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. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
41 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
42 * All rights reserved.
44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
46 * Permission to use, copy, modify and distribute this software and
47 * its documentation is hereby granted, provided that both the copyright
48 * notice and this permission notice appear in all copies of the
49 * software, derivative works or modified versions, and any portions
50 * thereof, and that both notices appear in supporting documentation.
52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
56 * Carnegie Mellon requests users of this software to return to
58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
59 * School of Computer Science
60 * Carnegie Mellon University
61 * Pittsburgh PA 15213-3890
63 * any improvements or extensions that they make and grant Carnegie the
64 * rights to redistribute these changes.
66 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $
67 * $DragonFly: src/sys/vm/vm_map.c,v 1.56 2007/04/29 18:25:41 dillon Exp $
71 * Virtual memory mapping module.
74 #include <sys/param.h>
75 #include <sys/systm.h>
76 #include <sys/kernel.h>
78 #include <sys/serialize.h>
80 #include <sys/vmmeter.h>
82 #include <sys/vnode.h>
83 #include <sys/resourcevar.h>
86 #include <sys/malloc.h>
89 #include <vm/vm_param.h>
91 #include <vm/vm_map.h>
92 #include <vm/vm_page.h>
93 #include <vm/vm_object.h>
94 #include <vm/vm_pager.h>
95 #include <vm/vm_kern.h>
96 #include <vm/vm_extern.h>
97 #include <vm/swap_pager.h>
98 #include <vm/vm_zone.h>
100 #include <sys/thread2.h>
101 #include <sys/sysref2.h>
104 * Virtual memory maps provide for the mapping, protection, and sharing
105 * of virtual memory objects. In addition, this module provides for an
106 * efficient virtual copy of memory from one map to another.
108 * Synchronization is required prior to most operations.
110 * Maps consist of an ordered doubly-linked list of simple entries.
111 * A hint and a RB tree is used to speed-up lookups.
113 * Callers looking to modify maps specify start/end addresses which cause
114 * the related map entry to be clipped if necessary, and then later
115 * recombined if the pieces remained compatible.
117 * Virtual copy operations are performed by copying VM object references
118 * from one map to another, and then marking both regions as copy-on-write.
120 static void vmspace_terminate(struct vmspace *vm);
121 static void vmspace_lock(struct vmspace *vm);
122 static void vmspace_unlock(struct vmspace *vm);
123 static void vmspace_dtor(void *obj, void *private);
125 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore");
127 struct sysref_class vmspace_sysref_class = {
130 .proto = SYSREF_PROTO_VMSPACE,
131 .offset = offsetof(struct vmspace, vm_sysref),
132 .objsize = sizeof(struct vmspace),
134 .flags = SRC_MANAGEDINIT,
135 .dtor = vmspace_dtor,
137 .terminate = (sysref_terminate_func_t)vmspace_terminate,
138 .lock = (sysref_lock_func_t)vmspace_lock,
139 .unlock = (sysref_lock_func_t)vmspace_unlock
145 static struct vm_zone mapentzone_store, mapzone_store;
146 static vm_zone_t mapentzone, mapzone;
147 static struct vm_object mapentobj, mapobj;
149 static struct vm_map_entry map_entry_init[MAX_MAPENT];
150 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU];
151 static struct vm_map map_init[MAX_KMAP];
153 static void vm_map_entry_shadow(vm_map_entry_t entry);
154 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *);
155 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *);
156 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
157 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
158 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *);
159 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t);
160 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t,
162 static void vm_map_split (vm_map_entry_t);
163 static void vm_map_unclip_range (vm_map_t map, vm_map_entry_t start_entry, vm_offset_t start, vm_offset_t end, int *count, int flags);
166 * Initialize the vm_map module. Must be called before any other vm_map
169 * Map and entry structures are allocated from the general purpose
170 * memory pool with some exceptions:
172 * - The kernel map is allocated statically.
173 * - Initial kernel map entries are allocated out of a static pool.
175 * These restrictions are necessary since malloc() uses the
176 * maps and requires map entries.
178 * Called from the low level boot code only.
183 mapzone = &mapzone_store;
184 zbootinit(mapzone, "MAP", sizeof (struct vm_map),
186 mapentzone = &mapentzone_store;
187 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry),
188 map_entry_init, MAX_MAPENT);
192 * Called prior to any vmspace allocations.
194 * Called from the low level boot code only.
199 zinitna(mapentzone, &mapentobj, NULL, 0, 0,
200 ZONE_USE_RESERVE | ZONE_SPECIAL, 1);
201 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1);
208 * Red black tree functions
210 * The caller must hold the related map lock.
212 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b);
213 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare);
215 /* a->start is address, and the only field has to be initialized */
217 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b)
219 if (a->start < b->start)
221 else if (a->start > b->start)
227 * Allocate a vmspace structure, including a vm_map and pmap.
228 * Initialize numerous fields. While the initial allocation is zerod,
229 * subsequence reuse from the objcache leaves elements of the structure
230 * intact (particularly the pmap), so portions must be zerod.
232 * The structure is not considered activated until we call sysref_activate().
237 vmspace_alloc(vm_offset_t min, vm_offset_t max)
241 lwkt_gettoken(&vmspace_token);
242 vm = sysref_alloc(&vmspace_sysref_class);
243 bzero(&vm->vm_startcopy,
244 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy);
245 vm_map_init(&vm->vm_map, min, max, NULL);
246 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */
247 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */
249 vm->vm_exitingcnt = 0;
250 cpu_vmspace_alloc(vm);
251 sysref_activate(&vm->vm_sysref);
252 lwkt_reltoken(&vmspace_token);
258 * dtor function - Some elements of the pmap are retained in the
259 * free-cached vmspaces to improve performance. We have to clean them up
260 * here before returning the vmspace to the memory pool.
265 vmspace_dtor(void *obj, void *private)
267 struct vmspace *vm = obj;
269 pmap_puninit(vmspace_pmap(vm));
273 * Called in two cases:
275 * (1) When the last sysref is dropped, but exitingcnt might still be
278 * (2) When there are no sysrefs (i.e. refcnt is negative) left and the
279 * exitingcnt becomes zero
281 * sysref will not scrap the object until we call sysref_put() once more
282 * after the last ref has been dropped.
284 * Interlocked by the sysref API.
287 vmspace_terminate(struct vmspace *vm)
292 * If exitingcnt is non-zero we can't get rid of the entire vmspace
293 * yet, but we can scrap user memory.
295 lwkt_gettoken(&vmspace_token);
296 if (vm->vm_exitingcnt) {
298 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS,
299 VM_MAX_USER_ADDRESS);
300 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS,
301 VM_MAX_USER_ADDRESS);
302 lwkt_reltoken(&vmspace_token);
305 cpu_vmspace_free(vm);
308 * Make sure any SysV shm is freed, it might not have in
313 KKASSERT(vm->vm_upcalls == NULL);
316 * Lock the map, to wait out all other references to it.
317 * Delete all of the mappings and pages they hold, then call
318 * the pmap module to reclaim anything left.
320 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
321 vm_map_lock(&vm->vm_map);
322 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
323 vm->vm_map.max_offset, &count);
324 vm_map_unlock(&vm->vm_map);
325 vm_map_entry_release(count);
327 pmap_release(vmspace_pmap(vm));
328 sysref_put(&vm->vm_sysref);
329 lwkt_reltoken(&vmspace_token);
333 * vmspaces are not currently locked.
336 vmspace_lock(struct vmspace *vm __unused)
341 vmspace_unlock(struct vmspace *vm __unused)
346 * This is called during exit indicating that the vmspace is no
347 * longer in used by an exiting process, but the process has not yet
353 vmspace_exitbump(struct vmspace *vm)
355 lwkt_gettoken(&vmspace_token);
357 lwkt_reltoken(&vmspace_token);
361 * This is called in the wait*() handling code. The vmspace can be terminated
362 * after the last wait is finished using it.
367 vmspace_exitfree(struct proc *p)
371 lwkt_gettoken(&vmspace_token);
375 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref))
376 vmspace_terminate(vm);
377 lwkt_reltoken(&vmspace_token);
381 * Swap useage is determined by taking the proportional swap used by
382 * VM objects backing the VM map. To make up for fractional losses,
383 * if the VM object has any swap use at all the associated map entries
384 * count for at least 1 swap page.
389 vmspace_swap_count(struct vmspace *vmspace)
391 vm_map_t map = &vmspace->vm_map;
397 lwkt_gettoken(&vmspace_token);
398 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
399 switch(cur->maptype) {
400 case VM_MAPTYPE_NORMAL:
401 case VM_MAPTYPE_VPAGETABLE:
402 if ((object = cur->object.vm_object) == NULL)
404 if (object->swblock_count) {
405 n = (cur->end - cur->start) / PAGE_SIZE;
406 count += object->swblock_count *
407 SWAP_META_PAGES * n / object->size + 1;
414 lwkt_reltoken(&vmspace_token);
419 * Calculate the approximate number of anonymous pages in use by
420 * this vmspace. To make up for fractional losses, we count each
421 * VM object as having at least 1 anonymous page.
426 vmspace_anonymous_count(struct vmspace *vmspace)
428 vm_map_t map = &vmspace->vm_map;
433 lwkt_gettoken(&vmspace_token);
434 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
435 switch(cur->maptype) {
436 case VM_MAPTYPE_NORMAL:
437 case VM_MAPTYPE_VPAGETABLE:
438 if ((object = cur->object.vm_object) == NULL)
440 if (object->type != OBJT_DEFAULT &&
441 object->type != OBJT_SWAP) {
444 count += object->resident_page_count;
450 lwkt_reltoken(&vmspace_token);
455 * Creates and returns a new empty VM map with the given physical map
456 * structure, and having the given lower and upper address bounds.
461 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max)
464 result = zalloc(mapzone);
465 vm_map_init(result, min, max, pmap);
470 * Initialize an existing vm_map structure such as that in the vmspace
471 * structure. The pmap is initialized elsewhere.
476 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap)
478 map->header.next = map->header.prev = &map->header;
479 RB_INIT(&map->rb_root);
484 map->min_offset = min;
485 map->max_offset = max;
487 map->first_free = &map->header;
488 map->hint = &map->header;
491 lockinit(&map->lock, "thrd_sleep", 0, 0);
495 * Shadow the vm_map_entry's object. This typically needs to be done when
496 * a write fault is taken on an entry which had previously been cloned by
497 * fork(). The shared object (which might be NULL) must become private so
498 * we add a shadow layer above it.
500 * Object allocation for anonymous mappings is defered as long as possible.
501 * When creating a shadow, however, the underlying object must be instantiated
502 * so it can be shared.
504 * If the map segment is governed by a virtual page table then it is
505 * possible to address offsets beyond the mapped area. Just allocate
506 * a maximally sized object for this case.
508 * The vm_map must be exclusively locked.
509 * No other requirements.
513 vm_map_entry_shadow(vm_map_entry_t entry)
515 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
516 vm_object_shadow(&entry->object.vm_object, &entry->offset,
517 0x7FFFFFFF); /* XXX */
519 vm_object_shadow(&entry->object.vm_object, &entry->offset,
520 atop(entry->end - entry->start));
522 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
526 * Allocate an object for a vm_map_entry.
