2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
39 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40 * All rights reserved.
42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
44 * Permission to use, copy, modify and distribute this software and
45 * its documentation is hereby granted, provided that both the copyright
46 * notice and this permission notice appear in all copies of the
47 * software, derivative works or modified versions, and any portions
48 * thereof, and that both notices appear in supporting documentation.
50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
54 * Carnegie Mellon requests users of this software to return to
56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
57 * School of Computer Science
58 * Carnegie Mellon University
59 * Pittsburgh PA 15213-3890
61 * any improvements or extensions that they make and grant Carnegie the
62 * rights to redistribute these changes.
64 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $
65 * $DragonFly: src/sys/vm/vm_map.c,v 1.7 2003/07/23 07:14:19 dillon Exp $
69 * Virtual memory mapping module.
72 #include <sys/param.h>
73 #include <sys/systm.h>
76 #include <sys/vmmeter.h>
78 #include <sys/vnode.h>
79 #include <sys/resourcevar.h>
83 #include <vm/vm_param.h>
85 #include <vm/vm_map.h>
86 #include <vm/vm_page.h>
87 #include <vm/vm_object.h>
88 #include <vm/vm_pager.h>
89 #include <vm/vm_kern.h>
90 #include <vm/vm_extern.h>
91 #include <vm/swap_pager.h>
92 #include <vm/vm_zone.h>
95 * Virtual memory maps provide for the mapping, protection,
96 * and sharing of virtual memory objects. In addition,
97 * this module provides for an efficient virtual copy of
98 * memory from one map to another.
100 * Synchronization is required prior to most operations.
102 * Maps consist of an ordered doubly-linked list of simple
103 * entries; a single hint is used to speed up lookups.
105 * Since portions of maps are specified by start/end addresses,
106 * which may not align with existing map entries, all
107 * routines merely "clip" entries to these start/end values.
108 * [That is, an entry is split into two, bordering at a
109 * start or end value.] Note that these clippings may not
110 * always be necessary (as the two resulting entries are then
111 * not changed); however, the clipping is done for convenience.
113 * As mentioned above, virtual copy operations are performed
114 * by copying VM object references from one map to
115 * another, and then marking both regions as copy-on-write.
121 * Initialize the vm_map module. Must be called before
122 * any other vm_map routines.
124 * Map and entry structures are allocated from the general
125 * purpose memory pool with some exceptions:
127 * - The kernel map and kmem submap are allocated statically.
128 * - Kernel map entries are allocated out of a static pool.
130 * These restrictions are necessary since malloc() uses the
131 * maps and requires map entries.
134 static struct vm_zone kmapentzone_store, mapentzone_store, mapzone_store;
135 static vm_zone_t mapentzone, kmapentzone, mapzone, vmspace_zone;
136 static struct vm_object kmapentobj, mapentobj, mapobj;
138 static struct vm_map_entry map_entry_init[MAX_MAPENT];
139 static struct vm_map_entry kmap_entry_init[MAX_KMAPENT];
140 static struct vm_map map_init[MAX_KMAP];
142 static void _vm_map_clip_end __P((vm_map_t, vm_map_entry_t, vm_offset_t));
143 static void _vm_map_clip_start __P((vm_map_t, vm_map_entry_t, vm_offset_t));
144 static vm_map_entry_t vm_map_entry_create __P((vm_map_t));
145 static void vm_map_entry_delete __P((vm_map_t, vm_map_entry_t));
146 static void vm_map_entry_dispose __P((vm_map_t, vm_map_entry_t));
147 static void vm_map_entry_unwire __P((vm_map_t, vm_map_entry_t));
148 static void vm_map_copy_entry __P((vm_map_t, vm_map_t, vm_map_entry_t,
150 static void vm_map_split __P((vm_map_entry_t));
151 static void vm_map_unclip_range __P((vm_map_t map, vm_map_entry_t start_entry, vm_offset_t start, vm_offset_t end, int flags));
156 mapzone = &mapzone_store;
157 zbootinit(mapzone, "MAP", sizeof (struct vm_map),
159 kmapentzone = &kmapentzone_store;
160 zbootinit(kmapentzone, "KMAP ENTRY", sizeof (struct vm_map_entry),
161 kmap_entry_init, MAX_KMAPENT);
162 mapentzone = &mapentzone_store;
163 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry),
164 map_entry_init, MAX_MAPENT);
168 * Allocate a vmspace structure, including a vm_map and pmap,
169 * and initialize those structures. The refcnt is set to 1.
170 * The remaining fields must be initialized by the caller.
173 vmspace_alloc(min, max)
174 vm_offset_t min, max;
178 vm = zalloc(vmspace_zone);
179 vm_map_init(&vm->vm_map, min, max);
180 pmap_pinit(vmspace_pmap(vm));
181 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */
184 vm->vm_exitingcnt = 0;
190 zinitna(kmapentzone, &kmapentobj,
191 NULL, 0, lmin((VM_MAX_KERNEL_ADDRESS - KERNBASE) / PAGE_SIZE,
192 vmstats.v_page_count) / 8, ZONE_INTERRUPT, 1);
193 zinitna(mapentzone, &mapentobj,
195 zinitna(mapzone, &mapobj,
197 vmspace_zone = zinit("VMSPACE", sizeof (struct vmspace), 0, 0, 3);
203 vmspace_dofree(struct vmspace *vm)
206 * Make sure any SysV shm is freed, it might not have in
212 * Lock the map, to wait out all other references to it.
213 * Delete all of the mappings and pages they hold, then call
214 * the pmap module to reclaim anything left.
216 vm_map_lock(&vm->vm_map);
217 (void) vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
218 vm->vm_map.max_offset);
219 vm_map_unlock(&vm->vm_map);
221 pmap_release(vmspace_pmap(vm));
222 zfree(vmspace_zone, vm);
226 vmspace_free(struct vmspace *vm)
228 if (vm->vm_refcnt == 0)
229 panic("vmspace_free: attempt to free already freed vmspace");
231 if (--vm->vm_refcnt == 0 && vm->vm_exitingcnt == 0)
236 vmspace_exitfree(struct proc *p)
244 * cleanup by parent process wait()ing on exiting child. vm_refcnt
245 * may not be 0 (e.g. fork() and child exits without exec()ing).
246 * exitingcnt may increment above 0 and drop back down to zero
247 * several times while vm_refcnt is held non-zero. vm_refcnt
248 * may also increment above 0 and drop back down to zero several
249 * times while vm_exitingcnt is held non-zero.
251 * The last wait on the exiting child's vmspace will clean up
252 * the remainder of the vmspace.
254 if (--vm->vm_exitingcnt == 0 && vm->vm_refcnt == 0)
259 * vmspace_swap_count() - count the approximate swap useage in pages for a
262 * Swap useage is determined by taking the proportional swap used by
263 * VM objects backing the VM map. To make up for fractional losses,
264 * if the VM object has any swap use at all the associated map entries
265 * count for at least 1 swap page.
268 vmspace_swap_count(struct vmspace *vmspace)
270 vm_map_t map = &vmspace->vm_map;
274 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
277 if ((cur->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 &&
278 (object = cur->object.vm_object) != NULL &&
279 object->type == OBJT_SWAP
281 int n = (cur->end - cur->start) / PAGE_SIZE;
283 if (object->un_pager.swp.swp_bcount) {
284 count += object->un_pager.swp.swp_bcount *
285 SWAP_META_PAGES * n / object->size + 1;
296 * Creates and returns a new empty VM map with
297 * the given physical map structure, and having
298 * the given lower and upper address bounds.
301 vm_map_create(pmap, min, max)
303 vm_offset_t min, max;
307 result = zalloc(mapzone);
308 vm_map_init(result, min, max);
314 * Initialize an existing vm_map structure
315 * such as that in the vmspace structure.
316 * The pmap is set elsewhere.
319 vm_map_init(map, min, max)
321 vm_offset_t min, max;
323 map->header.next = map->header.prev = &map->header;
328 map->min_offset = min;
329 map->max_offset = max;
330 map->first_free = &map->header;
331 map->hint = &map->header;
333 lockinit(&map->lock, 0, "thrd_sleep", 0, LK_NOPAUSE);
337 * vm_map_entry_create: [ internal use only ]
339 * Allocates a VM map entry for insertion. No entry fields are filled
340 * in. this ruotine may be called from an interrupt.
342 static vm_map_entry_t
343 vm_map_entry_create(map)
346 vm_map_entry_t new_entry;
348 if (map->system_map || !mapentzone)
349 new_entry = zalloc(kmapentzone);
351 new_entry = zalloc(mapentzone);
352 if (new_entry == NULL)
353 panic("vm_map_entry_create: kernel resources exhausted");
358 * vm_map_entry_dispose: [ internal use only ]
360 * Dispose of a vm_map_entry that is no longer being referenced. This
361 * function may be called from an interrupt.
364 vm_map_entry_dispose(map, entry)
366 vm_map_entry_t entry;
368 if (map->system_map || !mapentzone)
369 zfree(kmapentzone, entry);
371 zfree(mapentzone, entry);
376 * vm_map_entry_{un,}link:
378 * Insert/remove entries from maps.
381 vm_map_entry_link(vm_map_t map,
382 vm_map_entry_t after_where,
383 vm_map_entry_t entry)
386 entry->prev = after_where;
387 entry->next = after_where->next;
388 entry->next->prev = entry;
389 after_where->next = entry;
393 vm_map_entry_unlink(vm_map_t map,
394 vm_map_entry_t entry)
399 if (entry->eflags & MAP_ENTRY_IN_TRANSITION)
400 panic("vm_map_entry_unlink: attempt to mess with locked entry! %p", entry);
411 * Saves the specified entry as the hint for
414 #define SAVE_HINT(map,value) \
415 (map)->hint = (value);
418 * vm_map_lookup_entry: [ internal use only ]
420 * Finds the map entry containing (or
421 * immediately preceding) the specified address
422 * in the given map; the entry is returned
423 * in the "entry" parameter. The boolean
424 * result indicates whether the address is
425 * actually contained in the map.
