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_object_drop(object);
1271 vm_map_entry_release(count);
1272 return (KERN_NO_SPACE);
1276 result = vm_map_insert(map, &count, object, offset,
1277 start, start + length,
1282 vm_object_drop(object);
1284 vm_map_entry_release(count);
1290 * Simplify the given map entry by merging with either neighbor. This
1291 * routine also has the ability to merge with both neighbors.
1293 * This routine guarentees that the passed entry remains valid (though
1294 * possibly extended). When merging, this routine may delete one or
1295 * both neighbors. No action is taken on entries which have their
1296 * in-transition flag set.
1298 * The map must be exclusively locked.
1301 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1303 vm_map_entry_t next, prev;
1304 vm_size_t prevsize, esize;
1306 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1307 ++mycpu->gd_cnt.v_intrans_coll;
1311 if (entry->maptype == VM_MAPTYPE_SUBMAP)
1315 if (prev != &map->header) {
1316 prevsize = prev->end - prev->start;
1317 if ( (prev->end == entry->start) &&
1318 (prev->maptype == entry->maptype) &&
1319 (prev->object.vm_object == entry->object.vm_object) &&
1320 (!prev->object.vm_object ||
1321 (prev->offset + prevsize == entry->offset)) &&
1322 (prev->eflags == entry->eflags) &&
1323 (prev->protection == entry->protection) &&
1324 (prev->max_protection == entry->max_protection) &&
1325 (prev->inheritance == entry->inheritance) &&
1326 (prev->wired_count == entry->wired_count)) {
1327 if (map->first_free == prev)
1328 map->first_free = entry;
1329 if (map->hint == prev)
1331 vm_map_entry_unlink(map, prev);
1332 entry->start = prev->start;
1333 entry->offset = prev->offset;
1334 if (prev->object.vm_object)
1335 vm_object_deallocate(prev->object.vm_object);
1336 vm_map_entry_dispose(map, prev, countp);
1341 if (next != &map->header) {
1342 esize = entry->end - entry->start;
1343 if ((entry->end == next->start) &&
1344 (next->maptype == entry->maptype) &&
1345 (next->object.vm_object == entry->object.vm_object) &&
1346 (!entry->object.vm_object ||
1347 (entry->offset + esize == next->offset)) &&
1348 (next->eflags == entry->eflags) &&
1349 (next->protection == entry->protection) &&
1350 (next->max_protection == entry->max_protection) &&
1351 (next->inheritance == entry->inheritance) &&
1352 (next->wired_count == entry->wired_count)) {
1353 if (map->first_free == next)
1354 map->first_free = entry;
1355 if (map->hint == next)
1357 vm_map_entry_unlink(map, next);
1358 entry->end = next->end;
1359 if (next->object.vm_object)
1360 vm_object_deallocate(next->object.vm_object);
1361 vm_map_entry_dispose(map, next, countp);
1367 * Asserts that the given entry begins at or after the specified address.
1368 * If necessary, it splits the entry into two.
1370 #define vm_map_clip_start(map, entry, startaddr, countp) \
1372 if (startaddr > entry->start) \
1373 _vm_map_clip_start(map, entry, startaddr, countp); \
1377 * This routine is called only when it is known that the entry must be split.
1379 * The map must be exclusively locked.
1382 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1385 vm_map_entry_t new_entry;
1388 * Split off the front portion -- note that we must insert the new
1389 * entry BEFORE this one, so that this entry has the specified
1393 vm_map_simplify_entry(map, entry, countp);
1396 * If there is no object backing this entry, we might as well create
1397 * one now. If we defer it, an object can get created after the map
1398 * is clipped, and individual objects will be created for the split-up
1399 * map. This is a bit of a hack, but is also about the best place to
1400 * put this improvement.
1402 if (entry->object.vm_object == NULL && !map->system_map) {
1403 vm_map_entry_allocate_object(entry);
1406 new_entry = vm_map_entry_create(map, countp);
1407 *new_entry = *entry;
1409 new_entry->end = start;
1410 entry->offset += (start - entry->start);
1411 entry->start = start;
1413 vm_map_entry_link(map, entry->prev, new_entry);
1415 switch(entry->maptype) {
1416 case VM_MAPTYPE_NORMAL:
1417 case VM_MAPTYPE_VPAGETABLE:
1418 if (new_entry->object.vm_object) {
1419 vm_object_hold(new_entry->object.vm_object);
1420 vm_object_chain_wait(new_entry->object.vm_object);
1421 vm_object_reference_locked(new_entry->object.vm_object);
1422 vm_object_drop(new_entry->object.vm_object);
1431 * Asserts that the given entry ends at or before the specified address.
1432 * If necessary, it splits the entry into two.
1434 * The map must be exclusively locked.
1436 #define vm_map_clip_end(map, entry, endaddr, countp) \
1438 if (endaddr < entry->end) \
1439 _vm_map_clip_end(map, entry, endaddr, countp); \
1443 * This routine is called only when it is known that the entry must be split.
1445 * The map must be exclusively locked.
1448 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1451 vm_map_entry_t new_entry;
1454 * If there is no object backing this entry, we might as well create
1455 * one now. If we defer it, an object can get created after the map
1456 * is clipped, and individual objects will be created for the split-up
1457 * map. This is a bit of a hack, but is also about the best place to
1458 * put this improvement.
1461 if (entry->object.vm_object == NULL && !map->system_map) {
1462 vm_map_entry_allocate_object(entry);
1466 * Create a new entry and insert it AFTER the specified entry
1469 new_entry = vm_map_entry_create(map, countp);
1470 *new_entry = *entry;
1472 new_entry->start = entry->end = end;
1473 new_entry->offset += (end - entry->start);
1475 vm_map_entry_link(map, entry, new_entry);
1477 switch(entry->maptype) {
1478 case VM_MAPTYPE_NORMAL:
1479 case VM_MAPTYPE_VPAGETABLE:
1480 if (new_entry->object.vm_object) {
1481 vm_object_hold(new_entry->object.vm_object);
1482 vm_object_chain_wait(new_entry->object.vm_object);
1483 vm_object_reference_locked(new_entry->object.vm_object);
1484 vm_object_drop(new_entry->object.vm_object);
1493 * Asserts that the starting and ending region addresses fall within the
1494 * valid range for the map.
1496 #define VM_MAP_RANGE_CHECK(map, start, end) \
1498 if (start < vm_map_min(map)) \
1499 start = vm_map_min(map); \
1500 if (end > vm_map_max(map)) \
1501 end = vm_map_max(map); \
1507 * Used to block when an in-transition collison occurs. The map
1508 * is unlocked for the sleep and relocked before the return.
1511 vm_map_transition_wait(vm_map_t map)
1513 tsleep_interlock(map, 0);
1515 tsleep(map, PINTERLOCKED, "vment", 0);
1520 * When we do blocking operations with the map lock held it is
1521 * possible that a clip might have occured on our in-transit entry,
1522 * requiring an adjustment to the entry in our loop. These macros
1523 * help the pageable and clip_range code deal with the case. The
1524 * conditional costs virtually nothing if no clipping has occured.
1527 #define CLIP_CHECK_BACK(entry, save_start) \
1529 while (entry->start != save_start) { \
1530 entry = entry->prev; \
1531 KASSERT(entry != &map->header, ("bad entry clip")); \
1535 #define CLIP_CHECK_FWD(entry, save_end) \
1537 while (entry->end != save_end) { \
1538 entry = entry->next; \
1539 KASSERT(entry != &map->header, ("bad entry clip")); \
1545 * Clip the specified range and return the base entry. The
1546 * range may cover several entries starting at the returned base
1547 * and the first and last entry in the covering sequence will be
1548 * properly clipped to the requested start and end address.
1550 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1553 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1554 * covered by the requested range.
1556 * The map must be exclusively locked on entry and will remain locked
1557 * on return. If no range exists or the range contains holes and you
1558 * specified that no holes were allowed, NULL will be returned. This
1559 * routine may temporarily unlock the map in order avoid a deadlock when
1564 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end,
1565 int *countp, int flags)
1567 vm_map_entry_t start_entry;
1568 vm_map_entry_t entry;
1571 * Locate the entry and effect initial clipping. The in-transition
1572 * case does not occur very often so do not try to optimize it.
1575 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1577 entry = start_entry;
1578 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1579 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1580 ++mycpu->gd_cnt.v_intrans_coll;
1581 ++mycpu->gd_cnt.v_intrans_wait;
1582 vm_map_transition_wait(map);
1584 * entry and/or start_entry may have been clipped while
1585 * we slept, or may have gone away entirely. We have
1586 * to restart from the lookup.
