2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
34 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
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.
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.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
64 * Virtual memory mapping module.
67 #include <sys/cdefs.h>
68 __FBSDID("$FreeBSD$");
70 #include <sys/param.h>
71 #include <sys/systm.h>
73 #include <sys/kernel.h>
76 #include <sys/mutex.h>
78 #include <sys/vmmeter.h>
80 #include <sys/vnode.h>
81 #include <sys/racct.h>
82 #include <sys/resourcevar.h>
83 #include <sys/rwlock.h>
85 #include <sys/sysctl.h>
86 #include <sys/sysent.h>
90 #include <vm/vm_param.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>
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.
109 * Synchronization is required prior to most operations.
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.
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.
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.
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,
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);
145 static void vm_map_zdtor(void *mem, int size, void *arg);
146 static void vmspace_zdtor(void *mem, int size, void *arg);
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,
151 static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
152 vm_offset_t failed_addr);
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)))
159 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type
162 #define PROC_VMSPACE_LOCK(p) do { } while (0)
163 #define PROC_VMSPACE_UNLOCK(p) do { } while (0)
166 * VM_MAP_RANGE_CHECK: [ internal use only ]
168 * Asserts that the starting and ending region
169 * addresses fall within the valid range of the map.
171 #define VM_MAP_RANGE_CHECK(map, start, end) \
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); \
184 * Initialize the vm_map module. Must be called before
185 * any other vm_map routines.
187 * Map and entry structures are allocated from the general
188 * purpose memory pool with some exceptions:
190 * - The kernel map and kmem submap are allocated statically.
191 * - Kernel map entries are allocated out of a static pool.
193 * These restrictions are necessary since malloc() uses the
194 * maps and requires map entries.
200 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF);
201 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL,
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,
220 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
224 vmspace_zinit(void *mem, int size, int flags)
228 vm = (struct vmspace *)mem;
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));
237 vm_map_zinit(void *mem, int size, int flags)
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)");
250 vmspace_zdtor(void *mem, int size, void *arg)
254 vm = (struct vmspace *)mem;
256 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg);
259 vm_map_zdtor(void *mem, int size, void *arg)
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));
271 #endif /* INVARIANTS */
274 * Allocate a vmspace structure, including a vm_map and pmap,
275 * and initialize those structures. The refcnt is set to 1.
277 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit().
280 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit)
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);
290 CTR1(KTR_VM, "vmspace_alloc: %p", vm);
291 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max);
306 vmspace_container_reset(struct proc *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);
320 vmspace_dofree(struct vmspace *vm)
323 CTR1(KTR_VM, "vmspace_free: %p", vm);
326 * Make sure any SysV shm is freed, it might not have been in
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.
336 (void)vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map),
337 vm_map_max(&vm->vm_map));
339 pmap_release(vmspace_pmap(vm));
340 vm->vm_map.pmap = NULL;
341 uma_zfree(vmspace_zone, vm);
345 vmspace_free(struct vmspace *vm)
348 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
349 "vmspace_free() called");
351 if (vm->vm_refcnt == 0)
352 panic("vmspace_free: attempt to free already freed vmspace");
354 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1)
359 vmspace_exitfree(struct proc *p)
363 PROC_VMSPACE_LOCK(p);
366 PROC_VMSPACE_UNLOCK(p);
367 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace"));
372 vmspace_exit(struct thread *td)
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.
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.
392 atomic_add_int(&vmspace0.vm_refcnt, 1);
393 refcnt = vm->vm_refcnt;
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);
402 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt - 1));
404 if (p->p_vmspace != vm) {
405 /* vmspace not yet freed, switch back */
406 PROC_VMSPACE_LOCK(p);
408 PROC_VMSPACE_UNLOCK(p);
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);
421 vmspace_container_reset(p);
425 /* Acquire reference to vmspace owned by another process. */
428 vmspace_acquire_ref(struct proc *p)
433 PROC_VMSPACE_LOCK(p);
436 PROC_VMSPACE_UNLOCK(p);
439 refcnt = vm->vm_refcnt;
441 if (refcnt <= 0) { /* Avoid 0->1 transition */
442 PROC_VMSPACE_UNLOCK(p);
445 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt + 1));
446 if (vm != p->p_vmspace) {
447 PROC_VMSPACE_UNLOCK(p);
451 PROC_VMSPACE_UNLOCK(p);
456 * Switch between vmspaces in an AIO kernel process.
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.
471 vmspace_switch_aio(struct vmspace *newvm)
473 struct vmspace *oldvm;
475 /* XXX: Need some way to assert that this is an aio daemon. */
477 KASSERT(newvm->vm_refcnt > 0,
478 ("vmspace_switch_aio: newvm unreferenced"));
480 oldvm = curproc->p_vmspace;
485 * Point to the new address space and refer to it.
487 curproc->p_vmspace = newvm;
488 atomic_add_int(&newvm->vm_refcnt, 1);
490 /* Activate the new mapping. */
491 pmap_activate(curthread);
497 _vm_map_lock(vm_map_t map, const char *file, int line)
501 mtx_lock_flags_(&map->system_mtx, 0, file, line);
503 sx_xlock_(&map->lock, file, line);
508 vm_map_entry_set_vnode_text(vm_map_entry_t entry, bool add)
514 if ((entry->eflags & MAP_ENTRY_VN_EXEC) == 0)
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;
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));
529 * Mostly, we do not lock the backing object. It is
530 * referenced by the entry we are processing, so it cannot go
535 if (object->type == OBJT_DEAD) {
537 * For OBJT_DEAD objects, v_writecount was handled in
538 * vnode_pager_dealloc().
540 } else if (object->type == OBJT_VNODE) {
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));
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.
551 VM_OBJECT_RLOCK(object);
552 if ((object->flags & OBJ_TMPFS) != 0) {
553 vp = object->un_pager.swp.swp_tmpfs;
559 VM_OBJECT_RUNLOCK(object);
562 ("vm_map_entry_set_vnode_text: wrong object type, "
563 "entry %p, object %p, add %d", entry, object, add));
567 VOP_SET_TEXT_CHECKED(vp);
569 vn_lock(vp, LK_SHARED | LK_RETRY);
570 VOP_UNSET_TEXT_CHECKED(vp);
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.
582 #define defer_next right
585 vm_map_process_deferred(void)
588 vm_map_entry_t entry, next;
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 |
599 if ((entry->eflags & MAP_ENTRY_WRITECNT) != 0) {
601 * Decrement the object's writemappings and
602 * possibly the vnode's v_writecount.
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,
611 vm_map_entry_set_vnode_text(entry, false);
612 vm_map_entry_deallocate(entry, FALSE);
619 _vm_map_assert_locked(vm_map_t map, const char *file, int line)
623 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
625 sx_assert_(&map->lock, SA_XLOCKED, file, line);
628 #define VM_MAP_ASSERT_LOCKED(map) \
629 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE)
631 enum { VMMAP_CHECK_NONE, VMMAP_CHECK_UNLOCK, VMMAP_CHECK_ALL };
633 static int enable_vmmap_check = VMMAP_CHECK_UNLOCK;
635 static int enable_vmmap_check = VMMAP_CHECK_NONE;
637 SYSCTL_INT(_debug, OID_AUTO, vmmap_check, CTLFLAG_RWTUN,
638 &enable_vmmap_check, 0, "Enable vm map consistency checking");
640 static void _vm_map_assert_consistent(vm_map_t map, int check);
642 #define VM_MAP_ASSERT_CONSISTENT(map) \
643 _vm_map_assert_consistent(map, VMMAP_CHECK_ALL)
645 #define VM_MAP_UNLOCK_CONSISTENT(map) do { \
646 if (map->nupdates > map->nentries) { \
647 _vm_map_assert_consistent(map, VMMAP_CHECK_UNLOCK); \
652 #define VM_MAP_UNLOCK_CONSISTENT(map)
655 #define VM_MAP_ASSERT_LOCKED(map)
656 #define VM_MAP_ASSERT_CONSISTENT(map)
657 #define VM_MAP_UNLOCK_CONSISTENT(map)
658 #endif /* INVARIANTS */
661 _vm_map_unlock(vm_map_t map, const char *file, int line)
664 VM_MAP_UNLOCK_CONSISTENT(map);
666 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
668 sx_xunlock_(&map->lock, file, line);
669 vm_map_process_deferred();
674 _vm_map_lock_read(vm_map_t map, const char *file, int line)
678 mtx_lock_flags_(&map->system_mtx, 0, file, line);
680 sx_slock_(&map->lock, file, line);
684 _vm_map_unlock_read(vm_map_t map, const char *file, int line)
688 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
690 sx_sunlock_(&map->lock, file, line);
691 vm_map_process_deferred();
696 _vm_map_trylock(vm_map_t map, const char *file, int line)
700 error = map->system_map ?
701 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
702 !sx_try_xlock_(&map->lock, file, line);
709 _vm_map_trylock_read(vm_map_t map, const char *file, int line)
713 error = map->system_map ?
714 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
715 !sx_try_slock_(&map->lock, file, line);
720 * _vm_map_lock_upgrade: [ internal use only ]
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.
727 * Requires that the map be read locked.
730 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line)
732 unsigned int last_timestamp;
734 if (map->system_map) {
735 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
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();
742 * If the map's timestamp does not change while the
743 * map is unlocked, then the upgrade succeeds.
745 sx_xlock_(&map->lock, file, line);
746 if (last_timestamp != map->timestamp) {
747 sx_xunlock_(&map->lock, file, line);
757 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
760 if (map->system_map) {
761 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
763 VM_MAP_UNLOCK_CONSISTENT(map);
764 sx_downgrade_(&map->lock, file, line);
771 * Returns a non-zero value if the caller holds a write (exclusive) lock
772 * on the specified map and the value "0" otherwise.
775 vm_map_locked(vm_map_t map)
779 return (mtx_owned(&map->system_mtx));
781 return (sx_xlocked(&map->lock));
785 * _vm_map_unlock_and_wait:
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
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.
799 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line)
802 VM_MAP_UNLOCK_CONSISTENT(map);
803 mtx_lock(&map_sleep_mtx);
805 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
807 sx_xunlock_(&map->lock, file, line);
808 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps",
815 * Awaken any threads that have slept on the map using
816 * vm_map_unlock_and_wait().
819 vm_map_wakeup(vm_map_t map)
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().
827 mtx_lock(&map_sleep_mtx);
828 mtx_unlock(&map_sleep_mtx);
833 vm_map_busy(vm_map_t map)
836 VM_MAP_ASSERT_LOCKED(map);
841 vm_map_unbusy(vm_map_t map)
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);
853 vm_map_wait_busy(vm_map_t map)
856 VM_MAP_ASSERT_LOCKED(map);
858 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0);
860 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0);
862 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0);
868 vmspace_resident_count(struct vmspace *vmspace)
870 return pmap_resident_count(vmspace_pmap(vmspace));
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.
881 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max)
885 result = uma_zalloc(mapzone, M_WAITOK);
886 CTR1(KTR_VM, "vm_map_create: %p", result);
887 _vm_map_init(result, pmap, min, max);
892 * Initialize an existing vm_map structure
893 * such as that in the vmspace structure.
896 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
899 map->header.eflags = MAP_ENTRY_HEADER;
900 map->needs_wakeup = FALSE;
903 map->header.end = min;
904 map->header.start = max;
906 map->header.left = map->header.right = &map->header;
917 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
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");
926 * vm_map_entry_dispose: [ internal use only ]
928 * Inverse of vm_map_entry_create.
931 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry)
933 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry);
937 * vm_map_entry_create: [ internal use only ]
939 * Allocates a VM map entry for insertion.
940 * No entry fields are filled in.
942 static vm_map_entry_t
943 vm_map_entry_create(vm_map_t map)
945 vm_map_entry_t new_entry;
948 new_entry = uma_zalloc(kmapentzone, M_NOWAIT);
950 new_entry = uma_zalloc(mapentzone, M_WAITOK);
951 if (new_entry == NULL)
952 panic("vm_map_entry_create: kernel resources exhausted");
957 * vm_map_entry_set_behavior:
959 * Set the expected access behavior, either normal, random, or
963 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior)
965 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) |
966 (behavior & MAP_ENTRY_BEHAV_MASK);
970 * vm_map_entry_max_free_{left,right}:
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.
976 static inline vm_size_t
977 vm_map_entry_max_free_left(vm_map_entry_t root, vm_map_entry_t left_ancestor)
980 return (root->left != left_ancestor ?
981 root->left->max_free : root->start - left_ancestor->end);
984 static inline vm_size_t
985 vm_map_entry_max_free_right(vm_map_entry_t root, vm_map_entry_t right_ancestor)
988 return (root->right != right_ancestor ?
989 root->right->max_free : right_ancestor->start - root->end);
993 * vm_map_entry_{pred,succ}:
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.
999 static inline vm_map_entry_t
1000 vm_map_entry_pred(vm_map_entry_t entry)
1002 vm_map_entry_t prior;
1004 prior = entry->left;
1005 if (prior->right->start < entry->start) {
1007 prior = prior->right;
1008 while (prior->right != entry);
1013 static inline vm_size_t
1014 vm_size_max(vm_size_t a, vm_size_t b)
1017 return (a > b ? a : b);
1020 #define SPLAY_LEFT_STEP(root, y, llist, rlist, test) do { \
1022 vm_size_t max_free; \
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. \
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. */ \
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);\
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; \
1058 root = y != llist ? y : NULL; \
1061 #define SPLAY_RIGHT_STEP(root, y, llist, rlist, test) do { \
1063 vm_size_t max_free; \
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. \
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. */ \
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);\
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; \
1099 root = y != rlist ? y : NULL; \
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.
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)
1116 vm_map_entry_t left, right, root, y;
1118 left = right = &map->header;
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);
1138 static __always_inline void
1139 vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *rlist)
1141 vm_map_entry_t hi, right, y;
1144 hi = root->right == right ? NULL : root->right;
1148 SPLAY_LEFT_STEP(hi, y, root, right, true);
1153 static __always_inline void
1154 vm_map_splay_findprev(vm_map_entry_t root, vm_map_entry_t *llist)
1156 vm_map_entry_t left, lo, y;
1159 lo = root->left == left ? NULL : root->left;
1163 SPLAY_RIGHT_STEP(lo, y, left, root, true);
1169 vm_map_entry_swap(vm_map_entry_t *a, vm_map_entry_t *b)
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.