428 vm_map_lookup_entry(map, address, entry)
431 vm_map_entry_t *entry; /* OUT */
437 * Start looking either from the head of the list, or from the hint.
442 if (cur == &map->header)
445 if (address >= cur->start) {
447 * Go from hint to end of list.
449 * But first, make a quick check to see if we are already looking
450 * at the entry we want (which is usually the case). Note also
451 * that we don't need to save the hint here... it is the same
452 * hint (unless we are at the header, in which case the hint
453 * didn't buy us anything anyway).
456 if ((cur != last) && (cur->end > address)) {
462 * Go from start to hint, *inclusively*
465 cur = map->header.next;
472 while (cur != last) {
473 if (cur->end > address) {
474 if (address >= cur->start) {
476 * Save this lookup for future hints, and
489 SAVE_HINT(map, *entry);
496 * Inserts the given whole VM object into the target
497 * map at the specified address range. The object's
498 * size should match that of the address range.
500 * Requires that the map be locked, and leaves it so.
502 * If object is non-NULL, ref count must be bumped by caller
503 * prior to making call to account for the new entry.
506 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
507 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max,
510 vm_map_entry_t new_entry;
511 vm_map_entry_t prev_entry;
512 vm_map_entry_t temp_entry;
513 vm_eflags_t protoeflags;
516 * Check that the start and end points are not bogus.
519 if ((start < map->min_offset) || (end > map->max_offset) ||
521 return (KERN_INVALID_ADDRESS);
524 * Find the entry prior to the proposed starting address; if it's part
525 * of an existing entry, this range is bogus.
528 if (vm_map_lookup_entry(map, start, &temp_entry))
529 return (KERN_NO_SPACE);
531 prev_entry = temp_entry;
534 * Assert that the next entry doesn't overlap the end point.
537 if ((prev_entry->next != &map->header) &&
538 (prev_entry->next->start < end))
539 return (KERN_NO_SPACE);
543 if (cow & MAP_COPY_ON_WRITE)
544 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY;
546 if (cow & MAP_NOFAULT) {
547 protoeflags |= MAP_ENTRY_NOFAULT;
549 KASSERT(object == NULL,
550 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
552 if (cow & MAP_DISABLE_SYNCER)
553 protoeflags |= MAP_ENTRY_NOSYNC;
554 if (cow & MAP_DISABLE_COREDUMP)
555 protoeflags |= MAP_ENTRY_NOCOREDUMP;
559 * When object is non-NULL, it could be shared with another
560 * process. We have to set or clear OBJ_ONEMAPPING
563 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
564 vm_object_clear_flag(object, OBJ_ONEMAPPING);
567 else if ((prev_entry != &map->header) &&
568 (prev_entry->eflags == protoeflags) &&
569 (prev_entry->end == start) &&
570 (prev_entry->wired_count == 0) &&
571 ((prev_entry->object.vm_object == NULL) ||
572 vm_object_coalesce(prev_entry->object.vm_object,
573 OFF_TO_IDX(prev_entry->offset),
574 (vm_size_t)(prev_entry->end - prev_entry->start),
575 (vm_size_t)(end - prev_entry->end)))) {
577 * We were able to extend the object. Determine if we
578 * can extend the previous map entry to include the
581 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
582 (prev_entry->protection == prot) &&
583 (prev_entry->max_protection == max)) {
584 map->size += (end - prev_entry->end);
585 prev_entry->end = end;
586 vm_map_simplify_entry(map, prev_entry);
587 return (KERN_SUCCESS);
591 * If we can extend the object but cannot extend the
592 * map entry, we have to create a new map entry. We
593 * must bump the ref count on the extended object to
594 * account for it. object may be NULL.
596 object = prev_entry->object.vm_object;
597 offset = prev_entry->offset +
598 (prev_entry->end - prev_entry->start);
599 vm_object_reference(object);
603 * NOTE: if conditionals fail, object can be NULL here. This occurs
604 * in things like the buffer map where we manage kva but do not manage
612 new_entry = vm_map_entry_create(map);
613 new_entry->start = start;
614 new_entry->end = end;
616 new_entry->eflags = protoeflags;
617 new_entry->object.vm_object = object;
618 new_entry->offset = offset;
619 new_entry->avail_ssize = 0;
621 new_entry->inheritance = VM_INHERIT_DEFAULT;
622 new_entry->protection = prot;
623 new_entry->max_protection = max;
624 new_entry->wired_count = 0;
627 * Insert the new entry into the list
630 vm_map_entry_link(map, prev_entry, new_entry);
631 map->size += new_entry->end - new_entry->start;
634 * Update the free space hint
636 if ((map->first_free == prev_entry) &&
637 (prev_entry->end >= new_entry->start)) {
638 map->first_free = new_entry;
643 * Temporarily removed to avoid MAP_STACK panic, due to
644 * MAP_STACK being a huge hack. Will be added back in
645 * when MAP_STACK (and the user stack mapping) is fixed.
648 * It may be possible to simplify the entry
650 vm_map_simplify_entry(map, new_entry);
653 if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) {
654 pmap_object_init_pt(map->pmap, start,
655 object, OFF_TO_IDX(offset), end - start,
656 cow & MAP_PREFAULT_PARTIAL);
659 return (KERN_SUCCESS);
663 * Find sufficient space for `length' bytes in the given map, starting at
664 * `start'. The map must be locked. Returns 0 on success, 1 on no space.
667 vm_map_findspace(map, start, length, addr)
673 vm_map_entry_t entry, next;
676 if (start < map->min_offset)
677 start = map->min_offset;
678 if (start > map->max_offset)
682 * Look for the first possible address; if there's already something
683 * at this address, we have to start after it.
685 if (start == map->min_offset) {
686 if ((entry = map->first_free) != &map->header)
691 if (vm_map_lookup_entry(map, start, &tmp))
697 * Look through the rest of the map, trying to fit a new region in the
698 * gap between existing regions, or after the very last region.
700 for (;; start = (entry = next)->end) {
702 * Find the end of the proposed new region. Be sure we didn't
703 * go beyond the end of the map, or wrap around the address;
704 * if so, we lose. Otherwise, if this is the last entry, or
705 * if the proposed new region fits before the next entry, we
708 end = start + length;
709 if (end > map->max_offset || end < start)
712 if (next == &map->header || next->start >= end)
715 SAVE_HINT(map, entry);
717 if (map == kernel_map) {
719 if ((ksize = round_page(start + length)) > kernel_vm_end) {
720 pmap_growkernel(ksize);
727 * vm_map_find finds an unallocated region in the target address
728 * map with the given length. The search is defined to be
729 * first-fit from the specified address; the region found is
730 * returned in the same parameter.
732 * If object is non-NULL, ref count must be bumped by caller
733 * prior to making call to account for the new entry.
736 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
737 vm_offset_t *addr, /* IN/OUT */
738 vm_size_t length, boolean_t find_space, vm_prot_t prot,
739 vm_prot_t max, int cow)
746 if (map == kmem_map || map == mb_map)
751 if (vm_map_findspace(map, start, length, addr)) {
753 if (map == kmem_map || map == mb_map)
755 return (KERN_NO_SPACE);
759 result = vm_map_insert(map, object, offset,
760 start, start + length, prot, max, cow);
763 if (map == kmem_map || map == mb_map)
770 * vm_map_simplify_entry:
772 * Simplify the given map entry by merging with either neighbor. This
773 * routine also has the ability to merge with both neighbors.
775 * The map must be locked.
777 * This routine guarentees that the passed entry remains valid (though
778 * possibly extended). When merging, this routine may delete one or
779 * both neighbors. No action is taken on entries which have their
780 * in-transition flag set.
783 vm_map_simplify_entry(map, entry)
785 vm_map_entry_t entry;
787 vm_map_entry_t next, prev;
788 vm_size_t prevsize, esize;
790 if (entry->eflags & (MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) {
791 ++mycpu->gd_cnt.v_intrans_coll;
796 if (prev != &map->header) {
797 prevsize = prev->end - prev->start;
798 if ( (prev->end == entry->start) &&
799 (prev->object.vm_object == entry->object.vm_object) &&
800 (!prev->object.vm_object ||
801 (prev->offset + prevsize == entry->offset)) &&
802 (prev->eflags == entry->eflags) &&
803 (prev->protection == entry->protection) &&
804 (prev->max_protection == entry->max_protection) &&
805 (prev->inheritance == entry->inheritance) &&
806 (prev->wired_count == entry->wired_count)) {
807 if (map->first_free == prev)
808 map->first_free = entry;
809 if (map->hint == prev)
811 vm_map_entry_unlink(map, prev);
812 entry->start = prev->start;
813 entry->offset = prev->offset;
814 if (prev->object.vm_object)
815 vm_object_deallocate(prev->object.vm_object);
816 vm_map_entry_dispose(map, prev);
821 if (next != &map->header) {
822 esize = entry->end - entry->start;
823 if ((entry->end == next->start) &&
824 (next->object.vm_object == entry->object.vm_object) &&
825 (!entry->object.vm_object ||
826 (entry->offset + esize == next->offset)) &&
827 (next->eflags == entry->eflags) &&
828 (next->protection == entry->protection) &&
829 (next->max_protection == entry->max_protection) &&
830 (next->inheritance == entry->inheritance) &&
831 (next->wired_count == entry->wired_count)) {
832 if (map->first_free == next)
833 map->first_free = entry;
834 if (map->hint == next)
836 vm_map_entry_unlink(map, next);
837 entry->end = next->end;
838 if (next->object.vm_object)
839 vm_object_deallocate(next->object.vm_object);
840 vm_map_entry_dispose(map, next);
845 * vm_map_clip_start: [ internal use only ]
847 * Asserts that the given entry begins at or after
848 * the specified address; if necessary,
849 * it splits the entry into two.
851 #define vm_map_clip_start(map, entry, startaddr) \
853 if (startaddr > entry->start) \
854 _vm_map_clip_start(map, entry, startaddr); \
858 * This routine is called only when it is known that
859 * the entry must be split.
