4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
41 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
42 * All rights reserved.
44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
46 * Permission to use, copy, modify and distribute this software and
47 * its documentation is hereby granted, provided that both the copyright
48 * notice and this permission notice appear in all copies of the
49 * software, derivative works or modified versions, and any portions
50 * thereof, and that both notices appear in supporting documentation.
52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
56 * Carnegie Mellon requests users of this software to return to
58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
59 * School of Computer Science
60 * Carnegie Mellon University
61 * Pittsburgh PA 15213-3890
63 * any improvements or extensions that they make and grant Carnegie the
64 * rights to redistribute these changes.
66 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $
70 * Virtual memory mapping module.
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/kernel.h>
77 #include <sys/serialize.h>
79 #include <sys/vmmeter.h>
81 #include <sys/vnode.h>
82 #include <sys/resourcevar.h>
85 #include <sys/malloc.h>
88 #include <vm/vm_param.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_page.h>
92 #include <vm/vm_object.h>
93 #include <vm/vm_pager.h>
94 #include <vm/vm_kern.h>
95 #include <vm/vm_extern.h>
96 #include <vm/swap_pager.h>
97 #include <vm/vm_zone.h>
99 #include <sys/thread2.h>
100 #include <sys/sysref2.h>
101 #include <sys/random.h>
102 #include <sys/sysctl.h>
105 * Virtual memory maps provide for the mapping, protection, and sharing
106 * of virtual memory objects. In addition, this module provides for an
107 * efficient virtual copy of memory from one map to another.
109 * Synchronization is required prior to most operations.
111 * Maps consist of an ordered doubly-linked list of simple entries.
112 * A hint and a RB tree is used to speed-up lookups.
114 * Callers looking to modify maps specify start/end addresses which cause
115 * the related map entry to be clipped if necessary, and then later
116 * recombined if the pieces remained compatible.
118 * Virtual copy operations are performed by copying VM object references
119 * from one map to another, and then marking both regions as copy-on-write.
121 static void vmspace_terminate(struct vmspace
*vm
);
122 static void vmspace_lock(struct vmspace
*vm
);
123 static void vmspace_unlock(struct vmspace
*vm
);
124 static void vmspace_dtor(void *obj
, void *private);
126 MALLOC_DEFINE(M_VMSPACE
, "vmspace", "vmspace objcache backingstore");
128 struct sysref_class vmspace_sysref_class
= {
131 .proto
= SYSREF_PROTO_VMSPACE
,
132 .offset
= offsetof(struct vmspace
, vm_sysref
),
133 .objsize
= sizeof(struct vmspace
),
135 .flags
= SRC_MANAGEDINIT
,
136 .dtor
= vmspace_dtor
,
138 .terminate
= (sysref_terminate_func_t
)vmspace_terminate
,
139 .lock
= (sysref_lock_func_t
)vmspace_lock
,
140 .unlock
= (sysref_lock_func_t
)vmspace_unlock
145 * per-cpu page table cross mappings are initialized in early boot
146 * and might require a considerable number of vm_map_entry structures.
148 #define VMEPERCPU (MAXCPU+1)
150 static struct vm_zone mapentzone_store
, mapzone_store
;
151 static vm_zone_t mapentzone
, mapzone
;
152 static struct vm_object mapentobj
, mapobj
;
154 static struct vm_map_entry map_entry_init
[MAX_MAPENT
];
155 static struct vm_map_entry cpu_map_entry_init
[MAXCPU
][VMEPERCPU
];
156 static struct vm_map map_init
[MAX_KMAP
];
158 static int randomize_mmap
;
159 SYSCTL_INT(_vm
, OID_AUTO
, randomize_mmap
, CTLFLAG_RW
, &randomize_mmap
, 0,
160 "Randomize mmap offsets");
162 static void vm_map_entry_shadow(vm_map_entry_t entry
, int addref
);
163 static vm_map_entry_t
vm_map_entry_create(vm_map_t map
, int *);
164 static void vm_map_entry_dispose (vm_map_t map
, vm_map_entry_t entry
, int *);
165 static void _vm_map_clip_end (vm_map_t
, vm_map_entry_t
, vm_offset_t
, int *);
166 static void _vm_map_clip_start (vm_map_t
, vm_map_entry_t
, vm_offset_t
, int *);
167 static void vm_map_entry_delete (vm_map_t
, vm_map_entry_t
, int *);
168 static void vm_map_entry_unwire (vm_map_t
, vm_map_entry_t
);
169 static void vm_map_copy_entry (vm_map_t
, vm_map_t
, vm_map_entry_t
,
171 static void vm_map_unclip_range (vm_map_t map
, vm_map_entry_t start_entry
, vm_offset_t start
, vm_offset_t end
, int *count
, int flags
);
174 * Initialize the vm_map module. Must be called before any other vm_map
177 * Map and entry structures are allocated from the general purpose
178 * memory pool with some exceptions:
180 * - The kernel map is allocated statically.
181 * - Initial kernel map entries are allocated out of a static pool.
183 * These restrictions are necessary since malloc() uses the
184 * maps and requires map entries.
186 * Called from the low level boot code only.
191 mapzone
= &mapzone_store
;
192 zbootinit(mapzone
, "MAP", sizeof (struct vm_map
),
194 mapentzone
= &mapentzone_store
;
195 zbootinit(mapentzone
, "MAP ENTRY", sizeof (struct vm_map_entry
),
196 map_entry_init
, MAX_MAPENT
);
200 * Called prior to any vmspace allocations.
202 * Called from the low level boot code only.
207 zinitna(mapentzone
, &mapentobj
, NULL
, 0, 0,
208 ZONE_USE_RESERVE
| ZONE_SPECIAL
, 1);
209 zinitna(mapzone
, &mapobj
, NULL
, 0, 0, 0, 1);
216 * Red black tree functions
218 * The caller must hold the related map lock.
220 static int rb_vm_map_compare(vm_map_entry_t a
, vm_map_entry_t b
);
221 RB_GENERATE(vm_map_rb_tree
, vm_map_entry
, rb_entry
, rb_vm_map_compare
);
223 /* a->start is address, and the only field has to be initialized */
225 rb_vm_map_compare(vm_map_entry_t a
, vm_map_entry_t b
)
227 if (a
->start
< b
->start
)
229 else if (a
->start
> b
->start
)
235 * Allocate a vmspace structure, including a vm_map and pmap.
236 * Initialize numerous fields. While the initial allocation is zerod,
237 * subsequence reuse from the objcache leaves elements of the structure
238 * intact (particularly the pmap), so portions must be zerod.
240 * The structure is not considered activated until we call sysref_activate().
245 vmspace_alloc(vm_offset_t min
, vm_offset_t max
)
249 vm
= sysref_alloc(&vmspace_sysref_class
);
250 bzero(&vm
->vm_startcopy
,
251 (char *)&vm
->vm_endcopy
- (char *)&vm
->vm_startcopy
);
252 vm_map_init(&vm
->vm_map
, min
, max
, NULL
); /* initializes token */
255 * Use a hold to prevent any additional racing hold from terminating
256 * the vmspace before we manage to activate it. This also acquires
257 * the token for safety.
259 KKASSERT(vm
->vm_holdcount
== 0);
260 KKASSERT(vm
->vm_exitingcnt
== 0);
262 pmap_pinit(vmspace_pmap(vm
)); /* (some fields reused) */
263 vm
->vm_map
.pmap
= vmspace_pmap(vm
); /* XXX */
266 cpu_vmspace_alloc(vm
);
267 sysref_activate(&vm
->vm_sysref
);
274 * Free a primary reference to a vmspace. This can trigger a
275 * stage-1 termination.
278 vmspace_free(struct vmspace
*vm
)
281 * We want all finalization to occur via vmspace_drop() so we
282 * need to hold the vm around the put.
285 sysref_put(&vm
->vm_sysref
);
290 vmspace_ref(struct vmspace
*vm
)
292 sysref_get(&vm
->vm_sysref
);
296 vmspace_hold(struct vmspace
*vm
)
298 refcount_acquire(&vm
->vm_holdcount
);
299 lwkt_gettoken(&vm
->vm_map
.token
);
303 vmspace_drop(struct vmspace
*vm
)
305 lwkt_reltoken(&vm
->vm_map
.token
);
306 if (refcount_release(&vm
->vm_holdcount
)) {
307 if (vm
->vm_exitingcnt
== 0 &&
308 sysref_isinactive(&vm
->vm_sysref
)) {
309 vmspace_terminate(vm
);
315 * dtor function - Some elements of the pmap are retained in the
316 * free-cached vmspaces to improve performance. We have to clean them up
317 * here before returning the vmspace to the memory pool.
322 vmspace_dtor(void *obj
, void *private)
324 struct vmspace
*vm
= obj
;
326 pmap_puninit(vmspace_pmap(vm
));
330 * Called in three cases:
332 * (1) When the last sysref is dropped and the vmspace becomes inactive.
333 * (holdcount will not be 0 because the vmspace is held through the op)
335 * (2) When exitingcount becomes 0 on the last reap
336 * (holdcount will not be 0 because the vmspace is held through the op)
338 * (3) When the holdcount becomes 0 in addition to the above two
340 * sysref will not scrap the object until we call sysref_put() once more
341 * after the last ref has been dropped.
343 * VMSPACE_EXIT1 flags the primary deactivation
344 * VMSPACE_EXIT2 flags the last reap
347 vmspace_terminate(struct vmspace
*vm
)
354 lwkt_gettoken(&vm
->vm_map
.token
);
355 if ((vm
->vm_flags
& VMSPACE_EXIT1
) == 0) {
356 vm
->vm_flags
|= VMSPACE_EXIT1
;
358 pmap_remove_pages(vmspace_pmap(vm
), VM_MIN_USER_ADDRESS
,
359 VM_MAX_USER_ADDRESS
);
360 vm_map_remove(&vm
->vm_map
, VM_MIN_USER_ADDRESS
,
361 VM_MAX_USER_ADDRESS
);
363 if ((vm
->vm_flags
& VMSPACE_EXIT2
) == 0 && vm
->vm_exitingcnt
== 0) {
364 vm
->vm_flags
|= VMSPACE_EXIT2
;
365 cpu_vmspace_free(vm
);
369 * Lock the map, to wait out all other references to it.
370 * Delete all of the mappings and pages they hold, then call
371 * the pmap module to reclaim anything left.
373 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
374 vm_map_lock(&vm
->vm_map
);
375 vm_map_delete(&vm
->vm_map
, vm
->vm_map
.min_offset
,
376 vm
->vm_map
.max_offset
, &count
);
377 vm_map_unlock(&vm
->vm_map
);
378 vm_map_entry_release(count
);
380 lwkt_gettoken(&vmspace_pmap(vm
)->pm_token
);
381 pmap_release(vmspace_pmap(vm
));
382 lwkt_reltoken(&vmspace_pmap(vm
)->pm_token
);
385 lwkt_reltoken(&vm
->vm_map
.token
);
386 if (vm
->vm_exitingcnt
== 0 && vm
->vm_holdcount
== 0) {
387 KKASSERT(vm
->vm_flags
& VMSPACE_EXIT1
);
388 KKASSERT(vm
->vm_flags
& VMSPACE_EXIT2
);
389 sysref_put(&vm
->vm_sysref
);
394 * vmspaces are not currently locked.
397 vmspace_lock(struct vmspace
*vm __unused
)
402 vmspace_unlock(struct vmspace
*vm __unused
)
407 * This is called during exit indicating that the vmspace is no
408 * longer in used by an exiting process, but the process has not yet
414 vmspace_exitbump(struct vmspace
*vm
)
418 vmspace_drop(vm
); /* handles termination sequencing */
422 * Decrement the exitingcnt and issue the stage-2 termination if it becomes
423 * zero and the stage1 termination has already occured.
428 vmspace_exitfree(struct proc
*p
)
435 KKASSERT(vm
->vm_exitingcnt
> 0);
436 if (--vm
->vm_exitingcnt
== 0 && sysref_isinactive(&vm
->vm_sysref
))
437 vmspace_terminate(vm
);
438 vmspace_drop(vm
); /* handles termination sequencing */
442 * Swap useage is determined by taking the proportional swap used by
443 * VM objects backing the VM map. To make up for fractional losses,
444 * if the VM object has any swap use at all the associated map entries
445 * count for at least 1 swap page.
450 vmspace_swap_count(struct vmspace
*vm
)
452 vm_map_t map
= &vm
->vm_map
;
459 for (cur
= map
->header
.next
; cur
!= &map
->header
; cur
= cur
->next
) {
460 switch(cur
->maptype
) {
461 case VM_MAPTYPE_NORMAL
:
462 case VM_MAPTYPE_VPAGETABLE
:
463 if ((object
= cur
->object
.vm_object
) == NULL
)
465 if (object
->swblock_count
) {
466 n
= (cur
->end
- cur
->start
) / PAGE_SIZE
;
467 count
+= object
->swblock_count
*
468 SWAP_META_PAGES
* n
/ object
->size
+ 1;
481 * Calculate the approximate number of anonymous pages in use by
482 * this vmspace. To make up for fractional losses, we count each
483 * VM object as having at least 1 anonymous page.
488 vmspace_anonymous_count(struct vmspace
*vm
)
490 vm_map_t map
= &vm
->vm_map
;
496 for (cur
= map
->header
.next
; cur
!= &map
->header
; cur
= cur
->next
) {
497 switch(cur
->maptype
) {
498 case VM_MAPTYPE_NORMAL
:
499 case VM_MAPTYPE_VPAGETABLE
:
500 if ((object
= cur
->object
.vm_object
) == NULL
)
502 if (object
->type
!= OBJT_DEFAULT
&&
503 object
->type
!= OBJT_SWAP
) {
506 count
+= object
->resident_page_count
;
518 * Creates and returns a new empty VM map with the given physical map
519 * structure, and having the given lower and upper address bounds.
524 vm_map_create(vm_map_t result
, pmap_t pmap
, vm_offset_t min
, vm_offset_t max
)
527 result
= zalloc(mapzone
);
528 vm_map_init(result
, min
, max
, pmap
);
533 * Initialize an existing vm_map structure such as that in the vmspace
534 * structure. The pmap is initialized elsewhere.
