4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
62 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $
66 * Virtual memory mapping module.
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/kernel.h>
73 #include <sys/serialize.h>
75 #include <sys/vmmeter.h>
77 #include <sys/vnode.h>
78 #include <sys/resourcevar.h>
81 #include <sys/malloc.h>
82 #include <sys/objcache.h>
85 #include <vm/vm_param.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_page.h>
89 #include <vm/vm_object.h>
90 #include <vm/vm_pager.h>
91 #include <vm/vm_kern.h>
92 #include <vm/vm_extern.h>
93 #include <vm/swap_pager.h>
94 #include <vm/vm_zone.h>
96 #include <sys/random.h>
97 #include <sys/sysctl.h>
98 #include <sys/spinlock.h>
100 #include <sys/thread2.h>
101 #include <sys/spinlock2.h>
104 * Virtual memory maps provide for the mapping, protection, and sharing
105 * of virtual memory objects. In addition, this module provides for an
106 * efficient virtual copy of memory from one map to another.
108 * Synchronization is required prior to most operations.
110 * Maps consist of an ordered doubly-linked list of simple entries.
111 * A hint and a RB tree is used to speed-up lookups.
113 * Callers looking to modify maps specify start/end addresses which cause
114 * the related map entry to be clipped if necessary, and then later
115 * recombined if the pieces remained compatible.
117 * Virtual copy operations are performed by copying VM object references
118 * from one map to another, and then marking both regions as copy-on-write.
120 static boolean_t
vmspace_ctor(void *obj
, void *privdata
, int ocflags
);
121 static void vmspace_dtor(void *obj
, void *privdata
);
122 static void vmspace_terminate(struct vmspace
*vm
, int final
);
124 MALLOC_DEFINE(M_VMSPACE
, "vmspace", "vmspace objcache backingstore");
125 static struct objcache
*vmspace_cache
;
128 * per-cpu page table cross mappings are initialized in early boot
129 * and might require a considerable number of vm_map_entry structures.
131 #define MAPENTRYBSP_CACHE (MAXCPU+1)
132 #define MAPENTRYAP_CACHE 8
134 static struct vm_zone mapentzone_store
;
135 static vm_zone_t mapentzone
;
136 static struct vm_object mapentobj
;
138 static struct vm_map_entry map_entry_init
[MAX_MAPENT
];
139 static struct vm_map_entry cpu_map_entry_init_bsp
[MAPENTRYBSP_CACHE
];
140 static struct vm_map_entry cpu_map_entry_init_ap
[MAXCPU
][MAPENTRYAP_CACHE
];
142 static int randomize_mmap
;
143 SYSCTL_INT(_vm
, OID_AUTO
, randomize_mmap
, CTLFLAG_RW
, &randomize_mmap
, 0,
144 "Randomize mmap offsets");
145 static int vm_map_relock_enable
= 1;
146 SYSCTL_INT(_vm
, OID_AUTO
, map_relock_enable
, CTLFLAG_RW
,
147 &vm_map_relock_enable
, 0, "Randomize mmap offsets");
149 static void vmspace_drop_notoken(struct vmspace
*vm
);
150 static void vm_map_entry_shadow(vm_map_entry_t entry
, int addref
);
151 static vm_map_entry_t
vm_map_entry_create(vm_map_t map
, int *);
152 static void vm_map_entry_dispose (vm_map_t map
, vm_map_entry_t entry
, int *);
153 static void _vm_map_clip_end (vm_map_t
, vm_map_entry_t
, vm_offset_t
, int *);
154 static void _vm_map_clip_start (vm_map_t
, vm_map_entry_t
, vm_offset_t
, int *);
155 static void vm_map_entry_delete (vm_map_t
, vm_map_entry_t
, int *);
156 static void vm_map_entry_unwire (vm_map_t
, vm_map_entry_t
);
157 static void vm_map_copy_entry (vm_map_t
, vm_map_t
, vm_map_entry_t
,
159 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
);
162 * Initialize the vm_map module. Must be called before any other vm_map
165 * Map and entry structures are allocated from the general purpose
166 * memory pool with some exceptions:
168 * - The kernel map is allocated statically.
169 * - Initial kernel map entries are allocated out of a static pool.
170 * - We must set ZONE_SPECIAL here or the early boot code can get
171 * stuck if there are >63 cores.
173 * These restrictions are necessary since malloc() uses the
174 * maps and requires map entries.
176 * Called from the low level boot code only.
181 mapentzone
= &mapentzone_store
;
182 zbootinit(mapentzone
, "MAP ENTRY", sizeof (struct vm_map_entry
),
183 map_entry_init
, MAX_MAPENT
);
184 mapentzone_store
.zflags
|= ZONE_SPECIAL
;
188 * Called prior to any vmspace allocations.
190 * Called from the low level boot code only.
195 vmspace_cache
= objcache_create_mbacked(M_VMSPACE
,
196 sizeof(struct vmspace
),
198 vmspace_ctor
, vmspace_dtor
,
200 zinitna(mapentzone
, &mapentobj
, NULL
, 0, 0,
201 ZONE_USE_RESERVE
| ZONE_SPECIAL
);
207 * objcache support. We leave the pmap root cached as long as possible
208 * for performance reasons.
212 vmspace_ctor(void *obj
, void *privdata
, int ocflags
)
214 struct vmspace
*vm
= obj
;
216 bzero(vm
, sizeof(*vm
));
217 vm
->vm_refcnt
= VM_REF_DELETED
;
224 vmspace_dtor(void *obj
, void *privdata
)
226 struct vmspace
*vm
= obj
;
228 KKASSERT(vm
->vm_refcnt
== VM_REF_DELETED
);
229 pmap_puninit(vmspace_pmap(vm
));
233 * Red black tree functions
235 * The caller must hold the related map lock.
237 static int rb_vm_map_compare(vm_map_entry_t a
, vm_map_entry_t b
);
238 RB_GENERATE(vm_map_rb_tree
, vm_map_entry
, rb_entry
, rb_vm_map_compare
);
240 /* a->start is address, and the only field has to be initialized */
242 rb_vm_map_compare(vm_map_entry_t a
, vm_map_entry_t b
)
244 if (a
->start
< b
->start
)
246 else if (a
->start
> b
->start
)
252 * Initialize vmspace ref/hold counts vmspace0. There is a holdcnt for
256 vmspace_initrefs(struct vmspace
*vm
)
263 * Allocate a vmspace structure, including a vm_map and pmap.
264 * Initialize numerous fields. While the initial allocation is zerod,
265 * subsequence reuse from the objcache leaves elements of the structure
266 * intact (particularly the pmap), so portions must be zerod.
268 * Returns a referenced vmspace.
273 vmspace_alloc(vm_offset_t min
, vm_offset_t max
)
277 vm
= objcache_get(vmspace_cache
, M_WAITOK
);
279 bzero(&vm
->vm_startcopy
,
280 (char *)&vm
->vm_endcopy
- (char *)&vm
->vm_startcopy
);
281 vm_map_init(&vm
->vm_map
, min
, max
, NULL
); /* initializes token */
284 * NOTE: hold to acquires token for safety.
286 * On return vmspace is referenced (refs=1, hold=1). That is,
287 * each refcnt also has a holdcnt. There can be additional holds
288 * (holdcnt) above and beyond the refcnt. Finalization is handled in
289 * two stages, one on refs 1->0, and the the second on hold 1->0.
291 KKASSERT(vm
->vm_holdcnt
== 0);
292 KKASSERT(vm
->vm_refcnt
== VM_REF_DELETED
);
293 vmspace_initrefs(vm
);
295 pmap_pinit(vmspace_pmap(vm
)); /* (some fields reused) */
296 vm
->vm_map
.pmap
= vmspace_pmap(vm
); /* XXX */
299 cpu_vmspace_alloc(vm
);
306 * NOTE: Can return 0 if the vmspace is exiting.
309 vmspace_getrefs(struct vmspace
*vm
)
315 if (n
& VM_REF_DELETED
)
321 vmspace_hold(struct vmspace
*vm
)
323 atomic_add_int(&vm
->vm_holdcnt
, 1);
324 lwkt_gettoken(&vm
->vm_map
.token
);
328 * Drop with final termination interlock.
331 vmspace_drop(struct vmspace
*vm
)
333 lwkt_reltoken(&vm
->vm_map
.token
);
334 vmspace_drop_notoken(vm
);
338 vmspace_drop_notoken(struct vmspace
*vm
)
340 if (atomic_fetchadd_int(&vm
->vm_holdcnt
, -1) == 1) {
341 if (vm
->vm_refcnt
& VM_REF_DELETED
)
342 vmspace_terminate(vm
, 1);
347 * A vmspace object must not be in a terminated state to be able to obtain
348 * additional refs on it.
350 * These are official references to the vmspace, the count is used to check
351 * for vmspace sharing. Foreign accessors should use 'hold' and not 'ref'.
353 * XXX we need to combine hold & ref together into one 64-bit field to allow
354 * holds to prevent stage-1 termination.
357 vmspace_ref(struct vmspace
*vm
)
361 atomic_add_int(&vm
->vm_holdcnt
, 1);
362 n
= atomic_fetchadd_int(&vm
->vm_refcnt
, 1);
363 KKASSERT((n
& VM_REF_DELETED
) == 0);
367 * Release a ref on the vmspace. On the 1->0 transition we do stage-1
368 * termination of the vmspace. Then, on the final drop of the hold we
369 * will do stage-2 final termination.
372 vmspace_rel(struct vmspace
*vm
)
377 * Drop refs. Each ref also has a hold which is also dropped.
379 * When refs hits 0 compete to get the VM_REF_DELETED flag (hold
380 * prevent finalization) to start termination processing.
381 * Finalization occurs when the last hold count drops to 0.
383 n
= atomic_fetchadd_int(&vm
->vm_refcnt
, -1) - 1;
385 if (atomic_cmpset_int(&vm
->vm_refcnt
, 0, VM_REF_DELETED
)) {
386 vmspace_terminate(vm
, 0);
392 vmspace_drop_notoken(vm
);
396 * This is called during exit indicating that the vmspace is no
397 * longer in used by an exiting process, but the process has not yet
400 * We drop refs, allowing for stage-1 termination, but maintain a holdcnt
401 * to prevent stage-2 until the process is reaped. Note hte order of
402 * operation, we must hold first.
407 vmspace_relexit(struct vmspace
*vm
)
409 atomic_add_int(&vm
->vm_holdcnt
, 1);
414 * Called during reap to disconnect the remainder of the vmspace from
415 * the process. On the hold drop the vmspace termination is finalized.
420 vmspace_exitfree(struct proc
*p
)
426 vmspace_drop_notoken(vm
);
430 * Called in two cases:
432 * (1) When the last refcnt is dropped and the vmspace becomes inactive,
433 * called with final == 0. refcnt will be (u_int)-1 at this point,
434 * and holdcnt will still be non-zero.
436 * (2) When holdcnt becomes 0, called with final == 1. There should no
437 * longer be anyone with access to the vmspace.
439 * VMSPACE_EXIT1 flags the primary deactivation
440 * VMSPACE_EXIT2 flags the last reap
443 vmspace_terminate(struct vmspace
*vm
, int final
)
447 lwkt_gettoken(&vm
->vm_map
.token
);
449 KKASSERT((vm
->vm_flags
& VMSPACE_EXIT1
) == 0);
450 vm
->vm_flags
|= VMSPACE_EXIT1
;
453 * Get rid of most of the resources. Leave the kernel pmap
456 * If the pmap does not contain wired pages we can bulk-delete
457 * the pmap as a performance optimization before removing the
460 * If the pmap contains wired pages we cannot do this
461 * pre-optimization because currently vm_fault_unwire()
462 * expects the pmap pages to exist and will not decrement
463 * p->wire_count if they do not.
466 if (vmspace_pmap(vm
)->pm_stats
.wired_count
) {
467 vm_map_remove(&vm
->vm_map
, VM_MIN_USER_ADDRESS
,
468 VM_MAX_USER_ADDRESS
);
469 pmap_remove_pages(vmspace_pmap(vm
), VM_MIN_USER_ADDRESS
,
470 VM_MAX_USER_ADDRESS
);
472 pmap_remove_pages(vmspace_pmap(vm
), VM_MIN_USER_ADDRESS
,
473 VM_MAX_USER_ADDRESS
);
474 vm_map_remove(&vm
->vm_map
, VM_MIN_USER_ADDRESS
,
475 VM_MAX_USER_ADDRESS
);
477 lwkt_reltoken(&vm
->vm_map
.token
);
479 KKASSERT((vm
->vm_flags
& VMSPACE_EXIT1
) != 0);
480 KKASSERT((vm
->vm_flags
& VMSPACE_EXIT2
) == 0);
483 * Get rid of remaining basic resources.
485 vm
->vm_flags
|= VMSPACE_EXIT2
;
488 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
489 vm_map_lock(&vm
->vm_map
);
490 cpu_vmspace_free(vm
);
493 * Lock the map, to wait out all other references to it.
494 * Delete all of the mappings and pages they hold, then call
495 * the pmap module to reclaim anything left.
497 vm_map_delete(&vm
->vm_map
, vm
->vm_map
.min_offset
,
498 vm
->vm_map
.max_offset
, &count
);
499 vm_map_unlock(&vm
->vm_map
);
500 vm_map_entry_release(count
);
502 pmap_release(vmspace_pmap(vm
));
503 lwkt_reltoken(&vm
->vm_map
.token
);
504 objcache_put(vmspace_cache
, vm
);
509 * Swap useage is determined by taking the proportional swap used by
510 * VM objects backing the VM map. To make up for fractional losses,
511 * if the VM object has any swap use at all the associated map entries
512 * count for at least 1 swap page.
517 vmspace_swap_count(struct vmspace
*vm
)
519 vm_map_t map
= &vm
->vm_map
;
522 vm_offset_t count
= 0;
526 for (cur
= map
->header
.next
; cur
!= &map
->header
; cur
= cur
->next
) {
527 switch(cur
->maptype
) {
528 case VM_MAPTYPE_NORMAL
:
529 case VM_MAPTYPE_VPAGETABLE
:
530 if ((object
= cur
->object
.vm_object
) == NULL
)
532 if (object
->swblock_count
) {
533 n
= (cur
->end
- cur
->start
) / PAGE_SIZE
;
534 count
+= object
->swblock_count
*
535 SWAP_META_PAGES
* n
/ object
->size
+ 1;
548 * Calculate the approximate number of anonymous pages in use by
549 * this vmspace. To make up for fractional losses, we count each
550 * VM object as having at least 1 anonymous page.
555 vmspace_anonymous_count(struct vmspace
*vm
)
557 vm_map_t map
= &vm
->vm_map
;
560 vm_offset_t count
= 0;
563 for (cur
= map
->header
.next
; cur
!= &map
->header
; cur
= cur
->next
) {
564 switch(cur
->maptype
) {
565 case VM_MAPTYPE_NORMAL
:
566 case VM_MAPTYPE_VPAGETABLE
:
567 if ((object
= cur
->object
.vm_object
) == NULL
)
569 if (object
->type
!= OBJT_DEFAULT
&&
570 object
->type
!= OBJT_SWAP
) {
573 count
+= object
->resident_page_count
;
585 * Initialize an existing vm_map structure such as that in the vmspace
586 * structure. The pmap is initialized elsewhere.
591 vm_map_init(struct vm_map
*map
, vm_offset_t min
, vm_offset_t max
, pmap_t pmap
)
593 map
->header
.next
= map
->header
.prev
= &map
->header
;
594 RB_INIT(&map
->rb_root
);
595 spin_init(&map
->ilock_spin
, "ilock");
596 map
->ilock_base
= NULL
;
600 map
->min_offset
= min
;
601 map
->max_offset
= max
;
603 map
->first_free
= &map
->header
;
604 map
->hint
= &map
->header
;
607 lwkt_token_init(&map
->token
, "vm_map");
608 lockinit(&map
->lock
, "vm_maplk", (hz
+ 9) / 10, 0);
612 * Shadow the vm_map_entry's object. This typically needs to be done when
613 * a write fault is taken on an entry which had previously been cloned by
614 * fork(). The shared object (which might be NULL) must become private so
615 * we add a shadow layer above it.
