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 $
70 * Virtual memory mapping module.
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/kernel.h>
77 #include <sys/serialize.h>
79 #include <sys/vmmeter.h>
81 #include <sys/vnode.h>
82 #include <sys/resourcevar.h>
85 #include <sys/malloc.h>
88 #include <vm/vm_param.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_page.h>
92 #include <vm/vm_object.h>
93 #include <vm/vm_pager.h>
94 #include <vm/vm_kern.h>
95 #include <vm/vm_extern.h>
96 #include <vm/swap_pager.h>
97 #include <vm/vm_zone.h>
99 #include <sys/thread2.h>
100 #include <sys/sysref2.h>
101 #include <sys/random.h>
102 #include <sys/sysctl.h>
105 * Virtual memory maps provide for the mapping, protection, and sharing
106 * of virtual memory objects. In addition, this module provides for an
107 * efficient virtual copy of memory from one map to another.
109 * Synchronization is required prior to most operations.
111 * Maps consist of an ordered doubly-linked list of simple entries.
112 * A hint and a RB tree is used to speed-up lookups.
114 * Callers looking to modify maps specify start/end addresses which cause
115 * the related map entry to be clipped if necessary, and then later
116 * recombined if the pieces remained compatible.
118 * Virtual copy operations are performed by copying VM object references
119 * from one map to another, and then marking both regions as copy-on-write.
121 static void vmspace_terminate(struct vmspace *vm);
122 static void vmspace_lock(struct vmspace *vm);
123 static void vmspace_unlock(struct vmspace *vm);
124 static void vmspace_dtor(void *obj, void *private);
126 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore");
128 struct sysref_class vmspace_sysref_class = {
131 .proto = SYSREF_PROTO_VMSPACE,
132 .offset = offsetof(struct vmspace, vm_sysref),
133 .objsize = sizeof(struct vmspace),
135 .flags = SRC_MANAGEDINIT,
136 .dtor = vmspace_dtor,
138 .terminate = (sysref_terminate_func_t)vmspace_terminate,
139 .lock = (sysref_lock_func_t)vmspace_lock,
140 .unlock = (sysref_lock_func_t)vmspace_unlock
145 * per-cpu page table cross mappings are initialized in early boot
146 * and might require a considerable number of vm_map_entry structures.
148 #define VMEPERCPU (MAXCPU+1)
150 static struct vm_zone mapentzone_store, mapzone_store;
151 static vm_zone_t mapentzone, mapzone;
152 static struct vm_object mapentobj, mapobj;
154 static struct vm_map_entry map_entry_init[MAX_MAPENT];
155 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU];
156 static struct vm_map map_init[MAX_KMAP];
158 static int randomize_mmap;
159 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0,
160 "Randomize mmap offsets");
162 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref);
163 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *);
164 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *);
165 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
166 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
167 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *);
168 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t);
169 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t,
171 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);
174 * Initialize the vm_map module. Must be called before any other vm_map
177 * Map and entry structures are allocated from the general purpose
178 * memory pool with some exceptions:
180 * - The kernel map is allocated statically.
181 * - Initial kernel map entries are allocated out of a static pool.
183 * These restrictions are necessary since malloc() uses the
184 * maps and requires map entries.
186 * Called from the low level boot code only.
191 mapzone = &mapzone_store;
192 zbootinit(mapzone, "MAP", sizeof (struct vm_map),
194 mapentzone = &mapentzone_store;
195 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry),
196 map_entry_init, MAX_MAPENT);
200 * Called prior to any vmspace allocations.
202 * Called from the low level boot code only.
207 zinitna(mapentzone, &mapentobj, NULL, 0, 0,
208 ZONE_USE_RESERVE | ZONE_SPECIAL, 1);
209 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1);
216 * Red black tree functions
218 * The caller must hold the related map lock.
220 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b);
221 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare);
223 /* a->start is address, and the only field has to be initialized */
225 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b)
227 if (a->start < b->start)
229 else if (a->start > b->start)
235 * Allocate a vmspace structure, including a vm_map and pmap.
236 * Initialize numerous fields. While the initial allocation is zerod,
237 * subsequence reuse from the objcache leaves elements of the structure
238 * intact (particularly the pmap), so portions must be zerod.
240 * The structure is not considered activated until we call sysref_activate().
245 vmspace_alloc(vm_offset_t min, vm_offset_t max)
249 vm = sysref_alloc(&vmspace_sysref_class);
250 bzero(&vm->vm_startcopy,
251 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy);
252 vm_map_init(&vm->vm_map, min, max, NULL); /* initializes token */
255 * Use a hold to prevent any additional racing hold from terminating
256 * the vmspace before we manage to activate it. This also acquires
257 * the token for safety.
259 KKASSERT(vm->vm_holdcount == 0);
260 KKASSERT(vm->vm_exitingcnt == 0);
262 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */
263 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */
266 cpu_vmspace_alloc(vm);
267 sysref_activate(&vm->vm_sysref);
274 * Free a primary reference to a vmspace. This can trigger a
275 * stage-1 termination.
278 vmspace_free(struct vmspace *vm)
281 * We want all finalization to occur via vmspace_drop() so we
282 * need to hold the vm around the put.
285 sysref_put(&vm->vm_sysref);
290 vmspace_ref(struct vmspace *vm)
292 sysref_get(&vm->vm_sysref);
296 vmspace_hold(struct vmspace *vm)
298 refcount_acquire(&vm->vm_holdcount);
299 lwkt_gettoken(&vm->vm_map.token);
303 vmspace_drop(struct vmspace *vm)
305 lwkt_reltoken(&vm->vm_map.token);
306 if (refcount_release(&vm->vm_holdcount)) {
307 if (vm->vm_exitingcnt == 0 &&
308 sysref_isinactive(&vm->vm_sysref)) {
309 vmspace_terminate(vm);
315 * dtor function - Some elements of the pmap are retained in the
316 * free-cached vmspaces to improve performance. We have to clean them up
317 * here before returning the vmspace to the memory pool.
322 vmspace_dtor(void *obj, void *private)
324 struct vmspace *vm = obj;
326 pmap_puninit(vmspace_pmap(vm));
330 * Called in three cases:
332 * (1) When the last sysref is dropped and the vmspace becomes inactive.
333 * (holdcount will not be 0 because the vmspace is held through the op)
335 * (2) When exitingcount becomes 0 on the last reap
336 * (holdcount will not be 0 because the vmspace is held through the op)
338 * (3) When the holdcount becomes 0 in addition to the above two
340 * sysref will not scrap the object until we call sysref_put() once more
341 * after the last ref has been dropped.
343 * VMSPACE_EXIT1 flags the primary deactivation
344 * VMSPACE_EXIT2 flags the last reap
347 vmspace_terminate(struct vmspace *vm)
354 lwkt_gettoken(&vm->vm_map.token);
355 if ((vm->vm_flags & VMSPACE_EXIT1) == 0) {
356 vm->vm_flags |= VMSPACE_EXIT1;
358 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS,
359 VM_MAX_USER_ADDRESS);
360 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS,
361 VM_MAX_USER_ADDRESS);
363 if ((vm->vm_flags & VMSPACE_EXIT2) == 0 && vm->vm_exitingcnt == 0) {
364 vm->vm_flags |= VMSPACE_EXIT2;
365 cpu_vmspace_free(vm);
367 KKASSERT(vm->vm_upcalls == NULL);
370 * Lock the map, to wait out all other references to it.
371 * Delete all of the mappings and pages they hold, then call
372 * the pmap module to reclaim anything left.
374 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
375 vm_map_lock(&vm->vm_map);
376 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
377 vm->vm_map.max_offset, &count);
378 vm_map_unlock(&vm->vm_map);
379 vm_map_entry_release(count);
381 lwkt_gettoken(&vmspace_pmap(vm)->pm_token);
382 pmap_release(vmspace_pmap(vm));
383 lwkt_reltoken(&vmspace_pmap(vm)->pm_token);
386 lwkt_reltoken(&vm->vm_map.token);
387 if (vm->vm_exitingcnt == 0 && vm->vm_holdcount == 0) {
388 KKASSERT(vm->vm_flags & VMSPACE_EXIT1);
389 KKASSERT(vm->vm_flags & VMSPACE_EXIT2);
390 sysref_put(&vm->vm_sysref);
395 * vmspaces are not currently locked.
398 vmspace_lock(struct vmspace *vm __unused)
403 vmspace_unlock(struct vmspace *vm __unused)
408 * This is called during exit indicating that the vmspace is no
409 * longer in used by an exiting process, but the process has not yet
415 vmspace_exitbump(struct vmspace *vm)
419 vmspace_drop(vm); /* handles termination sequencing */
423 * Decrement the exitingcnt and issue the stage-2 termination if it becomes
424 * zero and the stage1 termination has already occured.
429 vmspace_exitfree(struct proc *p)
436 KKASSERT(vm->vm_exitingcnt > 0);
437 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref))
438 vmspace_terminate(vm);
439 vmspace_drop(vm); /* handles termination sequencing */
443 * Swap useage is determined by taking the proportional swap used by
444 * VM objects backing the VM map. To make up for fractional losses,
445 * if the VM object has any swap use at all the associated map entries
446 * count for at least 1 swap page.
451 vmspace_swap_count(struct vmspace *vm)
453 vm_map_t map = &vm->vm_map;
460 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
461 switch(cur->maptype) {
462 case VM_MAPTYPE_NORMAL:
463 case VM_MAPTYPE_VPAGETABLE:
464 if ((object = cur->object.vm_object) == NULL)
466 if (object->swblock_count) {
467 n = (cur->end - cur->start) / PAGE_SIZE;
468 count += object->swblock_count *
469 SWAP_META_PAGES * n / object->size + 1;
482 * Calculate the approximate number of anonymous pages in use by
483 * this vmspace. To make up for fractional losses, we count each
484 * VM object as having at least 1 anonymous page.
489 vmspace_anonymous_count(struct vmspace *vm)
491 vm_map_t map = &vm->vm_map;
497 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
498 switch(cur->maptype) {
499 case VM_MAPTYPE_NORMAL:
500 case VM_MAPTYPE_VPAGETABLE:
501 if ((object = cur->object.vm_object) == NULL)
503 if (object->type != OBJT_DEFAULT &&
504 object->type != OBJT_SWAP) {
507 count += object->resident_page_count;
519 * Creates and returns a new empty VM map with the given physical map
520 * structure, and having the given lower and upper address bounds.
525 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max)
528 result = zalloc(mapzone);
529 vm_map_init(result, min, max, pmap);
534 * Initialize an existing vm_map structure such as that in the vmspace
535 * structure. The pmap is initialized elsewhere.
540 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap)
542 map->header.next = map->header.prev = &map->header;
543 RB_INIT(&map->rb_root);
547 map->min_offset = min;
548 map->max_offset = max;
550 map->first_free = &map->header;
551 map->hint = &map->header;
554 lwkt_token_init(&map->token, "vm_map");
555 lockinit(&map->lock, "thrd_sleep", (hz + 9) / 10, 0);
556 TUNABLE_INT("vm.cache_vmspaces", &vmspace_sysref_class.nom_cache);
560 * Shadow the vm_map_entry's object. This typically needs to be done when
561 * a write fault is taken on an entry which had previously been cloned by
562 * fork(). The shared object (which might be NULL) must become private so
563 * we add a shadow layer above it.
565 * Object allocation for anonymous mappings is defered as long as possible.
566 * When creating a shadow, however, the underlying object must be instantiated
567 * so it can be shared.
569 * If the map segment is governed by a virtual page table then it is
570 * possible to address offsets beyond the mapped area. Just allocate
571 * a maximally sized object for this case.
573 * The vm_map must be exclusively locked.
574 * No other requirements.
578 vm_map_entry_shadow(vm_map_entry_t entry, int addref)
580 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
581 vm_object_shadow(&entry->object.vm_object, &entry->offset,
582 0x7FFFFFFF, addref); /* XXX */
584 vm_object_shadow(&entry->object.vm_object, &entry->offset,
585 atop(entry->end - entry->start), addref);
587 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
591 * Allocate an object for a vm_map_entry.
