 1016 1017 return (a > b ? a : b); 1018 } 1019 1020 #define SPLAY_LEFT_STEP(root, y, llist, rlist, test) do { \ 1021 vm_map_entry_t z; \ 1022 vm_size_t max_free; \ 1023 \ 1024 /* \ 1025 * Infer root->right->max_free == root->max_free when \ 1026 * y->max_free < root->max_free || root->max_free == 0. \ 1027 * Otherwise, look right to find it. \ 1028 */ \ 1029 y = root->left; \ 1030 max_free = root->max_free; \ 1031 KASSERT(max_free == vm_size_max( \ 1032 vm_map_entry_max_free_left(root, llist), \ 1033 vm_map_entry_max_free_right(root, rlist)), \ 1034 ("%s: max_free invariant fails", __func__)); \ 1035 if (max_free - 1 < vm_map_entry_max_free_left(root, llist)) \ 1036 max_free = vm_map_entry_max_free_right(root, rlist); \ 1037 if (y != llist && (test)) { \ 1038 /* Rotate right and make y root. */ \ 1039 z = y->right; \ 1040 if (z != root) { \ 1041 root->left = z; \ 1042 y->right = root; \ 1043 if (max_free < y->max_free) \ 1044 root->max_free = max_free = \ 1045 vm_size_max(max_free, z->max_free); \ 1046 } else if (max_free < y->max_free) \ 1047 root->max_free = max_free = \ 1048 vm_size_max(max_free, root->start - y->end);\ 1049 root = y; \ 1050 y = root->left; \ 1051 } \ 1052 /* Copy right->max_free. Put root on rlist. */ \ 1053 root->max_free = max_free; \ 1054 KASSERT(max_free == vm_map_entry_max_free_right(root, rlist), \ 1055 ("%s: max_free not copied from right", __func__)); \ 1056 root->left = rlist; \ 1057 rlist = root; \ 1058 root = y != llist ? y : NULL; \ 1059 } while (0) 1060 1061 #define SPLAY_RIGHT_STEP(root, y, llist, rlist, test) do { \ 1062 vm_map_entry_t z; \ 1063 vm_size_t max_free; \ 1064 \ 1065 /* \ 1066 * Infer root->left->max_free == root->max_free when \ 1067 * y->max_free < root->max_free || root->max_free == 0. \ 1068 * Otherwise, look left to find it. \ 1069 */ \ 1070 y = root->right; \ 1071 max_free = root->max_free; \ 1072 KASSERT(max_free == vm_size_max( \ 1073 vm_map_entry_max_free_left(root, llist), \ 1074 vm_map_entry_max_free_right(root, rlist)), \ 1075 ("%s: max_free invariant fails", __func__)); \ 1076 if (max_free - 1 < vm_map_entry_max_free_right(root, rlist)) \ 1077 max_free = vm_map_entry_max_free_left(root, llist); \ 1078 if (y != rlist && (test)) { \ 1079 /* Rotate left and make y root. */ \ 1080 z = y->left; \ 1081 if (z != root) { \ 1082 root->right = z; \ 1083 y->left = root; \ 1084 if (max_free < y->max_free) \ 1085 root->max_free = max_free = \ 1086 vm_size_max(max_free, z->max_free); \ 1087 } else if (max_free < y->max_free) \ 1088 root->max_free = max_free = \ 1089 vm_size_max(max_free, y->start - root->end);\ 1090 root = y; \ 1091 y = root->right; \ 1092 } \ 1093 /* Copy left->max_free. Put root on llist. */ \ 1094 root->max_free = max_free; \ 1095 KASSERT(max_free == vm_map_entry_max_free_left(root, llist), \ 1096 ("%s: max_free not copied from left", __func__)); \ 1097 root->right = llist; \ 1098 llist = root; \ 1099 root = y != rlist ? y : NULL; \ 1100 } while (0) 1101 1102 /* 1103 * Walk down the tree until we find addr or a gap where addr would go, breaking 1104 * off left and right subtrees of nodes less than, or greater than addr. Treat 1105 * subtrees with root->max_free < length as empty trees. llist and rlist are 1106 * the two sides in reverse order (bottom-up), with llist linked by the right 1107 * pointer and rlist linked by the left pointer in the vm_map_entry, and both 1108 * lists terminated by &map->header. This function, and the subsequent call to 1109 * vm_map_splay_merge_{left,right,pred,succ}, rely on the start and end address 1110 * values in &map->header. 1111 */ 1112 static __always_inline vm_map_entry_t 1113 vm_map_splay_split(vm_map_t map, vm_offset_t addr, vm_size_t length, 1114 vm_map_entry_t *llist, vm_map_entry_t *rlist) 1115 { 1116 vm_map_entry_t left, right, root, y; 1117 1118 left = right = &map->header; 1119 root = map->root; 1120 while (root != NULL && root->max_free >= length) { 1121 KASSERT(left->end <= root->start && 1122 root->end <= right->start, 1123 ("%s: root not within tree bounds", __func__)); 1124 if (addr < root->start) { 1125 SPLAY_LEFT_STEP(root, y, left, right, 1126 y->max_free >= length && addr < y->start); 1127 } else if (addr >= root->end) { 1128 SPLAY_RIGHT_STEP(root, y, left, right, 1129 y->max_free >= length && addr >= y->end); 1130 } else 1131 break; 1132 } 1133 *llist = left; 1134 *rlist = right; 1135 return (root); 1136 } 1137 1138 static __always_inline void 1139 vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *rlist) 1140 { 1141 vm_map_entry_t hi, right, y; 1142 1143 right = *rlist; 1144 hi = root->right == right ? NULL : root->right; 1145 if (hi == NULL) 1146 return; 1147 do 1148 SPLAY_LEFT_STEP(hi, y, root, right, true); 1149 while (hi != NULL); 1150 *rlist = right; 1151 } 1152 1153 static __always_inline void 1154 vm_map_splay_findprev(vm_map_entry_t root, vm_map_entry_t *llist) 1155 { 1156 vm_map_entry_t left, lo, y; 1157 1158 left = *llist; 1159 lo = root->left == left ? NULL : root->left; 1160 if (lo == NULL) 1161 return; 1162 do 1163 SPLAY_RIGHT_STEP(lo, y, left, root, true); 1164 while (lo != NULL); 1165 *llist = left; 1166 } 1167 1168 static inline void 1169 vm_map_entry_swap(vm_map_entry_t *a, vm_map_entry_t *b) 1170 { 1171 vm_map_entry_t tmp; 1172 1173 tmp = *b; 1174 *b = *a; 1175 *a = tmp; 1176 } 1177 1178 /* 1179 * Walk back up the two spines, flip the pointers and set max_free. The 1180 * subtrees of the root go at the bottom of llist and rlist. 1181 */ 1182 static vm_size_t 1183 vm_map_splay_merge_left_walk(vm_map_entry_t header, vm_map_entry_t root, 1184 vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t llist) 1185 { 1186 do { 1187 /* 1188 * The max_free values of the children of llist are in 1189 * llist->max_free and max_free. Update with the 1190 * max value. 1191 */ 1192 llist->max_free = max_free = 1193 vm_size_max(llist->max_free, max_free); 1194 vm_map_entry_swap(&llist->right, &tail); 1195 vm_map_entry_swap(&tail, &llist); 1196 } while (llist != header); 1197 root->left = tail; 1198 return (max_free); 1199 } 1200 1201 /* 1202 * When llist is known to be the predecessor of root. 1203 */ 1204 static inline vm_size_t 1205 vm_map_splay_merge_pred(vm_map_entry_t header, vm_map_entry_t root, 1206 vm_map_entry_t llist) 1207 { 1208 vm_size_t max_free; 1209 1210 max_free = root->start - llist->end; 1211 if (llist != header) { 1212 max_free = vm_map_splay_merge_left_walk(header, root, 1213 root, max_free, llist); 1214 } else { 1215 root->left = header; 1216 header->right = root; 1217 } 1218 return (max_free); 1219 } 1220 1221 /* 1222 * When llist may or may not be the predecessor of root. 1223 */ 1224 static inline vm_size_t 1225 vm_map_splay_merge_left(vm_map_entry_t header, vm_map_entry_t root, 1226 vm_map_entry_t llist) 1227 { 1228 vm_size_t max_free; 1229 1230 max_free = vm_map_entry_max_free_left(root, llist); 1231 if (llist != header) { 1232 max_free = vm_map_splay_merge_left_walk(header, root, 1233 root->left == llist ? root : root->left, 1234 max_free, llist); 1235 } 1236 return (max_free); 1237 } 1238 1239 static vm_size_t 1240 vm_map_splay_merge_right_walk(vm_map_entry_t header, vm_map_entry_t root, 1241 vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t rlist) 1242 { 1243 do { 1244 /* 1245 * The max_free values of the children of rlist are in 1246 * rlist->max_free and max_free. Update with the 1247 * max value. 1248 */ 1249 rlist->max_free = max_free = 1250 vm_size_max(rlist->max_free, max_free); 1251 vm_map_entry_swap(&rlist->left, &tail); 1252 vm_map_entry_swap(&tail, &rlist); 1253 } while (rlist != header); 1254 root->right = tail; 1255 return (max_free); 1256 } 1257 1258 /* 1259 * When rlist is known to be the succecessor of root. 1260 */ 1261 static inline vm_size_t 1262 vm_map_splay_merge_succ(vm_map_entry_t header, vm_map_entry_t root, 1263 vm_map_entry_t rlist) 1264 { 1265 vm_size_t max_free; 1266 1267 max_free = rlist->start - root->end; 1268 if (rlist != header) { 1269 max_free = vm_map_splay_merge_right_walk(header, root, 1270 root, max_free, rlist); 1271 } else { 1272 root->right = header; 1273 header->left = root; 1274 } 1275 return (max_free); 1276 } 1277 1278 /* 1279 * When rlist may or may not be the succecessor of root. 1280 */ 1281 static inline vm_size_t 1282 vm_map_splay_merge_right(vm_map_entry_t header, vm_map_entry_t root, 1283 vm_map_entry_t rlist) 1284 { 1285 vm_size_t max_free; 1286 1287 max_free = vm_map_entry_max_free_right(root, rlist); 1288 if (rlist != header) { 1289 max_free = vm_map_splay_merge_right_walk(header, root, 1290 root->right == rlist ? root : root->right, 1291 max_free, rlist); 1292 } 1293 return (max_free); 1294 } 1295 1296 /* 1297 * vm_map_splay: 1298 * 1299 * The Sleator and Tarjan top-down splay algorithm with the 1300 * following variation. Max_free must be computed bottom-up, so 1301 * on the downward pass, maintain the left and right spines in 1302 * reverse order. Then, make a second pass up each side to fix 1303 * the pointers and compute max_free. The time bound is O(log n) 1304 * amortized. 1305 * 1306 * The tree is threaded, which means that there are no null pointers. 1307 * When a node has no left child, its left pointer points to its 1308 * predecessor, which the last ancestor on the search path from the root 1309 * where the search branched right. Likewise, when a node has no right 1310 * child, its right pointer points to its successor. The map header node 1311 * is the predecessor of the first map entry, and the successor of the 1312 * last. 1313 * 1314 * The new root is the vm_map_entry containing "addr", or else an 1315 * adjacent entry (lower if possible) if addr is not in the tree. 1316 * 1317 * The map must be locked, and leaves it so. 1318 * 1319 * Returns: the new root. 1320 */ 1321 static vm_map_entry_t 1322 vm_map_splay(vm_map_t map, vm_offset_t addr) 1323 { 1324 vm_map_entry_t header, llist, rlist, root; 1325 vm_size_t max_free_left, max_free_right; 1326 1327 header = &map->header; 1328 root = vm_map_splay_split(map, addr, 0, &llist, &rlist); 1329 if (root != NULL) { 1330 max_free_left = vm_map_splay_merge_left(header, root, llist); 1331 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1332 } else if (llist != header) { 1333 /* 1334 * Recover the greatest node in the left 1335 * subtree and make it the root. 1336 */ 1337 root = llist; 1338 llist = root->right; 1339 max_free_left = vm_map_splay_merge_left(header, root, llist); 1340 max_free_right = vm_map_splay_merge_succ(header, root, rlist); 1341 } else if (rlist != header) { 1342 /* 1343 * Recover the least node in the right 1344 * subtree and make it the root. 1345 */ 1346 root = rlist; 1347 rlist = root->left; 1348 max_free_left = vm_map_splay_merge_pred(header, root, llist); 1349 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1350 } else { 1351 /* There is no root. */ 1352 return (NULL); 1353 } 1354 root->max_free = vm_size_max(max_free_left, max_free_right); 1355 map->root = root; 1356 VM_MAP_ASSERT_CONSISTENT(map); 1357 return (root); 1358 } 1359 1360 /* 1361 * vm_map_entry_{un,}link: 1362 * 1363 * Insert/remove entries from maps. On linking, if new entry clips 1364 * existing entry, trim existing entry to avoid overlap, and manage 1365 * offsets. On unlinking, merge disappearing entry with neighbor, if 1366 * called for, and manage offsets. Callers should not modify fields in 1367 * entries already mapped. 1368 */ 1369 static void 1370 vm_map_entry_link(vm_map_t map, vm_map_entry_t entry) 1371 { 1372 vm_map_entry_t header, llist, rlist, root; 1373 vm_size_t max_free_left, max_free_right; 1374 1375 CTR3(KTR_VM, 1376 "vm_map_entry_link: map %p, nentries %d, entry %p", map, 1377 map->nentries, entry); 1378 VM_MAP_ASSERT_LOCKED(map); 1379 map->nentries++; 1380 header = &map->header; 1381 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist); 1382 if (root == NULL) { 1383 /* 1384 * The new entry does not overlap any existing entry in the 1385 * map, so it becomes the new root of the map tree. 1386 */ 1387 max_free_left = vm_map_splay_merge_pred(header, entry, llist); 1388 max_free_right = vm_map_splay_merge_succ(header, entry, rlist); 1389 } else if (entry->start == root->start) { 1390 /* 1391 * The new entry is a clone of root, with only the end field 1392 * changed. The root entry will be shrunk to abut the new 1393 * entry, and will be the right child of the new root entry in 1394 * the modified map. 1395 */ 1396 KASSERT(entry->end < root->end, 1397 ("%s: clip_start not within entry", __func__)); 1398 vm_map_splay_findprev(root, &llist); 1399 root->offset += entry->end - root->start; 1400 root->start = entry->end; 1401 max_free_left = vm_map_splay_merge_pred(header, entry, llist); 1402 max_free_right = root->max_free = vm_size_max( 1403 vm_map_splay_merge_pred(entry, root, entry), 1404 vm_map_splay_merge_right(header, root, rlist)); 1405 } else { 1406 /* 1407 * The new entry is a clone of root, with only the start field 1408 * changed. The root entry will be shrunk to abut the new 1409 * entry, and will be the left child of the new root entry in 1410 * the modified map. 1411 */ 1412 KASSERT(entry->end == root->end, 1413 ("%s: clip_start not within entry", __func__)); 1414 vm_map_splay_findnext(root, &rlist); 1415 entry->offset += entry->start - root->start; 1416 root->end = entry->start; 1417 max_free_left = root->max_free = vm_size_max( 1418 vm_map_splay_merge_left(header, root, llist), 1419 vm_map_splay_merge_succ(entry, root, entry)); 1420 max_free_right = vm_map_splay_merge_succ(header, entry, rlist); 1421 } 1422 entry->max_free = vm_size_max(max_free_left, max_free_right); 1423 map->root = entry; 1424 VM_MAP_ASSERT_CONSISTENT(map); 1425 } 1426 1427 enum unlink_merge_type { 1428 UNLINK_MERGE_NONE, 1429 UNLINK_MERGE_NEXT 1430 }; 1431 1432 static void 1433 vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry, 1434 enum unlink_merge_type op) 1435 { 1436 vm_map_entry_t header, llist, rlist, root; 1437 vm_size_t max_free_left, max_free_right; 1438 1439 VM_MAP_ASSERT_LOCKED(map); 1440 header = &map->header; 1441 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist); 1442 KASSERT(root != NULL, 1443 ("vm_map_entry_unlink: unlink object not mapped")); 1444 1445 vm_map_splay_findprev(root, &llist); 1446 vm_map_splay_findnext(root, &rlist); 1447 if (op == UNLINK_MERGE_NEXT) { 1448 rlist->start = root->start; 1449 rlist->offset = root->offset; 1450 } 1451 if (llist != header) { 1452 root = llist; 1453 llist = root->right; 1454 max_free_left = vm_map_splay_merge_left(header, root, llist); 1455 max_free_right = vm_map_splay_merge_succ(header, root, rlist); 1456 } else if (rlist != header) { 1457 root = rlist; 1458 rlist = root->left; 1459 max_free_left = vm_map_splay_merge_pred(header, root, llist); 1460 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1461 } else { 1462 header->left = header->right = header; 1463 root = NULL; 1464 } 1465 if (root != NULL) 1466 root->max_free = vm_size_max(max_free_left, max_free_right); 1467 map->root = root; 1468 VM_MAP_ASSERT_CONSISTENT(map); 1469 map->nentries--; 1470 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map, 1471 map->nentries, entry); 1472 } 1473 1474 /* 1475 * vm_map_entry_resize: 1476 * 1477 * Resize a vm_map_entry, recompute the amount of free space that 1478 * follows it and propagate that value up the tree. 1479 * 1480 * The map must be locked, and leaves it so. 1481 */ 1482 static void 1483 vm_map_entry_resize(vm_map_t map, vm_map_entry_t entry, vm_size_t grow_amount) 1484 { 1485 vm_map_entry_t header, llist, rlist, root; 1486 1487 VM_MAP_ASSERT_LOCKED(map); 1488 header = &map->header; 1489 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist); 1490 KASSERT(root != NULL, ("%s: resize object not mapped", __func__)); 1491 vm_map_splay_findnext(root, &rlist); 1492 entry->end += grow_amount; 1493 root->max_free = vm_size_max( 1494 vm_map_splay_merge_left(header, root, llist), 1495 vm_map_splay_merge_succ(header, root, rlist)); 1496 map->root = root; 1497 VM_MAP_ASSERT_CONSISTENT(map); 1498 CTR4(KTR_VM, "%s: map %p, nentries %d, entry %p", 1499 __func__, map, map->nentries, entry); 1500 } 1501 1502 /* 1503 * vm_map_lookup_entry: [ internal use only ] 1504 * 1505 * Finds the map entry containing (or 1506 * immediately preceding) the specified address 1507 * in the given map; the entry is returned 1508 * in the "entry" parameter. The boolean 1509 * result indicates whether the address is 1510 * actually contained in the map. 1511 */ 1512 boolean_t 1513 vm_map_lookup_entry( 1514 vm_map_t map, 1515 vm_offset_t address, 1516 vm_map_entry_t *entry) /* OUT */ 1517 { 1518 vm_map_entry_t cur, header, lbound, ubound; 1519 boolean_t locked; 1520 1521 /* 1522 * If the map is empty, then the map entry immediately preceding 1523 * "address" is the map's header. 