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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
62 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $
66 * Virtual memory mapping module.
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/kernel.h>
73 #include <sys/serialize.h>
75 #include <sys/vmmeter.h>
77 #include <sys/vnode.h>
78 #include <sys/resourcevar.h>
81 #include <sys/malloc.h>
82 #include <sys/objcache.h>
85 #include <vm/vm_param.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_page.h>
89 #include <vm/vm_object.h>
90 #include <vm/vm_pager.h>
91 #include <vm/vm_kern.h>
92 #include <vm/vm_extern.h>
93 #include <vm/swap_pager.h>
94 #include <vm/vm_zone.h>
96 #include <sys/thread2.h>
97 #include <sys/random.h>
98 #include <sys/sysctl.h>
101 * Virtual memory maps provide for the mapping, protection, and sharing
102 * of virtual memory objects. In addition, this module provides for an
103 * efficient virtual copy of memory from one map to another.
105 * Synchronization is required prior to most operations.
107 * Maps consist of an ordered doubly-linked list of simple entries.
108 * A hint and a RB tree is used to speed-up lookups.
110 * Callers looking to modify maps specify start/end addresses which cause
111 * the related map entry to be clipped if necessary, and then later
112 * recombined if the pieces remained compatible.
114 * Virtual copy operations are performed by copying VM object references
115 * from one map to another, and then marking both regions as copy-on-write.
117 static __boolean_t vmspace_ctor(void *obj, void *privdata, int ocflags);
118 static void vmspace_dtor(void *obj, void *privdata);
119 static void vmspace_terminate(struct vmspace *vm, int final);
121 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore");
122 static struct objcache *vmspace_cache;
125 * per-cpu page table cross mappings are initialized in early boot
126 * and might require a considerable number of vm_map_entry structures.
128 #define MAPENTRYBSP_CACHE (MAXCPU+1)
129 #define MAPENTRYAP_CACHE 8
131 static struct vm_zone mapentzone_store, mapzone_store;
132 static vm_zone_t mapentzone, mapzone;
133 static struct vm_object mapentobj, mapobj;
135 static struct vm_map_entry map_entry_init[MAX_MAPENT];
136 static struct vm_map_entry cpu_map_entry_init_bsp[MAPENTRYBSP_CACHE];
137 static struct vm_map_entry cpu_map_entry_init_ap[MAXCPU][MAPENTRYAP_CACHE];
138 static struct vm_map map_init[MAX_KMAP];
140 static int randomize_mmap;
141 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0,
142 "Randomize mmap offsets");
143 static int vm_map_relock_enable = 1;
144 SYSCTL_INT(_vm, OID_AUTO, map_relock_enable, CTLFLAG_RW,
145 &vm_map_relock_enable, 0, "Randomize mmap offsets");
147 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref);
148 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *);
149 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *);
150 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
151 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
152 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *);
153 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t);
154 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t,
156 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);
159 * Initialize the vm_map module. Must be called before any other vm_map
162 * Map and entry structures are allocated from the general purpose
163 * memory pool with some exceptions:
165 * - The kernel map is allocated statically.
166 * - Initial kernel map entries are allocated out of a static pool.
167 * - We must set ZONE_SPECIAL here or the early boot code can get
168 * stuck if there are >63 cores.
170 * These restrictions are necessary since malloc() uses the
171 * maps and requires map entries.
173 * Called from the low level boot code only.
178 mapzone = &mapzone_store;
179 zbootinit(mapzone, "MAP", sizeof (struct vm_map),
181 mapentzone = &mapentzone_store;
182 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry),
183 map_entry_init, MAX_MAPENT);
184 mapentzone_store.zflags |= ZONE_SPECIAL;
188 * Called prior to any vmspace allocations.
190 * Called from the low level boot code only.
195 vmspace_cache = objcache_create_mbacked(M_VMSPACE,
196 sizeof(struct vmspace),
198 vmspace_ctor, vmspace_dtor,
200 zinitna(mapentzone, &mapentobj, NULL, 0, 0,
201 ZONE_USE_RESERVE | ZONE_SPECIAL, 1);
202 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1);
208 * objcache support. We leave the pmap root cached as long as possible
209 * for performance reasons.
213 vmspace_ctor(void *obj, void *privdata, int ocflags)
215 struct vmspace *vm = obj;
217 bzero(vm, sizeof(*vm));
218 vm->vm_refcnt = (u_int)-1;
225 vmspace_dtor(void *obj, void *privdata)
227 struct vmspace *vm = obj;
229 KKASSERT(vm->vm_refcnt == (u_int)-1);
230 pmap_puninit(vmspace_pmap(vm));
234 * Red black tree functions
236 * The caller must hold the related map lock.
238 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b);
239 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare);
241 /* a->start is address, and the only field has to be initialized */
243 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b)
245 if (a->start < b->start)
247 else if (a->start > b->start)
253 * Initialize vmspace ref/hold counts vmspace0. There is a holdcnt for
257 vmspace_initrefs(struct vmspace *vm)
264 * Allocate a vmspace structure, including a vm_map and pmap.
265 * Initialize numerous fields. While the initial allocation is zerod,
266 * subsequence reuse from the objcache leaves elements of the structure
267 * intact (particularly the pmap), so portions must be zerod.
269 * Returns a referenced vmspace.
274 vmspace_alloc(vm_offset_t min, vm_offset_t max)
278 vm = objcache_get(vmspace_cache, M_WAITOK);
280 bzero(&vm->vm_startcopy,
281 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy);
282 vm_map_init(&vm->vm_map, min, max, NULL); /* initializes token */
285 * NOTE: hold to acquires token for safety.
287 * On return vmspace is referenced (refs=1, hold=1). That is,
288 * each refcnt also has a holdcnt. There can be additional holds
289 * (holdcnt) above and beyond the refcnt. Finalization is handled in
290 * two stages, one on refs 1->0, and the the second on hold 1->0.
292 KKASSERT(vm->vm_holdcnt == 0);
293 KKASSERT(vm->vm_refcnt == (u_int)-1);
294 vmspace_initrefs(vm);
296 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */
297 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */
300 cpu_vmspace_alloc(vm);
307 * NOTE: Can return -1 if the vmspace is exiting.
310 vmspace_getrefs(struct vmspace *vm)
312 return ((int)vm->vm_refcnt);
316 * A vmspace object must already have a non-zero hold to be able to gain
317 * further holds on it.
320 vmspace_hold_notoken(struct vmspace *vm)
322 KKASSERT(vm->vm_holdcnt != 0);
323 refcount_acquire(&vm->vm_holdcnt);
327 vmspace_drop_notoken(struct vmspace *vm)
329 if (refcount_release(&vm->vm_holdcnt)) {
330 if (vm->vm_refcnt == (u_int)-1) {
331 vmspace_terminate(vm, 1);
337 vmspace_hold(struct vmspace *vm)
339 vmspace_hold_notoken(vm);
340 lwkt_gettoken(&vm->vm_map.token);
344 vmspace_drop(struct vmspace *vm)
346 lwkt_reltoken(&vm->vm_map.token);
347 vmspace_drop_notoken(vm);
351 * A vmspace object must not be in a terminated state to be able to obtain
352 * additional refs on it.
354 * Ref'ing a vmspace object also increments its hold count.
357 vmspace_ref(struct vmspace *vm)
359 KKASSERT((int)vm->vm_refcnt >= 0);
360 vmspace_hold_notoken(vm);
361 refcount_acquire(&vm->vm_refcnt);
365 * Release a ref on the vmspace. On the 1->0 transition we do stage-1
366 * termination of the vmspace. Then, on the final drop of the hold we
367 * will do stage-2 final termination.
370 vmspace_rel(struct vmspace *vm)
372 if (refcount_release(&vm->vm_refcnt)) {
373 vm->vm_refcnt = (u_int)-1; /* no other refs possible */
374 vmspace_terminate(vm, 0);
376 vmspace_drop_notoken(vm);
380 * This is called during exit indicating that the vmspace is no
381 * longer in used by an exiting process, but the process has not yet
384 * We release the refcnt but not the associated holdcnt.
389 vmspace_relexit(struct vmspace *vm)
391 if (refcount_release(&vm->vm_refcnt)) {
392 vm->vm_refcnt = (u_int)-1; /* no other refs possible */
393 vmspace_terminate(vm, 0);
398 * Called during reap to disconnect the remainder of the vmspace from
399 * the process. On the hold drop the vmspace termination is finalized.
404 vmspace_exitfree(struct proc *p)
410 vmspace_drop_notoken(vm);
414 * Called in two cases:
416 * (1) When the last refcnt is dropped and the vmspace becomes inactive,
417 * called with final == 0. refcnt will be (u_int)-1 at this point,
418 * and holdcnt will still be non-zero.
420 * (2) When holdcnt becomes 0, called with final == 1. There should no
421 * longer be anyone with access to the vmspace.
423 * VMSPACE_EXIT1 flags the primary deactivation
424 * VMSPACE_EXIT2 flags the last reap
427 vmspace_terminate(struct vmspace *vm, int final)
431 lwkt_gettoken(&vm->vm_map.token);
433 KKASSERT((vm->vm_flags & VMSPACE_EXIT1) == 0);
436 * Get rid of most of the resources. Leave the kernel pmap
439 vm->vm_flags |= VMSPACE_EXIT1;
441 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS,
442 VM_MAX_USER_ADDRESS);
443 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS,
444 VM_MAX_USER_ADDRESS);
445 lwkt_reltoken(&vm->vm_map.token);
447 KKASSERT((vm->vm_flags & VMSPACE_EXIT1) != 0);
448 KKASSERT((vm->vm_flags & VMSPACE_EXIT2) == 0);
451 * Get rid of remaining basic resources.
453 vm->vm_flags |= VMSPACE_EXIT2;
454 cpu_vmspace_free(vm);
458 * Lock the map, to wait out all other references to it.
459 * Delete all of the mappings and pages they hold, then call
460 * the pmap module to reclaim anything left.
462 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
463 vm_map_lock(&vm->vm_map);
464 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
465 vm->vm_map.max_offset, &count);
466 vm_map_unlock(&vm->vm_map);
467 vm_map_entry_release(count);
469 lwkt_gettoken(&vmspace_pmap(vm)->pm_token);
470 pmap_release(vmspace_pmap(vm));
471 lwkt_reltoken(&vmspace_pmap(vm)->pm_token);
472 lwkt_reltoken(&vm->vm_map.token);
473 objcache_put(vmspace_cache, vm);
478 * Swap useage is determined by taking the proportional swap used by
479 * VM objects backing the VM map. To make up for fractional losses,
480 * if the VM object has any swap use at all the associated map entries
481 * count for at least 1 swap page.
486 vmspace_swap_count(struct vmspace *vm)
488 vm_map_t map = &vm->vm_map;
495 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
496 switch(cur->maptype) {
497 case VM_MAPTYPE_NORMAL:
498 case VM_MAPTYPE_VPAGETABLE:
499 if ((object = cur->object.vm_object) == NULL)
501 if (object->swblock_count) {
502 n = (cur->end - cur->start) / PAGE_SIZE;
503 count += object->swblock_count *
504 SWAP_META_PAGES * n / object->size + 1;
517 * Calculate the approximate number of anonymous pages in use by
518 * this vmspace. To make up for fractional losses, we count each
519 * VM object as having at least 1 anonymous page.
524 vmspace_anonymous_count(struct vmspace *vm)
526 vm_map_t map = &vm->vm_map;
532 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
533 switch(cur->maptype) {
534 case VM_MAPTYPE_NORMAL:
535 case VM_MAPTYPE_VPAGETABLE:
536 if ((object = cur->object.vm_object) == NULL)
538 if (object->type != OBJT_DEFAULT &&
539 object->type != OBJT_SWAP) {
542 count += object->resident_page_count;
554 * Creates and returns a new empty VM map with the given physical map
555 * structure, and having the given lower and upper address bounds.
560 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max)
563 result = zalloc(mapzone);
564 vm_map_init(result, min, max, pmap);
569 * Initialize an existing vm_map structure such as that in the vmspace
570 * structure. The pmap is initialized elsewhere.
575 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap)
577 map->header.next = map->header.prev = &map->header;
578 RB_INIT(&map->rb_root);
582 map->min_offset = min;
583 map->max_offset = max;
585 map->first_free = &map->header;
586 map->hint = &map->header;
589 lwkt_token_init(&map->token, "vm_map");
590 lockinit(&map->lock, "vm_maplk", (hz + 9) / 10, 0);
594 * Shadow the vm_map_entry's object. This typically needs to be done when
595 * a write fault is taken on an entry which had previously been cloned by
596 * fork(). The shared object (which might be NULL) must become private so
597 * we add a shadow layer above it.
599 * Object allocation for anonymous mappings is defered as long as possible.
600 * When creating a shadow, however, the underlying object must be instantiated
601 * so it can be shared.
603 * If the map segment is governed by a virtual page table then it is
604 * possible to address offsets beyond the mapped area. Just allocate
605 * a maximally sized object for this case.