1592 * Since we hold an exclusive map lock we do not have to restart
1593 * after clipping, even though clipping may block in zalloc.
1595 vm_map_clip_start(map, entry, start, countp);
1596 vm_map_clip_end(map, entry, end, countp);
1597 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1600 * Scan entries covered by the range. When working on the next
1601 * entry a restart need only re-loop on the current entry which
1602 * we have already locked, since 'next' may have changed. Also,
1603 * even though entry is safe, it may have been clipped so we
1604 * have to iterate forwards through the clip after sleeping.
1606 while (entry->next != &map->header && entry->next->start < end) {
1607 vm_map_entry_t next = entry->next;
1609 if (flags & MAP_CLIP_NO_HOLES) {
1610 if (next->start > entry->end) {
1611 vm_map_unclip_range(map, start_entry,
1612 start, entry->end, countp, flags);
1617 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1618 vm_offset_t save_end = entry->end;
1619 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1620 ++mycpu->gd_cnt.v_intrans_coll;
1621 ++mycpu->gd_cnt.v_intrans_wait;
1622 vm_map_transition_wait(map);
1625 * clips might have occured while we blocked.
1627 CLIP_CHECK_FWD(entry, save_end);
1628 CLIP_CHECK_BACK(start_entry, start);
1632 * No restart necessary even though clip_end may block, we
1633 * are holding the map lock.
1635 vm_map_clip_end(map, next, end, countp);
1636 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1639 if (flags & MAP_CLIP_NO_HOLES) {
1640 if (entry->end != end) {
1641 vm_map_unclip_range(map, start_entry,
1642 start, entry->end, countp, flags);
1646 return(start_entry);
1650 * Undo the effect of vm_map_clip_range(). You should pass the same
1651 * flags and the same range that you passed to vm_map_clip_range().
1652 * This code will clear the in-transition flag on the entries and
1653 * wake up anyone waiting. This code will also simplify the sequence
1654 * and attempt to merge it with entries before and after the sequence.
1656 * The map must be locked on entry and will remain locked on return.
1658 * Note that you should also pass the start_entry returned by
1659 * vm_map_clip_range(). However, if you block between the two calls
1660 * with the map unlocked please be aware that the start_entry may
1661 * have been clipped and you may need to scan it backwards to find
1662 * the entry corresponding with the original start address. You are
1663 * responsible for this, vm_map_unclip_range() expects the correct
1664 * start_entry to be passed to it and will KASSERT otherwise.
1668 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1669 vm_offset_t start, vm_offset_t end,
1670 int *countp, int flags)
1672 vm_map_entry_t entry;
1674 entry = start_entry;
1676 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1677 while (entry != &map->header && entry->start < end) {
1678 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1679 ("in-transition flag not set during unclip on: %p",
1681 KASSERT(entry->end <= end,
1682 ("unclip_range: tail wasn't clipped"));
1683 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1684 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1685 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1688 entry = entry->next;
1692 * Simplification does not block so there is no restart case.
1694 entry = start_entry;
1695 while (entry != &map->header && entry->start < end) {
1696 vm_map_simplify_entry(map, entry, countp);
1697 entry = entry->next;
1702 * Mark the given range as handled by a subordinate map.
1704 * This range must have been created with vm_map_find(), and no other
1705 * operations may have been performed on this range prior to calling
1708 * Submappings cannot be removed.
1713 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1715 vm_map_entry_t entry;
1716 int result = KERN_INVALID_ARGUMENT;
1719 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1722 VM_MAP_RANGE_CHECK(map, start, end);
1724 if (vm_map_lookup_entry(map, start, &entry)) {
1725 vm_map_clip_start(map, entry, start, &count);
1727 entry = entry->next;
1730 vm_map_clip_end(map, entry, end, &count);
1732 if ((entry->start == start) && (entry->end == end) &&
1733 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1734 (entry->object.vm_object == NULL)) {
1735 entry->object.sub_map = submap;
1736 entry->maptype = VM_MAPTYPE_SUBMAP;
1737 result = KERN_SUCCESS;
1740 vm_map_entry_release(count);
1746 * Sets the protection of the specified address region in the target map.
1747 * If "set_max" is specified, the maximum protection is to be set;
1748 * otherwise, only the current protection is affected.
1750 * The protection is not applicable to submaps, but is applicable to normal
1751 * maps and maps governed by virtual page tables. For example, when operating
1752 * on a virtual page table our protection basically controls how COW occurs
1753 * on the backing object, whereas the virtual page table abstraction itself
1754 * is an abstraction for userland.
1759 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1760 vm_prot_t new_prot, boolean_t set_max)
1762 vm_map_entry_t current;
1763 vm_map_entry_t entry;
1766 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1769 VM_MAP_RANGE_CHECK(map, start, end);
1771 if (vm_map_lookup_entry(map, start, &entry)) {
1772 vm_map_clip_start(map, entry, start, &count);
1774 entry = entry->next;
1778 * Make a first pass to check for protection violations.
1781 while ((current != &map->header) && (current->start < end)) {
1782 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1784 vm_map_entry_release(count);
1785 return (KERN_INVALID_ARGUMENT);
1787 if ((new_prot & current->max_protection) != new_prot) {
1789 vm_map_entry_release(count);
1790 return (KERN_PROTECTION_FAILURE);
1792 current = current->next;
1796 * Go back and fix up protections. [Note that clipping is not
1797 * necessary the second time.]
1801 while ((current != &map->header) && (current->start < end)) {
1804 vm_map_clip_end(map, current, end, &count);
1806 old_prot = current->protection;
1808 current->protection =
1809 (current->max_protection = new_prot) &
1812 current->protection = new_prot;
1816 * Update physical map if necessary. Worry about copy-on-write
1817 * here -- CHECK THIS XXX
1820 if (current->protection != old_prot) {
1821 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1824 pmap_protect(map->pmap, current->start,
1826 current->protection & MASK(current));
1830 vm_map_simplify_entry(map, current, &count);
1832 current = current->next;
1836 vm_map_entry_release(count);
1837 return (KERN_SUCCESS);
1841 * This routine traverses a processes map handling the madvise
1842 * system call. Advisories are classified as either those effecting
1843 * the vm_map_entry structure, or those effecting the underlying
1846 * The <value> argument is used for extended madvise calls.
1851 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1852 int behav, off_t value)
1854 vm_map_entry_t current, entry;
1860 * Some madvise calls directly modify the vm_map_entry, in which case
1861 * we need to use an exclusive lock on the map and we need to perform
1862 * various clipping operations. Otherwise we only need a read-lock
1866 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1870 case MADV_SEQUENTIAL:
1884 vm_map_lock_read(map);
1887 vm_map_entry_release(count);
1892 * Locate starting entry and clip if necessary.
1895 VM_MAP_RANGE_CHECK(map, start, end);
1897 if (vm_map_lookup_entry(map, start, &entry)) {
1899 vm_map_clip_start(map, entry, start, &count);
1901 entry = entry->next;
1906 * madvise behaviors that are implemented in the vm_map_entry.
1908 * We clip the vm_map_entry so that behavioral changes are
1909 * limited to the specified address range.
1911 for (current = entry;
1912 (current != &map->header) && (current->start < end);
1913 current = current->next
1915 if (current->maptype == VM_MAPTYPE_SUBMAP)
1918 vm_map_clip_end(map, current, end, &count);
1922 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
1924 case MADV_SEQUENTIAL:
1925 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
1928 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
1931 current->eflags |= MAP_ENTRY_NOSYNC;
1934 current->eflags &= ~MAP_ENTRY_NOSYNC;
1937 current->eflags |= MAP_ENTRY_NOCOREDUMP;
1940 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
1944 * Invalidate the related pmap entries, used
1945 * to flush portions of the real kernel's
1946 * pmap when the caller has removed or
1947 * modified existing mappings in a virtual
1950 pmap_remove(map->pmap,
1951 current->start, current->end);
1955 * Set the page directory page for a map
1956 * governed by a virtual page table. Mark
1957 * the entry as being governed by a virtual
1958 * page table if it is not.
1960 * XXX the page directory page is stored
1961 * in the avail_ssize field if the map_entry.
1963 * XXX the map simplification code does not
1964 * compare this field so weird things may
1965 * happen if you do not apply this function
1966 * to the entire mapping governed by the
1967 * virtual page table.
1969 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
1973 current->aux.master_pde = value;
1974 pmap_remove(map->pmap,
1975 current->start, current->end);
1981 vm_map_simplify_entry(map, current, &count);
1989 * madvise behaviors that are implemented in the underlying
1992 * Since we don't clip the vm_map_entry, we have to clip
1993 * the vm_object pindex and count.