617 * Object allocation for anonymous mappings is defered as long as possible.
618 * When creating a shadow, however, the underlying object must be instantiated
619 * so it can be shared.
621 * If the map segment is governed by a virtual page table then it is
622 * possible to address offsets beyond the mapped area. Just allocate
623 * a maximally sized object for this case.
625 * If addref is non-zero an additional reference is added to the returned
626 * entry. This mechanic exists because the additional reference might have
627 * to be added atomically and not after return to prevent a premature
630 * The vm_map must be exclusively locked.
631 * No other requirements.
635 vm_map_entry_shadow(vm_map_entry_t entry
, int addref
)
637 if (entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
638 vm_object_shadow(&entry
->object
.vm_object
, &entry
->offset
,
639 0x7FFFFFFF, addref
); /* XXX */
641 vm_object_shadow(&entry
->object
.vm_object
, &entry
->offset
,
642 atop(entry
->end
- entry
->start
), addref
);
644 entry
->eflags
&= ~MAP_ENTRY_NEEDS_COPY
;
648 * Allocate an object for a vm_map_entry.
650 * Object allocation for anonymous mappings is defered as long as possible.
651 * This function is called when we can defer no longer, generally when a map
652 * entry might be split or forked or takes a page fault.
654 * If the map segment is governed by a virtual page table then it is
655 * possible to address offsets beyond the mapped area. Just allocate
656 * a maximally sized object for this case.
658 * The vm_map must be exclusively locked.
659 * No other requirements.
662 vm_map_entry_allocate_object(vm_map_entry_t entry
)
666 if (entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
667 obj
= vm_object_allocate(OBJT_DEFAULT
, 0x7FFFFFFF); /* XXX */
669 obj
= vm_object_allocate(OBJT_DEFAULT
,
670 atop(entry
->end
- entry
->start
));
672 entry
->object
.vm_object
= obj
;
677 * Set an initial negative count so the first attempt to reserve
678 * space preloads a bunch of vm_map_entry's for this cpu. Also
679 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
680 * map a new page for vm_map_entry structures. SMP systems are
681 * particularly sensitive.
683 * This routine is called in early boot so we cannot just call
684 * vm_map_entry_reserve().
686 * Called from the low level boot code only (for each cpu)
688 * WARNING! Take care not to have too-big a static/BSS structure here
689 * as MAXCPU can be 256+, otherwise the loader's 64MB heap
690 * can get blown out by the kernel plus the initrd image.
693 vm_map_entry_reserve_cpu_init(globaldata_t gd
)
695 vm_map_entry_t entry
;
699 gd
->gd_vme_avail
-= MAP_RESERVE_COUNT
* 2;
700 if (gd
->gd_cpuid
== 0) {
701 entry
= &cpu_map_entry_init_bsp
[0];
702 count
= MAPENTRYBSP_CACHE
;
704 entry
= &cpu_map_entry_init_ap
[gd
->gd_cpuid
][0];
705 count
= MAPENTRYAP_CACHE
;
707 for (i
= 0; i
< count
; ++i
, ++entry
) {
708 entry
->next
= gd
->gd_vme_base
;
709 gd
->gd_vme_base
= entry
;
714 * Reserves vm_map_entry structures so code later on can manipulate
715 * map_entry structures within a locked map without blocking trying
716 * to allocate a new vm_map_entry.
721 vm_map_entry_reserve(int count
)
723 struct globaldata
*gd
= mycpu
;
724 vm_map_entry_t entry
;
727 * Make sure we have enough structures in gd_vme_base to handle
728 * the reservation request.
730 * The critical section protects access to the per-cpu gd.
733 while (gd
->gd_vme_avail
< count
) {
734 entry
= zalloc(mapentzone
);
735 entry
->next
= gd
->gd_vme_base
;
736 gd
->gd_vme_base
= entry
;
739 gd
->gd_vme_avail
-= count
;
746 * Releases previously reserved vm_map_entry structures that were not
747 * used. If we have too much junk in our per-cpu cache clean some of
753 vm_map_entry_release(int count
)
755 struct globaldata
*gd
= mycpu
;
756 vm_map_entry_t entry
;
759 gd
->gd_vme_avail
+= count
;
760 while (gd
->gd_vme_avail
> MAP_RESERVE_SLOP
) {
761 entry
= gd
->gd_vme_base
;
762 KKASSERT(entry
!= NULL
);
763 gd
->gd_vme_base
= entry
->next
;
766 zfree(mapentzone
, entry
);
773 * Reserve map entry structures for use in kernel_map itself. These
774 * entries have *ALREADY* been reserved on a per-cpu basis when the map
775 * was inited. This function is used by zalloc() to avoid a recursion
776 * when zalloc() itself needs to allocate additional kernel memory.
778 * This function works like the normal reserve but does not load the
779 * vm_map_entry cache (because that would result in an infinite
780 * recursion). Note that gd_vme_avail may go negative. This is expected.
782 * Any caller of this function must be sure to renormalize after
783 * potentially eating entries to ensure that the reserve supply
789 vm_map_entry_kreserve(int count
)
791 struct globaldata
*gd
= mycpu
;
794 gd
->gd_vme_avail
-= count
;
796 KASSERT(gd
->gd_vme_base
!= NULL
,
797 ("no reserved entries left, gd_vme_avail = %d",
803 * Release previously reserved map entries for kernel_map. We do not
804 * attempt to clean up like the normal release function as this would
805 * cause an unnecessary (but probably not fatal) deep procedure call.
810 vm_map_entry_krelease(int count
)
812 struct globaldata
*gd
= mycpu
;
815 gd
->gd_vme_avail
+= count
;
820 * Allocates a VM map entry for insertion. No entry fields are filled in.
822 * The entries should have previously been reserved. The reservation count
823 * is tracked in (*countp).
827 static vm_map_entry_t
828 vm_map_entry_create(vm_map_t map
, int *countp
)
830 struct globaldata
*gd
= mycpu
;
831 vm_map_entry_t entry
;
833 KKASSERT(*countp
> 0);
836 entry
= gd
->gd_vme_base
;
837 KASSERT(entry
!= NULL
, ("gd_vme_base NULL! count %d", *countp
));
838 gd
->gd_vme_base
= entry
->next
;
845 * Dispose of a vm_map_entry that is no longer being referenced.
850 vm_map_entry_dispose(vm_map_t map
, vm_map_entry_t entry
, int *countp
)
852 struct globaldata
*gd
= mycpu
;
854 KKASSERT(map
->hint
!= entry
);
855 KKASSERT(map
->first_free
!= entry
);
859 entry
->next
= gd
->gd_vme_base
;
860 gd
->gd_vme_base
= entry
;
866 * Insert/remove entries from maps.
868 * The related map must be exclusively locked.
869 * The caller must hold map->token
870 * No other requirements.
873 vm_map_entry_link(vm_map_t map
,
874 vm_map_entry_t after_where
,
875 vm_map_entry_t entry
)
877 ASSERT_VM_MAP_LOCKED(map
);
880 entry
->prev
= after_where
;
881 entry
->next
= after_where
->next
;
882 entry
->next
->prev
= entry
;
883 after_where
->next
= entry
;
884 if (vm_map_rb_tree_RB_INSERT(&map
->rb_root
, entry
))
885 panic("vm_map_entry_link: dup addr map %p ent %p", map
, entry
);
889 vm_map_entry_unlink(vm_map_t map
,
890 vm_map_entry_t entry
)
895 ASSERT_VM_MAP_LOCKED(map
);
897 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
898 panic("vm_map_entry_unlink: attempt to mess with "
899 "locked entry! %p", entry
);
905 vm_map_rb_tree_RB_REMOVE(&map
->rb_root
, entry
);
910 * Finds the map entry containing (or immediately preceding) the specified
911 * address in the given map. The entry is returned in (*entry).
913 * The boolean result indicates whether the address is actually contained
916 * The related map must be locked.
917 * No other requirements.
920 vm_map_lookup_entry(vm_map_t map
, vm_offset_t address
, vm_map_entry_t
*entry
)
925 ASSERT_VM_MAP_LOCKED(map
);
928 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive
929 * the hint code with the red-black lookup meets with system crashes
930 * and lockups. We do not yet know why.
932 * It is possible that the problem is related to the setting
933 * of the hint during map_entry deletion, in the code specified
934 * at the GGG comment later on in this file.
936 * YYY More likely it's because this function can be called with
937 * a shared lock on the map, resulting in map->hint updates possibly
938 * racing. Fixed now but untested.
941 * Quickly check the cached hint, there's a good chance of a match.
945 if (tmp
!= &map
->header
) {
946 if (address
>= tmp
->start
&& address
< tmp
->end
) {
954 * Locate the record from the top of the tree. 'last' tracks the
955 * closest prior record and is returned if no match is found, which
956 * in binary tree terms means tracking the most recent right-branch
957 * taken. If there is no prior record, &map->header is returned.
960 tmp
= RB_ROOT(&map
->rb_root
);
963 if (address
>= tmp
->start
) {
964 if (address
< tmp
->end
) {
970 tmp
= RB_RIGHT(tmp
, rb_entry
);
972 tmp
= RB_LEFT(tmp
, rb_entry
);
980 * Inserts the given whole VM object into the target map at the specified
981 * address range. The object's size should match that of the address range.
983 * The map must be exclusively locked.
984 * The object must be held.
985 * The caller must have reserved sufficient vm_map_entry structures.
987 * If object is non-NULL, ref count must be bumped by caller prior to
988 * making call to account for the new entry.
991 vm_map_insert(vm_map_t map
, int *countp
, void *map_object
, void *map_aux
,
992 vm_ooffset_t offset
, vm_offset_t start
, vm_offset_t end
,
993 vm_maptype_t maptype
, vm_subsys_t id
,
994 vm_prot_t prot
, vm_prot_t max
, int cow
)
996 vm_map_entry_t new_entry
;
997 vm_map_entry_t prev_entry
;
998 vm_map_entry_t temp_entry
;
999 vm_eflags_t protoeflags
;
1003 if (maptype
== VM_MAPTYPE_UKSMAP
)
1006 object
= map_object
;
1008 ASSERT_VM_MAP_LOCKED(map
);
1010 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object
));
1013 * Check that the start and end points are not bogus.
1015 if ((start
< map
->min_offset
) || (end
> map
->max_offset
) ||
1017 return (KERN_INVALID_ADDRESS
);
1020 * Find the entry prior to the proposed starting address; if it's part
1021 * of an existing entry, this range is bogus.
1023 if (vm_map_lookup_entry(map
, start
, &temp_entry
))
1024 return (KERN_NO_SPACE
);
1026 prev_entry
= temp_entry
;
1029 * Assert that the next entry doesn't overlap the end point.
1032 if ((prev_entry
->next
!= &map
->header
) &&
1033 (prev_entry
->next
->start
< end
))
1034 return (KERN_NO_SPACE
);
1038 if (cow
& MAP_COPY_ON_WRITE
)
1039 protoeflags
|= MAP_ENTRY_COW
|MAP_ENTRY_NEEDS_COPY
;
1041 if (cow
& MAP_NOFAULT
) {
1042 protoeflags
|= MAP_ENTRY_NOFAULT
;
1044 KASSERT(object
== NULL
,
1045 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
1047 if (cow
& MAP_DISABLE_SYNCER
)
1048 protoeflags
|= MAP_ENTRY_NOSYNC
;
1049 if (cow
& MAP_DISABLE_COREDUMP
)
1050 protoeflags
|= MAP_ENTRY_NOCOREDUMP
;
1051 if (cow
& MAP_IS_STACK
)
1052 protoeflags
|= MAP_ENTRY_STACK
;
1053 if (cow
& MAP_IS_KSTACK
)
1054 protoeflags
|= MAP_ENTRY_KSTACK
;
1056 lwkt_gettoken(&map
->token
);
1060 * When object is non-NULL, it could be shared with another
1061 * process. We have to set or clear OBJ_ONEMAPPING
1064 * NOTE: This flag is only applicable to DEFAULT and SWAP
1065 * objects and will already be clear in other types
1066 * of objects, so a shared object lock is ok for
1069 if ((object
->ref_count
> 1) || (object
->shadow_count
!= 0)) {
1070 vm_object_clear_flag(object
, OBJ_ONEMAPPING
);
1073 else if ((prev_entry
!= &map
->header
) &&
1074 (prev_entry
->eflags
== protoeflags
) &&
1075 (prev_entry
->end
== start
) &&
1076 (prev_entry
->wired_count
== 0) &&
1077 (prev_entry
->id
== id
) &&
1078 prev_entry
->maptype
== maptype
&&
1079 maptype
== VM_MAPTYPE_NORMAL
&&
1080 ((prev_entry
->object
.vm_object
== NULL
) ||
1081 vm_object_coalesce(prev_entry
->object
.vm_object
,
1082 OFF_TO_IDX(prev_entry
->offset
),
1083 (vm_size_t
)(prev_entry
->end
- prev_entry
->start
),
1084 (vm_size_t
)(end
- prev_entry
->end
)))) {
1086 * We were able to extend the object. Determine if we
1087 * can extend the previous map entry to include the
1088 * new range as well.
1090 if ((prev_entry
->inheritance
== VM_INHERIT_DEFAULT
) &&
1091 (prev_entry
->protection
== prot
) &&
1092 (prev_entry
->max_protection
== max
)) {
1093 map
->size
+= (end
- prev_entry
->end
);
1094 prev_entry
->end
= end
;
1095 vm_map_simplify_entry(map
, prev_entry
, countp
);
1096 lwkt_reltoken(&map
->token
);
1097 return (KERN_SUCCESS
);
1101 * If we can extend the object but cannot extend the
1102 * map entry, we have to create a new map entry. We
1103 * must bump the ref count on the extended object to
1104 * account for it. object may be NULL.
1106 * XXX if object is NULL should we set offset to 0 here ?
1108 object
= prev_entry
->object
.vm_object
;
1109 offset
= prev_entry
->offset
+
1110 (prev_entry
->end
- prev_entry
->start
);
1112 vm_object_hold(object
);
1113 vm_object_chain_wait(object
, 0);
1114 vm_object_reference_locked(object
);
1116 map_object
= object
;
1121 * NOTE: if conditionals fail, object can be NULL here. This occurs
1122 * in things like the buffer map where we manage kva but do not manage
1127 * Create a new entry
1130 new_entry
= vm_map_entry_create(map
, countp
);
1131 new_entry
->start
= start
;
1132 new_entry
->end
= end
;
1135 new_entry
->maptype
= maptype
;
1136 new_entry
->eflags
= protoeflags
;
1137 new_entry
->object
.map_object
= map_object
;
1138 new_entry
->aux
.master_pde
= 0; /* in case size is different */
1139 new_entry
->aux
.map_aux
= map_aux
;
1140 new_entry
->offset
= offset
;
1142 new_entry
->inheritance
= VM_INHERIT_DEFAULT
;
1143 new_entry
->protection
= prot
;
1144 new_entry
->max_protection
= max
;
1145 new_entry
->wired_count
= 0;
1148 * Insert the new entry into the list
1151 vm_map_entry_link(map
, prev_entry
, new_entry
);
1152 map
->size
+= new_entry
->end
- new_entry
->start
;
1155 * Update the free space hint. Entries cannot overlap.
1156 * An exact comparison is needed to avoid matching
1157 * against the map->header.
1159 if ((map
->first_free
== prev_entry
) &&
1160 (prev_entry
->end
== new_entry
->start
)) {
1161 map
->first_free
= new_entry
;
1166 * Temporarily removed to avoid MAP_STACK panic, due to
1167 * MAP_STACK being a huge hack. Will be added back in
1168 * when MAP_STACK (and the user stack mapping) is fixed.