607 * If addref is non-zero an additional reference is added to the returned
608 * entry. This mechanic exists because the additional reference might have
609 * to be added atomically and not after return to prevent a premature
612 * The vm_map must be exclusively locked.
613 * No other requirements.
617 vm_map_entry_shadow(vm_map_entry_t entry, int addref)
619 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
620 vm_object_shadow(&entry->object.vm_object, &entry->offset,
621 0x7FFFFFFF, addref); /* XXX */
623 vm_object_shadow(&entry->object.vm_object, &entry->offset,
624 atop(entry->end - entry->start), addref);
626 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
630 * Allocate an object for a vm_map_entry.
632 * Object allocation for anonymous mappings is defered as long as possible.
633 * This function is called when we can defer no longer, generally when a map
634 * entry might be split or forked or takes a page fault.
636 * If the map segment is governed by a virtual page table then it is
637 * possible to address offsets beyond the mapped area. Just allocate
638 * a maximally sized object for this case.
640 * The vm_map must be exclusively locked.
641 * No other requirements.
644 vm_map_entry_allocate_object(vm_map_entry_t entry)
648 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
649 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */
651 obj = vm_object_allocate(OBJT_DEFAULT,
652 atop(entry->end - entry->start));
654 entry->object.vm_object = obj;
659 * Set an initial negative count so the first attempt to reserve
660 * space preloads a bunch of vm_map_entry's for this cpu. Also
661 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
662 * map a new page for vm_map_entry structures. SMP systems are
663 * particularly sensitive.
665 * This routine is called in early boot so we cannot just call
666 * vm_map_entry_reserve().
668 * Called from the low level boot code only (for each cpu)
670 * WARNING! Take care not to have too-big a static/BSS structure here
671 * as MAXCPU can be 256+, otherwise the loader's 64MB heap
672 * can get blown out by the kernel plus the initrd image.
675 vm_map_entry_reserve_cpu_init(globaldata_t gd)
677 vm_map_entry_t entry;
681 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2;
682 if (gd->gd_cpuid == 0) {
683 entry = &cpu_map_entry_init_bsp[0];
684 count = MAPENTRYBSP_CACHE;
686 entry = &cpu_map_entry_init_ap[gd->gd_cpuid][0];
687 count = MAPENTRYAP_CACHE;
689 for (i = 0; i < count; ++i, ++entry) {
690 entry->next = gd->gd_vme_base;
691 gd->gd_vme_base = entry;
696 * Reserves vm_map_entry structures so code later on can manipulate
697 * map_entry structures within a locked map without blocking trying
698 * to allocate a new vm_map_entry.
703 vm_map_entry_reserve(int count)
705 struct globaldata *gd = mycpu;
706 vm_map_entry_t entry;
709 * Make sure we have enough structures in gd_vme_base to handle
710 * the reservation request.
712 * The critical section protects access to the per-cpu gd.
715 while (gd->gd_vme_avail < count) {
716 entry = zalloc(mapentzone);
717 entry->next = gd->gd_vme_base;
718 gd->gd_vme_base = entry;
721 gd->gd_vme_avail -= count;
728 * Releases previously reserved vm_map_entry structures that were not
729 * used. If we have too much junk in our per-cpu cache clean some of
735 vm_map_entry_release(int count)
737 struct globaldata *gd = mycpu;
738 vm_map_entry_t entry;
741 gd->gd_vme_avail += count;
742 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) {
743 entry = gd->gd_vme_base;
744 KKASSERT(entry != NULL);
745 gd->gd_vme_base = entry->next;
748 zfree(mapentzone, entry);
755 * Reserve map entry structures for use in kernel_map itself. These
756 * entries have *ALREADY* been reserved on a per-cpu basis when the map
757 * was inited. This function is used by zalloc() to avoid a recursion
758 * when zalloc() itself needs to allocate additional kernel memory.
760 * This function works like the normal reserve but does not load the
761 * vm_map_entry cache (because that would result in an infinite
762 * recursion). Note that gd_vme_avail may go negative. This is expected.
764 * Any caller of this function must be sure to renormalize after
765 * potentially eating entries to ensure that the reserve supply
771 vm_map_entry_kreserve(int count)
773 struct globaldata *gd = mycpu;
776 gd->gd_vme_avail -= count;
778 KASSERT(gd->gd_vme_base != NULL,
779 ("no reserved entries left, gd_vme_avail = %d",
785 * Release previously reserved map entries for kernel_map. We do not
786 * attempt to clean up like the normal release function as this would
787 * cause an unnecessary (but probably not fatal) deep procedure call.
792 vm_map_entry_krelease(int count)
794 struct globaldata *gd = mycpu;
797 gd->gd_vme_avail += count;
802 * Allocates a VM map entry for insertion. No entry fields are filled in.
804 * The entries should have previously been reserved. The reservation count
805 * is tracked in (*countp).
809 static vm_map_entry_t
810 vm_map_entry_create(vm_map_t map, int *countp)
812 struct globaldata *gd = mycpu;
813 vm_map_entry_t entry;
815 KKASSERT(*countp > 0);
818 entry = gd->gd_vme_base;
819 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp));
820 gd->gd_vme_base = entry->next;
827 * Dispose of a vm_map_entry that is no longer being referenced.
832 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp)
834 struct globaldata *gd = mycpu;
836 KKASSERT(map->hint != entry);
837 KKASSERT(map->first_free != entry);
841 entry->next = gd->gd_vme_base;
842 gd->gd_vme_base = entry;
848 * Insert/remove entries from maps.
850 * The related map must be exclusively locked.
851 * The caller must hold map->token
852 * No other requirements.
855 vm_map_entry_link(vm_map_t map,
856 vm_map_entry_t after_where,
857 vm_map_entry_t entry)
859 ASSERT_VM_MAP_LOCKED(map);
862 entry->prev = after_where;
863 entry->next = after_where->next;
864 entry->next->prev = entry;
865 after_where->next = entry;
866 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry))
867 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry);
871 vm_map_entry_unlink(vm_map_t map,
872 vm_map_entry_t entry)
877 ASSERT_VM_MAP_LOCKED(map);
879 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
880 panic("vm_map_entry_unlink: attempt to mess with "
881 "locked entry! %p", entry);
887 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry);
892 * Finds the map entry containing (or immediately preceding) the specified
893 * address in the given map. The entry is returned in (*entry).
895 * The boolean result indicates whether the address is actually contained
898 * The related map must be locked.
899 * No other requirements.
902 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry)
907 ASSERT_VM_MAP_LOCKED(map);
910 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive
911 * the hint code with the red-black lookup meets with system crashes
912 * and lockups. We do not yet know why.
914 * It is possible that the problem is related to the setting
915 * of the hint during map_entry deletion, in the code specified
916 * at the GGG comment later on in this file.
918 * YYY More likely it's because this function can be called with
919 * a shared lock on the map, resulting in map->hint updates possibly
920 * racing. Fixed now but untested.
923 * Quickly check the cached hint, there's a good chance of a match.
927 if (tmp != &map->header) {
928 if (address >= tmp->start && address < tmp->end) {
936 * Locate the record from the top of the tree. 'last' tracks the
937 * closest prior record and is returned if no match is found, which
938 * in binary tree terms means tracking the most recent right-branch
939 * taken. If there is no prior record, &map->header is returned.
942 tmp = RB_ROOT(&map->rb_root);
945 if (address >= tmp->start) {
946 if (address < tmp->end) {
952 tmp = RB_RIGHT(tmp, rb_entry);
954 tmp = RB_LEFT(tmp, rb_entry);
962 * Inserts the given whole VM object into the target map at the specified
963 * address range. The object's size should match that of the address range.
965 * The map must be exclusively locked.
966 * The object must be held.
967 * The caller must have reserved sufficient vm_map_entry structures.
969 * If object is non-NULL, ref count must be bumped by caller prior to
970 * making call to account for the new entry.
973 vm_map_insert(vm_map_t map, int *countp, void *map_object, void *map_aux,
974 vm_ooffset_t offset, vm_offset_t start, vm_offset_t end,
975 vm_maptype_t maptype,
976 vm_prot_t prot, vm_prot_t max, int cow)
978 vm_map_entry_t new_entry;
979 vm_map_entry_t prev_entry;
980 vm_map_entry_t temp_entry;
981 vm_eflags_t protoeflags;
985 if (maptype == VM_MAPTYPE_UKSMAP)
990 ASSERT_VM_MAP_LOCKED(map);
992 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
995 * Check that the start and end points are not bogus.
997 if ((start < map->min_offset) || (end > map->max_offset) ||
999 return (KERN_INVALID_ADDRESS);
1002 * Find the entry prior to the proposed starting address; if it's part
1003 * of an existing entry, this range is bogus.
1005 if (vm_map_lookup_entry(map, start, &temp_entry))
1006 return (KERN_NO_SPACE);
1008 prev_entry = temp_entry;
1011 * Assert that the next entry doesn't overlap the end point.
1014 if ((prev_entry->next != &map->header) &&
1015 (prev_entry->next->start < end))
1016 return (KERN_NO_SPACE);
1020 if (cow & MAP_COPY_ON_WRITE)
1021 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY;
1023 if (cow & MAP_NOFAULT) {
1024 protoeflags |= MAP_ENTRY_NOFAULT;
1026 KASSERT(object == NULL,
1027 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
1029 if (cow & MAP_DISABLE_SYNCER)
1030 protoeflags |= MAP_ENTRY_NOSYNC;
1031 if (cow & MAP_DISABLE_COREDUMP)
1032 protoeflags |= MAP_ENTRY_NOCOREDUMP;
1033 if (cow & MAP_IS_STACK)
1034 protoeflags |= MAP_ENTRY_STACK;
1035 if (cow & MAP_IS_KSTACK)
1036 protoeflags |= MAP_ENTRY_KSTACK;
1038 lwkt_gettoken(&map->token);
1042 * When object is non-NULL, it could be shared with another
1043 * process. We have to set or clear OBJ_ONEMAPPING
1046 * NOTE: This flag is only applicable to DEFAULT and SWAP
1047 * objects and will already be clear in other types
1048 * of objects, so a shared object lock is ok for
1051 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
1052 vm_object_clear_flag(object, OBJ_ONEMAPPING);
1055 else if ((prev_entry != &map->header) &&
1056 (prev_entry->eflags == protoeflags) &&
1057 (prev_entry->end == start) &&
1058 (prev_entry->wired_count == 0) &&
1059 prev_entry->maptype == maptype &&
1060 maptype == VM_MAPTYPE_NORMAL &&
1061 ((prev_entry->object.vm_object == NULL) ||
1062 vm_object_coalesce(prev_entry->object.vm_object,
1063 OFF_TO_IDX(prev_entry->offset),
1064 (vm_size_t)(prev_entry->end - prev_entry->start),
1065 (vm_size_t)(end - prev_entry->end)))) {
1067 * We were able to extend the object. Determine if we
1068 * can extend the previous map entry to include the
1069 * new range as well.
1071 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
1072 (prev_entry->protection == prot) &&
1073 (prev_entry->max_protection == max)) {
1074 map->size += (end - prev_entry->end);
1075 prev_entry->end = end;
1076 vm_map_simplify_entry(map, prev_entry, countp);
1077 lwkt_reltoken(&map->token);
1078 return (KERN_SUCCESS);
1082 * If we can extend the object but cannot extend the
1083 * map entry, we have to create a new map entry. We
1084 * must bump the ref count on the extended object to
1085 * account for it. object may be NULL.
1087 * XXX if object is NULL should we set offset to 0 here ?
1089 object = prev_entry->object.vm_object;
1090 offset = prev_entry->offset +
1091 (prev_entry->end - prev_entry->start);
1093 vm_object_hold(object);
1094 vm_object_chain_wait(object, 0);
1095 vm_object_reference_locked(object);
1097 map_object = object;
1102 * NOTE: if conditionals fail, object can be NULL here. This occurs
1103 * in things like the buffer map where we manage kva but do not manage
1108 * Create a new entry
1111 new_entry = vm_map_entry_create(map, countp);
1112 new_entry->start = start;
1113 new_entry->end = end;
1115 new_entry->maptype = maptype;
1116 new_entry->eflags = protoeflags;
1117 new_entry->object.map_object = map_object;
1118 new_entry->aux.master_pde = 0; /* in case size is different */
1119 new_entry->aux.map_aux = map_aux;
1120 new_entry->offset = offset;
1122 new_entry->inheritance = VM_INHERIT_DEFAULT;
1123 new_entry->protection = prot;
1124 new_entry->max_protection = max;
1125 new_entry->wired_count = 0;
1128 * Insert the new entry into the list
1131 vm_map_entry_link(map, prev_entry, new_entry);
1132 map->size += new_entry->end - new_entry->start;
1135 * Update the free space hint. Entries cannot overlap.
1136 * An exact comparison is needed to avoid matching
1137 * against the map->header.