593 * Object allocation for anonymous mappings is defered as long as possible.
594 * This function is called when we can defer no longer, generally when a map
595 * entry might be split or forked or takes a page fault.
597 * If the map segment is governed by a virtual page table then it is
598 * possible to address offsets beyond the mapped area. Just allocate
599 * a maximally sized object for this case.
601 * The vm_map must be exclusively locked.
602 * No other requirements.
605 vm_map_entry_allocate_object(vm_map_entry_t entry)
609 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
610 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */
612 obj = vm_object_allocate(OBJT_DEFAULT,
613 atop(entry->end - entry->start));
615 entry->object.vm_object = obj;
620 * Set an initial negative count so the first attempt to reserve
621 * space preloads a bunch of vm_map_entry's for this cpu. Also
622 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
623 * map a new page for vm_map_entry structures. SMP systems are
624 * particularly sensitive.
626 * This routine is called in early boot so we cannot just call
627 * vm_map_entry_reserve().
629 * Called from the low level boot code only (for each cpu)
632 vm_map_entry_reserve_cpu_init(globaldata_t gd)
634 vm_map_entry_t entry;
637 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2;
638 entry = &cpu_map_entry_init[gd->gd_cpuid][0];
639 for (i = 0; i < VMEPERCPU; ++i, ++entry) {
640 entry->next = gd->gd_vme_base;
641 gd->gd_vme_base = entry;
646 * Reserves vm_map_entry structures so code later on can manipulate
647 * map_entry structures within a locked map without blocking trying
648 * to allocate a new vm_map_entry.
653 vm_map_entry_reserve(int count)
655 struct globaldata *gd = mycpu;
656 vm_map_entry_t entry;
659 * Make sure we have enough structures in gd_vme_base to handle
660 * the reservation request.
662 * The critical section protects access to the per-cpu gd.
665 while (gd->gd_vme_avail < count) {
666 entry = zalloc(mapentzone);
667 entry->next = gd->gd_vme_base;
668 gd->gd_vme_base = entry;
671 gd->gd_vme_avail -= count;
678 * Releases previously reserved vm_map_entry structures that were not
679 * used. If we have too much junk in our per-cpu cache clean some of
685 vm_map_entry_release(int count)
687 struct globaldata *gd = mycpu;
688 vm_map_entry_t entry;
691 gd->gd_vme_avail += count;
692 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) {
693 entry = gd->gd_vme_base;
694 KKASSERT(entry != NULL);
695 gd->gd_vme_base = entry->next;
698 zfree(mapentzone, entry);
705 * Reserve map entry structures for use in kernel_map itself. These
706 * entries have *ALREADY* been reserved on a per-cpu basis when the map
707 * was inited. This function is used by zalloc() to avoid a recursion
708 * when zalloc() itself needs to allocate additional kernel memory.
710 * This function works like the normal reserve but does not load the
711 * vm_map_entry cache (because that would result in an infinite
712 * recursion). Note that gd_vme_avail may go negative. This is expected.
714 * Any caller of this function must be sure to renormalize after
715 * potentially eating entries to ensure that the reserve supply
721 vm_map_entry_kreserve(int count)
723 struct globaldata *gd = mycpu;
726 gd->gd_vme_avail -= count;
728 KASSERT(gd->gd_vme_base != NULL,
729 ("no reserved entries left, gd_vme_avail = %d",
735 * Release previously reserved map entries for kernel_map. We do not
736 * attempt to clean up like the normal release function as this would
737 * cause an unnecessary (but probably not fatal) deep procedure call.
742 vm_map_entry_krelease(int count)
744 struct globaldata *gd = mycpu;
747 gd->gd_vme_avail += count;
752 * Allocates a VM map entry for insertion. No entry fields are filled in.
754 * The entries should have previously been reserved. The reservation count
755 * is tracked in (*countp).
759 static vm_map_entry_t
760 vm_map_entry_create(vm_map_t map, int *countp)
762 struct globaldata *gd = mycpu;
763 vm_map_entry_t entry;
765 KKASSERT(*countp > 0);
768 entry = gd->gd_vme_base;
769 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp));
770 gd->gd_vme_base = entry->next;
777 * Dispose of a vm_map_entry that is no longer being referenced.
782 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp)
784 struct globaldata *gd = mycpu;
786 KKASSERT(map->hint != entry);
787 KKASSERT(map->first_free != entry);
791 entry->next = gd->gd_vme_base;
792 gd->gd_vme_base = entry;
798 * Insert/remove entries from maps.
800 * The related map must be exclusively locked.
801 * The caller must hold map->token
802 * No other requirements.
805 vm_map_entry_link(vm_map_t map,
806 vm_map_entry_t after_where,
807 vm_map_entry_t entry)
809 ASSERT_VM_MAP_LOCKED(map);
812 entry->prev = after_where;
813 entry->next = after_where->next;
814 entry->next->prev = entry;
815 after_where->next = entry;
816 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry))
817 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry);
821 vm_map_entry_unlink(vm_map_t map,
822 vm_map_entry_t entry)
827 ASSERT_VM_MAP_LOCKED(map);
829 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
830 panic("vm_map_entry_unlink: attempt to mess with "
831 "locked entry! %p", entry);
837 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry);
842 * Finds the map entry containing (or immediately preceding) the specified
843 * address in the given map. The entry is returned in (*entry).
845 * The boolean result indicates whether the address is actually contained
848 * The related map must be locked.
849 * No other requirements.
852 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry)
857 ASSERT_VM_MAP_LOCKED(map);
860 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive
861 * the hint code with the red-black lookup meets with system crashes
862 * and lockups. We do not yet know why.
864 * It is possible that the problem is related to the setting
865 * of the hint during map_entry deletion, in the code specified
866 * at the GGG comment later on in this file.
868 * YYY More likely it's because this function can be called with
869 * a shared lock on the map, resulting in map->hint updates possibly
870 * racing. Fixed now but untested.
873 * Quickly check the cached hint, there's a good chance of a match.
877 if (tmp != &map->header) {
878 if (address >= tmp->start && address < tmp->end) {
886 * Locate the record from the top of the tree. 'last' tracks the
887 * closest prior record and is returned if no match is found, which
888 * in binary tree terms means tracking the most recent right-branch
889 * taken. If there is no prior record, &map->header is returned.
892 tmp = RB_ROOT(&map->rb_root);
895 if (address >= tmp->start) {
896 if (address < tmp->end) {
902 tmp = RB_RIGHT(tmp, rb_entry);
904 tmp = RB_LEFT(tmp, rb_entry);
912 * Inserts the given whole VM object into the target map at the specified
913 * address range. The object's size should match that of the address range.
915 * The map must be exclusively locked.
916 * The object must be held.
917 * The caller must have reserved sufficient vm_map_entry structures.
919 * If object is non-NULL, ref count must be bumped by caller prior to
920 * making call to account for the new entry.
923 vm_map_insert(vm_map_t map, int *countp,
924 vm_object_t object, vm_ooffset_t offset,
925 vm_offset_t start, vm_offset_t end,
926 vm_maptype_t maptype,
927 vm_prot_t prot, vm_prot_t max,
930 vm_map_entry_t new_entry;
931 vm_map_entry_t prev_entry;
932 vm_map_entry_t temp_entry;
933 vm_eflags_t protoeflags;
936 ASSERT_VM_MAP_LOCKED(map);
938 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
941 * Check that the start and end points are not bogus.
943 if ((start < map->min_offset) || (end > map->max_offset) ||
945 return (KERN_INVALID_ADDRESS);
948 * Find the entry prior to the proposed starting address; if it's part
949 * of an existing entry, this range is bogus.
951 if (vm_map_lookup_entry(map, start, &temp_entry))
952 return (KERN_NO_SPACE);
954 prev_entry = temp_entry;
957 * Assert that the next entry doesn't overlap the end point.
960 if ((prev_entry->next != &map->header) &&
961 (prev_entry->next->start < end))
962 return (KERN_NO_SPACE);
966 if (cow & MAP_COPY_ON_WRITE)
967 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY;
969 if (cow & MAP_NOFAULT) {
970 protoeflags |= MAP_ENTRY_NOFAULT;
972 KASSERT(object == NULL,
973 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
975 if (cow & MAP_DISABLE_SYNCER)
976 protoeflags |= MAP_ENTRY_NOSYNC;
977 if (cow & MAP_DISABLE_COREDUMP)
978 protoeflags |= MAP_ENTRY_NOCOREDUMP;
979 if (cow & MAP_IS_STACK)
980 protoeflags |= MAP_ENTRY_STACK;
981 if (cow & MAP_IS_KSTACK)
982 protoeflags |= MAP_ENTRY_KSTACK;
984 lwkt_gettoken(&map->token);
988 * When object is non-NULL, it could be shared with another
989 * process. We have to set or clear OBJ_ONEMAPPING
992 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
993 vm_object_clear_flag(object, OBJ_ONEMAPPING);
996 else if ((prev_entry != &map->header) &&
997 (prev_entry->eflags == protoeflags) &&
998 (prev_entry->end == start) &&
999 (prev_entry->wired_count == 0) &&
1000 prev_entry->maptype == maptype &&
1001 ((prev_entry->object.vm_object == NULL) ||
1002 vm_object_coalesce(prev_entry->object.vm_object,
1003 OFF_TO_IDX(prev_entry->offset),
1004 (vm_size_t)(prev_entry->end - prev_entry->start),
1005 (vm_size_t)(end - prev_entry->end)))) {
1007 * We were able to extend the object. Determine if we
1008 * can extend the previous map entry to include the
1009 * new range as well.
1011 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
1012 (prev_entry->protection == prot) &&
1013 (prev_entry->max_protection == max)) {
1014 map->size += (end - prev_entry->end);
1015 prev_entry->end = end;
1016 vm_map_simplify_entry(map, prev_entry, countp);
1017 lwkt_reltoken(&map->token);
1018 return (KERN_SUCCESS);
1022 * If we can extend the object but cannot extend the
1023 * map entry, we have to create a new map entry. We
1024 * must bump the ref count on the extended object to
1025 * account for it. object may be NULL.
1027 object = prev_entry->object.vm_object;
1028 offset = prev_entry->offset +
1029 (prev_entry->end - prev_entry->start);
1031 vm_object_hold(object);
1032 vm_object_chain_wait(object);
1033 vm_object_reference_locked(object);
1039 * NOTE: if conditionals fail, object can be NULL here. This occurs
1040 * in things like the buffer map where we manage kva but do not manage
1045 * Create a new entry
1048 new_entry = vm_map_entry_create(map, countp);
1049 new_entry->start = start;
1050 new_entry->end = end;
1052 new_entry->maptype = maptype;
1053 new_entry->eflags = protoeflags;
1054 new_entry->object.vm_object = object;
1055 new_entry->offset = offset;
1056 new_entry->aux.master_pde = 0;
1058 new_entry->inheritance = VM_INHERIT_DEFAULT;
1059 new_entry->protection = prot;
1060 new_entry->max_protection = max;
1061 new_entry->wired_count = 0;
1064 * Insert the new entry into the list
1067 vm_map_entry_link(map, prev_entry, new_entry);
1068 map->size += new_entry->end - new_entry->start;
1071 * Update the free space hint. Entries cannot overlap.
1072 * An exact comparison is needed to avoid matching
1073 * against the map->header.
1075 if ((map->first_free == prev_entry) &&
1076 (prev_entry->end == new_entry->start)) {
1077 map->first_free = new_entry;
1082 * Temporarily removed to avoid MAP_STACK panic, due to
1083 * MAP_STACK being a huge hack. Will be added back in
1084 * when MAP_STACK (and the user stack mapping) is fixed.