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)
1188 * The max_free values of the children of llist are in
1189 * llist->max_free and max_free. Update with the
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);
1202 * When llist is known to be the predecessor of root.
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)
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);
1215 root->left = header;
1216 header->right = root;
1222 * When llist may or may not be the predecessor of root.
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)
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,
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)
1245 * The max_free values of the children of rlist are in
1246 * rlist->max_free and max_free. Update with the
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);
1259 * When rlist is known to be the succecessor of root.
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)
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);
1272 root->right = header;
1273 header->left = root;
1279 * When rlist may or may not be the succecessor of root.
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)
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,
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)
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
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.
1317 * The map must be locked, and leaves it so.
1319 * Returns: the new root.
1321 static vm_map_entry_t
1322 vm_map_splay(vm_map_t map, vm_offset_t addr)
1324 vm_map_entry_t header, llist, rlist, root;
1325 vm_size_t max_free_left, max_free_right;
1327 header = &map->header;
1328 root = vm_map_splay_split(map, addr, 0, &llist, &rlist);
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) {
1334 * Recover the greatest node in the left
1335 * subtree and make it the root.
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) {
1343 * Recover the least node in the right
1344 * subtree and make it the root.
1348 max_free_left = vm_map_splay_merge_pred(header, root, llist);
1349 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1351 /* There is no root. */
1354 root->max_free = vm_size_max(max_free_left, max_free_right);
1356 VM_MAP_ASSERT_CONSISTENT(map);
1361 * vm_map_entry_{un,}link:
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.
1370 vm_map_entry_link(vm_map_t map, vm_map_entry_t entry)
1372 vm_map_entry_t header, llist, rlist, root;
1373 vm_size_t max_free_left, max_free_right;
1376 "vm_map_entry_link: map %p, nentries %d, entry %p", map,
1377 map->nentries, entry);
1378 VM_MAP_ASSERT_LOCKED(map);
1380 header = &map->header;
1381 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
1384 * The new entry does not overlap any existing entry in the
1385 * map, so it becomes the new root of the map tree.
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) {
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
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));
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
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);
1422 entry->max_free = vm_size_max(max_free_left, max_free_right);
1424 VM_MAP_ASSERT_CONSISTENT(map);
1427 enum unlink_merge_type {
1433 vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry,
1434 enum unlink_merge_type op)
1436 vm_map_entry_t header, llist, rlist, root;
1437 vm_size_t max_free_left, max_free_right;
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"));
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;
1451 if (llist != header) {
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) {
1459 max_free_left = vm_map_splay_merge_pred(header, root, llist);
1460 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1462 header->left = header->right = header;
1466 root->max_free = vm_size_max(max_free_left, max_free_right);
1468 VM_MAP_ASSERT_CONSISTENT(map);
1470 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map,
1471 map->nentries, entry);
1475 * vm_map_entry_resize:
1477 * Resize a vm_map_entry, recompute the amount of free space that
1478 * follows it and propagate that value up the tree.
1480 * The map must be locked, and leaves it so.
1483 vm_map_entry_resize(vm_map_t map, vm_map_entry_t entry, vm_size_t grow_amount)
1485 vm_map_entry_t header, llist, rlist, root;
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));
1497 VM_MAP_ASSERT_CONSISTENT(map);
1498 CTR4(KTR_VM, "%s: map %p, nentries %d, entry %p",
1499 __func__, map, map->nentries, entry);
1503 * vm_map_lookup_entry: [ internal use only ]
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.
1513 vm_map_lookup_entry(
1515 vm_offset_t address,
1516 vm_map_entry_t *entry) /* OUT */
1518 vm_map_entry_t cur, header, lbound, ubound;
1522 * If the map is empty, then the map entry immediately preceding
1523 * "address" is the map's header.
1525 header = &map->header;
1531 if (address >= cur->start && cur->end > address) {
1535 if ((locked = vm_map_locked(map)) ||
1536 sx_try_upgrade(&map->lock)) {
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.
1543 cur = vm_map_splay(map, address);
1545 VM_MAP_UNLOCK_CONSISTENT(map);
1546 sx_downgrade(&map->lock);
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".
1554 if (address < cur->start) {
1559 return (address < cur->end);
1562 * Since the map is only locked for read access, perform a
1563 * standard binary search tree lookup for "address".
1565 lbound = ubound = header;
1567 if (address < cur->start) {
1572 } else if (cur->end <= address) {
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.
1593 * Requires that the map be locked, and leaves it so.
1595 * If object is non-NULL, ref count must be bumped by caller
1596 * prior to making call to account for the new entry.
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)
1602 vm_map_entry_t new_entry, next_entry, prev_entry;
1604 vm_eflags_t protoeflags;
1605 vm_inherit_t inheritance;
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));
1617 * Check that the start and end points are not bogus.
1619 if (start == end || !vm_map_range_valid(map, start, end))
1620 return (KERN_INVALID_ADDRESS);
1623 * Find the entry prior to the proposed starting address; if it's part
1624 * of an existing entry, this range is bogus.
1626 if (vm_map_lookup_entry(map, start, &prev_entry))
1627 return (KERN_NO_SPACE);
1630 * Assert that the next entry doesn't overlap the end point.
1632 next_entry = vm_map_entry_succ(prev_entry);
1633 if (next_entry->start < end)
1634 return (KERN_NO_SPACE);
1636 if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL ||
1637 max != VM_PROT_NONE))
1638 return (KERN_INVALID_ARGUMENT);
1641 if (cow & MAP_COPY_ON_WRITE)
1642 protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY;
1643 if (cow & MAP_NOFAULT)
1644 protoeflags |= MAP_ENTRY_NOFAULT;
1645 if (cow & MAP_DISABLE_SYNCER)
1646 protoeflags |= MAP_ENTRY_NOSYNC;
1647 if (cow & MAP_DISABLE_COREDUMP)
1648 protoeflags |= MAP_ENTRY_NOCOREDUMP;
1649 if (cow & MAP_STACK_GROWS_DOWN)
1650 protoeflags |= MAP_ENTRY_GROWS_DOWN;
1651 if (cow & MAP_STACK_GROWS_UP)
1652 protoeflags |= MAP_ENTRY_GROWS_UP;
1653 if (cow & MAP_WRITECOUNT)
1654 protoeflags |= MAP_ENTRY_WRITECNT;
1655 if (cow & MAP_VN_EXEC)
1656 protoeflags |= MAP_ENTRY_VN_EXEC;
1657 if ((cow & MAP_CREATE_GUARD) != 0)
1658 protoeflags |= MAP_ENTRY_GUARD;
1659 if ((cow & MAP_CREATE_STACK_GAP_DN) != 0)
1660 protoeflags |= MAP_ENTRY_STACK_GAP_DN;
1661 if ((cow & MAP_CREATE_STACK_GAP_UP) != 0)
1662 protoeflags |= MAP_ENTRY_STACK_GAP_UP;
1663 if (cow & MAP_INHERIT_SHARE)
1664 inheritance = VM_INHERIT_SHARE;
1666 inheritance = VM_INHERIT_DEFAULT;
1669 if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0)
1671 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) &&
1672 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) {
1673 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start))
1674 return (KERN_RESOURCE_SHORTAGE);
1675 KASSERT(object == NULL ||
1676 (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 ||
1677 object->cred == NULL,
1678 ("overcommit: vm_map_insert o %p", object));
1679 cred = curthread->td_ucred;
1683 /* Expand the kernel pmap, if necessary. */
1684 if (map == kernel_map && end > kernel_vm_end)
1685 pmap_growkernel(end);
1686 if (object != NULL) {
1688 * OBJ_ONEMAPPING must be cleared unless this mapping
1689 * is trivially proven to be the only mapping for any
1690 * of the object's pages. (Object granularity
1691 * reference counting is insufficient to recognize
1692 * aliases with precision.)
1694 if ((object->flags & OBJ_ANON) != 0) {
1695 VM_OBJECT_WLOCK(object);
1696 if (object->ref_count > 1 || object->shadow_count != 0)
1697 vm_object_clear_flag(object, OBJ_ONEMAPPING);
1698 VM_OBJECT_WUNLOCK(object);
1700 } else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) ==
1702 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP |
1703 MAP_VN_EXEC)) == 0 &&
1704 prev_entry->end == start && (prev_entry->cred == cred ||
1705 (prev_entry->object.vm_object != NULL &&
1706 prev_entry->object.vm_object->cred == cred)) &&
1707 vm_object_coalesce(prev_entry->object.vm_object,
1709 (vm_size_t)(prev_entry->end - prev_entry->start),
1710 (vm_size_t)(end - prev_entry->end), cred != NULL &&
1711 (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) {
1713 * We were able to extend the object. Determine if we
1714 * can extend the previous map entry to include the
1715 * new range as well.
1717 if (prev_entry->inheritance == inheritance &&
1718 prev_entry->protection == prot &&
1719 prev_entry->max_protection == max &&
1720 prev_entry->wired_count == 0) {
1721 KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) ==
1722 0, ("prev_entry %p has incoherent wiring",
1724 if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0)
1725 map->size += end - prev_entry->end;
1726 vm_map_entry_resize(map, prev_entry,
1727 end - prev_entry->end);
1728 vm_map_try_merge_entries(map, prev_entry, next_entry);
1729 return (KERN_SUCCESS);
1733 * If we can extend the object but cannot extend the
1734 * map entry, we have to create a new map entry. We
1735 * must bump the ref count on the extended object to
1736 * account for it. object may be NULL.
1738 object = prev_entry->object.vm_object;
1739 offset = prev_entry->offset +
1740 (prev_entry->end - prev_entry->start);
1741 vm_object_reference(object);
1742 if (cred != NULL && object != NULL && object->cred != NULL &&
1743 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
1744 /* Object already accounts for this uid. */
1752 * Create a new entry
1754 new_entry = vm_map_entry_create(map);
1755 new_entry->start = start;
1756 new_entry->end = end;
1757 new_entry->cred = NULL;
1759 new_entry->eflags = protoeflags;
1760 new_entry->object.vm_object = object;
1761 new_entry->offset = offset;
1763 new_entry->inheritance = inheritance;
1764 new_entry->protection = prot;
1765 new_entry->max_protection = max;
1766 new_entry->wired_count = 0;
1767 new_entry->wiring_thread = NULL;
1768 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT;
1769 new_entry->next_read = start;
1771 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry),
1772 ("overcommit: vm_map_insert leaks vm_map %p", new_entry));
1773 new_entry->cred = cred;
1776 * Insert the new entry into the list
1778 vm_map_entry_link(map, new_entry);
1779 if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0)
1780 map->size += new_entry->end - new_entry->start;
1783 * Try to coalesce the new entry with both the previous and next
1784 * entries in the list. Previously, we only attempted to coalesce
1785 * with the previous entry when object is NULL. Here, we handle the
1786 * other cases, which are less common.
1788 vm_map_try_merge_entries(map, prev_entry, new_entry);
1789 vm_map_try_merge_entries(map, new_entry, next_entry);
1791 if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) {
1792 vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset),
1793 end - start, cow & MAP_PREFAULT_PARTIAL);
1796 return (KERN_SUCCESS);
1802 * Find the first fit (lowest VM address) for "length" free bytes
1803 * beginning at address >= start in the given map.
1805 * In a vm_map_entry, "max_free" is the maximum amount of
1806 * contiguous free space between an entry in its subtree and a
1807 * neighbor of that entry. This allows finding a free region in
1808 * one path down the tree, so O(log n) amortized with splay
1811 * The map must be locked, and leaves it so.
1813 * Returns: starting address if sufficient space,
1814 * vm_map_max(map)-length+1 if insufficient space.
1817 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length)
1819 vm_map_entry_t header, llist, rlist, root, y;
1820 vm_size_t left_length, max_free_left, max_free_right;
1821 vm_offset_t gap_end;
1824 * Request must fit within min/max VM address and must avoid
1827 start = MAX(start, vm_map_min(map));
1828 if (start >= vm_map_max(map) || length > vm_map_max(map) - start)
1829 return (vm_map_max(map) - length + 1);
1831 /* Empty tree means wide open address space. */
1832 if (map->root == NULL)
1836 * After splay_split, if start is within an entry, push it to the start
1837 * of the following gap. If rlist is at the end of the gap containing
1838 * start, save the end of that gap in gap_end to see if the gap is big
1839 * enough; otherwise set gap_end to start skip gap-checking and move
1840 * directly to a search of the right subtree.
1842 header = &map->header;
1843 root = vm_map_splay_split(map, start, length, &llist, &rlist);
1844 gap_end = rlist->start;
1847 if (root->right != rlist)
1849 max_free_left = vm_map_splay_merge_left(header, root, llist);
1850 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1851 } else if (rlist != header) {
1854 max_free_left = vm_map_splay_merge_pred(header, root, llist);
1855 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1858 llist = root->right;
1859 max_free_left = vm_map_splay_merge_left(header, root, llist);
1860 max_free_right = vm_map_splay_merge_succ(header, root, rlist);
1862 root->max_free = vm_size_max(max_free_left, max_free_right);
1864 VM_MAP_ASSERT_CONSISTENT(map);
1865 if (length <= gap_end - start)
1868 /* With max_free, can immediately tell if no solution. */
1869 if (root->right == header || length > root->right->max_free)
1870 return (vm_map_max(map) - length + 1);
1873 * Splay for the least large-enough gap in the right subtree.
