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 vmspace_zone;
132 static int vmspace_zinit(void *mem, int size, int flags);
133 static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min,
135 static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map);
136 static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry);
137 static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry);
138 static int vm_map_growstack(vm_map_t map, vm_offset_t addr,
139 vm_map_entry_t gap_entry);
140 static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
141 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags);
143 static void vmspace_zdtor(void *mem, int size, void *arg);
145 static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos,
146 vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max,
148 static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
149 vm_offset_t failed_addr);
151 #define ENTRY_CHARGED(e) ((e)->cred != NULL || \
152 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \
153 !((e)->eflags & MAP_ENTRY_NEEDS_COPY)))
156 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type
159 #define PROC_VMSPACE_LOCK(p) do { } while (0)
160 #define PROC_VMSPACE_UNLOCK(p) do { } while (0)
163 * VM_MAP_RANGE_CHECK: [ internal use only ]
165 * Asserts that the starting and ending region
166 * addresses fall within the valid range of the map.
168 #define VM_MAP_RANGE_CHECK(map, start, end) \
170 if (start < vm_map_min(map)) \
171 start = vm_map_min(map); \
172 if (end > vm_map_max(map)) \
173 end = vm_map_max(map); \
178 #ifndef UMA_MD_SMALL_ALLOC
181 * Allocate a new slab for kernel map entries. The kernel map may be locked or
182 * unlocked, depending on whether the request is coming from the kernel map or a
183 * submap. This function allocates a virtual address range directly from the
184 * kernel map instead of the kmem_* layer to avoid recursion on the kernel map
185 * lock and also to avoid triggering allocator recursion in the vmem boundary
189 kmapent_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
195 *pflag = UMA_SLAB_PRIV;
197 if (!(locked = vm_map_locked(kernel_map)))
198 vm_map_lock(kernel_map);
199 addr = vm_map_findspace(kernel_map, vm_map_min(kernel_map), bytes);
200 if (addr + bytes < addr || addr + bytes > vm_map_max(kernel_map))
201 panic("%s: kernel map is exhausted", __func__);
202 error = vm_map_insert(kernel_map, NULL, 0, addr, addr + bytes,
203 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
204 if (error != KERN_SUCCESS)
205 panic("%s: vm_map_insert() failed: %d", __func__, error);
207 vm_map_unlock(kernel_map);
208 error = kmem_back_domain(domain, kernel_object, addr, bytes, M_NOWAIT |
209 M_USE_RESERVE | (wait & M_ZERO));
210 if (error == KERN_SUCCESS) {
211 return ((void *)addr);
214 vm_map_lock(kernel_map);
215 vm_map_delete(kernel_map, addr, bytes);
217 vm_map_unlock(kernel_map);
223 kmapent_free(void *item, vm_size_t size, uint8_t pflag)
228 if ((pflag & UMA_SLAB_PRIV) == 0)
232 addr = (vm_offset_t)item;
233 kmem_unback(kernel_object, addr, size);
234 error = vm_map_remove(kernel_map, addr, addr + size);
235 KASSERT(error == KERN_SUCCESS,
236 ("%s: vm_map_remove failed: %d", __func__, error));
240 * The worst-case upper bound on the number of kernel map entries that may be
241 * created before the zone must be replenished in _vm_map_unlock().
243 #define KMAPENT_RESERVE 1
245 #endif /* !UMD_MD_SMALL_ALLOC */
250 * Initialize the vm_map module. Must be called before any other vm_map
253 * User map and entry structures are allocated from the general purpose
254 * memory pool. Kernel maps are statically defined. Kernel map entries
255 * require special handling to avoid recursion; see the comments above
256 * kmapent_alloc() and in vm_map_entry_create().
261 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF);
264 * Disable the use of per-CPU buckets: map entry allocation is
265 * serialized by the kernel map lock.
267 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry),
268 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
269 UMA_ZONE_VM | UMA_ZONE_NOBUCKET);
270 #ifndef UMA_MD_SMALL_ALLOC
271 /* Reserve an extra map entry for use when replenishing the reserve. */
272 uma_zone_reserve(kmapentzone, KMAPENT_RESERVE + 1);
273 uma_prealloc(kmapentzone, KMAPENT_RESERVE + 1);
274 uma_zone_set_allocf(kmapentzone, kmapent_alloc);
275 uma_zone_set_freef(kmapentzone, kmapent_free);
278 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry),
279 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
280 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL,
286 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
290 vmspace_zinit(void *mem, int size, int flags)
295 vm = (struct vmspace *)mem;
298 memset(map, 0, sizeof(*map));
299 mtx_init(&map->system_mtx, "vm map (system)", NULL,
300 MTX_DEF | MTX_DUPOK);
301 sx_init(&map->lock, "vm map (user)");
302 PMAP_LOCK_INIT(vmspace_pmap(vm));
308 vmspace_zdtor(void *mem, int size, void *arg)
312 vm = (struct vmspace *)mem;
313 KASSERT(vm->vm_map.nentries == 0,
314 ("vmspace %p nentries == %d on free", vm, vm->vm_map.nentries));
315 KASSERT(vm->vm_map.size == 0,
316 ("vmspace %p size == %ju on free", vm, (uintmax_t)vm->vm_map.size));
318 #endif /* INVARIANTS */
321 * Allocate a vmspace structure, including a vm_map and pmap,
322 * and initialize those structures. The refcnt is set to 1.
325 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit)
329 vm = uma_zalloc(vmspace_zone, M_WAITOK);
330 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL"));
331 if (!pinit(vmspace_pmap(vm))) {
332 uma_zfree(vmspace_zone, vm);
335 CTR1(KTR_VM, "vmspace_alloc: %p", vm);
336 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max);
337 refcount_init(&vm->vm_refcnt, 1);
351 vmspace_container_reset(struct proc *p)
355 racct_set(p, RACCT_DATA, 0);
356 racct_set(p, RACCT_STACK, 0);
357 racct_set(p, RACCT_RSS, 0);
358 racct_set(p, RACCT_MEMLOCK, 0);
359 racct_set(p, RACCT_VMEM, 0);
365 vmspace_dofree(struct vmspace *vm)
368 CTR1(KTR_VM, "vmspace_free: %p", vm);
371 * Make sure any SysV shm is freed, it might not have been in
377 * Lock the map, to wait out all other references to it.
378 * Delete all of the mappings and pages they hold, then call
379 * the pmap module to reclaim anything left.
381 (void)vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map),
382 vm_map_max(&vm->vm_map));
384 pmap_release(vmspace_pmap(vm));
385 vm->vm_map.pmap = NULL;
386 uma_zfree(vmspace_zone, vm);
390 vmspace_free(struct vmspace *vm)
393 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
394 "vmspace_free() called");
396 if (refcount_release(&vm->vm_refcnt))
401 vmspace_exitfree(struct proc *p)
405 PROC_VMSPACE_LOCK(p);
408 PROC_VMSPACE_UNLOCK(p);
409 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace"));
414 vmspace_exit(struct thread *td)
424 * Prepare to release the vmspace reference. The thread that releases
425 * the last reference is responsible for tearing down the vmspace.
426 * However, threads not releasing the final reference must switch to the
427 * kernel's vmspace0 before the decrement so that the subsequent pmap
428 * deactivation does not modify a freed vmspace.
430 refcount_acquire(&vmspace0.vm_refcnt);
431 if (!(released = refcount_release_if_last(&vm->vm_refcnt))) {
432 if (p->p_vmspace != &vmspace0) {
433 PROC_VMSPACE_LOCK(p);
434 p->p_vmspace = &vmspace0;
435 PROC_VMSPACE_UNLOCK(p);
438 released = refcount_release(&vm->vm_refcnt);
442 * pmap_remove_pages() expects the pmap to be active, so switch
443 * back first if necessary.
445 if (p->p_vmspace != vm) {
446 PROC_VMSPACE_LOCK(p);
448 PROC_VMSPACE_UNLOCK(p);
451 pmap_remove_pages(vmspace_pmap(vm));
452 PROC_VMSPACE_LOCK(p);
453 p->p_vmspace = &vmspace0;
454 PROC_VMSPACE_UNLOCK(p);
460 vmspace_container_reset(p);
464 /* Acquire reference to vmspace owned by another process. */
467 vmspace_acquire_ref(struct proc *p)
471 PROC_VMSPACE_LOCK(p);
473 if (vm == NULL || !refcount_acquire_if_not_zero(&vm->vm_refcnt)) {
474 PROC_VMSPACE_UNLOCK(p);
477 if (vm != p->p_vmspace) {
478 PROC_VMSPACE_UNLOCK(p);
482 PROC_VMSPACE_UNLOCK(p);
487 * Switch between vmspaces in an AIO kernel process.
489 * The new vmspace is either the vmspace of a user process obtained
490 * from an active AIO request or the initial vmspace of the AIO kernel
491 * process (when it is idling). Because user processes will block to
492 * drain any active AIO requests before proceeding in exit() or
493 * execve(), the reference count for vmspaces from AIO requests can
494 * never be 0. Similarly, AIO kernel processes hold an extra
495 * reference on their initial vmspace for the life of the process. As
496 * a result, the 'newvm' vmspace always has a non-zero reference
497 * count. This permits an additional reference on 'newvm' to be
498 * acquired via a simple atomic increment rather than the loop in
499 * vmspace_acquire_ref() above.
502 vmspace_switch_aio(struct vmspace *newvm)
504 struct vmspace *oldvm;
506 /* XXX: Need some way to assert that this is an aio daemon. */
508 KASSERT(refcount_load(&newvm->vm_refcnt) > 0,
509 ("vmspace_switch_aio: newvm unreferenced"));
511 oldvm = curproc->p_vmspace;
516 * Point to the new address space and refer to it.
518 curproc->p_vmspace = newvm;
519 refcount_acquire(&newvm->vm_refcnt);
521 /* Activate the new mapping. */
522 pmap_activate(curthread);
528 _vm_map_lock(vm_map_t map, const char *file, int line)
532 mtx_lock_flags_(&map->system_mtx, 0, file, line);
534 sx_xlock_(&map->lock, file, line);
539 vm_map_entry_set_vnode_text(vm_map_entry_t entry, bool add)
545 if ((entry->eflags & MAP_ENTRY_VN_EXEC) == 0)
547 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
548 ("Submap with execs"));
549 object = entry->object.vm_object;
550 KASSERT(object != NULL, ("No object for text, entry %p", entry));
551 if ((object->flags & OBJ_ANON) != 0)
552 object = object->handle;
554 KASSERT(object->backing_object == NULL,
555 ("non-anon object %p shadows", object));
556 KASSERT(object != NULL, ("No content object for text, entry %p obj %p",
557 entry, entry->object.vm_object));
560 * Mostly, we do not lock the backing object. It is
561 * referenced by the entry we are processing, so it cannot go
566 if (object->type == OBJT_DEAD) {
568 * For OBJT_DEAD objects, v_writecount was handled in
569 * vnode_pager_dealloc().
571 } else if (object->type == OBJT_VNODE) {
573 } else if (object->type == OBJT_SWAP) {
574 KASSERT((object->flags & OBJ_TMPFS_NODE) != 0,
575 ("vm_map_entry_set_vnode_text: swap and !TMPFS "
576 "entry %p, object %p, add %d", entry, object, add));
578 * Tmpfs VREG node, which was reclaimed, has
579 * OBJ_TMPFS_NODE flag set, but not OBJ_TMPFS. In
580 * this case there is no v_writecount to adjust.
582 VM_OBJECT_RLOCK(object);
583 if ((object->flags & OBJ_TMPFS) != 0) {
584 vp = object->un_pager.swp.swp_tmpfs;
590 VM_OBJECT_RUNLOCK(object);
593 ("vm_map_entry_set_vnode_text: wrong object type, "
594 "entry %p, object %p, add %d", entry, object, add));
598 VOP_SET_TEXT_CHECKED(vp);
600 vn_lock(vp, LK_SHARED | LK_RETRY);
601 VOP_UNSET_TEXT_CHECKED(vp);
610 * Use a different name for this vm_map_entry field when it's use
611 * is not consistent with its use as part of an ordered search tree.
613 #define defer_next right
616 vm_map_process_deferred(void)
619 vm_map_entry_t entry, next;
623 entry = td->td_map_def_user;
624 td->td_map_def_user = NULL;
625 while (entry != NULL) {
626 next = entry->defer_next;
627 MPASS((entry->eflags & (MAP_ENTRY_WRITECNT |
628 MAP_ENTRY_VN_EXEC)) != (MAP_ENTRY_WRITECNT |
630 if ((entry->eflags & MAP_ENTRY_WRITECNT) != 0) {
632 * Decrement the object's writemappings and
633 * possibly the vnode's v_writecount.
635 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
636 ("Submap with writecount"));
637 object = entry->object.vm_object;
638 KASSERT(object != NULL, ("No object for writecount"));
639 vm_pager_release_writecount(object, entry->start,
642 vm_map_entry_set_vnode_text(entry, false);
643 vm_map_entry_deallocate(entry, FALSE);
650 _vm_map_assert_locked(vm_map_t map, const char *file, int line)
654 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
656 sx_assert_(&map->lock, SA_XLOCKED, file, line);
659 #define VM_MAP_ASSERT_LOCKED(map) \
660 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE)
662 enum { VMMAP_CHECK_NONE, VMMAP_CHECK_UNLOCK, VMMAP_CHECK_ALL };
664 static int enable_vmmap_check = VMMAP_CHECK_UNLOCK;
666 static int enable_vmmap_check = VMMAP_CHECK_NONE;
668 SYSCTL_INT(_debug, OID_AUTO, vmmap_check, CTLFLAG_RWTUN,
669 &enable_vmmap_check, 0, "Enable vm map consistency checking");
671 static void _vm_map_assert_consistent(vm_map_t map, int check);
673 #define VM_MAP_ASSERT_CONSISTENT(map) \
674 _vm_map_assert_consistent(map, VMMAP_CHECK_ALL)
676 #define VM_MAP_UNLOCK_CONSISTENT(map) do { \
677 if (map->nupdates > map->nentries) { \
678 _vm_map_assert_consistent(map, VMMAP_CHECK_UNLOCK); \
683 #define VM_MAP_UNLOCK_CONSISTENT(map)
686 #define VM_MAP_ASSERT_LOCKED(map)
687 #define VM_MAP_ASSERT_CONSISTENT(map)
688 #define VM_MAP_UNLOCK_CONSISTENT(map)
689 #endif /* INVARIANTS */
692 _vm_map_unlock(vm_map_t map, const char *file, int line)
695 VM_MAP_UNLOCK_CONSISTENT(map);
696 if (map->system_map) {
697 #ifndef UMA_MD_SMALL_ALLOC
698 if (map == kernel_map && (map->flags & MAP_REPLENISH) != 0) {
699 uma_prealloc(kmapentzone, 1);
700 map->flags &= ~MAP_REPLENISH;
703 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
705 sx_xunlock_(&map->lock, file, line);
706 vm_map_process_deferred();
711 _vm_map_lock_read(vm_map_t map, const char *file, int line)
715 mtx_lock_flags_(&map->system_mtx, 0, file, line);
717 sx_slock_(&map->lock, file, line);
721 _vm_map_unlock_read(vm_map_t map, const char *file, int line)
724 if (map->system_map) {
725 KASSERT((map->flags & MAP_REPLENISH) == 0,
726 ("%s: MAP_REPLENISH leaked", __func__));
727 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
729 sx_sunlock_(&map->lock, file, line);
730 vm_map_process_deferred();
735 _vm_map_trylock(vm_map_t map, const char *file, int line)
739 error = map->system_map ?
740 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
741 !sx_try_xlock_(&map->lock, file, line);
748 _vm_map_trylock_read(vm_map_t map, const char *file, int line)
752 error = map->system_map ?
753 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
754 !sx_try_slock_(&map->lock, file, line);
759 * _vm_map_lock_upgrade: [ internal use only ]
761 * Tries to upgrade a read (shared) lock on the specified map to a write
762 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a
763 * non-zero value if the upgrade fails. If the upgrade fails, the map is
764 * returned without a read or write lock held.
766 * Requires that the map be read locked.
769 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line)
771 unsigned int last_timestamp;
773 if (map->system_map) {
774 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
776 if (!sx_try_upgrade_(&map->lock, file, line)) {
777 last_timestamp = map->timestamp;
778 sx_sunlock_(&map->lock, file, line);
779 vm_map_process_deferred();
781 * If the map's timestamp does not change while the
782 * map is unlocked, then the upgrade succeeds.
784 sx_xlock_(&map->lock, file, line);
785 if (last_timestamp != map->timestamp) {
786 sx_xunlock_(&map->lock, file, line);
796 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
799 if (map->system_map) {
800 KASSERT((map->flags & MAP_REPLENISH) == 0,
801 ("%s: MAP_REPLENISH leaked", __func__));
802 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
804 VM_MAP_UNLOCK_CONSISTENT(map);
805 sx_downgrade_(&map->lock, file, line);
812 * Returns a non-zero value if the caller holds a write (exclusive) lock
813 * on the specified map and the value "0" otherwise.
816 vm_map_locked(vm_map_t map)
820 return (mtx_owned(&map->system_mtx));
822 return (sx_xlocked(&map->lock));
826 * _vm_map_unlock_and_wait:
828 * Atomically releases the lock on the specified map and puts the calling
829 * thread to sleep. The calling thread will remain asleep until either
830 * vm_map_wakeup() is performed on the map or the specified timeout is
833 * WARNING! This function does not perform deferred deallocations of
834 * objects and map entries. Therefore, the calling thread is expected to
835 * reacquire the map lock after reawakening and later perform an ordinary
836 * unlock operation, such as vm_map_unlock(), before completing its
837 * operation on the map.