528 * Object allocation for anonymous mappings is defered as long as possible.
529 * This function is called when we can defer no longer, generally when a map
530 * entry might be split or forked or takes a page fault.
532 * If the map segment is governed by a virtual page table then it is
533 * possible to address offsets beyond the mapped area. Just allocate
534 * a maximally sized object for this case.
536 * The vm_map must be exclusively locked.
537 * No other requirements.
540 vm_map_entry_allocate_object(vm_map_entry_t entry)
544 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
545 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */
547 obj = vm_object_allocate(OBJT_DEFAULT,
548 atop(entry->end - entry->start));
550 entry->object.vm_object = obj;
555 * Set an initial negative count so the first attempt to reserve
556 * space preloads a bunch of vm_map_entry's for this cpu. Also
557 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
558 * map a new page for vm_map_entry structures. SMP systems are
559 * particularly sensitive.
561 * This routine is called in early boot so we cannot just call
562 * vm_map_entry_reserve().
564 * Called from the low level boot code only (for each cpu)
567 vm_map_entry_reserve_cpu_init(globaldata_t gd)
569 vm_map_entry_t entry;
572 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2;
573 entry = &cpu_map_entry_init[gd->gd_cpuid][0];
574 for (i = 0; i < VMEPERCPU; ++i, ++entry) {
575 entry->next = gd->gd_vme_base;
576 gd->gd_vme_base = entry;
581 * Reserves vm_map_entry structures so code later on can manipulate
582 * map_entry structures within a locked map without blocking trying
583 * to allocate a new vm_map_entry.
588 vm_map_entry_reserve(int count)
590 struct globaldata *gd = mycpu;
591 vm_map_entry_t entry;
594 * Make sure we have enough structures in gd_vme_base to handle
595 * the reservation request.
598 while (gd->gd_vme_avail < count) {
599 entry = zalloc(mapentzone);
600 entry->next = gd->gd_vme_base;
601 gd->gd_vme_base = entry;
604 gd->gd_vme_avail -= count;
611 * Releases previously reserved vm_map_entry structures that were not
612 * used. If we have too much junk in our per-cpu cache clean some of
618 vm_map_entry_release(int count)
620 struct globaldata *gd = mycpu;
621 vm_map_entry_t entry;
624 gd->gd_vme_avail += count;
625 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) {
626 entry = gd->gd_vme_base;
627 KKASSERT(entry != NULL);
628 gd->gd_vme_base = entry->next;
631 zfree(mapentzone, entry);
638 * Reserve map entry structures for use in kernel_map itself. These
639 * entries have *ALREADY* been reserved on a per-cpu basis when the map
640 * was inited. This function is used by zalloc() to avoid a recursion
641 * when zalloc() itself needs to allocate additional kernel memory.
643 * This function works like the normal reserve but does not load the
644 * vm_map_entry cache (because that would result in an infinite
645 * recursion). Note that gd_vme_avail may go negative. This is expected.
647 * Any caller of this function must be sure to renormalize after
648 * potentially eating entries to ensure that the reserve supply
654 vm_map_entry_kreserve(int count)
656 struct globaldata *gd = mycpu;
659 gd->gd_vme_avail -= count;
661 KASSERT(gd->gd_vme_base != NULL,
662 ("no reserved entries left, gd_vme_avail = %d\n",
668 * Release previously reserved map entries for kernel_map. We do not
669 * attempt to clean up like the normal release function as this would
670 * cause an unnecessary (but probably not fatal) deep procedure call.
675 vm_map_entry_krelease(int count)
677 struct globaldata *gd = mycpu;
680 gd->gd_vme_avail += count;
685 * Allocates a VM map entry for insertion. No entry fields are filled in.
687 * The entries should have previously been reserved. The reservation count
688 * is tracked in (*countp).
692 static vm_map_entry_t
693 vm_map_entry_create(vm_map_t map, int *countp)
695 struct globaldata *gd = mycpu;
696 vm_map_entry_t entry;
698 KKASSERT(*countp > 0);
701 entry = gd->gd_vme_base;
702 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp));
703 gd->gd_vme_base = entry->next;
710 * Dispose of a vm_map_entry that is no longer being referenced.
715 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp)
717 struct globaldata *gd = mycpu;
719 KKASSERT(map->hint != entry);
720 KKASSERT(map->first_free != entry);
724 entry->next = gd->gd_vme_base;
725 gd->gd_vme_base = entry;
731 * Insert/remove entries from maps.
733 * The related map must be exclusively locked.
734 * No other requirements.
736 * NOTE! We currently acquire the vmspace_token only to avoid races
737 * against the pageout daemon's calls to vmspace_*_count(), which
738 * are unable to safely lock the vm_map without potentially
742 vm_map_entry_link(vm_map_t map,
743 vm_map_entry_t after_where,
744 vm_map_entry_t entry)
746 ASSERT_VM_MAP_LOCKED(map);
748 lwkt_gettoken(&vmspace_token);
750 entry->prev = after_where;
751 entry->next = after_where->next;
752 entry->next->prev = entry;
753 after_where->next = entry;
754 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry))
755 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry);
756 lwkt_reltoken(&vmspace_token);
760 vm_map_entry_unlink(vm_map_t map,
761 vm_map_entry_t entry)
766 ASSERT_VM_MAP_LOCKED(map);
768 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
769 panic("vm_map_entry_unlink: attempt to mess with "
770 "locked entry! %p", entry);
772 lwkt_gettoken(&vmspace_token);
777 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry);
779 lwkt_reltoken(&vmspace_token);
783 * Finds the map entry containing (or immediately preceding) the specified
784 * address in the given map. The entry is returned in (*entry).
786 * The boolean result indicates whether the address is actually contained
789 * The related map must be locked.
790 * No other requirements.
793 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry)
798 ASSERT_VM_MAP_LOCKED(map);
801 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive
802 * the hint code with the red-black lookup meets with system crashes
803 * and lockups. We do not yet know why.
805 * It is possible that the problem is related to the setting
806 * of the hint during map_entry deletion, in the code specified
807 * at the GGG comment later on in this file.
810 * Quickly check the cached hint, there's a good chance of a match.
812 if (map->hint != &map->header) {
814 if (address >= tmp->start && address < tmp->end) {
822 * Locate the record from the top of the tree. 'last' tracks the
823 * closest prior record and is returned if no match is found, which
824 * in binary tree terms means tracking the most recent right-branch
825 * taken. If there is no prior record, &map->header is returned.
828 tmp = RB_ROOT(&map->rb_root);
831 if (address >= tmp->start) {
832 if (address < tmp->end) {
838 tmp = RB_RIGHT(tmp, rb_entry);
840 tmp = RB_LEFT(tmp, rb_entry);
848 * Inserts the given whole VM object into the target map at the specified
849 * address range. The object's size should match that of the address range.
851 * The map must be exclusively locked.
852 * The caller must have reserved sufficient vm_map_entry structures.
854 * If object is non-NULL, ref count must be bumped by caller
855 * prior to making call to account for the new entry.
858 vm_map_insert(vm_map_t map, int *countp,
859 vm_object_t object, vm_ooffset_t offset,
860 vm_offset_t start, vm_offset_t end,
861 vm_maptype_t maptype,
862 vm_prot_t prot, vm_prot_t max,
865 vm_map_entry_t new_entry;
866 vm_map_entry_t prev_entry;
867 vm_map_entry_t temp_entry;
868 vm_eflags_t protoeflags;
870 ASSERT_VM_MAP_LOCKED(map);
873 * Check that the start and end points are not bogus.
875 if ((start < map->min_offset) || (end > map->max_offset) ||
877 return (KERN_INVALID_ADDRESS);
880 * Find the entry prior to the proposed starting address; if it's part
881 * of an existing entry, this range is bogus.
883 if (vm_map_lookup_entry(map, start, &temp_entry))
884 return (KERN_NO_SPACE);
886 prev_entry = temp_entry;
889 * Assert that the next entry doesn't overlap the end point.
892 if ((prev_entry->next != &map->header) &&
893 (prev_entry->next->start < end))
894 return (KERN_NO_SPACE);
898 if (cow & MAP_COPY_ON_WRITE)
899 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY;
901 if (cow & MAP_NOFAULT) {
902 protoeflags |= MAP_ENTRY_NOFAULT;
904 KASSERT(object == NULL,
905 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
907 if (cow & MAP_DISABLE_SYNCER)
908 protoeflags |= MAP_ENTRY_NOSYNC;
909 if (cow & MAP_DISABLE_COREDUMP)
910 protoeflags |= MAP_ENTRY_NOCOREDUMP;
911 if (cow & MAP_IS_STACK)
912 protoeflags |= MAP_ENTRY_STACK;
913 if (cow & MAP_IS_KSTACK)
914 protoeflags |= MAP_ENTRY_KSTACK;
916 lwkt_gettoken(&vm_token);
917 lwkt_gettoken(&vmobj_token);
921 * When object is non-NULL, it could be shared with another
922 * process. We have to set or clear OBJ_ONEMAPPING
925 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
926 vm_object_clear_flag(object, OBJ_ONEMAPPING);
929 else if ((prev_entry != &map->header) &&
930 (prev_entry->eflags == protoeflags) &&
931 (prev_entry->end == start) &&
932 (prev_entry->wired_count == 0) &&
933 prev_entry->maptype == maptype &&
934 ((prev_entry->object.vm_object == NULL) ||
935 vm_object_coalesce(prev_entry->object.vm_object,
936 OFF_TO_IDX(prev_entry->offset),
937 (vm_size_t)(prev_entry->end - prev_entry->start),
938 (vm_size_t)(end - prev_entry->end)))) {
940 * We were able to extend the object. Determine if we
941 * can extend the previous map entry to include the
944 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
945 (prev_entry->protection == prot) &&
946 (prev_entry->max_protection == max)) {
947 lwkt_reltoken(&vmobj_token);
948 lwkt_reltoken(&vm_token);
949 map->size += (end - prev_entry->end);
950 prev_entry->end = end;
951 vm_map_simplify_entry(map, prev_entry, countp);
952 return (KERN_SUCCESS);
956 * If we can extend the object but cannot extend the
957 * map entry, we have to create a new map entry. We
958 * must bump the ref count on the extended object to
959 * account for it. object may be NULL.
961 object = prev_entry->object.vm_object;
962 offset = prev_entry->offset +
963 (prev_entry->end - prev_entry->start);
964 vm_object_reference_locked(object);
967 lwkt_reltoken(&vmobj_token);
968 lwkt_reltoken(&vm_token);
971 * NOTE: if conditionals fail, object can be NULL here. This occurs
972 * in things like the buffer map where we manage kva but do not manage
980 new_entry = vm_map_entry_create(map, countp);
981 new_entry->start = start;
982 new_entry->end = end;
984 new_entry->maptype = maptype;
985 new_entry->eflags = protoeflags;
986 new_entry->object.vm_object = object;
987 new_entry->offset = offset;
988 new_entry->aux.master_pde = 0;
990 new_entry->inheritance = VM_INHERIT_DEFAULT;
991 new_entry->protection = prot;
992 new_entry->max_protection = max;
993 new_entry->wired_count = 0;
996 * Insert the new entry into the list
999 vm_map_entry_link(map, prev_entry, new_entry);
1000 map->size += new_entry->end - new_entry->start;
1003 * Update the free space hint. Entries cannot overlap.
