4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
62 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $
66 * Virtual memory mapping module.
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/kernel.h>
73 #include <sys/serialize.h>
75 #include <sys/vmmeter.h>
77 #include <sys/vnode.h>
78 #include <sys/resourcevar.h>
81 #include <sys/malloc.h>
82 #include <sys/objcache.h>
85 #include <vm/vm_param.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_page.h>
89 #include <vm/vm_object.h>
90 #include <vm/vm_pager.h>
91 #include <vm/vm_kern.h>
92 #include <vm/vm_extern.h>
93 #include <vm/swap_pager.h>
94 #include <vm/vm_zone.h>
96 #include <sys/thread2.h>
97 #include <sys/random.h>
98 #include <sys/sysctl.h>
101 * Virtual memory maps provide for the mapping, protection, and sharing
102 * of virtual memory objects. In addition, this module provides for an
103 * efficient virtual copy of memory from one map to another.
105 * Synchronization is required prior to most operations.
107 * Maps consist of an ordered doubly-linked list of simple entries.
108 * A hint and a RB tree is used to speed-up lookups.
110 * Callers looking to modify maps specify start/end addresses which cause
111 * the related map entry to be clipped if necessary, and then later
112 * recombined if the pieces remained compatible.
114 * Virtual copy operations are performed by copying VM object references
115 * from one map to another, and then marking both regions as copy-on-write.
117 static boolean_t vmspace_ctor(void *obj, void *privdata, int ocflags);
118 static void vmspace_dtor(void *obj, void *privdata);
119 static void vmspace_terminate(struct vmspace *vm, int final);
121 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore");
122 static struct objcache *vmspace_cache;
125 * per-cpu page table cross mappings are initialized in early boot
126 * and might require a considerable number of vm_map_entry structures.
128 #define MAPENTRYBSP_CACHE (MAXCPU+1)
129 #define MAPENTRYAP_CACHE 8
131 static struct vm_zone mapentzone_store;
132 static vm_zone_t mapentzone;
133 static struct vm_object mapentobj;
135 static struct vm_map_entry map_entry_init[MAX_MAPENT];
136 static struct vm_map_entry cpu_map_entry_init_bsp[MAPENTRYBSP_CACHE];
137 static struct vm_map_entry cpu_map_entry_init_ap[MAXCPU][MAPENTRYAP_CACHE];
139 static int randomize_mmap;
140 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0,
141 "Randomize mmap offsets");
142 static int vm_map_relock_enable = 1;
143 SYSCTL_INT(_vm, OID_AUTO, map_relock_enable, CTLFLAG_RW,
144 &vm_map_relock_enable, 0, "Randomize mmap offsets");
146 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref);
147 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *);
148 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *);
149 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
150 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
151 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *);
152 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t);
153 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t,
155 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);
158 * Initialize the vm_map module. Must be called before any other vm_map
161 * Map and entry structures are allocated from the general purpose
162 * memory pool with some exceptions:
164 * - The kernel map is allocated statically.
165 * - Initial kernel map entries are allocated out of a static pool.
166 * - We must set ZONE_SPECIAL here or the early boot code can get
167 * stuck if there are >63 cores.
169 * These restrictions are necessary since malloc() uses the
170 * maps and requires map entries.
172 * Called from the low level boot code only.
177 mapentzone = &mapentzone_store;
178 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry),
179 map_entry_init, MAX_MAPENT);
180 mapentzone_store.zflags |= ZONE_SPECIAL;
184 * Called prior to any vmspace allocations.
186 * Called from the low level boot code only.
191 vmspace_cache = objcache_create_mbacked(M_VMSPACE,
192 sizeof(struct vmspace),
194 vmspace_ctor, vmspace_dtor,
196 zinitna(mapentzone, &mapentobj, NULL, 0, 0,
197 ZONE_USE_RESERVE | ZONE_SPECIAL);
203 * objcache support. We leave the pmap root cached as long as possible
204 * for performance reasons.
208 vmspace_ctor(void *obj, void *privdata, int ocflags)
210 struct vmspace *vm = obj;
212 bzero(vm, sizeof(*vm));
213 vm->vm_refcnt = (u_int)-1;
220 vmspace_dtor(void *obj, void *privdata)
222 struct vmspace *vm = obj;
224 KKASSERT(vm->vm_refcnt == (u_int)-1);
225 pmap_puninit(vmspace_pmap(vm));
229 * Red black tree functions
231 * The caller must hold the related map lock.
233 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b);
234 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare);
236 /* a->start is address, and the only field has to be initialized */
238 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b)
240 if (a->start < b->start)
242 else if (a->start > b->start)
248 * Initialize vmspace ref/hold counts vmspace0. There is a holdcnt for
252 vmspace_initrefs(struct vmspace *vm)
259 * Allocate a vmspace structure, including a vm_map and pmap.
260 * Initialize numerous fields. While the initial allocation is zerod,
261 * subsequence reuse from the objcache leaves elements of the structure
262 * intact (particularly the pmap), so portions must be zerod.
264 * Returns a referenced vmspace.
269 vmspace_alloc(vm_offset_t min, vm_offset_t max)
273 vm = objcache_get(vmspace_cache, M_WAITOK);
275 bzero(&vm->vm_startcopy,
276 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy);
277 vm_map_init(&vm->vm_map, min, max, NULL); /* initializes token */
280 * NOTE: hold to acquires token for safety.
282 * On return vmspace is referenced (refs=1, hold=1). That is,
283 * each refcnt also has a holdcnt. There can be additional holds
284 * (holdcnt) above and beyond the refcnt. Finalization is handled in
285 * two stages, one on refs 1->0, and the the second on hold 1->0.
287 KKASSERT(vm->vm_holdcnt == 0);
288 KKASSERT(vm->vm_refcnt == (u_int)-1);
289 vmspace_initrefs(vm);
291 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */
292 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */
295 cpu_vmspace_alloc(vm);
302 * NOTE: Can return -1 if the vmspace is exiting.
305 vmspace_getrefs(struct vmspace *vm)
307 return ((int)vm->vm_refcnt);
311 * A vmspace object must already have a non-zero hold to be able to gain
312 * further holds on it.
315 vmspace_hold_notoken(struct vmspace *vm)
317 KKASSERT(vm->vm_holdcnt != 0);
318 refcount_acquire(&vm->vm_holdcnt);
322 vmspace_drop_notoken(struct vmspace *vm)
324 if (refcount_release(&vm->vm_holdcnt)) {
325 if (vm->vm_refcnt == (u_int)-1) {
326 vmspace_terminate(vm, 1);
332 vmspace_hold(struct vmspace *vm)
334 vmspace_hold_notoken(vm);
335 lwkt_gettoken(&vm->vm_map.token);
339 vmspace_drop(struct vmspace *vm)
341 lwkt_reltoken(&vm->vm_map.token);
342 vmspace_drop_notoken(vm);
346 * A vmspace object must not be in a terminated state to be able to obtain
347 * additional refs on it.
349 * Ref'ing a vmspace object also increments its hold count.
352 vmspace_ref(struct vmspace *vm)
354 KKASSERT((int)vm->vm_refcnt >= 0);
355 vmspace_hold_notoken(vm);
356 refcount_acquire(&vm->vm_refcnt);
360 * Release a ref on the vmspace. On the 1->0 transition we do stage-1
361 * termination of the vmspace. Then, on the final drop of the hold we
362 * will do stage-2 final termination.
365 vmspace_rel(struct vmspace *vm)
367 if (refcount_release(&vm->vm_refcnt)) {
368 vm->vm_refcnt = (u_int)-1; /* no other refs possible */
369 vmspace_terminate(vm, 0);
371 vmspace_drop_notoken(vm);
375 * This is called during exit indicating that the vmspace is no
376 * longer in used by an exiting process, but the process has not yet
379 * We release the refcnt but not the associated holdcnt.
384 vmspace_relexit(struct vmspace *vm)
386 if (refcount_release(&vm->vm_refcnt)) {
387 vm->vm_refcnt = (u_int)-1; /* no other refs possible */
388 vmspace_terminate(vm, 0);
393 * Called during reap to disconnect the remainder of the vmspace from
394 * the process. On the hold drop the vmspace termination is finalized.
399 vmspace_exitfree(struct proc *p)
405 vmspace_drop_notoken(vm);
409 * Called in two cases:
411 * (1) When the last refcnt is dropped and the vmspace becomes inactive,
412 * called with final == 0. refcnt will be (u_int)-1 at this point,
413 * and holdcnt will still be non-zero.
415 * (2) When holdcnt becomes 0, called with final == 1. There should no
416 * longer be anyone with access to the vmspace.
418 * VMSPACE_EXIT1 flags the primary deactivation
419 * VMSPACE_EXIT2 flags the last reap
422 vmspace_terminate(struct vmspace *vm, int final)
426 lwkt_gettoken(&vm->vm_map.token);
428 KKASSERT((vm->vm_flags & VMSPACE_EXIT1) == 0);
431 * Get rid of most of the resources. Leave the kernel pmap
434 * If the pmap does not contain wired pages we can bulk-delete
435 * the pmap as a performance optimization before removing the
438 * If the pmap contains wired pages we cannot do this
439 * pre-optimization because currently vm_fault_unwire()
440 * expects the pmap pages to exist and will not decrement
441 * p->wire_count if they do not.
444 if (vmspace_pmap(vm)->pm_stats.wired_count) {
445 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS,
446 VM_MAX_USER_ADDRESS);
447 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS,
448 VM_MAX_USER_ADDRESS);
450 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS,
451 VM_MAX_USER_ADDRESS);
452 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS,
453 VM_MAX_USER_ADDRESS);
455 lwkt_reltoken(&vm->vm_map.token);
456 vm->vm_flags |= VMSPACE_EXIT1;
458 KKASSERT((vm->vm_flags & VMSPACE_EXIT1) != 0);
459 KKASSERT((vm->vm_flags & VMSPACE_EXIT2) == 0);
462 * Get rid of remaining basic resources.
464 vm->vm_flags |= VMSPACE_EXIT2;
467 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
468 vm_map_lock(&vm->vm_map);
469 cpu_vmspace_free(vm);
472 * Lock the map, to wait out all other references to it.
473 * Delete all of the mappings and pages they hold, then call
474 * the pmap module to reclaim anything left.
476 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
477 vm->vm_map.max_offset, &count);
478 vm_map_unlock(&vm->vm_map);
479 vm_map_entry_release(count);
481 pmap_release(vmspace_pmap(vm));
482 lwkt_reltoken(&vm->vm_map.token);
483 objcache_put(vmspace_cache, vm);
488 * Swap useage is determined by taking the proportional swap used by
489 * VM objects backing the VM map. To make up for fractional losses,
490 * if the VM object has any swap use at all the associated map entries
491 * count for at least 1 swap page.
496 vmspace_swap_count(struct vmspace *vm)
498 vm_map_t map = &vm->vm_map;
501 vm_offset_t count = 0;
505 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
506 switch(cur->maptype) {
507 case VM_MAPTYPE_NORMAL:
508 case VM_MAPTYPE_VPAGETABLE:
509 if ((object = cur->object.vm_object) == NULL)
511 if (object->swblock_count) {
512 n = (cur->end - cur->start) / PAGE_SIZE;
513 count += object->swblock_count *
514 SWAP_META_PAGES * n / object->size + 1;
527 * Calculate the approximate number of anonymous pages in use by
528 * this vmspace. To make up for fractional losses, we count each
529 * VM object as having at least 1 anonymous page.
534 vmspace_anonymous_count(struct vmspace *vm)
536 vm_map_t map = &vm->vm_map;
539 vm_offset_t count = 0;
542 for (cur = map->header.next; cur != &map->header; cur = cur->next) {
543 switch(cur->maptype) {
544 case VM_MAPTYPE_NORMAL:
545 case VM_MAPTYPE_VPAGETABLE:
546 if ((object = cur->object.vm_object) == NULL)
548 if (object->type != OBJT_DEFAULT &&
549 object->type != OBJT_SWAP) {
552 count += object->resident_page_count;
564 * Initialize an existing vm_map structure such as that in the vmspace
565 * structure. The pmap is initialized elsewhere.
570 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap)
572 map->header.next = map->header.prev = &map->header;
573 RB_INIT(&map->rb_root);
577 map->min_offset = min;
578 map->max_offset = max;
580 map->first_free = &map->header;
581 map->hint = &map->header;
584 lwkt_token_init(&map->token, "vm_map");
585 lockinit(&map->lock, "vm_maplk", (hz + 9) / 10, 0);
589 * Shadow the vm_map_entry's object. This typically needs to be done when
590 * a write fault is taken on an entry which had previously been cloned by
591 * fork(). The shared object (which might be NULL) must become private so
592 * we add a shadow layer above it.
594 * Object allocation for anonymous mappings is defered as long as possible.
595 * When creating a shadow, however, the underlying object must be instantiated
596 * so it can be shared.
598 * If the map segment is governed by a virtual page table then it is
599 * possible to address offsets beyond the mapped area. Just allocate
600 * a maximally sized object for this case.
602 * If addref is non-zero an additional reference is added to the returned
603 * entry. This mechanic exists because the additional reference might have
604 * to be added atomically and not after return to prevent a premature
607 * The vm_map must be exclusively locked.