1995 * NOTE! We currently do not support these functions on
1996 * virtual page tables.
1998 for (current = entry;
1999 (current != &map->header) && (current->start < end);
2000 current = current->next
2002 vm_offset_t useStart;
2004 if (current->maptype != VM_MAPTYPE_NORMAL)
2007 pindex = OFF_TO_IDX(current->offset);
2008 count = atop(current->end - current->start);
2009 useStart = current->start;
2011 if (current->start < start) {
2012 pindex += atop(start - current->start);
2013 count -= atop(start - current->start);
2016 if (current->end > end)
2017 count -= atop(current->end - end);
2022 vm_object_madvise(current->object.vm_object,
2023 pindex, count, behav);
2026 * Try to populate the page table. Mappings governed
2027 * by virtual page tables cannot be pre-populated
2028 * without a lot of work so don't try.
2030 if (behav == MADV_WILLNEED &&
2031 current->maptype != VM_MAPTYPE_VPAGETABLE) {
2032 pmap_object_init_pt(
2035 current->protection,
2036 current->object.vm_object,
2038 (count << PAGE_SHIFT),
2039 MAP_PREFAULT_MADVISE
2043 vm_map_unlock_read(map);
2045 vm_map_entry_release(count);
2051 * Sets the inheritance of the specified address range in the target map.
2052 * Inheritance affects how the map will be shared with child maps at the
2053 * time of vm_map_fork.
2056 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
2057 vm_inherit_t new_inheritance)
2059 vm_map_entry_t entry;
2060 vm_map_entry_t temp_entry;
2063 switch (new_inheritance) {
2064 case VM_INHERIT_NONE:
2065 case VM_INHERIT_COPY:
2066 case VM_INHERIT_SHARE:
2069 return (KERN_INVALID_ARGUMENT);
2072 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2075 VM_MAP_RANGE_CHECK(map, start, end);
2077 if (vm_map_lookup_entry(map, start, &temp_entry)) {
2079 vm_map_clip_start(map, entry, start, &count);
2081 entry = temp_entry->next;
2083 while ((entry != &map->header) && (entry->start < end)) {
2084 vm_map_clip_end(map, entry, end, &count);
2086 entry->inheritance = new_inheritance;
2088 vm_map_simplify_entry(map, entry, &count);
2090 entry = entry->next;
2093 vm_map_entry_release(count);
2094 return (KERN_SUCCESS);
2098 * Implement the semantics of mlock
2101 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2102 boolean_t new_pageable)
2104 vm_map_entry_t entry;
2105 vm_map_entry_t start_entry;
2107 int rv = KERN_SUCCESS;
2110 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2112 VM_MAP_RANGE_CHECK(map, start, real_end);
2115 start_entry = vm_map_clip_range(map, start, end, &count,
2117 if (start_entry == NULL) {
2119 vm_map_entry_release(count);
2120 return (KERN_INVALID_ADDRESS);
2123 if (new_pageable == 0) {
2124 entry = start_entry;
2125 while ((entry != &map->header) && (entry->start < end)) {
2126 vm_offset_t save_start;
2127 vm_offset_t save_end;
2130 * Already user wired or hard wired (trivial cases)
2132 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2133 entry = entry->next;
2136 if (entry->wired_count != 0) {
2137 entry->wired_count++;
2138 entry->eflags |= MAP_ENTRY_USER_WIRED;
2139 entry = entry->next;
2144 * A new wiring requires instantiation of appropriate
2145 * management structures and the faulting in of the
2148 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2149 int copyflag = entry->eflags &
2150 MAP_ENTRY_NEEDS_COPY;
2151 if (copyflag && ((entry->protection &
2152 VM_PROT_WRITE) != 0)) {
2153 vm_map_entry_shadow(entry, 0);
2154 } else if (entry->object.vm_object == NULL &&
2156 vm_map_entry_allocate_object(entry);
2159 entry->wired_count++;
2160 entry->eflags |= MAP_ENTRY_USER_WIRED;
2163 * Now fault in the area. Note that vm_fault_wire()
2164 * may release the map lock temporarily, it will be
2165 * relocked on return. The in-transition
2166 * flag protects the entries.
2168 save_start = entry->start;
2169 save_end = entry->end;
2170 rv = vm_fault_wire(map, entry, TRUE);
2172 CLIP_CHECK_BACK(entry, save_start);
2174 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2175 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2176 entry->wired_count = 0;
2177 if (entry->end == save_end)
2179 entry = entry->next;
2180 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2182 end = save_start; /* unwire the rest */
2186 * note that even though the entry might have been
2187 * clipped, the USER_WIRED flag we set prevents
2188 * duplication so we do not have to do a
2191 entry = entry->next;
2195 * If we failed fall through to the unwiring section to
2196 * unwire what we had wired so far. 'end' has already
2203 * start_entry might have been clipped if we unlocked the
2204 * map and blocked. No matter how clipped it has gotten
2205 * there should be a fragment that is on our start boundary.
2207 CLIP_CHECK_BACK(start_entry, start);
2211 * Deal with the unwiring case.
2215 * This is the unwiring case. We must first ensure that the
2216 * range to be unwired is really wired down. We know there
2219 entry = start_entry;
2220 while ((entry != &map->header) && (entry->start < end)) {
2221 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2222 rv = KERN_INVALID_ARGUMENT;
2225 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2226 entry = entry->next;
2230 * Now decrement the wiring count for each region. If a region
2231 * becomes completely unwired, unwire its physical pages and
2235 * The map entries are processed in a loop, checking to
2236 * make sure the entry is wired and asserting it has a wired
2237 * count. However, another loop was inserted more-or-less in
2238 * the middle of the unwiring path. This loop picks up the
2239 * "entry" loop variable from the first loop without first
2240 * setting it to start_entry. Naturally, the secound loop
2241 * is never entered and the pages backing the entries are
2242 * never unwired. This can lead to a leak of wired pages.
2244 entry = start_entry;
2245 while ((entry != &map->header) && (entry->start < end)) {
2246 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2247 ("expected USER_WIRED on entry %p", entry));
2248 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2249 entry->wired_count--;
2250 if (entry->wired_count == 0)
2251 vm_fault_unwire(map, entry);
2252 entry = entry->next;
2256 vm_map_unclip_range(map, start_entry, start, real_end, &count,
2260 vm_map_entry_release(count);
2265 * Sets the pageability of the specified address range in the target map.
2266 * Regions specified as not pageable require locked-down physical
2267 * memory and physical page maps.
2269 * The map must not be locked, but a reference must remain to the map
2270 * throughout the call.
2272 * This function may be called via the zalloc path and must properly
2273 * reserve map entries for kernel_map.
2278 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2280 vm_map_entry_t entry;
2281 vm_map_entry_t start_entry;
2283 int rv = KERN_SUCCESS;
2286 if (kmflags & KM_KRESERVE)
2287 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2289 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2291 VM_MAP_RANGE_CHECK(map, start, real_end);
2294 start_entry = vm_map_clip_range(map, start, end, &count,
2296 if (start_entry == NULL) {
2298 rv = KERN_INVALID_ADDRESS;
2301 if ((kmflags & KM_PAGEABLE) == 0) {
2305 * 1. Holding the write lock, we create any shadow or zero-fill
2306 * objects that need to be created. Then we clip each map
2307 * entry to the region to be wired and increment its wiring
2308 * count. We create objects before clipping the map entries
2309 * to avoid object proliferation.
2311 * 2. We downgrade to a read lock, and call vm_fault_wire to
2312 * fault in the pages for any newly wired area (wired_count is
2315 * Downgrading to a read lock for vm_fault_wire avoids a
2316 * possible deadlock with another process that may have faulted
2317 * on one of the pages to be wired (it would mark the page busy,
2318 * blocking us, then in turn block on the map lock that we
2319 * hold). Because of problems in the recursive lock package,
2320 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2321 * any actions that require the write lock must be done
2322 * beforehand. Because we keep the read lock on the map, the
2323 * copy-on-write status of the entries we modify here cannot
2326 entry = start_entry;
2327 while ((entry != &map->header) && (entry->start < end)) {
2329 * Trivial case if the entry is already wired
2331 if (entry->wired_count) {
2332 entry->wired_count++;
2333 entry = entry->next;
2338 * The entry is being newly wired, we have to setup
2339 * appropriate management structures. A shadow
2340 * object is required for a copy-on-write region,
2341 * or a normal object for a zero-fill region. We
2342 * do not have to do this for entries that point to sub
2343 * maps because we won't hold the lock on the sub map.
