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>
102 #include <sys/random.h>
103 #include <sys/sysctl.h>
106 * Virtual memory maps provide for the mapping, protection, and sharing
107 * of virtual memory objects. In addition, this module provides for an
108 * efficient virtual copy of memory from one map to another.
110 * Synchronization is required prior to most operations.
112 * Maps consist of an ordered doubly-linked list of simple entries.
113 * A hint and a RB tree is used to speed-up lookups.
115 * Callers looking to modify maps specify start/end addresses which cause
116 * the related map entry to be clipped if necessary, and then later
117 * recombined if the pieces remained compatible.
119 * Virtual copy operations are performed by copying VM object references
120 * from one map to another, and then marking both regions as copy-on-write.
122 static void vmspace_terminate(struct vmspace *vm);
123 static void vmspace_lock(struct vmspace *vm);
124 static void vmspace_unlock(struct vmspace *vm);
125 static void vmspace_dtor(void *obj, void *private);
127 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore");
129 struct sysref_class vmspace_sysref_class = {
132 .proto = SYSREF_PROTO_VMSPACE,
133 .offset = offsetof(struct vmspace, vm_sysref),
134 .objsize = sizeof(struct vmspace),
136 .flags = SRC_MANAGEDINIT,
137 .dtor = vmspace_dtor,
139 .terminate = (sysref_terminate_func_t)vmspace_terminate,
140 .lock = (sysref_lock_func_t)vmspace_lock,
141 .unlock = (sysref_lock_func_t)vmspace_unlock
146 * per-cpu page table cross mappings are initialized in early boot
147 * and might require a considerable number of vm_map_entry structures.
149 #define VMEPERCPU (MAXCPU+1)
151 static struct vm_zone mapentzone_store, mapzone_store;
152 static vm_zone_t mapentzone, mapzone;
153 static struct vm_object mapentobj, mapobj;
155 static struct vm_map_entry map_entry_init[MAX_MAPENT];
156 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU];
157 static struct vm_map map_init[MAX_KMAP];
159 static int randomize_mmap;
160 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0,
161 "Randomize mmap offsets");
163 static void vm_map_entry_shadow(vm_map_entry_t entry);
164 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *);
165 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *);
166 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
167 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
168 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *);
169 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t);
170 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t,
172 static void vm_map_split (vm_map_entry_t);
173 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);
176 * Initialize the vm_map module. Must be called before any other vm_map
179 * Map and entry structures are allocated from the general purpose
180 * memory pool with some exceptions:
182 * - The kernel map is allocated statically.
183 * - Initial kernel map entries are allocated out of a static pool.
185 * These restrictions are necessary since malloc() uses the
186 * maps and requires map entries.
188 * Called from the low level boot code only.
193 mapzone = &mapzone_store;
194 zbootinit(mapzone, "MAP", sizeof (struct vm_map),
196 mapentzone = &mapentzone_store;
197 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry),
198 map_entry_init, MAX_MAPENT);
202 * Called prior to any vmspace allocations.
204 * Called from the low level boot code only.
209 zinitna(mapentzone, &mapentobj, NULL, 0, 0,
210 ZONE_USE_RESERVE | ZONE_SPECIAL, 1);
211 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1);
218 * Red black tree functions
220 * The caller must hold the related map lock.
222 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b);
223 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare);
225 /* a->start is address, and the only field has to be initialized */
227 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b)
229 if (a->start < b->start)
231 else if (a->start > b->start)
237 * Allocate a vmspace structure, including a vm_map and pmap.
238 * Initialize numerous fields. While the initial allocation is zerod,
239 * subsequence reuse from the objcache leaves elements of the structure
240 * intact (particularly the pmap), so portions must be zerod.
242 * The structure is not considered activated until we call sysref_activate().
247 vmspace_alloc(vm_offset_t min, vm_offset_t max)
251 lwkt_gettoken(&vmspace_token);
252 vm = sysref_alloc(&vmspace_sysref_class);
253 bzero(&vm->vm_startcopy,
254 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy);
255 vm_map_init(&vm->vm_map, min, max, NULL);
256 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */
257 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */
259 vm->vm_exitingcnt = 0;
260 cpu_vmspace_alloc(vm);
261 sysref_activate(&vm->vm_sysref);
262 lwkt_reltoken(&vmspace_token);
268 * dtor function - Some elements of the pmap are retained in the
269 * free-cached vmspaces to improve performance. We have to clean them up
270 * here before returning the vmspace to the memory pool.
275 vmspace_dtor(void *obj, void *private)
277 struct vmspace *vm = obj;
279 pmap_puninit(vmspace_pmap(vm));
283 * Called in two cases:
285 * (1) When the last sysref is dropped, but exitingcnt might still be
288 * (2) When there are no sysrefs (i.e. refcnt is negative) left and the
289 * exitingcnt becomes zero
291 * sysref will not scrap the object until we call sysref_put() once more
292 * after the last ref has been dropped.
294 * Interlocked by the sysref API.
297 vmspace_terminate(struct vmspace *vm)
302 * If exitingcnt is non-zero we can't get rid of the entire vmspace
303 * yet, but we can scrap user memory.
305 lwkt_gettoken(&vmspace_token);
306 if (vm->vm_exitingcnt) {
308 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS,
309 VM_MAX_USER_ADDRESS);
310 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS,
311 VM_MAX_USER_ADDRESS);
312 lwkt_reltoken(&vmspace_token);
315 cpu_vmspace_free(vm);
318 * Make sure any SysV shm is freed, it might not have in
323 KKASSERT(vm->vm_upcalls == NULL);
326 * Lock the map, to wait out all other references to it.
327 * Delete all of the mappings and pages they hold, then call
328 * the pmap module to reclaim anything left.
330 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
331 vm_map_lock(&vm->vm_map);
332 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
333 vm->vm_map.max_offset, &count);
334 vm_map_unlock(&vm->vm_map);
335 vm_map_entry_release(count);
337 pmap_release(vmspace_pmap(vm));
338 sysref_put(&vm->vm_sysref);
339 lwkt_reltoken(&vmspace_token);
343 * vmspaces are not currently locked.
346 vmspace_lock(struct vmspace *vm __unused)
351 vmspace_unlock(struct vmspace *vm __unused)
356 * This is called during exit indicating that the vmspace is no
357 * longer in used by an exiting process, but the process has not yet
363 vmspace_exitbump(struct vmspace *vm)
365 lwkt_gettoken(&vmspace_token);
367 lwkt_reltoken(&vmspace_token);
371 * This is called in the wait*() handling code. The vmspace can be terminated
372 * after the last wait is finished using it.
377 vmspace_exitfree(struct proc *p)
381 lwkt_gettoken(&vmspace_token);
385 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref))
386 vmspace_terminate(vm);
387 lwkt_reltoken(&vmspace_token);
391 * Swap useage is determined by taking the proportional swap used by
392 * VM objects backing the VM map. To make up for fractional losses,
393 * if the VM object has any swap use at all the associated map entries
394 * count for at least 1 swap page.
399 vmspace_swap_count(struct vmspace *vmspace)
401 vm_map_t map = &vmspace->vm_map;
407 lwkt_gettoken(&vmspace_token);
408 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
409 switch(cur->maptype) {
410 case VM_MAPTYPE_NORMAL:
411 case VM_MAPTYPE_VPAGETABLE:
412 if ((object = cur->object.vm_object) == NULL)
414 if (object->swblock_count) {
415 n = (cur->end - cur->start) / PAGE_SIZE;
416 count += object->swblock_count *
417 SWAP_META_PAGES * n / object->size + 1;
424 lwkt_reltoken(&vmspace_token);
429 * Calculate the approximate number of anonymous pages in use by
430 * this vmspace. To make up for fractional losses, we count each
431 * VM object as having at least 1 anonymous page.
436 vmspace_anonymous_count(struct vmspace *vmspace)
438 vm_map_t map = &vmspace->vm_map;
443 lwkt_gettoken(&vmspace_token);
444 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
445 switch(cur->maptype) {
446 case VM_MAPTYPE_NORMAL:
447 case VM_MAPTYPE_VPAGETABLE:
448 if ((object = cur->object.vm_object) == NULL)
450 if (object->type != OBJT_DEFAULT &&
451 object->type != OBJT_SWAP) {
454 count += object->resident_page_count;
460 lwkt_reltoken(&vmspace_token);
465 * Creates and returns a new empty VM map with the given physical map
466 * structure, and having the given lower and upper address bounds.
471 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max)
474 result = zalloc(mapzone);
475 vm_map_init(result, min, max, pmap);
480 * Initialize an existing vm_map structure such as that in the vmspace
481 * structure. The pmap is initialized elsewhere.
486 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap)
488 map->header.next = map->header.prev = &map->header;
489 RB_INIT(&map->rb_root);
493 map->min_offset = min;
494 map->max_offset = max;
496 map->first_free = &map->header;
497 map->hint = &map->header;
500 lockinit(&map->lock, "thrd_sleep", 0, 0);
501 TUNABLE_INT("vm.cache_vmspaces", &vmspace_sysref_class.nom_cache);
505 * Shadow the vm_map_entry's object. This typically needs to be done when
506 * a write fault is taken on an entry which had previously been cloned by
507 * fork(). The shared object (which might be NULL) must become private so
508 * we add a shadow layer above it.
510 * Object allocation for anonymous mappings is defered as long as possible.
511 * When creating a shadow, however, the underlying object must be instantiated
512 * so it can be shared.
514 * If the map segment is governed by a virtual page table then it is
515 * possible to address offsets beyond the mapped area. Just allocate
516 * a maximally sized object for this case.
518 * The vm_map must be exclusively locked.
519 * No other requirements.
523 vm_map_entry_shadow(vm_map_entry_t entry)
525 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
526 vm_object_shadow(&entry->object.vm_object, &entry->offset,
527 0x7FFFFFFF); /* XXX */
529 vm_object_shadow(&entry->object.vm_object, &entry->offset,
530 atop(entry->end - entry->start));
532 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
536 * Allocate an object for a vm_map_entry.
538 * Object allocation for anonymous mappings is defered as long as possible.
539 * This function is called when we can defer no longer, generally when a map
540 * entry might be split or forked or takes a page fault.
542 * If the map segment is governed by a virtual page table then it is
543 * possible to address offsets beyond the mapped area. Just allocate
544 * a maximally sized object for this case.
546 * The vm_map must be exclusively locked.
547 * No other requirements.
550 vm_map_entry_allocate_object(vm_map_entry_t entry)
554 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
555 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */
557 obj = vm_object_allocate(OBJT_DEFAULT,
558 atop(entry->end - entry->start));
560 entry->object.vm_object = obj;
565 * Set an initial negative count so the first attempt to reserve
566 * space preloads a bunch of vm_map_entry's for this cpu. Also
567 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
568 * map a new page for vm_map_entry structures. SMP systems are
569 * particularly sensitive.
571 * This routine is called in early boot so we cannot just call
572 * vm_map_entry_reserve().