862 _vm_map_clip_start(map, entry, start)
864 vm_map_entry_t entry;
867 vm_map_entry_t new_entry;
870 * Split off the front portion -- note that we must insert the new
871 * entry BEFORE this one, so that this entry has the specified
875 vm_map_simplify_entry(map, entry);
878 * If there is no object backing this entry, we might as well create
879 * one now. If we defer it, an object can get created after the map
880 * is clipped, and individual objects will be created for the split-up
881 * map. This is a bit of a hack, but is also about the best place to
882 * put this improvement.
885 if (entry->object.vm_object == NULL && !map->system_map) {
887 object = vm_object_allocate(OBJT_DEFAULT,
888 atop(entry->end - entry->start));
889 entry->object.vm_object = object;
893 new_entry = vm_map_entry_create(map);
896 new_entry->end = start;
897 entry->offset += (start - entry->start);
898 entry->start = start;
900 vm_map_entry_link(map, entry->prev, new_entry);
902 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
903 vm_object_reference(new_entry->object.vm_object);
908 * vm_map_clip_end: [ internal use only ]
910 * Asserts that the given entry ends at or before
911 * the specified address; if necessary,
912 * it splits the entry into two.
915 #define vm_map_clip_end(map, entry, endaddr) \
917 if (endaddr < entry->end) \
918 _vm_map_clip_end(map, entry, endaddr); \
922 * This routine is called only when it is known that
923 * the entry must be split.
926 _vm_map_clip_end(map, entry, end)
928 vm_map_entry_t entry;
931 vm_map_entry_t new_entry;
934 * If there is no object backing this entry, we might as well create
935 * one now. If we defer it, an object can get created after the map
936 * is clipped, and individual objects will be created for the split-up
937 * map. This is a bit of a hack, but is also about the best place to
938 * put this improvement.
941 if (entry->object.vm_object == NULL && !map->system_map) {
943 object = vm_object_allocate(OBJT_DEFAULT,
944 atop(entry->end - entry->start));
945 entry->object.vm_object = object;
950 * Create a new entry and insert it AFTER the specified entry
953 new_entry = vm_map_entry_create(map);
956 new_entry->start = entry->end = end;
957 new_entry->offset += (end - entry->start);
959 vm_map_entry_link(map, entry, new_entry);
961 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
962 vm_object_reference(new_entry->object.vm_object);
967 * VM_MAP_RANGE_CHECK: [ internal use only ]
969 * Asserts that the starting and ending region
970 * addresses fall within the valid range of the map.
972 #define VM_MAP_RANGE_CHECK(map, start, end) \
974 if (start < vm_map_min(map)) \
975 start = vm_map_min(map); \
976 if (end > vm_map_max(map)) \
977 end = vm_map_max(map); \
983 * vm_map_transition_wait: [ kernel use only ]
985 * Used to block when an in-transition collison occurs. The map
986 * is unlocked for the sleep and relocked before the return.
990 vm_map_transition_wait(vm_map_t map)
993 tsleep(map, 0, "vment", 0);
1001 * When we do blocking operations with the map lock held it is
1002 * possible that a clip might have occured on our in-transit entry,
1003 * requiring an adjustment to the entry in our loop. These macros
1004 * help the pageable and clip_range code deal with the case. The
1005 * conditional costs virtually nothing if no clipping has occured.
1008 #define CLIP_CHECK_BACK(entry, save_start) \
1010 while (entry->start != save_start) { \
1011 entry = entry->prev; \
1012 KASSERT(entry != &map->header, ("bad entry clip")); \
1016 #define CLIP_CHECK_FWD(entry, save_end) \
1018 while (entry->end != save_end) { \
1019 entry = entry->next; \
1020 KASSERT(entry != &map->header, ("bad entry clip")); \
1026 * vm_map_clip_range: [ kernel use only ]
1028 * Clip the specified range and return the base entry. The
1029 * range may cover several entries starting at the returned base
1030 * and the first and last entry in the covering sequence will be
1031 * properly clipped to the requested start and end address.
1033 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1036 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1037 * covered by the requested range.
1039 * The map must be exclusively locked on entry and will remain locked
1040 * on return. If no range exists or the range contains holes and you
1041 * specified that no holes were allowed, NULL will be returned. This
1042 * routine may temporarily unlock the map in order avoid a deadlock when
1047 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
1049 vm_map_entry_t start_entry;
1050 vm_map_entry_t entry;
1053 * Locate the entry and effect initial clipping. The in-transition
1054 * case does not occur very often so do not try to optimize it.
1057 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1059 entry = start_entry;
1060 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1061 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1062 ++mycpu->gd_cnt.v_intrans_coll;
1063 ++mycpu->gd_cnt.v_intrans_wait;
1064 vm_map_transition_wait(map);
1066 * entry and/or start_entry may have been clipped while
1067 * we slept, or may have gone away entirely. We have
1068 * to restart from the lookup.
1073 * Since we hold an exclusive map lock we do not have to restart
1074 * after clipping, even though clipping may block in zalloc.
1076 vm_map_clip_start(map, entry, start);
1077 vm_map_clip_end(map, entry, end);
1078 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1081 * Scan entries covered by the range. When working on the next
1082 * entry a restart need only re-loop on the current entry which
1083 * we have already locked, since 'next' may have changed. Also,
1084 * even though entry is safe, it may have been clipped so we
1085 * have to iterate forwards through the clip after sleeping.
1087 while (entry->next != &map->header && entry->next->start < end) {
1088 vm_map_entry_t next = entry->next;
1090 if (flags & MAP_CLIP_NO_HOLES) {
1091 if (next->start > entry->end) {
1092 vm_map_unclip_range(map, start_entry,
1093 start, entry->end, flags);
1098 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1099 vm_offset_t save_end = entry->end;
1100 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1101 ++mycpu->gd_cnt.v_intrans_coll;
1102 ++mycpu->gd_cnt.v_intrans_wait;
1103 vm_map_transition_wait(map);
1106 * clips might have occured while we blocked.
1108 CLIP_CHECK_FWD(entry, save_end);
1109 CLIP_CHECK_BACK(start_entry, start);
1113 * No restart necessary even though clip_end may block, we
1114 * are holding the map lock.
1116 vm_map_clip_end(map, next, end);
1117 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1120 if (flags & MAP_CLIP_NO_HOLES) {
1121 if (entry->end != end) {
1122 vm_map_unclip_range(map, start_entry,
1123 start, entry->end, flags);
1127 return(start_entry);
1131 * vm_map_unclip_range: [ kernel use only ]
1133 * Undo the effect of vm_map_clip_range(). You should pass the same
1134 * flags and the same range that you passed to vm_map_clip_range().
1135 * This code will clear the in-transition flag on the entries and
1136 * wake up anyone waiting. This code will also simplify the sequence
1137 * and attempt to merge it with entries before and after the sequence.
1139 * The map must be locked on entry and will remain locked on return.
1141 * Note that you should also pass the start_entry returned by
1142 * vm_map_clip_range(). However, if you block between the two calls
1143 * with the map unlocked please be aware that the start_entry may
1144 * have been clipped and you may need to scan it backwards to find
1145 * the entry corresponding with the original start address. You are
1146 * responsible for this, vm_map_unclip_range() expects the correct
1147 * start_entry to be passed to it and will KASSERT otherwise.
1151 vm_map_unclip_range(
1153 vm_map_entry_t start_entry,
1158 vm_map_entry_t entry;
1160 entry = start_entry;
1162 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1163 while (entry != &map->header && entry->start < end) {
1164 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, ("in-transition flag not set during unclip on: %p", entry));
1165 KASSERT(entry->end <= end, ("unclip_range: tail wasn't clipped"));
1166 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1167 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1168 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1171 entry = entry->next;
1175 * Simplification does not block so there is no restart case.
1177 entry = start_entry;
1178 while (entry != &map->header && entry->start < end) {
1179 vm_map_simplify_entry(map, entry);
1180 entry = entry->next;
1185 * vm_map_submap: [ kernel use only ]
1187 * Mark the given range as handled by a subordinate map.
1189 * This range must have been created with vm_map_find,
1190 * and no other operations may have been performed on this
1191 * range prior to calling vm_map_submap.
1193 * Only a limited number of operations can be performed
1194 * within this rage after calling vm_map_submap:
1196 * [Don't try vm_map_copy!]
1198 * To remove a submapping, one must first remove the
1199 * range from the superior map, and then destroy the
1200 * submap (if desired). [Better yet, don't try it.]
1203 vm_map_submap(map, start, end, submap)
1209 vm_map_entry_t entry;
1210 int result = KERN_INVALID_ARGUMENT;
1214 VM_MAP_RANGE_CHECK(map, start, end);
1216 if (vm_map_lookup_entry(map, start, &entry)) {
1217 vm_map_clip_start(map, entry, start);
1219 entry = entry->next;
1222 vm_map_clip_end(map, entry, end);
1224 if ((entry->start == start) && (entry->end == end) &&
1225 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1226 (entry->object.vm_object == NULL)) {
1227 entry->object.sub_map = submap;
1228 entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
1229 result = KERN_SUCCESS;
1239 * Sets the protection of the specified address
1240 * region in the target map. If "set_max" is
1241 * specified, the maximum protection is to be set;
1242 * otherwise, only the current protection is affected.
1245 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1246 vm_prot_t new_prot, boolean_t set_max)
1248 vm_map_entry_t current;
1249 vm_map_entry_t entry;
1253 VM_MAP_RANGE_CHECK(map, start, end);
1255 if (vm_map_lookup_entry(map, start, &entry)) {
1256 vm_map_clip_start(map, entry, start);
1258 entry = entry->next;
1262 * Make a first pass to check for protection violations.
1266 while ((current != &map->header) && (current->start < end)) {
1267 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
1269 return (KERN_INVALID_ARGUMENT);
1271 if ((new_prot & current->max_protection) != new_prot) {
1273 return (KERN_PROTECTION_FAILURE);
1275 current = current->next;
1279 * Go back and fix up protections. [Note that clipping is not
1280 * necessary the second time.]