608 * No other requirements.
612 vm_map_entry_shadow(vm_map_entry_t entry, int addref)
614 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
615 vm_object_shadow(&entry->object.vm_object, &entry->offset,
616 0x7FFFFFFF, addref); /* XXX */
618 vm_object_shadow(&entry->object.vm_object, &entry->offset,
619 atop(entry->end - entry->start), addref);
621 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
625 * Allocate an object for a vm_map_entry.
627 * Object allocation for anonymous mappings is defered as long as possible.
628 * This function is called when we can defer no longer, generally when a map
629 * entry might be split or forked or takes a page fault.
631 * If the map segment is governed by a virtual page table then it is
632 * possible to address offsets beyond the mapped area. Just allocate
633 * a maximally sized object for this case.
635 * The vm_map must be exclusively locked.
636 * No other requirements.
639 vm_map_entry_allocate_object(vm_map_entry_t entry)
643 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
644 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */
646 obj = vm_object_allocate(OBJT_DEFAULT,
647 atop(entry->end - entry->start));
649 entry->object.vm_object = obj;
654 * Set an initial negative count so the first attempt to reserve
655 * space preloads a bunch of vm_map_entry's for this cpu. Also
656 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
657 * map a new page for vm_map_entry structures. SMP systems are
658 * particularly sensitive.
660 * This routine is called in early boot so we cannot just call
661 * vm_map_entry_reserve().
663 * Called from the low level boot code only (for each cpu)
665 * WARNING! Take care not to have too-big a static/BSS structure here
666 * as MAXCPU can be 256+, otherwise the loader's 64MB heap
667 * can get blown out by the kernel plus the initrd image.
670 vm_map_entry_reserve_cpu_init(globaldata_t gd)
672 vm_map_entry_t entry;
676 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2;
677 if (gd->gd_cpuid == 0) {
678 entry = &cpu_map_entry_init_bsp[0];
679 count = MAPENTRYBSP_CACHE;
681 entry = &cpu_map_entry_init_ap[gd->gd_cpuid][0];
682 count = MAPENTRYAP_CACHE;
684 for (i = 0; i < count; ++i, ++entry) {
685 entry->next = gd->gd_vme_base;
686 gd->gd_vme_base = entry;
691 * Reserves vm_map_entry structures so code later on can manipulate
692 * map_entry structures within a locked map without blocking trying
693 * to allocate a new vm_map_entry.
698 vm_map_entry_reserve(int count)
700 struct globaldata *gd = mycpu;
701 vm_map_entry_t entry;
704 * Make sure we have enough structures in gd_vme_base to handle
705 * the reservation request.
707 * The critical section protects access to the per-cpu gd.
710 while (gd->gd_vme_avail < count) {
711 entry = zalloc(mapentzone);
712 entry->next = gd->gd_vme_base;
713 gd->gd_vme_base = entry;
716 gd->gd_vme_avail -= count;
723 * Releases previously reserved vm_map_entry structures that were not
724 * used. If we have too much junk in our per-cpu cache clean some of
730 vm_map_entry_release(int count)
732 struct globaldata *gd = mycpu;
733 vm_map_entry_t entry;
736 gd->gd_vme_avail += count;
737 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) {
738 entry = gd->gd_vme_base;
739 KKASSERT(entry != NULL);
740 gd->gd_vme_base = entry->next;
743 zfree(mapentzone, entry);
750 * Reserve map entry structures for use in kernel_map itself. These
751 * entries have *ALREADY* been reserved on a per-cpu basis when the map
752 * was inited. This function is used by zalloc() to avoid a recursion
753 * when zalloc() itself needs to allocate additional kernel memory.
755 * This function works like the normal reserve but does not load the
756 * vm_map_entry cache (because that would result in an infinite
757 * recursion). Note that gd_vme_avail may go negative. This is expected.
759 * Any caller of this function must be sure to renormalize after
760 * potentially eating entries to ensure that the reserve supply
766 vm_map_entry_kreserve(int count)
768 struct globaldata *gd = mycpu;
771 gd->gd_vme_avail -= count;
773 KASSERT(gd->gd_vme_base != NULL,
774 ("no reserved entries left, gd_vme_avail = %d",
780 * Release previously reserved map entries for kernel_map. We do not
781 * attempt to clean up like the normal release function as this would
782 * cause an unnecessary (but probably not fatal) deep procedure call.
787 vm_map_entry_krelease(int count)
789 struct globaldata *gd = mycpu;
792 gd->gd_vme_avail += count;
797 * Allocates a VM map entry for insertion. No entry fields are filled in.
799 * The entries should have previously been reserved. The reservation count
800 * is tracked in (*countp).
804 static vm_map_entry_t
805 vm_map_entry_create(vm_map_t map, int *countp)
807 struct globaldata *gd = mycpu;
808 vm_map_entry_t entry;
810 KKASSERT(*countp > 0);
813 entry = gd->gd_vme_base;
814 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp));
815 gd->gd_vme_base = entry->next;
822 * Dispose of a vm_map_entry that is no longer being referenced.
827 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp)
829 struct globaldata *gd = mycpu;
831 KKASSERT(map->hint != entry);
832 KKASSERT(map->first_free != entry);
836 entry->next = gd->gd_vme_base;
837 gd->gd_vme_base = entry;
843 * Insert/remove entries from maps.
845 * The related map must be exclusively locked.
846 * The caller must hold map->token
847 * No other requirements.
850 vm_map_entry_link(vm_map_t map,
851 vm_map_entry_t after_where,
852 vm_map_entry_t entry)
854 ASSERT_VM_MAP_LOCKED(map);
857 entry->prev = after_where;
858 entry->next = after_where->next;
859 entry->next->prev = entry;
860 after_where->next = entry;
861 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry))
862 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry);
866 vm_map_entry_unlink(vm_map_t map,
867 vm_map_entry_t entry)
872 ASSERT_VM_MAP_LOCKED(map);
874 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
875 panic("vm_map_entry_unlink: attempt to mess with "
876 "locked entry! %p", entry);
882 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry);
887 * Finds the map entry containing (or immediately preceding) the specified
888 * address in the given map. The entry is returned in (*entry).
890 * The boolean result indicates whether the address is actually contained
893 * The related map must be locked.
894 * No other requirements.
897 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry)
902 ASSERT_VM_MAP_LOCKED(map);
905 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive
906 * the hint code with the red-black lookup meets with system crashes
907 * and lockups. We do not yet know why.
909 * It is possible that the problem is related to the setting
910 * of the hint during map_entry deletion, in the code specified
911 * at the GGG comment later on in this file.
913 * YYY More likely it's because this function can be called with
914 * a shared lock on the map, resulting in map->hint updates possibly
915 * racing. Fixed now but untested.
918 * Quickly check the cached hint, there's a good chance of a match.
922 if (tmp != &map->header) {
923 if (address >= tmp->start && address < tmp->end) {
931 * Locate the record from the top of the tree. 'last' tracks the
932 * closest prior record and is returned if no match is found, which
933 * in binary tree terms means tracking the most recent right-branch
934 * taken. If there is no prior record, &map->header is returned.
937 tmp = RB_ROOT(&map->rb_root);
940 if (address >= tmp->start) {
941 if (address < tmp->end) {
947 tmp = RB_RIGHT(tmp, rb_entry);
949 tmp = RB_LEFT(tmp, rb_entry);
957 * Inserts the given whole VM object into the target map at the specified
958 * address range. The object's size should match that of the address range.
960 * The map must be exclusively locked.
961 * The object must be held.
962 * The caller must have reserved sufficient vm_map_entry structures.
964 * If object is non-NULL, ref count must be bumped by caller prior to
965 * making call to account for the new entry.
968 vm_map_insert(vm_map_t map, int *countp, void *map_object, void *map_aux,
969 vm_ooffset_t offset, vm_offset_t start, vm_offset_t end,
970 vm_maptype_t maptype, vm_subsys_t id,
971 vm_prot_t prot, vm_prot_t max, int cow)
973 vm_map_entry_t new_entry;
974 vm_map_entry_t prev_entry;
975 vm_map_entry_t temp_entry;
976 vm_eflags_t protoeflags;
980 if (maptype == VM_MAPTYPE_UKSMAP)
985 ASSERT_VM_MAP_LOCKED(map);
987 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
990 * Check that the start and end points are not bogus.
992 if ((start < map->min_offset) || (end > map->max_offset) ||
994 return (KERN_INVALID_ADDRESS);
997 * Find the entry prior to the proposed starting address; if it's part
998 * of an existing entry, this range is bogus.
1000 if (vm_map_lookup_entry(map, start, &temp_entry))
1001 return (KERN_NO_SPACE);
1003 prev_entry = temp_entry;
1006 * Assert that the next entry doesn't overlap the end point.
1009 if ((prev_entry->next != &map->header) &&
1010 (prev_entry->next->start < end))
1011 return (KERN_NO_SPACE);
1015 if (cow & MAP_COPY_ON_WRITE)
1016 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY;
1018 if (cow & MAP_NOFAULT) {
1019 protoeflags |= MAP_ENTRY_NOFAULT;
1021 KASSERT(object == NULL,
1022 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
1024 if (cow & MAP_DISABLE_SYNCER)
1025 protoeflags |= MAP_ENTRY_NOSYNC;
1026 if (cow & MAP_DISABLE_COREDUMP)
1027 protoeflags |= MAP_ENTRY_NOCOREDUMP;
1028 if (cow & MAP_IS_STACK)
1029 protoeflags |= MAP_ENTRY_STACK;
1030 if (cow & MAP_IS_KSTACK)
1031 protoeflags |= MAP_ENTRY_KSTACK;
1033 lwkt_gettoken(&map->token);
1037 * When object is non-NULL, it could be shared with another
1038 * process. We have to set or clear OBJ_ONEMAPPING
1041 * NOTE: This flag is only applicable to DEFAULT and SWAP
1042 * objects and will already be clear in other types
1043 * of objects, so a shared object lock is ok for
1046 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
1047 vm_object_clear_flag(object, OBJ_ONEMAPPING);
1050 else if ((prev_entry != &map->header) &&
1051 (prev_entry->eflags == protoeflags) &&
1052 (prev_entry->end == start) &&
1053 (prev_entry->wired_count == 0) &&
1054 (prev_entry->id == id) &&
1055 prev_entry->maptype == maptype &&
1056 maptype == VM_MAPTYPE_NORMAL &&
1057 ((prev_entry->object.vm_object == NULL) ||
1058 vm_object_coalesce(prev_entry->object.vm_object,
1059 OFF_TO_IDX(prev_entry->offset),
1060 (vm_size_t)(prev_entry->end - prev_entry->start),
1061 (vm_size_t)(end - prev_entry->end)))) {
1063 * We were able to extend the object. Determine if we
1064 * can extend the previous map entry to include the
1065 * new range as well.
1067 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
1068 (prev_entry->protection == prot) &&
1069 (prev_entry->max_protection == max)) {
1070 map->size += (end - prev_entry->end);
1071 prev_entry->end = end;
1072 vm_map_simplify_entry(map, prev_entry, countp);
1073 lwkt_reltoken(&map->token);
1074 return (KERN_SUCCESS);
1078 * If we can extend the object but cannot extend the
1079 * map entry, we have to create a new map entry. We
1080 * must bump the ref count on the extended object to
1081 * account for it. object may be NULL.
1083 * XXX if object is NULL should we set offset to 0 here ?
1085 object = prev_entry->object.vm_object;
1086 offset = prev_entry->offset +
1087 (prev_entry->end - prev_entry->start);
1089 vm_object_hold(object);
1090 vm_object_chain_wait(object, 0);
1091 vm_object_reference_locked(object);
1093 map_object = object;
1098 * NOTE: if conditionals fail, object can be NULL here. This occurs
1099 * in things like the buffer map where we manage kva but do not manage
1104 * Create a new entry
1107 new_entry = vm_map_entry_create(map, countp);
1108 new_entry->start = start;
1109 new_entry->end = end;
1112 new_entry->maptype = maptype;
1113 new_entry->eflags = protoeflags;
1114 new_entry->object.map_object = map_object;
1115 new_entry->aux.master_pde = 0; /* in case size is different */
1116 new_entry->aux.map_aux = map_aux;
1117 new_entry->offset = offset;
1119 new_entry->inheritance = VM_INHERIT_DEFAULT;
1120 new_entry->protection = prot;
1121 new_entry->max_protection = max;
1122 new_entry->wired_count = 0;
1125 * Insert the new entry into the list
1128 vm_map_entry_link(map, prev_entry, new_entry);
1129 map->size += new_entry->end - new_entry->start;
1132 * Update the free space hint. Entries cannot overlap.
1133 * An exact comparison is needed to avoid matching
1134 * against the map->header.
1136 if ((map->first_free == prev_entry) &&
1137 (prev_entry->end == new_entry->start)) {
1138 map->first_free = new_entry;
1143 * Temporarily removed to avoid MAP_STACK panic, due to
1144 * MAP_STACK being a huge hack. Will be added back in
1145 * when MAP_STACK (and the user stack mapping) is fixed.