1087 * It may be possible to simplify the entry
1089 vm_map_simplify_entry(map, new_entry, countp);
1093 * Try to pre-populate the page table. Mappings governed by virtual
1094 * page tables cannot be prepopulated without a lot of work, so
1097 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) &&
1098 maptype != VM_MAPTYPE_VPAGETABLE) {
1099 pmap_object_init_pt(map->pmap, start, prot,
1100 object, OFF_TO_IDX(offset), end - start,
1101 cow & MAP_PREFAULT_PARTIAL);
1104 vm_object_drop(object);
1106 lwkt_reltoken(&map->token);
1107 return (KERN_SUCCESS);
1111 * Find sufficient space for `length' bytes in the given map, starting at
1112 * `start'. Returns 0 on success, 1 on no space.
1114 * This function will returned an arbitrarily aligned pointer. If no
1115 * particular alignment is required you should pass align as 1. Note that
1116 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1117 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1120 * 'align' should be a power of 2 but is not required to be.
1122 * The map must be exclusively locked.
1123 * No other requirements.
1126 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1127 vm_size_t align, int flags, vm_offset_t *addr)
1129 vm_map_entry_t entry, next;
1131 vm_offset_t align_mask;
1133 if (start < map->min_offset)
1134 start = map->min_offset;
1135 if (start > map->max_offset)
1139 * If the alignment is not a power of 2 we will have to use
1140 * a mod/division, set align_mask to a special value.
1142 if ((align | (align - 1)) + 1 != (align << 1))
1143 align_mask = (vm_offset_t)-1;
1145 align_mask = align - 1;
1148 * Look for the first possible address; if there's already something
1149 * at this address, we have to start after it.
1151 if (start == map->min_offset) {
1152 if ((entry = map->first_free) != &map->header)
1157 if (vm_map_lookup_entry(map, start, &tmp))
1163 * Look through the rest of the map, trying to fit a new region in the
1164 * gap between existing regions, or after the very last region.
1166 for (;; start = (entry = next)->end) {
1168 * Adjust the proposed start by the requested alignment,
1169 * be sure that we didn't wrap the address.
1171 if (align_mask == (vm_offset_t)-1)
1172 end = ((start + align - 1) / align) * align;
1174 end = (start + align_mask) & ~align_mask;
1179 * Find the end of the proposed new region. Be sure we didn't
1180 * go beyond the end of the map, or wrap around the address.
1181 * Then check to see if this is the last entry or if the
1182 * proposed end fits in the gap between this and the next
1185 end = start + length;
1186 if (end > map->max_offset || end < start)
1191 * If the next entry's start address is beyond the desired
1192 * end address we may have found a good entry.
1194 * If the next entry is a stack mapping we do not map into
1195 * the stack's reserved space.
1197 * XXX continue to allow mapping into the stack's reserved
1198 * space if doing a MAP_STACK mapping inside a MAP_STACK
1199 * mapping, for backwards compatibility. But the caller
1200 * really should use MAP_STACK | MAP_TRYFIXED if they
1203 if (next == &map->header)
1205 if (next->start >= end) {
1206 if ((next->eflags & MAP_ENTRY_STACK) == 0)
1208 if (flags & MAP_STACK)
1210 if (next->start - next->aux.avail_ssize >= end)
1217 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1218 * if it fails. The kernel_map is locked and nothing can steal
1219 * our address space if pmap_growkernel() blocks.
1221 * NOTE: This may be unconditionally called for kldload areas on
1222 * x86_64 because these do not bump kernel_vm_end (which would
1223 * fill 128G worth of page tables!). Therefore we must not
1226 if (map == &kernel_map) {
1229 kstop = round_page(start + length);
1230 if (kstop > kernel_vm_end)
1231 pmap_growkernel(start, kstop);
1238 * vm_map_find finds an unallocated region in the target address map with
1239 * the given length and allocates it. The search is defined to be first-fit
1240 * from the specified address; the region found is returned in the same
1243 * If object is non-NULL, ref count must be bumped by caller
1244 * prior to making call to account for the new entry.
1246 * No requirements. This function will lock the map temporarily.
1249 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1250 vm_offset_t *addr, vm_size_t length, vm_size_t align,
1252 vm_maptype_t maptype,
1253 vm_prot_t prot, vm_prot_t max,
1262 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1265 vm_object_hold(object);
1267 if (vm_map_findspace(map, start, length, align, 0, addr)) {
1269 vm_map_entry_release(count);
1270 return (KERN_NO_SPACE);
1274 result = vm_map_insert(map, &count, object, offset,
1275 start, start + length,
1280 vm_object_drop(object);
1282 vm_map_entry_release(count);
1288 * Simplify the given map entry by merging with either neighbor. This
1289 * routine also has the ability to merge with both neighbors.
1291 * This routine guarentees that the passed entry remains valid (though
1292 * possibly extended). When merging, this routine may delete one or
1293 * both neighbors. No action is taken on entries which have their
1294 * in-transition flag set.
1296 * The map must be exclusively locked.
1299 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1301 vm_map_entry_t next, prev;
1302 vm_size_t prevsize, esize;
1304 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1305 ++mycpu->gd_cnt.v_intrans_coll;
1309 if (entry->maptype == VM_MAPTYPE_SUBMAP)
1313 if (prev != &map->header) {
1314 prevsize = prev->end - prev->start;
1315 if ( (prev->end == entry->start) &&
1316 (prev->maptype == entry->maptype) &&
1317 (prev->object.vm_object == entry->object.vm_object) &&
1318 (!prev->object.vm_object ||
1319 (prev->offset + prevsize == entry->offset)) &&
1320 (prev->eflags == entry->eflags) &&
1321 (prev->protection == entry->protection) &&
1322 (prev->max_protection == entry->max_protection) &&
1323 (prev->inheritance == entry->inheritance) &&
1324 (prev->wired_count == entry->wired_count)) {
1325 if (map->first_free == prev)
1326 map->first_free = entry;
1327 if (map->hint == prev)
1329 vm_map_entry_unlink(map, prev);
1330 entry->start = prev->start;
1331 entry->offset = prev->offset;
1332 if (prev->object.vm_object)
1333 vm_object_deallocate(prev->object.vm_object);
1334 vm_map_entry_dispose(map, prev, countp);
1339 if (next != &map->header) {
1340 esize = entry->end - entry->start;
1341 if ((entry->end == next->start) &&
1342 (next->maptype == entry->maptype) &&
1343 (next->object.vm_object == entry->object.vm_object) &&
1344 (!entry->object.vm_object ||
1345 (entry->offset + esize == next->offset)) &&
1346 (next->eflags == entry->eflags) &&
1347 (next->protection == entry->protection) &&
1348 (next->max_protection == entry->max_protection) &&
1349 (next->inheritance == entry->inheritance) &&
1350 (next->wired_count == entry->wired_count)) {
1351 if (map->first_free == next)
1352 map->first_free = entry;
1353 if (map->hint == next)
1355 vm_map_entry_unlink(map, next);
1356 entry->end = next->end;
1357 if (next->object.vm_object)
1358 vm_object_deallocate(next->object.vm_object);
1359 vm_map_entry_dispose(map, next, countp);
1365 * Asserts that the given entry begins at or after the specified address.
1366 * If necessary, it splits the entry into two.
1368 #define vm_map_clip_start(map, entry, startaddr, countp) \
1370 if (startaddr > entry->start) \
1371 _vm_map_clip_start(map, entry, startaddr, countp); \
1375 * This routine is called only when it is known that the entry must be split.
1377 * The map must be exclusively locked.
1380 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1383 vm_map_entry_t new_entry;
1386 * Split off the front portion -- note that we must insert the new
1387 * entry BEFORE this one, so that this entry has the specified
1391 vm_map_simplify_entry(map, entry, countp);
1394 * If there is no object backing this entry, we might as well create
1395 * one now. If we defer it, an object can get created after the map
1396 * is clipped, and individual objects will be created for the split-up
1397 * map. This is a bit of a hack, but is also about the best place to
1398 * put this improvement.
1400 if (entry->object.vm_object == NULL && !map->system_map) {
1401 vm_map_entry_allocate_object(entry);
1404 new_entry = vm_map_entry_create(map, countp);
1405 *new_entry = *entry;
1407 new_entry->end = start;
1408 entry->offset += (start - entry->start);
1409 entry->start = start;
1411 vm_map_entry_link(map, entry->prev, new_entry);
1413 switch(entry->maptype) {
1414 case VM_MAPTYPE_NORMAL:
1415 case VM_MAPTYPE_VPAGETABLE:
1416 if (new_entry->object.vm_object) {
1417 vm_object_hold(new_entry->object.vm_object);
1418 vm_object_chain_wait(new_entry->object.vm_object);
1419 vm_object_reference_locked(new_entry->object.vm_object);
1420 vm_object_drop(new_entry->object.vm_object);
1429 * Asserts that the given entry ends at or before the specified address.
1430 * If necessary, it splits the entry into two.
1432 * The map must be exclusively locked.
1434 #define vm_map_clip_end(map, entry, endaddr, countp) \
1436 if (endaddr < entry->end) \
1437 _vm_map_clip_end(map, entry, endaddr, countp); \
1441 * This routine is called only when it is known that the entry must be split.
1443 * The map must be exclusively locked.
1446 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1449 vm_map_entry_t new_entry;
1452 * If there is no object backing this entry, we might as well create
1453 * one now. If we defer it, an object can get created after the map
1454 * is clipped, and individual objects will be created for the split-up
1455 * map. This is a bit of a hack, but is also about the best place to
1456 * put this improvement.
1459 if (entry->object.vm_object == NULL && !map->system_map) {
1460 vm_map_entry_allocate_object(entry);
1464 * Create a new entry and insert it AFTER the specified entry
1467 new_entry = vm_map_entry_create(map, countp);
1468 *new_entry = *entry;
1470 new_entry->start = entry->end = end;
1471 new_entry->offset += (end - entry->start);
1473 vm_map_entry_link(map, entry, new_entry);
1475 switch(entry->maptype) {
1476 case VM_MAPTYPE_NORMAL:
1477 case VM_MAPTYPE_VPAGETABLE:
1478 if (new_entry->object.vm_object) {
1479 vm_object_hold(new_entry->object.vm_object);
1480 vm_object_chain_wait(new_entry->object.vm_object);
1481 vm_object_reference_locked(new_entry->object.vm_object);
1482 vm_object_drop(new_entry->object.vm_object);
1491 * Asserts that the starting and ending region addresses fall within the
1492 * valid range for the map.
1494 #define VM_MAP_RANGE_CHECK(map, start, end) \
1496 if (start < vm_map_min(map)) \
1497 start = vm_map_min(map); \
1498 if (end > vm_map_max(map)) \
1499 end = vm_map_max(map); \
1505 * Used to block when an in-transition collison occurs. The map
1506 * is unlocked for the sleep and relocked before the return.
1509 vm_map_transition_wait(vm_map_t map)
1511 tsleep_interlock(map, 0);
1513 tsleep(map, PINTERLOCKED, "vment", 0);
1518 * When we do blocking operations with the map lock held it is
1519 * possible that a clip might have occured on our in-transit entry,
1520 * requiring an adjustment to the entry in our loop. These macros
1521 * help the pageable and clip_range code deal with the case. The
1522 * conditional costs virtually nothing if no clipping has occured.
1525 #define CLIP_CHECK_BACK(entry, save_start) \
1527 while (entry->start != save_start) { \
1528 entry = entry->prev; \
1529 KASSERT(entry != &map->header, ("bad entry clip")); \
1533 #define CLIP_CHECK_FWD(entry, save_end) \
1535 while (entry->end != save_end) { \
1536 entry = entry->next; \
1537 KASSERT(entry != &map->header, ("bad entry clip")); \
1543 * Clip the specified range and return the base entry. The
1544 * range may cover several entries starting at the returned base
1545 * and the first and last entry in the covering sequence will be
1546 * properly clipped to the requested start and end address.
1548 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1551 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1552 * covered by the requested range.
1554 * The map must be exclusively locked on entry and will remain locked
1555 * on return. If no range exists or the range contains holes and you
1556 * specified that no holes were allowed, NULL will be returned. This
1557 * routine may temporarily unlock the map in order avoid a deadlock when
1562 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end,
1563 int *countp, int flags)
1565 vm_map_entry_t start_entry;
1566 vm_map_entry_t entry;
1569 * Locate the entry and effect initial clipping. The in-transition
1570 * case does not occur very often so do not try to optimize it.