1875 llist = rlist = header;
1876 for (left_length = 0;;
1877 left_length = vm_map_entry_max_free_left(root, llist)) {
1878 if (length <= left_length)
1879 SPLAY_LEFT_STEP(root, y, llist, rlist,
1880 length <= vm_map_entry_max_free_left(y, llist));
1882 SPLAY_RIGHT_STEP(root, y, llist, rlist,
1883 length > vm_map_entry_max_free_left(y, root));
1888 llist = root->right;
1889 max_free_left = vm_map_splay_merge_left(header, root, llist);
1890 if (rlist == header) {
1891 root->max_free = vm_size_max(max_free_left,
1892 vm_map_splay_merge_succ(header, root, rlist));
1896 y->max_free = vm_size_max(
1897 vm_map_splay_merge_pred(root, y, root),
1898 vm_map_splay_merge_right(header, y, rlist));
1899 root->max_free = vm_size_max(max_free_left, y->max_free);
1902 VM_MAP_ASSERT_CONSISTENT(map);
1907 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1908 vm_offset_t start, vm_size_t length, vm_prot_t prot,
1909 vm_prot_t max, int cow)
1914 end = start + length;
1915 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
1917 ("vm_map_fixed: non-NULL backing object for stack"));
1919 VM_MAP_RANGE_CHECK(map, start, end);
1920 if ((cow & MAP_CHECK_EXCL) == 0)
1921 vm_map_delete(map, start, end);
1922 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
1923 result = vm_map_stack_locked(map, start, length, sgrowsiz,
1926 result = vm_map_insert(map, object, offset, start, end,
1933 static const int aslr_pages_rnd_64[2] = {0x1000, 0x10};
1934 static const int aslr_pages_rnd_32[2] = {0x100, 0x4};
1936 static int cluster_anon = 1;
1937 SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW,
1939 "Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always");
1942 clustering_anon_allowed(vm_offset_t addr)
1945 switch (cluster_anon) {
1956 static long aslr_restarts;
1957 SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD,
1959 "Number of aslr failures");
1961 #define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31)
1964 * Searches for the specified amount of free space in the given map with the
1965 * specified alignment. Performs an address-ordered, first-fit search from
1966 * the given address "*addr", with an optional upper bound "max_addr". If the
1967 * parameter "alignment" is zero, then the alignment is computed from the
1968 * given (object, offset) pair so as to enable the greatest possible use of
1969 * superpage mappings. Returns KERN_SUCCESS and the address of the free space
1970 * in "*addr" if successful. Otherwise, returns KERN_NO_SPACE.
1972 * The map must be locked. Initially, there must be at least "length" bytes
1973 * of free space at the given address.
1976 vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1977 vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr,
1978 vm_offset_t alignment)
1980 vm_offset_t aligned_addr, free_addr;
1982 VM_MAP_ASSERT_LOCKED(map);
1984 KASSERT(free_addr == vm_map_findspace(map, free_addr, length),
1985 ("caller failed to provide space %#jx at address %p",
1986 (uintmax_t)length, (void *)free_addr));
1989 * At the start of every iteration, the free space at address
1990 * "*addr" is at least "length" bytes.
1993 pmap_align_superpage(object, offset, addr, length);
1994 else if ((*addr & (alignment - 1)) != 0) {
1995 *addr &= ~(alignment - 1);
1998 aligned_addr = *addr;
1999 if (aligned_addr == free_addr) {
2001 * Alignment did not change "*addr", so "*addr" must
2002 * still provide sufficient free space.
2004 return (KERN_SUCCESS);
2008 * Test for address wrap on "*addr". A wrapped "*addr" could
2009 * be a valid address, in which case vm_map_findspace() cannot
2010 * be relied upon to fail.
2012 if (aligned_addr < free_addr)
2013 return (KERN_NO_SPACE);
2014 *addr = vm_map_findspace(map, aligned_addr, length);
2015 if (*addr + length > vm_map_max(map) ||
2016 (max_addr != 0 && *addr + length > max_addr))
2017 return (KERN_NO_SPACE);
2019 if (free_addr == aligned_addr) {
2021 * If a successful call to vm_map_findspace() did not
2022 * change "*addr", then "*addr" must still be aligned
2023 * and provide sufficient free space.
2025 return (KERN_SUCCESS);
2031 * vm_map_find finds an unallocated region in the target address
2032 * map with the given length. The search is defined to be
2033 * first-fit from the specified address; the region found is
2034 * returned in the same parameter.
2036 * If object is non-NULL, ref count must be bumped by caller
2037 * prior to making call to account for the new entry.
2040 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2041 vm_offset_t *addr, /* IN/OUT */
2042 vm_size_t length, vm_offset_t max_addr, int find_space,
2043 vm_prot_t prot, vm_prot_t max, int cow)
2045 vm_offset_t alignment, curr_min_addr, min_addr;
2046 int gap, pidx, rv, try;
2047 bool cluster, en_aslr, update_anon;
2049 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
2051 ("vm_map_find: non-NULL backing object for stack"));
2052 MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE &&
2053 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0));
2054 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL ||
2055 (object->flags & OBJ_COLORED) == 0))
2056 find_space = VMFS_ANY_SPACE;
2057 if (find_space >> 8 != 0) {
2058 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags"));
2059 alignment = (vm_offset_t)1 << (find_space >> 8);
2062 en_aslr = (map->flags & MAP_ASLR) != 0;
2063 update_anon = cluster = clustering_anon_allowed(*addr) &&
2064 (map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 &&
2065 find_space != VMFS_NO_SPACE && object == NULL &&
2066 (cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP |
2067 MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE;
2068 curr_min_addr = min_addr = *addr;
2069 if (en_aslr && min_addr == 0 && !cluster &&
2070 find_space != VMFS_NO_SPACE &&
2071 (map->flags & MAP_ASLR_IGNSTART) != 0)
2072 curr_min_addr = min_addr = vm_map_min(map);
2076 curr_min_addr = map->anon_loc;
2077 if (curr_min_addr == 0)
2080 if (find_space != VMFS_NO_SPACE) {
2081 KASSERT(find_space == VMFS_ANY_SPACE ||
2082 find_space == VMFS_OPTIMAL_SPACE ||
2083 find_space == VMFS_SUPER_SPACE ||
2084 alignment != 0, ("unexpected VMFS flag"));
2087 * When creating an anonymous mapping, try clustering
2088 * with an existing anonymous mapping first.
2090 * We make up to two attempts to find address space
2091 * for a given find_space value. The first attempt may
2092 * apply randomization or may cluster with an existing
2093 * anonymous mapping. If this first attempt fails,
2094 * perform a first-fit search of the available address
2097 * If all tries failed, and find_space is
2098 * VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE.
2099 * Again enable clustering and randomization.
2106 * Second try: we failed either to find a
2107 * suitable region for randomizing the
2108 * allocation, or to cluster with an existing
2109 * mapping. Retry with free run.
2111 curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ?
2112 vm_map_min(map) : min_addr;
2113 atomic_add_long(&aslr_restarts, 1);
2116 if (try == 1 && en_aslr && !cluster) {
2118 * Find space for allocation, including
2119 * gap needed for later randomization.
2121 pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 &&
2122 (find_space == VMFS_SUPER_SPACE || find_space ==
2123 VMFS_OPTIMAL_SPACE) ? 1 : 0;
2124 gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR &&
2125 (max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ?
2126 aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx];
2127 *addr = vm_map_findspace(map, curr_min_addr,
2128 length + gap * pagesizes[pidx]);
2129 if (*addr + length + gap * pagesizes[pidx] >
2132 /* And randomize the start address. */
2133 *addr += (arc4random() % gap) * pagesizes[pidx];
2134 if (max_addr != 0 && *addr + length > max_addr)
2137 *addr = vm_map_findspace(map, curr_min_addr, length);
2138 if (*addr + length > vm_map_max(map) ||
2139 (max_addr != 0 && *addr + length > max_addr)) {
2150 if (find_space != VMFS_ANY_SPACE &&
2151 (rv = vm_map_alignspace(map, object, offset, addr, length,
2152 max_addr, alignment)) != KERN_SUCCESS) {
2153 if (find_space == VMFS_OPTIMAL_SPACE) {
2154 find_space = VMFS_ANY_SPACE;
2155 curr_min_addr = min_addr;
2156 cluster = update_anon;
2162 } else if ((cow & MAP_REMAP) != 0) {
2163 if (!vm_map_range_valid(map, *addr, *addr + length)) {
2164 rv = KERN_INVALID_ADDRESS;
2167 vm_map_delete(map, *addr, *addr + length);
2169 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
2170 rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot,
2173 rv = vm_map_insert(map, object, offset, *addr, *addr + length,
2176 if (rv == KERN_SUCCESS && update_anon)
2177 map->anon_loc = *addr + length;
2184 * vm_map_find_min() is a variant of vm_map_find() that takes an
2185 * additional parameter (min_addr) and treats the given address
2186 * (*addr) differently. Specifically, it treats *addr as a hint
2187 * and not as the minimum address where the mapping is created.
2189 * This function works in two phases. First, it tries to
2190 * allocate above the hint. If that fails and the hint is
2191 * greater than min_addr, it performs a second pass, replacing
2192 * the hint with min_addr as the minimum address for the
2196 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2197 vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr,
2198 vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max,
2206 rv = vm_map_find(map, object, offset, addr, length, max_addr,
2207 find_space, prot, max, cow);
2208 if (rv == KERN_SUCCESS || min_addr >= hint)
2210 *addr = hint = min_addr;
2215 * A map entry with any of the following flags set must not be merged with
2218 #define MAP_ENTRY_NOMERGE_MASK (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \
2219 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_VN_EXEC)
2222 vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry)
2225 KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 ||
2226 (entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0,
2227 ("vm_map_mergeable_neighbors: neither %p nor %p are mergeable",
2229 return (prev->end == entry->start &&
2230 prev->object.vm_object == entry->object.vm_object &&
2231 (prev->object.vm_object == NULL ||
2232 prev->offset + (prev->end - prev->start) == entry->offset) &&
2233 prev->eflags == entry->eflags &&
2234 prev->protection == entry->protection &&
2235 prev->max_protection == entry->max_protection &&
2236 prev->inheritance == entry->inheritance &&
2237 prev->wired_count == entry->wired_count &&
2238 prev->cred == entry->cred);
2242 vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry)
2246 * If the backing object is a vnode object, vm_object_deallocate()
2247 * calls vrele(). However, vrele() does not lock the vnode because
2248 * the vnode has additional references. Thus, the map lock can be
2249 * kept without causing a lock-order reversal with the vnode lock.
2251 * Since we count the number of virtual page mappings in
2252 * object->un_pager.vnp.writemappings, the writemappings value
2253 * should not be adjusted when the entry is disposed of.
2255 if (entry->object.vm_object != NULL)
2256 vm_object_deallocate(entry->object.vm_object);
2257 if (entry->cred != NULL)
2258 crfree(entry->cred);
2259 vm_map_entry_dispose(map, entry);
2263 * vm_map_try_merge_entries:
2265 * Compare the given map entry to its predecessor, and merge its precessor
2266 * into it if possible. The entry remains valid, and may be extended.
2267 * The predecessor may be deleted.
2269 * The map must be locked.
2272 vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev_entry,
2273 vm_map_entry_t entry)
2276 VM_MAP_ASSERT_LOCKED(map);
2277 if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 &&
2278 vm_map_mergeable_neighbors(prev_entry, entry)) {
2279 vm_map_entry_unlink(map, prev_entry, UNLINK_MERGE_NEXT);
2280 vm_map_merged_neighbor_dispose(map, prev_entry);
2285 * vm_map_entry_back:
2287 * Allocate an object to back a map entry.
2290 vm_map_entry_back(vm_map_entry_t entry)
2294 KASSERT(entry->object.vm_object == NULL,
2295 ("map entry %p has backing object", entry));
2296 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
2297 ("map entry %p is a submap", entry));
2298 object = vm_object_allocate_anon(atop(entry->end - entry->start), NULL,
2299 entry->cred, entry->end - entry->start);
2300 entry->object.vm_object = object;
2306 * vm_map_entry_charge_object
2308 * If there is no object backing this entry, create one. Otherwise, if
2309 * the entry has cred, give it to the backing object.
2312 vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry)
2315 VM_MAP_ASSERT_LOCKED(map);
2316 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
2317 ("map entry %p is a submap", entry));
2318 if (entry->object.vm_object == NULL && !map->system_map &&
2319 (entry->eflags & MAP_ENTRY_GUARD) == 0)
2320 vm_map_entry_back(entry);
2321 else if (entry->object.vm_object != NULL &&
2322 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
2323 entry->cred != NULL) {
2324 VM_OBJECT_WLOCK(entry->object.vm_object);
2325 KASSERT(entry->object.vm_object->cred == NULL,
2326 ("OVERCOMMIT: %s: both cred e %p", __func__, entry));
2327 entry->object.vm_object->cred = entry->cred;
2328 entry->object.vm_object->charge = entry->end - entry->start;
2329 VM_OBJECT_WUNLOCK(entry->object.vm_object);
2335 * vm_map_entry_clone
2337 * Create a duplicate map entry for clipping.
2339 static vm_map_entry_t
2340 vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry)
2342 vm_map_entry_t new_entry;
2344 VM_MAP_ASSERT_LOCKED(map);
2347 * Create a backing object now, if none exists, so that more individual
2348 * objects won't be created after the map entry is split.
2350 vm_map_entry_charge_object(map, entry);
2352 /* Clone the entry. */
2353 new_entry = vm_map_entry_create(map);
2354 *new_entry = *entry;
2355 if (new_entry->cred != NULL)
2356 crhold(entry->cred);
2357 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
2358 vm_object_reference(new_entry->object.vm_object);
2359 vm_map_entry_set_vnode_text(new_entry, true);
2361 * The object->un_pager.vnp.writemappings for the object of
2362 * MAP_ENTRY_WRITECNT type entry shall be kept as is here. The
2363 * virtual pages are re-distributed among the clipped entries,
2364 * so the sum is left the same.
2371 * vm_map_clip_start: [ internal use only ]
2373 * Asserts that the given entry begins at or after
2374 * the specified address; if necessary,
2375 * it splits the entry into two.
2378 vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start)
2380 vm_map_entry_t new_entry;
2382 if (start <= entry->start)
2385 VM_MAP_ASSERT_LOCKED(map);
2386 KASSERT(entry->end > start && entry->start < start,
2387 ("%s: invalid clip of entry %p", __func__, entry));
2389 new_entry = vm_map_entry_clone(map, entry);
2392 * Split off the front portion. Insert the new entry BEFORE this one,
2393 * so that this entry has the specified starting address.
2395 new_entry->end = start;
2396 vm_map_entry_link(map, new_entry);
2400 * vm_map_lookup_clip_start:
2402 * Find the entry at or just after 'start', and clip it if 'start' is in
2403 * the interior of the entry. Return entry after 'start', and in
2404 * prev_entry set the entry before 'start'.