1285 while ((current != &map->header) && (current->start < end)) {
1288 vm_map_clip_end(map, current, end);
1290 old_prot = current->protection;
1292 current->protection =
1293 (current->max_protection = new_prot) &
1296 current->protection = new_prot;
1299 * Update physical map if necessary. Worry about copy-on-write
1300 * here -- CHECK THIS XXX
1303 if (current->protection != old_prot) {
1304 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1307 pmap_protect(map->pmap, current->start,
1309 current->protection & MASK(current));
1313 vm_map_simplify_entry(map, current);
1315 current = current->next;
1319 return (KERN_SUCCESS);
1325 * This routine traverses a processes map handling the madvise
1326 * system call. Advisories are classified as either those effecting
1327 * the vm_map_entry structure, or those effecting the underlying
1332 vm_map_madvise(map, start, end, behav)
1334 vm_offset_t start, end;
1337 vm_map_entry_t current, entry;
1341 * Some madvise calls directly modify the vm_map_entry, in which case
1342 * we need to use an exclusive lock on the map and we need to perform
1343 * various clipping operations. Otherwise we only need a read-lock
1349 case MADV_SEQUENTIAL:
1361 vm_map_lock_read(map);
1364 return (KERN_INVALID_ARGUMENT);
1368 * Locate starting entry and clip if necessary.
1371 VM_MAP_RANGE_CHECK(map, start, end);
1373 if (vm_map_lookup_entry(map, start, &entry)) {
1375 vm_map_clip_start(map, entry, start);
1377 entry = entry->next;
1382 * madvise behaviors that are implemented in the vm_map_entry.
1384 * We clip the vm_map_entry so that behavioral changes are
1385 * limited to the specified address range.
1387 for (current = entry;
1388 (current != &map->header) && (current->start < end);
1389 current = current->next
1391 if (current->eflags & MAP_ENTRY_IS_SUB_MAP)
1394 vm_map_clip_end(map, current, end);
1398 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
1400 case MADV_SEQUENTIAL:
1401 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
1404 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
1407 current->eflags |= MAP_ENTRY_NOSYNC;
1410 current->eflags &= ~MAP_ENTRY_NOSYNC;
1413 current->eflags |= MAP_ENTRY_NOCOREDUMP;
1416 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
1421 vm_map_simplify_entry(map, current);
1429 * madvise behaviors that are implemented in the underlying
1432 * Since we don't clip the vm_map_entry, we have to clip
1433 * the vm_object pindex and count.
1435 for (current = entry;
1436 (current != &map->header) && (current->start < end);
1437 current = current->next
1439 vm_offset_t useStart;
1441 if (current->eflags & MAP_ENTRY_IS_SUB_MAP)
1444 pindex = OFF_TO_IDX(current->offset);
1445 count = atop(current->end - current->start);
1446 useStart = current->start;
1448 if (current->start < start) {
1449 pindex += atop(start - current->start);
1450 count -= atop(start - current->start);
1453 if (current->end > end)
1454 count -= atop(current->end - end);
1459 vm_object_madvise(current->object.vm_object,
1460 pindex, count, behav);
1461 if (behav == MADV_WILLNEED) {
1462 pmap_object_init_pt(
1465 current->object.vm_object,
1467 (count << PAGE_SHIFT),
1468 MAP_PREFAULT_MADVISE
1472 vm_map_unlock_read(map);
1481 * Sets the inheritance of the specified address
1482 * range in the target map. Inheritance
1483 * affects how the map will be shared with
1484 * child maps at the time of vm_map_fork.
1487 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
1488 vm_inherit_t new_inheritance)
1490 vm_map_entry_t entry;
1491 vm_map_entry_t temp_entry;
1493 switch (new_inheritance) {
1494 case VM_INHERIT_NONE:
1495 case VM_INHERIT_COPY:
1496 case VM_INHERIT_SHARE:
1499 return (KERN_INVALID_ARGUMENT);
1504 VM_MAP_RANGE_CHECK(map, start, end);
1506 if (vm_map_lookup_entry(map, start, &temp_entry)) {
1508 vm_map_clip_start(map, entry, start);
1510 entry = temp_entry->next;
1512 while ((entry != &map->header) && (entry->start < end)) {
1513 vm_map_clip_end(map, entry, end);
1515 entry->inheritance = new_inheritance;
1517 vm_map_simplify_entry(map, entry);
1519 entry = entry->next;
1523 return (KERN_SUCCESS);
1527 * Implement the semantics of mlock
1530 vm_map_user_pageable(map, start, real_end, new_pageable)
1533 vm_offset_t real_end;
1534 boolean_t new_pageable;
1536 vm_map_entry_t entry;
1537 vm_map_entry_t start_entry;
1539 int rv = KERN_SUCCESS;
1542 VM_MAP_RANGE_CHECK(map, start, real_end);
1545 start_entry = vm_map_clip_range(map, start, end, MAP_CLIP_NO_HOLES);
1546 if (start_entry == NULL) {
1548 return (KERN_INVALID_ADDRESS);
1551 if (new_pageable == 0) {
1552 entry = start_entry;
1553 while ((entry != &map->header) && (entry->start < end)) {
1554 vm_offset_t save_start;
1555 vm_offset_t save_end;
1558 * Already user wired or hard wired (trivial cases)
1560 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
1561 entry = entry->next;
1564 if (entry->wired_count != 0) {
1565 entry->wired_count++;
1566 entry->eflags |= MAP_ENTRY_USER_WIRED;
1567 entry = entry->next;
1572 * A new wiring requires instantiation of appropriate
1573 * management structures and the faulting in of the
1576 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
1577 int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY;
1578 if (copyflag && ((entry->protection & VM_PROT_WRITE) != 0)) {
1580 vm_object_shadow(&entry->object.vm_object,
1582 atop(entry->end - entry->start));
1583 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
1585 } else if (entry->object.vm_object == NULL &&
1588 entry->object.vm_object =
1589 vm_object_allocate(OBJT_DEFAULT,
1590 atop(entry->end - entry->start));
1591 entry->offset = (vm_offset_t) 0;
1595 entry->wired_count++;
1596 entry->eflags |= MAP_ENTRY_USER_WIRED;
1599 * Now fault in the area. The map lock needs to be
1600 * manipulated to avoid deadlocks. The in-transition
1601 * flag protects the entries.
1603 save_start = entry->start;
1604 save_end = entry->end;
1607 rv = vm_fault_user_wire(map, save_start, save_end);
1610 CLIP_CHECK_BACK(entry, save_start);
1612 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
1613 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
1614 entry->wired_count = 0;
1615 if (entry->end == save_end)
1617 entry = entry->next;
1618 KASSERT(entry != &map->header, ("bad entry clip during backout"));
1620 end = save_start; /* unwire the rest */
1624 * note that even though the entry might have been
1625 * clipped, the USER_WIRED flag we set prevents
1626 * duplication so we do not have to do a
1629 entry = entry->next;
1633 * If we failed fall through to the unwiring section to
1634 * unwire what we had wired so far. 'end' has already
1641 * start_entry might have been clipped if we unlocked the
1642 * map and blocked. No matter how clipped it has gotten
1643 * there should be a fragment that is on our start boundary.
1645 CLIP_CHECK_BACK(start_entry, start);
1649 * Deal with the unwiring case.
1653 * This is the unwiring case. We must first ensure that the
1654 * range to be unwired is really wired down. We know there
1657 entry = start_entry;
1658 while ((entry != &map->header) && (entry->start < end)) {
1659 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
1660 rv = KERN_INVALID_ARGUMENT;
1663 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
1664 entry = entry->next;
1668 * Now decrement the wiring count for each region. If a region
1669 * becomes completely unwired, unwire its physical pages and
1672 while ((entry != &map->header) && (entry->start < end)) {
1673 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, ("expected USER_WIRED on entry %p", entry));
1674 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
1675 entry->wired_count--;
1676 if (entry->wired_count == 0)
1677 vm_fault_unwire(map, entry->start, entry->end);
1678 entry = entry->next;
1682 vm_map_unclip_range(map, start_entry, start, real_end,
1692 * Sets the pageability of the specified address
1693 * range in the target map. Regions specified
1694 * as not pageable require locked-down physical
1695 * memory and physical page maps.
1697 * The map must not be locked, but a reference
1698 * must remain to the map throughout the call.
1701 vm_map_pageable(map, start, real_end, new_pageable)
1704 vm_offset_t real_end;
1705 boolean_t new_pageable;
1707 vm_map_entry_t entry;
1708 vm_map_entry_t start_entry;
1710 int rv = KERN_SUCCESS;
1714 VM_MAP_RANGE_CHECK(map, start, real_end);
1717 start_entry = vm_map_clip_range(map, start, end, MAP_CLIP_NO_HOLES);
1718 if (start_entry == NULL) {
1720 return (KERN_INVALID_ADDRESS);
1722 if (new_pageable == 0) {
1726 * 1. Holding the write lock, we create any shadow or zero-fill
1727 * objects that need to be created. Then we clip each map
1728 * entry to the region to be wired and increment its wiring
1729 * count. We create objects before clipping the map entries
1730 * to avoid object proliferation.
1732 * 2. We downgrade to a read lock, and call vm_fault_wire to
1733 * fault in the pages for any newly wired area (wired_count is
1736 * Downgrading to a read lock for vm_fault_wire avoids a
1737 * possible deadlock with another process that may have faulted
1738 * on one of the pages to be wired (it would mark the page busy,
1739 * blocking us, then in turn block on the map lock that we
1740 * hold). Because of problems in the recursive lock package,
1741 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
1742 * any actions that require the write lock must be done
1743 * beforehand. Because we keep the read lock on the map, the
1744 * copy-on-write status of the entries we modify here cannot
1748 entry = start_entry;
1749 while ((entry != &map->header) && (entry->start < end)) {
1751 * Trivial case if the entry is already wired
1753 if (entry->wired_count) {
1754 entry->wired_count++;
1755 entry = entry->next;
1760 * The entry is being newly wired, we have to setup
1761 * appropriate management structures. A shadow
1762 * object is required for a copy-on-write region,
1763 * or a normal object for a zero-fill region. We
1764 * do not have to do this for entries that point to sub
1765 * maps because we won't hold the lock on the sub map.