840 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line)
843 VM_MAP_UNLOCK_CONSISTENT(map);
844 mtx_lock(&map_sleep_mtx);
845 if (map->system_map) {
846 KASSERT((map->flags & MAP_REPLENISH) == 0,
847 ("%s: MAP_REPLENISH leaked", __func__));
848 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
850 sx_xunlock_(&map->lock, file, line);
852 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps",
859 * Awaken any threads that have slept on the map using
860 * vm_map_unlock_and_wait().
863 vm_map_wakeup(vm_map_t map)
867 * Acquire and release map_sleep_mtx to prevent a wakeup()
868 * from being performed (and lost) between the map unlock
869 * and the msleep() in _vm_map_unlock_and_wait().
871 mtx_lock(&map_sleep_mtx);
872 mtx_unlock(&map_sleep_mtx);
877 vm_map_busy(vm_map_t map)
880 VM_MAP_ASSERT_LOCKED(map);
885 vm_map_unbusy(vm_map_t map)
888 VM_MAP_ASSERT_LOCKED(map);
889 KASSERT(map->busy, ("vm_map_unbusy: not busy"));
890 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) {
891 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP);
897 vm_map_wait_busy(vm_map_t map)
900 VM_MAP_ASSERT_LOCKED(map);
902 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0);
904 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0);
906 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0);
912 vmspace_resident_count(struct vmspace *vmspace)
914 return pmap_resident_count(vmspace_pmap(vmspace));
918 * Initialize an existing vm_map structure
919 * such as that in the vmspace structure.
922 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
925 map->header.eflags = MAP_ENTRY_HEADER;
926 map->needs_wakeup = FALSE;
929 map->header.end = min;
930 map->header.start = max;
932 map->header.left = map->header.right = &map->header;
943 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
946 _vm_map_init(map, pmap, min, max);
947 mtx_init(&map->system_mtx, "vm map (system)", NULL,
948 MTX_DEF | MTX_DUPOK);
949 sx_init(&map->lock, "vm map (user)");
953 * vm_map_entry_dispose: [ internal use only ]
955 * Inverse of vm_map_entry_create.
958 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry)
960 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry);
964 * vm_map_entry_create: [ internal use only ]
966 * Allocates a VM map entry for insertion.
967 * No entry fields are filled in.
969 static vm_map_entry_t
970 vm_map_entry_create(vm_map_t map)
972 vm_map_entry_t new_entry;
974 #ifndef UMA_MD_SMALL_ALLOC
975 if (map == kernel_map) {
976 VM_MAP_ASSERT_LOCKED(map);
979 * A new slab of kernel map entries cannot be allocated at this
980 * point because the kernel map has not yet been updated to
981 * reflect the caller's request. Therefore, we allocate a new
982 * map entry, dipping into the reserve if necessary, and set a
983 * flag indicating that the reserve must be replenished before
984 * the map is unlocked.
986 new_entry = uma_zalloc(kmapentzone, M_NOWAIT | M_NOVM);
987 if (new_entry == NULL) {
988 new_entry = uma_zalloc(kmapentzone,
989 M_NOWAIT | M_NOVM | M_USE_RESERVE);
990 kernel_map->flags |= MAP_REPLENISH;
994 if (map->system_map) {
995 new_entry = uma_zalloc(kmapentzone, M_NOWAIT);
997 new_entry = uma_zalloc(mapentzone, M_WAITOK);
999 KASSERT(new_entry != NULL,
1000 ("vm_map_entry_create: kernel resources exhausted"));
1005 * vm_map_entry_set_behavior:
1007 * Set the expected access behavior, either normal, random, or
1011 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior)
1013 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) |
1014 (behavior & MAP_ENTRY_BEHAV_MASK);
1018 * vm_map_entry_max_free_{left,right}:
1020 * Compute the size of the largest free gap between two entries,
1021 * one the root of a tree and the other the ancestor of that root
1022 * that is the least or greatest ancestor found on the search path.
1024 static inline vm_size_t
1025 vm_map_entry_max_free_left(vm_map_entry_t root, vm_map_entry_t left_ancestor)
1028 return (root->left != left_ancestor ?
1029 root->left->max_free : root->start - left_ancestor->end);
1032 static inline vm_size_t
1033 vm_map_entry_max_free_right(vm_map_entry_t root, vm_map_entry_t right_ancestor)
1036 return (root->right != right_ancestor ?
1037 root->right->max_free : right_ancestor->start - root->end);
1041 * vm_map_entry_{pred,succ}:
1043 * Find the {predecessor, successor} of the entry by taking one step
1044 * in the appropriate direction and backtracking as much as necessary.
1045 * vm_map_entry_succ is defined in vm_map.h.
1047 static inline vm_map_entry_t
1048 vm_map_entry_pred(vm_map_entry_t entry)
1050 vm_map_entry_t prior;
1052 prior = entry->left;
1053 if (prior->right->start < entry->start) {
1055 prior = prior->right;
1056 while (prior->right != entry);
1061 static inline vm_size_t
1062 vm_size_max(vm_size_t a, vm_size_t b)
1065 return (a > b ? a : b);
1068 #define SPLAY_LEFT_STEP(root, y, llist, rlist, test) do { \
1070 vm_size_t max_free; \
1073 * Infer root->right->max_free == root->max_free when \
1074 * y->max_free < root->max_free || root->max_free == 0. \
1075 * Otherwise, look right to find it. \
1078 max_free = root->max_free; \
1079 KASSERT(max_free == vm_size_max( \
1080 vm_map_entry_max_free_left(root, llist), \
1081 vm_map_entry_max_free_right(root, rlist)), \
1082 ("%s: max_free invariant fails", __func__)); \
1083 if (max_free - 1 < vm_map_entry_max_free_left(root, llist)) \
1084 max_free = vm_map_entry_max_free_right(root, rlist); \
1085 if (y != llist && (test)) { \
1086 /* Rotate right and make y root. */ \
1091 if (max_free < y->max_free) \
1092 root->max_free = max_free = \
1093 vm_size_max(max_free, z->max_free); \
1094 } else if (max_free < y->max_free) \
1095 root->max_free = max_free = \
1096 vm_size_max(max_free, root->start - y->end);\
1100 /* Copy right->max_free. Put root on rlist. */ \
1101 root->max_free = max_free; \
1102 KASSERT(max_free == vm_map_entry_max_free_right(root, rlist), \
1103 ("%s: max_free not copied from right", __func__)); \
1104 root->left = rlist; \
1106 root = y != llist ? y : NULL; \
1109 #define SPLAY_RIGHT_STEP(root, y, llist, rlist, test) do { \
1111 vm_size_t max_free; \
1114 * Infer root->left->max_free == root->max_free when \
1115 * y->max_free < root->max_free || root->max_free == 0. \
1116 * Otherwise, look left to find it. \
1119 max_free = root->max_free; \
1120 KASSERT(max_free == vm_size_max( \
1121 vm_map_entry_max_free_left(root, llist), \
1122 vm_map_entry_max_free_right(root, rlist)), \
1123 ("%s: max_free invariant fails", __func__)); \
1124 if (max_free - 1 < vm_map_entry_max_free_right(root, rlist)) \
1125 max_free = vm_map_entry_max_free_left(root, llist); \
1126 if (y != rlist && (test)) { \
1127 /* Rotate left and make y root. */ \
1132 if (max_free < y->max_free) \
1133 root->max_free = max_free = \
1134 vm_size_max(max_free, z->max_free); \
1135 } else if (max_free < y->max_free) \
1136 root->max_free = max_free = \
1137 vm_size_max(max_free, y->start - root->end);\
1141 /* Copy left->max_free. Put root on llist. */ \
1142 root->max_free = max_free; \
1143 KASSERT(max_free == vm_map_entry_max_free_left(root, llist), \
1144 ("%s: max_free not copied from left", __func__)); \
1145 root->right = llist; \
1147 root = y != rlist ? y : NULL; \
1151 * Walk down the tree until we find addr or a gap where addr would go, breaking
1152 * off left and right subtrees of nodes less than, or greater than addr. Treat
1153 * subtrees with root->max_free < length as empty trees. llist and rlist are
1154 * the two sides in reverse order (bottom-up), with llist linked by the right
1155 * pointer and rlist linked by the left pointer in the vm_map_entry, and both
1156 * lists terminated by &map->header. This function, and the subsequent call to
1157 * vm_map_splay_merge_{left,right,pred,succ}, rely on the start and end address
1158 * values in &map->header.
1160 static __always_inline vm_map_entry_t
1161 vm_map_splay_split(vm_map_t map, vm_offset_t addr, vm_size_t length,
1162 vm_map_entry_t *llist, vm_map_entry_t *rlist)
1164 vm_map_entry_t left, right, root, y;
1166 left = right = &map->header;
1168 while (root != NULL && root->max_free >= length) {
1169 KASSERT(left->end <= root->start &&
1170 root->end <= right->start,
1171 ("%s: root not within tree bounds", __func__));
1172 if (addr < root->start) {
1173 SPLAY_LEFT_STEP(root, y, left, right,
1174 y->max_free >= length && addr < y->start);
1175 } else if (addr >= root->end) {
1176 SPLAY_RIGHT_STEP(root, y, left, right,
1177 y->max_free >= length && addr >= y->end);
1186 static __always_inline void
1187 vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *rlist)
1189 vm_map_entry_t hi, right, y;
1192 hi = root->right == right ? NULL : root->right;
1196 SPLAY_LEFT_STEP(hi, y, root, right, true);
1201 static __always_inline void
1202 vm_map_splay_findprev(vm_map_entry_t root, vm_map_entry_t *llist)
1204 vm_map_entry_t left, lo, y;
1207 lo = root->left == left ? NULL : root->left;
1211 SPLAY_RIGHT_STEP(lo, y, left, root, true);
1217 vm_map_entry_swap(vm_map_entry_t *a, vm_map_entry_t *b)
1227 * Walk back up the two spines, flip the pointers and set max_free. The
1228 * subtrees of the root go at the bottom of llist and rlist.
1231 vm_map_splay_merge_left_walk(vm_map_entry_t header, vm_map_entry_t root,
1232 vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t llist)
1236 * The max_free values of the children of llist are in
1237 * llist->max_free and max_free. Update with the
1240 llist->max_free = max_free =
1241 vm_size_max(llist->max_free, max_free);
1242 vm_map_entry_swap(&llist->right, &tail);
1243 vm_map_entry_swap(&tail, &llist);
1244 } while (llist != header);
1250 * When llist is known to be the predecessor of root.
1252 static inline vm_size_t
1253 vm_map_splay_merge_pred(vm_map_entry_t header, vm_map_entry_t root,
1254 vm_map_entry_t llist)
1258 max_free = root->start - llist->end;
1259 if (llist != header) {
1260 max_free = vm_map_splay_merge_left_walk(header, root,
1261 root, max_free, llist);
1263 root->left = header;
1264 header->right = root;
1270 * When llist may or may not be the predecessor of root.
1272 static inline vm_size_t
1273 vm_map_splay_merge_left(vm_map_entry_t header, vm_map_entry_t root,
1274 vm_map_entry_t llist)
1278 max_free = vm_map_entry_max_free_left(root, llist);
1279 if (llist != header) {
1280 max_free = vm_map_splay_merge_left_walk(header, root,
1281 root->left == llist ? root : root->left,
1288 vm_map_splay_merge_right_walk(vm_map_entry_t header, vm_map_entry_t root,
1289 vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t rlist)
1293 * The max_free values of the children of rlist are in
1294 * rlist->max_free and max_free. Update with the
1297 rlist->max_free = max_free =
1298 vm_size_max(rlist->max_free, max_free);
1299 vm_map_entry_swap(&rlist->left, &tail);
1300 vm_map_entry_swap(&tail, &rlist);
1301 } while (rlist != header);
1307 * When rlist is known to be the succecessor of root.
1309 static inline vm_size_t
1310 vm_map_splay_merge_succ(vm_map_entry_t header, vm_map_entry_t root,
1311 vm_map_entry_t rlist)
1315 max_free = rlist->start - root->end;
1316 if (rlist != header) {
1317 max_free = vm_map_splay_merge_right_walk(header, root,
1318 root, max_free, rlist);
1320 root->right = header;
1321 header->left = root;
1327 * When rlist may or may not be the succecessor of root.
1329 static inline vm_size_t
1330 vm_map_splay_merge_right(vm_map_entry_t header, vm_map_entry_t root,
1331 vm_map_entry_t rlist)
1335 max_free = vm_map_entry_max_free_right(root, rlist);
1336 if (rlist != header) {
1337 max_free = vm_map_splay_merge_right_walk(header, root,
1338 root->right == rlist ? root : root->right,
1347 * The Sleator and Tarjan top-down splay algorithm with the
1348 * following variation. Max_free must be computed bottom-up, so
1349 * on the downward pass, maintain the left and right spines in
1350 * reverse order. Then, make a second pass up each side to fix
1351 * the pointers and compute max_free. The time bound is O(log n)
1354 * The tree is threaded, which means that there are no null pointers.
1355 * When a node has no left child, its left pointer points to its
1356 * predecessor, which the last ancestor on the search path from the root
1357 * where the search branched right. Likewise, when a node has no right
1358 * child, its right pointer points to its successor. The map header node
1359 * is the predecessor of the first map entry, and the successor of the
1362 * The new root is the vm_map_entry containing "addr", or else an
1363 * adjacent entry (lower if possible) if addr is not in the tree.
1365 * The map must be locked, and leaves it so.
1367 * Returns: the new root.
1369 static vm_map_entry_t
1370 vm_map_splay(vm_map_t map, vm_offset_t addr)
1372 vm_map_entry_t header, llist, rlist, root;
1373 vm_size_t max_free_left, max_free_right;
1375 header = &map->header;
1376 root = vm_map_splay_split(map, addr, 0, &llist, &rlist);
1378 max_free_left = vm_map_splay_merge_left(header, root, llist);
1379 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1380 } else if (llist != header) {
1382 * Recover the greatest node in the left
1383 * subtree and make it the root.
1386 llist = root->right;
1387 max_free_left = vm_map_splay_merge_left(header, root, llist);
1388 max_free_right = vm_map_splay_merge_succ(header, root, rlist);
1389 } else if (rlist != header) {
1391 * Recover the least node in the right
1392 * subtree and make it the root.
1396 max_free_left = vm_map_splay_merge_pred(header, root, llist);
1397 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1399 /* There is no root. */
1402 root->max_free = vm_size_max(max_free_left, max_free_right);
1404 VM_MAP_ASSERT_CONSISTENT(map);
1409 * vm_map_entry_{un,}link:
1411 * Insert/remove entries from maps. On linking, if new entry clips
1412 * existing entry, trim existing entry to avoid overlap, and manage
1413 * offsets. On unlinking, merge disappearing entry with neighbor, if
1414 * called for, and manage offsets. Callers should not modify fields in
1415 * entries already mapped.
1418 vm_map_entry_link(vm_map_t map, vm_map_entry_t entry)
1420 vm_map_entry_t header, llist, rlist, root;
1421 vm_size_t max_free_left, max_free_right;
1424 "vm_map_entry_link: map %p, nentries %d, entry %p", map,
1425 map->nentries, entry);
1426 VM_MAP_ASSERT_LOCKED(map);
1428 header = &map->header;
1429 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
1432 * The new entry does not overlap any existing entry in the
1433 * map, so it becomes the new root of the map tree.
1435 max_free_left = vm_map_splay_merge_pred(header, entry, llist);
1436 max_free_right = vm_map_splay_merge_succ(header, entry, rlist);
1437 } else if (entry->start == root->start) {
1439 * The new entry is a clone of root, with only the end field
1440 * changed. The root entry will be shrunk to abut the new
1441 * entry, and will be the right child of the new root entry in
1444 KASSERT(entry->end < root->end,
1445 ("%s: clip_start not within entry", __func__));
1446 vm_map_splay_findprev(root, &llist);
1447 root->offset += entry->end - root->start;
1448 root->start = entry->end;
1449 max_free_left = vm_map_splay_merge_pred(header, entry, llist);
1450 max_free_right = root->max_free = vm_size_max(
1451 vm_map_splay_merge_pred(entry, root, entry),
1452 vm_map_splay_merge_right(header, root, rlist));
1455 * The new entry is a clone of root, with only the start field
1456 * changed. The root entry will be shrunk to abut the new
1457 * entry, and will be the left child of the new root entry in
1460 KASSERT(entry->end == root->end,
1461 ("%s: clip_start not within entry", __func__));
1462 vm_map_splay_findnext(root, &rlist);
1463 entry->offset += entry->start - root->start;
1464 root->end = entry->start;
1465 max_free_left = root->max_free = vm_size_max(
1466 vm_map_splay_merge_left(header, root, llist),
1467 vm_map_splay_merge_succ(entry, root, entry));
1468 max_free_right = vm_map_splay_merge_succ(header, entry, rlist);
1470 entry->max_free = vm_size_max(max_free_left, max_free_right);
1472 VM_MAP_ASSERT_CONSISTENT(map);
1475 enum unlink_merge_type {
1481 vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry,
1482 enum unlink_merge_type op)
1484 vm_map_entry_t header, llist, rlist, root;
1485 vm_size_t max_free_left, max_free_right;
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,
1491 ("vm_map_entry_unlink: unlink object not mapped"));
1493 vm_map_splay_findprev(root, &llist);
1494 vm_map_splay_findnext(root, &rlist);
1495 if (op == UNLINK_MERGE_NEXT) {
1496 rlist->start = root->start;
1497 rlist->offset = root->offset;
1499 if (llist != header) {
1501 llist = root->right;
1502 max_free_left = vm_map_splay_merge_left(header, root, llist);
1503 max_free_right = vm_map_splay_merge_succ(header, root, rlist);
1504 } else if (rlist != header) {
1507 max_free_left = vm_map_splay_merge_pred(header, root, llist);
1508 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1510 header->left = header->right = header;
1514 root->max_free = vm_size_max(max_free_left, max_free_right);
1516 VM_MAP_ASSERT_CONSISTENT(map);
1518 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map,
1519 map->nentries, entry);
1523 * vm_map_entry_resize:
1525 * Resize a vm_map_entry, recompute the amount of free space that
1526 * follows it and propagate that value up the tree.