1139 if ((map->first_free == prev_entry) &&
1140 (prev_entry->end == new_entry->start)) {
1141 map->first_free = new_entry;
1146 * Temporarily removed to avoid MAP_STACK panic, due to
1147 * MAP_STACK being a huge hack. Will be added back in
1148 * when MAP_STACK (and the user stack mapping) is fixed.
1151 * It may be possible to simplify the entry
1153 vm_map_simplify_entry(map, new_entry, countp);
1157 * Try to pre-populate the page table. Mappings governed by virtual
1158 * page tables cannot be prepopulated without a lot of work, so
1161 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) &&
1162 maptype != VM_MAPTYPE_VPAGETABLE &&
1163 maptype != VM_MAPTYPE_UKSMAP) {
1165 if (vm_map_relock_enable && (cow & MAP_PREFAULT_RELOCK)) {
1167 vm_object_lock_swap();
1168 vm_object_drop(object);
1170 pmap_object_init_pt(map->pmap, start, prot,
1171 object, OFF_TO_IDX(offset), end - start,
1172 cow & MAP_PREFAULT_PARTIAL);
1174 vm_object_hold(object);
1175 vm_object_lock_swap();
1179 vm_object_drop(object);
1181 lwkt_reltoken(&map->token);
1182 return (KERN_SUCCESS);
1186 * Find sufficient space for `length' bytes in the given map, starting at
1187 * `start'. Returns 0 on success, 1 on no space.
1189 * This function will returned an arbitrarily aligned pointer. If no
1190 * particular alignment is required you should pass align as 1. Note that
1191 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1192 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1195 * 'align' should be a power of 2 but is not required to be.
1197 * The map must be exclusively locked.
1198 * No other requirements.
1201 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1202 vm_size_t align, int flags, vm_offset_t *addr)
1204 vm_map_entry_t entry, next;
1206 vm_offset_t align_mask;
1208 if (start < map->min_offset)
1209 start = map->min_offset;
1210 if (start > map->max_offset)
1214 * If the alignment is not a power of 2 we will have to use
1215 * a mod/division, set align_mask to a special value.
1217 if ((align | (align - 1)) + 1 != (align << 1))
1218 align_mask = (vm_offset_t)-1;
1220 align_mask = align - 1;
1223 * Look for the first possible address; if there's already something
1224 * at this address, we have to start after it.
1226 if (start == map->min_offset) {
1227 if ((entry = map->first_free) != &map->header)
1232 if (vm_map_lookup_entry(map, start, &tmp))
1238 * Look through the rest of the map, trying to fit a new region in the
1239 * gap between existing regions, or after the very last region.
1241 for (;; start = (entry = next)->end) {
1243 * Adjust the proposed start by the requested alignment,
1244 * be sure that we didn't wrap the address.
1246 if (align_mask == (vm_offset_t)-1)
1247 end = ((start + align - 1) / align) * align;
1249 end = (start + align_mask) & ~align_mask;
1254 * Find the end of the proposed new region. Be sure we didn't
1255 * go beyond the end of the map, or wrap around the address.
1256 * Then check to see if this is the last entry or if the
1257 * proposed end fits in the gap between this and the next
1260 end = start + length;
1261 if (end > map->max_offset || end < start)
1266 * If the next entry's start address is beyond the desired
1267 * end address we may have found a good entry.
1269 * If the next entry is a stack mapping we do not map into
1270 * the stack's reserved space.
1272 * XXX continue to allow mapping into the stack's reserved
1273 * space if doing a MAP_STACK mapping inside a MAP_STACK
1274 * mapping, for backwards compatibility. But the caller
1275 * really should use MAP_STACK | MAP_TRYFIXED if they
1278 if (next == &map->header)
1280 if (next->start >= end) {
1281 if ((next->eflags & MAP_ENTRY_STACK) == 0)
1283 if (flags & MAP_STACK)
1285 if (next->start - next->aux.avail_ssize >= end)
1292 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1293 * if it fails. The kernel_map is locked and nothing can steal
1294 * our address space if pmap_growkernel() blocks.
1296 * NOTE: This may be unconditionally called for kldload areas on
1297 * x86_64 because these do not bump kernel_vm_end (which would
1298 * fill 128G worth of page tables!). Therefore we must not
1301 if (map == &kernel_map) {
1304 kstop = round_page(start + length);
1305 if (kstop > kernel_vm_end)
1306 pmap_growkernel(start, kstop);
1313 * vm_map_find finds an unallocated region in the target address map with
1314 * the given length and allocates it. The search is defined to be first-fit
1315 * from the specified address; the region found is returned in the same
1318 * If object is non-NULL, ref count must be bumped by caller
1319 * prior to making call to account for the new entry.
1321 * No requirements. This function will lock the map temporarily.
1324 vm_map_find(vm_map_t map, void *map_object, void *map_aux,
1325 vm_ooffset_t offset, vm_offset_t *addr,
1326 vm_size_t length, vm_size_t align,
1328 vm_maptype_t maptype,
1329 vm_prot_t prot, vm_prot_t max,
1337 if (maptype == VM_MAPTYPE_UKSMAP)
1340 object = map_object;
1344 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1347 vm_object_hold_shared(object);
1349 if (vm_map_findspace(map, start, length, align, 0, addr)) {
1351 vm_object_drop(object);
1353 vm_map_entry_release(count);
1354 return (KERN_NO_SPACE);
1358 result = vm_map_insert(map, &count, map_object, map_aux,
1359 offset, start, start + length,
1360 maptype, prot, max, cow);
1362 vm_object_drop(object);
1364 vm_map_entry_release(count);
1370 * Simplify the given map entry by merging with either neighbor. This
1371 * routine also has the ability to merge with both neighbors.
1373 * This routine guarentees that the passed entry remains valid (though
1374 * possibly extended). When merging, this routine may delete one or
1375 * both neighbors. No action is taken on entries which have their
1376 * in-transition flag set.
1378 * The map must be exclusively locked.
1381 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1383 vm_map_entry_t next, prev;
1384 vm_size_t prevsize, esize;
1386 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1387 ++mycpu->gd_cnt.v_intrans_coll;
1391 if (entry->maptype == VM_MAPTYPE_SUBMAP)
1393 if (entry->maptype == VM_MAPTYPE_UKSMAP)
1397 if (prev != &map->header) {
1398 prevsize = prev->end - prev->start;
1399 if ( (prev->end == entry->start) &&
1400 (prev->maptype == entry->maptype) &&
1401 (prev->object.vm_object == entry->object.vm_object) &&
1402 (!prev->object.vm_object ||
1403 (prev->offset + prevsize == entry->offset)) &&
1404 (prev->eflags == entry->eflags) &&
1405 (prev->protection == entry->protection) &&
1406 (prev->max_protection == entry->max_protection) &&
1407 (prev->inheritance == entry->inheritance) &&
1408 (prev->wired_count == entry->wired_count)) {
1409 if (map->first_free == prev)
1410 map->first_free = entry;
1411 if (map->hint == prev)
1413 vm_map_entry_unlink(map, prev);
1414 entry->start = prev->start;
1415 entry->offset = prev->offset;
1416 if (prev->object.vm_object)
1417 vm_object_deallocate(prev->object.vm_object);
1418 vm_map_entry_dispose(map, prev, countp);
1423 if (next != &map->header) {
1424 esize = entry->end - entry->start;
1425 if ((entry->end == next->start) &&
1426 (next->maptype == entry->maptype) &&
1427 (next->object.vm_object == entry->object.vm_object) &&
1428 (!entry->object.vm_object ||
1429 (entry->offset + esize == next->offset)) &&
1430 (next->eflags == entry->eflags) &&
1431 (next->protection == entry->protection) &&
1432 (next->max_protection == entry->max_protection) &&
1433 (next->inheritance == entry->inheritance) &&
1434 (next->wired_count == entry->wired_count)) {
1435 if (map->first_free == next)
1436 map->first_free = entry;
1437 if (map->hint == next)
1439 vm_map_entry_unlink(map, next);
1440 entry->end = next->end;
1441 if (next->object.vm_object)
1442 vm_object_deallocate(next->object.vm_object);
1443 vm_map_entry_dispose(map, next, countp);
1449 * Asserts that the given entry begins at or after the specified address.
1450 * If necessary, it splits the entry into two.
1452 #define vm_map_clip_start(map, entry, startaddr, countp) \
1454 if (startaddr > entry->start) \
1455 _vm_map_clip_start(map, entry, startaddr, countp); \
1459 * This routine is called only when it is known that the entry must be split.
1461 * The map must be exclusively locked.
1464 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1467 vm_map_entry_t new_entry;
1470 * Split off the front portion -- note that we must insert the new
1471 * entry BEFORE this one, so that this entry has the specified
1475 vm_map_simplify_entry(map, entry, countp);
1478 * If there is no object backing this entry, we might as well create
1479 * one now. If we defer it, an object can get created after the map
1480 * is clipped, and individual objects will be created for the split-up
1481 * map. This is a bit of a hack, but is also about the best place to
1482 * put this improvement.
1484 if (entry->object.vm_object == NULL && !map->system_map) {
1485 vm_map_entry_allocate_object(entry);
1488 new_entry = vm_map_entry_create(map, countp);
1489 *new_entry = *entry;
1491 new_entry->end = start;
1492 entry->offset += (start - entry->start);
1493 entry->start = start;
1495 vm_map_entry_link(map, entry->prev, new_entry);
1497 switch(entry->maptype) {
1498 case VM_MAPTYPE_NORMAL:
1499 case VM_MAPTYPE_VPAGETABLE:
1500 if (new_entry->object.vm_object) {
1501 vm_object_hold(new_entry->object.vm_object);
1502 vm_object_chain_wait(new_entry->object.vm_object, 0);
1503 vm_object_reference_locked(new_entry->object.vm_object);
1504 vm_object_drop(new_entry->object.vm_object);
1513 * Asserts that the given entry ends at or before the specified address.
1514 * If necessary, it splits the entry into two.
1516 * The map must be exclusively locked.
1518 #define vm_map_clip_end(map, entry, endaddr, countp) \
1520 if (endaddr < entry->end) \
1521 _vm_map_clip_end(map, entry, endaddr, countp); \
1525 * This routine is called only when it is known that the entry must be split.
1527 * The map must be exclusively locked.
1530 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1533 vm_map_entry_t new_entry;
1536 * If there is no object backing this entry, we might as well create
1537 * one now. If we defer it, an object can get created after the map
1538 * is clipped, and individual objects will be created for the split-up
1539 * map. This is a bit of a hack, but is also about the best place to
1540 * put this improvement.
1543 if (entry->object.vm_object == NULL && !map->system_map) {
1544 vm_map_entry_allocate_object(entry);
1548 * Create a new entry and insert it AFTER the specified entry
1551 new_entry = vm_map_entry_create(map, countp);
1552 *new_entry = *entry;
1554 new_entry->start = entry->end = end;
1555 new_entry->offset += (end - entry->start);
1557 vm_map_entry_link(map, entry, new_entry);
1559 switch(entry->maptype) {
1560 case VM_MAPTYPE_NORMAL:
1561 case VM_MAPTYPE_VPAGETABLE:
1562 if (new_entry->object.vm_object) {
1563 vm_object_hold(new_entry->object.vm_object);
1564 vm_object_chain_wait(new_entry->object.vm_object, 0);
1565 vm_object_reference_locked(new_entry->object.vm_object);
1566 vm_object_drop(new_entry->object.vm_object);
1575 * Asserts that the starting and ending region addresses fall within the
1576 * valid range for the map.
1578 #define VM_MAP_RANGE_CHECK(map, start, end) \
1580 if (start < vm_map_min(map)) \
1581 start = vm_map_min(map); \
1582 if (end > vm_map_max(map)) \
1583 end = vm_map_max(map); \
1589 * Used to block when an in-transition collison occurs. The map
1590 * is unlocked for the sleep and relocked before the return.
1593 vm_map_transition_wait(vm_map_t map)
1595 tsleep_interlock(map, 0);
1597 tsleep(map, PINTERLOCKED, "vment", 0);
1602 * When we do blocking operations with the map lock held it is
1603 * possible that a clip might have occured on our in-transit entry,
1604 * requiring an adjustment to the entry in our loop. These macros
1605 * help the pageable and clip_range code deal with the case. The
1606 * conditional costs virtually nothing if no clipping has occured.
1609 #define CLIP_CHECK_BACK(entry, save_start) \
1611 while (entry->start != save_start) { \
1612 entry = entry->prev; \
1613 KASSERT(entry != &map->header, ("bad entry clip")); \
1617 #define CLIP_CHECK_FWD(entry, save_end) \
1619 while (entry->end != save_end) { \
1620 entry = entry->next; \
1621 KASSERT(entry != &map->header, ("bad entry clip")); \
1627 * Clip the specified range and return the base entry. The
1628 * range may cover several entries starting at the returned base
1629 * and the first and last entry in the covering sequence will be
1630 * properly clipped to the requested start and end address.
1632 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1635 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1636 * covered by the requested range.