1524 */ 1525 header = &map->header; 1526 cur = map->root; 1527 if (cur == NULL) { 1528 *entry = header; 1529 return (FALSE); 1530 } 1531 if (address >= cur->start && cur->end > address) { 1532 *entry = cur; 1533 return (TRUE); 1534 } 1535 if ((locked = vm_map_locked(map)) || 1536 sx_try_upgrade(&map->lock)) { 1537 /* 1538 * Splay requires a write lock on the map. However, it only 1539 * restructures the binary search tree; it does not otherwise 1540 * change the map. Thus, the map's timestamp need not change 1541 * on a temporary upgrade. 1542 */ 1543 cur = vm_map_splay(map, address); 1544 if (!locked) { 1545 VM_MAP_UNLOCK_CONSISTENT(map); 1546 sx_downgrade(&map->lock); 1547 } 1548 1549 /* 1550 * If "address" is contained within a map entry, the new root 1551 * is that map entry. Otherwise, the new root is a map entry 1552 * immediately before or after "address". 1553 */ 1554 if (address < cur->start) { 1555 *entry = header; 1556 return (FALSE); 1557 } 1558 *entry = cur; 1559 return (address < cur->end); 1560 } 1561 /* 1562 * Since the map is only locked for read access, perform a 1563 * standard binary search tree lookup for "address". 1564 */ 1565 lbound = ubound = header; 1566 for (;;) { 1567 if (address < cur->start) { 1568 ubound = cur; 1569 cur = cur->left; 1570 if (cur == lbound) 1571 break; 1572 } else if (cur->end <= address) { 1573 lbound = cur; 1574 cur = cur->right; 1575 if (cur == ubound) 1576 break; 1577 } else { 1578 *entry = cur; 1579 return (TRUE); 1580 } 1581 } 1582 *entry = lbound; 1583 return (FALSE); 1584 } 1585 1586 /* 1587 * vm_map_insert: 1588 * 1589 * Inserts the given whole VM object into the target 1590 * map at the specified address range. The object's 1591 * size should match that of the address range. 1592 * 1593 * Requires that the map be locked, and leaves it so. 1594 * 1595 * If object is non-NULL, ref count must be bumped by caller 1596 * prior to making call to account for the new entry. 1597 */ 1598 int 1599 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1600 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow) 1601 { 1602 vm_map_entry_t new_entry, next_entry, prev_entry; 1603 struct ucred *cred; 1604 vm_eflags_t protoeflags; 1605 vm_inherit_t inheritance; 1606 1607 VM_MAP_ASSERT_LOCKED(map); 1608 KASSERT(object != kernel_object || 1609 (cow & MAP_COPY_ON_WRITE) == 0, 1610 ("vm_map_insert: kernel object and COW")); 1611 KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0, 1612 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 1613 KASSERT((prot & ~max) == 0, 1614 ("prot %#x is not subset of max_prot %#x", prot, max)); 1615 1616 /* 1617 * Check that the start and end points are not bogus. 1618 */ 1619 if (start < vm_map_min(map) || end > vm_map_max(map) || 1620 start >= end) 1621 return (KERN_INVALID_ADDRESS); 1622 1623 /* 1624 * Find the entry prior to the proposed starting address; if it's part 1625 * of an existing entry, this range is bogus. 1626 */ 1627 if (vm_map_lookup_entry(map, start, &prev_entry)) 1628 return (KERN_NO_SPACE); 1629 1630 /* 1631 * Assert that the next entry doesn't overlap the end point. 1632 */ 1633 next_entry = vm_map_entry_succ(prev_entry); 1634 if (next_entry->start < end) 1635 return (KERN_NO_SPACE); 1636 1637 if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL || 1638 max != VM_PROT_NONE)) 1639 return (KERN_INVALID_ARGUMENT); 1640 1641 protoeflags = 0; 1642 if (cow & MAP_COPY_ON_WRITE) 1643 protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY; 1644 if (cow & MAP_NOFAULT) 1645 protoeflags |= MAP_ENTRY_NOFAULT; 1646 if (cow & MAP_DISABLE_SYNCER) 1647 protoeflags |= MAP_ENTRY_NOSYNC; 1648 if (cow & MAP_DISABLE_COREDUMP) 1649 protoeflags |= MAP_ENTRY_NOCOREDUMP; 1650 if (cow & MAP_STACK_GROWS_DOWN) 1651 protoeflags |= MAP_ENTRY_GROWS_DOWN; 1652 if (cow & MAP_STACK_GROWS_UP) 1653 protoeflags |= MAP_ENTRY_GROWS_UP; 1654 if (cow & MAP_WRITECOUNT) 1655 protoeflags |= MAP_ENTRY_WRITECNT; 1656 if (cow & MAP_VN_EXEC) 1657 protoeflags |= MAP_ENTRY_VN_EXEC; 1658 if ((cow & MAP_CREATE_GUARD) != 0) 1659 protoeflags |= MAP_ENTRY_GUARD; 1660 if ((cow & MAP_CREATE_STACK_GAP_DN) != 0) 1661 protoeflags |= MAP_ENTRY_STACK_GAP_DN; 1662 if ((cow & MAP_CREATE_STACK_GAP_UP) != 0) 1663 protoeflags |= MAP_ENTRY_STACK_GAP_UP; 1664 if (cow & MAP_INHERIT_SHARE) 1665 inheritance = VM_INHERIT_SHARE; 1666 else 1667 inheritance = VM_INHERIT_DEFAULT; 1668 1669 cred = NULL; 1670 if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0) 1671 goto charged; 1672 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) && 1673 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) { 1674 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start)) 1675 return (KERN_RESOURCE_SHORTAGE); 1676 KASSERT(object == NULL || 1677 (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 || 1678 object->cred == NULL, 1679 ("overcommit: vm_map_insert o %p", object)); 1680 cred = curthread->td_ucred; 1681 } 1682 1683 charged: 1684 /* Expand the kernel pmap, if necessary. */ 1685 if (map == kernel_map && end > kernel_vm_end) 1686 pmap_growkernel(end); 1687 if (object != NULL) { 1688 /* 1689 * OBJ_ONEMAPPING must be cleared unless this mapping 1690 * is trivially proven to be the only mapping for any 1691 * of the object's pages. (Object granularity 1692 * reference counting is insufficient to recognize 1693 * aliases with precision.) 1694 */ 1695 if ((object->flags & OBJ_ANON) != 0) { 1696 VM_OBJECT_WLOCK(object); 1697 if (object->ref_count > 1 || object->shadow_count != 0) 1698 vm_object_clear_flag(object, OBJ_ONEMAPPING); 1699 VM_OBJECT_WUNLOCK(object); 1700 } 1701 } else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) == 1702 protoeflags && 1703 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP | 1704 MAP_VN_EXEC)) == 0 && 1705 prev_entry->end == start && (prev_entry->cred == cred || 1706 (prev_entry->object.vm_object != NULL && 1707 prev_entry->object.vm_object->cred == cred)) && 1708 vm_object_coalesce(prev_entry->object.vm_object, 1709 prev_entry->offset, 1710 (vm_size_t)(prev_entry->end - prev_entry->start), 1711 (vm_size_t)(end - prev_entry->end), cred != NULL && 1712 (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) { 1713 /* 1714 * We were able to extend the object. Determine if we 1715 * can extend the previous map entry to include the 1716 * new range as well. 1717 */ 1718 if (prev_entry->inheritance == inheritance && 1719 prev_entry->protection == prot && 1720 prev_entry->max_protection == max && 1721 prev_entry->wired_count == 0) { 1722 KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) == 1723 0, ("prev_entry %p has incoherent wiring", 1724 prev_entry)); 1725 if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0) 1726 map->size += end - prev_entry->end; 1727 vm_map_entry_resize(map, prev_entry, 1728 end - prev_entry->end); 1729 vm_map_try_merge_entries(map, prev_entry, next_entry); 1730 return (KERN_SUCCESS); 1731 } 1732 1733 /* 1734 * If we can extend the object but cannot extend the 1735 * map entry, we have to create a new map entry. We 1736 * must bump the ref count on the extended object to 1737 * account for it. object may be NULL. 1738 */ 1739 object = prev_entry->object.vm_object; 1740 offset = prev_entry->offset + 1741 (prev_entry->end - prev_entry->start); 1742 vm_object_reference(object); 1743 if (cred != NULL && object != NULL && object->cred != NULL && 1744 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 1745 /* Object already accounts for this uid. */ 1746 cred = NULL; 1747 } 1748 } 1749 if (cred != NULL) 1750 crhold(cred); 1751 1752 /* 1753 * Create a new entry 1754 */ 1755 new_entry = vm_map_entry_create(map); 1756 new_entry->start = start; 1757 new_entry->end = end; 1758 new_entry->cred = NULL; 1759 1760 new_entry->eflags = protoeflags; 1761 new_entry->object.vm_object = object; 1762 new_entry->offset = offset; 1763 1764 new_entry->inheritance = inheritance; 1765 new_entry->protection = prot; 1766 new_entry->max_protection = max; 1767 new_entry->wired_count = 0; 1768 new_entry->wiring_thread = NULL; 1769 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT; 1770 new_entry->next_read = start; 1771 1772 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry), 1773 ("overcommit: vm_map_insert leaks vm_map %p", new_entry)); 1774 new_entry->cred = cred; 1775 1776 /* 1777 * Insert the new entry into the list 1778 */ 1779 vm_map_entry_link(map, new_entry); 1780 if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0) 1781 map->size += new_entry->end - new_entry->start; 1782 1783 /* 1784 * Try to coalesce the new entry with both the previous and next 1785 * entries in the list. Previously, we only attempted to coalesce 1786 * with the previous entry when object is NULL. Here, we handle the 1787 * other cases, which are less common. 1788 */ 1789 vm_map_try_merge_entries(map, prev_entry, new_entry); 1790 vm_map_try_merge_entries(map, new_entry, next_entry); 1791 1792 if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) { 1793 vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset), 1794 end - start, cow & MAP_PREFAULT_PARTIAL); 1795 } 1796 1797 return (KERN_SUCCESS); 1798 } 1799 1800 /* 1801 * vm_map_findspace: 1802 * 1803 * Find the first fit (lowest VM address) for "length" free bytes 1804 * beginning at address >= start in the given map. 1805 * 1806 * In a vm_map_entry, "max_free" is the maximum amount of 1807 * contiguous free space between an entry in its subtree and a 1808 * neighbor of that entry. This allows finding a free region in 1809 * one path down the tree, so O(log n) amortized with splay 1810 * trees. 1811 * 1812 * The map must be locked, and leaves it so. 1813 * 1814 * Returns: starting address if sufficient space, 1815 * vm_map_max(map)-length+1 if insufficient space. 1816 */ 1817 vm_offset_t 1818 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length) 1819 { 1820 vm_map_entry_t header, llist, rlist, root, y; 1821 vm_size_t left_length, max_free_left, max_free_right; 1822 vm_offset_t gap_end; 1823 1824 /* 1825 * Request must fit within min/max VM address and must avoid 1826 * address wrap. 1827 */ 1828 start = MAX(start, vm_map_min(map)); 1829 if (start >= vm_map_max(map) || length > vm_map_max(map) - start) 1830 return (vm_map_max(map) - length + 1); 1831 1832 /* Empty tree means wide open address space. */ 1833 if (map->root == NULL) 1834 return (start); 1835 1836 /* 1837 * After splay_split, if start is within an entry, push it to the start 1838 * of the following gap. If rlist is at the end of the gap containing 1839 * start, save the end of that gap in gap_end to see if the gap is big 1840 * enough; otherwise set gap_end to start skip gap-checking and move 1841 * directly to a search of the right subtree. 1842 */ 1843 header = &map->header; 1844 root = vm_map_splay_split(map, start, length, &llist, &rlist); 1845 gap_end = rlist->start; 1846 if (root != NULL) { 1847 start = root->end; 1848 if (root->right != rlist) 1849 gap_end = start; 1850 max_free_left = vm_map_splay_merge_left(header, root, llist); 1851 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1852 } else if (rlist != header) { 1853 root = rlist; 1854 rlist = root->left; 1855 max_free_left = vm_map_splay_merge_pred(header, root, llist); 1856 max_free_right = vm_map_splay_merge_right(header, root, rlist); 1857 } else { 1858 root = llist; 1859 llist = root->right; 1860 max_free_left = vm_map_splay_merge_left(header, root, llist); 1861 max_free_right = vm_map_splay_merge_succ(header, root, rlist); 1862 } 1863 root->max_free = vm_size_max(max_free_left, max_free_right); 1864 map->root = root; 1865 VM_MAP_ASSERT_CONSISTENT(map); 1866 if (length <= gap_end - start) 1867 return (start); 1868 1869 /* With max_free, can immediately tell if no solution. */ 1870 if (root->right == header || length > root->right->max_free) 1871 return (vm_map_max(map) - length + 1); 1872 1873 /* 1874 * Splay for the least large-enough gap in the right subtree. 1875 */ 1876 llist = rlist = header; 1877 for (left_length = 0;; 1878 left_length = vm_map_entry_max_free_left(root, llist)) { 1879 if (length <= left_length) 1880 SPLAY_LEFT_STEP(root, y, llist, rlist, 1881 length <= vm_map_entry_max_free_left(y, llist)); 1882 else 1883 SPLAY_RIGHT_STEP(root, y, llist, rlist, 1884 length > vm_map_entry_max_free_left(y, root)); 1885 if (root == NULL) 1886 break; 1887 } 1888 root = llist; 1889 llist = root->right; 1890 max_free_left = vm_map_splay_merge_left(header, root, llist); 1891 if (rlist == header) { 1892 root->max_free = vm_size_max(max_free_left, 1893 vm_map_splay_merge_succ(header, root, rlist)); 1894 } else { 1895 y = rlist; 1896 rlist = y->left; 1897 y->max_free = vm_size_max( 1898 vm_map_splay_merge_pred(root, y, root), 1899 vm_map_splay_merge_right(header, y, rlist)); 1900 root->max_free = vm_size_max(max_free_left, y->max_free); 1901 } 1902 map->root = root; 1903 VM_MAP_ASSERT_CONSISTENT(map); 1904 return (root->end); 1905 } 1906 1907 int 1908 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1909 vm_offset_t start, vm_size_t length, vm_prot_t prot, 1910 vm_prot_t max, int cow) 1911 { 1912 vm_offset_t end; 1913 int result; 1914 1915 end = start + length; 1916 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 1917 object == NULL, 1918 ("vm_map_fixed: non-NULL backing object for stack")); 1919 vm_map_lock(map); 1920 VM_MAP_RANGE_CHECK(map, start, end); 1921 if ((cow & MAP_CHECK_EXCL) == 0) 1922 vm_map_delete(map, start, end); 1923 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 1924 result = vm_map_stack_locked(map, start, length, sgrowsiz, 1925 prot, max, cow); 1926 } else { 1927 result = vm_map_insert(map, object, offset, start, end, 1928 prot, max, cow); 1929 } 1930 vm_map_unlock(map); 1931 return (result); 1932 } 1933 1934 static const int aslr_pages_rnd_64[2] = {0x1000, 0x10}; 1935 static const int aslr_pages_rnd_32[2] = {0x100, 0x4}; 1936 1937 static int cluster_anon = 1; 1938 SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW, 1939 &cluster_anon, 0, 1940 "Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always"); 1941 1942 static bool 1943 clustering_anon_allowed(vm_offset_t addr) 1944 { 1945 1946 switch (cluster_anon) { 1947 case 0: 1948 return (false); 1949 case 1: 1950 return (addr == 0); 1951 case 2: 1952 default: 1953 return (true); 1954 } 1955 } 1956 1957 static long aslr_restarts; 1958 SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD, 1959 &aslr_restarts, 0, 1960 "Number of aslr failures"); 1961 1962 #define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31) 1963 1964 /* 1965 * Searches for the specified amount of free space in the given map with the 1966 * specified alignment. Performs an address-ordered, first-fit search from 1967 * the given address "*addr", with an optional upper bound "max_addr". If the 1968 * parameter "alignment" is zero, then the alignment is computed from the 1969 * given (object, offset) pair so as to enable the greatest possible use of 1970 * superpage mappings. Returns KERN_SUCCESS and the address of the free space 1971 * in "*addr" if successful. Otherwise, returns KERN_NO_SPACE. 1972 * 1973 * The map must be locked. Initially, there must be at least "length" bytes 1974 * of free space at the given address. 1975 */ 1976 static int 1977 vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1978 vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr, 1979 vm_offset_t alignment) 1980 { 1981 vm_offset_t aligned_addr, free_addr; 1982 1983 VM_MAP_ASSERT_LOCKED(map); 1984 free_addr = *addr; 1985 KASSERT(free_addr == vm_map_findspace(map, free_addr, length), 1986 ("caller failed to provide space %#jx at address %p", 1987 (uintmax_t)length, (void *)free_addr)); 1988 for (;;) { 1989 /* 1990 * At the start of every iteration, the free space at address 1991 * "*addr" is at least "length" bytes. 