539 vm_map_init(struct vm_map
*map
, vm_offset_t min
, vm_offset_t max
, pmap_t pmap
)
541 map
->header
.next
= map
->header
.prev
= &map
->header
;
542 RB_INIT(&map
->rb_root
);
546 map
->min_offset
= min
;
547 map
->max_offset
= max
;
549 map
->first_free
= &map
->header
;
550 map
->hint
= &map
->header
;
553 lwkt_token_init(&map
->token
, "vm_map");
554 lockinit(&map
->lock
, "thrd_sleep", (hz
+ 9) / 10, 0);
555 TUNABLE_INT("vm.cache_vmspaces", &vmspace_sysref_class
.nom_cache
);
559 * Shadow the vm_map_entry's object. This typically needs to be done when
560 * a write fault is taken on an entry which had previously been cloned by
561 * fork(). The shared object (which might be NULL) must become private so
562 * we add a shadow layer above it.
564 * Object allocation for anonymous mappings is defered as long as possible.
565 * When creating a shadow, however, the underlying object must be instantiated
566 * so it can be shared.
568 * If the map segment is governed by a virtual page table then it is
569 * possible to address offsets beyond the mapped area. Just allocate
570 * a maximally sized object for this case.
572 * The vm_map must be exclusively locked.
573 * No other requirements.
577 vm_map_entry_shadow(vm_map_entry_t entry
, int addref
)
579 if (entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
580 vm_object_shadow(&entry
->object
.vm_object
, &entry
->offset
,
581 0x7FFFFFFF, addref
); /* XXX */
583 vm_object_shadow(&entry
->object
.vm_object
, &entry
->offset
,
584 atop(entry
->end
- entry
->start
), addref
);
586 entry
->eflags
&= ~MAP_ENTRY_NEEDS_COPY
;
590 * Allocate an object for a vm_map_entry.
592 * Object allocation for anonymous mappings is defered as long as possible.
593 * This function is called when we can defer no longer, generally when a map
594 * entry might be split or forked or takes a page fault.
596 * If the map segment is governed by a virtual page table then it is
597 * possible to address offsets beyond the mapped area. Just allocate
598 * a maximally sized object for this case.
600 * The vm_map must be exclusively locked.
601 * No other requirements.
604 vm_map_entry_allocate_object(vm_map_entry_t entry
)
608 if (entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
609 obj
= vm_object_allocate(OBJT_DEFAULT
, 0x7FFFFFFF); /* XXX */
611 obj
= vm_object_allocate(OBJT_DEFAULT
,
612 atop(entry
->end
- entry
->start
));
614 entry
->object
.vm_object
= obj
;
619 * Set an initial negative count so the first attempt to reserve
620 * space preloads a bunch of vm_map_entry's for this cpu. Also
621 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
622 * map a new page for vm_map_entry structures. SMP systems are
623 * particularly sensitive.
625 * This routine is called in early boot so we cannot just call
626 * vm_map_entry_reserve().
628 * Called from the low level boot code only (for each cpu)
631 vm_map_entry_reserve_cpu_init(globaldata_t gd
)
633 vm_map_entry_t entry
;
636 gd
->gd_vme_avail
-= MAP_RESERVE_COUNT
* 2;
637 entry
= &cpu_map_entry_init
[gd
->gd_cpuid
][0];
638 for (i
= 0; i
< VMEPERCPU
; ++i
, ++entry
) {
639 entry
->next
= gd
->gd_vme_base
;
640 gd
->gd_vme_base
= entry
;
645 * Reserves vm_map_entry structures so code later on can manipulate
646 * map_entry structures within a locked map without blocking trying
647 * to allocate a new vm_map_entry.
652 vm_map_entry_reserve(int count
)
654 struct globaldata
*gd
= mycpu
;
655 vm_map_entry_t entry
;
658 * Make sure we have enough structures in gd_vme_base to handle
659 * the reservation request.
661 * The critical section protects access to the per-cpu gd.
664 while (gd
->gd_vme_avail
< count
) {
665 entry
= zalloc(mapentzone
);
666 entry
->next
= gd
->gd_vme_base
;
667 gd
->gd_vme_base
= entry
;
670 gd
->gd_vme_avail
-= count
;
677 * Releases previously reserved vm_map_entry structures that were not
678 * used. If we have too much junk in our per-cpu cache clean some of
684 vm_map_entry_release(int count
)
686 struct globaldata
*gd
= mycpu
;
687 vm_map_entry_t entry
;
690 gd
->gd_vme_avail
+= count
;
691 while (gd
->gd_vme_avail
> MAP_RESERVE_SLOP
) {
692 entry
= gd
->gd_vme_base
;
693 KKASSERT(entry
!= NULL
);
694 gd
->gd_vme_base
= entry
->next
;
697 zfree(mapentzone
, entry
);
704 * Reserve map entry structures for use in kernel_map itself. These
705 * entries have *ALREADY* been reserved on a per-cpu basis when the map
706 * was inited. This function is used by zalloc() to avoid a recursion
707 * when zalloc() itself needs to allocate additional kernel memory.
709 * This function works like the normal reserve but does not load the
710 * vm_map_entry cache (because that would result in an infinite
711 * recursion). Note that gd_vme_avail may go negative. This is expected.
713 * Any caller of this function must be sure to renormalize after
714 * potentially eating entries to ensure that the reserve supply
720 vm_map_entry_kreserve(int count
)
722 struct globaldata
*gd
= mycpu
;
725 gd
->gd_vme_avail
-= count
;
727 KASSERT(gd
->gd_vme_base
!= NULL
,
728 ("no reserved entries left, gd_vme_avail = %d",
734 * Release previously reserved map entries for kernel_map. We do not
735 * attempt to clean up like the normal release function as this would
736 * cause an unnecessary (but probably not fatal) deep procedure call.
741 vm_map_entry_krelease(int count
)
743 struct globaldata
*gd
= mycpu
;
746 gd
->gd_vme_avail
+= count
;
751 * Allocates a VM map entry for insertion. No entry fields are filled in.
753 * The entries should have previously been reserved. The reservation count
754 * is tracked in (*countp).
758 static vm_map_entry_t
759 vm_map_entry_create(vm_map_t map
, int *countp
)
761 struct globaldata
*gd
= mycpu
;
762 vm_map_entry_t entry
;
764 KKASSERT(*countp
> 0);
767 entry
= gd
->gd_vme_base
;
768 KASSERT(entry
!= NULL
, ("gd_vme_base NULL! count %d", *countp
));
769 gd
->gd_vme_base
= entry
->next
;
776 * Dispose of a vm_map_entry that is no longer being referenced.
781 vm_map_entry_dispose(vm_map_t map
, vm_map_entry_t entry
, int *countp
)
783 struct globaldata
*gd
= mycpu
;
785 KKASSERT(map
->hint
!= entry
);
786 KKASSERT(map
->first_free
!= entry
);
790 entry
->next
= gd
->gd_vme_base
;
791 gd
->gd_vme_base
= entry
;
797 * Insert/remove entries from maps.
799 * The related map must be exclusively locked.
800 * The caller must hold map->token
801 * No other requirements.
804 vm_map_entry_link(vm_map_t map
,
805 vm_map_entry_t after_where
,
806 vm_map_entry_t entry
)
808 ASSERT_VM_MAP_LOCKED(map
);
811 entry
->prev
= after_where
;
812 entry
->next
= after_where
->next
;
813 entry
->next
->prev
= entry
;
814 after_where
->next
= entry
;
815 if (vm_map_rb_tree_RB_INSERT(&map
->rb_root
, entry
))
816 panic("vm_map_entry_link: dup addr map %p ent %p", map
, entry
);
820 vm_map_entry_unlink(vm_map_t map
,
821 vm_map_entry_t entry
)
826 ASSERT_VM_MAP_LOCKED(map
);
828 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
829 panic("vm_map_entry_unlink: attempt to mess with "
830 "locked entry! %p", entry
);
836 vm_map_rb_tree_RB_REMOVE(&map
->rb_root
, entry
);
841 * Finds the map entry containing (or immediately preceding) the specified
842 * address in the given map. The entry is returned in (*entry).
844 * The boolean result indicates whether the address is actually contained
847 * The related map must be locked.
848 * No other requirements.
851 vm_map_lookup_entry(vm_map_t map
, vm_offset_t address
, vm_map_entry_t
*entry
)
856 ASSERT_VM_MAP_LOCKED(map
);
859 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive
860 * the hint code with the red-black lookup meets with system crashes
861 * and lockups. We do not yet know why.
863 * It is possible that the problem is related to the setting
864 * of the hint during map_entry deletion, in the code specified
865 * at the GGG comment later on in this file.
867 * YYY More likely it's because this function can be called with
868 * a shared lock on the map, resulting in map->hint updates possibly
869 * racing. Fixed now but untested.
872 * Quickly check the cached hint, there's a good chance of a match.
876 if (tmp
!= &map
->header
) {
877 if (address
>= tmp
->start
&& address
< tmp
->end
) {
885 * Locate the record from the top of the tree. 'last' tracks the
886 * closest prior record and is returned if no match is found, which
887 * in binary tree terms means tracking the most recent right-branch
888 * taken. If there is no prior record, &map->header is returned.
891 tmp
= RB_ROOT(&map
->rb_root
);
894 if (address
>= tmp
->start
) {
895 if (address
< tmp
->end
) {
901 tmp
= RB_RIGHT(tmp
, rb_entry
);
903 tmp
= RB_LEFT(tmp
, rb_entry
);
911 * Inserts the given whole VM object into the target map at the specified
912 * address range. The object's size should match that of the address range.
914 * The map must be exclusively locked.
915 * The object must be held.
916 * The caller must have reserved sufficient vm_map_entry structures.
918 * If object is non-NULL, ref count must be bumped by caller prior to
919 * making call to account for the new entry.
922 vm_map_insert(vm_map_t map
, int *countp
,
923 vm_object_t object
, vm_ooffset_t offset
,
924 vm_offset_t start
, vm_offset_t end
,
925 vm_maptype_t maptype
,
926 vm_prot_t prot
, vm_prot_t max
,
929 vm_map_entry_t new_entry
;
930 vm_map_entry_t prev_entry
;
931 vm_map_entry_t temp_entry
;
932 vm_eflags_t protoeflags
;
935 ASSERT_VM_MAP_LOCKED(map
);
937 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object
));
940 * Check that the start and end points are not bogus.
942 if ((start
< map
->min_offset
) || (end
> map
->max_offset
) ||
944 return (KERN_INVALID_ADDRESS
);
947 * Find the entry prior to the proposed starting address; if it's part
948 * of an existing entry, this range is bogus.
950 if (vm_map_lookup_entry(map
, start
, &temp_entry
))
951 return (KERN_NO_SPACE
);
953 prev_entry
= temp_entry
;
956 * Assert that the next entry doesn't overlap the end point.
959 if ((prev_entry
->next
!= &map
->header
) &&
960 (prev_entry
->next
->start
< end
))
961 return (KERN_NO_SPACE
);
965 if (cow
& MAP_COPY_ON_WRITE
)
966 protoeflags
|= MAP_ENTRY_COW
|MAP_ENTRY_NEEDS_COPY
;
968 if (cow
& MAP_NOFAULT
) {
969 protoeflags
|= MAP_ENTRY_NOFAULT
;
971 KASSERT(object
== NULL
,
972 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
974 if (cow
& MAP_DISABLE_SYNCER
)
975 protoeflags
|= MAP_ENTRY_NOSYNC
;
976 if (cow
& MAP_DISABLE_COREDUMP
)
977 protoeflags
|= MAP_ENTRY_NOCOREDUMP
;
978 if (cow
& MAP_IS_STACK
)
979 protoeflags
|= MAP_ENTRY_STACK
;
980 if (cow
& MAP_IS_KSTACK
)
981 protoeflags
|= MAP_ENTRY_KSTACK
;
983 lwkt_gettoken(&map
->token
);
987 * When object is non-NULL, it could be shared with another
988 * process. We have to set or clear OBJ_ONEMAPPING
991 if ((object
->ref_count
> 1) || (object
->shadow_count
!= 0)) {
992 vm_object_clear_flag(object
, OBJ_ONEMAPPING
);
995 else if ((prev_entry
!= &map
->header
) &&
996 (prev_entry
->eflags
== protoeflags
) &&
997 (prev_entry
->end
== start
) &&
998 (prev_entry
->wired_count
== 0) &&
999 prev_entry
->maptype
== maptype
&&
1000 ((prev_entry
->object
.vm_object
== NULL
) ||
1001 vm_object_coalesce(prev_entry
->object
.vm_object
,
1002 OFF_TO_IDX(prev_entry
->offset
),
1003 (vm_size_t
)(prev_entry
->end
- prev_entry
->start
),
1004 (vm_size_t
)(end
- prev_entry
->end
)))) {
1006 * We were able to extend the object. Determine if we
1007 * can extend the previous map entry to include the
1008 * new range as well.
1010 if ((prev_entry
->inheritance
== VM_INHERIT_DEFAULT
) &&
1011 (prev_entry
->protection
== prot
) &&
1012 (prev_entry
->max_protection
== max
)) {
1013 map
->size
+= (end
- prev_entry
->end
);
1014 prev_entry
->end
= end
;
1015 vm_map_simplify_entry(map
, prev_entry
, countp
);
1016 lwkt_reltoken(&map
->token
);
1017 return (KERN_SUCCESS
);
1021 * If we can extend the object but cannot extend the
1022 * map entry, we have to create a new map entry. We
1023 * must bump the ref count on the extended object to
1024 * account for it. object may be NULL.
1026 object
= prev_entry
->object
.vm_object
;
1027 offset
= prev_entry
->offset
+
1028 (prev_entry
->end
- prev_entry
->start
);
1030 vm_object_hold(object
);
1031 vm_object_chain_wait(object
);
1032 vm_object_reference_locked(object
);
1038 * NOTE: if conditionals fail, object can be NULL here. This occurs
1039 * in things like the buffer map where we manage kva but do not manage
1044 * Create a new entry
1047 new_entry
= vm_map_entry_create(map
, countp
);
1048 new_entry
->start
= start
;
1049 new_entry
->end
= end
;
1051 new_entry
->maptype
= maptype
;
1052 new_entry
->eflags
= protoeflags
;
1053 new_entry
->object
.vm_object
= object
;
1054 new_entry
->offset
= offset
;
1055 new_entry
->aux
.master_pde
= 0;
1057 new_entry
->inheritance
= VM_INHERIT_DEFAULT
;
1058 new_entry
->protection
= prot
;
1059 new_entry
->max_protection
= max
;
1060 new_entry
->wired_count
= 0;
1063 * Insert the new entry into the list
1066 vm_map_entry_link(map
, prev_entry
, new_entry
);
1067 map
->size
+= new_entry
->end
- new_entry
->start
;
1070 * Update the free space hint. Entries cannot overlap.