2345 if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2346 int copyflag = entry->eflags &
2347 MAP_ENTRY_NEEDS_COPY;
2348 if (copyflag && ((entry->protection &
2349 VM_PROT_WRITE) != 0)) {
2350 vm_map_entry_shadow(entry, 0);
2351 } else if (entry->object.vm_object == NULL &&
2353 vm_map_entry_allocate_object(entry);
2357 entry->wired_count++;
2358 entry = entry->next;
2366 * HACK HACK HACK HACK
2368 * vm_fault_wire() temporarily unlocks the map to avoid
2369 * deadlocks. The in-transition flag from vm_map_clip_range
2370 * call should protect us from changes while the map is
2373 * NOTE: Previously this comment stated that clipping might
2374 * still occur while the entry is unlocked, but from
2375 * what I can tell it actually cannot.
2377 * It is unclear whether the CLIP_CHECK_*() calls
2378 * are still needed but we keep them in anyway.
2380 * HACK HACK HACK HACK
2383 entry = start_entry;
2384 while (entry != &map->header && entry->start < end) {
2386 * If vm_fault_wire fails for any page we need to undo
2387 * what has been done. We decrement the wiring count
2388 * for those pages which have not yet been wired (now)
2389 * and unwire those that have (later).
2391 vm_offset_t save_start = entry->start;
2392 vm_offset_t save_end = entry->end;
2394 if (entry->wired_count == 1)
2395 rv = vm_fault_wire(map, entry, FALSE);
2397 CLIP_CHECK_BACK(entry, save_start);
2399 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2400 entry->wired_count = 0;
2401 if (entry->end == save_end)
2403 entry = entry->next;
2404 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2409 CLIP_CHECK_FWD(entry, save_end);
2410 entry = entry->next;
2414 * If a failure occured undo everything by falling through
2415 * to the unwiring code. 'end' has already been adjusted
2419 kmflags |= KM_PAGEABLE;
2422 * start_entry is still IN_TRANSITION but may have been
2423 * clipped since vm_fault_wire() unlocks and relocks the
2424 * map. No matter how clipped it has gotten there should
2425 * be a fragment that is on our start boundary.
2427 CLIP_CHECK_BACK(start_entry, start);
2430 if (kmflags & KM_PAGEABLE) {
2432 * This is the unwiring case. We must first ensure that the
2433 * range to be unwired is really wired down. We know there
2436 entry = start_entry;
2437 while ((entry != &map->header) && (entry->start < end)) {
2438 if (entry->wired_count == 0) {
2439 rv = KERN_INVALID_ARGUMENT;
2442 entry = entry->next;
2446 * Now decrement the wiring count for each region. If a region
2447 * becomes completely unwired, unwire its physical pages and
2450 entry = start_entry;
2451 while ((entry != &map->header) && (entry->start < end)) {
2452 entry->wired_count--;
2453 if (entry->wired_count == 0)
2454 vm_fault_unwire(map, entry);
2455 entry = entry->next;
2459 vm_map_unclip_range(map, start_entry, start, real_end,
2460 &count, MAP_CLIP_NO_HOLES);
2464 if (kmflags & KM_KRESERVE)
2465 vm_map_entry_krelease(count);
2467 vm_map_entry_release(count);
2472 * Mark a newly allocated address range as wired but do not fault in
2473 * the pages. The caller is expected to load the pages into the object.
2475 * The map must be locked on entry and will remain locked on return.
2476 * No other requirements.
2479 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2482 vm_map_entry_t scan;
2483 vm_map_entry_t entry;
2485 entry = vm_map_clip_range(map, addr, addr + size,
2486 countp, MAP_CLIP_NO_HOLES);
2488 scan != &map->header && scan->start < addr + size;
2489 scan = scan->next) {
2490 KKASSERT(entry->wired_count == 0);
2491 entry->wired_count = 1;
2493 vm_map_unclip_range(map, entry, addr, addr + size,
2494 countp, MAP_CLIP_NO_HOLES);
2498 * Push any dirty cached pages in the address range to their pager.
2499 * If syncio is TRUE, dirty pages are written synchronously.
2500 * If invalidate is TRUE, any cached pages are freed as well.
2502 * This routine is called by sys_msync()
2504 * Returns an error if any part of the specified range is not mapped.
2509 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2510 boolean_t syncio, boolean_t invalidate)
2512 vm_map_entry_t current;
2513 vm_map_entry_t entry;
2517 vm_ooffset_t offset;
2519 vm_map_lock_read(map);
2520 VM_MAP_RANGE_CHECK(map, start, end);
2521 if (!vm_map_lookup_entry(map, start, &entry)) {
2522 vm_map_unlock_read(map);
2523 return (KERN_INVALID_ADDRESS);
2525 lwkt_gettoken(&map->token);
2528 * Make a first pass to check for holes.
2530 for (current = entry; current->start < end; current = current->next) {
2531 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2532 lwkt_reltoken(&map->token);
2533 vm_map_unlock_read(map);
2534 return (KERN_INVALID_ARGUMENT);
2536 if (end > current->end &&
2537 (current->next == &map->header ||
2538 current->end != current->next->start)) {
2539 lwkt_reltoken(&map->token);
2540 vm_map_unlock_read(map);
2541 return (KERN_INVALID_ADDRESS);
2546 pmap_remove(vm_map_pmap(map), start, end);
2549 * Make a second pass, cleaning/uncaching pages from the indicated
2552 for (current = entry; current->start < end; current = current->next) {
2553 offset = current->offset + (start - current->start);
2554 size = (end <= current->end ? end : current->end) - start;
2555 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2557 vm_map_entry_t tentry;
2560 smap = current->object.sub_map;
2561 vm_map_lock_read(smap);
2562 vm_map_lookup_entry(smap, offset, &tentry);
2563 tsize = tentry->end - offset;
2566 object = tentry->object.vm_object;
2567 offset = tentry->offset + (offset - tentry->start);
2568 vm_map_unlock_read(smap);
2570 object = current->object.vm_object;
2574 vm_object_hold(object);
2577 * Note that there is absolutely no sense in writing out
2578 * anonymous objects, so we track down the vnode object
2580 * We invalidate (remove) all pages from the address space
2581 * anyway, for semantic correctness.
2583 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2584 * may start out with a NULL object.
2586 while (object && (tobj = object->backing_object) != NULL) {
2587 vm_object_hold(tobj);
2588 if (tobj == object->backing_object) {
2589 vm_object_lock_swap();
2590 offset += object->backing_object_offset;
2591 vm_object_drop(object);
2593 if (object->size < OFF_TO_IDX(offset + size))
2594 size = IDX_TO_OFF(object->size) -
2598 vm_object_drop(tobj);
2600 if (object && (object->type == OBJT_VNODE) &&
2601 (current->protection & VM_PROT_WRITE) &&
2602 (object->flags & OBJ_NOMSYNC) == 0) {
2604 * Flush pages if writing is allowed, invalidate them
2605 * if invalidation requested. Pages undergoing I/O
2606 * will be ignored by vm_object_page_remove().
2608 * We cannot lock the vnode and then wait for paging
2609 * to complete without deadlocking against vm_fault.
2610 * Instead we simply call vm_object_page_remove() and
2611 * allow it to block internally on a page-by-page
2612 * basis when it encounters pages undergoing async
2617 /* no chain wait needed for vnode objects */
2618 vm_object_reference_locked(object);
2619 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2620 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2621 flags |= invalidate ? OBJPC_INVAL : 0;
2624 * When operating on a virtual page table just
2625 * flush the whole object. XXX we probably ought
2628 switch(current->maptype) {
2629 case VM_MAPTYPE_NORMAL:
2630 vm_object_page_clean(object,
2632 OFF_TO_IDX(offset + size + PAGE_MASK),
2635 case VM_MAPTYPE_VPAGETABLE:
2636 vm_object_page_clean(object, 0, 0, flags);
2639 vn_unlock(((struct vnode *)object->handle));
2640 vm_object_deallocate_locked(object);
2642 if (object && invalidate &&
2643 ((object->type == OBJT_VNODE) ||
2644 (object->type == OBJT_DEVICE))) {
2646 (object->type == OBJT_DEVICE) ? FALSE : TRUE;
2647 /* no chain wait needed for vnode/device objects */
2648 vm_object_reference_locked(object);
2649 switch(current->maptype) {
2650 case VM_MAPTYPE_NORMAL:
2651 vm_object_page_remove(object,
2653 OFF_TO_IDX(offset + size + PAGE_MASK),
2656 case VM_MAPTYPE_VPAGETABLE:
2657 vm_object_page_remove(object, 0, 0, clean_only);
2660 vm_object_deallocate_locked(object);
2664 vm_object_drop(object);
2667 lwkt_reltoken(&map->token);
2668 vm_map_unlock_read(map);
2670 return (KERN_SUCCESS);
2674 * Make the region specified by this entry pageable.
