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);
494 map->min_offset = min;
495 map->max_offset = max;
497 map->first_free = &map->header;
498 map->hint = &map->header;
501 lockinit(&map->lock, "thrd_sleep", 0, 0);
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
935 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
936 vm_object_clear_flag(object, OBJ_ONEMAPPING);
939 else if ((prev_entry != &map->header) &&
940 (prev_entry->eflags == protoeflags) &&
941 (prev_entry->end == start) &&
942 (prev_entry->wired_count == 0) &&
943 prev_entry->maptype == maptype &&
944 ((prev_entry->object.vm_object == NULL) ||
945 vm_object_coalesce(prev_entry->object.vm_object,
946 OFF_TO_IDX(prev_entry->offset),
947 (vm_size_t)(prev_entry->end - prev_entry->start),
948 (vm_size_t)(end - prev_entry->end)))) {
950 * We were able to extend the object. Determine if we
951 * can extend the previous map entry to include the
954 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
955 (prev_entry->protection == prot) &&
956 (prev_entry->max_protection == max)) {
957 lwkt_reltoken(&vmobj_token);
958 lwkt_reltoken(&vm_token);
959 map->size += (end - prev_entry->end);
960 prev_entry->end = end;
961 vm_map_simplify_entry(map, prev_entry, countp);
962 return (KERN_SUCCESS);
966 * If we can extend the object but cannot extend the
967 * map entry, we have to create a new map entry. We
968 * must bump the ref count on the extended object to
969 * account for it. object may be NULL.
971 object = prev_entry->object.vm_object;
972 offset = prev_entry->offset +
973 (prev_entry->end - prev_entry->start);
974 vm_object_reference_locked(object);
977 lwkt_reltoken(&vmobj_token);
978 lwkt_reltoken(&vm_token);
981 * NOTE: if conditionals fail, object can be NULL here. This occurs
982 * in things like the buffer map where we manage kva but do not manage
990 new_entry = vm_map_entry_create(map, countp);
991 new_entry->start = start;
992 new_entry->end = end;
994 new_entry->maptype = maptype;
995 new_entry->eflags = protoeflags;
996 new_entry->object.vm_object = object;
997 new_entry->offset = offset;
998 new_entry->aux.master_pde = 0;
1000 new_entry->inheritance = VM_INHERIT_DEFAULT;
1001 new_entry->protection = prot;
1002 new_entry->max_protection = max;
1003 new_entry->wired_count = 0;
1006 * Insert the new entry into the list
1009 vm_map_entry_link(map, prev_entry, new_entry);
1010 map->size += new_entry->end - new_entry->start;
1013 * Update the free space hint. Entries cannot overlap.
1014 * An exact comparison is needed to avoid matching
1015 * against the map->header.
1017 if ((map->first_free == prev_entry) &&
1018 (prev_entry->end == new_entry->start)) {
1019 map->first_free = new_entry;
1024 * Temporarily removed to avoid MAP_STACK panic, due to
1025 * MAP_STACK being a huge hack. Will be added back in
1026 * when MAP_STACK (and the user stack mapping) is fixed.
1029 * It may be possible to simplify the entry
1031 vm_map_simplify_entry(map, new_entry, countp);
1035 * Try to pre-populate the page table. Mappings governed by virtual
1036 * page tables cannot be prepopulated without a lot of work, so
1039 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) &&
1040 maptype != VM_MAPTYPE_VPAGETABLE) {
1041 pmap_object_init_pt(map->pmap, start, prot,
1042 object, OFF_TO_IDX(offset), end - start,
1043 cow & MAP_PREFAULT_PARTIAL);
1046 return (KERN_SUCCESS);
1050 * Find sufficient space for `length' bytes in the given map, starting at
1051 * `start'. Returns 0 on success, 1 on no space.
1053 * This function will returned an arbitrarily aligned pointer. If no
1054 * particular alignment is required you should pass align as 1. Note that
1055 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1056 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1059 * 'align' should be a power of 2 but is not required to be.
1061 * The map must be exclusively locked.
1062 * No other requirements.
1065 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1066 vm_size_t align, int flags, vm_offset_t *addr)
1068 vm_map_entry_t entry, next;
1070 vm_offset_t align_mask;
1072 if (start < map->min_offset)
1073 start = map->min_offset;
1074 if (start > map->max_offset)
1078 * If the alignment is not a power of 2 we will have to use
1079 * a mod/division, set align_mask to a special value.
1081 if ((align | (align - 1)) + 1 != (align << 1))
1082 align_mask = (vm_offset_t)-1;
1084 align_mask = align - 1;
1087 * Look for the first possible address; if there's already something
1088 * at this address, we have to start after it.
1090 if (start == map->min_offset) {
1091 if ((entry = map->first_free) != &map->header)
1096 if (vm_map_lookup_entry(map, start, &tmp))
1102 * Look through the rest of the map, trying to fit a new region in the
1103 * gap between existing regions, or after the very last region.
1105 for (;; start = (entry = next)->end) {
1107 * Adjust the proposed start by the requested alignment,
1108 * be sure that we didn't wrap the address.
1110 if (align_mask == (vm_offset_t)-1)
1111 end = ((start + align - 1) / align) * align;
1113 end = (start + align_mask) & ~align_mask;
1118 * Find the end of the proposed new region. Be sure we didn't
1119 * go beyond the end of the map, or wrap around the address.
1120 * Then check to see if this is the last entry or if the
1121 * proposed end fits in the gap between this and the next
1124 end = start + length;
1125 if (end > map->max_offset || end < start)
1130 * If the next entry's start address is beyond the desired
1131 * end address we may have found a good entry.
1133 * If the next entry is a stack mapping we do not map into
1134 * the stack's reserved space.
1136 * XXX continue to allow mapping into the stack's reserved
1137 * space if doing a MAP_STACK mapping inside a MAP_STACK
1138 * mapping, for backwards compatibility. But the caller
1139 * really should use MAP_STACK | MAP_TRYFIXED if they
1142 if (next == &map->header)
1144 if (next->start >= end) {
1145 if ((next->eflags & MAP_ENTRY_STACK) == 0)
1147 if (flags & MAP_STACK)
1149 if (next->start - next->aux.avail_ssize >= end)
1156 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1157 * if it fails. The kernel_map is locked and nothing can steal
1158 * our address space if pmap_growkernel() blocks.
1160 * NOTE: This may be unconditionally called for kldload areas on
1161 * x86_64 because these do not bump kernel_vm_end (which would
1162 * fill 128G worth of page tables!). Therefore we must not
1165 if (map == &kernel_map) {
1168 kstop = round_page(start + length);
1169 if (kstop > kernel_vm_end)
1170 pmap_growkernel(start, kstop);
1177 * vm_map_find finds an unallocated region in the target address map with
1178 * the given length. The search is defined to be first-fit from the
1179 * specified address; the region found is returned in the same parameter.
1181 * If object is non-NULL, ref count must be bumped by caller
1182 * prior to making call to account for the new entry.
1184 * No requirements. This function will lock the map temporarily.
1187 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1188 vm_offset_t *addr, vm_size_t length, vm_size_t align,
1190 vm_maptype_t maptype,
1191 vm_prot_t prot, vm_prot_t max,
1200 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1203 if (vm_map_findspace(map, start, length, align, 0, addr)) {
1205 vm_map_entry_release(count);
1206 return (KERN_NO_SPACE);
1210 result = vm_map_insert(map, &count, object, offset,
1211 start, start + length,
1216 vm_map_entry_release(count);
1222 * Simplify the given map entry by merging with either neighbor. This
1223 * routine also has the ability to merge with both neighbors.
1225 * This routine guarentees that the passed entry remains valid (though
1226 * possibly extended). When merging, this routine may delete one or
1227 * both neighbors. No action is taken on entries which have their
1228 * in-transition flag set.
1230 * The map must be exclusively locked.