1071 * An exact comparison is needed to avoid matching
1072 * against the map->header.
1074 if ((map
->first_free
== prev_entry
) &&
1075 (prev_entry
->end
== new_entry
->start
)) {
1076 map
->first_free
= new_entry
;
1081 * Temporarily removed to avoid MAP_STACK panic, due to
1082 * MAP_STACK being a huge hack. Will be added back in
1083 * when MAP_STACK (and the user stack mapping) is fixed.
1086 * It may be possible to simplify the entry
1088 vm_map_simplify_entry(map
, new_entry
, countp
);
1092 * Try to pre-populate the page table. Mappings governed by virtual
1093 * page tables cannot be prepopulated without a lot of work, so
1096 if ((cow
& (MAP_PREFAULT
|MAP_PREFAULT_PARTIAL
)) &&
1097 maptype
!= VM_MAPTYPE_VPAGETABLE
) {
1098 pmap_object_init_pt(map
->pmap
, start
, prot
,
1099 object
, OFF_TO_IDX(offset
), end
- start
,
1100 cow
& MAP_PREFAULT_PARTIAL
);
1103 vm_object_drop(object
);
1105 lwkt_reltoken(&map
->token
);
1106 return (KERN_SUCCESS
);
1110 * Find sufficient space for `length' bytes in the given map, starting at
1111 * `start'. Returns 0 on success, 1 on no space.
1113 * This function will returned an arbitrarily aligned pointer. If no
1114 * particular alignment is required you should pass align as 1. Note that
1115 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1116 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1119 * 'align' should be a power of 2 but is not required to be.
1121 * The map must be exclusively locked.
1122 * No other requirements.
1125 vm_map_findspace(vm_map_t map
, vm_offset_t start
, vm_size_t length
,
1126 vm_size_t align
, int flags
, vm_offset_t
*addr
)
1128 vm_map_entry_t entry
, next
;
1130 vm_offset_t align_mask
;
1132 if (start
< map
->min_offset
)
1133 start
= map
->min_offset
;
1134 if (start
> map
->max_offset
)
1138 * If the alignment is not a power of 2 we will have to use
1139 * a mod/division, set align_mask to a special value.
1141 if ((align
| (align
- 1)) + 1 != (align
<< 1))
1142 align_mask
= (vm_offset_t
)-1;
1144 align_mask
= align
- 1;
1147 * Look for the first possible address; if there's already something
1148 * at this address, we have to start after it.
1150 if (start
== map
->min_offset
) {
1151 if ((entry
= map
->first_free
) != &map
->header
)
1156 if (vm_map_lookup_entry(map
, start
, &tmp
))
1162 * Look through the rest of the map, trying to fit a new region in the
1163 * gap between existing regions, or after the very last region.
1165 for (;; start
= (entry
= next
)->end
) {
1167 * Adjust the proposed start by the requested alignment,
1168 * be sure that we didn't wrap the address.
1170 if (align_mask
== (vm_offset_t
)-1)
1171 end
= ((start
+ align
- 1) / align
) * align
;
1173 end
= (start
+ align_mask
) & ~align_mask
;
1178 * Find the end of the proposed new region. Be sure we didn't
1179 * go beyond the end of the map, or wrap around the address.
1180 * Then check to see if this is the last entry or if the
1181 * proposed end fits in the gap between this and the next
1184 end
= start
+ length
;
1185 if (end
> map
->max_offset
|| end
< start
)
1190 * If the next entry's start address is beyond the desired
1191 * end address we may have found a good entry.
1193 * If the next entry is a stack mapping we do not map into
1194 * the stack's reserved space.
1196 * XXX continue to allow mapping into the stack's reserved
1197 * space if doing a MAP_STACK mapping inside a MAP_STACK
1198 * mapping, for backwards compatibility. But the caller
1199 * really should use MAP_STACK | MAP_TRYFIXED if they
1202 if (next
== &map
->header
)
1204 if (next
->start
>= end
) {
1205 if ((next
->eflags
& MAP_ENTRY_STACK
) == 0)
1207 if (flags
& MAP_STACK
)
1209 if (next
->start
- next
->aux
.avail_ssize
>= end
)
1216 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1217 * if it fails. The kernel_map is locked and nothing can steal
1218 * our address space if pmap_growkernel() blocks.
1220 * NOTE: This may be unconditionally called for kldload areas on
1221 * x86_64 because these do not bump kernel_vm_end (which would
1222 * fill 128G worth of page tables!). Therefore we must not
1225 if (map
== &kernel_map
) {
1228 kstop
= round_page(start
+ length
);
1229 if (kstop
> kernel_vm_end
)
1230 pmap_growkernel(start
, kstop
);
1237 * vm_map_find finds an unallocated region in the target address map with
1238 * the given length and allocates it. The search is defined to be first-fit
1239 * from the specified address; the region found is returned in the same
1242 * If object is non-NULL, ref count must be bumped by caller
1243 * prior to making call to account for the new entry.
1245 * No requirements. This function will lock the map temporarily.
1248 vm_map_find(vm_map_t map
, vm_object_t object
, vm_ooffset_t offset
,
1249 vm_offset_t
*addr
, vm_size_t length
, vm_size_t align
,
1251 vm_maptype_t maptype
,
1252 vm_prot_t prot
, vm_prot_t max
,
1261 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1264 vm_object_hold(object
);
1266 if (vm_map_findspace(map
, start
, length
, align
, 0, addr
)) {
1268 vm_object_drop(object
);
1270 vm_map_entry_release(count
);
1271 return (KERN_NO_SPACE
);
1275 result
= vm_map_insert(map
, &count
, object
, offset
,
1276 start
, start
+ length
,
1281 vm_object_drop(object
);
1283 vm_map_entry_release(count
);
1289 * Simplify the given map entry by merging with either neighbor. This
1290 * routine also has the ability to merge with both neighbors.
1292 * This routine guarentees that the passed entry remains valid (though
1293 * possibly extended). When merging, this routine may delete one or
1294 * both neighbors. No action is taken on entries which have their
1295 * in-transition flag set.
1297 * The map must be exclusively locked.
1300 vm_map_simplify_entry(vm_map_t map
, vm_map_entry_t entry
, int *countp
)
1302 vm_map_entry_t next
, prev
;
1303 vm_size_t prevsize
, esize
;
1305 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
1306 ++mycpu
->gd_cnt
.v_intrans_coll
;
1310 if (entry
->maptype
== VM_MAPTYPE_SUBMAP
)
1314 if (prev
!= &map
->header
) {
1315 prevsize
= prev
->end
- prev
->start
;
1316 if ( (prev
->end
== entry
->start
) &&
1317 (prev
->maptype
== entry
->maptype
) &&
1318 (prev
->object
.vm_object
== entry
->object
.vm_object
) &&
1319 (!prev
->object
.vm_object
||
1320 (prev
->offset
+ prevsize
== entry
->offset
)) &&
1321 (prev
->eflags
== entry
->eflags
) &&
1322 (prev
->protection
== entry
->protection
) &&
1323 (prev
->max_protection
== entry
->max_protection
) &&
1324 (prev
->inheritance
== entry
->inheritance
) &&
1325 (prev
->wired_count
== entry
->wired_count
)) {
1326 if (map
->first_free
== prev
)
1327 map
->first_free
= entry
;
1328 if (map
->hint
== prev
)
1330 vm_map_entry_unlink(map
, prev
);
1331 entry
->start
= prev
->start
;
1332 entry
->offset
= prev
->offset
;
1333 if (prev
->object
.vm_object
)
1334 vm_object_deallocate(prev
->object
.vm_object
);
1335 vm_map_entry_dispose(map
, prev
, countp
);
1340 if (next
!= &map
->header
) {
1341 esize
= entry
->end
- entry
->start
;
1342 if ((entry
->end
== next
->start
) &&
1343 (next
->maptype
== entry
->maptype
) &&
1344 (next
->object
.vm_object
== entry
->object
.vm_object
) &&
1345 (!entry
->object
.vm_object
||
1346 (entry
->offset
+ esize
== next
->offset
)) &&
1347 (next
->eflags
== entry
->eflags
) &&
1348 (next
->protection
== entry
->protection
) &&
1349 (next
->max_protection
== entry
->max_protection
) &&
1350 (next
->inheritance
== entry
->inheritance
) &&
1351 (next
->wired_count
== entry
->wired_count
)) {
1352 if (map
->first_free
== next
)
1353 map
->first_free
= entry
;
1354 if (map
->hint
== next
)
1356 vm_map_entry_unlink(map
, next
);
1357 entry
->end
= next
->end
;
1358 if (next
->object
.vm_object
)
1359 vm_object_deallocate(next
->object
.vm_object
);
1360 vm_map_entry_dispose(map
, next
, countp
);
1366 * Asserts that the given entry begins at or after the specified address.
1367 * If necessary, it splits the entry into two.
1369 #define vm_map_clip_start(map, entry, startaddr, countp) \
1371 if (startaddr > entry->start) \
1372 _vm_map_clip_start(map, entry, startaddr, countp); \
1376 * This routine is called only when it is known that the entry must be split.
1378 * The map must be exclusively locked.
1381 _vm_map_clip_start(vm_map_t map
, vm_map_entry_t entry
, vm_offset_t start
,
1384 vm_map_entry_t new_entry
;
1387 * Split off the front portion -- note that we must insert the new
1388 * entry BEFORE this one, so that this entry has the specified
1392 vm_map_simplify_entry(map
, entry
, countp
);
1395 * If there is no object backing this entry, we might as well create
1396 * one now. If we defer it, an object can get created after the map
1397 * is clipped, and individual objects will be created for the split-up
1398 * map. This is a bit of a hack, but is also about the best place to
1399 * put this improvement.
1401 if (entry
->object
.vm_object
== NULL
&& !map
->system_map
) {
1402 vm_map_entry_allocate_object(entry
);
1405 new_entry
= vm_map_entry_create(map
, countp
);
1406 *new_entry
= *entry
;
1408 new_entry
->end
= start
;
1409 entry
->offset
+= (start
- entry
->start
);
1410 entry
->start
= start
;
1412 vm_map_entry_link(map
, entry
->prev
, new_entry
);
1414 switch(entry
->maptype
) {
1415 case VM_MAPTYPE_NORMAL
:
1416 case VM_MAPTYPE_VPAGETABLE
:
1417 if (new_entry
->object
.vm_object
) {
1418 vm_object_hold(new_entry
->object
.vm_object
);
1419 vm_object_chain_wait(new_entry
->object
.vm_object
);
1420 vm_object_reference_locked(new_entry
->object
.vm_object
);
1421 vm_object_drop(new_entry
->object
.vm_object
);
1430 * Asserts that the given entry ends at or before the specified address.
1431 * If necessary, it splits the entry into two.
1433 * The map must be exclusively locked.
1435 #define vm_map_clip_end(map, entry, endaddr, countp) \
1437 if (endaddr < entry->end) \
1438 _vm_map_clip_end(map, entry, endaddr, countp); \
1442 * This routine is called only when it is known that the entry must be split.
1444 * The map must be exclusively locked.
1447 _vm_map_clip_end(vm_map_t map
, vm_map_entry_t entry
, vm_offset_t end
,
1450 vm_map_entry_t new_entry
;
1453 * If there is no object backing this entry, we might as well create
1454 * one now. If we defer it, an object can get created after the map
1455 * is clipped, and individual objects will be created for the split-up
1456 * map. This is a bit of a hack, but is also about the best place to
1457 * put this improvement.
1460 if (entry
->object
.vm_object
== NULL
&& !map
->system_map
) {
1461 vm_map_entry_allocate_object(entry
);
1465 * Create a new entry and insert it AFTER the specified entry
1468 new_entry
= vm_map_entry_create(map
, countp
);
1469 *new_entry
= *entry
;
1471 new_entry
->start
= entry
->end
= end
;
1472 new_entry
->offset
+= (end
- entry
->start
);
1474 vm_map_entry_link(map
, entry
, new_entry
);
1476 switch(entry
->maptype
) {
1477 case VM_MAPTYPE_NORMAL
:
1478 case VM_MAPTYPE_VPAGETABLE
:
1479 if (new_entry
->object
.vm_object
) {
1480 vm_object_hold(new_entry
->object
.vm_object
);
1481 vm_object_chain_wait(new_entry
->object
.vm_object
);
1482 vm_object_reference_locked(new_entry
->object
.vm_object
);
1483 vm_object_drop(new_entry
->object
.vm_object
);
1492 * Asserts that the starting and ending region addresses fall within the
1493 * valid range for the map.
1495 #define VM_MAP_RANGE_CHECK(map, start, end) \
1497 if (start < vm_map_min(map)) \
1498 start = vm_map_min(map); \
1499 if (end > vm_map_max(map)) \
1500 end = vm_map_max(map); \
1506 * Used to block when an in-transition collison occurs. The map
1507 * is unlocked for the sleep and relocked before the return.
1510 vm_map_transition_wait(vm_map_t map
)
1512 tsleep_interlock(map
, 0);
1514 tsleep(map
, PINTERLOCKED
, "vment", 0);
1519 * When we do blocking operations with the map lock held it is
1520 * possible that a clip might have occured on our in-transit entry,
1521 * requiring an adjustment to the entry in our loop. These macros
1522 * help the pageable and clip_range code deal with the case. The
1523 * conditional costs virtually nothing if no clipping has occured.
1526 #define CLIP_CHECK_BACK(entry, save_start) \
1528 while (entry->start != save_start) { \
1529 entry = entry->prev; \
1530 KASSERT(entry != &map->header, ("bad entry clip")); \
1534 #define CLIP_CHECK_FWD(entry, save_end) \
1536 while (entry->end != save_end) { \
1537 entry = entry->next; \
1538 KASSERT(entry != &map->header, ("bad entry clip")); \
1544 * Clip the specified range and return the base entry. The
1545 * range may cover several entries starting at the returned base
1546 * and the first and last entry in the covering sequence will be
1547 * properly clipped to the requested start and end address.
1549 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1552 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1553 * covered by the requested range.
1555 * The map must be exclusively locked on entry and will remain locked
1556 * on return. If no range exists or the range contains holes and you
1557 * specified that no holes were allowed, NULL will be returned. This
1558 * routine may temporarily unlock the map in order avoid a deadlock when
1563 vm_map_clip_range(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
1564 int *countp
, int flags
)
1566 vm_map_entry_t start_entry
;
1567 vm_map_entry_t entry
;
1570 * Locate the entry and effect initial clipping. The in-transition
1571 * case does not occur very often so do not try to optimize it.