574 * Called from the low level boot code only (for each cpu)
577 vm_map_entry_reserve_cpu_init(globaldata_t gd)
579 vm_map_entry_t entry;
582 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2;
583 entry = &cpu_map_entry_init[gd->gd_cpuid][0];
584 for (i = 0; i < VMEPERCPU; ++i, ++entry) {
585 entry->next = gd->gd_vme_base;
586 gd->gd_vme_base = entry;
591 * Reserves vm_map_entry structures so code later on can manipulate
592 * map_entry structures within a locked map without blocking trying
593 * to allocate a new vm_map_entry.
598 vm_map_entry_reserve(int count)
600 struct globaldata *gd = mycpu;
601 vm_map_entry_t entry;
604 * Make sure we have enough structures in gd_vme_base to handle
605 * the reservation request.
608 while (gd->gd_vme_avail < count) {
609 entry = zalloc(mapentzone);
610 entry->next = gd->gd_vme_base;
611 gd->gd_vme_base = entry;
614 gd->gd_vme_avail -= count;
621 * Releases previously reserved vm_map_entry structures that were not
622 * used. If we have too much junk in our per-cpu cache clean some of
628 vm_map_entry_release(int count)
630 struct globaldata *gd = mycpu;
631 vm_map_entry_t entry;
634 gd->gd_vme_avail += count;
635 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) {
636 entry = gd->gd_vme_base;
637 KKASSERT(entry != NULL);
638 gd->gd_vme_base = entry->next;
641 zfree(mapentzone, entry);
648 * Reserve map entry structures for use in kernel_map itself. These
649 * entries have *ALREADY* been reserved on a per-cpu basis when the map
650 * was inited. This function is used by zalloc() to avoid a recursion
651 * when zalloc() itself needs to allocate additional kernel memory.
653 * This function works like the normal reserve but does not load the
654 * vm_map_entry cache (because that would result in an infinite
655 * recursion). Note that gd_vme_avail may go negative. This is expected.
657 * Any caller of this function must be sure to renormalize after
658 * potentially eating entries to ensure that the reserve supply
664 vm_map_entry_kreserve(int count)
666 struct globaldata *gd = mycpu;
669 gd->gd_vme_avail -= count;
671 KASSERT(gd->gd_vme_base != NULL,
672 ("no reserved entries left, gd_vme_avail = %d\n",
678 * Release previously reserved map entries for kernel_map. We do not
679 * attempt to clean up like the normal release function as this would
680 * cause an unnecessary (but probably not fatal) deep procedure call.
685 vm_map_entry_krelease(int count)
687 struct globaldata *gd = mycpu;
690 gd->gd_vme_avail += count;
695 * Allocates a VM map entry for insertion. No entry fields are filled in.
697 * The entries should have previously been reserved. The reservation count
698 * is tracked in (*countp).
702 static vm_map_entry_t
703 vm_map_entry_create(vm_map_t map, int *countp)
705 struct globaldata *gd = mycpu;
706 vm_map_entry_t entry;
708 KKASSERT(*countp > 0);
711 entry = gd->gd_vme_base;
712 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp));
713 gd->gd_vme_base = entry->next;
720 * Dispose of a vm_map_entry that is no longer being referenced.
725 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp)
727 struct globaldata *gd = mycpu;
729 KKASSERT(map->hint != entry);
730 KKASSERT(map->first_free != entry);
734 entry->next = gd->gd_vme_base;
735 gd->gd_vme_base = entry;
741 * Insert/remove entries from maps.
743 * The related map must be exclusively locked.
744 * No other requirements.
746 * NOTE! We currently acquire the vmspace_token only to avoid races
747 * against the pageout daemon's calls to vmspace_*_count(), which
748 * are unable to safely lock the vm_map without potentially
752 vm_map_entry_link(vm_map_t map,
753 vm_map_entry_t after_where,
754 vm_map_entry_t entry)
756 ASSERT_VM_MAP_LOCKED(map);
758 lwkt_gettoken(&vmspace_token);
760 entry->prev = after_where;
761 entry->next = after_where->next;
762 entry->next->prev = entry;
763 after_where->next = entry;
764 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry))
765 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry);
766 lwkt_reltoken(&vmspace_token);
770 vm_map_entry_unlink(vm_map_t map,
771 vm_map_entry_t entry)
776 ASSERT_VM_MAP_LOCKED(map);
778 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
779 panic("vm_map_entry_unlink: attempt to mess with "
780 "locked entry! %p", entry);
782 lwkt_gettoken(&vmspace_token);
787 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry);
789 lwkt_reltoken(&vmspace_token);
793 * Finds the map entry containing (or immediately preceding) the specified
794 * address in the given map. The entry is returned in (*entry).
796 * The boolean result indicates whether the address is actually contained
799 * The related map must be locked.
800 * No other requirements.
803 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry)
808 ASSERT_VM_MAP_LOCKED(map);
811 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive
812 * the hint code with the red-black lookup meets with system crashes
813 * and lockups. We do not yet know why.
815 * It is possible that the problem is related to the setting
816 * of the hint during map_entry deletion, in the code specified
817 * at the GGG comment later on in this file.
820 * Quickly check the cached hint, there's a good chance of a match.
822 if (map->hint != &map->header) {
824 if (address >= tmp->start && address < tmp->end) {
832 * Locate the record from the top of the tree. 'last' tracks the
833 * closest prior record and is returned if no match is found, which
834 * in binary tree terms means tracking the most recent right-branch
835 * taken. If there is no prior record, &map->header is returned.
838 tmp = RB_ROOT(&map->rb_root);
841 if (address >= tmp->start) {
842 if (address < tmp->end) {
848 tmp = RB_RIGHT(tmp, rb_entry);
850 tmp = RB_LEFT(tmp, rb_entry);
858 * Inserts the given whole VM object into the target map at the specified
859 * address range. The object's size should match that of the address range.
861 * The map must be exclusively locked.
862 * The caller must have reserved sufficient vm_map_entry structures.
864 * If object is non-NULL, ref count must be bumped by caller
865 * prior to making call to account for the new entry.
868 vm_map_insert(vm_map_t map, int *countp,
869 vm_object_t object, vm_ooffset_t offset,
870 vm_offset_t start, vm_offset_t end,
871 vm_maptype_t maptype,
872 vm_prot_t prot, vm_prot_t max,
875 vm_map_entry_t new_entry;
876 vm_map_entry_t prev_entry;
877 vm_map_entry_t temp_entry;
878 vm_eflags_t protoeflags;
880 ASSERT_VM_MAP_LOCKED(map);
883 * Check that the start and end points are not bogus.
885 if ((start < map->min_offset) || (end > map->max_offset) ||
887 return (KERN_INVALID_ADDRESS);
890 * Find the entry prior to the proposed starting address; if it's part
891 * of an existing entry, this range is bogus.
893 if (vm_map_lookup_entry(map, start, &temp_entry))
894 return (KERN_NO_SPACE);
896 prev_entry = temp_entry;
899 * Assert that the next entry doesn't overlap the end point.
902 if ((prev_entry->next != &map->header) &&
903 (prev_entry->next->start < end))
904 return (KERN_NO_SPACE);
908 if (cow & MAP_COPY_ON_WRITE)
909 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY;
911 if (cow & MAP_NOFAULT) {
912 protoeflags |= MAP_ENTRY_NOFAULT;
914 KASSERT(object == NULL,
915 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
917 if (cow & MAP_DISABLE_SYNCER)
918 protoeflags |= MAP_ENTRY_NOSYNC;
919 if (cow & MAP_DISABLE_COREDUMP)
920 protoeflags |= MAP_ENTRY_NOCOREDUMP;
921 if (cow & MAP_IS_STACK)
922 protoeflags |= MAP_ENTRY_STACK;
923 if (cow & MAP_IS_KSTACK)
924 protoeflags |= MAP_ENTRY_KSTACK;
926 lwkt_gettoken(&vm_token);
927 lwkt_gettoken(&vmobj_token);
931 * When object is non-NULL, it could be shared with another
932 * process. We have to set or clear OBJ_ONEMAPPING
936 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
937 vm_object_clear_flag(object, OBJ_ONEMAPPING);
940 else if ((prev_entry != &map->header) &&
941 (prev_entry->eflags == protoeflags) &&
942 (prev_entry->end == start) &&
943 (prev_entry->wired_count == 0) &&
944 prev_entry->maptype == maptype &&
945 ((prev_entry->object.vm_object == NULL) ||
946 vm_object_coalesce(prev_entry->object.vm_object,
947 OFF_TO_IDX(prev_entry->offset),
948 (vm_size_t)(prev_entry->end - prev_entry->start),
949 (vm_size_t)(end - prev_entry->end)))) {
951 * We were able to extend the object. Determine if we
952 * can extend the previous map entry to include the
955 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
956 (prev_entry->protection == prot) &&
957 (prev_entry->max_protection == max)) {
958 lwkt_reltoken(&vmobj_token);
959 lwkt_reltoken(&vm_token);
960 map->size += (end - prev_entry->end);
961 prev_entry->end = end;
962 vm_map_simplify_entry(map, prev_entry, countp);
963 return (KERN_SUCCESS);
967 * If we can extend the object but cannot extend the
968 * map entry, we have to create a new map entry. We
969 * must bump the ref count on the extended object to
970 * account for it. object may be NULL.
972 object = prev_entry->object.vm_object;
973 offset = prev_entry->offset +
974 (prev_entry->end - prev_entry->start);
975 vm_object_reference_locked(object);
978 lwkt_reltoken(&vmobj_token);
979 lwkt_reltoken(&vm_token);
982 * NOTE: if conditionals fail, object can be NULL here. This occurs
983 * in things like the buffer map where we manage kva but do not manage
991 new_entry = vm_map_entry_create(map, countp);
992 new_entry->start = start;
993 new_entry->end = end;
995 new_entry->maptype = maptype;
996 new_entry->eflags = protoeflags;
997 new_entry->object.vm_object = object;
998 new_entry->offset = offset;
999 new_entry->aux.master_pde = 0;
1001 new_entry->inheritance = VM_INHERIT_DEFAULT;
1002 new_entry->protection = prot;
1003 new_entry->max_protection = max;
1004 new_entry->wired_count = 0;
1007 * Insert the new entry into the list
1010 vm_map_entry_link(map, prev_entry, new_entry);
1011 map->size += new_entry->end - new_entry->start;
1014 * Update the free space hint. Entries cannot overlap.
1015 * An exact comparison is needed to avoid matching
1016 * against the map->header.
1018 if ((map->first_free == prev_entry) &&
1019 (prev_entry->end == new_entry->start)) {
1020 map->first_free = new_entry;
1025 * Temporarily removed to avoid MAP_STACK panic, due to
1026 * MAP_STACK being a huge hack. Will be added back in
1027 * when MAP_STACK (and the user stack mapping) is fixed.
1030 * It may be possible to simplify the entry
1032 vm_map_simplify_entry(map, new_entry, countp);
1036 * Try to pre-populate the page table. Mappings governed by virtual
1037 * page tables cannot be prepopulated without a lot of work, so
1040 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) &&
1041 maptype != VM_MAPTYPE_VPAGETABLE) {
1042 pmap_object_init_pt(map->pmap, start, prot,
1043 object, OFF_TO_IDX(offset), end - start,
1044 cow & MAP_PREFAULT_PARTIAL);
1047 return (KERN_SUCCESS);
1051 * Find sufficient space for `length' bytes in the given map, starting at
1052 * `start'. Returns 0 on success, 1 on no space.