1992 */ 1993 if (alignment == 0) 1994 pmap_align_superpage(object, offset, addr, length); 1995 else if ((*addr & (alignment - 1)) != 0) { 1996 *addr &= ~(alignment - 1); 1997 *addr += alignment; 1998 } 1999 aligned_addr = *addr; 2000 if (aligned_addr == free_addr) { 2001 /* 2002 * Alignment did not change "*addr", so "*addr" must 2003 * still provide sufficient free space. 2004 */ 2005 return (KERN_SUCCESS); 2006 } 2007 2008 /* 2009 * Test for address wrap on "*addr". A wrapped "*addr" could 2010 * be a valid address, in which case vm_map_findspace() cannot 2011 * be relied upon to fail. 2012 */ 2013 if (aligned_addr < free_addr) 2014 return (KERN_NO_SPACE); 2015 *addr = vm_map_findspace(map, aligned_addr, length); 2016 if (*addr + length > vm_map_max(map) || 2017 (max_addr != 0 && *addr + length > max_addr)) 2018 return (KERN_NO_SPACE); 2019 free_addr = *addr; 2020 if (free_addr == aligned_addr) { 2021 /* 2022 * If a successful call to vm_map_findspace() did not 2023 * change "*addr", then "*addr" must still be aligned 2024 * and provide sufficient free space. 2025 */ 2026 return (KERN_SUCCESS); 2027 } 2028 } 2029 } 2030 2031 /* 2032 * vm_map_find finds an unallocated region in the target address 2033 * map with the given length. The search is defined to be 2034 * first-fit from the specified address; the region found is 2035 * returned in the same parameter. 2036 * 2037 * If object is non-NULL, ref count must be bumped by caller 2038 * prior to making call to account for the new entry. 2039 */ 2040 int 2041 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 2042 vm_offset_t *addr, /* IN/OUT */ 2043 vm_size_t length, vm_offset_t max_addr, int find_space, 2044 vm_prot_t prot, vm_prot_t max, int cow) 2045 { 2046 vm_offset_t alignment, curr_min_addr, min_addr; 2047 int gap, pidx, rv, try; 2048 bool cluster, en_aslr, update_anon; 2049 2050 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 || 2051 object == NULL, 2052 ("vm_map_find: non-NULL backing object for stack")); 2053 MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE && 2054 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0)); 2055 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL || 2056 (object->flags & OBJ_COLORED) == 0)) 2057 find_space = VMFS_ANY_SPACE; 2058 if (find_space >> 8 != 0) { 2059 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags")); 2060 alignment = (vm_offset_t)1 << (find_space >> 8); 2061 } else 2062 alignment = 0; 2063 en_aslr = (map->flags & MAP_ASLR) != 0; 2064 update_anon = cluster = clustering_anon_allowed(*addr) && 2065 (map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 && 2066 find_space != VMFS_NO_SPACE && object == NULL && 2067 (cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP | 2068 MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE; 2069 curr_min_addr = min_addr = *addr; 2070 if (en_aslr && min_addr == 0 && !cluster && 2071 find_space != VMFS_NO_SPACE && 2072 (map->flags & MAP_ASLR_IGNSTART) != 0) 2073 curr_min_addr = min_addr = vm_map_min(map); 2074 try = 0; 2075 vm_map_lock(map); 2076 if (cluster) { 2077 curr_min_addr = map->anon_loc; 2078 if (curr_min_addr == 0) 2079 cluster = false; 2080 } 2081 if (find_space != VMFS_NO_SPACE) { 2082 KASSERT(find_space == VMFS_ANY_SPACE || 2083 find_space == VMFS_OPTIMAL_SPACE || 2084 find_space == VMFS_SUPER_SPACE || 2085 alignment != 0, ("unexpected VMFS flag")); 2086 again: 2087 /* 2088 * When creating an anonymous mapping, try clustering 2089 * with an existing anonymous mapping first. 2090 * 2091 * We make up to two attempts to find address space 2092 * for a given find_space value. The first attempt may 2093 * apply randomization or may cluster with an existing 2094 * anonymous mapping. If this first attempt fails, 2095 * perform a first-fit search of the available address 2096 * space. 2097 * 2098 * If all tries failed, and find_space is 2099 * VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE. 2100 * Again enable clustering and randomization. 2101 */ 2102 try++; 2103 MPASS(try <= 2); 2104 2105 if (try == 2) { 2106 /* 2107 * Second try: we failed either to find a 2108 * suitable region for randomizing the 2109 * allocation, or to cluster with an existing 2110 * mapping. Retry with free run. 2111 */ 2112 curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ? 2113 vm_map_min(map) : min_addr; 2114 atomic_add_long(&aslr_restarts, 1); 2115 } 2116 2117 if (try == 1 && en_aslr && !cluster) { 2118 /* 2119 * Find space for allocation, including 2120 * gap needed for later randomization. 2121 */ 2122 pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 && 2123 (find_space == VMFS_SUPER_SPACE || find_space == 2124 VMFS_OPTIMAL_SPACE) ? 1 : 0; 2125 gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR && 2126 (max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ? 2127 aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx]; 2128 *addr = vm_map_findspace(map, curr_min_addr, 2129 length + gap * pagesizes[pidx]); 2130 if (*addr + length + gap * pagesizes[pidx] > 2131 vm_map_max(map)) 2132 goto again; 2133 /* And randomize the start address. */ 2134 *addr += (arc4random() % gap) * pagesizes[pidx]; 2135 if (max_addr != 0 && *addr + length > max_addr) 2136 goto again; 2137 } else { 2138 *addr = vm_map_findspace(map, curr_min_addr, length); 2139 if (*addr + length > vm_map_max(map) || 2140 (max_addr != 0 && *addr + length > max_addr)) { 2141 if (cluster) { 2142 cluster = false; 2143 MPASS(try == 1); 2144 goto again; 2145 } 2146 rv = KERN_NO_SPACE; 2147 goto done; 2148 } 2149 } 2150 2151 if (find_space != VMFS_ANY_SPACE && 2152 (rv = vm_map_alignspace(map, object, offset, addr, length, 2153 max_addr, alignment)) != KERN_SUCCESS) { 2154 if (find_space == VMFS_OPTIMAL_SPACE) { 2155 find_space = VMFS_ANY_SPACE; 2156 curr_min_addr = min_addr; 2157 cluster = update_anon; 2158 try = 0; 2159 goto again; 2160 } 2161 goto done; 2162 } 2163 } else if ((cow & MAP_REMAP) != 0) { 2164 if (*addr < vm_map_min(map) || 2165 *addr + length > vm_map_max(map) || 2166 *addr + length <= length) { 2167 rv = KERN_INVALID_ADDRESS; 2168 goto done; 2169 } 2170 vm_map_delete(map, *addr, *addr + length); 2171 } 2172 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) { 2173 rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot, 2174 max, cow); 2175 } else { 2176 rv = vm_map_insert(map, object, offset, *addr, *addr + length, 2177 prot, max, cow); 2178 } 2179 if (rv == KERN_SUCCESS && update_anon) 2180 map->anon_loc = *addr + length; 2181 done: 2182 vm_map_unlock(map); 2183 return (rv); 2184 } 2185 2186 /* 2187 * vm_map_find_min() is a variant of vm_map_find() that takes an 2188 * additional parameter (min_addr) and treats the given address 2189 * (*addr) differently. Specifically, it treats *addr as a hint 2190 * and not as the minimum address where the mapping is created. 2191 * 2192 * This function works in two phases. First, it tries to 2193 * allocate above the hint. If that fails and the hint is 2194 * greater than min_addr, it performs a second pass, replacing 2195 * the hint with min_addr as the minimum address for the 2196 * allocation. 2197 */ 2198 int 2199 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 2200 vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr, 2201 vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max, 2202 int cow) 2203 { 2204 vm_offset_t hint; 2205 int rv; 2206 2207 hint = *addr; 2208 for (;;) { 2209 rv = vm_map_find(map, object, offset, addr, length, max_addr, 2210 find_space, prot, max, cow); 2211 if (rv == KERN_SUCCESS || min_addr >= hint) 2212 return (rv); 2213 *addr = hint = min_addr; 2214 } 2215 } 2216 2217 /* 2218 * A map entry with any of the following flags set must not be merged with 2219 * another entry. 2220 */ 2221 #define MAP_ENTRY_NOMERGE_MASK (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \ 2222 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_VN_EXEC) 2223 2224 static bool 2225 vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry) 2226 { 2227 2228 KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 || 2229 (entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0, 2230 ("vm_map_mergeable_neighbors: neither %p nor %p are mergeable", 2231 prev, entry)); 2232 return (prev->end == entry->start && 2233 prev->object.vm_object == entry->object.vm_object && 2234 (prev->object.vm_object == NULL || 2235 prev->offset + (prev->end - prev->start) == entry->offset) && 2236 prev->eflags == entry->eflags && 2237 prev->protection == entry->protection && 2238 prev->max_protection == entry->max_protection && 2239 prev->inheritance == entry->inheritance && 2240 prev->wired_count == entry->wired_count && 2241 prev->cred == entry->cred); 2242 } 2243 2244 static void 2245 vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry) 2246 { 2247 2248 /* 2249 * If the backing object is a vnode object, vm_object_deallocate() 2250 * calls vrele(). However, vrele() does not lock the vnode because 2251 * the vnode has additional references. Thus, the map lock can be 2252 * kept without causing a lock-order reversal with the vnode lock. 2253 * 2254 * Since we count the number of virtual page mappings in 2255 * object->un_pager.vnp.writemappings, the writemappings value 2256 * should not be adjusted when the entry is disposed of. 2257 */ 2258 if (entry->object.vm_object != NULL) 2259 vm_object_deallocate(entry->object.vm_object); 2260 if (entry->cred != NULL) 2261 crfree(entry->cred); 2262 vm_map_entry_dispose(map, entry); 2263 } 2264 2265 /* 2266 * vm_map_try_merge_entries: 2267 * 2268 * Compare the given map entry to its predecessor, and merge its precessor 2269 * into it if possible. The entry remains valid, and may be extended. 2270 * The predecessor may be deleted. 2271 * 2272 * The map must be locked. 2273 */ 2274 void 2275 vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev_entry, 2276 vm_map_entry_t entry) 2277 { 2278 2279 VM_MAP_ASSERT_LOCKED(map); 2280 if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 && 2281 vm_map_mergeable_neighbors(prev_entry, entry)) { 2282 vm_map_entry_unlink(map, prev_entry, UNLINK_MERGE_NEXT); 2283 vm_map_merged_neighbor_dispose(map, prev_entry); 2284 } 2285 } 2286 2287 /* 2288 * vm_map_entry_back: 2289 * 2290 * Allocate an object to back a map entry. 2291 */ 2292 static inline void 2293 vm_map_entry_back(vm_map_entry_t entry) 2294 { 2295 vm_object_t object; 2296 2297 KASSERT(entry->object.vm_object == NULL, 2298 ("map entry %p has backing object", entry)); 2299 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 2300 ("map entry %p is a submap", entry)); 2301 object = vm_object_allocate_anon(atop(entry->end - entry->start), NULL, 2302 entry->cred, entry->end - entry->start); 2303 entry->object.vm_object = object; 2304 entry->offset = 0; 2305 entry->cred = NULL; 2306 } 2307 2308 /* 2309 * vm_map_entry_charge_object 2310 * 2311 * If there is no object backing this entry, create one. Otherwise, if 2312 * the entry has cred, give it to the backing object. 2313 */ 2314 static inline void 2315 vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry) 2316 { 2317 2318 VM_MAP_ASSERT_LOCKED(map); 2319 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, 2320 ("map entry %p is a submap", entry)); 2321 if (entry->object.vm_object == NULL && !map->system_map && 2322 (entry->eflags & MAP_ENTRY_GUARD) == 0) 2323 vm_map_entry_back(entry); 2324 else if (entry->object.vm_object != NULL && 2325 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && 2326 entry->cred != NULL) { 2327 VM_OBJECT_WLOCK(entry->object.vm_object); 2328 KASSERT(entry->object.vm_object->cred == NULL, 2329 ("OVERCOMMIT: %s: both cred e %p", __func__, entry)); 2330 entry->object.vm_object->cred = entry->cred; 2331 entry->object.vm_object->charge = entry->end - entry->start; 2332 VM_OBJECT_WUNLOCK(entry->object.vm_object); 2333 entry->cred = NULL; 2334 } 2335 } 2336 2337 /* 2338 * vm_map_entry_clone 2339 * 2340 * Create a duplicate map entry for clipping. 2341 */ 2342 static vm_map_entry_t 2343 vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry) 2344 { 2345 vm_map_entry_t new_entry; 2346 2347 VM_MAP_ASSERT_LOCKED(map); 2348 2349 /* 2350 * Create a backing object now, if none exists, so that more individual 2351 * objects won't be created after the map entry is split. 2352 */ 2353 vm_map_entry_charge_object(map, entry); 2354 2355 /* Clone the entry. */ 2356 new_entry = vm_map_entry_create(map); 2357 *new_entry = *entry; 2358 if (new_entry->cred != NULL) 2359 crhold(entry->cred); 2360 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { 2361 vm_object_reference(new_entry->object.vm_object); 2362 vm_map_entry_set_vnode_text(new_entry, true); 2363 /* 2364 * The object->un_pager.vnp.writemappings for the object of 2365 * MAP_ENTRY_WRITECNT type entry shall be kept as is here. The 2366 * virtual pages are re-distributed among the clipped entries, 2367 * so the sum is left the same. 2368 */ 2369 } 2370 return (new_entry); 2371 } 2372 2373 /* 2374 * vm_map_clip_start: [ internal use only ] 2375 * 2376 * Asserts that the given entry begins at or after 2377 * the specified address; if necessary, 2378 * it splits the entry into two. 2379 */ 2380 #define vm_map_clip_start(map, entry, startaddr) \ 2381 { \ 2382 if (startaddr > entry->start) \ 2383 _vm_map_clip_start(map, entry, startaddr); \ 2384 } 2385 2386 /* 2387 * This routine is called only when it is known that 2388 * the entry must be split. 2389 */ 2390 static inline void 2391 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start) 2392 { 2393 vm_map_entry_t new_entry; 2394 2395 VM_MAP_ASSERT_LOCKED(map); 2396 KASSERT(entry->end > start && entry->start < start, 2397 ("_vm_map_clip_start: invalid clip of entry %p", entry)); 2398 2399 new_entry = vm_map_entry_clone(map, entry); 2400 2401 /* 2402 * Split off the front portion. Insert the new entry BEFORE this one, 2403 * so that this entry has the specified starting address. 2404 */ 2405 new_entry->end = start; 2406 vm_map_entry_link(map, new_entry); 2407 } 2408 2409 /* 2410 * vm_map_lookup_clip_start: 2411 * 2412 * Find the entry at or just after 'start', and clip it if 'start' is in 2413 * the interior of the entry. Return entry after 'start', and in 2414 * prev_entry set the entry before 'start'. 2415 */ 2416 static inline vm_map_entry_t 2417 vm_map_lookup_clip_start(vm_map_t map, vm_offset_t start, 2418 vm_map_entry_t *prev_entry) 2419 { 2420 vm_map_entry_t 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 #define vm_map_clip_end(map, entry, endaddr) \ 2439 { \ 2440 if ((endaddr) < (entry->end)) \ 2441 _vm_map_clip_end((map), (entry), (endaddr)); \ 2442 } 2443 2444 /* 2445 * This routine is called only when it is known that 2446 * the entry must be split. 2447 */ 2448 static inline void 2449 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end) 2450 { 2451 vm_map_entry_t new_entry; 2452 2453 VM_MAP_ASSERT_LOCKED(map); 2454 KASSERT(entry->start < end && entry->end > end, 2455 ("_vm_map_clip_end: invalid clip of entry %p", entry)); 2456 2457 new_entry = vm_map_entry_clone(map, entry); 2458 2459 /* 2460 * Split off the back portion. Insert the new entry AFTER this one, 2461 * so that this entry has the specified ending address. 2462 */ 2463 new_entry->start = end; 2464 vm_map_entry_link(map, new_entry); 2465 } 2466 2467 /* 2468 * vm_map_submap: [ kernel use only ] 2469 * 2470 * Mark the given range as handled by a subordinate map. 2471 * 2472 * This range must have been created with vm_map_find, 2473 * and no other operations may have been performed on this 2474 * range prior to calling vm_map_submap. 