1574 if (vm_map_lookup_entry(map
, start
, &start_entry
) == FALSE
)
1576 entry
= start_entry
;
1577 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
1578 entry
->eflags
|= MAP_ENTRY_NEEDS_WAKEUP
;
1579 ++mycpu
->gd_cnt
.v_intrans_coll
;
1580 ++mycpu
->gd_cnt
.v_intrans_wait
;
1581 vm_map_transition_wait(map
);
1583 * entry and/or start_entry may have been clipped while
1584 * we slept, or may have gone away entirely. We have
1585 * to restart from the lookup.
1591 * Since we hold an exclusive map lock we do not have to restart
1592 * after clipping, even though clipping may block in zalloc.
1594 vm_map_clip_start(map
, entry
, start
, countp
);
1595 vm_map_clip_end(map
, entry
, end
, countp
);
1596 entry
->eflags
|= MAP_ENTRY_IN_TRANSITION
;
1599 * Scan entries covered by the range. When working on the next
1600 * entry a restart need only re-loop on the current entry which
1601 * we have already locked, since 'next' may have changed. Also,
1602 * even though entry is safe, it may have been clipped so we
1603 * have to iterate forwards through the clip after sleeping.
1605 while (entry
->next
!= &map
->header
&& entry
->next
->start
< end
) {
1606 vm_map_entry_t next
= entry
->next
;
1608 if (flags
& MAP_CLIP_NO_HOLES
) {
1609 if (next
->start
> entry
->end
) {
1610 vm_map_unclip_range(map
, start_entry
,
1611 start
, entry
->end
, countp
, flags
);
1616 if (next
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
1617 vm_offset_t save_end
= entry
->end
;
1618 next
->eflags
|= MAP_ENTRY_NEEDS_WAKEUP
;
1619 ++mycpu
->gd_cnt
.v_intrans_coll
;
1620 ++mycpu
->gd_cnt
.v_intrans_wait
;
1621 vm_map_transition_wait(map
);
1624 * clips might have occured while we blocked.
1626 CLIP_CHECK_FWD(entry
, save_end
);
1627 CLIP_CHECK_BACK(start_entry
, start
);
1631 * No restart necessary even though clip_end may block, we
1632 * are holding the map lock.
1634 vm_map_clip_end(map
, next
, end
, countp
);
1635 next
->eflags
|= MAP_ENTRY_IN_TRANSITION
;
1638 if (flags
& MAP_CLIP_NO_HOLES
) {
1639 if (entry
->end
!= end
) {
1640 vm_map_unclip_range(map
, start_entry
,
1641 start
, entry
->end
, countp
, flags
);
1645 return(start_entry
);
1649 * Undo the effect of vm_map_clip_range(). You should pass the same
1650 * flags and the same range that you passed to vm_map_clip_range().
1651 * This code will clear the in-transition flag on the entries and
1652 * wake up anyone waiting. This code will also simplify the sequence
1653 * and attempt to merge it with entries before and after the sequence.
1655 * The map must be locked on entry and will remain locked on return.
1657 * Note that you should also pass the start_entry returned by
1658 * vm_map_clip_range(). However, if you block between the two calls
1659 * with the map unlocked please be aware that the start_entry may
1660 * have been clipped and you may need to scan it backwards to find
1661 * the entry corresponding with the original start address. You are
1662 * responsible for this, vm_map_unclip_range() expects the correct
1663 * start_entry to be passed to it and will KASSERT otherwise.
1667 vm_map_unclip_range(vm_map_t map
, vm_map_entry_t start_entry
,
1668 vm_offset_t start
, vm_offset_t end
,
1669 int *countp
, int flags
)
1671 vm_map_entry_t entry
;
1673 entry
= start_entry
;
1675 KASSERT(entry
->start
== start
, ("unclip_range: illegal base entry"));
1676 while (entry
!= &map
->header
&& entry
->start
< end
) {
1677 KASSERT(entry
->eflags
& MAP_ENTRY_IN_TRANSITION
,
1678 ("in-transition flag not set during unclip on: %p",
1680 KASSERT(entry
->end
<= end
,
1681 ("unclip_range: tail wasn't clipped"));
1682 entry
->eflags
&= ~MAP_ENTRY_IN_TRANSITION
;
1683 if (entry
->eflags
& MAP_ENTRY_NEEDS_WAKEUP
) {
1684 entry
->eflags
&= ~MAP_ENTRY_NEEDS_WAKEUP
;
1687 entry
= entry
->next
;
1691 * Simplification does not block so there is no restart case.
1693 entry
= start_entry
;
1694 while (entry
!= &map
->header
&& entry
->start
< end
) {
1695 vm_map_simplify_entry(map
, entry
, countp
);
1696 entry
= entry
->next
;
1701 * Mark the given range as handled by a subordinate map.
1703 * This range must have been created with vm_map_find(), and no other
1704 * operations may have been performed on this range prior to calling
1707 * Submappings cannot be removed.
1712 vm_map_submap(vm_map_t map
, vm_offset_t start
, vm_offset_t end
, vm_map_t submap
)
1714 vm_map_entry_t entry
;
1715 int result
= KERN_INVALID_ARGUMENT
;
1718 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1721 VM_MAP_RANGE_CHECK(map
, start
, end
);
1723 if (vm_map_lookup_entry(map
, start
, &entry
)) {
1724 vm_map_clip_start(map
, entry
, start
, &count
);
1726 entry
= entry
->next
;
1729 vm_map_clip_end(map
, entry
, end
, &count
);
1731 if ((entry
->start
== start
) && (entry
->end
== end
) &&
1732 ((entry
->eflags
& MAP_ENTRY_COW
) == 0) &&
1733 (entry
->object
.vm_object
== NULL
)) {
1734 entry
->object
.sub_map
= submap
;
1735 entry
->maptype
= VM_MAPTYPE_SUBMAP
;
1736 result
= KERN_SUCCESS
;
1739 vm_map_entry_release(count
);
1745 * Sets the protection of the specified address region in the target map.
1746 * If "set_max" is specified, the maximum protection is to be set;
1747 * otherwise, only the current protection is affected.
1749 * The protection is not applicable to submaps, but is applicable to normal
1750 * maps and maps governed by virtual page tables. For example, when operating
1751 * on a virtual page table our protection basically controls how COW occurs
1752 * on the backing object, whereas the virtual page table abstraction itself
1753 * is an abstraction for userland.
1758 vm_map_protect(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
1759 vm_prot_t new_prot
, boolean_t set_max
)
1761 vm_map_entry_t current
;
1762 vm_map_entry_t entry
;
1765 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1768 VM_MAP_RANGE_CHECK(map
, start
, end
);
1770 if (vm_map_lookup_entry(map
, start
, &entry
)) {
1771 vm_map_clip_start(map
, entry
, start
, &count
);
1773 entry
= entry
->next
;
1777 * Make a first pass to check for protection violations.
1780 while ((current
!= &map
->header
) && (current
->start
< end
)) {
1781 if (current
->maptype
== VM_MAPTYPE_SUBMAP
) {
1783 vm_map_entry_release(count
);
1784 return (KERN_INVALID_ARGUMENT
);
1786 if ((new_prot
& current
->max_protection
) != new_prot
) {
1788 vm_map_entry_release(count
);
1789 return (KERN_PROTECTION_FAILURE
);
1791 current
= current
->next
;
1795 * Go back and fix up protections. [Note that clipping is not
1796 * necessary the second time.]
1800 while ((current
!= &map
->header
) && (current
->start
< end
)) {
1803 vm_map_clip_end(map
, current
, end
, &count
);
1805 old_prot
= current
->protection
;
1807 current
->protection
=
1808 (current
->max_protection
= new_prot
) &
1811 current
->protection
= new_prot
;
1815 * Update physical map if necessary. Worry about copy-on-write
1816 * here -- CHECK THIS XXX
1819 if (current
->protection
!= old_prot
) {
1820 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1823 pmap_protect(map
->pmap
, current
->start
,
1825 current
->protection
& MASK(current
));
1829 vm_map_simplify_entry(map
, current
, &count
);
1831 current
= current
->next
;
1835 vm_map_entry_release(count
);
1836 return (KERN_SUCCESS
);
1840 * This routine traverses a processes map handling the madvise
1841 * system call. Advisories are classified as either those effecting
1842 * the vm_map_entry structure, or those effecting the underlying
1845 * The <value> argument is used for extended madvise calls.
1850 vm_map_madvise(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
1851 int behav
, off_t value
)
1853 vm_map_entry_t current
, entry
;
1859 * Some madvise calls directly modify the vm_map_entry, in which case
1860 * we need to use an exclusive lock on the map and we need to perform
1861 * various clipping operations. Otherwise we only need a read-lock
1865 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1869 case MADV_SEQUENTIAL
:
1883 vm_map_lock_read(map
);
1886 vm_map_entry_release(count
);
1891 * Locate starting entry and clip if necessary.
1894 VM_MAP_RANGE_CHECK(map
, start
, end
);
1896 if (vm_map_lookup_entry(map
, start
, &entry
)) {
1898 vm_map_clip_start(map
, entry
, start
, &count
);
1900 entry
= entry
->next
;
1905 * madvise behaviors that are implemented in the vm_map_entry.
1907 * We clip the vm_map_entry so that behavioral changes are
1908 * limited to the specified address range.
1910 for (current
= entry
;
1911 (current
!= &map
->header
) && (current
->start
< end
);
1912 current
= current
->next
1914 if (current
->maptype
== VM_MAPTYPE_SUBMAP
)
1917 vm_map_clip_end(map
, current
, end
, &count
);
1921 vm_map_entry_set_behavior(current
, MAP_ENTRY_BEHAV_NORMAL
);
1923 case MADV_SEQUENTIAL
:
1924 vm_map_entry_set_behavior(current
, MAP_ENTRY_BEHAV_SEQUENTIAL
);
1927 vm_map_entry_set_behavior(current
, MAP_ENTRY_BEHAV_RANDOM
);
1930 current
->eflags
|= MAP_ENTRY_NOSYNC
;
1933 current
->eflags
&= ~MAP_ENTRY_NOSYNC
;
1936 current
->eflags
|= MAP_ENTRY_NOCOREDUMP
;
1939 current
->eflags
&= ~MAP_ENTRY_NOCOREDUMP
;
1943 * Invalidate the related pmap entries, used
1944 * to flush portions of the real kernel's
1945 * pmap when the caller has removed or
1946 * modified existing mappings in a virtual
1949 pmap_remove(map
->pmap
,
1950 current
->start
, current
->end
);
1954 * Set the page directory page for a map
1955 * governed by a virtual page table. Mark
1956 * the entry as being governed by a virtual
1957 * page table if it is not.
1959 * XXX the page directory page is stored
1960 * in the avail_ssize field if the map_entry.
1962 * XXX the map simplification code does not
1963 * compare this field so weird things may
1964 * happen if you do not apply this function
1965 * to the entire mapping governed by the
1966 * virtual page table.
1968 if (current
->maptype
!= VM_MAPTYPE_VPAGETABLE
) {
1972 current
->aux
.master_pde
= value
;
1973 pmap_remove(map
->pmap
,
1974 current
->start
, current
->end
);
1980 vm_map_simplify_entry(map
, current
, &count
);
1988 * madvise behaviors that are implemented in the underlying
1991 * Since we don't clip the vm_map_entry, we have to clip
1992 * the vm_object pindex and count.
1994 * NOTE! We currently do not support these functions on
1995 * virtual page tables.
1997 for (current
= entry
;
1998 (current
!= &map
->header
) && (current
->start
< end
);
1999 current
= current
->next
2001 vm_offset_t useStart
;
2003 if (current
->maptype
!= VM_MAPTYPE_NORMAL
)
2006 pindex
= OFF_TO_IDX(current
->offset
);
2007 count
= atop(current
->end
- current
->start
);
2008 useStart
= current
->start
;
2010 if (current
->start
< start
) {
2011 pindex
+= atop(start
- current
->start
);
2012 count
-= atop(start
- current
->start
);
2015 if (current
->end
> end
)
2016 count
-= atop(current
->end
- end
);
2021 vm_object_madvise(current
->object
.vm_object
,
2022 pindex
, count
, behav
);
2025 * Try to populate the page table. Mappings governed
2026 * by virtual page tables cannot be pre-populated
2027 * without a lot of work so don't try.
2029 if (behav
== MADV_WILLNEED
&&
2030 current
->maptype
!= VM_MAPTYPE_VPAGETABLE
) {
2031 pmap_object_init_pt(
2034 current
->protection
,
2035 current
->object
.vm_object
,
2037 (count
<< PAGE_SHIFT
),
2038 MAP_PREFAULT_MADVISE
2042 vm_map_unlock_read(map
);
2044 vm_map_entry_release(count
);
2050 * Sets the inheritance of the specified address range in the target map.
2051 * Inheritance affects how the map will be shared with child maps at the
2052 * time of vm_map_fork.