1233 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1235 vm_map_entry_t next, prev;
1236 vm_size_t prevsize, esize;
1238 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1239 ++mycpu->gd_cnt.v_intrans_coll;
1243 if (entry->maptype == VM_MAPTYPE_SUBMAP)
1247 if (prev != &map->header) {
1248 prevsize = prev->end - prev->start;
1249 if ( (prev->end == entry->start) &&
1250 (prev->maptype == entry->maptype) &&
1251 (prev->object.vm_object == entry->object.vm_object) &&
1252 (!prev->object.vm_object ||
1253 (prev->offset + prevsize == entry->offset)) &&
1254 (prev->eflags == entry->eflags) &&
1255 (prev->protection == entry->protection) &&
1256 (prev->max_protection == entry->max_protection) &&
1257 (prev->inheritance == entry->inheritance) &&
1258 (prev->wired_count == entry->wired_count)) {
1259 if (map->first_free == prev)
1260 map->first_free = entry;
1261 if (map->hint == prev)
1263 vm_map_entry_unlink(map, prev);
1264 entry->start = prev->start;
1265 entry->offset = prev->offset;
1266 if (prev->object.vm_object)
1267 vm_object_deallocate(prev->object.vm_object);
1268 vm_map_entry_dispose(map, prev, countp);
1273 if (next != &map->header) {
1274 esize = entry->end - entry->start;
1275 if ((entry->end == next->start) &&
1276 (next->maptype == entry->maptype) &&
1277 (next->object.vm_object == entry->object.vm_object) &&
1278 (!entry->object.vm_object ||
1279 (entry->offset + esize == next->offset)) &&
1280 (next->eflags == entry->eflags) &&
1281 (next->protection == entry->protection) &&
1282 (next->max_protection == entry->max_protection) &&
1283 (next->inheritance == entry->inheritance) &&
1284 (next->wired_count == entry->wired_count)) {
1285 if (map->first_free == next)
1286 map->first_free = entry;
1287 if (map->hint == next)
1289 vm_map_entry_unlink(map, next);
1290 entry->end = next->end;
1291 if (next->object.vm_object)
1292 vm_object_deallocate(next->object.vm_object);
1293 vm_map_entry_dispose(map, next, countp);
1299 * Asserts that the given entry begins at or after the specified address.
1300 * If necessary, it splits the entry into two.
1302 #define vm_map_clip_start(map, entry, startaddr, countp) \
1304 if (startaddr > entry->start) \
1305 _vm_map_clip_start(map, entry, startaddr, countp); \
1309 * This routine is called only when it is known that the entry must be split.
1311 * The map must be exclusively locked.
1314 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1317 vm_map_entry_t new_entry;
1320 * Split off the front portion -- note that we must insert the new
1321 * entry BEFORE this one, so that this entry has the specified
1325 vm_map_simplify_entry(map, entry, countp);
1328 * If there is no object backing this entry, we might as well create
1329 * one now. If we defer it, an object can get created after the map
1330 * is clipped, and individual objects will be created for the split-up
1331 * map. This is a bit of a hack, but is also about the best place to
1332 * put this improvement.
1334 if (entry->object.vm_object == NULL && !map->system_map) {
1335 vm_map_entry_allocate_object(entry);
1338 new_entry = vm_map_entry_create(map, countp);
1339 *new_entry = *entry;
1341 new_entry->end = start;
1342 entry->offset += (start - entry->start);
1343 entry->start = start;
1345 vm_map_entry_link(map, entry->prev, new_entry);
1347 switch(entry->maptype) {
1348 case VM_MAPTYPE_NORMAL:
1349 case VM_MAPTYPE_VPAGETABLE:
1350 vm_object_reference(new_entry->object.vm_object);
1358 * Asserts that the given entry ends at or before the specified address.
1359 * If necessary, it splits the entry into two.
1361 * The map must be exclusively locked.
1363 #define vm_map_clip_end(map, entry, endaddr, countp) \
1365 if (endaddr < entry->end) \
1366 _vm_map_clip_end(map, entry, endaddr, countp); \
1370 * This routine is called only when it is known that the entry must be split.
1372 * The map must be exclusively locked.
1375 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1378 vm_map_entry_t new_entry;
1381 * If there is no object backing this entry, we might as well create
1382 * one now. If we defer it, an object can get created after the map
1383 * is clipped, and individual objects will be created for the split-up
1384 * map. This is a bit of a hack, but is also about the best place to
1385 * put this improvement.
1388 if (entry->object.vm_object == NULL && !map->system_map) {
1389 vm_map_entry_allocate_object(entry);
1393 * Create a new entry and insert it AFTER the specified entry
1396 new_entry = vm_map_entry_create(map, countp);
1397 *new_entry = *entry;
1399 new_entry->start = entry->end = end;
1400 new_entry->offset += (end - entry->start);
1402 vm_map_entry_link(map, entry, new_entry);
1404 switch(entry->maptype) {
1405 case VM_MAPTYPE_NORMAL:
1406 case VM_MAPTYPE_VPAGETABLE:
1407 vm_object_reference(new_entry->object.vm_object);
1415 * Asserts that the starting and ending region addresses fall within the
1416 * valid range for the map.
1418 #define VM_MAP_RANGE_CHECK(map, start, end) \
1420 if (start < vm_map_min(map)) \
1421 start = vm_map_min(map); \
1422 if (end > vm_map_max(map)) \
1423 end = vm_map_max(map); \
1429 * Used to block when an in-transition collison occurs. The map
1430 * is unlocked for the sleep and relocked before the return.
1433 vm_map_transition_wait(vm_map_t map)
1435 tsleep_interlock(map, 0);
1437 tsleep(map, PINTERLOCKED, "vment", 0);
1442 * When we do blocking operations with the map lock held it is
1443 * possible that a clip might have occured on our in-transit entry,
1444 * requiring an adjustment to the entry in our loop. These macros
1445 * help the pageable and clip_range code deal with the case. The
1446 * conditional costs virtually nothing if no clipping has occured.
1449 #define CLIP_CHECK_BACK(entry, save_start) \
1451 while (entry->start != save_start) { \
1452 entry = entry->prev; \
1453 KASSERT(entry != &map->header, ("bad entry clip")); \
1457 #define CLIP_CHECK_FWD(entry, save_end) \
1459 while (entry->end != save_end) { \
1460 entry = entry->next; \
1461 KASSERT(entry != &map->header, ("bad entry clip")); \
1467 * Clip the specified range and return the base entry. The
1468 * range may cover several entries starting at the returned base
1469 * and the first and last entry in the covering sequence will be
1470 * properly clipped to the requested start and end address.
1472 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1475 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1476 * covered by the requested range.
1478 * The map must be exclusively locked on entry and will remain locked
1479 * on return. If no range exists or the range contains holes and you
1480 * specified that no holes were allowed, NULL will be returned. This
1481 * routine may temporarily unlock the map in order avoid a deadlock when
1486 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end,
1487 int *countp, int flags)
1489 vm_map_entry_t start_entry;
1490 vm_map_entry_t entry;
1493 * Locate the entry and effect initial clipping. The in-transition
1494 * case does not occur very often so do not try to optimize it.
1497 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1499 entry = start_entry;
1500 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1501 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1502 ++mycpu->gd_cnt.v_intrans_coll;
1503 ++mycpu->gd_cnt.v_intrans_wait;
1504 vm_map_transition_wait(map);
1506 * entry and/or start_entry may have been clipped while
1507 * we slept, or may have gone away entirely. We have
1508 * to restart from the lookup.
1514 * Since we hold an exclusive map lock we do not have to restart
1515 * after clipping, even though clipping may block in zalloc.
1517 vm_map_clip_start(map, entry, start, countp);
1518 vm_map_clip_end(map, entry, end, countp);
1519 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1522 * Scan entries covered by the range. When working on the next
1523 * entry a restart need only re-loop on the current entry which
1524 * we have already locked, since 'next' may have changed. Also,
1525 * even though entry is safe, it may have been clipped so we
1526 * have to iterate forwards through the clip after sleeping.
1528 while (entry->next != &map->header && entry->next->start < end) {
1529 vm_map_entry_t next = entry->next;
1531 if (flags & MAP_CLIP_NO_HOLES) {
1532 if (next->start > entry->end) {
1533 vm_map_unclip_range(map, start_entry,
1534 start, entry->end, countp, flags);
1539 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1540 vm_offset_t save_end = entry->end;
1541 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1542 ++mycpu->gd_cnt.v_intrans_coll;
1543 ++mycpu->gd_cnt.v_intrans_wait;
1544 vm_map_transition_wait(map);
1547 * clips might have occured while we blocked.
1549 CLIP_CHECK_FWD(entry, save_end);
1550 CLIP_CHECK_BACK(start_entry, start);
1554 * No restart necessary even though clip_end may block, we
1555 * are holding the map lock.
1557 vm_map_clip_end(map, next, end, countp);
1558 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1561 if (flags & MAP_CLIP_NO_HOLES) {
1562 if (entry->end != end) {
1563 vm_map_unclip_range(map, start_entry,
1564 start, entry->end, countp, flags);
1568 return(start_entry);
1572 * Undo the effect of vm_map_clip_range(). You should pass the same
1573 * flags and the same range that you passed to vm_map_clip_range().
1574 * This code will clear the in-transition flag on the entries and
1575 * wake up anyone waiting. This code will also simplify the sequence
1576 * and attempt to merge it with entries before and after the sequence.
1578 * The map must be locked on entry and will remain locked on return.
1580 * Note that you should also pass the start_entry returned by
1581 * vm_map_clip_range(). However, if you block between the two calls
1582 * with the map unlocked please be aware that the start_entry may
1583 * have been clipped and you may need to scan it backwards to find
1584 * the entry corresponding with the original start address. You are
1585 * responsible for this, vm_map_unclip_range() expects the correct
1586 * start_entry to be passed to it and will KASSERT otherwise.