1638 * The map must be exclusively locked on entry and will remain locked
1639 * on return. If no range exists or the range contains holes and you
1640 * specified that no holes were allowed, NULL will be returned. This
1641 * routine may temporarily unlock the map in order avoid a deadlock when
1646 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end,
1647 int *countp, int flags)
1649 vm_map_entry_t start_entry;
1650 vm_map_entry_t entry;
1653 * Locate the entry and effect initial clipping. The in-transition
1654 * case does not occur very often so do not try to optimize it.
1657 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1659 entry = start_entry;
1660 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1661 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1662 ++mycpu->gd_cnt.v_intrans_coll;
1663 ++mycpu->gd_cnt.v_intrans_wait;
1664 vm_map_transition_wait(map);
1666 * entry and/or start_entry may have been clipped while
1667 * we slept, or may have gone away entirely. We have
1668 * to restart from the lookup.
1674 * Since we hold an exclusive map lock we do not have to restart
1675 * after clipping, even though clipping may block in zalloc.
1677 vm_map_clip_start(map, entry, start, countp);
1678 vm_map_clip_end(map, entry, end, countp);
1679 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1682 * Scan entries covered by the range. When working on the next
1683 * entry a restart need only re-loop on the current entry which
1684 * we have already locked, since 'next' may have changed. Also,
1685 * even though entry is safe, it may have been clipped so we
1686 * have to iterate forwards through the clip after sleeping.
1688 while (entry->next != &map->header && entry->next->start < end) {
1689 vm_map_entry_t next = entry->next;
1691 if (flags & MAP_CLIP_NO_HOLES) {
1692 if (next->start > entry->end) {
1693 vm_map_unclip_range(map, start_entry,
1694 start, entry->end, countp, flags);
1699 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1700 vm_offset_t save_end = entry->end;
1701 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1702 ++mycpu->gd_cnt.v_intrans_coll;
1703 ++mycpu->gd_cnt.v_intrans_wait;
1704 vm_map_transition_wait(map);
1707 * clips might have occured while we blocked.
1709 CLIP_CHECK_FWD(entry, save_end);
1710 CLIP_CHECK_BACK(start_entry, start);
1714 * No restart necessary even though clip_end may block, we
1715 * are holding the map lock.
1717 vm_map_clip_end(map, next, end, countp);
1718 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1721 if (flags & MAP_CLIP_NO_HOLES) {
1722 if (entry->end != end) {
1723 vm_map_unclip_range(map, start_entry,
1724 start, entry->end, countp, flags);
1728 return(start_entry);
1732 * Undo the effect of vm_map_clip_range(). You should pass the same
1733 * flags and the same range that you passed to vm_map_clip_range().
1734 * This code will clear the in-transition flag on the entries and
1735 * wake up anyone waiting. This code will also simplify the sequence
1736 * and attempt to merge it with entries before and after the sequence.
1738 * The map must be locked on entry and will remain locked on return.
1740 * Note that you should also pass the start_entry returned by
1741 * vm_map_clip_range(). However, if you block between the two calls
1742 * with the map unlocked please be aware that the start_entry may
1743 * have been clipped and you may need to scan it backwards to find
1744 * the entry corresponding with the original start address. You are
1745 * responsible for this, vm_map_unclip_range() expects the correct
1746 * start_entry to be passed to it and will KASSERT otherwise.
1750 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1751 vm_offset_t start, vm_offset_t end,
1752 int *countp, int flags)
1754 vm_map_entry_t entry;
1756 entry = start_entry;
1758 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1759 while (entry != &map->header && entry->start < end) {
1760 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1761 ("in-transition flag not set during unclip on: %p",
1763 KASSERT(entry->end <= end,
1764 ("unclip_range: tail wasn't clipped"));
1765 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1766 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1767 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1770 entry = entry->next;
1774 * Simplification does not block so there is no restart case.
1776 entry = start_entry;
1777 while (entry != &map->header && entry->start < end) {
1778 vm_map_simplify_entry(map, entry, countp);
1779 entry = entry->next;
1784 * Mark the given range as handled by a subordinate map.
1786 * This range must have been created with vm_map_find(), and no other
1787 * operations may have been performed on this range prior to calling
1790 * Submappings cannot be removed.
1795 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1797 vm_map_entry_t entry;
1798 int result = KERN_INVALID_ARGUMENT;
1801 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1804 VM_MAP_RANGE_CHECK(map, start, end);
1806 if (vm_map_lookup_entry(map, start, &entry)) {
1807 vm_map_clip_start(map, entry, start, &count);
1809 entry = entry->next;
1812 vm_map_clip_end(map, entry, end, &count);
1814 if ((entry->start == start) && (entry->end == end) &&
1815 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1816 (entry->object.vm_object == NULL)) {
1817 entry->object.sub_map = submap;
1818 entry->maptype = VM_MAPTYPE_SUBMAP;
1819 result = KERN_SUCCESS;
1822 vm_map_entry_release(count);
1828 * Sets the protection of the specified address region in the target map.
1829 * If "set_max" is specified, the maximum protection is to be set;
1830 * otherwise, only the current protection is affected.
1832 * The protection is not applicable to submaps, but is applicable to normal
1833 * maps and maps governed by virtual page tables. For example, when operating
1834 * on a virtual page table our protection basically controls how COW occurs
1835 * on the backing object, whereas the virtual page table abstraction itself
1836 * is an abstraction for userland.
1841 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1842 vm_prot_t new_prot, boolean_t set_max)
1844 vm_map_entry_t current;
1845 vm_map_entry_t entry;
1848 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1851 VM_MAP_RANGE_CHECK(map, start, end);
1853 if (vm_map_lookup_entry(map, start, &entry)) {
1854 vm_map_clip_start(map, entry, start, &count);
1856 entry = entry->next;
1860 * Make a first pass to check for protection violations.
1863 while ((current != &map->header) && (current->start < end)) {
1864 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1866 vm_map_entry_release(count);
1867 return (KERN_INVALID_ARGUMENT);
1869 if ((new_prot & current->max_protection) != new_prot) {
1871 vm_map_entry_release(count);
1872 return (KERN_PROTECTION_FAILURE);
1874 current = current->next;
1878 * Go back and fix up protections. [Note that clipping is not
1879 * necessary the second time.]
1883 while ((current != &map->header) && (current->start < end)) {
1886 vm_map_clip_end(map, current, end, &count);
1888 old_prot = current->protection;
1890 current->protection =
1891 (current->max_protection = new_prot) &
1894 current->protection = new_prot;
1898 * Update physical map if necessary. Worry about copy-on-write
1899 * here -- CHECK THIS XXX
1902 if (current->protection != old_prot) {
1903 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1906 pmap_protect(map->pmap, current->start,
1908 current->protection & MASK(current));
1912 vm_map_simplify_entry(map, current, &count);
1914 current = current->next;
1918 vm_map_entry_release(count);
1919 return (KERN_SUCCESS);
1923 * This routine traverses a processes map handling the madvise
1924 * system call. Advisories are classified as either those effecting
1925 * the vm_map_entry structure, or those effecting the underlying
1928 * The <value> argument is used for extended madvise calls.
1933 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1934 int behav, off_t value)
1936 vm_map_entry_t current, entry;
1942 * Some madvise calls directly modify the vm_map_entry, in which case
1943 * we need to use an exclusive lock on the map and we need to perform
1944 * various clipping operations. Otherwise we only need a read-lock
1948 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1952 case MADV_SEQUENTIAL:
1966 vm_map_lock_read(map);
1969 vm_map_entry_release(count);
1974 * Locate starting entry and clip if necessary.
1977 VM_MAP_RANGE_CHECK(map, start, end);
1979 if (vm_map_lookup_entry(map, start, &entry)) {
1981 vm_map_clip_start(map, entry, start, &count);
1983 entry = entry->next;
1988 * madvise behaviors that are implemented in the vm_map_entry.
1990 * We clip the vm_map_entry so that behavioral changes are
1991 * limited to the specified address range.
1993 for (current = entry;
1994 (current != &map->header) && (current->start < end);
1995 current = current->next
1997 if (current->maptype == VM_MAPTYPE_SUBMAP)
2000 vm_map_clip_end(map, current, end, &count);
2004 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
2006 case MADV_SEQUENTIAL:
2007 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
2010 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
2013 current->eflags |= MAP_ENTRY_NOSYNC;
2016 current->eflags &= ~MAP_ENTRY_NOSYNC;
2019 current->eflags |= MAP_ENTRY_NOCOREDUMP;
2022 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
2026 * Invalidate the related pmap entries, used
2027 * to flush portions of the real kernel's
2028 * pmap when the caller has removed or
2029 * modified existing mappings in a virtual
2032 pmap_remove(map->pmap,
2033 current->start, current->end);
2037 * Set the page directory page for a map
2038 * governed by a virtual page table. Mark
2039 * the entry as being governed by a virtual
2040 * page table if it is not.
2042 * XXX the page directory page is stored
2043 * in the avail_ssize field if the map_entry.
2045 * XXX the map simplification code does not
2046 * compare this field so weird things may
2047 * happen if you do not apply this function
2048 * to the entire mapping governed by the
2049 * virtual page table.
2051 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
2055 current->aux.master_pde = value;
2056 pmap_remove(map->pmap,
2057 current->start, current->end);
2063 vm_map_simplify_entry(map, current, &count);
2071 * madvise behaviors that are implemented in the underlying
2074 * Since we don't clip the vm_map_entry, we have to clip
2075 * the vm_object pindex and count.
2077 * NOTE! We currently do not support these functions on
2078 * virtual page tables.
2080 for (current = entry;
2081 (current != &map->header) && (current->start < end);
2082 current = current->next
2084 vm_offset_t useStart;
2086 if (current->maptype != VM_MAPTYPE_NORMAL)
2089 pindex = OFF_TO_IDX(current->offset);
2090 count = atop(current->end - current->start);
2091 useStart = current->start;
2093 if (current->start < start) {
2094 pindex += atop(start - current->start);
2095 count -= atop(start - current->start);
2098 if (current->end > end)
2099 count -= atop(current->end - end);
2104 vm_object_madvise(current->object.vm_object,
2105 pindex, count, behav);
2108 * Try to populate the page table. Mappings governed
2109 * by virtual page tables cannot be pre-populated
2110 * without a lot of work so don't try.
2112 if (behav == MADV_WILLNEED &&
2113 current->maptype != VM_MAPTYPE_VPAGETABLE) {
2114 pmap_object_init_pt(
2117 current->protection,
2118 current->object.vm_object,
2120 (count << PAGE_SHIFT),
2121 MAP_PREFAULT_MADVISE
2125 vm_map_unlock_read(map);
2127 vm_map_entry_release(count);
2133 * Sets the inheritance of the specified address range in the target map.
2134 * Inheritance affects how the map will be shared with child maps at the
2135 * time of vm_map_fork.
2138 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
2139 vm_inherit_t new_inheritance)
2141 vm_map_entry_t entry;
2142 vm_map_entry_t temp_entry;
2145 switch (new_inheritance) {
2146 case VM_INHERIT_NONE:
2147 case VM_INHERIT_COPY:
2148 case VM_INHERIT_SHARE:
2151 return (KERN_INVALID_ARGUMENT);
2154 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2157 VM_MAP_RANGE_CHECK(map, start, end);
2159 if (vm_map_lookup_entry(map, start, &temp_entry)) {
2161 vm_map_clip_start(map, entry, start, &count);
2163 entry = temp_entry->next;
2165 while ((entry != &map->header) && (entry->start < end)) {
2166 vm_map_clip_end(map, entry, end, &count);
2168 entry->inheritance = new_inheritance;
2170 vm_map_simplify_entry(map, entry, &count);
2172 entry = entry->next;
2175 vm_map_entry_release(count);
2176 return (KERN_SUCCESS);
2180 * Implement the semantics of mlock
2183 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2184 boolean_t new_pageable)
2186 vm_map_entry_t entry;
2187 vm_map_entry_t start_entry;
2189 int rv = KERN_SUCCESS;
2192 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2194 VM_MAP_RANGE_CHECK(map, start, real_end);
2197 start_entry = vm_map_clip_range(map, start, end, &count,
2199 if (start_entry == NULL) {
2201 vm_map_entry_release(count);
2202 return (KERN_INVALID_ADDRESS);
2205 if (new_pageable == 0) {
2206 entry = start_entry;
2207 while ((entry != &map->header) && (entry->start < end)) {
2208 vm_offset_t save_start;
2209 vm_offset_t save_end;
2212 * Already user wired or hard wired (trivial cases)
2214 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2215 entry = entry->next;
2218 if (entry->wired_count != 0) {
2219 entry->wired_count++;
2220 entry->eflags |= MAP_ENTRY_USER_WIRED;
2221 entry = entry->next;
2226 * A new wiring requires instantiation of appropriate
2227 * management structures and the faulting in of the
2230 if (entry->maptype == VM_MAPTYPE_NORMAL ||
2231 entry->maptype == VM_MAPTYPE_VPAGETABLE) {
2232 int copyflag = entry->eflags &
2233 MAP_ENTRY_NEEDS_COPY;
2234 if (copyflag && ((entry->protection &
2235 VM_PROT_WRITE) != 0)) {
2236 vm_map_entry_shadow(entry, 0);
2237 } else if (entry->object.vm_object == NULL &&
2239 vm_map_entry_allocate_object(entry);
2242 entry->wired_count++;
2243 entry->eflags |= MAP_ENTRY_USER_WIRED;
2246 * Now fault in the area. Note that vm_fault_wire()
2247 * may release the map lock temporarily, it will be
2248 * relocked on return. The in-transition
2249 * flag protects the entries.