2055 vm_map_inherit(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
2056 vm_inherit_t new_inheritance
)
2058 vm_map_entry_t entry
;
2059 vm_map_entry_t temp_entry
;
2062 switch (new_inheritance
) {
2063 case VM_INHERIT_NONE
:
2064 case VM_INHERIT_COPY
:
2065 case VM_INHERIT_SHARE
:
2068 return (KERN_INVALID_ARGUMENT
);
2071 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
2074 VM_MAP_RANGE_CHECK(map
, start
, end
);
2076 if (vm_map_lookup_entry(map
, start
, &temp_entry
)) {
2078 vm_map_clip_start(map
, entry
, start
, &count
);
2080 entry
= temp_entry
->next
;
2082 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2083 vm_map_clip_end(map
, entry
, end
, &count
);
2085 entry
->inheritance
= new_inheritance
;
2087 vm_map_simplify_entry(map
, entry
, &count
);
2089 entry
= entry
->next
;
2092 vm_map_entry_release(count
);
2093 return (KERN_SUCCESS
);
2097 * Implement the semantics of mlock
2100 vm_map_unwire(vm_map_t map
, vm_offset_t start
, vm_offset_t real_end
,
2101 boolean_t new_pageable
)
2103 vm_map_entry_t entry
;
2104 vm_map_entry_t start_entry
;
2106 int rv
= KERN_SUCCESS
;
2109 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
2111 VM_MAP_RANGE_CHECK(map
, start
, real_end
);
2114 start_entry
= vm_map_clip_range(map
, start
, end
, &count
,
2116 if (start_entry
== NULL
) {
2118 vm_map_entry_release(count
);
2119 return (KERN_INVALID_ADDRESS
);
2122 if (new_pageable
== 0) {
2123 entry
= start_entry
;
2124 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2125 vm_offset_t save_start
;
2126 vm_offset_t save_end
;
2129 * Already user wired or hard wired (trivial cases)
2131 if (entry
->eflags
& MAP_ENTRY_USER_WIRED
) {
2132 entry
= entry
->next
;
2135 if (entry
->wired_count
!= 0) {
2136 entry
->wired_count
++;
2137 entry
->eflags
|= MAP_ENTRY_USER_WIRED
;
2138 entry
= entry
->next
;
2143 * A new wiring requires instantiation of appropriate
2144 * management structures and the faulting in of the
2147 if (entry
->maptype
!= VM_MAPTYPE_SUBMAP
) {
2148 int copyflag
= entry
->eflags
&
2149 MAP_ENTRY_NEEDS_COPY
;
2150 if (copyflag
&& ((entry
->protection
&
2151 VM_PROT_WRITE
) != 0)) {
2152 vm_map_entry_shadow(entry
, 0);
2153 } else if (entry
->object
.vm_object
== NULL
&&
2155 vm_map_entry_allocate_object(entry
);
2158 entry
->wired_count
++;
2159 entry
->eflags
|= MAP_ENTRY_USER_WIRED
;
2162 * Now fault in the area. Note that vm_fault_wire()
2163 * may release the map lock temporarily, it will be
2164 * relocked on return. The in-transition
2165 * flag protects the entries.
2167 save_start
= entry
->start
;
2168 save_end
= entry
->end
;
2169 rv
= vm_fault_wire(map
, entry
, TRUE
);
2171 CLIP_CHECK_BACK(entry
, save_start
);
2173 KASSERT(entry
->wired_count
== 1, ("bad wired_count on entry"));
2174 entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
2175 entry
->wired_count
= 0;
2176 if (entry
->end
== save_end
)
2178 entry
= entry
->next
;
2179 KASSERT(entry
!= &map
->header
, ("bad entry clip during backout"));
2181 end
= save_start
; /* unwire the rest */
2185 * note that even though the entry might have been
2186 * clipped, the USER_WIRED flag we set prevents
2187 * duplication so we do not have to do a
2190 entry
= entry
->next
;
2194 * If we failed fall through to the unwiring section to
2195 * unwire what we had wired so far. 'end' has already
2202 * start_entry might have been clipped if we unlocked the
2203 * map and blocked. No matter how clipped it has gotten
2204 * there should be a fragment that is on our start boundary.
2206 CLIP_CHECK_BACK(start_entry
, start
);
2210 * Deal with the unwiring case.
2214 * This is the unwiring case. We must first ensure that the
2215 * range to be unwired is really wired down. We know there
2218 entry
= start_entry
;
2219 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2220 if ((entry
->eflags
& MAP_ENTRY_USER_WIRED
) == 0) {
2221 rv
= KERN_INVALID_ARGUMENT
;
2224 KASSERT(entry
->wired_count
!= 0, ("wired count was 0 with USER_WIRED set! %p", entry
));
2225 entry
= entry
->next
;
2229 * Now decrement the wiring count for each region. If a region
2230 * becomes completely unwired, unwire its physical pages and
2234 * The map entries are processed in a loop, checking to
2235 * make sure the entry is wired and asserting it has a wired
2236 * count. However, another loop was inserted more-or-less in
2237 * the middle of the unwiring path. This loop picks up the
2238 * "entry" loop variable from the first loop without first
2239 * setting it to start_entry. Naturally, the secound loop
2240 * is never entered and the pages backing the entries are
2241 * never unwired. This can lead to a leak of wired pages.
2243 entry
= start_entry
;
2244 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2245 KASSERT(entry
->eflags
& MAP_ENTRY_USER_WIRED
,
2246 ("expected USER_WIRED on entry %p", entry
));
2247 entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
2248 entry
->wired_count
--;
2249 if (entry
->wired_count
== 0)
2250 vm_fault_unwire(map
, entry
);
2251 entry
= entry
->next
;
2255 vm_map_unclip_range(map
, start_entry
, start
, real_end
, &count
,
2259 vm_map_entry_release(count
);
2264 * Sets the pageability of the specified address range in the target map.
2265 * Regions specified as not pageable require locked-down physical
2266 * memory and physical page maps.
2268 * The map must not be locked, but a reference must remain to the map
2269 * throughout the call.
2271 * This function may be called via the zalloc path and must properly
2272 * reserve map entries for kernel_map.
2277 vm_map_wire(vm_map_t map
, vm_offset_t start
, vm_offset_t real_end
, int kmflags
)
2279 vm_map_entry_t entry
;
2280 vm_map_entry_t start_entry
;
2282 int rv
= KERN_SUCCESS
;
2285 if (kmflags
& KM_KRESERVE
)
2286 count
= vm_map_entry_kreserve(MAP_RESERVE_COUNT
);
2288 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
2290 VM_MAP_RANGE_CHECK(map
, start
, real_end
);
2293 start_entry
= vm_map_clip_range(map
, start
, end
, &count
,
2295 if (start_entry
== NULL
) {
2297 rv
= KERN_INVALID_ADDRESS
;
2300 if ((kmflags
& KM_PAGEABLE
) == 0) {
2304 * 1. Holding the write lock, we create any shadow or zero-fill
2305 * objects that need to be created. Then we clip each map
2306 * entry to the region to be wired and increment its wiring
2307 * count. We create objects before clipping the map entries
2308 * to avoid object proliferation.
2310 * 2. We downgrade to a read lock, and call vm_fault_wire to
2311 * fault in the pages for any newly wired area (wired_count is
2314 * Downgrading to a read lock for vm_fault_wire avoids a
2315 * possible deadlock with another process that may have faulted
2316 * on one of the pages to be wired (it would mark the page busy,
2317 * blocking us, then in turn block on the map lock that we
2318 * hold). Because of problems in the recursive lock package,
2319 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2320 * any actions that require the write lock must be done
2321 * beforehand. Because we keep the read lock on the map, the
2322 * copy-on-write status of the entries we modify here cannot
2325 entry
= start_entry
;
2326 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2328 * Trivial case if the entry is already wired
2330 if (entry
->wired_count
) {
2331 entry
->wired_count
++;
2332 entry
= entry
->next
;
2337 * The entry is being newly wired, we have to setup
2338 * appropriate management structures. A shadow
2339 * object is required for a copy-on-write region,
2340 * or a normal object for a zero-fill region. We
2341 * do not have to do this for entries that point to sub
2342 * maps because we won't hold the lock on the sub map.
2344 if (entry
->maptype
!= VM_MAPTYPE_SUBMAP
) {
2345 int copyflag
= entry
->eflags
&
2346 MAP_ENTRY_NEEDS_COPY
;
2347 if (copyflag
&& ((entry
->protection
&
2348 VM_PROT_WRITE
) != 0)) {
2349 vm_map_entry_shadow(entry
, 0);
2350 } else if (entry
->object
.vm_object
== NULL
&&
2352 vm_map_entry_allocate_object(entry
);
2356 entry
->wired_count
++;
2357 entry
= entry
->next
;
2365 * HACK HACK HACK HACK
2367 * vm_fault_wire() temporarily unlocks the map to avoid
2368 * deadlocks. The in-transition flag from vm_map_clip_range
2369 * call should protect us from changes while the map is
2372 * NOTE: Previously this comment stated that clipping might
2373 * still occur while the entry is unlocked, but from
2374 * what I can tell it actually cannot.
2376 * It is unclear whether the CLIP_CHECK_*() calls
2377 * are still needed but we keep them in anyway.
2379 * HACK HACK HACK HACK
2382 entry
= start_entry
;
2383 while (entry
!= &map
->header
&& entry
->start
< end
) {
2385 * If vm_fault_wire fails for any page we need to undo
2386 * what has been done. We decrement the wiring count
2387 * for those pages which have not yet been wired (now)
2388 * and unwire those that have (later).
2390 vm_offset_t save_start
= entry
->start
;
2391 vm_offset_t save_end
= entry
->end
;
2393 if (entry
->wired_count
== 1)
2394 rv
= vm_fault_wire(map
, entry
, FALSE
);
2396 CLIP_CHECK_BACK(entry
, save_start
);
2398 KASSERT(entry
->wired_count
== 1, ("wired_count changed unexpectedly"));
2399 entry
->wired_count
= 0;
2400 if (entry
->end
== save_end
)
2402 entry
= entry
->next
;
2403 KASSERT(entry
!= &map
->header
, ("bad entry clip during backout"));
2408 CLIP_CHECK_FWD(entry
, save_end
);
2409 entry
= entry
->next
;
2413 * If a failure occured undo everything by falling through
2414 * to the unwiring code. 'end' has already been adjusted
2418 kmflags
|= KM_PAGEABLE
;
2421 * start_entry is still IN_TRANSITION but may have been
2422 * clipped since vm_fault_wire() unlocks and relocks the
2423 * map. No matter how clipped it has gotten there should
2424 * be a fragment that is on our start boundary.
2426 CLIP_CHECK_BACK(start_entry
, start
);
2429 if (kmflags
& KM_PAGEABLE
) {
2431 * This is the unwiring case. We must first ensure that the
2432 * range to be unwired is really wired down. We know there
2435 entry
= start_entry
;
2436 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2437 if (entry
->wired_count
== 0) {
2438 rv
= KERN_INVALID_ARGUMENT
;
2441 entry
= entry
->next
;
2445 * Now decrement the wiring count for each region. If a region
2446 * becomes completely unwired, unwire its physical pages and
2449 entry
= start_entry
;
2450 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2451 entry
->wired_count
--;
2452 if (entry
->wired_count
== 0)
2453 vm_fault_unwire(map
, entry
);
2454 entry
= entry
->next
;
2458 vm_map_unclip_range(map
, start_entry
, start
, real_end
,
2459 &count
, MAP_CLIP_NO_HOLES
);
2463 if (kmflags
& KM_KRESERVE
)
2464 vm_map_entry_krelease(count
);
2466 vm_map_entry_release(count
);
2471 * Mark a newly allocated address range as wired but do not fault in
2472 * the pages. The caller is expected to load the pages into the object.
2474 * The map must be locked on entry and will remain locked on return.
2475 * No other requirements.
2478 vm_map_set_wired_quick(vm_map_t map
, vm_offset_t addr
, vm_size_t size
,
2481 vm_map_entry_t scan
;
2482 vm_map_entry_t entry
;
2484 entry
= vm_map_clip_range(map
, addr
, addr
+ size
,
2485 countp
, MAP_CLIP_NO_HOLES
);
2487 scan
!= &map
->header
&& scan
->start
< addr
+ size
;
2488 scan
= scan
->next
) {
2489 KKASSERT(scan
->wired_count
== 0);
2490 scan
->wired_count
= 1;
2492 vm_map_unclip_range(map
, entry
, addr
, addr
+ size
,
2493 countp
, MAP_CLIP_NO_HOLES
);
2497 * Push any dirty cached pages in the address range to their pager.
2498 * If syncio is TRUE, dirty pages are written synchronously.
2499 * If invalidate is TRUE, any cached pages are freed as well.
2501 * This routine is called by sys_msync()
2503 * Returns an error if any part of the specified range is not mapped.
2508 vm_map_clean(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
2509 boolean_t syncio
, boolean_t invalidate
)
2511 vm_map_entry_t current
;
2512 vm_map_entry_t entry
;
2516 vm_ooffset_t offset
;
2518 vm_map_lock_read(map
);
2519 VM_MAP_RANGE_CHECK(map
, start
, end
);
2520 if (!vm_map_lookup_entry(map
, start
, &entry
)) {
2521 vm_map_unlock_read(map
);
2522 return (KERN_INVALID_ADDRESS
);
2524 lwkt_gettoken(&map
->token
);
2527 * Make a first pass to check for holes.
2529 for (current
= entry
; current
->start
< end
; current
= current
->next
) {
2530 if (current
->maptype
== VM_MAPTYPE_SUBMAP
) {
2531 lwkt_reltoken(&map
->token
);
2532 vm_map_unlock_read(map
);
2533 return (KERN_INVALID_ARGUMENT
);
2535 if (end
> current
->end
&&
2536 (current
->next
== &map
->header
||
2537 current
->end
!= current
->next
->start
)) {
2538 lwkt_reltoken(&map
->token
);
2539 vm_map_unlock_read(map
);
2540 return (KERN_INVALID_ADDRESS
);
2545 pmap_remove(vm_map_pmap(map
), start
, end
);
2548 * Make a second pass, cleaning/uncaching pages from the indicated
2551 for (current
= entry
; current
->start
< end
; current
= current
->next
) {
2552 offset
= current
->offset
+ (start
- current
->start
);
2553 size
= (end
<= current
->end
? end
: current
->end
) - start
;
2554 if (current
->maptype
== VM_MAPTYPE_SUBMAP
) {
2556 vm_map_entry_t tentry
;
2559 smap
= current
->object
.sub_map
;
2560 vm_map_lock_read(smap
);
2561 vm_map_lookup_entry(smap
, offset
, &tentry
);
2562 tsize
= tentry
->end
- offset
;
2565 object
= tentry
->object
.vm_object
;
2566 offset
= tentry
->offset
+ (offset
- tentry
->start
);
2567 vm_map_unlock_read(smap
);
2569 object
= current
->object
.vm_object
;
2573 vm_object_hold(object
);
2576 * Note that there is absolutely no sense in writing out
2577 * anonymous objects, so we track down the vnode object
2579 * We invalidate (remove) all pages from the address space
2580 * anyway, for semantic correctness.
2582 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2583 * may start out with a NULL object.
2585 while (object
&& (tobj
= object
->backing_object
) != NULL
) {
2586 vm_object_hold(tobj
);
2587 if (tobj
== object
->backing_object
) {
2588 vm_object_lock_swap();
2589 offset
+= object
->backing_object_offset
;
2590 vm_object_drop(object
);
2592 if (object
->size
< OFF_TO_IDX(offset
+ size
))
2593 size
= IDX_TO_OFF(object
->size
) -
2597 vm_object_drop(tobj
);
2599 if (object
&& (object
->type
== OBJT_VNODE
) &&
2600 (current
->protection
& VM_PROT_WRITE
) &&
2601 (object
->flags
& OBJ_NOMSYNC
) == 0) {
2603 * Flush pages if writing is allowed, invalidate them
2604 * if invalidation requested. Pages undergoing I/O
2605 * will be ignored by vm_object_page_remove().