1171 * It may be possible to simplify the entry
1173 vm_map_simplify_entry(map
, new_entry
, countp
);
1177 * Try to pre-populate the page table. Mappings governed by virtual
1178 * page tables cannot be prepopulated without a lot of work, so
1181 if ((cow
& (MAP_PREFAULT
|MAP_PREFAULT_PARTIAL
)) &&
1182 maptype
!= VM_MAPTYPE_VPAGETABLE
&&
1183 maptype
!= VM_MAPTYPE_UKSMAP
) {
1185 if (vm_map_relock_enable
&& (cow
& MAP_PREFAULT_RELOCK
)) {
1187 vm_object_lock_swap();
1188 vm_object_drop(object
);
1190 pmap_object_init_pt(map
->pmap
, start
, prot
,
1191 object
, OFF_TO_IDX(offset
), end
- start
,
1192 cow
& MAP_PREFAULT_PARTIAL
);
1194 vm_object_hold(object
);
1195 vm_object_lock_swap();
1199 vm_object_drop(object
);
1201 lwkt_reltoken(&map
->token
);
1202 return (KERN_SUCCESS
);
1206 * Find sufficient space for `length' bytes in the given map, starting at
1207 * `start'. Returns 0 on success, 1 on no space.
1209 * This function will returned an arbitrarily aligned pointer. If no
1210 * particular alignment is required you should pass align as 1. Note that
1211 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1212 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1215 * 'align' should be a power of 2 but is not required to be.
1217 * The map must be exclusively locked.
1218 * No other requirements.
1221 vm_map_findspace(vm_map_t map
, vm_offset_t start
, vm_size_t length
,
1222 vm_size_t align
, int flags
, vm_offset_t
*addr
)
1224 vm_map_entry_t entry
, next
;
1226 vm_offset_t align_mask
;
1228 if (start
< map
->min_offset
)
1229 start
= map
->min_offset
;
1230 if (start
> map
->max_offset
)
1234 * If the alignment is not a power of 2 we will have to use
1235 * a mod/division, set align_mask to a special value.
1237 if ((align
| (align
- 1)) + 1 != (align
<< 1))
1238 align_mask
= (vm_offset_t
)-1;
1240 align_mask
= align
- 1;
1243 * Look for the first possible address; if there's already something
1244 * at this address, we have to start after it.
1246 if (start
== map
->min_offset
) {
1247 if ((entry
= map
->first_free
) != &map
->header
)
1252 if (vm_map_lookup_entry(map
, start
, &tmp
))
1258 * Look through the rest of the map, trying to fit a new region in the
1259 * gap between existing regions, or after the very last region.
1261 for (;; start
= (entry
= next
)->end
) {
1263 * Adjust the proposed start by the requested alignment,
1264 * be sure that we didn't wrap the address.
1266 if (align_mask
== (vm_offset_t
)-1)
1267 end
= roundup(start
, align
);
1269 end
= (start
+ align_mask
) & ~align_mask
;
1274 * Find the end of the proposed new region. Be sure we didn't
1275 * go beyond the end of the map, or wrap around the address.
1276 * Then check to see if this is the last entry or if the
1277 * proposed end fits in the gap between this and the next
1280 end
= start
+ length
;
1281 if (end
> map
->max_offset
|| end
< start
)
1286 * If the next entry's start address is beyond the desired
1287 * end address we may have found a good entry.
1289 * If the next entry is a stack mapping we do not map into
1290 * the stack's reserved space.
1292 * XXX continue to allow mapping into the stack's reserved
1293 * space if doing a MAP_STACK mapping inside a MAP_STACK
1294 * mapping, for backwards compatibility. But the caller
1295 * really should use MAP_STACK | MAP_TRYFIXED if they
1298 if (next
== &map
->header
)
1300 if (next
->start
>= end
) {
1301 if ((next
->eflags
& MAP_ENTRY_STACK
) == 0)
1303 if (flags
& MAP_STACK
)
1305 if (next
->start
- next
->aux
.avail_ssize
>= end
)
1312 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1313 * if it fails. The kernel_map is locked and nothing can steal
1314 * our address space if pmap_growkernel() blocks.
1316 * NOTE: This may be unconditionally called for kldload areas on
1317 * x86_64 because these do not bump kernel_vm_end (which would
1318 * fill 128G worth of page tables!). Therefore we must not
1321 if (map
== &kernel_map
) {
1324 kstop
= round_page(start
+ length
);
1325 if (kstop
> kernel_vm_end
)
1326 pmap_growkernel(start
, kstop
);
1333 * vm_map_find finds an unallocated region in the target address map with
1334 * the given length and allocates it. The search is defined to be first-fit
1335 * from the specified address; the region found is returned in the same
1338 * If object is non-NULL, ref count must be bumped by caller
1339 * prior to making call to account for the new entry.
1341 * No requirements. This function will lock the map temporarily.
1344 vm_map_find(vm_map_t map
, void *map_object
, void *map_aux
,
1345 vm_ooffset_t offset
, vm_offset_t
*addr
,
1346 vm_size_t length
, vm_size_t align
, boolean_t fitit
,
1347 vm_maptype_t maptype
, vm_subsys_t id
,
1348 vm_prot_t prot
, vm_prot_t max
, int cow
)
1355 if (maptype
== VM_MAPTYPE_UKSMAP
)
1358 object
= map_object
;
1362 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1365 vm_object_hold_shared(object
);
1367 if (vm_map_findspace(map
, start
, length
, align
, 0, addr
)) {
1369 vm_object_drop(object
);
1371 vm_map_entry_release(count
);
1372 return (KERN_NO_SPACE
);
1376 result
= vm_map_insert(map
, &count
, map_object
, map_aux
,
1377 offset
, start
, start
+ length
,
1378 maptype
, id
, prot
, max
, cow
);
1380 vm_object_drop(object
);
1382 vm_map_entry_release(count
);
1388 * Simplify the given map entry by merging with either neighbor. This
1389 * routine also has the ability to merge with both neighbors.
1391 * This routine guarentees that the passed entry remains valid (though
1392 * possibly extended). When merging, this routine may delete one or
1393 * both neighbors. No action is taken on entries which have their
1394 * in-transition flag set.
1396 * The map must be exclusively locked.
1399 vm_map_simplify_entry(vm_map_t map
, vm_map_entry_t entry
, int *countp
)
1401 vm_map_entry_t next
, prev
;
1402 vm_size_t prevsize
, esize
;
1404 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
1405 ++mycpu
->gd_cnt
.v_intrans_coll
;
1409 if (entry
->maptype
== VM_MAPTYPE_SUBMAP
)
1411 if (entry
->maptype
== VM_MAPTYPE_UKSMAP
)
1415 if (prev
!= &map
->header
) {
1416 prevsize
= prev
->end
- prev
->start
;
1417 if ( (prev
->end
== entry
->start
) &&
1418 (prev
->maptype
== entry
->maptype
) &&
1419 (prev
->object
.vm_object
== entry
->object
.vm_object
) &&
1420 (!prev
->object
.vm_object
||
1421 (prev
->offset
+ prevsize
== entry
->offset
)) &&
1422 (prev
->eflags
== entry
->eflags
) &&
1423 (prev
->protection
== entry
->protection
) &&
1424 (prev
->max_protection
== entry
->max_protection
) &&
1425 (prev
->inheritance
== entry
->inheritance
) &&
1426 (prev
->id
== entry
->id
) &&
1427 (prev
->wired_count
== entry
->wired_count
)) {
1428 if (map
->first_free
== prev
)
1429 map
->first_free
= entry
;
1430 if (map
->hint
== prev
)
1432 vm_map_entry_unlink(map
, prev
);
1433 entry
->start
= prev
->start
;
1434 entry
->offset
= prev
->offset
;
1435 if (prev
->object
.vm_object
)
1436 vm_object_deallocate(prev
->object
.vm_object
);
1437 vm_map_entry_dispose(map
, prev
, countp
);
1442 if (next
!= &map
->header
) {
1443 esize
= entry
->end
- entry
->start
;
1444 if ((entry
->end
== next
->start
) &&
1445 (next
->maptype
== entry
->maptype
) &&
1446 (next
->object
.vm_object
== entry
->object
.vm_object
) &&
1447 (!entry
->object
.vm_object
||
1448 (entry
->offset
+ esize
== next
->offset
)) &&
1449 (next
->eflags
== entry
->eflags
) &&
1450 (next
->protection
== entry
->protection
) &&
1451 (next
->max_protection
== entry
->max_protection
) &&
1452 (next
->inheritance
== entry
->inheritance
) &&
1453 (next
->id
== entry
->id
) &&
1454 (next
->wired_count
== entry
->wired_count
)) {
1455 if (map
->first_free
== next
)
1456 map
->first_free
= entry
;
1457 if (map
->hint
== next
)
1459 vm_map_entry_unlink(map
, next
);
1460 entry
->end
= next
->end
;
1461 if (next
->object
.vm_object
)
1462 vm_object_deallocate(next
->object
.vm_object
);
1463 vm_map_entry_dispose(map
, next
, countp
);
1469 * Asserts that the given entry begins at or after the specified address.
1470 * If necessary, it splits the entry into two.
1472 #define vm_map_clip_start(map, entry, startaddr, countp) \
1474 if (startaddr > entry->start) \
1475 _vm_map_clip_start(map, entry, startaddr, countp); \
1479 * This routine is called only when it is known that the entry must be split.
1481 * The map must be exclusively locked.
1484 _vm_map_clip_start(vm_map_t map
, vm_map_entry_t entry
, vm_offset_t start
,
1487 vm_map_entry_t new_entry
;
1490 * Split off the front portion -- note that we must insert the new
1491 * entry BEFORE this one, so that this entry has the specified
1495 vm_map_simplify_entry(map
, entry
, countp
);
1498 * If there is no object backing this entry, we might as well create
1499 * one now. If we defer it, an object can get created after the map
1500 * is clipped, and individual objects will be created for the split-up
1501 * map. This is a bit of a hack, but is also about the best place to
1502 * put this improvement.
1504 if (entry
->object
.vm_object
== NULL
&& !map
->system_map
) {
1505 vm_map_entry_allocate_object(entry
);
1508 new_entry
= vm_map_entry_create(map
, countp
);
1509 *new_entry
= *entry
;
1511 new_entry
->end
= start
;
1512 entry
->offset
+= (start
- entry
->start
);
1513 entry
->start
= start
;
1515 vm_map_entry_link(map
, entry
->prev
, new_entry
);
1517 switch(entry
->maptype
) {
1518 case VM_MAPTYPE_NORMAL
:
1519 case VM_MAPTYPE_VPAGETABLE
:
1520 if (new_entry
->object
.vm_object
) {
1521 vm_object_hold(new_entry
->object
.vm_object
);
1522 vm_object_chain_wait(new_entry
->object
.vm_object
, 0);
1523 vm_object_reference_locked(new_entry
->object
.vm_object
);
1524 vm_object_drop(new_entry
->object
.vm_object
);
1533 * Asserts that the given entry ends at or before the specified address.
1534 * If necessary, it splits the entry into two.
1536 * The map must be exclusively locked.
1538 #define vm_map_clip_end(map, entry, endaddr, countp) \
1540 if (endaddr < entry->end) \
1541 _vm_map_clip_end(map, entry, endaddr, countp); \
1545 * This routine is called only when it is known that the entry must be split.
1547 * The map must be exclusively locked.
1550 _vm_map_clip_end(vm_map_t map
, vm_map_entry_t entry
, vm_offset_t end
,
1553 vm_map_entry_t new_entry
;
1556 * If there is no object backing this entry, we might as well create
1557 * one now. If we defer it, an object can get created after the map
1558 * is clipped, and individual objects will be created for the split-up
1559 * map. This is a bit of a hack, but is also about the best place to
1560 * put this improvement.
1563 if (entry
->object
.vm_object
== NULL
&& !map
->system_map
) {
1564 vm_map_entry_allocate_object(entry
);
1568 * Create a new entry and insert it AFTER the specified entry
1571 new_entry
= vm_map_entry_create(map
, countp
);
1572 *new_entry
= *entry
;
1574 new_entry
->start
= entry
->end
= end
;
1575 new_entry
->offset
+= (end
- entry
->start
);
1577 vm_map_entry_link(map
, entry
, new_entry
);
1579 switch(entry
->maptype
) {
1580 case VM_MAPTYPE_NORMAL
:
1581 case VM_MAPTYPE_VPAGETABLE
:
1582 if (new_entry
->object
.vm_object
) {
1583 vm_object_hold(new_entry
->object
.vm_object
);
1584 vm_object_chain_wait(new_entry
->object
.vm_object
, 0);
1585 vm_object_reference_locked(new_entry
->object
.vm_object
);
1586 vm_object_drop(new_entry
->object
.vm_object
);
1595 * Asserts that the starting and ending region addresses fall within the
1596 * valid range for the map.
1598 #define VM_MAP_RANGE_CHECK(map, start, end) \
1600 if (start < vm_map_min(map)) \
1601 start = vm_map_min(map); \
1602 if (end > vm_map_max(map)) \
1603 end = vm_map_max(map); \
1609 * Used to block when an in-transition collison occurs. The map
1610 * is unlocked for the sleep and relocked before the return.
1613 vm_map_transition_wait(vm_map_t map
)
1615 tsleep_interlock(map
, 0);
1617 tsleep(map
, PINTERLOCKED
, "vment", 0);
1622 * When we do blocking operations with the map lock held it is
1623 * possible that a clip might have occured on our in-transit entry,
1624 * requiring an adjustment to the entry in our loop. These macros
1625 * help the pageable and clip_range code deal with the case. The
1626 * conditional costs virtually nothing if no clipping has occured.
1629 #define CLIP_CHECK_BACK(entry, save_start) \
1631 while (entry->start != save_start) { \
1632 entry = entry->prev; \
1633 KASSERT(entry != &map->header, ("bad entry clip")); \
1637 #define CLIP_CHECK_FWD(entry, save_end) \
1639 while (entry->end != save_end) { \
1640 entry = entry->next; \
1641 KASSERT(entry != &map->header, ("bad entry clip")); \
1647 * Clip the specified range and return the base entry. The
1648 * range may cover several entries starting at the returned base
1649 * and the first and last entry in the covering sequence will be
1650 * properly clipped to the requested start and end address.
1652 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1655 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1656 * covered by the requested range.
1658 * The map must be exclusively locked on entry and will remain locked
1659 * on return. If no range exists or the range contains holes and you
1660 * specified that no holes were allowed, NULL will be returned. This
1661 * routine may temporarily unlock the map in order avoid a deadlock when
1666 vm_map_clip_range(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
1667 int *countp
, int flags
)
1669 vm_map_entry_t start_entry
;
1670 vm_map_entry_t entry
;
1673 * Locate the entry and effect initial clipping. The in-transition
1674 * case does not occur very often so do not try to optimize it.
1677 if (vm_map_lookup_entry(map
, start
, &start_entry
) == FALSE
)
1679 entry
= start_entry
;
1680 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
1681 entry
->eflags
|= MAP_ENTRY_NEEDS_WAKEUP
;
1682 ++mycpu
->gd_cnt
.v_intrans_coll
;
1683 ++mycpu
->gd_cnt
.v_intrans_wait
;
1684 vm_map_transition_wait(map
);
1686 * entry and/or start_entry may have been clipped while
1687 * we slept, or may have gone away entirely. We have
1688 * to restart from the lookup.
1694 * Since we hold an exclusive map lock we do not have to restart
1695 * after clipping, even though clipping may block in zalloc.
1697 vm_map_clip_start(map
, entry
, start
, countp
);
1698 vm_map_clip_end(map
, entry
, end
, countp
);
1699 entry
->eflags
|= MAP_ENTRY_IN_TRANSITION
;
1702 * Scan entries covered by the range. When working on the next
1703 * entry a restart need only re-loop on the current entry which
1704 * we have already locked, since 'next' may have changed. Also,
1705 * even though entry is safe, it may have been clipped so we
1706 * have to iterate forwards through the clip after sleeping.