2475 * 2476 * Only a limited number of operations can be performed 2477 * within this rage after calling vm_map_submap: 2478 * vm_fault 2479 * [Don't try vm_map_copy!] 2480 * 2481 * To remove a submapping, one must first remove the 2482 * range from the superior map, and then destroy the 2483 * submap (if desired). [Better yet, don't try it.] 2484 */ 2485 int 2486 vm_map_submap( 2487 vm_map_t map, 2488 vm_offset_t start, 2489 vm_offset_t end, 2490 vm_map_t submap) 2491 { 2492 vm_map_entry_t entry; 2493 int result; 2494 2495 result = KERN_INVALID_ARGUMENT; 2496 2497 vm_map_lock(submap); 2498 submap->flags |= MAP_IS_SUB_MAP; 2499 vm_map_unlock(submap); 2500 2501 vm_map_lock(map); 2502 VM_MAP_RANGE_CHECK(map, start, end); 2503 if (vm_map_lookup_entry(map, start, &entry) && entry->end >= end && 2504 (entry->eflags & MAP_ENTRY_COW) == 0 && 2505 entry->object.vm_object == NULL) { 2506 vm_map_clip_start(map, entry, start); 2507 vm_map_clip_end(map, entry, end); 2508 entry->object.sub_map = submap; 2509 entry->eflags |= MAP_ENTRY_IS_SUB_MAP; 2510 result = KERN_SUCCESS; 2511 } 2512 vm_map_unlock(map); 2513 2514 if (result != KERN_SUCCESS) { 2515 vm_map_lock(submap); 2516 submap->flags &= ~MAP_IS_SUB_MAP; 2517 vm_map_unlock(submap); 2518 } 2519 return (result); 2520 } 2521 2522 /* 2523 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified 2524 */ 2525 #define MAX_INIT_PT 96 2526 2527 /* 2528 * vm_map_pmap_enter: 2529 * 2530 * Preload the specified map's pmap with mappings to the specified 2531 * object's memory-resident pages. No further physical pages are 2532 * allocated, and no further virtual pages are retrieved from secondary 2533 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a 2534 * limited number of page mappings are created at the low-end of the 2535 * specified address range. (For this purpose, a superpage mapping 2536 * counts as one page mapping.) Otherwise, all resident pages within 2537 * the specified address range are mapped. 2538 */ 2539 static void 2540 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot, 2541 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags) 2542 { 2543 vm_offset_t start; 2544 vm_page_t p, p_start; 2545 vm_pindex_t mask, psize, threshold, tmpidx; 2546 2547 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) 2548 return; 2549 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 2550 VM_OBJECT_WLOCK(object); 2551 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 2552 pmap_object_init_pt(map->pmap, addr, object, pindex, 2553 size); 2554 VM_OBJECT_WUNLOCK(object); 2555 return; 2556 } 2557 VM_OBJECT_LOCK_DOWNGRADE(object); 2558 } else 2559 VM_OBJECT_RLOCK(object); 2560 2561 psize = atop(size); 2562 if (psize + pindex > object->size) { 2563 if (pindex >= object->size) { 2564 VM_OBJECT_RUNLOCK(object); 2565 return; 2566 } 2567 psize = object->size - pindex; 2568 } 2569 2570 start = 0; 2571 p_start = NULL; 2572 threshold = MAX_INIT_PT; 2573 2574 p = vm_page_find_least(object, pindex); 2575 /* 2576 * Assert: the variable p is either (1) the page with the 2577 * least pindex greater than or equal to the parameter pindex 2578 * or (2) NULL. 2579 */ 2580 for (; 2581 p != NULL && (tmpidx = p->pindex - pindex) < psize; 2582 p = TAILQ_NEXT(p, listq)) { 2583 /* 2584 * don't allow an madvise to blow away our really 2585 * free pages allocating pv entries. 2586 */ 2587 if (((flags & MAP_PREFAULT_MADVISE) != 0 && 2588 vm_page_count_severe()) || 2589 ((flags & MAP_PREFAULT_PARTIAL) != 0 && 2590 tmpidx >= threshold)) { 2591 psize = tmpidx; 2592 break; 2593 } 2594 if (vm_page_all_valid(p)) { 2595 if (p_start == NULL) { 2596 start = addr + ptoa(tmpidx); 2597 p_start = p; 2598 } 2599 /* Jump ahead if a superpage mapping is possible. */ 2600 if (p->psind > 0 && ((addr + ptoa(tmpidx)) & 2601 (pagesizes[p->psind] - 1)) == 0) { 2602 mask = atop(pagesizes[p->psind]) - 1; 2603 if (tmpidx + mask < psize && 2604 vm_page_ps_test(p, PS_ALL_VALID, NULL)) { 2605 p += mask; 2606 threshold += mask; 2607 } 2608 } 2609 } else if (p_start != NULL) { 2610 pmap_enter_object(map->pmap, start, addr + 2611 ptoa(tmpidx), p_start, prot); 2612 p_start = NULL; 2613 } 2614 } 2615 if (p_start != NULL) 2616 pmap_enter_object(map->pmap, start, addr + ptoa(psize), 2617 p_start, prot); 2618 VM_OBJECT_RUNLOCK(object); 2619 } 2620 2621 /* 2622 * vm_map_protect: 2623 * 2624 * Sets the protection of the specified address 2625 * region in the target map. If "set_max" is 2626 * specified, the maximum protection is to be set; 2627 * otherwise, only the current protection is affected. 2628 */ 2629 int 2630 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 2631 vm_prot_t new_prot, boolean_t set_max) 2632 { 2633 vm_map_entry_t entry, first_entry, in_tran, prev_entry; 2634 vm_object_t obj; 2635 struct ucred *cred; 2636 vm_prot_t old_prot; 2637 int rv; 2638 2639 if (start == end) 2640 return (KERN_SUCCESS); 2641 2642 again: 2643 in_tran = NULL; 2644 vm_map_lock(map); 2645 2646 /* 2647 * Ensure that we are not concurrently wiring pages. vm_map_wire() may 2648 * need to fault pages into the map and will drop the map lock while 2649 * doing so, and the VM object may end up in an inconsistent state if we 2650 * update the protection on the map entry in between faults. 2651 */ 2652 vm_map_wait_busy(map); 2653 2654 VM_MAP_RANGE_CHECK(map, start, end); 2655 2656 if (!vm_map_lookup_entry(map, start, &first_entry)) 2657 first_entry = vm_map_entry_succ(first_entry); 2658 2659 /* 2660 * Make a first pass to check for protection violations. 2661 */ 2662 for (entry = first_entry; entry->start < end; 2663 entry = vm_map_entry_succ(entry)) { 2664 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) 2665 continue; 2666 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 2667 vm_map_unlock(map); 2668 return (KERN_INVALID_ARGUMENT); 2669 } 2670 if ((new_prot & entry->max_protection) != new_prot) { 2671 vm_map_unlock(map); 2672 return (KERN_PROTECTION_FAILURE); 2673 } 2674 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0) 2675 in_tran = entry; 2676 } 2677 2678 /* 2679 * Postpone the operation until all in-transition map entries have 2680 * stabilized. An in-transition entry might already have its pages 2681 * wired and wired_count incremented, but not yet have its 2682 * MAP_ENTRY_USER_WIRED flag set. In which case, we would fail to call 2683 * vm_fault_copy_entry() in the final loop below. 2684 */ 2685 if (in_tran != NULL) { 2686 in_tran->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2687 vm_map_unlock_and_wait(map, 0); 2688 goto again; 2689 } 2690 2691 /* 2692 * Before changing the protections, try to reserve swap space for any 2693 * private (i.e., copy-on-write) mappings that are transitioning from 2694 * read-only to read/write access. If a reservation fails, break out 2695 * of this loop early and let the next loop simplify the entries, since 2696 * some may now be mergeable. 2697 */ 2698 rv = KERN_SUCCESS; 2699 vm_map_clip_start(map, first_entry, start); 2700 for (entry = first_entry; entry->start < end; 2701 entry = vm_map_entry_succ(entry)) { 2702 vm_map_clip_end(map, entry, end); 2703 2704 if (set_max || 2705 ((new_prot & ~entry->protection) & VM_PROT_WRITE) == 0 || 2706 ENTRY_CHARGED(entry) || 2707 (entry->eflags & MAP_ENTRY_GUARD) != 0) { 2708 continue; 2709 } 2710 2711 cred = curthread->td_ucred; 2712 obj = entry->object.vm_object; 2713 2714 if (obj == NULL || 2715 (entry->eflags & MAP_ENTRY_NEEDS_COPY) != 0) { 2716 if (!swap_reserve(entry->end - entry->start)) { 2717 rv = KERN_RESOURCE_SHORTAGE; 2718 end = entry->end; 2719 break; 2720 } 2721 crhold(cred); 2722 entry->cred = cred; 2723 continue; 2724 } 2725 2726 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) 2727 continue; 2728 VM_OBJECT_WLOCK(obj); 2729 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) { 2730 VM_OBJECT_WUNLOCK(obj); 2731 continue; 2732 } 2733 2734 /* 2735 * Charge for the whole object allocation now, since 2736 * we cannot distinguish between non-charged and 2737 * charged clipped mapping of the same object later. 2738 */ 2739 KASSERT(obj->charge == 0, 2740 ("vm_map_protect: object %p overcharged (entry %p)", 2741 obj, entry)); 2742 if (!swap_reserve(ptoa(obj->size))) { 2743 VM_OBJECT_WUNLOCK(obj); 2744 rv = KERN_RESOURCE_SHORTAGE; 2745 end = entry->end; 2746 break; 2747 } 2748 2749 crhold(cred); 2750 obj->cred = cred; 2751 obj->charge = ptoa(obj->size); 2752 VM_OBJECT_WUNLOCK(obj); 2753 } 2754 2755 /* 2756 * If enough swap space was available, go back and fix up protections. 2757 * Otherwise, just simplify entries, since some may have been modified. 2758 * [Note that clipping is not necessary the second time.] 2759 */ 2760 for (prev_entry = vm_map_entry_pred(first_entry), entry = first_entry; 2761 entry->start < end; 2762 vm_map_try_merge_entries(map, prev_entry, entry), 2763 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 2764 if (rv != KERN_SUCCESS || 2765 (entry->eflags & MAP_ENTRY_GUARD) != 0) 2766 continue; 2767 2768 old_prot = entry->protection; 2769 2770 if (set_max) 2771 entry->protection = 2772 (entry->max_protection = new_prot) & 2773 old_prot; 2774 else 2775 entry->protection = new_prot; 2776 2777 /* 2778 * For user wired map entries, the normal lazy evaluation of 2779 * write access upgrades through soft page faults is 2780 * undesirable. Instead, immediately copy any pages that are 2781 * copy-on-write and enable write access in the physical map. 2782 */ 2783 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0 && 2784 (entry->protection & VM_PROT_WRITE) != 0 && 2785 (old_prot & VM_PROT_WRITE) == 0) 2786 vm_fault_copy_entry(map, map, entry, entry, NULL); 2787 2788 /* 2789 * When restricting access, update the physical map. Worry 2790 * about copy-on-write here. 2791 */ 2792 if ((old_prot & ~entry->protection) != 0) { 2793 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 2794 VM_PROT_ALL) 2795 pmap_protect(map->pmap, entry->start, 2796 entry->end, 2797 entry->protection & MASK(entry)); 2798 #undef MASK 2799 } 2800 } 2801 vm_map_try_merge_entries(map, prev_entry, entry); 2802 vm_map_unlock(map); 2803 return (rv); 2804 } 2805 2806 /* 2807 * vm_map_madvise: 2808 * 2809 * This routine traverses a processes map handling the madvise 2810 * system call. Advisories are classified as either those effecting 2811 * the vm_map_entry structure, or those effecting the underlying 2812 * objects. 2813 */ 2814 int 2815 vm_map_madvise( 2816 vm_map_t map, 2817 vm_offset_t start, 2818 vm_offset_t end, 2819 int behav) 2820 { 2821 vm_map_entry_t entry, prev_entry; 2822 bool modify_map; 2823 2824 /* 2825 * Some madvise calls directly modify the vm_map_entry, in which case 2826 * we need to use an exclusive lock on the map and we need to perform 2827 * various clipping operations. Otherwise we only need a read-lock 2828 * on the map. 2829 */ 2830 switch(behav) { 2831 case MADV_NORMAL: 2832 case MADV_SEQUENTIAL: 2833 case MADV_RANDOM: 2834 case MADV_NOSYNC: 2835 case MADV_AUTOSYNC: 2836 case MADV_NOCORE: 2837 case MADV_CORE: 2838 if (start == end) 2839 return (0); 2840 modify_map = true; 2841 vm_map_lock(map); 2842 break; 2843 case MADV_WILLNEED: 2844 case MADV_DONTNEED: 2845 case MADV_FREE: 2846 if (start == end) 2847 return (0); 2848 modify_map = false; 2849 vm_map_lock_read(map); 2850 break; 2851 default: 2852 return (EINVAL); 2853 } 2854 2855 /* 2856 * Locate starting entry and clip if necessary. 2857 */ 2858 VM_MAP_RANGE_CHECK(map, start, end); 2859 2860 if (modify_map) { 2861 /* 2862 * madvise behaviors that are implemented in the vm_map_entry. 2863 * 2864 * We clip the vm_map_entry so that behavioral changes are 2865 * limited to the specified address range. 2866 */ 2867 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry); 2868 entry->start < end; 2869 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 2870 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 2871 continue; 2872 2873 vm_map_clip_end(map, entry, end); 2874 2875 switch (behav) { 2876 case MADV_NORMAL: 2877 vm_map_entry_set_behavior(entry, 2878 MAP_ENTRY_BEHAV_NORMAL); 2879 break; 2880 case MADV_SEQUENTIAL: 2881 vm_map_entry_set_behavior(entry, 2882 MAP_ENTRY_BEHAV_SEQUENTIAL); 2883 break; 2884 case MADV_RANDOM: 2885 vm_map_entry_set_behavior(entry, 2886 MAP_ENTRY_BEHAV_RANDOM); 2887 break; 2888 case MADV_NOSYNC: 2889 entry->eflags |= MAP_ENTRY_NOSYNC; 2890 break; 2891 case MADV_AUTOSYNC: 2892 entry->eflags &= ~MAP_ENTRY_NOSYNC; 2893 break; 2894 case MADV_NOCORE: 2895 entry->eflags |= MAP_ENTRY_NOCOREDUMP; 2896 break; 2897 case MADV_CORE: 2898 entry->eflags &= ~MAP_ENTRY_NOCOREDUMP; 2899 break; 2900 default: 2901 break; 2902 } 2903 vm_map_try_merge_entries(map, prev_entry, entry); 2904 } 2905 vm_map_try_merge_entries(map, prev_entry, entry); 2906 vm_map_unlock(map); 2907 } else { 2908 vm_pindex_t pstart, pend; 2909 2910 /* 2911 * madvise behaviors that are implemented in the underlying 2912 * vm_object. 2913 * 2914 * Since we don't clip the vm_map_entry, we have to clip 2915 * the vm_object pindex and count. 2916 */ 2917 if (!vm_map_lookup_entry(map, start, &entry)) 2918 entry = vm_map_entry_succ(entry); 2919 for (; entry->start < end; 2920 entry = vm_map_entry_succ(entry)) { 2921 vm_offset_t useEnd, useStart; 2922 2923 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 2924 continue; 2925 2926 /* 2927 * MADV_FREE would otherwise rewind time to 2928 * the creation of the shadow object. Because 2929 * we hold the VM map read-locked, neither the 2930 * entry's object nor the presence of a 2931 * backing object can change. 2932 */ 2933 if (behav == MADV_FREE && 2934 entry->object.vm_object != NULL && 2935 entry->object.vm_object->backing_object != NULL) 2936 continue; 2937 2938 pstart = OFF_TO_IDX(entry->offset); 2939 pend = pstart + atop(entry->end - entry->start); 2940 useStart = entry->start; 2941 useEnd = entry->end; 2942 2943 if (entry->start < start) { 2944 pstart += atop(start - entry->start); 2945 useStart = start; 2946 } 2947 if (entry->end > end) { 2948 pend -= atop(entry->end - end); 2949 useEnd = end; 2950 } 2951 2952 if (pstart >= pend) 2953 continue; 2954 2955 /* 2956 * Perform the pmap_advise() before clearing 2957 * PGA_REFERENCED in vm_page_advise(). Otherwise, a 2958 * concurrent pmap operation, such as pmap_remove(), 2959 * could clear a reference in the pmap and set 2960 * PGA_REFERENCED on the page before the pmap_advise() 2961 * had completed. Consequently, the page would appear 2962 * referenced based upon an old reference that 2963 * occurred before this pmap_advise() ran. 2964 */ 2965 if (behav == MADV_DONTNEED || behav == MADV_FREE) 2966 pmap_advise(map->pmap, useStart, useEnd, 2967 behav); 2968 2969 vm_object_madvise(entry->object.vm_object, pstart, 2970 pend, behav); 2971 2972 /* 2973 * Pre-populate paging structures in the 2974 * WILLNEED case. For wired entries, the 2975 * paging structures are already populated. 2976 */ 2977 if (behav == MADV_WILLNEED && 2978 entry->wired_count == 0) { 2979 vm_map_pmap_enter(map, 2980 useStart, 2981 entry->protection, 2982 entry->object.vm_object, 2983 pstart, 2984 ptoa(pend - pstart), 2985 MAP_PREFAULT_MADVISE 2986 ); 2987 } 2988 } 2989 vm_map_unlock_read(map); 2990 } 2991 return (0); 2992 } 2993 2994 2995 /* 2996 * vm_map_inherit: 2997 * 2998 * Sets the inheritance of the specified address 2999 * range in the target map. Inheritance 3000 * affects how the map will be shared with 3001 * child maps at the time of vmspace_fork. 3002 */ 3003 int 3004 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 3005 vm_inherit_t new_inheritance) 3006 { 3007 vm_map_entry_t entry, prev_entry; 3008 3009 switch (new_inheritance) { 3010 case VM_INHERIT_NONE: 3011 case VM_INHERIT_COPY: 3012 case VM_INHERIT_SHARE: 3013 case VM_INHERIT_ZERO: 3014 break; 3015 default: 3016 return (KERN_INVALID_ARGUMENT); 3017 } 3018 if (start == end) 3019 return (KERN_SUCCESS); 3020 vm_map_lock(map); 3021 VM_MAP_RANGE_CHECK(map, start, end); 3022 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry); 3023 entry->start < end; 3024 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3025 vm_map_clip_end(map, entry, end); 3026 if ((entry->eflags & MAP_ENTRY_GUARD) == 0 || 3027 new_inheritance != VM_INHERIT_ZERO) 3028 entry->inheritance = new_inheritance; 3029 vm_map_try_merge_entries(map, prev_entry, entry); 3030 } 3031 vm_map_try_merge_entries(map, prev_entry, entry); 3032 vm_map_unlock(map); 3033 return (KERN_SUCCESS); 3034 } 3035 3036 /* 3037 * vm_map_entry_in_transition: 3038 * 3039 * Release the map lock, and sleep until the entry is no longer in 3040 * transition. Awake and acquire the map lock. If the map changed while 3041 * another held the lock, lookup a possibly-changed entry at or after the 3042 * 'start' position of the old entry. 