2676 * The vm_map must be exclusively locked.
2679 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2681 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2682 entry->wired_count = 0;
2683 vm_fault_unwire(map, entry);
2687 * Deallocate the given entry from the target map.
2689 * The vm_map must be exclusively locked.
2692 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2694 vm_map_entry_unlink(map, entry);
2695 map->size -= entry->end - entry->start;
2697 switch(entry->maptype) {
2698 case VM_MAPTYPE_NORMAL:
2699 case VM_MAPTYPE_VPAGETABLE:
2700 vm_object_deallocate(entry->object.vm_object);
2706 vm_map_entry_dispose(map, entry, countp);
2710 * Deallocates the given address range from the target map.
2712 * The vm_map must be exclusively locked.
2715 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2718 vm_map_entry_t entry;
2719 vm_map_entry_t first_entry;
2721 ASSERT_VM_MAP_LOCKED(map);
2722 lwkt_gettoken(&map->token);
2725 * Find the start of the region, and clip it. Set entry to point
2726 * at the first record containing the requested address or, if no
2727 * such record exists, the next record with a greater address. The
2728 * loop will run from this point until a record beyond the termination
2729 * address is encountered.
2731 * map->hint must be adjusted to not point to anything we delete,
2732 * so set it to the entry prior to the one being deleted.
2734 * GGG see other GGG comment.
2736 if (vm_map_lookup_entry(map, start, &first_entry)) {
2737 entry = first_entry;
2738 vm_map_clip_start(map, entry, start, countp);
2739 map->hint = entry->prev; /* possible problem XXX */
2741 map->hint = first_entry; /* possible problem XXX */
2742 entry = first_entry->next;
2746 * If a hole opens up prior to the current first_free then
2747 * adjust first_free. As with map->hint, map->first_free
2748 * cannot be left set to anything we might delete.
2750 if (entry == &map->header) {
2751 map->first_free = &map->header;
2752 } else if (map->first_free->start >= start) {
2753 map->first_free = entry->prev;
2757 * Step through all entries in this region
2759 while ((entry != &map->header) && (entry->start < end)) {
2760 vm_map_entry_t next;
2762 vm_pindex_t offidxstart, offidxend, count;
2765 * If we hit an in-transition entry we have to sleep and
2766 * retry. It's easier (and not really slower) to just retry
2767 * since this case occurs so rarely and the hint is already
2768 * pointing at the right place. We have to reset the
2769 * start offset so as not to accidently delete an entry
2770 * another process just created in vacated space.
2772 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2773 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2774 start = entry->start;
2775 ++mycpu->gd_cnt.v_intrans_coll;
2776 ++mycpu->gd_cnt.v_intrans_wait;
2777 vm_map_transition_wait(map);
2780 vm_map_clip_end(map, entry, end, countp);
2786 offidxstart = OFF_TO_IDX(entry->offset);
2787 count = OFF_TO_IDX(e - s);
2788 object = entry->object.vm_object;
2791 * Unwire before removing addresses from the pmap; otherwise,
2792 * unwiring will put the entries back in the pmap.
2794 if (entry->wired_count != 0)
2795 vm_map_entry_unwire(map, entry);
2797 offidxend = offidxstart + count;
2799 if (object == &kernel_object) {
2800 vm_object_hold(object);
2801 vm_object_page_remove(object, offidxstart,
2803 vm_object_drop(object);
2804 } else if (object && object->type != OBJT_DEFAULT &&
2805 object->type != OBJT_SWAP) {
2807 * vnode object routines cannot be chain-locked
2809 vm_object_hold(object);
2810 pmap_remove(map->pmap, s, e);
2811 vm_object_drop(object);
2812 } else if (object) {
2813 vm_object_hold(object);
2814 vm_object_chain_acquire(object);
2815 pmap_remove(map->pmap, s, e);
2817 if (object != NULL &&
2818 object->ref_count != 1 &&
2819 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2821 (object->type == OBJT_DEFAULT ||
2822 object->type == OBJT_SWAP)) {
2823 vm_object_collapse(object, NULL);
2824 vm_object_page_remove(object, offidxstart,
2826 if (object->type == OBJT_SWAP) {
2827 swap_pager_freespace(object,
2831 if (offidxend >= object->size &&
2832 offidxstart < object->size) {
2833 object->size = offidxstart;
2836 vm_object_chain_release(object);
2837 vm_object_drop(object);
2841 * Delete the entry (which may delete the object) only after
2842 * removing all pmap entries pointing to its pages.
2843 * (Otherwise, its page frames may be reallocated, and any
2844 * modify bits will be set in the wrong object!)
2846 vm_map_entry_delete(map, entry, countp);
2849 lwkt_reltoken(&map->token);
2850 return (KERN_SUCCESS);
2854 * Remove the given address range from the target map.
2855 * This is the exported form of vm_map_delete.
2860 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
2865 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2867 VM_MAP_RANGE_CHECK(map, start, end);
2868 result = vm_map_delete(map, start, end, &count);
2870 vm_map_entry_release(count);
2876 * Assert that the target map allows the specified privilege on the
2877 * entire address region given. The entire region must be allocated.
2879 * The caller must specify whether the vm_map is already locked or not.
2882 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2883 vm_prot_t protection, boolean_t have_lock)
2885 vm_map_entry_t entry;
2886 vm_map_entry_t tmp_entry;
2889 if (have_lock == FALSE)
2890 vm_map_lock_read(map);
2892 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
2893 if (have_lock == FALSE)
2894 vm_map_unlock_read(map);
2900 while (start < end) {
2901 if (entry == &map->header) {
2909 if (start < entry->start) {
2914 * Check protection associated with entry.
2917 if ((entry->protection & protection) != protection) {
2921 /* go to next entry */
2924 entry = entry->next;
2926 if (have_lock == FALSE)
2927 vm_map_unlock_read(map);
2932 * If appropriate this function shadows the original object with a new object
2933 * and moves the VM pages from the original object to the new object.
2934 * The original object will also be collapsed, if possible.
2936 * We can only do this for normal memory objects with a single mapping, and
2937 * it only makes sense to do it if there are 2 or more refs on the original
2938 * object. i.e. typically a memory object that has been extended into
2939 * multiple vm_map_entry's with non-overlapping ranges.
2941 * This makes it easier to remove unused pages and keeps object inheritance
2942 * from being a negative impact on memory usage.
2944 * On return the (possibly new) entry->object.vm_object will have an
2945 * additional ref on it for the caller to dispose of (usually by cloning
2946 * the vm_map_entry). The additional ref had to be done in this routine
2947 * to avoid racing a collapse. The object's ONEMAPPING flag will also be
2950 * The vm_map must be locked and its token held.
2953 vm_map_split(vm_map_entry_t entry)
2957 vm_object_t oobject;
2959 oobject = entry->object.vm_object;
2960 vm_object_hold(oobject);
2961 vm_object_chain_wait(oobject);
2962 vm_object_reference_locked(oobject);
2963 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
2964 vm_object_drop(oobject);
2967 vm_object_t oobject, nobject, bobject;
2970 vm_pindex_t offidxstart, offidxend, idx;
2972 vm_ooffset_t offset;
2975 * Setup. Chain lock the original object throughout the entire
2976 * routine to prevent new page faults from occuring.
2978 * XXX can madvise WILLNEED interfere with us too?
2980 oobject = entry->object.vm_object;
2981 vm_object_hold(oobject);
2982 vm_object_chain_acquire(oobject);
2985 * Original object cannot be split?
2987 if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT &&
2988 oobject->type != OBJT_SWAP)) {
2989 vm_object_chain_release(oobject);
2990 vm_object_reference_locked(oobject);
2991 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
2992 vm_object_drop(oobject);
2997 * Collapse original object with its backing store as an
2998 * optimization to reduce chain lengths when possible.
3000 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's
3001 * for oobject, so there's no point collapsing it.
3003 * Then re-check whether the object can be split.
3005 vm_object_collapse(oobject, NULL);
3007 if (oobject->ref_count <= 1 ||
3008 (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) ||
3009 (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) {
3010 vm_object_chain_release(oobject);
3011 vm_object_reference_locked(oobject);
3012 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3013 vm_object_drop(oobject);
3018 * Acquire the chain lock on the backing object.