1054 * This function will returned an arbitrarily aligned pointer. If no
1055 * particular alignment is required you should pass align as 1. Note that
1056 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1057 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1060 * 'align' should be a power of 2 but is not required to be.
1062 * The map must be exclusively locked.
1063 * No other requirements.
1066 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1067 vm_size_t align, int flags, vm_offset_t *addr)
1069 vm_map_entry_t entry, next;
1071 vm_offset_t align_mask;
1073 if (start < map->min_offset)
1074 start = map->min_offset;
1075 if (start > map->max_offset)
1079 * If the alignment is not a power of 2 we will have to use
1080 * a mod/division, set align_mask to a special value.
1082 if ((align | (align - 1)) + 1 != (align << 1))
1083 align_mask = (vm_offset_t)-1;
1085 align_mask = align - 1;
1088 * Look for the first possible address; if there's already something
1089 * at this address, we have to start after it.
1091 if (start == map->min_offset) {
1092 if ((entry = map->first_free) != &map->header)
1097 if (vm_map_lookup_entry(map, start, &tmp))
1103 * Look through the rest of the map, trying to fit a new region in the
1104 * gap between existing regions, or after the very last region.
1106 for (;; start = (entry = next)->end) {
1108 * Adjust the proposed start by the requested alignment,
1109 * be sure that we didn't wrap the address.
1111 if (align_mask == (vm_offset_t)-1)
1112 end = ((start + align - 1) / align) * align;
1114 end = (start + align_mask) & ~align_mask;
1119 * Find the end of the proposed new region. Be sure we didn't
1120 * go beyond the end of the map, or wrap around the address.
1121 * Then check to see if this is the last entry or if the
1122 * proposed end fits in the gap between this and the next
1125 end = start + length;
1126 if (end > map->max_offset || end < start)
1131 * If the next entry's start address is beyond the desired
1132 * end address we may have found a good entry.
1134 * If the next entry is a stack mapping we do not map into
1135 * the stack's reserved space.
1137 * XXX continue to allow mapping into the stack's reserved
1138 * space if doing a MAP_STACK mapping inside a MAP_STACK
1139 * mapping, for backwards compatibility. But the caller
1140 * really should use MAP_STACK | MAP_TRYFIXED if they
1143 if (next == &map->header)
1145 if (next->start >= end) {
1146 if ((next->eflags & MAP_ENTRY_STACK) == 0)
1148 if (flags & MAP_STACK)
1150 if (next->start - next->aux.avail_ssize >= end)
1157 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1158 * if it fails. The kernel_map is locked and nothing can steal
1159 * our address space if pmap_growkernel() blocks.
1161 * NOTE: This may be unconditionally called for kldload areas on
1162 * x86_64 because these do not bump kernel_vm_end (which would
1163 * fill 128G worth of page tables!). Therefore we must not
1166 if (map == &kernel_map) {
1169 kstop = round_page(start + length);
1170 if (kstop > kernel_vm_end)
1171 pmap_growkernel(start, kstop);
1178 * vm_map_find finds an unallocated region in the target address map with
1179 * the given length. The search is defined to be first-fit from the
1180 * specified address; the region found is returned in the same parameter.
1182 * If object is non-NULL, ref count must be bumped by caller
1183 * prior to making call to account for the new entry.
1185 * No requirements. This function will lock the map temporarily.
1188 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1189 vm_offset_t *addr, vm_size_t length, vm_size_t align,
1191 vm_maptype_t maptype,
1192 vm_prot_t prot, vm_prot_t max,
1201 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1204 if (vm_map_findspace(map, start, length, align, 0, addr)) {
1206 vm_map_entry_release(count);
1207 return (KERN_NO_SPACE);
1211 result = vm_map_insert(map, &count, object, offset,
1212 start, start + length,
1217 vm_map_entry_release(count);
1223 * Simplify the given map entry by merging with either neighbor. This
1224 * routine also has the ability to merge with both neighbors.
1226 * This routine guarentees that the passed entry remains valid (though
1227 * possibly extended). When merging, this routine may delete one or
1228 * both neighbors. No action is taken on entries which have their
1229 * in-transition flag set.
1231 * The map must be exclusively locked.
1234 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1236 vm_map_entry_t next, prev;
1237 vm_size_t prevsize, esize;
1239 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1240 ++mycpu->gd_cnt.v_intrans_coll;
1244 if (entry->maptype == VM_MAPTYPE_SUBMAP)
1248 if (prev != &map->header) {
1249 prevsize = prev->end - prev->start;
1250 if ( (prev->end == entry->start) &&
1251 (prev->maptype == entry->maptype) &&
1252 (prev->object.vm_object == entry->object.vm_object) &&
1253 (!prev->object.vm_object ||
1254 (prev->offset + prevsize == entry->offset)) &&
1255 (prev->eflags == entry->eflags) &&
1256 (prev->protection == entry->protection) &&
1257 (prev->max_protection == entry->max_protection) &&
1258 (prev->inheritance == entry->inheritance) &&
1259 (prev->wired_count == entry->wired_count)) {
1260 if (map->first_free == prev)
1261 map->first_free = entry;
1262 if (map->hint == prev)
1264 vm_map_entry_unlink(map, prev);
1265 entry->start = prev->start;
1266 entry->offset = prev->offset;
1267 if (prev->object.vm_object)
1268 vm_object_deallocate(prev->object.vm_object);
1269 vm_map_entry_dispose(map, prev, countp);
1274 if (next != &map->header) {
1275 esize = entry->end - entry->start;
1276 if ((entry->end == next->start) &&
1277 (next->maptype == entry->maptype) &&
1278 (next->object.vm_object == entry->object.vm_object) &&
1279 (!entry->object.vm_object ||
1280 (entry->offset + esize == next->offset)) &&
1281 (next->eflags == entry->eflags) &&
1282 (next->protection == entry->protection) &&
1283 (next->max_protection == entry->max_protection) &&
1284 (next->inheritance == entry->inheritance) &&
1285 (next->wired_count == entry->wired_count)) {
1286 if (map->first_free == next)
1287 map->first_free = entry;
1288 if (map->hint == next)
1290 vm_map_entry_unlink(map, next);
1291 entry->end = next->end;
1292 if (next->object.vm_object)
1293 vm_object_deallocate(next->object.vm_object);
1294 vm_map_entry_dispose(map, next, countp);
1300 * Asserts that the given entry begins at or after the specified address.
1301 * If necessary, it splits the entry into two.
1303 #define vm_map_clip_start(map, entry, startaddr, countp) \
1305 if (startaddr > entry->start) \
1306 _vm_map_clip_start(map, entry, startaddr, countp); \
1310 * This routine is called only when it is known that the entry must be split.
1312 * The map must be exclusively locked.
1315 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1318 vm_map_entry_t new_entry;
1321 * Split off the front portion -- note that we must insert the new
1322 * entry BEFORE this one, so that this entry has the specified
1326 vm_map_simplify_entry(map, entry, countp);
1329 * If there is no object backing this entry, we might as well create
1330 * one now. If we defer it, an object can get created after the map
1331 * is clipped, and individual objects will be created for the split-up
1332 * map. This is a bit of a hack, but is also about the best place to
1333 * put this improvement.
1335 if (entry->object.vm_object == NULL && !map->system_map) {
1336 vm_map_entry_allocate_object(entry);
1339 new_entry = vm_map_entry_create(map, countp);
1340 *new_entry = *entry;
1342 new_entry->end = start;
1343 entry->offset += (start - entry->start);
1344 entry->start = start;
1346 vm_map_entry_link(map, entry->prev, new_entry);
1348 switch(entry->maptype) {
1349 case VM_MAPTYPE_NORMAL:
1350 case VM_MAPTYPE_VPAGETABLE:
1351 vm_object_reference(new_entry->object.vm_object);
1359 * Asserts that the given entry ends at or before the specified address.
1360 * If necessary, it splits the entry into two.
1362 * The map must be exclusively locked.
1364 #define vm_map_clip_end(map, entry, endaddr, countp) \
1366 if (endaddr < entry->end) \
1367 _vm_map_clip_end(map, entry, endaddr, countp); \
1371 * This routine is called only when it is known that the entry must be split.
1373 * The map must be exclusively locked.
1376 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1379 vm_map_entry_t new_entry;
1382 * If there is no object backing this entry, we might as well create
1383 * one now. If we defer it, an object can get created after the map
1384 * is clipped, and individual objects will be created for the split-up
1385 * map. This is a bit of a hack, but is also about the best place to
1386 * put this improvement.
1389 if (entry->object.vm_object == NULL && !map->system_map) {
1390 vm_map_entry_allocate_object(entry);
1394 * Create a new entry and insert it AFTER the specified entry
1397 new_entry = vm_map_entry_create(map, countp);
1398 *new_entry = *entry;
1400 new_entry->start = entry->end = end;
1401 new_entry->offset += (end - entry->start);
1403 vm_map_entry_link(map, entry, new_entry);
1405 switch(entry->maptype) {
1406 case VM_MAPTYPE_NORMAL:
1407 case VM_MAPTYPE_VPAGETABLE:
1408 vm_object_reference(new_entry->object.vm_object);
1416 * Asserts that the starting and ending region addresses fall within the
1417 * valid range for the map.
1419 #define VM_MAP_RANGE_CHECK(map, start, end) \
1421 if (start < vm_map_min(map)) \
1422 start = vm_map_min(map); \
1423 if (end > vm_map_max(map)) \
1424 end = vm_map_max(map); \
1430 * Used to block when an in-transition collison occurs. The map
1431 * is unlocked for the sleep and relocked before the return.
1434 vm_map_transition_wait(vm_map_t map)
1436 tsleep_interlock(map, 0);
1438 tsleep(map, PINTERLOCKED, "vment", 0);
1443 * When we do blocking operations with the map lock held it is
1444 * possible that a clip might have occured on our in-transit entry,
1445 * requiring an adjustment to the entry in our loop. These macros
1446 * help the pageable and clip_range code deal with the case. The
1447 * conditional costs virtually nothing if no clipping has occured.
1450 #define CLIP_CHECK_BACK(entry, save_start) \
1452 while (entry->start != save_start) { \
1453 entry = entry->prev; \
1454 KASSERT(entry != &map->header, ("bad entry clip")); \
1458 #define CLIP_CHECK_FWD(entry, save_end) \
1460 while (entry->end != save_end) { \
1461 entry = entry->next; \
1462 KASSERT(entry != &map->header, ("bad entry clip")); \
1468 * Clip the specified range and return the base entry. The
1469 * range may cover several entries starting at the returned base
1470 * and the first and last entry in the covering sequence will be
1471 * properly clipped to the requested start and end address.
1473 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1476 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1477 * covered by the requested range.
1479 * The map must be exclusively locked on entry and will remain locked
1480 * on return. If no range exists or the range contains holes and you
1481 * specified that no holes were allowed, NULL will be returned. This
1482 * routine may temporarily unlock the map in order avoid a deadlock when
1487 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end,
1488 int *countp, int flags)
1490 vm_map_entry_t start_entry;
1491 vm_map_entry_t entry;
1494 * Locate the entry and effect initial clipping. The in-transition
1495 * case does not occur very often so do not try to optimize it.