1148 * It may be possible to simplify the entry
1150 vm_map_simplify_entry(map, new_entry, countp);
1154 * Try to pre-populate the page table. Mappings governed by virtual
1155 * page tables cannot be prepopulated without a lot of work, so
1158 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) &&
1159 maptype != VM_MAPTYPE_VPAGETABLE &&
1160 maptype != VM_MAPTYPE_UKSMAP) {
1162 if (vm_map_relock_enable && (cow & MAP_PREFAULT_RELOCK)) {
1164 vm_object_lock_swap();
1165 vm_object_drop(object);
1167 pmap_object_init_pt(map->pmap, start, prot,
1168 object, OFF_TO_IDX(offset), end - start,
1169 cow & MAP_PREFAULT_PARTIAL);
1171 vm_object_hold(object);
1172 vm_object_lock_swap();
1176 vm_object_drop(object);
1178 lwkt_reltoken(&map->token);
1179 return (KERN_SUCCESS);
1183 * Find sufficient space for `length' bytes in the given map, starting at
1184 * `start'. Returns 0 on success, 1 on no space.
1186 * This function will returned an arbitrarily aligned pointer. If no
1187 * particular alignment is required you should pass align as 1. Note that
1188 * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1189 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1192 * 'align' should be a power of 2 but is not required to be.
1194 * The map must be exclusively locked.
1195 * No other requirements.
1198 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1199 vm_size_t align, int flags, vm_offset_t *addr)
1201 vm_map_entry_t entry, next;
1203 vm_offset_t align_mask;
1205 if (start < map->min_offset)
1206 start = map->min_offset;
1207 if (start > map->max_offset)
1211 * If the alignment is not a power of 2 we will have to use
1212 * a mod/division, set align_mask to a special value.
1214 if ((align | (align - 1)) + 1 != (align << 1))
1215 align_mask = (vm_offset_t)-1;
1217 align_mask = align - 1;
1220 * Look for the first possible address; if there's already something
1221 * at this address, we have to start after it.
1223 if (start == map->min_offset) {
1224 if ((entry = map->first_free) != &map->header)
1229 if (vm_map_lookup_entry(map, start, &tmp))
1235 * Look through the rest of the map, trying to fit a new region in the
1236 * gap between existing regions, or after the very last region.
1238 for (;; start = (entry = next)->end) {
1240 * Adjust the proposed start by the requested alignment,
1241 * be sure that we didn't wrap the address.
1243 if (align_mask == (vm_offset_t)-1)
1244 end = roundup(start, align);
1246 end = (start + align_mask) & ~align_mask;
1251 * Find the end of the proposed new region. Be sure we didn't
1252 * go beyond the end of the map, or wrap around the address.
1253 * Then check to see if this is the last entry or if the
1254 * proposed end fits in the gap between this and the next
1257 end = start + length;
1258 if (end > map->max_offset || end < start)
1263 * If the next entry's start address is beyond the desired
1264 * end address we may have found a good entry.
1266 * If the next entry is a stack mapping we do not map into
1267 * the stack's reserved space.
1269 * XXX continue to allow mapping into the stack's reserved
1270 * space if doing a MAP_STACK mapping inside a MAP_STACK
1271 * mapping, for backwards compatibility. But the caller
1272 * really should use MAP_STACK | MAP_TRYFIXED if they
1275 if (next == &map->header)
1277 if (next->start >= end) {
1278 if ((next->eflags & MAP_ENTRY_STACK) == 0)
1280 if (flags & MAP_STACK)
1282 if (next->start - next->aux.avail_ssize >= end)
1289 * Grow the kernel_map if necessary. pmap_growkernel() will panic
1290 * if it fails. The kernel_map is locked and nothing can steal
1291 * our address space if pmap_growkernel() blocks.
1293 * NOTE: This may be unconditionally called for kldload areas on
1294 * x86_64 because these do not bump kernel_vm_end (which would
1295 * fill 128G worth of page tables!). Therefore we must not
1298 if (map == &kernel_map) {
1301 kstop = round_page(start + length);
1302 if (kstop > kernel_vm_end)
1303 pmap_growkernel(start, kstop);
1310 * vm_map_find finds an unallocated region in the target address map with
1311 * the given length and allocates it. The search is defined to be first-fit
1312 * from the specified address; the region found is returned in the same
1315 * If object is non-NULL, ref count must be bumped by caller
1316 * prior to making call to account for the new entry.
1318 * No requirements. This function will lock the map temporarily.
1321 vm_map_find(vm_map_t map, void *map_object, void *map_aux,
1322 vm_ooffset_t offset, vm_offset_t *addr,
1323 vm_size_t length, vm_size_t align, boolean_t fitit,
1324 vm_maptype_t maptype, vm_subsys_t id,
1325 vm_prot_t prot, vm_prot_t max, int cow)
1332 if (maptype == VM_MAPTYPE_UKSMAP)
1335 object = map_object;
1339 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1342 vm_object_hold_shared(object);
1344 if (vm_map_findspace(map, start, length, align, 0, addr)) {
1346 vm_object_drop(object);
1348 vm_map_entry_release(count);
1349 return (KERN_NO_SPACE);
1353 result = vm_map_insert(map, &count, map_object, map_aux,
1354 offset, start, start + length,
1355 maptype, id, prot, max, cow);
1357 vm_object_drop(object);
1359 vm_map_entry_release(count);
1365 * Simplify the given map entry by merging with either neighbor. This
1366 * routine also has the ability to merge with both neighbors.
1368 * This routine guarentees that the passed entry remains valid (though
1369 * possibly extended). When merging, this routine may delete one or
1370 * both neighbors. No action is taken on entries which have their
1371 * in-transition flag set.
1373 * The map must be exclusively locked.
1376 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1378 vm_map_entry_t next, prev;
1379 vm_size_t prevsize, esize;
1381 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1382 ++mycpu->gd_cnt.v_intrans_coll;
1386 if (entry->maptype == VM_MAPTYPE_SUBMAP)
1388 if (entry->maptype == VM_MAPTYPE_UKSMAP)
1392 if (prev != &map->header) {
1393 prevsize = prev->end - prev->start;
1394 if ( (prev->end == entry->start) &&
1395 (prev->maptype == entry->maptype) &&
1396 (prev->object.vm_object == entry->object.vm_object) &&
1397 (!prev->object.vm_object ||
1398 (prev->offset + prevsize == entry->offset)) &&
1399 (prev->eflags == entry->eflags) &&
1400 (prev->protection == entry->protection) &&
1401 (prev->max_protection == entry->max_protection) &&
1402 (prev->inheritance == entry->inheritance) &&
1403 (prev->id == entry->id) &&
1404 (prev->wired_count == entry->wired_count)) {
1405 if (map->first_free == prev)
1406 map->first_free = entry;
1407 if (map->hint == prev)
1409 vm_map_entry_unlink(map, prev);
1410 entry->start = prev->start;
1411 entry->offset = prev->offset;
1412 if (prev->object.vm_object)
1413 vm_object_deallocate(prev->object.vm_object);
1414 vm_map_entry_dispose(map, prev, countp);
1419 if (next != &map->header) {
1420 esize = entry->end - entry->start;
1421 if ((entry->end == next->start) &&
1422 (next->maptype == entry->maptype) &&
1423 (next->object.vm_object == entry->object.vm_object) &&
1424 (!entry->object.vm_object ||
1425 (entry->offset + esize == next->offset)) &&
1426 (next->eflags == entry->eflags) &&
1427 (next->protection == entry->protection) &&
1428 (next->max_protection == entry->max_protection) &&
1429 (next->inheritance == entry->inheritance) &&
1430 (next->id == entry->id) &&
1431 (next->wired_count == entry->wired_count)) {
1432 if (map->first_free == next)
1433 map->first_free = entry;
1434 if (map->hint == next)
1436 vm_map_entry_unlink(map, next);
1437 entry->end = next->end;
1438 if (next->object.vm_object)
1439 vm_object_deallocate(next->object.vm_object);
1440 vm_map_entry_dispose(map, next, countp);
1446 * Asserts that the given entry begins at or after the specified address.
1447 * If necessary, it splits the entry into two.
1449 #define vm_map_clip_start(map, entry, startaddr, countp) \
1451 if (startaddr > entry->start) \
1452 _vm_map_clip_start(map, entry, startaddr, countp); \
1456 * This routine is called only when it is known that the entry must be split.
1458 * The map must be exclusively locked.
1461 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1464 vm_map_entry_t new_entry;
1467 * Split off the front portion -- note that we must insert the new
1468 * entry BEFORE this one, so that this entry has the specified
1472 vm_map_simplify_entry(map, entry, countp);
1475 * If there is no object backing this entry, we might as well create
1476 * one now. If we defer it, an object can get created after the map
1477 * is clipped, and individual objects will be created for the split-up
1478 * map. This is a bit of a hack, but is also about the best place to
1479 * put this improvement.
1481 if (entry->object.vm_object == NULL && !map->system_map) {
1482 vm_map_entry_allocate_object(entry);
1485 new_entry = vm_map_entry_create(map, countp);
1486 *new_entry = *entry;
1488 new_entry->end = start;
1489 entry->offset += (start - entry->start);
1490 entry->start = start;
1492 vm_map_entry_link(map, entry->prev, new_entry);
1494 switch(entry->maptype) {
1495 case VM_MAPTYPE_NORMAL:
1496 case VM_MAPTYPE_VPAGETABLE:
1497 if (new_entry->object.vm_object) {
1498 vm_object_hold(new_entry->object.vm_object);
1499 vm_object_chain_wait(new_entry->object.vm_object, 0);
1500 vm_object_reference_locked(new_entry->object.vm_object);
1501 vm_object_drop(new_entry->object.vm_object);
1510 * Asserts that the given entry ends at or before the specified address.
1511 * If necessary, it splits the entry into two.
1513 * The map must be exclusively locked.
1515 #define vm_map_clip_end(map, entry, endaddr, countp) \
1517 if (endaddr < entry->end) \
1518 _vm_map_clip_end(map, entry, endaddr, countp); \
1522 * This routine is called only when it is known that the entry must be split.
1524 * The map must be exclusively locked.
1527 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1530 vm_map_entry_t new_entry;
1533 * If there is no object backing this entry, we might as well create
1534 * one now. If we defer it, an object can get created after the map
1535 * is clipped, and individual objects will be created for the split-up
1536 * map. This is a bit of a hack, but is also about the best place to
1537 * put this improvement.
1540 if (entry->object.vm_object == NULL && !map->system_map) {
1541 vm_map_entry_allocate_object(entry);
1545 * Create a new entry and insert it AFTER the specified entry
1548 new_entry = vm_map_entry_create(map, countp);
1549 *new_entry = *entry;
1551 new_entry->start = entry->end = end;
1552 new_entry->offset += (end - entry->start);
1554 vm_map_entry_link(map, entry, new_entry);
1556 switch(entry->maptype) {
1557 case VM_MAPTYPE_NORMAL:
1558 case VM_MAPTYPE_VPAGETABLE:
1559 if (new_entry->object.vm_object) {
1560 vm_object_hold(new_entry->object.vm_object);
1561 vm_object_chain_wait(new_entry->object.vm_object, 0);
1562 vm_object_reference_locked(new_entry->object.vm_object);
1563 vm_object_drop(new_entry->object.vm_object);
1572 * Asserts that the starting and ending region addresses fall within the
1573 * valid range for the map.
1575 #define VM_MAP_RANGE_CHECK(map, start, end) \
1577 if (start < vm_map_min(map)) \
1578 start = vm_map_min(map); \
1579 if (end > vm_map_max(map)) \
1580 end = vm_map_max(map); \
1586 * Used to block when an in-transition collison occurs. The map
1587 * is unlocked for the sleep and relocked before the return.
1590 vm_map_transition_wait(vm_map_t map)
1592 tsleep_interlock(map, 0);
1594 tsleep(map, PINTERLOCKED, "vment", 0);
1599 * When we do blocking operations with the map lock held it is
1600 * possible that a clip might have occured on our in-transit entry,
1601 * requiring an adjustment to the entry in our loop. These macros
1602 * help the pageable and clip_range code deal with the case. The
1603 * conditional costs virtually nothing if no clipping has occured.
1606 #define CLIP_CHECK_BACK(entry, save_start) \
1608 while (entry->start != save_start) { \
1609 entry = entry->prev; \
1610 KASSERT(entry != &map->header, ("bad entry clip")); \
1614 #define CLIP_CHECK_FWD(entry, save_end) \
1616 while (entry->end != save_end) { \
1617 entry = entry->next; \
1618 KASSERT(entry != &map->header, ("bad entry clip")); \
1624 * Clip the specified range and return the base entry. The
1625 * range may cover several entries starting at the returned base
1626 * and the first and last entry in the covering sequence will be
1627 * properly clipped to the requested start and end address.
1629 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1632 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1633 * covered by the requested range.
1635 * The map must be exclusively locked on entry and will remain locked
1636 * on return. If no range exists or the range contains holes and you
1637 * specified that no holes were allowed, NULL will be returned. This
1638 * routine may temporarily unlock the map in order avoid a deadlock when
1643 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end,
1644 int *countp, int flags)
1646 vm_map_entry_t start_entry;
1647 vm_map_entry_t entry;
1650 * Locate the entry and effect initial clipping. The in-transition
1651 * case does not occur very often so do not try to optimize it.