2607 * We cannot lock the vnode and then wait for paging
2608 * to complete without deadlocking against vm_fault.
2609 * Instead we simply call vm_object_page_remove() and
2610 * allow it to block internally on a page-by-page
2611 * basis when it encounters pages undergoing async
2616 /* no chain wait needed for vnode objects */
2617 vm_object_reference_locked(object
);
2618 vn_lock(object
->handle
, LK_EXCLUSIVE
| LK_RETRY
);
2619 flags
= (syncio
|| invalidate
) ? OBJPC_SYNC
: 0;
2620 flags
|= invalidate
? OBJPC_INVAL
: 0;
2623 * When operating on a virtual page table just
2624 * flush the whole object. XXX we probably ought
2627 switch(current
->maptype
) {
2628 case VM_MAPTYPE_NORMAL
:
2629 vm_object_page_clean(object
,
2631 OFF_TO_IDX(offset
+ size
+ PAGE_MASK
),
2634 case VM_MAPTYPE_VPAGETABLE
:
2635 vm_object_page_clean(object
, 0, 0, flags
);
2638 vn_unlock(((struct vnode
*)object
->handle
));
2639 vm_object_deallocate_locked(object
);
2641 if (object
&& invalidate
&&
2642 ((object
->type
== OBJT_VNODE
) ||
2643 (object
->type
== OBJT_DEVICE
))) {
2645 (object
->type
== OBJT_DEVICE
) ? FALSE
: TRUE
;
2646 /* no chain wait needed for vnode/device objects */
2647 vm_object_reference_locked(object
);
2648 switch(current
->maptype
) {
2649 case VM_MAPTYPE_NORMAL
:
2650 vm_object_page_remove(object
,
2652 OFF_TO_IDX(offset
+ size
+ PAGE_MASK
),
2655 case VM_MAPTYPE_VPAGETABLE
:
2656 vm_object_page_remove(object
, 0, 0, clean_only
);
2659 vm_object_deallocate_locked(object
);
2663 vm_object_drop(object
);
2666 lwkt_reltoken(&map
->token
);
2667 vm_map_unlock_read(map
);
2669 return (KERN_SUCCESS
);
2673 * Make the region specified by this entry pageable.
2675 * The vm_map must be exclusively locked.
2678 vm_map_entry_unwire(vm_map_t map
, vm_map_entry_t entry
)
2680 entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
2681 entry
->wired_count
= 0;
2682 vm_fault_unwire(map
, entry
);
2686 * Deallocate the given entry from the target map.
2688 * The vm_map must be exclusively locked.
2691 vm_map_entry_delete(vm_map_t map
, vm_map_entry_t entry
, int *countp
)
2693 vm_map_entry_unlink(map
, entry
);
2694 map
->size
-= entry
->end
- entry
->start
;
2696 switch(entry
->maptype
) {
2697 case VM_MAPTYPE_NORMAL
:
2698 case VM_MAPTYPE_VPAGETABLE
:
2699 vm_object_deallocate(entry
->object
.vm_object
);
2705 vm_map_entry_dispose(map
, entry
, countp
);
2709 * Deallocates the given address range from the target map.
2711 * The vm_map must be exclusively locked.
2714 vm_map_delete(vm_map_t map
, vm_offset_t start
, vm_offset_t end
, int *countp
)
2717 vm_map_entry_t entry
;
2718 vm_map_entry_t first_entry
;
2720 ASSERT_VM_MAP_LOCKED(map
);
2721 lwkt_gettoken(&map
->token
);
2724 * Find the start of the region, and clip it. Set entry to point
2725 * at the first record containing the requested address or, if no
2726 * such record exists, the next record with a greater address. The
2727 * loop will run from this point until a record beyond the termination
2728 * address is encountered.
2730 * map->hint must be adjusted to not point to anything we delete,
2731 * so set it to the entry prior to the one being deleted.
2733 * GGG see other GGG comment.
2735 if (vm_map_lookup_entry(map
, start
, &first_entry
)) {
2736 entry
= first_entry
;
2737 vm_map_clip_start(map
, entry
, start
, countp
);
2738 map
->hint
= entry
->prev
; /* possible problem XXX */
2740 map
->hint
= first_entry
; /* possible problem XXX */
2741 entry
= first_entry
->next
;
2745 * If a hole opens up prior to the current first_free then
2746 * adjust first_free. As with map->hint, map->first_free
2747 * cannot be left set to anything we might delete.
2749 if (entry
== &map
->header
) {
2750 map
->first_free
= &map
->header
;
2751 } else if (map
->first_free
->start
>= start
) {
2752 map
->first_free
= entry
->prev
;
2756 * Step through all entries in this region
2758 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2759 vm_map_entry_t next
;
2761 vm_pindex_t offidxstart
, offidxend
, count
;
2764 * If we hit an in-transition entry we have to sleep and
2765 * retry. It's easier (and not really slower) to just retry
2766 * since this case occurs so rarely and the hint is already
2767 * pointing at the right place. We have to reset the
2768 * start offset so as not to accidently delete an entry
2769 * another process just created in vacated space.
2771 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
2772 entry
->eflags
|= MAP_ENTRY_NEEDS_WAKEUP
;
2773 start
= entry
->start
;
2774 ++mycpu
->gd_cnt
.v_intrans_coll
;
2775 ++mycpu
->gd_cnt
.v_intrans_wait
;
2776 vm_map_transition_wait(map
);
2779 vm_map_clip_end(map
, entry
, end
, countp
);
2785 offidxstart
= OFF_TO_IDX(entry
->offset
);
2786 count
= OFF_TO_IDX(e
- s
);
2787 object
= entry
->object
.vm_object
;
2790 * Unwire before removing addresses from the pmap; otherwise,
2791 * unwiring will put the entries back in the pmap.
2793 if (entry
->wired_count
!= 0)
2794 vm_map_entry_unwire(map
, entry
);
2796 offidxend
= offidxstart
+ count
;
2798 if (object
== &kernel_object
) {
2799 vm_object_hold(object
);
2800 vm_object_page_remove(object
, offidxstart
,
2802 vm_object_drop(object
);
2803 } else if (object
&& object
->type
!= OBJT_DEFAULT
&&
2804 object
->type
!= OBJT_SWAP
) {
2806 * vnode object routines cannot be chain-locked
2808 vm_object_hold(object
);
2809 pmap_remove(map
->pmap
, s
, e
);
2810 vm_object_drop(object
);
2811 } else if (object
) {
2812 vm_object_hold(object
);
2813 vm_object_chain_acquire(object
);
2814 pmap_remove(map
->pmap
, s
, e
);
2816 if (object
!= NULL
&&
2817 object
->ref_count
!= 1 &&
2818 (object
->flags
& (OBJ_NOSPLIT
|OBJ_ONEMAPPING
)) ==
2820 (object
->type
== OBJT_DEFAULT
||
2821 object
->type
== OBJT_SWAP
)) {
2822 vm_object_collapse(object
, NULL
);
2823 vm_object_page_remove(object
, offidxstart
,
2825 if (object
->type
== OBJT_SWAP
) {
2826 swap_pager_freespace(object
,
2830 if (offidxend
>= object
->size
&&
2831 offidxstart
< object
->size
) {
2832 object
->size
= offidxstart
;
2835 vm_object_chain_release(object
);
2836 vm_object_drop(object
);
2840 * Delete the entry (which may delete the object) only after
2841 * removing all pmap entries pointing to its pages.
2842 * (Otherwise, its page frames may be reallocated, and any
2843 * modify bits will be set in the wrong object!)
2845 vm_map_entry_delete(map
, entry
, countp
);
2848 lwkt_reltoken(&map
->token
);
2849 return (KERN_SUCCESS
);
2853 * Remove the given address range from the target map.
2854 * This is the exported form of vm_map_delete.
2859 vm_map_remove(vm_map_t map
, vm_offset_t start
, vm_offset_t end
)
2864 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
2866 VM_MAP_RANGE_CHECK(map
, start
, end
);
2867 result
= vm_map_delete(map
, start
, end
, &count
);
2869 vm_map_entry_release(count
);
2875 * Assert that the target map allows the specified privilege on the
2876 * entire address region given. The entire region must be allocated.
2878 * The caller must specify whether the vm_map is already locked or not.
2881 vm_map_check_protection(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
2882 vm_prot_t protection
, boolean_t have_lock
)
2884 vm_map_entry_t entry
;
2885 vm_map_entry_t tmp_entry
;
2888 if (have_lock
== FALSE
)
2889 vm_map_lock_read(map
);
2891 if (!vm_map_lookup_entry(map
, start
, &tmp_entry
)) {
2892 if (have_lock
== FALSE
)
2893 vm_map_unlock_read(map
);
2899 while (start
< end
) {
2900 if (entry
== &map
->header
) {
2908 if (start
< entry
->start
) {
2913 * Check protection associated with entry.
2916 if ((entry
->protection
& protection
) != protection
) {
2920 /* go to next entry */
2923 entry
= entry
->next
;
2925 if (have_lock
== FALSE
)
2926 vm_map_unlock_read(map
);
2931 * If appropriate this function shadows the original object with a new object
2932 * and moves the VM pages from the original object to the new object.
2933 * The original object will also be collapsed, if possible.
2935 * We can only do this for normal memory objects with a single mapping, and
2936 * it only makes sense to do it if there are 2 or more refs on the original
2937 * object. i.e. typically a memory object that has been extended into
2938 * multiple vm_map_entry's with non-overlapping ranges.
2940 * This makes it easier to remove unused pages and keeps object inheritance
2941 * from being a negative impact on memory usage.
2943 * On return the (possibly new) entry->object.vm_object will have an
2944 * additional ref on it for the caller to dispose of (usually by cloning
2945 * the vm_map_entry). The additional ref had to be done in this routine
2946 * to avoid racing a collapse. The object's ONEMAPPING flag will also be
2949 * The vm_map must be locked and its token held.
2952 vm_map_split(vm_map_entry_t entry
)
2956 vm_object_t oobject
;
2958 oobject
= entry
->object
.vm_object
;
2959 vm_object_hold(oobject
);
2960 vm_object_chain_wait(oobject
);
2961 vm_object_reference_locked(oobject
);
2962 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
2963 vm_object_drop(oobject
);
2966 vm_object_t oobject
, nobject
, bobject
;
2969 vm_pindex_t offidxstart
, offidxend
, idx
;
2971 vm_ooffset_t offset
;
2974 * Setup. Chain lock the original object throughout the entire
2975 * routine to prevent new page faults from occuring.
2977 * XXX can madvise WILLNEED interfere with us too?
2979 oobject
= entry
->object
.vm_object
;
2980 vm_object_hold(oobject
);
2981 vm_object_chain_acquire(oobject
);
2984 * Original object cannot be split?
2986 if (oobject
->handle
== NULL
|| (oobject
->type
!= OBJT_DEFAULT
&&
2987 oobject
->type
!= OBJT_SWAP
)) {
2988 vm_object_chain_release(oobject
);
2989 vm_object_reference_locked(oobject
);
2990 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
2991 vm_object_drop(oobject
);
2996 * Collapse original object with its backing store as an
2997 * optimization to reduce chain lengths when possible.
2999 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's
3000 * for oobject, so there's no point collapsing it.
3002 * Then re-check whether the object can be split.
3004 vm_object_collapse(oobject
, NULL
);
3006 if (oobject
->ref_count
<= 1 ||
3007 (oobject
->type
!= OBJT_DEFAULT
&& oobject
->type
!= OBJT_SWAP
) ||
3008 (oobject
->flags
& (OBJ_NOSPLIT
|OBJ_ONEMAPPING
)) != OBJ_ONEMAPPING
) {
3009 vm_object_chain_release(oobject
);
3010 vm_object_reference_locked(oobject
);
3011 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
3012 vm_object_drop(oobject
);
3017 * Acquire the chain lock on the backing object.
3019 * Give bobject an additional ref count for when it will be shadowed
3022 if ((bobject
= oobject
->backing_object
) != NULL
) {
3023 vm_object_hold(bobject
);
3024 vm_object_chain_wait(bobject
);
3025 vm_object_reference_locked(bobject
);
3026 vm_object_chain_acquire(bobject
);
3027 KKASSERT(bobject
->backing_object
== bobject
);
3028 KKASSERT((bobject
->flags
& OBJ_DEAD
) == 0);
3032 * Calculate the object page range and allocate the new object.
3034 offset
= entry
->offset
;
3038 offidxstart
= OFF_TO_IDX(offset
);
3039 offidxend
= offidxstart
+ OFF_TO_IDX(e
- s
);
3040 size
= offidxend
- offidxstart
;
3042 switch(oobject
->type
) {
3044 nobject
= default_pager_alloc(NULL
, IDX_TO_OFF(size
),
3048 nobject
= swap_pager_alloc(NULL
, IDX_TO_OFF(size
),
3057 if (nobject
== NULL
) {
3059 vm_object_chain_release(bobject
);
3060 vm_object_deallocate(bobject
);
3061 vm_object_drop(bobject
);
3063 vm_object_chain_release(oobject
);
3064 vm_object_reference_locked(oobject
);
3065 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
3066 vm_object_drop(oobject
);
3071 * The new object will replace entry->object.vm_object so it needs
3072 * a second reference (the caller expects an additional ref).
3074 vm_object_hold(nobject
);
3075 vm_object_reference_locked(nobject
);
3076 vm_object_chain_acquire(nobject
);
3079 * nobject shadows bobject (oobject already shadows bobject).
3082 nobject
->backing_object_offset
=
3083 oobject
->backing_object_offset
+ IDX_TO_OFF(offidxstart
);
3084 nobject
->backing_object
= bobject
;
3085 bobject
->shadow_count
++;
3086 bobject
->generation
++;
3087 LIST_INSERT_HEAD(&bobject
->shadow_head
, nobject
, shadow_list
);
3088 vm_object_clear_flag(bobject
, OBJ_ONEMAPPING
); /* XXX? */
3089 vm_object_chain_release(bobject
);
3090 vm_object_drop(bobject
);
3094 * Move the VM pages from oobject to nobject
3096 for (idx
= 0; idx
< size
; idx
++) {
3099 m
= vm_page_lookup_busy_wait(oobject
, offidxstart
+ idx
,
3105 * We must wait for pending I/O to complete before we can
3108 * We do not have to VM_PROT_NONE the page as mappings should
3109 * not be changed by this operation.