1498 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1500 entry = start_entry;
1501 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1502 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1503 ++mycpu->gd_cnt.v_intrans_coll;
1504 ++mycpu->gd_cnt.v_intrans_wait;
1505 vm_map_transition_wait(map);
1507 * entry and/or start_entry may have been clipped while
1508 * we slept, or may have gone away entirely. We have
1509 * to restart from the lookup.
1515 * Since we hold an exclusive map lock we do not have to restart
1516 * after clipping, even though clipping may block in zalloc.
1518 vm_map_clip_start(map, entry, start, countp);
1519 vm_map_clip_end(map, entry, end, countp);
1520 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1523 * Scan entries covered by the range. When working on the next
1524 * entry a restart need only re-loop on the current entry which
1525 * we have already locked, since 'next' may have changed. Also,
1526 * even though entry is safe, it may have been clipped so we
1527 * have to iterate forwards through the clip after sleeping.
1529 while (entry->next != &map->header && entry->next->start < end) {
1530 vm_map_entry_t next = entry->next;
1532 if (flags & MAP_CLIP_NO_HOLES) {
1533 if (next->start > entry->end) {
1534 vm_map_unclip_range(map, start_entry,
1535 start, entry->end, countp, flags);
1540 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1541 vm_offset_t save_end = entry->end;
1542 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1543 ++mycpu->gd_cnt.v_intrans_coll;
1544 ++mycpu->gd_cnt.v_intrans_wait;
1545 vm_map_transition_wait(map);
1548 * clips might have occured while we blocked.
1550 CLIP_CHECK_FWD(entry, save_end);
1551 CLIP_CHECK_BACK(start_entry, start);
1555 * No restart necessary even though clip_end may block, we
1556 * are holding the map lock.
1558 vm_map_clip_end(map, next, end, countp);
1559 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1562 if (flags & MAP_CLIP_NO_HOLES) {
1563 if (entry->end != end) {
1564 vm_map_unclip_range(map, start_entry,
1565 start, entry->end, countp, flags);
1569 return(start_entry);
1573 * Undo the effect of vm_map_clip_range(). You should pass the same
1574 * flags and the same range that you passed to vm_map_clip_range().
1575 * This code will clear the in-transition flag on the entries and
1576 * wake up anyone waiting. This code will also simplify the sequence
1577 * and attempt to merge it with entries before and after the sequence.
1579 * The map must be locked on entry and will remain locked on return.
1581 * Note that you should also pass the start_entry returned by
1582 * vm_map_clip_range(). However, if you block between the two calls
1583 * with the map unlocked please be aware that the start_entry may
1584 * have been clipped and you may need to scan it backwards to find
1585 * the entry corresponding with the original start address. You are
1586 * responsible for this, vm_map_unclip_range() expects the correct
1587 * start_entry to be passed to it and will KASSERT otherwise.
1591 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1592 vm_offset_t start, vm_offset_t end,
1593 int *countp, int flags)
1595 vm_map_entry_t entry;
1597 entry = start_entry;
1599 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1600 while (entry != &map->header && entry->start < end) {
1601 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1602 ("in-transition flag not set during unclip on: %p",
1604 KASSERT(entry->end <= end,
1605 ("unclip_range: tail wasn't clipped"));
1606 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1607 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1608 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1611 entry = entry->next;
1615 * Simplification does not block so there is no restart case.
1617 entry = start_entry;
1618 while (entry != &map->header && entry->start < end) {
1619 vm_map_simplify_entry(map, entry, countp);
1620 entry = entry->next;
1625 * Mark the given range as handled by a subordinate map.
1627 * This range must have been created with vm_map_find(), and no other
1628 * operations may have been performed on this range prior to calling
1631 * Submappings cannot be removed.
1636 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1638 vm_map_entry_t entry;
1639 int result = KERN_INVALID_ARGUMENT;
1642 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1645 VM_MAP_RANGE_CHECK(map, start, end);
1647 if (vm_map_lookup_entry(map, start, &entry)) {
1648 vm_map_clip_start(map, entry, start, &count);
1650 entry = entry->next;
1653 vm_map_clip_end(map, entry, end, &count);
1655 if ((entry->start == start) && (entry->end == end) &&
1656 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1657 (entry->object.vm_object == NULL)) {
1658 entry->object.sub_map = submap;
1659 entry->maptype = VM_MAPTYPE_SUBMAP;
1660 result = KERN_SUCCESS;
1663 vm_map_entry_release(count);
1669 * Sets the protection of the specified address region in the target map.
1670 * If "set_max" is specified, the maximum protection is to be set;
1671 * otherwise, only the current protection is affected.
1673 * The protection is not applicable to submaps, but is applicable to normal
1674 * maps and maps governed by virtual page tables. For example, when operating
1675 * on a virtual page table our protection basically controls how COW occurs
1676 * on the backing object, whereas the virtual page table abstraction itself
1677 * is an abstraction for userland.
1682 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1683 vm_prot_t new_prot, boolean_t set_max)
1685 vm_map_entry_t current;
1686 vm_map_entry_t entry;
1689 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1692 VM_MAP_RANGE_CHECK(map, start, end);
1694 if (vm_map_lookup_entry(map, start, &entry)) {
1695 vm_map_clip_start(map, entry, start, &count);
1697 entry = entry->next;
1701 * Make a first pass to check for protection violations.
1704 while ((current != &map->header) && (current->start < end)) {
1705 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1707 vm_map_entry_release(count);
1708 return (KERN_INVALID_ARGUMENT);
1710 if ((new_prot & current->max_protection) != new_prot) {
1712 vm_map_entry_release(count);
1713 return (KERN_PROTECTION_FAILURE);
1715 current = current->next;
1719 * Go back and fix up protections. [Note that clipping is not
1720 * necessary the second time.]
1724 while ((current != &map->header) && (current->start < end)) {
1727 vm_map_clip_end(map, current, end, &count);
1729 old_prot = current->protection;
1731 current->protection =
1732 (current->max_protection = new_prot) &
1735 current->protection = new_prot;
1739 * Update physical map if necessary. Worry about copy-on-write
1740 * here -- CHECK THIS XXX
1743 if (current->protection != old_prot) {
1744 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1747 pmap_protect(map->pmap, current->start,
1749 current->protection & MASK(current));
1753 vm_map_simplify_entry(map, current, &count);
1755 current = current->next;
1759 vm_map_entry_release(count);
1760 return (KERN_SUCCESS);
1764 * This routine traverses a processes map handling the madvise
1765 * system call. Advisories are classified as either those effecting
1766 * the vm_map_entry structure, or those effecting the underlying
1769 * The <value> argument is used for extended madvise calls.
1774 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1775 int behav, off_t value)
1777 vm_map_entry_t current, entry;
1783 * Some madvise calls directly modify the vm_map_entry, in which case
1784 * we need to use an exclusive lock on the map and we need to perform
1785 * various clipping operations. Otherwise we only need a read-lock
1789 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1793 case MADV_SEQUENTIAL:
1807 vm_map_lock_read(map);
1810 vm_map_entry_release(count);
1815 * Locate starting entry and clip if necessary.
1818 VM_MAP_RANGE_CHECK(map, start, end);
1820 if (vm_map_lookup_entry(map, start, &entry)) {
1822 vm_map_clip_start(map, entry, start, &count);
1824 entry = entry->next;
1829 * madvise behaviors that are implemented in the vm_map_entry.
1831 * We clip the vm_map_entry so that behavioral changes are
1832 * limited to the specified address range.
1834 for (current = entry;
1835 (current != &map->header) && (current->start < end);
1836 current = current->next
1838 if (current->maptype == VM_MAPTYPE_SUBMAP)
1841 vm_map_clip_end(map, current, end, &count);
1845 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
1847 case MADV_SEQUENTIAL:
1848 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
1851 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
1854 current->eflags |= MAP_ENTRY_NOSYNC;
1857 current->eflags &= ~MAP_ENTRY_NOSYNC;
1860 current->eflags |= MAP_ENTRY_NOCOREDUMP;
1863 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
1867 * Invalidate the related pmap entries, used
1868 * to flush portions of the real kernel's
1869 * pmap when the caller has removed or
1870 * modified existing mappings in a virtual
1873 pmap_remove(map->pmap,
1874 current->start, current->end);
1878 * Set the page directory page for a map
1879 * governed by a virtual page table. Mark
1880 * the entry as being governed by a virtual
1881 * page table if it is not.
1883 * XXX the page directory page is stored
1884 * in the avail_ssize field if the map_entry.
1886 * XXX the map simplification code does not
1887 * compare this field so weird things may
1888 * happen if you do not apply this function
1889 * to the entire mapping governed by the
1890 * virtual page table.
1892 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
1896 current->aux.master_pde = value;
1897 pmap_remove(map->pmap,
1898 current->start, current->end);
1904 vm_map_simplify_entry(map, current, &count);
1912 * madvise behaviors that are implemented in the underlying
1915 * Since we don't clip the vm_map_entry, we have to clip
1916 * the vm_object pindex and count.
1918 * NOTE! We currently do not support these functions on
1919 * virtual page tables.
1921 for (current = entry;
1922 (current != &map->header) && (current->start < end);
1923 current = current->next
1925 vm_offset_t useStart;
1927 if (current->maptype != VM_MAPTYPE_NORMAL)
1930 pindex = OFF_TO_IDX(current->offset);
1931 count = atop(current->end - current->start);
1932 useStart = current->start;
1934 if (current->start < start) {
1935 pindex += atop(start - current->start);
1936 count -= atop(start - current->start);
1939 if (current->end > end)
1940 count -= atop(current->end - end);
1945 vm_object_madvise(current->object.vm_object,
1946 pindex, count, behav);
1949 * Try to populate the page table. Mappings governed
1950 * by virtual page tables cannot be pre-populated
1951 * without a lot of work so don't try.
1953 if (behav == MADV_WILLNEED &&
1954 current->maptype != VM_MAPTYPE_VPAGETABLE) {
1955 pmap_object_init_pt(
1958 current->protection,
1959 current->object.vm_object,
1961 (count << PAGE_SHIFT),
1962 MAP_PREFAULT_MADVISE
1966 vm_map_unlock_read(map);
1968 vm_map_entry_release(count);
1974 * Sets the inheritance of the specified address range in the target map.
1975 * Inheritance affects how the map will be shared with child maps at the
1976 * time of vm_map_fork.