1654 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1656 entry = start_entry;
1657 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1658 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1659 ++mycpu->gd_cnt.v_intrans_coll;
1660 ++mycpu->gd_cnt.v_intrans_wait;
1661 vm_map_transition_wait(map);
1663 * entry and/or start_entry may have been clipped while
1664 * we slept, or may have gone away entirely. We have
1665 * to restart from the lookup.
1671 * Since we hold an exclusive map lock we do not have to restart
1672 * after clipping, even though clipping may block in zalloc.
1674 vm_map_clip_start(map, entry, start, countp);
1675 vm_map_clip_end(map, entry, end, countp);
1676 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1679 * Scan entries covered by the range. When working on the next
1680 * entry a restart need only re-loop on the current entry which
1681 * we have already locked, since 'next' may have changed. Also,
1682 * even though entry is safe, it may have been clipped so we
1683 * have to iterate forwards through the clip after sleeping.
1685 while (entry->next != &map->header && entry->next->start < end) {
1686 vm_map_entry_t next = entry->next;
1688 if (flags & MAP_CLIP_NO_HOLES) {
1689 if (next->start > entry->end) {
1690 vm_map_unclip_range(map, start_entry,
1691 start, entry->end, countp, flags);
1696 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1697 vm_offset_t save_end = entry->end;
1698 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1699 ++mycpu->gd_cnt.v_intrans_coll;
1700 ++mycpu->gd_cnt.v_intrans_wait;
1701 vm_map_transition_wait(map);
1704 * clips might have occured while we blocked.
1706 CLIP_CHECK_FWD(entry, save_end);
1707 CLIP_CHECK_BACK(start_entry, start);
1711 * No restart necessary even though clip_end may block, we
1712 * are holding the map lock.
1714 vm_map_clip_end(map, next, end, countp);
1715 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1718 if (flags & MAP_CLIP_NO_HOLES) {
1719 if (entry->end != end) {
1720 vm_map_unclip_range(map, start_entry,
1721 start, entry->end, countp, flags);
1725 return(start_entry);
1729 * Undo the effect of vm_map_clip_range(). You should pass the same
1730 * flags and the same range that you passed to vm_map_clip_range().
1731 * This code will clear the in-transition flag on the entries and
1732 * wake up anyone waiting. This code will also simplify the sequence
1733 * and attempt to merge it with entries before and after the sequence.
1735 * The map must be locked on entry and will remain locked on return.
1737 * Note that you should also pass the start_entry returned by
1738 * vm_map_clip_range(). However, if you block between the two calls
1739 * with the map unlocked please be aware that the start_entry may
1740 * have been clipped and you may need to scan it backwards to find
1741 * the entry corresponding with the original start address. You are
1742 * responsible for this, vm_map_unclip_range() expects the correct
1743 * start_entry to be passed to it and will KASSERT otherwise.
1747 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1748 vm_offset_t start, vm_offset_t end,
1749 int *countp, int flags)
1751 vm_map_entry_t entry;
1753 entry = start_entry;
1755 KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1756 while (entry != &map->header && entry->start < end) {
1757 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1758 ("in-transition flag not set during unclip on: %p",
1760 KASSERT(entry->end <= end,
1761 ("unclip_range: tail wasn't clipped"));
1762 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1763 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1764 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1767 entry = entry->next;
1771 * Simplification does not block so there is no restart case.
1773 entry = start_entry;
1774 while (entry != &map->header && entry->start < end) {
1775 vm_map_simplify_entry(map, entry, countp);
1776 entry = entry->next;
1781 * Mark the given range as handled by a subordinate map.
1783 * This range must have been created with vm_map_find(), and no other
1784 * operations may have been performed on this range prior to calling
1787 * Submappings cannot be removed.
1792 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1794 vm_map_entry_t entry;
1795 int result = KERN_INVALID_ARGUMENT;
1798 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1801 VM_MAP_RANGE_CHECK(map, start, end);
1803 if (vm_map_lookup_entry(map, start, &entry)) {
1804 vm_map_clip_start(map, entry, start, &count);
1806 entry = entry->next;
1809 vm_map_clip_end(map, entry, end, &count);
1811 if ((entry->start == start) && (entry->end == end) &&
1812 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1813 (entry->object.vm_object == NULL)) {
1814 entry->object.sub_map = submap;
1815 entry->maptype = VM_MAPTYPE_SUBMAP;
1816 result = KERN_SUCCESS;
1819 vm_map_entry_release(count);
1825 * Sets the protection of the specified address region in the target map.
1826 * If "set_max" is specified, the maximum protection is to be set;
1827 * otherwise, only the current protection is affected.
1829 * The protection is not applicable to submaps, but is applicable to normal
1830 * maps and maps governed by virtual page tables. For example, when operating
1831 * on a virtual page table our protection basically controls how COW occurs
1832 * on the backing object, whereas the virtual page table abstraction itself
1833 * is an abstraction for userland.
1838 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1839 vm_prot_t new_prot, boolean_t set_max)
1841 vm_map_entry_t current;
1842 vm_map_entry_t entry;
1845 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1848 VM_MAP_RANGE_CHECK(map, start, end);
1850 if (vm_map_lookup_entry(map, start, &entry)) {
1851 vm_map_clip_start(map, entry, start, &count);
1853 entry = entry->next;
1857 * Make a first pass to check for protection violations.
1860 while ((current != &map->header) && (current->start < end)) {
1861 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1863 vm_map_entry_release(count);
1864 return (KERN_INVALID_ARGUMENT);
1866 if ((new_prot & current->max_protection) != new_prot) {
1868 vm_map_entry_release(count);
1869 return (KERN_PROTECTION_FAILURE);
1871 current = current->next;
1875 * Go back and fix up protections. [Note that clipping is not
1876 * necessary the second time.]
1880 while ((current != &map->header) && (current->start < end)) {
1883 vm_map_clip_end(map, current, end, &count);
1885 old_prot = current->protection;
1887 current->protection =
1888 (current->max_protection = new_prot) &
1891 current->protection = new_prot;
1895 * Update physical map if necessary. Worry about copy-on-write
1896 * here -- CHECK THIS XXX
1899 if (current->protection != old_prot) {
1900 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1903 pmap_protect(map->pmap, current->start,
1905 current->protection & MASK(current));
1909 vm_map_simplify_entry(map, current, &count);
1911 current = current->next;
1915 vm_map_entry_release(count);
1916 return (KERN_SUCCESS);
1920 * This routine traverses a processes map handling the madvise
1921 * system call. Advisories are classified as either those effecting
1922 * the vm_map_entry structure, or those effecting the underlying
1925 * The <value> argument is used for extended madvise calls.
1930 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1931 int behav, off_t value)
1933 vm_map_entry_t current, entry;
1939 * Some madvise calls directly modify the vm_map_entry, in which case
1940 * we need to use an exclusive lock on the map and we need to perform
1941 * various clipping operations. Otherwise we only need a read-lock
1945 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1949 case MADV_SEQUENTIAL:
1963 vm_map_lock_read(map);
1966 vm_map_entry_release(count);
1971 * Locate starting entry and clip if necessary.
1974 VM_MAP_RANGE_CHECK(map, start, end);
1976 if (vm_map_lookup_entry(map, start, &entry)) {
1978 vm_map_clip_start(map, entry, start, &count);
1980 entry = entry->next;
1985 * madvise behaviors that are implemented in the vm_map_entry.
1987 * We clip the vm_map_entry so that behavioral changes are
1988 * limited to the specified address range.
1990 for (current = entry;
1991 (current != &map->header) && (current->start < end);
1992 current = current->next
1994 if (current->maptype == VM_MAPTYPE_SUBMAP)
1997 vm_map_clip_end(map, current, end, &count);
2001 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
2003 case MADV_SEQUENTIAL:
2004 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
2007 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
2010 current->eflags |= MAP_ENTRY_NOSYNC;
2013 current->eflags &= ~MAP_ENTRY_NOSYNC;
2016 current->eflags |= MAP_ENTRY_NOCOREDUMP;
2019 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
2023 * Set the page directory page for a map
2024 * governed by a virtual page table. Mark
2025 * the entry as being governed by a virtual
2026 * page table if it is not.
2028 * XXX the page directory page is stored
2029 * in the avail_ssize field if the map_entry.
2031 * XXX the map simplification code does not
2032 * compare this field so weird things may
2033 * happen if you do not apply this function
2034 * to the entire mapping governed by the
2035 * virtual page table.
2037 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
2041 current->aux.master_pde = value;
2042 pmap_remove(map->pmap,
2043 current->start, current->end);
2047 * Invalidate the related pmap entries, used
2048 * to flush portions of the real kernel's
2049 * pmap when the caller has removed or
2050 * modified existing mappings in a virtual
2053 * (exclusive locked map version)
2055 pmap_remove(map->pmap,
2056 current->start, current->end);
2062 vm_map_simplify_entry(map, current, &count);
2070 * madvise behaviors that are implemented in the underlying
2073 * Since we don't clip the vm_map_entry, we have to clip
2074 * the vm_object pindex and count.
2076 * NOTE! These functions are only supported on normal maps,
2077 * except MADV_INVAL which is also supported on
2078 * virtual page tables.
2080 for (current = entry;
2081 (current != &map->header) && (current->start < end);
2082 current = current->next
2084 vm_offset_t useStart;
2086 if (current->maptype != VM_MAPTYPE_NORMAL &&
2087 (current->maptype != VM_MAPTYPE_VPAGETABLE ||
2088 behav != MADV_INVAL)) {
2092 pindex = OFF_TO_IDX(current->offset);
2093 delta = atop(current->end - current->start);
2094 useStart = current->start;
2096 if (current->start < start) {
2097 pindex += atop(start - current->start);
2098 delta -= atop(start - current->start);
2101 if (current->end > end)
2102 delta -= atop(current->end - end);
2104 if ((vm_spindex_t)delta <= 0)
2107 if (behav == MADV_INVAL) {
2109 * Invalidate the related pmap entries, used
2110 * to flush portions of the real kernel's
2111 * pmap when the caller has removed or
2112 * modified existing mappings in a virtual
2115 * (shared locked map version)
2117 KASSERT(useStart >= VM_MIN_USER_ADDRESS &&
2118 useStart + ptoa(delta) <=
2119 VM_MAX_USER_ADDRESS,
2120 ("Bad range %016jx-%016jx (%016jx)",
2121 useStart, useStart + ptoa(delta),
2123 pmap_remove(map->pmap,
2125 useStart + ptoa(delta));
2127 vm_object_madvise(current->object.vm_object,
2128 pindex, delta, behav);
2132 * Try to populate the page table. Mappings governed
2133 * by virtual page tables cannot be pre-populated
2134 * without a lot of work so don't try.
2136 if (behav == MADV_WILLNEED &&
2137 current->maptype != VM_MAPTYPE_VPAGETABLE) {
2138 pmap_object_init_pt(
2141 current->protection,
2142 current->object.vm_object,
2144 (count << PAGE_SHIFT),
2145 MAP_PREFAULT_MADVISE
2149 vm_map_unlock_read(map);
2151 vm_map_entry_release(count);
2157 * Sets the inheritance of the specified address range in the target map.
2158 * Inheritance affects how the map will be shared with child maps at the
2159 * time of vm_map_fork.
2162 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
2163 vm_inherit_t new_inheritance)
2165 vm_map_entry_t entry;
2166 vm_map_entry_t temp_entry;
2169 switch (new_inheritance) {
2170 case VM_INHERIT_NONE:
2171 case VM_INHERIT_COPY:
2172 case VM_INHERIT_SHARE:
2175 return (KERN_INVALID_ARGUMENT);
2178 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2181 VM_MAP_RANGE_CHECK(map, start, end);
2183 if (vm_map_lookup_entry(map, start, &temp_entry)) {
2185 vm_map_clip_start(map, entry, start, &count);
2187 entry = temp_entry->next;
2189 while ((entry != &map->header) && (entry->start < end)) {
2190 vm_map_clip_end(map, entry, end, &count);
2192 entry->inheritance = new_inheritance;
2194 vm_map_simplify_entry(map, entry, &count);
2196 entry = entry->next;
2199 vm_map_entry_release(count);
2200 return (KERN_SUCCESS);
2204 * Implement the semantics of mlock
2207 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2208 boolean_t new_pageable)
2210 vm_map_entry_t entry;
2211 vm_map_entry_t start_entry;
2213 int rv = KERN_SUCCESS;
2216 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2218 VM_MAP_RANGE_CHECK(map, start, real_end);
2221 start_entry = vm_map_clip_range(map, start, end, &count,
2223 if (start_entry == NULL) {
2225 vm_map_entry_release(count);
2226 return (KERN_INVALID_ADDRESS);
2229 if (new_pageable == 0) {
2230 entry = start_entry;
2231 while ((entry != &map->header) && (entry->start < end)) {
2232 vm_offset_t save_start;
2233 vm_offset_t save_end;
2236 * Already user wired or hard wired (trivial cases)
2238 if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2239 entry = entry->next;
2242 if (entry->wired_count != 0) {
2243 entry->wired_count++;
2244 entry->eflags |= MAP_ENTRY_USER_WIRED;
2245 entry = entry->next;
2250 * A new wiring requires instantiation of appropriate
2251 * management structures and the faulting in of the
2254 if (entry->maptype == VM_MAPTYPE_NORMAL ||
2255 entry->maptype == VM_MAPTYPE_VPAGETABLE) {
2256 int copyflag = entry->eflags &
2257 MAP_ENTRY_NEEDS_COPY;
2258 if (copyflag && ((entry->protection &
2259 VM_PROT_WRITE) != 0)) {
2260 vm_map_entry_shadow(entry, 0);
2261 } else if (entry->object.vm_object == NULL &&
2263 vm_map_entry_allocate_object(entry);
2266 entry->wired_count++;
2267 entry->eflags |= MAP_ENTRY_USER_WIRED;
2270 * Now fault in the area. Note that vm_fault_wire()
2271 * may release the map lock temporarily, it will be
2272 * relocked on return. The in-transition
2273 * flag protects the entries.