1573 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1575 entry = start_entry;
1576 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1577 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1578 ++mycpu->gd_cnt.v_intrans_coll;
1579 ++mycpu->gd_cnt.v_intrans_wait;
1580 vm_map_transition_wait(map);
1582 * entry and/or start_entry may have been clipped while
1583 * we slept, or may have gone away entirely. We have
1584 * to restart from the lookup.
1590 * Since we hold an exclusive map lock we do not have to restart
1591 * after clipping, even though clipping may block in zalloc.
1593 vm_map_clip_start(map, entry, start, countp);
1594 vm_map_clip_end(map, entry, end, countp);
1595 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1598 * Scan entries covered by the range. When working on the next
1599 * entry a restart need only re-loop on the current entry which
1600 * we have already locked, since 'next' may have changed. Also,
1601 * even though entry is safe, it may have been clipped so we
1602 * have to iterate forwards through the clip after sleeping.
1604 while (entry->next != &map->header && entry->next->start < end) {
1605 vm_map_entry_t next = entry->next;
1607 if (flags & MAP_CLIP_NO_HOLES) {
1608 if (next->start > entry->end) {
1609 vm_map_unclip_range(map, start_entry,
1610 start, entry->end, countp, flags);
1615 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1616 vm_offset_t save_end = entry->end;
1617 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1618 ++mycpu->gd_cnt.v_intrans_coll;
1619 ++mycpu->gd_cnt.v_intrans_wait;
1620 vm_map_transition_wait(map);
1623 * clips might have occured while we blocked.
1625 CLIP_CHECK_FWD(entry, save_end);
1626 CLIP_CHECK_BACK(start_entry, start);
1630 * No restart necessary even though clip_end may block, we
1631 * are holding the map lock.
1633 vm_map_clip_end(map, next, end, countp);
1634 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1637 if (flags & MAP_CLIP_NO_HOLES) {
1638 if (entry->end != end) {
1639 vm_map_unclip_range(map, start_entry,
1640 start, entry->end, countp, flags);
1644 return(start_entry);
1648 * Undo the effect of vm_map_clip_range(). You should pass the same
1649 * flags and the same range that you passed to vm_map_clip_range().
1650 * This code will clear the in-transition flag on the entries and
1651 * wake up anyone waiting. This code will also simplify the sequence
1652 * and attempt to merge it with entries before and after the sequence.
1654 * The map must be locked on entry and will remain locked on return.
1656 * Note that you should also pass the start_entry returned by
1657 * vm_map_clip_range(). However, if you block between the two calls
1658 * with the map unlocked please be aware that the start_entry may
1659 * have been clipped and you may need to scan it backwards to find
1660 * the entry corresponding with the original start address. You are
1661 * responsible for this, vm_map_unclip_range() expects the correct
1662 * start_entry to be passed to it and will KASSERT otherwise.
1666 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1667 vm_offset_t start, vm_offset_t end,
1668 int *countp, int flags)
1670 vm_map_entry_t entry;
1672 entry = start_entry;
1674 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1675 while (entry != &map->header && entry->start < end) {
1676 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1677 ("in-transition flag not set during unclip on: %p",
1679 KASSERT(entry->end <= end,
1680 ("unclip_range: tail wasn't clipped"));
1681 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1682 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1683 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1686 entry = entry->next;
1690 * Simplification does not block so there is no restart case.
1692 entry = start_entry;
1693 while (entry != &map->header && entry->start < end) {
1694 vm_map_simplify_entry(map, entry, countp);
1695 entry = entry->next;
1700 * Mark the given range as handled by a subordinate map.
1702 * This range must have been created with vm_map_find(), and no other
1703 * operations may have been performed on this range prior to calling
1706 * Submappings cannot be removed.
1711 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1713 vm_map_entry_t entry;
1714 int result = KERN_INVALID_ARGUMENT;
1717 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1720 VM_MAP_RANGE_CHECK(map, start, end);
1722 if (vm_map_lookup_entry(map, start, &entry)) {
1723 vm_map_clip_start(map, entry, start, &count);
1725 entry = entry->next;
1728 vm_map_clip_end(map, entry, end, &count);
1730 if ((entry->start == start) && (entry->end == end) &&
1731 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1732 (entry->object.vm_object == NULL)) {
1733 entry->object.sub_map = submap;
1734 entry->maptype = VM_MAPTYPE_SUBMAP;
1735 result = KERN_SUCCESS;
1738 vm_map_entry_release(count);
1744 * Sets the protection of the specified address region in the target map.
1745 * If "set_max" is specified, the maximum protection is to be set;
1746 * otherwise, only the current protection is affected.
1748 * The protection is not applicable to submaps, but is applicable to normal
1749 * maps and maps governed by virtual page tables. For example, when operating
1750 * on a virtual page table our protection basically controls how COW occurs
1751 * on the backing object, whereas the virtual page table abstraction itself
1752 * is an abstraction for userland.
1757 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1758 vm_prot_t new_prot, boolean_t set_max)
1760 vm_map_entry_t current;
1761 vm_map_entry_t entry;
1764 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1767 VM_MAP_RANGE_CHECK(map, start, end);
1769 if (vm_map_lookup_entry(map, start, &entry)) {
1770 vm_map_clip_start(map, entry, start, &count);
1772 entry = entry->next;
1776 * Make a first pass to check for protection violations.
1779 while ((current != &map->header) && (current->start < end)) {
1780 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1782 vm_map_entry_release(count);
1783 return (KERN_INVALID_ARGUMENT);
1785 if ((new_prot & current->max_protection) != new_prot) {
1787 vm_map_entry_release(count);
1788 return (KERN_PROTECTION_FAILURE);
1790 current = current->next;
1794 * Go back and fix up protections. [Note that clipping is not
1795 * necessary the second time.]
1799 while ((current != &map->header) && (current->start < end)) {
1802 vm_map_clip_end(map, current, end, &count);
1804 old_prot = current->protection;
1806 current->protection =
1807 (current->max_protection = new_prot) &
1810 current->protection = new_prot;
1814 * Update physical map if necessary. Worry about copy-on-write
1815 * here -- CHECK THIS XXX
1818 if (current->protection != old_prot) {
1819 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1822 pmap_protect(map->pmap, current->start,
1824 current->protection & MASK(current));
1828 vm_map_simplify_entry(map, current, &count);
1830 current = current->next;
1834 vm_map_entry_release(count);
1835 return (KERN_SUCCESS);
1839 * This routine traverses a processes map handling the madvise
1840 * system call. Advisories are classified as either those effecting
1841 * the vm_map_entry structure, or those effecting the underlying
1844 * The <value> argument is used for extended madvise calls.
1849 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1850 int behav, off_t value)
1852 vm_map_entry_t current, entry;
1858 * Some madvise calls directly modify the vm_map_entry, in which case
1859 * we need to use an exclusive lock on the map and we need to perform
1860 * various clipping operations. Otherwise we only need a read-lock
1864 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1868 case MADV_SEQUENTIAL:
1882 vm_map_lock_read(map);
1885 vm_map_entry_release(count);
1890 * Locate starting entry and clip if necessary.
1893 VM_MAP_RANGE_CHECK(map, start, end);
1895 if (vm_map_lookup_entry(map, start, &entry)) {
1897 vm_map_clip_start(map, entry, start, &count);
1899 entry = entry->next;
1904 * madvise behaviors that are implemented in the vm_map_entry.
1906 * We clip the vm_map_entry so that behavioral changes are
1907 * limited to the specified address range.
1909 for (current = entry;
1910 (current != &map->header) && (current->start < end);
1911 current = current->next
1913 if (current->maptype == VM_MAPTYPE_SUBMAP)
1916 vm_map_clip_end(map, current, end, &count);
1920 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
1922 case MADV_SEQUENTIAL:
1923 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
1926 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
1929 current->eflags |= MAP_ENTRY_NOSYNC;
1932 current->eflags &= ~MAP_ENTRY_NOSYNC;
1935 current->eflags |= MAP_ENTRY_NOCOREDUMP;
1938 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
1942 * Invalidate the related pmap entries, used
1943 * to flush portions of the real kernel's
1944 * pmap when the caller has removed or
1945 * modified existing mappings in a virtual
1948 pmap_remove(map->pmap,
1949 current->start, current->end);
1953 * Set the page directory page for a map
1954 * governed by a virtual page table. Mark
1955 * the entry as being governed by a virtual
1956 * page table if it is not.
1958 * XXX the page directory page is stored
1959 * in the avail_ssize field if the map_entry.
1961 * XXX the map simplification code does not
1962 * compare this field so weird things may
1963 * happen if you do not apply this function
1964 * to the entire mapping governed by the
1965 * virtual page table.
1967 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
1971 current->aux.master_pde = value;
1972 pmap_remove(map->pmap,
1973 current->start, current->end);
1979 vm_map_simplify_entry(map, current, &count);
1987 * madvise behaviors that are implemented in the underlying
1990 * Since we don't clip the vm_map_entry, we have to clip
1991 * the vm_object pindex and count.
1993 * NOTE! We currently do not support these functions on
1994 * virtual page tables.
1996 for (current = entry;
1997 (current != &map->header) && (current->start < end);
1998 current = current->next
2000 vm_offset_t useStart;
2002 if (current->maptype != VM_MAPTYPE_NORMAL)
2005 pindex = OFF_TO_IDX(current->offset);
2006 count = atop(current->end - current->start);
2007 useStart = current->start;
2009 if (current->start < start) {
2010 pindex += atop(start - current->start);
2011 count -= atop(start - current->start);
2014 if (current->end > end)
2015 count -= atop(current->end - end);
2020 vm_object_madvise(current->object.vm_object,
2021 pindex, count, behav);
2024 * Try to populate the page table. Mappings governed
2025 * by virtual page tables cannot be pre-populated
2026 * without a lot of work so don't try.
2028 if (behav == MADV_WILLNEED &&
2029 current->maptype != VM_MAPTYPE_VPAGETABLE) {
2030 pmap_object_init_pt(
2033 current->protection,
2034 current->object.vm_object,
2036 (count << PAGE_SHIFT),
2037 MAP_PREFAULT_MADVISE
2041 vm_map_unlock_read(map);
2043 vm_map_entry_release(count);
2049 * Sets the inheritance of the specified address range in the target map.
2050 * Inheritance affects how the map will be shared with child maps at the
2051 * time of vm_map_fork.
2054 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
2055 vm_inherit_t new_inheritance)
2057 vm_map_entry_t entry;
2058 vm_map_entry_t temp_entry;
2061 switch (new_inheritance) {
2062 case VM_INHERIT_NONE:
2063 case VM_INHERIT_COPY:
2064 case VM_INHERIT_SHARE:
2067 return (KERN_INVALID_ARGUMENT);
2070 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2073 VM_MAP_RANGE_CHECK(map, start, end);
2075 if (vm_map_lookup_entry(map, start, &temp_entry)) {
2077 vm_map_clip_start(map, entry, start, &count);
2079 entry = temp_entry->next;
2081 while ((entry != &map->header) && (entry->start < end)) {
2082 vm_map_clip_end(map, entry, end, &count);
2084 entry->inheritance = new_inheritance;
2086 vm_map_simplify_entry(map, entry, &count);
2088 entry = entry->next;
2091 vm_map_entry_release(count);
2092 return (KERN_SUCCESS);
2096 * Implement the semantics of mlock
2099 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2100 boolean_t new_pageable)
2102 vm_map_entry_t entry;
2103 vm_map_entry_t start_entry;
2105 int rv = KERN_SUCCESS;
2108 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2110 VM_MAP_RANGE_CHECK(map, start, real_end);
2113 start_entry = vm_map_clip_range(map, start, end, &count,
2115 if (start_entry == NULL) {
2117 vm_map_entry_release(count);
2118 return (KERN_INVALID_ADDRESS);
2121 if (new_pageable == 0) {
2122 entry = start_entry;
2123 while ((entry != &map->header) && (entry->start < end)) {
2124 vm_offset_t save_start;
2125 vm_offset_t save_end;
2128 * Already user wired or hard wired (trivial cases)
2130 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2131 entry = entry->next;
2134 if (entry->wired_count != 0) {
2135 entry->wired_count++;
2136 entry->eflags |= MAP_ENTRY_USER_WIRED;
2137 entry = entry->next;
2142 * A new wiring requires instantiation of appropriate
2143 * management structures and the faulting in of the
2146 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2147 int copyflag = entry->eflags &
2148 MAP_ENTRY_NEEDS_COPY;
2149 if (copyflag && ((entry->protection &
2150 VM_PROT_WRITE) != 0)) {
2151 vm_map_entry_shadow(entry, 0);
2152 } else if (entry->object.vm_object == NULL &&
2154 vm_map_entry_allocate_object(entry);
2157 entry->wired_count++;
2158 entry->eflags |= MAP_ENTRY_USER_WIRED;
2161 * Now fault in the area. Note that vm_fault_wire()
2162 * may release the map lock temporarily, it will be
2163 * relocked on return. The in-transition
2164 * flag protects the entries.