1979 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
1980 vm_inherit_t new_inheritance)
1982 vm_map_entry_t entry;
1983 vm_map_entry_t temp_entry;
1986 switch (new_inheritance) {
1987 case VM_INHERIT_NONE:
1988 case VM_INHERIT_COPY:
1989 case VM_INHERIT_SHARE:
1992 return (KERN_INVALID_ARGUMENT);
1995 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1998 VM_MAP_RANGE_CHECK(map, start, end);
2000 if (vm_map_lookup_entry(map, start, &temp_entry)) {
2002 vm_map_clip_start(map, entry, start, &count);
2004 entry = temp_entry->next;
2006 while ((entry != &map->header) && (entry->start < end)) {
2007 vm_map_clip_end(map, entry, end, &count);
2009 entry->inheritance = new_inheritance;
2011 vm_map_simplify_entry(map, entry, &count);
2013 entry = entry->next;
2016 vm_map_entry_release(count);
2017 return (KERN_SUCCESS);
2021 * Implement the semantics of mlock
2024 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2025 boolean_t new_pageable)
2027 vm_map_entry_t entry;
2028 vm_map_entry_t start_entry;
2030 int rv = KERN_SUCCESS;
2033 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2035 VM_MAP_RANGE_CHECK(map, start, real_end);
2038 start_entry = vm_map_clip_range(map, start, end, &count,
2040 if (start_entry == NULL) {
2042 vm_map_entry_release(count);
2043 return (KERN_INVALID_ADDRESS);
2046 if (new_pageable == 0) {
2047 entry = start_entry;
2048 while ((entry != &map->header) && (entry->start < end)) {
2049 vm_offset_t save_start;
2050 vm_offset_t save_end;
2053 * Already user wired or hard wired (trivial cases)
2055 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2056 entry = entry->next;
2059 if (entry->wired_count != 0) {
2060 entry->wired_count++;
2061 entry->eflags |= MAP_ENTRY_USER_WIRED;
2062 entry = entry->next;
2067 * A new wiring requires instantiation of appropriate
2068 * management structures and the faulting in of the
2071 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2072 int copyflag = entry->eflags &
2073 MAP_ENTRY_NEEDS_COPY;
2074 if (copyflag && ((entry->protection &
2075 VM_PROT_WRITE) != 0)) {
2076 vm_map_entry_shadow(entry);
2077 } else if (entry->object.vm_object == NULL &&
2079 vm_map_entry_allocate_object(entry);
2082 entry->wired_count++;
2083 entry->eflags |= MAP_ENTRY_USER_WIRED;
2086 * Now fault in the area. Note that vm_fault_wire()
2087 * may release the map lock temporarily, it will be
2088 * relocked on return. The in-transition
2089 * flag protects the entries.
2091 save_start = entry->start;
2092 save_end = entry->end;
2093 rv = vm_fault_wire(map, entry, TRUE);
2095 CLIP_CHECK_BACK(entry, save_start);
2097 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2098 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2099 entry->wired_count = 0;
2100 if (entry->end == save_end)
2102 entry = entry->next;
2103 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2105 end = save_start; /* unwire the rest */
2109 * note that even though the entry might have been
2110 * clipped, the USER_WIRED flag we set prevents
2111 * duplication so we do not have to do a
2114 entry = entry->next;
2118 * If we failed fall through to the unwiring section to
2119 * unwire what we had wired so far. 'end' has already
2126 * start_entry might have been clipped if we unlocked the
2127 * map and blocked. No matter how clipped it has gotten
2128 * there should be a fragment that is on our start boundary.
2130 CLIP_CHECK_BACK(start_entry, start);
2134 * Deal with the unwiring case.
2138 * This is the unwiring case. We must first ensure that the
2139 * range to be unwired is really wired down. We know there
2142 entry = start_entry;
2143 while ((entry != &map->header) && (entry->start < end)) {
2144 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2145 rv = KERN_INVALID_ARGUMENT;
2148 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2149 entry = entry->next;
2153 * Now decrement the wiring count for each region. If a region
2154 * becomes completely unwired, unwire its physical pages and
2158 * The map entries are processed in a loop, checking to
2159 * make sure the entry is wired and asserting it has a wired
2160 * count. However, another loop was inserted more-or-less in
2161 * the middle of the unwiring path. This loop picks up the
2162 * "entry" loop variable from the first loop without first
2163 * setting it to start_entry. Naturally, the secound loop
2164 * is never entered and the pages backing the entries are
2165 * never unwired. This can lead to a leak of wired pages.
2167 entry = start_entry;
2168 while ((entry != &map->header) && (entry->start < end)) {
2169 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2170 ("expected USER_WIRED on entry %p", entry));
2171 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2172 entry->wired_count--;
2173 if (entry->wired_count == 0)
2174 vm_fault_unwire(map, entry);
2175 entry = entry->next;
2179 vm_map_unclip_range(map, start_entry, start, real_end, &count,
2183 vm_map_entry_release(count);
2188 * Sets the pageability of the specified address range in the target map.
2189 * Regions specified as not pageable require locked-down physical
2190 * memory and physical page maps.
2192 * The map must not be locked, but a reference must remain to the map
2193 * throughout the call.
2195 * This function may be called via the zalloc path and must properly
2196 * reserve map entries for kernel_map.
2201 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2203 vm_map_entry_t entry;
2204 vm_map_entry_t start_entry;
2206 int rv = KERN_SUCCESS;
2209 if (kmflags & KM_KRESERVE)
2210 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2212 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2214 VM_MAP_RANGE_CHECK(map, start, real_end);
2217 start_entry = vm_map_clip_range(map, start, end, &count,
2219 if (start_entry == NULL) {
2221 rv = KERN_INVALID_ADDRESS;
2224 if ((kmflags & KM_PAGEABLE) == 0) {
2228 * 1. Holding the write lock, we create any shadow or zero-fill
2229 * objects that need to be created. Then we clip each map
2230 * entry to the region to be wired and increment its wiring
2231 * count. We create objects before clipping the map entries
2232 * to avoid object proliferation.
2234 * 2. We downgrade to a read lock, and call vm_fault_wire to
2235 * fault in the pages for any newly wired area (wired_count is
2238 * Downgrading to a read lock for vm_fault_wire avoids a
2239 * possible deadlock with another process that may have faulted
2240 * on one of the pages to be wired (it would mark the page busy,
2241 * blocking us, then in turn block on the map lock that we
2242 * hold). Because of problems in the recursive lock package,
2243 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2244 * any actions that require the write lock must be done
2245 * beforehand. Because we keep the read lock on the map, the
2246 * copy-on-write status of the entries we modify here cannot
2249 entry = start_entry;
2250 while ((entry != &map->header) && (entry->start < end)) {
2252 * Trivial case if the entry is already wired
2254 if (entry->wired_count) {
2255 entry->wired_count++;
2256 entry = entry->next;
2261 * The entry is being newly wired, we have to setup
2262 * appropriate management structures. A shadow
2263 * object is required for a copy-on-write region,
2264 * or a normal object for a zero-fill region. We
2265 * do not have to do this for entries that point to sub
2266 * maps because we won't hold the lock on the sub map.
2268 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2269 int copyflag = entry->eflags &
2270 MAP_ENTRY_NEEDS_COPY;
2271 if (copyflag && ((entry->protection &
2272 VM_PROT_WRITE) != 0)) {
2273 vm_map_entry_shadow(entry);
2274 } else if (entry->object.vm_object == NULL &&
2276 vm_map_entry_allocate_object(entry);
2280 entry->wired_count++;
2281 entry = entry->next;
2289 * HACK HACK HACK HACK
2291 * vm_fault_wire() temporarily unlocks the map to avoid
2292 * deadlocks. The in-transition flag from vm_map_clip_range
2293 * call should protect us from changes while the map is
2296 * NOTE: Previously this comment stated that clipping might
2297 * still occur while the entry is unlocked, but from
2298 * what I can tell it actually cannot.
2300 * It is unclear whether the CLIP_CHECK_*() calls
2301 * are still needed but we keep them in anyway.
2303 * HACK HACK HACK HACK
2306 entry = start_entry;
2307 while (entry != &map->header && entry->start < end) {
2309 * If vm_fault_wire fails for any page we need to undo
2310 * what has been done. We decrement the wiring count
2311 * for those pages which have not yet been wired (now)
2312 * and unwire those that have (later).
2314 vm_offset_t save_start = entry->start;
2315 vm_offset_t save_end = entry->end;
2317 if (entry->wired_count == 1)
2318 rv = vm_fault_wire(map, entry, FALSE);
2320 CLIP_CHECK_BACK(entry, save_start);
2322 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2323 entry->wired_count = 0;
2324 if (entry->end == save_end)
2326 entry = entry->next;
2327 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2332 CLIP_CHECK_FWD(entry, save_end);
2333 entry = entry->next;
2337 * If a failure occured undo everything by falling through
2338 * to the unwiring code. 'end' has already been adjusted
2342 kmflags |= KM_PAGEABLE;
2345 * start_entry is still IN_TRANSITION but may have been
2346 * clipped since vm_fault_wire() unlocks and relocks the
2347 * map. No matter how clipped it has gotten there should
2348 * be a fragment that is on our start boundary.
2350 CLIP_CHECK_BACK(start_entry, start);
2353 if (kmflags & KM_PAGEABLE) {
2355 * This is the unwiring case. We must first ensure that the
2356 * range to be unwired is really wired down. We know there
2359 entry = start_entry;
2360 while ((entry != &map->header) && (entry->start < end)) {
2361 if (entry->wired_count == 0) {
2362 rv = KERN_INVALID_ARGUMENT;
2365 entry = entry->next;
2369 * Now decrement the wiring count for each region. If a region
2370 * becomes completely unwired, unwire its physical pages and
2373 entry = start_entry;
2374 while ((entry != &map->header) && (entry->start < end)) {
2375 entry->wired_count--;
2376 if (entry->wired_count == 0)
2377 vm_fault_unwire(map, entry);
2378 entry = entry->next;
2382 vm_map_unclip_range(map, start_entry, start, real_end,
2383 &count, MAP_CLIP_NO_HOLES);
2387 if (kmflags & KM_KRESERVE)
2388 vm_map_entry_krelease(count);
2390 vm_map_entry_release(count);
2395 * Mark a newly allocated address range as wired but do not fault in
2396 * the pages. The caller is expected to load the pages into the object.
2398 * The map must be locked on entry and will remain locked on return.
2399 * No other requirements.
2402 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2405 vm_map_entry_t scan;
2406 vm_map_entry_t entry;
2408 entry = vm_map_clip_range(map, addr, addr + size,
2409 countp, MAP_CLIP_NO_HOLES);
2411 scan != &map->header && scan->start < addr + size;
2412 scan = scan->next) {
2413 KKASSERT(entry->wired_count == 0);
2414 entry->wired_count = 1;
2416 vm_map_unclip_range(map, entry, addr, addr + size,
2417 countp, MAP_CLIP_NO_HOLES);
2421 * Push any dirty cached pages in the address range to their pager.
2422 * If syncio is TRUE, dirty pages are written synchronously.
2423 * If invalidate is TRUE, any cached pages are freed as well.
2425 * This routine is called by sys_msync()
2427 * Returns an error if any part of the specified range is not mapped.
2432 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2433 boolean_t syncio, boolean_t invalidate)
2435 vm_map_entry_t current;
2436 vm_map_entry_t entry;
2439 vm_ooffset_t offset;
2441 vm_map_lock_read(map);
2442 VM_MAP_RANGE_CHECK(map, start, end);
2443 if (!vm_map_lookup_entry(map, start, &entry)) {
2444 vm_map_unlock_read(map);
2445 return (KERN_INVALID_ADDRESS);
2448 * Make a first pass to check for holes.