3043 */ 3044 static vm_map_entry_t 3045 vm_map_entry_in_transition(vm_map_t map, vm_offset_t in_start, 3046 vm_offset_t *io_end, bool holes_ok, vm_map_entry_t in_entry) 3047 { 3048 vm_map_entry_t entry; 3049 vm_offset_t start; 3050 u_int last_timestamp; 3051 3052 VM_MAP_ASSERT_LOCKED(map); 3053 KASSERT((in_entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3054 ("not in-tranition map entry %p", in_entry)); 3055 /* 3056 * We have not yet clipped the entry. 3057 */ 3058 start = MAX(in_start, in_entry->start); 3059 in_entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 3060 last_timestamp = map->timestamp; 3061 if (vm_map_unlock_and_wait(map, 0)) { 3062 /* 3063 * Allow interruption of user wiring/unwiring? 3064 */ 3065 } 3066 vm_map_lock(map); 3067 if (last_timestamp + 1 == map->timestamp) 3068 return (in_entry); 3069 3070 /* 3071 * Look again for the entry because the map was modified while it was 3072 * unlocked. Specifically, the entry may have been clipped, merged, or 3073 * deleted. 3074 */ 3075 if (!vm_map_lookup_entry(map, start, &entry)) { 3076 if (!holes_ok) { 3077 *io_end = start; 3078 return (NULL); 3079 } 3080 entry = vm_map_entry_succ(entry); 3081 } 3082 return (entry); 3083 } 3084 3085 /* 3086 * vm_map_unwire: 3087 * 3088 * Implements both kernel and user unwiring. 3089 */ 3090 int 3091 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end, 3092 int flags) 3093 { 3094 vm_map_entry_t entry, first_entry, next_entry, prev_entry; 3095 int rv; 3096 bool holes_ok, need_wakeup, user_unwire; 3097 3098 if (start == end) 3099 return (KERN_SUCCESS); 3100 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0; 3101 user_unwire = (flags & VM_MAP_WIRE_USER) != 0; 3102 vm_map_lock(map); 3103 VM_MAP_RANGE_CHECK(map, start, end); 3104 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3105 if (holes_ok) 3106 first_entry = vm_map_entry_succ(first_entry); 3107 else { 3108 vm_map_unlock(map); 3109 return (KERN_INVALID_ADDRESS); 3110 } 3111 } 3112 rv = KERN_SUCCESS; 3113 for (entry = first_entry; entry->start < end; entry = next_entry) { 3114 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 3115 /* 3116 * We have not yet clipped the entry. 3117 */ 3118 next_entry = vm_map_entry_in_transition(map, start, 3119 &end, holes_ok, entry); 3120 if (next_entry == NULL) { 3121 if (entry == first_entry) { 3122 vm_map_unlock(map); 3123 return (KERN_INVALID_ADDRESS); 3124 } 3125 rv = KERN_INVALID_ADDRESS; 3126 break; 3127 } 3128 first_entry = (entry == first_entry) ? 3129 next_entry : NULL; 3130 continue; 3131 } 3132 vm_map_clip_start(map, entry, start); 3133 vm_map_clip_end(map, entry, end); 3134 /* 3135 * Mark the entry in case the map lock is released. (See 3136 * above.) 3137 */ 3138 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 3139 entry->wiring_thread == NULL, 3140 ("owned map entry %p", entry)); 3141 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 3142 entry->wiring_thread = curthread; 3143 next_entry = vm_map_entry_succ(entry); 3144 /* 3145 * Check the map for holes in the specified region. 3146 * If holes_ok, skip this check. 3147 */ 3148 if (!holes_ok && 3149 entry->end < end && next_entry->start > entry->end) { 3150 end = entry->end; 3151 rv = KERN_INVALID_ADDRESS; 3152 break; 3153 } 3154 /* 3155 * If system unwiring, require that the entry is system wired. 3156 */ 3157 if (!user_unwire && 3158 vm_map_entry_system_wired_count(entry) == 0) { 3159 end = entry->end; 3160 rv = KERN_INVALID_ARGUMENT; 3161 break; 3162 } 3163 } 3164 need_wakeup = false; 3165 if (first_entry == NULL && 3166 !vm_map_lookup_entry(map, start, &first_entry)) { 3167 KASSERT(holes_ok, ("vm_map_unwire: lookup failed")); 3168 prev_entry = first_entry; 3169 entry = vm_map_entry_succ(first_entry); 3170 } else { 3171 prev_entry = vm_map_entry_pred(first_entry); 3172 entry = first_entry; 3173 } 3174 for (; entry->start < end; 3175 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3176 /* 3177 * If holes_ok was specified, an empty 3178 * space in the unwired region could have been mapped 3179 * while the map lock was dropped for draining 3180 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread 3181 * could be simultaneously wiring this new mapping 3182 * entry. Detect these cases and skip any entries 3183 * marked as in transition by us. 3184 */ 3185 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 3186 entry->wiring_thread != curthread) { 3187 KASSERT(holes_ok, 3188 ("vm_map_unwire: !HOLESOK and new/changed entry")); 3189 continue; 3190 } 3191 3192 if (rv == KERN_SUCCESS && (!user_unwire || 3193 (entry->eflags & MAP_ENTRY_USER_WIRED))) { 3194 if (entry->wired_count == 1) 3195 vm_map_entry_unwire(map, entry); 3196 else 3197 entry->wired_count--; 3198 if (user_unwire) 3199 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 3200 } 3201 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3202 ("vm_map_unwire: in-transition flag missing %p", entry)); 3203 KASSERT(entry->wiring_thread == curthread, 3204 ("vm_map_unwire: alien wire %p", entry)); 3205 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 3206 entry->wiring_thread = NULL; 3207 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 3208 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 3209 need_wakeup = true; 3210 } 3211 vm_map_try_merge_entries(map, prev_entry, entry); 3212 } 3213 vm_map_try_merge_entries(map, prev_entry, entry); 3214 vm_map_unlock(map); 3215 if (need_wakeup) 3216 vm_map_wakeup(map); 3217 return (rv); 3218 } 3219 3220 static void 3221 vm_map_wire_user_count_sub(u_long npages) 3222 { 3223 3224 atomic_subtract_long(&vm_user_wire_count, npages); 3225 } 3226 3227 static bool 3228 vm_map_wire_user_count_add(u_long npages) 3229 { 3230 u_long wired; 3231 3232 wired = vm_user_wire_count; 3233 do { 3234 if (npages + wired > vm_page_max_user_wired) 3235 return (false); 3236 } while (!atomic_fcmpset_long(&vm_user_wire_count, &wired, 3237 npages + wired)); 3238 3239 return (true); 3240 } 3241 3242 /* 3243 * vm_map_wire_entry_failure: 3244 * 3245 * Handle a wiring failure on the given entry. 3246 * 3247 * The map should be locked. 3248 */ 3249 static void 3250 vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry, 3251 vm_offset_t failed_addr) 3252 { 3253 3254 VM_MAP_ASSERT_LOCKED(map); 3255 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 && 3256 entry->wired_count == 1, 3257 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry)); 3258 KASSERT(failed_addr < entry->end, 3259 ("vm_map_wire_entry_failure: entry %p was fully wired", entry)); 3260 3261 /* 3262 * If any pages at the start of this entry were successfully wired, 3263 * then unwire them. 3264 */ 3265 if (failed_addr > entry->start) { 3266 pmap_unwire(map->pmap, entry->start, failed_addr); 3267 vm_object_unwire(entry->object.vm_object, entry->offset, 3268 failed_addr - entry->start, PQ_ACTIVE); 3269 } 3270 3271 /* 3272 * Assign an out-of-range value to represent the failure to wire this 3273 * entry. 3274 */ 3275 entry->wired_count = -1; 3276 } 3277 3278 int 3279 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) 3280 { 3281 int rv; 3282 3283 vm_map_lock(map); 3284 rv = vm_map_wire_locked(map, start, end, flags); 3285 vm_map_unlock(map); 3286 return (rv); 3287 } 3288 3289 3290 /* 3291 * vm_map_wire_locked: 3292 * 3293 * Implements both kernel and user wiring. Returns with the map locked, 3294 * the map lock may be dropped. 3295 */ 3296 int 3297 vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags) 3298 { 3299 vm_map_entry_t entry, first_entry, next_entry, prev_entry; 3300 vm_offset_t faddr, saved_end, saved_start; 3301 u_long npages; 3302 u_int last_timestamp; 3303 int rv; 3304 bool holes_ok, need_wakeup, user_wire; 3305 vm_prot_t prot; 3306 3307 VM_MAP_ASSERT_LOCKED(map); 3308 3309 if (start == end) 3310 return (KERN_SUCCESS); 3311 prot = 0; 3312 if (flags & VM_MAP_WIRE_WRITE) 3313 prot |= VM_PROT_WRITE; 3314 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0; 3315 user_wire = (flags & VM_MAP_WIRE_USER) != 0; 3316 VM_MAP_RANGE_CHECK(map, start, end); 3317 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3318 if (holes_ok) 3319 first_entry = vm_map_entry_succ(first_entry); 3320 else 3321 return (KERN_INVALID_ADDRESS); 3322 } 3323 for (entry = first_entry; entry->start < end; entry = next_entry) { 3324 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 3325 /* 3326 * We have not yet clipped the entry. 3327 */ 3328 next_entry = vm_map_entry_in_transition(map, start, 3329 &end, holes_ok, entry); 3330 if (next_entry == NULL) { 3331 if (entry == first_entry) 3332 return (KERN_INVALID_ADDRESS); 3333 rv = KERN_INVALID_ADDRESS; 3334 goto done; 3335 } 3336 first_entry = (entry == first_entry) ? 3337 next_entry : NULL; 3338 continue; 3339 } 3340 vm_map_clip_start(map, entry, start); 3341 vm_map_clip_end(map, entry, end); 3342 /* 3343 * Mark the entry in case the map lock is released. (See 3344 * above.) 3345 */ 3346 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 && 3347 entry->wiring_thread == NULL, 3348 ("owned map entry %p", entry)); 3349 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 3350 entry->wiring_thread = curthread; 3351 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 3352 || (entry->protection & prot) != prot) { 3353 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED; 3354 if (!holes_ok) { 3355 end = entry->end; 3356 rv = KERN_INVALID_ADDRESS; 3357 goto done; 3358 } 3359 } else if (entry->wired_count == 0) { 3360 entry->wired_count++; 3361 3362 npages = atop(entry->end - entry->start); 3363 if (user_wire && !vm_map_wire_user_count_add(npages)) { 3364 vm_map_wire_entry_failure(map, entry, 3365 entry->start); 3366 end = entry->end; 3367 rv = KERN_RESOURCE_SHORTAGE; 3368 goto done; 3369 } 3370 3371 /* 3372 * Release the map lock, relying on the in-transition 3373 * mark. Mark the map busy for fork. 3374 */ 3375 saved_start = entry->start; 3376 saved_end = entry->end; 3377 last_timestamp = map->timestamp; 3378 vm_map_busy(map); 3379 vm_map_unlock(map); 3380 3381 faddr = saved_start; 3382 do { 3383 /* 3384 * Simulate a fault to get the page and enter 3385 * it into the physical map. 3386 */ 3387 if ((rv = vm_fault(map, faddr, 3388 VM_PROT_NONE, VM_FAULT_WIRE, NULL)) != 3389 KERN_SUCCESS) 3390 break; 3391 } while ((faddr += PAGE_SIZE) < saved_end); 3392 vm_map_lock(map); 3393 vm_map_unbusy(map); 3394 if (last_timestamp + 1 != map->timestamp) { 3395 /* 3396 * Look again for the entry because the map was 3397 * modified while it was unlocked. The entry 3398 * may have been clipped, but NOT merged or 3399 * deleted. 3400 */ 3401 if (!vm_map_lookup_entry(map, saved_start, 3402 &next_entry)) 3403 KASSERT(false, 3404 ("vm_map_wire: lookup failed")); 3405 first_entry = (entry == first_entry) ? 3406 next_entry : NULL; 3407 for (entry = next_entry; entry->end < saved_end; 3408 entry = vm_map_entry_succ(entry)) { 3409 /* 3410 * In case of failure, handle entries 3411 * that were not fully wired here; 3412 * fully wired entries are handled 3413 * later. 3414 */ 3415 if (rv != KERN_SUCCESS && 3416 faddr < entry->end) 3417 vm_map_wire_entry_failure(map, 3418 entry, faddr); 3419 } 3420 } 3421 if (rv != KERN_SUCCESS) { 3422 vm_map_wire_entry_failure(map, entry, faddr); 3423 if (user_wire) 3424 vm_map_wire_user_count_sub(npages); 3425 end = entry->end; 3426 goto done; 3427 } 3428 } else if (!user_wire || 3429 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 3430 entry->wired_count++; 3431 } 3432 /* 3433 * Check the map for holes in the specified region. 3434 * If holes_ok was specified, skip this check. 3435 */ 3436 next_entry = vm_map_entry_succ(entry); 3437 if (!holes_ok && 3438 entry->end < end && next_entry->start > entry->end) { 3439 end = entry->end; 3440 rv = KERN_INVALID_ADDRESS; 3441 goto done; 3442 } 3443 } 3444 rv = KERN_SUCCESS; 3445 done: 3446 need_wakeup = false; 3447 if (first_entry == NULL && 3448 !vm_map_lookup_entry(map, start, &first_entry)) { 3449 KASSERT(holes_ok, ("vm_map_wire: lookup failed")); 3450 prev_entry = first_entry; 3451 entry = vm_map_entry_succ(first_entry); 3452 } else { 3453 prev_entry = vm_map_entry_pred(first_entry); 3454 entry = first_entry; 3455 } 3456 for (; entry->start < end; 3457 prev_entry = entry, entry = vm_map_entry_succ(entry)) { 3458 /* 3459 * If holes_ok was specified, an empty 3460 * space in the unwired region could have been mapped 3461 * while the map lock was dropped for faulting in the 3462 * pages or draining MAP_ENTRY_IN_TRANSITION. 3463 * Moreover, another thread could be simultaneously 3464 * wiring this new mapping entry. Detect these cases 3465 * and skip any entries marked as in transition not by us. 3466 */ 3467 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 || 3468 entry->wiring_thread != curthread) { 3469 KASSERT(holes_ok, 3470 ("vm_map_wire: !HOLESOK and new/changed entry")); 3471 continue; 3472 } 3473 3474 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) { 3475 /* do nothing */ 3476 } else if (rv == KERN_SUCCESS) { 3477 if (user_wire) 3478 entry->eflags |= MAP_ENTRY_USER_WIRED; 3479 } else if (entry->wired_count == -1) { 3480 /* 3481 * Wiring failed on this entry. Thus, unwiring is 3482 * unnecessary. 3483 */ 3484 entry->wired_count = 0; 3485 } else if (!user_wire || 3486 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 3487 /* 3488 * Undo the wiring. Wiring succeeded on this entry 3489 * but failed on a later entry. 3490 */ 3491 if (entry->wired_count == 1) { 3492 vm_map_entry_unwire(map, entry); 3493 if (user_wire) 3494 vm_map_wire_user_count_sub( 3495 atop(entry->end - entry->start)); 3496 } else 3497 entry->wired_count--; 3498 } 3499 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0, 3500 ("vm_map_wire: in-transition flag missing %p", entry)); 3501 KASSERT(entry->wiring_thread == curthread, 3502 ("vm_map_wire: alien wire %p", entry)); 3503 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION | 3504 MAP_ENTRY_WIRE_SKIPPED); 3505 entry->wiring_thread = NULL; 3506 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 3507 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 3508 need_wakeup = true; 3509 } 3510 vm_map_try_merge_entries(map, prev_entry, entry); 3511 } 3512 vm_map_try_merge_entries(map, prev_entry, entry); 3513 if (need_wakeup) 3514 vm_map_wakeup(map); 3515 return (rv); 3516 } 3517 3518 /* 3519 * vm_map_sync 3520 * 3521 * Push any dirty cached pages in the address range to their pager. 3522 * If syncio is TRUE, dirty pages are written synchronously. 3523 * If invalidate is TRUE, any cached pages are freed as well. 3524 * 3525 * If the size of the region from start to end is zero, we are 3526 * supposed to flush all modified pages within the region containing 3527 * start. Unfortunately, a region can be split or coalesced with 3528 * neighboring regions, making it difficult to determine what the 3529 * original region was. Therefore, we approximate this requirement by 3530 * flushing the current region containing start. 3531 * 3532 * Returns an error if any part of the specified range is not mapped. 3533 */ 3534 int 3535 vm_map_sync( 3536 vm_map_t map, 3537 vm_offset_t start, 3538 vm_offset_t end, 3539 boolean_t syncio, 3540 boolean_t invalidate) 3541 { 3542 vm_map_entry_t entry, first_entry, next_entry; 3543 vm_size_t size; 3544 vm_object_t object; 3545 vm_ooffset_t offset; 3546 unsigned int last_timestamp; 3547 boolean_t failed; 3548 3549 vm_map_lock_read(map); 3550 VM_MAP_RANGE_CHECK(map, start, end); 3551 if (!vm_map_lookup_entry(map, start, &first_entry)) { 3552 vm_map_unlock_read(map); 3553 return (KERN_INVALID_ADDRESS); 3554 } else if (start == end) { 3555 start = first_entry->start; 3556 end = first_entry->end; 3557 } 3558 /* 3559 * Make a first pass to check for user-wired memory and holes. 