1708 while (entry
->next
!= &map
->header
&& entry
->next
->start
< end
) {
1709 vm_map_entry_t next
= entry
->next
;
1711 if (flags
& MAP_CLIP_NO_HOLES
) {
1712 if (next
->start
> entry
->end
) {
1713 vm_map_unclip_range(map
, start_entry
,
1714 start
, entry
->end
, countp
, flags
);
1719 if (next
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
1720 vm_offset_t save_end
= entry
->end
;
1721 next
->eflags
|= MAP_ENTRY_NEEDS_WAKEUP
;
1722 ++mycpu
->gd_cnt
.v_intrans_coll
;
1723 ++mycpu
->gd_cnt
.v_intrans_wait
;
1724 vm_map_transition_wait(map
);
1727 * clips might have occured while we blocked.
1729 CLIP_CHECK_FWD(entry
, save_end
);
1730 CLIP_CHECK_BACK(start_entry
, start
);
1734 * No restart necessary even though clip_end may block, we
1735 * are holding the map lock.
1737 vm_map_clip_end(map
, next
, end
, countp
);
1738 next
->eflags
|= MAP_ENTRY_IN_TRANSITION
;
1741 if (flags
& MAP_CLIP_NO_HOLES
) {
1742 if (entry
->end
!= end
) {
1743 vm_map_unclip_range(map
, start_entry
,
1744 start
, entry
->end
, countp
, flags
);
1748 return(start_entry
);
1752 * Undo the effect of vm_map_clip_range(). You should pass the same
1753 * flags and the same range that you passed to vm_map_clip_range().
1754 * This code will clear the in-transition flag on the entries and
1755 * wake up anyone waiting. This code will also simplify the sequence
1756 * and attempt to merge it with entries before and after the sequence.
1758 * The map must be locked on entry and will remain locked on return.
1760 * Note that you should also pass the start_entry returned by
1761 * vm_map_clip_range(). However, if you block between the two calls
1762 * with the map unlocked please be aware that the start_entry may
1763 * have been clipped and you may need to scan it backwards to find
1764 * the entry corresponding with the original start address. You are
1765 * responsible for this, vm_map_unclip_range() expects the correct
1766 * start_entry to be passed to it and will KASSERT otherwise.
1770 vm_map_unclip_range(vm_map_t map
, vm_map_entry_t start_entry
,
1771 vm_offset_t start
, vm_offset_t end
,
1772 int *countp
, int flags
)
1774 vm_map_entry_t entry
;
1776 entry
= start_entry
;
1778 KASSERT(entry
->start
== start
, ("unclip_range: illegal base entry"));
1779 while (entry
!= &map
->header
&& entry
->start
< end
) {
1780 KASSERT(entry
->eflags
& MAP_ENTRY_IN_TRANSITION
,
1781 ("in-transition flag not set during unclip on: %p",
1783 KASSERT(entry
->end
<= end
,
1784 ("unclip_range: tail wasn't clipped"));
1785 entry
->eflags
&= ~MAP_ENTRY_IN_TRANSITION
;
1786 if (entry
->eflags
& MAP_ENTRY_NEEDS_WAKEUP
) {
1787 entry
->eflags
&= ~MAP_ENTRY_NEEDS_WAKEUP
;
1790 entry
= entry
->next
;
1794 * Simplification does not block so there is no restart case.
1796 entry
= start_entry
;
1797 while (entry
!= &map
->header
&& entry
->start
< end
) {
1798 vm_map_simplify_entry(map
, entry
, countp
);
1799 entry
= entry
->next
;
1804 * Mark the given range as handled by a subordinate map.
1806 * This range must have been created with vm_map_find(), and no other
1807 * operations may have been performed on this range prior to calling
1810 * Submappings cannot be removed.
1815 vm_map_submap(vm_map_t map
, vm_offset_t start
, vm_offset_t end
, vm_map_t submap
)
1817 vm_map_entry_t entry
;
1818 int result
= KERN_INVALID_ARGUMENT
;
1821 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1824 VM_MAP_RANGE_CHECK(map
, start
, end
);
1826 if (vm_map_lookup_entry(map
, start
, &entry
)) {
1827 vm_map_clip_start(map
, entry
, start
, &count
);
1829 entry
= entry
->next
;
1832 vm_map_clip_end(map
, entry
, end
, &count
);
1834 if ((entry
->start
== start
) && (entry
->end
== end
) &&
1835 ((entry
->eflags
& MAP_ENTRY_COW
) == 0) &&
1836 (entry
->object
.vm_object
== NULL
)) {
1837 entry
->object
.sub_map
= submap
;
1838 entry
->maptype
= VM_MAPTYPE_SUBMAP
;
1839 result
= KERN_SUCCESS
;
1842 vm_map_entry_release(count
);
1848 * Sets the protection of the specified address region in the target map.
1849 * If "set_max" is specified, the maximum protection is to be set;
1850 * otherwise, only the current protection is affected.
1852 * The protection is not applicable to submaps, but is applicable to normal
1853 * maps and maps governed by virtual page tables. For example, when operating
1854 * on a virtual page table our protection basically controls how COW occurs
1855 * on the backing object, whereas the virtual page table abstraction itself
1856 * is an abstraction for userland.
1861 vm_map_protect(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
1862 vm_prot_t new_prot
, boolean_t set_max
)
1864 vm_map_entry_t current
;
1865 vm_map_entry_t entry
;
1868 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1871 VM_MAP_RANGE_CHECK(map
, start
, end
);
1873 if (vm_map_lookup_entry(map
, start
, &entry
)) {
1874 vm_map_clip_start(map
, entry
, start
, &count
);
1876 entry
= entry
->next
;
1880 * Make a first pass to check for protection violations.
1883 while ((current
!= &map
->header
) && (current
->start
< end
)) {
1884 if (current
->maptype
== VM_MAPTYPE_SUBMAP
) {
1886 vm_map_entry_release(count
);
1887 return (KERN_INVALID_ARGUMENT
);
1889 if ((new_prot
& current
->max_protection
) != new_prot
) {
1891 vm_map_entry_release(count
);
1892 return (KERN_PROTECTION_FAILURE
);
1894 current
= current
->next
;
1898 * Go back and fix up protections. [Note that clipping is not
1899 * necessary the second time.]
1903 while ((current
!= &map
->header
) && (current
->start
< end
)) {
1906 vm_map_clip_end(map
, current
, end
, &count
);
1908 old_prot
= current
->protection
;
1910 current
->max_protection
= new_prot
;
1911 current
->protection
= new_prot
& old_prot
;
1913 current
->protection
= new_prot
;
1917 * Update physical map if necessary. Worry about copy-on-write
1918 * here -- CHECK THIS XXX
1921 if (current
->protection
!= old_prot
) {
1922 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1925 pmap_protect(map
->pmap
, current
->start
,
1927 current
->protection
& MASK(current
));
1931 vm_map_simplify_entry(map
, current
, &count
);
1933 current
= current
->next
;
1937 vm_map_entry_release(count
);
1938 return (KERN_SUCCESS
);
1942 * This routine traverses a processes map handling the madvise
1943 * system call. Advisories are classified as either those effecting
1944 * the vm_map_entry structure, or those effecting the underlying
1947 * The <value> argument is used for extended madvise calls.
1952 vm_map_madvise(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
1953 int behav
, off_t value
)
1955 vm_map_entry_t current
, entry
;
1961 * Some madvise calls directly modify the vm_map_entry, in which case
1962 * we need to use an exclusive lock on the map and we need to perform
1963 * various clipping operations. Otherwise we only need a read-lock
1966 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
1970 case MADV_SEQUENTIAL
:
1984 vm_map_lock_read(map
);
1987 vm_map_entry_release(count
);
1992 * Locate starting entry and clip if necessary.
1995 VM_MAP_RANGE_CHECK(map
, start
, end
);
1997 if (vm_map_lookup_entry(map
, start
, &entry
)) {
1999 vm_map_clip_start(map
, entry
, start
, &count
);
2001 entry
= entry
->next
;
2006 * madvise behaviors that are implemented in the vm_map_entry.
2008 * We clip the vm_map_entry so that behavioral changes are
2009 * limited to the specified address range.
2011 for (current
= entry
;
2012 (current
!= &map
->header
) && (current
->start
< end
);
2013 current
= current
->next
2015 if (current
->maptype
== VM_MAPTYPE_SUBMAP
)
2018 vm_map_clip_end(map
, current
, end
, &count
);
2022 vm_map_entry_set_behavior(current
, MAP_ENTRY_BEHAV_NORMAL
);
2024 case MADV_SEQUENTIAL
:
2025 vm_map_entry_set_behavior(current
, MAP_ENTRY_BEHAV_SEQUENTIAL
);
2028 vm_map_entry_set_behavior(current
, MAP_ENTRY_BEHAV_RANDOM
);
2031 current
->eflags
|= MAP_ENTRY_NOSYNC
;
2034 current
->eflags
&= ~MAP_ENTRY_NOSYNC
;
2037 current
->eflags
|= MAP_ENTRY_NOCOREDUMP
;
2040 current
->eflags
&= ~MAP_ENTRY_NOCOREDUMP
;
2044 * Set the page directory page for a map
2045 * governed by a virtual page table. Mark
2046 * the entry as being governed by a virtual
2047 * page table if it is not.
2049 * XXX the page directory page is stored
2050 * in the avail_ssize field if the map_entry.
2052 * XXX the map simplification code does not
2053 * compare this field so weird things may
2054 * happen if you do not apply this function
2055 * to the entire mapping governed by the
2056 * virtual page table.
2058 if (current
->maptype
!= VM_MAPTYPE_VPAGETABLE
) {
2062 current
->aux
.master_pde
= value
;
2063 pmap_remove(map
->pmap
,
2064 current
->start
, current
->end
);
2068 * Invalidate the related pmap entries, used
2069 * to flush portions of the real kernel's
2070 * pmap when the caller has removed or
2071 * modified existing mappings in a virtual
2074 * (exclusive locked map version does not
2075 * need the range interlock).
2077 pmap_remove(map
->pmap
,
2078 current
->start
, current
->end
);
2084 vm_map_simplify_entry(map
, current
, &count
);
2092 * madvise behaviors that are implemented in the underlying
2095 * Since we don't clip the vm_map_entry, we have to clip
2096 * the vm_object pindex and count.
2098 * NOTE! These functions are only supported on normal maps,
2099 * except MADV_INVAL which is also supported on
2100 * virtual page tables.
2102 for (current
= entry
;
2103 (current
!= &map
->header
) && (current
->start
< end
);
2104 current
= current
->next
2106 vm_offset_t useStart
;
2108 if (current
->maptype
!= VM_MAPTYPE_NORMAL
&&
2109 (current
->maptype
!= VM_MAPTYPE_VPAGETABLE
||
2110 behav
!= MADV_INVAL
)) {
2114 pindex
= OFF_TO_IDX(current
->offset
);
2115 delta
= atop(current
->end
- current
->start
);
2116 useStart
= current
->start
;
2118 if (current
->start
< start
) {
2119 pindex
+= atop(start
- current
->start
);
2120 delta
-= atop(start
- current
->start
);
2123 if (current
->end
> end
)
2124 delta
-= atop(current
->end
- end
);
2126 if ((vm_spindex_t
)delta
<= 0)
2129 if (behav
== MADV_INVAL
) {
2131 * Invalidate the related pmap entries, used
2132 * to flush portions of the real kernel's
2133 * pmap when the caller has removed or
2134 * modified existing mappings in a virtual
2137 * (shared locked map version needs the
2138 * interlock, see vm_fault()).
2140 struct vm_map_ilock ilock
;
2142 KASSERT(useStart
>= VM_MIN_USER_ADDRESS
&&
2143 useStart
+ ptoa(delta
) <=
2144 VM_MAX_USER_ADDRESS
,
2145 ("Bad range %016jx-%016jx (%016jx)",
2146 useStart
, useStart
+ ptoa(delta
),
2148 vm_map_interlock(map
, &ilock
,
2150 useStart
+ ptoa(delta
));
2151 pmap_remove(map
->pmap
,
2153 useStart
+ ptoa(delta
));
2154 vm_map_deinterlock(map
, &ilock
);
2156 vm_object_madvise(current
->object
.vm_object
,
2157 pindex
, delta
, behav
);
2161 * Try to populate the page table. Mappings governed
2162 * by virtual page tables cannot be pre-populated
2163 * without a lot of work so don't try.
2165 if (behav
== MADV_WILLNEED
&&
2166 current
->maptype
!= VM_MAPTYPE_VPAGETABLE
) {
2167 pmap_object_init_pt(
2170 current
->protection
,
2171 current
->object
.vm_object
,
2173 (count
<< PAGE_SHIFT
),
2174 MAP_PREFAULT_MADVISE
2178 vm_map_unlock_read(map
);
2180 vm_map_entry_release(count
);
2186 * Sets the inheritance of the specified address range in the target map.
2187 * Inheritance affects how the map will be shared with child maps at the
2188 * time of vm_map_fork.
2191 vm_map_inherit(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
2192 vm_inherit_t new_inheritance
)
2194 vm_map_entry_t entry
;
2195 vm_map_entry_t temp_entry
;
2198 switch (new_inheritance
) {
2199 case VM_INHERIT_NONE
:
2200 case VM_INHERIT_COPY
:
2201 case VM_INHERIT_SHARE
:
2204 return (KERN_INVALID_ARGUMENT
);
2207 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
2210 VM_MAP_RANGE_CHECK(map
, start
, end
);
2212 if (vm_map_lookup_entry(map
, start
, &temp_entry
)) {
2214 vm_map_clip_start(map
, entry
, start
, &count
);
2216 entry
= temp_entry
->next
;
2218 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2219 vm_map_clip_end(map
, entry
, end
, &count
);
2221 entry
->inheritance
= new_inheritance
;
2223 vm_map_simplify_entry(map
, entry
, &count
);
2225 entry
= entry
->next
;
2228 vm_map_entry_release(count
);
2229 return (KERN_SUCCESS
);
2233 * Implement the semantics of mlock
2236 vm_map_unwire(vm_map_t map
, vm_offset_t start
, vm_offset_t real_end
,
2237 boolean_t new_pageable
)
2239 vm_map_entry_t entry
;
2240 vm_map_entry_t start_entry
;
2242 int rv
= KERN_SUCCESS
;
2245 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
2247 VM_MAP_RANGE_CHECK(map
, start
, real_end
);
2250 start_entry
= vm_map_clip_range(map
, start
, end
, &count
,
2252 if (start_entry
== NULL
) {
2254 vm_map_entry_release(count
);
2255 return (KERN_INVALID_ADDRESS
);
2258 if (new_pageable
== 0) {
2259 entry
= start_entry
;
2260 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2261 vm_offset_t save_start
;
2262 vm_offset_t save_end
;
2265 * Already user wired or hard wired (trivial cases)
2267 if (entry
->eflags
& MAP_ENTRY_USER_WIRED
) {
2268 entry
= entry
->next
;
2271 if (entry
->wired_count
!= 0) {
2272 entry
->wired_count
++;
2273 entry
->eflags
|= MAP_ENTRY_USER_WIRED
;
2274 entry
= entry
->next
;
2279 * A new wiring requires instantiation of appropriate
2280 * management structures and the faulting in of the
2283 if (entry
->maptype
== VM_MAPTYPE_NORMAL
||
2284 entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
2285 int copyflag
= entry
->eflags
&
2286 MAP_ENTRY_NEEDS_COPY
;
2287 if (copyflag
&& ((entry
->protection
&
2288 VM_PROT_WRITE
) != 0)) {
2289 vm_map_entry_shadow(entry
, 0);
2290 } else if (entry
->object
.vm_object
== NULL
&&
2292 vm_map_entry_allocate_object(entry
);
2295 entry
->wired_count
++;
2296 entry
->eflags
|= MAP_ENTRY_USER_WIRED
;
2299 * Now fault in the area. Note that vm_fault_wire()
2300 * may release the map lock temporarily, it will be
2301 * relocked on return. The in-transition
2302 * flag protects the entries.