1590 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1591 vm_offset_t start, vm_offset_t end,
1592 int *countp, int flags)
1594 vm_map_entry_t entry;
1596 entry = start_entry;
1598 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1599 while (entry != &map->header && entry->start < end) {
1600 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1601 ("in-transition flag not set during unclip on: %p",
1603 KASSERT(entry->end <= end,
1604 ("unclip_range: tail wasn't clipped"));
1605 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1606 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1607 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1610 entry = entry->next;
1614 * Simplification does not block so there is no restart case.
1616 entry = start_entry;
1617 while (entry != &map->header && entry->start < end) {
1618 vm_map_simplify_entry(map, entry, countp);
1619 entry = entry->next;
1624 * Mark the given range as handled by a subordinate map.
1626 * This range must have been created with vm_map_find(), and no other
1627 * operations may have been performed on this range prior to calling
1630 * Submappings cannot be removed.
1635 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1637 vm_map_entry_t entry;
1638 int result = KERN_INVALID_ARGUMENT;
1641 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1644 VM_MAP_RANGE_CHECK(map, start, end);
1646 if (vm_map_lookup_entry(map, start, &entry)) {
1647 vm_map_clip_start(map, entry, start, &count);
1649 entry = entry->next;
1652 vm_map_clip_end(map, entry, end, &count);
1654 if ((entry->start == start) && (entry->end == end) &&
1655 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1656 (entry->object.vm_object == NULL)) {
1657 entry->object.sub_map = submap;
1658 entry->maptype = VM_MAPTYPE_SUBMAP;
1659 result = KERN_SUCCESS;
1662 vm_map_entry_release(count);
1668 * Sets the protection of the specified address region in the target map.
1669 * If "set_max" is specified, the maximum protection is to be set;
1670 * otherwise, only the current protection is affected.
1672 * The protection is not applicable to submaps, but is applicable to normal
1673 * maps and maps governed by virtual page tables. For example, when operating
1674 * on a virtual page table our protection basically controls how COW occurs
1675 * on the backing object, whereas the virtual page table abstraction itself
1676 * is an abstraction for userland.
1681 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1682 vm_prot_t new_prot, boolean_t set_max)
1684 vm_map_entry_t current;
1685 vm_map_entry_t entry;
1688 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1691 VM_MAP_RANGE_CHECK(map, start, end);
1693 if (vm_map_lookup_entry(map, start, &entry)) {
1694 vm_map_clip_start(map, entry, start, &count);
1696 entry = entry->next;
1700 * Make a first pass to check for protection violations.
1703 while ((current != &map->header) && (current->start < end)) {
1704 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1706 vm_map_entry_release(count);
1707 return (KERN_INVALID_ARGUMENT);
1709 if ((new_prot & current->max_protection) != new_prot) {
1711 vm_map_entry_release(count);
1712 return (KERN_PROTECTION_FAILURE);
1714 current = current->next;
1718 * Go back and fix up protections. [Note that clipping is not
1719 * necessary the second time.]
1723 while ((current != &map->header) && (current->start < end)) {
1726 vm_map_clip_end(map, current, end, &count);
1728 old_prot = current->protection;
1730 current->protection =
1731 (current->max_protection = new_prot) &
1734 current->protection = new_prot;
1738 * Update physical map if necessary. Worry about copy-on-write
1739 * here -- CHECK THIS XXX
1742 if (current->protection != old_prot) {
1743 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1746 pmap_protect(map->pmap, current->start,
1748 current->protection & MASK(current));
1752 vm_map_simplify_entry(map, current, &count);
1754 current = current->next;
1758 vm_map_entry_release(count);
1759 return (KERN_SUCCESS);
1763 * This routine traverses a processes map handling the madvise
1764 * system call. Advisories are classified as either those effecting
1765 * the vm_map_entry structure, or those effecting the underlying
1768 * The <value> argument is used for extended madvise calls.
1773 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1774 int behav, off_t value)
1776 vm_map_entry_t current, entry;
1782 * Some madvise calls directly modify the vm_map_entry, in which case
1783 * we need to use an exclusive lock on the map and we need to perform
1784 * various clipping operations. Otherwise we only need a read-lock
1788 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1792 case MADV_SEQUENTIAL:
1806 vm_map_lock_read(map);
1809 vm_map_entry_release(count);
1814 * Locate starting entry and clip if necessary.
1817 VM_MAP_RANGE_CHECK(map, start, end);
1819 if (vm_map_lookup_entry(map, start, &entry)) {
1821 vm_map_clip_start(map, entry, start, &count);
1823 entry = entry->next;
1828 * madvise behaviors that are implemented in the vm_map_entry.
1830 * We clip the vm_map_entry so that behavioral changes are
1831 * limited to the specified address range.
1833 for (current = entry;
1834 (current != &map->header) && (current->start < end);
1835 current = current->next
1837 if (current->maptype == VM_MAPTYPE_SUBMAP)
1840 vm_map_clip_end(map, current, end, &count);
1844 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
1846 case MADV_SEQUENTIAL:
1847 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
1850 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
1853 current->eflags |= MAP_ENTRY_NOSYNC;
1856 current->eflags &= ~MAP_ENTRY_NOSYNC;
1859 current->eflags |= MAP_ENTRY_NOCOREDUMP;
1862 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
1866 * Invalidate the related pmap entries, used
1867 * to flush portions of the real kernel's
1868 * pmap when the caller has removed or
1869 * modified existing mappings in a virtual
1872 pmap_remove(map->pmap,
1873 current->start, current->end);
1877 * Set the page directory page for a map
1878 * governed by a virtual page table. Mark
1879 * the entry as being governed by a virtual
1880 * page table if it is not.
1882 * XXX the page directory page is stored
1883 * in the avail_ssize field if the map_entry.
1885 * XXX the map simplification code does not
1886 * compare this field so weird things may
1887 * happen if you do not apply this function
1888 * to the entire mapping governed by the
1889 * virtual page table.
1891 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
1895 current->aux.master_pde = value;
1896 pmap_remove(map->pmap,
1897 current->start, current->end);
1903 vm_map_simplify_entry(map, current, &count);
1911 * madvise behaviors that are implemented in the underlying
1914 * Since we don't clip the vm_map_entry, we have to clip
1915 * the vm_object pindex and count.
1917 * NOTE! We currently do not support these functions on
1918 * virtual page tables.
1920 for (current = entry;
1921 (current != &map->header) && (current->start < end);
1922 current = current->next
1924 vm_offset_t useStart;
1926 if (current->maptype != VM_MAPTYPE_NORMAL)
1929 pindex = OFF_TO_IDX(current->offset);
1930 count = atop(current->end - current->start);
1931 useStart = current->start;
1933 if (current->start < start) {
1934 pindex += atop(start - current->start);
1935 count -= atop(start - current->start);
1938 if (current->end > end)
1939 count -= atop(current->end - end);
1944 vm_object_madvise(current->object.vm_object,
1945 pindex, count, behav);
1948 * Try to populate the page table. Mappings governed
1949 * by virtual page tables cannot be pre-populated
1950 * without a lot of work so don't try.
1952 if (behav == MADV_WILLNEED &&
1953 current->maptype != VM_MAPTYPE_VPAGETABLE) {
1954 pmap_object_init_pt(
1957 current->protection,
1958 current->object.vm_object,
1960 (count << PAGE_SHIFT),
1961 MAP_PREFAULT_MADVISE
1965 vm_map_unlock_read(map);
1967 vm_map_entry_release(count);
1973 * Sets the inheritance of the specified address range in the target map.
1974 * Inheritance affects how the map will be shared with child maps at the
1975 * time of vm_map_fork.