2166 save_start = entry->start;
2167 save_end = entry->end;
2168 rv = vm_fault_wire(map, entry, TRUE);
2170 CLIP_CHECK_BACK(entry, save_start);
2172 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2173 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2174 entry->wired_count = 0;
2175 if (entry->end == save_end)
2177 entry = entry->next;
2178 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2180 end = save_start; /* unwire the rest */
2184 * note that even though the entry might have been
2185 * clipped, the USER_WIRED flag we set prevents
2186 * duplication so we do not have to do a
2189 entry = entry->next;
2193 * If we failed fall through to the unwiring section to
2194 * unwire what we had wired so far. 'end' has already
2201 * start_entry might have been clipped if we unlocked the
2202 * map and blocked. No matter how clipped it has gotten
2203 * there should be a fragment that is on our start boundary.
2205 CLIP_CHECK_BACK(start_entry, start);
2209 * Deal with the unwiring case.
2213 * This is the unwiring case. We must first ensure that the
2214 * range to be unwired is really wired down. We know there
2217 entry = start_entry;
2218 while ((entry != &map->header) && (entry->start < end)) {
2219 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2220 rv = KERN_INVALID_ARGUMENT;
2223 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2224 entry = entry->next;
2228 * Now decrement the wiring count for each region. If a region
2229 * becomes completely unwired, unwire its physical pages and
2233 * The map entries are processed in a loop, checking to
2234 * make sure the entry is wired and asserting it has a wired
2235 * count. However, another loop was inserted more-or-less in
2236 * the middle of the unwiring path. This loop picks up the
2237 * "entry" loop variable from the first loop without first
2238 * setting it to start_entry. Naturally, the secound loop
2239 * is never entered and the pages backing the entries are
2240 * never unwired. This can lead to a leak of wired pages.
2242 entry = start_entry;
2243 while ((entry != &map->header) && (entry->start < end)) {
2244 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2245 ("expected USER_WIRED on entry %p", entry));
2246 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2247 entry->wired_count--;
2248 if (entry->wired_count == 0)
2249 vm_fault_unwire(map, entry);
2250 entry = entry->next;
2254 vm_map_unclip_range(map, start_entry, start, real_end, &count,
2258 vm_map_entry_release(count);
2263 * Sets the pageability of the specified address range in the target map.
2264 * Regions specified as not pageable require locked-down physical
2265 * memory and physical page maps.
2267 * The map must not be locked, but a reference must remain to the map
2268 * throughout the call.
2270 * This function may be called via the zalloc path and must properly
2271 * reserve map entries for kernel_map.
2276 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2278 vm_map_entry_t entry;
2279 vm_map_entry_t start_entry;
2281 int rv = KERN_SUCCESS;
2284 if (kmflags & KM_KRESERVE)
2285 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2287 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2289 VM_MAP_RANGE_CHECK(map, start, real_end);
2292 start_entry = vm_map_clip_range(map, start, end, &count,
2294 if (start_entry == NULL) {
2296 rv = KERN_INVALID_ADDRESS;
2299 if ((kmflags & KM_PAGEABLE) == 0) {
2303 * 1. Holding the write lock, we create any shadow or zero-fill
2304 * objects that need to be created. Then we clip each map
2305 * entry to the region to be wired and increment its wiring
2306 * count. We create objects before clipping the map entries
2307 * to avoid object proliferation.
2309 * 2. We downgrade to a read lock, and call vm_fault_wire to
2310 * fault in the pages for any newly wired area (wired_count is
2313 * Downgrading to a read lock for vm_fault_wire avoids a
2314 * possible deadlock with another process that may have faulted
2315 * on one of the pages to be wired (it would mark the page busy,
2316 * blocking us, then in turn block on the map lock that we
2317 * hold). Because of problems in the recursive lock package,
2318 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2319 * any actions that require the write lock must be done
2320 * beforehand. Because we keep the read lock on the map, the
2321 * copy-on-write status of the entries we modify here cannot
2324 entry = start_entry;
2325 while ((entry != &map->header) && (entry->start < end)) {
2327 * Trivial case if the entry is already wired
2329 if (entry->wired_count) {
2330 entry->wired_count++;
2331 entry = entry->next;
2336 * The entry is being newly wired, we have to setup
2337 * appropriate management structures. A shadow
2338 * object is required for a copy-on-write region,
2339 * or a normal object for a zero-fill region. We
2340 * do not have to do this for entries that point to sub
2341 * maps because we won't hold the lock on the sub map.
2343 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2344 int copyflag = entry->eflags &
2345 MAP_ENTRY_NEEDS_COPY;
2346 if (copyflag && ((entry->protection &
2347 VM_PROT_WRITE) != 0)) {
2348 vm_map_entry_shadow(entry, 0);
2349 } else if (entry->object.vm_object == NULL &&
2351 vm_map_entry_allocate_object(entry);
2355 entry->wired_count++;
2356 entry = entry->next;
2364 * HACK HACK HACK HACK
2366 * vm_fault_wire() temporarily unlocks the map to avoid
2367 * deadlocks. The in-transition flag from vm_map_clip_range
2368 * call should protect us from changes while the map is
2371 * NOTE: Previously this comment stated that clipping might
2372 * still occur while the entry is unlocked, but from
2373 * what I can tell it actually cannot.
2375 * It is unclear whether the CLIP_CHECK_*() calls
2376 * are still needed but we keep them in anyway.
2378 * HACK HACK HACK HACK
2381 entry = start_entry;
2382 while (entry != &map->header && entry->start < end) {
2384 * If vm_fault_wire fails for any page we need to undo
2385 * what has been done. We decrement the wiring count
2386 * for those pages which have not yet been wired (now)
2387 * and unwire those that have (later).
2389 vm_offset_t save_start = entry->start;
2390 vm_offset_t save_end = entry->end;
2392 if (entry->wired_count == 1)
2393 rv = vm_fault_wire(map, entry, FALSE);
2395 CLIP_CHECK_BACK(entry, save_start);
2397 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2398 entry->wired_count = 0;
2399 if (entry->end == save_end)
2401 entry = entry->next;
2402 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2407 CLIP_CHECK_FWD(entry, save_end);
2408 entry = entry->next;
2412 * If a failure occured undo everything by falling through
2413 * to the unwiring code. 'end' has already been adjusted
2417 kmflags |= KM_PAGEABLE;
2420 * start_entry is still IN_TRANSITION but may have been
2421 * clipped since vm_fault_wire() unlocks and relocks the
2422 * map. No matter how clipped it has gotten there should
2423 * be a fragment that is on our start boundary.
2425 CLIP_CHECK_BACK(start_entry, start);
2428 if (kmflags & KM_PAGEABLE) {
2430 * This is the unwiring case. We must first ensure that the
2431 * range to be unwired is really wired down. We know there
2434 entry = start_entry;
2435 while ((entry != &map->header) && (entry->start < end)) {
2436 if (entry->wired_count == 0) {
2437 rv = KERN_INVALID_ARGUMENT;
2440 entry = entry->next;
2444 * Now decrement the wiring count for each region. If a region
2445 * becomes completely unwired, unwire its physical pages and
2448 entry = start_entry;
2449 while ((entry != &map->header) && (entry->start < end)) {
2450 entry->wired_count--;
2451 if (entry->wired_count == 0)
2452 vm_fault_unwire(map, entry);
2453 entry = entry->next;
2457 vm_map_unclip_range(map, start_entry, start, real_end,
2458 &count, MAP_CLIP_NO_HOLES);
2462 if (kmflags & KM_KRESERVE)
2463 vm_map_entry_krelease(count);
2465 vm_map_entry_release(count);
2470 * Mark a newly allocated address range as wired but do not fault in
2471 * the pages. The caller is expected to load the pages into the object.
2473 * The map must be locked on entry and will remain locked on return.
2474 * No other requirements.
2477 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2480 vm_map_entry_t scan;
2481 vm_map_entry_t entry;
2483 entry = vm_map_clip_range(map, addr, addr + size,
2484 countp, MAP_CLIP_NO_HOLES);
2486 scan != &map->header && scan->start < addr + size;
2487 scan = scan->next) {
2488 KKASSERT(entry->wired_count == 0);
2489 entry->wired_count = 1;
2491 vm_map_unclip_range(map, entry, addr, addr + size,
2492 countp, MAP_CLIP_NO_HOLES);
2496 * Push any dirty cached pages in the address range to their pager.
2497 * If syncio is TRUE, dirty pages are written synchronously.
2498 * If invalidate is TRUE, any cached pages are freed as well.
2500 * This routine is called by sys_msync()
2502 * Returns an error if any part of the specified range is not mapped.
2507 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2508 boolean_t syncio, boolean_t invalidate)
2510 vm_map_entry_t current;
2511 vm_map_entry_t entry;
2515 vm_ooffset_t offset;
2517 vm_map_lock_read(map);
2518 VM_MAP_RANGE_CHECK(map, start, end);
2519 if (!vm_map_lookup_entry(map, start, &entry)) {
2520 vm_map_unlock_read(map);
2521 return (KERN_INVALID_ADDRESS);
2523 lwkt_gettoken(&map->token);
2526 * Make a first pass to check for holes.
2528 for (current = entry; current->start < end; current = current->next) {
2529 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2530 lwkt_reltoken(&map->token);
2531 vm_map_unlock_read(map);
2532 return (KERN_INVALID_ARGUMENT);
2534 if (end > current->end &&
2535 (current->next == &map->header ||
2536 current->end != current->next->start)) {
2537 lwkt_reltoken(&map->token);
2538 vm_map_unlock_read(map);
2539 return (KERN_INVALID_ADDRESS);
2544 pmap_remove(vm_map_pmap(map), start, end);
2547 * Make a second pass, cleaning/uncaching pages from the indicated
2550 for (current = entry; current->start < end; current = current->next) {
2551 offset = current->offset + (start - current->start);
2552 size = (end <= current->end ? end : current->end) - start;
2553 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2555 vm_map_entry_t tentry;
2558 smap = current->object.sub_map;
2559 vm_map_lock_read(smap);
2560 vm_map_lookup_entry(smap, offset, &tentry);
2561 tsize = tentry->end - offset;
2564 object = tentry->object.vm_object;
2565 offset = tentry->offset + (offset - tentry->start);
2566 vm_map_unlock_read(smap);
2568 object = current->object.vm_object;
2572 vm_object_hold(object);
2575 * Note that there is absolutely no sense in writing out
2576 * anonymous objects, so we track down the vnode object
2578 * We invalidate (remove) all pages from the address space
2579 * anyway, for semantic correctness.
2581 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2582 * may start out with a NULL object.