1528 * The map must be locked, and leaves it so.
1531 vm_map_entry_resize(vm_map_t map, vm_map_entry_t entry, vm_size_t grow_amount)
1533 vm_map_entry_t header, llist, rlist, root;
1535 VM_MAP_ASSERT_LOCKED(map);
1536 header = &map->header;
1537 root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
1538 KASSERT(root != NULL, ("%s: resize object not mapped", __func__));
1539 vm_map_splay_findnext(root, &rlist);
1540 entry->end += grow_amount;
1541 root->max_free = vm_size_max(
1542 vm_map_splay_merge_left(header, root, llist),
1543 vm_map_splay_merge_succ(header, root, rlist));
1545 VM_MAP_ASSERT_CONSISTENT(map);
1546 CTR4(KTR_VM, "%s: map %p, nentries %d, entry %p",
1547 __func__, map, map->nentries, entry);
1551 * vm_map_lookup_entry: [ internal use only ]
1553 * Finds the map entry containing (or
1554 * immediately preceding) the specified address
1555 * in the given map; the entry is returned
1556 * in the "entry" parameter. The boolean
1557 * result indicates whether the address is
1558 * actually contained in the map.
1561 vm_map_lookup_entry(
1563 vm_offset_t address,
1564 vm_map_entry_t *entry) /* OUT */
1566 vm_map_entry_t cur, header, lbound, ubound;
1570 * If the map is empty, then the map entry immediately preceding
1571 * "address" is the map's header.
1573 header = &map->header;
1579 if (address >= cur->start && cur->end > address) {
1583 if ((locked = vm_map_locked(map)) ||
1584 sx_try_upgrade(&map->lock)) {
1586 * Splay requires a write lock on the map. However, it only
1587 * restructures the binary search tree; it does not otherwise
1588 * change the map. Thus, the map's timestamp need not change
1589 * on a temporary upgrade.
1591 cur = vm_map_splay(map, address);
1593 VM_MAP_UNLOCK_CONSISTENT(map);
1594 sx_downgrade(&map->lock);
1598 * If "address" is contained within a map entry, the new root
1599 * is that map entry. Otherwise, the new root is a map entry
1600 * immediately before or after "address".
1602 if (address < cur->start) {
1607 return (address < cur->end);
1610 * Since the map is only locked for read access, perform a
1611 * standard binary search tree lookup for "address".
1613 lbound = ubound = header;
1615 if (address < cur->start) {
1620 } else if (cur->end <= address) {
1637 * Inserts the given whole VM object into the target
1638 * map at the specified address range. The object's
1639 * size should match that of the address range.
1641 * Requires that the map be locked, and leaves it so.
1643 * If object is non-NULL, ref count must be bumped by caller
1644 * prior to making call to account for the new entry.
1647 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1648 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow)
1650 vm_map_entry_t new_entry, next_entry, prev_entry;
1652 vm_eflags_t protoeflags;
1653 vm_inherit_t inheritance;
1657 VM_MAP_ASSERT_LOCKED(map);
1658 KASSERT(object != kernel_object ||
1659 (cow & MAP_COPY_ON_WRITE) == 0,
1660 ("vm_map_insert: kernel object and COW"));
1661 KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0 ||
1662 (cow & MAP_SPLIT_BOUNDARY_MASK) != 0,
1663 ("vm_map_insert: paradoxical MAP_NOFAULT request, obj %p cow %#x",
1665 KASSERT((prot & ~max) == 0,
1666 ("prot %#x is not subset of max_prot %#x", prot, max));
1669 * Check that the start and end points are not bogus.
1671 if (start == end || !vm_map_range_valid(map, start, end))
1672 return (KERN_INVALID_ADDRESS);
1675 * Find the entry prior to the proposed starting address; if it's part
1676 * of an existing entry, this range is bogus.
1678 if (vm_map_lookup_entry(map, start, &prev_entry))
1679 return (KERN_NO_SPACE);
1682 * Assert that the next entry doesn't overlap the end point.
1684 next_entry = vm_map_entry_succ(prev_entry);
1685 if (next_entry->start < end)
1686 return (KERN_NO_SPACE);
1688 if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL ||
1689 max != VM_PROT_NONE))
1690 return (KERN_INVALID_ARGUMENT);
1693 if (cow & MAP_COPY_ON_WRITE)
1694 protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY;
1695 if (cow & MAP_NOFAULT)
1696 protoeflags |= MAP_ENTRY_NOFAULT;
1697 if (cow & MAP_DISABLE_SYNCER)
1698 protoeflags |= MAP_ENTRY_NOSYNC;
1699 if (cow & MAP_DISABLE_COREDUMP)
1700 protoeflags |= MAP_ENTRY_NOCOREDUMP;
1701 if (cow & MAP_STACK_GROWS_DOWN)
1702 protoeflags |= MAP_ENTRY_GROWS_DOWN;
1703 if (cow & MAP_STACK_GROWS_UP)
1704 protoeflags |= MAP_ENTRY_GROWS_UP;
1705 if (cow & MAP_WRITECOUNT)
1706 protoeflags |= MAP_ENTRY_WRITECNT;
1707 if (cow & MAP_VN_EXEC)
1708 protoeflags |= MAP_ENTRY_VN_EXEC;
1709 if ((cow & MAP_CREATE_GUARD) != 0)
1710 protoeflags |= MAP_ENTRY_GUARD;
1711 if ((cow & MAP_CREATE_STACK_GAP_DN) != 0)
1712 protoeflags |= MAP_ENTRY_STACK_GAP_DN;
1713 if ((cow & MAP_CREATE_STACK_GAP_UP) != 0)
1714 protoeflags |= MAP_ENTRY_STACK_GAP_UP;
1715 if (cow & MAP_INHERIT_SHARE)
1716 inheritance = VM_INHERIT_SHARE;
1718 inheritance = VM_INHERIT_DEFAULT;
1719 if ((cow & MAP_SPLIT_BOUNDARY_MASK) != 0) {
1720 /* This magically ignores index 0, for usual page size. */
1721 bidx = (cow & MAP_SPLIT_BOUNDARY_MASK) >>
1722 MAP_SPLIT_BOUNDARY_SHIFT;
1723 if (bidx >= MAXPAGESIZES)
1724 return (KERN_INVALID_ARGUMENT);
1725 bdry = pagesizes[bidx] - 1;
1726 if ((start & bdry) != 0 || (end & bdry) != 0)
1727 return (KERN_INVALID_ARGUMENT);
1728 protoeflags |= bidx << MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
1732 if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0)
1734 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) &&
1735 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) {
1736 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start))
1737 return (KERN_RESOURCE_SHORTAGE);
1738 KASSERT(object == NULL ||
1739 (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 ||
1740 object->cred == NULL,
1741 ("overcommit: vm_map_insert o %p", object));
1742 cred = curthread->td_ucred;
1746 /* Expand the kernel pmap, if necessary. */
1747 if (map == kernel_map && end > kernel_vm_end)
1748 pmap_growkernel(end);
1749 if (object != NULL) {
1751 * OBJ_ONEMAPPING must be cleared unless this mapping
1752 * is trivially proven to be the only mapping for any
1753 * of the object's pages. (Object granularity
1754 * reference counting is insufficient to recognize
1755 * aliases with precision.)
1757 if ((object->flags & OBJ_ANON) != 0) {
1758 VM_OBJECT_WLOCK(object);
1759 if (object->ref_count > 1 || object->shadow_count != 0)
1760 vm_object_clear_flag(object, OBJ_ONEMAPPING);
1761 VM_OBJECT_WUNLOCK(object);
1763 } else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) ==
1765 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP |
1766 MAP_VN_EXEC)) == 0 &&
1767 prev_entry->end == start && (prev_entry->cred == cred ||
1768 (prev_entry->object.vm_object != NULL &&
1769 prev_entry->object.vm_object->cred == cred)) &&
1770 vm_object_coalesce(prev_entry->object.vm_object,
1772 (vm_size_t)(prev_entry->end - prev_entry->start),
1773 (vm_size_t)(end - prev_entry->end), cred != NULL &&
1774 (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) {
1776 * We were able to extend the object. Determine if we
1777 * can extend the previous map entry to include the
1778 * new range as well.
1780 if (prev_entry->inheritance == inheritance &&
1781 prev_entry->protection == prot &&
1782 prev_entry->max_protection == max &&
1783 prev_entry->wired_count == 0) {
1784 KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) ==
1785 0, ("prev_entry %p has incoherent wiring",
1787 if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0)
1788 map->size += end - prev_entry->end;
1789 vm_map_entry_resize(map, prev_entry,
1790 end - prev_entry->end);
1791 vm_map_try_merge_entries(map, prev_entry, next_entry);
1792 return (KERN_SUCCESS);
1796 * If we can extend the object but cannot extend the
1797 * map entry, we have to create a new map entry. We
1798 * must bump the ref count on the extended object to
1799 * account for it. object may be NULL.
1801 object = prev_entry->object.vm_object;
1802 offset = prev_entry->offset +
1803 (prev_entry->end - prev_entry->start);
1804 vm_object_reference(object);
1805 if (cred != NULL && object != NULL && object->cred != NULL &&
1806 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
1807 /* Object already accounts for this uid. */
1815 * Create a new entry
1817 new_entry = vm_map_entry_create(map);
1818 new_entry->start = start;
1819 new_entry->end = end;
1820 new_entry->cred = NULL;
1822 new_entry->eflags = protoeflags;
1823 new_entry->object.vm_object = object;
1824 new_entry->offset = offset;
1826 new_entry->inheritance = inheritance;
1827 new_entry->protection = prot;
1828 new_entry->max_protection = max;
1829 new_entry->wired_count = 0;
1830 new_entry->wiring_thread = NULL;
1831 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT;
1832 new_entry->next_read = start;
1834 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry),
1835 ("overcommit: vm_map_insert leaks vm_map %p", new_entry));
1836 new_entry->cred = cred;
1839 * Insert the new entry into the list
1841 vm_map_entry_link(map, new_entry);
1842 if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0)
1843 map->size += new_entry->end - new_entry->start;
1846 * Try to coalesce the new entry with both the previous and next
1847 * entries in the list. Previously, we only attempted to coalesce
1848 * with the previous entry when object is NULL. Here, we handle the
1849 * other cases, which are less common.
1851 vm_map_try_merge_entries(map, prev_entry, new_entry);
1852 vm_map_try_merge_entries(map, new_entry, next_entry);
1854 if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) {
1855 vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset),
1856 end - start, cow & MAP_PREFAULT_PARTIAL);
1859 return (KERN_SUCCESS);
1865 * Find the first fit (lowest VM address) for "length" free bytes
1866 * beginning at address >= start in the given map.
1868 * In a vm_map_entry, "max_free" is the maximum amount of
1869 * contiguous free space between an entry in its subtree and a
1870 * neighbor of that entry. This allows finding a free region in
1871 * one path down the tree, so O(log n) amortized with splay
1874 * The map must be locked, and leaves it so.
1876 * Returns: starting address if sufficient space,
1877 * vm_map_max(map)-length+1 if insufficient space.
1880 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length)
1882 vm_map_entry_t header, llist, rlist, root, y;
1883 vm_size_t left_length, max_free_left, max_free_right;
1884 vm_offset_t gap_end;
1886 VM_MAP_ASSERT_LOCKED(map);
1889 * Request must fit within min/max VM address and must avoid
1892 start = MAX(start, vm_map_min(map));
1893 if (start >= vm_map_max(map) || length > vm_map_max(map) - start)
1894 return (vm_map_max(map) - length + 1);
1896 /* Empty tree means wide open address space. */
1897 if (map->root == NULL)
1901 * After splay_split, if start is within an entry, push it to the start
1902 * of the following gap. If rlist is at the end of the gap containing
1903 * start, save the end of that gap in gap_end to see if the gap is big
1904 * enough; otherwise set gap_end to start skip gap-checking and move
1905 * directly to a search of the right subtree.
1907 header = &map->header;
1908 root = vm_map_splay_split(map, start, length, &llist, &rlist);
1909 gap_end = rlist->start;
1912 if (root->right != rlist)
1914 max_free_left = vm_map_splay_merge_left(header, root, llist);
1915 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1916 } else if (rlist != header) {
1919 max_free_left = vm_map_splay_merge_pred(header, root, llist);
1920 max_free_right = vm_map_splay_merge_right(header, root, rlist);
1923 llist = root->right;
1924 max_free_left = vm_map_splay_merge_left(header, root, llist);
1925 max_free_right = vm_map_splay_merge_succ(header, root, rlist);
1927 root->max_free = vm_size_max(max_free_left, max_free_right);
1929 VM_MAP_ASSERT_CONSISTENT(map);
1930 if (length <= gap_end - start)
1933 /* With max_free, can immediately tell if no solution. */
1934 if (root->right == header || length > root->right->max_free)
1935 return (vm_map_max(map) - length + 1);
1938 * Splay for the least large-enough gap in the right subtree.
1940 llist = rlist = header;
1941 for (left_length = 0;;
1942 left_length = vm_map_entry_max_free_left(root, llist)) {
1943 if (length <= left_length)
1944 SPLAY_LEFT_STEP(root, y, llist, rlist,
1945 length <= vm_map_entry_max_free_left(y, llist));
1947 SPLAY_RIGHT_STEP(root, y, llist, rlist,
1948 length > vm_map_entry_max_free_left(y, root));
1953 llist = root->right;
1954 max_free_left = vm_map_splay_merge_left(header, root, llist);
1955 if (rlist == header) {
1956 root->max_free = vm_size_max(max_free_left,
1957 vm_map_splay_merge_succ(header, root, rlist));
1961 y->max_free = vm_size_max(
1962 vm_map_splay_merge_pred(root, y, root),
1963 vm_map_splay_merge_right(header, y, rlist));
1964 root->max_free = vm_size_max(max_free_left, y->max_free);
1967 VM_MAP_ASSERT_CONSISTENT(map);
1972 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1973 vm_offset_t start, vm_size_t length, vm_prot_t prot,
1974 vm_prot_t max, int cow)
1979 end = start + length;
1980 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
1982 ("vm_map_fixed: non-NULL backing object for stack"));
1984 VM_MAP_RANGE_CHECK(map, start, end);
1985 if ((cow & MAP_CHECK_EXCL) == 0) {
1986 result = vm_map_delete(map, start, end);
1987 if (result != KERN_SUCCESS)
1990 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
1991 result = vm_map_stack_locked(map, start, length, sgrowsiz,
1994 result = vm_map_insert(map, object, offset, start, end,
2002 static const int aslr_pages_rnd_64[2] = {0x1000, 0x10};
2003 static const int aslr_pages_rnd_32[2] = {0x100, 0x4};
2005 static int cluster_anon = 1;
2006 SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW,
2008 "Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always");
2011 clustering_anon_allowed(vm_offset_t addr)
2014 switch (cluster_anon) {
2025 static long aslr_restarts;
2026 SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD,
2028 "Number of aslr failures");
2031 * Searches for the specified amount of free space in the given map with the
2032 * specified alignment. Performs an address-ordered, first-fit search from
2033 * the given address "*addr", with an optional upper bound "max_addr". If the
2034 * parameter "alignment" is zero, then the alignment is computed from the
2035 * given (object, offset) pair so as to enable the greatest possible use of
2036 * superpage mappings. Returns KERN_SUCCESS and the address of the free space
2037 * in "*addr" if successful. Otherwise, returns KERN_NO_SPACE.
2039 * The map must be locked. Initially, there must be at least "length" bytes
2040 * of free space at the given address.
2043 vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2044 vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr,
2045 vm_offset_t alignment)
2047 vm_offset_t aligned_addr, free_addr;
2049 VM_MAP_ASSERT_LOCKED(map);
2051 KASSERT(free_addr == vm_map_findspace(map, free_addr, length),
2052 ("caller failed to provide space %#jx at address %p",
2053 (uintmax_t)length, (void *)free_addr));
2056 * At the start of every iteration, the free space at address
2057 * "*addr" is at least "length" bytes.
2060 pmap_align_superpage(object, offset, addr, length);
2061 else if ((*addr & (alignment - 1)) != 0) {
2062 *addr &= ~(alignment - 1);
2065 aligned_addr = *addr;
2066 if (aligned_addr == free_addr) {
2068 * Alignment did not change "*addr", so "*addr" must
2069 * still provide sufficient free space.
2071 return (KERN_SUCCESS);
2075 * Test for address wrap on "*addr". A wrapped "*addr" could
2076 * be a valid address, in which case vm_map_findspace() cannot
2077 * be relied upon to fail.