1004 * An exact comparison is needed to avoid matching
1005 * against the map->header.
1007 if ((map->first_free == prev_entry) &&
1008 (prev_entry->end == new_entry->start)) {
1009 map->first_free = new_entry;
1014 * Temporarily removed to avoid MAP_STACK panic, due to
1015 * MAP_STACK being a huge hack. Will be added back in
1016 * when MAP_STACK (and the user stack mapping) is fixed.
1019 * It may be possible to simplify the entry
1021 vm_map_simplify_entry(map, new_entry, countp);
1025 * Try to pre-populate the page table. Mappings governed by virtual
1026 * page tables cannot be prepopulated without a lot of work, so
1029 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) &&
1030 maptype != VM_MAPTYPE_VPAGETABLE) {
1031 pmap_object_init_pt(map->pmap, start, prot,
1032 object, OFF_TO_IDX(offset), end - start,
1033 cow & MAP_PREFAULT_PARTIAL);
1036 return (KERN_SUCCESS);
1040 * Find sufficient space for `length' bytes in the given map, starting at
1041 * `start'. Returns 0 on success, 1 on no space.
1043 * This function will returned an arbitrarily aligned pointer. If no
1044 * particular alignment is required you should pass align as 1. Note that
1045 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1046 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1049 * 'align' should be a power of 2 but is not required to be.
1051 * The map must be exclusively locked.
1052 * No other requirements.
1055 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1056 vm_size_t align, int flags, vm_offset_t *addr)
1058 vm_map_entry_t entry, next;
1060 vm_offset_t align_mask;
1062 if (start < map->min_offset)
1063 start = map->min_offset;
1064 if (start > map->max_offset)
1068 * If the alignment is not a power of 2 we will have to use
1069 * a mod/division, set align_mask to a special value.
1071 if ((align | (align - 1)) + 1 != (align << 1))
1072 align_mask = (vm_offset_t)-1;
1074 align_mask = align - 1;
1077 * Look for the first possible address; if there's already something
1078 * at this address, we have to start after it.
1080 if (start == map->min_offset) {
1081 if ((entry = map->first_free) != &map->header)
1086 if (vm_map_lookup_entry(map, start, &tmp))
1092 * Look through the rest of the map, trying to fit a new region in the
1093 * gap between existing regions, or after the very last region.
1095 for (;; start = (entry = next)->end) {
1097 * Adjust the proposed start by the requested alignment,
1098 * be sure that we didn't wrap the address.
1100 if (align_mask == (vm_offset_t)-1)
1101 end = ((start + align - 1) / align) * align;
1103 end = (start + align_mask) & ~align_mask;
1108 * Find the end of the proposed new region. Be sure we didn't
1109 * go beyond the end of the map, or wrap around the address.
1110 * Then check to see if this is the last entry or if the
1111 * proposed end fits in the gap between this and the next
1114 end = start + length;
1115 if (end > map->max_offset || end < start)
1120 * If the next entry's start address is beyond the desired
1121 * end address we may have found a good entry.
1123 * If the next entry is a stack mapping we do not map into
1124 * the stack's reserved space.
1126 * XXX continue to allow mapping into the stack's reserved
1127 * space if doing a MAP_STACK mapping inside a MAP_STACK
1128 * mapping, for backwards compatibility. But the caller
1129 * really should use MAP_STACK | MAP_TRYFIXED if they
1132 if (next == &map->header)
1134 if (next->start >= end) {
1135 if ((next->eflags & MAP_ENTRY_STACK) == 0)
1137 if (flags & MAP_STACK)
1139 if (next->start - next->aux.avail_ssize >= end)
1146 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1147 * if it fails. The kernel_map is locked and nothing can steal
1148 * our address space if pmap_growkernel() blocks.
1150 * NOTE: This may be unconditionally called for kldload areas on
1151 * x86_64 because these do not bump kernel_vm_end (which would
1152 * fill 128G worth of page tables!). Therefore we must not
1155 if (map == &kernel_map) {
1158 kstop = round_page(start + length);
1159 if (kstop > kernel_vm_end)
1160 pmap_growkernel(start, kstop);
1167 * vm_map_find finds an unallocated region in the target address map with
1168 * the given length. The search is defined to be first-fit from the
1169 * specified address; the region found is returned in the same parameter.
1171 * If object is non-NULL, ref count must be bumped by caller
1172 * prior to making call to account for the new entry.
1174 * No requirements. This function will lock the map temporarily.
1177 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1178 vm_offset_t *addr, vm_size_t length, vm_size_t align,
1180 vm_maptype_t maptype,
1181 vm_prot_t prot, vm_prot_t max,
1190 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1193 if (vm_map_findspace(map, start, length, align, 0, addr)) {
1195 vm_map_entry_release(count);
1196 return (KERN_NO_SPACE);
1200 result = vm_map_insert(map, &count, object, offset,
1201 start, start + length,
1206 vm_map_entry_release(count);
1212 * Simplify the given map entry by merging with either neighbor. This
1213 * routine also has the ability to merge with both neighbors.
1215 * This routine guarentees that the passed entry remains valid (though
1216 * possibly extended). When merging, this routine may delete one or
1217 * both neighbors. No action is taken on entries which have their
1218 * in-transition flag set.
1220 * The map must be exclusively locked.
1223 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1225 vm_map_entry_t next, prev;
1226 vm_size_t prevsize, esize;
1228 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1229 ++mycpu->gd_cnt.v_intrans_coll;
1233 if (entry->maptype == VM_MAPTYPE_SUBMAP)
1237 if (prev != &map->header) {
1238 prevsize = prev->end - prev->start;
1239 if ( (prev->end == entry->start) &&
1240 (prev->maptype == entry->maptype) &&
1241 (prev->object.vm_object == entry->object.vm_object) &&
1242 (!prev->object.vm_object ||
1243 (prev->offset + prevsize == entry->offset)) &&
1244 (prev->eflags == entry->eflags) &&
1245 (prev->protection == entry->protection) &&
1246 (prev->max_protection == entry->max_protection) &&
1247 (prev->inheritance == entry->inheritance) &&
1248 (prev->wired_count == entry->wired_count)) {
1249 if (map->first_free == prev)
1250 map->first_free = entry;
1251 if (map->hint == prev)
1253 vm_map_entry_unlink(map, prev);
1254 entry->start = prev->start;
1255 entry->offset = prev->offset;
1256 if (prev->object.vm_object)
1257 vm_object_deallocate(prev->object.vm_object);
1258 vm_map_entry_dispose(map, prev, countp);
1263 if (next != &map->header) {
1264 esize = entry->end - entry->start;
1265 if ((entry->end == next->start) &&
1266 (next->maptype == entry->maptype) &&
1267 (next->object.vm_object == entry->object.vm_object) &&
1268 (!entry->object.vm_object ||
1269 (entry->offset + esize == next->offset)) &&
1270 (next->eflags == entry->eflags) &&
1271 (next->protection == entry->protection) &&
1272 (next->max_protection == entry->max_protection) &&
1273 (next->inheritance == entry->inheritance) &&
1274 (next->wired_count == entry->wired_count)) {
1275 if (map->first_free == next)
1276 map->first_free = entry;
1277 if (map->hint == next)
1279 vm_map_entry_unlink(map, next);
1280 entry->end = next->end;
1281 if (next->object.vm_object)
1282 vm_object_deallocate(next->object.vm_object);
1283 vm_map_entry_dispose(map, next, countp);
1289 * Asserts that the given entry begins at or after the specified address.
1290 * If necessary, it splits the entry into two.
1292 #define vm_map_clip_start(map, entry, startaddr, countp) \
1294 if (startaddr > entry->start) \
1295 _vm_map_clip_start(map, entry, startaddr, countp); \
1299 * This routine is called only when it is known that the entry must be split.
1301 * The map must be exclusively locked.
1304 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1307 vm_map_entry_t new_entry;
1310 * Split off the front portion -- note that we must insert the new
1311 * entry BEFORE this one, so that this entry has the specified
1315 vm_map_simplify_entry(map, entry, countp);
1318 * If there is no object backing this entry, we might as well create
1319 * one now. If we defer it, an object can get created after the map
1320 * is clipped, and individual objects will be created for the split-up
1321 * map. This is a bit of a hack, but is also about the best place to
1322 * put this improvement.
1324 if (entry->object.vm_object == NULL && !map->system_map) {
1325 vm_map_entry_allocate_object(entry);
1328 new_entry = vm_map_entry_create(map, countp);
1329 *new_entry = *entry;
1331 new_entry->end = start;
1332 entry->offset += (start - entry->start);
1333 entry->start = start;
1335 vm_map_entry_link(map, entry->prev, new_entry);
1337 switch(entry->maptype) {
1338 case VM_MAPTYPE_NORMAL:
1339 case VM_MAPTYPE_VPAGETABLE:
1340 vm_object_reference(new_entry->object.vm_object);
1348 * Asserts that the given entry ends at or before the specified address.
1349 * If necessary, it splits the entry into two.
1351 * The map must be exclusively locked.
1353 #define vm_map_clip_end(map, entry, endaddr, countp) \
1355 if (endaddr < entry->end) \
1356 _vm_map_clip_end(map, entry, endaddr, countp); \
1360 * This routine is called only when it is known that the entry must be split.
1362 * The map must be exclusively locked.
1365 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1368 vm_map_entry_t new_entry;
1371 * If there is no object backing this entry, we might as well create
1372 * one now. If we defer it, an object can get created after the map
1373 * is clipped, and individual objects will be created for the split-up
1374 * map. This is a bit of a hack, but is also about the best place to
1375 * put this improvement.
1378 if (entry->object.vm_object == NULL && !map->system_map) {
1379 vm_map_entry_allocate_object(entry);
1383 * Create a new entry and insert it AFTER the specified entry
1386 new_entry = vm_map_entry_create(map, countp);
1387 *new_entry = *entry;
1389 new_entry->start = entry->end = end;
1390 new_entry->offset += (end - entry->start);
1392 vm_map_entry_link(map, entry, new_entry);
1394 switch(entry->maptype) {
1395 case VM_MAPTYPE_NORMAL:
1396 case VM_MAPTYPE_VPAGETABLE:
1397 vm_object_reference(new_entry->object.vm_object);
1405 * Asserts that the starting and ending region addresses fall within the
1406 * valid range for the map.
1408 #define VM_MAP_RANGE_CHECK(map, start, end) \
1410 if (start < vm_map_min(map)) \
1411 start = vm_map_min(map); \
1412 if (end > vm_map_max(map)) \
1413 end = vm_map_max(map); \
1419 * Used to block when an in-transition collison occurs. The map
1420 * is unlocked for the sleep and relocked before the return.
1423 vm_map_transition_wait(vm_map_t map)
1425 tsleep_interlock(map, 0);
1427 tsleep(map, PINTERLOCKED, "vment", 0);
1432 * When we do blocking operations with the map lock held it is
1433 * possible that a clip might have occured on our in-transit entry,
1434 * requiring an adjustment to the entry in our loop. These macros
1435 * help the pageable and clip_range code deal with the case. The
1436 * conditional costs virtually nothing if no clipping has occured.