2584 while (object && (tobj = object->backing_object) != NULL) {
2585 vm_object_hold(tobj);
2586 if (tobj == object->backing_object) {
2587 vm_object_lock_swap();
2588 offset += object->backing_object_offset;
2589 vm_object_drop(object);
2591 if (object->size < OFF_TO_IDX(offset + size))
2592 size = IDX_TO_OFF(object->size) -
2596 vm_object_drop(tobj);
2598 if (object && (object->type == OBJT_VNODE) &&
2599 (current->protection & VM_PROT_WRITE) &&
2600 (object->flags & OBJ_NOMSYNC) == 0) {
2602 * Flush pages if writing is allowed, invalidate them
2603 * if invalidation requested. Pages undergoing I/O
2604 * will be ignored by vm_object_page_remove().
2606 * We cannot lock the vnode and then wait for paging
2607 * to complete without deadlocking against vm_fault.
2608 * Instead we simply call vm_object_page_remove() and
2609 * allow it to block internally on a page-by-page
2610 * basis when it encounters pages undergoing async
2615 /* no chain wait needed for vnode objects */
2616 vm_object_reference_locked(object);
2617 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2618 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2619 flags |= invalidate ? OBJPC_INVAL : 0;
2622 * When operating on a virtual page table just
2623 * flush the whole object. XXX we probably ought
2626 switch(current->maptype) {
2627 case VM_MAPTYPE_NORMAL:
2628 vm_object_page_clean(object,
2630 OFF_TO_IDX(offset + size + PAGE_MASK),
2633 case VM_MAPTYPE_VPAGETABLE:
2634 vm_object_page_clean(object, 0, 0, flags);
2637 vn_unlock(((struct vnode *)object->handle));
2638 vm_object_deallocate_locked(object);
2640 if (object && invalidate &&
2641 ((object->type == OBJT_VNODE) ||
2642 (object->type == OBJT_DEVICE))) {
2644 (object->type == OBJT_DEVICE) ? FALSE : TRUE;
2645 /* no chain wait needed for vnode/device objects */
2646 vm_object_reference_locked(object);
2647 switch(current->maptype) {
2648 case VM_MAPTYPE_NORMAL:
2649 vm_object_page_remove(object,
2651 OFF_TO_IDX(offset + size + PAGE_MASK),
2654 case VM_MAPTYPE_VPAGETABLE:
2655 vm_object_page_remove(object, 0, 0, clean_only);
2658 vm_object_deallocate_locked(object);
2662 vm_object_drop(object);
2665 lwkt_reltoken(&map->token);
2666 vm_map_unlock_read(map);
2668 return (KERN_SUCCESS);
2672 * Make the region specified by this entry pageable.
2674 * The vm_map must be exclusively locked.
2677 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2679 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2680 entry->wired_count = 0;
2681 vm_fault_unwire(map, entry);
2685 * Deallocate the given entry from the target map.
2687 * The vm_map must be exclusively locked.
2690 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2692 vm_map_entry_unlink(map, entry);
2693 map->size -= entry->end - entry->start;
2695 switch(entry->maptype) {
2696 case VM_MAPTYPE_NORMAL:
2697 case VM_MAPTYPE_VPAGETABLE:
2698 vm_object_deallocate(entry->object.vm_object);
2704 vm_map_entry_dispose(map, entry, countp);
2708 * Deallocates the given address range from the target map.
2710 * The vm_map must be exclusively locked.
2713 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2716 vm_map_entry_t entry;
2717 vm_map_entry_t first_entry;
2719 ASSERT_VM_MAP_LOCKED(map);
2720 lwkt_gettoken(&map->token);
2723 * Find the start of the region, and clip it. Set entry to point
2724 * at the first record containing the requested address or, if no
2725 * such record exists, the next record with a greater address. The
2726 * loop will run from this point until a record beyond the termination
2727 * address is encountered.
2729 * map->hint must be adjusted to not point to anything we delete,
2730 * so set it to the entry prior to the one being deleted.
2732 * GGG see other GGG comment.
2734 if (vm_map_lookup_entry(map, start, &first_entry)) {
2735 entry = first_entry;
2736 vm_map_clip_start(map, entry, start, countp);
2737 map->hint = entry->prev; /* possible problem XXX */
2739 map->hint = first_entry; /* possible problem XXX */
2740 entry = first_entry->next;
2744 * If a hole opens up prior to the current first_free then
2745 * adjust first_free. As with map->hint, map->first_free
2746 * cannot be left set to anything we might delete.
2748 if (entry == &map->header) {
2749 map->first_free = &map->header;
2750 } else if (map->first_free->start >= start) {
2751 map->first_free = entry->prev;
2755 * Step through all entries in this region
2757 while ((entry != &map->header) && (entry->start < end)) {
2758 vm_map_entry_t next;
2760 vm_pindex_t offidxstart, offidxend, count;
2763 * If we hit an in-transition entry we have to sleep and
2764 * retry. It's easier (and not really slower) to just retry
2765 * since this case occurs so rarely and the hint is already
2766 * pointing at the right place. We have to reset the
2767 * start offset so as not to accidently delete an entry
2768 * another process just created in vacated space.
2770 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2771 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2772 start = entry->start;
2773 ++mycpu->gd_cnt.v_intrans_coll;
2774 ++mycpu->gd_cnt.v_intrans_wait;
2775 vm_map_transition_wait(map);
2778 vm_map_clip_end(map, entry, end, countp);
2784 offidxstart = OFF_TO_IDX(entry->offset);
2785 count = OFF_TO_IDX(e - s);
2786 object = entry->object.vm_object;
2789 * Unwire before removing addresses from the pmap; otherwise,
2790 * unwiring will put the entries back in the pmap.
2792 if (entry->wired_count != 0)
2793 vm_map_entry_unwire(map, entry);
2795 offidxend = offidxstart + count;
2797 if (object == &kernel_object) {
2798 vm_object_hold(object);
2799 vm_object_page_remove(object, offidxstart,
2801 vm_object_drop(object);
2802 } else if (object && object->type != OBJT_DEFAULT &&
2803 object->type != OBJT_SWAP) {
2805 * vnode object routines cannot be chain-locked
2807 vm_object_hold(object);
2808 pmap_remove(map->pmap, s, e);
2809 vm_object_drop(object);
2810 } else if (object) {
2811 vm_object_hold(object);
2812 vm_object_chain_acquire(object);
2813 pmap_remove(map->pmap, s, e);
2815 if (object != NULL &&
2816 object->ref_count != 1 &&
2817 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2819 (object->type == OBJT_DEFAULT ||
2820 object->type == OBJT_SWAP)) {
2821 vm_object_collapse(object, NULL);
2822 vm_object_page_remove(object, offidxstart,
2824 if (object->type == OBJT_SWAP) {
2825 swap_pager_freespace(object,
2829 if (offidxend >= object->size &&
2830 offidxstart < object->size) {
2831 object->size = offidxstart;
2834 vm_object_chain_release(object);
2835 vm_object_drop(object);
2839 * Delete the entry (which may delete the object) only after
2840 * removing all pmap entries pointing to its pages.
2841 * (Otherwise, its page frames may be reallocated, and any
2842 * modify bits will be set in the wrong object!)
2844 vm_map_entry_delete(map, entry, countp);
2847 lwkt_reltoken(&map->token);
2848 return (KERN_SUCCESS);
2852 * Remove the given address range from the target map.
2853 * This is the exported form of vm_map_delete.
2858 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
2863 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2865 VM_MAP_RANGE_CHECK(map, start, end);
2866 result = vm_map_delete(map, start, end, &count);
2868 vm_map_entry_release(count);
2874 * Assert that the target map allows the specified privilege on the
2875 * entire address region given. The entire region must be allocated.
2877 * The caller must specify whether the vm_map is already locked or not.
2880 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2881 vm_prot_t protection, boolean_t have_lock)
2883 vm_map_entry_t entry;
2884 vm_map_entry_t tmp_entry;
2887 if (have_lock == FALSE)
2888 vm_map_lock_read(map);
2890 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
2891 if (have_lock == FALSE)
2892 vm_map_unlock_read(map);
2898 while (start < end) {
2899 if (entry == &map->header) {
2907 if (start < entry->start) {
2912 * Check protection associated with entry.
2915 if ((entry->protection & protection) != protection) {
2919 /* go to next entry */
2922 entry = entry->next;
2924 if (have_lock == FALSE)
2925 vm_map_unlock_read(map);
2930 * If appropriate this function shadows the original object with a new object
2931 * and moves the VM pages from the original object to the new object.
2932 * The original object will also be collapsed, if possible.
2934 * We can only do this for normal memory objects with a single mapping, and
2935 * it only makes sense to do it if there are 2 or more refs on the original
2936 * object. i.e. typically a memory object that has been extended into
2937 * multiple vm_map_entry's with non-overlapping ranges.
2939 * This makes it easier to remove unused pages and keeps object inheritance
2940 * from being a negative impact on memory usage.
2942 * On return the (possibly new) entry->object.vm_object will have an
2943 * additional ref on it for the caller to dispose of (usually by cloning
2944 * the vm_map_entry). The additional ref had to be done in this routine
2945 * to avoid racing a collapse. The object's ONEMAPPING flag will also be
2948 * The vm_map must be locked and its token held.
2951 vm_map_split(vm_map_entry_t entry)
2955 vm_object_t oobject;
2957 oobject = entry->object.vm_object;
2958 vm_object_hold(oobject);
2959 vm_object_chain_wait(oobject);
2960 vm_object_reference_locked(oobject);
2961 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
2962 vm_object_drop(oobject);
2965 vm_object_t oobject, nobject, bobject;
2968 vm_pindex_t offidxstart, offidxend, idx;
2970 vm_ooffset_t offset;
2973 * Setup. Chain lock the original object throughout the entire
2974 * routine to prevent new page faults from occuring.
2976 * XXX can madvise WILLNEED interfere with us too?
2978 oobject = entry->object.vm_object;
2979 vm_object_hold(oobject);
2980 vm_object_chain_acquire(oobject);
2983 * Original object cannot be split?
2985 if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT &&
2986 oobject->type != OBJT_SWAP)) {
2987 vm_object_chain_release(oobject);
2988 vm_object_reference_locked(oobject);
2989 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
2990 vm_object_drop(oobject);
2995 * Collapse original object with its backing store as an
2996 * optimization to reduce chain lengths when possible.
2998 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's
2999 * for oobject, so there's no point collapsing it.
3001 * Then re-check whether the object can be split.
3003 vm_object_collapse(oobject, NULL);
3005 if (oobject->ref_count <= 1 ||
3006 (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) ||
3007 (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) {
3008 vm_object_chain_release(oobject);
3009 vm_object_reference_locked(oobject);
3010 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3011 vm_object_drop(oobject);
3016 * Acquire the chain lock on the backing object.
3018 * Give bobject an additional ref count for when it will be shadowed
3021 if ((bobject = oobject->backing_object) != NULL) {
3022 vm_object_hold(bobject);
3023 vm_object_chain_wait(bobject);
3024 vm_object_reference_locked(bobject);
3025 vm_object_chain_acquire(bobject);
3026 KKASSERT(bobject->backing_object == bobject);
3027 KKASSERT((bobject->flags & OBJ_DEAD) == 0);
3031 * Calculate the object page range and allocate the new object.
3033 offset = entry->offset;
3037 offidxstart = OFF_TO_IDX(offset);
3038 offidxend = offidxstart + OFF_TO_IDX(e - s);
3039 size = offidxend - offidxstart;
3041 switch(oobject->type) {
3043 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size),
3047 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size),
3056 if (nobject == NULL) {
3058 vm_object_chain_release(bobject);
3059 vm_object_deallocate(bobject);
3060 vm_object_drop(bobject);
3062 vm_object_chain_release(oobject);
3063 vm_object_reference_locked(oobject);
3064 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3065 vm_object_drop(oobject);
3070 * The new object will replace entry->object.vm_object so it needs
3071 * a second reference (the caller expects an additional ref).
3073 vm_object_hold(nobject);
3074 vm_object_reference_locked(nobject);
3075 vm_object_chain_acquire(nobject);
3078 * nobject shadows bobject (oobject already shadows bobject).