2251 save_start = entry->start;
2252 save_end = entry->end;
2253 rv = vm_fault_wire(map, entry, TRUE, 0);
2255 CLIP_CHECK_BACK(entry, save_start);
2257 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2258 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2259 entry->wired_count = 0;
2260 if (entry->end == save_end)
2262 entry = entry->next;
2263 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2265 end = save_start; /* unwire the rest */
2269 * note that even though the entry might have been
2270 * clipped, the USER_WIRED flag we set prevents
2271 * duplication so we do not have to do a
2274 entry = entry->next;
2278 * If we failed fall through to the unwiring section to
2279 * unwire what we had wired so far. 'end' has already
2286 * start_entry might have been clipped if we unlocked the
2287 * map and blocked. No matter how clipped it has gotten
2288 * there should be a fragment that is on our start boundary.
2290 CLIP_CHECK_BACK(start_entry, start);
2294 * Deal with the unwiring case.
2298 * This is the unwiring case. We must first ensure that the
2299 * range to be unwired is really wired down. We know there
2302 entry = start_entry;
2303 while ((entry != &map->header) && (entry->start < end)) {
2304 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2305 rv = KERN_INVALID_ARGUMENT;
2308 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2309 entry = entry->next;
2313 * Now decrement the wiring count for each region. If a region
2314 * becomes completely unwired, unwire its physical pages and
2318 * The map entries are processed in a loop, checking to
2319 * make sure the entry is wired and asserting it has a wired
2320 * count. However, another loop was inserted more-or-less in
2321 * the middle of the unwiring path. This loop picks up the
2322 * "entry" loop variable from the first loop without first
2323 * setting it to start_entry. Naturally, the secound loop
2324 * is never entered and the pages backing the entries are
2325 * never unwired. This can lead to a leak of wired pages.
2327 entry = start_entry;
2328 while ((entry != &map->header) && (entry->start < end)) {
2329 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2330 ("expected USER_WIRED on entry %p", entry));
2331 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2332 entry->wired_count--;
2333 if (entry->wired_count == 0)
2334 vm_fault_unwire(map, entry);
2335 entry = entry->next;
2339 vm_map_unclip_range(map, start_entry, start, real_end, &count,
2343 vm_map_entry_release(count);
2348 * Sets the pageability of the specified address range in the target map.
2349 * Regions specified as not pageable require locked-down physical
2350 * memory and physical page maps.
2352 * The map must not be locked, but a reference must remain to the map
2353 * throughout the call.
2355 * This function may be called via the zalloc path and must properly
2356 * reserve map entries for kernel_map.
2361 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2363 vm_map_entry_t entry;
2364 vm_map_entry_t start_entry;
2366 int rv = KERN_SUCCESS;
2369 if (kmflags & KM_KRESERVE)
2370 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2372 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2374 VM_MAP_RANGE_CHECK(map, start, real_end);
2377 start_entry = vm_map_clip_range(map, start, end, &count,
2379 if (start_entry == NULL) {
2381 rv = KERN_INVALID_ADDRESS;
2384 if ((kmflags & KM_PAGEABLE) == 0) {
2388 * 1. Holding the write lock, we create any shadow or zero-fill
2389 * objects that need to be created. Then we clip each map
2390 * entry to the region to be wired and increment its wiring
2391 * count. We create objects before clipping the map entries
2392 * to avoid object proliferation.
2394 * 2. We downgrade to a read lock, and call vm_fault_wire to
2395 * fault in the pages for any newly wired area (wired_count is
2398 * Downgrading to a read lock for vm_fault_wire avoids a
2399 * possible deadlock with another process that may have faulted
2400 * on one of the pages to be wired (it would mark the page busy,
2401 * blocking us, then in turn block on the map lock that we
2402 * hold). Because of problems in the recursive lock package,
2403 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2404 * any actions that require the write lock must be done
2405 * beforehand. Because we keep the read lock on the map, the
2406 * copy-on-write status of the entries we modify here cannot
2409 entry = start_entry;
2410 while ((entry != &map->header) && (entry->start < end)) {
2412 * Trivial case if the entry is already wired
2414 if (entry->wired_count) {
2415 entry->wired_count++;
2416 entry = entry->next;
2421 * The entry is being newly wired, we have to setup
2422 * appropriate management structures. A shadow
2423 * object is required for a copy-on-write region,
2424 * or a normal object for a zero-fill region. We
2425 * do not have to do this for entries that point to sub
2426 * maps because we won't hold the lock on the sub map.
2428 if (entry->maptype == VM_MAPTYPE_NORMAL ||
2429 entry->maptype == VM_MAPTYPE_VPAGETABLE) {
2430 int copyflag = entry->eflags &
2431 MAP_ENTRY_NEEDS_COPY;
2432 if (copyflag && ((entry->protection &
2433 VM_PROT_WRITE) != 0)) {
2434 vm_map_entry_shadow(entry, 0);
2435 } else if (entry->object.vm_object == NULL &&
2437 vm_map_entry_allocate_object(entry);
2441 entry->wired_count++;
2442 entry = entry->next;
2450 * HACK HACK HACK HACK
2452 * vm_fault_wire() temporarily unlocks the map to avoid
2453 * deadlocks. The in-transition flag from vm_map_clip_range
2454 * call should protect us from changes while the map is
2457 * NOTE: Previously this comment stated that clipping might
2458 * still occur while the entry is unlocked, but from
2459 * what I can tell it actually cannot.
2461 * It is unclear whether the CLIP_CHECK_*() calls
2462 * are still needed but we keep them in anyway.
2464 * HACK HACK HACK HACK
2467 entry = start_entry;
2468 while (entry != &map->header && entry->start < end) {
2470 * If vm_fault_wire fails for any page we need to undo
2471 * what has been done. We decrement the wiring count
2472 * for those pages which have not yet been wired (now)
2473 * and unwire those that have (later).
2475 vm_offset_t save_start = entry->start;
2476 vm_offset_t save_end = entry->end;
2478 if (entry->wired_count == 1)
2479 rv = vm_fault_wire(map, entry, FALSE, kmflags);
2481 CLIP_CHECK_BACK(entry, save_start);
2483 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2484 entry->wired_count = 0;
2485 if (entry->end == save_end)
2487 entry = entry->next;
2488 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2493 CLIP_CHECK_FWD(entry, save_end);
2494 entry = entry->next;
2498 * If a failure occured undo everything by falling through
2499 * to the unwiring code. 'end' has already been adjusted
2503 kmflags |= KM_PAGEABLE;
2506 * start_entry is still IN_TRANSITION but may have been
2507 * clipped since vm_fault_wire() unlocks and relocks the
2508 * map. No matter how clipped it has gotten there should
2509 * be a fragment that is on our start boundary.
2511 CLIP_CHECK_BACK(start_entry, start);
2514 if (kmflags & KM_PAGEABLE) {
2516 * This is the unwiring case. We must first ensure that the
2517 * range to be unwired is really wired down. We know there
2520 entry = start_entry;
2521 while ((entry != &map->header) && (entry->start < end)) {
2522 if (entry->wired_count == 0) {
2523 rv = KERN_INVALID_ARGUMENT;
2526 entry = entry->next;
2530 * Now decrement the wiring count for each region. If a region
2531 * becomes completely unwired, unwire its physical pages and
2534 entry = start_entry;
2535 while ((entry != &map->header) && (entry->start < end)) {
2536 entry->wired_count--;
2537 if (entry->wired_count == 0)
2538 vm_fault_unwire(map, entry);
2539 entry = entry->next;
2543 vm_map_unclip_range(map, start_entry, start, real_end,
2544 &count, MAP_CLIP_NO_HOLES);
2548 if (kmflags & KM_KRESERVE)
2549 vm_map_entry_krelease(count);
2551 vm_map_entry_release(count);
2556 * Mark a newly allocated address range as wired but do not fault in
2557 * the pages. The caller is expected to load the pages into the object.
2559 * The map must be locked on entry and will remain locked on return.
2560 * No other requirements.
2563 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2566 vm_map_entry_t scan;
2567 vm_map_entry_t entry;
2569 entry = vm_map_clip_range(map, addr, addr + size,
2570 countp, MAP_CLIP_NO_HOLES);
2572 scan != &map->header && scan->start < addr + size;
2573 scan = scan->next) {
2574 KKASSERT(scan->wired_count == 0);
2575 scan->wired_count = 1;
2577 vm_map_unclip_range(map, entry, addr, addr + size,
2578 countp, MAP_CLIP_NO_HOLES);
2582 * Push any dirty cached pages in the address range to their pager.
2583 * If syncio is TRUE, dirty pages are written synchronously.
2584 * If invalidate is TRUE, any cached pages are freed as well.
2586 * This routine is called by sys_msync()
2588 * Returns an error if any part of the specified range is not mapped.
2593 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2594 boolean_t syncio, boolean_t invalidate)
2596 vm_map_entry_t current;
2597 vm_map_entry_t entry;
2601 vm_ooffset_t offset;
2603 vm_map_lock_read(map);
2604 VM_MAP_RANGE_CHECK(map, start, end);
2605 if (!vm_map_lookup_entry(map, start, &entry)) {
2606 vm_map_unlock_read(map);
2607 return (KERN_INVALID_ADDRESS);
2609 lwkt_gettoken(&map->token);
2612 * Make a first pass to check for holes.
2614 for (current = entry; current->start < end; current = current->next) {
2615 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2616 lwkt_reltoken(&map->token);
2617 vm_map_unlock_read(map);
2618 return (KERN_INVALID_ARGUMENT);
2620 if (end > current->end &&
2621 (current->next == &map->header ||
2622 current->end != current->next->start)) {
2623 lwkt_reltoken(&map->token);
2624 vm_map_unlock_read(map);
2625 return (KERN_INVALID_ADDRESS);
2630 pmap_remove(vm_map_pmap(map), start, end);
2633 * Make a second pass, cleaning/uncaching pages from the indicated
2636 for (current = entry; current->start < end; current = current->next) {
2637 offset = current->offset + (start - current->start);
2638 size = (end <= current->end ? end : current->end) - start;
2640 switch(current->maptype) {
2641 case VM_MAPTYPE_SUBMAP:
2644 vm_map_entry_t tentry;
2647 smap = current->object.sub_map;
2648 vm_map_lock_read(smap);
2649 vm_map_lookup_entry(smap, offset, &tentry);
2650 tsize = tentry->end - offset;
2653 object = tentry->object.vm_object;
2654 offset = tentry->offset + (offset - tentry->start);
2655 vm_map_unlock_read(smap);
2658 case VM_MAPTYPE_NORMAL:
2659 case VM_MAPTYPE_VPAGETABLE:
2660 object = current->object.vm_object;
2668 vm_object_hold(object);
2671 * Note that there is absolutely no sense in writing out
2672 * anonymous objects, so we track down the vnode object
2674 * We invalidate (remove) all pages from the address space
2675 * anyway, for semantic correctness.
2677 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2678 * may start out with a NULL object.
2680 while (object && (tobj = object->backing_object) != NULL) {
2681 vm_object_hold(tobj);
2682 if (tobj == object->backing_object) {
2683 vm_object_lock_swap();
2684 offset += object->backing_object_offset;
2685 vm_object_drop(object);
2687 if (object->size < OFF_TO_IDX(offset + size))
2688 size = IDX_TO_OFF(object->size) -
2692 vm_object_drop(tobj);
2694 if (object && (object->type == OBJT_VNODE) &&
2695 (current->protection & VM_PROT_WRITE) &&
2696 (object->flags & OBJ_NOMSYNC) == 0) {
2698 * Flush pages if writing is allowed, invalidate them
2699 * if invalidation requested. Pages undergoing I/O
2700 * will be ignored by vm_object_page_remove().
2702 * We cannot lock the vnode and then wait for paging
2703 * to complete without deadlocking against vm_fault.