2275 save_start = entry->start;
2276 save_end = entry->end;
2277 rv = vm_fault_wire(map, entry, TRUE, 0);
2279 CLIP_CHECK_BACK(entry, save_start);
2281 KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2282 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2283 entry->wired_count = 0;
2284 if (entry->end == save_end)
2286 entry = entry->next;
2287 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2289 end = save_start; /* unwire the rest */
2293 * note that even though the entry might have been
2294 * clipped, the USER_WIRED flag we set prevents
2295 * duplication so we do not have to do a
2298 entry = entry->next;
2302 * If we failed fall through to the unwiring section to
2303 * unwire what we had wired so far. 'end' has already
2310 * start_entry might have been clipped if we unlocked the
2311 * map and blocked. No matter how clipped it has gotten
2312 * there should be a fragment that is on our start boundary.
2314 CLIP_CHECK_BACK(start_entry, start);
2318 * Deal with the unwiring case.
2322 * This is the unwiring case. We must first ensure that the
2323 * range to be unwired is really wired down. We know there
2326 entry = start_entry;
2327 while ((entry != &map->header) && (entry->start < end)) {
2328 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2329 rv = KERN_INVALID_ARGUMENT;
2332 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2333 entry = entry->next;
2337 * Now decrement the wiring count for each region. If a region
2338 * becomes completely unwired, unwire its physical pages and
2342 * The map entries are processed in a loop, checking to
2343 * make sure the entry is wired and asserting it has a wired
2344 * count. However, another loop was inserted more-or-less in
2345 * the middle of the unwiring path. This loop picks up the
2346 * "entry" loop variable from the first loop without first
2347 * setting it to start_entry. Naturally, the secound loop
2348 * is never entered and the pages backing the entries are
2349 * never unwired. This can lead to a leak of wired pages.
2351 entry = start_entry;
2352 while ((entry != &map->header) && (entry->start < end)) {
2353 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2354 ("expected USER_WIRED on entry %p", entry));
2355 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2356 entry->wired_count--;
2357 if (entry->wired_count == 0)
2358 vm_fault_unwire(map, entry);
2359 entry = entry->next;
2363 vm_map_unclip_range(map, start_entry, start, real_end, &count,
2367 vm_map_entry_release(count);
2372 * Sets the pageability of the specified address range in the target map.
2373 * Regions specified as not pageable require locked-down physical
2374 * memory and physical page maps.
2376 * The map must not be locked, but a reference must remain to the map
2377 * throughout the call.
2379 * This function may be called via the zalloc path and must properly
2380 * reserve map entries for kernel_map.
2385 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2387 vm_map_entry_t entry;
2388 vm_map_entry_t start_entry;
2390 int rv = KERN_SUCCESS;
2393 if (kmflags & KM_KRESERVE)
2394 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2396 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2398 VM_MAP_RANGE_CHECK(map, start, real_end);
2401 start_entry = vm_map_clip_range(map, start, end, &count,
2403 if (start_entry == NULL) {
2405 rv = KERN_INVALID_ADDRESS;
2408 if ((kmflags & KM_PAGEABLE) == 0) {
2412 * 1. Holding the write lock, we create any shadow or zero-fill
2413 * objects that need to be created. Then we clip each map
2414 * entry to the region to be wired and increment its wiring
2415 * count. We create objects before clipping the map entries
2416 * to avoid object proliferation.
2418 * 2. We downgrade to a read lock, and call vm_fault_wire to
2419 * fault in the pages for any newly wired area (wired_count is
2422 * Downgrading to a read lock for vm_fault_wire avoids a
2423 * possible deadlock with another process that may have faulted
2424 * on one of the pages to be wired (it would mark the page busy,
2425 * blocking us, then in turn block on the map lock that we
2426 * hold). Because of problems in the recursive lock package,
2427 * we cannot upgrade to a write lock in vm_map_lookup. Thus,
2428 * any actions that require the write lock must be done
2429 * beforehand. Because we keep the read lock on the map, the
2430 * copy-on-write status of the entries we modify here cannot
2433 entry = start_entry;
2434 while ((entry != &map->header) && (entry->start < end)) {
2436 * Trivial case if the entry is already wired
2438 if (entry->wired_count) {
2439 entry->wired_count++;
2440 entry = entry->next;
2445 * The entry is being newly wired, we have to setup
2446 * appropriate management structures. A shadow
2447 * object is required for a copy-on-write region,
2448 * or a normal object for a zero-fill region. We
2449 * do not have to do this for entries that point to sub
2450 * maps because we won't hold the lock on the sub map.
2452 if (entry->maptype == VM_MAPTYPE_NORMAL ||
2453 entry->maptype == VM_MAPTYPE_VPAGETABLE) {
2454 int copyflag = entry->eflags &
2455 MAP_ENTRY_NEEDS_COPY;
2456 if (copyflag && ((entry->protection &
2457 VM_PROT_WRITE) != 0)) {
2458 vm_map_entry_shadow(entry, 0);
2459 } else if (entry->object.vm_object == NULL &&
2461 vm_map_entry_allocate_object(entry);
2465 entry->wired_count++;
2466 entry = entry->next;
2474 * HACK HACK HACK HACK
2476 * vm_fault_wire() temporarily unlocks the map to avoid
2477 * deadlocks. The in-transition flag from vm_map_clip_range
2478 * call should protect us from changes while the map is
2481 * NOTE: Previously this comment stated that clipping might
2482 * still occur while the entry is unlocked, but from
2483 * what I can tell it actually cannot.
2485 * It is unclear whether the CLIP_CHECK_*() calls
2486 * are still needed but we keep them in anyway.
2488 * HACK HACK HACK HACK
2491 entry = start_entry;
2492 while (entry != &map->header && entry->start < end) {
2494 * If vm_fault_wire fails for any page we need to undo
2495 * what has been done. We decrement the wiring count
2496 * for those pages which have not yet been wired (now)
2497 * and unwire those that have (later).
2499 vm_offset_t save_start = entry->start;
2500 vm_offset_t save_end = entry->end;
2502 if (entry->wired_count == 1)
2503 rv = vm_fault_wire(map, entry, FALSE, kmflags);
2505 CLIP_CHECK_BACK(entry, save_start);
2507 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2508 entry->wired_count = 0;
2509 if (entry->end == save_end)
2511 entry = entry->next;
2512 KASSERT(entry != &map->header, ("bad entry clip during backout"));
2517 CLIP_CHECK_FWD(entry, save_end);
2518 entry = entry->next;
2522 * If a failure occured undo everything by falling through
2523 * to the unwiring code. 'end' has already been adjusted
2527 kmflags |= KM_PAGEABLE;
2530 * start_entry is still IN_TRANSITION but may have been
2531 * clipped since vm_fault_wire() unlocks and relocks the
2532 * map. No matter how clipped it has gotten there should
2533 * be a fragment that is on our start boundary.
2535 CLIP_CHECK_BACK(start_entry, start);
2538 if (kmflags & KM_PAGEABLE) {
2540 * This is the unwiring case. We must first ensure that the
2541 * range to be unwired is really wired down. We know there
2544 entry = start_entry;
2545 while ((entry != &map->header) && (entry->start < end)) {
2546 if (entry->wired_count == 0) {
2547 rv = KERN_INVALID_ARGUMENT;
2550 entry = entry->next;
2554 * Now decrement the wiring count for each region. If a region
2555 * becomes completely unwired, unwire its physical pages and
2558 entry = start_entry;
2559 while ((entry != &map->header) && (entry->start < end)) {
2560 entry->wired_count--;
2561 if (entry->wired_count == 0)
2562 vm_fault_unwire(map, entry);
2563 entry = entry->next;
2567 vm_map_unclip_range(map, start_entry, start, real_end,
2568 &count, MAP_CLIP_NO_HOLES);
2572 if (kmflags & KM_KRESERVE)
2573 vm_map_entry_krelease(count);
2575 vm_map_entry_release(count);
2580 * Mark a newly allocated address range as wired but do not fault in
2581 * the pages. The caller is expected to load the pages into the object.
2583 * The map must be locked on entry and will remain locked on return.
2584 * No other requirements.
2587 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2590 vm_map_entry_t scan;
2591 vm_map_entry_t entry;
2593 entry = vm_map_clip_range(map, addr, addr + size,
2594 countp, MAP_CLIP_NO_HOLES);
2596 scan != &map->header && scan->start < addr + size;
2597 scan = scan->next) {
2598 KKASSERT(scan->wired_count == 0);
2599 scan->wired_count = 1;
2601 vm_map_unclip_range(map, entry, addr, addr + size,
2602 countp, MAP_CLIP_NO_HOLES);
2606 * Push any dirty cached pages in the address range to their pager.
2607 * If syncio is TRUE, dirty pages are written synchronously.
2608 * If invalidate is TRUE, any cached pages are freed as well.
2610 * This routine is called by sys_msync()
2612 * Returns an error if any part of the specified range is not mapped.
2617 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2618 boolean_t syncio, boolean_t invalidate)
2620 vm_map_entry_t current;
2621 vm_map_entry_t entry;
2625 vm_ooffset_t offset;
2627 vm_map_lock_read(map);
2628 VM_MAP_RANGE_CHECK(map, start, end);
2629 if (!vm_map_lookup_entry(map, start, &entry)) {
2630 vm_map_unlock_read(map);
2631 return (KERN_INVALID_ADDRESS);
2633 lwkt_gettoken(&map->token);
2636 * Make a first pass to check for holes.
2638 for (current = entry; current->start < end; current = current->next) {
2639 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2640 lwkt_reltoken(&map->token);
2641 vm_map_unlock_read(map);
2642 return (KERN_INVALID_ARGUMENT);
2644 if (end > current->end &&
2645 (current->next == &map->header ||
2646 current->end != current->next->start)) {
2647 lwkt_reltoken(&map->token);
2648 vm_map_unlock_read(map);
2649 return (KERN_INVALID_ADDRESS);
2654 pmap_remove(vm_map_pmap(map), start, end);
2657 * Make a second pass, cleaning/uncaching pages from the indicated
2660 for (current = entry; current->start < end; current = current->next) {
2661 offset = current->offset + (start - current->start);
2662 size = (end <= current->end ? end : current->end) - start;
2664 switch(current->maptype) {
2665 case VM_MAPTYPE_SUBMAP:
2668 vm_map_entry_t tentry;
2671 smap = current->object.sub_map;
2672 vm_map_lock_read(smap);
2673 vm_map_lookup_entry(smap, offset, &tentry);
2674 tsize = tentry->end - offset;
2677 object = tentry->object.vm_object;
2678 offset = tentry->offset + (offset - tentry->start);
2679 vm_map_unlock_read(smap);
2682 case VM_MAPTYPE_NORMAL:
2683 case VM_MAPTYPE_VPAGETABLE:
2684 object = current->object.vm_object;
2692 vm_object_hold(object);
2695 * Note that there is absolutely no sense in writing out
2696 * anonymous objects, so we track down the vnode object
2698 * We invalidate (remove) all pages from the address space
2699 * anyway, for semantic correctness.
2701 * note: certain anonymous maps, such as MAP_NOSYNC maps,
2702 * may start out with a NULL object.
2704 while (object && (tobj = object->backing_object) != NULL) {
2705 vm_object_hold(tobj);
2706 if (tobj == object->backing_object) {
2707 vm_object_lock_swap();
2708 offset += object->backing_object_offset;
2709 vm_object_drop(object);
2711 if (object->size < OFF_TO_IDX(offset + size))
2712 size = IDX_TO_OFF(object->size) -
2716 vm_object_drop(tobj);
2718 if (object && (object->type == OBJT_VNODE) &&
2719 (current->protection & VM_PROT_WRITE) &&
2720 (object->flags & OBJ_NOMSYNC) == 0) {
2722 * Flush pages if writing is allowed, invalidate them
2723 * if invalidation requested. Pages undergoing I/O
2724 * will be ignored by vm_object_page_remove().
2726 * We cannot lock the vnode and then wait for paging
2727 * to complete without deadlocking against vm_fault.