2304 save_start
= entry
->start
;
2305 save_end
= entry
->end
;
2306 rv
= vm_fault_wire(map
, entry
, TRUE
, 0);
2308 CLIP_CHECK_BACK(entry
, save_start
);
2310 KASSERT(entry
->wired_count
== 1, ("bad wired_count on entry"));
2311 entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
2312 entry
->wired_count
= 0;
2313 if (entry
->end
== save_end
)
2315 entry
= entry
->next
;
2316 KASSERT(entry
!= &map
->header
, ("bad entry clip during backout"));
2318 end
= save_start
; /* unwire the rest */
2322 * note that even though the entry might have been
2323 * clipped, the USER_WIRED flag we set prevents
2324 * duplication so we do not have to do a
2327 entry
= entry
->next
;
2331 * If we failed fall through to the unwiring section to
2332 * unwire what we had wired so far. 'end' has already
2339 * start_entry might have been clipped if we unlocked the
2340 * map and blocked. No matter how clipped it has gotten
2341 * there should be a fragment that is on our start boundary.
2343 CLIP_CHECK_BACK(start_entry
, start
);
2347 * Deal with the unwiring case.
2351 * This is the unwiring case. We must first ensure that the
2352 * range to be unwired is really wired down. We know there
2355 entry
= start_entry
;
2356 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2357 if ((entry
->eflags
& MAP_ENTRY_USER_WIRED
) == 0) {
2358 rv
= KERN_INVALID_ARGUMENT
;
2361 KASSERT(entry
->wired_count
!= 0, ("wired count was 0 with USER_WIRED set! %p", entry
));
2362 entry
= entry
->next
;
2366 * Now decrement the wiring count for each region. If a region
2367 * becomes completely unwired, unwire its physical pages and
2371 * The map entries are processed in a loop, checking to
2372 * make sure the entry is wired and asserting it has a wired
2373 * count. However, another loop was inserted more-or-less in
2374 * the middle of the unwiring path. This loop picks up the
2375 * "entry" loop variable from the first loop without first
2376 * setting it to start_entry. Naturally, the secound loop
2377 * is never entered and the pages backing the entries are
2378 * never unwired. This can lead to a leak of wired pages.
2380 entry
= start_entry
;
2381 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2382 KASSERT(entry
->eflags
& MAP_ENTRY_USER_WIRED
,
2383 ("expected USER_WIRED on entry %p", entry
));
2384 entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
2385 entry
->wired_count
--;
2386 if (entry
->wired_count
== 0)
2387 vm_fault_unwire(map
, entry
);
2388 entry
= entry
->next
;
2392 vm_map_unclip_range(map
, start_entry
, start
, real_end
, &count
,
2396 vm_map_entry_release(count
);
2401 * Sets the pageability of the specified address range in the target map.
2402 * Regions specified as not pageable require locked-down physical
2403 * memory and physical page maps.
2405 * The map must not be locked, but a reference must remain to the map
2406 * throughout the call.
2408 * This function may be called via the zalloc path and must properly
2409 * reserve map entries for kernel_map.
2414 vm_map_wire(vm_map_t map
, vm_offset_t start
, vm_offset_t real_end
, int kmflags
)
2416 vm_map_entry_t entry
;
2417 vm_map_entry_t start_entry
;
2419 int rv
= KERN_SUCCESS
;
2422 if (kmflags
& KM_KRESERVE
)
2423 count
= vm_map_entry_kreserve(MAP_RESERVE_COUNT
);
2425 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
2427 VM_MAP_RANGE_CHECK(map
, start
, real_end
);
2430 start_entry
= vm_map_clip_range(map
, start
, end
, &count
,
2432 if (start_entry
== NULL
) {
2434 rv
= KERN_INVALID_ADDRESS
;
2437 if ((kmflags
& KM_PAGEABLE
) == 0) {
2441 * 1. Holding the write lock, we create any shadow or zero-fill
2442 * objects that need to be created. Then we clip each map
2443 * entry to the region to be wired and increment its wiring
2444 * count. We create objects before clipping the map entries
2445 * to avoid object proliferation.
2447 * 2. We downgrade to a read lock, and call vm_fault_wire to
2448 * fault in the pages for any newly wired area (wired_count is
2451 * Downgrading to a read lock for vm_fault_wire avoids a
2452 * possible deadlock with another process that may have faulted
2453 * on one of the pages to be wired (it would mark the page busy,
2454 * blocking us, then in turn block on the map lock that we
2455 * hold). Because of problems in the recursive lock package,
2456 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2457 * any actions that require the write lock must be done
2458 * beforehand. Because we keep the read lock on the map, the
2459 * copy-on-write status of the entries we modify here cannot
2462 entry
= start_entry
;
2463 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2465 * Trivial case if the entry is already wired
2467 if (entry
->wired_count
) {
2468 entry
->wired_count
++;
2469 entry
= entry
->next
;
2474 * The entry is being newly wired, we have to setup
2475 * appropriate management structures. A shadow
2476 * object is required for a copy-on-write region,
2477 * or a normal object for a zero-fill region. We
2478 * do not have to do this for entries that point to sub
2479 * maps because we won't hold the lock on the sub map.
2481 if (entry
->maptype
== VM_MAPTYPE_NORMAL
||
2482 entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
2483 int copyflag
= entry
->eflags
&
2484 MAP_ENTRY_NEEDS_COPY
;
2485 if (copyflag
&& ((entry
->protection
&
2486 VM_PROT_WRITE
) != 0)) {
2487 vm_map_entry_shadow(entry
, 0);
2488 } else if (entry
->object
.vm_object
== NULL
&&
2490 vm_map_entry_allocate_object(entry
);
2494 entry
->wired_count
++;
2495 entry
= entry
->next
;
2503 * HACK HACK HACK HACK
2505 * vm_fault_wire() temporarily unlocks the map to avoid
2506 * deadlocks. The in-transition flag from vm_map_clip_range
2507 * call should protect us from changes while the map is
2510 * NOTE: Previously this comment stated that clipping might
2511 * still occur while the entry is unlocked, but from
2512 * what I can tell it actually cannot.
2514 * It is unclear whether the CLIP_CHECK_*() calls
2515 * are still needed but we keep them in anyway.
2517 * HACK HACK HACK HACK
2520 entry
= start_entry
;
2521 while (entry
!= &map
->header
&& entry
->start
< end
) {
2523 * If vm_fault_wire fails for any page we need to undo
2524 * what has been done. We decrement the wiring count
2525 * for those pages which have not yet been wired (now)
2526 * and unwire those that have (later).
2528 vm_offset_t save_start
= entry
->start
;
2529 vm_offset_t save_end
= entry
->end
;
2531 if (entry
->wired_count
== 1)
2532 rv
= vm_fault_wire(map
, entry
, FALSE
, kmflags
);
2534 CLIP_CHECK_BACK(entry
, save_start
);
2536 KASSERT(entry
->wired_count
== 1, ("wired_count changed unexpectedly"));
2537 entry
->wired_count
= 0;
2538 if (entry
->end
== save_end
)
2540 entry
= entry
->next
;
2541 KASSERT(entry
!= &map
->header
, ("bad entry clip during backout"));
2546 CLIP_CHECK_FWD(entry
, save_end
);
2547 entry
= entry
->next
;
2551 * If a failure occured undo everything by falling through
2552 * to the unwiring code. 'end' has already been adjusted
2556 kmflags
|= KM_PAGEABLE
;
2559 * start_entry is still IN_TRANSITION but may have been
2560 * clipped since vm_fault_wire() unlocks and relocks the
2561 * map. No matter how clipped it has gotten there should
2562 * be a fragment that is on our start boundary.
2564 CLIP_CHECK_BACK(start_entry
, start
);
2567 if (kmflags
& KM_PAGEABLE
) {
2569 * This is the unwiring case. We must first ensure that the
2570 * range to be unwired is really wired down. We know there
2573 entry
= start_entry
;
2574 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2575 if (entry
->wired_count
== 0) {
2576 rv
= KERN_INVALID_ARGUMENT
;
2579 entry
= entry
->next
;
2583 * Now decrement the wiring count for each region. If a region
2584 * becomes completely unwired, unwire its physical pages and
2587 entry
= start_entry
;
2588 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2589 entry
->wired_count
--;
2590 if (entry
->wired_count
== 0)
2591 vm_fault_unwire(map
, entry
);
2592 entry
= entry
->next
;
2596 vm_map_unclip_range(map
, start_entry
, start
, real_end
,
2597 &count
, MAP_CLIP_NO_HOLES
);
2601 if (kmflags
& KM_KRESERVE
)
2602 vm_map_entry_krelease(count
);
2604 vm_map_entry_release(count
);
2609 * Mark a newly allocated address range as wired but do not fault in
2610 * the pages. The caller is expected to load the pages into the object.
2612 * The map must be locked on entry and will remain locked on return.
2613 * No other requirements.
2616 vm_map_set_wired_quick(vm_map_t map
, vm_offset_t addr
, vm_size_t size
,
2619 vm_map_entry_t scan
;
2620 vm_map_entry_t entry
;
2622 entry
= vm_map_clip_range(map
, addr
, addr
+ size
,
2623 countp
, MAP_CLIP_NO_HOLES
);
2625 scan
!= &map
->header
&& scan
->start
< addr
+ size
;
2626 scan
= scan
->next
) {
2627 KKASSERT(scan
->wired_count
== 0);
2628 scan
->wired_count
= 1;
2630 vm_map_unclip_range(map
, entry
, addr
, addr
+ size
,
2631 countp
, MAP_CLIP_NO_HOLES
);
2635 * Push any dirty cached pages in the address range to their pager.
2636 * If syncio is TRUE, dirty pages are written synchronously.
2637 * If invalidate is TRUE, any cached pages are freed as well.
2639 * This routine is called by sys_msync()
2641 * Returns an error if any part of the specified range is not mapped.
2646 vm_map_clean(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
2647 boolean_t syncio
, boolean_t invalidate
)
2649 vm_map_entry_t current
;
2650 vm_map_entry_t entry
;
2654 vm_ooffset_t offset
;
2656 vm_map_lock_read(map
);
2657 VM_MAP_RANGE_CHECK(map
, start
, end
);
2658 if (!vm_map_lookup_entry(map
, start
, &entry
)) {
2659 vm_map_unlock_read(map
);
2660 return (KERN_INVALID_ADDRESS
);
2662 lwkt_gettoken(&map
->token
);
2665 * Make a first pass to check for holes.
2667 for (current
= entry
; current
->start
< end
; current
= current
->next
) {
2668 if (current
->maptype
== VM_MAPTYPE_SUBMAP
) {
2669 lwkt_reltoken(&map
->token
);
2670 vm_map_unlock_read(map
);
2671 return (KERN_INVALID_ARGUMENT
);
2673 if (end
> current
->end
&&
2674 (current
->next
== &map
->header
||
2675 current
->end
!= current
->next
->start
)) {
2676 lwkt_reltoken(&map
->token
);
2677 vm_map_unlock_read(map
);
2678 return (KERN_INVALID_ADDRESS
);
2683 pmap_remove(vm_map_pmap(map
), start
, end
);
2686 * Make a second pass, cleaning/uncaching pages from the indicated
2689 for (current
= entry
; current
->start
< end
; current
= current
->next
) {
2690 offset
= current
->offset
+ (start
- current
->start
);
2691 size
= (end
<= current
->end
? end
: current
->end
) - start
;
2693 switch(current
->maptype
) {
2694 case VM_MAPTYPE_SUBMAP
:
2697 vm_map_entry_t tentry
;
2700 smap
= current
->object
.sub_map
;
2701 vm_map_lock_read(smap
);
2702 vm_map_lookup_entry(smap
, offset
, &tentry
);
2703 tsize
= tentry
->end
- offset
;
2706 object
= tentry
->object
.vm_object
;
2707 offset
= tentry
->offset
+ (offset
- tentry
->start
);
2708 vm_map_unlock_read(smap
);
2711 case VM_MAPTYPE_NORMAL
:
2712 case VM_MAPTYPE_VPAGETABLE
:
2713 object
= current
->object
.vm_object
;
2721 vm_object_hold(object
);
2724 * Note that there is absolutely no sense in writing out
2725 * anonymous objects, so we track down the vnode object
2727 * We invalidate (remove) all pages from the address space
2728 * anyway, for semantic correctness.
2730 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2731 * may start out with a NULL object.
2733 while (object
&& (tobj
= object
->backing_object
) != NULL
) {
2734 vm_object_hold(tobj
);
2735 if (tobj
== object
->backing_object
) {
2736 vm_object_lock_swap();
2737 offset
+= object
->backing_object_offset
;
2738 vm_object_drop(object
);
2740 if (object
->size
< OFF_TO_IDX(offset
+ size
))
2741 size
= IDX_TO_OFF(object
->size
) -
2745 vm_object_drop(tobj
);
2747 if (object
&& (object
->type
== OBJT_VNODE
) &&
2748 (current
->protection
& VM_PROT_WRITE
) &&
2749 (object
->flags
& OBJ_NOMSYNC
) == 0) {
2751 * Flush pages if writing is allowed, invalidate them
2752 * if invalidation requested. Pages undergoing I/O
2753 * will be ignored by vm_object_page_remove().
2755 * We cannot lock the vnode and then wait for paging
2756 * to complete without deadlocking against vm_fault.
2757 * Instead we simply call vm_object_page_remove() and
2758 * allow it to block internally on a page-by-page
2759 * basis when it encounters pages undergoing async
2764 /* no chain wait needed for vnode objects */
2765 vm_object_reference_locked(object
);
2766 vn_lock(object
->handle
, LK_EXCLUSIVE
| LK_RETRY
);
2767 flags
= (syncio
|| invalidate
) ? OBJPC_SYNC
: 0;
2768 flags
|= invalidate
? OBJPC_INVAL
: 0;
2771 * When operating on a virtual page table just
2772 * flush the whole object. XXX we probably ought
2775 switch(current
->maptype
) {
2776 case VM_MAPTYPE_NORMAL
:
2777 vm_object_page_clean(object
,
2779 OFF_TO_IDX(offset
+ size
+ PAGE_MASK
),
2782 case VM_MAPTYPE_VPAGETABLE
:
2783 vm_object_page_clean(object
, 0, 0, flags
);
2786 vn_unlock(((struct vnode
*)object
->handle
));
2787 vm_object_deallocate_locked(object
);
2789 if (object
&& invalidate
&&
2790 ((object
->type
== OBJT_VNODE
) ||
2791 (object
->type
== OBJT_DEVICE
) ||
2792 (object
->type
== OBJT_MGTDEVICE
))) {
2794 ((object
->type
== OBJT_DEVICE
) ||
2795 (object
->type
== OBJT_MGTDEVICE
)) ? FALSE
: TRUE
;
2796 /* no chain wait needed for vnode/device objects */
2797 vm_object_reference_locked(object
);
2798 switch(current
->maptype
) {
2799 case VM_MAPTYPE_NORMAL
:
2800 vm_object_page_remove(object
,
2802 OFF_TO_IDX(offset
+ size
+ PAGE_MASK
),
2805 case VM_MAPTYPE_VPAGETABLE
:
2806 vm_object_page_remove(object
, 0, 0, clean_only
);
2809 vm_object_deallocate_locked(object
);
2813 vm_object_drop(object
);
2816 lwkt_reltoken(&map
->token
);
2817 vm_map_unlock_read(map
);
2819 return (KERN_SUCCESS
);
2823 * Make the region specified by this entry pageable.
2825 * The vm_map must be exclusively locked.