3111 * NOTE: The act of renaming a page updates chaingen for both
3114 vm_page_rename(m
, nobject
, idx
);
3115 /* page automatically made dirty by rename and cache handled */
3116 /* page remains busy */
3119 if (oobject
->type
== OBJT_SWAP
) {
3120 vm_object_pip_add(oobject
, 1);
3122 * copy oobject pages into nobject and destroy unneeded
3123 * pages in shadow object.
3125 swap_pager_copy(oobject
, nobject
, offidxstart
, 0);
3126 vm_object_pip_wakeup(oobject
);
3130 * Wakeup the pages we played with. No spl protection is needed
3131 * for a simple wakeup.
3133 for (idx
= 0; idx
< size
; idx
++) {
3134 m
= vm_page_lookup(nobject
, idx
);
3136 KKASSERT(m
->flags
& PG_BUSY
);
3140 entry
->object
.vm_object
= nobject
;
3141 entry
->offset
= 0LL;
3146 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the
3147 * related pages were moved and are no longer applicable to the
3150 * NOTE: Deallocate oobject (due to its entry->object.vm_object being
3151 * replaced by nobject).
3153 vm_object_chain_release(nobject
);
3154 vm_object_drop(nobject
);
3156 vm_object_chain_release(bobject
);
3157 vm_object_drop(bobject
);
3159 vm_object_chain_release(oobject
);
3160 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/
3161 vm_object_deallocate_locked(oobject
);
3162 vm_object_drop(oobject
);
3167 * Copies the contents of the source entry to the destination
3168 * entry. The entries *must* be aligned properly.
3170 * The vm_maps must be exclusively locked.
3171 * The vm_map's token must be held.
3173 * Because the maps are locked no faults can be in progress during the
3177 vm_map_copy_entry(vm_map_t src_map
, vm_map_t dst_map
,
3178 vm_map_entry_t src_entry
, vm_map_entry_t dst_entry
)
3180 vm_object_t src_object
;
3182 if (dst_entry
->maptype
== VM_MAPTYPE_SUBMAP
)
3184 if (src_entry
->maptype
== VM_MAPTYPE_SUBMAP
)
3187 if (src_entry
->wired_count
== 0) {
3189 * If the source entry is marked needs_copy, it is already
3192 if ((src_entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) == 0) {
3193 pmap_protect(src_map
->pmap
,
3196 src_entry
->protection
& ~VM_PROT_WRITE
);
3200 * Make a copy of the object.
3202 * The object must be locked prior to checking the object type
3203 * and for the call to vm_object_collapse() and vm_map_split().
3204 * We cannot use *_hold() here because the split code will
3205 * probably try to destroy the object. The lock is a pool
3206 * token and doesn't care.
3208 * We must bump src_map->timestamp when setting
3209 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault
3210 * to retry, otherwise the concurrent fault might improperly
3211 * install a RW pte when its supposed to be a RO(COW) pte.
3212 * This race can occur because a vnode-backed fault may have
3213 * to temporarily release the map lock.
3215 if (src_entry
->object
.vm_object
!= NULL
) {
3216 vm_map_split(src_entry
);
3217 src_object
= src_entry
->object
.vm_object
;
3218 dst_entry
->object
.vm_object
= src_object
;
3219 src_entry
->eflags
|= (MAP_ENTRY_COW
|
3220 MAP_ENTRY_NEEDS_COPY
);
3221 dst_entry
->eflags
|= (MAP_ENTRY_COW
|
3222 MAP_ENTRY_NEEDS_COPY
);
3223 dst_entry
->offset
= src_entry
->offset
;
3224 ++src_map
->timestamp
;
3226 dst_entry
->object
.vm_object
= NULL
;
3227 dst_entry
->offset
= 0;
3230 pmap_copy(dst_map
->pmap
, src_map
->pmap
, dst_entry
->start
,
3231 dst_entry
->end
- dst_entry
->start
, src_entry
->start
);
3234 * Of course, wired down pages can't be set copy-on-write.
3235 * Cause wired pages to be copied into the new map by
3236 * simulating faults (the new pages are pageable)
3238 vm_fault_copy_entry(dst_map
, src_map
, dst_entry
, src_entry
);
3244 * Create a new process vmspace structure and vm_map
3245 * based on those of an existing process. The new map
3246 * is based on the old map, according to the inheritance
3247 * values on the regions in that map.
3249 * The source map must not be locked.
3253 vmspace_fork(struct vmspace
*vm1
)
3255 struct vmspace
*vm2
;
3256 vm_map_t old_map
= &vm1
->vm_map
;
3258 vm_map_entry_t old_entry
;
3259 vm_map_entry_t new_entry
;
3263 lwkt_gettoken(&vm1
->vm_map
.token
);
3264 vm_map_lock(old_map
);
3266 vm2
= vmspace_alloc(old_map
->min_offset
, old_map
->max_offset
);
3267 lwkt_gettoken(&vm2
->vm_map
.token
);
3268 bcopy(&vm1
->vm_startcopy
, &vm2
->vm_startcopy
,
3269 (caddr_t
)&vm1
->vm_endcopy
- (caddr_t
)&vm1
->vm_startcopy
);
3270 new_map
= &vm2
->vm_map
; /* XXX */
3271 new_map
->timestamp
= 1;
3273 vm_map_lock(new_map
);
3276 old_entry
= old_map
->header
.next
;
3277 while (old_entry
!= &old_map
->header
) {
3279 old_entry
= old_entry
->next
;
3282 count
= vm_map_entry_reserve(count
+ MAP_RESERVE_COUNT
);
3284 old_entry
= old_map
->header
.next
;
3285 while (old_entry
!= &old_map
->header
) {
3286 if (old_entry
->maptype
== VM_MAPTYPE_SUBMAP
)
3287 panic("vm_map_fork: encountered a submap");
3289 switch (old_entry
->inheritance
) {
3290 case VM_INHERIT_NONE
:
3292 case VM_INHERIT_SHARE
:
3294 * Clone the entry, creating the shared object if
3297 if (old_entry
->object
.vm_object
== NULL
)
3298 vm_map_entry_allocate_object(old_entry
);
3300 if (old_entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) {
3302 * Shadow a map_entry which needs a copy,
3303 * replacing its object with a new object
3304 * that points to the old one. Ask the
3305 * shadow code to automatically add an
3306 * additional ref. We can't do it afterwords
3307 * because we might race a collapse. The call
3308 * to vm_map_entry_shadow() will also clear
3311 vm_map_entry_shadow(old_entry
, 1);
3314 * We will make a shared copy of the object,
3315 * and must clear OBJ_ONEMAPPING.
3317 * XXX assert that object.vm_object != NULL
3318 * since we allocate it above.
3320 if (old_entry
->object
.vm_object
) {
3321 object
= old_entry
->object
.vm_object
;
3322 vm_object_hold(object
);
3323 vm_object_chain_wait(object
);
3324 vm_object_reference_locked(object
);
3325 vm_object_clear_flag(object
,
3327 vm_object_drop(object
);
3332 * Clone the entry. We've already bumped the ref on
3335 new_entry
= vm_map_entry_create(new_map
, &count
);
3336 *new_entry
= *old_entry
;
3337 new_entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
3338 new_entry
->wired_count
= 0;
3341 * Insert the entry into the new map -- we know we're
3342 * inserting at the end of the new map.
3345 vm_map_entry_link(new_map
, new_map
->header
.prev
,
3349 * Update the physical map
3351 pmap_copy(new_map
->pmap
, old_map
->pmap
,
3353 (old_entry
->end
- old_entry
->start
),
3356 case VM_INHERIT_COPY
:
3358 * Clone the entry and link into the map.
3360 new_entry
= vm_map_entry_create(new_map
, &count
);
3361 *new_entry
= *old_entry
;
3362 new_entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
3363 new_entry
->wired_count
= 0;
3364 new_entry
->object
.vm_object
= NULL
;
3365 vm_map_entry_link(new_map
, new_map
->header
.prev
,
3367 vm_map_copy_entry(old_map
, new_map
, old_entry
,
3371 old_entry
= old_entry
->next
;
3374 new_map
->size
= old_map
->size
;
3375 vm_map_unlock(old_map
);
3376 vm_map_unlock(new_map
);
3377 vm_map_entry_release(count
);
3379 lwkt_reltoken(&vm2
->vm_map
.token
);
3380 lwkt_reltoken(&vm1
->vm_map
.token
);
3386 * Create an auto-grow stack entry
3391 vm_map_stack (vm_map_t map
, vm_offset_t addrbos
, vm_size_t max_ssize
,
3392 int flags
, vm_prot_t prot
, vm_prot_t max
, int cow
)
3394 vm_map_entry_t prev_entry
;
3395 vm_map_entry_t new_stack_entry
;
3396 vm_size_t init_ssize
;
3399 vm_offset_t tmpaddr
;
3401 cow
|= MAP_IS_STACK
;
3403 if (max_ssize
< sgrowsiz
)
3404 init_ssize
= max_ssize
;
3406 init_ssize
= sgrowsiz
;
3408 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
3412 * Find space for the mapping
3414 if ((flags
& (MAP_FIXED
| MAP_TRYFIXED
)) == 0) {
3415 if (vm_map_findspace(map
, addrbos
, max_ssize
, 1,
3418 vm_map_entry_release(count
);
3419 return (KERN_NO_SPACE
);
3424 /* If addr is already mapped, no go */
3425 if (vm_map_lookup_entry(map
, addrbos
, &prev_entry
)) {
3427 vm_map_entry_release(count
);
3428 return (KERN_NO_SPACE
);
3432 /* XXX already handled by kern_mmap() */
3433 /* If we would blow our VMEM resource limit, no go */
3434 if (map
->size
+ init_ssize
>
3435 curproc
->p_rlimit
[RLIMIT_VMEM
].rlim_cur
) {
3437 vm_map_entry_release(count
);
3438 return (KERN_NO_SPACE
);
3443 * If we can't accomodate max_ssize in the current mapping,
3444 * no go. However, we need to be aware that subsequent user
3445 * mappings might map into the space we have reserved for
3446 * stack, and currently this space is not protected.
3448 * Hopefully we will at least detect this condition
3449 * when we try to grow the stack.
3451 if ((prev_entry
->next
!= &map
->header
) &&
3452 (prev_entry
->next
->start
< addrbos
+ max_ssize
)) {
3454 vm_map_entry_release(count
);
3455 return (KERN_NO_SPACE
);
3459 * We initially map a stack of only init_ssize. We will
3460 * grow as needed later. Since this is to be a grow
3461 * down stack, we map at the top of the range.
3463 * Note: we would normally expect prot and max to be
3464 * VM_PROT_ALL, and cow to be 0. Possibly we should
3465 * eliminate these as input parameters, and just
3466 * pass these values here in the insert call.
3468 rv
= vm_map_insert(map
, &count
,
3469 NULL
, 0, addrbos
+ max_ssize
- init_ssize
,
3470 addrbos
+ max_ssize
,
3475 /* Now set the avail_ssize amount */
3476 if (rv
== KERN_SUCCESS
) {
3477 if (prev_entry
!= &map
->header
)
3478 vm_map_clip_end(map
, prev_entry
, addrbos
+ max_ssize
- init_ssize
, &count
);
3479 new_stack_entry
= prev_entry
->next
;
3480 if (new_stack_entry
->end
!= addrbos
+ max_ssize
||
3481 new_stack_entry
->start
!= addrbos
+ max_ssize
- init_ssize
)
3482 panic ("Bad entry start/end for new stack entry");
3484 new_stack_entry
->aux
.avail_ssize
= max_ssize
- init_ssize
;
3488 vm_map_entry_release(count
);
3493 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3494 * desired address is already mapped, or if we successfully grow
3495 * the stack. Also returns KERN_SUCCESS if addr is outside the
3496 * stack range (this is strange, but preserves compatibility with
3497 * the grow function in vm_machdep.c).
3502 vm_map_growstack (struct proc
*p
, vm_offset_t addr
)
3504 vm_map_entry_t prev_entry
;
3505 vm_map_entry_t stack_entry
;
3506 vm_map_entry_t new_stack_entry
;
3507 struct vmspace
*vm
= p
->p_vmspace
;
3508 vm_map_t map
= &vm
->vm_map
;
3511 int rv
= KERN_SUCCESS
;
3513 int use_read_lock
= 1;
3516 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
3519 vm_map_lock_read(map
);
3523 /* If addr is already in the entry range, no need to grow.*/
3524 if (vm_map_lookup_entry(map
, addr
, &prev_entry
))
3527 if ((stack_entry
= prev_entry
->next
) == &map
->header
)
3529 if (prev_entry
== &map
->header
)
3530 end
= stack_entry
->start
- stack_entry
->aux
.avail_ssize
;
3532 end
= prev_entry
->end
;
3535 * This next test mimics the old grow function in vm_machdep.c.
3536 * It really doesn't quite make sense, but we do it anyway
3537 * for compatibility.
3539 * If not growable stack, return success. This signals the
3540 * caller to proceed as he would normally with normal vm.
3542 if (stack_entry
->aux
.avail_ssize
< 1 ||
3543 addr
>= stack_entry
->start
||
3544 addr
< stack_entry
->start
- stack_entry
->aux
.avail_ssize
) {
3548 /* Find the minimum grow amount */
3549 grow_amount
= roundup (stack_entry
->start
- addr
, PAGE_SIZE
);
3550 if (grow_amount
> stack_entry
->aux
.avail_ssize
) {
3556 * If there is no longer enough space between the entries
3557 * nogo, and adjust the available space. Note: this
3558 * should only happen if the user has mapped into the
3559 * stack area after the stack was created, and is
3560 * probably an error.
3562 * This also effectively destroys any guard page the user
3563 * might have intended by limiting the stack size.