3560 */ 3561 for (entry = first_entry; entry->start < end; entry = next_entry) { 3562 if (invalidate && 3563 (entry->eflags & MAP_ENTRY_USER_WIRED) != 0) { 3564 vm_map_unlock_read(map); 3565 return (KERN_INVALID_ARGUMENT); 3566 } 3567 next_entry = vm_map_entry_succ(entry); 3568 if (end > entry->end && 3569 entry->end != next_entry->start) { 3570 vm_map_unlock_read(map); 3571 return (KERN_INVALID_ADDRESS); 3572 } 3573 } 3574 3575 if (invalidate) 3576 pmap_remove(map->pmap, start, end); 3577 failed = FALSE; 3578 3579 /* 3580 * Make a second pass, cleaning/uncaching pages from the indicated 3581 * objects as we go. 3582 */ 3583 for (entry = first_entry; entry->start < end;) { 3584 offset = entry->offset + (start - entry->start); 3585 size = (end <= entry->end ? end : entry->end) - start; 3586 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) { 3587 vm_map_t smap; 3588 vm_map_entry_t tentry; 3589 vm_size_t tsize; 3590 3591 smap = entry->object.sub_map; 3592 vm_map_lock_read(smap); 3593 (void) vm_map_lookup_entry(smap, offset, &tentry); 3594 tsize = tentry->end - offset; 3595 if (tsize < size) 3596 size = tsize; 3597 object = tentry->object.vm_object; 3598 offset = tentry->offset + (offset - tentry->start); 3599 vm_map_unlock_read(smap); 3600 } else { 3601 object = entry->object.vm_object; 3602 } 3603 vm_object_reference(object); 3604 last_timestamp = map->timestamp; 3605 vm_map_unlock_read(map); 3606 if (!vm_object_sync(object, offset, size, syncio, invalidate)) 3607 failed = TRUE; 3608 start += size; 3609 vm_object_deallocate(object); 3610 vm_map_lock_read(map); 3611 if (last_timestamp == map->timestamp || 3612 !vm_map_lookup_entry(map, start, &entry)) 3613 entry = vm_map_entry_succ(entry); 3614 } 3615 3616 vm_map_unlock_read(map); 3617 return (failed ? KERN_FAILURE : KERN_SUCCESS); 3618 } 3619 3620 /* 3621 * vm_map_entry_unwire: [ internal use only ] 3622 * 3623 * Make the region specified by this entry pageable. 3624 * 3625 * The map in question should be locked. 3626 * [This is the reason for this routine's existence.] 3627 */ 3628 static void 3629 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 3630 { 3631 vm_size_t size; 3632 3633 VM_MAP_ASSERT_LOCKED(map); 3634 KASSERT(entry->wired_count > 0, 3635 ("vm_map_entry_unwire: entry %p isn't wired", entry)); 3636 3637 size = entry->end - entry->start; 3638 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0) 3639 vm_map_wire_user_count_sub(atop(size)); 3640 pmap_unwire(map->pmap, entry->start, entry->end); 3641 vm_object_unwire(entry->object.vm_object, entry->offset, size, 3642 PQ_ACTIVE); 3643 entry->wired_count = 0; 3644 } 3645 3646 static void 3647 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map) 3648 { 3649 3650 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) 3651 vm_object_deallocate(entry->object.vm_object); 3652 uma_zfree(system_map ? kmapentzone : mapentzone, entry); 3653 } 3654 3655 /* 3656 * vm_map_entry_delete: [ internal use only ] 3657 * 3658 * Deallocate the given entry from the target map. 3659 */ 3660 static void 3661 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry) 3662 { 3663 vm_object_t object; 3664 vm_pindex_t offidxstart, offidxend, count, size1; 3665 vm_size_t size; 3666 3667 vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE); 3668 object = entry->object.vm_object; 3669 3670 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) { 3671 MPASS(entry->cred == NULL); 3672 MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0); 3673 MPASS(object == NULL); 3674 vm_map_entry_deallocate(entry, map->system_map); 3675 return; 3676 } 3677 3678 size = entry->end - entry->start; 3679 map->size -= size; 3680 3681 if (entry->cred != NULL) { 3682 swap_release_by_cred(size, entry->cred); 3683 crfree(entry->cred); 3684 } 3685 3686 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) { 3687 entry->object.vm_object = NULL; 3688 } else if ((object->flags & OBJ_ANON) != 0 || 3689 object == kernel_object) { 3690 KASSERT(entry->cred == NULL || object->cred == NULL || 3691 (entry->eflags & MAP_ENTRY_NEEDS_COPY), 3692 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry)); 3693 count = atop(size); 3694 offidxstart = OFF_TO_IDX(entry->offset); 3695 offidxend = offidxstart + count; 3696 VM_OBJECT_WLOCK(object); 3697 if (object->ref_count != 1 && 3698 ((object->flags & OBJ_ONEMAPPING) != 0 || 3699 object == kernel_object)) { 3700 vm_object_collapse(object); 3701 3702 /* 3703 * The option OBJPR_NOTMAPPED can be passed here 3704 * because vm_map_delete() already performed 3705 * pmap_remove() on the only mapping to this range 3706 * of pages. 3707 */ 3708 vm_object_page_remove(object, offidxstart, offidxend, 3709 OBJPR_NOTMAPPED); 3710 if (object->type == OBJT_SWAP) 3711 swap_pager_freespace(object, offidxstart, 3712 count); 3713 if (offidxend >= object->size && 3714 offidxstart < object->size) { 3715 size1 = object->size; 3716 object->size = offidxstart; 3717 if (object->cred != NULL) { 3718 size1 -= object->size; 3719 KASSERT(object->charge >= ptoa(size1), 3720 ("object %p charge < 0", object)); 3721 swap_release_by_cred(ptoa(size1), 3722 object->cred); 3723 object->charge -= ptoa(size1); 3724 } 3725 } 3726 } 3727 VM_OBJECT_WUNLOCK(object); 3728 } 3729 if (map->system_map) 3730 vm_map_entry_deallocate(entry, TRUE); 3731 else { 3732 entry->defer_next = curthread->td_map_def_user; 3733 curthread->td_map_def_user = entry; 3734 } 3735 } 3736 3737 /* 3738 * vm_map_delete: [ internal use only ] 3739 * 3740 * Deallocates the given address range from the target 3741 * map. 3742 */ 3743 int 3744 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end) 3745 { 3746 vm_map_entry_t entry, next_entry; 3747 3748 VM_MAP_ASSERT_LOCKED(map); 3749 if (start == end) 3750 return (KERN_SUCCESS); 3751 3752 /* 3753 * Find the start of the region, and clip it. 3754 * Step through all entries in this region. 3755 */ 3756 for (entry = vm_map_lookup_clip_start(map, start, &entry); 3757 entry->start < end; entry = next_entry) { 3758 /* 3759 * Wait for wiring or unwiring of an entry to complete. 3760 * Also wait for any system wirings to disappear on 3761 * user maps. 3762 */ 3763 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 || 3764 (vm_map_pmap(map) != kernel_pmap && 3765 vm_map_entry_system_wired_count(entry) != 0)) { 3766 unsigned int last_timestamp; 3767 vm_offset_t saved_start; 3768 3769 saved_start = entry->start; 3770 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 3771 last_timestamp = map->timestamp; 3772 (void) vm_map_unlock_and_wait(map, 0); 3773 vm_map_lock(map); 3774 if (last_timestamp + 1 != map->timestamp) { 3775 /* 3776 * Look again for the entry because the map was 3777 * modified while it was unlocked. 3778 * Specifically, the entry may have been 3779 * clipped, merged, or deleted. 3780 */ 3781 next_entry = vm_map_lookup_clip_start(map, 3782 saved_start, &next_entry); 3783 } else 3784 next_entry = entry; 3785 continue; 3786 } 3787 vm_map_clip_end(map, entry, end); 3788 next_entry = vm_map_entry_succ(entry); 3789 3790 /* 3791 * Unwire before removing addresses from the pmap; otherwise, 3792 * unwiring will put the entries back in the pmap. 3793 */ 3794 if (entry->wired_count != 0) 3795 vm_map_entry_unwire(map, entry); 3796 3797 /* 3798 * Remove mappings for the pages, but only if the 3799 * mappings could exist. For instance, it does not 3800 * make sense to call pmap_remove() for guard entries. 3801 */ 3802 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || 3803 entry->object.vm_object != NULL) 3804 pmap_remove(map->pmap, entry->start, entry->end); 3805 3806 if (entry->end == map->anon_loc) 3807 map->anon_loc = entry->start; 3808 3809 /* 3810 * Delete the entry only after removing all pmap 3811 * entries pointing to its pages. (Otherwise, its 3812 * page frames may be reallocated, and any modify bits 3813 * will be set in the wrong object!) 3814 */ 3815 vm_map_entry_delete(map, entry); 3816 } 3817 return (KERN_SUCCESS); 3818 } 3819 3820 /* 3821 * vm_map_remove: 3822 * 3823 * Remove the given address range from the target map. 3824 * This is the exported form of vm_map_delete. 3825 */ 3826 int 3827 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 3828 { 3829 int result; 3830 3831 vm_map_lock(map); 3832 VM_MAP_RANGE_CHECK(map, start, end); 3833 result = vm_map_delete(map, start, end); 3834 vm_map_unlock(map); 3835 return (result); 3836 } 3837 3838 /* 3839 * vm_map_check_protection: 3840 * 3841 * Assert that the target map allows the specified privilege on the 3842 * entire address region given. The entire region must be allocated. 3843 * 3844 * WARNING! This code does not and should not check whether the 3845 * contents of the region is accessible. For example a smaller file 3846 * might be mapped into a larger address space. 3847 * 3848 * NOTE! This code is also called by munmap(). 3849 * 3850 * The map must be locked. A read lock is sufficient. 3851 */ 3852 boolean_t 3853 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 3854 vm_prot_t protection) 3855 { 3856 vm_map_entry_t entry; 3857 vm_map_entry_t tmp_entry; 3858 3859 if (!vm_map_lookup_entry(map, start, &tmp_entry)) 3860 return (FALSE); 3861 entry = tmp_entry; 3862 3863 while (start < end) { 3864 /* 3865 * No holes allowed! 3866 */ 3867 if (start < entry->start) 3868 return (FALSE); 3869 /* 3870 * Check protection associated with entry. 3871 */ 3872 if ((entry->protection & protection) != protection) 3873 return (FALSE); 3874 /* go to next entry */ 3875 start = entry->end; 3876 entry = vm_map_entry_succ(entry); 3877 } 3878 return (TRUE); 3879 } 3880 3881 3882 /* 3883 * 3884 * vm_map_copy_swap_object: 3885 * 3886 * Copies a swap-backed object from an existing map entry to a 3887 * new one. Carries forward the swap charge. May change the 3888 * src object on return. 3889 */ 3890 static void 3891 vm_map_copy_swap_object(vm_map_entry_t src_entry, vm_map_entry_t dst_entry, 3892 vm_offset_t size, vm_ooffset_t *fork_charge) 3893 { 3894 vm_object_t src_object; 3895 struct ucred *cred; 3896 int charged; 3897 3898 src_object = src_entry->object.vm_object; 3899 charged = ENTRY_CHARGED(src_entry); 3900 if ((src_object->flags & OBJ_ANON) != 0) { 3901 VM_OBJECT_WLOCK(src_object); 3902 vm_object_collapse(src_object); 3903 if ((src_object->flags & OBJ_ONEMAPPING) != 0) { 3904 vm_object_split(src_entry); 3905 src_object = src_entry->object.vm_object; 3906 } 3907 vm_object_reference_locked(src_object); 3908 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 3909 VM_OBJECT_WUNLOCK(src_object); 3910 } else 3911 vm_object_reference(src_object); 3912 if (src_entry->cred != NULL && 3913 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3914 KASSERT(src_object->cred == NULL, 3915 ("OVERCOMMIT: vm_map_copy_anon_entry: cred %p", 3916 src_object)); 3917 src_object->cred = src_entry->cred; 3918 src_object->charge = size; 3919 } 3920 dst_entry->object.vm_object = src_object; 3921 if (charged) { 3922 cred = curthread->td_ucred; 3923 crhold(cred); 3924 dst_entry->cred = cred; 3925 *fork_charge += size; 3926 if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) { 3927 crhold(cred); 3928 src_entry->cred = cred; 3929 *fork_charge += size; 3930 } 3931 } 3932 } 3933 3934 /* 3935 * vm_map_copy_entry: 3936 * 3937 * Copies the contents of the source entry to the destination 3938 * entry. The entries *must* be aligned properly. 3939 */ 3940 static void 3941 vm_map_copy_entry( 3942 vm_map_t src_map, 3943 vm_map_t dst_map, 3944 vm_map_entry_t src_entry, 3945 vm_map_entry_t dst_entry, 3946 vm_ooffset_t *fork_charge) 3947 { 3948 vm_object_t src_object; 3949 vm_map_entry_t fake_entry; 3950 vm_offset_t size; 3951 3952 VM_MAP_ASSERT_LOCKED(dst_map); 3953 3954 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP) 3955 return; 3956 3957 if (src_entry->wired_count == 0 || 3958 (src_entry->protection & VM_PROT_WRITE) == 0) { 3959 /* 3960 * If the source entry is marked needs_copy, it is already 3961 * write-protected. 3962 */ 3963 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && 3964 (src_entry->protection & VM_PROT_WRITE) != 0) { 3965 pmap_protect(src_map->pmap, 3966 src_entry->start, 3967 src_entry->end, 3968 src_entry->protection & ~VM_PROT_WRITE); 3969 } 3970 3971 /* 3972 * Make a copy of the object. 3973 */ 3974 size = src_entry->end - src_entry->start; 3975 if ((src_object = src_entry->object.vm_object) != NULL) { 3976 if (src_object->type == OBJT_DEFAULT || 3977 src_object->type == OBJT_SWAP) { 3978 vm_map_copy_swap_object(src_entry, dst_entry, 3979 size, fork_charge); 3980 /* May have split/collapsed, reload obj. */ 3981 src_object = src_entry->object.vm_object; 3982 } else { 3983 vm_object_reference(src_object); 3984 dst_entry->object.vm_object = src_object; 3985 } 3986 src_entry->eflags |= MAP_ENTRY_COW | 3987 MAP_ENTRY_NEEDS_COPY; 3988 dst_entry->eflags |= MAP_ENTRY_COW | 3989 MAP_ENTRY_NEEDS_COPY; 3990 dst_entry->offset = src_entry->offset; 3991 if (src_entry->eflags & MAP_ENTRY_WRITECNT) { 3992 /* 3993 * MAP_ENTRY_WRITECNT cannot 3994 * indicate write reference from 3995 * src_entry, since the entry is 3996 * marked as needs copy. Allocate a 3997 * fake entry that is used to 3998 * decrement object->un_pager writecount 3999 * at the appropriate time. Attach 4000 * fake_entry to the deferred list. 4001 */ 4002 fake_entry = vm_map_entry_create(dst_map); 4003 fake_entry->eflags = MAP_ENTRY_WRITECNT; 4004 src_entry->eflags &= ~MAP_ENTRY_WRITECNT; 4005 vm_object_reference(src_object); 4006 fake_entry->object.vm_object = src_object; 4007 fake_entry->start = src_entry->start; 4008 fake_entry->end = src_entry->end; 4009 fake_entry->defer_next = 4010 curthread->td_map_def_user; 4011 curthread->td_map_def_user = fake_entry; 4012 } 4013 4014 pmap_copy(dst_map->pmap, src_map->pmap, 4015 dst_entry->start, dst_entry->end - dst_entry->start, 4016 src_entry->start); 4017 } else { 4018 dst_entry->object.vm_object = NULL; 4019 dst_entry->offset = 0; 4020 if (src_entry->cred != NULL) { 4021 dst_entry->cred = curthread->td_ucred; 4022 crhold(dst_entry->cred); 4023 *fork_charge += size; 4024 } 4025 } 4026 } else { 4027 /* 4028 * We don't want to make writeable wired pages copy-on-write. 4029 * Immediately copy these pages into the new map by simulating 4030 * page faults. The new pages are pageable. 4031 */ 4032 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry, 4033 fork_charge); 4034 } 4035 } 4036 4037 /* 4038 * vmspace_map_entry_forked: 4039 * Update the newly-forked vmspace each time a map entry is inherited 4040 * or copied. The values for vm_dsize and vm_tsize are approximate 4041 * (and mostly-obsolete ideas in the face of mmap(2) et al.) 4042 */ 4043 static void 4044 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2, 4045 vm_map_entry_t entry) 4046 { 4047 vm_size_t entrysize; 4048 vm_offset_t newend; 4049 4050 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) 4051 return; 4052 entrysize = entry->end - entry->start; 4053 vm2->vm_map.size += entrysize; 4054 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) { 4055 vm2->vm_ssize += btoc(entrysize); 4056 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr && 4057 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) { 4058 newend = MIN(entry->end, 4059 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)); 4060 vm2->vm_dsize += btoc(newend - entry->start); 4061 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr && 4062 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) { 4063 newend = MIN(entry->end, 4064 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)); 4065 vm2->vm_tsize += btoc(newend - entry->start); 4066 } 4067 } 4068 4069 /* 4070 * vmspace_fork: 4071 * Create a new process vmspace structure and vm_map 4072 * based on those of an existing process. The new map 4073 * is based on the old map, according to the inheritance 4074 * values on the regions in that map. 4075 * 4076 * XXX It might be worth coalescing the entries added to the new vmspace. 4077 * 4078 * The source map must not be locked. 4079 */ 4080 struct vmspace * 4081 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) 4082 { 4083 struct vmspace *vm2; 4084 vm_map_t new_map, old_map; 4085 vm_map_entry_t new_entry, old_entry; 4086 vm_object_t object; 4087 int error, locked; 4088 vm_inherit_t inh; 4089 4090 old_map = &vm1->vm_map; 4091 /* Copy immutable fields of vm1 to vm2. */ 4092 vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map), 4093 pmap_pinit); 4094 if (vm2 == NULL) 4095 return (NULL); 4096 4097 vm2->vm_taddr = vm1->vm_taddr; 4098 vm2->vm_daddr = vm1->vm_daddr; 4099 vm2->vm_maxsaddr = vm1->vm_maxsaddr; 4100 vm_map_lock(old_map); 4101 if (old_map->busy) 4102 vm_map_wait_busy(old_map); 4103 new_map = &vm2->vm_map; 4104 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */ 4105 KASSERT(locked, ("vmspace_fork: lock failed")); 4106 4107 error = pmap_vmspace_copy(new_map->pmap, old_map->pmap); 4108 if (error != 0) { 4109 sx_xunlock(&old_map->lock); 4110 sx_xunlock(&new_map->lock); 4111 vm_map_process_deferred(); 4112 vmspace_free(vm2); 4113 return (NULL); 4114 } 4115 4116 new_map->anon_loc = old_map->anon_loc; 4117 4118 VM_MAP_ENTRY_FOREACH(old_entry, old_map) { 4119 if ((old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) 4120 panic("vm_map_fork: encountered a submap"); 4121 4122 inh = old_entry->inheritance; 4123 if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 && 4124 inh != VM_INHERIT_NONE) 4125 inh = VM_INHERIT_COPY; 4126 4127 switch (inh) { 4128 case VM_INHERIT_NONE: 4129 break; 4130 4131 case VM_INHERIT_SHARE: 4132 /* 4133 * Clone the entry, creating the shared object if 4134 * necessary. 