2828 vm_map_entry_unwire(vm_map_t map
, vm_map_entry_t entry
)
2830 entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
2831 entry
->wired_count
= 0;
2832 vm_fault_unwire(map
, entry
);
2836 * Deallocate the given entry from the target map.
2838 * The vm_map must be exclusively locked.
2841 vm_map_entry_delete(vm_map_t map
, vm_map_entry_t entry
, int *countp
)
2843 vm_map_entry_unlink(map
, entry
);
2844 map
->size
-= entry
->end
- entry
->start
;
2846 switch(entry
->maptype
) {
2847 case VM_MAPTYPE_NORMAL
:
2848 case VM_MAPTYPE_VPAGETABLE
:
2849 case VM_MAPTYPE_SUBMAP
:
2850 vm_object_deallocate(entry
->object
.vm_object
);
2852 case VM_MAPTYPE_UKSMAP
:
2859 vm_map_entry_dispose(map
, entry
, countp
);
2863 * Deallocates the given address range from the target map.
2865 * The vm_map must be exclusively locked.
2868 vm_map_delete(vm_map_t map
, vm_offset_t start
, vm_offset_t end
, int *countp
)
2871 vm_map_entry_t entry
;
2872 vm_map_entry_t first_entry
;
2874 ASSERT_VM_MAP_LOCKED(map
);
2875 lwkt_gettoken(&map
->token
);
2878 * Find the start of the region, and clip it. Set entry to point
2879 * at the first record containing the requested address or, if no
2880 * such record exists, the next record with a greater address. The
2881 * loop will run from this point until a record beyond the termination
2882 * address is encountered.
2884 * map->hint must be adjusted to not point to anything we delete,
2885 * so set it to the entry prior to the one being deleted.
2887 * GGG see other GGG comment.
2889 if (vm_map_lookup_entry(map
, start
, &first_entry
)) {
2890 entry
= first_entry
;
2891 vm_map_clip_start(map
, entry
, start
, countp
);
2892 map
->hint
= entry
->prev
; /* possible problem XXX */
2894 map
->hint
= first_entry
; /* possible problem XXX */
2895 entry
= first_entry
->next
;
2899 * If a hole opens up prior to the current first_free then
2900 * adjust first_free. As with map->hint, map->first_free
2901 * cannot be left set to anything we might delete.
2903 if (entry
== &map
->header
) {
2904 map
->first_free
= &map
->header
;
2905 } else if (map
->first_free
->start
>= start
) {
2906 map
->first_free
= entry
->prev
;
2910 * Step through all entries in this region
2912 while ((entry
!= &map
->header
) && (entry
->start
< end
)) {
2913 vm_map_entry_t next
;
2915 vm_pindex_t offidxstart
, offidxend
, count
;
2918 * If we hit an in-transition entry we have to sleep and
2919 * retry. It's easier (and not really slower) to just retry
2920 * since this case occurs so rarely and the hint is already
2921 * pointing at the right place. We have to reset the
2922 * start offset so as not to accidently delete an entry
2923 * another process just created in vacated space.
2925 if (entry
->eflags
& MAP_ENTRY_IN_TRANSITION
) {
2926 entry
->eflags
|= MAP_ENTRY_NEEDS_WAKEUP
;
2927 start
= entry
->start
;
2928 ++mycpu
->gd_cnt
.v_intrans_coll
;
2929 ++mycpu
->gd_cnt
.v_intrans_wait
;
2930 vm_map_transition_wait(map
);
2933 vm_map_clip_end(map
, entry
, end
, countp
);
2939 offidxstart
= OFF_TO_IDX(entry
->offset
);
2940 count
= OFF_TO_IDX(e
- s
);
2942 switch(entry
->maptype
) {
2943 case VM_MAPTYPE_NORMAL
:
2944 case VM_MAPTYPE_VPAGETABLE
:
2945 case VM_MAPTYPE_SUBMAP
:
2946 object
= entry
->object
.vm_object
;
2954 * Unwire before removing addresses from the pmap; otherwise,
2955 * unwiring will put the entries back in the pmap.
2957 if (entry
->wired_count
!= 0)
2958 vm_map_entry_unwire(map
, entry
);
2960 offidxend
= offidxstart
+ count
;
2962 if (object
== &kernel_object
) {
2963 vm_object_hold(object
);
2964 vm_object_page_remove(object
, offidxstart
,
2966 vm_object_drop(object
);
2967 } else if (object
&& object
->type
!= OBJT_DEFAULT
&&
2968 object
->type
!= OBJT_SWAP
) {
2970 * vnode object routines cannot be chain-locked,
2971 * but since we aren't removing pages from the
2972 * object here we can use a shared hold.
2974 vm_object_hold_shared(object
);
2975 pmap_remove(map
->pmap
, s
, e
);
2976 vm_object_drop(object
);
2977 } else if (object
) {
2978 vm_object_hold(object
);
2979 vm_object_chain_acquire(object
, 0);
2980 pmap_remove(map
->pmap
, s
, e
);
2982 if (object
!= NULL
&&
2983 object
->ref_count
!= 1 &&
2984 (object
->flags
& (OBJ_NOSPLIT
|OBJ_ONEMAPPING
)) ==
2986 (object
->type
== OBJT_DEFAULT
||
2987 object
->type
== OBJT_SWAP
)) {
2988 vm_object_collapse(object
, NULL
);
2989 vm_object_page_remove(object
, offidxstart
,
2991 if (object
->type
== OBJT_SWAP
) {
2992 swap_pager_freespace(object
,
2996 if (offidxend
>= object
->size
&&
2997 offidxstart
< object
->size
) {
2998 object
->size
= offidxstart
;
3001 vm_object_chain_release(object
);
3002 vm_object_drop(object
);
3003 } else if (entry
->maptype
== VM_MAPTYPE_UKSMAP
) {
3004 pmap_remove(map
->pmap
, s
, e
);
3008 * Delete the entry (which may delete the object) only after
3009 * removing all pmap entries pointing to its pages.
3010 * (Otherwise, its page frames may be reallocated, and any
3011 * modify bits will be set in the wrong object!)
3013 vm_map_entry_delete(map
, entry
, countp
);
3016 lwkt_reltoken(&map
->token
);
3017 return (KERN_SUCCESS
);
3021 * Remove the given address range from the target map.
3022 * This is the exported form of vm_map_delete.
3027 vm_map_remove(vm_map_t map
, vm_offset_t start
, vm_offset_t end
)
3032 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
3034 VM_MAP_RANGE_CHECK(map
, start
, end
);
3035 result
= vm_map_delete(map
, start
, end
, &count
);
3037 vm_map_entry_release(count
);
3043 * Assert that the target map allows the specified privilege on the
3044 * entire address region given. The entire region must be allocated.
3046 * The caller must specify whether the vm_map is already locked or not.
3049 vm_map_check_protection(vm_map_t map
, vm_offset_t start
, vm_offset_t end
,
3050 vm_prot_t protection
, boolean_t have_lock
)
3052 vm_map_entry_t entry
;
3053 vm_map_entry_t tmp_entry
;
3056 if (have_lock
== FALSE
)
3057 vm_map_lock_read(map
);
3059 if (!vm_map_lookup_entry(map
, start
, &tmp_entry
)) {
3060 if (have_lock
== FALSE
)
3061 vm_map_unlock_read(map
);
3067 while (start
< end
) {
3068 if (entry
== &map
->header
) {
3076 if (start
< entry
->start
) {
3081 * Check protection associated with entry.
3084 if ((entry
->protection
& protection
) != protection
) {
3088 /* go to next entry */
3091 entry
= entry
->next
;
3093 if (have_lock
== FALSE
)
3094 vm_map_unlock_read(map
);
3099 * If appropriate this function shadows the original object with a new object
3100 * and moves the VM pages from the original object to the new object.
3101 * The original object will also be collapsed, if possible.
3103 * We can only do this for normal memory objects with a single mapping, and
3104 * it only makes sense to do it if there are 2 or more refs on the original
3105 * object. i.e. typically a memory object that has been extended into
3106 * multiple vm_map_entry's with non-overlapping ranges.
3108 * This makes it easier to remove unused pages and keeps object inheritance
3109 * from being a negative impact on memory usage.
3111 * On return the (possibly new) entry->object.vm_object will have an
3112 * additional ref on it for the caller to dispose of (usually by cloning
3113 * the vm_map_entry). The additional ref had to be done in this routine
3114 * to avoid racing a collapse. The object's ONEMAPPING flag will also be
3117 * The vm_map must be locked and its token held.
3120 vm_map_split(vm_map_entry_t entry
)
3123 vm_object_t oobject
, nobject
, bobject
;
3126 vm_pindex_t offidxstart
, offidxend
, idx
;
3128 vm_ooffset_t offset
;
3132 * Optimize away object locks for vnode objects. Important exit/exec
3135 * OBJ_ONEMAPPING doesn't apply to vnode objects but clear the flag
3138 oobject
= entry
->object
.vm_object
;
3139 if (oobject
->type
!= OBJT_DEFAULT
&& oobject
->type
!= OBJT_SWAP
) {
3140 vm_object_reference_quick(oobject
);
3141 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
3146 * Setup. Chain lock the original object throughout the entire
3147 * routine to prevent new page faults from occuring.
3149 * XXX can madvise WILLNEED interfere with us too?
3151 vm_object_hold(oobject
);
3152 vm_object_chain_acquire(oobject
, 0);
3155 * Original object cannot be split? Might have also changed state.
3157 if (oobject
->handle
== NULL
|| (oobject
->type
!= OBJT_DEFAULT
&&
3158 oobject
->type
!= OBJT_SWAP
)) {
3159 vm_object_chain_release(oobject
);
3160 vm_object_reference_locked(oobject
);
3161 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
3162 vm_object_drop(oobject
);
3167 * Collapse original object with its backing store as an
3168 * optimization to reduce chain lengths when possible.
3170 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's
3171 * for oobject, so there's no point collapsing it.
3173 * Then re-check whether the object can be split.
3175 vm_object_collapse(oobject
, NULL
);
3177 if (oobject
->ref_count
<= 1 ||
3178 (oobject
->type
!= OBJT_DEFAULT
&& oobject
->type
!= OBJT_SWAP
) ||
3179 (oobject
->flags
& (OBJ_NOSPLIT
|OBJ_ONEMAPPING
)) != OBJ_ONEMAPPING
) {
3180 vm_object_chain_release(oobject
);
3181 vm_object_reference_locked(oobject
);
3182 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
3183 vm_object_drop(oobject
);
3188 * Acquire the chain lock on the backing object.
3190 * Give bobject an additional ref count for when it will be shadowed
3194 if ((bobject
= oobject
->backing_object
) != NULL
) {
3195 if (bobject
->type
!= OBJT_VNODE
) {
3197 vm_object_hold(bobject
);
3198 vm_object_chain_wait(bobject
, 0);
3199 /* ref for shadowing below */
3200 vm_object_reference_locked(bobject
);
3201 vm_object_chain_acquire(bobject
, 0);
3202 KKASSERT(bobject
->backing_object
== bobject
);
3203 KKASSERT((bobject
->flags
& OBJ_DEAD
) == 0);
3206 * vnodes are not placed on the shadow list but
3207 * they still get another ref for the backing_object
3210 vm_object_reference_quick(bobject
);
3215 * Calculate the object page range and allocate the new object.
3217 offset
= entry
->offset
;
3221 offidxstart
= OFF_TO_IDX(offset
);
3222 offidxend
= offidxstart
+ OFF_TO_IDX(e
- s
);
3223 size
= offidxend
- offidxstart
;
3225 switch(oobject
->type
) {
3227 nobject
= default_pager_alloc(NULL
, IDX_TO_OFF(size
),
3231 nobject
= swap_pager_alloc(NULL
, IDX_TO_OFF(size
),
3240 if (nobject
== NULL
) {
3242 if (useshadowlist
) {
3243 vm_object_chain_release(bobject
);
3244 vm_object_deallocate(bobject
);
3245 vm_object_drop(bobject
);
3247 vm_object_deallocate(bobject
);
3250 vm_object_chain_release(oobject
);
3251 vm_object_reference_locked(oobject
);
3252 vm_object_clear_flag(oobject
, OBJ_ONEMAPPING
);
3253 vm_object_drop(oobject
);
3258 * The new object will replace entry->object.vm_object so it needs
3259 * a second reference (the caller expects an additional ref).
3261 vm_object_hold(nobject
);
3262 vm_object_reference_locked(nobject
);
3263 vm_object_chain_acquire(nobject
, 0);
3266 * nobject shadows bobject (oobject already shadows bobject).
3268 * Adding an object to bobject's shadow list requires refing bobject
3269 * which we did above in the useshadowlist case.
3272 nobject
->backing_object_offset
=
3273 oobject
->backing_object_offset
+ IDX_TO_OFF(offidxstart
);
3274 nobject
->backing_object
= bobject
;
3275 if (useshadowlist
) {
3276 bobject
->shadow_count
++;
3277 atomic_add_int(&bobject
->generation
, 1);
3278 LIST_INSERT_HEAD(&bobject
->shadow_head
,
3279 nobject
, shadow_list
);
3280 vm_object_clear_flag(bobject
, OBJ_ONEMAPPING
); /*XXX*/
3281 vm_object_chain_release(bobject
);
3282 vm_object_drop(bobject
);
3283 vm_object_set_flag(nobject
, OBJ_ONSHADOW
);
3288 * Move the VM pages from oobject to nobject
3290 for (idx
= 0; idx
< size
; idx
++) {
3293 m
= vm_page_lookup_busy_wait(oobject
, offidxstart
+ idx
,
3299 * We must wait for pending I/O to complete before we can
3302 * We do not have to VM_PROT_NONE the page as mappings should
3303 * not be changed by this operation.
3305 * NOTE: The act of renaming a page updates chaingen for both
3308 vm_page_rename(m
, nobject
, idx
);
3309 /* page automatically made dirty by rename and cache handled */
3310 /* page remains busy */
3313 if (oobject
->type
== OBJT_SWAP
) {
3314 vm_object_pip_add(oobject
, 1);
3316 * copy oobject pages into nobject and destroy unneeded
3317 * pages in shadow object.
3319 swap_pager_copy(oobject
, nobject
, offidxstart
, 0);
3320 vm_object_pip_wakeup(oobject
);
3324 * Wakeup the pages we played with. No spl protection is needed
3325 * for a simple wakeup.
3327 for (idx
= 0; idx
< size
; idx
++) {
3328 m
= vm_page_lookup(nobject
, idx
);
3330 KKASSERT(m
->flags
& PG_BUSY
);
3334 entry
->object
.vm_object
= nobject
;
3335 entry
->offset
= 0LL;
3340 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the
3341 * related pages were moved and are no longer applicable to the
3344 * NOTE: Deallocate oobject (due to its entry->object.vm_object being
3345 * replaced by nobject).
3347 vm_object_chain_release(nobject
);
3348 vm_object_drop(nobject
);
3349 if (bobject
&& useshadowlist
) {
3350 vm_object_chain_release(bobject
);
3351 vm_object_drop(bobject
);
3353 vm_object_chain_release(oobject
);
3354 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/
3355 vm_object_deallocate_locked(oobject
);
3356 vm_object_drop(oobject
);
3360 * Copies the contents of the source entry to the destination
3361 * entry. The entries *must* be aligned properly.
3363 * The vm_maps must be exclusively locked.
3364 * The vm_map's token must be held.
3366 * Because the maps are locked no faults can be in progress during the
3370 vm_map_copy_entry(vm_map_t src_map
, vm_map_t dst_map
,
3371 vm_map_entry_t src_entry
, vm_map_entry_t dst_entry
)
3373 vm_object_t src_object
;
3375 if (dst_entry
->maptype
== VM_MAPTYPE_SUBMAP
||
3376 dst_entry
->maptype
== VM_MAPTYPE_UKSMAP
)
3378 if (src_entry
->maptype
== VM_MAPTYPE_SUBMAP
||
3379 src_entry
->maptype
== VM_MAPTYPE_UKSMAP
)
3382 if (src_entry
->wired_count
== 0) {
3384 * If the source entry is marked needs_copy, it is already
3387 if ((src_entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) == 0) {
3388 pmap_protect(src_map
->pmap
,
3391 src_entry
->protection
& ~VM_PROT_WRITE
);
3395 * Make a copy of the object.