2406 static inline vm_map_entry_t
2407 vm_map_lookup_clip_start(vm_map_t map, vm_offset_t start,
2408 vm_map_entry_t *prev_entry)
2410 vm_map_entry_t entry;
2412 if (vm_map_lookup_entry(map, start, prev_entry)) {
2413 entry = *prev_entry;
2414 vm_map_clip_start(map, entry, start);
2415 *prev_entry = vm_map_entry_pred(entry);
2417 entry = vm_map_entry_succ(*prev_entry);
2422 * vm_map_clip_end: [ internal use only ]
2424 * Asserts that the given entry ends at or before
2425 * the specified address; if necessary,
2426 * it splits the entry into two.
2429 vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end)
2431 vm_map_entry_t new_entry;
2433 if (end >= entry->end)
2436 VM_MAP_ASSERT_LOCKED(map);
2437 KASSERT(entry->start < end && entry->end > end,
2438 ("%s: invalid clip of entry %p", __func__, entry));
2440 new_entry = vm_map_entry_clone(map, entry);
2443 * Split off the back portion. Insert the new entry AFTER this one,
2444 * so that this entry has the specified ending address.
2446 new_entry->start = end;
2447 vm_map_entry_link(map, new_entry);
2451 * vm_map_submap: [ kernel use only ]
2453 * Mark the given range as handled by a subordinate map.
2455 * This range must have been created with vm_map_find,
2456 * and no other operations may have been performed on this
2457 * range prior to calling vm_map_submap.
2459 * Only a limited number of operations can be performed
2460 * within this rage after calling vm_map_submap:
2462 * [Don't try vm_map_copy!]
2464 * To remove a submapping, one must first remove the
2465 * range from the superior map, and then destroy the
2466 * submap (if desired). [Better yet, don't try it.]
2475 vm_map_entry_t entry;
2478 result = KERN_INVALID_ARGUMENT;
2480 vm_map_lock(submap);
2481 submap->flags |= MAP_IS_SUB_MAP;
2482 vm_map_unlock(submap);
2485 VM_MAP_RANGE_CHECK(map, start, end);
2486 if (vm_map_lookup_entry(map, start, &entry) && entry->end >= end &&
2487 (entry->eflags & MAP_ENTRY_COW) == 0 &&
2488 entry->object.vm_object == NULL) {
2489 vm_map_clip_start(map, entry, start);
2490 vm_map_clip_end(map, entry, end);
2491 entry->object.sub_map = submap;
2492 entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
2493 result = KERN_SUCCESS;
2497 if (result != KERN_SUCCESS) {
2498 vm_map_lock(submap);
2499 submap->flags &= ~MAP_IS_SUB_MAP;
2500 vm_map_unlock(submap);
2506 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified
2508 #define MAX_INIT_PT 96
2511 * vm_map_pmap_enter:
2513 * Preload the specified map's pmap with mappings to the specified
2514 * object's memory-resident pages. No further physical pages are
2515 * allocated, and no further virtual pages are retrieved from secondary
2516 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a
2517 * limited number of page mappings are created at the low-end of the
2518 * specified address range. (For this purpose, a superpage mapping
2519 * counts as one page mapping.) Otherwise, all resident pages within
2520 * the specified address range are mapped.
2523 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
2524 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags)
2527 vm_page_t p, p_start;
2528 vm_pindex_t mask, psize, threshold, tmpidx;
2530 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL)
2532 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2533 VM_OBJECT_WLOCK(object);
2534 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2535 pmap_object_init_pt(map->pmap, addr, object, pindex,
2537 VM_OBJECT_WUNLOCK(object);
2540 VM_OBJECT_LOCK_DOWNGRADE(object);
2542 VM_OBJECT_RLOCK(object);
2545 if (psize + pindex > object->size) {
2546 if (pindex >= object->size) {
2547 VM_OBJECT_RUNLOCK(object);
2550 psize = object->size - pindex;
2555 threshold = MAX_INIT_PT;
2557 p = vm_page_find_least(object, pindex);
2559 * Assert: the variable p is either (1) the page with the
2560 * least pindex greater than or equal to the parameter pindex
2564 p != NULL && (tmpidx = p->pindex - pindex) < psize;
2565 p = TAILQ_NEXT(p, listq)) {
2567 * don't allow an madvise to blow away our really
2568 * free pages allocating pv entries.
2570 if (((flags & MAP_PREFAULT_MADVISE) != 0 &&
2571 vm_page_count_severe()) ||
2572 ((flags & MAP_PREFAULT_PARTIAL) != 0 &&
2573 tmpidx >= threshold)) {
2577 if (vm_page_all_valid(p)) {
2578 if (p_start == NULL) {
2579 start = addr + ptoa(tmpidx);
2582 /* Jump ahead if a superpage mapping is possible. */
2583 if (p->psind > 0 && ((addr + ptoa(tmpidx)) &
2584 (pagesizes[p->psind] - 1)) == 0) {
2585 mask = atop(pagesizes[p->psind]) - 1;
2586 if (tmpidx + mask < psize &&
2587 vm_page_ps_test(p, PS_ALL_VALID, NULL)) {
2592 } else if (p_start != NULL) {
2593 pmap_enter_object(map->pmap, start, addr +
2594 ptoa(tmpidx), p_start, prot);
2598 if (p_start != NULL)
2599 pmap_enter_object(map->pmap, start, addr + ptoa(psize),
2601 VM_OBJECT_RUNLOCK(object);
2607 * Sets the protection of the specified address
2608 * region in the target map. If "set_max" is
2609 * specified, the maximum protection is to be set;
2610 * otherwise, only the current protection is affected.
2613 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
2614 vm_prot_t new_prot, boolean_t set_max)
2616 vm_map_entry_t entry, first_entry, in_tran, prev_entry;
2623 return (KERN_SUCCESS);
2630 * Ensure that we are not concurrently wiring pages. vm_map_wire() may
2631 * need to fault pages into the map and will drop the map lock while
2632 * doing so, and the VM object may end up in an inconsistent state if we
2633 * update the protection on the map entry in between faults.
2635 vm_map_wait_busy(map);
2637 VM_MAP_RANGE_CHECK(map, start, end);
2639 if (!vm_map_lookup_entry(map, start, &first_entry))
2640 first_entry = vm_map_entry_succ(first_entry);
2643 * Make a first pass to check for protection violations.
2645 for (entry = first_entry; entry->start < end;
2646 entry = vm_map_entry_succ(entry)) {
2647 if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
2649 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
2651 return (KERN_INVALID_ARGUMENT);
2653 if ((new_prot & entry->max_protection) != new_prot) {
2655 return (KERN_PROTECTION_FAILURE);
2657 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0)
2662 * Postpone the operation until all in-transition map entries have
2663 * stabilized. An in-transition entry might already have its pages
2664 * wired and wired_count incremented, but not yet have its
2665 * MAP_ENTRY_USER_WIRED flag set. In which case, we would fail to call
2666 * vm_fault_copy_entry() in the final loop below.
2668 if (in_tran != NULL) {
2669 in_tran->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2670 vm_map_unlock_and_wait(map, 0);
2675 * Before changing the protections, try to reserve swap space for any
2676 * private (i.e., copy-on-write) mappings that are transitioning from
2677 * read-only to read/write access. If a reservation fails, break out
2678 * of this loop early and let the next loop simplify the entries, since
2679 * some may now be mergeable.
2682 vm_map_clip_start(map, first_entry, start);
2683 for (entry = first_entry; entry->start < end;
2684 entry = vm_map_entry_succ(entry)) {
2685 vm_map_clip_end(map, entry, end);
2688 ((new_prot & ~entry->protection) & VM_PROT_WRITE) == 0 ||
2689 ENTRY_CHARGED(entry) ||
2690 (entry->eflags & MAP_ENTRY_GUARD) != 0) {
2694 cred = curthread->td_ucred;
2695 obj = entry->object.vm_object;
2698 (entry->eflags & MAP_ENTRY_NEEDS_COPY) != 0) {
2699 if (!swap_reserve(entry->end - entry->start)) {
2700 rv = KERN_RESOURCE_SHORTAGE;
2709 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP)
2711 VM_OBJECT_WLOCK(obj);
2712 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) {
2713 VM_OBJECT_WUNLOCK(obj);
2718 * Charge for the whole object allocation now, since
2719 * we cannot distinguish between non-charged and
2720 * charged clipped mapping of the same object later.
2722 KASSERT(obj->charge == 0,
2723 ("vm_map_protect: object %p overcharged (entry %p)",
2725 if (!swap_reserve(ptoa(obj->size))) {
2726 VM_OBJECT_WUNLOCK(obj);
2727 rv = KERN_RESOURCE_SHORTAGE;
2734 obj->charge = ptoa(obj->size);
2735 VM_OBJECT_WUNLOCK(obj);
2739 * If enough swap space was available, go back and fix up protections.
2740 * Otherwise, just simplify entries, since some may have been modified.
2741 * [Note that clipping is not necessary the second time.]
2743 for (prev_entry = vm_map_entry_pred(first_entry), entry = first_entry;
2745 vm_map_try_merge_entries(map, prev_entry, entry),
2746 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
2747 if (rv != KERN_SUCCESS ||
2748 (entry->eflags & MAP_ENTRY_GUARD) != 0)
2751 old_prot = entry->protection;
2755 (entry->max_protection = new_prot) &
2758 entry->protection = new_prot;
2761 * For user wired map entries, the normal lazy evaluation of
2762 * write access upgrades through soft page faults is
2763 * undesirable. Instead, immediately copy any pages that are
2764 * copy-on-write and enable write access in the physical map.
2766 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0 &&
2767 (entry->protection & VM_PROT_WRITE) != 0 &&
2768 (old_prot & VM_PROT_WRITE) == 0)
2769 vm_fault_copy_entry(map, map, entry, entry, NULL);
2772 * When restricting access, update the physical map. Worry
2773 * about copy-on-write here.
2775 if ((old_prot & ~entry->protection) != 0) {
2776 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
2778 pmap_protect(map->pmap, entry->start,
2780 entry->protection & MASK(entry));
2784 vm_map_try_merge_entries(map, prev_entry, entry);
2792 * This routine traverses a processes map handling the madvise
2793 * system call. Advisories are classified as either those effecting
2794 * the vm_map_entry structure, or those effecting the underlying
2804 vm_map_entry_t entry, prev_entry;
2808 * Some madvise calls directly modify the vm_map_entry, in which case
2809 * we need to use an exclusive lock on the map and we need to perform
2810 * various clipping operations. Otherwise we only need a read-lock
2815 case MADV_SEQUENTIAL:
2832 vm_map_lock_read(map);
2839 * Locate starting entry and clip if necessary.
2841 VM_MAP_RANGE_CHECK(map, start, end);
2845 * madvise behaviors that are implemented in the vm_map_entry.
2847 * We clip the vm_map_entry so that behavioral changes are
2848 * limited to the specified address range.
2850 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry);
2852 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
2853 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
2856 vm_map_clip_end(map, entry, end);
2860 vm_map_entry_set_behavior(entry,
2861 MAP_ENTRY_BEHAV_NORMAL);
2863 case MADV_SEQUENTIAL:
2864 vm_map_entry_set_behavior(entry,
2865 MAP_ENTRY_BEHAV_SEQUENTIAL);
2868 vm_map_entry_set_behavior(entry,
2869 MAP_ENTRY_BEHAV_RANDOM);
2872 entry->eflags |= MAP_ENTRY_NOSYNC;
2875 entry->eflags &= ~MAP_ENTRY_NOSYNC;
2878 entry->eflags |= MAP_ENTRY_NOCOREDUMP;
2881 entry->eflags &= ~MAP_ENTRY_NOCOREDUMP;
2886 vm_map_try_merge_entries(map, prev_entry, entry);
2888 vm_map_try_merge_entries(map, prev_entry, entry);
2891 vm_pindex_t pstart, pend;
2894 * madvise behaviors that are implemented in the underlying
2897 * Since we don't clip the vm_map_entry, we have to clip
2898 * the vm_object pindex and count.
2900 if (!vm_map_lookup_entry(map, start, &entry))
2901 entry = vm_map_entry_succ(entry);
2902 for (; entry->start < end;
2903 entry = vm_map_entry_succ(entry)) {
2904 vm_offset_t useEnd, useStart;
2906 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
2910 * MADV_FREE would otherwise rewind time to
2911 * the creation of the shadow object. Because
2912 * we hold the VM map read-locked, neither the
2913 * entry's object nor the presence of a
2914 * backing object can change.
2916 if (behav == MADV_FREE &&
2917 entry->object.vm_object != NULL &&
2918 entry->object.vm_object->backing_object != NULL)
2921 pstart = OFF_TO_IDX(entry->offset);
2922 pend = pstart + atop(entry->end - entry->start);
2923 useStart = entry->start;
2924 useEnd = entry->end;
2926 if (entry->start < start) {
2927 pstart += atop(start - entry->start);
2930 if (entry->end > end) {
2931 pend -= atop(entry->end - end);
2939 * Perform the pmap_advise() before clearing
2940 * PGA_REFERENCED in vm_page_advise(). Otherwise, a
2941 * concurrent pmap operation, such as pmap_remove(),
2942 * could clear a reference in the pmap and set
2943 * PGA_REFERENCED on the page before the pmap_advise()
2944 * had completed. Consequently, the page would appear
2945 * referenced based upon an old reference that
2946 * occurred before this pmap_advise() ran.
2948 if (behav == MADV_DONTNEED || behav == MADV_FREE)
2949 pmap_advise(map->pmap, useStart, useEnd,
2952 vm_object_madvise(entry->object.vm_object, pstart,
2956 * Pre-populate paging structures in the
2957 * WILLNEED case. For wired entries, the
2958 * paging structures are already populated.
2960 if (behav == MADV_WILLNEED &&
2961 entry->wired_count == 0) {
2962 vm_map_pmap_enter(map,
2965 entry->object.vm_object,
2967 ptoa(pend - pstart),
2968 MAP_PREFAULT_MADVISE
2972 vm_map_unlock_read(map);
2981 * Sets the inheritance of the specified address
2982 * range in the target map. Inheritance
2983 * affects how the map will be shared with
2984 * child maps at the time of vmspace_fork.