2079 if (aligned_addr < free_addr)
2080 return (KERN_NO_SPACE);
2081 *addr = vm_map_findspace(map, aligned_addr, length);
2082 if (*addr + length > vm_map_max(map) ||
2083 (max_addr != 0 && *addr + length > max_addr))
2084 return (KERN_NO_SPACE);
2086 if (free_addr == aligned_addr) {
2088 * If a successful call to vm_map_findspace() did not
2089 * change "*addr", then "*addr" must still be aligned
2090 * and provide sufficient free space.
2092 return (KERN_SUCCESS);
2098 vm_map_find_aligned(vm_map_t map, vm_offset_t *addr, vm_size_t length,
2099 vm_offset_t max_addr, vm_offset_t alignment)
2101 /* XXXKIB ASLR eh ? */
2102 *addr = vm_map_findspace(map, *addr, length);
2103 if (*addr + length > vm_map_max(map) ||
2104 (max_addr != 0 && *addr + length > max_addr))
2105 return (KERN_NO_SPACE);
2106 return (vm_map_alignspace(map, NULL, 0, addr, length, max_addr,
2111 * vm_map_find finds an unallocated region in the target address
2112 * map with the given length. The search is defined to be
2113 * first-fit from the specified address; the region found is
2114 * returned in the same parameter.
2116 * If object is non-NULL, ref count must be bumped by caller
2117 * prior to making call to account for the new entry.
2120 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2121 vm_offset_t *addr, /* IN/OUT */
2122 vm_size_t length, vm_offset_t max_addr, int find_space,
2123 vm_prot_t prot, vm_prot_t max, int cow)
2125 vm_offset_t alignment, curr_min_addr, min_addr;
2126 int gap, pidx, rv, try;
2127 bool cluster, en_aslr, update_anon;
2129 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
2131 ("vm_map_find: non-NULL backing object for stack"));
2132 MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE &&
2133 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0));
2134 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL ||
2135 (object->flags & OBJ_COLORED) == 0))
2136 find_space = VMFS_ANY_SPACE;
2137 if (find_space >> 8 != 0) {
2138 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags"));
2139 alignment = (vm_offset_t)1 << (find_space >> 8);
2142 en_aslr = (map->flags & MAP_ASLR) != 0;
2143 update_anon = cluster = clustering_anon_allowed(*addr) &&
2144 (map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 &&
2145 find_space != VMFS_NO_SPACE && object == NULL &&
2146 (cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP |
2147 MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE;
2148 curr_min_addr = min_addr = *addr;
2149 if (en_aslr && min_addr == 0 && !cluster &&
2150 find_space != VMFS_NO_SPACE &&
2151 (map->flags & MAP_ASLR_IGNSTART) != 0)
2152 curr_min_addr = min_addr = vm_map_min(map);
2156 curr_min_addr = map->anon_loc;
2157 if (curr_min_addr == 0)
2160 if (find_space != VMFS_NO_SPACE) {
2161 KASSERT(find_space == VMFS_ANY_SPACE ||
2162 find_space == VMFS_OPTIMAL_SPACE ||
2163 find_space == VMFS_SUPER_SPACE ||
2164 alignment != 0, ("unexpected VMFS flag"));
2167 * When creating an anonymous mapping, try clustering
2168 * with an existing anonymous mapping first.
2170 * We make up to two attempts to find address space
2171 * for a given find_space value. The first attempt may
2172 * apply randomization or may cluster with an existing
2173 * anonymous mapping. If this first attempt fails,
2174 * perform a first-fit search of the available address
2177 * If all tries failed, and find_space is
2178 * VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE.
2179 * Again enable clustering and randomization.
2186 * Second try: we failed either to find a
2187 * suitable region for randomizing the
2188 * allocation, or to cluster with an existing
2189 * mapping. Retry with free run.
2191 curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ?
2192 vm_map_min(map) : min_addr;
2193 atomic_add_long(&aslr_restarts, 1);
2196 if (try == 1 && en_aslr && !cluster) {
2198 * Find space for allocation, including
2199 * gap needed for later randomization.
2201 pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 &&
2202 (find_space == VMFS_SUPER_SPACE || find_space ==
2203 VMFS_OPTIMAL_SPACE) ? 1 : 0;
2204 gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR &&
2205 (max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ?
2206 aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx];
2207 *addr = vm_map_findspace(map, curr_min_addr,
2208 length + gap * pagesizes[pidx]);
2209 if (*addr + length + gap * pagesizes[pidx] >
2212 /* And randomize the start address. */
2213 *addr += (arc4random() % gap) * pagesizes[pidx];
2214 if (max_addr != 0 && *addr + length > max_addr)
2217 *addr = vm_map_findspace(map, curr_min_addr, length);
2218 if (*addr + length > vm_map_max(map) ||
2219 (max_addr != 0 && *addr + length > max_addr)) {
2230 if (find_space != VMFS_ANY_SPACE &&
2231 (rv = vm_map_alignspace(map, object, offset, addr, length,
2232 max_addr, alignment)) != KERN_SUCCESS) {
2233 if (find_space == VMFS_OPTIMAL_SPACE) {
2234 find_space = VMFS_ANY_SPACE;
2235 curr_min_addr = min_addr;
2236 cluster = update_anon;
2242 } else if ((cow & MAP_REMAP) != 0) {
2243 if (!vm_map_range_valid(map, *addr, *addr + length)) {
2244 rv = KERN_INVALID_ADDRESS;
2247 rv = vm_map_delete(map, *addr, *addr + length);
2248 if (rv != KERN_SUCCESS)
2251 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
2252 rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot,
2255 rv = vm_map_insert(map, object, offset, *addr, *addr + length,
2258 if (rv == KERN_SUCCESS && update_anon)
2259 map->anon_loc = *addr + length;
2266 * vm_map_find_min() is a variant of vm_map_find() that takes an
2267 * additional parameter (min_addr) and treats the given address
2268 * (*addr) differently. Specifically, it treats *addr as a hint
2269 * and not as the minimum address where the mapping is created.
2271 * This function works in two phases. First, it tries to
2272 * allocate above the hint. If that fails and the hint is
2273 * greater than min_addr, it performs a second pass, replacing
2274 * the hint with min_addr as the minimum address for the
2278 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2279 vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr,
2280 vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max,
2288 rv = vm_map_find(map, object, offset, addr, length, max_addr,
2289 find_space, prot, max, cow);
2290 if (rv == KERN_SUCCESS || min_addr >= hint)
2292 *addr = hint = min_addr;
2297 * A map entry with any of the following flags set must not be merged with
2300 #define MAP_ENTRY_NOMERGE_MASK (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \
2301 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_VN_EXEC)
2304 vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry)
2307 KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 ||
2308 (entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0,
2309 ("vm_map_mergeable_neighbors: neither %p nor %p are mergeable",
2311 return (prev->end == entry->start &&
2312 prev->object.vm_object == entry->object.vm_object &&
2313 (prev->object.vm_object == NULL ||
2314 prev->offset + (prev->end - prev->start) == entry->offset) &&
2315 prev->eflags == entry->eflags &&
2316 prev->protection == entry->protection &&
2317 prev->max_protection == entry->max_protection &&
2318 prev->inheritance == entry->inheritance &&
2319 prev->wired_count == entry->wired_count &&
2320 prev->cred == entry->cred);
2324 vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry)
2328 * If the backing object is a vnode object, vm_object_deallocate()
2329 * calls vrele(). However, vrele() does not lock the vnode because
2330 * the vnode has additional references. Thus, the map lock can be
2331 * kept without causing a lock-order reversal with the vnode lock.
2333 * Since we count the number of virtual page mappings in
2334 * object->un_pager.vnp.writemappings, the writemappings value
2335 * should not be adjusted when the entry is disposed of.
2337 if (entry->object.vm_object != NULL)
2338 vm_object_deallocate(entry->object.vm_object);
2339 if (entry->cred != NULL)
2340 crfree(entry->cred);
2341 vm_map_entry_dispose(map, entry);
2345 * vm_map_try_merge_entries:
2347 * Compare the given map entry to its predecessor, and merge its precessor
2348 * into it if possible. The entry remains valid, and may be extended.
2349 * The predecessor may be deleted.
2351 * The map must be locked.
2354 vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev_entry,
2355 vm_map_entry_t entry)
2358 VM_MAP_ASSERT_LOCKED(map);
2359 if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 &&
2360 vm_map_mergeable_neighbors(prev_entry, entry)) {
2361 vm_map_entry_unlink(map, prev_entry, UNLINK_MERGE_NEXT);
2362 vm_map_merged_neighbor_dispose(map, prev_entry);
2367 * vm_map_entry_back:
2369 * Allocate an object to back a map entry.
2372 vm_map_entry_back(vm_map_entry_t entry)
2376 KASSERT(entry->object.vm_object == NULL,
2377 ("map entry %p has backing object", entry));
2378 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
2379 ("map entry %p is a submap", entry));
2380 object = vm_object_allocate_anon(atop(entry->end - entry->start), NULL,
2381 entry->cred, entry->end - entry->start);
2382 entry->object.vm_object = object;
2388 * vm_map_entry_charge_object
2390 * If there is no object backing this entry, create one. Otherwise, if
2391 * the entry has cred, give it to the backing object.
2394 vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry)
2397 VM_MAP_ASSERT_LOCKED(map);
2398 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
2399 ("map entry %p is a submap", entry));
2400 if (entry->object.vm_object == NULL && !map->system_map &&
2401 (entry->eflags & MAP_ENTRY_GUARD) == 0)
2402 vm_map_entry_back(entry);
2403 else if (entry->object.vm_object != NULL &&
2404 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
2405 entry->cred != NULL) {
2406 VM_OBJECT_WLOCK(entry->object.vm_object);
2407 KASSERT(entry->object.vm_object->cred == NULL,
2408 ("OVERCOMMIT: %s: both cred e %p", __func__, entry));
2409 entry->object.vm_object->cred = entry->cred;
2410 entry->object.vm_object->charge = entry->end - entry->start;
2411 VM_OBJECT_WUNLOCK(entry->object.vm_object);
2417 * vm_map_entry_clone
2419 * Create a duplicate map entry for clipping.
2421 static vm_map_entry_t
2422 vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry)
2424 vm_map_entry_t new_entry;
2426 VM_MAP_ASSERT_LOCKED(map);
2429 * Create a backing object now, if none exists, so that more individual
2430 * objects won't be created after the map entry is split.
2432 vm_map_entry_charge_object(map, entry);
2434 /* Clone the entry. */
2435 new_entry = vm_map_entry_create(map);
2436 *new_entry = *entry;
2437 if (new_entry->cred != NULL)
2438 crhold(entry->cred);
2439 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
2440 vm_object_reference(new_entry->object.vm_object);
2441 vm_map_entry_set_vnode_text(new_entry, true);
2443 * The object->un_pager.vnp.writemappings for the object of
2444 * MAP_ENTRY_WRITECNT type entry shall be kept as is here. The
2445 * virtual pages are re-distributed among the clipped entries,
2446 * so the sum is left the same.
2453 * vm_map_clip_start: [ internal use only ]
2455 * Asserts that the given entry begins at or after
2456 * the specified address; if necessary,
2457 * it splits the entry into two.
2460 vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t startaddr)
2462 vm_map_entry_t new_entry;
2465 if (!map->system_map)
2466 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2467 "%s: map %p entry %p start 0x%jx", __func__, map, entry,
2468 (uintmax_t)startaddr);
2470 if (startaddr <= entry->start)
2471 return (KERN_SUCCESS);
2473 VM_MAP_ASSERT_LOCKED(map);
2474 KASSERT(entry->end > startaddr && entry->start < startaddr,
2475 ("%s: invalid clip of entry %p", __func__, entry));
2477 bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
2478 MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
2479 if (bdry_idx != 0) {
2480 if ((startaddr & (pagesizes[bdry_idx] - 1)) != 0)
2481 return (KERN_INVALID_ARGUMENT);
2484 new_entry = vm_map_entry_clone(map, entry);
2487 * Split off the front portion. Insert the new entry BEFORE this one,
2488 * so that this entry has the specified starting address.
2490 new_entry->end = startaddr;
2491 vm_map_entry_link(map, new_entry);
2492 return (KERN_SUCCESS);
2496 * vm_map_lookup_clip_start:
2498 * Find the entry at or just after 'start', and clip it if 'start' is in
2499 * the interior of the entry. Return entry after 'start', and in
2500 * prev_entry set the entry before 'start'.
2503 vm_map_lookup_clip_start(vm_map_t map, vm_offset_t start,
2504 vm_map_entry_t *res_entry, vm_map_entry_t *prev_entry)
2506 vm_map_entry_t entry;
2509 if (!map->system_map)
2510 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2511 "%s: map %p start 0x%jx prev %p", __func__, map,
2512 (uintmax_t)start, prev_entry);
2514 if (vm_map_lookup_entry(map, start, prev_entry)) {
2515 entry = *prev_entry;
2516 rv = vm_map_clip_start(map, entry, start);
2517 if (rv != KERN_SUCCESS)
2519 *prev_entry = vm_map_entry_pred(entry);
2521 entry = vm_map_entry_succ(*prev_entry);
2523 return (KERN_SUCCESS);
2527 * vm_map_clip_end: [ internal use only ]
2529 * Asserts that the given entry ends at or before
2530 * the specified address; if necessary,
2531 * it splits the entry into two.
2534 vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t endaddr)
2536 vm_map_entry_t new_entry;
2539 if (!map->system_map)
2540 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2541 "%s: map %p entry %p end 0x%jx", __func__, map, entry,
2542 (uintmax_t)endaddr);
2544 if (endaddr >= entry->end)
2545 return (KERN_SUCCESS);
2547 VM_MAP_ASSERT_LOCKED(map);
2548 KASSERT(entry->start < endaddr && entry->end > endaddr,
2549 ("%s: invalid clip of entry %p", __func__, entry));
2551 bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
2552 MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
2553 if (bdry_idx != 0) {
2554 if ((endaddr & (pagesizes[bdry_idx] - 1)) != 0)
2555 return (KERN_INVALID_ARGUMENT);
2558 new_entry = vm_map_entry_clone(map, entry);
2561 * Split off the back portion. Insert the new entry AFTER this one,
2562 * so that this entry has the specified ending address.
2564 new_entry->start = endaddr;
2565 vm_map_entry_link(map, new_entry);
2567 return (KERN_SUCCESS);
2571 * vm_map_submap: [ kernel use only ]
2573 * Mark the given range as handled by a subordinate map.
2575 * This range must have been created with vm_map_find,
2576 * and no other operations may have been performed on this
2577 * range prior to calling vm_map_submap.
2579 * Only a limited number of operations can be performed
2580 * within this rage after calling vm_map_submap:
2582 * [Don't try vm_map_copy!]
2584 * To remove a submapping, one must first remove the
2585 * range from the superior map, and then destroy the
2586 * submap (if desired). [Better yet, don't try it.]
2595 vm_map_entry_t entry;
2598 result = KERN_INVALID_ARGUMENT;
2600 vm_map_lock(submap);
2601 submap->flags |= MAP_IS_SUB_MAP;
2602 vm_map_unlock(submap);
2605 VM_MAP_RANGE_CHECK(map, start, end);
2606 if (vm_map_lookup_entry(map, start, &entry) && entry->end >= end &&
2607 (entry->eflags & MAP_ENTRY_COW) == 0 &&
2608 entry->object.vm_object == NULL) {
2609 result = vm_map_clip_start(map, entry, start);
2610 if (result != KERN_SUCCESS)
2612 result = vm_map_clip_end(map, entry, end);
2613 if (result != KERN_SUCCESS)
2615 entry->object.sub_map = submap;
2616 entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
2617 result = KERN_SUCCESS;
2622 if (result != KERN_SUCCESS) {
2623 vm_map_lock(submap);
2624 submap->flags &= ~MAP_IS_SUB_MAP;
2625 vm_map_unlock(submap);
2631 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified
2633 #define MAX_INIT_PT 96
2636 * vm_map_pmap_enter:
2638 * Preload the specified map's pmap with mappings to the specified
2639 * object's memory-resident pages. No further physical pages are
2640 * allocated, and no further virtual pages are retrieved from secondary
2641 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a
2642 * limited number of page mappings are created at the low-end of the
2643 * specified address range. (For this purpose, a superpage mapping
2644 * counts as one page mapping.) Otherwise, all resident pages within
2645 * the specified address range are mapped.
2648 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
2649 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags)
2652 vm_page_t p, p_start;
2653 vm_pindex_t mask, psize, threshold, tmpidx;
2655 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL)
2657 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2658 VM_OBJECT_WLOCK(object);
2659 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2660 pmap_object_init_pt(map->pmap, addr, object, pindex,
2662 VM_OBJECT_WUNLOCK(object);
2665 VM_OBJECT_LOCK_DOWNGRADE(object);
2667 VM_OBJECT_RLOCK(object);
2670 if (psize + pindex > object->size) {
2671 if (pindex >= object->size) {
2672 VM_OBJECT_RUNLOCK(object);
2675 psize = object->size - pindex;
2680 threshold = MAX_INIT_PT;
2682 p = vm_page_find_least(object, pindex);
2684 * Assert: the variable p is either (1) the page with the
2685 * least pindex greater than or equal to the parameter pindex
2689 p != NULL && (tmpidx = p->pindex - pindex) < psize;
2690 p = TAILQ_NEXT(p, listq)) {
2692 * don't allow an madvise to blow away our really
2693 * free pages allocating pv entries.