3397 * The object must be locked prior to checking the object type
3398 * and for the call to vm_object_collapse() and vm_map_split().
3399 * We cannot use *_hold() here because the split code will
3400 * probably try to destroy the object. The lock is a pool
3401 * token and doesn't care.
3403 * We must bump src_map->timestamp when setting
3404 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault
3405 * to retry, otherwise the concurrent fault might improperly
3406 * install a RW pte when its supposed to be a RO(COW) pte.
3407 * This race can occur because a vnode-backed fault may have
3408 * to temporarily release the map lock.
3410 if (src_entry
->object
.vm_object
!= NULL
) {
3411 vm_map_split(src_entry
);
3412 src_object
= src_entry
->object
.vm_object
;
3413 dst_entry
->object
.vm_object
= src_object
;
3414 src_entry
->eflags
|= (MAP_ENTRY_COW
|
3415 MAP_ENTRY_NEEDS_COPY
);
3416 dst_entry
->eflags
|= (MAP_ENTRY_COW
|
3417 MAP_ENTRY_NEEDS_COPY
);
3418 dst_entry
->offset
= src_entry
->offset
;
3419 ++src_map
->timestamp
;
3421 dst_entry
->object
.vm_object
= NULL
;
3422 dst_entry
->offset
= 0;
3425 pmap_copy(dst_map
->pmap
, src_map
->pmap
, dst_entry
->start
,
3426 dst_entry
->end
- dst_entry
->start
, src_entry
->start
);
3429 * Of course, wired down pages can't be set copy-on-write.
3430 * Cause wired pages to be copied into the new map by
3431 * simulating faults (the new pages are pageable)
3433 vm_fault_copy_entry(dst_map
, src_map
, dst_entry
, src_entry
);
3439 * Create a new process vmspace structure and vm_map
3440 * based on those of an existing process. The new map
3441 * is based on the old map, according to the inheritance
3442 * values on the regions in that map.
3444 * The source map must not be locked.
3447 static void vmspace_fork_normal_entry(vm_map_t old_map
, vm_map_t new_map
,
3448 vm_map_entry_t old_entry
, int *countp
);
3449 static void vmspace_fork_uksmap_entry(vm_map_t old_map
, vm_map_t new_map
,
3450 vm_map_entry_t old_entry
, int *countp
);
3453 vmspace_fork(struct vmspace
*vm1
)
3455 struct vmspace
*vm2
;
3456 vm_map_t old_map
= &vm1
->vm_map
;
3458 vm_map_entry_t old_entry
;
3461 lwkt_gettoken(&vm1
->vm_map
.token
);
3462 vm_map_lock(old_map
);
3464 vm2
= vmspace_alloc(old_map
->min_offset
, old_map
->max_offset
);
3465 lwkt_gettoken(&vm2
->vm_map
.token
);
3466 bcopy(&vm1
->vm_startcopy
, &vm2
->vm_startcopy
,
3467 (caddr_t
)&vm1
->vm_endcopy
- (caddr_t
)&vm1
->vm_startcopy
);
3468 new_map
= &vm2
->vm_map
; /* XXX */
3469 new_map
->timestamp
= 1;
3471 vm_map_lock(new_map
);
3474 old_entry
= old_map
->header
.next
;
3475 while (old_entry
!= &old_map
->header
) {
3477 old_entry
= old_entry
->next
;
3480 count
= vm_map_entry_reserve(count
+ MAP_RESERVE_COUNT
);
3482 old_entry
= old_map
->header
.next
;
3483 while (old_entry
!= &old_map
->header
) {
3484 switch(old_entry
->maptype
) {
3485 case VM_MAPTYPE_SUBMAP
:
3486 panic("vm_map_fork: encountered a submap");
3488 case VM_MAPTYPE_UKSMAP
:
3489 vmspace_fork_uksmap_entry(old_map
, new_map
,
3492 case VM_MAPTYPE_NORMAL
:
3493 case VM_MAPTYPE_VPAGETABLE
:
3494 vmspace_fork_normal_entry(old_map
, new_map
,
3498 old_entry
= old_entry
->next
;
3501 new_map
->size
= old_map
->size
;
3502 vm_map_unlock(old_map
);
3503 vm_map_unlock(new_map
);
3504 vm_map_entry_release(count
);
3506 lwkt_reltoken(&vm2
->vm_map
.token
);
3507 lwkt_reltoken(&vm1
->vm_map
.token
);
3514 vmspace_fork_normal_entry(vm_map_t old_map
, vm_map_t new_map
,
3515 vm_map_entry_t old_entry
, int *countp
)
3517 vm_map_entry_t new_entry
;
3520 switch (old_entry
->inheritance
) {
3521 case VM_INHERIT_NONE
:
3523 case VM_INHERIT_SHARE
:
3525 * Clone the entry, creating the shared object if
3528 if (old_entry
->object
.vm_object
== NULL
)
3529 vm_map_entry_allocate_object(old_entry
);
3531 if (old_entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) {
3533 * Shadow a map_entry which needs a copy,
3534 * replacing its object with a new object
3535 * that points to the old one. Ask the
3536 * shadow code to automatically add an
3537 * additional ref. We can't do it afterwords
3538 * because we might race a collapse. The call
3539 * to vm_map_entry_shadow() will also clear
3542 vm_map_entry_shadow(old_entry
, 1);
3543 } else if (old_entry
->object
.vm_object
) {
3545 * We will make a shared copy of the object,
3546 * and must clear OBJ_ONEMAPPING.
3548 * Optimize vnode objects. OBJ_ONEMAPPING
3549 * is non-applicable but clear it anyway,
3550 * and its terminal so we don'th ave to deal
3551 * with chains. Reduces SMP conflicts.
3553 * XXX assert that object.vm_object != NULL
3554 * since we allocate it above.
3556 object
= old_entry
->object
.vm_object
;
3557 if (object
->type
== OBJT_VNODE
) {
3558 vm_object_reference_quick(object
);
3559 vm_object_clear_flag(object
,
3562 vm_object_hold(object
);
3563 vm_object_chain_wait(object
, 0);
3564 vm_object_reference_locked(object
);
3565 vm_object_clear_flag(object
,
3567 vm_object_drop(object
);
3572 * Clone the entry. We've already bumped the ref on
3575 new_entry
= vm_map_entry_create(new_map
, countp
);
3576 *new_entry
= *old_entry
;
3577 new_entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
3578 new_entry
->wired_count
= 0;
3581 * Insert the entry into the new map -- we know we're
3582 * inserting at the end of the new map.
3585 vm_map_entry_link(new_map
, new_map
->header
.prev
,
3589 * Update the physical map
3591 pmap_copy(new_map
->pmap
, old_map
->pmap
,
3593 (old_entry
->end
- old_entry
->start
),
3596 case VM_INHERIT_COPY
:
3598 * Clone the entry and link into the map.
3600 new_entry
= vm_map_entry_create(new_map
, countp
);
3601 *new_entry
= *old_entry
;
3602 new_entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
3603 new_entry
->wired_count
= 0;
3604 new_entry
->object
.vm_object
= NULL
;
3605 vm_map_entry_link(new_map
, new_map
->header
.prev
,
3607 vm_map_copy_entry(old_map
, new_map
, old_entry
,
3614 * When forking user-kernel shared maps, the map might change in the
3615 * child so do not try to copy the underlying pmap entries.
3619 vmspace_fork_uksmap_entry(vm_map_t old_map
, vm_map_t new_map
,
3620 vm_map_entry_t old_entry
, int *countp
)
3622 vm_map_entry_t new_entry
;
3624 new_entry
= vm_map_entry_create(new_map
, countp
);
3625 *new_entry
= *old_entry
;
3626 new_entry
->eflags
&= ~MAP_ENTRY_USER_WIRED
;
3627 new_entry
->wired_count
= 0;
3628 vm_map_entry_link(new_map
, new_map
->header
.prev
,
3633 * Create an auto-grow stack entry
3638 vm_map_stack (vm_map_t map
, vm_offset_t addrbos
, vm_size_t max_ssize
,
3639 int flags
, vm_prot_t prot
, vm_prot_t max
, int cow
)
3641 vm_map_entry_t prev_entry
;
3642 vm_map_entry_t new_stack_entry
;
3643 vm_size_t init_ssize
;
3646 vm_offset_t tmpaddr
;
3648 cow
|= MAP_IS_STACK
;
3650 if (max_ssize
< sgrowsiz
)
3651 init_ssize
= max_ssize
;
3653 init_ssize
= sgrowsiz
;
3655 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
3659 * Find space for the mapping
3661 if ((flags
& (MAP_FIXED
| MAP_TRYFIXED
)) == 0) {
3662 if (vm_map_findspace(map
, addrbos
, max_ssize
, 1,
3665 vm_map_entry_release(count
);
3666 return (KERN_NO_SPACE
);
3671 /* If addr is already mapped, no go */
3672 if (vm_map_lookup_entry(map
, addrbos
, &prev_entry
)) {
3674 vm_map_entry_release(count
);
3675 return (KERN_NO_SPACE
);
3679 /* XXX already handled by kern_mmap() */
3680 /* If we would blow our VMEM resource limit, no go */
3681 if (map
->size
+ init_ssize
>
3682 curproc
->p_rlimit
[RLIMIT_VMEM
].rlim_cur
) {
3684 vm_map_entry_release(count
);
3685 return (KERN_NO_SPACE
);
3690 * If we can't accomodate max_ssize in the current mapping,
3691 * no go. However, we need to be aware that subsequent user
3692 * mappings might map into the space we have reserved for
3693 * stack, and currently this space is not protected.
3695 * Hopefully we will at least detect this condition
3696 * when we try to grow the stack.
3698 if ((prev_entry
->next
!= &map
->header
) &&
3699 (prev_entry
->next
->start
< addrbos
+ max_ssize
)) {
3701 vm_map_entry_release(count
);
3702 return (KERN_NO_SPACE
);
3706 * We initially map a stack of only init_ssize. We will
3707 * grow as needed later. Since this is to be a grow
3708 * down stack, we map at the top of the range.
3710 * Note: we would normally expect prot and max to be
3711 * VM_PROT_ALL, and cow to be 0. Possibly we should
3712 * eliminate these as input parameters, and just
3713 * pass these values here in the insert call.
3715 rv
= vm_map_insert(map
, &count
, NULL
, NULL
,
3716 0, addrbos
+ max_ssize
- init_ssize
,
3717 addrbos
+ max_ssize
,
3719 VM_SUBSYS_STACK
, prot
, max
, cow
);
3721 /* Now set the avail_ssize amount */
3722 if (rv
== KERN_SUCCESS
) {
3723 if (prev_entry
!= &map
->header
)
3724 vm_map_clip_end(map
, prev_entry
, addrbos
+ max_ssize
- init_ssize
, &count
);
3725 new_stack_entry
= prev_entry
->next
;
3726 if (new_stack_entry
->end
!= addrbos
+ max_ssize
||
3727 new_stack_entry
->start
!= addrbos
+ max_ssize
- init_ssize
)
3728 panic ("Bad entry start/end for new stack entry");
3730 new_stack_entry
->aux
.avail_ssize
= max_ssize
- init_ssize
;
3734 vm_map_entry_release(count
);
3739 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3740 * desired address is already mapped, or if we successfully grow
3741 * the stack. Also returns KERN_SUCCESS if addr is outside the
3742 * stack range (this is strange, but preserves compatibility with
3743 * the grow function in vm_machdep.c).
3748 vm_map_growstack (vm_map_t map
, vm_offset_t addr
)
3750 vm_map_entry_t prev_entry
;
3751 vm_map_entry_t stack_entry
;
3752 vm_map_entry_t new_stack_entry
;
3758 int rv
= KERN_SUCCESS
;
3760 int use_read_lock
= 1;
3766 lp
= curthread
->td_lwp
;
3767 p
= curthread
->td_proc
;
3768 KKASSERT(lp
!= NULL
);
3769 vm
= lp
->lwp_vmspace
;
3772 * Growstack is only allowed on the current process. We disallow
3773 * other use cases, e.g. trying to access memory via procfs that
3774 * the stack hasn't grown into.
3776 if (map
!= &vm
->vm_map
) {
3777 return KERN_FAILURE
;
3780 count
= vm_map_entry_reserve(MAP_RESERVE_COUNT
);
3783 vm_map_lock_read(map
);
3787 /* If addr is already in the entry range, no need to grow.*/
3788 if (vm_map_lookup_entry(map
, addr
, &prev_entry
))
3791 if ((stack_entry
= prev_entry
->next
) == &map
->header
)
3793 if (prev_entry
== &map
->header
)
3794 end
= stack_entry
->start
- stack_entry
->aux
.avail_ssize
;
3796 end
= prev_entry
->end
;
3799 * This next test mimics the old grow function in vm_machdep.c.
3800 * It really doesn't quite make sense, but we do it anyway
3801 * for compatibility.
3803 * If not growable stack, return success. This signals the
3804 * caller to proceed as he would normally with normal vm.
3806 if (stack_entry
->aux
.avail_ssize
< 1 ||
3807 addr
>= stack_entry
->start
||
3808 addr
< stack_entry
->start
- stack_entry
->aux
.avail_ssize
) {
3812 /* Find the minimum grow amount */
3813 grow_amount
= roundup (stack_entry
->start
- addr
, PAGE_SIZE
);
3814 if (grow_amount
> stack_entry
->aux
.avail_ssize
) {
3820 * If there is no longer enough space between the entries
3821 * nogo, and adjust the available space. Note: this
3822 * should only happen if the user has mapped into the
3823 * stack area after the stack was created, and is
3824 * probably an error.
3826 * This also effectively destroys any guard page the user
3827 * might have intended by limiting the stack size.
3829 if (grow_amount
> stack_entry
->start
- end
) {
3830 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
3836 stack_entry
->aux
.avail_ssize
= stack_entry
->start
- end
;
3841 is_procstack
= addr
>= (vm_offset_t
)vm
->vm_maxsaddr
;
3843 /* If this is the main process stack, see if we're over the
3846 if (is_procstack
&& (ctob(vm
->vm_ssize
) + grow_amount
>
3847 p
->p_rlimit
[RLIMIT_STACK
].rlim_cur
)) {
3852 /* Round up the grow amount modulo SGROWSIZ */
3853 grow_amount
= roundup (grow_amount
, sgrowsiz
);
3854 if (grow_amount
> stack_entry
->aux
.avail_ssize
) {
3855 grow_amount
= stack_entry
->aux
.avail_ssize
;
3857 if (is_procstack
&& (ctob(vm
->vm_ssize
) + grow_amount
>
3858 p
->p_rlimit
[RLIMIT_STACK
].rlim_cur
)) {
3859 grow_amount
= p
->p_rlimit
[RLIMIT_STACK
].rlim_cur
-
3863 /* If we would blow our VMEM resource limit, no go */
3864 if (map
->size
+ grow_amount
> p
->p_rlimit
[RLIMIT_VMEM
].rlim_cur
) {
3869 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
3876 /* Get the preliminary new entry start value */
3877 addr
= stack_entry
->start
- grow_amount
;
3879 /* If this puts us into the previous entry, cut back our growth
3880 * to the available space. Also, see the note above.