1978 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
1979 vm_inherit_t new_inheritance)
1981 vm_map_entry_t entry;
1982 vm_map_entry_t temp_entry;
1985 switch (new_inheritance) {
1986 case VM_INHERIT_NONE:
1987 case VM_INHERIT_COPY:
1988 case VM_INHERIT_SHARE:
1991 return (KERN_INVALID_ARGUMENT);
1994 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1997 VM_MAP_RANGE_CHECK(map, start, end);
1999 if (vm_map_lookup_entry(map, start, &temp_entry)) {
2001 vm_map_clip_start(map, entry, start, &count);
2003 entry = temp_entry->next;
2005 while ((entry != &map->header) && (entry->start < end)) {
2006 vm_map_clip_end(map, entry, end, &count);
2008 entry->inheritance = new_inheritance;
2010 vm_map_simplify_entry(map, entry, &count);
2012 entry = entry->next;
2015 vm_map_entry_release(count);
2016 return (KERN_SUCCESS);
2020 * Implement the semantics of mlock
2023 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2024 boolean_t new_pageable)
2026 vm_map_entry_t entry;
2027 vm_map_entry_t start_entry;
2029 int rv = KERN_SUCCESS;
2032 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2034 VM_MAP_RANGE_CHECK(map, start, real_end);
2037 start_entry = vm_map_clip_range(map, start, end, &count,
2039 if (start_entry == NULL) {
2041 vm_map_entry_release(count);
2042 return (KERN_INVALID_ADDRESS);
2045 if (new_pageable == 0) {
2046 entry = start_entry;
2047 while ((entry != &map->header) && (entry->start < end)) {
2048 vm_offset_t save_start;
2049 vm_offset_t save_end;
2052 * Already user wired or hard wired (trivial cases)
2054 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2055 entry = entry->next;
2058 if (entry->wired_count != 0) {
2059 entry->wired_count++;
2060 entry->eflags |= MAP_ENTRY_USER_WIRED;
2061 entry = entry->next;
2066 * A new wiring requires instantiation of appropriate
2067 * management structures and the faulting in of the
2070 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2071 int copyflag = entry->eflags &
2072 MAP_ENTRY_NEEDS_COPY;
2073 if (copyflag && ((entry->protection &
2074 VM_PROT_WRITE) != 0)) {
2075 vm_map_entry_shadow(entry);
2076 } else if (entry->object.vm_object == NULL &&
2078 vm_map_entry_allocate_object(entry);
2081 entry->wired_count++;
2082 entry->eflags |= MAP_ENTRY_USER_WIRED;
2085 * Now fault in the area. Note that vm_fault_wire()
2086 * may release the map lock temporarily, it will be
2087 * relocked on return. The in-transition
2088 * flag protects the entries.
2090 save_start = entry->start;
2091 save_end = entry->end;
2092 rv = vm_fault_wire(map, entry, TRUE);
2094 CLIP_CHECK_BACK(entry, save_start);
2096 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2097 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2098 entry->wired_count = 0;
2099 if (entry->end == save_end)
2101 entry = entry->next;
2102 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2104 end = save_start; /* unwire the rest */
2108 * note that even though the entry might have been
2109 * clipped, the USER_WIRED flag we set prevents
2110 * duplication so we do not have to do a
2113 entry = entry->next;
2117 * If we failed fall through to the unwiring section to
2118 * unwire what we had wired so far. 'end' has already
2125 * start_entry might have been clipped if we unlocked the
2126 * map and blocked. No matter how clipped it has gotten
2127 * there should be a fragment that is on our start boundary.
2129 CLIP_CHECK_BACK(start_entry, start);
2133 * Deal with the unwiring case.
2137 * This is the unwiring case. We must first ensure that the
2138 * range to be unwired is really wired down. We know there
2141 entry = start_entry;
2142 while ((entry != &map->header) && (entry->start < end)) {
2143 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2144 rv = KERN_INVALID_ARGUMENT;
2147 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2148 entry = entry->next;
2152 * Now decrement the wiring count for each region. If a region
2153 * becomes completely unwired, unwire its physical pages and
2157 * The map entries are processed in a loop, checking to
2158 * make sure the entry is wired and asserting it has a wired
2159 * count. However, another loop was inserted more-or-less in
2160 * the middle of the unwiring path. This loop picks up the
2161 * "entry" loop variable from the first loop without first
2162 * setting it to start_entry. Naturally, the secound loop
2163 * is never entered and the pages backing the entries are
2164 * never unwired. This can lead to a leak of wired pages.
2166 entry = start_entry;
2167 while ((entry != &map->header) && (entry->start < end)) {
2168 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2169 ("expected USER_WIRED on entry %p", entry));
2170 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2171 entry->wired_count--;
2172 if (entry->wired_count == 0)
2173 vm_fault_unwire(map, entry);
2174 entry = entry->next;
2178 vm_map_unclip_range(map, start_entry, start, real_end, &count,
2182 vm_map_entry_release(count);
2187 * Sets the pageability of the specified address range in the target map.
2188 * Regions specified as not pageable require locked-down physical
2189 * memory and physical page maps.
2191 * The map must not be locked, but a reference must remain to the map
2192 * throughout the call.
2194 * This function may be called via the zalloc path and must properly
2195 * reserve map entries for kernel_map.
2200 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2202 vm_map_entry_t entry;
2203 vm_map_entry_t start_entry;
2205 int rv = KERN_SUCCESS;
2208 if (kmflags & KM_KRESERVE)
2209 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2211 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2213 VM_MAP_RANGE_CHECK(map, start, real_end);
2216 start_entry = vm_map_clip_range(map, start, end, &count,
2218 if (start_entry == NULL) {
2220 rv = KERN_INVALID_ADDRESS;
2223 if ((kmflags & KM_PAGEABLE) == 0) {
2227 * 1. Holding the write lock, we create any shadow or zero-fill
2228 * objects that need to be created. Then we clip each map
2229 * entry to the region to be wired and increment its wiring
2230 * count. We create objects before clipping the map entries
2231 * to avoid object proliferation.
2233 * 2. We downgrade to a read lock, and call vm_fault_wire to
2234 * fault in the pages for any newly wired area (wired_count is
2237 * Downgrading to a read lock for vm_fault_wire avoids a
2238 * possible deadlock with another process that may have faulted
2239 * on one of the pages to be wired (it would mark the page busy,
2240 * blocking us, then in turn block on the map lock that we
2241 * hold). Because of problems in the recursive lock package,
2242 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2243 * any actions that require the write lock must be done
2244 * beforehand. Because we keep the read lock on the map, the
2245 * copy-on-write status of the entries we modify here cannot
2248 entry = start_entry;
2249 while ((entry != &map->header) && (entry->start < end)) {
2251 * Trivial case if the entry is already wired
2253 if (entry->wired_count) {
2254 entry->wired_count++;
2255 entry = entry->next;
2260 * The entry is being newly wired, we have to setup
2261 * appropriate management structures. A shadow
2262 * object is required for a copy-on-write region,
2263 * or a normal object for a zero-fill region. We
2264 * do not have to do this for entries that point to sub
2265 * maps because we won't hold the lock on the sub map.
2267 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2268 int copyflag = entry->eflags &
2269 MAP_ENTRY_NEEDS_COPY;
2270 if (copyflag && ((entry->protection &
2271 VM_PROT_WRITE) != 0)) {
2272 vm_map_entry_shadow(entry);
2273 } else if (entry->object.vm_object == NULL &&
2275 vm_map_entry_allocate_object(entry);
2279 entry->wired_count++;
2280 entry = entry->next;
2288 * HACK HACK HACK HACK
2290 * vm_fault_wire() temporarily unlocks the map to avoid
2291 * deadlocks. The in-transition flag from vm_map_clip_range
2292 * call should protect us from changes while the map is
2295 * NOTE: Previously this comment stated that clipping might
2296 * still occur while the entry is unlocked, but from
2297 * what I can tell it actually cannot.
2299 * It is unclear whether the CLIP_CHECK_*() calls
2300 * are still needed but we keep them in anyway.
2302 * HACK HACK HACK HACK
2305 entry = start_entry;
2306 while (entry != &map->header && entry->start < end) {
2308 * If vm_fault_wire fails for any page we need to undo
2309 * what has been done. We decrement the wiring count
2310 * for those pages which have not yet been wired (now)
2311 * and unwire those that have (later).
2313 vm_offset_t save_start = entry->start;
2314 vm_offset_t save_end = entry->end;
2316 if (entry->wired_count == 1)
2317 rv = vm_fault_wire(map, entry, FALSE);
2319 CLIP_CHECK_BACK(entry, save_start);
2321 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2322 entry->wired_count = 0;
2323 if (entry->end == save_end)
2325 entry = entry->next;
2326 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2331 CLIP_CHECK_FWD(entry, save_end);
2332 entry = entry->next;
2336 * If a failure occured undo everything by falling through
2337 * to the unwiring code. 'end' has already been adjusted
2341 kmflags |= KM_PAGEABLE;
2344 * start_entry is still IN_TRANSITION but may have been
2345 * clipped since vm_fault_wire() unlocks and relocks the
2346 * map. No matter how clipped it has gotten there should
2347 * be a fragment that is on our start boundary.
2349 CLIP_CHECK_BACK(start_entry, start);
2352 if (kmflags & KM_PAGEABLE) {
2354 * This is the unwiring case. We must first ensure that the
2355 * range to be unwired is really wired down. We know there
2358 entry = start_entry;
2359 while ((entry != &map->header) && (entry->start < end)) {
2360 if (entry->wired_count == 0) {
2361 rv = KERN_INVALID_ARGUMENT;
2364 entry = entry->next;
2368 * Now decrement the wiring count for each region. If a region
2369 * becomes completely unwired, unwire its physical pages and
2372 entry = start_entry;
2373 while ((entry != &map->header) && (entry->start < end)) {
2374 entry->wired_count--;
2375 if (entry->wired_count == 0)
2376 vm_fault_unwire(map, entry);
2377 entry = entry->next;
2381 vm_map_unclip_range(map, start_entry, start, real_end,
2382 &count, MAP_CLIP_NO_HOLES);
2386 if (kmflags & KM_KRESERVE)
2387 vm_map_entry_krelease(count);
2389 vm_map_entry_release(count);
2394 * Mark a newly allocated address range as wired but do not fault in
2395 * the pages. The caller is expected to load the pages into the object.