2704 * Instead we simply call vm_object_page_remove() and
2705 * allow it to block internally on a page-by-page
2706 * basis when it encounters pages undergoing async
2711 /* no chain wait needed for vnode objects */
2712 vm_object_reference_locked(object);
2713 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2714 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2715 flags |= invalidate ? OBJPC_INVAL : 0;
2718 * When operating on a virtual page table just
2719 * flush the whole object. XXX we probably ought
2722 switch(current->maptype) {
2723 case VM_MAPTYPE_NORMAL:
2724 vm_object_page_clean(object,
2726 OFF_TO_IDX(offset + size + PAGE_MASK),
2729 case VM_MAPTYPE_VPAGETABLE:
2730 vm_object_page_clean(object, 0, 0, flags);
2733 vn_unlock(((struct vnode *)object->handle));
2734 vm_object_deallocate_locked(object);
2736 if (object && invalidate &&
2737 ((object->type == OBJT_VNODE) ||
2738 (object->type == OBJT_DEVICE) ||
2739 (object->type == OBJT_MGTDEVICE))) {
2741 ((object->type == OBJT_DEVICE) ||
2742 (object->type == OBJT_MGTDEVICE)) ? FALSE : TRUE;
2743 /* no chain wait needed for vnode/device objects */
2744 vm_object_reference_locked(object);
2745 switch(current->maptype) {
2746 case VM_MAPTYPE_NORMAL:
2747 vm_object_page_remove(object,
2749 OFF_TO_IDX(offset + size + PAGE_MASK),
2752 case VM_MAPTYPE_VPAGETABLE:
2753 vm_object_page_remove(object, 0, 0, clean_only);
2756 vm_object_deallocate_locked(object);
2760 vm_object_drop(object);
2763 lwkt_reltoken(&map->token);
2764 vm_map_unlock_read(map);
2766 return (KERN_SUCCESS);
2770 * Make the region specified by this entry pageable.
2772 * The vm_map must be exclusively locked.
2775 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2777 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2778 entry->wired_count = 0;
2779 vm_fault_unwire(map, entry);
2783 * Deallocate the given entry from the target map.
2785 * The vm_map must be exclusively locked.
2788 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2790 vm_map_entry_unlink(map, entry);
2791 map->size -= entry->end - entry->start;
2793 switch(entry->maptype) {
2794 case VM_MAPTYPE_NORMAL:
2795 case VM_MAPTYPE_VPAGETABLE:
2796 case VM_MAPTYPE_SUBMAP:
2797 vm_object_deallocate(entry->object.vm_object);
2799 case VM_MAPTYPE_UKSMAP:
2806 vm_map_entry_dispose(map, entry, countp);
2810 * Deallocates the given address range from the target map.
2812 * The vm_map must be exclusively locked.
2815 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2818 vm_map_entry_t entry;
2819 vm_map_entry_t first_entry;
2821 ASSERT_VM_MAP_LOCKED(map);
2822 lwkt_gettoken(&map->token);
2825 * Find the start of the region, and clip it. Set entry to point
2826 * at the first record containing the requested address or, if no
2827 * such record exists, the next record with a greater address. The
2828 * loop will run from this point until a record beyond the termination
2829 * address is encountered.
2831 * map->hint must be adjusted to not point to anything we delete,
2832 * so set it to the entry prior to the one being deleted.
2834 * GGG see other GGG comment.
2836 if (vm_map_lookup_entry(map, start, &first_entry)) {
2837 entry = first_entry;
2838 vm_map_clip_start(map, entry, start, countp);
2839 map->hint = entry->prev; /* possible problem XXX */
2841 map->hint = first_entry; /* possible problem XXX */
2842 entry = first_entry->next;
2846 * If a hole opens up prior to the current first_free then
2847 * adjust first_free. As with map->hint, map->first_free
2848 * cannot be left set to anything we might delete.
2850 if (entry == &map->header) {
2851 map->first_free = &map->header;
2852 } else if (map->first_free->start >= start) {
2853 map->first_free = entry->prev;
2857 * Step through all entries in this region
2859 while ((entry != &map->header) && (entry->start < end)) {
2860 vm_map_entry_t next;
2862 vm_pindex_t offidxstart, offidxend, count;
2865 * If we hit an in-transition entry we have to sleep and
2866 * retry. It's easier (and not really slower) to just retry
2867 * since this case occurs so rarely and the hint is already
2868 * pointing at the right place. We have to reset the
2869 * start offset so as not to accidently delete an entry
2870 * another process just created in vacated space.
2872 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2873 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2874 start = entry->start;
2875 ++mycpu->gd_cnt.v_intrans_coll;
2876 ++mycpu->gd_cnt.v_intrans_wait;
2877 vm_map_transition_wait(map);
2880 vm_map_clip_end(map, entry, end, countp);
2886 offidxstart = OFF_TO_IDX(entry->offset);
2887 count = OFF_TO_IDX(e - s);
2889 switch(entry->maptype) {
2890 case VM_MAPTYPE_NORMAL:
2891 case VM_MAPTYPE_VPAGETABLE:
2892 case VM_MAPTYPE_SUBMAP:
2893 object = entry->object.vm_object;
2901 * Unwire before removing addresses from the pmap; otherwise,
2902 * unwiring will put the entries back in the pmap.
2904 if (entry->wired_count != 0)
2905 vm_map_entry_unwire(map, entry);
2907 offidxend = offidxstart + count;
2909 if (object == &kernel_object) {
2910 vm_object_hold(object);
2911 vm_object_page_remove(object, offidxstart,
2913 vm_object_drop(object);
2914 } else if (object && object->type != OBJT_DEFAULT &&
2915 object->type != OBJT_SWAP) {
2917 * vnode object routines cannot be chain-locked,
2918 * but since we aren't removing pages from the
2919 * object here we can use a shared hold.
2921 vm_object_hold_shared(object);
2922 pmap_remove(map->pmap, s, e);
2923 vm_object_drop(object);
2924 } else if (object) {
2925 vm_object_hold(object);
2926 vm_object_chain_acquire(object, 0);
2927 pmap_remove(map->pmap, s, e);
2929 if (object != NULL &&
2930 object->ref_count != 1 &&
2931 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2933 (object->type == OBJT_DEFAULT ||
2934 object->type == OBJT_SWAP)) {
2935 vm_object_collapse(object, NULL);
2936 vm_object_page_remove(object, offidxstart,
2938 if (object->type == OBJT_SWAP) {
2939 swap_pager_freespace(object,
2943 if (offidxend >= object->size &&
2944 offidxstart < object->size) {
2945 object->size = offidxstart;
2948 vm_object_chain_release(object);
2949 vm_object_drop(object);
2950 } else if (entry->maptype == VM_MAPTYPE_UKSMAP) {
2951 pmap_remove(map->pmap, s, e);
2955 * Delete the entry (which may delete the object) only after
2956 * removing all pmap entries pointing to its pages.
2957 * (Otherwise, its page frames may be reallocated, and any
2958 * modify bits will be set in the wrong object!)
2960 vm_map_entry_delete(map, entry, countp);
2963 lwkt_reltoken(&map->token);
2964 return (KERN_SUCCESS);
2968 * Remove the given address range from the target map.
2969 * This is the exported form of vm_map_delete.
2974 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
2979 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2981 VM_MAP_RANGE_CHECK(map, start, end);
2982 result = vm_map_delete(map, start, end, &count);
2984 vm_map_entry_release(count);
2990 * Assert that the target map allows the specified privilege on the
2991 * entire address region given. The entire region must be allocated.
2993 * The caller must specify whether the vm_map is already locked or not.
2996 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2997 vm_prot_t protection, boolean_t have_lock)
2999 vm_map_entry_t entry;
3000 vm_map_entry_t tmp_entry;
3003 if (have_lock == FALSE)
3004 vm_map_lock_read(map);
3006 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
3007 if (have_lock == FALSE)
3008 vm_map_unlock_read(map);
3014 while (start < end) {
3015 if (entry == &map->header) {
3023 if (start < entry->start) {
3028 * Check protection associated with entry.
3031 if ((entry->protection & protection) != protection) {
3035 /* go to next entry */
3038 entry = entry->next;
3040 if (have_lock == FALSE)
3041 vm_map_unlock_read(map);
3046 * If appropriate this function shadows the original object with a new object
3047 * and moves the VM pages from the original object to the new object.
3048 * The original object will also be collapsed, if possible.
3050 * We can only do this for normal memory objects with a single mapping, and
3051 * it only makes sense to do it if there are 2 or more refs on the original
3052 * object. i.e. typically a memory object that has been extended into
3053 * multiple vm_map_entry's with non-overlapping ranges.
3055 * This makes it easier to remove unused pages and keeps object inheritance
3056 * from being a negative impact on memory usage.
3058 * On return the (possibly new) entry->object.vm_object will have an
3059 * additional ref on it for the caller to dispose of (usually by cloning
3060 * the vm_map_entry). The additional ref had to be done in this routine
3061 * to avoid racing a collapse. The object's ONEMAPPING flag will also be
3064 * The vm_map must be locked and its token held.
3067 vm_map_split(vm_map_entry_t entry)
3070 vm_object_t oobject, nobject, bobject;
3073 vm_pindex_t offidxstart, offidxend, idx;
3075 vm_ooffset_t offset;
3079 * Optimize away object locks for vnode objects. Important exit/exec
3082 * OBJ_ONEMAPPING doesn't apply to vnode objects but clear the flag
3085 oobject = entry->object.vm_object;
3086 if (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) {
3087 vm_object_reference_quick(oobject);
3088 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3093 * Setup. Chain lock the original object throughout the entire
3094 * routine to prevent new page faults from occuring.
3096 * XXX can madvise WILLNEED interfere with us too?
3098 vm_object_hold(oobject);
3099 vm_object_chain_acquire(oobject, 0);
3102 * Original object cannot be split? Might have also changed state.
3104 if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT &&
3105 oobject->type != OBJT_SWAP)) {
3106 vm_object_chain_release(oobject);
3107 vm_object_reference_locked(oobject);
3108 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3109 vm_object_drop(oobject);
3114 * Collapse original object with its backing store as an
3115 * optimization to reduce chain lengths when possible.
3117 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's
3118 * for oobject, so there's no point collapsing it.
3120 * Then re-check whether the object can be split.
3122 vm_object_collapse(oobject, NULL);
3124 if (oobject->ref_count <= 1 ||
3125 (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) ||
3126 (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) {
3127 vm_object_chain_release(oobject);
3128 vm_object_reference_locked(oobject);
3129 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3130 vm_object_drop(oobject);
3135 * Acquire the chain lock on the backing object.
3137 * Give bobject an additional ref count for when it will be shadowed
3141 if ((bobject = oobject->backing_object) != NULL) {
3142 if (bobject->type != OBJT_VNODE) {
3144 vm_object_hold(bobject);
3145 vm_object_chain_wait(bobject, 0);
3146 /* ref for shadowing below */
3147 vm_object_reference_locked(bobject);
3148 vm_object_chain_acquire(bobject, 0);
3149 KKASSERT(bobject->backing_object == bobject);
3150 KKASSERT((bobject->flags & OBJ_DEAD) == 0);
3153 * vnodes are not placed on the shadow list but
3154 * they still get another ref for the backing_object
3157 vm_object_reference_quick(bobject);
3162 * Calculate the object page range and allocate the new object.
3164 offset = entry->offset;
3168 offidxstart = OFF_TO_IDX(offset);
3169 offidxend = offidxstart + OFF_TO_IDX(e - s);
3170 size = offidxend - offidxstart;
3172 switch(oobject->type) {
3174 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size),
3178 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size),
3187 if (nobject == NULL) {
3189 if (useshadowlist) {
3190 vm_object_chain_release(bobject);
3191 vm_object_deallocate(bobject);
3192 vm_object_drop(bobject);
3194 vm_object_deallocate(bobject);
3197 vm_object_chain_release(oobject);
3198 vm_object_reference_locked(oobject);
3199 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3200 vm_object_drop(oobject);
3205 * The new object will replace entry->object.vm_object so it needs
3206 * a second reference (the caller expects an additional ref).
3208 vm_object_hold(nobject);
3209 vm_object_reference_locked(nobject);
3210 vm_object_chain_acquire(nobject, 0);
3213 * nobject shadows bobject (oobject already shadows bobject).
3215 * Adding an object to bobject's shadow list requires refing bobject
3216 * which we did above in the useshadowlist case.
3219 nobject->backing_object_offset =
3220 oobject->backing_object_offset + IDX_TO_OFF(offidxstart);
3221 nobject->backing_object = bobject;
3222 if (useshadowlist) {
3223 bobject->shadow_count++;
3224 bobject->generation++;
3225 LIST_INSERT_HEAD(&bobject->shadow_head,
3226 nobject, shadow_list);
3227 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /*XXX*/
3228 vm_object_chain_release(bobject);
3229 vm_object_drop(bobject);
3230 vm_object_set_flag(nobject, OBJ_ONSHADOW);
3235 * Move the VM pages from oobject to nobject
3237 for (idx = 0; idx < size; idx++) {
3240 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx,
3246 * We must wait for pending I/O to complete before we can
3249 * We do not have to VM_PROT_NONE the page as mappings should
3250 * not be changed by this operation.