1767 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
1768 int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY;
1770 ((entry->protection & VM_PROT_WRITE) != 0)) {
1772 vm_object_shadow(&entry->object.vm_object,
1774 atop(entry->end - entry->start));
1775 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
1776 } else if (entry->object.vm_object == NULL &&
1778 entry->object.vm_object =
1779 vm_object_allocate(OBJT_DEFAULT,
1780 atop(entry->end - entry->start));
1781 entry->offset = (vm_offset_t) 0;
1785 entry->wired_count++;
1786 entry = entry->next;
1794 * HACK HACK HACK HACK
1796 * Unlock the map to avoid deadlocks. The in-transit flag
1797 * protects us from most changes but note that
1798 * clipping may still occur. To prevent clipping from
1799 * occuring after the unlock, except for when we are
1800 * blocking in vm_fault_wire, we must run at splvm().
1801 * Otherwise our accesses to entry->start and entry->end
1802 * could be corrupted. We have to set splvm() prior to
1803 * unlocking so start_entry does not change out from
1804 * under us at the very beginning of the loop.
1806 * HACK HACK HACK HACK
1812 entry = start_entry;
1813 while (entry != &map->header && entry->start < end) {
1815 * If vm_fault_wire fails for any page we need to undo
1816 * what has been done. We decrement the wiring count
1817 * for those pages which have not yet been wired (now)
1818 * and unwire those that have (later).
1820 vm_offset_t save_start = entry->start;
1821 vm_offset_t save_end = entry->end;
1823 if (entry->wired_count == 1)
1824 rv = vm_fault_wire(map, entry->start, entry->end);
1826 CLIP_CHECK_BACK(entry, save_start);
1828 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
1829 entry->wired_count = 0;
1830 if (entry->end == save_end)
1832 entry = entry->next;
1833 KASSERT(entry != &map->header, ("bad entry clip during backout"));
1838 CLIP_CHECK_FWD(entry, save_end);
1839 entry = entry->next;
1844 * relock. start_entry is still IN_TRANSITION and must
1845 * still exist, but may have been clipped (handled just
1851 * If a failure occured undo everything by falling through
1852 * to the unwiring code. 'end' has already been adjusted
1859 * start_entry might have been clipped if we unlocked the
1860 * map and blocked. No matter how clipped it has gotten
1861 * there should be a fragment that is on our start boundary.
1863 CLIP_CHECK_BACK(start_entry, start);
1868 * This is the unwiring case. We must first ensure that the
1869 * range to be unwired is really wired down. We know there
1872 entry = start_entry;
1873 while ((entry != &map->header) && (entry->start < end)) {
1874 if (entry->wired_count == 0) {
1875 rv = KERN_INVALID_ARGUMENT;
1878 entry = entry->next;
1882 * Now decrement the wiring count for each region. If a region
1883 * becomes completely unwired, unwire its physical pages and
1886 entry = start_entry;
1887 while ((entry != &map->header) && (entry->start < end)) {
1888 entry->wired_count--;
1889 if (entry->wired_count == 0)
1890 vm_fault_unwire(map, entry->start, entry->end);
1891 entry = entry->next;
1895 vm_map_unclip_range(map, start_entry, start, real_end,
1905 * Push any dirty cached pages in the address range to their pager.
1906 * If syncio is TRUE, dirty pages are written synchronously.
1907 * If invalidate is TRUE, any cached pages are freed as well.
1909 * Returns an error if any part of the specified range is not mapped.
1912 vm_map_clean(map, start, end, syncio, invalidate)
1917 boolean_t invalidate;
1919 vm_map_entry_t current;
1920 vm_map_entry_t entry;
1923 vm_ooffset_t offset;
1925 vm_map_lock_read(map);
1926 VM_MAP_RANGE_CHECK(map, start, end);
1927 if (!vm_map_lookup_entry(map, start, &entry)) {
1928 vm_map_unlock_read(map);
1929 return (KERN_INVALID_ADDRESS);
1932 * Make a first pass to check for holes.
1934 for (current = entry; current->start < end; current = current->next) {
1935 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
1936 vm_map_unlock_read(map);
1937 return (KERN_INVALID_ARGUMENT);
1939 if (end > current->end &&
1940 (current->next == &map->header ||
1941 current->end != current->next->start)) {
1942 vm_map_unlock_read(map);
1943 return (KERN_INVALID_ADDRESS);
1948 pmap_remove(vm_map_pmap(map), start, end);
1950 * Make a second pass, cleaning/uncaching pages from the indicated
1953 for (current = entry; current->start < end; current = current->next) {
1954 offset = current->offset + (start - current->start);
1955 size = (end <= current->end ? end : current->end) - start;
1956 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
1958 vm_map_entry_t tentry;
1961 smap = current->object.sub_map;
1962 vm_map_lock_read(smap);
1963 (void) vm_map_lookup_entry(smap, offset, &tentry);
1964 tsize = tentry->end - offset;
1967 object = tentry->object.vm_object;
1968 offset = tentry->offset + (offset - tentry->start);
1969 vm_map_unlock_read(smap);
1971 object = current->object.vm_object;
1974 * Note that there is absolutely no sense in writing out
1975 * anonymous objects, so we track down the vnode object
1977 * We invalidate (remove) all pages from the address space
1978 * anyway, for semantic correctness.
1980 * note: certain anonymous maps, such as MAP_NOSYNC maps,
1981 * may start out with a NULL object.
1983 while (object && object->backing_object) {
1984 object = object->backing_object;
1985 offset += object->backing_object_offset;
1986 if (object->size < OFF_TO_IDX( offset + size))
1987 size = IDX_TO_OFF(object->size) - offset;
1989 if (object && (object->type == OBJT_VNODE) &&
1990 (current->protection & VM_PROT_WRITE)) {
1992 * Flush pages if writing is allowed, invalidate them
1993 * if invalidation requested. Pages undergoing I/O
1994 * will be ignored by vm_object_page_remove().
1996 * We cannot lock the vnode and then wait for paging
1997 * to complete without deadlocking against vm_fault.
1998 * Instead we simply call vm_object_page_remove() and
1999 * allow it to block internally on a page-by-page
2000 * basis when it encounters pages undergoing async
2005 vm_object_reference(object);
2006 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY, curthread);
2007 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2008 flags |= invalidate ? OBJPC_INVAL : 0;
2009 vm_object_page_clean(object,
2011 OFF_TO_IDX(offset + size + PAGE_MASK),
2013 VOP_UNLOCK(object->handle, 0, curthread);
2014 vm_object_deallocate(object);
2016 if (object && invalidate &&
2017 ((object->type == OBJT_VNODE) ||
2018 (object->type == OBJT_DEVICE))) {
2019 vm_object_reference(object);
2020 vm_object_page_remove(object,
2022 OFF_TO_IDX(offset + size + PAGE_MASK),
2024 vm_object_deallocate(object);
2029 vm_map_unlock_read(map);
2030 return (KERN_SUCCESS);
2034 * vm_map_entry_unwire: [ internal use only ]
2036 * Make the region specified by this entry pageable.
2038 * The map in question should be locked.
2039 * [This is the reason for this routine's existence.]
2042 vm_map_entry_unwire(map, entry)
2044 vm_map_entry_t entry;
2046 vm_fault_unwire(map, entry->start, entry->end);
2047 entry->wired_count = 0;
2051 * vm_map_entry_delete: [ internal use only ]
2053 * Deallocate the given entry from the target map.
2056 vm_map_entry_delete(map, entry)
2058 vm_map_entry_t entry;
2060 vm_map_entry_unlink(map, entry);
2061 map->size -= entry->end - entry->start;
2063 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
2064 vm_object_deallocate(entry->object.vm_object);
2067 vm_map_entry_dispose(map, entry);
2071 * vm_map_delete: [ internal use only ]
2073 * Deallocates the given address range from the target
2077 vm_map_delete(map, start, end)
2083 vm_map_entry_t entry;
2084 vm_map_entry_t first_entry;
2087 * Find the start of the region, and clip it
2091 if (!vm_map_lookup_entry(map, start, &first_entry))
2092 entry = first_entry->next;
2094 entry = first_entry;
2095 vm_map_clip_start(map, entry, start);
2097 * Fix the lookup hint now, rather than each time though the
2100 SAVE_HINT(map, entry->prev);
2104 * Save the free space hint
2107 if (entry == &map->header) {
2108 map->first_free = &map->header;
2109 } else if (map->first_free->start >= start) {
2110 map->first_free = entry->prev;
2114 * Step through all entries in this region
2117 while ((entry != &map->header) && (entry->start < end)) {
2118 vm_map_entry_t next;
2120 vm_pindex_t offidxstart, offidxend, count;
2123 * If we hit an in-transition entry we have to sleep and
2124 * retry. It's easier (and not really slower) to just retry
2125 * since this case occurs so rarely and the hint is already
2126 * pointing at the right place. We have to reset the
2127 * start offset so as not to accidently delete an entry
2128 * another process just created in vacated space.
2130 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2131 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2132 start = entry->start;
2133 ++mycpu->gd_cnt.v_intrans_coll;
2134 ++mycpu->gd_cnt.v_intrans_wait;
2135 vm_map_transition_wait(map);
2138 vm_map_clip_end(map, entry, end);
2144 offidxstart = OFF_TO_IDX(entry->offset);
2145 count = OFF_TO_IDX(e - s);
2146 object = entry->object.vm_object;
2149 * Unwire before removing addresses from the pmap; otherwise,
2150 * unwiring will put the entries back in the pmap.