3883 stack_entry
->aux
.avail_ssize
= stack_entry
->start
- end
;
3887 rv
= vm_map_insert(map
, &count
, NULL
, NULL
,
3888 0, addr
, stack_entry
->start
,
3890 VM_SUBSYS_STACK
, VM_PROT_ALL
, VM_PROT_ALL
, 0);
3892 /* Adjust the available stack space by the amount we grew. */
3893 if (rv
== KERN_SUCCESS
) {
3894 if (prev_entry
!= &map
->header
)
3895 vm_map_clip_end(map
, prev_entry
, addr
, &count
);
3896 new_stack_entry
= prev_entry
->next
;
3897 if (new_stack_entry
->end
!= stack_entry
->start
||
3898 new_stack_entry
->start
!= addr
)
3899 panic ("Bad stack grow start/end in new stack entry");
3901 new_stack_entry
->aux
.avail_ssize
=
3902 stack_entry
->aux
.avail_ssize
-
3903 (new_stack_entry
->end
- new_stack_entry
->start
);
3905 vm
->vm_ssize
+= btoc(new_stack_entry
->end
-
3906 new_stack_entry
->start
);
3909 if (map
->flags
& MAP_WIREFUTURE
)
3910 vm_map_unwire(map
, new_stack_entry
->start
,
3911 new_stack_entry
->end
, FALSE
);
3916 vm_map_unlock_read(map
);
3919 vm_map_entry_release(count
);
3924 * Unshare the specified VM space for exec. If other processes are
3925 * mapped to it, then create a new one. The new vmspace is null.
3930 vmspace_exec(struct proc
*p
, struct vmspace
*vmcopy
)
3932 struct vmspace
*oldvmspace
= p
->p_vmspace
;
3933 struct vmspace
*newvmspace
;
3934 vm_map_t map
= &p
->p_vmspace
->vm_map
;
3937 * If we are execing a resident vmspace we fork it, otherwise
3938 * we create a new vmspace. Note that exitingcnt is not
3939 * copied to the new vmspace.
3941 lwkt_gettoken(&oldvmspace
->vm_map
.token
);
3943 newvmspace
= vmspace_fork(vmcopy
);
3944 lwkt_gettoken(&newvmspace
->vm_map
.token
);
3946 newvmspace
= vmspace_alloc(map
->min_offset
, map
->max_offset
);
3947 lwkt_gettoken(&newvmspace
->vm_map
.token
);
3948 bcopy(&oldvmspace
->vm_startcopy
, &newvmspace
->vm_startcopy
,
3949 (caddr_t
)&oldvmspace
->vm_endcopy
-
3950 (caddr_t
)&oldvmspace
->vm_startcopy
);
3954 * Finish initializing the vmspace before assigning it
3955 * to the process. The vmspace will become the current vmspace
3958 pmap_pinit2(vmspace_pmap(newvmspace
));
3959 pmap_replacevm(p
, newvmspace
, 0);
3960 lwkt_reltoken(&newvmspace
->vm_map
.token
);
3961 lwkt_reltoken(&oldvmspace
->vm_map
.token
);
3962 vmspace_rel(oldvmspace
);
3966 * Unshare the specified VM space for forcing COW. This
3967 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3970 vmspace_unshare(struct proc
*p
)
3972 struct vmspace
*oldvmspace
= p
->p_vmspace
;
3973 struct vmspace
*newvmspace
;
3975 lwkt_gettoken(&oldvmspace
->vm_map
.token
);
3976 if (vmspace_getrefs(oldvmspace
) == 1) {
3977 lwkt_reltoken(&oldvmspace
->vm_map
.token
);
3980 newvmspace
= vmspace_fork(oldvmspace
);
3981 lwkt_gettoken(&newvmspace
->vm_map
.token
);
3982 pmap_pinit2(vmspace_pmap(newvmspace
));
3983 pmap_replacevm(p
, newvmspace
, 0);
3984 lwkt_reltoken(&newvmspace
->vm_map
.token
);
3985 lwkt_reltoken(&oldvmspace
->vm_map
.token
);
3986 vmspace_rel(oldvmspace
);
3990 * vm_map_hint: return the beginning of the best area suitable for
3991 * creating a new mapping with "prot" protection.
3996 vm_map_hint(struct proc
*p
, vm_offset_t addr
, vm_prot_t prot
)
3998 struct vmspace
*vms
= p
->p_vmspace
;
4000 if (!randomize_mmap
|| addr
!= 0) {
4002 * Set a reasonable start point for the hint if it was
4003 * not specified or if it falls within the heap space.
4004 * Hinted mmap()s do not allocate out of the heap space.
4007 (addr
>= round_page((vm_offset_t
)vms
->vm_taddr
) &&
4008 addr
< round_page((vm_offset_t
)vms
->vm_daddr
+ maxdsiz
))) {
4009 addr
= round_page((vm_offset_t
)vms
->vm_daddr
+ maxdsiz
);
4014 addr
= (vm_offset_t
)vms
->vm_daddr
+ MAXDSIZ
;
4015 addr
+= karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ
) - 1);
4017 return (round_page(addr
));
4021 * Finds the VM object, offset, and protection for a given virtual address
4022 * in the specified map, assuming a page fault of the type specified.
4024 * Leaves the map in question locked for read; return values are guaranteed
4025 * until a vm_map_lookup_done call is performed. Note that the map argument
4026 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
4028 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
4031 * If a lookup is requested with "write protection" specified, the map may
4032 * be changed to perform virtual copying operations, although the data
4033 * referenced will remain the same.
4038 vm_map_lookup(vm_map_t
*var_map
, /* IN/OUT */
4040 vm_prot_t fault_typea
,
4041 vm_map_entry_t
*out_entry
, /* OUT */
4042 vm_object_t
*object
, /* OUT */
4043 vm_pindex_t
*pindex
, /* OUT */
4044 vm_prot_t
*out_prot
, /* OUT */
4045 boolean_t
*wired
) /* OUT */
4047 vm_map_entry_t entry
;
4048 vm_map_t map
= *var_map
;
4050 vm_prot_t fault_type
= fault_typea
;
4051 int use_read_lock
= 1;
4052 int rv
= KERN_SUCCESS
;
4056 vm_map_lock_read(map
);
4061 * If the map has an interesting hint, try it before calling full
4062 * blown lookup routine.
4069 if ((entry
== &map
->header
) ||
4070 (vaddr
< entry
->start
) || (vaddr
>= entry
->end
)) {
4071 vm_map_entry_t tmp_entry
;
4074 * Entry was either not a valid hint, or the vaddr was not
4075 * contained in the entry, so do a full lookup.
4077 if (!vm_map_lookup_entry(map
, vaddr
, &tmp_entry
)) {
4078 rv
= KERN_INVALID_ADDRESS
;
4089 if (entry
->maptype
== VM_MAPTYPE_SUBMAP
) {
4090 vm_map_t old_map
= map
;
4092 *var_map
= map
= entry
->object
.sub_map
;
4094 vm_map_unlock_read(old_map
);
4096 vm_map_unlock(old_map
);
4102 * Check whether this task is allowed to have this page.
4103 * Note the special case for MAP_ENTRY_COW pages with an override.
4104 * This is to implement a forced COW for debuggers.
4106 if (fault_type
& VM_PROT_OVERRIDE_WRITE
)
4107 prot
= entry
->max_protection
;
4109 prot
= entry
->protection
;
4111 fault_type
&= (VM_PROT_READ
|VM_PROT_WRITE
|VM_PROT_EXECUTE
);
4112 if ((fault_type
& prot
) != fault_type
) {
4113 rv
= KERN_PROTECTION_FAILURE
;
4117 if ((entry
->eflags
& MAP_ENTRY_USER_WIRED
) &&
4118 (entry
->eflags
& MAP_ENTRY_COW
) &&
4119 (fault_type
& VM_PROT_WRITE
) &&
4120 (fault_typea
& VM_PROT_OVERRIDE_WRITE
) == 0) {
4121 rv
= KERN_PROTECTION_FAILURE
;
4126 * If this page is not pageable, we have to get it for all possible
4129 *wired
= (entry
->wired_count
!= 0);
4131 prot
= fault_type
= entry
->protection
;
4134 * Virtual page tables may need to update the accessed (A) bit
4135 * in a page table entry. Upgrade the fault to a write fault for
4136 * that case if the map will support it. If the map does not support
4137 * it the page table entry simply will not be updated.
4139 if (entry
->maptype
== VM_MAPTYPE_VPAGETABLE
) {
4140 if (prot
& VM_PROT_WRITE
)
4141 fault_type
|= VM_PROT_WRITE
;
4144 if (curthread
->td_lwp
&& curthread
->td_lwp
->lwp_vmspace
&&
4145 pmap_emulate_ad_bits(&curthread
->td_lwp
->lwp_vmspace
->vm_pmap
)) {
4146 if ((prot
& VM_PROT_WRITE
) == 0)
4147 fault_type
|= VM_PROT_WRITE
;
4151 * Only NORMAL and VPAGETABLE maps are object-based. UKSMAPs are not.
4153 if (entry
->maptype
!= VM_MAPTYPE_NORMAL
&&
4154 entry
->maptype
!= VM_MAPTYPE_VPAGETABLE
) {
4160 * If the entry was copy-on-write, we either ...
4162 if (entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) {
4164 * If we want to write the page, we may as well handle that
4165 * now since we've got the map locked.
4167 * If we don't need to write the page, we just demote the
4168 * permissions allowed.
4171 if (fault_type
& VM_PROT_WRITE
) {
4173 * Not allowed if TDF_NOFAULT is set as the shadowing
4174 * operation can deadlock against the faulting
4175 * function due to the copy-on-write.
4177 if (curthread
->td_flags
& TDF_NOFAULT
) {
4178 rv
= KERN_FAILURE_NOFAULT
;
4183 * Make a new object, and place it in the object
4184 * chain. Note that no new references have appeared
4185 * -- one just moved from the map to the new
4189 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
4196 vm_map_entry_shadow(entry
, 0);
4199 * We're attempting to read a copy-on-write page --
4200 * don't allow writes.
4203 prot
&= ~VM_PROT_WRITE
;
4208 * Create an object if necessary.
4210 if (entry
->object
.vm_object
== NULL
&& !map
->system_map
) {
4211 if (use_read_lock
&& vm_map_lock_upgrade(map
)) {
4217 vm_map_entry_allocate_object(entry
);
4221 * Return the object/offset from this entry. If the entry was
4222 * copy-on-write or empty, it has been fixed up.
4224 *object
= entry
->object
.vm_object
;
4227 *pindex
= OFF_TO_IDX((vaddr
- entry
->start
) + entry
->offset
);
4230 * Return whether this is the only map sharing this data. On
4231 * success we return with a read lock held on the map. On failure
4232 * we return with the map unlocked.
4236 if (rv
== KERN_SUCCESS
) {
4237 if (use_read_lock
== 0)
4238 vm_map_lock_downgrade(map
);
4239 } else if (use_read_lock
) {
4240 vm_map_unlock_read(map
);
4248 * Releases locks acquired by a vm_map_lookup()
4249 * (according to the handle returned by that lookup).
4251 * No other requirements.
4254 vm_map_lookup_done(vm_map_t map
, vm_map_entry_t entry
, int count
)
4257 * Unlock the main-level map
4259 vm_map_unlock_read(map
);
4261 vm_map_entry_release(count
);
4265 * Quick hack, needs some help to make it more SMP friendly.
4268 vm_map_interlock(vm_map_t map
, struct vm_map_ilock
*ilock
,
4269 vm_offset_t ran_beg
, vm_offset_t ran_end
)
4271 struct vm_map_ilock
*scan
;
4273 ilock
->ran_beg
= ran_beg
;
4274 ilock
->ran_end
= ran_end
;
4277 spin_lock(&map
->ilock_spin
);
4279 for (scan
= map
->ilock_base
; scan
; scan
= scan
->next
) {
4280 if (ran_end
> scan
->ran_beg
&& ran_beg
< scan
->ran_end
) {
4281 scan
->flags
|= ILOCK_WAITING
;
4282 ssleep(scan
, &map
->ilock_spin
, 0, "ilock", 0);
4286 ilock
->next
= map
->ilock_base
;
4287 map
->ilock_base
= ilock
;
4288 spin_unlock(&map
->ilock_spin
);
4292 vm_map_deinterlock(vm_map_t map
, struct vm_map_ilock
*ilock
)
4294 struct vm_map_ilock
*scan
;
4295 struct vm_map_ilock
**scanp
;
4297 spin_lock(&map
->ilock_spin
);
4298 scanp
= &map
->ilock_base
;
4299 while ((scan
= *scanp
) != NULL
) {
4300 if (scan
== ilock
) {
4301 *scanp
= ilock
->next
;
4302 spin_unlock(&map
->ilock_spin
);
4303 if (ilock
->flags
& ILOCK_WAITING
)
4307 scanp
= &scan
->next
;
4309 spin_unlock(&map
->ilock_spin
);
4310 panic("vm_map_deinterlock: missing ilock!");
4313 #include "opt_ddb.h"
4315 #include <sys/kernel.h>
4317 #include <ddb/ddb.h>
4322 DB_SHOW_COMMAND(map
, vm_map_print
)
4325 /* XXX convert args. */
4326 vm_map_t map
= (vm_map_t
)addr
;
4327 boolean_t full
= have_addr
;
4329 vm_map_entry_t entry
;
4331 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4333 (void *)map
->pmap
, map
->nentries
, map
->timestamp
);
4336 if (!full
&& db_indent
)
4340 for (entry
= map
->header
.next
; entry
!= &map
->header
;
4341 entry
= entry
->next
) {
4342 db_iprintf("map entry %p: start=%p, end=%p\n",
4343 (void *)entry
, (void *)entry
->start
, (void *)entry
->end
);
4346 static char *inheritance_name
[4] =
4347 {"share", "copy", "none", "donate_copy"};
4349 db_iprintf(" prot=%x/%x/%s",
4351 entry
->max_protection
,
4352 inheritance_name
[(int)(unsigned char)
4353 entry
->inheritance
]);
4354 if (entry
->wired_count
!= 0)
4355 db_printf(", wired");
4357 switch(entry
->maptype
) {
4358 case VM_MAPTYPE_SUBMAP
:
4359 /* XXX no %qd in kernel. Truncate entry->offset. */
4360 db_printf(", share=%p, offset=0x%lx\n",
4361 (void *)entry
->object
.sub_map
,
4362 (long)entry
->offset
);
4364 if ((entry
->prev
== &map
->header
) ||
4365 (entry
->prev
->object
.sub_map
!=
4366 entry
->object
.sub_map
)) {
4368 vm_map_print((db_expr_t
)(intptr_t)
4369 entry
->object
.sub_map
,
4374 case VM_MAPTYPE_NORMAL
:
4375 case VM_MAPTYPE_VPAGETABLE
:
4376 /* XXX no %qd in kernel. Truncate entry->offset. */
4377 db_printf(", object=%p, offset=0x%lx",
4378 (void *)entry
->object
.vm_object
,
4379 (long)entry
->offset
);
4380 if (entry
->eflags
& MAP_ENTRY_COW
)
4381 db_printf(", copy (%s)",
4382 (entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) ? "needed" : "done");
4386 if ((entry
->prev
== &map
->header
) ||
4387 (entry
->prev
->object
.vm_object
!=
4388 entry
->object
.vm_object
)) {
4390 vm_object_print((db_expr_t
)(intptr_t)
4391 entry
->object
.vm_object
,
4397 case VM_MAPTYPE_UKSMAP
:
4398 db_printf(", uksmap=%p, offset=0x%lx",
4399 (void *)entry
->object
.uksmap
,
4400 (long)entry
->offset
);
4401 if (entry
->eflags
& MAP_ENTRY_COW
)
4402 db_printf(", copy (%s)",
4403 (entry
->eflags
& MAP_ENTRY_NEEDS_COPY
) ? "needed" : "done");
4419 DB_SHOW_COMMAND(procvm
, procvm
)
4424 p
= (struct proc
*) addr
;
4429 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
4430 (void *)p
, (void *)p
->p_vmspace
, (void *)&p
->p_vmspace
->vm_map
,
4431 (void *)vmspace_pmap(p
->p_vmspace
));
4433 vm_map_print((db_expr_t
)(intptr_t)&p
->p_vmspace
->vm_map
, 1, 0, NULL
);