2728 * Instead we simply call vm_object_page_remove() and
2729 * allow it to block internally on a page-by-page
2730 * basis when it encounters pages undergoing async
2735 /* no chain wait needed for vnode objects */
2736 vm_object_reference_locked(object);
2737 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2738 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2739 flags |= invalidate ? OBJPC_INVAL : 0;
2742 * When operating on a virtual page table just
2743 * flush the whole object. XXX we probably ought
2746 switch(current->maptype) {
2747 case VM_MAPTYPE_NORMAL:
2748 vm_object_page_clean(object,
2750 OFF_TO_IDX(offset + size + PAGE_MASK),
2753 case VM_MAPTYPE_VPAGETABLE:
2754 vm_object_page_clean(object, 0, 0, flags);
2757 vn_unlock(((struct vnode *)object->handle));
2758 vm_object_deallocate_locked(object);
2760 if (object && invalidate &&
2761 ((object->type == OBJT_VNODE) ||
2762 (object->type == OBJT_DEVICE) ||
2763 (object->type == OBJT_MGTDEVICE))) {
2765 ((object->type == OBJT_DEVICE) ||
2766 (object->type == OBJT_MGTDEVICE)) ? FALSE : TRUE;
2767 /* no chain wait needed for vnode/device objects */
2768 vm_object_reference_locked(object);
2769 switch(current->maptype) {
2770 case VM_MAPTYPE_NORMAL:
2771 vm_object_page_remove(object,
2773 OFF_TO_IDX(offset + size + PAGE_MASK),
2776 case VM_MAPTYPE_VPAGETABLE:
2777 vm_object_page_remove(object, 0, 0, clean_only);
2780 vm_object_deallocate_locked(object);
2784 vm_object_drop(object);
2787 lwkt_reltoken(&map->token);
2788 vm_map_unlock_read(map);
2790 return (KERN_SUCCESS);
2794 * Make the region specified by this entry pageable.
2796 * The vm_map must be exclusively locked.
2799 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2801 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2802 entry->wired_count = 0;
2803 vm_fault_unwire(map, entry);
2807 * Deallocate the given entry from the target map.
2809 * The vm_map must be exclusively locked.
2812 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2814 vm_map_entry_unlink(map, entry);
2815 map->size -= entry->end - entry->start;
2817 switch(entry->maptype) {
2818 case VM_MAPTYPE_NORMAL:
2819 case VM_MAPTYPE_VPAGETABLE:
2820 case VM_MAPTYPE_SUBMAP:
2821 vm_object_deallocate(entry->object.vm_object);
2823 case VM_MAPTYPE_UKSMAP:
2830 vm_map_entry_dispose(map, entry, countp);
2834 * Deallocates the given address range from the target map.
2836 * The vm_map must be exclusively locked.
2839 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2842 vm_map_entry_t entry;
2843 vm_map_entry_t first_entry;
2845 ASSERT_VM_MAP_LOCKED(map);
2846 lwkt_gettoken(&map->token);
2849 * Find the start of the region, and clip it. Set entry to point
2850 * at the first record containing the requested address or, if no
2851 * such record exists, the next record with a greater address. The
2852 * loop will run from this point until a record beyond the termination
2853 * address is encountered.
2855 * map->hint must be adjusted to not point to anything we delete,
2856 * so set it to the entry prior to the one being deleted.
2858 * GGG see other GGG comment.
2860 if (vm_map_lookup_entry(map, start, &first_entry)) {
2861 entry = first_entry;
2862 vm_map_clip_start(map, entry, start, countp);
2863 map->hint = entry->prev; /* possible problem XXX */
2865 map->hint = first_entry; /* possible problem XXX */
2866 entry = first_entry->next;
2870 * If a hole opens up prior to the current first_free then
2871 * adjust first_free. As with map->hint, map->first_free
2872 * cannot be left set to anything we might delete.
2874 if (entry == &map->header) {
2875 map->first_free = &map->header;
2876 } else if (map->first_free->start >= start) {
2877 map->first_free = entry->prev;
2881 * Step through all entries in this region
2883 while ((entry != &map->header) && (entry->start < end)) {
2884 vm_map_entry_t next;
2886 vm_pindex_t offidxstart, offidxend, count;
2889 * If we hit an in-transition entry we have to sleep and
2890 * retry. It's easier (and not really slower) to just retry
2891 * since this case occurs so rarely and the hint is already
2892 * pointing at the right place. We have to reset the
2893 * start offset so as not to accidently delete an entry
2894 * another process just created in vacated space.
2896 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2897 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2898 start = entry->start;
2899 ++mycpu->gd_cnt.v_intrans_coll;
2900 ++mycpu->gd_cnt.v_intrans_wait;
2901 vm_map_transition_wait(map);
2904 vm_map_clip_end(map, entry, end, countp);
2910 offidxstart = OFF_TO_IDX(entry->offset);
2911 count = OFF_TO_IDX(e - s);
2913 switch(entry->maptype) {
2914 case VM_MAPTYPE_NORMAL:
2915 case VM_MAPTYPE_VPAGETABLE:
2916 case VM_MAPTYPE_SUBMAP:
2917 object = entry->object.vm_object;
2925 * Unwire before removing addresses from the pmap; otherwise,
2926 * unwiring will put the entries back in the pmap.
2928 if (entry->wired_count != 0)
2929 vm_map_entry_unwire(map, entry);
2931 offidxend = offidxstart + count;
2933 if (object == &kernel_object) {
2934 vm_object_hold(object);
2935 vm_object_page_remove(object, offidxstart,
2937 vm_object_drop(object);
2938 } else if (object && object->type != OBJT_DEFAULT &&
2939 object->type != OBJT_SWAP) {
2941 * vnode object routines cannot be chain-locked,
2942 * but since we aren't removing pages from the
2943 * object here we can use a shared hold.
2945 vm_object_hold_shared(object);
2946 pmap_remove(map->pmap, s, e);
2947 vm_object_drop(object);
2948 } else if (object) {
2949 vm_object_hold(object);
2950 vm_object_chain_acquire(object, 0);
2951 pmap_remove(map->pmap, s, e);
2953 if (object != NULL &&
2954 object->ref_count != 1 &&
2955 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2957 (object->type == OBJT_DEFAULT ||
2958 object->type == OBJT_SWAP)) {
2959 vm_object_collapse(object, NULL);
2960 vm_object_page_remove(object, offidxstart,
2962 if (object->type == OBJT_SWAP) {
2963 swap_pager_freespace(object,
2967 if (offidxend >= object->size &&
2968 offidxstart < object->size) {
2969 object->size = offidxstart;
2972 vm_object_chain_release(object);
2973 vm_object_drop(object);
2974 } else if (entry->maptype == VM_MAPTYPE_UKSMAP) {
2975 pmap_remove(map->pmap, s, e);
2979 * Delete the entry (which may delete the object) only after
2980 * removing all pmap entries pointing to its pages.
2981 * (Otherwise, its page frames may be reallocated, and any
2982 * modify bits will be set in the wrong object!)
2984 vm_map_entry_delete(map, entry, countp);
2987 lwkt_reltoken(&map->token);
2988 return (KERN_SUCCESS);
2992 * Remove the given address range from the target map.
2993 * This is the exported form of vm_map_delete.
2998 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
3003 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3005 VM_MAP_RANGE_CHECK(map, start, end);
3006 result = vm_map_delete(map, start, end, &count);
3008 vm_map_entry_release(count);
3014 * Assert that the target map allows the specified privilege on the
3015 * entire address region given. The entire region must be allocated.
3017 * The caller must specify whether the vm_map is already locked or not.
3020 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
3021 vm_prot_t protection, boolean_t have_lock)
3023 vm_map_entry_t entry;
3024 vm_map_entry_t tmp_entry;
3027 if (have_lock == FALSE)
3028 vm_map_lock_read(map);
3030 if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
3031 if (have_lock == FALSE)
3032 vm_map_unlock_read(map);
3038 while (start < end) {
3039 if (entry == &map->header) {
3047 if (start < entry->start) {
3052 * Check protection associated with entry.
3055 if ((entry->protection & protection) != protection) {
3059 /* go to next entry */
3062 entry = entry->next;
3064 if (have_lock == FALSE)
3065 vm_map_unlock_read(map);
3070 * If appropriate this function shadows the original object with a new object
3071 * and moves the VM pages from the original object to the new object.
3072 * The original object will also be collapsed, if possible.
3074 * We can only do this for normal memory objects with a single mapping, and
3075 * it only makes sense to do it if there are 2 or more refs on the original
3076 * object. i.e. typically a memory object that has been extended into
3077 * multiple vm_map_entry's with non-overlapping ranges.
3079 * This makes it easier to remove unused pages and keeps object inheritance
3080 * from being a negative impact on memory usage.
3082 * On return the (possibly new) entry->object.vm_object will have an
3083 * additional ref on it for the caller to dispose of (usually by cloning
3084 * the vm_map_entry). The additional ref had to be done in this routine
3085 * to avoid racing a collapse. The object's ONEMAPPING flag will also be
3088 * The vm_map must be locked and its token held.
3091 vm_map_split(vm_map_entry_t entry)
3094 vm_object_t oobject, nobject, bobject;
3097 vm_pindex_t offidxstart, offidxend, idx;
3099 vm_ooffset_t offset;
3103 * Optimize away object locks for vnode objects. Important exit/exec
3106 * OBJ_ONEMAPPING doesn't apply to vnode objects but clear the flag
3109 oobject = entry->object.vm_object;
3110 if (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) {
3111 vm_object_reference_quick(oobject);
3112 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3117 * Setup. Chain lock the original object throughout the entire
3118 * routine to prevent new page faults from occuring.
3120 * XXX can madvise WILLNEED interfere with us too?
3122 vm_object_hold(oobject);
3123 vm_object_chain_acquire(oobject, 0);
3126 * Original object cannot be split? Might have also changed state.
3128 if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT &&
3129 oobject->type != OBJT_SWAP)) {
3130 vm_object_chain_release(oobject);
3131 vm_object_reference_locked(oobject);
3132 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3133 vm_object_drop(oobject);
3138 * Collapse original object with its backing store as an
3139 * optimization to reduce chain lengths when possible.
3141 * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's
3142 * for oobject, so there's no point collapsing it.
3144 * Then re-check whether the object can be split.
3146 vm_object_collapse(oobject, NULL);
3148 if (oobject->ref_count <= 1 ||
3149 (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) ||
3150 (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) {
3151 vm_object_chain_release(oobject);
3152 vm_object_reference_locked(oobject);
3153 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3154 vm_object_drop(oobject);
3159 * Acquire the chain lock on the backing object.
3161 * Give bobject an additional ref count for when it will be shadowed
3165 if ((bobject = oobject->backing_object) != NULL) {
3166 if (bobject->type != OBJT_VNODE) {
3168 vm_object_hold(bobject);
3169 vm_object_chain_wait(bobject, 0);
3170 /* ref for shadowing below */
3171 vm_object_reference_locked(bobject);
3172 vm_object_chain_acquire(bobject, 0);
3173 KKASSERT(bobject->backing_object == bobject);
3174 KKASSERT((bobject->flags & OBJ_DEAD) == 0);
3177 * vnodes are not placed on the shadow list but
3178 * they still get another ref for the backing_object
3181 vm_object_reference_quick(bobject);
3186 * Calculate the object page range and allocate the new object.
3188 offset = entry->offset;
3192 offidxstart = OFF_TO_IDX(offset);
3193 offidxend = offidxstart + OFF_TO_IDX(e - s);
3194 size = offidxend - offidxstart;
3196 switch(oobject->type) {
3198 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size),
3202 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size),
3211 if (nobject == NULL) {
3213 if (useshadowlist) {
3214 vm_object_chain_release(bobject);
3215 vm_object_deallocate(bobject);
3216 vm_object_drop(bobject);
3218 vm_object_deallocate(bobject);
3221 vm_object_chain_release(oobject);
3222 vm_object_reference_locked(oobject);
3223 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3224 vm_object_drop(oobject);
3229 * The new object will replace entry->object.vm_object so it needs
3230 * a second reference (the caller expects an additional ref).
3232 vm_object_hold(nobject);
3233 vm_object_reference_locked(nobject);
3234 vm_object_chain_acquire(nobject, 0);
3237 * nobject shadows bobject (oobject already shadows bobject).
3239 * Adding an object to bobject's shadow list requires refing bobject
3240 * which we did above in the useshadowlist case.
3243 nobject->backing_object_offset =
3244 oobject->backing_object_offset + IDX_TO_OFF(offidxstart);
3245 nobject->backing_object = bobject;
3246 if (useshadowlist) {
3247 bobject->shadow_count++;
3248 bobject->generation++;
3249 LIST_INSERT_HEAD(&bobject->shadow_head,
3250 nobject, shadow_list);
3251 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /*XXX*/
3252 vm_object_chain_release(bobject);
3253 vm_object_drop(bobject);
3254 vm_object_set_flag(nobject, OBJ_ONSHADOW);
3259 * Move the VM pages from oobject to nobject
3261 for (idx = 0; idx < size; idx++) {
3264 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx,
3270 * We must wait for pending I/O to complete before we can
3273 * We do not have to VM_PROT_NONE the page as mappings should
3274 * not be changed by this operation.