2450 for (current = entry; current->start < end; current = current->next) {
2451 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2452 vm_map_unlock_read(map);
2453 return (KERN_INVALID_ARGUMENT);
2455 if (end > current->end &&
2456 (current->next == &map->header ||
2457 current->end != current->next->start)) {
2458 vm_map_unlock_read(map);
2459 return (KERN_INVALID_ADDRESS);
2464 pmap_remove(vm_map_pmap(map), start, end);
2467 * Make a second pass, cleaning/uncaching pages from the indicated
2470 * Hold vm_token to avoid blocking in vm_object_reference()
2472 lwkt_gettoken(&vm_token);
2473 lwkt_gettoken(&vmobj_token);
2475 for (current = entry; current->start < end; current = current->next) {
2476 offset = current->offset + (start - current->start);
2477 size = (end <= current->end ? end : current->end) - start;
2478 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2480 vm_map_entry_t tentry;
2483 smap = current->object.sub_map;
2484 vm_map_lock_read(smap);
2485 vm_map_lookup_entry(smap, offset, &tentry);
2486 tsize = tentry->end - offset;
2489 object = tentry->object.vm_object;
2490 offset = tentry->offset + (offset - tentry->start);
2491 vm_map_unlock_read(smap);
2493 object = current->object.vm_object;
2496 * Note that there is absolutely no sense in writing out
2497 * anonymous objects, so we track down the vnode object
2499 * We invalidate (remove) all pages from the address space
2500 * anyway, for semantic correctness.
2502 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2503 * may start out with a NULL object.
2505 while (object && object->backing_object) {
2506 offset += object->backing_object_offset;
2507 object = object->backing_object;
2508 if (object->size < OFF_TO_IDX( offset + size))
2509 size = IDX_TO_OFF(object->size) - offset;
2511 if (object && (object->type == OBJT_VNODE) &&
2512 (current->protection & VM_PROT_WRITE) &&
2513 (object->flags & OBJ_NOMSYNC) == 0) {
2515 * Flush pages if writing is allowed, invalidate them
2516 * if invalidation requested. Pages undergoing I/O
2517 * will be ignored by vm_object_page_remove().
2519 * We cannot lock the vnode and then wait for paging
2520 * to complete without deadlocking against vm_fault.
2521 * Instead we simply call vm_object_page_remove() and
2522 * allow it to block internally on a page-by-page
2523 * basis when it encounters pages undergoing async
2528 vm_object_reference_locked(object);
2529 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2530 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2531 flags |= invalidate ? OBJPC_INVAL : 0;
2534 * When operating on a virtual page table just
2535 * flush the whole object. XXX we probably ought
2538 switch(current->maptype) {
2539 case VM_MAPTYPE_NORMAL:
2540 vm_object_page_clean(object,
2542 OFF_TO_IDX(offset + size + PAGE_MASK),
2545 case VM_MAPTYPE_VPAGETABLE:
2546 vm_object_page_clean(object, 0, 0, flags);
2549 vn_unlock(((struct vnode *)object->handle));
2550 vm_object_deallocate_locked(object);
2552 if (object && invalidate &&
2553 ((object->type == OBJT_VNODE) ||
2554 (object->type == OBJT_DEVICE))) {
2556 (object->type == OBJT_DEVICE) ? FALSE : TRUE;
2557 vm_object_reference_locked(object);
2558 switch(current->maptype) {
2559 case VM_MAPTYPE_NORMAL:
2560 vm_object_page_remove(object,
2562 OFF_TO_IDX(offset + size + PAGE_MASK),
2565 case VM_MAPTYPE_VPAGETABLE:
2566 vm_object_page_remove(object, 0, 0, clean_only);
2569 vm_object_deallocate_locked(object);
2574 lwkt_reltoken(&vmobj_token);
2575 lwkt_reltoken(&vm_token);
2576 vm_map_unlock_read(map);
2578 return (KERN_SUCCESS);
2582 * Make the region specified by this entry pageable.
2584 * The vm_map must be exclusively locked.
2587 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2589 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2590 entry->wired_count = 0;
2591 vm_fault_unwire(map, entry);
2595 * Deallocate the given entry from the target map.
2597 * The vm_map must be exclusively locked.
2600 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2602 vm_map_entry_unlink(map, entry);
2603 map->size -= entry->end - entry->start;
2605 switch(entry->maptype) {
2606 case VM_MAPTYPE_NORMAL:
2607 case VM_MAPTYPE_VPAGETABLE:
2608 vm_object_deallocate(entry->object.vm_object);
2614 vm_map_entry_dispose(map, entry, countp);
2618 * Deallocates the given address range from the target map.
2620 * The vm_map must be exclusively locked.
2623 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2626 vm_map_entry_t entry;
2627 vm_map_entry_t first_entry;
2629 ASSERT_VM_MAP_LOCKED(map);
2632 * Find the start of the region, and clip it. Set entry to point
2633 * at the first record containing the requested address or, if no
2634 * such record exists, the next record with a greater address. The
2635 * loop will run from this point until a record beyond the termination
2636 * address is encountered.
2638 * map->hint must be adjusted to not point to anything we delete,
2639 * so set it to the entry prior to the one being deleted.
2641 * GGG see other GGG comment.
2643 if (vm_map_lookup_entry(map, start, &first_entry)) {
2644 entry = first_entry;
2645 vm_map_clip_start(map, entry, start, countp);
2646 map->hint = entry->prev; /* possible problem XXX */
2648 map->hint = first_entry; /* possible problem XXX */
2649 entry = first_entry->next;
2653 * If a hole opens up prior to the current first_free then
2654 * adjust first_free. As with map->hint, map->first_free
2655 * cannot be left set to anything we might delete.
2657 if (entry == &map->header) {
2658 map->first_free = &map->header;
2659 } else if (map->first_free->start >= start) {
2660 map->first_free = entry->prev;
2664 * Step through all entries in this region
2666 while ((entry != &map->header) && (entry->start < end)) {
2667 vm_map_entry_t next;
2669 vm_pindex_t offidxstart, offidxend, count;
2672 * If we hit an in-transition entry we have to sleep and
2673 * retry. It's easier (and not really slower) to just retry
2674 * since this case occurs so rarely and the hint is already
2675 * pointing at the right place. We have to reset the
2676 * start offset so as not to accidently delete an entry
2677 * another process just created in vacated space.
2679 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2680 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2681 start = entry->start;
2682 ++mycpu->gd_cnt.v_intrans_coll;
2683 ++mycpu->gd_cnt.v_intrans_wait;
2684 vm_map_transition_wait(map);
2687 vm_map_clip_end(map, entry, end, countp);
2693 offidxstart = OFF_TO_IDX(entry->offset);
2694 count = OFF_TO_IDX(e - s);
2695 object = entry->object.vm_object;
2698 * Unwire before removing addresses from the pmap; otherwise,
2699 * unwiring will put the entries back in the pmap.
2701 if (entry->wired_count != 0)
2702 vm_map_entry_unwire(map, entry);
2704 offidxend = offidxstart + count;
2707 * Hold vm_token when manipulating vm_objects,
2709 * Hold vmobj_token when potentially adding or removing
2710 * objects (collapse requires both).
2712 lwkt_gettoken(&vm_token);
2713 lwkt_gettoken(&vmobj_token);
2714 vm_object_hold(object);
2716 if (object == &kernel_object) {
2717 vm_object_page_remove(object, offidxstart,
2720 pmap_remove(map->pmap, s, e);
2722 if (object != NULL &&
2723 object->ref_count != 1 &&
2724 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2726 (object->type == OBJT_DEFAULT ||
2727 object->type == OBJT_SWAP)) {
2728 vm_object_collapse(object);
2729 vm_object_page_remove(object, offidxstart,
2731 if (object->type == OBJT_SWAP) {
2732 swap_pager_freespace(object,
2736 if (offidxend >= object->size &&
2737 offidxstart < object->size) {
2738 object->size = offidxstart;
2743 vm_object_drop(object);
2744 lwkt_reltoken(&vmobj_token);
2745 lwkt_reltoken(&vm_token);
2748 * Delete the entry (which may delete the object) only after
2749 * removing all pmap entries pointing to its pages.
2750 * (Otherwise, its page frames may be reallocated, and any
2751 * modify bits will be set in the wrong object!)
2753 vm_map_entry_delete(map, entry, countp);
2756 return (KERN_SUCCESS);
2760 * Remove the given address range from the target map.
2761 * This is the exported form of vm_map_delete.
2766 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
2771 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2773 VM_MAP_RANGE_CHECK(map, start, end);
2774 result = vm_map_delete(map, start, end, &count);
2776 vm_map_entry_release(count);
2782 * Assert that the target map allows the specified privilege on the
2783 * entire address region given. The entire region must be allocated.
2785 * The caller must specify whether the vm_map is already locked or not.
2788 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2789 vm_prot_t protection, boolean_t have_lock)
2791 vm_map_entry_t entry;
2792 vm_map_entry_t tmp_entry;
2795 if (have_lock == FALSE)
2796 vm_map_lock_read(map);
2798 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
2799 if (have_lock == FALSE)
2800 vm_map_unlock_read(map);
2806 while (start < end) {
2807 if (entry == &map->header) {
2815 if (start < entry->start) {
2820 * Check protection associated with entry.
2823 if ((entry->protection & protection) != protection) {
2827 /* go to next entry */
2830 entry = entry->next;
2832 if (have_lock == FALSE)
2833 vm_map_unlock_read(map);
2838 * Split the pages in a map entry into a new object. This affords
2839 * easier removal of unused pages, and keeps object inheritance from
2840 * being a negative impact on memory usage.
2842 * The vm_map must be exclusively locked.
2843 * The orig_object should be held.
2846 vm_map_split(vm_map_entry_t entry)
2849 vm_object_t orig_object, new_object, source;
2851 vm_pindex_t offidxstart, offidxend, idx;
2853 vm_ooffset_t offset;
2855 orig_object = entry->object.vm_object;
2856 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
2858 if (orig_object->ref_count <= 1)
2861 offset = entry->offset;
2865 offidxstart = OFF_TO_IDX(offset);
2866 offidxend = offidxstart + OFF_TO_IDX(e - s);
2867 size = offidxend - offidxstart;
2869 switch(orig_object->type) {
2871 new_object = default_pager_alloc(NULL, IDX_TO_OFF(size),
2875 new_object = swap_pager_alloc(NULL, IDX_TO_OFF(size),
2883 if (new_object == NULL)
2887 * vm_token required when manipulating vm_objects.
2889 lwkt_gettoken(&vm_token);
2890 lwkt_gettoken(&vmobj_token);
2892 vm_object_hold(new_object);
2894 source = orig_object->backing_object;
2895 if (source != NULL) {
2896 vm_object_hold(source);
2897 /* Referenced by new_object */
2898 vm_object_reference_locked(source);
2899 LIST_INSERT_HEAD(&source->shadow_head,
2900 new_object, shadow_list);
2901 vm_object_clear_flag(source, OBJ_ONEMAPPING);
2902 new_object->backing_object_offset =
2903 orig_object->backing_object_offset +
2904 IDX_TO_OFF(offidxstart);
2905 new_object->backing_object = source;
2906 source->shadow_count++;
2907 source->generation++;
2908 vm_object_drop(source);
2911 for (idx = 0; idx < size; idx++) {
2915 m = vm_page_lookup(orig_object, offidxstart + idx);
2920 * We must wait for pending I/O to complete before we can
2923 * We do not have to VM_PROT_NONE the page as mappings should
2924 * not be changed by this operation.