1439 #define CLIP_CHECK_BACK(entry, save_start) \
1441 while (entry->start != save_start) { \
1442 entry = entry->prev; \
1443 KASSERT(entry != &map->header, ("bad entry clip")); \
1447 #define CLIP_CHECK_FWD(entry, save_end) \
1449 while (entry->end != save_end) { \
1450 entry = entry->next; \
1451 KASSERT(entry != &map->header, ("bad entry clip")); \
1457 * Clip the specified range and return the base entry. The
1458 * range may cover several entries starting at the returned base
1459 * and the first and last entry in the covering sequence will be
1460 * properly clipped to the requested start and end address.
1462 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1465 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1466 * covered by the requested range.
1468 * The map must be exclusively locked on entry and will remain locked
1469 * on return. If no range exists or the range contains holes and you
1470 * specified that no holes were allowed, NULL will be returned. This
1471 * routine may temporarily unlock the map in order avoid a deadlock when
1476 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end,
1477 int *countp, int flags)
1479 vm_map_entry_t start_entry;
1480 vm_map_entry_t entry;
1483 * Locate the entry and effect initial clipping. The in-transition
1484 * case does not occur very often so do not try to optimize it.
1487 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1489 entry = start_entry;
1490 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1491 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1492 ++mycpu->gd_cnt.v_intrans_coll;
1493 ++mycpu->gd_cnt.v_intrans_wait;
1494 vm_map_transition_wait(map);
1496 * entry and/or start_entry may have been clipped while
1497 * we slept, or may have gone away entirely. We have
1498 * to restart from the lookup.
1504 * Since we hold an exclusive map lock we do not have to restart
1505 * after clipping, even though clipping may block in zalloc.
1507 vm_map_clip_start(map, entry, start, countp);
1508 vm_map_clip_end(map, entry, end, countp);
1509 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1512 * Scan entries covered by the range. When working on the next
1513 * entry a restart need only re-loop on the current entry which
1514 * we have already locked, since 'next' may have changed. Also,
1515 * even though entry is safe, it may have been clipped so we
1516 * have to iterate forwards through the clip after sleeping.
1518 while (entry->next != &map->header && entry->next->start < end) {
1519 vm_map_entry_t next = entry->next;
1521 if (flags & MAP_CLIP_NO_HOLES) {
1522 if (next->start > entry->end) {
1523 vm_map_unclip_range(map, start_entry,
1524 start, entry->end, countp, flags);
1529 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1530 vm_offset_t save_end = entry->end;
1531 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1532 ++mycpu->gd_cnt.v_intrans_coll;
1533 ++mycpu->gd_cnt.v_intrans_wait;
1534 vm_map_transition_wait(map);
1537 * clips might have occured while we blocked.
1539 CLIP_CHECK_FWD(entry, save_end);
1540 CLIP_CHECK_BACK(start_entry, start);
1544 * No restart necessary even though clip_end may block, we
1545 * are holding the map lock.
1547 vm_map_clip_end(map, next, end, countp);
1548 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1551 if (flags & MAP_CLIP_NO_HOLES) {
1552 if (entry->end != end) {
1553 vm_map_unclip_range(map, start_entry,
1554 start, entry->end, countp, flags);
1558 return(start_entry);
1562 * Undo the effect of vm_map_clip_range(). You should pass the same
1563 * flags and the same range that you passed to vm_map_clip_range().
1564 * This code will clear the in-transition flag on the entries and
1565 * wake up anyone waiting. This code will also simplify the sequence
1566 * and attempt to merge it with entries before and after the sequence.
1568 * The map must be locked on entry and will remain locked on return.
1570 * Note that you should also pass the start_entry returned by
1571 * vm_map_clip_range(). However, if you block between the two calls
1572 * with the map unlocked please be aware that the start_entry may
1573 * have been clipped and you may need to scan it backwards to find
1574 * the entry corresponding with the original start address. You are
1575 * responsible for this, vm_map_unclip_range() expects the correct
1576 * start_entry to be passed to it and will KASSERT otherwise.
1580 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1581 vm_offset_t start, vm_offset_t end,
1582 int *countp, int flags)
1584 vm_map_entry_t entry;
1586 entry = start_entry;
1588 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1589 while (entry != &map->header && entry->start < end) {
1590 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1591 ("in-transition flag not set during unclip on: %p",
1593 KASSERT(entry->end <= end,
1594 ("unclip_range: tail wasn't clipped"));
1595 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1596 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1597 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1600 entry = entry->next;
1604 * Simplification does not block so there is no restart case.
1606 entry = start_entry;
1607 while (entry != &map->header && entry->start < end) {
1608 vm_map_simplify_entry(map, entry, countp);
1609 entry = entry->next;
1614 * Mark the given range as handled by a subordinate map.
1616 * This range must have been created with vm_map_find(), and no other
1617 * operations may have been performed on this range prior to calling
1620 * Submappings cannot be removed.
1625 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1627 vm_map_entry_t entry;
1628 int result = KERN_INVALID_ARGUMENT;
1631 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1634 VM_MAP_RANGE_CHECK(map, start, end);
1636 if (vm_map_lookup_entry(map, start, &entry)) {
1637 vm_map_clip_start(map, entry, start, &count);
1639 entry = entry->next;
1642 vm_map_clip_end(map, entry, end, &count);
1644 if ((entry->start == start) && (entry->end == end) &&
1645 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1646 (entry->object.vm_object == NULL)) {
1647 entry->object.sub_map = submap;
1648 entry->maptype = VM_MAPTYPE_SUBMAP;
1649 result = KERN_SUCCESS;
1652 vm_map_entry_release(count);
1658 * Sets the protection of the specified address region in the target map.
1659 * If "set_max" is specified, the maximum protection is to be set;
1660 * otherwise, only the current protection is affected.
1662 * The protection is not applicable to submaps, but is applicable to normal
1663 * maps and maps governed by virtual page tables. For example, when operating
1664 * on a virtual page table our protection basically controls how COW occurs
1665 * on the backing object, whereas the virtual page table abstraction itself
1666 * is an abstraction for userland.
1671 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1672 vm_prot_t new_prot, boolean_t set_max)
1674 vm_map_entry_t current;
1675 vm_map_entry_t entry;
1678 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1681 VM_MAP_RANGE_CHECK(map, start, end);
1683 if (vm_map_lookup_entry(map, start, &entry)) {
1684 vm_map_clip_start(map, entry, start, &count);
1686 entry = entry->next;
1690 * Make a first pass to check for protection violations.
1693 while ((current != &map->header) && (current->start < end)) {
1694 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1696 vm_map_entry_release(count);
1697 return (KERN_INVALID_ARGUMENT);
1699 if ((new_prot & current->max_protection) != new_prot) {
1701 vm_map_entry_release(count);
1702 return (KERN_PROTECTION_FAILURE);
1704 current = current->next;
1708 * Go back and fix up protections. [Note that clipping is not
1709 * necessary the second time.]
1713 while ((current != &map->header) && (current->start < end)) {
1716 vm_map_clip_end(map, current, end, &count);
1718 old_prot = current->protection;
1720 current->protection =
1721 (current->max_protection = new_prot) &
1724 current->protection = new_prot;
1728 * Update physical map if necessary. Worry about copy-on-write
1729 * here -- CHECK THIS XXX
1732 if (current->protection != old_prot) {
1733 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1736 pmap_protect(map->pmap, current->start,
1738 current->protection & MASK(current));
1742 vm_map_simplify_entry(map, current, &count);
1744 current = current->next;
1748 vm_map_entry_release(count);
1749 return (KERN_SUCCESS);
1753 * This routine traverses a processes map handling the madvise
1754 * system call. Advisories are classified as either those effecting
1755 * the vm_map_entry structure, or those effecting the underlying
1758 * The <value> argument is used for extended madvise calls.
1763 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1764 int behav, off_t value)
1766 vm_map_entry_t current, entry;
1772 * Some madvise calls directly modify the vm_map_entry, in which case
1773 * we need to use an exclusive lock on the map and we need to perform
1774 * various clipping operations. Otherwise we only need a read-lock
1778 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1782 case MADV_SEQUENTIAL:
1796 vm_map_lock_read(map);
1799 vm_map_entry_release(count);
1804 * Locate starting entry and clip if necessary.
1807 VM_MAP_RANGE_CHECK(map, start, end);
1809 if (vm_map_lookup_entry(map, start, &entry)) {
1811 vm_map_clip_start(map, entry, start, &count);
1813 entry = entry->next;
1818 * madvise behaviors that are implemented in the vm_map_entry.
1820 * We clip the vm_map_entry so that behavioral changes are
1821 * limited to the specified address range.
1823 for (current = entry;
1824 (current != &map->header) && (current->start < end);
1825 current = current->next
1827 if (current->maptype == VM_MAPTYPE_SUBMAP)
1830 vm_map_clip_end(map, current, end, &count);
1834 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
1836 case MADV_SEQUENTIAL:
1837 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
1840 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
1843 current->eflags |= MAP_ENTRY_NOSYNC;
1846 current->eflags &= ~MAP_ENTRY_NOSYNC;
1849 current->eflags |= MAP_ENTRY_NOCOREDUMP;
1852 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
1856 * Invalidate the related pmap entries, used
1857 * to flush portions of the real kernel's
1858 * pmap when the caller has removed or
1859 * modified existing mappings in a virtual
1862 pmap_remove(map->pmap,
1863 current->start, current->end);
1867 * Set the page directory page for a map
1868 * governed by a virtual page table. Mark
1869 * the entry as being governed by a virtual
1870 * page table if it is not.
1872 * XXX the page directory page is stored
1873 * in the avail_ssize field if the map_entry.
1875 * XXX the map simplification code does not
1876 * compare this field so weird things may
1877 * happen if you do not apply this function
1878 * to the entire mapping governed by the
1879 * virtual page table.
1881 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
1885 current->aux.master_pde = value;
1886 pmap_remove(map->pmap,
1887 current->start, current->end);
1893 vm_map_simplify_entry(map, current, &count);
1901 * madvise behaviors that are implemented in the underlying
1904 * Since we don't clip the vm_map_entry, we have to clip
1905 * the vm_object pindex and count.
1907 * NOTE! We currently do not support these functions on
1908 * virtual page tables.
1910 for (current = entry;
1911 (current != &map->header) && (current->start < end);
1912 current = current->next
1914 vm_offset_t useStart;
1916 if (current->maptype != VM_MAPTYPE_NORMAL)
1919 pindex = OFF_TO_IDX(current->offset);
1920 count = atop(current->end - current->start);
1921 useStart = current->start;
1923 if (current->start < start) {
1924 pindex += atop(start - current->start);
1925 count -= atop(start - current->start);
1928 if (current->end > end)
1929 count -= atop(current->end - end);
1934 vm_object_madvise(current->object.vm_object,
1935 pindex, count, behav);
1938 * Try to populate the page table. Mappings governed
1939 * by virtual page tables cannot be pre-populated
1940 * without a lot of work so don't try.
1942 if (behav == MADV_WILLNEED &&
1943 current->maptype != VM_MAPTYPE_VPAGETABLE) {
1944 pmap_object_init_pt(
1947 current->protection,
1948 current->object.vm_object,
1950 (count << PAGE_SHIFT),
1951 MAP_PREFAULT_MADVISE
1955 vm_map_unlock_read(map);
1957 vm_map_entry_release(count);
1963 * Sets the inheritance of the specified address range in the target map.
1964 * Inheritance affects how the map will be shared with child maps at the
1965 * time of vm_map_fork.
1968 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
1969 vm_inherit_t new_inheritance)
1971 vm_map_entry_t entry;
1972 vm_map_entry_t temp_entry;
1975 switch (new_inheritance) {
1976 case VM_INHERIT_NONE:
1977 case VM_INHERIT_COPY:
1978 case VM_INHERIT_SHARE:
1981 return (KERN_INVALID_ARGUMENT);
1984 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1987 VM_MAP_RANGE_CHECK(map, start, end);
1989 if (vm_map_lookup_entry(map, start, &temp_entry)) {
1991 vm_map_clip_start(map, entry, start, &count);
1993 entry = temp_entry->next;
1995 while ((entry != &map->header) && (entry->start < end)) {
1996 vm_map_clip_end(map, entry, end, &count);
1998 entry->inheritance = new_inheritance;
2000 vm_map_simplify_entry(map, entry, &count);
2002 entry = entry->next;
2005 vm_map_entry_release(count);
2006 return (KERN_SUCCESS);
2010 * Implement the semantics of mlock
2013 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2014 boolean_t new_pageable)
2016 vm_map_entry_t entry;
2017 vm_map_entry_t start_entry;
2019 int rv = KERN_SUCCESS;
2022 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2024 VM_MAP_RANGE_CHECK(map, start, real_end);
2027 start_entry = vm_map_clip_range(map, start, end, &count,
2029 if (start_entry == NULL) {
2031 vm_map_entry_release(count);
2032 return (KERN_INVALID_ADDRESS);
2035 if (new_pageable == 0) {
2036 entry = start_entry;
2037 while ((entry != &map->header) && (entry->start < end)) {
2038 vm_offset_t save_start;
2039 vm_offset_t save_end;
2042 * Already user wired or hard wired (trivial cases)
2044 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2045 entry = entry->next;
2048 if (entry->wired_count != 0) {
2049 entry->wired_count++;
2050 entry->eflags |= MAP_ENTRY_USER_WIRED;
2051 entry = entry->next;
2056 * A new wiring requires instantiation of appropriate
2057 * management structures and the faulting in of the
2060 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2061 int copyflag = entry->eflags &
2062 MAP_ENTRY_NEEDS_COPY;
2063 if (copyflag && ((entry->protection &
2064 VM_PROT_WRITE) != 0)) {
2065 vm_map_entry_shadow(entry);
2066 } else if (entry->object.vm_object == NULL &&
2068 vm_map_entry_allocate_object(entry);
2071 entry->wired_count++;
2072 entry->eflags |= MAP_ENTRY_USER_WIRED;
2075 * Now fault in the area. Note that vm_fault_wire()
2076 * may release the map lock temporarily, it will be
2077 * relocked on return. The in-transition
2078 * flag protects the entries.
2080 save_start = entry->start;
2081 save_end = entry->end;
2082 rv = vm_fault_wire(map, entry, TRUE);
2084 CLIP_CHECK_BACK(entry, save_start);
2086 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2087 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2088 entry->wired_count = 0;
2089 if (entry->end == save_end)
2091 entry = entry->next;
2092 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2094 end = save_start; /* unwire the rest */
2098 * note that even though the entry might have been
2099 * clipped, the USER_WIRED flag we set prevents
2100 * duplication so we do not have to do a
2103 entry = entry->next;
2107 * If we failed fall through to the unwiring section to
2108 * unwire what we had wired so far. 'end' has already
2115 * start_entry might have been clipped if we unlocked the
2116 * map and blocked. No matter how clipped it has gotten
2117 * there should be a fragment that is on our start boundary.
2119 CLIP_CHECK_BACK(start_entry, start);
2123 * Deal with the unwiring case.
2127 * This is the unwiring case. We must first ensure that the
2128 * range to be unwired is really wired down. We know there
2131 entry = start_entry;
2132 while ((entry != &map->header) && (entry->start < end)) {
2133 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2134 rv = KERN_INVALID_ARGUMENT;
2137 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2138 entry = entry->next;
2142 * Now decrement the wiring count for each region. If a region
2143 * becomes completely unwired, unwire its physical pages and
2147 * The map entries are processed in a loop, checking to
2148 * make sure the entry is wired and asserting it has a wired
2149 * count. However, another loop was inserted more-or-less in
2150 * the middle of the unwiring path. This loop picks up the
2151 * "entry" loop variable from the first loop without first
2152 * setting it to start_entry. Naturally, the secound loop
2153 * is never entered and the pages backing the entries are
2154 * never unwired. This can lead to a leak of wired pages.
2156 entry = start_entry;
2157 while ((entry != &map->header) && (entry->start < end)) {
2158 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2159 ("expected USER_WIRED on entry %p", entry));
2160 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2161 entry->wired_count--;
2162 if (entry->wired_count == 0)
2163 vm_fault_unwire(map, entry);
2164 entry = entry->next;
2168 vm_map_unclip_range(map, start_entry, start, real_end, &count,
2172 vm_map_entry_release(count);
2177 * Sets the pageability of the specified address range in the target map.
2178 * Regions specified as not pageable require locked-down physical
2179 * memory and physical page maps.
2181 * The map must not be locked, but a reference must remain to the map
2182 * throughout the call.
2184 * This function may be called via the zalloc path and must properly
2185 * reserve map entries for kernel_map.
2190 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2192 vm_map_entry_t entry;
2193 vm_map_entry_t start_entry;
2195 int rv = KERN_SUCCESS;
2198 if (kmflags & KM_KRESERVE)
2199 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2201 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2203 VM_MAP_RANGE_CHECK(map, start, real_end);
2206 start_entry = vm_map_clip_range(map, start, end, &count,
2208 if (start_entry == NULL) {
2210 rv = KERN_INVALID_ADDRESS;
2213 if ((kmflags & KM_PAGEABLE) == 0) {
2217 * 1. Holding the write lock, we create any shadow or zero-fill
2218 * objects that need to be created. Then we clip each map
2219 * entry to the region to be wired and increment its wiring
2220 * count. We create objects before clipping the map entries
2221 * to avoid object proliferation.
2223 * 2. We downgrade to a read lock, and call vm_fault_wire to
2224 * fault in the pages for any newly wired area (wired_count is
2227 * Downgrading to a read lock for vm_fault_wire avoids a
2228 * possible deadlock with another process that may have faulted
2229 * on one of the pages to be wired (it would mark the page busy,
2230 * blocking us, then in turn block on the map lock that we
2231 * hold). Because of problems in the recursive lock package,
2232 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2233 * any actions that require the write lock must be done
2234 * beforehand. Because we keep the read lock on the map, the
2235 * copy-on-write status of the entries we modify here cannot
2238 entry = start_entry;
2239 while ((entry != &map->header) && (entry->start < end)) {
2241 * Trivial case if the entry is already wired
2243 if (entry->wired_count) {
2244 entry->wired_count++;
2245 entry = entry->next;
2250 * The entry is being newly wired, we have to setup
2251 * appropriate management structures. A shadow
2252 * object is required for a copy-on-write region,
2253 * or a normal object for a zero-fill region. We
2254 * do not have to do this for entries that point to sub
2255 * maps because we won't hold the lock on the sub map.
2257 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2258 int copyflag = entry->eflags &
2259 MAP_ENTRY_NEEDS_COPY;
2260 if (copyflag && ((entry->protection &
2261 VM_PROT_WRITE) != 0)) {
2262 vm_map_entry_shadow(entry);
2263 } else if (entry->object.vm_object == NULL &&
2265 vm_map_entry_allocate_object(entry);
2269 entry->wired_count++;
2270 entry = entry->next;
2278 * HACK HACK HACK HACK
2280 * vm_fault_wire() temporarily unlocks the map to avoid
2281 * deadlocks. The in-transition flag from vm_map_clip_range
2282 * call should protect us from changes while the map is
2285 * NOTE: Previously this comment stated that clipping might
2286 * still occur while the entry is unlocked, but from
2287 * what I can tell it actually cannot.
2289 * It is unclear whether the CLIP_CHECK_*() calls
2290 * are still needed but we keep them in anyway.
2292 * HACK HACK HACK HACK
2295 entry = start_entry;
2296 while (entry != &map->header && entry->start < end) {
2298 * If vm_fault_wire fails for any page we need to undo
2299 * what has been done. We decrement the wiring count
2300 * for those pages which have not yet been wired (now)
2301 * and unwire those that have (later).
2303 vm_offset_t save_start = entry->start;
2304 vm_offset_t save_end = entry->end;
2306 if (entry->wired_count == 1)
2307 rv = vm_fault_wire(map, entry, FALSE);
2309 CLIP_CHECK_BACK(entry, save_start);
2311 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2312 entry->wired_count = 0;
2313 if (entry->end == save_end)
2315 entry = entry->next;
2316 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2321 CLIP_CHECK_FWD(entry, save_end);
2322 entry = entry->next;
2326 * If a failure occured undo everything by falling through
2327 * to the unwiring code. 'end' has already been adjusted
2331 kmflags |= KM_PAGEABLE;
2334 * start_entry is still IN_TRANSITION but may have been
2335 * clipped since vm_fault_wire() unlocks and relocks the
2336 * map. No matter how clipped it has gotten there should
2337 * be a fragment that is on our start boundary.
2339 CLIP_CHECK_BACK(start_entry, start);
2342 if (kmflags & KM_PAGEABLE) {
2344 * This is the unwiring case. We must first ensure that the
2345 * range to be unwired is really wired down. We know there
2348 entry = start_entry;
2349 while ((entry != &map->header) && (entry->start < end)) {
2350 if (entry->wired_count == 0) {
2351 rv = KERN_INVALID_ARGUMENT;
2354 entry = entry->next;
2358 * Now decrement the wiring count for each region. If a region
2359 * becomes completely unwired, unwire its physical pages and
2362 entry = start_entry;
2363 while ((entry != &map->header) && (entry->start < end)) {
2364 entry->wired_count--;
2365 if (entry->wired_count == 0)
2366 vm_fault_unwire(map, entry);
2367 entry = entry->next;
2371 vm_map_unclip_range(map, start_entry, start, real_end,
2372 &count, MAP_CLIP_NO_HOLES);
2376 if (kmflags & KM_KRESERVE)
2377 vm_map_entry_krelease(count);
2379 vm_map_entry_release(count);
2384 * Mark a newly allocated address range as wired but do not fault in
2385 * the pages. The caller is expected to load the pages into the object.
2387 * The map must be locked on entry and will remain locked on return.
2388 * No other requirements.
2391 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2394 vm_map_entry_t scan;
2395 vm_map_entry_t entry;
2397 entry = vm_map_clip_range(map, addr, addr + size,
2398 countp, MAP_CLIP_NO_HOLES);
2400 scan != &map->header && scan->start < addr + size;
2401 scan = scan->next) {
2402 KKASSERT(entry->wired_count == 0);
2403 entry->wired_count = 1;
2405 vm_map_unclip_range(map, entry, addr, addr + size,
2406 countp, MAP_CLIP_NO_HOLES);
2410 * Push any dirty cached pages in the address range to their pager.
2411 * If syncio is TRUE, dirty pages are written synchronously.
2412 * If invalidate is TRUE, any cached pages are freed as well.
2414 * This routine is called by sys_msync()
2416 * Returns an error if any part of the specified range is not mapped.
2421 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2422 boolean_t syncio, boolean_t invalidate)
2424 vm_map_entry_t current;
2425 vm_map_entry_t entry;
2428 vm_ooffset_t offset;
2430 vm_map_lock_read(map);
2431 VM_MAP_RANGE_CHECK(map, start, end);
2432 if (!vm_map_lookup_entry(map, start, &entry)) {
2433 vm_map_unlock_read(map);
2434 return (KERN_INVALID_ADDRESS);
2437 * Make a first pass to check for holes.
2439 for (current = entry; current->start < end; current = current->next) {
2440 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2441 vm_map_unlock_read(map);
2442 return (KERN_INVALID_ARGUMENT);
2444 if (end > current->end &&
2445 (current->next == &map->header ||
2446 current->end != current->next->start)) {
2447 vm_map_unlock_read(map);
2448 return (KERN_INVALID_ADDRESS);
2453 pmap_remove(vm_map_pmap(map), start, end);
2456 * Make a second pass, cleaning/uncaching pages from the indicated
2459 * Hold vm_token to avoid blocking in vm_object_reference()
2461 lwkt_gettoken(&vm_token);
2462 lwkt_gettoken(&vmobj_token);
2464 for (current = entry; current->start < end; current = current->next) {
2465 offset = current->offset + (start - current->start);
2466 size = (end <= current->end ? end : current->end) - start;
2467 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2469 vm_map_entry_t tentry;
2472 smap = current->object.sub_map;
2473 vm_map_lock_read(smap);
2474 vm_map_lookup_entry(smap, offset, &tentry);
2475 tsize = tentry->end - offset;
2478 object = tentry->object.vm_object;
2479 offset = tentry->offset + (offset - tentry->start);
2480 vm_map_unlock_read(smap);
2482 object = current->object.vm_object;
2485 * Note that there is absolutely no sense in writing out
2486 * anonymous objects, so we track down the vnode object
2488 * We invalidate (remove) all pages from the address space
2489 * anyway, for semantic correctness.
2491 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2492 * may start out with a NULL object.
2494 while (object && object->backing_object) {
2495 offset += object->backing_object_offset;
2496 object = object->backing_object;
2497 if (object->size < OFF_TO_IDX( offset + size))
2498 size = IDX_TO_OFF(object->size) - offset;
2500 if (object && (object->type == OBJT_VNODE) &&
2501 (current->protection & VM_PROT_WRITE) &&
2502 (object->flags & OBJ_NOMSYNC) == 0) {
2504 * Flush pages if writing is allowed, invalidate them
2505 * if invalidation requested. Pages undergoing I/O
2506 * will be ignored by vm_object_page_remove().
2508 * We cannot lock the vnode and then wait for paging
2509 * to complete without deadlocking against vm_fault.
2510 * Instead we simply call vm_object_page_remove() and
2511 * allow it to block internally on a page-by-page
2512 * basis when it encounters pages undergoing async
2517 vm_object_reference_locked(object);
2518 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2519 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2520 flags |= invalidate ? OBJPC_INVAL : 0;
2523 * When operating on a virtual page table just
2524 * flush the whole object. XXX we probably ought
2527 switch(current->maptype) {
2528 case VM_MAPTYPE_NORMAL:
2529 vm_object_page_clean(object,
2531 OFF_TO_IDX(offset + size + PAGE_MASK),
2534 case VM_MAPTYPE_VPAGETABLE:
2535 vm_object_page_clean(object, 0, 0, flags);
2538 vn_unlock(((struct vnode *)object->handle));
2539 vm_object_deallocate_locked(object);
2541 if (object && invalidate &&
2542 ((object->type == OBJT_VNODE) ||
2543 (object->type == OBJT_DEVICE))) {
2545 (object->type == OBJT_DEVICE) ? FALSE : TRUE;
2546 vm_object_reference_locked(object);
2547 switch(current->maptype) {
2548 case VM_MAPTYPE_NORMAL:
2549 vm_object_page_remove(object,
2551 OFF_TO_IDX(offset + size + PAGE_MASK),
2554 case VM_MAPTYPE_VPAGETABLE:
2555 vm_object_page_remove(object, 0, 0, clean_only);
2558 vm_object_deallocate_locked(object);
2563 lwkt_reltoken(&vmobj_token);
2564 lwkt_reltoken(&vm_token);
2565 vm_map_unlock_read(map);
2567 return (KERN_SUCCESS);
2571 * Make the region specified by this entry pageable.
2573 * The vm_map must be exclusively locked.
2576 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2578 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2579 entry->wired_count = 0;
2580 vm_fault_unwire(map, entry);
2584 * Deallocate the given entry from the target map.
2586 * The vm_map must be exclusively locked.
2589 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2591 vm_map_entry_unlink(map, entry);
2592 map->size -= entry->end - entry->start;
2594 switch(entry->maptype) {
2595 case VM_MAPTYPE_NORMAL:
2596 case VM_MAPTYPE_VPAGETABLE:
2597 vm_object_deallocate(entry->object.vm_object);
2603 vm_map_entry_dispose(map, entry, countp);
2607 * Deallocates the given address range from the target map.
2609 * The vm_map must be exclusively locked.
2612 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2615 vm_map_entry_t entry;
2616 vm_map_entry_t first_entry;
2618 ASSERT_VM_MAP_LOCKED(map);
2621 * Find the start of the region, and clip it. Set entry to point
2622 * at the first record containing the requested address or, if no
2623 * such record exists, the next record with a greater address. The
2624 * loop will run from this point until a record beyond the termination
2625 * address is encountered.
2627 * map->hint must be adjusted to not point to anything we delete,
2628 * so set it to the entry prior to the one being deleted.
2630 * GGG see other GGG comment.
2632 if (vm_map_lookup_entry(map, start, &first_entry)) {
2633 entry = first_entry;
2634 vm_map_clip_start(map, entry, start, countp);
2635 map->hint = entry->prev; /* possible problem XXX */
2637 map->hint = first_entry; /* possible problem XXX */
2638 entry = first_entry->next;
2642 * If a hole opens up prior to the current first_free then
2643 * adjust first_free. As with map->hint, map->first_free
2644 * cannot be left set to anything we might delete.
2646 if (entry == &map->header) {
2647 map->first_free = &map->header;
2648 } else if (map->first_free->start >= start) {
2649 map->first_free = entry->prev;
2653 * Step through all entries in this region
2655 while ((entry != &map->header) && (entry->start < end)) {
2656 vm_map_entry_t next;
2658 vm_pindex_t offidxstart, offidxend, count;
2661 * If we hit an in-transition entry we have to sleep and
2662 * retry. It's easier (and not really slower) to just retry
2663 * since this case occurs so rarely and the hint is already
2664 * pointing at the right place. We have to reset the
2665 * start offset so as not to accidently delete an entry
2666 * another process just created in vacated space.
2668 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2669 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2670 start = entry->start;
2671 ++mycpu->gd_cnt.v_intrans_coll;
2672 ++mycpu->gd_cnt.v_intrans_wait;
2673 vm_map_transition_wait(map);
2676 vm_map_clip_end(map, entry, end, countp);
2682 offidxstart = OFF_TO_IDX(entry->offset);
2683 count = OFF_TO_IDX(e - s);
2684 object = entry->object.vm_object;
2687 * Unwire before removing addresses from the pmap; otherwise,
2688 * unwiring will put the entries back in the pmap.
2690 if (entry->wired_count != 0)
2691 vm_map_entry_unwire(map, entry);
2693 offidxend = offidxstart + count;
2696 * Hold vm_token when manipulating vm_objects,
2698 * Hold vmobj_token when potentially adding or removing
2699 * objects (collapse requires both).
2701 lwkt_gettoken(&vm_token);
2702 lwkt_gettoken(&vmobj_token);
2704 if (object == &kernel_object) {
2705 vm_object_page_remove(object, offidxstart,
2708 pmap_remove(map->pmap, s, e);
2710 if (object != NULL &&
2711 object->ref_count != 1 &&
2712 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2714 (object->type == OBJT_DEFAULT ||
2715 object->type == OBJT_SWAP)) {
2716 vm_object_collapse(object);
2717 vm_object_page_remove(object, offidxstart,
2719 if (object->type == OBJT_SWAP) {
2720 swap_pager_freespace(object,
2724 if (offidxend >= object->size &&
2725 offidxstart < object->size) {
2726 object->size = offidxstart;
2730 lwkt_reltoken(&vmobj_token);
2731 lwkt_reltoken(&vm_token);
2734 * Delete the entry (which may delete the object) only after
2735 * removing all pmap entries pointing to its pages.
2736 * (Otherwise, its page frames may be reallocated, and any
2737 * modify bits will be set in the wrong object!)
2739 vm_map_entry_delete(map, entry, countp);
2742 return (KERN_SUCCESS);
2746 * Remove the given address range from the target map.
2747 * This is the exported form of vm_map_delete.
2752 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
2757 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2759 VM_MAP_RANGE_CHECK(map, start, end);
2760 result = vm_map_delete(map, start, end, &count);
2762 vm_map_entry_release(count);
2768 * Assert that the target map allows the specified privilege on the
2769 * entire address region given. The entire region must be allocated.
2771 * The caller must specify whether the vm_map is already locked or not.
2774 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2775 vm_prot_t protection, boolean_t have_lock)
2777 vm_map_entry_t entry;
2778 vm_map_entry_t tmp_entry;
2781 if (have_lock == FALSE)
2782 vm_map_lock_read(map);
2784 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
2785 if (have_lock == FALSE)
2786 vm_map_unlock_read(map);
2792 while (start < end) {
2793 if (entry == &map->header) {
2801 if (start < entry->start) {
2806 * Check protection associated with entry.
2809 if ((entry->protection & protection) != protection) {
2813 /* go to next entry */
2816 entry = entry->next;
2818 if (have_lock == FALSE)
2819 vm_map_unlock_read(map);
2824 * Split the pages in a map entry into a new object. This affords
2825 * easier removal of unused pages, and keeps object inheritance from
2826 * being a negative impact on memory usage.
2828 * The vm_map must be exclusively locked.
2831 vm_map_split(vm_map_entry_t entry)
2834 vm_object_t orig_object, new_object, source;
2836 vm_pindex_t offidxstart, offidxend, idx;
2838 vm_ooffset_t offset;
2840 orig_object = entry->object.vm_object;
2841 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
2843 if (orig_object->ref_count <= 1)
2846 offset = entry->offset;
2850 offidxstart = OFF_TO_IDX(offset);
2851 offidxend = offidxstart + OFF_TO_IDX(e - s);
2852 size = offidxend - offidxstart;
2854 switch(orig_object->type) {
2856 new_object = default_pager_alloc(NULL, IDX_TO_OFF(size),
2860 new_object = swap_pager_alloc(NULL, IDX_TO_OFF(size),
2868 if (new_object == NULL)
2872 * vm_token required when manipulating vm_objects.
2874 lwkt_gettoken(&vm_token);
2875 lwkt_gettoken(&vmobj_token);
2877 source = orig_object->backing_object;
2878 if (source != NULL) {
2879 /* Referenced by new_object */
2880 vm_object_reference_locked(source);
2881 LIST_INSERT_HEAD(&source->shadow_head,
2882 new_object, shadow_list);
2883 vm_object_clear_flag(source, OBJ_ONEMAPPING);
2884 new_object->backing_object_offset =
2885 orig_object->backing_object_offset +
2886 IDX_TO_OFF(offidxstart);
2887 new_object->backing_object = source;
2888 source->shadow_count++;
2889 source->generation++;
2892 for (idx = 0; idx < size; idx++) {
2896 m = vm_page_lookup(orig_object, offidxstart + idx);
2901 * We must wait for pending I/O to complete before we can
2904 * We do not have to VM_PROT_NONE the page as mappings should
2905 * not be changed by this operation.
2907 if (vm_page_sleep_busy(m, TRUE, "spltwt"))
2910 vm_page_rename(m, new_object, idx);
2911 /* page automatically made dirty by rename and cache handled */
2915 if (orig_object->type == OBJT_SWAP) {
2916 vm_object_pip_add(orig_object, 1);
2918 * copy orig_object pages into new_object
2919 * and destroy unneeded pages in
2922 swap_pager_copy(orig_object, new_object, offidxstart, 0);
2923 vm_object_pip_wakeup(orig_object);
2927 * Wakeup the pages we played with. No spl protection is needed
2928 * for a simple wakeup.
2930 for (idx = 0; idx < size; idx++) {
2931 m = vm_page_lookup(new_object, idx);
2936 entry->object.vm_object = new_object;
2937 entry->offset = 0LL;
2938 vm_object_deallocate_locked(orig_object);
2939 lwkt_reltoken(&vmobj_token);
2940 lwkt_reltoken(&vm_token);
2944 * Copies the contents of the source entry to the destination
2945 * entry. The entries *must* be aligned properly.
2947 * The vm_map must be exclusively locked.
2948 * vm_token must be held
2951 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
2952 vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
2954 vm_object_t src_object;
2956 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP)
2958 if (src_entry->maptype == VM_MAPTYPE_SUBMAP)
2961 ASSERT_LWKT_TOKEN_HELD(&vm_token);
2962 lwkt_gettoken(&vmobj_token); /* required for collapse */
2964 if (src_entry->wired_count == 0) {
2966 * If the source entry is marked needs_copy, it is already
2969 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
2970 pmap_protect(src_map->pmap,
2973 src_entry->protection & ~VM_PROT_WRITE);
2977 * Make a copy of the object.
2979 if ((src_object = src_entry->object.vm_object) != NULL) {
2980 if ((src_object->handle == NULL) &&
2981 (src_object->type == OBJT_DEFAULT ||
2982 src_object->type == OBJT_SWAP)) {
2983 vm_object_collapse(src_object);
2984 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) {
2985 vm_map_split(src_entry);
2986 src_object = src_entry->object.vm_object;
2990 vm_object_reference_locked(src_object);
2991 vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
2992 dst_entry->object.vm_object = src_object;
2993 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
2994 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
2995 dst_entry->offset = src_entry->offset;
2997 dst_entry->object.vm_object = NULL;
2998 dst_entry->offset = 0;
3001 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3002 dst_entry->end - dst_entry->start, src_entry->start);
3005 * Of course, wired down pages can't be set copy-on-write.
3006 * Cause wired pages to be copied into the new map by
3007 * simulating faults (the new pages are pageable)
3009 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3011 lwkt_reltoken(&vmobj_token);
3016 * Create a new process vmspace structure and vm_map
3017 * based on those of an existing process. The new map
3018 * is based on the old map, according to the inheritance
3019 * values on the regions in that map.
3021 * The source map must not be locked.
3025 vmspace_fork(struct vmspace *vm1)
3027 struct vmspace *vm2;
3028 vm_map_t old_map = &vm1->vm_map;
3030 vm_map_entry_t old_entry;
3031 vm_map_entry_t new_entry;
3035 lwkt_gettoken(&vm_token);
3036 lwkt_gettoken(&vmspace_token);
3037 lwkt_gettoken(&vmobj_token);
3038 vm_map_lock(old_map);
3039 old_map->infork = 1;
3042 * XXX Note: upcalls are not copied.
3044 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3045 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3046 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3047 new_map = &vm2->vm_map; /* XXX */
3048 new_map->timestamp = 1;
3050 vm_map_lock(new_map);
3053 old_entry = old_map->header.next;
3054 while (old_entry != &old_map->header) {
3056 old_entry = old_entry->next;
3059 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3061 old_entry = old_map->header.next;
3062 while (old_entry != &old_map->header) {
3063 if (old_entry->maptype == VM_MAPTYPE_SUBMAP)
3064 panic("vm_map_fork: encountered a submap");
3066 switch (old_entry->inheritance) {
3067 case VM_INHERIT_NONE:
3069 case VM_INHERIT_SHARE:
3071 * Clone the entry, creating the shared object if
3074 object = old_entry->object.vm_object;
3075 if (object == NULL) {
3076 vm_map_entry_allocate_object(old_entry);
3077 object = old_entry->object.vm_object;
3081 * Add the reference before calling vm_map_entry_shadow
3082 * to insure that a shadow object is created.
3084 vm_object_reference_locked(object);
3085 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3086 vm_map_entry_shadow(old_entry);
3087 /* Transfer the second reference too. */
3088 vm_object_reference_locked(
3089 old_entry->object.vm_object);
3090 vm_object_deallocate_locked(object);
3091 object = old_entry->object.vm_object;
3093 vm_object_clear_flag(object, OBJ_ONEMAPPING);
3096 * Clone the entry, referencing the shared object.
3098 new_entry = vm_map_entry_create(new_map, &count);
3099 *new_entry = *old_entry;
3100 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3101 new_entry->wired_count = 0;
3104 * Insert the entry into the new map -- we know we're
3105 * inserting at the end of the new map.
3108 vm_map_entry_link(new_map, new_map->header.prev,
3112 * Update the physical map
3114 pmap_copy(new_map->pmap, old_map->pmap,
3116 (old_entry->end - old_entry->start),
3119 case VM_INHERIT_COPY:
3121 * Clone the entry and link into the map.
3123 new_entry = vm_map_entry_create(new_map, &count);
3124 *new_entry = *old_entry;
3125 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3126 new_entry->wired_count = 0;
3127 new_entry->object.vm_object = NULL;
3128 vm_map_entry_link(new_map, new_map->header.prev,
3130 vm_map_copy_entry(old_map, new_map, old_entry,
3134 old_entry = old_entry->next;
3137 new_map->size = old_map->size;
3138 old_map->infork = 0;
3139 vm_map_unlock(old_map);
3140 vm_map_unlock(new_map);
3141 vm_map_entry_release(count);
3143 lwkt_reltoken(&vmobj_token);
3144 lwkt_reltoken(&vmspace_token);
3145 lwkt_reltoken(&vm_token);
3151 * Create an auto-grow stack entry
3156 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3157 int flags, vm_prot_t prot, vm_prot_t max, int cow)
3159 vm_map_entry_t prev_entry;
3160 vm_map_entry_t new_stack_entry;
3161 vm_size_t init_ssize;
3164 vm_offset_t tmpaddr;
3166 cow |= MAP_IS_STACK;
3168 if (max_ssize < sgrowsiz)
3169 init_ssize = max_ssize;
3171 init_ssize = sgrowsiz;
3173 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3177 * Find space for the mapping
3179 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3180 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3183 vm_map_entry_release(count);
3184 return (KERN_NO_SPACE);
3189 /* If addr is already mapped, no go */
3190 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3192 vm_map_entry_release(count);
3193 return (KERN_NO_SPACE);
3197 /* XXX already handled by kern_mmap() */
3198 /* If we would blow our VMEM resource limit, no go */
3199 if (map->size + init_ssize >
3200 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3202 vm_map_entry_release(count);
3203 return (KERN_NO_SPACE);
3208 * If we can't accomodate max_ssize in the current mapping,
3209 * no go. However, we need to be aware that subsequent user
3210 * mappings might map into the space we have reserved for
3211 * stack, and currently this space is not protected.
3213 * Hopefully we will at least detect this condition
3214 * when we try to grow the stack.
3216 if ((prev_entry->next != &map->header) &&
3217 (prev_entry->next->start < addrbos + max_ssize)) {
3219 vm_map_entry_release(count);
3220 return (KERN_NO_SPACE);
3224 * We initially map a stack of only init_ssize. We will
3225 * grow as needed later. Since this is to be a grow
3226 * down stack, we map at the top of the range.
3228 * Note: we would normally expect prot and max to be
3229 * VM_PROT_ALL, and cow to be 0. Possibly we should
3230 * eliminate these as input parameters, and just
3231 * pass these values here in the insert call.
3233 rv = vm_map_insert(map, &count,
3234 NULL, 0, addrbos + max_ssize - init_ssize,
3235 addrbos + max_ssize,
3240 /* Now set the avail_ssize amount */
3241 if (rv == KERN_SUCCESS) {
3242 if (prev_entry != &map->header)
3243 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3244 new_stack_entry = prev_entry->next;
3245 if (new_stack_entry->end != addrbos + max_ssize ||
3246 new_stack_entry->start != addrbos + max_ssize - init_ssize)
3247 panic ("Bad entry start/end for new stack entry");
3249 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3253 vm_map_entry_release(count);
3258 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3259 * desired address is already mapped, or if we successfully grow
3260 * the stack. Also returns KERN_SUCCESS if addr is outside the
3261 * stack range (this is strange, but preserves compatibility with
3262 * the grow function in vm_machdep.c).
3267 vm_map_growstack (struct proc *p, vm_offset_t addr)
3269 vm_map_entry_t prev_entry;
3270 vm_map_entry_t stack_entry;
3271 vm_map_entry_t new_stack_entry;
3272 struct vmspace *vm = p->p_vmspace;
3273 vm_map_t map = &vm->vm_map;
3276 int rv = KERN_SUCCESS;
3278 int use_read_lock = 1;
3281 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3284 vm_map_lock_read(map);
3288 /* If addr is already in the entry range, no need to grow.*/
3289 if (vm_map_lookup_entry(map, addr, &prev_entry))
3292 if ((stack_entry = prev_entry->next) == &map->header)
3294 if (prev_entry == &map->header)
3295 end = stack_entry->start - stack_entry->aux.avail_ssize;
3297 end = prev_entry->end;
3300 * This next test mimics the old grow function in vm_machdep.c.
3301 * It really doesn't quite make sense, but we do it anyway
3302 * for compatibility.
3304 * If not growable stack, return success. This signals the
3305 * caller to proceed as he would normally with normal vm.
3307 if (stack_entry->aux.avail_ssize < 1 ||
3308 addr >= stack_entry->start ||
3309 addr < stack_entry->start - stack_entry->aux.avail_ssize) {
3313 /* Find the minimum grow amount */
3314 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3315 if (grow_amount > stack_entry->aux.avail_ssize) {
3321 * If there is no longer enough space between the entries
3322 * nogo, and adjust the available space. Note: this
3323 * should only happen if the user has mapped into the
3324 * stack area after the stack was created, and is
3325 * probably an error.
3327 * This also effectively destroys any guard page the user
3328 * might have intended by limiting the stack size.
3330 if (grow_amount > stack_entry->start - end) {
3331 if (use_read_lock && vm_map_lock_upgrade(map)) {
3336 stack_entry->aux.avail_ssize = stack_entry->start - end;
3341 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3343 /* If this is the main process stack, see if we're over the
3346 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3347 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3352 /* Round up the grow amount modulo SGROWSIZ */
3353 grow_amount = roundup (grow_amount, sgrowsiz);
3354 if (grow_amount > stack_entry->aux.avail_ssize) {
3355 grow_amount = stack_entry->aux.avail_ssize;
3357 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3358 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3359 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3363 /* If we would blow our VMEM resource limit, no go */
3364 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3369 if (use_read_lock && vm_map_lock_upgrade(map)) {
3375 /* Get the preliminary new entry start value */
3376 addr = stack_entry->start - grow_amount;
3378 /* If this puts us into the previous entry, cut back our growth
3379 * to the available space. Also, see the note above.
3382 stack_entry->aux.avail_ssize = stack_entry->start - end;
3386 rv = vm_map_insert(map, &count,
3387 NULL, 0, addr, stack_entry->start,
3389 VM_PROT_ALL, VM_PROT_ALL,
3392 /* Adjust the available stack space by the amount we grew. */
3393 if (rv == KERN_SUCCESS) {
3394 if (prev_entry != &map->header)
3395 vm_map_clip_end(map, prev_entry, addr, &count);
3396 new_stack_entry = prev_entry->next;
3397 if (new_stack_entry->end != stack_entry->start ||
3398 new_stack_entry->start != addr)
3399 panic ("Bad stack grow start/end in new stack entry");
3401 new_stack_entry->aux.avail_ssize =
3402 stack_entry->aux.avail_ssize -
3403 (new_stack_entry->end - new_stack_entry->start);
3405 vm->vm_ssize += btoc(new_stack_entry->end -
3406 new_stack_entry->start);
3409 if (map->flags & MAP_WIREFUTURE)
3410 vm_map_unwire(map, new_stack_entry->start,
3411 new_stack_entry->end, FALSE);
3416 vm_map_unlock_read(map);
3419 vm_map_entry_release(count);
3424 * Unshare the specified VM space for exec. If other processes are
3425 * mapped to it, then create a new one. The new vmspace is null.
3430 vmspace_exec(struct proc *p, struct vmspace *vmcopy)
3432 struct vmspace *oldvmspace = p->p_vmspace;
3433 struct vmspace *newvmspace;
3434 vm_map_t map = &p->p_vmspace->vm_map;
3437 * If we are execing a resident vmspace we fork it, otherwise
3438 * we create a new vmspace. Note that exitingcnt and upcalls
3439 * are not copied to the new vmspace.
3441 lwkt_gettoken(&vmspace_token);
3443 newvmspace = vmspace_fork(vmcopy);
3445 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3446 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3447 (caddr_t)&oldvmspace->vm_endcopy -
3448 (caddr_t)&oldvmspace->vm_startcopy);
3452 * Finish initializing the vmspace before assigning it
3453 * to the process. The vmspace will become the current vmspace
3456 pmap_pinit2(vmspace_pmap(newvmspace));
3457 pmap_replacevm(p, newvmspace, 0);
3458 sysref_put(&oldvmspace->vm_sysref);
3459 lwkt_reltoken(&vmspace_token);
3463 * Unshare the specified VM space for forcing COW. This
3464 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3466 * The exitingcnt test is not strictly necessary but has been
3467 * included for code sanity (to make the code a bit more deterministic).
3470 vmspace_unshare(struct proc *p)
3472 struct vmspace *oldvmspace = p->p_vmspace;
3473 struct vmspace *newvmspace;
3475 lwkt_gettoken(&vmspace_token);
3476 if (oldvmspace->vm_sysref.refcnt == 1 && oldvmspace->vm_exitingcnt == 0)
3478 newvmspace = vmspace_fork(oldvmspace);
3479 pmap_pinit2(vmspace_pmap(newvmspace));
3480 pmap_replacevm(p, newvmspace, 0);
3481 sysref_put(&oldvmspace->vm_sysref);
3482 lwkt_reltoken(&vmspace_token);
3486 * Finds the VM object, offset, and protection for a given virtual address
3487 * in the specified map, assuming a page fault of the type specified.
3489 * Leaves the map in question locked for read; return values are guaranteed
3490 * until a vm_map_lookup_done call is performed. Note that the map argument
3491 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3493 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3496 * If a lookup is requested with "write protection" specified, the map may
3497 * be changed to perform virtual copying operations, although the data
3498 * referenced will remain the same.
3503 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
3505 vm_prot_t fault_typea,
3506 vm_map_entry_t *out_entry, /* OUT */
3507 vm_object_t *object, /* OUT */
3508 vm_pindex_t *pindex, /* OUT */
3509 vm_prot_t *out_prot, /* OUT */
3510 boolean_t *wired) /* OUT */
3512 vm_map_entry_t entry;
3513 vm_map_t map = *var_map;
3515 vm_prot_t fault_type = fault_typea;
3516 int use_read_lock = 1;
3517 int rv = KERN_SUCCESS;
3521 vm_map_lock_read(map);
3526 * If the map has an interesting hint, try it before calling full
3527 * blown lookup routine.
3532 if ((entry == &map->header) ||
3533 (vaddr < entry->start) || (vaddr >= entry->end)) {
3534 vm_map_entry_t tmp_entry;
3537 * Entry was either not a valid hint, or the vaddr was not
3538 * contained in the entry, so do a full lookup.
3540 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
3541 rv = KERN_INVALID_ADDRESS;
3552 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3553 vm_map_t old_map = map;
3555 *var_map = map = entry->object.sub_map;
3557 vm_map_unlock_read(old_map);
3559 vm_map_unlock(old_map);
3565 * Check whether this task is allowed to have this page.
3566 * Note the special case for MAP_ENTRY_COW
3567 * pages with an override. This is to implement a forced
3568 * COW for debuggers.
3571 if (fault_type & VM_PROT_OVERRIDE_WRITE)
3572 prot = entry->max_protection;
3574 prot = entry->protection;
3576 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
3577 if ((fault_type & prot) != fault_type) {
3578 rv = KERN_PROTECTION_FAILURE;
3582 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
3583 (entry->eflags & MAP_ENTRY_COW) &&
3584 (fault_type & VM_PROT_WRITE) &&
3585 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
3586 rv = KERN_PROTECTION_FAILURE;
3591 * If this page is not pageable, we have to get it for all possible
3594 *wired = (entry->wired_count != 0);
3596 prot = fault_type = entry->protection;
3599 * Virtual page tables may need to update the accessed (A) bit
3600 * in a page table entry. Upgrade the fault to a write fault for
3601 * that case if the map will support it. If the map does not support
3602 * it the page table entry simply will not be updated.
3604 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
3605 if (prot & VM_PROT_WRITE)
3606 fault_type |= VM_PROT_WRITE;
3610 * If the entry was copy-on-write, we either ...
3612 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3614 * If we want to write the page, we may as well handle that
3615 * now since we've got the map locked.
3617 * If we don't need to write the page, we just demote the
3618 * permissions allowed.
3621 if (fault_type & VM_PROT_WRITE) {
3623 * Make a new object, and place it in the object
3624 * chain. Note that no new references have appeared
3625 * -- one just moved from the map to the new
3629 if (use_read_lock && vm_map_lock_upgrade(map)) {
3635 vm_map_entry_shadow(entry);
3638 * We're attempting to read a copy-on-write page --
3639 * don't allow writes.
3642 prot &= ~VM_PROT_WRITE;
3647 * Create an object if necessary.
3649 if (entry->object.vm_object == NULL &&
3651 if (use_read_lock && vm_map_lock_upgrade(map)) {
3656 vm_map_entry_allocate_object(entry);
3660 * Return the object/offset from this entry. If the entry was
3661 * copy-on-write or empty, it has been fixed up.
3664 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
3665 *object = entry->object.vm_object;
3668 * Return whether this is the only map sharing this data. On
3669 * success we return with a read lock held on the map. On failure
3670 * we return with the map unlocked.
3674 if (rv == KERN_SUCCESS) {
3675 if (use_read_lock == 0)
3676 vm_map_lock_downgrade(map);
3677 } else if (use_read_lock) {
3678 vm_map_unlock_read(map);
3686 * Releases locks acquired by a vm_map_lookup()
3687 * (according to the handle returned by that lookup).
3689 * No other requirements.
3692 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
3695 * Unlock the main-level map
3697 vm_map_unlock_read(map);
3699 vm_map_entry_release(count);
3702 #include "opt_ddb.h"
3704 #include <sys/kernel.h>
3706 #include <ddb/ddb.h>
3711 DB_SHOW_COMMAND(map, vm_map_print)
3714 /* XXX convert args. */
3715 vm_map_t map = (vm_map_t)addr;
3716 boolean_t full = have_addr;
3718 vm_map_entry_t entry;
3720 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
3722 (void *)map->pmap, map->nentries, map->timestamp);
3725 if (!full && db_indent)
3729 for (entry = map->header.next; entry != &map->header;
3730 entry = entry->next) {
3731 db_iprintf("map entry %p: start=%p, end=%p\n",
3732 (void *)entry, (void *)entry->start, (void *)entry->end);
3735 static char *inheritance_name[4] =
3736 {"share", "copy", "none", "donate_copy"};
3738 db_iprintf(" prot=%x/%x/%s",
3740 entry->max_protection,
3741 inheritance_name[(int)(unsigned char)entry->inheritance]);
3742 if (entry->wired_count != 0)
3743 db_printf(", wired");
3745 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3746 /* XXX no %qd in kernel. Truncate entry->offset. */
3747 db_printf(", share=%p, offset=0x%lx\n",
3748 (void *)entry->object.sub_map,
3749 (long)entry->offset);
3751 if ((entry->prev == &map->header) ||
3752 (entry->prev->object.sub_map !=
3753 entry->object.sub_map)) {
3755 vm_map_print((db_expr_t)(intptr_t)
3756 entry->object.sub_map,
3761 /* XXX no %qd in kernel. Truncate entry->offset. */
3762 db_printf(", object=%p, offset=0x%lx",
3763 (void *)entry->object.vm_object,
3764 (long)entry->offset);
3765 if (entry->eflags & MAP_ENTRY_COW)
3766 db_printf(", copy (%s)",
3767 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
3771 if ((entry->prev == &map->header) ||
3772 (entry->prev->object.vm_object !=
3773 entry->object.vm_object)) {
3775 vm_object_print((db_expr_t)(intptr_t)
3776 entry->object.vm_object,
3791 DB_SHOW_COMMAND(procvm, procvm)
3796 p = (struct proc *) addr;
3801 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
3802 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
3803 (void *)vmspace_pmap(p->p_vmspace));
3805 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);