3276 * NOTE: The act of renaming a page updates chaingen for both
3279 vm_page_rename(m, nobject, idx);
3280 /* page automatically made dirty by rename and cache handled */
3281 /* page remains busy */
3284 if (oobject->type == OBJT_SWAP) {
3285 vm_object_pip_add(oobject, 1);
3287 * copy oobject pages into nobject and destroy unneeded
3288 * pages in shadow object.
3290 swap_pager_copy(oobject, nobject, offidxstart, 0);
3291 vm_object_pip_wakeup(oobject);
3295 * Wakeup the pages we played with. No spl protection is needed
3296 * for a simple wakeup.
3298 for (idx = 0; idx < size; idx++) {
3299 m = vm_page_lookup(nobject, idx);
3301 KKASSERT(m->flags & PG_BUSY);
3305 entry->object.vm_object = nobject;
3306 entry->offset = 0LL;
3311 * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the
3312 * related pages were moved and are no longer applicable to the
3315 * NOTE: Deallocate oobject (due to its entry->object.vm_object being
3316 * replaced by nobject).
3318 vm_object_chain_release(nobject);
3319 vm_object_drop(nobject);
3320 if (bobject && useshadowlist) {
3321 vm_object_chain_release(bobject);
3322 vm_object_drop(bobject);
3324 vm_object_chain_release(oobject);
3325 /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/
3326 vm_object_deallocate_locked(oobject);
3327 vm_object_drop(oobject);
3331 * Copies the contents of the source entry to the destination
3332 * entry. The entries *must* be aligned properly.
3334 * The vm_maps must be exclusively locked.
3335 * The vm_map's token must be held.
3337 * Because the maps are locked no faults can be in progress during the
3341 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
3342 vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
3344 vm_object_t src_object;
3346 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP ||
3347 dst_entry->maptype == VM_MAPTYPE_UKSMAP)
3349 if (src_entry->maptype == VM_MAPTYPE_SUBMAP ||
3350 src_entry->maptype == VM_MAPTYPE_UKSMAP)
3353 if (src_entry->wired_count == 0) {
3355 * If the source entry is marked needs_copy, it is already
3358 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
3359 pmap_protect(src_map->pmap,
3362 src_entry->protection & ~VM_PROT_WRITE);
3366 * Make a copy of the object.
3368 * The object must be locked prior to checking the object type
3369 * and for the call to vm_object_collapse() and vm_map_split().
3370 * We cannot use *_hold() here because the split code will
3371 * probably try to destroy the object. The lock is a pool
3372 * token and doesn't care.
3374 * We must bump src_map->timestamp when setting
3375 * MAP_ENTRY_NEEDS_COPY to force any concurrent fault
3376 * to retry, otherwise the concurrent fault might improperly
3377 * install a RW pte when its supposed to be a RO(COW) pte.
3378 * This race can occur because a vnode-backed fault may have
3379 * to temporarily release the map lock.
3381 if (src_entry->object.vm_object != NULL) {
3382 vm_map_split(src_entry);
3383 src_object = src_entry->object.vm_object;
3384 dst_entry->object.vm_object = src_object;
3385 src_entry->eflags |= (MAP_ENTRY_COW |
3386 MAP_ENTRY_NEEDS_COPY);
3387 dst_entry->eflags |= (MAP_ENTRY_COW |
3388 MAP_ENTRY_NEEDS_COPY);
3389 dst_entry->offset = src_entry->offset;
3390 ++src_map->timestamp;
3392 dst_entry->object.vm_object = NULL;
3393 dst_entry->offset = 0;
3396 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3397 dst_entry->end - dst_entry->start, src_entry->start);
3400 * Of course, wired down pages can't be set copy-on-write.
3401 * Cause wired pages to be copied into the new map by
3402 * simulating faults (the new pages are pageable)
3404 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3410 * Create a new process vmspace structure and vm_map
3411 * based on those of an existing process. The new map
3412 * is based on the old map, according to the inheritance
3413 * values on the regions in that map.
3415 * The source map must not be locked.
3418 static void vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map,
3419 vm_map_entry_t old_entry, int *countp);
3420 static void vmspace_fork_uksmap_entry(vm_map_t old_map, vm_map_t new_map,
3421 vm_map_entry_t old_entry, int *countp);
3424 vmspace_fork(struct vmspace *vm1)
3426 struct vmspace *vm2;
3427 vm_map_t old_map = &vm1->vm_map;
3429 vm_map_entry_t old_entry;
3432 lwkt_gettoken(&vm1->vm_map.token);
3433 vm_map_lock(old_map);
3435 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3436 lwkt_gettoken(&vm2->vm_map.token);
3437 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3438 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3439 new_map = &vm2->vm_map; /* XXX */
3440 new_map->timestamp = 1;
3442 vm_map_lock(new_map);
3445 old_entry = old_map->header.next;
3446 while (old_entry != &old_map->header) {
3448 old_entry = old_entry->next;
3451 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3453 old_entry = old_map->header.next;
3454 while (old_entry != &old_map->header) {
3455 switch(old_entry->maptype) {
3456 case VM_MAPTYPE_SUBMAP:
3457 panic("vm_map_fork: encountered a submap");
3459 case VM_MAPTYPE_UKSMAP:
3460 vmspace_fork_uksmap_entry(old_map, new_map,
3463 case VM_MAPTYPE_NORMAL:
3464 case VM_MAPTYPE_VPAGETABLE:
3465 vmspace_fork_normal_entry(old_map, new_map,
3469 old_entry = old_entry->next;
3472 new_map->size = old_map->size;
3473 vm_map_unlock(old_map);
3474 vm_map_unlock(new_map);
3475 vm_map_entry_release(count);
3477 lwkt_reltoken(&vm2->vm_map.token);
3478 lwkt_reltoken(&vm1->vm_map.token);
3485 vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map,
3486 vm_map_entry_t old_entry, int *countp)
3488 vm_map_entry_t new_entry;
3491 switch (old_entry->inheritance) {
3492 case VM_INHERIT_NONE:
3494 case VM_INHERIT_SHARE:
3496 * Clone the entry, creating the shared object if
3499 if (old_entry->object.vm_object == NULL)
3500 vm_map_entry_allocate_object(old_entry);
3502 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3504 * Shadow a map_entry which needs a copy,
3505 * replacing its object with a new object
3506 * that points to the old one. Ask the
3507 * shadow code to automatically add an
3508 * additional ref. We can't do it afterwords
3509 * because we might race a collapse. The call
3510 * to vm_map_entry_shadow() will also clear
3513 vm_map_entry_shadow(old_entry, 1);
3514 } else if (old_entry->object.vm_object) {
3516 * We will make a shared copy of the object,
3517 * and must clear OBJ_ONEMAPPING.
3519 * Optimize vnode objects. OBJ_ONEMAPPING
3520 * is non-applicable but clear it anyway,
3521 * and its terminal so we don'th ave to deal
3522 * with chains. Reduces SMP conflicts.
3524 * XXX assert that object.vm_object != NULL
3525 * since we allocate it above.
3527 object = old_entry->object.vm_object;
3528 if (object->type == OBJT_VNODE) {
3529 vm_object_reference_quick(object);
3530 vm_object_clear_flag(object,
3533 vm_object_hold(object);
3534 vm_object_chain_wait(object, 0);
3535 vm_object_reference_locked(object);
3536 vm_object_clear_flag(object,
3538 vm_object_drop(object);
3543 * Clone the entry. We've already bumped the ref on
3546 new_entry = vm_map_entry_create(new_map, countp);
3547 *new_entry = *old_entry;
3548 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3549 new_entry->wired_count = 0;
3552 * Insert the entry into the new map -- we know we're
3553 * inserting at the end of the new map.
3556 vm_map_entry_link(new_map, new_map->header.prev,
3560 * Update the physical map
3562 pmap_copy(new_map->pmap, old_map->pmap,
3564 (old_entry->end - old_entry->start),
3567 case VM_INHERIT_COPY:
3569 * Clone the entry and link into the map.
3571 new_entry = vm_map_entry_create(new_map, countp);
3572 *new_entry = *old_entry;
3573 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3574 new_entry->wired_count = 0;
3575 new_entry->object.vm_object = NULL;
3576 vm_map_entry_link(new_map, new_map->header.prev,
3578 vm_map_copy_entry(old_map, new_map, old_entry,
3585 * When forking user-kernel shared maps, the map might change in the
3586 * child so do not try to copy the underlying pmap entries.
3590 vmspace_fork_uksmap_entry(vm_map_t old_map, vm_map_t new_map,
3591 vm_map_entry_t old_entry, int *countp)
3593 vm_map_entry_t new_entry;
3595 new_entry = vm_map_entry_create(new_map, countp);
3596 *new_entry = *old_entry;
3597 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3598 new_entry->wired_count = 0;
3599 vm_map_entry_link(new_map, new_map->header.prev,
3604 * Create an auto-grow stack entry
3609 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3610 int flags, vm_prot_t prot, vm_prot_t max, int cow)
3612 vm_map_entry_t prev_entry;
3613 vm_map_entry_t new_stack_entry;
3614 vm_size_t init_ssize;
3617 vm_offset_t tmpaddr;
3619 cow |= MAP_IS_STACK;
3621 if (max_ssize < sgrowsiz)
3622 init_ssize = max_ssize;
3624 init_ssize = sgrowsiz;
3626 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3630 * Find space for the mapping
3632 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3633 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3636 vm_map_entry_release(count);
3637 return (KERN_NO_SPACE);
3642 /* If addr is already mapped, no go */
3643 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3645 vm_map_entry_release(count);
3646 return (KERN_NO_SPACE);
3650 /* XXX already handled by kern_mmap() */
3651 /* If we would blow our VMEM resource limit, no go */
3652 if (map->size + init_ssize >
3653 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3655 vm_map_entry_release(count);
3656 return (KERN_NO_SPACE);
3661 * If we can't accomodate max_ssize in the current mapping,
3662 * no go. However, we need to be aware that subsequent user
3663 * mappings might map into the space we have reserved for
3664 * stack, and currently this space is not protected.
3666 * Hopefully we will at least detect this condition
3667 * when we try to grow the stack.
3669 if ((prev_entry->next != &map->header) &&
3670 (prev_entry->next->start < addrbos + max_ssize)) {
3672 vm_map_entry_release(count);
3673 return (KERN_NO_SPACE);
3677 * We initially map a stack of only init_ssize. We will
3678 * grow as needed later. Since this is to be a grow
3679 * down stack, we map at the top of the range.
3681 * Note: we would normally expect prot and max to be
3682 * VM_PROT_ALL, and cow to be 0. Possibly we should
3683 * eliminate these as input parameters, and just
3684 * pass these values here in the insert call.
3686 rv = vm_map_insert(map, &count, NULL, NULL,
3687 0, addrbos + max_ssize - init_ssize,
3688 addrbos + max_ssize,
3690 VM_SUBSYS_STACK, prot, max, cow);
3692 /* Now set the avail_ssize amount */
3693 if (rv == KERN_SUCCESS) {
3694 if (prev_entry != &map->header)
3695 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3696 new_stack_entry = prev_entry->next;
3697 if (new_stack_entry->end != addrbos + max_ssize ||
3698 new_stack_entry->start != addrbos + max_ssize - init_ssize)
3699 panic ("Bad entry start/end for new stack entry");
3701 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3705 vm_map_entry_release(count);
3710 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
3711 * desired address is already mapped, or if we successfully grow
3712 * the stack. Also returns KERN_SUCCESS if addr is outside the
3713 * stack range (this is strange, but preserves compatibility with
3714 * the grow function in vm_machdep.c).
3719 vm_map_growstack (struct proc *p, vm_offset_t addr)
3721 vm_map_entry_t prev_entry;
3722 vm_map_entry_t stack_entry;
3723 vm_map_entry_t new_stack_entry;
3724 struct vmspace *vm = p->p_vmspace;
3725 vm_map_t map = &vm->vm_map;
3728 int rv = KERN_SUCCESS;
3730 int use_read_lock = 1;
3733 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3736 vm_map_lock_read(map);
3740 /* If addr is already in the entry range, no need to grow.*/
3741 if (vm_map_lookup_entry(map, addr, &prev_entry))
3744 if ((stack_entry = prev_entry->next) == &map->header)
3746 if (prev_entry == &map->header)
3747 end = stack_entry->start - stack_entry->aux.avail_ssize;
3749 end = prev_entry->end;
3752 * This next test mimics the old grow function in vm_machdep.c.
3753 * It really doesn't quite make sense, but we do it anyway
3754 * for compatibility.
3756 * If not growable stack, return success. This signals the
3757 * caller to proceed as he would normally with normal vm.
3759 if (stack_entry->aux.avail_ssize < 1 ||
3760 addr >= stack_entry->start ||
3761 addr < stack_entry->start - stack_entry->aux.avail_ssize) {
3765 /* Find the minimum grow amount */
3766 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3767 if (grow_amount > stack_entry->aux.avail_ssize) {
3773 * If there is no longer enough space between the entries
3774 * nogo, and adjust the available space. Note: this
3775 * should only happen if the user has mapped into the
3776 * stack area after the stack was created, and is
3777 * probably an error.