3252 * NOTE: The act of renaming a page updates chaingen for both
3255 vm_page_rename(m, nobject, idx);
3256 /* page automatically made dirty by rename and cache handled */
3257 /* page remains busy */
3260 if (oobject->type == OBJT_SWAP) {
3261 vm_object_pip_add(oobject, 1);
3263 * copy oobject pages into nobject and destroy unneeded
3264 * pages in shadow object.
3266 swap_pager_copy(oobject, nobject, offidxstart, 0);
3267 vm_object_pip_wakeup(oobject);
3271 * Wakeup the pages we played with. No spl protection is needed
3272 * for a simple wakeup.
3274 for (idx = 0; idx < size; idx++) {
3275 m = vm_page_lookup(nobject, idx);
3277 KKASSERT(m->flags & PG_BUSY);
3281 entry->object.vm_object = nobject;
3282 entry->offset = 0LL;
3287 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the
3288 * related pages were moved and are no longer applicable to the
3291 * NOTE: Deallocate oobject (due to its entry->object.vm_object being
3292 * replaced by nobject).
3294 vm_object_chain_release(nobject);
3295 vm_object_drop(nobject);
3296 if (bobject && useshadowlist) {
3297 vm_object_chain_release(bobject);
3298 vm_object_drop(bobject);
3300 vm_object_chain_release(oobject);
3301 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/
3302 vm_object_deallocate_locked(oobject);
3303 vm_object_drop(oobject);
3307 * Copies the contents of the source entry to the destination
3308 * entry. The entries *must* be aligned properly.
3310 * The vm_maps must be exclusively locked.
3311 * The vm_map's token must be held.
3313 * Because the maps are locked no faults can be in progress during the
3317 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
3318 vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
3320 vm_object_t src_object;
3322 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP ||
3323 dst_entry->maptype == VM_MAPTYPE_UKSMAP)
3325 if (src_entry->maptype == VM_MAPTYPE_SUBMAP ||
3326 src_entry->maptype == VM_MAPTYPE_UKSMAP)
3329 if (src_entry->wired_count == 0) {
3331 * If the source entry is marked needs_copy, it is already
3334 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
3335 pmap_protect(src_map->pmap,
3338 src_entry->protection & ~VM_PROT_WRITE);
3342 * Make a copy of the object.
3344 * The object must be locked prior to checking the object type
3345 * and for the call to vm_object_collapse() and vm_map_split().
3346 * We cannot use *_hold() here because the split code will
3347 * probably try to destroy the object. The lock is a pool
3348 * token and doesn't care.
3350 * We must bump src_map->timestamp when setting
3351 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault
3352 * to retry, otherwise the concurrent fault might improperly
3353 * install a RW pte when its supposed to be a RO(COW) pte.
3354 * This race can occur because a vnode-backed fault may have
3355 * to temporarily release the map lock.
3357 if (src_entry->object.vm_object != NULL) {
3358 vm_map_split(src_entry);
3359 src_object = src_entry->object.vm_object;
3360 dst_entry->object.vm_object = src_object;
3361 src_entry->eflags |= (MAP_ENTRY_COW |
3362 MAP_ENTRY_NEEDS_COPY);
3363 dst_entry->eflags |= (MAP_ENTRY_COW |
3364 MAP_ENTRY_NEEDS_COPY);
3365 dst_entry->offset = src_entry->offset;
3366 ++src_map->timestamp;
3368 dst_entry->object.vm_object = NULL;
3369 dst_entry->offset = 0;
3372 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3373 dst_entry->end - dst_entry->start, src_entry->start);
3376 * Of course, wired down pages can't be set copy-on-write.
3377 * Cause wired pages to be copied into the new map by
3378 * simulating faults (the new pages are pageable)
3380 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3386 * Create a new process vmspace structure and vm_map
3387 * based on those of an existing process. The new map
3388 * is based on the old map, according to the inheritance
3389 * values on the regions in that map.
3391 * The source map must not be locked.
3394 static void vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map,
3395 vm_map_entry_t old_entry, int *countp);
3396 static void vmspace_fork_uksmap_entry(vm_map_t old_map, vm_map_t new_map,
3397 vm_map_entry_t old_entry, int *countp);
3400 vmspace_fork(struct vmspace *vm1)
3402 struct vmspace *vm2;
3403 vm_map_t old_map = &vm1->vm_map;
3405 vm_map_entry_t old_entry;
3408 lwkt_gettoken(&vm1->vm_map.token);
3409 vm_map_lock(old_map);
3411 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3412 lwkt_gettoken(&vm2->vm_map.token);
3413 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3414 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3415 new_map = &vm2->vm_map; /* XXX */
3416 new_map->timestamp = 1;
3418 vm_map_lock(new_map);
3421 old_entry = old_map->header.next;
3422 while (old_entry != &old_map->header) {
3424 old_entry = old_entry->next;
3427 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3429 old_entry = old_map->header.next;
3430 while (old_entry != &old_map->header) {
3431 switch(old_entry->maptype) {
3432 case VM_MAPTYPE_SUBMAP:
3433 panic("vm_map_fork: encountered a submap");
3435 case VM_MAPTYPE_UKSMAP:
3436 vmspace_fork_uksmap_entry(old_map, new_map,
3439 case VM_MAPTYPE_NORMAL:
3440 case VM_MAPTYPE_VPAGETABLE:
3441 vmspace_fork_normal_entry(old_map, new_map,
3445 old_entry = old_entry->next;
3448 new_map->size = old_map->size;
3449 vm_map_unlock(old_map);
3450 vm_map_unlock(new_map);
3451 vm_map_entry_release(count);
3453 lwkt_reltoken(&vm2->vm_map.token);
3454 lwkt_reltoken(&vm1->vm_map.token);
3461 vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map,
3462 vm_map_entry_t old_entry, int *countp)
3464 vm_map_entry_t new_entry;
3467 switch (old_entry->inheritance) {
3468 case VM_INHERIT_NONE:
3470 case VM_INHERIT_SHARE:
3472 * Clone the entry, creating the shared object if
3475 if (old_entry->object.vm_object == NULL)
3476 vm_map_entry_allocate_object(old_entry);
3478 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3480 * Shadow a map_entry which needs a copy,
3481 * replacing its object with a new object
3482 * that points to the old one. Ask the
3483 * shadow code to automatically add an
3484 * additional ref. We can't do it afterwords
3485 * because we might race a collapse. The call
3486 * to vm_map_entry_shadow() will also clear
3489 vm_map_entry_shadow(old_entry, 1);
3490 } else if (old_entry->object.vm_object) {
3492 * We will make a shared copy of the object,
3493 * and must clear OBJ_ONEMAPPING.
3495 * Optimize vnode objects. OBJ_ONEMAPPING
3496 * is non-applicable but clear it anyway,
3497 * and its terminal so we don'th ave to deal
3498 * with chains. Reduces SMP conflicts.
3500 * XXX assert that object.vm_object != NULL
3501 * since we allocate it above.
3503 object = old_entry->object.vm_object;
3504 if (object->type == OBJT_VNODE) {
3505 vm_object_reference_quick(object);
3506 vm_object_clear_flag(object,
3509 vm_object_hold(object);
3510 vm_object_chain_wait(object, 0);
3511 vm_object_reference_locked(object);
3512 vm_object_clear_flag(object,
3514 vm_object_drop(object);
3519 * Clone the entry. We've already bumped the ref on
3522 new_entry = vm_map_entry_create(new_map, countp);
3523 *new_entry = *old_entry;
3524 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3525 new_entry->wired_count = 0;
3528 * Insert the entry into the new map -- we know we're
3529 * inserting at the end of the new map.
3532 vm_map_entry_link(new_map, new_map->header.prev,
3536 * Update the physical map
3538 pmap_copy(new_map->pmap, old_map->pmap,
3540 (old_entry->end - old_entry->start),
3543 case VM_INHERIT_COPY:
3545 * Clone the entry and link into the map.
3547 new_entry = vm_map_entry_create(new_map, countp);
3548 *new_entry = *old_entry;
3549 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3550 new_entry->wired_count = 0;
3551 new_entry->object.vm_object = NULL;
3552 vm_map_entry_link(new_map, new_map->header.prev,
3554 vm_map_copy_entry(old_map, new_map, old_entry,
3561 * When forking user-kernel shared maps, the map might change in the
3562 * child so do not try to copy the underlying pmap entries.
3566 vmspace_fork_uksmap_entry(vm_map_t old_map, vm_map_t new_map,
3567 vm_map_entry_t old_entry, int *countp)
3569 vm_map_entry_t new_entry;
3571 new_entry = vm_map_entry_create(new_map, countp);
3572 *new_entry = *old_entry;
3573 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3574 new_entry->wired_count = 0;
3575 vm_map_entry_link(new_map, new_map->header.prev,
3580 * Create an auto-grow stack entry
3585 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3586 int flags, vm_prot_t prot, vm_prot_t max, int cow)
3588 vm_map_entry_t prev_entry;
3589 vm_map_entry_t new_stack_entry;
3590 vm_size_t init_ssize;
3593 vm_offset_t tmpaddr;
3595 cow |= MAP_IS_STACK;
3597 if (max_ssize < sgrowsiz)
3598 init_ssize = max_ssize;
3600 init_ssize = sgrowsiz;
3602 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3606 * Find space for the mapping
3608 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3609 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3612 vm_map_entry_release(count);
3613 return (KERN_NO_SPACE);
3618 /* If addr is already mapped, no go */
3619 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3621 vm_map_entry_release(count);
3622 return (KERN_NO_SPACE);
3626 /* XXX already handled by kern_mmap() */
3627 /* If we would blow our VMEM resource limit, no go */
3628 if (map->size + init_ssize >
3629 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3631 vm_map_entry_release(count);
3632 return (KERN_NO_SPACE);
3637 * If we can't accomodate max_ssize in the current mapping,
3638 * no go. However, we need to be aware that subsequent user
3639 * mappings might map into the space we have reserved for
3640 * stack, and currently this space is not protected.
3642 * Hopefully we will at least detect this condition
3643 * when we try to grow the stack.
3645 if ((prev_entry->next != &map->header) &&
3646 (prev_entry->next->start < addrbos + max_ssize)) {
3648 vm_map_entry_release(count);
3649 return (KERN_NO_SPACE);
3653 * We initially map a stack of only init_ssize. We will
3654 * grow as needed later. Since this is to be a grow
3655 * down stack, we map at the top of the range.
3657 * Note: we would normally expect prot and max to be
3658 * VM_PROT_ALL, and cow to be 0. Possibly we should
3659 * eliminate these as input parameters, and just
3660 * pass these values here in the insert call.
3662 rv = vm_map_insert(map, &count, NULL, NULL,
3663 0, addrbos + max_ssize - init_ssize,
3664 addrbos + max_ssize,
3668 /* Now set the avail_ssize amount */
3669 if (rv == KERN_SUCCESS) {
3670 if (prev_entry != &map->header)
3671 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3672 new_stack_entry = prev_entry->next;
3673 if (new_stack_entry->end != addrbos + max_ssize ||
3674 new_stack_entry->start != addrbos + max_ssize - init_ssize)
3675 panic ("Bad entry start/end for new stack entry");
3677 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3681 vm_map_entry_release(count);
3686 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3687 * desired address is already mapped, or if we successfully grow
3688 * the stack. Also returns KERN_SUCCESS if addr is outside the
3689 * stack range (this is strange, but preserves compatibility with
3690 * the grow function in vm_machdep.c).
3695 vm_map_growstack (struct proc *p, vm_offset_t addr)
3697 vm_map_entry_t prev_entry;
3698 vm_map_entry_t stack_entry;
3699 vm_map_entry_t new_stack_entry;
3700 struct vmspace *vm = p->p_vmspace;
3701 vm_map_t map = &vm->vm_map;
3704 int rv = KERN_SUCCESS;
3706 int use_read_lock = 1;
3709 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3712 vm_map_lock_read(map);
3716 /* If addr is already in the entry range, no need to grow.*/
3717 if (vm_map_lookup_entry(map, addr, &prev_entry))
3720 if ((stack_entry = prev_entry->next) == &map->header)
3722 if (prev_entry == &map->header)
3723 end = stack_entry->start - stack_entry->aux.avail_ssize;
3725 end = prev_entry->end;
3728 * This next test mimics the old grow function in vm_machdep.c.
3729 * It really doesn't quite make sense, but we do it anyway
3730 * for compatibility.
3732 * If not growable stack, return success. This signals the
3733 * caller to proceed as he would normally with normal vm.
3735 if (stack_entry->aux.avail_ssize < 1 ||
3736 addr >= stack_entry->start ||
3737 addr < stack_entry->start - stack_entry->aux.avail_ssize) {
3741 /* Find the minimum grow amount */
3742 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3743 if (grow_amount > stack_entry->aux.avail_ssize) {
3749 * If there is no longer enough space between the entries
3750 * nogo, and adjust the available space. Note: this
3751 * should only happen if the user has mapped into the
3752 * stack area after the stack was created, and is
3753 * probably an error.
3755 * This also effectively destroys any guard page the user
3756 * might have intended by limiting the stack size.