2987 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
2988 vm_inherit_t new_inheritance)
2990 vm_map_entry_t entry, prev_entry;
2992 switch (new_inheritance) {
2993 case VM_INHERIT_NONE:
2994 case VM_INHERIT_COPY:
2995 case VM_INHERIT_SHARE:
2996 case VM_INHERIT_ZERO:
2999 return (KERN_INVALID_ARGUMENT);
3002 return (KERN_SUCCESS);
3004 VM_MAP_RANGE_CHECK(map, start, end);
3005 for (entry = vm_map_lookup_clip_start(map, start, &prev_entry);
3007 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3008 vm_map_clip_end(map, entry, end);
3009 if ((entry->eflags & MAP_ENTRY_GUARD) == 0 ||
3010 new_inheritance != VM_INHERIT_ZERO)
3011 entry->inheritance = new_inheritance;
3012 vm_map_try_merge_entries(map, prev_entry, entry);
3014 vm_map_try_merge_entries(map, prev_entry, entry);
3016 return (KERN_SUCCESS);
3020 * vm_map_entry_in_transition:
3022 * Release the map lock, and sleep until the entry is no longer in
3023 * transition. Awake and acquire the map lock. If the map changed while
3024 * another held the lock, lookup a possibly-changed entry at or after the
3025 * 'start' position of the old entry.
3027 static vm_map_entry_t
3028 vm_map_entry_in_transition(vm_map_t map, vm_offset_t in_start,
3029 vm_offset_t *io_end, bool holes_ok, vm_map_entry_t in_entry)
3031 vm_map_entry_t entry;
3033 u_int last_timestamp;
3035 VM_MAP_ASSERT_LOCKED(map);
3036 KASSERT((in_entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3037 ("not in-tranition map entry %p", in_entry));
3039 * We have not yet clipped the entry.
3041 start = MAX(in_start, in_entry->start);
3042 in_entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
3043 last_timestamp = map->timestamp;
3044 if (vm_map_unlock_and_wait(map, 0)) {
3046 * Allow interruption of user wiring/unwiring?
3050 if (last_timestamp + 1 == map->timestamp)
3054 * Look again for the entry because the map was modified while it was
3055 * unlocked. Specifically, the entry may have been clipped, merged, or
3058 if (!vm_map_lookup_entry(map, start, &entry)) {
3063 entry = vm_map_entry_succ(entry);
3071 * Implements both kernel and user unwiring.
3074 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
3077 vm_map_entry_t entry, first_entry, next_entry, prev_entry;
3079 bool holes_ok, need_wakeup, user_unwire;
3082 return (KERN_SUCCESS);
3083 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
3084 user_unwire = (flags & VM_MAP_WIRE_USER) != 0;
3086 VM_MAP_RANGE_CHECK(map, start, end);
3087 if (!vm_map_lookup_entry(map, start, &first_entry)) {
3089 first_entry = vm_map_entry_succ(first_entry);
3092 return (KERN_INVALID_ADDRESS);
3096 for (entry = first_entry; entry->start < end; entry = next_entry) {
3097 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
3099 * We have not yet clipped the entry.
3101 next_entry = vm_map_entry_in_transition(map, start,
3102 &end, holes_ok, entry);
3103 if (next_entry == NULL) {
3104 if (entry == first_entry) {
3106 return (KERN_INVALID_ADDRESS);
3108 rv = KERN_INVALID_ADDRESS;
3111 first_entry = (entry == first_entry) ?
3115 vm_map_clip_start(map, entry, start);
3116 vm_map_clip_end(map, entry, end);
3118 * Mark the entry in case the map lock is released. (See
3121 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
3122 entry->wiring_thread == NULL,
3123 ("owned map entry %p", entry));
3124 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
3125 entry->wiring_thread = curthread;
3126 next_entry = vm_map_entry_succ(entry);
3128 * Check the map for holes in the specified region.
3129 * If holes_ok, skip this check.
3132 entry->end < end && next_entry->start > entry->end) {
3134 rv = KERN_INVALID_ADDRESS;
3138 * If system unwiring, require that the entry is system wired.
3141 vm_map_entry_system_wired_count(entry) == 0) {
3143 rv = KERN_INVALID_ARGUMENT;
3147 need_wakeup = false;
3148 if (first_entry == NULL &&
3149 !vm_map_lookup_entry(map, start, &first_entry)) {
3150 KASSERT(holes_ok, ("vm_map_unwire: lookup failed"));
3151 prev_entry = first_entry;
3152 entry = vm_map_entry_succ(first_entry);
3154 prev_entry = vm_map_entry_pred(first_entry);
3155 entry = first_entry;
3157 for (; entry->start < end;
3158 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3160 * If holes_ok was specified, an empty
3161 * space in the unwired region could have been mapped
3162 * while the map lock was dropped for draining
3163 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread
3164 * could be simultaneously wiring this new mapping
3165 * entry. Detect these cases and skip any entries
3166 * marked as in transition by us.
3168 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
3169 entry->wiring_thread != curthread) {
3171 ("vm_map_unwire: !HOLESOK and new/changed entry"));
3175 if (rv == KERN_SUCCESS && (!user_unwire ||
3176 (entry->eflags & MAP_ENTRY_USER_WIRED))) {
3177 if (entry->wired_count == 1)
3178 vm_map_entry_unwire(map, entry);
3180 entry->wired_count--;
3182 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3184 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3185 ("vm_map_unwire: in-transition flag missing %p", entry));
3186 KASSERT(entry->wiring_thread == curthread,
3187 ("vm_map_unwire: alien wire %p", entry));
3188 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
3189 entry->wiring_thread = NULL;
3190 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
3191 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
3194 vm_map_try_merge_entries(map, prev_entry, entry);
3196 vm_map_try_merge_entries(map, prev_entry, entry);
3204 vm_map_wire_user_count_sub(u_long npages)
3207 atomic_subtract_long(&vm_user_wire_count, npages);
3211 vm_map_wire_user_count_add(u_long npages)
3215 wired = vm_user_wire_count;
3217 if (npages + wired > vm_page_max_user_wired)
3219 } while (!atomic_fcmpset_long(&vm_user_wire_count, &wired,
3226 * vm_map_wire_entry_failure:
3228 * Handle a wiring failure on the given entry.
3230 * The map should be locked.
3233 vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
3234 vm_offset_t failed_addr)
3237 VM_MAP_ASSERT_LOCKED(map);
3238 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 &&
3239 entry->wired_count == 1,
3240 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry));
3241 KASSERT(failed_addr < entry->end,
3242 ("vm_map_wire_entry_failure: entry %p was fully wired", entry));
3245 * If any pages at the start of this entry were successfully wired,
3248 if (failed_addr > entry->start) {
3249 pmap_unwire(map->pmap, entry->start, failed_addr);
3250 vm_object_unwire(entry->object.vm_object, entry->offset,
3251 failed_addr - entry->start, PQ_ACTIVE);
3255 * Assign an out-of-range value to represent the failure to wire this
3258 entry->wired_count = -1;
3262 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
3267 rv = vm_map_wire_locked(map, start, end, flags);
3274 * vm_map_wire_locked:
3276 * Implements both kernel and user wiring. Returns with the map locked,
3277 * the map lock may be dropped.
3280 vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
3282 vm_map_entry_t entry, first_entry, next_entry, prev_entry;
3283 vm_offset_t faddr, saved_end, saved_start;
3285 u_int last_timestamp;
3287 bool holes_ok, need_wakeup, user_wire;
3290 VM_MAP_ASSERT_LOCKED(map);
3293 return (KERN_SUCCESS);
3295 if (flags & VM_MAP_WIRE_WRITE)
3296 prot |= VM_PROT_WRITE;
3297 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
3298 user_wire = (flags & VM_MAP_WIRE_USER) != 0;
3299 VM_MAP_RANGE_CHECK(map, start, end);
3300 if (!vm_map_lookup_entry(map, start, &first_entry)) {
3302 first_entry = vm_map_entry_succ(first_entry);
3304 return (KERN_INVALID_ADDRESS);
3306 for (entry = first_entry; entry->start < end; entry = next_entry) {
3307 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
3309 * We have not yet clipped the entry.
3311 next_entry = vm_map_entry_in_transition(map, start,
3312 &end, holes_ok, entry);
3313 if (next_entry == NULL) {
3314 if (entry == first_entry)
3315 return (KERN_INVALID_ADDRESS);
3316 rv = KERN_INVALID_ADDRESS;
3319 first_entry = (entry == first_entry) ?
3323 vm_map_clip_start(map, entry, start);
3324 vm_map_clip_end(map, entry, end);
3326 * Mark the entry in case the map lock is released. (See
3329 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
3330 entry->wiring_thread == NULL,
3331 ("owned map entry %p", entry));
3332 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
3333 entry->wiring_thread = curthread;
3334 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0
3335 || (entry->protection & prot) != prot) {
3336 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED;
3339 rv = KERN_INVALID_ADDRESS;
3342 } else if (entry->wired_count == 0) {
3343 entry->wired_count++;
3345 npages = atop(entry->end - entry->start);
3346 if (user_wire && !vm_map_wire_user_count_add(npages)) {
3347 vm_map_wire_entry_failure(map, entry,
3350 rv = KERN_RESOURCE_SHORTAGE;
3355 * Release the map lock, relying on the in-transition
3356 * mark. Mark the map busy for fork.
3358 saved_start = entry->start;
3359 saved_end = entry->end;
3360 last_timestamp = map->timestamp;
3364 faddr = saved_start;
3367 * Simulate a fault to get the page and enter
3368 * it into the physical map.
3370 if ((rv = vm_fault(map, faddr,
3371 VM_PROT_NONE, VM_FAULT_WIRE, NULL)) !=
3374 } while ((faddr += PAGE_SIZE) < saved_end);
3377 if (last_timestamp + 1 != map->timestamp) {
3379 * Look again for the entry because the map was
3380 * modified while it was unlocked. The entry
3381 * may have been clipped, but NOT merged or
3384 if (!vm_map_lookup_entry(map, saved_start,
3387 ("vm_map_wire: lookup failed"));
3388 first_entry = (entry == first_entry) ?
3390 for (entry = next_entry; entry->end < saved_end;
3391 entry = vm_map_entry_succ(entry)) {
3393 * In case of failure, handle entries
3394 * that were not fully wired here;
3395 * fully wired entries are handled
3398 if (rv != KERN_SUCCESS &&
3400 vm_map_wire_entry_failure(map,
3404 if (rv != KERN_SUCCESS) {
3405 vm_map_wire_entry_failure(map, entry, faddr);
3407 vm_map_wire_user_count_sub(npages);
3411 } else if (!user_wire ||
3412 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
3413 entry->wired_count++;
3416 * Check the map for holes in the specified region.
3417 * If holes_ok was specified, skip this check.
3419 next_entry = vm_map_entry_succ(entry);
3421 entry->end < end && next_entry->start > entry->end) {
3423 rv = KERN_INVALID_ADDRESS;
3429 need_wakeup = false;
3430 if (first_entry == NULL &&
3431 !vm_map_lookup_entry(map, start, &first_entry)) {
3432 KASSERT(holes_ok, ("vm_map_wire: lookup failed"));
3433 prev_entry = first_entry;
3434 entry = vm_map_entry_succ(first_entry);
3436 prev_entry = vm_map_entry_pred(first_entry);
3437 entry = first_entry;
3439 for (; entry->start < end;
3440 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3442 * If holes_ok was specified, an empty
3443 * space in the unwired region could have been mapped
3444 * while the map lock was dropped for faulting in the
3445 * pages or draining MAP_ENTRY_IN_TRANSITION.
3446 * Moreover, another thread could be simultaneously
3447 * wiring this new mapping entry. Detect these cases
3448 * and skip any entries marked as in transition not by us.
3450 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
3451 entry->wiring_thread != curthread) {
3453 ("vm_map_wire: !HOLESOK and new/changed entry"));
3457 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) {
3459 } else if (rv == KERN_SUCCESS) {
3461 entry->eflags |= MAP_ENTRY_USER_WIRED;
3462 } else if (entry->wired_count == -1) {
3464 * Wiring failed on this entry. Thus, unwiring is
3467 entry->wired_count = 0;
3468 } else if (!user_wire ||
3469 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
3471 * Undo the wiring. Wiring succeeded on this entry
3472 * but failed on a later entry.
3474 if (entry->wired_count == 1) {
3475 vm_map_entry_unwire(map, entry);
3477 vm_map_wire_user_count_sub(
3478 atop(entry->end - entry->start));
3480 entry->wired_count--;
3482 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3483 ("vm_map_wire: in-transition flag missing %p", entry));
3484 KASSERT(entry->wiring_thread == curthread,
3485 ("vm_map_wire: alien wire %p", entry));
3486 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION |
3487 MAP_ENTRY_WIRE_SKIPPED);
3488 entry->wiring_thread = NULL;
3489 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
3490 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
3493 vm_map_try_merge_entries(map, prev_entry, entry);
3495 vm_map_try_merge_entries(map, prev_entry, entry);
3504 * Push any dirty cached pages in the address range to their pager.
3505 * If syncio is TRUE, dirty pages are written synchronously.
3506 * If invalidate is TRUE, any cached pages are freed as well.
3508 * If the size of the region from start to end is zero, we are
3509 * supposed to flush all modified pages within the region containing
3510 * start. Unfortunately, a region can be split or coalesced with
3511 * neighboring regions, making it difficult to determine what the
3512 * original region was. Therefore, we approximate this requirement by
3513 * flushing the current region containing start.
3515 * Returns an error if any part of the specified range is not mapped.
3523 boolean_t invalidate)
3525 vm_map_entry_t entry, first_entry, next_entry;
3528 vm_ooffset_t offset;
3529 unsigned int last_timestamp;
3532 vm_map_lock_read(map);
3533 VM_MAP_RANGE_CHECK(map, start, end);
3534 if (!vm_map_lookup_entry(map, start, &first_entry)) {
3535 vm_map_unlock_read(map);
3536 return (KERN_INVALID_ADDRESS);
3537 } else if (start == end) {
3538 start = first_entry->start;
3539 end = first_entry->end;
3542 * Make a first pass to check for user-wired memory and holes.