2152 if (entry->wired_count != 0) {
2153 vm_map_entry_unwire(map, entry);
2156 offidxend = offidxstart + count;
2158 if ((object == kernel_object) || (object == kmem_object)) {
2159 vm_object_page_remove(object, offidxstart, offidxend, FALSE);
2161 pmap_remove(map->pmap, s, e);
2162 if (object != NULL &&
2163 object->ref_count != 1 &&
2164 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING &&
2165 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
2166 vm_object_collapse(object);
2167 vm_object_page_remove(object, offidxstart, offidxend, FALSE);
2168 if (object->type == OBJT_SWAP) {
2169 swap_pager_freespace(object, offidxstart, count);
2171 if (offidxend >= object->size &&
2172 offidxstart < object->size) {
2173 object->size = offidxstart;
2179 * Delete the entry (which may delete the object) only after
2180 * removing all pmap entries pointing to its pages.
2181 * (Otherwise, its page frames may be reallocated, and any
2182 * modify bits will be set in the wrong object!)
2184 vm_map_entry_delete(map, entry);
2187 return (KERN_SUCCESS);
2193 * Remove the given address range from the target map.
2194 * This is the exported form of vm_map_delete.
2197 vm_map_remove(map, start, end)
2204 if (map == kmem_map || map == mb_map)
2208 VM_MAP_RANGE_CHECK(map, start, end);
2209 result = vm_map_delete(map, start, end);
2212 if (map == kmem_map || map == mb_map)
2219 * vm_map_check_protection:
2221 * Assert that the target map allows the specified
2222 * privilege on the entire address region given.
2223 * The entire region must be allocated.
2226 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2227 vm_prot_t protection)
2229 vm_map_entry_t entry;
2230 vm_map_entry_t tmp_entry;
2232 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
2237 while (start < end) {
2238 if (entry == &map->header) {
2245 if (start < entry->start) {
2249 * Check protection associated with entry.
2252 if ((entry->protection & protection) != protection) {
2255 /* go to next entry */
2258 entry = entry->next;
2264 * Split the pages in a map entry into a new object. This affords
2265 * easier removal of unused pages, and keeps object inheritance from
2266 * being a negative impact on memory usage.
2270 vm_map_entry_t entry;
2273 vm_object_t orig_object, new_object, source;
2275 vm_pindex_t offidxstart, offidxend, idx;
2277 vm_ooffset_t offset;
2279 orig_object = entry->object.vm_object;
2280 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
2282 if (orig_object->ref_count <= 1)
2285 offset = entry->offset;
2289 offidxstart = OFF_TO_IDX(offset);
2290 offidxend = offidxstart + OFF_TO_IDX(e - s);
2291 size = offidxend - offidxstart;
2293 new_object = vm_pager_allocate(orig_object->type,
2294 NULL, IDX_TO_OFF(size), VM_PROT_ALL, 0LL);
2295 if (new_object == NULL)
2298 source = orig_object->backing_object;
2299 if (source != NULL) {
2300 vm_object_reference(source); /* Referenced by new_object */
2301 LIST_INSERT_HEAD(&source->shadow_head,
2302 new_object, shadow_list);
2303 vm_object_clear_flag(source, OBJ_ONEMAPPING);
2304 new_object->backing_object_offset =
2305 orig_object->backing_object_offset + IDX_TO_OFF(offidxstart);
2306 new_object->backing_object = source;
2307 source->shadow_count++;
2308 source->generation++;
2311 for (idx = 0; idx < size; idx++) {
2315 m = vm_page_lookup(orig_object, offidxstart + idx);
2320 * We must wait for pending I/O to complete before we can
2323 * We do not have to VM_PROT_NONE the page as mappings should
2324 * not be changed by this operation.
2326 if (vm_page_sleep_busy(m, TRUE, "spltwt"))
2330 vm_page_rename(m, new_object, idx);
2331 /* page automatically made dirty by rename and cache handled */
2335 if (orig_object->type == OBJT_SWAP) {
2336 vm_object_pip_add(orig_object, 1);
2338 * copy orig_object pages into new_object
2339 * and destroy unneeded pages in
2342 swap_pager_copy(orig_object, new_object, offidxstart, 0);
2343 vm_object_pip_wakeup(orig_object);
2346 for (idx = 0; idx < size; idx++) {
2347 m = vm_page_lookup(new_object, idx);
2353 entry->object.vm_object = new_object;
2354 entry->offset = 0LL;
2355 vm_object_deallocate(orig_object);
2359 * vm_map_copy_entry:
2361 * Copies the contents of the source entry to the destination
2362 * entry. The entries *must* be aligned properly.
2365 vm_map_copy_entry(src_map, dst_map, src_entry, dst_entry)
2366 vm_map_t src_map, dst_map;
2367 vm_map_entry_t src_entry, dst_entry;
2369 vm_object_t src_object;
2371 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP)
2374 if (src_entry->wired_count == 0) {
2377 * If the source entry is marked needs_copy, it is already
2380 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
2381 pmap_protect(src_map->pmap,
2384 src_entry->protection & ~VM_PROT_WRITE);
2388 * Make a copy of the object.
2390 if ((src_object = src_entry->object.vm_object) != NULL) {
2392 if ((src_object->handle == NULL) &&
2393 (src_object->type == OBJT_DEFAULT ||
2394 src_object->type == OBJT_SWAP)) {
2395 vm_object_collapse(src_object);
2396 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) {
2397 vm_map_split(src_entry);
2398 src_object = src_entry->object.vm_object;
2402 vm_object_reference(src_object);
2403 vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
2404 dst_entry->object.vm_object = src_object;
2405 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
2406 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
2407 dst_entry->offset = src_entry->offset;
2409 dst_entry->object.vm_object = NULL;
2410 dst_entry->offset = 0;
2413 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
2414 dst_entry->end - dst_entry->start, src_entry->start);
2417 * Of course, wired down pages can't be set copy-on-write.
2418 * Cause wired pages to be copied into the new map by
2419 * simulating faults (the new pages are pageable)
2421 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
2427 * Create a new process vmspace structure and vm_map
2428 * based on those of an existing process. The new map
2429 * is based on the old map, according to the inheritance
2430 * values on the regions in that map.
2432 * The source map must not be locked.
2436 struct vmspace *vm1;
2438 struct vmspace *vm2;
2439 vm_map_t old_map = &vm1->vm_map;
2441 vm_map_entry_t old_entry;
2442 vm_map_entry_t new_entry;
2445 vm_map_lock(old_map);
2446 old_map->infork = 1;
2448 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
2449 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
2450 (caddr_t) (vm1 + 1) - (caddr_t) &vm1->vm_startcopy);
2451 new_map = &vm2->vm_map; /* XXX */
2452 new_map->timestamp = 1;
2454 old_entry = old_map->header.next;
2456 while (old_entry != &old_map->header) {
2457 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP)
2458 panic("vm_map_fork: encountered a submap");
2460 switch (old_entry->inheritance) {
2461 case VM_INHERIT_NONE:
2464 case VM_INHERIT_SHARE:
2466 * Clone the entry, creating the shared object if necessary.
2468 object = old_entry->object.vm_object;
2469 if (object == NULL) {
2470 object = vm_object_allocate(OBJT_DEFAULT,
2471 atop(old_entry->end - old_entry->start));
2472 old_entry->object.vm_object = object;
2473 old_entry->offset = (vm_offset_t) 0;
2477 * Add the reference before calling vm_object_shadow
2478 * to insure that a shadow object is created.
2480 vm_object_reference(object);
2481 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
2482 vm_object_shadow(&old_entry->object.vm_object,
2484 atop(old_entry->end - old_entry->start));
2485 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
2486 /* Transfer the second reference too. */
2487 vm_object_reference(
2488 old_entry->object.vm_object);
2489 vm_object_deallocate(object);
2490 object = old_entry->object.vm_object;
2492 vm_object_clear_flag(object, OBJ_ONEMAPPING);
2495 * Clone the entry, referencing the shared object.
2497 new_entry = vm_map_entry_create(new_map);
2498 *new_entry = *old_entry;
2499 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2500 new_entry->wired_count = 0;
2503 * Insert the entry into the new map -- we know we're
2504 * inserting at the end of the new map.
2507 vm_map_entry_link(new_map, new_map->header.prev,
2511 * Update the physical map
2514 pmap_copy(new_map->pmap, old_map->pmap,
2516 (old_entry->end - old_entry->start),
2520 case VM_INHERIT_COPY:
2522 * Clone the entry and link into the map.
2524 new_entry = vm_map_entry_create(new_map);
2525 *new_entry = *old_entry;
2526 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2527 new_entry->wired_count = 0;
2528 new_entry->object.vm_object = NULL;
2529 vm_map_entry_link(new_map, new_map->header.prev,
2531 vm_map_copy_entry(old_map, new_map, old_entry,
2535 old_entry = old_entry->next;
2538 new_map->size = old_map->size;
2539 old_map->infork = 0;
2540 vm_map_unlock(old_map);
2546 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
2547 vm_prot_t prot, vm_prot_t max, int cow)
2549 vm_map_entry_t prev_entry;
2550 vm_map_entry_t new_stack_entry;
2551 vm_size_t init_ssize;
2554 if (VM_MIN_ADDRESS > 0 && addrbos < VM_MIN_ADDRESS)
2555 return (KERN_NO_SPACE);
2557 if (max_ssize < sgrowsiz)
2558 init_ssize = max_ssize;
2560 init_ssize = sgrowsiz;
2564 /* If addr is already mapped, no go */
2565 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
2567 return (KERN_NO_SPACE);
2570 /* If we would blow our VMEM resource limit, no go */
2571 if (map->size + init_ssize >
2572 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
2574 return (KERN_NO_SPACE);
2577 /* If we can't accomodate max_ssize in the current mapping,
2578 * no go. However, we need to be aware that subsequent user
2579 * mappings might map into the space we have reserved for
2580 * stack, and currently this space is not protected.
2582 * Hopefully we will at least detect this condition
2583 * when we try to grow the stack.
2585 if ((prev_entry->next != &map->header) &&
2586 (prev_entry->next->start < addrbos + max_ssize)) {
2588 return (KERN_NO_SPACE);
2591 /* We initially map a stack of only init_ssize. We will
2592 * grow as needed later. Since this is to be a grow
2593 * down stack, we map at the top of the range.