3020 * Give bobject an additional ref count for when it will be shadowed
3023 if ((bobject = oobject->backing_object) != NULL) {
3024 vm_object_hold(bobject);
3025 vm_object_chain_wait(bobject);
3026 vm_object_reference_locked(bobject);
3027 vm_object_chain_acquire(bobject);
3028 KKASSERT(bobject->backing_object == bobject);
3029 KKASSERT((bobject->flags & OBJ_DEAD) == 0);
3033 * Calculate the object page range and allocate the new object.
3035 offset = entry->offset;
3039 offidxstart = OFF_TO_IDX(offset);
3040 offidxend = offidxstart + OFF_TO_IDX(e - s);
3041 size = offidxend - offidxstart;
3043 switch(oobject->type) {
3045 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size),
3049 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size),
3058 if (nobject == NULL) {
3060 vm_object_chain_release(bobject);
3061 vm_object_deallocate(bobject);
3062 vm_object_drop(bobject);
3064 vm_object_chain_release(oobject);
3065 vm_object_reference_locked(oobject);
3066 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3067 vm_object_drop(oobject);
3072 * The new object will replace entry->object.vm_object so it needs
3073 * a second reference (the caller expects an additional ref).
3075 vm_object_hold(nobject);
3076 vm_object_reference_locked(nobject);
3077 vm_object_chain_acquire(nobject);
3080 * nobject shadows bobject (oobject already shadows bobject).
3083 nobject->backing_object_offset =
3084 oobject->backing_object_offset + IDX_TO_OFF(offidxstart);
3085 nobject->backing_object = bobject;
3086 bobject->shadow_count++;
3087 bobject->generation++;
3088 LIST_INSERT_HEAD(&bobject->shadow_head, nobject, shadow_list);
3089 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /* XXX? */
3090 vm_object_chain_release(bobject);
3091 vm_object_drop(bobject);
3095 * Move the VM pages from oobject to nobject
3097 for (idx = 0; idx < size; idx++) {
3100 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx,
3106 * We must wait for pending I/O to complete before we can
3109 * We do not have to VM_PROT_NONE the page as mappings should
3110 * not be changed by this operation.
3112 * NOTE: The act of renaming a page updates chaingen for both
3115 vm_page_rename(m, nobject, idx);
3116 /* page automatically made dirty by rename and cache handled */
3117 /* page remains busy */
3120 if (oobject->type == OBJT_SWAP) {
3121 vm_object_pip_add(oobject, 1);
3123 * copy oobject pages into nobject and destroy unneeded
3124 * pages in shadow object.
3126 swap_pager_copy(oobject, nobject, offidxstart, 0);
3127 vm_object_pip_wakeup(oobject);
3131 * Wakeup the pages we played with. No spl protection is needed
3132 * for a simple wakeup.
3134 for (idx = 0; idx < size; idx++) {
3135 m = vm_page_lookup(nobject, idx);
3137 KKASSERT(m->flags & PG_BUSY);
3141 entry->object.vm_object = nobject;
3142 entry->offset = 0LL;
3147 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the
3148 * related pages were moved and are no longer applicable to the
3151 * NOTE: Deallocate oobject (due to its entry->object.vm_object being
3152 * replaced by nobject).
3154 vm_object_chain_release(nobject);
3155 vm_object_drop(nobject);
3157 vm_object_chain_release(bobject);
3158 vm_object_drop(bobject);
3160 vm_object_chain_release(oobject);
3161 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/
3162 vm_object_deallocate_locked(oobject);
3163 vm_object_drop(oobject);
3168 * Copies the contents of the source entry to the destination
3169 * entry. The entries *must* be aligned properly.
3171 * The vm_maps must be exclusively locked.
3172 * The vm_map's token must be held.
3174 * Because the maps are locked no faults can be in progress during the
3178 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
3179 vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
3181 vm_object_t src_object;
3183 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP)
3185 if (src_entry->maptype == VM_MAPTYPE_SUBMAP)
3188 if (src_entry->wired_count == 0) {
3190 * If the source entry is marked needs_copy, it is already
3193 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
3194 pmap_protect(src_map->pmap,
3197 src_entry->protection & ~VM_PROT_WRITE);
3201 * Make a copy of the object.
3203 * The object must be locked prior to checking the object type
3204 * and for the call to vm_object_collapse() and vm_map_split().
3205 * We cannot use *_hold() here because the split code will
3206 * probably try to destroy the object. The lock is a pool
3207 * token and doesn't care.
3209 * We must bump src_map->timestamp when setting
3210 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault
3211 * to retry, otherwise the concurrent fault might improperly
3212 * install a RW pte when its supposed to be a RO(COW) pte.
3213 * This race can occur because a vnode-backed fault may have
3214 * to temporarily release the map lock.
3216 if (src_entry->object.vm_object != NULL) {
3217 vm_map_split(src_entry);
3218 src_object = src_entry->object.vm_object;
3219 dst_entry->object.vm_object = src_object;
3220 src_entry->eflags |= (MAP_ENTRY_COW |
3221 MAP_ENTRY_NEEDS_COPY);
3222 dst_entry->eflags |= (MAP_ENTRY_COW |
3223 MAP_ENTRY_NEEDS_COPY);
3224 dst_entry->offset = src_entry->offset;
3225 ++src_map->timestamp;
3227 dst_entry->object.vm_object = NULL;
3228 dst_entry->offset = 0;
3231 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3232 dst_entry->end - dst_entry->start, src_entry->start);
3235 * Of course, wired down pages can't be set copy-on-write.
3236 * Cause wired pages to be copied into the new map by
3237 * simulating faults (the new pages are pageable)
3239 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3245 * Create a new process vmspace structure and vm_map
3246 * based on those of an existing process. The new map
3247 * is based on the old map, according to the inheritance
3248 * values on the regions in that map.
3250 * The source map must not be locked.
3254 vmspace_fork(struct vmspace *vm1)
3256 struct vmspace *vm2;
3257 vm_map_t old_map = &vm1->vm_map;
3259 vm_map_entry_t old_entry;
3260 vm_map_entry_t new_entry;
3264 lwkt_gettoken(&vm1->vm_map.token);
3265 vm_map_lock(old_map);
3268 * XXX Note: upcalls are not copied.
3270 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3271 lwkt_gettoken(&vm2->vm_map.token);
3272 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3273 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3274 new_map = &vm2->vm_map; /* XXX */
3275 new_map->timestamp = 1;
3277 vm_map_lock(new_map);
3280 old_entry = old_map->header.next;
3281 while (old_entry != &old_map->header) {
3283 old_entry = old_entry->next;
3286 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3288 old_entry = old_map->header.next;
3289 while (old_entry != &old_map->header) {
3290 if (old_entry->maptype == VM_MAPTYPE_SUBMAP)
3291 panic("vm_map_fork: encountered a submap");
3293 switch (old_entry->inheritance) {
3294 case VM_INHERIT_NONE:
3296 case VM_INHERIT_SHARE:
3298 * Clone the entry, creating the shared object if
3301 if (old_entry->object.vm_object == NULL)
3302 vm_map_entry_allocate_object(old_entry);
3304 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3306 * Shadow a map_entry which needs a copy,
3307 * replacing its object with a new object
3308 * that points to the old one. Ask the
3309 * shadow code to automatically add an
3310 * additional ref. We can't do it afterwords
3311 * because we might race a collapse. The call
3312 * to vm_map_entry_shadow() will also clear
3315 vm_map_entry_shadow(old_entry, 1);
3318 * We will make a shared copy of the object,
3319 * and must clear OBJ_ONEMAPPING.
3321 * XXX assert that object.vm_object != NULL
3322 * since we allocate it above.
3324 if (old_entry->object.vm_object) {
3325 object = old_entry->object.vm_object;
3326 vm_object_hold(object);
3327 vm_object_chain_wait(object);
3328 vm_object_reference_locked(object);
3329 vm_object_clear_flag(object,
3331 vm_object_drop(object);
3336 * Clone the entry. We've already bumped the ref on
3339 new_entry = vm_map_entry_create(new_map, &count);
3340 *new_entry = *old_entry;
3341 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3342 new_entry->wired_count = 0;
3345 * Insert the entry into the new map -- we know we're
3346 * inserting at the end of the new map.
3349 vm_map_entry_link(new_map, new_map->header.prev,
3353 * Update the physical map
3355 pmap_copy(new_map->pmap, old_map->pmap,
3357 (old_entry->end - old_entry->start),
3360 case VM_INHERIT_COPY:
3362 * Clone the entry and link into the map.