3758 if (grow_amount > stack_entry->start - end) {
3759 if (use_read_lock && vm_map_lock_upgrade(map)) {
3765 stack_entry->aux.avail_ssize = stack_entry->start - end;
3770 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3772 /* If this is the main process stack, see if we're over the
3775 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3776 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3781 /* Round up the grow amount modulo SGROWSIZ */
3782 grow_amount = roundup (grow_amount, sgrowsiz);
3783 if (grow_amount > stack_entry->aux.avail_ssize) {
3784 grow_amount = stack_entry->aux.avail_ssize;
3786 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3787 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3788 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3792 /* If we would blow our VMEM resource limit, no go */
3793 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3798 if (use_read_lock && vm_map_lock_upgrade(map)) {
3805 /* Get the preliminary new entry start value */
3806 addr = stack_entry->start - grow_amount;
3808 /* If this puts us into the previous entry, cut back our growth
3809 * to the available space. Also, see the note above.
3812 stack_entry->aux.avail_ssize = stack_entry->start - end;
3816 rv = vm_map_insert(map, &count, NULL, NULL,
3817 0, addr, stack_entry->start,
3819 VM_PROT_ALL, VM_PROT_ALL, 0);
3821 /* Adjust the available stack space by the amount we grew. */
3822 if (rv == KERN_SUCCESS) {
3823 if (prev_entry != &map->header)
3824 vm_map_clip_end(map, prev_entry, addr, &count);
3825 new_stack_entry = prev_entry->next;
3826 if (new_stack_entry->end != stack_entry->start ||
3827 new_stack_entry->start != addr)
3828 panic ("Bad stack grow start/end in new stack entry");
3830 new_stack_entry->aux.avail_ssize =
3831 stack_entry->aux.avail_ssize -
3832 (new_stack_entry->end - new_stack_entry->start);
3834 vm->vm_ssize += btoc(new_stack_entry->end -
3835 new_stack_entry->start);
3838 if (map->flags & MAP_WIREFUTURE)
3839 vm_map_unwire(map, new_stack_entry->start,
3840 new_stack_entry->end, FALSE);
3845 vm_map_unlock_read(map);
3848 vm_map_entry_release(count);
3853 * Unshare the specified VM space for exec. If other processes are
3854 * mapped to it, then create a new one. The new vmspace is null.
3859 vmspace_exec(struct proc *p, struct vmspace *vmcopy)
3861 struct vmspace *oldvmspace = p->p_vmspace;
3862 struct vmspace *newvmspace;
3863 vm_map_t map = &p->p_vmspace->vm_map;
3866 * If we are execing a resident vmspace we fork it, otherwise
3867 * we create a new vmspace. Note that exitingcnt is not
3868 * copied to the new vmspace.
3870 lwkt_gettoken(&oldvmspace->vm_map.token);
3872 newvmspace = vmspace_fork(vmcopy);
3873 lwkt_gettoken(&newvmspace->vm_map.token);
3875 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3876 lwkt_gettoken(&newvmspace->vm_map.token);
3877 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3878 (caddr_t)&oldvmspace->vm_endcopy -
3879 (caddr_t)&oldvmspace->vm_startcopy);
3883 * Finish initializing the vmspace before assigning it
3884 * to the process. The vmspace will become the current vmspace
3887 pmap_pinit2(vmspace_pmap(newvmspace));
3888 pmap_replacevm(p, newvmspace, 0);
3889 lwkt_reltoken(&newvmspace->vm_map.token);
3890 lwkt_reltoken(&oldvmspace->vm_map.token);
3891 vmspace_rel(oldvmspace);
3895 * Unshare the specified VM space for forcing COW. This
3896 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3899 vmspace_unshare(struct proc *p)
3901 struct vmspace *oldvmspace = p->p_vmspace;
3902 struct vmspace *newvmspace;
3904 lwkt_gettoken(&oldvmspace->vm_map.token);
3905 if (vmspace_getrefs(oldvmspace) == 1) {
3906 lwkt_reltoken(&oldvmspace->vm_map.token);
3909 newvmspace = vmspace_fork(oldvmspace);
3910 lwkt_gettoken(&newvmspace->vm_map.token);
3911 pmap_pinit2(vmspace_pmap(newvmspace));
3912 pmap_replacevm(p, newvmspace, 0);
3913 lwkt_reltoken(&newvmspace->vm_map.token);
3914 lwkt_reltoken(&oldvmspace->vm_map.token);
3915 vmspace_rel(oldvmspace);
3919 * vm_map_hint: return the beginning of the best area suitable for
3920 * creating a new mapping with "prot" protection.
3925 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot)
3927 struct vmspace *vms = p->p_vmspace;
3929 if (!randomize_mmap || addr != 0) {
3931 * Set a reasonable start point for the hint if it was
3932 * not specified or if it falls within the heap space.
3933 * Hinted mmap()s do not allocate out of the heap space.
3936 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
3937 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) {
3938 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
3947 * If executable skip first two pages, otherwise start
3948 * after data + heap region.
3950 if ((prot & VM_PROT_EXECUTE) &&
3951 ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) {
3952 addr = (PAGE_SIZE * 2) +
3953 (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1));
3954 return (round_page(addr));
3956 #endif /* __i386__ */
3959 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ;
3960 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1);
3962 return (round_page(addr));
3966 * Finds the VM object, offset, and protection for a given virtual address
3967 * in the specified map, assuming a page fault of the type specified.
3969 * Leaves the map in question locked for read; return values are guaranteed
3970 * until a vm_map_lookup_done call is performed. Note that the map argument
3971 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3973 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3976 * If a lookup is requested with "write protection" specified, the map may
3977 * be changed to perform virtual copying operations, although the data
3978 * referenced will remain the same.
3983 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
3985 vm_prot_t fault_typea,
3986 vm_map_entry_t *out_entry, /* OUT */
3987 vm_object_t *object, /* OUT */
3988 vm_pindex_t *pindex, /* OUT */
3989 vm_prot_t *out_prot, /* OUT */
3990 boolean_t *wired) /* OUT */
3992 vm_map_entry_t entry;
3993 vm_map_t map = *var_map;
3995 vm_prot_t fault_type = fault_typea;
3996 int use_read_lock = 1;
3997 int rv = KERN_SUCCESS;
4001 vm_map_lock_read(map);
4006 * If the map has an interesting hint, try it before calling full
4007 * blown lookup routine.
4014 if ((entry == &map->header) ||
4015 (vaddr < entry->start) || (vaddr >= entry->end)) {
4016 vm_map_entry_t tmp_entry;
4019 * Entry was either not a valid hint, or the vaddr was not
4020 * contained in the entry, so do a full lookup.
4022 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
4023 rv = KERN_INVALID_ADDRESS;
4034 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
4035 vm_map_t old_map = map;
4037 *var_map = map = entry->object.sub_map;
4039 vm_map_unlock_read(old_map);
4041 vm_map_unlock(old_map);
4047 * Check whether this task is allowed to have this page.
4048 * Note the special case for MAP_ENTRY_COW
4049 * pages with an override. This is to implement a forced
4050 * COW for debuggers.
4053 if (fault_type & VM_PROT_OVERRIDE_WRITE)
4054 prot = entry->max_protection;
4056 prot = entry->protection;
4058 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
4059 if ((fault_type & prot) != fault_type) {
4060 rv = KERN_PROTECTION_FAILURE;
4064 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
4065 (entry->eflags & MAP_ENTRY_COW) &&
4066 (fault_type & VM_PROT_WRITE) &&
4067 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
4068 rv = KERN_PROTECTION_FAILURE;
4073 * If this page is not pageable, we have to get it for all possible
4076 *wired = (entry->wired_count != 0);
4078 prot = fault_type = entry->protection;
4081 * Virtual page tables may need to update the accessed (A) bit
4082 * in a page table entry. Upgrade the fault to a write fault for
4083 * that case if the map will support it. If the map does not support
4084 * it the page table entry simply will not be updated.
4086 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
4087 if (prot & VM_PROT_WRITE)
4088 fault_type |= VM_PROT_WRITE;
4091 if (curthread->td_lwp && curthread->td_lwp->lwp_vmspace &&
4092 pmap_emulate_ad_bits(&curthread->td_lwp->lwp_vmspace->vm_pmap)) {
4093 if ((prot & VM_PROT_WRITE) == 0)
4094 fault_type |= VM_PROT_WRITE;
4098 * Only NORMAL and VPAGETABLE maps are object-based. UKSMAPs are not.
4100 if (entry->maptype != VM_MAPTYPE_NORMAL &&
4101 entry->maptype != VM_MAPTYPE_VPAGETABLE) {
4107 * If the entry was copy-on-write, we either ...
4109 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4111 * If we want to write the page, we may as well handle that
4112 * now since we've got the map locked.
4114 * If we don't need to write the page, we just demote the
4115 * permissions allowed.
4118 if (fault_type & VM_PROT_WRITE) {
4120 * Make a new object, and place it in the object
4121 * chain. Note that no new references have appeared
4122 * -- one just moved from the map to the new
4126 if (use_read_lock && vm_map_lock_upgrade(map)) {
4133 vm_map_entry_shadow(entry, 0);
4136 * We're attempting to read a copy-on-write page --
4137 * don't allow writes.
4140 prot &= ~VM_PROT_WRITE;
4145 * Create an object if necessary.
4147 if (entry->object.vm_object == NULL && !map->system_map) {
4148 if (use_read_lock && vm_map_lock_upgrade(map)) {
4154 vm_map_entry_allocate_object(entry);
4158 * Return the object/offset from this entry. If the entry was
4159 * copy-on-write or empty, it has been fixed up.
4161 *object = entry->object.vm_object;
4164 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
4167 * Return whether this is the only map sharing this data. On
4168 * success we return with a read lock held on the map. On failure
4169 * we return with the map unlocked.
4173 if (rv == KERN_SUCCESS) {
4174 if (use_read_lock == 0)
4175 vm_map_lock_downgrade(map);
4176 } else if (use_read_lock) {
4177 vm_map_unlock_read(map);
4185 * Releases locks acquired by a vm_map_lookup()
4186 * (according to the handle returned by that lookup).
4188 * No other requirements.
4191 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
4194 * Unlock the main-level map
4196 vm_map_unlock_read(map);
4198 vm_map_entry_release(count);
4201 #include "opt_ddb.h"
4203 #include <sys/kernel.h>
4205 #include <ddb/ddb.h>
4210 DB_SHOW_COMMAND(map, vm_map_print)
4213 /* XXX convert args. */
4214 vm_map_t map = (vm_map_t)addr;
4215 boolean_t full = have_addr;
4217 vm_map_entry_t entry;
4219 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4221 (void *)map->pmap, map->nentries, map->timestamp);
4224 if (!full && db_indent)
4228 for (entry = map->header.next; entry != &map->header;
4229 entry = entry->next) {
4230 db_iprintf("map entry %p: start=%p, end=%p\n",
4231 (void *)entry, (void *)entry->start, (void *)entry->end);
4234 static char *inheritance_name[4] =
4235 {"share", "copy", "none", "donate_copy"};
4237 db_iprintf(" prot=%x/%x/%s",
4239 entry->max_protection,
4240 inheritance_name[(int)(unsigned char)entry->inheritance]);
4241 if (entry->wired_count != 0)
4242 db_printf(", wired");
4244 switch(entry->maptype) {
4245 case VM_MAPTYPE_SUBMAP:
4246 /* XXX no %qd in kernel. Truncate entry->offset. */
4247 db_printf(", share=%p, offset=0x%lx\n",
4248 (void *)entry->object.sub_map,
4249 (long)entry->offset);
4251 if ((entry->prev == &map->header) ||
4252 (entry->prev->object.sub_map !=
4253 entry->object.sub_map)) {
4255 vm_map_print((db_expr_t)(intptr_t)
4256 entry->object.sub_map,
4261 case VM_MAPTYPE_NORMAL:
4262 case VM_MAPTYPE_VPAGETABLE:
4263 /* XXX no %qd in kernel. Truncate entry->offset. */
4264 db_printf(", object=%p, offset=0x%lx",
4265 (void *)entry->object.vm_object,
4266 (long)entry->offset);
4267 if (entry->eflags & MAP_ENTRY_COW)
4268 db_printf(", copy (%s)",
4269 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
4273 if ((entry->prev == &map->header) ||
4274 (entry->prev->object.vm_object !=
4275 entry->object.vm_object)) {
4277 vm_object_print((db_expr_t)(intptr_t)
4278 entry->object.vm_object,
4284 case VM_MAPTYPE_UKSMAP:
4285 db_printf(", uksmap=%p, offset=0x%lx",
4286 (void *)entry->object.uksmap,
4287 (long)entry->offset);
4288 if (entry->eflags & MAP_ENTRY_COW)
4289 db_printf(", copy (%s)",
4290 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
4306 DB_SHOW_COMMAND(procvm, procvm)
4311 p = (struct proc *) addr;
4316 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
4317 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
4318 (void *)vmspace_pmap(p->p_vmspace));
4320 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);