2397 * The map must be locked on entry and will remain locked on return.
2398 * No other requirements.
2401 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2404 vm_map_entry_t scan;
2405 vm_map_entry_t entry;
2407 entry = vm_map_clip_range(map, addr, addr + size,
2408 countp, MAP_CLIP_NO_HOLES);
2410 scan != &map->header && scan->start < addr + size;
2411 scan = scan->next) {
2412 KKASSERT(entry->wired_count == 0);
2413 entry->wired_count = 1;
2415 vm_map_unclip_range(map, entry, addr, addr + size,
2416 countp, MAP_CLIP_NO_HOLES);
2420 * Push any dirty cached pages in the address range to their pager.
2421 * If syncio is TRUE, dirty pages are written synchronously.
2422 * If invalidate is TRUE, any cached pages are freed as well.
2424 * This routine is called by sys_msync()
2426 * Returns an error if any part of the specified range is not mapped.
2431 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2432 boolean_t syncio, boolean_t invalidate)
2434 vm_map_entry_t current;
2435 vm_map_entry_t entry;
2438 vm_ooffset_t offset;
2440 vm_map_lock_read(map);
2441 VM_MAP_RANGE_CHECK(map, start, end);
2442 if (!vm_map_lookup_entry(map, start, &entry)) {
2443 vm_map_unlock_read(map);
2444 return (KERN_INVALID_ADDRESS);
2447 * Make a first pass to check for holes.
2449 for (current = entry; current->start < end; current = current->next) {
2450 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2451 vm_map_unlock_read(map);
2452 return (KERN_INVALID_ARGUMENT);
2454 if (end > current->end &&
2455 (current->next == &map->header ||
2456 current->end != current->next->start)) {
2457 vm_map_unlock_read(map);
2458 return (KERN_INVALID_ADDRESS);
2463 pmap_remove(vm_map_pmap(map), start, end);
2466 * Make a second pass, cleaning/uncaching pages from the indicated
2469 * Hold vm_token to avoid blocking in vm_object_reference()
2471 lwkt_gettoken(&vm_token);
2472 lwkt_gettoken(&vmobj_token);
2474 for (current = entry; current->start < end; current = current->next) {
2475 offset = current->offset + (start - current->start);
2476 size = (end <= current->end ? end : current->end) - start;
2477 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2479 vm_map_entry_t tentry;
2482 smap = current->object.sub_map;
2483 vm_map_lock_read(smap);
2484 vm_map_lookup_entry(smap, offset, &tentry);
2485 tsize = tentry->end - offset;
2488 object = tentry->object.vm_object;
2489 offset = tentry->offset + (offset - tentry->start);
2490 vm_map_unlock_read(smap);
2492 object = current->object.vm_object;
2495 * Note that there is absolutely no sense in writing out
2496 * anonymous objects, so we track down the vnode object
2498 * We invalidate (remove) all pages from the address space
2499 * anyway, for semantic correctness.
2501 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2502 * may start out with a NULL object.
2504 while (object && object->backing_object) {
2505 offset += object->backing_object_offset;
2506 object = object->backing_object;
2507 if (object->size < OFF_TO_IDX( offset + size))
2508 size = IDX_TO_OFF(object->size) - offset;
2510 if (object && (object->type == OBJT_VNODE) &&
2511 (current->protection & VM_PROT_WRITE) &&
2512 (object->flags & OBJ_NOMSYNC) == 0) {
2514 * Flush pages if writing is allowed, invalidate them
2515 * if invalidation requested. Pages undergoing I/O
2516 * will be ignored by vm_object_page_remove().
2518 * We cannot lock the vnode and then wait for paging
2519 * to complete without deadlocking against vm_fault.
2520 * Instead we simply call vm_object_page_remove() and
2521 * allow it to block internally on a page-by-page
2522 * basis when it encounters pages undergoing async
2527 vm_object_reference_locked(object);
2528 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2529 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2530 flags |= invalidate ? OBJPC_INVAL : 0;
2533 * When operating on a virtual page table just
2534 * flush the whole object. XXX we probably ought
2537 switch(current->maptype) {
2538 case VM_MAPTYPE_NORMAL:
2539 vm_object_page_clean(object,
2541 OFF_TO_IDX(offset + size + PAGE_MASK),
2544 case VM_MAPTYPE_VPAGETABLE:
2545 vm_object_page_clean(object, 0, 0, flags);
2548 vn_unlock(((struct vnode *)object->handle));
2549 vm_object_deallocate_locked(object);
2551 if (object && invalidate &&
2552 ((object->type == OBJT_VNODE) ||
2553 (object->type == OBJT_DEVICE))) {
2555 (object->type == OBJT_DEVICE) ? FALSE : TRUE;
2556 vm_object_reference_locked(object);
2557 switch(current->maptype) {
2558 case VM_MAPTYPE_NORMAL:
2559 vm_object_page_remove(object,
2561 OFF_TO_IDX(offset + size + PAGE_MASK),
2564 case VM_MAPTYPE_VPAGETABLE:
2565 vm_object_page_remove(object, 0, 0, clean_only);
2568 vm_object_deallocate_locked(object);
2573 lwkt_reltoken(&vmobj_token);
2574 lwkt_reltoken(&vm_token);
2575 vm_map_unlock_read(map);
2577 return (KERN_SUCCESS);
2581 * Make the region specified by this entry pageable.
2583 * The vm_map must be exclusively locked.
2586 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2588 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2589 entry->wired_count = 0;
2590 vm_fault_unwire(map, entry);
2594 * Deallocate the given entry from the target map.
2596 * The vm_map must be exclusively locked.
2599 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2601 vm_map_entry_unlink(map, entry);
2602 map->size -= entry->end - entry->start;
2604 switch(entry->maptype) {
2605 case VM_MAPTYPE_NORMAL:
2606 case VM_MAPTYPE_VPAGETABLE:
2607 vm_object_deallocate(entry->object.vm_object);
2613 vm_map_entry_dispose(map, entry, countp);
2617 * Deallocates the given address range from the target map.
2619 * The vm_map must be exclusively locked.
2622 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2625 vm_map_entry_t entry;
2626 vm_map_entry_t first_entry;
2628 ASSERT_VM_MAP_LOCKED(map);
2631 * Find the start of the region, and clip it. Set entry to point
2632 * at the first record containing the requested address or, if no
2633 * such record exists, the next record with a greater address. The
2634 * loop will run from this point until a record beyond the termination
2635 * address is encountered.
2637 * map->hint must be adjusted to not point to anything we delete,
2638 * so set it to the entry prior to the one being deleted.
2640 * GGG see other GGG comment.
2642 if (vm_map_lookup_entry(map, start, &first_entry)) {
2643 entry = first_entry;
2644 vm_map_clip_start(map, entry, start, countp);
2645 map->hint = entry->prev; /* possible problem XXX */
2647 map->hint = first_entry; /* possible problem XXX */
2648 entry = first_entry->next;
2652 * If a hole opens up prior to the current first_free then
2653 * adjust first_free. As with map->hint, map->first_free
2654 * cannot be left set to anything we might delete.
2656 if (entry == &map->header) {
2657 map->first_free = &map->header;
2658 } else if (map->first_free->start >= start) {
2659 map->first_free = entry->prev;
2663 * Step through all entries in this region
2665 while ((entry != &map->header) && (entry->start < end)) {
2666 vm_map_entry_t next;
2668 vm_pindex_t offidxstart, offidxend, count;
2671 * If we hit an in-transition entry we have to sleep and
2672 * retry. It's easier (and not really slower) to just retry
2673 * since this case occurs so rarely and the hint is already
2674 * pointing at the right place. We have to reset the
2675 * start offset so as not to accidently delete an entry
2676 * another process just created in vacated space.
2678 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2679 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2680 start = entry->start;
2681 ++mycpu->gd_cnt.v_intrans_coll;
2682 ++mycpu->gd_cnt.v_intrans_wait;
2683 vm_map_transition_wait(map);
2686 vm_map_clip_end(map, entry, end, countp);
2692 offidxstart = OFF_TO_IDX(entry->offset);
2693 count = OFF_TO_IDX(e - s);
2694 object = entry->object.vm_object;
2697 * Unwire before removing addresses from the pmap; otherwise,
2698 * unwiring will put the entries back in the pmap.
2700 if (entry->wired_count != 0)
2701 vm_map_entry_unwire(map, entry);
2703 offidxend = offidxstart + count;
2706 * Hold vm_token when manipulating vm_objects,
2708 * Hold vmobj_token when potentially adding or removing
2709 * objects (collapse requires both).