3364 new_entry = vm_map_entry_create(new_map, &count);
3365 *new_entry = *old_entry;
3366 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3367 new_entry->wired_count = 0;
3368 new_entry->object.vm_object = NULL;
3369 vm_map_entry_link(new_map, new_map->header.prev,
3371 vm_map_copy_entry(old_map, new_map, old_entry,
3375 old_entry = old_entry->next;
3378 new_map->size = old_map->size;
3379 vm_map_unlock(old_map);
3380 vm_map_unlock(new_map);
3381 vm_map_entry_release(count);
3383 lwkt_reltoken(&vm2->vm_map.token);
3384 lwkt_reltoken(&vm1->vm_map.token);
3390 * Create an auto-grow stack entry
3395 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3396 int flags, vm_prot_t prot, vm_prot_t max, int cow)
3398 vm_map_entry_t prev_entry;
3399 vm_map_entry_t new_stack_entry;
3400 vm_size_t init_ssize;
3403 vm_offset_t tmpaddr;
3405 cow |= MAP_IS_STACK;
3407 if (max_ssize < sgrowsiz)
3408 init_ssize = max_ssize;
3410 init_ssize = sgrowsiz;
3412 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3416 * Find space for the mapping
3418 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3419 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3422 vm_map_entry_release(count);
3423 return (KERN_NO_SPACE);
3428 /* If addr is already mapped, no go */
3429 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3431 vm_map_entry_release(count);
3432 return (KERN_NO_SPACE);
3436 /* XXX already handled by kern_mmap() */
3437 /* If we would blow our VMEM resource limit, no go */
3438 if (map->size + init_ssize >
3439 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3441 vm_map_entry_release(count);
3442 return (KERN_NO_SPACE);
3447 * If we can't accomodate max_ssize in the current mapping,
3448 * no go. However, we need to be aware that subsequent user
3449 * mappings might map into the space we have reserved for
3450 * stack, and currently this space is not protected.
3452 * Hopefully we will at least detect this condition
3453 * when we try to grow the stack.
3455 if ((prev_entry->next != &map->header) &&
3456 (prev_entry->next->start < addrbos + max_ssize)) {
3458 vm_map_entry_release(count);
3459 return (KERN_NO_SPACE);
3463 * We initially map a stack of only init_ssize. We will
3464 * grow as needed later. Since this is to be a grow
3465 * down stack, we map at the top of the range.
3467 * Note: we would normally expect prot and max to be
3468 * VM_PROT_ALL, and cow to be 0. Possibly we should
3469 * eliminate these as input parameters, and just
3470 * pass these values here in the insert call.
3472 rv = vm_map_insert(map, &count,
3473 NULL, 0, addrbos + max_ssize - init_ssize,
3474 addrbos + max_ssize,
3479 /* Now set the avail_ssize amount */
3480 if (rv == KERN_SUCCESS) {
3481 if (prev_entry != &map->header)
3482 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3483 new_stack_entry = prev_entry->next;
3484 if (new_stack_entry->end != addrbos + max_ssize ||
3485 new_stack_entry->start != addrbos + max_ssize - init_ssize)
3486 panic ("Bad entry start/end for new stack entry");
3488 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3492 vm_map_entry_release(count);
3497 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3498 * desired address is already mapped, or if we successfully grow
3499 * the stack. Also returns KERN_SUCCESS if addr is outside the
3500 * stack range (this is strange, but preserves compatibility with
3501 * the grow function in vm_machdep.c).
3506 vm_map_growstack (struct proc *p, vm_offset_t addr)
3508 vm_map_entry_t prev_entry;
3509 vm_map_entry_t stack_entry;
3510 vm_map_entry_t new_stack_entry;
3511 struct vmspace *vm = p->p_vmspace;
3512 vm_map_t map = &vm->vm_map;
3515 int rv = KERN_SUCCESS;
3517 int use_read_lock = 1;
3520 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3523 vm_map_lock_read(map);
3527 /* If addr is already in the entry range, no need to grow.*/
3528 if (vm_map_lookup_entry(map, addr, &prev_entry))
3531 if ((stack_entry = prev_entry->next) == &map->header)
3533 if (prev_entry == &map->header)
3534 end = stack_entry->start - stack_entry->aux.avail_ssize;
3536 end = prev_entry->end;
3539 * This next test mimics the old grow function in vm_machdep.c.
3540 * It really doesn't quite make sense, but we do it anyway
3541 * for compatibility.
3543 * If not growable stack, return success. This signals the
3544 * caller to proceed as he would normally with normal vm.
3546 if (stack_entry->aux.avail_ssize < 1 ||
3547 addr >= stack_entry->start ||
3548 addr < stack_entry->start - stack_entry->aux.avail_ssize) {
3552 /* Find the minimum grow amount */
3553 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3554 if (grow_amount > stack_entry->aux.avail_ssize) {
3560 * If there is no longer enough space between the entries
3561 * nogo, and adjust the available space. Note: this
3562 * should only happen if the user has mapped into the
3563 * stack area after the stack was created, and is
3564 * probably an error.
3566 * This also effectively destroys any guard page the user
3567 * might have intended by limiting the stack size.
3569 if (grow_amount > stack_entry->start - end) {
3570 if (use_read_lock && vm_map_lock_upgrade(map)) {
3576 stack_entry->aux.avail_ssize = stack_entry->start - end;
3581 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3583 /* If this is the main process stack, see if we're over the
3586 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3587 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3592 /* Round up the grow amount modulo SGROWSIZ */
3593 grow_amount = roundup (grow_amount, sgrowsiz);
3594 if (grow_amount > stack_entry->aux.avail_ssize) {
3595 grow_amount = stack_entry->aux.avail_ssize;
3597 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3598 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3599 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3603 /* If we would blow our VMEM resource limit, no go */
3604 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3609 if (use_read_lock && vm_map_lock_upgrade(map)) {
3616 /* Get the preliminary new entry start value */
3617 addr = stack_entry->start - grow_amount;
3619 /* If this puts us into the previous entry, cut back our growth
3620 * to the available space. Also, see the note above.
3623 stack_entry->aux.avail_ssize = stack_entry->start - end;
3627 rv = vm_map_insert(map, &count,
3628 NULL, 0, addr, stack_entry->start,
3630 VM_PROT_ALL, VM_PROT_ALL,
3633 /* Adjust the available stack space by the amount we grew. */
3634 if (rv == KERN_SUCCESS) {
3635 if (prev_entry != &map->header)
3636 vm_map_clip_end(map, prev_entry, addr, &count);
3637 new_stack_entry = prev_entry->next;
3638 if (new_stack_entry->end != stack_entry->start ||
3639 new_stack_entry->start != addr)
3640 panic ("Bad stack grow start/end in new stack entry");
3642 new_stack_entry->aux.avail_ssize =
3643 stack_entry->aux.avail_ssize -
3644 (new_stack_entry->end - new_stack_entry->start);
3646 vm->vm_ssize += btoc(new_stack_entry->end -
3647 new_stack_entry->start);
3650 if (map->flags & MAP_WIREFUTURE)
3651 vm_map_unwire(map, new_stack_entry->start,
3652 new_stack_entry->end, FALSE);
3657 vm_map_unlock_read(map);
3660 vm_map_entry_release(count);
3665 * Unshare the specified VM space for exec. If other processes are
3666 * mapped to it, then create a new one. The new vmspace is null.
3671 vmspace_exec(struct proc *p, struct vmspace *vmcopy)
3673 struct vmspace *oldvmspace = p->p_vmspace;
3674 struct vmspace *newvmspace;
3675 vm_map_t map = &p->p_vmspace->vm_map;
3678 * If we are execing a resident vmspace we fork it, otherwise
3679 * we create a new vmspace. Note that exitingcnt and upcalls
3680 * are not copied to the new vmspace.