2695 if (((flags & MAP_PREFAULT_MADVISE) != 0 &&
2696 vm_page_count_severe()) ||
2697 ((flags & MAP_PREFAULT_PARTIAL) != 0 &&
2698 tmpidx >= threshold)) {
2702 if (vm_page_all_valid(p)) {
2703 if (p_start == NULL) {
2704 start = addr + ptoa(tmpidx);
2707 /* Jump ahead if a superpage mapping is possible. */
2708 if (p->psind > 0 && ((addr + ptoa(tmpidx)) &
2709 (pagesizes[p->psind] - 1)) == 0) {
2710 mask = atop(pagesizes[p->psind]) - 1;
2711 if (tmpidx + mask < psize &&
2712 vm_page_ps_test(p, PS_ALL_VALID, NULL)) {
2717 } else if (p_start != NULL) {
2718 pmap_enter_object(map->pmap, start, addr +
2719 ptoa(tmpidx), p_start, prot);
2723 if (p_start != NULL)
2724 pmap_enter_object(map->pmap, start, addr + ptoa(psize),
2726 VM_OBJECT_RUNLOCK(object);
2732 * Sets the protection of the specified address
2733 * region in the target map. If "set_max" is
2734 * specified, the maximum protection is to be set;
2735 * otherwise, only the current protection is affected.
2738 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
2739 vm_prot_t new_prot, boolean_t set_max)
2741 vm_map_entry_t entry, first_entry, in_tran, prev_entry;
2748 return (KERN_SUCCESS);
2755 * Ensure that we are not concurrently wiring pages. vm_map_wire() may
2756 * need to fault pages into the map and will drop the map lock while
2757 * doing so, and the VM object may end up in an inconsistent state if we
2758 * update the protection on the map entry in between faults.
2760 vm_map_wait_busy(map);
2762 VM_MAP_RANGE_CHECK(map, start, end);
2764 if (!vm_map_lookup_entry(map, start, &first_entry))
2765 first_entry = vm_map_entry_succ(first_entry);
2768 * Make a first pass to check for protection violations.
2770 for (entry = first_entry; entry->start < end;
2771 entry = vm_map_entry_succ(entry)) {
2772 if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
2774 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
2776 return (KERN_INVALID_ARGUMENT);
2778 if ((new_prot & entry->max_protection) != new_prot) {
2780 return (KERN_PROTECTION_FAILURE);
2782 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0)
2787 * Postpone the operation until all in-transition map entries have
2788 * stabilized. An in-transition entry might already have its pages
2789 * wired and wired_count incremented, but not yet have its
2790 * MAP_ENTRY_USER_WIRED flag set. In which case, we would fail to call
2791 * vm_fault_copy_entry() in the final loop below.
2793 if (in_tran != NULL) {
2794 in_tran->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2795 vm_map_unlock_and_wait(map, 0);
2800 * Before changing the protections, try to reserve swap space for any
2801 * private (i.e., copy-on-write) mappings that are transitioning from
2802 * read-only to read/write access. If a reservation fails, break out
2803 * of this loop early and let the next loop simplify the entries, since
2804 * some may now be mergeable.
2806 rv = vm_map_clip_start(map, first_entry, start);
2807 if (rv != KERN_SUCCESS) {
2811 for (entry = first_entry; entry->start < end;
2812 entry = vm_map_entry_succ(entry)) {
2813 rv = vm_map_clip_end(map, entry, end);
2814 if (rv != KERN_SUCCESS) {
2820 ((new_prot & ~entry->protection) & VM_PROT_WRITE) == 0 ||
2821 ENTRY_CHARGED(entry) ||
2822 (entry->eflags & MAP_ENTRY_GUARD) != 0) {
2826 cred = curthread->td_ucred;
2827 obj = entry->object.vm_object;
2830 (entry->eflags & MAP_ENTRY_NEEDS_COPY) != 0) {
2831 if (!swap_reserve(entry->end - entry->start)) {
2832 rv = KERN_RESOURCE_SHORTAGE;
2841 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP)
2843 VM_OBJECT_WLOCK(obj);
2844 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) {
2845 VM_OBJECT_WUNLOCK(obj);
2850 * Charge for the whole object allocation now, since
2851 * we cannot distinguish between non-charged and
2852 * charged clipped mapping of the same object later.
2854 KASSERT(obj->charge == 0,
2855 ("vm_map_protect: object %p overcharged (entry %p)",
2857 if (!swap_reserve(ptoa(obj->size))) {
2858 VM_OBJECT_WUNLOCK(obj);
2859 rv = KERN_RESOURCE_SHORTAGE;
2866 obj->charge = ptoa(obj->size);
2867 VM_OBJECT_WUNLOCK(obj);
2871 * If enough swap space was available, go back and fix up protections.
2872 * Otherwise, just simplify entries, since some may have been modified.
2873 * [Note that clipping is not necessary the second time.]
2875 for (prev_entry = vm_map_entry_pred(first_entry), entry = first_entry;
2877 vm_map_try_merge_entries(map, prev_entry, entry),
2878 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
2879 if (rv != KERN_SUCCESS ||
2880 (entry->eflags & MAP_ENTRY_GUARD) != 0)
2883 old_prot = entry->protection;
2887 (entry->max_protection = new_prot) &
2890 entry->protection = new_prot;
2893 * For user wired map entries, the normal lazy evaluation of
2894 * write access upgrades through soft page faults is
2895 * undesirable. Instead, immediately copy any pages that are
2896 * copy-on-write and enable write access in the physical map.
2898 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0 &&
2899 (entry->protection & VM_PROT_WRITE) != 0 &&
2900 (old_prot & VM_PROT_WRITE) == 0)
2901 vm_fault_copy_entry(map, map, entry, entry, NULL);
2904 * When restricting access, update the physical map. Worry
2905 * about copy-on-write here.
2907 if ((old_prot & ~entry->protection) != 0) {
2908 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
2910 pmap_protect(map->pmap, entry->start,
2912 entry->protection & MASK(entry));
2916 vm_map_try_merge_entries(map, prev_entry, entry);
2924 * This routine traverses a processes map handling the madvise
2925 * system call. Advisories are classified as either those effecting
2926 * the vm_map_entry structure, or those effecting the underlying
2936 vm_map_entry_t entry, prev_entry;
2941 * Some madvise calls directly modify the vm_map_entry, in which case
2942 * we need to use an exclusive lock on the map and we need to perform
2943 * various clipping operations. Otherwise we only need a read-lock
2948 case MADV_SEQUENTIAL:
2965 vm_map_lock_read(map);
2972 * Locate starting entry and clip if necessary.
2974 VM_MAP_RANGE_CHECK(map, start, end);
2978 * madvise behaviors that are implemented in the vm_map_entry.
2980 * We clip the vm_map_entry so that behavioral changes are
2981 * limited to the specified address range.
2983 rv = vm_map_lookup_clip_start(map, start, &entry, &prev_entry);
2984 if (rv != KERN_SUCCESS) {
2986 return (vm_mmap_to_errno(rv));
2989 for (; entry->start < end; prev_entry = entry,
2990 entry = vm_map_entry_succ(entry)) {
2991 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
2994 rv = vm_map_clip_end(map, entry, end);
2995 if (rv != KERN_SUCCESS) {
2997 return (vm_mmap_to_errno(rv));
3002 vm_map_entry_set_behavior(entry,
3003 MAP_ENTRY_BEHAV_NORMAL);
3005 case MADV_SEQUENTIAL:
3006 vm_map_entry_set_behavior(entry,
3007 MAP_ENTRY_BEHAV_SEQUENTIAL);
3010 vm_map_entry_set_behavior(entry,
3011 MAP_ENTRY_BEHAV_RANDOM);
3014 entry->eflags |= MAP_ENTRY_NOSYNC;
3017 entry->eflags &= ~MAP_ENTRY_NOSYNC;
3020 entry->eflags |= MAP_ENTRY_NOCOREDUMP;
3023 entry->eflags &= ~MAP_ENTRY_NOCOREDUMP;
3028 vm_map_try_merge_entries(map, prev_entry, entry);
3030 vm_map_try_merge_entries(map, prev_entry, entry);
3033 vm_pindex_t pstart, pend;
3036 * madvise behaviors that are implemented in the underlying
3039 * Since we don't clip the vm_map_entry, we have to clip
3040 * the vm_object pindex and count.
3042 if (!vm_map_lookup_entry(map, start, &entry))
3043 entry = vm_map_entry_succ(entry);
3044 for (; entry->start < end;
3045 entry = vm_map_entry_succ(entry)) {
3046 vm_offset_t useEnd, useStart;
3048 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
3052 * MADV_FREE would otherwise rewind time to
3053 * the creation of the shadow object. Because
3054 * we hold the VM map read-locked, neither the
3055 * entry's object nor the presence of a
3056 * backing object can change.
3058 if (behav == MADV_FREE &&
3059 entry->object.vm_object != NULL &&
3060 entry->object.vm_object->backing_object != NULL)
3063 pstart = OFF_TO_IDX(entry->offset);
3064 pend = pstart + atop(entry->end - entry->start);
3065 useStart = entry->start;
3066 useEnd = entry->end;
3068 if (entry->start < start) {
3069 pstart += atop(start - entry->start);
3072 if (entry->end > end) {
3073 pend -= atop(entry->end - end);
3081 * Perform the pmap_advise() before clearing
3082 * PGA_REFERENCED in vm_page_advise(). Otherwise, a
3083 * concurrent pmap operation, such as pmap_remove(),
3084 * could clear a reference in the pmap and set
3085 * PGA_REFERENCED on the page before the pmap_advise()
3086 * had completed. Consequently, the page would appear
3087 * referenced based upon an old reference that
3088 * occurred before this pmap_advise() ran.
3090 if (behav == MADV_DONTNEED || behav == MADV_FREE)
3091 pmap_advise(map->pmap, useStart, useEnd,
3094 vm_object_madvise(entry->object.vm_object, pstart,
3098 * Pre-populate paging structures in the
3099 * WILLNEED case. For wired entries, the
3100 * paging structures are already populated.
3102 if (behav == MADV_WILLNEED &&
3103 entry->wired_count == 0) {
3104 vm_map_pmap_enter(map,
3107 entry->object.vm_object,
3109 ptoa(pend - pstart),
3110 MAP_PREFAULT_MADVISE
3114 vm_map_unlock_read(map);
3122 * Sets the inheritance of the specified address
3123 * range in the target map. Inheritance
3124 * affects how the map will be shared with
3125 * child maps at the time of vmspace_fork.
3128 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
3129 vm_inherit_t new_inheritance)
3131 vm_map_entry_t entry, lentry, prev_entry, start_entry;
3134 switch (new_inheritance) {
3135 case VM_INHERIT_NONE:
3136 case VM_INHERIT_COPY:
3137 case VM_INHERIT_SHARE:
3138 case VM_INHERIT_ZERO:
3141 return (KERN_INVALID_ARGUMENT);
3144 return (KERN_SUCCESS);
3146 VM_MAP_RANGE_CHECK(map, start, end);
3147 rv = vm_map_lookup_clip_start(map, start, &start_entry, &prev_entry);
3148 if (rv != KERN_SUCCESS)
3150 if (vm_map_lookup_entry(map, end - 1, &lentry)) {
3151 rv = vm_map_clip_end(map, lentry, end);
3152 if (rv != KERN_SUCCESS)
3155 if (new_inheritance == VM_INHERIT_COPY) {
3156 for (entry = start_entry; entry->start < end;
3157 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3158 if ((entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK)
3160 rv = KERN_INVALID_ARGUMENT;
3165 for (entry = start_entry; entry->start < end; prev_entry = entry,
3166 entry = vm_map_entry_succ(entry)) {
3167 KASSERT(entry->end <= end, ("non-clipped entry %p end %jx %jx",
3168 entry, (uintmax_t)entry->end, (uintmax_t)end));
3169 if ((entry->eflags & MAP_ENTRY_GUARD) == 0 ||
3170 new_inheritance != VM_INHERIT_ZERO)
3171 entry->inheritance = new_inheritance;
3172 vm_map_try_merge_entries(map, prev_entry, entry);
3174 vm_map_try_merge_entries(map, prev_entry, entry);
3181 * vm_map_entry_in_transition:
3183 * Release the map lock, and sleep until the entry is no longer in
3184 * transition. Awake and acquire the map lock. If the map changed while
3185 * another held the lock, lookup a possibly-changed entry at or after the
3186 * 'start' position of the old entry.
3188 static vm_map_entry_t
3189 vm_map_entry_in_transition(vm_map_t map, vm_offset_t in_start,
3190 vm_offset_t *io_end, bool holes_ok, vm_map_entry_t in_entry)
3192 vm_map_entry_t entry;
3194 u_int last_timestamp;
3196 VM_MAP_ASSERT_LOCKED(map);
3197 KASSERT((in_entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3198 ("not in-tranition map entry %p", in_entry));
3200 * We have not yet clipped the entry.
3202 start = MAX(in_start, in_entry->start);
3203 in_entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
3204 last_timestamp = map->timestamp;
3205 if (vm_map_unlock_and_wait(map, 0)) {
3207 * Allow interruption of user wiring/unwiring?
3211 if (last_timestamp + 1 == map->timestamp)
3215 * Look again for the entry because the map was modified while it was
3216 * unlocked. Specifically, the entry may have been clipped, merged, or
3219 if (!vm_map_lookup_entry(map, start, &entry)) {
3224 entry = vm_map_entry_succ(entry);
3232 * Implements both kernel and user unwiring.
3235 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
3238 vm_map_entry_t entry, first_entry, next_entry, prev_entry;
3240 bool holes_ok, need_wakeup, user_unwire;
3243 return (KERN_SUCCESS);
3244 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
3245 user_unwire = (flags & VM_MAP_WIRE_USER) != 0;
3247 VM_MAP_RANGE_CHECK(map, start, end);
3248 if (!vm_map_lookup_entry(map, start, &first_entry)) {
3250 first_entry = vm_map_entry_succ(first_entry);
3253 return (KERN_INVALID_ADDRESS);
3257 for (entry = first_entry; entry->start < end; entry = next_entry) {
3258 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
3260 * We have not yet clipped the entry.
3262 next_entry = vm_map_entry_in_transition(map, start,
3263 &end, holes_ok, entry);
3264 if (next_entry == NULL) {
3265 if (entry == first_entry) {
3267 return (KERN_INVALID_ADDRESS);
3269 rv = KERN_INVALID_ADDRESS;
3272 first_entry = (entry == first_entry) ?
3276 rv = vm_map_clip_start(map, entry, start);
3277 if (rv != KERN_SUCCESS)
3279 rv = vm_map_clip_end(map, entry, end);
3280 if (rv != KERN_SUCCESS)
3284 * Mark the entry in case the map lock is released. (See
3287 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
3288 entry->wiring_thread == NULL,
3289 ("owned map entry %p", entry));
3290 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
3291 entry->wiring_thread = curthread;
3292 next_entry = vm_map_entry_succ(entry);
3294 * Check the map for holes in the specified region.
3295 * If holes_ok, skip this check.
3298 entry->end < end && next_entry->start > entry->end) {
3300 rv = KERN_INVALID_ADDRESS;
3304 * If system unwiring, require that the entry is system wired.
3307 vm_map_entry_system_wired_count(entry) == 0) {
3309 rv = KERN_INVALID_ARGUMENT;
3313 need_wakeup = false;
3314 if (first_entry == NULL &&
3315 !vm_map_lookup_entry(map, start, &first_entry)) {
3316 KASSERT(holes_ok, ("vm_map_unwire: lookup failed"));
3317 prev_entry = first_entry;
3318 entry = vm_map_entry_succ(first_entry);
3320 prev_entry = vm_map_entry_pred(first_entry);
3321 entry = first_entry;
3323 for (; entry->start < end;
3324 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3326 * If holes_ok was specified, an empty
3327 * space in the unwired region could have been mapped
3328 * while the map lock was dropped for draining
3329 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread
3330 * could be simultaneously wiring this new mapping
3331 * entry. Detect these cases and skip any entries
3332 * marked as in transition by us.
3334 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
3335 entry->wiring_thread != curthread) {
3337 ("vm_map_unwire: !HOLESOK and new/changed entry"));
3341 if (rv == KERN_SUCCESS && (!user_unwire ||
3342 (entry->eflags & MAP_ENTRY_USER_WIRED))) {
3343 if (entry->wired_count == 1)
3344 vm_map_entry_unwire(map, entry);
3346 entry->wired_count--;
3348 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3350 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3351 ("vm_map_unwire: in-transition flag missing %p", entry));
3352 KASSERT(entry->wiring_thread == curthread,
3353 ("vm_map_unwire: alien wire %p", entry));
3354 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
3355 entry->wiring_thread = NULL;
3356 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
3357 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
3360 vm_map_try_merge_entries(map, prev_entry, entry);
3362 vm_map_try_merge_entries(map, prev_entry, entry);
3370 vm_map_wire_user_count_sub(u_long npages)
3373 atomic_subtract_long(&vm_user_wire_count, npages);
3377 vm_map_wire_user_count_add(u_long npages)
3381 wired = vm_user_wire_count;
3383 if (npages + wired > vm_page_max_user_wired)
3385 } while (!atomic_fcmpset_long(&vm_user_wire_count, &wired,
3392 * vm_map_wire_entry_failure:
3394 * Handle a wiring failure on the given entry.
3396 * The map should be locked.