3565 if (grow_amount
> stack_entry
->start
- end
) {
3566 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
3572 stack_entry
->aux
.avail_ssize
= stack_entry
->start
- end
;
3577 is_procstack
= addr
>= (vm_offset_t
)vm
->vm_maxsaddr
;
3579 /* If this is the main process stack, see if we're over the
3582 if (is_procstack
&& (ctob(vm
->vm_ssize
) + grow_amount
>
3583 p
->p_rlimit
[RLIMIT_STACK
].rlim_cur
)) {
3588 /* Round up the grow amount modulo SGROWSIZ */
3589 grow_amount
= roundup (grow_amount
, sgrowsiz
);
3590 if (grow_amount
> stack_entry
->aux
.avail_ssize
) {
3591 grow_amount
= stack_entry
->aux
.avail_ssize
;
3593 if (is_procstack
&& (ctob(vm
->vm_ssize
) + grow_amount
>
3594 p
->p_rlimit
[RLIMIT_STACK
].rlim_cur
)) {
3595 grow_amount
= p
->p_rlimit
[RLIMIT_STACK
].rlim_cur
-
3599 /* If we would blow our VMEM resource limit, no go */
3600 if (map
->size
+ grow_amount
> p
->p_rlimit
[RLIMIT_VMEM
].rlim_cur
) {
3605 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
3612 /* Get the preliminary new entry start value */
3613 addr
= stack_entry
->start
- grow_amount
;
3615 /* If this puts us into the previous entry, cut back our growth
3616 * to the available space. Also, see the note above.
3619 stack_entry
->aux
.avail_ssize
= stack_entry
->start
- end
;
3623 rv
= vm_map_insert(map
, &count
,
3624 NULL
, 0, addr
, stack_entry
->start
,
3626 VM_PROT_ALL
, VM_PROT_ALL
,
3629 /* Adjust the available stack space by the amount we grew. */
3630 if (rv
== KERN_SUCCESS
) {
3631 if (prev_entry
!= &map
->header
)
3632 vm_map_clip_end(map
, prev_entry
, addr
, &count
);
3633 new_stack_entry
= prev_entry
->next
;
3634 if (new_stack_entry
->end
!= stack_entry
->start
||
3635 new_stack_entry
->start
!= addr
)
3636 panic ("Bad stack grow start/end in new stack entry");
3638 new_stack_entry
->aux
.avail_ssize
=
3639 stack_entry
->aux
.avail_ssize
-
3640 (new_stack_entry
->end
- new_stack_entry
->start
);
3642 vm
->vm_ssize
+= btoc(new_stack_entry
->end
-
3643 new_stack_entry
->start
);
3646 if (map
->flags
& MAP_WIREFUTURE
)
3647 vm_map_unwire(map
, new_stack_entry
->start
,
3648 new_stack_entry
->end
, FALSE
);
3653 vm_map_unlock_read(map
);
3656 vm_map_entry_release(count
);
3661 * Unshare the specified VM space for exec. If other processes are
3662 * mapped to it, then create a new one. The new vmspace is null.
3667 vmspace_exec(struct proc
*p
, struct vmspace
*vmcopy
)
3669 struct vmspace
*oldvmspace
= p
->p_vmspace
;
3670 struct vmspace
*newvmspace
;
3671 vm_map_t map
= &p
->p_vmspace
->vm_map
;
3674 * If we are execing a resident vmspace we fork it, otherwise
3675 * we create a new vmspace. Note that exitingcnt is not
3676 * copied to the new vmspace.
3678 lwkt_gettoken(&oldvmspace
->vm_map
.token
);
3680 newvmspace
= vmspace_fork(vmcopy
);
3681 lwkt_gettoken(&newvmspace
->vm_map
.token
);
3683 newvmspace
= vmspace_alloc(map
->min_offset
, map
->max_offset
);
3684 lwkt_gettoken(&newvmspace
->vm_map
.token
);
3685 bcopy(&oldvmspace
->vm_startcopy
, &newvmspace
->vm_startcopy
,
3686 (caddr_t
)&oldvmspace
->vm_endcopy
-
3687 (caddr_t
)&oldvmspace
->vm_startcopy
);
3691 * Finish initializing the vmspace before assigning it
3692 * to the process. The vmspace will become the current vmspace
3695 pmap_pinit2(vmspace_pmap(newvmspace
));
3696 pmap_replacevm(p
, newvmspace
, 0);
3697 lwkt_reltoken(&newvmspace
->vm_map
.token
);
3698 lwkt_reltoken(&oldvmspace
->vm_map
.token
);
3699 vmspace_free(oldvmspace
);
3703 * Unshare the specified VM space for forcing COW. This
3704 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3707 vmspace_unshare(struct proc
*p
)
3709 struct vmspace
*oldvmspace
= p
->p_vmspace
;
3710 struct vmspace
*newvmspace
;
3712 lwkt_gettoken(&oldvmspace
->vm_map
.token
);
3713 if (oldvmspace
->vm_sysref
.refcnt
== 1) {
3714 lwkt_reltoken(&oldvmspace
->vm_map
.token
);
3717 newvmspace
= vmspace_fork(oldvmspace
);
3718 lwkt_gettoken(&newvmspace
->vm_map
.token
);
3719 pmap_pinit2(vmspace_pmap(newvmspace
));
3720 pmap_replacevm(p
, newvmspace
, 0);
3721 lwkt_reltoken(&newvmspace
->vm_map
.token
);
3722 lwkt_reltoken(&oldvmspace
->vm_map
.token
);
3723 vmspace_free(oldvmspace
);
3727 * vm_map_hint: return the beginning of the best area suitable for
3728 * creating a new mapping with "prot" protection.
3733 vm_map_hint(struct proc
*p
, vm_offset_t addr
, vm_prot_t prot
)
3735 struct vmspace
*vms
= p
->p_vmspace
;
3737 if (!randomize_mmap
) {
3739 * Set a reasonable start point for the hint if it was
3740 * not specified or if it falls within the heap space.
3741 * Hinted mmap()s do not allocate out of the heap space.
3744 (addr
>= round_page((vm_offset_t
)vms
->vm_taddr
) &&
3745 addr
< round_page((vm_offset_t
)vms
->vm_daddr
+ maxdsiz
))) {
3746 addr
= round_page((vm_offset_t
)vms
->vm_daddr
+ maxdsiz
);
3752 if (addr
!= 0 && addr
>= (vm_offset_t
)vms
->vm_daddr
)
3758 * If executable skip first two pages, otherwise start
3759 * after data + heap region.
3761 if ((prot
& VM_PROT_EXECUTE
) &&
3762 ((vm_offset_t
)vms
->vm_daddr
>= I386_MAX_EXE_ADDR
)) {
3763 addr
= (PAGE_SIZE
* 2) +
3764 (karc4random() & (I386_MAX_EXE_ADDR
/ 2 - 1));
3765 return (round_page(addr
));
3767 #endif /* __i386__ */
3770 addr
= (vm_offset_t
)vms
->vm_daddr
+ MAXDSIZ
;
3771 addr
+= karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ
) - 1);
3773 return (round_page(addr
));
3777 * Finds the VM object, offset, and protection for a given virtual address
3778 * in the specified map, assuming a page fault of the type specified.
3780 * Leaves the map in question locked for read; return values are guaranteed
3781 * until a vm_map_lookup_done call is performed. Note that the map argument
3782 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3784 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3787 * If a lookup is requested with "write protection" specified, the map may
3788 * be changed to perform virtual copying operations, although the data
3789 * referenced will remain the same.
3794 vm_map_lookup(vm_map_t
*var_map
, /* IN/OUT */
3796 vm_prot_t fault_typea
,
3797 vm_map_entry_t
*out_entry
, /* OUT */
3798 vm_object_t
*object
, /* OUT */
3799 vm_pindex_t
*pindex
, /* OUT */
3800 vm_prot_t
*out_prot
, /* OUT */
3801 boolean_t
*wired
) /* OUT */
3803 vm_map_entry_t entry
;
3804 vm_map_t map
= *var_map
;
3806 vm_prot_t fault_type
= fault_typea
;
3807 int use_read_lock
= 1;
3808 int rv
= KERN_SUCCESS
;
3812 vm_map_lock_read(map
);
3817 * If the map has an interesting hint, try it before calling full
3818 * blown lookup routine.
3825 if ((entry
== &map
->header
) ||
3826 (vaddr
< entry
->start
) || (vaddr
>= entry
->end
)) {
3827 vm_map_entry_t tmp_entry
;
3830 * Entry was either not a valid hint, or the vaddr was not
3831 * contained in the entry, so do a full lookup.
3833 if (!vm_map_lookup_entry(map
, vaddr
, &tmp_entry
)) {
3834 rv
= KERN_INVALID_ADDRESS
;
3845 if (entry
->maptype
== VM_MAPTYPE_SUBMAP
) {
3846 vm_map_t old_map
= map
;
3848 *var_map
= map
= entry
->object
.sub_map
;
3850 vm_map_unlock_read(old_map
);
3852 vm_map_unlock(old_map
);
3858 * Check whether this task is allowed to have this page.
3859 * Note the special case for MAP_ENTRY_COW
3860 * pages with an override. This is to implement a forced
3861 * COW for debuggers.
3864 if (fault_type
& VM_PROT_OVERRIDE_WRITE
)
3865 prot
= entry
->max_protection
;
3867 prot
= entry
->protection
;
3869 fault_type
&= (VM_PROT_READ
|VM_PROT_WRITE
|VM_PROT_EXECUTE
);
3870 if ((fault_type
& prot
) != fault_type
) {
3871 rv
= KERN_PROTECTION_FAILURE
;
3875 if ((entry
->eflags
& MAP_ENTRY_USER_WIRED
) &&
3876 (entry
->eflags
& MAP_ENTRY_COW
) &&
3877 (fault_type
& VM_PROT_WRITE
) &&
3878 (fault_typea
& VM_PROT_OVERRIDE_WRITE
) == 0) {
3879 rv
= KERN_PROTECTION_FAILURE
;
3884 * If this page is not pageable, we have to get it for all possible
3887 *wired
= (entry
->wired_count
!= 0);
3889 prot
= fault_type
= entry
->protection
;
3892 * Virtual page tables may need to update the accessed (A) bit
3893 * in a page table entry. Upgrade the fault to a write fault for
3894 * that case if the map will support it. If the map does not support
3895 * it the page table entry simply will not be updated.
3897 if (entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
3898 if (prot
& VM_PROT_WRITE
)
3899 fault_type
|= VM_PROT_WRITE
;
3903 * If the entry was copy-on-write, we either ...
3905 if (entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) {
3907 * If we want to write the page, we may as well handle that
3908 * now since we've got the map locked.
3910 * If we don't need to write the page, we just demote the
3911 * permissions allowed.
3914 if (fault_type
& VM_PROT_WRITE
) {
3916 * Make a new object, and place it in the object
3917 * chain. Note that no new references have appeared
3918 * -- one just moved from the map to the new
3922 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
3929 vm_map_entry_shadow(entry
, 0);
3932 * We're attempting to read a copy-on-write page --
3933 * don't allow writes.
3936 prot
&= ~VM_PROT_WRITE
;
3941 * Create an object if necessary.
3943 if (entry
->object
.vm_object
== NULL
&& !map
->system_map
) {
3944 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
3950 vm_map_entry_allocate_object(entry
);
3954 * Return the object/offset from this entry. If the entry was
3955 * copy-on-write or empty, it has been fixed up.
3958 *pindex
= OFF_TO_IDX((vaddr
- entry
->start
) + entry
->offset
);
3959 *object
= entry
->object
.vm_object
;
3962 * Return whether this is the only map sharing this data. On
3963 * success we return with a read lock held on the map. On failure
3964 * we return with the map unlocked.
3968 if (rv
== KERN_SUCCESS
) {
3969 if (use_read_lock
== 0)
3970 vm_map_lock_downgrade(map
);
3971 } else if (use_read_lock
) {
3972 vm_map_unlock_read(map
);
3980 * Releases locks acquired by a vm_map_lookup()
3981 * (according to the handle returned by that lookup).
3983 * No other requirements.
3986 vm_map_lookup_done(vm_map_t map
, vm_map_entry_t entry
, int count
)
3989 * Unlock the main-level map
3991 vm_map_unlock_read(map
);
3993 vm_map_entry_release(count
);
3996 #include "opt_ddb.h"
3998 #include <sys/kernel.h>
4000 #include <ddb/ddb.h>
4005 DB_SHOW_COMMAND(map
, vm_map_print
)
4008 /* XXX convert args. */
4009 vm_map_t map
= (vm_map_t
)addr
;
4010 boolean_t full
= have_addr
;
4012 vm_map_entry_t entry
;
4014 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4016 (void *)map
->pmap
, map
->nentries
, map
->timestamp
);
4019 if (!full
&& db_indent
)
4023 for (entry
= map
->header
.next
; entry
!= &map
->header
;
4024 entry
= entry
->next
) {
4025 db_iprintf("map entry %p: start=%p, end=%p\n",
4026 (void *)entry
, (void *)entry
->start
, (void *)entry
->end
);
4029 static char *inheritance_name
[4] =
4030 {"share", "copy", "none", "donate_copy"};
4032 db_iprintf(" prot=%x/%x/%s",
4034 entry
->max_protection
,
4035 inheritance_name
[(int)(unsigned char)entry
->inheritance
]);
4036 if (entry
->wired_count
!= 0)
4037 db_printf(", wired");
4039 if (entry
->maptype
== VM_MAPTYPE_SUBMAP
) {
4040 /* XXX no %qd in kernel. Truncate entry->offset. */
4041 db_printf(", share=%p, offset=0x%lx\n",
4042 (void *)entry
->object
.sub_map
,
4043 (long)entry
->offset
);
4045 if ((entry
->prev
== &map
->header
) ||
4046 (entry
->prev
->object
.sub_map
!=
4047 entry
->object
.sub_map
)) {
4049 vm_map_print((db_expr_t
)(intptr_t)
4050 entry
->object
.sub_map
,
4055 /* XXX no %qd in kernel. Truncate entry->offset. */
4056 db_printf(", object=%p, offset=0x%lx",
4057 (void *)entry
->object
.vm_object
,
4058 (long)entry
->offset
);
4059 if (entry
->eflags
& MAP_ENTRY_COW
)
4060 db_printf(", copy (%s)",
4061 (entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) ? "needed" : "done");
4065 if ((entry
->prev
== &map
->header
) ||
4066 (entry
->prev
->object
.vm_object
!=
4067 entry
->object
.vm_object
)) {
4069 vm_object_print((db_expr_t
)(intptr_t)
4070 entry
->object
.vm_object
,
4085 DB_SHOW_COMMAND(procvm
, procvm
)
4090 p
= (struct proc
*) addr
;
4095 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
4096 (void *)p
, (void *)p
->p_vmspace
, (void *)&p
->p_vmspace
->vm_map
,
4097 (void *)vmspace_pmap(p
->p_vmspace
));
4099 vm_map_print((db_expr_t
)(intptr_t)&p
->p_vmspace
->vm_map
, 1, 0, NULL
);