3682 lwkt_gettoken(&oldvmspace->vm_map.token);
3684 newvmspace = vmspace_fork(vmcopy);
3685 lwkt_gettoken(&newvmspace->vm_map.token);
3687 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3688 lwkt_gettoken(&newvmspace->vm_map.token);
3689 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3690 (caddr_t)&oldvmspace->vm_endcopy -
3691 (caddr_t)&oldvmspace->vm_startcopy);
3695 * Finish initializing the vmspace before assigning it
3696 * to the process. The vmspace will become the current vmspace
3699 pmap_pinit2(vmspace_pmap(newvmspace));
3700 pmap_replacevm(p, newvmspace, 0);
3701 lwkt_reltoken(&newvmspace->vm_map.token);
3702 lwkt_reltoken(&oldvmspace->vm_map.token);
3703 vmspace_free(oldvmspace);
3707 * Unshare the specified VM space for forcing COW. This
3708 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3711 vmspace_unshare(struct proc *p)
3713 struct vmspace *oldvmspace = p->p_vmspace;
3714 struct vmspace *newvmspace;
3716 lwkt_gettoken(&oldvmspace->vm_map.token);
3717 if (oldvmspace->vm_sysref.refcnt == 1) {
3718 lwkt_reltoken(&oldvmspace->vm_map.token);
3721 newvmspace = vmspace_fork(oldvmspace);
3722 lwkt_gettoken(&newvmspace->vm_map.token);
3723 pmap_pinit2(vmspace_pmap(newvmspace));
3724 pmap_replacevm(p, newvmspace, 0);
3725 lwkt_reltoken(&newvmspace->vm_map.token);
3726 lwkt_reltoken(&oldvmspace->vm_map.token);
3727 vmspace_free(oldvmspace);
3731 * vm_map_hint: return the beginning of the best area suitable for
3732 * creating a new mapping with "prot" protection.
3737 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot)
3739 struct vmspace *vms = p->p_vmspace;
3741 if (!randomize_mmap) {
3743 * Set a reasonable start point for the hint if it was
3744 * not specified or if it falls within the heap space.
3745 * Hinted mmap()s do not allocate out of the heap space.
3748 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
3749 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) {
3750 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
3756 if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr)
3762 * If executable skip first two pages, otherwise start
3763 * after data + heap region.
3765 if ((prot & VM_PROT_EXECUTE) &&
3766 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) {
3767 addr = (PAGE_SIZE * 2) +
3768 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1));
3769 return (round_page(addr));
3771 #endif /* __i386__ */
3774 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ;
3775 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1);
3777 return (round_page(addr));
3781 * Finds the VM object, offset, and protection for a given virtual address
3782 * in the specified map, assuming a page fault of the type specified.
3784 * Leaves the map in question locked for read; return values are guaranteed
3785 * until a vm_map_lookup_done call is performed. Note that the map argument
3786 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3788 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3791 * If a lookup is requested with "write protection" specified, the map may
3792 * be changed to perform virtual copying operations, although the data
3793 * referenced will remain the same.
3798 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
3800 vm_prot_t fault_typea,
3801 vm_map_entry_t *out_entry, /* OUT */
3802 vm_object_t *object, /* OUT */
3803 vm_pindex_t *pindex, /* OUT */
3804 vm_prot_t *out_prot, /* OUT */
3805 boolean_t *wired) /* OUT */
3807 vm_map_entry_t entry;
3808 vm_map_t map = *var_map;
3810 vm_prot_t fault_type = fault_typea;
3811 int use_read_lock = 1;
3812 int rv = KERN_SUCCESS;
3816 vm_map_lock_read(map);
3821 * If the map has an interesting hint, try it before calling full
3822 * blown lookup routine.
3829 if ((entry == &map->header) ||
3830 (vaddr < entry->start) || (vaddr >= entry->end)) {
3831 vm_map_entry_t tmp_entry;
3834 * Entry was either not a valid hint, or the vaddr was not
3835 * contained in the entry, so do a full lookup.
3837 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
3838 rv = KERN_INVALID_ADDRESS;
3849 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3850 vm_map_t old_map = map;
3852 *var_map = map = entry->object.sub_map;
3854 vm_map_unlock_read(old_map);
3856 vm_map_unlock(old_map);
3862 * Check whether this task is allowed to have this page.
3863 * Note the special case for MAP_ENTRY_COW
3864 * pages with an override. This is to implement a forced
3865 * COW for debuggers.
3868 if (fault_type & VM_PROT_OVERRIDE_WRITE)
3869 prot = entry->max_protection;
3871 prot = entry->protection;
3873 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
3874 if ((fault_type & prot) != fault_type) {
3875 rv = KERN_PROTECTION_FAILURE;
3879 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
3880 (entry->eflags & MAP_ENTRY_COW) &&
3881 (fault_type & VM_PROT_WRITE) &&
3882 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
3883 rv = KERN_PROTECTION_FAILURE;
3888 * If this page is not pageable, we have to get it for all possible
3891 *wired = (entry->wired_count != 0);
3893 prot = fault_type = entry->protection;
3896 * Virtual page tables may need to update the accessed (A) bit
3897 * in a page table entry. Upgrade the fault to a write fault for
3898 * that case if the map will support it. If the map does not support
3899 * it the page table entry simply will not be updated.
3901 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
3902 if (prot & VM_PROT_WRITE)
3903 fault_type |= VM_PROT_WRITE;
3907 * If the entry was copy-on-write, we either ...
3909 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3911 * If we want to write the page, we may as well handle that
3912 * now since we've got the map locked.
3914 * If we don't need to write the page, we just demote the
3915 * permissions allowed.
3918 if (fault_type & VM_PROT_WRITE) {
3920 * Make a new object, and place it in the object
3921 * chain. Note that no new references have appeared
3922 * -- one just moved from the map to the new
3926 if (use_read_lock && vm_map_lock_upgrade(map)) {
3933 vm_map_entry_shadow(entry, 0);
3936 * We're attempting to read a copy-on-write page --
3937 * don't allow writes.
3940 prot &= ~VM_PROT_WRITE;
3945 * Create an object if necessary.
3947 if (entry->object.vm_object == NULL && !map->system_map) {
3948 if (use_read_lock && vm_map_lock_upgrade(map)) {
3954 vm_map_entry_allocate_object(entry);
3958 * Return the object/offset from this entry. If the entry was
3959 * copy-on-write or empty, it has been fixed up.
3962 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
3963 *object = entry->object.vm_object;
3966 * Return whether this is the only map sharing this data. On
3967 * success we return with a read lock held on the map. On failure
3968 * we return with the map unlocked.
3972 if (rv == KERN_SUCCESS) {
3973 if (use_read_lock == 0)
3974 vm_map_lock_downgrade(map);
3975 } else if (use_read_lock) {
3976 vm_map_unlock_read(map);
3984 * Releases locks acquired by a vm_map_lookup()
3985 * (according to the handle returned by that lookup).
3987 * No other requirements.
3990 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
3993 * Unlock the main-level map
3995 vm_map_unlock_read(map);
3997 vm_map_entry_release(count);
4000 #include "opt_ddb.h"
4002 #include <sys/kernel.h>
4004 #include <ddb/ddb.h>
4009 DB_SHOW_COMMAND(map, vm_map_print)
4012 /* XXX convert args. */
4013 vm_map_t map = (vm_map_t)addr;
4014 boolean_t full = have_addr;
4016 vm_map_entry_t entry;
4018 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4020 (void *)map->pmap, map->nentries, map->timestamp);
4023 if (!full && db_indent)
4027 for (entry = map->header.next; entry != &map->header;
4028 entry = entry->next) {
4029 db_iprintf("map entry %p: start=%p, end=%p\n",
4030 (void *)entry, (void *)entry->start, (void *)entry->end);
4033 static char *inheritance_name[4] =
4034 {"share", "copy", "none", "donate_copy"};
4036 db_iprintf(" prot=%x/%x/%s",
4038 entry->max_protection,
4039 inheritance_name[(int)(unsigned char)entry->inheritance]);
4040 if (entry->wired_count != 0)
4041 db_printf(", wired");
4043 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
4044 /* XXX no %qd in kernel. Truncate entry->offset. */
4045 db_printf(", share=%p, offset=0x%lx\n",
4046 (void *)entry->object.sub_map,
4047 (long)entry->offset);
4049 if ((entry->prev == &map->header) ||
4050 (entry->prev->object.sub_map !=
4051 entry->object.sub_map)) {
4053 vm_map_print((db_expr_t)(intptr_t)
4054 entry->object.sub_map,
4059 /* XXX no %qd in kernel. Truncate entry->offset. */
4060 db_printf(", object=%p, offset=0x%lx",
4061 (void *)entry->object.vm_object,
4062 (long)entry->offset);
4063 if (entry->eflags & MAP_ENTRY_COW)
4064 db_printf(", copy (%s)",
4065 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
4069 if ((entry->prev == &map->header) ||
4070 (entry->prev->object.vm_object !=
4071 entry->object.vm_object)) {
4073 vm_object_print((db_expr_t)(intptr_t)
4074 entry->object.vm_object,
4089 DB_SHOW_COMMAND(procvm, procvm)
4094 p = (struct proc *) addr;
4099 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
4100 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
4101 (void *)vmspace_pmap(p->p_vmspace));
4103 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);