2926 if (vm_page_sleep_busy(m, TRUE, "spltwt"))
2929 vm_page_rename(m, new_object, idx);
2930 /* page automatically made dirty by rename and cache handled */
2934 if (orig_object->type == OBJT_SWAP) {
2935 vm_object_pip_add(orig_object, 1);
2937 * copy orig_object pages into new_object
2938 * and destroy unneeded pages in
2941 swap_pager_copy(orig_object, new_object, offidxstart, 0);
2942 vm_object_pip_wakeup(orig_object);
2946 * Wakeup the pages we played with. No spl protection is needed
2947 * for a simple wakeup.
2949 for (idx = 0; idx < size; idx++) {
2950 m = vm_page_lookup(new_object, idx);
2955 entry->object.vm_object = new_object;
2956 entry->offset = 0LL;
2957 vm_object_deallocate_locked(orig_object);
2958 vm_object_drop(new_object);
2959 lwkt_reltoken(&vmobj_token);
2960 lwkt_reltoken(&vm_token);
2964 * Copies the contents of the source entry to the destination
2965 * entry. The entries *must* be aligned properly.
2967 * The vm_map must be exclusively locked.
2968 * vm_token must be held
2971 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
2972 vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
2974 vm_object_t src_object;
2976 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP)
2978 if (src_entry->maptype == VM_MAPTYPE_SUBMAP)
2981 ASSERT_LWKT_TOKEN_HELD(&vm_token);
2982 lwkt_gettoken(&vmobj_token); /* required for collapse */
2984 if (src_entry->wired_count == 0) {
2986 * If the source entry is marked needs_copy, it is already
2989 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
2990 pmap_protect(src_map->pmap,
2993 src_entry->protection & ~VM_PROT_WRITE);
2997 * Make a copy of the object.
2999 if ((src_object = src_entry->object.vm_object) != NULL) {
3000 if ((src_object->handle == NULL) &&
3001 (src_object->type == OBJT_DEFAULT ||
3002 src_object->type == OBJT_SWAP)) {
3003 vm_object_collapse(src_object);
3004 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) {
3005 vm_map_split(src_entry);
3006 src_object = src_entry->object.vm_object;
3010 vm_object_reference_locked(src_object);
3011 vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
3012 dst_entry->object.vm_object = src_object;
3013 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
3014 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
3015 dst_entry->offset = src_entry->offset;
3017 dst_entry->object.vm_object = NULL;
3018 dst_entry->offset = 0;
3021 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3022 dst_entry->end - dst_entry->start, src_entry->start);
3025 * Of course, wired down pages can't be set copy-on-write.
3026 * Cause wired pages to be copied into the new map by
3027 * simulating faults (the new pages are pageable)
3029 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3031 lwkt_reltoken(&vmobj_token);
3036 * Create a new process vmspace structure and vm_map
3037 * based on those of an existing process. The new map
3038 * is based on the old map, according to the inheritance
3039 * values on the regions in that map.
3041 * The source map must not be locked.
3045 vmspace_fork(struct vmspace *vm1)
3047 struct vmspace *vm2;
3048 vm_map_t old_map = &vm1->vm_map;
3050 vm_map_entry_t old_entry;
3051 vm_map_entry_t new_entry;
3055 lwkt_gettoken(&vm_token);
3056 lwkt_gettoken(&vmspace_token);
3057 lwkt_gettoken(&vmobj_token);
3058 vm_map_lock(old_map);
3061 * XXX Note: upcalls are not copied.
3063 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3064 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3065 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3066 new_map = &vm2->vm_map; /* XXX */
3067 new_map->timestamp = 1;
3069 vm_map_lock(new_map);
3072 old_entry = old_map->header.next;
3073 while (old_entry != &old_map->header) {
3075 old_entry = old_entry->next;
3078 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3080 old_entry = old_map->header.next;
3081 while (old_entry != &old_map->header) {
3082 if (old_entry->maptype == VM_MAPTYPE_SUBMAP)
3083 panic("vm_map_fork: encountered a submap");
3085 switch (old_entry->inheritance) {
3086 case VM_INHERIT_NONE:
3088 case VM_INHERIT_SHARE:
3090 * Clone the entry, creating the shared object if
3093 object = old_entry->object.vm_object;
3094 if (object == NULL) {
3095 vm_map_entry_allocate_object(old_entry);
3096 object = old_entry->object.vm_object;
3100 * Add the reference before calling vm_map_entry_shadow
3101 * to insure that a shadow object is created.
3103 vm_object_reference_locked(object);
3104 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3105 vm_map_entry_shadow(old_entry);
3106 /* Transfer the second reference too. */
3107 vm_object_reference_locked(
3108 old_entry->object.vm_object);
3109 vm_object_deallocate_locked(object);
3110 object = old_entry->object.vm_object;
3112 vm_object_clear_flag(object, OBJ_ONEMAPPING);
3115 * Clone the entry, referencing the shared object.
3117 new_entry = vm_map_entry_create(new_map, &count);
3118 *new_entry = *old_entry;
3119 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3120 new_entry->wired_count = 0;
3123 * Insert the entry into the new map -- we know we're
3124 * inserting at the end of the new map.
3127 vm_map_entry_link(new_map, new_map->header.prev,
3131 * Update the physical map
3133 pmap_copy(new_map->pmap, old_map->pmap,
3135 (old_entry->end - old_entry->start),
3138 case VM_INHERIT_COPY:
3140 * Clone the entry and link into the map.
3142 new_entry = vm_map_entry_create(new_map, &count);
3143 *new_entry = *old_entry;
3144 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3145 new_entry->wired_count = 0;
3146 new_entry->object.vm_object = NULL;
3147 vm_map_entry_link(new_map, new_map->header.prev,
3149 vm_map_copy_entry(old_map, new_map, old_entry,
3153 old_entry = old_entry->next;
3156 new_map->size = old_map->size;
3157 vm_map_unlock(old_map);
3158 vm_map_unlock(new_map);
3159 vm_map_entry_release(count);
3161 lwkt_reltoken(&vmobj_token);
3162 lwkt_reltoken(&vmspace_token);
3163 lwkt_reltoken(&vm_token);
3169 * Create an auto-grow stack entry
3174 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3175 int flags, vm_prot_t prot, vm_prot_t max, int cow)
3177 vm_map_entry_t prev_entry;
3178 vm_map_entry_t new_stack_entry;
3179 vm_size_t init_ssize;
3182 vm_offset_t tmpaddr;
3184 cow |= MAP_IS_STACK;
3186 if (max_ssize < sgrowsiz)
3187 init_ssize = max_ssize;
3189 init_ssize = sgrowsiz;
3191 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3195 * Find space for the mapping
3197 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3198 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3201 vm_map_entry_release(count);
3202 return (KERN_NO_SPACE);
3207 /* If addr is already mapped, no go */
3208 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3210 vm_map_entry_release(count);
3211 return (KERN_NO_SPACE);
3215 /* XXX already handled by kern_mmap() */
3216 /* If we would blow our VMEM resource limit, no go */
3217 if (map->size + init_ssize >
3218 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3220 vm_map_entry_release(count);
3221 return (KERN_NO_SPACE);
3226 * If we can't accomodate max_ssize in the current mapping,
3227 * no go. However, we need to be aware that subsequent user
3228 * mappings might map into the space we have reserved for
3229 * stack, and currently this space is not protected.
3231 * Hopefully we will at least detect this condition
3232 * when we try to grow the stack.
3234 if ((prev_entry->next != &map->header) &&
3235 (prev_entry->next->start < addrbos + max_ssize)) {
3237 vm_map_entry_release(count);
3238 return (KERN_NO_SPACE);
3242 * We initially map a stack of only init_ssize. We will
3243 * grow as needed later. Since this is to be a grow
3244 * down stack, we map at the top of the range.
3246 * Note: we would normally expect prot and max to be
3247 * VM_PROT_ALL, and cow to be 0. Possibly we should
3248 * eliminate these as input parameters, and just
3249 * pass these values here in the insert call.
3251 rv = vm_map_insert(map, &count,
3252 NULL, 0, addrbos + max_ssize - init_ssize,
3253 addrbos + max_ssize,
3258 /* Now set the avail_ssize amount */
3259 if (rv == KERN_SUCCESS) {
3260 if (prev_entry != &map->header)
3261 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3262 new_stack_entry = prev_entry->next;
3263 if (new_stack_entry->end != addrbos + max_ssize ||
3264 new_stack_entry->start != addrbos + max_ssize - init_ssize)
3265 panic ("Bad entry start/end for new stack entry");
3267 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3271 vm_map_entry_release(count);
3276 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3277 * desired address is already mapped, or if we successfully grow
3278 * the stack. Also returns KERN_SUCCESS if addr is outside the
3279 * stack range (this is strange, but preserves compatibility with
3280 * the grow function in vm_machdep.c).
3285 vm_map_growstack (struct proc *p, vm_offset_t addr)
3287 vm_map_entry_t prev_entry;
3288 vm_map_entry_t stack_entry;
3289 vm_map_entry_t new_stack_entry;
3290 struct vmspace *vm = p->p_vmspace;
3291 vm_map_t map = &vm->vm_map;
3294 int rv = KERN_SUCCESS;
3296 int use_read_lock = 1;
3299 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3302 vm_map_lock_read(map);
3306 /* If addr is already in the entry range, no need to grow.*/
3307 if (vm_map_lookup_entry(map, addr, &prev_entry))
3310 if ((stack_entry = prev_entry->next) == &map->header)
3312 if (prev_entry == &map->header)
3313 end = stack_entry->start - stack_entry->aux.avail_ssize;
3315 end = prev_entry->end;
3318 * This next test mimics the old grow function in vm_machdep.c.
3319 * It really doesn't quite make sense, but we do it anyway
3320 * for compatibility.
3322 * If not growable stack, return success. This signals the
3323 * caller to proceed as he would normally with normal vm.
3325 if (stack_entry->aux.avail_ssize < 1 ||
3326 addr >= stack_entry->start ||
3327 addr < stack_entry->start - stack_entry->aux.avail_ssize) {
3331 /* Find the minimum grow amount */
3332 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3333 if (grow_amount > stack_entry->aux.avail_ssize) {
3339 * If there is no longer enough space between the entries
3340 * nogo, and adjust the available space. Note: this
3341 * should only happen if the user has mapped into the
3342 * stack area after the stack was created, and is
3343 * probably an error.
3345 * This also effectively destroys any guard page the user
3346 * might have intended by limiting the stack size.