3399 vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
3400 vm_offset_t failed_addr)
3403 VM_MAP_ASSERT_LOCKED(map);
3404 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 &&
3405 entry->wired_count == 1,
3406 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry));
3407 KASSERT(failed_addr < entry->end,
3408 ("vm_map_wire_entry_failure: entry %p was fully wired", entry));
3411 * If any pages at the start of this entry were successfully wired,
3414 if (failed_addr > entry->start) {
3415 pmap_unwire(map->pmap, entry->start, failed_addr);
3416 vm_object_unwire(entry->object.vm_object, entry->offset,
3417 failed_addr - entry->start, PQ_ACTIVE);
3421 * Assign an out-of-range value to represent the failure to wire this
3424 entry->wired_count = -1;
3428 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
3433 rv = vm_map_wire_locked(map, start, end, flags);
3439 * vm_map_wire_locked:
3441 * Implements both kernel and user wiring. Returns with the map locked,
3442 * the map lock may be dropped.
3445 vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
3447 vm_map_entry_t entry, first_entry, next_entry, prev_entry;
3448 vm_offset_t faddr, saved_end, saved_start;
3449 u_long incr, npages;
3450 u_int bidx, last_timestamp;
3452 bool holes_ok, need_wakeup, user_wire;
3455 VM_MAP_ASSERT_LOCKED(map);
3458 return (KERN_SUCCESS);
3460 if (flags & VM_MAP_WIRE_WRITE)
3461 prot |= VM_PROT_WRITE;
3462 holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
3463 user_wire = (flags & VM_MAP_WIRE_USER) != 0;
3464 VM_MAP_RANGE_CHECK(map, start, end);
3465 if (!vm_map_lookup_entry(map, start, &first_entry)) {
3467 first_entry = vm_map_entry_succ(first_entry);
3469 return (KERN_INVALID_ADDRESS);
3471 for (entry = first_entry; entry->start < end; entry = next_entry) {
3472 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
3474 * We have not yet clipped the entry.
3476 next_entry = vm_map_entry_in_transition(map, start,
3477 &end, holes_ok, entry);
3478 if (next_entry == NULL) {
3479 if (entry == first_entry)
3480 return (KERN_INVALID_ADDRESS);
3481 rv = KERN_INVALID_ADDRESS;
3484 first_entry = (entry == first_entry) ?
3488 rv = vm_map_clip_start(map, entry, start);
3489 if (rv != KERN_SUCCESS)
3491 rv = vm_map_clip_end(map, entry, end);
3492 if (rv != KERN_SUCCESS)
3496 * Mark the entry in case the map lock is released. (See
3499 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
3500 entry->wiring_thread == NULL,
3501 ("owned map entry %p", entry));
3502 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
3503 entry->wiring_thread = curthread;
3504 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0
3505 || (entry->protection & prot) != prot) {
3506 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED;
3509 rv = KERN_INVALID_ADDRESS;
3512 } else if (entry->wired_count == 0) {
3513 entry->wired_count++;
3515 npages = atop(entry->end - entry->start);
3516 if (user_wire && !vm_map_wire_user_count_add(npages)) {
3517 vm_map_wire_entry_failure(map, entry,
3520 rv = KERN_RESOURCE_SHORTAGE;
3525 * Release the map lock, relying on the in-transition
3526 * mark. Mark the map busy for fork.
3528 saved_start = entry->start;
3529 saved_end = entry->end;
3530 last_timestamp = map->timestamp;
3531 bidx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK)
3532 >> MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
3533 incr = pagesizes[bidx];
3537 for (faddr = saved_start; faddr < saved_end;
3540 * Simulate a fault to get the page and enter
3541 * it into the physical map.
3543 rv = vm_fault(map, faddr, VM_PROT_NONE,
3544 VM_FAULT_WIRE, NULL);
3545 if (rv != KERN_SUCCESS)
3550 if (last_timestamp + 1 != map->timestamp) {
3552 * Look again for the entry because the map was
3553 * modified while it was unlocked. The entry
3554 * may have been clipped, but NOT merged or
3557 if (!vm_map_lookup_entry(map, saved_start,
3560 ("vm_map_wire: lookup failed"));
3561 first_entry = (entry == first_entry) ?
3563 for (entry = next_entry; entry->end < saved_end;
3564 entry = vm_map_entry_succ(entry)) {
3566 * In case of failure, handle entries
3567 * that were not fully wired here;
3568 * fully wired entries are handled
3571 if (rv != KERN_SUCCESS &&
3573 vm_map_wire_entry_failure(map,
3577 if (rv != KERN_SUCCESS) {
3578 vm_map_wire_entry_failure(map, entry, faddr);
3580 vm_map_wire_user_count_sub(npages);
3584 } else if (!user_wire ||
3585 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
3586 entry->wired_count++;
3589 * Check the map for holes in the specified region.
3590 * If holes_ok was specified, skip this check.
3592 next_entry = vm_map_entry_succ(entry);
3594 entry->end < end && next_entry->start > entry->end) {
3596 rv = KERN_INVALID_ADDRESS;
3602 need_wakeup = false;
3603 if (first_entry == NULL &&
3604 !vm_map_lookup_entry(map, start, &first_entry)) {
3605 KASSERT(holes_ok, ("vm_map_wire: lookup failed"));
3606 prev_entry = first_entry;
3607 entry = vm_map_entry_succ(first_entry);
3609 prev_entry = vm_map_entry_pred(first_entry);
3610 entry = first_entry;
3612 for (; entry->start < end;
3613 prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3615 * If holes_ok was specified, an empty
3616 * space in the unwired region could have been mapped
3617 * while the map lock was dropped for faulting in the
3618 * pages or draining MAP_ENTRY_IN_TRANSITION.
3619 * Moreover, another thread could be simultaneously
3620 * wiring this new mapping entry. Detect these cases
3621 * and skip any entries marked as in transition not by us.
3623 * Another way to get an entry not marked with
3624 * MAP_ENTRY_IN_TRANSITION is after failed clipping,
3625 * which set rv to KERN_INVALID_ARGUMENT.
3627 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
3628 entry->wiring_thread != curthread) {
3629 KASSERT(holes_ok || rv == KERN_INVALID_ARGUMENT,
3630 ("vm_map_wire: !HOLESOK and new/changed entry"));
3634 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) {
3636 } else if (rv == KERN_SUCCESS) {
3638 entry->eflags |= MAP_ENTRY_USER_WIRED;
3639 } else if (entry->wired_count == -1) {
3641 * Wiring failed on this entry. Thus, unwiring is
3644 entry->wired_count = 0;
3645 } else if (!user_wire ||
3646 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
3648 * Undo the wiring. Wiring succeeded on this entry
3649 * but failed on a later entry.
3651 if (entry->wired_count == 1) {
3652 vm_map_entry_unwire(map, entry);
3654 vm_map_wire_user_count_sub(
3655 atop(entry->end - entry->start));
3657 entry->wired_count--;
3659 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3660 ("vm_map_wire: in-transition flag missing %p", entry));
3661 KASSERT(entry->wiring_thread == curthread,
3662 ("vm_map_wire: alien wire %p", entry));
3663 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION |
3664 MAP_ENTRY_WIRE_SKIPPED);
3665 entry->wiring_thread = NULL;
3666 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
3667 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
3670 vm_map_try_merge_entries(map, prev_entry, entry);
3672 vm_map_try_merge_entries(map, prev_entry, entry);
3681 * Push any dirty cached pages in the address range to their pager.
3682 * If syncio is TRUE, dirty pages are written synchronously.
3683 * If invalidate is TRUE, any cached pages are freed as well.
3685 * If the size of the region from start to end is zero, we are
3686 * supposed to flush all modified pages within the region containing
3687 * start. Unfortunately, a region can be split or coalesced with
3688 * neighboring regions, making it difficult to determine what the
3689 * original region was. Therefore, we approximate this requirement by
3690 * flushing the current region containing start.
3692 * Returns an error if any part of the specified range is not mapped.
3700 boolean_t invalidate)
3702 vm_map_entry_t entry, first_entry, next_entry;
3705 vm_ooffset_t offset;
3706 unsigned int last_timestamp;
3710 vm_map_lock_read(map);
3711 VM_MAP_RANGE_CHECK(map, start, end);
3712 if (!vm_map_lookup_entry(map, start, &first_entry)) {
3713 vm_map_unlock_read(map);
3714 return (KERN_INVALID_ADDRESS);
3715 } else if (start == end) {
3716 start = first_entry->start;
3717 end = first_entry->end;
3721 * Make a first pass to check for user-wired memory, holes,
3722 * and partial invalidation of largepage mappings.
3724 for (entry = first_entry; entry->start < end; entry = next_entry) {
3726 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0) {
3727 vm_map_unlock_read(map);
3728 return (KERN_INVALID_ARGUMENT);
3730 bdry_idx = (entry->eflags &
3731 MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
3732 MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
3733 if (bdry_idx != 0 &&
3734 ((start & (pagesizes[bdry_idx] - 1)) != 0 ||
3735 (end & (pagesizes[bdry_idx] - 1)) != 0)) {
3736 vm_map_unlock_read(map);
3737 return (KERN_INVALID_ARGUMENT);
3740 next_entry = vm_map_entry_succ(entry);
3741 if (end > entry->end &&
3742 entry->end != next_entry->start) {
3743 vm_map_unlock_read(map);
3744 return (KERN_INVALID_ADDRESS);
3749 pmap_remove(map->pmap, start, end);
3753 * Make a second pass, cleaning/uncaching pages from the indicated
3756 for (entry = first_entry; entry->start < end;) {
3757 offset = entry->offset + (start - entry->start);
3758 size = (end <= entry->end ? end : entry->end) - start;
3759 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
3761 vm_map_entry_t tentry;
3764 smap = entry->object.sub_map;
3765 vm_map_lock_read(smap);
3766 (void) vm_map_lookup_entry(smap, offset, &tentry);
3767 tsize = tentry->end - offset;
3770 object = tentry->object.vm_object;
3771 offset = tentry->offset + (offset - tentry->start);
3772 vm_map_unlock_read(smap);
3774 object = entry->object.vm_object;
3776 vm_object_reference(object);
3777 last_timestamp = map->timestamp;
3778 vm_map_unlock_read(map);
3779 if (!vm_object_sync(object, offset, size, syncio, invalidate))
3782 vm_object_deallocate(object);
3783 vm_map_lock_read(map);
3784 if (last_timestamp == map->timestamp ||
3785 !vm_map_lookup_entry(map, start, &entry))
3786 entry = vm_map_entry_succ(entry);
3789 vm_map_unlock_read(map);
3790 return (failed ? KERN_FAILURE : KERN_SUCCESS);
3794 * vm_map_entry_unwire: [ internal use only ]
3796 * Make the region specified by this entry pageable.
3798 * The map in question should be locked.
3799 * [This is the reason for this routine's existence.]
3802 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
3806 VM_MAP_ASSERT_LOCKED(map);
3807 KASSERT(entry->wired_count > 0,
3808 ("vm_map_entry_unwire: entry %p isn't wired", entry));
3810 size = entry->end - entry->start;
3811 if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0)
3812 vm_map_wire_user_count_sub(atop(size));
3813 pmap_unwire(map->pmap, entry->start, entry->end);
3814 vm_object_unwire(entry->object.vm_object, entry->offset, size,
3816 entry->wired_count = 0;
3820 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map)
3823 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
3824 vm_object_deallocate(entry->object.vm_object);
3825 uma_zfree(system_map ? kmapentzone : mapentzone, entry);
3829 * vm_map_entry_delete: [ internal use only ]
3831 * Deallocate the given entry from the target map.
3834 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
3837 vm_pindex_t offidxstart, offidxend, size1;
3840 vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE);
3841 object = entry->object.vm_object;
3843 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) {
3844 MPASS(entry->cred == NULL);
3845 MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0);
3846 MPASS(object == NULL);
3847 vm_map_entry_deallocate(entry, map->system_map);
3851 size = entry->end - entry->start;
3854 if (entry->cred != NULL) {
3855 swap_release_by_cred(size, entry->cred);
3856 crfree(entry->cred);
3859 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) {
3860 entry->object.vm_object = NULL;
3861 } else if ((object->flags & OBJ_ANON) != 0 ||
3862 object == kernel_object) {
3863 KASSERT(entry->cred == NULL || object->cred == NULL ||
3864 (entry->eflags & MAP_ENTRY_NEEDS_COPY),
3865 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry));
3866 offidxstart = OFF_TO_IDX(entry->offset);
3867 offidxend = offidxstart + atop(size);
3868 VM_OBJECT_WLOCK(object);
3869 if (object->ref_count != 1 &&
3870 ((object->flags & OBJ_ONEMAPPING) != 0 ||
3871 object == kernel_object)) {
3872 vm_object_collapse(object);
3875 * The option OBJPR_NOTMAPPED can be passed here
3876 * because vm_map_delete() already performed
3877 * pmap_remove() on the only mapping to this range
3880 vm_object_page_remove(object, offidxstart, offidxend,
3882 if (offidxend >= object->size &&
3883 offidxstart < object->size) {
3884 size1 = object->size;
3885 object->size = offidxstart;
3886 if (object->cred != NULL) {
3887 size1 -= object->size;
3888 KASSERT(object->charge >= ptoa(size1),
3889 ("object %p charge < 0", object));
3890 swap_release_by_cred(ptoa(size1),
3892 object->charge -= ptoa(size1);
3896 VM_OBJECT_WUNLOCK(object);
3898 if (map->system_map)
3899 vm_map_entry_deallocate(entry, TRUE);
3901 entry->defer_next = curthread->td_map_def_user;
3902 curthread->td_map_def_user = entry;
3907 * vm_map_delete: [ internal use only ]
3909 * Deallocates the given address range from the target
3913 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
3915 vm_map_entry_t entry, next_entry, scratch_entry;
3918 VM_MAP_ASSERT_LOCKED(map);
3921 return (KERN_SUCCESS);
3924 * Find the start of the region, and clip it.
3925 * Step through all entries in this region.
3927 rv = vm_map_lookup_clip_start(map, start, &entry, &scratch_entry);
3928 if (rv != KERN_SUCCESS)
3930 for (; entry->start < end; entry = next_entry) {
3932 * Wait for wiring or unwiring of an entry to complete.
3933 * Also wait for any system wirings to disappear on
3936 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 ||
3937 (vm_map_pmap(map) != kernel_pmap &&
3938 vm_map_entry_system_wired_count(entry) != 0)) {
3939 unsigned int last_timestamp;
3940 vm_offset_t saved_start;
3942 saved_start = entry->start;
3943 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
3944 last_timestamp = map->timestamp;
3945 (void) vm_map_unlock_and_wait(map, 0);
3947 if (last_timestamp + 1 != map->timestamp) {
3949 * Look again for the entry because the map was
3950 * modified while it was unlocked.
3951 * Specifically, the entry may have been
3952 * clipped, merged, or deleted.
3954 rv = vm_map_lookup_clip_start(map, saved_start,
3955 &next_entry, &scratch_entry);
3956 if (rv != KERN_SUCCESS)
3963 /* XXXKIB or delete to the upper superpage boundary ? */
3964 rv = vm_map_clip_end(map, entry, end);
3965 if (rv != KERN_SUCCESS)
3967 next_entry = vm_map_entry_succ(entry);
3970 * Unwire before removing addresses from the pmap; otherwise,
3971 * unwiring will put the entries back in the pmap.
3973 if (entry->wired_count != 0)
3974 vm_map_entry_unwire(map, entry);
3977 * Remove mappings for the pages, but only if the
3978 * mappings could exist. For instance, it does not
3979 * make sense to call pmap_remove() for guard entries.
3981 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 ||
3982 entry->object.vm_object != NULL)
3983 pmap_remove(map->pmap, entry->start, entry->end);
3985 if (entry->end == map->anon_loc)
3986 map->anon_loc = entry->start;
3989 * Delete the entry only after removing all pmap
3990 * entries pointing to its pages. (Otherwise, its
3991 * page frames may be reallocated, and any modify bits
3992 * will be set in the wrong object!)
3994 vm_map_entry_delete(map, entry);
4002 * Remove the given address range from the target map.
4003 * This is the exported form of vm_map_delete.
4006 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
4011 VM_MAP_RANGE_CHECK(map, start, end);
4012 result = vm_map_delete(map, start, end);
4018 * vm_map_check_protection:
4020 * Assert that the target map allows the specified privilege on the
4021 * entire address region given. The entire region must be allocated.
4023 * WARNING! This code does not and should not check whether the
4024 * contents of the region is accessible. For example a smaller file
4025 * might be mapped into a larger address space.
4027 * NOTE! This code is also called by munmap().
4029 * The map must be locked. A read lock is sufficient.
4032 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
4033 vm_prot_t protection)
4035 vm_map_entry_t entry;
4036 vm_map_entry_t tmp_entry;
4038 if (!vm_map_lookup_entry(map, start, &tmp_entry))
4042 while (start < end) {
4046 if (start < entry->start)
4049 * Check protection associated with entry.
4051 if ((entry->protection & protection) != protection)
4053 /* go to next entry */
4055 entry = vm_map_entry_succ(entry);
4062 * vm_map_copy_swap_object:
4064 * Copies a swap-backed object from an existing map entry to a
4065 * new one. Carries forward the swap charge. May change the
4066 * src object on return.