4135 */ 4136 object = old_entry->object.vm_object; 4137 if (object == NULL) { 4138 vm_map_entry_back(old_entry); 4139 object = old_entry->object.vm_object; 4140 } 4141 4142 /* 4143 * Add the reference before calling vm_object_shadow 4144 * to insure that a shadow object is created. 4145 */ 4146 vm_object_reference(object); 4147 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4148 vm_object_shadow(&old_entry->object.vm_object, 4149 &old_entry->offset, 4150 old_entry->end - old_entry->start, 4151 old_entry->cred, 4152 /* Transfer the second reference too. */ 4153 true); 4154 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4155 old_entry->cred = NULL; 4156 4157 /* 4158 * As in vm_map_merged_neighbor_dispose(), 4159 * the vnode lock will not be acquired in 4160 * this call to vm_object_deallocate(). 4161 */ 4162 vm_object_deallocate(object); 4163 object = old_entry->object.vm_object; 4164 } else { 4165 VM_OBJECT_WLOCK(object); 4166 vm_object_clear_flag(object, OBJ_ONEMAPPING); 4167 if (old_entry->cred != NULL) { 4168 KASSERT(object->cred == NULL, 4169 ("vmspace_fork both cred")); 4170 object->cred = old_entry->cred; 4171 object->charge = old_entry->end - 4172 old_entry->start; 4173 old_entry->cred = NULL; 4174 } 4175 4176 /* 4177 * Assert the correct state of the vnode 4178 * v_writecount while the object is locked, to 4179 * not relock it later for the assertion 4180 * correctness. 4181 */ 4182 if (old_entry->eflags & MAP_ENTRY_WRITECNT && 4183 object->type == OBJT_VNODE) { 4184 KASSERT(((struct vnode *)object-> 4185 handle)->v_writecount > 0, 4186 ("vmspace_fork: v_writecount %p", 4187 object)); 4188 KASSERT(object->un_pager.vnp. 4189 writemappings > 0, 4190 ("vmspace_fork: vnp.writecount %p", 4191 object)); 4192 } 4193 VM_OBJECT_WUNLOCK(object); 4194 } 4195 4196 /* 4197 * Clone the entry, referencing the shared object. 4198 */ 4199 new_entry = vm_map_entry_create(new_map); 4200 *new_entry = *old_entry; 4201 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 4202 MAP_ENTRY_IN_TRANSITION); 4203 new_entry->wiring_thread = NULL; 4204 new_entry->wired_count = 0; 4205 if (new_entry->eflags & MAP_ENTRY_WRITECNT) { 4206 vm_pager_update_writecount(object, 4207 new_entry->start, new_entry->end); 4208 } 4209 vm_map_entry_set_vnode_text(new_entry, true); 4210 4211 /* 4212 * Insert the entry into the new map -- we know we're 4213 * inserting at the end of the new map. 4214 */ 4215 vm_map_entry_link(new_map, new_entry); 4216 vmspace_map_entry_forked(vm1, vm2, new_entry); 4217 4218 /* 4219 * Update the physical map 4220 */ 4221 pmap_copy(new_map->pmap, old_map->pmap, 4222 new_entry->start, 4223 (old_entry->end - old_entry->start), 4224 old_entry->start); 4225 break; 4226 4227 case VM_INHERIT_COPY: 4228 /* 4229 * Clone the entry and link into the map. 4230 */ 4231 new_entry = vm_map_entry_create(new_map); 4232 *new_entry = *old_entry; 4233 /* 4234 * Copied entry is COW over the old object. 4235 */ 4236 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED | 4237 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WRITECNT); 4238 new_entry->wiring_thread = NULL; 4239 new_entry->wired_count = 0; 4240 new_entry->object.vm_object = NULL; 4241 new_entry->cred = NULL; 4242 vm_map_entry_link(new_map, new_entry); 4243 vmspace_map_entry_forked(vm1, vm2, new_entry); 4244 vm_map_copy_entry(old_map, new_map, old_entry, 4245 new_entry, fork_charge); 4246 vm_map_entry_set_vnode_text(new_entry, true); 4247 break; 4248 4249 case VM_INHERIT_ZERO: 4250 /* 4251 * Create a new anonymous mapping entry modelled from 4252 * the old one. 4253 */ 4254 new_entry = vm_map_entry_create(new_map); 4255 memset(new_entry, 0, sizeof(*new_entry)); 4256 4257 new_entry->start = old_entry->start; 4258 new_entry->end = old_entry->end; 4259 new_entry->eflags = old_entry->eflags & 4260 ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION | 4261 MAP_ENTRY_WRITECNT | MAP_ENTRY_VN_EXEC); 4262 new_entry->protection = old_entry->protection; 4263 new_entry->max_protection = old_entry->max_protection; 4264 new_entry->inheritance = VM_INHERIT_ZERO; 4265 4266 vm_map_entry_link(new_map, new_entry); 4267 vmspace_map_entry_forked(vm1, vm2, new_entry); 4268 4269 new_entry->cred = curthread->td_ucred; 4270 crhold(new_entry->cred); 4271 *fork_charge += (new_entry->end - new_entry->start); 4272 4273 break; 4274 } 4275 } 4276 /* 4277 * Use inlined vm_map_unlock() to postpone handling the deferred 4278 * map entries, which cannot be done until both old_map and 4279 * new_map locks are released. 4280 */ 4281 sx_xunlock(&old_map->lock); 4282 sx_xunlock(&new_map->lock); 4283 vm_map_process_deferred(); 4284 4285 return (vm2); 4286 } 4287 4288 /* 4289 * Create a process's stack for exec_new_vmspace(). This function is never 4290 * asked to wire the newly created stack. 4291 */ 4292 int 4293 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 4294 vm_prot_t prot, vm_prot_t max, int cow) 4295 { 4296 vm_size_t growsize, init_ssize; 4297 rlim_t vmemlim; 4298 int rv; 4299 4300 MPASS((map->flags & MAP_WIREFUTURE) == 0); 4301 growsize = sgrowsiz; 4302 init_ssize = (max_ssize < growsize) ? max_ssize : growsize; 4303 vm_map_lock(map); 4304 vmemlim = lim_cur(curthread, RLIMIT_VMEM); 4305 /* If we would blow our VMEM resource limit, no go */ 4306 if (map->size + init_ssize > vmemlim) { 4307 rv = KERN_NO_SPACE; 4308 goto out; 4309 } 4310 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot, 4311 max, cow); 4312 out: 4313 vm_map_unlock(map); 4314 return (rv); 4315 } 4316 4317 static int stack_guard_page = 1; 4318 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN, 4319 &stack_guard_page, 0, 4320 "Specifies the number of guard pages for a stack that grows"); 4321 4322 static int 4323 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 4324 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) 4325 { 4326 vm_map_entry_t new_entry, prev_entry; 4327 vm_offset_t bot, gap_bot, gap_top, top; 4328 vm_size_t init_ssize, sgp; 4329 int orient, rv; 4330 4331 /* 4332 * The stack orientation is piggybacked with the cow argument. 4333 * Extract it into orient and mask the cow argument so that we 4334 * don't pass it around further. 4335 */ 4336 orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP); 4337 KASSERT(orient != 0, ("No stack grow direction")); 4338 KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP), 4339 ("bi-dir stack")); 4340 4341 if (addrbos < vm_map_min(map) || 4342 addrbos + max_ssize > vm_map_max(map) || 4343 addrbos + max_ssize <= addrbos) 4344 return (KERN_INVALID_ADDRESS); 4345 sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 || 4346 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 : 4347 (vm_size_t)stack_guard_page * PAGE_SIZE; 4348 if (sgp >= max_ssize) 4349 return (KERN_INVALID_ARGUMENT); 4350 4351 init_ssize = growsize; 4352 if (max_ssize < init_ssize + sgp) 4353 init_ssize = max_ssize - sgp; 4354 4355 /* If addr is already mapped, no go */ 4356 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) 4357 return (KERN_NO_SPACE); 4358 4359 /* 4360 * If we can't accommodate max_ssize in the current mapping, no go. 4361 */ 4362 if (vm_map_entry_succ(prev_entry)->start < addrbos + max_ssize) 4363 return (KERN_NO_SPACE); 4364 4365 /* 4366 * We initially map a stack of only init_ssize. We will grow as 4367 * needed later. Depending on the orientation of the stack (i.e. 4368 * the grow direction) we either map at the top of the range, the 4369 * bottom of the range or in the middle. 4370 * 4371 * Note: we would normally expect prot and max to be VM_PROT_ALL, 4372 * and cow to be 0. Possibly we should eliminate these as input 4373 * parameters, and just pass these values here in the insert call. 4374 */ 4375 if (orient == MAP_STACK_GROWS_DOWN) { 4376 bot = addrbos + max_ssize - init_ssize; 4377 top = bot + init_ssize; 4378 gap_bot = addrbos; 4379 gap_top = bot; 4380 } else /* if (orient == MAP_STACK_GROWS_UP) */ { 4381 bot = addrbos; 4382 top = bot + init_ssize; 4383 gap_bot = top; 4384 gap_top = addrbos + max_ssize; 4385 } 4386 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); 4387 if (rv != KERN_SUCCESS) 4388 return (rv); 4389 new_entry = vm_map_entry_succ(prev_entry); 4390 KASSERT(new_entry->end == top || new_entry->start == bot, 4391 ("Bad entry start/end for new stack entry")); 4392 KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 || 4393 (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0, 4394 ("new entry lacks MAP_ENTRY_GROWS_DOWN")); 4395 KASSERT((orient & MAP_STACK_GROWS_UP) == 0 || 4396 (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0, 4397 ("new entry lacks MAP_ENTRY_GROWS_UP")); 4398 if (gap_bot == gap_top) 4399 return (KERN_SUCCESS); 4400 rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE, 4401 VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ? 4402 MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP)); 4403 if (rv == KERN_SUCCESS) { 4404 /* 4405 * Gap can never successfully handle a fault, so 4406 * read-ahead logic is never used for it. Re-use 4407 * next_read of the gap entry to store 4408 * stack_guard_page for vm_map_growstack(). 4409 */ 4410 if (orient == MAP_STACK_GROWS_DOWN) 4411 vm_map_entry_pred(new_entry)->next_read = sgp; 4412 else 4413 vm_map_entry_succ(new_entry)->next_read = sgp; 4414 } else { 4415 (void)vm_map_delete(map, bot, top); 4416 } 4417 return (rv); 4418 } 4419 4420 /* 4421 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we 4422 * successfully grow the stack. 4423 */ 4424 static int 4425 vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry) 4426 { 4427 vm_map_entry_t stack_entry; 4428 struct proc *p; 4429 struct vmspace *vm; 4430 struct ucred *cred; 4431 vm_offset_t gap_end, gap_start, grow_start; 4432 vm_size_t grow_amount, guard, max_grow; 4433 rlim_t lmemlim, stacklim, vmemlim; 4434 int rv, rv1; 4435 bool gap_deleted, grow_down, is_procstack; 4436 #ifdef notyet 4437 uint64_t limit; 4438 #endif 4439 #ifdef RACCT 4440 int error; 4441 #endif 4442 4443 p = curproc; 4444 vm = p->p_vmspace; 4445 4446 /* 4447 * Disallow stack growth when the access is performed by a 4448 * debugger or AIO daemon. The reason is that the wrong 4449 * resource limits are applied. 4450 */ 4451 if (p != initproc && (map != &p->p_vmspace->vm_map || 4452 p->p_textvp == NULL)) 4453 return (KERN_FAILURE); 4454 4455 MPASS(!map->system_map); 4456 4457 lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK); 4458 stacklim = lim_cur(curthread, RLIMIT_STACK); 4459 vmemlim = lim_cur(curthread, RLIMIT_VMEM); 4460 retry: 4461 /* If addr is not in a hole for a stack grow area, no need to grow. */ 4462 if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry)) 4463 return (KERN_FAILURE); 4464 if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0) 4465 return (KERN_SUCCESS); 4466 if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) { 4467 stack_entry = vm_map_entry_succ(gap_entry); 4468 if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 || 4469 stack_entry->start != gap_entry->end) 4470 return (KERN_FAILURE); 4471 grow_amount = round_page(stack_entry->start - addr); 4472 grow_down = true; 4473 } else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) { 4474 stack_entry = vm_map_entry_pred(gap_entry); 4475 if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 || 4476 stack_entry->end != gap_entry->start) 4477 return (KERN_FAILURE); 4478 grow_amount = round_page(addr + 1 - stack_entry->end); 4479 grow_down = false; 4480 } else { 4481 return (KERN_FAILURE); 4482 } 4483 guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 || 4484 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 : 4485 gap_entry->next_read; 4486 max_grow = gap_entry->end - gap_entry->start; 4487 if (guard > max_grow) 4488 return (KERN_NO_SPACE); 4489 max_grow -= guard; 4490 if (grow_amount > max_grow) 4491 return (KERN_NO_SPACE); 4492 4493 /* 4494 * If this is the main process stack, see if we're over the stack 4495 * limit. 4496 */ 4497 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr && 4498 addr < (vm_offset_t)p->p_sysent->sv_usrstack; 4499 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) 4500 return (KERN_NO_SPACE); 4501 4502 #ifdef RACCT 4503 if (racct_enable) { 4504 PROC_LOCK(p); 4505 if (is_procstack && racct_set(p, RACCT_STACK, 4506 ctob(vm->vm_ssize) + grow_amount)) { 4507 PROC_UNLOCK(p); 4508 return (KERN_NO_SPACE); 4509 } 4510 PROC_UNLOCK(p); 4511 } 4512 #endif 4513 4514 grow_amount = roundup(grow_amount, sgrowsiz); 4515 if (grow_amount > max_grow) 4516 grow_amount = max_grow; 4517 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { 4518 grow_amount = trunc_page((vm_size_t)stacklim) - 4519 ctob(vm->vm_ssize); 4520 } 4521 4522 #ifdef notyet 4523 PROC_LOCK(p); 4524 limit = racct_get_available(p, RACCT_STACK); 4525 PROC_UNLOCK(p); 4526 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit)) 4527 grow_amount = limit - ctob(vm->vm_ssize); 4528 #endif 4529 4530 if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) { 4531 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) { 4532 rv = KERN_NO_SPACE; 4533 goto out; 4534 } 4535 #ifdef RACCT 4536 if (racct_enable) { 4537 PROC_LOCK(p); 4538 if (racct_set(p, RACCT_MEMLOCK, 4539 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) { 4540 PROC_UNLOCK(p); 4541 rv = KERN_NO_SPACE; 4542 goto out; 4543 } 4544 PROC_UNLOCK(p); 4545 } 4546 #endif 4547 } 4548 4549 /* If we would blow our VMEM resource limit, no go */ 4550 if (map->size + grow_amount > vmemlim) { 4551 rv = KERN_NO_SPACE; 4552 goto out; 4553 } 4554 #ifdef RACCT 4555 if (racct_enable) { 4556 PROC_LOCK(p); 4557 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) { 4558 PROC_UNLOCK(p); 4559 rv = KERN_NO_SPACE; 4560 goto out; 4561 } 4562 PROC_UNLOCK(p); 4563 } 4564 #endif 4565 4566 if (vm_map_lock_upgrade(map)) { 4567 gap_entry = NULL; 4568 vm_map_lock_read(map); 4569 goto retry; 4570 } 4571 4572 if (grow_down) { 4573 grow_start = gap_entry->end - grow_amount; 4574 if (gap_entry->start + grow_amount == gap_entry->end) { 4575 gap_start = gap_entry->start; 4576 gap_end = gap_entry->end; 4577 vm_map_entry_delete(map, gap_entry); 4578 gap_deleted = true; 4579 } else { 4580 MPASS(gap_entry->start < gap_entry->end - grow_amount); 4581 vm_map_entry_resize(map, gap_entry, -grow_amount); 4582 gap_deleted = false; 4583 } 4584 rv = vm_map_insert(map, NULL, 0, grow_start, 4585 grow_start + grow_amount, 4586 stack_entry->protection, stack_entry->max_protection, 4587 MAP_STACK_GROWS_DOWN); 4588 if (rv != KERN_SUCCESS) { 4589 if (gap_deleted) { 4590 rv1 = vm_map_insert(map, NULL, 0, gap_start, 4591 gap_end, VM_PROT_NONE, VM_PROT_NONE, 4592 MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN); 4593 MPASS(rv1 == KERN_SUCCESS); 4594 } else 4595 vm_map_entry_resize(map, gap_entry, 4596 grow_amount); 4597 } 4598 } else { 4599 grow_start = stack_entry->end; 4600 cred = stack_entry->cred; 4601 if (cred == NULL && stack_entry->object.vm_object != NULL) 4602 cred = stack_entry->object.vm_object->cred; 4603 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred)) 4604 rv = KERN_NO_SPACE; 4605 /* Grow the underlying object if applicable. */ 4606 else if (stack_entry->object.vm_object == NULL || 4607 vm_object_coalesce(stack_entry->object.vm_object, 4608 stack_entry->offset, 4609 (vm_size_t)(stack_entry->end - stack_entry->start), 4610 grow_amount, cred != NULL)) { 4611 if (gap_entry->start + grow_amount == gap_entry->end) { 4612 vm_map_entry_delete(map, gap_entry); 4613 vm_map_entry_resize(map, stack_entry, 4614 grow_amount); 4615 } else { 4616 gap_entry->start += grow_amount; 4617 stack_entry->end += grow_amount; 4618 } 4619 map->size += grow_amount; 4620 rv = KERN_SUCCESS; 4621 } else 4622 rv = KERN_FAILURE; 4623 } 4624 if (rv == KERN_SUCCESS && is_procstack) 4625 vm->vm_ssize += btoc(grow_amount); 4626 4627 /* 4628 * Heed the MAP_WIREFUTURE flag if it was set for this process. 