2595 * Note: we would normally expect prot and max to be
2596 * VM_PROT_ALL, and cow to be 0. Possibly we should
2597 * eliminate these as input parameters, and just
2598 * pass these values here in the insert call.
2600 rv = vm_map_insert(map, NULL, 0, addrbos + max_ssize - init_ssize,
2601 addrbos + max_ssize, prot, max, cow);
2603 /* Now set the avail_ssize amount */
2604 if (rv == KERN_SUCCESS){
2605 if (prev_entry != &map->header)
2606 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize);
2607 new_stack_entry = prev_entry->next;
2608 if (new_stack_entry->end != addrbos + max_ssize ||
2609 new_stack_entry->start != addrbos + max_ssize - init_ssize)
2610 panic ("Bad entry start/end for new stack entry");
2612 new_stack_entry->avail_ssize = max_ssize - init_ssize;
2619 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
2620 * desired address is already mapped, or if we successfully grow
2621 * the stack. Also returns KERN_SUCCESS if addr is outside the
2622 * stack range (this is strange, but preserves compatibility with
2623 * the grow function in vm_machdep.c).
2626 vm_map_growstack (struct proc *p, vm_offset_t addr)
2628 vm_map_entry_t prev_entry;
2629 vm_map_entry_t stack_entry;
2630 vm_map_entry_t new_stack_entry;
2631 struct vmspace *vm = p->p_vmspace;
2632 vm_map_t map = &vm->vm_map;
2635 int rv = KERN_SUCCESS;
2637 int use_read_lock = 1;
2641 vm_map_lock_read(map);
2645 /* If addr is already in the entry range, no need to grow.*/
2646 if (vm_map_lookup_entry(map, addr, &prev_entry))
2649 if ((stack_entry = prev_entry->next) == &map->header)
2651 if (prev_entry == &map->header)
2652 end = stack_entry->start - stack_entry->avail_ssize;
2654 end = prev_entry->end;
2656 /* This next test mimics the old grow function in vm_machdep.c.
2657 * It really doesn't quite make sense, but we do it anyway
2658 * for compatibility.
2660 * If not growable stack, return success. This signals the
2661 * caller to proceed as he would normally with normal vm.
2663 if (stack_entry->avail_ssize < 1 ||
2664 addr >= stack_entry->start ||
2665 addr < stack_entry->start - stack_entry->avail_ssize) {
2669 /* Find the minimum grow amount */
2670 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
2671 if (grow_amount > stack_entry->avail_ssize) {
2676 /* If there is no longer enough space between the entries
2677 * nogo, and adjust the available space. Note: this
2678 * should only happen if the user has mapped into the
2679 * stack area after the stack was created, and is
2680 * probably an error.
2682 * This also effectively destroys any guard page the user
2683 * might have intended by limiting the stack size.
2685 if (grow_amount > stack_entry->start - end) {
2686 if (use_read_lock && vm_map_lock_upgrade(map)) {
2691 stack_entry->avail_ssize = stack_entry->start - end;
2696 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
2698 /* If this is the main process stack, see if we're over the
2701 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
2702 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
2707 /* Round up the grow amount modulo SGROWSIZ */
2708 grow_amount = roundup (grow_amount, sgrowsiz);
2709 if (grow_amount > stack_entry->avail_ssize) {
2710 grow_amount = stack_entry->avail_ssize;
2712 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
2713 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
2714 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
2718 /* If we would blow our VMEM resource limit, no go */
2719 if (map->size + grow_amount >
2720 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
2725 if (use_read_lock && vm_map_lock_upgrade(map)) {
2731 /* Get the preliminary new entry start value */
2732 addr = stack_entry->start - grow_amount;
2734 /* If this puts us into the previous entry, cut back our growth
2735 * to the available space. Also, see the note above.
2738 stack_entry->avail_ssize = stack_entry->start - end;
2742 rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start,
2747 /* Adjust the available stack space by the amount we grew. */
2748 if (rv == KERN_SUCCESS) {
2749 if (prev_entry != &map->header)
2750 vm_map_clip_end(map, prev_entry, addr);
2751 new_stack_entry = prev_entry->next;
2752 if (new_stack_entry->end != stack_entry->start ||
2753 new_stack_entry->start != addr)
2754 panic ("Bad stack grow start/end in new stack entry");
2756 new_stack_entry->avail_ssize = stack_entry->avail_ssize -
2757 (new_stack_entry->end -
2758 new_stack_entry->start);
2760 vm->vm_ssize += btoc(new_stack_entry->end -
2761 new_stack_entry->start);
2767 vm_map_unlock_read(map);
2774 * Unshare the specified VM space for exec. If other processes are
2775 * mapped to it, then create a new one. The new vmspace is null.
2779 vmspace_exec(struct proc *p) {
2780 struct vmspace *oldvmspace = p->p_vmspace;
2781 struct vmspace *newvmspace;
2782 vm_map_t map = &p->p_vmspace->vm_map;
2784 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
2785 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
2786 (caddr_t) (newvmspace + 1) - (caddr_t) &newvmspace->vm_startcopy);
2788 * This code is written like this for prototype purposes. The
2789 * goal is to avoid running down the vmspace here, but let the
2790 * other process's that are still using the vmspace to finally
2791 * run it down. Even though there is little or no chance of blocking
2792 * here, it is a good idea to keep this form for future mods.
2794 vmspace_free(oldvmspace);
2795 p->p_vmspace = newvmspace;
2796 pmap_pinit2(vmspace_pmap(newvmspace));
2802 * Unshare the specified VM space for forcing COW. This
2803 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
2807 vmspace_unshare(struct proc *p) {
2808 struct vmspace *oldvmspace = p->p_vmspace;
2809 struct vmspace *newvmspace;
2811 if (oldvmspace->vm_refcnt == 1)
2813 newvmspace = vmspace_fork(oldvmspace);
2814 vmspace_free(oldvmspace);
2815 p->p_vmspace = newvmspace;
2816 pmap_pinit2(vmspace_pmap(newvmspace));
2825 * Finds the VM object, offset, and
2826 * protection for a given virtual address in the
2827 * specified map, assuming a page fault of the
2830 * Leaves the map in question locked for read; return
2831 * values are guaranteed until a vm_map_lookup_done
2832 * call is performed. Note that the map argument
2833 * is in/out; the returned map must be used in
2834 * the call to vm_map_lookup_done.
2836 * A handle (out_entry) is returned for use in
2837 * vm_map_lookup_done, to make that fast.
2839 * If a lookup is requested with "write protection"
2840 * specified, the map may be changed to perform virtual
2841 * copying operations, although the data referenced will
2845 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
2847 vm_prot_t fault_typea,
2848 vm_map_entry_t *out_entry, /* OUT */
2849 vm_object_t *object, /* OUT */
2850 vm_pindex_t *pindex, /* OUT */
2851 vm_prot_t *out_prot, /* OUT */
2852 boolean_t *wired) /* OUT */
2854 vm_map_entry_t entry;
2855 vm_map_t map = *var_map;
2857 vm_prot_t fault_type = fault_typea;
2858 int use_read_lock = 1;
2859 int rv = KERN_SUCCESS;
2863 vm_map_lock_read(map);
2868 * If the map has an interesting hint, try it before calling full
2869 * blown lookup routine.
2874 if ((entry == &map->header) ||
2875 (vaddr < entry->start) || (vaddr >= entry->end)) {
2876 vm_map_entry_t tmp_entry;
2879 * Entry was either not a valid hint, or the vaddr was not
2880 * contained in the entry, so do a full lookup.
2882 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
2883 rv = KERN_INVALID_ADDRESS;
2895 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
2896 vm_map_t old_map = map;
2898 *var_map = map = entry->object.sub_map;
2900 vm_map_unlock_read(old_map);
2902 vm_map_unlock(old_map);
2908 * Check whether this task is allowed to have this page.
2909 * Note the special case for MAP_ENTRY_COW
2910 * pages with an override. This is to implement a forced
2911 * COW for debuggers.
2914 if (fault_type & VM_PROT_OVERRIDE_WRITE)
2915 prot = entry->max_protection;
2917 prot = entry->protection;
2919 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
2920 if ((fault_type & prot) != fault_type) {
2921 rv = KERN_PROTECTION_FAILURE;
2925 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
2926 (entry->eflags & MAP_ENTRY_COW) &&
2927 (fault_type & VM_PROT_WRITE) &&
2928 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
2929 rv = KERN_PROTECTION_FAILURE;
2934 * If this page is not pageable, we have to get it for all possible
2938 *wired = (entry->wired_count != 0);
2940 prot = fault_type = entry->protection;
2943 * If the entry was copy-on-write, we either ...
2946 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
2948 * If we want to write the page, we may as well handle that
2949 * now since we've got the map locked.
2951 * If we don't need to write the page, we just demote the
2952 * permissions allowed.
2955 if (fault_type & VM_PROT_WRITE) {
2957 * Make a new object, and place it in the object
2958 * chain. Note that no new references have appeared
2959 * -- one just moved from the map to the new
2963 if (use_read_lock && vm_map_lock_upgrade(map)) {
2970 &entry->object.vm_object,
2972 atop(entry->end - entry->start));
2974 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
2977 * We're attempting to read a copy-on-write page --
2978 * don't allow writes.
2981 prot &= ~VM_PROT_WRITE;
2986 * Create an object if necessary.
2988 if (entry->object.vm_object == NULL &&
2990 if (use_read_lock && vm_map_lock_upgrade(map)) {
2995 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT,
2996 atop(entry->end - entry->start));
3001 * Return the object/offset from this entry. If the entry was
3002 * copy-on-write or empty, it has been fixed up.
3005 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
3006 *object = entry->object.vm_object;
3009 * Return whether this is the only map sharing this data. On
3010 * success we return with a read lock held on the map. On failure
3011 * we return with the map unlocked.
3015 if (rv == KERN_SUCCESS) {
3016 if (use_read_lock == 0)
3017 vm_map_lock_downgrade(map);
3018 } else if (use_read_lock) {
3019 vm_map_unlock_read(map);
3027 * vm_map_lookup_done:
3029 * Releases locks acquired by a vm_map_lookup
3030 * (according to the handle returned by that lookup).