2711 lwkt_gettoken(&vm_token);
2712 lwkt_gettoken(&vmobj_token);
2714 if (object == &kernel_object) {
2715 vm_object_page_remove(object, offidxstart,
2718 pmap_remove(map->pmap, s, e);
2720 if (object != NULL &&
2721 object->ref_count != 1 &&
2722 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2724 (object->type == OBJT_DEFAULT ||
2725 object->type == OBJT_SWAP)) {
2726 vm_object_collapse(object);
2727 vm_object_page_remove(object, offidxstart,
2729 if (object->type == OBJT_SWAP) {
2730 swap_pager_freespace(object,
2734 if (offidxend >= object->size &&
2735 offidxstart < object->size) {
2736 object->size = offidxstart;
2740 lwkt_reltoken(&vmobj_token);
2741 lwkt_reltoken(&vm_token);
2744 * Delete the entry (which may delete the object) only after
2745 * removing all pmap entries pointing to its pages.
2746 * (Otherwise, its page frames may be reallocated, and any
2747 * modify bits will be set in the wrong object!)
2749 vm_map_entry_delete(map, entry, countp);
2752 return (KERN_SUCCESS);
2756 * Remove the given address range from the target map.
2757 * This is the exported form of vm_map_delete.
2762 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
2767 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2769 VM_MAP_RANGE_CHECK(map, start, end);
2770 result = vm_map_delete(map, start, end, &count);
2772 vm_map_entry_release(count);
2778 * Assert that the target map allows the specified privilege on the
2779 * entire address region given. The entire region must be allocated.
2781 * The caller must specify whether the vm_map is already locked or not.
2784 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2785 vm_prot_t protection, boolean_t have_lock)
2787 vm_map_entry_t entry;
2788 vm_map_entry_t tmp_entry;
2791 if (have_lock == FALSE)
2792 vm_map_lock_read(map);
2794 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
2795 if (have_lock == FALSE)
2796 vm_map_unlock_read(map);
2802 while (start < end) {
2803 if (entry == &map->header) {
2811 if (start < entry->start) {
2816 * Check protection associated with entry.
2819 if ((entry->protection & protection) != protection) {
2823 /* go to next entry */
2826 entry = entry->next;
2828 if (have_lock == FALSE)
2829 vm_map_unlock_read(map);
2834 * Split the pages in a map entry into a new object. This affords
2835 * easier removal of unused pages, and keeps object inheritance from
2836 * being a negative impact on memory usage.
2838 * The vm_map must be exclusively locked.
2841 vm_map_split(vm_map_entry_t entry)
2844 vm_object_t orig_object, new_object, source;
2846 vm_pindex_t offidxstart, offidxend, idx;
2848 vm_ooffset_t offset;
2850 orig_object = entry->object.vm_object;
2851 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
2853 if (orig_object->ref_count <= 1)
2856 offset = entry->offset;
2860 offidxstart = OFF_TO_IDX(offset);
2861 offidxend = offidxstart + OFF_TO_IDX(e - s);
2862 size = offidxend - offidxstart;
2864 switch(orig_object->type) {
2866 new_object = default_pager_alloc(NULL, IDX_TO_OFF(size),
2870 new_object = swap_pager_alloc(NULL, IDX_TO_OFF(size),
2878 if (new_object == NULL)
2882 * vm_token required when manipulating vm_objects.
2884 lwkt_gettoken(&vm_token);
2885 lwkt_gettoken(&vmobj_token);
2887 source = orig_object->backing_object;
2888 if (source != NULL) {
2889 /* Referenced by new_object */
2890 vm_object_reference_locked(source);
2891 LIST_INSERT_HEAD(&source->shadow_head,
2892 new_object, shadow_list);
2893 vm_object_clear_flag(source, OBJ_ONEMAPPING);
2894 new_object->backing_object_offset =
2895 orig_object->backing_object_offset +
2896 IDX_TO_OFF(offidxstart);
2897 new_object->backing_object = source;
2898 source->shadow_count++;
2899 source->generation++;
2902 for (idx = 0; idx < size; idx++) {
2906 m = vm_page_lookup(orig_object, offidxstart + idx);
2911 * We must wait for pending I/O to complete before we can
2914 * We do not have to VM_PROT_NONE the page as mappings should
2915 * not be changed by this operation.
2917 if (vm_page_sleep_busy(m, TRUE, "spltwt"))
2920 vm_page_rename(m, new_object, idx);
2921 /* page automatically made dirty by rename and cache handled */
2925 if (orig_object->type == OBJT_SWAP) {
2926 vm_object_pip_add(orig_object, 1);
2928 * copy orig_object pages into new_object
2929 * and destroy unneeded pages in
2932 swap_pager_copy(orig_object, new_object, offidxstart, 0);
2933 vm_object_pip_wakeup(orig_object);
2937 * Wakeup the pages we played with. No spl protection is needed
2938 * for a simple wakeup.
2940 for (idx = 0; idx < size; idx++) {
2941 m = vm_page_lookup(new_object, idx);
2946 entry->object.vm_object = new_object;
2947 entry->offset = 0LL;
2948 vm_object_deallocate_locked(orig_object);
2949 lwkt_reltoken(&vmobj_token);
2950 lwkt_reltoken(&vm_token);
2954 * Copies the contents of the source entry to the destination
2955 * entry. The entries *must* be aligned properly.
2957 * The vm_map must be exclusively locked.
2958 * vm_token must be held
2961 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
2962 vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
2964 vm_object_t src_object;
2966 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP)
2968 if (src_entry->maptype == VM_MAPTYPE_SUBMAP)
2971 ASSERT_LWKT_TOKEN_HELD(&vm_token);
2972 lwkt_gettoken(&vmobj_token); /* required for collapse */
2974 if (src_entry->wired_count == 0) {
2976 * If the source entry is marked needs_copy, it is already
2979 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
2980 pmap_protect(src_map->pmap,
2983 src_entry->protection & ~VM_PROT_WRITE);
2987 * Make a copy of the object.
2989 if ((src_object = src_entry->object.vm_object) != NULL) {
2990 if ((src_object->handle == NULL) &&
2991 (src_object->type == OBJT_DEFAULT ||
2992 src_object->type == OBJT_SWAP)) {
2993 vm_object_collapse(src_object);
2994 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) {
2995 vm_map_split(src_entry);
2996 src_object = src_entry->object.vm_object;
3000 vm_object_reference_locked(src_object);
3001 vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
3002 dst_entry->object.vm_object = src_object;
3003 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
3004 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
3005 dst_entry->offset = src_entry->offset;
3007 dst_entry->object.vm_object = NULL;
3008 dst_entry->offset = 0;
3011 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3012 dst_entry->end - dst_entry->start, src_entry->start);
3015 * Of course, wired down pages can't be set copy-on-write.
3016 * Cause wired pages to be copied into the new map by
3017 * simulating faults (the new pages are pageable)
3019 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3021 lwkt_reltoken(&vmobj_token);
3026 * Create a new process vmspace structure and vm_map
3027 * based on those of an existing process. The new map
3028 * is based on the old map, according to the inheritance
3029 * values on the regions in that map.
3031 * The source map must not be locked.
3035 vmspace_fork(struct vmspace *vm1)
3037 struct vmspace *vm2;
3038 vm_map_t old_map = &vm1->vm_map;
3040 vm_map_entry_t old_entry;
3041 vm_map_entry_t new_entry;
3045 lwkt_gettoken(&vm_token);
3046 lwkt_gettoken(&vmspace_token);
3047 lwkt_gettoken(&vmobj_token);
3048 vm_map_lock(old_map);
3049 old_map->infork = 1;
3052 * XXX Note: upcalls are not copied.
3054 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3055 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3056 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3057 new_map = &vm2->vm_map; /* XXX */
3058 new_map->timestamp = 1;
3060 vm_map_lock(new_map);
3063 old_entry = old_map->header.next;
3064 while (old_entry != &old_map->header) {
3066 old_entry = old_entry->next;
3069 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3071 old_entry = old_map->header.next;
3072 while (old_entry != &old_map->header) {
3073 if (old_entry->maptype == VM_MAPTYPE_SUBMAP)
3074 panic("vm_map_fork: encountered a submap");
3076 switch (old_entry->inheritance) {
3077 case VM_INHERIT_NONE:
3079 case VM_INHERIT_SHARE:
3081 * Clone the entry, creating the shared object if
3084 object = old_entry->object.vm_object;
3085 if (object == NULL) {
3086 vm_map_entry_allocate_object(old_entry);
3087 object = old_entry->object.vm_object;
3091 * Add the reference before calling vm_map_entry_shadow
3092 * to insure that a shadow object is created.