4629 */ 4630 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) { 4631 rv = vm_map_wire_locked(map, grow_start, 4632 grow_start + grow_amount, 4633 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES); 4634 } 4635 vm_map_lock_downgrade(map); 4636 4637 out: 4638 #ifdef RACCT 4639 if (racct_enable && rv != KERN_SUCCESS) { 4640 PROC_LOCK(p); 4641 error = racct_set(p, RACCT_VMEM, map->size); 4642 KASSERT(error == 0, ("decreasing RACCT_VMEM failed")); 4643 if (!old_mlock) { 4644 error = racct_set(p, RACCT_MEMLOCK, 4645 ptoa(pmap_wired_count(map->pmap))); 4646 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed")); 4647 } 4648 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize)); 4649 KASSERT(error == 0, ("decreasing RACCT_STACK failed")); 4650 PROC_UNLOCK(p); 4651 } 4652 #endif 4653 4654 return (rv); 4655 } 4656 4657 /* 4658 * Unshare the specified VM space for exec. If other processes are 4659 * mapped to it, then create a new one. The new vmspace is null. 4660 */ 4661 int 4662 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser) 4663 { 4664 struct vmspace *oldvmspace = p->p_vmspace; 4665 struct vmspace *newvmspace; 4666 4667 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0, 4668 ("vmspace_exec recursed")); 4669 newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit); 4670 if (newvmspace == NULL) 4671 return (ENOMEM); 4672 newvmspace->vm_swrss = oldvmspace->vm_swrss; 4673 /* 4674 * This code is written like this for prototype purposes. The 4675 * goal is to avoid running down the vmspace here, but let the 4676 * other process's that are still using the vmspace to finally 4677 * run it down. Even though there is little or no chance of blocking 4678 * here, it is a good idea to keep this form for future mods. 4679 */ 4680 PROC_VMSPACE_LOCK(p); 4681 p->p_vmspace = newvmspace; 4682 PROC_VMSPACE_UNLOCK(p); 4683 if (p == curthread->td_proc) 4684 pmap_activate(curthread); 4685 curthread->td_pflags |= TDP_EXECVMSPC; 4686 return (0); 4687 } 4688 4689 /* 4690 * Unshare the specified VM space for forcing COW. This 4691 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 4692 */ 4693 int 4694 vmspace_unshare(struct proc *p) 4695 { 4696 struct vmspace *oldvmspace = p->p_vmspace; 4697 struct vmspace *newvmspace; 4698 vm_ooffset_t fork_charge; 4699 4700 if (oldvmspace->vm_refcnt == 1) 4701 return (0); 4702 fork_charge = 0; 4703 newvmspace = vmspace_fork(oldvmspace, &fork_charge); 4704 if (newvmspace == NULL) 4705 return (ENOMEM); 4706 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) { 4707 vmspace_free(newvmspace); 4708 return (ENOMEM); 4709 } 4710 PROC_VMSPACE_LOCK(p); 4711 p->p_vmspace = newvmspace; 4712 PROC_VMSPACE_UNLOCK(p); 4713 if (p == curthread->td_proc) 4714 pmap_activate(curthread); 4715 vmspace_free(oldvmspace); 4716 return (0); 4717 } 4718 4719 /* 4720 * vm_map_lookup: 4721 * 4722 * Finds the VM object, offset, and 4723 * protection for a given virtual address in the 4724 * specified map, assuming a page fault of the 4725 * type specified. 4726 * 4727 * Leaves the map in question locked for read; return 4728 * values are guaranteed until a vm_map_lookup_done 4729 * call is performed. Note that the map argument 4730 * is in/out; the returned map must be used in 4731 * the call to vm_map_lookup_done. 4732 * 4733 * A handle (out_entry) is returned for use in 4734 * vm_map_lookup_done, to make that fast. 4735 * 4736 * If a lookup is requested with "write protection" 4737 * specified, the map may be changed to perform virtual 4738 * copying operations, although the data referenced will 4739 * remain the same. 4740 */ 4741 int 4742 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 4743 vm_offset_t vaddr, 4744 vm_prot_t fault_typea, 4745 vm_map_entry_t *out_entry, /* OUT */ 4746 vm_object_t *object, /* OUT */ 4747 vm_pindex_t *pindex, /* OUT */ 4748 vm_prot_t *out_prot, /* OUT */ 4749 boolean_t *wired) /* OUT */ 4750 { 4751 vm_map_entry_t entry; 4752 vm_map_t map = *var_map; 4753 vm_prot_t prot; 4754 vm_prot_t fault_type; 4755 vm_object_t eobject; 4756 vm_size_t size; 4757 struct ucred *cred; 4758 4759 RetryLookup: 4760 4761 vm_map_lock_read(map); 4762 4763 RetryLookupLocked: 4764 /* 4765 * Lookup the faulting address. 4766 */ 4767 if (!vm_map_lookup_entry(map, vaddr, out_entry)) { 4768 vm_map_unlock_read(map); 4769 return (KERN_INVALID_ADDRESS); 4770 } 4771 4772 entry = *out_entry; 4773 4774 /* 4775 * Handle submaps. 4776 */ 4777 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 4778 vm_map_t old_map = map; 4779 4780 *var_map = map = entry->object.sub_map; 4781 vm_map_unlock_read(old_map); 4782 goto RetryLookup; 4783 } 4784 4785 /* 4786 * Check whether this task is allowed to have this page. 4787 */ 4788 prot = entry->protection; 4789 if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) { 4790 fault_typea &= ~VM_PROT_FAULT_LOOKUP; 4791 if (prot == VM_PROT_NONE && map != kernel_map && 4792 (entry->eflags & MAP_ENTRY_GUARD) != 0 && 4793 (entry->eflags & (MAP_ENTRY_STACK_GAP_DN | 4794 MAP_ENTRY_STACK_GAP_UP)) != 0 && 4795 vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS) 4796 goto RetryLookupLocked; 4797 } 4798 fault_type = fault_typea & VM_PROT_ALL; 4799 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) { 4800 vm_map_unlock_read(map); 4801 return (KERN_PROTECTION_FAILURE); 4802 } 4803 KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags & 4804 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) != 4805 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY), 4806 ("entry %p flags %x", entry, entry->eflags)); 4807 if ((fault_typea & VM_PROT_COPY) != 0 && 4808 (entry->max_protection & VM_PROT_WRITE) == 0 && 4809 (entry->eflags & MAP_ENTRY_COW) == 0) { 4810 vm_map_unlock_read(map); 4811 return (KERN_PROTECTION_FAILURE); 4812 } 4813 4814 /* 4815 * If this page is not pageable, we have to get it for all possible 4816 * accesses. 4817 */ 4818 *wired = (entry->wired_count != 0); 4819 if (*wired) 4820 fault_type = entry->protection; 4821 size = entry->end - entry->start; 4822 4823 /* 4824 * If the entry was copy-on-write, we either ... 4825 */ 4826 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4827 /* 4828 * If we want to write the page, we may as well handle that 4829 * now since we've got the map locked. 4830 * 4831 * If we don't need to write the page, we just demote the 4832 * permissions allowed. 4833 */ 4834 if ((fault_type & VM_PROT_WRITE) != 0 || 4835 (fault_typea & VM_PROT_COPY) != 0) { 4836 /* 4837 * Make a new object, and place it in the object 4838 * chain. Note that no new references have appeared 4839 * -- one just moved from the map to the new 4840 * object. 4841 */ 4842 if (vm_map_lock_upgrade(map)) 4843 goto RetryLookup; 4844 4845 if (entry->cred == NULL) { 4846 /* 4847 * The debugger owner is charged for 4848 * the memory. 4849 */ 4850 cred = curthread->td_ucred; 4851 crhold(cred); 4852 if (!swap_reserve_by_cred(size, cred)) { 4853 crfree(cred); 4854 vm_map_unlock(map); 4855 return (KERN_RESOURCE_SHORTAGE); 4856 } 4857 entry->cred = cred; 4858 } 4859 eobject = entry->object.vm_object; 4860 vm_object_shadow(&entry->object.vm_object, 4861 &entry->offset, size, entry->cred, false); 4862 if (eobject == entry->object.vm_object) { 4863 /* 4864 * The object was not shadowed. 4865 */ 4866 swap_release_by_cred(size, entry->cred); 4867 crfree(entry->cred); 4868 } 4869 entry->cred = NULL; 4870 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 4871 4872 vm_map_lock_downgrade(map); 4873 } else { 4874 /* 4875 * We're attempting to read a copy-on-write page -- 4876 * don't allow writes. 4877 */ 4878 prot &= ~VM_PROT_WRITE; 4879 } 4880 } 4881 4882 /* 4883 * Create an object if necessary. 4884 */ 4885 if (entry->object.vm_object == NULL && !map->system_map) { 4886 if (vm_map_lock_upgrade(map)) 4887 goto RetryLookup; 4888 entry->object.vm_object = vm_object_allocate_anon(atop(size), 4889 NULL, entry->cred, entry->cred != NULL ? size : 0); 4890 entry->offset = 0; 4891 entry->cred = NULL; 4892 vm_map_lock_downgrade(map); 4893 } 4894 4895 /* 4896 * Return the object/offset from this entry. If the entry was 4897 * copy-on-write or empty, it has been fixed up. 4898 */ 4899 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4900 *object = entry->object.vm_object; 4901 4902 *out_prot = prot; 4903 return (KERN_SUCCESS); 4904 } 4905 4906 /* 4907 * vm_map_lookup_locked: 4908 * 4909 * Lookup the faulting address. A version of vm_map_lookup that returns 4910 * KERN_FAILURE instead of blocking on map lock or memory allocation. 4911 */ 4912 int 4913 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */ 4914 vm_offset_t vaddr, 4915 vm_prot_t fault_typea, 4916 vm_map_entry_t *out_entry, /* OUT */ 4917 vm_object_t *object, /* OUT */ 4918 vm_pindex_t *pindex, /* OUT */ 4919 vm_prot_t *out_prot, /* OUT */ 4920 boolean_t *wired) /* OUT */ 4921 { 4922 vm_map_entry_t entry; 4923 vm_map_t map = *var_map; 4924 vm_prot_t prot; 4925 vm_prot_t fault_type = fault_typea; 4926 4927 /* 4928 * Lookup the faulting address. 4929 */ 4930 if (!vm_map_lookup_entry(map, vaddr, out_entry)) 4931 return (KERN_INVALID_ADDRESS); 4932 4933 entry = *out_entry; 4934 4935 /* 4936 * Fail if the entry refers to a submap. 4937 */ 4938 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) 4939 return (KERN_FAILURE); 4940 4941 /* 4942 * Check whether this task is allowed to have this page. 4943 */ 4944 prot = entry->protection; 4945 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 4946 if ((fault_type & prot) != fault_type) 4947 return (KERN_PROTECTION_FAILURE); 4948 4949 /* 4950 * If this page is not pageable, we have to get it for all possible 4951 * accesses. 4952 */ 4953 *wired = (entry->wired_count != 0); 4954 if (*wired) 4955 fault_type = entry->protection; 4956 4957 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 4958 /* 4959 * Fail if the entry was copy-on-write for a write fault. 4960 */ 4961 if (fault_type & VM_PROT_WRITE) 4962 return (KERN_FAILURE); 4963 /* 4964 * We're attempting to read a copy-on-write page -- 4965 * don't allow writes. 4966 */ 4967 prot &= ~VM_PROT_WRITE; 4968 } 4969 4970 /* 4971 * Fail if an object should be created. 4972 */ 4973 if (entry->object.vm_object == NULL && !map->system_map) 4974 return (KERN_FAILURE); 4975 4976 /* 4977 * Return the object/offset from this entry. If the entry was 4978 * copy-on-write or empty, it has been fixed up. 4979 */ 4980 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 4981 *object = entry->object.vm_object; 4982 4983 *out_prot = prot; 4984 return (KERN_SUCCESS); 4985 } 4986 4987 /* 4988 * vm_map_lookup_done: 4989 * 4990 * Releases locks acquired by a vm_map_lookup 4991 * (according to the handle returned by that lookup). 4992 */ 4993 void 4994 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry) 4995 { 4996 /* 4997 * Unlock the main-level map 4998 */ 4999 vm_map_unlock_read(map); 5000 } 5001 5002 vm_offset_t 5003 vm_map_max_KBI(const struct vm_map *map) 5004 { 5005 5006 return (vm_map_max(map)); 5007 } 5008 5009 vm_offset_t 5010 vm_map_min_KBI(const struct vm_map *map) 5011 { 5012 5013 return (vm_map_min(map)); 5014 } 5015 5016 pmap_t 5017 vm_map_pmap_KBI(vm_map_t map) 5018 { 5019 5020 return (map->pmap); 5021 } 5022 5023 #ifdef INVARIANTS 5024 static void 5025 _vm_map_assert_consistent(vm_map_t map, int check) 5026 { 5027 vm_map_entry_t entry, prev; 5028 vm_map_entry_t cur, header, lbound, ubound; 5029 vm_size_t max_left, max_right; 5030 5031 #ifdef DIAGNOSTIC 5032 ++map->nupdates; 5033 #endif 5034 if (enable_vmmap_check != check) 5035 return; 5036 5037 header = prev = &map->header; 5038 VM_MAP_ENTRY_FOREACH(entry, map) { 5039 KASSERT(prev->end <= entry->start, 5040 ("map %p prev->end = %jx, start = %jx", map, 5041 (uintmax_t)prev->end, (uintmax_t)entry->start)); 5042 KASSERT(entry->start < entry->end, 5043 ("map %p start = %jx, end = %jx", map, 5044 (uintmax_t)entry->start, (uintmax_t)entry->end)); 5045 KASSERT(entry->left == header || 5046 entry->left->start < entry->start, 5047 ("map %p left->start = %jx, start = %jx", map, 5048 (uintmax_t)entry->left->start, (uintmax_t)entry->start)); 5049 KASSERT(entry->right == header || 5050 entry->start < entry->right->start, 5051 ("map %p start = %jx, right->start = %jx", map, 5052 (uintmax_t)entry->start, (uintmax_t)entry->right->start)); 5053 cur = map->root; 5054 lbound = ubound = header; 5055 for (;;) { 5056 if (entry->start < cur->start) { 5057 ubound = cur; 5058 cur = cur->left; 5059 KASSERT(cur != lbound, 5060 ("map %p cannot find %jx", 5061 map, (uintmax_t)entry->start)); 5062 } else if (cur->end <= entry->start) { 5063 lbound = cur; 5064 cur = cur->right; 5065 KASSERT(cur != ubound, 5066 ("map %p cannot find %jx", 5067 map, (uintmax_t)entry->start)); 5068 } else { 5069 KASSERT(cur == entry, 5070 ("map %p cannot find %jx", 5071 map, (uintmax_t)entry->start)); 5072 break; 5073 } 5074 } 5075 max_left = vm_map_entry_max_free_left(entry, lbound); 5076 max_right = vm_map_entry_max_free_right(entry, ubound); 5077 KASSERT(entry->max_free == vm_size_max(max_left, max_right), 5078 ("map %p max = %jx, max_left = %jx, max_right = %jx", map, 5079 (uintmax_t)entry->max_free, 5080 (uintmax_t)max_left, (uintmax_t)max_right)); 5081 prev = entry; 5082 } 5083 KASSERT(prev->end <= entry->start, 5084 ("map %p prev->end = %jx, start = %jx", map, 5085 (uintmax_t)prev->end, (uintmax_t)entry->start)); 5086 } 5087 #endif 5088 5089 #include "opt_ddb.h" 5090 #ifdef DDB 5091 #include <sys/kernel.h> 5092 5093 #include <ddb/ddb.h> 5094 5095 static void 5096 vm_map_print(vm_map_t map) 5097 { 5098 vm_map_entry_t entry, prev; 5099 5100 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 5101 (void *)map, 5102 (void *)map->pmap, map->nentries, map->timestamp); 5103 5104 db_indent += 2; 5105 prev = &map->header; 5106 VM_MAP_ENTRY_FOREACH(entry, map) { 5107 db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n", 5108 (void *)entry, (void *)entry->start, (void *)entry->end, 5109 entry->eflags); 5110 { 5111 static char *inheritance_name[4] = 5112 {"share", "copy", "none", "donate_copy"}; 5113 5114 db_iprintf(" prot=%x/%x/%s", 5115 entry->protection, 5116 entry->max_protection, 5117 inheritance_name[(int)(unsigned char) 5118 entry->inheritance]); 5119 if (entry->wired_count != 0) 5120 db_printf(", wired"); 5121 } 5122 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 5123 db_printf(", share=%p, offset=0x%jx\n", 5124 (void *)entry->object.sub_map, 5125 (uintmax_t)entry->offset); 5126 if (prev == &map->header || 5127 prev->object.sub_map != 5128 entry->object.sub_map) { 5129 db_indent += 2; 5130 vm_map_print((vm_map_t)entry->object.sub_map); 5131 db_indent -= 2; 5132 } 5133 } else { 5134 if (entry->cred != NULL) 5135 db_printf(", ruid %d", entry->cred->cr_ruid); 5136 db_printf(", object=%p, offset=0x%jx", 5137 (void *)entry->object.vm_object, 5138 (uintmax_t)entry->offset); 5139 if (entry->object.vm_object && entry->object.vm_object->cred) 5140 db_printf(", obj ruid %d charge %jx", 5141 entry->object.vm_object->cred->cr_ruid, 5142 (uintmax_t)entry->object.vm_object->charge); 5143 if (entry->eflags & MAP_ENTRY_COW) 5144 db_printf(", copy (%s)", 5145 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 5146 db_printf("\n"); 5147 5148 if (prev == &map->header || 5149 prev->object.vm_object != 5150 entry->object.vm_object) { 5151 db_indent += 2; 5152 vm_object_print((db_expr_t)(intptr_t) 5153 entry->object.vm_object, 5154 0, 0, (char *)0); 5155 db_indent -= 2; 5156 } 5157 } 5158 prev = entry; 5159 } 5160 db_indent -= 2; 5161 } 5162 5163 DB_SHOW_COMMAND(map, map) 5164 { 5165 5166 if (!have_addr) { 5167 db_printf("usage: show map <addr>\n"); 5168 return; 5169 } 5170 vm_map_print((vm_map_t)addr); 5171 } 5172 5173 DB_SHOW_COMMAND(procvm, procvm) 5174 { 5175 struct proc *p; 5176 5177 if (have_addr) { 5178 p = db_lookup_proc(addr); 5179 } else { 5180 p = curproc; 5181 } 5182 5183 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 5184 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 5185 (void *)vmspace_pmap(p->p_vmspace)); 5186 5187 vm_map_print((vm_map_t)&p->p_vmspace->vm_map); 5188 } 5189 5190 #endif /* DDB */ 5191