3348 if (grow_amount > stack_entry->start - end) {
3349 if (use_read_lock && vm_map_lock_upgrade(map)) {
3354 stack_entry->aux.avail_ssize = stack_entry->start - end;
3359 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3361 /* If this is the main process stack, see if we're over the
3364 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3365 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3370 /* Round up the grow amount modulo SGROWSIZ */
3371 grow_amount = roundup (grow_amount, sgrowsiz);
3372 if (grow_amount > stack_entry->aux.avail_ssize) {
3373 grow_amount = stack_entry->aux.avail_ssize;
3375 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3376 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3377 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3381 /* If we would blow our VMEM resource limit, no go */
3382 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3387 if (use_read_lock && vm_map_lock_upgrade(map)) {
3393 /* Get the preliminary new entry start value */
3394 addr = stack_entry->start - grow_amount;
3396 /* If this puts us into the previous entry, cut back our growth
3397 * to the available space. Also, see the note above.
3400 stack_entry->aux.avail_ssize = stack_entry->start - end;
3404 rv = vm_map_insert(map, &count,
3405 NULL, 0, addr, stack_entry->start,
3407 VM_PROT_ALL, VM_PROT_ALL,
3410 /* Adjust the available stack space by the amount we grew. */
3411 if (rv == KERN_SUCCESS) {
3412 if (prev_entry != &map->header)
3413 vm_map_clip_end(map, prev_entry, addr, &count);
3414 new_stack_entry = prev_entry->next;
3415 if (new_stack_entry->end != stack_entry->start ||
3416 new_stack_entry->start != addr)
3417 panic ("Bad stack grow start/end in new stack entry");
3419 new_stack_entry->aux.avail_ssize =
3420 stack_entry->aux.avail_ssize -
3421 (new_stack_entry->end - new_stack_entry->start);
3423 vm->vm_ssize += btoc(new_stack_entry->end -
3424 new_stack_entry->start);
3427 if (map->flags & MAP_WIREFUTURE)
3428 vm_map_unwire(map, new_stack_entry->start,
3429 new_stack_entry->end, FALSE);
3434 vm_map_unlock_read(map);
3437 vm_map_entry_release(count);
3442 * Unshare the specified VM space for exec. If other processes are
3443 * mapped to it, then create a new one. The new vmspace is null.
3448 vmspace_exec(struct proc *p, struct vmspace *vmcopy)
3450 struct vmspace *oldvmspace = p->p_vmspace;
3451 struct vmspace *newvmspace;
3452 vm_map_t map = &p->p_vmspace->vm_map;
3455 * If we are execing a resident vmspace we fork it, otherwise
3456 * we create a new vmspace. Note that exitingcnt and upcalls
3457 * are not copied to the new vmspace.
3459 lwkt_gettoken(&vmspace_token);
3461 newvmspace = vmspace_fork(vmcopy);
3463 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3464 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3465 (caddr_t)&oldvmspace->vm_endcopy -
3466 (caddr_t)&oldvmspace->vm_startcopy);
3470 * Finish initializing the vmspace before assigning it
3471 * to the process. The vmspace will become the current vmspace
3474 pmap_pinit2(vmspace_pmap(newvmspace));
3475 pmap_replacevm(p, newvmspace, 0);
3476 sysref_put(&oldvmspace->vm_sysref);
3477 lwkt_reltoken(&vmspace_token);
3481 * Unshare the specified VM space for forcing COW. This
3482 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3484 * The exitingcnt test is not strictly necessary but has been
3485 * included for code sanity (to make the code a bit more deterministic).
3488 vmspace_unshare(struct proc *p)
3490 struct vmspace *oldvmspace = p->p_vmspace;
3491 struct vmspace *newvmspace;
3493 lwkt_gettoken(&vmspace_token);
3494 if (oldvmspace->vm_sysref.refcnt == 1 && oldvmspace->vm_exitingcnt == 0)
3496 newvmspace = vmspace_fork(oldvmspace);
3497 pmap_pinit2(vmspace_pmap(newvmspace));
3498 pmap_replacevm(p, newvmspace, 0);
3499 sysref_put(&oldvmspace->vm_sysref);
3500 lwkt_reltoken(&vmspace_token);
3504 * vm_map_hint: return the beginning of the best area suitable for
3505 * creating a new mapping with "prot" protection.
3510 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot)
3512 struct vmspace *vms = p->p_vmspace;
3514 if (!randomize_mmap) {
3516 * Set a reasonable start point for the hint if it was
3517 * not specified or if it falls within the heap space.
3518 * Hinted mmap()s do not allocate out of the heap space.
3521 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
3522 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) {
3523 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
3529 if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr)
3535 * If executable skip first two pages, otherwise start
3536 * after data + heap region.
3538 if ((prot & VM_PROT_EXECUTE) &&
3539 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) {
3540 addr = (PAGE_SIZE * 2) +
3541 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1));
3542 return (round_page(addr));
3544 #endif /* __i386__ */
3547 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ;
3548 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1);
3550 return (round_page(addr));
3554 * Finds the VM object, offset, and protection for a given virtual address
3555 * in the specified map, assuming a page fault of the type specified.
3557 * Leaves the map in question locked for read; return values are guaranteed
3558 * until a vm_map_lookup_done call is performed. Note that the map argument
3559 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3561 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3564 * If a lookup is requested with "write protection" specified, the map may
3565 * be changed to perform virtual copying operations, although the data
3566 * referenced will remain the same.
3571 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
3573 vm_prot_t fault_typea,
3574 vm_map_entry_t *out_entry, /* OUT */
3575 vm_object_t *object, /* OUT */
3576 vm_pindex_t *pindex, /* OUT */
3577 vm_prot_t *out_prot, /* OUT */
3578 boolean_t *wired) /* OUT */
3580 vm_map_entry_t entry;
3581 vm_map_t map = *var_map;
3583 vm_prot_t fault_type = fault_typea;
3584 int use_read_lock = 1;
3585 int rv = KERN_SUCCESS;
3589 vm_map_lock_read(map);
3594 * If the map has an interesting hint, try it before calling full
3595 * blown lookup routine.
3600 if ((entry == &map->header) ||
3601 (vaddr < entry->start) || (vaddr >= entry->end)) {
3602 vm_map_entry_t tmp_entry;
3605 * Entry was either not a valid hint, or the vaddr was not
3606 * contained in the entry, so do a full lookup.
3608 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
3609 rv = KERN_INVALID_ADDRESS;
3620 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3621 vm_map_t old_map = map;
3623 *var_map = map = entry->object.sub_map;
3625 vm_map_unlock_read(old_map);
3627 vm_map_unlock(old_map);
3633 * Check whether this task is allowed to have this page.
3634 * Note the special case for MAP_ENTRY_COW
3635 * pages with an override. This is to implement a forced
3636 * COW for debuggers.
3639 if (fault_type & VM_PROT_OVERRIDE_WRITE)
3640 prot = entry->max_protection;
3642 prot = entry->protection;
3644 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
3645 if ((fault_type & prot) != fault_type) {
3646 rv = KERN_PROTECTION_FAILURE;
3650 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
3651 (entry->eflags & MAP_ENTRY_COW) &&
3652 (fault_type & VM_PROT_WRITE) &&
3653 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
3654 rv = KERN_PROTECTION_FAILURE;
3659 * If this page is not pageable, we have to get it for all possible
3662 *wired = (entry->wired_count != 0);
3664 prot = fault_type = entry->protection;
3667 * Virtual page tables may need to update the accessed (A) bit
3668 * in a page table entry. Upgrade the fault to a write fault for
3669 * that case if the map will support it. If the map does not support
3670 * it the page table entry simply will not be updated.
3672 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
3673 if (prot & VM_PROT_WRITE)
3674 fault_type |= VM_PROT_WRITE;
3678 * If the entry was copy-on-write, we either ...
3680 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3682 * If we want to write the page, we may as well handle that
3683 * now since we've got the map locked.
3685 * If we don't need to write the page, we just demote the
3686 * permissions allowed.
3689 if (fault_type & VM_PROT_WRITE) {
3691 * Make a new object, and place it in the object
3692 * chain. Note that no new references have appeared
3693 * -- one just moved from the map to the new
3697 if (use_read_lock && vm_map_lock_upgrade(map)) {
3703 vm_map_entry_shadow(entry);
3706 * We're attempting to read a copy-on-write page --
3707 * don't allow writes.
3710 prot &= ~VM_PROT_WRITE;
3715 * Create an object if necessary.
3717 if (entry->object.vm_object == NULL &&
3719 if (use_read_lock && vm_map_lock_upgrade(map)) {
3724 vm_map_entry_allocate_object(entry);
3728 * Return the object/offset from this entry. If the entry was
3729 * copy-on-write or empty, it has been fixed up.
3732 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
3733 *object = entry->object.vm_object;
3736 * Return whether this is the only map sharing this data. On
3737 * success we return with a read lock held on the map. On failure
3738 * we return with the map unlocked.
3742 if (rv == KERN_SUCCESS) {
3743 if (use_read_lock == 0)
3744 vm_map_lock_downgrade(map);
3745 } else if (use_read_lock) {
3746 vm_map_unlock_read(map);
3754 * Releases locks acquired by a vm_map_lookup()
3755 * (according to the handle returned by that lookup).
3757 * No other requirements.
3760 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
3763 * Unlock the main-level map
3765 vm_map_unlock_read(map);
3767 vm_map_entry_release(count);
3770 #include "opt_ddb.h"
3772 #include <sys/kernel.h>
3774 #include <ddb/ddb.h>
3779 DB_SHOW_COMMAND(map, vm_map_print)
3782 /* XXX convert args. */
3783 vm_map_t map = (vm_map_t)addr;
3784 boolean_t full = have_addr;
3786 vm_map_entry_t entry;
3788 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
3790 (void *)map->pmap, map->nentries, map->timestamp);
3793 if (!full && db_indent)
3797 for (entry = map->header.next; entry != &map->header;
3798 entry = entry->next) {
3799 db_iprintf("map entry %p: start=%p, end=%p\n",
3800 (void *)entry, (void *)entry->start, (void *)entry->end);
3803 static char *inheritance_name[4] =
3804 {"share", "copy", "none", "donate_copy"};
3806 db_iprintf(" prot=%x/%x/%s",
3808 entry->max_protection,
3809 inheritance_name[(int)(unsigned char)entry->inheritance]);
3810 if (entry->wired_count != 0)
3811 db_printf(", wired");
3813 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3814 /* XXX no %qd in kernel. Truncate entry->offset. */
3815 db_printf(", share=%p, offset=0x%lx\n",
3816 (void *)entry->object.sub_map,
3817 (long)entry->offset);
3819 if ((entry->prev == &map->header) ||
3820 (entry->prev->object.sub_map !=
3821 entry->object.sub_map)) {
3823 vm_map_print((db_expr_t)(intptr_t)
3824 entry->object.sub_map,
3829 /* XXX no %qd in kernel. Truncate entry->offset. */
3830 db_printf(", object=%p, offset=0x%lx",
3831 (void *)entry->object.vm_object,
3832 (long)entry->offset);
3833 if (entry->eflags & MAP_ENTRY_COW)
3834 db_printf(", copy (%s)",
3835 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
3839 if ((entry->prev == &map->header) ||
3840 (entry->prev->object.vm_object !=
3841 entry->object.vm_object)) {
3843 vm_object_print((db_expr_t)(intptr_t)
3844 entry->object.vm_object,
3859 DB_SHOW_COMMAND(procvm, procvm)
3864 p = (struct proc *) addr;
3869 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
3870 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
3871 (void *)vmspace_pmap(p->p_vmspace));
3873 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);