3094 vm_object_reference_locked(object);
3095 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3096 vm_map_entry_shadow(old_entry);
3097 /* Transfer the second reference too. */
3098 vm_object_reference_locked(
3099 old_entry->object.vm_object);
3100 vm_object_deallocate_locked(object);
3101 object = old_entry->object.vm_object;
3103 vm_object_clear_flag(object, OBJ_ONEMAPPING);
3106 * Clone the entry, referencing the shared object.
3108 new_entry = vm_map_entry_create(new_map, &count);
3109 *new_entry = *old_entry;
3110 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3111 new_entry->wired_count = 0;
3114 * Insert the entry into the new map -- we know we're
3115 * inserting at the end of the new map.
3118 vm_map_entry_link(new_map, new_map->header.prev,
3122 * Update the physical map
3124 pmap_copy(new_map->pmap, old_map->pmap,
3126 (old_entry->end - old_entry->start),
3129 case VM_INHERIT_COPY:
3131 * Clone the entry and link into the map.
3133 new_entry = vm_map_entry_create(new_map, &count);
3134 *new_entry = *old_entry;
3135 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3136 new_entry->wired_count = 0;
3137 new_entry->object.vm_object = NULL;
3138 vm_map_entry_link(new_map, new_map->header.prev,
3140 vm_map_copy_entry(old_map, new_map, old_entry,
3144 old_entry = old_entry->next;
3147 new_map->size = old_map->size;
3148 old_map->infork = 0;
3149 vm_map_unlock(old_map);
3150 vm_map_unlock(new_map);
3151 vm_map_entry_release(count);
3153 lwkt_reltoken(&vmobj_token);
3154 lwkt_reltoken(&vmspace_token);
3155 lwkt_reltoken(&vm_token);
3161 * Create an auto-grow stack entry
3166 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3167 int flags, vm_prot_t prot, vm_prot_t max, int cow)
3169 vm_map_entry_t prev_entry;
3170 vm_map_entry_t new_stack_entry;
3171 vm_size_t init_ssize;
3174 vm_offset_t tmpaddr;
3176 cow |= MAP_IS_STACK;
3178 if (max_ssize < sgrowsiz)
3179 init_ssize = max_ssize;
3181 init_ssize = sgrowsiz;
3183 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3187 * Find space for the mapping
3189 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3190 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3193 vm_map_entry_release(count);
3194 return (KERN_NO_SPACE);
3199 /* If addr is already mapped, no go */
3200 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3202 vm_map_entry_release(count);
3203 return (KERN_NO_SPACE);
3207 /* XXX already handled by kern_mmap() */
3208 /* If we would blow our VMEM resource limit, no go */
3209 if (map->size + init_ssize >
3210 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3212 vm_map_entry_release(count);
3213 return (KERN_NO_SPACE);
3218 * If we can't accomodate max_ssize in the current mapping,
3219 * no go. However, we need to be aware that subsequent user
3220 * mappings might map into the space we have reserved for
3221 * stack, and currently this space is not protected.
3223 * Hopefully we will at least detect this condition
3224 * when we try to grow the stack.
3226 if ((prev_entry->next != &map->header) &&
3227 (prev_entry->next->start < addrbos + max_ssize)) {
3229 vm_map_entry_release(count);
3230 return (KERN_NO_SPACE);
3234 * We initially map a stack of only init_ssize. We will
3235 * grow as needed later. Since this is to be a grow
3236 * down stack, we map at the top of the range.
3238 * Note: we would normally expect prot and max to be
3239 * VM_PROT_ALL, and cow to be 0. Possibly we should
3240 * eliminate these as input parameters, and just
3241 * pass these values here in the insert call.
3243 rv = vm_map_insert(map, &count,
3244 NULL, 0, addrbos + max_ssize - init_ssize,
3245 addrbos + max_ssize,
3250 /* Now set the avail_ssize amount */
3251 if (rv == KERN_SUCCESS) {
3252 if (prev_entry != &map->header)
3253 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3254 new_stack_entry = prev_entry->next;
3255 if (new_stack_entry->end != addrbos + max_ssize ||
3256 new_stack_entry->start != addrbos + max_ssize - init_ssize)
3257 panic ("Bad entry start/end for new stack entry");
3259 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3263 vm_map_entry_release(count);
3268 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3269 * desired address is already mapped, or if we successfully grow
3270 * the stack. Also returns KERN_SUCCESS if addr is outside the
3271 * stack range (this is strange, but preserves compatibility with
3272 * the grow function in vm_machdep.c).
3277 vm_map_growstack (struct proc *p, vm_offset_t addr)
3279 vm_map_entry_t prev_entry;
3280 vm_map_entry_t stack_entry;
3281 vm_map_entry_t new_stack_entry;
3282 struct vmspace *vm = p->p_vmspace;
3283 vm_map_t map = &vm->vm_map;
3286 int rv = KERN_SUCCESS;
3288 int use_read_lock = 1;
3291 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3294 vm_map_lock_read(map);
3298 /* If addr is already in the entry range, no need to grow.*/
3299 if (vm_map_lookup_entry(map, addr, &prev_entry))
3302 if ((stack_entry = prev_entry->next) == &map->header)
3304 if (prev_entry == &map->header)
3305 end = stack_entry->start - stack_entry->aux.avail_ssize;
3307 end = prev_entry->end;
3310 * This next test mimics the old grow function in vm_machdep.c.
3311 * It really doesn't quite make sense, but we do it anyway
3312 * for compatibility.
3314 * If not growable stack, return success. This signals the
3315 * caller to proceed as he would normally with normal vm.
3317 if (stack_entry->aux.avail_ssize < 1 ||
3318 addr >= stack_entry->start ||
3319 addr < stack_entry->start - stack_entry->aux.avail_ssize) {
3323 /* Find the minimum grow amount */
3324 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3325 if (grow_amount > stack_entry->aux.avail_ssize) {
3331 * If there is no longer enough space between the entries
3332 * nogo, and adjust the available space. Note: this
3333 * should only happen if the user has mapped into the
3334 * stack area after the stack was created, and is
3335 * probably an error.
3337 * This also effectively destroys any guard page the user
3338 * might have intended by limiting the stack size.
3340 if (grow_amount > stack_entry->start - end) {
3341 if (use_read_lock && vm_map_lock_upgrade(map)) {
3346 stack_entry->aux.avail_ssize = stack_entry->start - end;
3351 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3353 /* If this is the main process stack, see if we're over the
3356 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3357 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3362 /* Round up the grow amount modulo SGROWSIZ */
3363 grow_amount = roundup (grow_amount, sgrowsiz);
3364 if (grow_amount > stack_entry->aux.avail_ssize) {
3365 grow_amount = stack_entry->aux.avail_ssize;
3367 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3368 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3369 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3373 /* If we would blow our VMEM resource limit, no go */
3374 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3379 if (use_read_lock && vm_map_lock_upgrade(map)) {
3385 /* Get the preliminary new entry start value */
3386 addr = stack_entry->start - grow_amount;
3388 /* If this puts us into the previous entry, cut back our growth
3389 * to the available space. Also, see the note above.
3392 stack_entry->aux.avail_ssize = stack_entry->start - end;
3396 rv = vm_map_insert(map, &count,
3397 NULL, 0, addr, stack_entry->start,
3399 VM_PROT_ALL, VM_PROT_ALL,
3402 /* Adjust the available stack space by the amount we grew. */
3403 if (rv == KERN_SUCCESS) {
3404 if (prev_entry != &map->header)
3405 vm_map_clip_end(map, prev_entry, addr, &count);
3406 new_stack_entry = prev_entry->next;
3407 if (new_stack_entry->end != stack_entry->start ||
3408 new_stack_entry->start != addr)
3409 panic ("Bad stack grow start/end in new stack entry");
3411 new_stack_entry->aux.avail_ssize =
3412 stack_entry->aux.avail_ssize -
3413 (new_stack_entry->end - new_stack_entry->start);
3415 vm->vm_ssize += btoc(new_stack_entry->end -
3416 new_stack_entry->start);
3419 if (map->flags & MAP_WIREFUTURE)
3420 vm_map_unwire(map, new_stack_entry->start,
3421 new_stack_entry->end, FALSE);
3426 vm_map_unlock_read(map);
3429 vm_map_entry_release(count);
3434 * Unshare the specified VM space for exec. If other processes are
3435 * mapped to it, then create a new one. The new vmspace is null.
3440 vmspace_exec(struct proc *p, struct vmspace *vmcopy)
3442 struct vmspace *oldvmspace = p->p_vmspace;
3443 struct vmspace *newvmspace;
3444 vm_map_t map = &p->p_vmspace->vm_map;
3447 * If we are execing a resident vmspace we fork it, otherwise
3448 * we create a new vmspace. Note that exitingcnt and upcalls
3449 * are not copied to the new vmspace.