3034 vm_map_lookup_done(map, entry)
3036 vm_map_entry_t entry;
3039 * Unlock the main-level map
3042 vm_map_unlock_read(map);
3046 * Implement uiomove with VM operations. This handles (and collateral changes)
3047 * support every combination of source object modification, and COW type
3051 vm_uiomove(mapa, srcobject, cp, cnta, uaddra, npages)
3053 vm_object_t srcobject;
3060 vm_object_t first_object, oldobject, object;
3061 vm_map_entry_t entry;
3065 vm_offset_t uaddr, start, end, tend;
3066 vm_pindex_t first_pindex, osize, oindex;
3079 if ((vm_map_lookup(&map, uaddr,
3080 VM_PROT_READ, &entry, &first_object,
3081 &first_pindex, &prot, &wired)) != KERN_SUCCESS) {
3085 vm_map_clip_start(map, entry, uaddr);
3088 tend = uaddr + tcnt;
3089 if (tend > entry->end) {
3090 tcnt = entry->end - uaddr;
3094 vm_map_clip_end(map, entry, tend);
3096 start = entry->start;
3101 oindex = OFF_TO_IDX(cp);
3104 for (idx = 0; idx < osize; idx++) {
3106 if ((m = vm_page_lookup(srcobject, oindex + idx)) == NULL) {
3107 vm_map_lookup_done(map, entry);
3111 * disallow busy or invalid pages, but allow
3112 * m->busy pages if they are entirely valid.
3114 if ((m->flags & PG_BUSY) ||
3115 ((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL)) {
3116 vm_map_lookup_done(map, entry);
3123 * If we are changing an existing map entry, just redirect
3124 * the object, and change mappings.
3126 if ((first_object->type == OBJT_VNODE) &&
3127 ((oldobject = entry->object.vm_object) == first_object)) {
3129 if ((entry->offset != cp) || (oldobject != srcobject)) {
3131 * Remove old window into the file
3133 pmap_remove (map->pmap, uaddr, tend);
3136 * Force copy on write for mmaped regions
3138 vm_object_pmap_copy_1 (srcobject, oindex, oindex + osize);
3141 * Point the object appropriately
3143 if (oldobject != srcobject) {
3146 * Set the object optimization hint flag
3148 vm_object_set_flag(srcobject, OBJ_OPT);
3149 vm_object_reference(srcobject);
3150 entry->object.vm_object = srcobject;
3153 vm_object_deallocate(oldobject);
3160 pmap_remove (map->pmap, uaddr, tend);
3163 } else if ((first_object->ref_count == 1) &&
3164 (first_object->size == osize) &&
3165 ((first_object->type == OBJT_DEFAULT) ||
3166 (first_object->type == OBJT_SWAP)) ) {
3168 oldobject = first_object->backing_object;
3170 if ((first_object->backing_object_offset != cp) ||
3171 (oldobject != srcobject)) {
3173 * Remove old window into the file
3175 pmap_remove (map->pmap, uaddr, tend);
3178 * Remove unneeded old pages
3180 vm_object_page_remove(first_object, 0, 0, 0);
3183 * Invalidate swap space
3185 if (first_object->type == OBJT_SWAP) {
3186 swap_pager_freespace(first_object,
3188 first_object->size);
3192 * Force copy on write for mmaped regions
3194 vm_object_pmap_copy_1 (srcobject, oindex, oindex + osize);
3197 * Point the object appropriately
3199 if (oldobject != srcobject) {
3202 * Set the object optimization hint flag
3204 vm_object_set_flag(srcobject, OBJ_OPT);
3205 vm_object_reference(srcobject);
3209 first_object, shadow_list);
3210 oldobject->shadow_count--;
3211 /* XXX bump generation? */
3212 vm_object_deallocate(oldobject);
3215 LIST_INSERT_HEAD(&srcobject->shadow_head,
3216 first_object, shadow_list);
3217 srcobject->shadow_count++;
3218 /* XXX bump generation? */
3220 first_object->backing_object = srcobject;
3222 first_object->backing_object_offset = cp;
3225 pmap_remove (map->pmap, uaddr, tend);
3228 * Otherwise, we have to do a logical mmap.
3232 vm_object_set_flag(srcobject, OBJ_OPT);
3233 vm_object_reference(srcobject);
3235 pmap_remove (map->pmap, uaddr, tend);
3237 vm_object_pmap_copy_1 (srcobject, oindex, oindex + osize);
3238 vm_map_lock_upgrade(map);
3240 if (entry == &map->header) {
3241 map->first_free = &map->header;
3242 } else if (map->first_free->start >= start) {
3243 map->first_free = entry->prev;
3246 SAVE_HINT(map, entry->prev);
3247 vm_map_entry_delete(map, entry);
3252 rv = vm_map_insert(map, object, ooffset, start, tend,
3253 VM_PROT_ALL, VM_PROT_ALL, MAP_COPY_ON_WRITE);
3255 if (rv != KERN_SUCCESS)
3256 panic("vm_uiomove: could not insert new entry: %d", rv);
3260 * Map the window directly, if it is already in memory
3262 pmap_object_init_pt(map->pmap, uaddr,
3263 srcobject, oindex, tcnt, 0);
3278 * Performs the copy_on_write operations necessary to allow the virtual copies
3279 * into user space to work. This has to be called for write(2) system calls
3280 * from other processes, file unlinking, and file size shrinkage.
3283 vm_freeze_copyopts(object, froma, toa)
3285 vm_pindex_t froma, toa;
3288 vm_object_t robject;
3291 if ((object == NULL) ||
3292 ((object->flags & OBJ_OPT) == 0))
3295 if (object->shadow_count > object->ref_count)
3296 panic("vm_freeze_copyopts: sc > rc");
3298 while((robject = LIST_FIRST(&object->shadow_head)) != NULL) {
3299 vm_pindex_t bo_pindex;
3300 vm_page_t m_in, m_out;
3302 bo_pindex = OFF_TO_IDX(robject->backing_object_offset);
3304 vm_object_reference(robject);
3306 vm_object_pip_wait(robject, "objfrz");
3308 if (robject->ref_count == 1) {
3309 vm_object_deallocate(robject);
3313 vm_object_pip_add(robject, 1);
3315 for (idx = 0; idx < robject->size; idx++) {
3317 m_out = vm_page_grab(robject, idx,
3318 VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
3320 if (m_out->valid == 0) {
3321 m_in = vm_page_grab(object, bo_pindex + idx,
3322 VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
3323 if (m_in->valid == 0) {
3324 rv = vm_pager_get_pages(object, &m_in, 1, 0);
3325 if (rv != VM_PAGER_OK) {
3326 printf("vm_freeze_copyopts: cannot read page from file: %lx\n", (long)m_in->pindex);
3329 vm_page_deactivate(m_in);
3332 vm_page_protect(m_in, VM_PROT_NONE);
3333 pmap_copy_page(VM_PAGE_TO_PHYS(m_in), VM_PAGE_TO_PHYS(m_out));
3334 m_out->valid = m_in->valid;
3335 vm_page_dirty(m_out);
3336 vm_page_activate(m_out);
3337 vm_page_wakeup(m_in);
3339 vm_page_wakeup(m_out);
3342 object->shadow_count--;
3343 object->ref_count--;
3344 LIST_REMOVE(robject, shadow_list);
3345 robject->backing_object = NULL;
3346 robject->backing_object_offset = 0;
3348 vm_object_pip_wakeup(robject);
3349 vm_object_deallocate(robject);
3352 vm_object_clear_flag(object, OBJ_OPT);
3355 #include "opt_ddb.h"
3357 #include <sys/kernel.h>
3359 #include <ddb/ddb.h>
3362 * vm_map_print: [ debug ]
3364 DB_SHOW_COMMAND(map, vm_map_print)
3367 /* XXX convert args. */
3368 vm_map_t map = (vm_map_t)addr;
3369 boolean_t full = have_addr;
3371 vm_map_entry_t entry;
3373 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
3375 (void *)map->pmap, map->nentries, map->timestamp);
3378 if (!full && db_indent)
3382 for (entry = map->header.next; entry != &map->header;
3383 entry = entry->next) {
3384 db_iprintf("map entry %p: start=%p, end=%p\n",
3385 (void *)entry, (void *)entry->start, (void *)entry->end);
3388 static char *inheritance_name[4] =
3389 {"share", "copy", "none", "donate_copy"};
3391 db_iprintf(" prot=%x/%x/%s",
3393 entry->max_protection,
3394 inheritance_name[(int)(unsigned char)entry->inheritance]);
3395 if (entry->wired_count != 0)
3396 db_printf(", wired");
3398 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
3399 /* XXX no %qd in kernel. Truncate entry->offset. */
3400 db_printf(", share=%p, offset=0x%lx\n",
3401 (void *)entry->object.sub_map,
3402 (long)entry->offset);
3404 if ((entry->prev == &map->header) ||
3405 (entry->prev->object.sub_map !=
3406 entry->object.sub_map)) {
3408 vm_map_print((db_expr_t)(intptr_t)
3409 entry->object.sub_map,
3410 full, 0, (char *)0);
3414 /* XXX no %qd in kernel. Truncate entry->offset. */
3415 db_printf(", object=%p, offset=0x%lx",
3416 (void *)entry->object.vm_object,
3417 (long)entry->offset);
3418 if (entry->eflags & MAP_ENTRY_COW)
3419 db_printf(", copy (%s)",
3420 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
3424 if ((entry->prev == &map->header) ||
3425 (entry->prev->object.vm_object !=
3426 entry->object.vm_object)) {
3428 vm_object_print((db_expr_t)(intptr_t)
3429 entry->object.vm_object,
3430 full, 0, (char *)0);
3442 DB_SHOW_COMMAND(procvm, procvm)
3447 p = (struct proc *) addr;
3452 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
3453 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
3454 (void *)vmspace_pmap(p->p_vmspace));
3456 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);