4069 vm_map_copy_swap_object(vm_map_entry_t src_entry, vm_map_entry_t dst_entry,
4070 vm_offset_t size, vm_ooffset_t *fork_charge)
4072 vm_object_t src_object;
4076 src_object = src_entry->object.vm_object;
4077 charged = ENTRY_CHARGED(src_entry);
4078 if ((src_object->flags & OBJ_ANON) != 0) {
4079 VM_OBJECT_WLOCK(src_object);
4080 vm_object_collapse(src_object);
4081 if ((src_object->flags & OBJ_ONEMAPPING) != 0) {
4082 vm_object_split(src_entry);
4083 src_object = src_entry->object.vm_object;
4085 vm_object_reference_locked(src_object);
4086 vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
4087 VM_OBJECT_WUNLOCK(src_object);
4089 vm_object_reference(src_object);
4090 if (src_entry->cred != NULL &&
4091 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
4092 KASSERT(src_object->cred == NULL,
4093 ("OVERCOMMIT: vm_map_copy_anon_entry: cred %p",
4095 src_object->cred = src_entry->cred;
4096 src_object->charge = size;
4098 dst_entry->object.vm_object = src_object;
4100 cred = curthread->td_ucred;
4102 dst_entry->cred = cred;
4103 *fork_charge += size;
4104 if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
4106 src_entry->cred = cred;
4107 *fork_charge += size;
4113 * vm_map_copy_entry:
4115 * Copies the contents of the source entry to the destination
4116 * entry. The entries *must* be aligned properly.
4122 vm_map_entry_t src_entry,
4123 vm_map_entry_t dst_entry,
4124 vm_ooffset_t *fork_charge)
4126 vm_object_t src_object;
4127 vm_map_entry_t fake_entry;
4130 VM_MAP_ASSERT_LOCKED(dst_map);
4132 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP)
4135 if (src_entry->wired_count == 0 ||
4136 (src_entry->protection & VM_PROT_WRITE) == 0) {
4138 * If the source entry is marked needs_copy, it is already
4141 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 &&
4142 (src_entry->protection & VM_PROT_WRITE) != 0) {
4143 pmap_protect(src_map->pmap,
4146 src_entry->protection & ~VM_PROT_WRITE);
4150 * Make a copy of the object.
4152 size = src_entry->end - src_entry->start;
4153 if ((src_object = src_entry->object.vm_object) != NULL) {
4154 if (src_object->type == OBJT_DEFAULT ||
4155 src_object->type == OBJT_SWAP) {
4156 vm_map_copy_swap_object(src_entry, dst_entry,
4158 /* May have split/collapsed, reload obj. */
4159 src_object = src_entry->object.vm_object;
4161 vm_object_reference(src_object);
4162 dst_entry->object.vm_object = src_object;
4164 src_entry->eflags |= MAP_ENTRY_COW |
4165 MAP_ENTRY_NEEDS_COPY;
4166 dst_entry->eflags |= MAP_ENTRY_COW |
4167 MAP_ENTRY_NEEDS_COPY;
4168 dst_entry->offset = src_entry->offset;
4169 if (src_entry->eflags & MAP_ENTRY_WRITECNT) {
4171 * MAP_ENTRY_WRITECNT cannot
4172 * indicate write reference from
4173 * src_entry, since the entry is
4174 * marked as needs copy. Allocate a
4175 * fake entry that is used to
4176 * decrement object->un_pager writecount
4177 * at the appropriate time. Attach
4178 * fake_entry to the deferred list.
4180 fake_entry = vm_map_entry_create(dst_map);
4181 fake_entry->eflags = MAP_ENTRY_WRITECNT;
4182 src_entry->eflags &= ~MAP_ENTRY_WRITECNT;
4183 vm_object_reference(src_object);
4184 fake_entry->object.vm_object = src_object;
4185 fake_entry->start = src_entry->start;
4186 fake_entry->end = src_entry->end;
4187 fake_entry->defer_next =
4188 curthread->td_map_def_user;
4189 curthread->td_map_def_user = fake_entry;
4192 pmap_copy(dst_map->pmap, src_map->pmap,
4193 dst_entry->start, dst_entry->end - dst_entry->start,
4196 dst_entry->object.vm_object = NULL;
4197 dst_entry->offset = 0;
4198 if (src_entry->cred != NULL) {
4199 dst_entry->cred = curthread->td_ucred;
4200 crhold(dst_entry->cred);
4201 *fork_charge += size;
4206 * We don't want to make writeable wired pages copy-on-write.
4207 * Immediately copy these pages into the new map by simulating
4208 * page faults. The new pages are pageable.
4210 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry,
4216 * vmspace_map_entry_forked:
4217 * Update the newly-forked vmspace each time a map entry is inherited
4218 * or copied. The values for vm_dsize and vm_tsize are approximate
4219 * (and mostly-obsolete ideas in the face of mmap(2) et al.)
4222 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2,
4223 vm_map_entry_t entry)
4225 vm_size_t entrysize;
4228 if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
4230 entrysize = entry->end - entry->start;
4231 vm2->vm_map.size += entrysize;
4232 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) {
4233 vm2->vm_ssize += btoc(entrysize);
4234 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr &&
4235 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) {
4236 newend = MIN(entry->end,
4237 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize));
4238 vm2->vm_dsize += btoc(newend - entry->start);
4239 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr &&
4240 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) {
4241 newend = MIN(entry->end,
4242 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize));
4243 vm2->vm_tsize += btoc(newend - entry->start);
4249 * Create a new process vmspace structure and vm_map
4250 * based on those of an existing process. The new map
4251 * is based on the old map, according to the inheritance
4252 * values on the regions in that map.
4254 * XXX It might be worth coalescing the entries added to the new vmspace.
4256 * The source map must not be locked.
4259 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
4261 struct vmspace *vm2;
4262 vm_map_t new_map, old_map;
4263 vm_map_entry_t new_entry, old_entry;
4268 old_map = &vm1->vm_map;
4269 /* Copy immutable fields of vm1 to vm2. */
4270 vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map),
4275 vm2->vm_taddr = vm1->vm_taddr;
4276 vm2->vm_daddr = vm1->vm_daddr;
4277 vm2->vm_maxsaddr = vm1->vm_maxsaddr;
4278 vm_map_lock(old_map);
4280 vm_map_wait_busy(old_map);
4281 new_map = &vm2->vm_map;
4282 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */
4283 KASSERT(locked, ("vmspace_fork: lock failed"));
4285 error = pmap_vmspace_copy(new_map->pmap, old_map->pmap);
4287 sx_xunlock(&old_map->lock);
4288 sx_xunlock(&new_map->lock);
4289 vm_map_process_deferred();
4294 new_map->anon_loc = old_map->anon_loc;
4295 new_map->flags |= old_map->flags & (MAP_ASLR | MAP_ASLR_IGNSTART);
4297 VM_MAP_ENTRY_FOREACH(old_entry, old_map) {
4298 if ((old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
4299 panic("vm_map_fork: encountered a submap");
4301 inh = old_entry->inheritance;
4302 if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 &&
4303 inh != VM_INHERIT_NONE)
4304 inh = VM_INHERIT_COPY;
4307 case VM_INHERIT_NONE:
4310 case VM_INHERIT_SHARE:
4312 * Clone the entry, creating the shared object if
4315 object = old_entry->object.vm_object;
4316 if (object == NULL) {
4317 vm_map_entry_back(old_entry);
4318 object = old_entry->object.vm_object;
4322 * Add the reference before calling vm_object_shadow
4323 * to insure that a shadow object is created.
4325 vm_object_reference(object);
4326 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4327 vm_object_shadow(&old_entry->object.vm_object,
4329 old_entry->end - old_entry->start,
4331 /* Transfer the second reference too. */
4333 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
4334 old_entry->cred = NULL;
4337 * As in vm_map_merged_neighbor_dispose(),
4338 * the vnode lock will not be acquired in
4339 * this call to vm_object_deallocate().
4341 vm_object_deallocate(object);
4342 object = old_entry->object.vm_object;
4344 VM_OBJECT_WLOCK(object);
4345 vm_object_clear_flag(object, OBJ_ONEMAPPING);
4346 if (old_entry->cred != NULL) {
4347 KASSERT(object->cred == NULL,
4348 ("vmspace_fork both cred"));
4349 object->cred = old_entry->cred;
4350 object->charge = old_entry->end -
4352 old_entry->cred = NULL;
4356 * Assert the correct state of the vnode
4357 * v_writecount while the object is locked, to
4358 * not relock it later for the assertion
4361 if (old_entry->eflags & MAP_ENTRY_WRITECNT &&
4362 object->type == OBJT_VNODE) {
4363 KASSERT(((struct vnode *)object->
4364 handle)->v_writecount > 0,
4365 ("vmspace_fork: v_writecount %p",
4367 KASSERT(object->un_pager.vnp.
4369 ("vmspace_fork: vnp.writecount %p",
4372 VM_OBJECT_WUNLOCK(object);
4376 * Clone the entry, referencing the shared object.
4378 new_entry = vm_map_entry_create(new_map);
4379 *new_entry = *old_entry;
4380 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
4381 MAP_ENTRY_IN_TRANSITION);
4382 new_entry->wiring_thread = NULL;
4383 new_entry->wired_count = 0;
4384 if (new_entry->eflags & MAP_ENTRY_WRITECNT) {
4385 vm_pager_update_writecount(object,
4386 new_entry->start, new_entry->end);
4388 vm_map_entry_set_vnode_text(new_entry, true);
4391 * Insert the entry into the new map -- we know we're
4392 * inserting at the end of the new map.
4394 vm_map_entry_link(new_map, new_entry);
4395 vmspace_map_entry_forked(vm1, vm2, new_entry);
4398 * Update the physical map
4400 pmap_copy(new_map->pmap, old_map->pmap,
4402 (old_entry->end - old_entry->start),
4406 case VM_INHERIT_COPY:
4408 * Clone the entry and link into the map.
4410 new_entry = vm_map_entry_create(new_map);
4411 *new_entry = *old_entry;
4413 * Copied entry is COW over the old object.
4415 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
4416 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WRITECNT);
4417 new_entry->wiring_thread = NULL;
4418 new_entry->wired_count = 0;
4419 new_entry->object.vm_object = NULL;
4420 new_entry->cred = NULL;
4421 vm_map_entry_link(new_map, new_entry);
4422 vmspace_map_entry_forked(vm1, vm2, new_entry);
4423 vm_map_copy_entry(old_map, new_map, old_entry,
4424 new_entry, fork_charge);
4425 vm_map_entry_set_vnode_text(new_entry, true);
4428 case VM_INHERIT_ZERO:
4430 * Create a new anonymous mapping entry modelled from
4433 new_entry = vm_map_entry_create(new_map);
4434 memset(new_entry, 0, sizeof(*new_entry));
4436 new_entry->start = old_entry->start;
4437 new_entry->end = old_entry->end;
4438 new_entry->eflags = old_entry->eflags &
4439 ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION |
4440 MAP_ENTRY_WRITECNT | MAP_ENTRY_VN_EXEC |
4441 MAP_ENTRY_SPLIT_BOUNDARY_MASK);
4442 new_entry->protection = old_entry->protection;
4443 new_entry->max_protection = old_entry->max_protection;
4444 new_entry->inheritance = VM_INHERIT_ZERO;
4446 vm_map_entry_link(new_map, new_entry);
4447 vmspace_map_entry_forked(vm1, vm2, new_entry);
4449 new_entry->cred = curthread->td_ucred;
4450 crhold(new_entry->cred);
4451 *fork_charge += (new_entry->end - new_entry->start);
4457 * Use inlined vm_map_unlock() to postpone handling the deferred
4458 * map entries, which cannot be done until both old_map and
4459 * new_map locks are released.
4461 sx_xunlock(&old_map->lock);
4462 sx_xunlock(&new_map->lock);
4463 vm_map_process_deferred();
4469 * Create a process's stack for exec_new_vmspace(). This function is never
4470 * asked to wire the newly created stack.
4473 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
4474 vm_prot_t prot, vm_prot_t max, int cow)
4476 vm_size_t growsize, init_ssize;
4480 MPASS((map->flags & MAP_WIREFUTURE) == 0);
4481 growsize = sgrowsiz;
4482 init_ssize = (max_ssize < growsize) ? max_ssize : growsize;
4484 vmemlim = lim_cur(curthread, RLIMIT_VMEM);
4485 /* If we would blow our VMEM resource limit, no go */
4486 if (map->size + init_ssize > vmemlim) {
4490 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot,
4497 static int stack_guard_page = 1;
4498 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN,
4499 &stack_guard_page, 0,
4500 "Specifies the number of guard pages for a stack that grows");
4503 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
4504 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow)
4506 vm_map_entry_t new_entry, prev_entry;
4507 vm_offset_t bot, gap_bot, gap_top, top;
4508 vm_size_t init_ssize, sgp;
4512 * The stack orientation is piggybacked with the cow argument.
4513 * Extract it into orient and mask the cow argument so that we
4514 * don't pass it around further.
4516 orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP);
4517 KASSERT(orient != 0, ("No stack grow direction"));
4518 KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP),
4521 if (max_ssize == 0 ||
4522 !vm_map_range_valid(map, addrbos, addrbos + max_ssize))
4523 return (KERN_INVALID_ADDRESS);
4524 sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
4525 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
4526 (vm_size_t)stack_guard_page * PAGE_SIZE;
4527 if (sgp >= max_ssize)
4528 return (KERN_INVALID_ARGUMENT);
4530 init_ssize = growsize;
4531 if (max_ssize < init_ssize + sgp)
4532 init_ssize = max_ssize - sgp;
4534 /* If addr is already mapped, no go */
4535 if (vm_map_lookup_entry(map, addrbos, &prev_entry))
4536 return (KERN_NO_SPACE);
4539 * If we can't accommodate max_ssize in the current mapping, no go.
4541 if (vm_map_entry_succ(prev_entry)->start < addrbos + max_ssize)
4542 return (KERN_NO_SPACE);
4545 * We initially map a stack of only init_ssize. We will grow as
4546 * needed later. Depending on the orientation of the stack (i.e.
4547 * the grow direction) we either map at the top of the range, the
4548 * bottom of the range or in the middle.
4550 * Note: we would normally expect prot and max to be VM_PROT_ALL,
4551 * and cow to be 0. Possibly we should eliminate these as input
4552 * parameters, and just pass these values here in the insert call.
4554 if (orient == MAP_STACK_GROWS_DOWN) {
4555 bot = addrbos + max_ssize - init_ssize;
4556 top = bot + init_ssize;
4559 } else /* if (orient == MAP_STACK_GROWS_UP) */ {
4561 top = bot + init_ssize;
4563 gap_top = addrbos + max_ssize;
4565 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow);
4566 if (rv != KERN_SUCCESS)
4568 new_entry = vm_map_entry_succ(prev_entry);
4569 KASSERT(new_entry->end == top || new_entry->start == bot,
4570 ("Bad entry start/end for new stack entry"));
4571 KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 ||
4572 (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0,
4573 ("new entry lacks MAP_ENTRY_GROWS_DOWN"));
4574 KASSERT((orient & MAP_STACK_GROWS_UP) == 0 ||
4575 (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0,
4576 ("new entry lacks MAP_ENTRY_GROWS_UP"));
4577 if (gap_bot == gap_top)
4578 return (KERN_SUCCESS);
4579 rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE,
4580 VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ?
4581 MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP));
4582 if (rv == KERN_SUCCESS) {
4584 * Gap can never successfully handle a fault, so
4585 * read-ahead logic is never used for it. Re-use
4586 * next_read of the gap entry to store
4587 * stack_guard_page for vm_map_growstack().
4589 if (orient == MAP_STACK_GROWS_DOWN)
4590 vm_map_entry_pred(new_entry)->next_read = sgp;
4592 vm_map_entry_succ(new_entry)->next_read = sgp;
4594 (void)vm_map_delete(map, bot, top);
4600 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we
4601 * successfully grow the stack.
4604 vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
4606 vm_map_entry_t stack_entry;
4610 vm_offset_t gap_end, gap_start, grow_start;
4611 vm_size_t grow_amount, guard, max_grow;
4612 rlim_t lmemlim, stacklim, vmemlim;
4614 bool gap_deleted, grow_down, is_procstack;
4626 * Disallow stack growth when the access is performed by a
4627 * debugger or AIO daemon. The reason is that the wrong
4628 * resource limits are applied.