3544 for (entry = first_entry; entry->start < end; entry = next_entry) {
3546 (entry->eflags & MAP_ENTRY_USER_WIRED) != 0) {
3547 vm_map_unlock_read(map);
3548 return (KERN_INVALID_ARGUMENT);
3550 next_entry = vm_map_entry_succ(entry);
3551 if (end > entry->end &&
3552 entry->end != next_entry->start) {
3553 vm_map_unlock_read(map);
3554 return (KERN_INVALID_ADDRESS);
3559 pmap_remove(map->pmap, start, end);
3563 * Make a second pass, cleaning/uncaching pages from the indicated
3566 for (entry = first_entry; entry->start < end;) {
3567 offset = entry->offset + (start - entry->start);
3568 size = (end <= entry->end ? end : entry->end) - start;
3569 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
3571 vm_map_entry_t tentry;
3574 smap = entry->object.sub_map;
3575 vm_map_lock_read(smap);
3576 (void) vm_map_lookup_entry(smap, offset, &tentry);
3577 tsize = tentry->end - offset;
3580 object = tentry->object.vm_object;
3581 offset = tentry->offset + (offset - tentry->start);
3582 vm_map_unlock_read(smap);
3584 object = entry->object.vm_object;
3586 vm_object_reference(object);
3587 last_timestamp = map->timestamp;
3588 vm_map_unlock_read(map);
3589 if (!vm_object_sync(object, offset, size, syncio, invalidate))
3592 vm_object_deallocate(object);
3593 vm_map_lock_read(map);
3594 if (last_timestamp == map->timestamp ||
3595 !vm_map_lookup_entry(map, start, &entry))
3596 entry = vm_map_entry_succ(entry);
3599 vm_map_unlock_read(map);
3600 return (failed ? KERN_FAILURE : KERN_SUCCESS);
3604 * vm_map_entry_unwire: [ internal use only ]
3606 * Make the region specified by this entry pageable.
3608 * The map in question should be locked.
3609 * [This is the reason for this routine's existence.]
3612 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
3616 VM_MAP_ASSERT_LOCKED(map);
3617 KASSERT(entry->wired_count > 0,
3618 ("vm_map_entry_unwire: entry %p isn't wired", entry));
3620 size = entry->end - entry->start;
3621 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0)
3622 vm_map_wire_user_count_sub(atop(size));
3623 pmap_unwire(map->pmap, entry->start, entry->end);
3624 vm_object_unwire(entry->object.vm_object, entry->offset, size,
3626 entry->wired_count = 0;
3630 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map)
3633 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
3634 vm_object_deallocate(entry->object.vm_object);
3635 uma_zfree(system_map ? kmapentzone : mapentzone, entry);
3639 * vm_map_entry_delete: [ internal use only ]
3641 * Deallocate the given entry from the target map.
3644 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
3647 vm_pindex_t offidxstart, offidxend, size1;
3650 vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE);
3651 object = entry->object.vm_object;
3653 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) {
3654 MPASS(entry->cred == NULL);
3655 MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0);
3656 MPASS(object == NULL);
3657 vm_map_entry_deallocate(entry, map->system_map);
3661 size = entry->end - entry->start;
3664 if (entry->cred != NULL) {
3665 swap_release_by_cred(size, entry->cred);
3666 crfree(entry->cred);
3669 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) {
3670 entry->object.vm_object = NULL;
3671 } else if ((object->flags & OBJ_ANON) != 0 ||
3672 object == kernel_object) {
3673 KASSERT(entry->cred == NULL || object->cred == NULL ||
3674 (entry->eflags & MAP_ENTRY_NEEDS_COPY),
3675 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry));
3676 offidxstart = OFF_TO_IDX(entry->offset);
3677 offidxend = offidxstart + atop(size);
3678 VM_OBJECT_WLOCK(object);
3679 if (object->ref_count != 1 &&
3680 ((object->flags & OBJ_ONEMAPPING) != 0 ||
3681 object == kernel_object)) {
3682 vm_object_collapse(object);
3685 * The option OBJPR_NOTMAPPED can be passed here
3686 * because vm_map_delete() already performed
3687 * pmap_remove() on the only mapping to this range
3690 vm_object_page_remove(object, offidxstart, offidxend,
3692 if (offidxend >= object->size &&
3693 offidxstart < object->size) {
3694 size1 = object->size;
3695 object->size = offidxstart;
3696 if (object->cred != NULL) {
3697 size1 -= object->size;
3698 KASSERT(object->charge >= ptoa(size1),
3699 ("object %p charge < 0", object));
3700 swap_release_by_cred(ptoa(size1),
3702 object->charge -= ptoa(size1);
3706 VM_OBJECT_WUNLOCK(object);
3708 if (map->system_map)
3709 vm_map_entry_deallocate(entry, TRUE);
3711 entry->defer_next = curthread->td_map_def_user;
3712 curthread->td_map_def_user = entry;
3717 * vm_map_delete: [ internal use only ]
3719 * Deallocates the given address range from the target
3723 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
3725 vm_map_entry_t entry, next_entry;
3727 VM_MAP_ASSERT_LOCKED(map);
3729 return (KERN_SUCCESS);
3732 * Find the start of the region, and clip it.
3733 * Step through all entries in this region.
3735 for (entry = vm_map_lookup_clip_start(map, start, &entry);
3736 entry->start < end; entry = next_entry) {
3738 * Wait for wiring or unwiring of an entry to complete.
3739 * Also wait for any system wirings to disappear on
3742 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 ||
3743 (vm_map_pmap(map) != kernel_pmap &&
3744 vm_map_entry_system_wired_count(entry) != 0)) {
3745 unsigned int last_timestamp;
3746 vm_offset_t saved_start;
3748 saved_start = entry->start;
3749 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
3750 last_timestamp = map->timestamp;
3751 (void) vm_map_unlock_and_wait(map, 0);
3753 if (last_timestamp + 1 != map->timestamp) {
3755 * Look again for the entry because the map was
3756 * modified while it was unlocked.
3757 * Specifically, the entry may have been
3758 * clipped, merged, or deleted.
3760 next_entry = vm_map_lookup_clip_start(map,
3761 saved_start, &next_entry);
3766 vm_map_clip_end(map, entry, end);
3767 next_entry = vm_map_entry_succ(entry);
3770 * Unwire before removing addresses from the pmap; otherwise,
3771 * unwiring will put the entries back in the pmap.
3773 if (entry->wired_count != 0)
3774 vm_map_entry_unwire(map, entry);
3777 * Remove mappings for the pages, but only if the
3778 * mappings could exist. For instance, it does not
3779 * make sense to call pmap_remove() for guard entries.
3781 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 ||
3782 entry->object.vm_object != NULL)
3783 pmap_remove(map->pmap, entry->start, entry->end);
3785 if (entry->end == map->anon_loc)
3786 map->anon_loc = entry->start;
3789 * Delete the entry only after removing all pmap
3790 * entries pointing to its pages. (Otherwise, its
3791 * page frames may be reallocated, and any modify bits
3792 * will be set in the wrong object!)
3794 vm_map_entry_delete(map, entry);
3796 return (KERN_SUCCESS);
3802 * Remove the given address range from the target map.
3803 * This is the exported form of vm_map_delete.
3806 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
3811 VM_MAP_RANGE_CHECK(map, start, end);
3812 result = vm_map_delete(map, start, end);
3818 * vm_map_check_protection:
3820 * Assert that the target map allows the specified privilege on the
3821 * entire address region given. The entire region must be allocated.
3823 * WARNING! This code does not and should not check whether the
3824 * contents of the region is accessible. For example a smaller file
3825 * might be mapped into a larger address space.
3827 * NOTE! This code is also called by munmap().
3829 * The map must be locked. A read lock is sufficient.
3832 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
3833 vm_prot_t protection)
3835 vm_map_entry_t entry;
3836 vm_map_entry_t tmp_entry;
3838 if (!vm_map_lookup_entry(map, start, &tmp_entry))
3842 while (start < end) {
3846 if (start < entry->start)
3849 * Check protection associated with entry.
3851 if ((entry->protection & protection) != protection)
3853 /* go to next entry */
3855 entry = vm_map_entry_succ(entry);
3863 * vm_map_copy_swap_object:
3865 * Copies a swap-backed object from an existing map entry to a
3866 * new one. Carries forward the swap charge. May change the
3867 * src object on return.
3870 vm_map_copy_swap_object(vm_map_entry_t src_entry, vm_map_entry_t dst_entry,
3871 vm_offset_t size, vm_ooffset_t *fork_charge)
3873 vm_object_t src_object;
3877 src_object = src_entry->object.vm_object;
3878 charged = ENTRY_CHARGED(src_entry);
3879 if ((src_object->flags & OBJ_ANON) != 0) {
3880 VM_OBJECT_WLOCK(src_object);
3881 vm_object_collapse(src_object);
3882 if ((src_object->flags & OBJ_ONEMAPPING) != 0) {
3883 vm_object_split(src_entry);
3884 src_object = src_entry->object.vm_object;
3886 vm_object_reference_locked(src_object);
3887 vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
3888 VM_OBJECT_WUNLOCK(src_object);
3890 vm_object_reference(src_object);
3891 if (src_entry->cred != NULL &&
3892 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
3893 KASSERT(src_object->cred == NULL,
3894 ("OVERCOMMIT: vm_map_copy_anon_entry: cred %p",
3896 src_object->cred = src_entry->cred;
3897 src_object->charge = size;
3899 dst_entry->object.vm_object = src_object;
3901 cred = curthread->td_ucred;
3903 dst_entry->cred = cred;
3904 *fork_charge += size;
3905 if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
3907 src_entry->cred = cred;
3908 *fork_charge += size;
3914 * vm_map_copy_entry:
3916 * Copies the contents of the source entry to the destination
3917 * entry. The entries *must* be aligned properly.
3923 vm_map_entry_t src_entry,
3924 vm_map_entry_t dst_entry,
3925 vm_ooffset_t *fork_charge)
3927 vm_object_t src_object;
3928 vm_map_entry_t fake_entry;
3931 VM_MAP_ASSERT_LOCKED(dst_map);
3933 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP)
3936 if (src_entry->wired_count == 0 ||
3937 (src_entry->protection & VM_PROT_WRITE) == 0) {
3939 * If the source entry is marked needs_copy, it is already
3942 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 &&
3943 (src_entry->protection & VM_PROT_WRITE) != 0) {
3944 pmap_protect(src_map->pmap,
3947 src_entry->protection & ~VM_PROT_WRITE);
3951 * Make a copy of the object.
3953 size = src_entry->end - src_entry->start;
3954 if ((src_object = src_entry->object.vm_object) != NULL) {
3955 if (src_object->type == OBJT_DEFAULT ||
3956 src_object->type == OBJT_SWAP) {
3957 vm_map_copy_swap_object(src_entry, dst_entry,
3959 /* May have split/collapsed, reload obj. */
3960 src_object = src_entry->object.vm_object;
3962 vm_object_reference(src_object);
3963 dst_entry->object.vm_object = src_object;
3965 src_entry->eflags |= MAP_ENTRY_COW |
3966 MAP_ENTRY_NEEDS_COPY;
3967 dst_entry->eflags |= MAP_ENTRY_COW |
3968 MAP_ENTRY_NEEDS_COPY;
3969 dst_entry->offset = src_entry->offset;
3970 if (src_entry->eflags & MAP_ENTRY_WRITECNT) {
3972 * MAP_ENTRY_WRITECNT cannot
3973 * indicate write reference from
3974 * src_entry, since the entry is
3975 * marked as needs copy. Allocate a
3976 * fake entry that is used to
3977 * decrement object->un_pager writecount
3978 * at the appropriate time. Attach
3979 * fake_entry to the deferred list.
3981 fake_entry = vm_map_entry_create(dst_map);
3982 fake_entry->eflags = MAP_ENTRY_WRITECNT;
3983 src_entry->eflags &= ~MAP_ENTRY_WRITECNT;
3984 vm_object_reference(src_object);
3985 fake_entry->object.vm_object = src_object;
3986 fake_entry->start = src_entry->start;
3987 fake_entry->end = src_entry->end;
3988 fake_entry->defer_next =
3989 curthread->td_map_def_user;
3990 curthread->td_map_def_user = fake_entry;
3993 pmap_copy(dst_map->pmap, src_map->pmap,
3994 dst_entry->start, dst_entry->end - dst_entry->start,
3997 dst_entry->object.vm_object = NULL;
3998 dst_entry->offset = 0;
3999 if (src_entry->cred != NULL) {
4000 dst_entry->cred = curthread->td_ucred;
4001 crhold(dst_entry->cred);
4002 *fork_charge += size;
4007 * We don't want to make writeable wired pages copy-on-write.
4008 * Immediately copy these pages into the new map by simulating
4009 * page faults. The new pages are pageable.
4011 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry,
4017 * vmspace_map_entry_forked:
4018 * Update the newly-forked vmspace each time a map entry is inherited
4019 * or copied. The values for vm_dsize and vm_tsize are approximate
4020 * (and mostly-obsolete ideas in the face of mmap(2) et al.)
4023 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2,
4024 vm_map_entry_t entry)
4026 vm_size_t entrysize;
4029 if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
4031 entrysize = entry->end - entry->start;
4032 vm2->vm_map.size += entrysize;
4033 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) {
4034 vm2->vm_ssize += btoc(entrysize);
4035 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr &&
4036 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) {
4037 newend = MIN(entry->end,
4038 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize));
4039 vm2->vm_dsize += btoc(newend - entry->start);
4040 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr &&
4041 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) {
4042 newend = MIN(entry->end,
4043 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize));
4044 vm2->vm_tsize += btoc(newend - entry->start);
4050 * Create a new process vmspace structure and vm_map
4051 * based on those of an existing process. The new map
4052 * is based on the old map, according to the inheritance
4053 * values on the regions in that map.
4055 * XXX It might be worth coalescing the entries added to the new vmspace.
4057 * The source map must not be locked.
4060 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
4062 struct vmspace *vm2;
4063 vm_map_t new_map, old_map;
4064 vm_map_entry_t new_entry, old_entry;
4069 old_map = &vm1->vm_map;
4070 /* Copy immutable fields of vm1 to vm2. */
4071 vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map),
4076 vm2->vm_taddr = vm1->vm_taddr;
4077 vm2->vm_daddr = vm1->vm_daddr;
4078 vm2->vm_maxsaddr = vm1->vm_maxsaddr;
4079 vm_map_lock(old_map);
4081 vm_map_wait_busy(old_map);
4082 new_map = &vm2->vm_map;
4083 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */
4084 KASSERT(locked, ("vmspace_fork: lock failed"));
4086 error = pmap_vmspace_copy(new_map->pmap, old_map->pmap);
4088 sx_xunlock(&old_map->lock);
4089 sx_xunlock(&new_map->lock);
4090 vm_map_process_deferred();
4095 new_map->anon_loc = old_map->anon_loc;
4097 VM_MAP_ENTRY_FOREACH(old_entry, old_map) {
4098 if ((old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
4099 panic("vm_map_fork: encountered a submap");
4101 inh = old_entry->inheritance;
4102 if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 &&
4103 inh != VM_INHERIT_NONE)
4104 inh = VM_INHERIT_COPY;
4107 case VM_INHERIT_NONE:
4110 case VM_INHERIT_SHARE:
4112 * Clone the entry, creating the shared object if
4115 object = old_entry->object.vm_object;
4116 if (object == NULL) {
4117 vm_map_entry_back(old_entry);
4118 object = old_entry->object.vm_object;
4122 * Add the reference before calling vm_object_shadow
4123 * to insure that a shadow object is created.