3081 nobject->backing_object_offset =
3082 oobject->backing_object_offset + IDX_TO_OFF(offidxstart);
3083 nobject->backing_object = bobject;
3084 bobject->shadow_count++;
3085 bobject->generation++;
3086 LIST_INSERT_HEAD(&bobject->shadow_head, nobject, shadow_list);
3087 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /* XXX? */
3088 vm_object_chain_release(bobject);
3089 vm_object_drop(bobject);
3093 * Move the VM pages from oobject to nobject
3095 for (idx = 0; idx < size; idx++) {
3098 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx,
3104 * We must wait for pending I/O to complete before we can
3107 * We do not have to VM_PROT_NONE the page as mappings should
3108 * not be changed by this operation.
3110 * NOTE: The act of renaming a page updates chaingen for both
3113 vm_page_rename(m, nobject, idx);
3114 /* page automatically made dirty by rename and cache handled */
3115 /* page remains busy */
3118 if (oobject->type == OBJT_SWAP) {
3119 vm_object_pip_add(oobject, 1);
3121 * copy oobject pages into nobject and destroy unneeded
3122 * pages in shadow object.
3124 swap_pager_copy(oobject, nobject, offidxstart, 0);
3125 vm_object_pip_wakeup(oobject);
3129 * Wakeup the pages we played with. No spl protection is needed
3130 * for a simple wakeup.
3132 for (idx = 0; idx < size; idx++) {
3133 m = vm_page_lookup(nobject, idx);
3135 KKASSERT(m->flags & PG_BUSY);
3139 entry->object.vm_object = nobject;
3140 entry->offset = 0LL;
3145 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the
3146 * related pages were moved and are no longer applicable to the
3149 * NOTE: Deallocate oobject (due to its entry->object.vm_object being
3150 * replaced by nobject).
3152 vm_object_chain_release(nobject);
3153 vm_object_drop(nobject);
3155 vm_object_chain_release(bobject);
3156 vm_object_drop(bobject);
3158 vm_object_chain_release(oobject);
3159 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/
3160 vm_object_deallocate_locked(oobject);
3161 vm_object_drop(oobject);
3166 * Copies the contents of the source entry to the destination
3167 * entry. The entries *must* be aligned properly.
3169 * The vm_maps must be exclusively locked.
3170 * The vm_map's token must be held.
3172 * Because the maps are locked no faults can be in progress during the
3176 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
3177 vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
3179 vm_object_t src_object;
3181 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP)
3183 if (src_entry->maptype == VM_MAPTYPE_SUBMAP)
3186 if (src_entry->wired_count == 0) {
3188 * If the source entry is marked needs_copy, it is already
3191 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
3192 pmap_protect(src_map->pmap,
3195 src_entry->protection & ~VM_PROT_WRITE);
3199 * Make a copy of the object.
3201 * The object must be locked prior to checking the object type
3202 * and for the call to vm_object_collapse() and vm_map_split().
3203 * We cannot use *_hold() here because the split code will
3204 * probably try to destroy the object. The lock is a pool
3205 * token and doesn't care.
3207 * We must bump src_map->timestamp when setting
3208 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault
3209 * to retry, otherwise the concurrent fault might improperly
3210 * install a RW pte when its supposed to be a RO(COW) pte.
3211 * This race can occur because a vnode-backed fault may have
3212 * to temporarily release the map lock.
3214 if (src_entry->object.vm_object != NULL) {
3215 vm_map_split(src_entry);
3216 src_object = src_entry->object.vm_object;
3217 dst_entry->object.vm_object = src_object;
3218 src_entry->eflags |= (MAP_ENTRY_COW |
3219 MAP_ENTRY_NEEDS_COPY);
3220 dst_entry->eflags |= (MAP_ENTRY_COW |
3221 MAP_ENTRY_NEEDS_COPY);
3222 dst_entry->offset = src_entry->offset;
3223 ++src_map->timestamp;
3225 dst_entry->object.vm_object = NULL;
3226 dst_entry->offset = 0;
3229 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3230 dst_entry->end - dst_entry->start, src_entry->start);
3233 * Of course, wired down pages can't be set copy-on-write.
3234 * Cause wired pages to be copied into the new map by
3235 * simulating faults (the new pages are pageable)
3237 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3243 * Create a new process vmspace structure and vm_map
3244 * based on those of an existing process. The new map
3245 * is based on the old map, according to the inheritance
3246 * values on the regions in that map.
3248 * The source map must not be locked.
3252 vmspace_fork(struct vmspace *vm1)
3254 struct vmspace *vm2;
3255 vm_map_t old_map = &vm1->vm_map;
3257 vm_map_entry_t old_entry;
3258 vm_map_entry_t new_entry;
3262 lwkt_gettoken(&vm1->vm_map.token);
3263 vm_map_lock(old_map);
3266 * XXX Note: upcalls are not copied.
3268 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3269 lwkt_gettoken(&vm2->vm_map.token);
3270 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3271 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3272 new_map = &vm2->vm_map; /* XXX */
3273 new_map->timestamp = 1;
3275 vm_map_lock(new_map);
3278 old_entry = old_map->header.next;
3279 while (old_entry != &old_map->header) {
3281 old_entry = old_entry->next;
3284 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3286 old_entry = old_map->header.next;
3287 while (old_entry != &old_map->header) {
3288 if (old_entry->maptype == VM_MAPTYPE_SUBMAP)
3289 panic("vm_map_fork: encountered a submap");
3291 switch (old_entry->inheritance) {
3292 case VM_INHERIT_NONE:
3294 case VM_INHERIT_SHARE:
3296 * Clone the entry, creating the shared object if
3299 if (old_entry->object.vm_object == NULL)
3300 vm_map_entry_allocate_object(old_entry);
3302 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3304 * Shadow a map_entry which needs a copy,
3305 * replacing its object with a new object
3306 * that points to the old one. Ask the
3307 * shadow code to automatically add an
3308 * additional ref. We can't do it afterwords
3309 * because we might race a collapse. The call
3310 * to vm_map_entry_shadow() will also clear
3313 vm_map_entry_shadow(old_entry, 1);
3316 * We will make a shared copy of the object,
3317 * and must clear OBJ_ONEMAPPING.
3319 * XXX assert that object.vm_object != NULL
3320 * since we allocate it above.
3322 if (old_entry->object.vm_object) {
3323 object = old_entry->object.vm_object;
3324 vm_object_hold(object);
3325 vm_object_chain_wait(object);
3326 vm_object_reference_locked(object);
3327 vm_object_clear_flag(object,
3329 vm_object_drop(object);
3334 * Clone the entry. We've already bumped the ref on
3337 new_entry = vm_map_entry_create(new_map, &count);
3338 *new_entry = *old_entry;
3339 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3340 new_entry->wired_count = 0;
3343 * Insert the entry into the new map -- we know we're
3344 * inserting at the end of the new map.
3347 vm_map_entry_link(new_map, new_map->header.prev,
3351 * Update the physical map
3353 pmap_copy(new_map->pmap, old_map->pmap,
3355 (old_entry->end - old_entry->start),
3358 case VM_INHERIT_COPY:
3360 * Clone the entry and link into the map.
3362 new_entry = vm_map_entry_create(new_map, &count);
3363 *new_entry = *old_entry;
3364 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3365 new_entry->wired_count = 0;
3366 new_entry->object.vm_object = NULL;
3367 vm_map_entry_link(new_map, new_map->header.prev,
3369 vm_map_copy_entry(old_map, new_map, old_entry,
3373 old_entry = old_entry->next;
3376 new_map->size = old_map->size;
3377 vm_map_unlock(old_map);
3378 vm_map_unlock(new_map);
3379 vm_map_entry_release(count);
3381 lwkt_reltoken(&vm2->vm_map.token);
3382 lwkt_reltoken(&vm1->vm_map.token);
3388 * Create an auto-grow stack entry
3393 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3394 int flags, vm_prot_t prot, vm_prot_t max, int cow)
3396 vm_map_entry_t prev_entry;
3397 vm_map_entry_t new_stack_entry;
3398 vm_size_t init_ssize;
3401 vm_offset_t tmpaddr;
3403 cow |= MAP_IS_STACK;
3405 if (max_ssize < sgrowsiz)
3406 init_ssize = max_ssize;
3408 init_ssize = sgrowsiz;
3410 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3414 * Find space for the mapping
3416 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3417 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3420 vm_map_entry_release(count);
3421 return (KERN_NO_SPACE);
3426 /* If addr is already mapped, no go */
3427 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3429 vm_map_entry_release(count);
3430 return (KERN_NO_SPACE);
3434 /* XXX already handled by kern_mmap() */
3435 /* If we would blow our VMEM resource limit, no go */
3436 if (map->size + init_ssize >
3437 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3439 vm_map_entry_release(count);
3440 return (KERN_NO_SPACE);
3445 * If we can't accomodate max_ssize in the current mapping,
3446 * no go. However, we need to be aware that subsequent user
3447 * mappings might map into the space we have reserved for
3448 * stack, and currently this space is not protected.
3450 * Hopefully we will at least detect this condition
3451 * when we try to grow the stack.
3453 if ((prev_entry->next != &map->header) &&
3454 (prev_entry->next->start < addrbos + max_ssize)) {
3456 vm_map_entry_release(count);
3457 return (KERN_NO_SPACE);
3461 * We initially map a stack of only init_ssize. We will
3462 * grow as needed later. Since this is to be a grow
3463 * down stack, we map at the top of the range.
3465 * Note: we would normally expect prot and max to be
3466 * VM_PROT_ALL, and cow to be 0. Possibly we should
3467 * eliminate these as input parameters, and just
3468 * pass these values here in the insert call.
3470 rv = vm_map_insert(map, &count,
3471 NULL, 0, addrbos + max_ssize - init_ssize,
3472 addrbos + max_ssize,
3477 /* Now set the avail_ssize amount */
3478 if (rv == KERN_SUCCESS) {
3479 if (prev_entry != &map->header)
3480 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3481 new_stack_entry = prev_entry->next;
3482 if (new_stack_entry->end != addrbos + max_ssize ||
3483 new_stack_entry->start != addrbos + max_ssize - init_ssize)
3484 panic ("Bad entry start/end for new stack entry");
3486 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3490 vm_map_entry_release(count);
3495 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3496 * desired address is already mapped, or if we successfully grow
3497 * the stack. Also returns KERN_SUCCESS if addr is outside the
3498 * stack range (this is strange, but preserves compatibility with
3499 * the grow function in vm_machdep.c).
3504 vm_map_growstack (struct proc *p, vm_offset_t addr)
3506 vm_map_entry_t prev_entry;
3507 vm_map_entry_t stack_entry;
3508 vm_map_entry_t new_stack_entry;
3509 struct vmspace *vm = p->p_vmspace;
3510 vm_map_t map = &vm->vm_map;
3513 int rv = KERN_SUCCESS;
3515 int use_read_lock = 1;
3518 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3521 vm_map_lock_read(map);
3525 /* If addr is already in the entry range, no need to grow.*/
3526 if (vm_map_lookup_entry(map, addr, &prev_entry))
3529 if ((stack_entry = prev_entry->next) == &map->header)
3531 if (prev_entry == &map->header)
3532 end = stack_entry->start - stack_entry->aux.avail_ssize;
3534 end = prev_entry->end;
3537 * This next test mimics the old grow function in vm_machdep.c.
3538 * It really doesn't quite make sense, but we do it anyway
3539 * for compatibility.
3541 * If not growable stack, return success. This signals the
3542 * caller to proceed as he would normally with normal vm.
3544 if (stack_entry->aux.avail_ssize < 1 ||
3545 addr >= stack_entry->start ||
3546 addr < stack_entry->start - stack_entry->aux.avail_ssize) {
3550 /* Find the minimum grow amount */
3551 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3552 if (grow_amount > stack_entry->aux.avail_ssize) {
3558 * If there is no longer enough space between the entries
3559 * nogo, and adjust the available space. Note: this
3560 * should only happen if the user has mapped into the
3561 * stack area after the stack was created, and is
3562 * probably an error.