3451 lwkt_gettoken(&vmspace_token);
3453 newvmspace = vmspace_fork(vmcopy);
3455 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3456 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3457 (caddr_t)&oldvmspace->vm_endcopy -
3458 (caddr_t)&oldvmspace->vm_startcopy);
3462 * Finish initializing the vmspace before assigning it
3463 * to the process. The vmspace will become the current vmspace
3466 pmap_pinit2(vmspace_pmap(newvmspace));
3467 pmap_replacevm(p, newvmspace, 0);
3468 sysref_put(&oldvmspace->vm_sysref);
3469 lwkt_reltoken(&vmspace_token);
3473 * Unshare the specified VM space for forcing COW. This
3474 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3476 * The exitingcnt test is not strictly necessary but has been
3477 * included for code sanity (to make the code a bit more deterministic).
3480 vmspace_unshare(struct proc *p)
3482 struct vmspace *oldvmspace = p->p_vmspace;
3483 struct vmspace *newvmspace;
3485 lwkt_gettoken(&vmspace_token);
3486 if (oldvmspace->vm_sysref.refcnt == 1 && oldvmspace->vm_exitingcnt == 0)
3488 newvmspace = vmspace_fork(oldvmspace);
3489 pmap_pinit2(vmspace_pmap(newvmspace));
3490 pmap_replacevm(p, newvmspace, 0);
3491 sysref_put(&oldvmspace->vm_sysref);
3492 lwkt_reltoken(&vmspace_token);
3496 * vm_map_hint: return the beginning of the best area suitable for
3497 * creating a new mapping with "prot" protection.
3502 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot)
3504 struct vmspace *vms = p->p_vmspace;
3506 if (!randomize_mmap) {
3508 * Set a reasonable start point for the hint if it was
3509 * not specified or if it falls within the heap space.
3510 * Hinted mmap()s do not allocate out of the heap space.
3513 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
3514 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) {
3515 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
3521 if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr)
3527 * If executable skip first two pages, otherwise start
3528 * after data + heap region.
3530 if ((prot & VM_PROT_EXECUTE) &&
3531 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) {
3532 addr = (PAGE_SIZE * 2) +
3533 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1));
3534 return (round_page(addr));
3536 #endif /* __i386__ */
3539 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ;
3540 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1);
3542 return (round_page(addr));
3546 * Finds the VM object, offset, and protection for a given virtual address
3547 * in the specified map, assuming a page fault of the type specified.
3549 * Leaves the map in question locked for read; return values are guaranteed
3550 * until a vm_map_lookup_done call is performed. Note that the map argument
3551 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3553 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3556 * If a lookup is requested with "write protection" specified, the map may
3557 * be changed to perform virtual copying operations, although the data
3558 * referenced will remain the same.
3563 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
3565 vm_prot_t fault_typea,
3566 vm_map_entry_t *out_entry, /* OUT */
3567 vm_object_t *object, /* OUT */
3568 vm_pindex_t *pindex, /* OUT */
3569 vm_prot_t *out_prot, /* OUT */
3570 boolean_t *wired) /* OUT */
3572 vm_map_entry_t entry;
3573 vm_map_t map = *var_map;
3575 vm_prot_t fault_type = fault_typea;
3576 int use_read_lock = 1;
3577 int rv = KERN_SUCCESS;
3581 vm_map_lock_read(map);
3586 * If the map has an interesting hint, try it before calling full
3587 * blown lookup routine.
3592 if ((entry == &map->header) ||
3593 (vaddr < entry->start) || (vaddr >= entry->end)) {
3594 vm_map_entry_t tmp_entry;
3597 * Entry was either not a valid hint, or the vaddr was not
3598 * contained in the entry, so do a full lookup.
3600 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
3601 rv = KERN_INVALID_ADDRESS;
3612 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3613 vm_map_t old_map = map;
3615 *var_map = map = entry->object.sub_map;
3617 vm_map_unlock_read(old_map);
3619 vm_map_unlock(old_map);
3625 * Check whether this task is allowed to have this page.
3626 * Note the special case for MAP_ENTRY_COW
3627 * pages with an override. This is to implement a forced
3628 * COW for debuggers.
3631 if (fault_type & VM_PROT_OVERRIDE_WRITE)
3632 prot = entry->max_protection;
3634 prot = entry->protection;
3636 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
3637 if ((fault_type & prot) != fault_type) {
3638 rv = KERN_PROTECTION_FAILURE;
3642 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
3643 (entry->eflags & MAP_ENTRY_COW) &&
3644 (fault_type & VM_PROT_WRITE) &&
3645 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
3646 rv = KERN_PROTECTION_FAILURE;
3651 * If this page is not pageable, we have to get it for all possible
3654 *wired = (entry->wired_count != 0);
3656 prot = fault_type = entry->protection;
3659 * Virtual page tables may need to update the accessed (A) bit
3660 * in a page table entry. Upgrade the fault to a write fault for
3661 * that case if the map will support it. If the map does not support
3662 * it the page table entry simply will not be updated.
3664 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
3665 if (prot & VM_PROT_WRITE)
3666 fault_type |= VM_PROT_WRITE;
3670 * If the entry was copy-on-write, we either ...
3672 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3674 * If we want to write the page, we may as well handle that
3675 * now since we've got the map locked.
3677 * If we don't need to write the page, we just demote the
3678 * permissions allowed.
3681 if (fault_type & VM_PROT_WRITE) {
3683 * Make a new object, and place it in the object
3684 * chain. Note that no new references have appeared
3685 * -- one just moved from the map to the new
3689 if (use_read_lock && vm_map_lock_upgrade(map)) {
3695 vm_map_entry_shadow(entry);
3698 * We're attempting to read a copy-on-write page --
3699 * don't allow writes.
3702 prot &= ~VM_PROT_WRITE;
3707 * Create an object if necessary.
3709 if (entry->object.vm_object == NULL &&
3711 if (use_read_lock && vm_map_lock_upgrade(map)) {
3716 vm_map_entry_allocate_object(entry);
3720 * Return the object/offset from this entry. If the entry was
3721 * copy-on-write or empty, it has been fixed up.
3724 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
3725 *object = entry->object.vm_object;
3728 * Return whether this is the only map sharing this data. On
3729 * success we return with a read lock held on the map. On failure
3730 * we return with the map unlocked.
3734 if (rv == KERN_SUCCESS) {
3735 if (use_read_lock == 0)
3736 vm_map_lock_downgrade(map);
3737 } else if (use_read_lock) {
3738 vm_map_unlock_read(map);
3746 * Releases locks acquired by a vm_map_lookup()
3747 * (according to the handle returned by that lookup).
3749 * No other requirements.
3752 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
3755 * Unlock the main-level map
3757 vm_map_unlock_read(map);
3759 vm_map_entry_release(count);
3762 #include "opt_ddb.h"
3764 #include <sys/kernel.h>
3766 #include <ddb/ddb.h>
3771 DB_SHOW_COMMAND(map, vm_map_print)
3774 /* XXX convert args. */
3775 vm_map_t map = (vm_map_t)addr;
3776 boolean_t full = have_addr;
3778 vm_map_entry_t entry;
3780 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
3782 (void *)map->pmap, map->nentries, map->timestamp);
3785 if (!full && db_indent)
3789 for (entry = map->header.next; entry != &map->header;
3790 entry = entry->next) {
3791 db_iprintf("map entry %p: start=%p, end=%p\n",
3792 (void *)entry, (void *)entry->start, (void *)entry->end);
3795 static char *inheritance_name[4] =
3796 {"share", "copy", "none", "donate_copy"};
3798 db_iprintf(" prot=%x/%x/%s",
3800 entry->max_protection,
3801 inheritance_name[(int)(unsigned char)entry->inheritance]);
3802 if (entry->wired_count != 0)
3803 db_printf(", wired");
3805 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3806 /* XXX no %qd in kernel. Truncate entry->offset. */
3807 db_printf(", share=%p, offset=0x%lx\n",
3808 (void *)entry->object.sub_map,
3809 (long)entry->offset);
3811 if ((entry->prev == &map->header) ||
3812 (entry->prev->object.sub_map !=
3813 entry->object.sub_map)) {
3815 vm_map_print((db_expr_t)(intptr_t)
3816 entry->object.sub_map,
3821 /* XXX no %qd in kernel. Truncate entry->offset. */
3822 db_printf(", object=%p, offset=0x%lx",
3823 (void *)entry->object.vm_object,
3824 (long)entry->offset);
3825 if (entry->eflags & MAP_ENTRY_COW)
3826 db_printf(", copy (%s)",
3827 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
3831 if ((entry->prev == &map->header) ||
3832 (entry->prev->object.vm_object !=
3833 entry->object.vm_object)) {
3835 vm_object_print((db_expr_t)(intptr_t)
3836 entry->object.vm_object,
3851 DB_SHOW_COMMAND(procvm, procvm)
3856 p = (struct proc *) addr;
3861 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
3862 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
3863 (void *)vmspace_pmap(p->p_vmspace));
3865 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);