4630 if (p != initproc && (map != &p->p_vmspace->vm_map ||
4631 p->p_textvp == NULL))
4632 return (KERN_FAILURE);
4634 MPASS(!map->system_map);
4636 lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK);
4637 stacklim = lim_cur(curthread, RLIMIT_STACK);
4638 vmemlim = lim_cur(curthread, RLIMIT_VMEM);
4640 /* If addr is not in a hole for a stack grow area, no need to grow. */
4641 if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry))
4642 return (KERN_FAILURE);
4643 if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0)
4644 return (KERN_SUCCESS);
4645 if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) {
4646 stack_entry = vm_map_entry_succ(gap_entry);
4647 if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 ||
4648 stack_entry->start != gap_entry->end)
4649 return (KERN_FAILURE);
4650 grow_amount = round_page(stack_entry->start - addr);
4652 } else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) {
4653 stack_entry = vm_map_entry_pred(gap_entry);
4654 if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 ||
4655 stack_entry->end != gap_entry->start)
4656 return (KERN_FAILURE);
4657 grow_amount = round_page(addr + 1 - stack_entry->end);
4660 return (KERN_FAILURE);
4662 guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
4663 (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
4664 gap_entry->next_read;
4665 max_grow = gap_entry->end - gap_entry->start;
4666 if (guard > max_grow)
4667 return (KERN_NO_SPACE);
4669 if (grow_amount > max_grow)
4670 return (KERN_NO_SPACE);
4673 * If this is the main process stack, see if we're over the stack
4676 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr &&
4677 addr < (vm_offset_t)p->p_sysent->sv_usrstack;
4678 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim))
4679 return (KERN_NO_SPACE);
4684 if (is_procstack && racct_set(p, RACCT_STACK,
4685 ctob(vm->vm_ssize) + grow_amount)) {
4687 return (KERN_NO_SPACE);
4693 grow_amount = roundup(grow_amount, sgrowsiz);
4694 if (grow_amount > max_grow)
4695 grow_amount = max_grow;
4696 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) {
4697 grow_amount = trunc_page((vm_size_t)stacklim) -
4703 limit = racct_get_available(p, RACCT_STACK);
4705 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit))
4706 grow_amount = limit - ctob(vm->vm_ssize);
4709 if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) {
4710 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) {
4717 if (racct_set(p, RACCT_MEMLOCK,
4718 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) {
4728 /* If we would blow our VMEM resource limit, no go */
4729 if (map->size + grow_amount > vmemlim) {
4736 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) {
4745 if (vm_map_lock_upgrade(map)) {
4747 vm_map_lock_read(map);
4752 grow_start = gap_entry->end - grow_amount;
4753 if (gap_entry->start + grow_amount == gap_entry->end) {
4754 gap_start = gap_entry->start;
4755 gap_end = gap_entry->end;
4756 vm_map_entry_delete(map, gap_entry);
4759 MPASS(gap_entry->start < gap_entry->end - grow_amount);
4760 vm_map_entry_resize(map, gap_entry, -grow_amount);
4761 gap_deleted = false;
4763 rv = vm_map_insert(map, NULL, 0, grow_start,
4764 grow_start + grow_amount,
4765 stack_entry->protection, stack_entry->max_protection,
4766 MAP_STACK_GROWS_DOWN);
4767 if (rv != KERN_SUCCESS) {
4769 rv1 = vm_map_insert(map, NULL, 0, gap_start,
4770 gap_end, VM_PROT_NONE, VM_PROT_NONE,
4771 MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN);
4772 MPASS(rv1 == KERN_SUCCESS);
4774 vm_map_entry_resize(map, gap_entry,
4778 grow_start = stack_entry->end;
4779 cred = stack_entry->cred;
4780 if (cred == NULL && stack_entry->object.vm_object != NULL)
4781 cred = stack_entry->object.vm_object->cred;
4782 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred))
4784 /* Grow the underlying object if applicable. */
4785 else if (stack_entry->object.vm_object == NULL ||
4786 vm_object_coalesce(stack_entry->object.vm_object,
4787 stack_entry->offset,
4788 (vm_size_t)(stack_entry->end - stack_entry->start),
4789 grow_amount, cred != NULL)) {
4790 if (gap_entry->start + grow_amount == gap_entry->end) {
4791 vm_map_entry_delete(map, gap_entry);
4792 vm_map_entry_resize(map, stack_entry,
4795 gap_entry->start += grow_amount;
4796 stack_entry->end += grow_amount;
4798 map->size += grow_amount;
4803 if (rv == KERN_SUCCESS && is_procstack)
4804 vm->vm_ssize += btoc(grow_amount);
4807 * Heed the MAP_WIREFUTURE flag if it was set for this process.
4809 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) {
4810 rv = vm_map_wire_locked(map, grow_start,
4811 grow_start + grow_amount,
4812 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
4814 vm_map_lock_downgrade(map);
4818 if (racct_enable && rv != KERN_SUCCESS) {
4820 error = racct_set(p, RACCT_VMEM, map->size);
4821 KASSERT(error == 0, ("decreasing RACCT_VMEM failed"));
4823 error = racct_set(p, RACCT_MEMLOCK,
4824 ptoa(pmap_wired_count(map->pmap)));
4825 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed"));
4827 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize));
4828 KASSERT(error == 0, ("decreasing RACCT_STACK failed"));
4837 * Unshare the specified VM space for exec. If other processes are
4838 * mapped to it, then create a new one. The new vmspace is null.
4841 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser)
4843 struct vmspace *oldvmspace = p->p_vmspace;
4844 struct vmspace *newvmspace;
4846 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0,
4847 ("vmspace_exec recursed"));
4848 newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit);
4849 if (newvmspace == NULL)
4851 newvmspace->vm_swrss = oldvmspace->vm_swrss;
4853 * This code is written like this for prototype purposes. The
4854 * goal is to avoid running down the vmspace here, but let the
4855 * other process's that are still using the vmspace to finally
4856 * run it down. Even though there is little or no chance of blocking
4857 * here, it is a good idea to keep this form for future mods.
4859 PROC_VMSPACE_LOCK(p);
4860 p->p_vmspace = newvmspace;
4861 PROC_VMSPACE_UNLOCK(p);
4862 if (p == curthread->td_proc)
4863 pmap_activate(curthread);
4864 curthread->td_pflags |= TDP_EXECVMSPC;
4869 * Unshare the specified VM space for forcing COW. This
4870 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
4873 vmspace_unshare(struct proc *p)
4875 struct vmspace *oldvmspace = p->p_vmspace;
4876 struct vmspace *newvmspace;
4877 vm_ooffset_t fork_charge;
4879 if (refcount_load(&oldvmspace->vm_refcnt) == 1)
4882 newvmspace = vmspace_fork(oldvmspace, &fork_charge);
4883 if (newvmspace == NULL)
4885 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) {
4886 vmspace_free(newvmspace);
4889 PROC_VMSPACE_LOCK(p);
4890 p->p_vmspace = newvmspace;
4891 PROC_VMSPACE_UNLOCK(p);
4892 if (p == curthread->td_proc)
4893 pmap_activate(curthread);
4894 vmspace_free(oldvmspace);
4901 * Finds the VM object, offset, and
4902 * protection for a given virtual address in the
4903 * specified map, assuming a page fault of the
4906 * Leaves the map in question locked for read; return
4907 * values are guaranteed until a vm_map_lookup_done
4908 * call is performed. Note that the map argument
4909 * is in/out; the returned map must be used in
4910 * the call to vm_map_lookup_done.
4912 * A handle (out_entry) is returned for use in
4913 * vm_map_lookup_done, to make that fast.
4915 * If a lookup is requested with "write protection"
4916 * specified, the map may be changed to perform virtual
4917 * copying operations, although the data referenced will
4921 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
4923 vm_prot_t fault_typea,
4924 vm_map_entry_t *out_entry, /* OUT */
4925 vm_object_t *object, /* OUT */
4926 vm_pindex_t *pindex, /* OUT */
4927 vm_prot_t *out_prot, /* OUT */
4928 boolean_t *wired) /* OUT */
4930 vm_map_entry_t entry;
4931 vm_map_t map = *var_map;
4933 vm_prot_t fault_type;
4934 vm_object_t eobject;
4940 vm_map_lock_read(map);
4944 * Lookup the faulting address.
4946 if (!vm_map_lookup_entry(map, vaddr, out_entry)) {
4947 vm_map_unlock_read(map);
4948 return (KERN_INVALID_ADDRESS);
4956 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
4957 vm_map_t old_map = map;
4959 *var_map = map = entry->object.sub_map;
4960 vm_map_unlock_read(old_map);
4965 * Check whether this task is allowed to have this page.
4967 prot = entry->protection;
4968 if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) {
4969 fault_typea &= ~VM_PROT_FAULT_LOOKUP;
4970 if (prot == VM_PROT_NONE && map != kernel_map &&
4971 (entry->eflags & MAP_ENTRY_GUARD) != 0 &&
4972 (entry->eflags & (MAP_ENTRY_STACK_GAP_DN |
4973 MAP_ENTRY_STACK_GAP_UP)) != 0 &&
4974 vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS)
4975 goto RetryLookupLocked;
4977 fault_type = fault_typea & VM_PROT_ALL;
4978 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) {
4979 vm_map_unlock_read(map);
4980 return (KERN_PROTECTION_FAILURE);
4982 KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags &
4983 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) !=
4984 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY),
4985 ("entry %p flags %x", entry, entry->eflags));
4986 if ((fault_typea & VM_PROT_COPY) != 0 &&
4987 (entry->max_protection & VM_PROT_WRITE) == 0 &&
4988 (entry->eflags & MAP_ENTRY_COW) == 0) {
4989 vm_map_unlock_read(map);
4990 return (KERN_PROTECTION_FAILURE);
4994 * If this page is not pageable, we have to get it for all possible
4997 *wired = (entry->wired_count != 0);
4999 fault_type = entry->protection;
5000 size = entry->end - entry->start;
5003 * If the entry was copy-on-write, we either ...
5005 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
5007 * If we want to write the page, we may as well handle that
5008 * now since we've got the map locked.
5010 * If we don't need to write the page, we just demote the
5011 * permissions allowed.
5013 if ((fault_type & VM_PROT_WRITE) != 0 ||
5014 (fault_typea & VM_PROT_COPY) != 0) {
5016 * Make a new object, and place it in the object
5017 * chain. Note that no new references have appeared
5018 * -- one just moved from the map to the new
5021 if (vm_map_lock_upgrade(map))
5024 if (entry->cred == NULL) {
5026 * The debugger owner is charged for
5029 cred = curthread->td_ucred;
5031 if (!swap_reserve_by_cred(size, cred)) {
5034 return (KERN_RESOURCE_SHORTAGE);
5038 eobject = entry->object.vm_object;
5039 vm_object_shadow(&entry->object.vm_object,
5040 &entry->offset, size, entry->cred, false);
5041 if (eobject == entry->object.vm_object) {
5043 * The object was not shadowed.
5045 swap_release_by_cred(size, entry->cred);
5046 crfree(entry->cred);
5049 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
5051 vm_map_lock_downgrade(map);
5054 * We're attempting to read a copy-on-write page --
5055 * don't allow writes.
5057 prot &= ~VM_PROT_WRITE;
5062 * Create an object if necessary.
5064 if (entry->object.vm_object == NULL && !map->system_map) {
5065 if (vm_map_lock_upgrade(map))
5067 entry->object.vm_object = vm_object_allocate_anon(atop(size),
5068 NULL, entry->cred, entry->cred != NULL ? size : 0);
5071 vm_map_lock_downgrade(map);
5075 * Return the object/offset from this entry. If the entry was
5076 * copy-on-write or empty, it has been fixed up.
5078 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
5079 *object = entry->object.vm_object;
5082 return (KERN_SUCCESS);
5086 * vm_map_lookup_locked:
5088 * Lookup the faulting address. A version of vm_map_lookup that returns
5089 * KERN_FAILURE instead of blocking on map lock or memory allocation.
5092 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */
5094 vm_prot_t fault_typea,
5095 vm_map_entry_t *out_entry, /* OUT */
5096 vm_object_t *object, /* OUT */
5097 vm_pindex_t *pindex, /* OUT */
5098 vm_prot_t *out_prot, /* OUT */
5099 boolean_t *wired) /* OUT */
5101 vm_map_entry_t entry;
5102 vm_map_t map = *var_map;
5104 vm_prot_t fault_type = fault_typea;
5107 * Lookup the faulting address.
5109 if (!vm_map_lookup_entry(map, vaddr, out_entry))
5110 return (KERN_INVALID_ADDRESS);
5115 * Fail if the entry refers to a submap.
5117 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
5118 return (KERN_FAILURE);
5121 * Check whether this task is allowed to have this page.
5123 prot = entry->protection;
5124 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
5125 if ((fault_type & prot) != fault_type)
5126 return (KERN_PROTECTION_FAILURE);
5129 * If this page is not pageable, we have to get it for all possible
5132 *wired = (entry->wired_count != 0);
5134 fault_type = entry->protection;
5136 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
5138 * Fail if the entry was copy-on-write for a write fault.
5140 if (fault_type & VM_PROT_WRITE)
5141 return (KERN_FAILURE);
5143 * We're attempting to read a copy-on-write page --
5144 * don't allow writes.
5146 prot &= ~VM_PROT_WRITE;
5150 * Fail if an object should be created.
5152 if (entry->object.vm_object == NULL && !map->system_map)
5153 return (KERN_FAILURE);
5156 * Return the object/offset from this entry. If the entry was
5157 * copy-on-write or empty, it has been fixed up.
5159 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
5160 *object = entry->object.vm_object;
5163 return (KERN_SUCCESS);
5167 * vm_map_lookup_done:
5169 * Releases locks acquired by a vm_map_lookup
5170 * (according to the handle returned by that lookup).
5173 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry)
5176 * Unlock the main-level map
5178 vm_map_unlock_read(map);
5182 vm_map_max_KBI(const struct vm_map *map)
5185 return (vm_map_max(map));
5189 vm_map_min_KBI(const struct vm_map *map)
5192 return (vm_map_min(map));
5196 vm_map_pmap_KBI(vm_map_t map)
5203 vm_map_range_valid_KBI(vm_map_t map, vm_offset_t start, vm_offset_t end)
5206 return (vm_map_range_valid(map, start, end));
5211 _vm_map_assert_consistent(vm_map_t map, int check)
5213 vm_map_entry_t entry, prev;
5214 vm_map_entry_t cur, header, lbound, ubound;
5215 vm_size_t max_left, max_right;
5220 if (enable_vmmap_check != check)
5223 header = prev = &map->header;
5224 VM_MAP_ENTRY_FOREACH(entry, map) {
5225 KASSERT(prev->end <= entry->start,
5226 ("map %p prev->end = %jx, start = %jx", map,
5227 (uintmax_t)prev->end, (uintmax_t)entry->start));
5228 KASSERT(entry->start < entry->end,
5229 ("map %p start = %jx, end = %jx", map,
5230 (uintmax_t)entry->start, (uintmax_t)entry->end));
5231 KASSERT(entry->left == header ||
5232 entry->left->start < entry->start,
5233 ("map %p left->start = %jx, start = %jx", map,
5234 (uintmax_t)entry->left->start, (uintmax_t)entry->start));
5235 KASSERT(entry->right == header ||
5236 entry->start < entry->right->start,
5237 ("map %p start = %jx, right->start = %jx", map,
5238 (uintmax_t)entry->start, (uintmax_t)entry->right->start));
5240 lbound = ubound = header;
5242 if (entry->start < cur->start) {
5245 KASSERT(cur != lbound,
5246 ("map %p cannot find %jx",
5247 map, (uintmax_t)entry->start));
5248 } else if (cur->end <= entry->start) {
5251 KASSERT(cur != ubound,
5252 ("map %p cannot find %jx",
5253 map, (uintmax_t)entry->start));
5255 KASSERT(cur == entry,
5256 ("map %p cannot find %jx",
5257 map, (uintmax_t)entry->start));
5261 max_left = vm_map_entry_max_free_left(entry, lbound);
5262 max_right = vm_map_entry_max_free_right(entry, ubound);
5263 KASSERT(entry->max_free == vm_size_max(max_left, max_right),
5264 ("map %p max = %jx, max_left = %jx, max_right = %jx", map,
5265 (uintmax_t)entry->max_free,
5266 (uintmax_t)max_left, (uintmax_t)max_right));
5269 KASSERT(prev->end <= entry->start,
5270 ("map %p prev->end = %jx, start = %jx", map,
5271 (uintmax_t)prev->end, (uintmax_t)entry->start));
5275 #include "opt_ddb.h"
5277 #include <sys/kernel.h>
5279 #include <ddb/ddb.h>
5282 vm_map_print(vm_map_t map)
5284 vm_map_entry_t entry, prev;
5286 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
5288 (void *)map->pmap, map->nentries, map->timestamp);
5291 prev = &map->header;
5292 VM_MAP_ENTRY_FOREACH(entry, map) {
5293 db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n",
5294 (void *)entry, (void *)entry->start, (void *)entry->end,
5297 static const char * const inheritance_name[4] =
5298 {"share", "copy", "none", "donate_copy"};
5300 db_iprintf(" prot=%x/%x/%s",
5302 entry->max_protection,
5303 inheritance_name[(int)(unsigned char)
5304 entry->inheritance]);
5305 if (entry->wired_count != 0)
5306 db_printf(", wired");
5308 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
5309 db_printf(", share=%p, offset=0x%jx\n",
5310 (void *)entry->object.sub_map,
5311 (uintmax_t)entry->offset);
5312 if (prev == &map->header ||
5313 prev->object.sub_map !=
5314 entry->object.sub_map) {
5316 vm_map_print((vm_map_t)entry->object.sub_map);
5320 if (entry->cred != NULL)
5321 db_printf(", ruid %d", entry->cred->cr_ruid);
5322 db_printf(", object=%p, offset=0x%jx",
5323 (void *)entry->object.vm_object,
5324 (uintmax_t)entry->offset);
5325 if (entry->object.vm_object && entry->object.vm_object->cred)
5326 db_printf(", obj ruid %d charge %jx",
5327 entry->object.vm_object->cred->cr_ruid,
5328 (uintmax_t)entry->object.vm_object->charge);
5329 if (entry->eflags & MAP_ENTRY_COW)
5330 db_printf(", copy (%s)",
5331 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
5334 if (prev == &map->header ||
5335 prev->object.vm_object !=
5336 entry->object.vm_object) {
5338 vm_object_print((db_expr_t)(intptr_t)
5339 entry->object.vm_object,
5349 DB_SHOW_COMMAND(map, map)
5353 db_printf("usage: show map <addr>\n");
5356 vm_map_print((vm_map_t)addr);
5359 DB_SHOW_COMMAND(procvm, procvm)
5364 p = db_lookup_proc(addr);
5369 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
5370 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
5371 (void *)vmspace_pmap(p->p_vmspace));
5373 vm_map_print((vm_map_t)&p->p_vmspace->vm_map);