3564 * This also effectively destroys any guard page the user
3565 * might have intended by limiting the stack size.
3567 if (grow_amount > stack_entry->start - end) {
3568 if (use_read_lock && vm_map_lock_upgrade(map)) {
3574 stack_entry->aux.avail_ssize = stack_entry->start - end;
3579 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3581 /* If this is the main process stack, see if we're over the
3584 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3585 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3590 /* Round up the grow amount modulo SGROWSIZ */
3591 grow_amount = roundup (grow_amount, sgrowsiz);
3592 if (grow_amount > stack_entry->aux.avail_ssize) {
3593 grow_amount = stack_entry->aux.avail_ssize;
3595 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3596 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3597 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3601 /* If we would blow our VMEM resource limit, no go */
3602 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3607 if (use_read_lock && vm_map_lock_upgrade(map)) {
3614 /* Get the preliminary new entry start value */
3615 addr = stack_entry->start - grow_amount;
3617 /* If this puts us into the previous entry, cut back our growth
3618 * to the available space. Also, see the note above.
3621 stack_entry->aux.avail_ssize = stack_entry->start - end;
3625 rv = vm_map_insert(map, &count,
3626 NULL, 0, addr, stack_entry->start,
3628 VM_PROT_ALL, VM_PROT_ALL,
3631 /* Adjust the available stack space by the amount we grew. */
3632 if (rv == KERN_SUCCESS) {
3633 if (prev_entry != &map->header)
3634 vm_map_clip_end(map, prev_entry, addr, &count);
3635 new_stack_entry = prev_entry->next;
3636 if (new_stack_entry->end != stack_entry->start ||
3637 new_stack_entry->start != addr)
3638 panic ("Bad stack grow start/end in new stack entry");
3640 new_stack_entry->aux.avail_ssize =
3641 stack_entry->aux.avail_ssize -
3642 (new_stack_entry->end - new_stack_entry->start);
3644 vm->vm_ssize += btoc(new_stack_entry->end -
3645 new_stack_entry->start);
3648 if (map->flags & MAP_WIREFUTURE)
3649 vm_map_unwire(map, new_stack_entry->start,
3650 new_stack_entry->end, FALSE);
3655 vm_map_unlock_read(map);
3658 vm_map_entry_release(count);
3663 * Unshare the specified VM space for exec. If other processes are
3664 * mapped to it, then create a new one. The new vmspace is null.
3669 vmspace_exec(struct proc *p, struct vmspace *vmcopy)
3671 struct vmspace *oldvmspace = p->p_vmspace;
3672 struct vmspace *newvmspace;
3673 vm_map_t map = &p->p_vmspace->vm_map;
3676 * If we are execing a resident vmspace we fork it, otherwise
3677 * we create a new vmspace. Note that exitingcnt and upcalls
3678 * are not copied to the new vmspace.
3680 lwkt_gettoken(&oldvmspace->vm_map.token);
3682 newvmspace = vmspace_fork(vmcopy);
3683 lwkt_gettoken(&newvmspace->vm_map.token);
3685 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3686 lwkt_gettoken(&newvmspace->vm_map.token);
3687 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3688 (caddr_t)&oldvmspace->vm_endcopy -
3689 (caddr_t)&oldvmspace->vm_startcopy);
3693 * Finish initializing the vmspace before assigning it
3694 * to the process. The vmspace will become the current vmspace
3697 pmap_pinit2(vmspace_pmap(newvmspace));
3698 pmap_replacevm(p, newvmspace, 0);
3699 lwkt_reltoken(&newvmspace->vm_map.token);
3700 lwkt_reltoken(&oldvmspace->vm_map.token);
3701 vmspace_free(oldvmspace);
3705 * Unshare the specified VM space for forcing COW. This
3706 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3709 vmspace_unshare(struct proc *p)
3711 struct vmspace *oldvmspace = p->p_vmspace;
3712 struct vmspace *newvmspace;
3714 lwkt_gettoken(&oldvmspace->vm_map.token);
3715 if (oldvmspace->vm_sysref.refcnt == 1) {
3716 lwkt_reltoken(&oldvmspace->vm_map.token);
3719 newvmspace = vmspace_fork(oldvmspace);
3720 lwkt_gettoken(&newvmspace->vm_map.token);
3721 pmap_pinit2(vmspace_pmap(newvmspace));
3722 pmap_replacevm(p, newvmspace, 0);
3723 lwkt_reltoken(&newvmspace->vm_map.token);
3724 lwkt_reltoken(&oldvmspace->vm_map.token);
3725 vmspace_free(oldvmspace);
3729 * vm_map_hint: return the beginning of the best area suitable for
3730 * creating a new mapping with "prot" protection.
3735 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot)
3737 struct vmspace *vms = p->p_vmspace;
3739 if (!randomize_mmap) {
3741 * Set a reasonable start point for the hint if it was
3742 * not specified or if it falls within the heap space.
3743 * Hinted mmap()s do not allocate out of the heap space.
3746 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
3747 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) {
3748 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
3754 if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr)
3760 * If executable skip first two pages, otherwise start
3761 * after data + heap region.
3763 if ((prot & VM_PROT_EXECUTE) &&
3764 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) {
3765 addr = (PAGE_SIZE * 2) +
3766 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1));
3767 return (round_page(addr));
3769 #endif /* __i386__ */
3772 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ;
3773 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1);
3775 return (round_page(addr));
3779 * Finds the VM object, offset, and protection for a given virtual address
3780 * in the specified map, assuming a page fault of the type specified.
3782 * Leaves the map in question locked for read; return values are guaranteed
3783 * until a vm_map_lookup_done call is performed. Note that the map argument
3784 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3786 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3789 * If a lookup is requested with "write protection" specified, the map may
3790 * be changed to perform virtual copying operations, although the data
3791 * referenced will remain the same.
3796 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
3798 vm_prot_t fault_typea,
3799 vm_map_entry_t *out_entry, /* OUT */
3800 vm_object_t *object, /* OUT */
3801 vm_pindex_t *pindex, /* OUT */
3802 vm_prot_t *out_prot, /* OUT */
3803 boolean_t *wired) /* OUT */
3805 vm_map_entry_t entry;
3806 vm_map_t map = *var_map;
3808 vm_prot_t fault_type = fault_typea;
3809 int use_read_lock = 1;
3810 int rv = KERN_SUCCESS;
3814 vm_map_lock_read(map);
3819 * If the map has an interesting hint, try it before calling full
3820 * blown lookup routine.
3827 if ((entry == &map->header) ||
3828 (vaddr < entry->start) || (vaddr >= entry->end)) {
3829 vm_map_entry_t tmp_entry;
3832 * Entry was either not a valid hint, or the vaddr was not
3833 * contained in the entry, so do a full lookup.
3835 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
3836 rv = KERN_INVALID_ADDRESS;
3847 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3848 vm_map_t old_map = map;
3850 *var_map = map = entry->object.sub_map;
3852 vm_map_unlock_read(old_map);
3854 vm_map_unlock(old_map);
3860 * Check whether this task is allowed to have this page.
3861 * Note the special case for MAP_ENTRY_COW
3862 * pages with an override. This is to implement a forced
3863 * COW for debuggers.
3866 if (fault_type & VM_PROT_OVERRIDE_WRITE)
3867 prot = entry->max_protection;
3869 prot = entry->protection;
3871 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
3872 if ((fault_type & prot) != fault_type) {
3873 rv = KERN_PROTECTION_FAILURE;
3877 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
3878 (entry->eflags & MAP_ENTRY_COW) &&
3879 (fault_type & VM_PROT_WRITE) &&
3880 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
3881 rv = KERN_PROTECTION_FAILURE;
3886 * If this page is not pageable, we have to get it for all possible
3889 *wired = (entry->wired_count != 0);
3891 prot = fault_type = entry->protection;
3894 * Virtual page tables may need to update the accessed (A) bit
3895 * in a page table entry. Upgrade the fault to a write fault for
3896 * that case if the map will support it. If the map does not support
3897 * it the page table entry simply will not be updated.
3899 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
3900 if (prot & VM_PROT_WRITE)
3901 fault_type |= VM_PROT_WRITE;
3905 * If the entry was copy-on-write, we either ...
3907 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3909 * If we want to write the page, we may as well handle that
3910 * now since we've got the map locked.
3912 * If we don't need to write the page, we just demote the
3913 * permissions allowed.
3916 if (fault_type & VM_PROT_WRITE) {
3918 * Make a new object, and place it in the object
3919 * chain. Note that no new references have appeared
3920 * -- one just moved from the map to the new
3924 if (use_read_lock && vm_map_lock_upgrade(map)) {
3931 vm_map_entry_shadow(entry, 0);
3934 * We're attempting to read a copy-on-write page --
3935 * don't allow writes.
3938 prot &= ~VM_PROT_WRITE;
3943 * Create an object if necessary.
3945 if (entry->object.vm_object == NULL && !map->system_map) {
3946 if (use_read_lock && vm_map_lock_upgrade(map)) {
3952 vm_map_entry_allocate_object(entry);
3956 * Return the object/offset from this entry. If the entry was
3957 * copy-on-write or empty, it has been fixed up.
3960 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
3961 *object = entry->object.vm_object;
3964 * Return whether this is the only map sharing this data. On
3965 * success we return with a read lock held on the map. On failure
3966 * we return with the map unlocked.
3970 if (rv == KERN_SUCCESS) {
3971 if (use_read_lock == 0)
3972 vm_map_lock_downgrade(map);
3973 } else if (use_read_lock) {
3974 vm_map_unlock_read(map);
3982 * Releases locks acquired by a vm_map_lookup()
3983 * (according to the handle returned by that lookup).
3985 * No other requirements.
3988 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
3991 * Unlock the main-level map
3993 vm_map_unlock_read(map);
3995 vm_map_entry_release(count);
3998 #include "opt_ddb.h"
4000 #include <sys/kernel.h>
4002 #include <ddb/ddb.h>
4007 DB_SHOW_COMMAND(map, vm_map_print)
4010 /* XXX convert args. */
4011 vm_map_t map = (vm_map_t)addr;
4012 boolean_t full = have_addr;
4014 vm_map_entry_t entry;
4016 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4018 (void *)map->pmap, map->nentries, map->timestamp);
4021 if (!full && db_indent)
4025 for (entry = map->header.next; entry != &map->header;
4026 entry = entry->next) {
4027 db_iprintf("map entry %p: start=%p, end=%p\n",
4028 (void *)entry, (void *)entry->start, (void *)entry->end);
4031 static char *inheritance_name[4] =
4032 {"share", "copy", "none", "donate_copy"};
4034 db_iprintf(" prot=%x/%x/%s",
4036 entry->max_protection,
4037 inheritance_name[(int)(unsigned char)entry->inheritance]);
4038 if (entry->wired_count != 0)
4039 db_printf(", wired");
4041 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
4042 /* XXX no %qd in kernel. Truncate entry->offset. */
4043 db_printf(", share=%p, offset=0x%lx\n",
4044 (void *)entry->object.sub_map,
4045 (long)entry->offset);
4047 if ((entry->prev == &map->header) ||
4048 (entry->prev->object.sub_map !=
4049 entry->object.sub_map)) {
4051 vm_map_print((db_expr_t)(intptr_t)
4052 entry->object.sub_map,
4057 /* XXX no %qd in kernel. Truncate entry->offset. */
4058 db_printf(", object=%p, offset=0x%lx",
4059 (void *)entry->object.vm_object,
4060 (long)entry->offset);
4061 if (entry->eflags & MAP_ENTRY_COW)
4062 db_printf(", copy (%s)",
4063 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
4067 if ((entry->prev == &map->header) ||
4068 (entry->prev->object.vm_object !=
4069 entry->object.vm_object)) {
4071 vm_object_print((db_expr_t)(intptr_t)
4072 entry->object.vm_object,
4087 DB_SHOW_COMMAND(procvm, procvm)
4092 p = (struct proc *) addr;
4097 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
4098 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
4099 (void *)vmspace_pmap(p->p_vmspace));
4101 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);