4125 vm_object_reference(object);
4126 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4127 vm_object_shadow(&old_entry->object.vm_object,
4129 old_entry->end - old_entry->start,
4131 /* Transfer the second reference too. */
4133 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
4134 old_entry->cred = NULL;
4137 * As in vm_map_merged_neighbor_dispose(),
4138 * the vnode lock will not be acquired in
4139 * this call to vm_object_deallocate().
4141 vm_object_deallocate(object);
4142 object = old_entry->object.vm_object;
4144 VM_OBJECT_WLOCK(object);
4145 vm_object_clear_flag(object, OBJ_ONEMAPPING);
4146 if (old_entry->cred != NULL) {
4147 KASSERT(object->cred == NULL,
4148 ("vmspace_fork both cred"));
4149 object->cred = old_entry->cred;
4150 object->charge = old_entry->end -
4152 old_entry->cred = NULL;
4156 * Assert the correct state of the vnode
4157 * v_writecount while the object is locked, to
4158 * not relock it later for the assertion
4161 if (old_entry->eflags & MAP_ENTRY_WRITECNT &&
4162 object->type == OBJT_VNODE) {
4163 KASSERT(((struct vnode *)object->
4164 handle)->v_writecount > 0,
4165 ("vmspace_fork: v_writecount %p",
4167 KASSERT(object->un_pager.vnp.
4169 ("vmspace_fork: vnp.writecount %p",
4172 VM_OBJECT_WUNLOCK(object);
4176 * Clone the entry, referencing the shared object.
4178 new_entry = vm_map_entry_create(new_map);
4179 *new_entry = *old_entry;
4180 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
4181 MAP_ENTRY_IN_TRANSITION);
4182 new_entry->wiring_thread = NULL;
4183 new_entry->wired_count = 0;
4184 if (new_entry->eflags & MAP_ENTRY_WRITECNT) {
4185 vm_pager_update_writecount(object,
4186 new_entry->start, new_entry->end);
4188 vm_map_entry_set_vnode_text(new_entry, true);
4191 * Insert the entry into the new map -- we know we're
4192 * inserting at the end of the new map.
4194 vm_map_entry_link(new_map, new_entry);
4195 vmspace_map_entry_forked(vm1, vm2, new_entry);
4198 * Update the physical map
4200 pmap_copy(new_map->pmap, old_map->pmap,
4202 (old_entry->end - old_entry->start),
4206 case VM_INHERIT_COPY:
4208 * Clone the entry and link into the map.
4210 new_entry = vm_map_entry_create(new_map);
4211 *new_entry = *old_entry;
4213 * Copied entry is COW over the old object.
4215 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
4216 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WRITECNT);
4217 new_entry->wiring_thread = NULL;
4218 new_entry->wired_count = 0;
4219 new_entry->object.vm_object = NULL;
4220 new_entry->cred = NULL;
4221 vm_map_entry_link(new_map, new_entry);
4222 vmspace_map_entry_forked(vm1, vm2, new_entry);
4223 vm_map_copy_entry(old_map, new_map, old_entry,
4224 new_entry, fork_charge);
4225 vm_map_entry_set_vnode_text(new_entry, true);
4228 case VM_INHERIT_ZERO:
4230 * Create a new anonymous mapping entry modelled from
4233 new_entry = vm_map_entry_create(new_map);
4234 memset(new_entry, 0, sizeof(*new_entry));
4236 new_entry->start = old_entry->start;
4237 new_entry->end = old_entry->end;
4238 new_entry->eflags = old_entry->eflags &
4239 ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION |
4240 MAP_ENTRY_WRITECNT | MAP_ENTRY_VN_EXEC);
4241 new_entry->protection = old_entry->protection;
4242 new_entry->max_protection = old_entry->max_protection;
4243 new_entry->inheritance = VM_INHERIT_ZERO;
4245 vm_map_entry_link(new_map, new_entry);
4246 vmspace_map_entry_forked(vm1, vm2, new_entry);
4248 new_entry->cred = curthread->td_ucred;
4249 crhold(new_entry->cred);
4250 *fork_charge += (new_entry->end - new_entry->start);
4256 * Use inlined vm_map_unlock() to postpone handling the deferred
4257 * map entries, which cannot be done until both old_map and
4258 * new_map locks are released.
4260 sx_xunlock(&old_map->lock);
4261 sx_xunlock(&new_map->lock);
4262 vm_map_process_deferred();
4268 * Create a process's stack for exec_new_vmspace(). This function is never
4269 * asked to wire the newly created stack.
4272 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
4273 vm_prot_t prot, vm_prot_t max, int cow)
4275 vm_size_t growsize, init_ssize;
4279 MPASS((map->flags & MAP_WIREFUTURE) == 0);
4280 growsize = sgrowsiz;
4281 init_ssize = (max_ssize < growsize) ? max_ssize : growsize;
4283 vmemlim = lim_cur(curthread, RLIMIT_VMEM);
4284 /* If we would blow our VMEM resource limit, no go */
4285 if (map->size + init_ssize > vmemlim) {
4289 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot,
4296 static int stack_guard_page = 1;
4297 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN,
4298 &stack_guard_page, 0,
4299 "Specifies the number of guard pages for a stack that grows");
4302 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
4303 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow)
4305 vm_map_entry_t new_entry, prev_entry;
4306 vm_offset_t bot, gap_bot, gap_top, top;
4307 vm_size_t init_ssize, sgp;
4311 * The stack orientation is piggybacked with the cow argument.
4312 * Extract it into orient and mask the cow argument so that we
4313 * don't pass it around further.
4315 orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP);
4316 KASSERT(orient != 0, ("No stack grow direction"));
4317 KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP),
4320 if (max_ssize == 0 ||
4321 !vm_map_range_valid(map, addrbos, addrbos + max_ssize))
4322 return (KERN_INVALID_ADDRESS);
4323 sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
4324 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
4325 (vm_size_t)stack_guard_page * PAGE_SIZE;
4326 if (sgp >= max_ssize)
4327 return (KERN_INVALID_ARGUMENT);
4329 init_ssize = growsize;
4330 if (max_ssize < init_ssize + sgp)
4331 init_ssize = max_ssize - sgp;
4333 /* If addr is already mapped, no go */
4334 if (vm_map_lookup_entry(map, addrbos, &prev_entry))
4335 return (KERN_NO_SPACE);
4338 * If we can't accommodate max_ssize in the current mapping, no go.
4340 if (vm_map_entry_succ(prev_entry)->start < addrbos + max_ssize)
4341 return (KERN_NO_SPACE);
4344 * We initially map a stack of only init_ssize. We will grow as
4345 * needed later. Depending on the orientation of the stack (i.e.
4346 * the grow direction) we either map at the top of the range, the
4347 * bottom of the range or in the middle.
4349 * Note: we would normally expect prot and max to be VM_PROT_ALL,
4350 * and cow to be 0. Possibly we should eliminate these as input
4351 * parameters, and just pass these values here in the insert call.
4353 if (orient == MAP_STACK_GROWS_DOWN) {
4354 bot = addrbos + max_ssize - init_ssize;
4355 top = bot + init_ssize;
4358 } else /* if (orient == MAP_STACK_GROWS_UP) */ {
4360 top = bot + init_ssize;
4362 gap_top = addrbos + max_ssize;
4364 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow);
4365 if (rv != KERN_SUCCESS)
4367 new_entry = vm_map_entry_succ(prev_entry);
4368 KASSERT(new_entry->end == top || new_entry->start == bot,
4369 ("Bad entry start/end for new stack entry"));
4370 KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 ||
4371 (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0,
4372 ("new entry lacks MAP_ENTRY_GROWS_DOWN"));
4373 KASSERT((orient & MAP_STACK_GROWS_UP) == 0 ||
4374 (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0,
4375 ("new entry lacks MAP_ENTRY_GROWS_UP"));
4376 if (gap_bot == gap_top)
4377 return (KERN_SUCCESS);
4378 rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE,
4379 VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ?
4380 MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP));
4381 if (rv == KERN_SUCCESS) {
4383 * Gap can never successfully handle a fault, so
4384 * read-ahead logic is never used for it. Re-use
4385 * next_read of the gap entry to store
4386 * stack_guard_page for vm_map_growstack().
4388 if (orient == MAP_STACK_GROWS_DOWN)
4389 vm_map_entry_pred(new_entry)->next_read = sgp;
4391 vm_map_entry_succ(new_entry)->next_read = sgp;
4393 (void)vm_map_delete(map, bot, top);
4399 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we
4400 * successfully grow the stack.
4403 vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
4405 vm_map_entry_t stack_entry;
4409 vm_offset_t gap_end, gap_start, grow_start;
4410 vm_size_t grow_amount, guard, max_grow;
4411 rlim_t lmemlim, stacklim, vmemlim;
4413 bool gap_deleted, grow_down, is_procstack;
4425 * Disallow stack growth when the access is performed by a
4426 * debugger or AIO daemon. The reason is that the wrong
4427 * resource limits are applied.
4429 if (p != initproc && (map != &p->p_vmspace->vm_map ||
4430 p->p_textvp == NULL))
4431 return (KERN_FAILURE);
4433 MPASS(!map->system_map);
4435 lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK);
4436 stacklim = lim_cur(curthread, RLIMIT_STACK);
4437 vmemlim = lim_cur(curthread, RLIMIT_VMEM);
4439 /* If addr is not in a hole for a stack grow area, no need to grow. */
4440 if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry))
4441 return (KERN_FAILURE);
4442 if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0)
4443 return (KERN_SUCCESS);
4444 if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) {
4445 stack_entry = vm_map_entry_succ(gap_entry);
4446 if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 ||
4447 stack_entry->start != gap_entry->end)
4448 return (KERN_FAILURE);
4449 grow_amount = round_page(stack_entry->start - addr);
4451 } else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) {
4452 stack_entry = vm_map_entry_pred(gap_entry);
4453 if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 ||
4454 stack_entry->end != gap_entry->start)
4455 return (KERN_FAILURE);
4456 grow_amount = round_page(addr + 1 - stack_entry->end);
4459 return (KERN_FAILURE);
4461 guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
4462 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
4463 gap_entry->next_read;
4464 max_grow = gap_entry->end - gap_entry->start;
4465 if (guard > max_grow)
4466 return (KERN_NO_SPACE);
4468 if (grow_amount > max_grow)
4469 return (KERN_NO_SPACE);
4472 * If this is the main process stack, see if we're over the stack
4475 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr &&
4476 addr < (vm_offset_t)p->p_sysent->sv_usrstack;
4477 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim))
4478 return (KERN_NO_SPACE);
4483 if (is_procstack && racct_set(p, RACCT_STACK,
4484 ctob(vm->vm_ssize) + grow_amount)) {
4486 return (KERN_NO_SPACE);
4492 grow_amount = roundup(grow_amount, sgrowsiz);
4493 if (grow_amount > max_grow)
4494 grow_amount = max_grow;
4495 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) {
4496 grow_amount = trunc_page((vm_size_t)stacklim) -
4502 limit = racct_get_available(p, RACCT_STACK);
4504 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit))
4505 grow_amount = limit - ctob(vm->vm_ssize);
4508 if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) {
4509 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) {
4516 if (racct_set(p, RACCT_MEMLOCK,
4517 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) {
4527 /* If we would blow our VMEM resource limit, no go */
4528 if (map->size + grow_amount > vmemlim) {
4535 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) {
4544 if (vm_map_lock_upgrade(map)) {
4546 vm_map_lock_read(map);
4551 grow_start = gap_entry->end - grow_amount;
4552 if (gap_entry->start + grow_amount == gap_entry->end) {
4553 gap_start = gap_entry->start;
4554 gap_end = gap_entry->end;
4555 vm_map_entry_delete(map, gap_entry);
4558 MPASS(gap_entry->start < gap_entry->end - grow_amount);
4559 vm_map_entry_resize(map, gap_entry, -grow_amount);
4560 gap_deleted = false;
4562 rv = vm_map_insert(map, NULL, 0, grow_start,
4563 grow_start + grow_amount,
4564 stack_entry->protection, stack_entry->max_protection,
4565 MAP_STACK_GROWS_DOWN);
4566 if (rv != KERN_SUCCESS) {
4568 rv1 = vm_map_insert(map, NULL, 0, gap_start,
4569 gap_end, VM_PROT_NONE, VM_PROT_NONE,
4570 MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN);
4571 MPASS(rv1 == KERN_SUCCESS);
4573 vm_map_entry_resize(map, gap_entry,
4577 grow_start = stack_entry->end;
4578 cred = stack_entry->cred;
4579 if (cred == NULL && stack_entry->object.vm_object != NULL)
4580 cred = stack_entry->object.vm_object->cred;
4581 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred))
4583 /* Grow the underlying object if applicable. */
4584 else if (stack_entry->object.vm_object == NULL ||
4585 vm_object_coalesce(stack_entry->object.vm_object,
4586 stack_entry->offset,
4587 (vm_size_t)(stack_entry->end - stack_entry->start),
4588 grow_amount, cred != NULL)) {
4589 if (gap_entry->start + grow_amount == gap_entry->end) {
4590 vm_map_entry_delete(map, gap_entry);
4591 vm_map_entry_resize(map, stack_entry,
4594 gap_entry->start += grow_amount;
4595 stack_entry->end += grow_amount;
4597 map->size += grow_amount;
4602 if (rv == KERN_SUCCESS && is_procstack)
4603 vm->vm_ssize += btoc(grow_amount);
4606 * Heed the MAP_WIREFUTURE flag if it was set for this process.
4608 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) {
4609 rv = vm_map_wire_locked(map, grow_start,
4610 grow_start + grow_amount,
4611 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
4613 vm_map_lock_downgrade(map);
4617 if (racct_enable && rv != KERN_SUCCESS) {
4619 error = racct_set(p, RACCT_VMEM, map->size);
4620 KASSERT(error == 0, ("decreasing RACCT_VMEM failed"));
4622 error = racct_set(p, RACCT_MEMLOCK,
4623 ptoa(pmap_wired_count(map->pmap)));
4624 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed"));
4626 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize));
4627 KASSERT(error == 0, ("decreasing RACCT_STACK failed"));
4636 * Unshare the specified VM space for exec. If other processes are
4637 * mapped to it, then create a new one. The new vmspace is null.
4640 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser)
4642 struct vmspace *oldvmspace = p->p_vmspace;
4643 struct vmspace *newvmspace;
4645 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0,
4646 ("vmspace_exec recursed"));
4647 newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit);
4648 if (newvmspace == NULL)
4650 newvmspace->vm_swrss = oldvmspace->vm_swrss;
4652 * This code is written like this for prototype purposes. The
4653 * goal is to avoid running down the vmspace here, but let the
4654 * other process's that are still using the vmspace to finally
4655 * run it down. Even though there is little or no chance of blocking
4656 * here, it is a good idea to keep this form for future mods.
4658 PROC_VMSPACE_LOCK(p);
4659 p->p_vmspace = newvmspace;
4660 PROC_VMSPACE_UNLOCK(p);
4661 if (p == curthread->td_proc)
4662 pmap_activate(curthread);
4663 curthread->td_pflags |= TDP_EXECVMSPC;
4668 * Unshare the specified VM space for forcing COW. This
4669 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
4672 vmspace_unshare(struct proc *p)
4674 struct vmspace *oldvmspace = p->p_vmspace;
4675 struct vmspace *newvmspace;
4676 vm_ooffset_t fork_charge;
4678 if (oldvmspace->vm_refcnt == 1)
4681 newvmspace = vmspace_fork(oldvmspace, &fork_charge);
4682 if (newvmspace == NULL)
4684 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) {
4685 vmspace_free(newvmspace);
4688 PROC_VMSPACE_LOCK(p);
4689 p->p_vmspace = newvmspace;
4690 PROC_VMSPACE_UNLOCK(p);
4691 if (p == curthread->td_proc)
4692 pmap_activate(curthread);
4693 vmspace_free(oldvmspace);
4700 * Finds the VM object, offset, and
4701 * protection for a given virtual address in the
4702 * specified map, assuming a page fault of the
4705 * Leaves the map in question locked for read; return
4706 * values are guaranteed until a vm_map_lookup_done
4707 * call is performed. Note that the map argument
4708 * is in/out; the returned map must be used in
4709 * the call to vm_map_lookup_done.
4711 * A handle (out_entry) is returned for use in
4712 * vm_map_lookup_done, to make that fast.
4714 * If a lookup is requested with "write protection"
4715 * specified, the map may be changed to perform virtual
4716 * copying operations, although the data referenced will
4720 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
4722 vm_prot_t fault_typea,
4723 vm_map_entry_t *out_entry, /* OUT */
4724 vm_object_t *object, /* OUT */
4725 vm_pindex_t *pindex, /* OUT */
4726 vm_prot_t *out_prot, /* OUT */
4727 boolean_t *wired) /* OUT */
4729 vm_map_entry_t entry;
4730 vm_map_t map = *var_map;
4732 vm_prot_t fault_type;
4733 vm_object_t eobject;
4739 vm_map_lock_read(map);
4743 * Lookup the faulting address.
4745 if (!vm_map_lookup_entry(map, vaddr, out_entry)) {
4746 vm_map_unlock_read(map);
4747 return (KERN_INVALID_ADDRESS);
4755 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
4756 vm_map_t old_map = map;
4758 *var_map = map = entry->object.sub_map;
4759 vm_map_unlock_read(old_map);
4764 * Check whether this task is allowed to have this page.
4766 prot = entry->protection;
4767 if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) {
4768 fault_typea &= ~VM_PROT_FAULT_LOOKUP;
4769 if (prot == VM_PROT_NONE && map != kernel_map &&
4770 (entry->eflags & MAP_ENTRY_GUARD) != 0 &&
4771 (entry->eflags & (MAP_ENTRY_STACK_GAP_DN |
4772 MAP_ENTRY_STACK_GAP_UP)) != 0 &&
4773 vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS)
4774 goto RetryLookupLocked;
4776 fault_type = fault_typea & VM_PROT_ALL;
4777 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) {
4778 vm_map_unlock_read(map);
4779 return (KERN_PROTECTION_FAILURE);
4781 KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags &
4782 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) !=
4783 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY),
4784 ("entry %p flags %x", entry, entry->eflags));
4785 if ((fault_typea & VM_PROT_COPY) != 0 &&
4786 (entry->max_protection & VM_PROT_WRITE) == 0 &&
4787 (entry->eflags & MAP_ENTRY_COW) == 0) {
4788 vm_map_unlock_read(map);
4789 return (KERN_PROTECTION_FAILURE);
4793 * If this page is not pageable, we have to get it for all possible
4796 *wired = (entry->wired_count != 0);
4798 fault_type = entry->protection;
4799 size = entry->end - entry->start;
4802 * If the entry was copy-on-write, we either ...
4804 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4806 * If we want to write the page, we may as well handle that
4807 * now since we've got the map locked.
4809 * If we don't need to write the page, we just demote the
4810 * permissions allowed.
4812 if ((fault_type & VM_PROT_WRITE) != 0 ||
4813 (fault_typea & VM_PROT_COPY) != 0) {
4815 * Make a new object, and place it in the object
4816 * chain. Note that no new references have appeared
4817 * -- one just moved from the map to the new
4820 if (vm_map_lock_upgrade(map))
4823 if (entry->cred == NULL) {
4825 * The debugger owner is charged for
4828 cred = curthread->td_ucred;
4830 if (!swap_reserve_by_cred(size, cred)) {
4833 return (KERN_RESOURCE_SHORTAGE);
4837 eobject = entry->object.vm_object;
4838 vm_object_shadow(&entry->object.vm_object,
4839 &entry->offset, size, entry->cred, false);
4840 if (eobject == entry->object.vm_object) {
4842 * The object was not shadowed.
4844 swap_release_by_cred(size, entry->cred);
4845 crfree(entry->cred);
4848 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
4850 vm_map_lock_downgrade(map);
4853 * We're attempting to read a copy-on-write page --
4854 * don't allow writes.
4856 prot &= ~VM_PROT_WRITE;
4861 * Create an object if necessary.
4863 if (entry->object.vm_object == NULL && !map->system_map) {
4864 if (vm_map_lock_upgrade(map))
4866 entry->object.vm_object = vm_object_allocate_anon(atop(size),
4867 NULL, entry->cred, entry->cred != NULL ? size : 0);
4870 vm_map_lock_downgrade(map);
4874 * Return the object/offset from this entry. If the entry was
4875 * copy-on-write or empty, it has been fixed up.
4877 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
4878 *object = entry->object.vm_object;
4881 return (KERN_SUCCESS);
4885 * vm_map_lookup_locked:
4887 * Lookup the faulting address. A version of vm_map_lookup that returns
4888 * KERN_FAILURE instead of blocking on map lock or memory allocation.
4891 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */
4893 vm_prot_t fault_typea,
4894 vm_map_entry_t *out_entry, /* OUT */
4895 vm_object_t *object, /* OUT */
4896 vm_pindex_t *pindex, /* OUT */
4897 vm_prot_t *out_prot, /* OUT */
4898 boolean_t *wired) /* OUT */
4900 vm_map_entry_t entry;
4901 vm_map_t map = *var_map;
4903 vm_prot_t fault_type = fault_typea;
4906 * Lookup the faulting address.
4908 if (!vm_map_lookup_entry(map, vaddr, out_entry))
4909 return (KERN_INVALID_ADDRESS);
4914 * Fail if the entry refers to a submap.
4916 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
4917 return (KERN_FAILURE);
4920 * Check whether this task is allowed to have this page.
4922 prot = entry->protection;
4923 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
4924 if ((fault_type & prot) != fault_type)
4925 return (KERN_PROTECTION_FAILURE);
4928 * If this page is not pageable, we have to get it for all possible
4931 *wired = (entry->wired_count != 0);
4933 fault_type = entry->protection;
4935 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4937 * Fail if the entry was copy-on-write for a write fault.
4939 if (fault_type & VM_PROT_WRITE)
4940 return (KERN_FAILURE);
4942 * We're attempting to read a copy-on-write page --
4943 * don't allow writes.
4945 prot &= ~VM_PROT_WRITE;
4949 * Fail if an object should be created.
4951 if (entry->object.vm_object == NULL && !map->system_map)
4952 return (KERN_FAILURE);
4955 * Return the object/offset from this entry. If the entry was
4956 * copy-on-write or empty, it has been fixed up.
4958 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
4959 *object = entry->object.vm_object;
4962 return (KERN_SUCCESS);
4966 * vm_map_lookup_done:
4968 * Releases locks acquired by a vm_map_lookup
4969 * (according to the handle returned by that lookup).
4972 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry)
4975 * Unlock the main-level map
4977 vm_map_unlock_read(map);
4981 vm_map_max_KBI(const struct vm_map *map)
4984 return (vm_map_max(map));
4988 vm_map_min_KBI(const struct vm_map *map)
4991 return (vm_map_min(map));
4995 vm_map_pmap_KBI(vm_map_t map)
5003 _vm_map_assert_consistent(vm_map_t map, int check)
5005 vm_map_entry_t entry, prev;
5006 vm_map_entry_t cur, header, lbound, ubound;
5007 vm_size_t max_left, max_right;
5012 if (enable_vmmap_check != check)
5015 header = prev = &map->header;
5016 VM_MAP_ENTRY_FOREACH(entry, map) {
5017 KASSERT(prev->end <= entry->start,
5018 ("map %p prev->end = %jx, start = %jx", map,
5019 (uintmax_t)prev->end, (uintmax_t)entry->start));
5020 KASSERT(entry->start < entry->end,
5021 ("map %p start = %jx, end = %jx", map,
5022 (uintmax_t)entry->start, (uintmax_t)entry->end));
5023 KASSERT(entry->left == header ||
5024 entry->left->start < entry->start,
5025 ("map %p left->start = %jx, start = %jx", map,
5026 (uintmax_t)entry->left->start, (uintmax_t)entry->start));
5027 KASSERT(entry->right == header ||
5028 entry->start < entry->right->start,
5029 ("map %p start = %jx, right->start = %jx", map,
5030 (uintmax_t)entry->start, (uintmax_t)entry->right->start));
5032 lbound = ubound = header;
5034 if (entry->start < cur->start) {
5037 KASSERT(cur != lbound,
5038 ("map %p cannot find %jx",
5039 map, (uintmax_t)entry->start));
5040 } else if (cur->end <= entry->start) {
5043 KASSERT(cur != ubound,
5044 ("map %p cannot find %jx",
5045 map, (uintmax_t)entry->start));
5047 KASSERT(cur == entry,
5048 ("map %p cannot find %jx",
5049 map, (uintmax_t)entry->start));
5053 max_left = vm_map_entry_max_free_left(entry, lbound);
5054 max_right = vm_map_entry_max_free_right(entry, ubound);
5055 KASSERT(entry->max_free == vm_size_max(max_left, max_right),
5056 ("map %p max = %jx, max_left = %jx, max_right = %jx", map,
5057 (uintmax_t)entry->max_free,
5058 (uintmax_t)max_left, (uintmax_t)max_right));
5061 KASSERT(prev->end <= entry->start,
5062 ("map %p prev->end = %jx, start = %jx", map,
5063 (uintmax_t)prev->end, (uintmax_t)entry->start));
5067 #include "opt_ddb.h"
5069 #include <sys/kernel.h>
5071 #include <ddb/ddb.h>
5074 vm_map_print(vm_map_t map)
5076 vm_map_entry_t entry, prev;
5078 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
5080 (void *)map->pmap, map->nentries, map->timestamp);
5083 prev = &map->header;
5084 VM_MAP_ENTRY_FOREACH(entry, map) {
5085 db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n",
5086 (void *)entry, (void *)entry->start, (void *)entry->end,
5089 static const char * const inheritance_name[4] =
5090 {"share", "copy", "none", "donate_copy"};
5092 db_iprintf(" prot=%x/%x/%s",
5094 entry->max_protection,
5095 inheritance_name[(int)(unsigned char)
5096 entry->inheritance]);
5097 if (entry->wired_count != 0)
5098 db_printf(", wired");
5100 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
5101 db_printf(", share=%p, offset=0x%jx\n",
5102 (void *)entry->object.sub_map,
5103 (uintmax_t)entry->offset);
5104 if (prev == &map->header ||
5105 prev->object.sub_map !=
5106 entry->object.sub_map) {
5108 vm_map_print((vm_map_t)entry->object.sub_map);
5112 if (entry->cred != NULL)
5113 db_printf(", ruid %d", entry->cred->cr_ruid);
5114 db_printf(", object=%p, offset=0x%jx",
5115 (void *)entry->object.vm_object,
5116 (uintmax_t)entry->offset);
5117 if (entry->object.vm_object && entry->object.vm_object->cred)
5118 db_printf(", obj ruid %d charge %jx",
5119 entry->object.vm_object->cred->cr_ruid,
5120 (uintmax_t)entry->object.vm_object->charge);
5121 if (entry->eflags & MAP_ENTRY_COW)
5122 db_printf(", copy (%s)",
5123 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
5126 if (prev == &map->header ||
5127 prev->object.vm_object !=
5128 entry->object.vm_object) {
5130 vm_object_print((db_expr_t)(intptr_t)
5131 entry->object.vm_object,
5141 DB_SHOW_COMMAND(map, map)
5145 db_printf("usage: show map <addr>\n");
5148 vm_map_print((vm_map_t)addr);
5151 DB_SHOW_COMMAND(procvm, procvm)
5156 p = db_lookup_proc(addr);
5161 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
5162 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
5163 (void *)vmspace_pmap(p->p_vmspace));
5165 vm_map_print((vm_map_t)&p->p_vmspace->vm_map);