3779 * This also effectively destroys any guard page the user
3780 * might have intended by limiting the stack size.
3782 if (grow_amount > stack_entry->start - end) {
3783 if (use_read_lock && vm_map_lock_upgrade(map)) {
3789 stack_entry->aux.avail_ssize = stack_entry->start - end;
3794 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3796 /* If this is the main process stack, see if we're over the
3799 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3800 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3805 /* Round up the grow amount modulo SGROWSIZ */
3806 grow_amount = roundup (grow_amount, sgrowsiz);
3807 if (grow_amount > stack_entry->aux.avail_ssize) {
3808 grow_amount = stack_entry->aux.avail_ssize;
3810 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3811 p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3812 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3816 /* If we would blow our VMEM resource limit, no go */
3817 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3822 if (use_read_lock && vm_map_lock_upgrade(map)) {
3829 /* Get the preliminary new entry start value */
3830 addr = stack_entry->start - grow_amount;
3832 /* If this puts us into the previous entry, cut back our growth
3833 * to the available space. Also, see the note above.
3836 stack_entry->aux.avail_ssize = stack_entry->start - end;
3840 rv = vm_map_insert(map, &count, NULL, NULL,
3841 0, addr, stack_entry->start,
3843 VM_SUBSYS_STACK, VM_PROT_ALL, VM_PROT_ALL, 0);
3845 /* Adjust the available stack space by the amount we grew. */
3846 if (rv == KERN_SUCCESS) {
3847 if (prev_entry != &map->header)
3848 vm_map_clip_end(map, prev_entry, addr, &count);
3849 new_stack_entry = prev_entry->next;
3850 if (new_stack_entry->end != stack_entry->start ||
3851 new_stack_entry->start != addr)
3852 panic ("Bad stack grow start/end in new stack entry");
3854 new_stack_entry->aux.avail_ssize =
3855 stack_entry->aux.avail_ssize -
3856 (new_stack_entry->end - new_stack_entry->start);
3858 vm->vm_ssize += btoc(new_stack_entry->end -
3859 new_stack_entry->start);
3862 if (map->flags & MAP_WIREFUTURE)
3863 vm_map_unwire(map, new_stack_entry->start,
3864 new_stack_entry->end, FALSE);
3869 vm_map_unlock_read(map);
3872 vm_map_entry_release(count);
3877 * Unshare the specified VM space for exec. If other processes are
3878 * mapped to it, then create a new one. The new vmspace is null.
3883 vmspace_exec(struct proc *p, struct vmspace *vmcopy)
3885 struct vmspace *oldvmspace = p->p_vmspace;
3886 struct vmspace *newvmspace;
3887 vm_map_t map = &p->p_vmspace->vm_map;
3890 * If we are execing a resident vmspace we fork it, otherwise
3891 * we create a new vmspace. Note that exitingcnt is not
3892 * copied to the new vmspace.
3894 lwkt_gettoken(&oldvmspace->vm_map.token);
3896 newvmspace = vmspace_fork(vmcopy);
3897 lwkt_gettoken(&newvmspace->vm_map.token);
3899 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3900 lwkt_gettoken(&newvmspace->vm_map.token);
3901 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3902 (caddr_t)&oldvmspace->vm_endcopy -
3903 (caddr_t)&oldvmspace->vm_startcopy);
3907 * Finish initializing the vmspace before assigning it
3908 * to the process. The vmspace will become the current vmspace
3911 pmap_pinit2(vmspace_pmap(newvmspace));
3912 pmap_replacevm(p, newvmspace, 0);
3913 lwkt_reltoken(&newvmspace->vm_map.token);
3914 lwkt_reltoken(&oldvmspace->vm_map.token);
3915 vmspace_rel(oldvmspace);
3919 * Unshare the specified VM space for forcing COW. This
3920 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3923 vmspace_unshare(struct proc *p)
3925 struct vmspace *oldvmspace = p->p_vmspace;
3926 struct vmspace *newvmspace;
3928 lwkt_gettoken(&oldvmspace->vm_map.token);
3929 if (vmspace_getrefs(oldvmspace) == 1) {
3930 lwkt_reltoken(&oldvmspace->vm_map.token);
3933 newvmspace = vmspace_fork(oldvmspace);
3934 lwkt_gettoken(&newvmspace->vm_map.token);
3935 pmap_pinit2(vmspace_pmap(newvmspace));
3936 pmap_replacevm(p, newvmspace, 0);
3937 lwkt_reltoken(&newvmspace->vm_map.token);
3938 lwkt_reltoken(&oldvmspace->vm_map.token);
3939 vmspace_rel(oldvmspace);
3943 * vm_map_hint: return the beginning of the best area suitable for
3944 * creating a new mapping with "prot" protection.
3949 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot)
3951 struct vmspace *vms = p->p_vmspace;
3953 if (!randomize_mmap || addr != 0) {
3955 * Set a reasonable start point for the hint if it was
3956 * not specified or if it falls within the heap space.
3957 * Hinted mmap()s do not allocate out of the heap space.
3960 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
3961 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) {
3962 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
3967 addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ;
3968 addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1);
3970 return (round_page(addr));
3974 * Finds the VM object, offset, and protection for a given virtual address
3975 * in the specified map, assuming a page fault of the type specified.
3977 * Leaves the map in question locked for read; return values are guaranteed
3978 * until a vm_map_lookup_done call is performed. Note that the map argument
3979 * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3981 * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3984 * If a lookup is requested with "write protection" specified, the map may
3985 * be changed to perform virtual copying operations, although the data
3986 * referenced will remain the same.
3991 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
3993 vm_prot_t fault_typea,
3994 vm_map_entry_t *out_entry, /* OUT */
3995 vm_object_t *object, /* OUT */
3996 vm_pindex_t *pindex, /* OUT */
3997 vm_prot_t *out_prot, /* OUT */
3998 boolean_t *wired) /* OUT */
4000 vm_map_entry_t entry;
4001 vm_map_t map = *var_map;
4003 vm_prot_t fault_type = fault_typea;
4004 int use_read_lock = 1;
4005 int rv = KERN_SUCCESS;
4009 vm_map_lock_read(map);
4014 * If the map has an interesting hint, try it before calling full
4015 * blown lookup routine.
4022 if ((entry == &map->header) ||
4023 (vaddr < entry->start) || (vaddr >= entry->end)) {
4024 vm_map_entry_t tmp_entry;
4027 * Entry was either not a valid hint, or the vaddr was not
4028 * contained in the entry, so do a full lookup.
4030 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
4031 rv = KERN_INVALID_ADDRESS;
4042 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
4043 vm_map_t old_map = map;
4045 *var_map = map = entry->object.sub_map;
4047 vm_map_unlock_read(old_map);
4049 vm_map_unlock(old_map);
4055 * Check whether this task is allowed to have this page.
4056 * Note the special case for MAP_ENTRY_COW
4057 * pages with an override. This is to implement a forced
4058 * COW for debuggers.
4061 if (fault_type & VM_PROT_OVERRIDE_WRITE)
4062 prot = entry->max_protection;
4064 prot = entry->protection;
4066 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
4067 if ((fault_type & prot) != fault_type) {
4068 rv = KERN_PROTECTION_FAILURE;
4072 if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
4073 (entry->eflags & MAP_ENTRY_COW) &&
4074 (fault_type & VM_PROT_WRITE) &&
4075 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
4076 rv = KERN_PROTECTION_FAILURE;
4081 * If this page is not pageable, we have to get it for all possible
4084 *wired = (entry->wired_count != 0);
4086 prot = fault_type = entry->protection;
4089 * Virtual page tables may need to update the accessed (A) bit
4090 * in a page table entry. Upgrade the fault to a write fault for
4091 * that case if the map will support it. If the map does not support
4092 * it the page table entry simply will not be updated.
4094 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
4095 if (prot & VM_PROT_WRITE)
4096 fault_type |= VM_PROT_WRITE;
4099 if (curthread->td_lwp && curthread->td_lwp->lwp_vmspace &&
4100 pmap_emulate_ad_bits(&curthread->td_lwp->lwp_vmspace->vm_pmap)) {
4101 if ((prot & VM_PROT_WRITE) == 0)
4102 fault_type |= VM_PROT_WRITE;
4106 * Only NORMAL and VPAGETABLE maps are object-based. UKSMAPs are not.
4108 if (entry->maptype != VM_MAPTYPE_NORMAL &&
4109 entry->maptype != VM_MAPTYPE_VPAGETABLE) {
4115 * If the entry was copy-on-write, we either ...
4117 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4119 * If we want to write the page, we may as well handle that
4120 * now since we've got the map locked.
4122 * If we don't need to write the page, we just demote the
4123 * permissions allowed.
4126 if (fault_type & VM_PROT_WRITE) {
4128 * Not allowed if TDF_NOFAULT is set as the shadowing
4129 * operation can deadlock against the faulting
4130 * function due to the copy-on-write.
4132 if (curthread->td_flags & TDF_NOFAULT) {
4133 rv = KERN_FAILURE_NOFAULT;
4138 * Make a new object, and place it in the object
4139 * chain. Note that no new references have appeared
4140 * -- one just moved from the map to the new
4144 if (use_read_lock && vm_map_lock_upgrade(map)) {
4151 vm_map_entry_shadow(entry, 0);
4154 * We're attempting to read a copy-on-write page --
4155 * don't allow writes.
4158 prot &= ~VM_PROT_WRITE;
4163 * Create an object if necessary.
4165 if (entry->object.vm_object == NULL && !map->system_map) {
4166 if (use_read_lock && vm_map_lock_upgrade(map)) {
4172 vm_map_entry_allocate_object(entry);
4176 * Return the object/offset from this entry. If the entry was
4177 * copy-on-write or empty, it has been fixed up.
4179 *object = entry->object.vm_object;
4182 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
4185 * Return whether this is the only map sharing this data. On
4186 * success we return with a read lock held on the map. On failure
4187 * we return with the map unlocked.
4191 if (rv == KERN_SUCCESS) {
4192 if (use_read_lock == 0)
4193 vm_map_lock_downgrade(map);
4194 } else if (use_read_lock) {
4195 vm_map_unlock_read(map);
4203 * Releases locks acquired by a vm_map_lookup()
4204 * (according to the handle returned by that lookup).
4206 * No other requirements.
4209 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
4212 * Unlock the main-level map
4214 vm_map_unlock_read(map);
4216 vm_map_entry_release(count);
4219 #include "opt_ddb.h"
4221 #include <sys/kernel.h>
4223 #include <ddb/ddb.h>
4228 DB_SHOW_COMMAND(map, vm_map_print)
4231 /* XXX convert args. */
4232 vm_map_t map = (vm_map_t)addr;
4233 boolean_t full = have_addr;
4235 vm_map_entry_t entry;
4237 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4239 (void *)map->pmap, map->nentries, map->timestamp);
4242 if (!full && db_indent)
4246 for (entry = map->header.next; entry != &map->header;
4247 entry = entry->next) {
4248 db_iprintf("map entry %p: start=%p, end=%p\n",
4249 (void *)entry, (void *)entry->start, (void *)entry->end);
4252 static char *inheritance_name[4] =
4253 {"share", "copy", "none", "donate_copy"};
4255 db_iprintf(" prot=%x/%x/%s",
4257 entry->max_protection,
4258 inheritance_name[(int)(unsigned char)entry->inheritance]);
4259 if (entry->wired_count != 0)
4260 db_printf(", wired");
4262 switch(entry->maptype) {
4263 case VM_MAPTYPE_SUBMAP:
4264 /* XXX no %qd in kernel. Truncate entry->offset. */
4265 db_printf(", share=%p, offset=0x%lx\n",
4266 (void *)entry->object.sub_map,
4267 (long)entry->offset);
4269 if ((entry->prev == &map->header) ||
4270 (entry->prev->object.sub_map !=
4271 entry->object.sub_map)) {
4273 vm_map_print((db_expr_t)(intptr_t)
4274 entry->object.sub_map,
4279 case VM_MAPTYPE_NORMAL:
4280 case VM_MAPTYPE_VPAGETABLE:
4281 /* XXX no %qd in kernel. Truncate entry->offset. */
4282 db_printf(", object=%p, offset=0x%lx",
4283 (void *)entry->object.vm_object,
4284 (long)entry->offset);
4285 if (entry->eflags & MAP_ENTRY_COW)
4286 db_printf(", copy (%s)",
4287 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
4291 if ((entry->prev == &map->header) ||
4292 (entry->prev->object.vm_object !=
4293 entry->object.vm_object)) {
4295 vm_object_print((db_expr_t)(intptr_t)
4296 entry->object.vm_object,
4302 case VM_MAPTYPE_UKSMAP:
4303 db_printf(", uksmap=%p, offset=0x%lx",
4304 (void *)entry->object.uksmap,
4305 (long)entry->offset);
4306 if (entry->eflags & MAP_ENTRY_COW)
4307 db_printf(", copy (%s)",
4308 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
4324 DB_SHOW_COMMAND(procvm, procvm)
4329 p = (struct proc *) addr;
4334 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
4335 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
4336 (void *)vmspace_pmap(p->p_vmspace));
4338 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL);