2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
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.
64 * Virtual memory mapping module.
67 #include <sys/cdefs.h>
68 __FBSDID("$FreeBSD$");
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/kernel.h>
75 #include <sys/mutex.h>
77 #include <sys/vmmeter.h>
79 #include <sys/vnode.h>
80 #include <sys/racct.h>
81 #include <sys/resourcevar.h>
82 #include <sys/rwlock.h>
84 #include <sys/sysctl.h>
85 #include <sys/sysent.h>
89 #include <vm/vm_param.h>
91 #include <vm/vm_map.h>
92 #include <vm/vm_page.h>
93 #include <vm/vm_object.h>
94 #include <vm/vm_pager.h>
95 #include <vm/vm_kern.h>
96 #include <vm/vm_extern.h>
97 #include <vm/vnode_pager.h>
98 #include <vm/swap_pager.h>
102 * Virtual memory maps provide for the mapping, protection,
103 * and sharing of virtual memory objects. In addition,
104 * this module provides for an efficient virtual copy of
105 * memory from one map to another.
107 * Synchronization is required prior to most operations.
109 * Maps consist of an ordered doubly-linked list of simple
110 * entries; a self-adjusting binary search tree of these
111 * entries is used to speed up lookups.
113 * Since portions of maps are specified by start/end addresses,
114 * which may not align with existing map entries, all
115 * routines merely "clip" entries to these start/end values.
116 * [That is, an entry is split into two, bordering at a
117 * start or end value.] Note that these clippings may not
118 * always be necessary (as the two resulting entries are then
119 * not changed); however, the clipping is done for convenience.
121 * As mentioned above, virtual copy operations are performed
122 * by copying VM object references from one map to
123 * another, and then marking both regions as copy-on-write.
126 static struct mtx map_sleep_mtx;
127 static uma_zone_t mapentzone;
128 static uma_zone_t kmapentzone;
129 static uma_zone_t mapzone;
130 static uma_zone_t vmspace_zone;
131 static int vmspace_zinit(void *mem, int size, int flags);
132 static int vm_map_zinit(void *mem, int ize, int flags);
133 static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min,
135 static int vm_map_alignspace(vm_map_t map, vm_object_t object,
136 vm_ooffset_t offset, vm_offset_t *addr, vm_size_t length,
137 vm_offset_t max_addr, vm_offset_t alignment);
138 static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map);
139 static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry);
140 static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry);
141 static int vm_map_growstack(vm_map_t map, vm_offset_t addr,
142 vm_map_entry_t gap_entry);
143 static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
144 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags);
146 static void vm_map_zdtor(void *mem, int size, void *arg);
147 static void vmspace_zdtor(void *mem, int size, void *arg);
149 static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos,
150 vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max,
152 static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
153 vm_offset_t failed_addr);
155 #define ENTRY_CHARGED(e) ((e)->cred != NULL || \
156 ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \
157 !((e)->eflags & MAP_ENTRY_NEEDS_COPY)))
160 * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type
163 #define PROC_VMSPACE_LOCK(p) do { } while (0)
164 #define PROC_VMSPACE_UNLOCK(p) do { } while (0)
167 * VM_MAP_RANGE_CHECK: [ internal use only ]
169 * Asserts that the starting and ending region
170 * addresses fall within the valid range of the map.
172 #define VM_MAP_RANGE_CHECK(map, start, end) \
174 if (start < vm_map_min(map)) \
175 start = vm_map_min(map); \
176 if (end > vm_map_max(map)) \
177 end = vm_map_max(map); \
185 * Initialize the vm_map module. Must be called before
186 * any other vm_map routines.
188 * Map and entry structures are allocated from the general
189 * purpose memory pool with some exceptions:
191 * - The kernel map and kmem submap are allocated statically.
192 * - Kernel map entries are allocated out of a static pool.
194 * These restrictions are necessary since malloc() uses the
195 * maps and requires map entries.
201 mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF);
202 mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL,
208 vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
209 uma_prealloc(mapzone, MAX_KMAP);
210 kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry),
211 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
212 UMA_ZONE_MTXCLASS | UMA_ZONE_VM);
213 mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry),
214 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
215 vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL,
221 vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
225 vmspace_zinit(void *mem, int size, int flags)
229 vm = (struct vmspace *)mem;
231 vm->vm_map.pmap = NULL;
232 (void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags);
233 PMAP_LOCK_INIT(vmspace_pmap(vm));
238 vm_map_zinit(void *mem, int size, int flags)
243 memset(map, 0, sizeof(*map));
244 mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK);
245 sx_init(&map->lock, "vm map (user)");
251 vmspace_zdtor(void *mem, int size, void *arg)
255 vm = (struct vmspace *)mem;
257 vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg);
260 vm_map_zdtor(void *mem, int size, void *arg)
265 KASSERT(map->nentries == 0,
266 ("map %p nentries == %d on free.",
267 map, map->nentries));
268 KASSERT(map->size == 0,
269 ("map %p size == %lu on free.",
270 map, (unsigned long)map->size));
272 #endif /* INVARIANTS */
275 * Allocate a vmspace structure, including a vm_map and pmap,
276 * and initialize those structures. The refcnt is set to 1.
278 * If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit().
281 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit)
285 vm = uma_zalloc(vmspace_zone, M_WAITOK);
286 KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL"));
287 if (!pinit(vmspace_pmap(vm))) {
288 uma_zfree(vmspace_zone, vm);
291 CTR1(KTR_VM, "vmspace_alloc: %p", vm);
292 _vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max);
307 vmspace_container_reset(struct proc *p)
311 racct_set(p, RACCT_DATA, 0);
312 racct_set(p, RACCT_STACK, 0);
313 racct_set(p, RACCT_RSS, 0);
314 racct_set(p, RACCT_MEMLOCK, 0);
315 racct_set(p, RACCT_VMEM, 0);
321 vmspace_dofree(struct vmspace *vm)
324 CTR1(KTR_VM, "vmspace_free: %p", vm);
327 * Make sure any SysV shm is freed, it might not have been in
333 * Lock the map, to wait out all other references to it.
334 * Delete all of the mappings and pages they hold, then call
335 * the pmap module to reclaim anything left.
337 (void)vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map),
338 vm_map_max(&vm->vm_map));
340 pmap_release(vmspace_pmap(vm));
341 vm->vm_map.pmap = NULL;
342 uma_zfree(vmspace_zone, vm);
346 vmspace_free(struct vmspace *vm)
349 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
350 "vmspace_free() called");
352 if (vm->vm_refcnt == 0)
353 panic("vmspace_free: attempt to free already freed vmspace");
355 if (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1)
360 vmspace_exitfree(struct proc *p)
364 PROC_VMSPACE_LOCK(p);
367 PROC_VMSPACE_UNLOCK(p);
368 KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace"));
373 vmspace_exit(struct thread *td)
380 * Release user portion of address space.
381 * This releases references to vnodes,
382 * which could cause I/O if the file has been unlinked.
383 * Need to do this early enough that we can still sleep.
385 * The last exiting process to reach this point releases as
386 * much of the environment as it can. vmspace_dofree() is the
387 * slower fallback in case another process had a temporary
388 * reference to the vmspace.
393 atomic_add_int(&vmspace0.vm_refcnt, 1);
394 refcnt = vm->vm_refcnt;
396 if (refcnt > 1 && p->p_vmspace != &vmspace0) {
397 /* Switch now since other proc might free vmspace */
398 PROC_VMSPACE_LOCK(p);
399 p->p_vmspace = &vmspace0;
400 PROC_VMSPACE_UNLOCK(p);
403 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt - 1));
405 if (p->p_vmspace != vm) {
406 /* vmspace not yet freed, switch back */
407 PROC_VMSPACE_LOCK(p);
409 PROC_VMSPACE_UNLOCK(p);
412 pmap_remove_pages(vmspace_pmap(vm));
413 /* Switch now since this proc will free vmspace */
414 PROC_VMSPACE_LOCK(p);
415 p->p_vmspace = &vmspace0;
416 PROC_VMSPACE_UNLOCK(p);
422 vmspace_container_reset(p);
426 /* Acquire reference to vmspace owned by another process. */
429 vmspace_acquire_ref(struct proc *p)
434 PROC_VMSPACE_LOCK(p);
437 PROC_VMSPACE_UNLOCK(p);
440 refcnt = vm->vm_refcnt;
442 if (refcnt <= 0) { /* Avoid 0->1 transition */
443 PROC_VMSPACE_UNLOCK(p);
446 } while (!atomic_fcmpset_int(&vm->vm_refcnt, &refcnt, refcnt + 1));
447 if (vm != p->p_vmspace) {
448 PROC_VMSPACE_UNLOCK(p);
452 PROC_VMSPACE_UNLOCK(p);
457 * Switch between vmspaces in an AIO kernel process.
459 * The AIO kernel processes switch to and from a user process's
460 * vmspace while performing an I/O operation on behalf of a user
461 * process. The new vmspace is either the vmspace of a user process
462 * obtained from an active AIO request or the initial vmspace of the
463 * AIO kernel process (when it is idling). Because user processes
464 * will block to drain any active AIO requests before proceeding in
465 * exit() or execve(), the vmspace reference count for these vmspaces
466 * can never be 0. This allows for a much simpler implementation than
467 * the loop in vmspace_acquire_ref() above. Similarly, AIO kernel
468 * processes hold an extra reference on their initial vmspace for the
469 * life of the process so that this guarantee is true for any vmspace
473 vmspace_switch_aio(struct vmspace *newvm)
475 struct vmspace *oldvm;
477 /* XXX: Need some way to assert that this is an aio daemon. */
479 KASSERT(newvm->vm_refcnt > 0,
480 ("vmspace_switch_aio: newvm unreferenced"));
482 oldvm = curproc->p_vmspace;
487 * Point to the new address space and refer to it.
489 curproc->p_vmspace = newvm;
490 atomic_add_int(&newvm->vm_refcnt, 1);
492 /* Activate the new mapping. */
493 pmap_activate(curthread);
495 /* Remove the daemon's reference to the old address space. */
496 KASSERT(oldvm->vm_refcnt > 1,
497 ("vmspace_switch_aio: oldvm dropping last reference"));
502 _vm_map_lock(vm_map_t map, const char *file, int line)
506 mtx_lock_flags_(&map->system_mtx, 0, file, line);
508 sx_xlock_(&map->lock, file, line);
513 vm_map_process_deferred(void)
516 vm_map_entry_t entry, next;
520 entry = td->td_map_def_user;
521 td->td_map_def_user = NULL;
522 while (entry != NULL) {
524 if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) {
526 * Decrement the object's writemappings and
527 * possibly the vnode's v_writecount.
529 KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
530 ("Submap with writecount"));
531 object = entry->object.vm_object;
532 KASSERT(object != NULL, ("No object for writecount"));
533 vnode_pager_release_writecount(object, entry->start,
536 vm_map_entry_deallocate(entry, FALSE);
542 _vm_map_unlock(vm_map_t map, const char *file, int line)
546 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
548 sx_xunlock_(&map->lock, file, line);
549 vm_map_process_deferred();
554 _vm_map_lock_read(vm_map_t map, const char *file, int line)
558 mtx_lock_flags_(&map->system_mtx, 0, file, line);
560 sx_slock_(&map->lock, file, line);
564 _vm_map_unlock_read(vm_map_t map, const char *file, int line)
568 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
570 sx_sunlock_(&map->lock, file, line);
571 vm_map_process_deferred();
576 _vm_map_trylock(vm_map_t map, const char *file, int line)
580 error = map->system_map ?
581 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
582 !sx_try_xlock_(&map->lock, file, line);
589 _vm_map_trylock_read(vm_map_t map, const char *file, int line)
593 error = map->system_map ?
594 !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
595 !sx_try_slock_(&map->lock, file, line);
600 * _vm_map_lock_upgrade: [ internal use only ]
602 * Tries to upgrade a read (shared) lock on the specified map to a write
603 * (exclusive) lock. Returns the value "0" if the upgrade succeeds and a
604 * non-zero value if the upgrade fails. If the upgrade fails, the map is
605 * returned without a read or write lock held.
607 * Requires that the map be read locked.
610 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line)
612 unsigned int last_timestamp;
614 if (map->system_map) {
615 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
617 if (!sx_try_upgrade_(&map->lock, file, line)) {
618 last_timestamp = map->timestamp;
619 sx_sunlock_(&map->lock, file, line);
620 vm_map_process_deferred();
622 * If the map's timestamp does not change while the
623 * map is unlocked, then the upgrade succeeds.
625 sx_xlock_(&map->lock, file, line);
626 if (last_timestamp != map->timestamp) {
627 sx_xunlock_(&map->lock, file, line);
637 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
640 if (map->system_map) {
641 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
643 sx_downgrade_(&map->lock, file, line);
649 * Returns a non-zero value if the caller holds a write (exclusive) lock
650 * on the specified map and the value "0" otherwise.
653 vm_map_locked(vm_map_t map)
657 return (mtx_owned(&map->system_mtx));
659 return (sx_xlocked(&map->lock));
664 _vm_map_assert_locked(vm_map_t map, const char *file, int line)
668 mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
670 sx_assert_(&map->lock, SA_XLOCKED, file, line);
673 #define VM_MAP_ASSERT_LOCKED(map) \
674 _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE)
676 #define VM_MAP_ASSERT_LOCKED(map)
680 * _vm_map_unlock_and_wait:
682 * Atomically releases the lock on the specified map and puts the calling
683 * thread to sleep. The calling thread will remain asleep until either
684 * vm_map_wakeup() is performed on the map or the specified timeout is
687 * WARNING! This function does not perform deferred deallocations of
688 * objects and map entries. Therefore, the calling thread is expected to
689 * reacquire the map lock after reawakening and later perform an ordinary
690 * unlock operation, such as vm_map_unlock(), before completing its
691 * operation on the map.
694 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line)
697 mtx_lock(&map_sleep_mtx);
699 mtx_unlock_flags_(&map->system_mtx, 0, file, line);
701 sx_xunlock_(&map->lock, file, line);
702 return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps",
709 * Awaken any threads that have slept on the map using
710 * vm_map_unlock_and_wait().
713 vm_map_wakeup(vm_map_t map)
717 * Acquire and release map_sleep_mtx to prevent a wakeup()
718 * from being performed (and lost) between the map unlock
719 * and the msleep() in _vm_map_unlock_and_wait().
721 mtx_lock(&map_sleep_mtx);
722 mtx_unlock(&map_sleep_mtx);
727 vm_map_busy(vm_map_t map)
730 VM_MAP_ASSERT_LOCKED(map);
735 vm_map_unbusy(vm_map_t map)
738 VM_MAP_ASSERT_LOCKED(map);
739 KASSERT(map->busy, ("vm_map_unbusy: not busy"));
740 if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) {
741 vm_map_modflags(map, 0, MAP_BUSY_WAKEUP);
747 vm_map_wait_busy(vm_map_t map)
750 VM_MAP_ASSERT_LOCKED(map);
752 vm_map_modflags(map, MAP_BUSY_WAKEUP, 0);
754 msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0);
756 sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0);
762 vmspace_resident_count(struct vmspace *vmspace)
764 return pmap_resident_count(vmspace_pmap(vmspace));
770 * Creates and returns a new empty VM map with
771 * the given physical map structure, and having
772 * the given lower and upper address bounds.
775 vm_map_create(pmap_t pmap, vm_offset_t min, vm_offset_t max)
779 result = uma_zalloc(mapzone, M_WAITOK);
780 CTR1(KTR_VM, "vm_map_create: %p", result);
781 _vm_map_init(result, pmap, min, max);
786 * Initialize an existing vm_map structure
787 * such as that in the vmspace structure.
790 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
793 map->header.next = map->header.prev = &map->header;
794 map->header.eflags = MAP_ENTRY_HEADER;
795 map->needs_wakeup = FALSE;
798 map->header.end = min;
799 map->header.start = max;
808 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
811 _vm_map_init(map, pmap, min, max);
812 mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK);
813 sx_init(&map->lock, "user map");
817 * vm_map_entry_dispose: [ internal use only ]
819 * Inverse of vm_map_entry_create.
822 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry)
824 uma_zfree(map->system_map ? kmapentzone : mapentzone, entry);
828 * vm_map_entry_create: [ internal use only ]
830 * Allocates a VM map entry for insertion.
831 * No entry fields are filled in.
833 static vm_map_entry_t
834 vm_map_entry_create(vm_map_t map)
836 vm_map_entry_t new_entry;
839 new_entry = uma_zalloc(kmapentzone, M_NOWAIT);
841 new_entry = uma_zalloc(mapentzone, M_WAITOK);
842 if (new_entry == NULL)
843 panic("vm_map_entry_create: kernel resources exhausted");
848 * vm_map_entry_set_behavior:
850 * Set the expected access behavior, either normal, random, or
854 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior)
856 entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) |
857 (behavior & MAP_ENTRY_BEHAV_MASK);
861 * vm_map_entry_set_max_free:
863 * Set the max_free field in a vm_map_entry.
866 vm_map_entry_set_max_free(vm_map_entry_t entry)
869 entry->max_free = entry->adj_free;
870 if (entry->left != NULL && entry->left->max_free > entry->max_free)
871 entry->max_free = entry->left->max_free;
872 if (entry->right != NULL && entry->right->max_free > entry->max_free)
873 entry->max_free = entry->right->max_free;
877 * vm_map_entry_splay:
879 * The Sleator and Tarjan top-down splay algorithm with the
880 * following variation. Max_free must be computed bottom-up, so
881 * on the downward pass, maintain the left and right spines in
882 * reverse order. Then, make a second pass up each side to fix
883 * the pointers and compute max_free. The time bound is O(log n)
886 * The new root is the vm_map_entry containing "addr", or else an
887 * adjacent entry (lower or higher) if addr is not in the tree.
889 * The map must be locked, and leaves it so.
891 * Returns: the new root.
893 static vm_map_entry_t
894 vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root)
896 vm_map_entry_t llist, rlist;
897 vm_map_entry_t ltree, rtree;
900 /* Special case of empty tree. */
905 * Pass One: Splay down the tree until we find addr or a NULL
906 * pointer where addr would go. llist and rlist are the two
907 * sides in reverse order (bottom-up), with llist linked by
908 * the right pointer and rlist linked by the left pointer in
909 * the vm_map_entry. Wait until Pass Two to set max_free on
915 /* root is never NULL in here. */
916 if (addr < root->start) {
920 if (addr < y->start && y->left != NULL) {
921 /* Rotate right and put y on rlist. */
922 root->left = y->right;
924 vm_map_entry_set_max_free(root);
929 /* Put root on rlist. */
934 } else if (addr >= root->end) {
938 if (addr >= y->end && y->right != NULL) {
939 /* Rotate left and put y on llist. */
940 root->right = y->left;
942 vm_map_entry_set_max_free(root);
947 /* Put root on llist. */
957 * Pass Two: Walk back up the two spines, flip the pointers
958 * and set max_free. The subtrees of the root go at the
959 * bottom of llist and rlist.
962 while (llist != NULL) {
964 llist->right = ltree;
965 vm_map_entry_set_max_free(llist);
970 while (rlist != NULL) {
973 vm_map_entry_set_max_free(rlist);
979 * Final assembly: add ltree and rtree as subtrees of root.
983 vm_map_entry_set_max_free(root);
989 * vm_map_entry_{un,}link:
991 * Insert/remove entries from maps.
994 vm_map_entry_link(vm_map_t map,
995 vm_map_entry_t after_where,
996 vm_map_entry_t entry)
1000 "vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map,
1001 map->nentries, entry, after_where);
1002 VM_MAP_ASSERT_LOCKED(map);
1003 KASSERT(after_where->end <= entry->start,
1004 ("vm_map_entry_link: prev end %jx new start %jx overlap",
1005 (uintmax_t)after_where->end, (uintmax_t)entry->start));
1006 KASSERT(entry->end <= after_where->next->start,
1007 ("vm_map_entry_link: new end %jx next start %jx overlap",
1008 (uintmax_t)entry->end, (uintmax_t)after_where->next->start));
1011 entry->prev = after_where;
1012 entry->next = after_where->next;
1013 entry->next->prev = entry;
1014 after_where->next = entry;
1016 if (after_where != &map->header) {
1017 if (after_where != map->root)
1018 vm_map_entry_splay(after_where->start, map->root);
1019 entry->right = after_where->right;
1020 entry->left = after_where;
1021 after_where->right = NULL;
1022 after_where->adj_free = entry->start - after_where->end;
1023 vm_map_entry_set_max_free(after_where);
1025 entry->right = map->root;
1028 entry->adj_free = entry->next->start - entry->end;
1029 vm_map_entry_set_max_free(entry);
1034 vm_map_entry_unlink(vm_map_t map,
1035 vm_map_entry_t entry)
1037 vm_map_entry_t next, prev, root;
1039 VM_MAP_ASSERT_LOCKED(map);
1040 if (entry != map->root)
1041 vm_map_entry_splay(entry->start, map->root);
1042 if (entry->left == NULL)
1043 root = entry->right;
1045 root = vm_map_entry_splay(entry->start, entry->left);
1046 root->right = entry->right;
1047 root->adj_free = entry->next->start - root->end;
1048 vm_map_entry_set_max_free(root);
1057 CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map,
1058 map->nentries, entry);
1062 * vm_map_entry_resize_free:
1064 * Recompute the amount of free space following a vm_map_entry
1065 * and propagate that value up the tree. Call this function after
1066 * resizing a map entry in-place, that is, without a call to
1067 * vm_map_entry_link() or _unlink().
1069 * The map must be locked, and leaves it so.
1072 vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry)
1076 * Using splay trees without parent pointers, propagating
1077 * max_free up the tree is done by moving the entry to the
1078 * root and making the change there.
1080 if (entry != map->root)
1081 map->root = vm_map_entry_splay(entry->start, map->root);
1083 entry->adj_free = entry->next->start - entry->end;
1084 vm_map_entry_set_max_free(entry);
1088 * vm_map_lookup_entry: [ internal use only ]
1090 * Finds the map entry containing (or
1091 * immediately preceding) the specified address
1092 * in the given map; the entry is returned
1093 * in the "entry" parameter. The boolean
1094 * result indicates whether the address is
1095 * actually contained in the map.
1098 vm_map_lookup_entry(
1100 vm_offset_t address,
1101 vm_map_entry_t *entry) /* OUT */
1107 * If the map is empty, then the map entry immediately preceding
1108 * "address" is the map's header.
1112 *entry = &map->header;
1113 else if (address >= cur->start && cur->end > address) {
1116 } else if ((locked = vm_map_locked(map)) ||
1117 sx_try_upgrade(&map->lock)) {
1119 * Splay requires a write lock on the map. However, it only
1120 * restructures the binary search tree; it does not otherwise
1121 * change the map. Thus, the map's timestamp need not change
1122 * on a temporary upgrade.
1124 map->root = cur = vm_map_entry_splay(address, cur);
1126 sx_downgrade(&map->lock);
1129 * If "address" is contained within a map entry, the new root
1130 * is that map entry. Otherwise, the new root is a map entry
1131 * immediately before or after "address".
1133 if (address >= cur->start) {
1135 if (cur->end > address)
1141 * Since the map is only locked for read access, perform a
1142 * standard binary search tree lookup for "address".
1145 if (address < cur->start) {
1146 if (cur->left == NULL) {
1151 } else if (cur->end > address) {
1155 if (cur->right == NULL) {
1168 * Inserts the given whole VM object into the target
1169 * map at the specified address range. The object's
1170 * size should match that of the address range.
1172 * Requires that the map be locked, and leaves it so.
1174 * If object is non-NULL, ref count must be bumped by caller
1175 * prior to making call to account for the new entry.
1178 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1179 vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow)
1181 vm_map_entry_t new_entry, prev_entry, temp_entry;
1183 vm_eflags_t protoeflags;
1184 vm_inherit_t inheritance;
1186 VM_MAP_ASSERT_LOCKED(map);
1187 KASSERT(object != kernel_object ||
1188 (cow & MAP_COPY_ON_WRITE) == 0,
1189 ("vm_map_insert: kernel object and COW"));
1190 KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0,
1191 ("vm_map_insert: paradoxical MAP_NOFAULT request"));
1192 KASSERT((prot & ~max) == 0,
1193 ("prot %#x is not subset of max_prot %#x", prot, max));
1196 * Check that the start and end points are not bogus.
1198 if (start < vm_map_min(map) || end > vm_map_max(map) ||
1200 return (KERN_INVALID_ADDRESS);
1203 * Find the entry prior to the proposed starting address; if it's part
1204 * of an existing entry, this range is bogus.
1206 if (vm_map_lookup_entry(map, start, &temp_entry))
1207 return (KERN_NO_SPACE);
1209 prev_entry = temp_entry;
1212 * Assert that the next entry doesn't overlap the end point.
1214 if (prev_entry->next->start < end)
1215 return (KERN_NO_SPACE);
1217 if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL ||
1218 max != VM_PROT_NONE))
1219 return (KERN_INVALID_ARGUMENT);
1222 if (cow & MAP_COPY_ON_WRITE)
1223 protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY;
1224 if (cow & MAP_NOFAULT)
1225 protoeflags |= MAP_ENTRY_NOFAULT;
1226 if (cow & MAP_DISABLE_SYNCER)
1227 protoeflags |= MAP_ENTRY_NOSYNC;
1228 if (cow & MAP_DISABLE_COREDUMP)
1229 protoeflags |= MAP_ENTRY_NOCOREDUMP;
1230 if (cow & MAP_STACK_GROWS_DOWN)
1231 protoeflags |= MAP_ENTRY_GROWS_DOWN;
1232 if (cow & MAP_STACK_GROWS_UP)
1233 protoeflags |= MAP_ENTRY_GROWS_UP;
1234 if (cow & MAP_VN_WRITECOUNT)
1235 protoeflags |= MAP_ENTRY_VN_WRITECNT;
1236 if ((cow & MAP_CREATE_GUARD) != 0)
1237 protoeflags |= MAP_ENTRY_GUARD;
1238 if ((cow & MAP_CREATE_STACK_GAP_DN) != 0)
1239 protoeflags |= MAP_ENTRY_STACK_GAP_DN;
1240 if ((cow & MAP_CREATE_STACK_GAP_UP) != 0)
1241 protoeflags |= MAP_ENTRY_STACK_GAP_UP;
1242 if (cow & MAP_INHERIT_SHARE)
1243 inheritance = VM_INHERIT_SHARE;
1245 inheritance = VM_INHERIT_DEFAULT;
1248 if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0)
1250 if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) &&
1251 ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) {
1252 if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start))
1253 return (KERN_RESOURCE_SHORTAGE);
1254 KASSERT(object == NULL ||
1255 (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 ||
1256 object->cred == NULL,
1257 ("overcommit: vm_map_insert o %p", object));
1258 cred = curthread->td_ucred;
1262 /* Expand the kernel pmap, if necessary. */
1263 if (map == kernel_map && end > kernel_vm_end)
1264 pmap_growkernel(end);
1265 if (object != NULL) {
1267 * OBJ_ONEMAPPING must be cleared unless this mapping
1268 * is trivially proven to be the only mapping for any
1269 * of the object's pages. (Object granularity
1270 * reference counting is insufficient to recognize
1271 * aliases with precision.)
1273 VM_OBJECT_WLOCK(object);
1274 if (object->ref_count > 1 || object->shadow_count != 0)
1275 vm_object_clear_flag(object, OBJ_ONEMAPPING);
1276 VM_OBJECT_WUNLOCK(object);
1277 } else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) ==
1279 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 &&
1280 prev_entry->end == start && (prev_entry->cred == cred ||
1281 (prev_entry->object.vm_object != NULL &&
1282 prev_entry->object.vm_object->cred == cred)) &&
1283 vm_object_coalesce(prev_entry->object.vm_object,
1285 (vm_size_t)(prev_entry->end - prev_entry->start),
1286 (vm_size_t)(end - prev_entry->end), cred != NULL &&
1287 (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) {
1289 * We were able to extend the object. Determine if we
1290 * can extend the previous map entry to include the
1291 * new range as well.
1293 if (prev_entry->inheritance == inheritance &&
1294 prev_entry->protection == prot &&
1295 prev_entry->max_protection == max &&
1296 prev_entry->wired_count == 0) {
1297 KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) ==
1298 0, ("prev_entry %p has incoherent wiring",
1300 if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0)
1301 map->size += end - prev_entry->end;
1302 prev_entry->end = end;
1303 vm_map_entry_resize_free(map, prev_entry);
1304 vm_map_simplify_entry(map, prev_entry);
1305 return (KERN_SUCCESS);
1309 * If we can extend the object but cannot extend the
1310 * map entry, we have to create a new map entry. We
1311 * must bump the ref count on the extended object to
1312 * account for it. object may be NULL.
1314 object = prev_entry->object.vm_object;
1315 offset = prev_entry->offset +
1316 (prev_entry->end - prev_entry->start);
1317 vm_object_reference(object);
1318 if (cred != NULL && object != NULL && object->cred != NULL &&
1319 !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
1320 /* Object already accounts for this uid. */
1328 * Create a new entry
1330 new_entry = vm_map_entry_create(map);
1331 new_entry->start = start;
1332 new_entry->end = end;
1333 new_entry->cred = NULL;
1335 new_entry->eflags = protoeflags;
1336 new_entry->object.vm_object = object;
1337 new_entry->offset = offset;
1339 new_entry->inheritance = inheritance;
1340 new_entry->protection = prot;
1341 new_entry->max_protection = max;
1342 new_entry->wired_count = 0;
1343 new_entry->wiring_thread = NULL;
1344 new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT;
1345 new_entry->next_read = start;
1347 KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry),
1348 ("overcommit: vm_map_insert leaks vm_map %p", new_entry));
1349 new_entry->cred = cred;
1352 * Insert the new entry into the list
1354 vm_map_entry_link(map, prev_entry, new_entry);
1355 if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0)
1356 map->size += new_entry->end - new_entry->start;
1359 * Try to coalesce the new entry with both the previous and next
1360 * entries in the list. Previously, we only attempted to coalesce
1361 * with the previous entry when object is NULL. Here, we handle the
1362 * other cases, which are less common.
1364 vm_map_simplify_entry(map, new_entry);
1366 if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) {
1367 vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset),
1368 end - start, cow & MAP_PREFAULT_PARTIAL);
1371 return (KERN_SUCCESS);
1377 * Find the first fit (lowest VM address) for "length" free bytes
1378 * beginning at address >= start in the given map.
1380 * In a vm_map_entry, "adj_free" is the amount of free space
1381 * adjacent (higher address) to this entry, and "max_free" is the
1382 * maximum amount of contiguous free space in its subtree. This
1383 * allows finding a free region in one path down the tree, so
1384 * O(log n) amortized with splay trees.
1386 * The map must be locked, and leaves it so.
1388 * Returns: 0 on success, and starting address in *addr,
1389 * 1 if insufficient space.
1392 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1393 vm_offset_t *addr) /* OUT */
1395 vm_map_entry_t entry;
1399 * Request must fit within min/max VM address and must avoid
1402 start = MAX(start, vm_map_min(map));
1403 if (start + length > vm_map_max(map) || start + length < start)
1406 /* Empty tree means wide open address space. */
1407 if (map->root == NULL) {
1413 * After splay, if start comes before root node, then there
1414 * must be a gap from start to the root.
1416 map->root = vm_map_entry_splay(start, map->root);
1417 if (start + length <= map->root->start) {
1423 * Root is the last node that might begin its gap before
1424 * start, and this is the last comparison where address
1425 * wrap might be a problem.
1427 st = (start > map->root->end) ? start : map->root->end;
1428 if (length <= map->root->end + map->root->adj_free - st) {
1433 /* With max_free, can immediately tell if no solution. */
1434 entry = map->root->right;
1435 if (entry == NULL || length > entry->max_free)
1439 * Search the right subtree in the order: left subtree, root,
1440 * right subtree (first fit). The previous splay implies that
1441 * all regions in the right subtree have addresses > start.
1443 while (entry != NULL) {
1444 if (entry->left != NULL && entry->left->max_free >= length)
1445 entry = entry->left;
1446 else if (entry->adj_free >= length) {
1450 entry = entry->right;
1453 /* Can't get here, so panic if we do. */
1454 panic("vm_map_findspace: max_free corrupt");
1458 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1459 vm_offset_t start, vm_size_t length, vm_prot_t prot,
1460 vm_prot_t max, int cow)
1465 end = start + length;
1466 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
1468 ("vm_map_fixed: non-NULL backing object for stack"));
1470 VM_MAP_RANGE_CHECK(map, start, end);
1471 if ((cow & MAP_CHECK_EXCL) == 0)
1472 vm_map_delete(map, start, end);
1473 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
1474 result = vm_map_stack_locked(map, start, length, sgrowsiz,
1477 result = vm_map_insert(map, object, offset, start, end,
1484 static const int aslr_pages_rnd_64[2] = {0x1000, 0x10};
1485 static const int aslr_pages_rnd_32[2] = {0x100, 0x4};
1487 static int cluster_anon = 1;
1488 SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW,
1490 "Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always");
1493 clustering_anon_allowed(vm_offset_t addr)
1496 switch (cluster_anon) {
1507 static long aslr_restarts;
1508 SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD,
1510 "Number of aslr failures");
1512 #define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31)
1515 * Searches for the specified amount of free space in the given map with the
1516 * specified alignment. Performs an address-ordered, first-fit search from
1517 * the given address "*addr", with an optional upper bound "max_addr". If the
1518 * parameter "alignment" is zero, then the alignment is computed from the
1519 * given (object, offset) pair so as to enable the greatest possible use of
1520 * superpage mappings. Returns KERN_SUCCESS and the address of the free space
1521 * in "*addr" if successful. Otherwise, returns KERN_NO_SPACE.
1523 * The map must be locked. Initially, there must be at least "length" bytes
1524 * of free space at the given address.
1527 vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1528 vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr,
1529 vm_offset_t alignment)
1531 vm_offset_t aligned_addr, free_addr;
1533 VM_MAP_ASSERT_LOCKED(map);
1535 KASSERT(!vm_map_findspace(map, free_addr, length, addr) &&
1536 free_addr == *addr, ("caller provided insufficient free space"));
1539 * At the start of every iteration, the free space at address
1540 * "*addr" is at least "length" bytes.
1543 pmap_align_superpage(object, offset, addr, length);
1544 else if ((*addr & (alignment - 1)) != 0) {
1545 *addr &= ~(alignment - 1);
1548 aligned_addr = *addr;
1549 if (aligned_addr == free_addr) {
1551 * Alignment did not change "*addr", so "*addr" must
1552 * still provide sufficient free space.
1554 return (KERN_SUCCESS);
1558 * Test for address wrap on "*addr". A wrapped "*addr" could
1559 * be a valid address, in which case vm_map_findspace() cannot
1560 * be relied upon to fail.
1562 if (aligned_addr < free_addr ||
1563 vm_map_findspace(map, aligned_addr, length, addr) ||
1564 (max_addr != 0 && *addr + length > max_addr))
1565 return (KERN_NO_SPACE);
1567 if (free_addr == aligned_addr) {
1569 * If a successful call to vm_map_findspace() did not
1570 * change "*addr", then "*addr" must still be aligned
1571 * and provide sufficient free space.
1573 return (KERN_SUCCESS);
1579 * vm_map_find finds an unallocated region in the target address
1580 * map with the given length. The search is defined to be
1581 * first-fit from the specified address; the region found is
1582 * returned in the same parameter.
1584 * If object is non-NULL, ref count must be bumped by caller
1585 * prior to making call to account for the new entry.
1588 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1589 vm_offset_t *addr, /* IN/OUT */
1590 vm_size_t length, vm_offset_t max_addr, int find_space,
1591 vm_prot_t prot, vm_prot_t max, int cow)
1593 vm_offset_t alignment, curr_min_addr, min_addr;
1594 int gap, pidx, rv, try;
1595 bool cluster, en_aslr, update_anon;
1597 KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
1599 ("vm_map_find: non-NULL backing object for stack"));
1600 MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE &&
1601 (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0));
1602 if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL ||
1603 (object->flags & OBJ_COLORED) == 0))
1604 find_space = VMFS_ANY_SPACE;
1605 if (find_space >> 8 != 0) {
1606 KASSERT((find_space & 0xff) == 0, ("bad VMFS flags"));
1607 alignment = (vm_offset_t)1 << (find_space >> 8);
1610 en_aslr = (map->flags & MAP_ASLR) != 0;
1611 update_anon = cluster = clustering_anon_allowed(*addr) &&
1612 (map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 &&
1613 find_space != VMFS_NO_SPACE && object == NULL &&
1614 (cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP |
1615 MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE;
1616 curr_min_addr = min_addr = *addr;
1617 if (en_aslr && min_addr == 0 && !cluster &&
1618 find_space != VMFS_NO_SPACE &&
1619 (map->flags & MAP_ASLR_IGNSTART) != 0)
1620 curr_min_addr = min_addr = vm_map_min(map);
1624 curr_min_addr = map->anon_loc;
1625 if (curr_min_addr == 0)
1628 if (find_space != VMFS_NO_SPACE) {
1629 KASSERT(find_space == VMFS_ANY_SPACE ||
1630 find_space == VMFS_OPTIMAL_SPACE ||
1631 find_space == VMFS_SUPER_SPACE ||
1632 alignment != 0, ("unexpected VMFS flag"));
1635 * When creating an anonymous mapping, try clustering
1636 * with an existing anonymous mapping first.
1638 * We make up to two attempts to find address space
1639 * for a given find_space value. The first attempt may
1640 * apply randomization or may cluster with an existing
1641 * anonymous mapping. If this first attempt fails,
1642 * perform a first-fit search of the available address
1645 * If all tries failed, and find_space is
1646 * VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE.
1647 * Again enable clustering and randomization.
1654 * Second try: we failed either to find a
1655 * suitable region for randomizing the
1656 * allocation, or to cluster with an existing
1657 * mapping. Retry with free run.
1659 curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ?
1660 vm_map_min(map) : min_addr;
1661 atomic_add_long(&aslr_restarts, 1);
1664 if (try == 1 && en_aslr && !cluster) {
1666 * Find space for allocation, including
1667 * gap needed for later randomization.
1669 pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 &&
1670 (find_space == VMFS_SUPER_SPACE || find_space ==
1671 VMFS_OPTIMAL_SPACE) ? 1 : 0;
1672 gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR &&
1673 (max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ?
1674 aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx];
1675 if (vm_map_findspace(map, curr_min_addr, length +
1676 gap * pagesizes[pidx], addr) ||
1677 (max_addr != 0 && *addr + length > max_addr))
1679 /* And randomize the start address. */
1680 *addr += (arc4random() % gap) * pagesizes[pidx];
1681 } else if (vm_map_findspace(map, curr_min_addr, length, addr) ||
1682 (max_addr != 0 && *addr + length > max_addr)) {
1692 if (find_space != VMFS_ANY_SPACE &&
1693 (rv = vm_map_alignspace(map, object, offset, addr, length,
1694 max_addr, alignment)) != KERN_SUCCESS) {
1695 if (find_space == VMFS_OPTIMAL_SPACE) {
1696 find_space = VMFS_ANY_SPACE;
1697 curr_min_addr = min_addr;
1698 cluster = update_anon;
1704 } else if ((cow & MAP_REMAP) != 0) {
1705 if (*addr < vm_map_min(map) ||
1706 *addr + length > vm_map_max(map) ||
1707 *addr + length <= length) {
1708 rv = KERN_INVALID_ADDRESS;
1711 vm_map_delete(map, *addr, *addr + length);
1713 if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
1714 rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot,
1717 rv = vm_map_insert(map, object, offset, *addr, *addr + length,
1720 if (rv == KERN_SUCCESS && update_anon)
1721 map->anon_loc = *addr + length;
1728 * vm_map_find_min() is a variant of vm_map_find() that takes an
1729 * additional parameter (min_addr) and treats the given address
1730 * (*addr) differently. Specifically, it treats *addr as a hint
1731 * and not as the minimum address where the mapping is created.
1733 * This function works in two phases. First, it tries to
1734 * allocate above the hint. If that fails and the hint is
1735 * greater than min_addr, it performs a second pass, replacing
1736 * the hint with min_addr as the minimum address for the
1740 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1741 vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr,
1742 vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max,
1750 rv = vm_map_find(map, object, offset, addr, length, max_addr,
1751 find_space, prot, max, cow);
1752 if (rv == KERN_SUCCESS || min_addr >= hint)
1754 *addr = hint = min_addr;
1759 * A map entry with any of the following flags set must not be merged with
1762 #define MAP_ENTRY_NOMERGE_MASK (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \
1763 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)
1766 vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry)
1769 KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 ||
1770 (entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0,
1771 ("vm_map_mergeable_neighbors: neither %p nor %p are mergeable",
1773 return (prev->end == entry->start &&
1774 prev->object.vm_object == entry->object.vm_object &&
1775 (prev->object.vm_object == NULL ||
1776 prev->offset + (prev->end - prev->start) == entry->offset) &&
1777 prev->eflags == entry->eflags &&
1778 prev->protection == entry->protection &&
1779 prev->max_protection == entry->max_protection &&
1780 prev->inheritance == entry->inheritance &&
1781 prev->wired_count == entry->wired_count &&
1782 prev->cred == entry->cred);
1786 vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry)
1790 * If the backing object is a vnode object, vm_object_deallocate()
1791 * calls vrele(). However, vrele() does not lock the vnode because
1792 * the vnode has additional references. Thus, the map lock can be
1793 * kept without causing a lock-order reversal with the vnode lock.
1795 * Since we count the number of virtual page mappings in
1796 * object->un_pager.vnp.writemappings, the writemappings value
1797 * should not be adjusted when the entry is disposed of.
1799 if (entry->object.vm_object != NULL)
1800 vm_object_deallocate(entry->object.vm_object);
1801 if (entry->cred != NULL)
1802 crfree(entry->cred);
1803 vm_map_entry_dispose(map, entry);
1807 * vm_map_simplify_entry:
1809 * Simplify the given map entry by merging with either neighbor. This
1810 * routine also has the ability to merge with both neighbors.
1812 * The map must be locked.
1814 * This routine guarantees that the passed entry remains valid (though
1815 * possibly extended). When merging, this routine may delete one or
1819 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry)
1821 vm_map_entry_t next, prev;
1823 if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) != 0)
1826 if (vm_map_mergeable_neighbors(prev, entry)) {
1827 vm_map_entry_unlink(map, prev);
1828 entry->start = prev->start;
1829 entry->offset = prev->offset;
1830 if (entry->prev != &map->header)
1831 vm_map_entry_resize_free(map, entry->prev);
1832 vm_map_merged_neighbor_dispose(map, prev);
1835 if (vm_map_mergeable_neighbors(entry, next)) {
1836 vm_map_entry_unlink(map, next);
1837 entry->end = next->end;
1838 vm_map_entry_resize_free(map, entry);
1839 vm_map_merged_neighbor_dispose(map, next);
1844 * vm_map_clip_start: [ internal use only ]
1846 * Asserts that the given entry begins at or after
1847 * the specified address; if necessary,
1848 * it splits the entry into two.
1850 #define vm_map_clip_start(map, entry, startaddr) \
1852 if (startaddr > entry->start) \
1853 _vm_map_clip_start(map, entry, startaddr); \
1857 * This routine is called only when it is known that
1858 * the entry must be split.
1861 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start)
1863 vm_map_entry_t new_entry;
1865 VM_MAP_ASSERT_LOCKED(map);
1866 KASSERT(entry->end > start && entry->start < start,
1867 ("_vm_map_clip_start: invalid clip of entry %p", entry));
1870 * Split off the front portion -- note that we must insert the new
1871 * entry BEFORE this one, so that this entry has the specified
1874 vm_map_simplify_entry(map, entry);
1877 * If there is no object backing this entry, we might as well create
1878 * one now. If we defer it, an object can get created after the map
1879 * is clipped, and individual objects will be created for the split-up
1880 * map. This is a bit of a hack, but is also about the best place to
1881 * put this improvement.
1883 if (entry->object.vm_object == NULL && !map->system_map &&
1884 (entry->eflags & MAP_ENTRY_GUARD) == 0) {
1886 object = vm_object_allocate(OBJT_DEFAULT,
1887 atop(entry->end - entry->start));
1888 entry->object.vm_object = object;
1890 if (entry->cred != NULL) {
1891 object->cred = entry->cred;
1892 object->charge = entry->end - entry->start;
1895 } else if (entry->object.vm_object != NULL &&
1896 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
1897 entry->cred != NULL) {
1898 VM_OBJECT_WLOCK(entry->object.vm_object);
1899 KASSERT(entry->object.vm_object->cred == NULL,
1900 ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry));
1901 entry->object.vm_object->cred = entry->cred;
1902 entry->object.vm_object->charge = entry->end - entry->start;
1903 VM_OBJECT_WUNLOCK(entry->object.vm_object);
1907 new_entry = vm_map_entry_create(map);
1908 *new_entry = *entry;
1910 new_entry->end = start;
1911 entry->offset += (start - entry->start);
1912 entry->start = start;
1913 if (new_entry->cred != NULL)
1914 crhold(entry->cred);
1916 vm_map_entry_link(map, entry->prev, new_entry);
1918 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
1919 vm_object_reference(new_entry->object.vm_object);
1921 * The object->un_pager.vnp.writemappings for the
1922 * object of MAP_ENTRY_VN_WRITECNT type entry shall be
1923 * kept as is here. The virtual pages are
1924 * re-distributed among the clipped entries, so the sum is
1931 * vm_map_clip_end: [ internal use only ]
1933 * Asserts that the given entry ends at or before
1934 * the specified address; if necessary,
1935 * it splits the entry into two.
1937 #define vm_map_clip_end(map, entry, endaddr) \
1939 if ((endaddr) < (entry->end)) \
1940 _vm_map_clip_end((map), (entry), (endaddr)); \
1944 * This routine is called only when it is known that
1945 * the entry must be split.
1948 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end)
1950 vm_map_entry_t new_entry;
1952 VM_MAP_ASSERT_LOCKED(map);
1953 KASSERT(entry->start < end && entry->end > end,
1954 ("_vm_map_clip_end: invalid clip of entry %p", entry));
1957 * If there is no object backing this entry, we might as well create
1958 * one now. If we defer it, an object can get created after the map
1959 * is clipped, and individual objects will be created for the split-up
1960 * map. This is a bit of a hack, but is also about the best place to
1961 * put this improvement.
1963 if (entry->object.vm_object == NULL && !map->system_map &&
1964 (entry->eflags & MAP_ENTRY_GUARD) == 0) {
1966 object = vm_object_allocate(OBJT_DEFAULT,
1967 atop(entry->end - entry->start));
1968 entry->object.vm_object = object;
1970 if (entry->cred != NULL) {
1971 object->cred = entry->cred;
1972 object->charge = entry->end - entry->start;
1975 } else if (entry->object.vm_object != NULL &&
1976 ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
1977 entry->cred != NULL) {
1978 VM_OBJECT_WLOCK(entry->object.vm_object);
1979 KASSERT(entry->object.vm_object->cred == NULL,
1980 ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry));
1981 entry->object.vm_object->cred = entry->cred;
1982 entry->object.vm_object->charge = entry->end - entry->start;
1983 VM_OBJECT_WUNLOCK(entry->object.vm_object);
1988 * Create a new entry and insert it AFTER the specified entry
1990 new_entry = vm_map_entry_create(map);
1991 *new_entry = *entry;
1993 new_entry->start = entry->end = end;
1994 new_entry->offset += (end - entry->start);
1995 if (new_entry->cred != NULL)
1996 crhold(entry->cred);
1998 vm_map_entry_link(map, entry, new_entry);
2000 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
2001 vm_object_reference(new_entry->object.vm_object);
2006 * vm_map_submap: [ kernel use only ]
2008 * Mark the given range as handled by a subordinate map.
2010 * This range must have been created with vm_map_find,
2011 * and no other operations may have been performed on this
2012 * range prior to calling vm_map_submap.
2014 * Only a limited number of operations can be performed
2015 * within this rage after calling vm_map_submap:
2017 * [Don't try vm_map_copy!]
2019 * To remove a submapping, one must first remove the
2020 * range from the superior map, and then destroy the
2021 * submap (if desired). [Better yet, don't try it.]
2030 vm_map_entry_t entry;
2033 result = KERN_INVALID_ARGUMENT;
2035 vm_map_lock(submap);
2036 submap->flags |= MAP_IS_SUB_MAP;
2037 vm_map_unlock(submap);
2041 VM_MAP_RANGE_CHECK(map, start, end);
2043 if (vm_map_lookup_entry(map, start, &entry)) {
2044 vm_map_clip_start(map, entry, start);
2046 entry = entry->next;
2048 vm_map_clip_end(map, entry, end);
2050 if ((entry->start == start) && (entry->end == end) &&
2051 ((entry->eflags & MAP_ENTRY_COW) == 0) &&
2052 (entry->object.vm_object == NULL)) {
2053 entry->object.sub_map = submap;
2054 entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
2055 result = KERN_SUCCESS;
2059 if (result != KERN_SUCCESS) {
2060 vm_map_lock(submap);
2061 submap->flags &= ~MAP_IS_SUB_MAP;
2062 vm_map_unlock(submap);
2068 * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified
2070 #define MAX_INIT_PT 96
2073 * vm_map_pmap_enter:
2075 * Preload the specified map's pmap with mappings to the specified
2076 * object's memory-resident pages. No further physical pages are
2077 * allocated, and no further virtual pages are retrieved from secondary
2078 * storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a
2079 * limited number of page mappings are created at the low-end of the
2080 * specified address range. (For this purpose, a superpage mapping
2081 * counts as one page mapping.) Otherwise, all resident pages within
2082 * the specified address range are mapped.
2085 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
2086 vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags)
2089 vm_page_t p, p_start;
2090 vm_pindex_t mask, psize, threshold, tmpidx;
2092 if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL)
2094 VM_OBJECT_RLOCK(object);
2095 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2096 VM_OBJECT_RUNLOCK(object);
2097 VM_OBJECT_WLOCK(object);
2098 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2099 pmap_object_init_pt(map->pmap, addr, object, pindex,
2101 VM_OBJECT_WUNLOCK(object);
2104 VM_OBJECT_LOCK_DOWNGRADE(object);
2108 if (psize + pindex > object->size) {
2109 if (object->size < pindex) {
2110 VM_OBJECT_RUNLOCK(object);
2113 psize = object->size - pindex;
2118 threshold = MAX_INIT_PT;
2120 p = vm_page_find_least(object, pindex);
2122 * Assert: the variable p is either (1) the page with the
2123 * least pindex greater than or equal to the parameter pindex
2127 p != NULL && (tmpidx = p->pindex - pindex) < psize;
2128 p = TAILQ_NEXT(p, listq)) {
2130 * don't allow an madvise to blow away our really
2131 * free pages allocating pv entries.
2133 if (((flags & MAP_PREFAULT_MADVISE) != 0 &&
2134 vm_page_count_severe()) ||
2135 ((flags & MAP_PREFAULT_PARTIAL) != 0 &&
2136 tmpidx >= threshold)) {
2140 if (p->valid == VM_PAGE_BITS_ALL) {
2141 if (p_start == NULL) {
2142 start = addr + ptoa(tmpidx);
2145 /* Jump ahead if a superpage mapping is possible. */
2146 if (p->psind > 0 && ((addr + ptoa(tmpidx)) &
2147 (pagesizes[p->psind] - 1)) == 0) {
2148 mask = atop(pagesizes[p->psind]) - 1;
2149 if (tmpidx + mask < psize &&
2150 vm_page_ps_test(p, PS_ALL_VALID, NULL)) {
2155 } else if (p_start != NULL) {
2156 pmap_enter_object(map->pmap, start, addr +
2157 ptoa(tmpidx), p_start, prot);
2161 if (p_start != NULL)
2162 pmap_enter_object(map->pmap, start, addr + ptoa(psize),
2164 VM_OBJECT_RUNLOCK(object);
2170 * Sets the protection of the specified address
2171 * region in the target map. If "set_max" is
2172 * specified, the maximum protection is to be set;
2173 * otherwise, only the current protection is affected.
2176 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
2177 vm_prot_t new_prot, boolean_t set_max)
2179 vm_map_entry_t current, entry;
2185 return (KERN_SUCCESS);
2190 * Ensure that we are not concurrently wiring pages. vm_map_wire() may
2191 * need to fault pages into the map and will drop the map lock while
2192 * doing so, and the VM object may end up in an inconsistent state if we
2193 * update the protection on the map entry in between faults.
2195 vm_map_wait_busy(map);
2197 VM_MAP_RANGE_CHECK(map, start, end);
2199 if (vm_map_lookup_entry(map, start, &entry)) {
2200 vm_map_clip_start(map, entry, start);
2202 entry = entry->next;
2206 * Make a first pass to check for protection violations.
2208 for (current = entry; current->start < end; current = current->next) {
2209 if ((current->eflags & MAP_ENTRY_GUARD) != 0)
2211 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
2213 return (KERN_INVALID_ARGUMENT);
2215 if ((new_prot & current->max_protection) != new_prot) {
2217 return (KERN_PROTECTION_FAILURE);
2222 * Do an accounting pass for private read-only mappings that
2223 * now will do cow due to allowed write (e.g. debugger sets
2224 * breakpoint on text segment)
2226 for (current = entry; current->start < end; current = current->next) {
2228 vm_map_clip_end(map, current, end);
2231 ((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 ||
2232 ENTRY_CHARGED(current) ||
2233 (current->eflags & MAP_ENTRY_GUARD) != 0) {
2237 cred = curthread->td_ucred;
2238 obj = current->object.vm_object;
2240 if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) {
2241 if (!swap_reserve(current->end - current->start)) {
2243 return (KERN_RESOURCE_SHORTAGE);
2246 current->cred = cred;
2250 VM_OBJECT_WLOCK(obj);
2251 if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) {
2252 VM_OBJECT_WUNLOCK(obj);
2257 * Charge for the whole object allocation now, since
2258 * we cannot distinguish between non-charged and
2259 * charged clipped mapping of the same object later.
2261 KASSERT(obj->charge == 0,
2262 ("vm_map_protect: object %p overcharged (entry %p)",
2264 if (!swap_reserve(ptoa(obj->size))) {
2265 VM_OBJECT_WUNLOCK(obj);
2267 return (KERN_RESOURCE_SHORTAGE);
2272 obj->charge = ptoa(obj->size);
2273 VM_OBJECT_WUNLOCK(obj);
2277 * Go back and fix up protections. [Note that clipping is not
2278 * necessary the second time.]
2280 for (current = entry; current->start < end; current = current->next) {
2281 if ((current->eflags & MAP_ENTRY_GUARD) != 0)
2284 old_prot = current->protection;
2287 current->protection =
2288 (current->max_protection = new_prot) &
2291 current->protection = new_prot;
2294 * For user wired map entries, the normal lazy evaluation of
2295 * write access upgrades through soft page faults is
2296 * undesirable. Instead, immediately copy any pages that are
2297 * copy-on-write and enable write access in the physical map.
2299 if ((current->eflags & MAP_ENTRY_USER_WIRED) != 0 &&
2300 (current->protection & VM_PROT_WRITE) != 0 &&
2301 (old_prot & VM_PROT_WRITE) == 0)
2302 vm_fault_copy_entry(map, map, current, current, NULL);
2305 * When restricting access, update the physical map. Worry
2306 * about copy-on-write here.
2308 if ((old_prot & ~current->protection) != 0) {
2309 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
2311 pmap_protect(map->pmap, current->start,
2313 current->protection & MASK(current));
2316 vm_map_simplify_entry(map, current);
2319 return (KERN_SUCCESS);
2325 * This routine traverses a processes map handling the madvise
2326 * system call. Advisories are classified as either those effecting
2327 * the vm_map_entry structure, or those effecting the underlying
2337 vm_map_entry_t current, entry;
2341 * Some madvise calls directly modify the vm_map_entry, in which case
2342 * we need to use an exclusive lock on the map and we need to perform
2343 * various clipping operations. Otherwise we only need a read-lock
2348 case MADV_SEQUENTIAL:
2365 vm_map_lock_read(map);
2372 * Locate starting entry and clip if necessary.
2374 VM_MAP_RANGE_CHECK(map, start, end);
2376 if (vm_map_lookup_entry(map, start, &entry)) {
2378 vm_map_clip_start(map, entry, start);
2380 entry = entry->next;
2385 * madvise behaviors that are implemented in the vm_map_entry.
2387 * We clip the vm_map_entry so that behavioral changes are
2388 * limited to the specified address range.
2390 for (current = entry; current->start < end;
2391 current = current->next) {
2392 if (current->eflags & MAP_ENTRY_IS_SUB_MAP)
2395 vm_map_clip_end(map, current, end);
2399 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
2401 case MADV_SEQUENTIAL:
2402 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
2405 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
2408 current->eflags |= MAP_ENTRY_NOSYNC;
2411 current->eflags &= ~MAP_ENTRY_NOSYNC;
2414 current->eflags |= MAP_ENTRY_NOCOREDUMP;
2417 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
2422 vm_map_simplify_entry(map, current);
2426 vm_pindex_t pstart, pend;
2429 * madvise behaviors that are implemented in the underlying
2432 * Since we don't clip the vm_map_entry, we have to clip
2433 * the vm_object pindex and count.
2435 for (current = entry; current->start < end;
2436 current = current->next) {
2437 vm_offset_t useEnd, useStart;
2439 if (current->eflags & MAP_ENTRY_IS_SUB_MAP)
2442 pstart = OFF_TO_IDX(current->offset);
2443 pend = pstart + atop(current->end - current->start);
2444 useStart = current->start;
2445 useEnd = current->end;
2447 if (current->start < start) {
2448 pstart += atop(start - current->start);
2451 if (current->end > end) {
2452 pend -= atop(current->end - end);
2460 * Perform the pmap_advise() before clearing
2461 * PGA_REFERENCED in vm_page_advise(). Otherwise, a
2462 * concurrent pmap operation, such as pmap_remove(),
2463 * could clear a reference in the pmap and set
2464 * PGA_REFERENCED on the page before the pmap_advise()
2465 * had completed. Consequently, the page would appear
2466 * referenced based upon an old reference that
2467 * occurred before this pmap_advise() ran.
2469 if (behav == MADV_DONTNEED || behav == MADV_FREE)
2470 pmap_advise(map->pmap, useStart, useEnd,
2473 vm_object_madvise(current->object.vm_object, pstart,
2477 * Pre-populate paging structures in the
2478 * WILLNEED case. For wired entries, the
2479 * paging structures are already populated.
2481 if (behav == MADV_WILLNEED &&
2482 current->wired_count == 0) {
2483 vm_map_pmap_enter(map,
2485 current->protection,
2486 current->object.vm_object,
2488 ptoa(pend - pstart),
2489 MAP_PREFAULT_MADVISE
2493 vm_map_unlock_read(map);
2502 * Sets the inheritance of the specified address
2503 * range in the target map. Inheritance
2504 * affects how the map will be shared with
2505 * child maps at the time of vmspace_fork.
2508 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
2509 vm_inherit_t new_inheritance)
2511 vm_map_entry_t entry;
2512 vm_map_entry_t temp_entry;
2514 switch (new_inheritance) {
2515 case VM_INHERIT_NONE:
2516 case VM_INHERIT_COPY:
2517 case VM_INHERIT_SHARE:
2518 case VM_INHERIT_ZERO:
2521 return (KERN_INVALID_ARGUMENT);
2524 return (KERN_SUCCESS);
2526 VM_MAP_RANGE_CHECK(map, start, end);
2527 if (vm_map_lookup_entry(map, start, &temp_entry)) {
2529 vm_map_clip_start(map, entry, start);
2531 entry = temp_entry->next;
2532 while (entry->start < end) {
2533 vm_map_clip_end(map, entry, end);
2534 if ((entry->eflags & MAP_ENTRY_GUARD) == 0 ||
2535 new_inheritance != VM_INHERIT_ZERO)
2536 entry->inheritance = new_inheritance;
2537 vm_map_simplify_entry(map, entry);
2538 entry = entry->next;
2541 return (KERN_SUCCESS);
2547 * Implements both kernel and user unwiring.
2550 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
2553 vm_map_entry_t entry, first_entry, tmp_entry;
2554 vm_offset_t saved_start;
2555 unsigned int last_timestamp;
2557 boolean_t need_wakeup, result, user_unwire;
2560 return (KERN_SUCCESS);
2561 user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE;
2563 VM_MAP_RANGE_CHECK(map, start, end);
2564 if (!vm_map_lookup_entry(map, start, &first_entry)) {
2565 if (flags & VM_MAP_WIRE_HOLESOK)
2566 first_entry = first_entry->next;
2569 return (KERN_INVALID_ADDRESS);
2572 last_timestamp = map->timestamp;
2573 entry = first_entry;
2574 while (entry->start < end) {
2575 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2577 * We have not yet clipped the entry.
2579 saved_start = (start >= entry->start) ? start :
2581 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2582 if (vm_map_unlock_and_wait(map, 0)) {
2584 * Allow interruption of user unwiring?
2588 if (last_timestamp+1 != map->timestamp) {
2590 * Look again for the entry because the map was
2591 * modified while it was unlocked.
2592 * Specifically, the entry may have been
2593 * clipped, merged, or deleted.
2595 if (!vm_map_lookup_entry(map, saved_start,
2597 if (flags & VM_MAP_WIRE_HOLESOK)
2598 tmp_entry = tmp_entry->next;
2600 if (saved_start == start) {
2602 * First_entry has been deleted.
2605 return (KERN_INVALID_ADDRESS);
2608 rv = KERN_INVALID_ADDRESS;
2612 if (entry == first_entry)
2613 first_entry = tmp_entry;
2618 last_timestamp = map->timestamp;
2621 vm_map_clip_start(map, entry, start);
2622 vm_map_clip_end(map, entry, end);
2624 * Mark the entry in case the map lock is released. (See
2627 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
2628 entry->wiring_thread == NULL,
2629 ("owned map entry %p", entry));
2630 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
2631 entry->wiring_thread = curthread;
2633 * Check the map for holes in the specified region.
2634 * If VM_MAP_WIRE_HOLESOK was specified, skip this check.
2636 if (((flags & VM_MAP_WIRE_HOLESOK) == 0) &&
2637 (entry->end < end && entry->next->start > entry->end)) {
2639 rv = KERN_INVALID_ADDRESS;
2643 * If system unwiring, require that the entry is system wired.
2646 vm_map_entry_system_wired_count(entry) == 0) {
2648 rv = KERN_INVALID_ARGUMENT;
2651 entry = entry->next;
2655 need_wakeup = FALSE;
2656 if (first_entry == NULL) {
2657 result = vm_map_lookup_entry(map, start, &first_entry);
2658 if (!result && (flags & VM_MAP_WIRE_HOLESOK))
2659 first_entry = first_entry->next;
2661 KASSERT(result, ("vm_map_unwire: lookup failed"));
2663 for (entry = first_entry; entry->start < end; entry = entry->next) {
2665 * If VM_MAP_WIRE_HOLESOK was specified, an empty
2666 * space in the unwired region could have been mapped
2667 * while the map lock was dropped for draining
2668 * MAP_ENTRY_IN_TRANSITION. Moreover, another thread
2669 * could be simultaneously wiring this new mapping
2670 * entry. Detect these cases and skip any entries
2671 * marked as in transition by us.
2673 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
2674 entry->wiring_thread != curthread) {
2675 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0,
2676 ("vm_map_unwire: !HOLESOK and new/changed entry"));
2680 if (rv == KERN_SUCCESS && (!user_unwire ||
2681 (entry->eflags & MAP_ENTRY_USER_WIRED))) {
2683 entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2684 if (entry->wired_count == 1)
2685 vm_map_entry_unwire(map, entry);
2687 entry->wired_count--;
2689 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
2690 ("vm_map_unwire: in-transition flag missing %p", entry));
2691 KASSERT(entry->wiring_thread == curthread,
2692 ("vm_map_unwire: alien wire %p", entry));
2693 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
2694 entry->wiring_thread = NULL;
2695 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
2696 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
2699 vm_map_simplify_entry(map, entry);
2708 * vm_map_wire_entry_failure:
2710 * Handle a wiring failure on the given entry.
2712 * The map should be locked.
2715 vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
2716 vm_offset_t failed_addr)
2719 VM_MAP_ASSERT_LOCKED(map);
2720 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 &&
2721 entry->wired_count == 1,
2722 ("vm_map_wire_entry_failure: entry %p isn't being wired", entry));
2723 KASSERT(failed_addr < entry->end,
2724 ("vm_map_wire_entry_failure: entry %p was fully wired", entry));
2727 * If any pages at the start of this entry were successfully wired,
2730 if (failed_addr > entry->start) {
2731 pmap_unwire(map->pmap, entry->start, failed_addr);
2732 vm_object_unwire(entry->object.vm_object, entry->offset,
2733 failed_addr - entry->start, PQ_ACTIVE);
2737 * Assign an out-of-range value to represent the failure to wire this
2740 entry->wired_count = -1;
2746 * Implements both kernel and user wiring.
2749 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
2752 vm_map_entry_t entry, first_entry, tmp_entry;
2753 vm_offset_t faddr, saved_end, saved_start;
2754 unsigned int last_timestamp;
2756 boolean_t need_wakeup, result, user_wire;
2760 return (KERN_SUCCESS);
2762 if (flags & VM_MAP_WIRE_WRITE)
2763 prot |= VM_PROT_WRITE;
2764 user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE;
2766 VM_MAP_RANGE_CHECK(map, start, end);
2767 if (!vm_map_lookup_entry(map, start, &first_entry)) {
2768 if (flags & VM_MAP_WIRE_HOLESOK)
2769 first_entry = first_entry->next;
2772 return (KERN_INVALID_ADDRESS);
2775 last_timestamp = map->timestamp;
2776 entry = first_entry;
2777 while (entry->start < end) {
2778 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2780 * We have not yet clipped the entry.
2782 saved_start = (start >= entry->start) ? start :
2784 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2785 if (vm_map_unlock_and_wait(map, 0)) {
2787 * Allow interruption of user wiring?
2791 if (last_timestamp + 1 != map->timestamp) {
2793 * Look again for the entry because the map was
2794 * modified while it was unlocked.
2795 * Specifically, the entry may have been
2796 * clipped, merged, or deleted.
2798 if (!vm_map_lookup_entry(map, saved_start,
2800 if (flags & VM_MAP_WIRE_HOLESOK)
2801 tmp_entry = tmp_entry->next;
2803 if (saved_start == start) {
2805 * first_entry has been deleted.
2808 return (KERN_INVALID_ADDRESS);
2811 rv = KERN_INVALID_ADDRESS;
2815 if (entry == first_entry)
2816 first_entry = tmp_entry;
2821 last_timestamp = map->timestamp;
2824 vm_map_clip_start(map, entry, start);
2825 vm_map_clip_end(map, entry, end);
2827 * Mark the entry in case the map lock is released. (See
2830 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
2831 entry->wiring_thread == NULL,
2832 ("owned map entry %p", entry));
2833 entry->eflags |= MAP_ENTRY_IN_TRANSITION;
2834 entry->wiring_thread = curthread;
2835 if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0
2836 || (entry->protection & prot) != prot) {
2837 entry->eflags |= MAP_ENTRY_WIRE_SKIPPED;
2838 if ((flags & VM_MAP_WIRE_HOLESOK) == 0) {
2840 rv = KERN_INVALID_ADDRESS;
2845 if (entry->wired_count == 0) {
2846 entry->wired_count++;
2847 saved_start = entry->start;
2848 saved_end = entry->end;
2851 * Release the map lock, relying on the in-transition
2852 * mark. Mark the map busy for fork.
2857 faddr = saved_start;
2860 * Simulate a fault to get the page and enter
2861 * it into the physical map.
2863 if ((rv = vm_fault(map, faddr, VM_PROT_NONE,
2864 VM_FAULT_WIRE)) != KERN_SUCCESS)
2866 } while ((faddr += PAGE_SIZE) < saved_end);
2869 if (last_timestamp + 1 != map->timestamp) {
2871 * Look again for the entry because the map was
2872 * modified while it was unlocked. The entry
2873 * may have been clipped, but NOT merged or
2876 result = vm_map_lookup_entry(map, saved_start,
2878 KASSERT(result, ("vm_map_wire: lookup failed"));
2879 if (entry == first_entry)
2880 first_entry = tmp_entry;
2884 while (entry->end < saved_end) {
2886 * In case of failure, handle entries
2887 * that were not fully wired here;
2888 * fully wired entries are handled
2891 if (rv != KERN_SUCCESS &&
2893 vm_map_wire_entry_failure(map,
2895 entry = entry->next;
2898 last_timestamp = map->timestamp;
2899 if (rv != KERN_SUCCESS) {
2900 vm_map_wire_entry_failure(map, entry, faddr);
2904 } else if (!user_wire ||
2905 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2906 entry->wired_count++;
2909 * Check the map for holes in the specified region.
2910 * If VM_MAP_WIRE_HOLESOK was specified, skip this check.
2913 if ((flags & VM_MAP_WIRE_HOLESOK) == 0 &&
2914 entry->end < end && entry->next->start > entry->end) {
2916 rv = KERN_INVALID_ADDRESS;
2919 entry = entry->next;
2923 need_wakeup = FALSE;
2924 if (first_entry == NULL) {
2925 result = vm_map_lookup_entry(map, start, &first_entry);
2926 if (!result && (flags & VM_MAP_WIRE_HOLESOK))
2927 first_entry = first_entry->next;
2929 KASSERT(result, ("vm_map_wire: lookup failed"));
2931 for (entry = first_entry; entry->start < end; entry = entry->next) {
2933 * If VM_MAP_WIRE_HOLESOK was specified, an empty
2934 * space in the unwired region could have been mapped
2935 * while the map lock was dropped for faulting in the
2936 * pages or draining MAP_ENTRY_IN_TRANSITION.
2937 * Moreover, another thread could be simultaneously
2938 * wiring this new mapping entry. Detect these cases
2939 * and skip any entries marked as in transition not by us.
2941 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
2942 entry->wiring_thread != curthread) {
2943 KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0,
2944 ("vm_map_wire: !HOLESOK and new/changed entry"));
2948 if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0)
2949 goto next_entry_done;
2951 if (rv == KERN_SUCCESS) {
2953 entry->eflags |= MAP_ENTRY_USER_WIRED;
2954 } else if (entry->wired_count == -1) {
2956 * Wiring failed on this entry. Thus, unwiring is
2959 entry->wired_count = 0;
2960 } else if (!user_wire ||
2961 (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2963 * Undo the wiring. Wiring succeeded on this entry
2964 * but failed on a later entry.
2966 if (entry->wired_count == 1)
2967 vm_map_entry_unwire(map, entry);
2969 entry->wired_count--;
2972 KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
2973 ("vm_map_wire: in-transition flag missing %p", entry));
2974 KASSERT(entry->wiring_thread == curthread,
2975 ("vm_map_wire: alien wire %p", entry));
2976 entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION |
2977 MAP_ENTRY_WIRE_SKIPPED);
2978 entry->wiring_thread = NULL;
2979 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
2980 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
2983 vm_map_simplify_entry(map, entry);
2994 * Push any dirty cached pages in the address range to their pager.
2995 * If syncio is TRUE, dirty pages are written synchronously.
2996 * If invalidate is TRUE, any cached pages are freed as well.
2998 * If the size of the region from start to end is zero, we are
2999 * supposed to flush all modified pages within the region containing
3000 * start. Unfortunately, a region can be split or coalesced with
3001 * neighboring regions, making it difficult to determine what the
3002 * original region was. Therefore, we approximate this requirement by
3003 * flushing the current region containing start.
3005 * Returns an error if any part of the specified range is not mapped.
3013 boolean_t invalidate)
3015 vm_map_entry_t current;
3016 vm_map_entry_t entry;
3019 vm_ooffset_t offset;
3020 unsigned int last_timestamp;
3023 vm_map_lock_read(map);
3024 VM_MAP_RANGE_CHECK(map, start, end);
3025 if (!vm_map_lookup_entry(map, start, &entry)) {
3026 vm_map_unlock_read(map);
3027 return (KERN_INVALID_ADDRESS);
3028 } else if (start == end) {
3029 start = entry->start;
3033 * Make a first pass to check for user-wired memory and holes.
3035 for (current = entry; current->start < end; current = current->next) {
3036 if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) {
3037 vm_map_unlock_read(map);
3038 return (KERN_INVALID_ARGUMENT);
3040 if (end > current->end &&
3041 current->end != current->next->start) {
3042 vm_map_unlock_read(map);
3043 return (KERN_INVALID_ADDRESS);
3048 pmap_remove(map->pmap, start, end);
3052 * Make a second pass, cleaning/uncaching pages from the indicated
3055 for (current = entry; current->start < end;) {
3056 offset = current->offset + (start - current->start);
3057 size = (end <= current->end ? end : current->end) - start;
3058 if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
3060 vm_map_entry_t tentry;
3063 smap = current->object.sub_map;
3064 vm_map_lock_read(smap);
3065 (void) vm_map_lookup_entry(smap, offset, &tentry);
3066 tsize = tentry->end - offset;
3069 object = tentry->object.vm_object;
3070 offset = tentry->offset + (offset - tentry->start);
3071 vm_map_unlock_read(smap);
3073 object = current->object.vm_object;
3075 vm_object_reference(object);
3076 last_timestamp = map->timestamp;
3077 vm_map_unlock_read(map);
3078 if (!vm_object_sync(object, offset, size, syncio, invalidate))
3081 vm_object_deallocate(object);
3082 vm_map_lock_read(map);
3083 if (last_timestamp == map->timestamp ||
3084 !vm_map_lookup_entry(map, start, ¤t))
3085 current = current->next;
3088 vm_map_unlock_read(map);
3089 return (failed ? KERN_FAILURE : KERN_SUCCESS);
3093 * vm_map_entry_unwire: [ internal use only ]
3095 * Make the region specified by this entry pageable.
3097 * The map in question should be locked.
3098 * [This is the reason for this routine's existence.]
3101 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
3104 VM_MAP_ASSERT_LOCKED(map);
3105 KASSERT(entry->wired_count > 0,
3106 ("vm_map_entry_unwire: entry %p isn't wired", entry));
3107 pmap_unwire(map->pmap, entry->start, entry->end);
3108 vm_object_unwire(entry->object.vm_object, entry->offset, entry->end -
3109 entry->start, PQ_ACTIVE);
3110 entry->wired_count = 0;
3114 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map)
3117 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
3118 vm_object_deallocate(entry->object.vm_object);
3119 uma_zfree(system_map ? kmapentzone : mapentzone, entry);
3123 * vm_map_entry_delete: [ internal use only ]
3125 * Deallocate the given entry from the target map.
3128 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
3131 vm_pindex_t offidxstart, offidxend, count, size1;
3134 vm_map_entry_unlink(map, entry);
3135 object = entry->object.vm_object;
3137 if ((entry->eflags & MAP_ENTRY_GUARD) != 0) {
3138 MPASS(entry->cred == NULL);
3139 MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0);
3140 MPASS(object == NULL);
3141 vm_map_entry_deallocate(entry, map->system_map);
3145 size = entry->end - entry->start;
3148 if (entry->cred != NULL) {
3149 swap_release_by_cred(size, entry->cred);
3150 crfree(entry->cred);
3153 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 &&
3155 KASSERT(entry->cred == NULL || object->cred == NULL ||
3156 (entry->eflags & MAP_ENTRY_NEEDS_COPY),
3157 ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry));
3159 offidxstart = OFF_TO_IDX(entry->offset);
3160 offidxend = offidxstart + count;
3161 VM_OBJECT_WLOCK(object);
3162 if (object->ref_count != 1 && ((object->flags & (OBJ_NOSPLIT |
3163 OBJ_ONEMAPPING)) == OBJ_ONEMAPPING ||
3164 object == kernel_object)) {
3165 vm_object_collapse(object);
3168 * The option OBJPR_NOTMAPPED can be passed here
3169 * because vm_map_delete() already performed
3170 * pmap_remove() on the only mapping to this range
3173 vm_object_page_remove(object, offidxstart, offidxend,
3175 if (object->type == OBJT_SWAP)
3176 swap_pager_freespace(object, offidxstart,
3178 if (offidxend >= object->size &&
3179 offidxstart < object->size) {
3180 size1 = object->size;
3181 object->size = offidxstart;
3182 if (object->cred != NULL) {
3183 size1 -= object->size;
3184 KASSERT(object->charge >= ptoa(size1),
3185 ("object %p charge < 0", object));
3186 swap_release_by_cred(ptoa(size1),
3188 object->charge -= ptoa(size1);
3192 VM_OBJECT_WUNLOCK(object);
3194 entry->object.vm_object = NULL;
3195 if (map->system_map)
3196 vm_map_entry_deallocate(entry, TRUE);
3198 entry->next = curthread->td_map_def_user;
3199 curthread->td_map_def_user = entry;
3204 * vm_map_delete: [ internal use only ]
3206 * Deallocates the given address range from the target
3210 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
3212 vm_map_entry_t entry;
3213 vm_map_entry_t first_entry;
3215 VM_MAP_ASSERT_LOCKED(map);
3217 return (KERN_SUCCESS);
3220 * Find the start of the region, and clip it
3222 if (!vm_map_lookup_entry(map, start, &first_entry))
3223 entry = first_entry->next;
3225 entry = first_entry;
3226 vm_map_clip_start(map, entry, start);
3230 * Step through all entries in this region
3232 while (entry->start < end) {
3233 vm_map_entry_t next;
3236 * Wait for wiring or unwiring of an entry to complete.
3237 * Also wait for any system wirings to disappear on
3240 if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 ||
3241 (vm_map_pmap(map) != kernel_pmap &&
3242 vm_map_entry_system_wired_count(entry) != 0)) {
3243 unsigned int last_timestamp;
3244 vm_offset_t saved_start;
3245 vm_map_entry_t tmp_entry;
3247 saved_start = entry->start;
3248 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
3249 last_timestamp = map->timestamp;
3250 (void) vm_map_unlock_and_wait(map, 0);
3252 if (last_timestamp + 1 != map->timestamp) {
3254 * Look again for the entry because the map was
3255 * modified while it was unlocked.
3256 * Specifically, the entry may have been
3257 * clipped, merged, or deleted.
3259 if (!vm_map_lookup_entry(map, saved_start,
3261 entry = tmp_entry->next;
3264 vm_map_clip_start(map, entry,
3270 vm_map_clip_end(map, entry, end);
3275 * Unwire before removing addresses from the pmap; otherwise,
3276 * unwiring will put the entries back in the pmap.
3278 if (entry->wired_count != 0)
3279 vm_map_entry_unwire(map, entry);
3282 * Remove mappings for the pages, but only if the
3283 * mappings could exist. For instance, it does not
3284 * make sense to call pmap_remove() for guard entries.
3286 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 ||
3287 entry->object.vm_object != NULL)
3288 pmap_remove(map->pmap, entry->start, entry->end);
3290 if (entry->end == map->anon_loc)
3291 map->anon_loc = entry->start;
3294 * Delete the entry only after removing all pmap
3295 * entries pointing to its pages. (Otherwise, its
3296 * page frames may be reallocated, and any modify bits
3297 * will be set in the wrong object!)
3299 vm_map_entry_delete(map, entry);
3302 return (KERN_SUCCESS);
3308 * Remove the given address range from the target map.
3309 * This is the exported form of vm_map_delete.
3312 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
3317 VM_MAP_RANGE_CHECK(map, start, end);
3318 result = vm_map_delete(map, start, end);
3324 * vm_map_check_protection:
3326 * Assert that the target map allows the specified privilege on the
3327 * entire address region given. The entire region must be allocated.
3329 * WARNING! This code does not and should not check whether the
3330 * contents of the region is accessible. For example a smaller file
3331 * might be mapped into a larger address space.
3333 * NOTE! This code is also called by munmap().
3335 * The map must be locked. A read lock is sufficient.
3338 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
3339 vm_prot_t protection)
3341 vm_map_entry_t entry;
3342 vm_map_entry_t tmp_entry;
3344 if (!vm_map_lookup_entry(map, start, &tmp_entry))
3348 while (start < end) {
3352 if (start < entry->start)
3355 * Check protection associated with entry.
3357 if ((entry->protection & protection) != protection)
3359 /* go to next entry */
3361 entry = entry->next;
3367 * vm_map_copy_entry:
3369 * Copies the contents of the source entry to the destination
3370 * entry. The entries *must* be aligned properly.
3376 vm_map_entry_t src_entry,
3377 vm_map_entry_t dst_entry,
3378 vm_ooffset_t *fork_charge)
3380 vm_object_t src_object;
3381 vm_map_entry_t fake_entry;
3386 VM_MAP_ASSERT_LOCKED(dst_map);
3388 if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP)
3391 if (src_entry->wired_count == 0 ||
3392 (src_entry->protection & VM_PROT_WRITE) == 0) {
3394 * If the source entry is marked needs_copy, it is already
3397 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 &&
3398 (src_entry->protection & VM_PROT_WRITE) != 0) {
3399 pmap_protect(src_map->pmap,
3402 src_entry->protection & ~VM_PROT_WRITE);
3406 * Make a copy of the object.
3408 size = src_entry->end - src_entry->start;
3409 if ((src_object = src_entry->object.vm_object) != NULL) {
3410 VM_OBJECT_WLOCK(src_object);
3411 charged = ENTRY_CHARGED(src_entry);
3412 if (src_object->handle == NULL &&
3413 (src_object->type == OBJT_DEFAULT ||
3414 src_object->type == OBJT_SWAP)) {
3415 vm_object_collapse(src_object);
3416 if ((src_object->flags & (OBJ_NOSPLIT |
3417 OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) {
3418 vm_object_split(src_entry);
3420 src_entry->object.vm_object;
3423 vm_object_reference_locked(src_object);
3424 vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
3425 if (src_entry->cred != NULL &&
3426 !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
3427 KASSERT(src_object->cred == NULL,
3428 ("OVERCOMMIT: vm_map_copy_entry: cred %p",
3430 src_object->cred = src_entry->cred;
3431 src_object->charge = size;
3433 VM_OBJECT_WUNLOCK(src_object);
3434 dst_entry->object.vm_object = src_object;
3436 cred = curthread->td_ucred;
3438 dst_entry->cred = cred;
3439 *fork_charge += size;
3440 if (!(src_entry->eflags &
3441 MAP_ENTRY_NEEDS_COPY)) {
3443 src_entry->cred = cred;
3444 *fork_charge += size;
3447 src_entry->eflags |= MAP_ENTRY_COW |
3448 MAP_ENTRY_NEEDS_COPY;
3449 dst_entry->eflags |= MAP_ENTRY_COW |
3450 MAP_ENTRY_NEEDS_COPY;
3451 dst_entry->offset = src_entry->offset;
3452 if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) {
3454 * MAP_ENTRY_VN_WRITECNT cannot
3455 * indicate write reference from
3456 * src_entry, since the entry is
3457 * marked as needs copy. Allocate a
3458 * fake entry that is used to
3459 * decrement object->un_pager.vnp.writecount
3460 * at the appropriate time. Attach
3461 * fake_entry to the deferred list.
3463 fake_entry = vm_map_entry_create(dst_map);
3464 fake_entry->eflags = MAP_ENTRY_VN_WRITECNT;
3465 src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT;
3466 vm_object_reference(src_object);
3467 fake_entry->object.vm_object = src_object;
3468 fake_entry->start = src_entry->start;
3469 fake_entry->end = src_entry->end;
3470 fake_entry->next = curthread->td_map_def_user;
3471 curthread->td_map_def_user = fake_entry;
3474 pmap_copy(dst_map->pmap, src_map->pmap,
3475 dst_entry->start, dst_entry->end - dst_entry->start,
3478 dst_entry->object.vm_object = NULL;
3479 dst_entry->offset = 0;
3480 if (src_entry->cred != NULL) {
3481 dst_entry->cred = curthread->td_ucred;
3482 crhold(dst_entry->cred);
3483 *fork_charge += size;
3488 * We don't want to make writeable wired pages copy-on-write.
3489 * Immediately copy these pages into the new map by simulating
3490 * page faults. The new pages are pageable.
3492 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry,
3498 * vmspace_map_entry_forked:
3499 * Update the newly-forked vmspace each time a map entry is inherited
3500 * or copied. The values for vm_dsize and vm_tsize are approximate
3501 * (and mostly-obsolete ideas in the face of mmap(2) et al.)
3504 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2,
3505 vm_map_entry_t entry)
3507 vm_size_t entrysize;
3510 if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
3512 entrysize = entry->end - entry->start;
3513 vm2->vm_map.size += entrysize;
3514 if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) {
3515 vm2->vm_ssize += btoc(entrysize);
3516 } else if (entry->start >= (vm_offset_t)vm1->vm_daddr &&
3517 entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) {
3518 newend = MIN(entry->end,
3519 (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize));
3520 vm2->vm_dsize += btoc(newend - entry->start);
3521 } else if (entry->start >= (vm_offset_t)vm1->vm_taddr &&
3522 entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) {
3523 newend = MIN(entry->end,
3524 (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize));
3525 vm2->vm_tsize += btoc(newend - entry->start);
3531 * Create a new process vmspace structure and vm_map
3532 * based on those of an existing process. The new map
3533 * is based on the old map, according to the inheritance
3534 * values on the regions in that map.
3536 * XXX It might be worth coalescing the entries added to the new vmspace.
3538 * The source map must not be locked.
3541 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
3543 struct vmspace *vm2;
3544 vm_map_t new_map, old_map;
3545 vm_map_entry_t new_entry, old_entry;
3550 old_map = &vm1->vm_map;
3551 /* Copy immutable fields of vm1 to vm2. */
3552 vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map),
3556 vm2->vm_taddr = vm1->vm_taddr;
3557 vm2->vm_daddr = vm1->vm_daddr;
3558 vm2->vm_maxsaddr = vm1->vm_maxsaddr;
3559 vm_map_lock(old_map);
3561 vm_map_wait_busy(old_map);
3562 new_map = &vm2->vm_map;
3563 locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */
3564 KASSERT(locked, ("vmspace_fork: lock failed"));
3566 new_map->anon_loc = old_map->anon_loc;
3567 old_entry = old_map->header.next;
3569 while (old_entry != &old_map->header) {
3570 if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP)
3571 panic("vm_map_fork: encountered a submap");
3573 inh = old_entry->inheritance;
3574 if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 &&
3575 inh != VM_INHERIT_NONE)
3576 inh = VM_INHERIT_COPY;
3579 case VM_INHERIT_NONE:
3582 case VM_INHERIT_SHARE:
3584 * Clone the entry, creating the shared object if necessary.
3586 object = old_entry->object.vm_object;
3587 if (object == NULL) {
3588 object = vm_object_allocate(OBJT_DEFAULT,
3589 atop(old_entry->end - old_entry->start));
3590 old_entry->object.vm_object = object;
3591 old_entry->offset = 0;
3592 if (old_entry->cred != NULL) {
3593 object->cred = old_entry->cred;
3594 object->charge = old_entry->end -
3596 old_entry->cred = NULL;
3601 * Add the reference before calling vm_object_shadow
3602 * to insure that a shadow object is created.
3604 vm_object_reference(object);
3605 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3606 vm_object_shadow(&old_entry->object.vm_object,
3608 old_entry->end - old_entry->start);
3609 old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
3610 /* Transfer the second reference too. */
3611 vm_object_reference(
3612 old_entry->object.vm_object);
3615 * As in vm_map_simplify_entry(), the
3616 * vnode lock will not be acquired in
3617 * this call to vm_object_deallocate().
3619 vm_object_deallocate(object);
3620 object = old_entry->object.vm_object;
3622 VM_OBJECT_WLOCK(object);
3623 vm_object_clear_flag(object, OBJ_ONEMAPPING);
3624 if (old_entry->cred != NULL) {
3625 KASSERT(object->cred == NULL, ("vmspace_fork both cred"));
3626 object->cred = old_entry->cred;
3627 object->charge = old_entry->end - old_entry->start;
3628 old_entry->cred = NULL;
3632 * Assert the correct state of the vnode
3633 * v_writecount while the object is locked, to
3634 * not relock it later for the assertion
3637 if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT &&
3638 object->type == OBJT_VNODE) {
3639 KASSERT(((struct vnode *)object->handle)->
3641 ("vmspace_fork: v_writecount %p", object));
3642 KASSERT(object->un_pager.vnp.writemappings > 0,
3643 ("vmspace_fork: vnp.writecount %p",
3646 VM_OBJECT_WUNLOCK(object);
3649 * Clone the entry, referencing the shared object.
3651 new_entry = vm_map_entry_create(new_map);
3652 *new_entry = *old_entry;
3653 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
3654 MAP_ENTRY_IN_TRANSITION);
3655 new_entry->wiring_thread = NULL;
3656 new_entry->wired_count = 0;
3657 if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) {
3658 vnode_pager_update_writecount(object,
3659 new_entry->start, new_entry->end);
3663 * Insert the entry into the new map -- we know we're
3664 * inserting at the end of the new map.
3666 vm_map_entry_link(new_map, new_map->header.prev,
3668 vmspace_map_entry_forked(vm1, vm2, new_entry);
3671 * Update the physical map
3673 pmap_copy(new_map->pmap, old_map->pmap,
3675 (old_entry->end - old_entry->start),
3679 case VM_INHERIT_COPY:
3681 * Clone the entry and link into the map.
3683 new_entry = vm_map_entry_create(new_map);
3684 *new_entry = *old_entry;
3686 * Copied entry is COW over the old object.
3688 new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
3689 MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT);
3690 new_entry->wiring_thread = NULL;
3691 new_entry->wired_count = 0;
3692 new_entry->object.vm_object = NULL;
3693 new_entry->cred = NULL;
3694 vm_map_entry_link(new_map, new_map->header.prev,
3696 vmspace_map_entry_forked(vm1, vm2, new_entry);
3697 vm_map_copy_entry(old_map, new_map, old_entry,
3698 new_entry, fork_charge);
3701 case VM_INHERIT_ZERO:
3703 * Create a new anonymous mapping entry modelled from
3706 new_entry = vm_map_entry_create(new_map);
3707 memset(new_entry, 0, sizeof(*new_entry));
3709 new_entry->start = old_entry->start;
3710 new_entry->end = old_entry->end;
3711 new_entry->eflags = old_entry->eflags &
3712 ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION |
3713 MAP_ENTRY_VN_WRITECNT);
3714 new_entry->protection = old_entry->protection;
3715 new_entry->max_protection = old_entry->max_protection;
3716 new_entry->inheritance = VM_INHERIT_ZERO;
3718 vm_map_entry_link(new_map, new_map->header.prev,
3720 vmspace_map_entry_forked(vm1, vm2, new_entry);
3722 new_entry->cred = curthread->td_ucred;
3723 crhold(new_entry->cred);
3724 *fork_charge += (new_entry->end - new_entry->start);
3728 old_entry = old_entry->next;
3731 * Use inlined vm_map_unlock() to postpone handling the deferred
3732 * map entries, which cannot be done until both old_map and
3733 * new_map locks are released.
3735 sx_xunlock(&old_map->lock);
3736 sx_xunlock(&new_map->lock);
3737 vm_map_process_deferred();
3743 * Create a process's stack for exec_new_vmspace(). This function is never
3744 * asked to wire the newly created stack.
3747 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3748 vm_prot_t prot, vm_prot_t max, int cow)
3750 vm_size_t growsize, init_ssize;
3754 MPASS((map->flags & MAP_WIREFUTURE) == 0);
3755 growsize = sgrowsiz;
3756 init_ssize = (max_ssize < growsize) ? max_ssize : growsize;
3758 vmemlim = lim_cur(curthread, RLIMIT_VMEM);
3759 /* If we would blow our VMEM resource limit, no go */
3760 if (map->size + init_ssize > vmemlim) {
3764 rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot,
3771 static int stack_guard_page = 1;
3772 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN,
3773 &stack_guard_page, 0,
3774 "Specifies the number of guard pages for a stack that grows");
3777 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3778 vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow)
3780 vm_map_entry_t new_entry, prev_entry;
3781 vm_offset_t bot, gap_bot, gap_top, top;
3782 vm_size_t init_ssize, sgp;
3786 * The stack orientation is piggybacked with the cow argument.
3787 * Extract it into orient and mask the cow argument so that we
3788 * don't pass it around further.
3790 orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP);
3791 KASSERT(orient != 0, ("No stack grow direction"));
3792 KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP),
3795 if (addrbos < vm_map_min(map) ||
3796 addrbos + max_ssize > vm_map_max(map) ||
3797 addrbos + max_ssize <= addrbos)
3798 return (KERN_INVALID_ADDRESS);
3799 sgp = (vm_size_t)stack_guard_page * PAGE_SIZE;
3800 if (sgp >= max_ssize)
3801 return (KERN_INVALID_ARGUMENT);
3803 init_ssize = growsize;
3804 if (max_ssize < init_ssize + sgp)
3805 init_ssize = max_ssize - sgp;
3807 /* If addr is already mapped, no go */
3808 if (vm_map_lookup_entry(map, addrbos, &prev_entry))
3809 return (KERN_NO_SPACE);
3812 * If we can't accommodate max_ssize in the current mapping, no go.
3814 if (prev_entry->next->start < addrbos + max_ssize)
3815 return (KERN_NO_SPACE);
3818 * We initially map a stack of only init_ssize. We will grow as
3819 * needed later. Depending on the orientation of the stack (i.e.
3820 * the grow direction) we either map at the top of the range, the
3821 * bottom of the range or in the middle.
3823 * Note: we would normally expect prot and max to be VM_PROT_ALL,
3824 * and cow to be 0. Possibly we should eliminate these as input
3825 * parameters, and just pass these values here in the insert call.
3827 if (orient == MAP_STACK_GROWS_DOWN) {
3828 bot = addrbos + max_ssize - init_ssize;
3829 top = bot + init_ssize;
3832 } else /* if (orient == MAP_STACK_GROWS_UP) */ {
3834 top = bot + init_ssize;
3836 gap_top = addrbos + max_ssize;
3838 rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow);
3839 if (rv != KERN_SUCCESS)
3841 new_entry = prev_entry->next;
3842 KASSERT(new_entry->end == top || new_entry->start == bot,
3843 ("Bad entry start/end for new stack entry"));
3844 KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 ||
3845 (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0,
3846 ("new entry lacks MAP_ENTRY_GROWS_DOWN"));
3847 KASSERT((orient & MAP_STACK_GROWS_UP) == 0 ||
3848 (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0,
3849 ("new entry lacks MAP_ENTRY_GROWS_UP"));
3850 rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE,
3851 VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ?
3852 MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP));
3853 if (rv != KERN_SUCCESS)
3854 (void)vm_map_delete(map, bot, top);
3859 * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we
3860 * successfully grow the stack.
3863 vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
3865 vm_map_entry_t stack_entry;
3869 vm_offset_t gap_end, gap_start, grow_start;
3870 size_t grow_amount, guard, max_grow;
3871 rlim_t lmemlim, stacklim, vmemlim;
3873 bool gap_deleted, grow_down, is_procstack;
3885 * Disallow stack growth when the access is performed by a
3886 * debugger or AIO daemon. The reason is that the wrong
3887 * resource limits are applied.
3889 if (map != &p->p_vmspace->vm_map || p->p_textvp == NULL)
3890 return (KERN_FAILURE);
3892 MPASS(!map->system_map);
3894 guard = stack_guard_page * PAGE_SIZE;
3895 lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK);
3896 stacklim = lim_cur(curthread, RLIMIT_STACK);
3897 vmemlim = lim_cur(curthread, RLIMIT_VMEM);
3899 /* If addr is not in a hole for a stack grow area, no need to grow. */
3900 if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry))
3901 return (KERN_FAILURE);
3902 if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0)
3903 return (KERN_SUCCESS);
3904 if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) {
3905 stack_entry = gap_entry->next;
3906 if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 ||
3907 stack_entry->start != gap_entry->end)
3908 return (KERN_FAILURE);
3909 grow_amount = round_page(stack_entry->start - addr);
3911 } else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) {
3912 stack_entry = gap_entry->prev;
3913 if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 ||
3914 stack_entry->end != gap_entry->start)
3915 return (KERN_FAILURE);
3916 grow_amount = round_page(addr + 1 - stack_entry->end);
3919 return (KERN_FAILURE);
3921 max_grow = gap_entry->end - gap_entry->start;
3922 if (guard > max_grow)
3923 return (KERN_NO_SPACE);
3925 if (grow_amount > max_grow)
3926 return (KERN_NO_SPACE);
3929 * If this is the main process stack, see if we're over the stack
3932 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr &&
3933 addr < (vm_offset_t)p->p_sysent->sv_usrstack;
3934 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim))
3935 return (KERN_NO_SPACE);
3940 if (is_procstack && racct_set(p, RACCT_STACK,
3941 ctob(vm->vm_ssize) + grow_amount)) {
3943 return (KERN_NO_SPACE);
3949 grow_amount = roundup(grow_amount, sgrowsiz);
3950 if (grow_amount > max_grow)
3951 grow_amount = max_grow;
3952 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) {
3953 grow_amount = trunc_page((vm_size_t)stacklim) -
3959 limit = racct_get_available(p, RACCT_STACK);
3961 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit))
3962 grow_amount = limit - ctob(vm->vm_ssize);
3965 if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) {
3966 if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) {
3973 if (racct_set(p, RACCT_MEMLOCK,
3974 ptoa(pmap_wired_count(map->pmap)) + grow_amount)) {
3984 /* If we would blow our VMEM resource limit, no go */
3985 if (map->size + grow_amount > vmemlim) {
3992 if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) {
4001 if (vm_map_lock_upgrade(map)) {
4003 vm_map_lock_read(map);
4008 grow_start = gap_entry->end - grow_amount;
4009 if (gap_entry->start + grow_amount == gap_entry->end) {
4010 gap_start = gap_entry->start;
4011 gap_end = gap_entry->end;
4012 vm_map_entry_delete(map, gap_entry);
4015 MPASS(gap_entry->start < gap_entry->end - grow_amount);
4016 gap_entry->end -= grow_amount;
4017 vm_map_entry_resize_free(map, gap_entry);
4018 gap_deleted = false;
4020 rv = vm_map_insert(map, NULL, 0, grow_start,
4021 grow_start + grow_amount,
4022 stack_entry->protection, stack_entry->max_protection,
4023 MAP_STACK_GROWS_DOWN);
4024 if (rv != KERN_SUCCESS) {
4026 rv1 = vm_map_insert(map, NULL, 0, gap_start,
4027 gap_end, VM_PROT_NONE, VM_PROT_NONE,
4028 MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN);
4029 MPASS(rv1 == KERN_SUCCESS);
4031 gap_entry->end += grow_amount;
4032 vm_map_entry_resize_free(map, gap_entry);
4036 grow_start = stack_entry->end;
4037 cred = stack_entry->cred;
4038 if (cred == NULL && stack_entry->object.vm_object != NULL)
4039 cred = stack_entry->object.vm_object->cred;
4040 if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred))
4042 /* Grow the underlying object if applicable. */
4043 else if (stack_entry->object.vm_object == NULL ||
4044 vm_object_coalesce(stack_entry->object.vm_object,
4045 stack_entry->offset,
4046 (vm_size_t)(stack_entry->end - stack_entry->start),
4047 (vm_size_t)grow_amount, cred != NULL)) {
4048 if (gap_entry->start + grow_amount == gap_entry->end)
4049 vm_map_entry_delete(map, gap_entry);
4051 gap_entry->start += grow_amount;
4052 stack_entry->end += grow_amount;
4053 map->size += grow_amount;
4054 vm_map_entry_resize_free(map, stack_entry);
4059 if (rv == KERN_SUCCESS && is_procstack)
4060 vm->vm_ssize += btoc(grow_amount);
4063 * Heed the MAP_WIREFUTURE flag if it was set for this process.
4065 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) {
4067 vm_map_wire(map, grow_start, grow_start + grow_amount,
4068 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
4069 vm_map_lock_read(map);
4071 vm_map_lock_downgrade(map);
4075 if (racct_enable && rv != KERN_SUCCESS) {
4077 error = racct_set(p, RACCT_VMEM, map->size);
4078 KASSERT(error == 0, ("decreasing RACCT_VMEM failed"));
4080 error = racct_set(p, RACCT_MEMLOCK,
4081 ptoa(pmap_wired_count(map->pmap)));
4082 KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed"));
4084 error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize));
4085 KASSERT(error == 0, ("decreasing RACCT_STACK failed"));
4094 * Unshare the specified VM space for exec. If other processes are
4095 * mapped to it, then create a new one. The new vmspace is null.
4098 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser)
4100 struct vmspace *oldvmspace = p->p_vmspace;
4101 struct vmspace *newvmspace;
4103 KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0,
4104 ("vmspace_exec recursed"));
4105 newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit);
4106 if (newvmspace == NULL)
4108 newvmspace->vm_swrss = oldvmspace->vm_swrss;
4110 * This code is written like this for prototype purposes. The
4111 * goal is to avoid running down the vmspace here, but let the
4112 * other process's that are still using the vmspace to finally
4113 * run it down. Even though there is little or no chance of blocking
4114 * here, it is a good idea to keep this form for future mods.
4116 PROC_VMSPACE_LOCK(p);
4117 p->p_vmspace = newvmspace;
4118 PROC_VMSPACE_UNLOCK(p);
4119 if (p == curthread->td_proc)
4120 pmap_activate(curthread);
4121 curthread->td_pflags |= TDP_EXECVMSPC;
4126 * Unshare the specified VM space for forcing COW. This
4127 * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
4130 vmspace_unshare(struct proc *p)
4132 struct vmspace *oldvmspace = p->p_vmspace;
4133 struct vmspace *newvmspace;
4134 vm_ooffset_t fork_charge;
4136 if (oldvmspace->vm_refcnt == 1)
4139 newvmspace = vmspace_fork(oldvmspace, &fork_charge);
4140 if (newvmspace == NULL)
4142 if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) {
4143 vmspace_free(newvmspace);
4146 PROC_VMSPACE_LOCK(p);
4147 p->p_vmspace = newvmspace;
4148 PROC_VMSPACE_UNLOCK(p);
4149 if (p == curthread->td_proc)
4150 pmap_activate(curthread);
4151 vmspace_free(oldvmspace);
4158 * Finds the VM object, offset, and
4159 * protection for a given virtual address in the
4160 * specified map, assuming a page fault of the
4163 * Leaves the map in question locked for read; return
4164 * values are guaranteed until a vm_map_lookup_done
4165 * call is performed. Note that the map argument
4166 * is in/out; the returned map must be used in
4167 * the call to vm_map_lookup_done.
4169 * A handle (out_entry) is returned for use in
4170 * vm_map_lookup_done, to make that fast.
4172 * If a lookup is requested with "write protection"
4173 * specified, the map may be changed to perform virtual
4174 * copying operations, although the data referenced will
4178 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
4180 vm_prot_t fault_typea,
4181 vm_map_entry_t *out_entry, /* OUT */
4182 vm_object_t *object, /* OUT */
4183 vm_pindex_t *pindex, /* OUT */
4184 vm_prot_t *out_prot, /* OUT */
4185 boolean_t *wired) /* OUT */
4187 vm_map_entry_t entry;
4188 vm_map_t map = *var_map;
4190 vm_prot_t fault_type = fault_typea;
4191 vm_object_t eobject;
4197 vm_map_lock_read(map);
4201 * Lookup the faulting address.
4203 if (!vm_map_lookup_entry(map, vaddr, out_entry)) {
4204 vm_map_unlock_read(map);
4205 return (KERN_INVALID_ADDRESS);
4213 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
4214 vm_map_t old_map = map;
4216 *var_map = map = entry->object.sub_map;
4217 vm_map_unlock_read(old_map);
4222 * Check whether this task is allowed to have this page.
4224 prot = entry->protection;
4225 if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) {
4226 fault_typea &= ~VM_PROT_FAULT_LOOKUP;
4227 if (prot == VM_PROT_NONE && map != kernel_map &&
4228 (entry->eflags & MAP_ENTRY_GUARD) != 0 &&
4229 (entry->eflags & (MAP_ENTRY_STACK_GAP_DN |
4230 MAP_ENTRY_STACK_GAP_UP)) != 0 &&
4231 vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS)
4232 goto RetryLookupLocked;
4234 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
4235 if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) {
4236 vm_map_unlock_read(map);
4237 return (KERN_PROTECTION_FAILURE);
4239 KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags &
4240 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) !=
4241 (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY),
4242 ("entry %p flags %x", entry, entry->eflags));
4243 if ((fault_typea & VM_PROT_COPY) != 0 &&
4244 (entry->max_protection & VM_PROT_WRITE) == 0 &&
4245 (entry->eflags & MAP_ENTRY_COW) == 0) {
4246 vm_map_unlock_read(map);
4247 return (KERN_PROTECTION_FAILURE);
4251 * If this page is not pageable, we have to get it for all possible
4254 *wired = (entry->wired_count != 0);
4256 fault_type = entry->protection;
4257 size = entry->end - entry->start;
4259 * If the entry was copy-on-write, we either ...
4261 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4263 * If we want to write the page, we may as well handle that
4264 * now since we've got the map locked.
4266 * If we don't need to write the page, we just demote the
4267 * permissions allowed.
4269 if ((fault_type & VM_PROT_WRITE) != 0 ||
4270 (fault_typea & VM_PROT_COPY) != 0) {
4272 * Make a new object, and place it in the object
4273 * chain. Note that no new references have appeared
4274 * -- one just moved from the map to the new
4277 if (vm_map_lock_upgrade(map))
4280 if (entry->cred == NULL) {
4282 * The debugger owner is charged for
4285 cred = curthread->td_ucred;
4287 if (!swap_reserve_by_cred(size, cred)) {
4290 return (KERN_RESOURCE_SHORTAGE);
4294 vm_object_shadow(&entry->object.vm_object,
4295 &entry->offset, size);
4296 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
4297 eobject = entry->object.vm_object;
4298 if (eobject->cred != NULL) {
4300 * The object was not shadowed.
4302 swap_release_by_cred(size, entry->cred);
4303 crfree(entry->cred);
4305 } else if (entry->cred != NULL) {
4306 VM_OBJECT_WLOCK(eobject);
4307 eobject->cred = entry->cred;
4308 eobject->charge = size;
4309 VM_OBJECT_WUNLOCK(eobject);
4313 vm_map_lock_downgrade(map);
4316 * We're attempting to read a copy-on-write page --
4317 * don't allow writes.
4319 prot &= ~VM_PROT_WRITE;
4324 * Create an object if necessary.
4326 if (entry->object.vm_object == NULL &&
4328 if (vm_map_lock_upgrade(map))
4330 entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT,
4333 if (entry->cred != NULL) {
4334 VM_OBJECT_WLOCK(entry->object.vm_object);
4335 entry->object.vm_object->cred = entry->cred;
4336 entry->object.vm_object->charge = size;
4337 VM_OBJECT_WUNLOCK(entry->object.vm_object);
4340 vm_map_lock_downgrade(map);
4344 * Return the object/offset from this entry. If the entry was
4345 * copy-on-write or empty, it has been fixed up.
4347 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
4348 *object = entry->object.vm_object;
4351 return (KERN_SUCCESS);
4355 * vm_map_lookup_locked:
4357 * Lookup the faulting address. A version of vm_map_lookup that returns
4358 * KERN_FAILURE instead of blocking on map lock or memory allocation.
4361 vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */
4363 vm_prot_t fault_typea,
4364 vm_map_entry_t *out_entry, /* OUT */
4365 vm_object_t *object, /* OUT */
4366 vm_pindex_t *pindex, /* OUT */
4367 vm_prot_t *out_prot, /* OUT */
4368 boolean_t *wired) /* OUT */
4370 vm_map_entry_t entry;
4371 vm_map_t map = *var_map;
4373 vm_prot_t fault_type = fault_typea;
4376 * Lookup the faulting address.
4378 if (!vm_map_lookup_entry(map, vaddr, out_entry))
4379 return (KERN_INVALID_ADDRESS);
4384 * Fail if the entry refers to a submap.
4386 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
4387 return (KERN_FAILURE);
4390 * Check whether this task is allowed to have this page.
4392 prot = entry->protection;
4393 fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
4394 if ((fault_type & prot) != fault_type)
4395 return (KERN_PROTECTION_FAILURE);
4398 * If this page is not pageable, we have to get it for all possible
4401 *wired = (entry->wired_count != 0);
4403 fault_type = entry->protection;
4405 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4407 * Fail if the entry was copy-on-write for a write fault.
4409 if (fault_type & VM_PROT_WRITE)
4410 return (KERN_FAILURE);
4412 * We're attempting to read a copy-on-write page --
4413 * don't allow writes.
4415 prot &= ~VM_PROT_WRITE;
4419 * Fail if an object should be created.
4421 if (entry->object.vm_object == NULL && !map->system_map)
4422 return (KERN_FAILURE);
4425 * Return the object/offset from this entry. If the entry was
4426 * copy-on-write or empty, it has been fixed up.
4428 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
4429 *object = entry->object.vm_object;
4432 return (KERN_SUCCESS);
4436 * vm_map_lookup_done:
4438 * Releases locks acquired by a vm_map_lookup
4439 * (according to the handle returned by that lookup).
4442 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry)
4445 * Unlock the main-level map
4447 vm_map_unlock_read(map);
4451 vm_map_max_KBI(const struct vm_map *map)
4454 return (vm_map_max(map));
4458 vm_map_min_KBI(const struct vm_map *map)
4461 return (vm_map_min(map));
4465 vm_map_pmap_KBI(vm_map_t map)
4471 #include "opt_ddb.h"
4473 #include <sys/kernel.h>
4475 #include <ddb/ddb.h>
4478 vm_map_print(vm_map_t map)
4480 vm_map_entry_t entry;
4482 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4484 (void *)map->pmap, map->nentries, map->timestamp);
4487 for (entry = map->header.next; entry != &map->header;
4488 entry = entry->next) {
4489 db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n",
4490 (void *)entry, (void *)entry->start, (void *)entry->end,
4493 static char *inheritance_name[4] =
4494 {"share", "copy", "none", "donate_copy"};
4496 db_iprintf(" prot=%x/%x/%s",
4498 entry->max_protection,
4499 inheritance_name[(int)(unsigned char)entry->inheritance]);
4500 if (entry->wired_count != 0)
4501 db_printf(", wired");
4503 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
4504 db_printf(", share=%p, offset=0x%jx\n",
4505 (void *)entry->object.sub_map,
4506 (uintmax_t)entry->offset);
4507 if ((entry->prev == &map->header) ||
4508 (entry->prev->object.sub_map !=
4509 entry->object.sub_map)) {
4511 vm_map_print((vm_map_t)entry->object.sub_map);
4515 if (entry->cred != NULL)
4516 db_printf(", ruid %d", entry->cred->cr_ruid);
4517 db_printf(", object=%p, offset=0x%jx",
4518 (void *)entry->object.vm_object,
4519 (uintmax_t)entry->offset);
4520 if (entry->object.vm_object && entry->object.vm_object->cred)
4521 db_printf(", obj ruid %d charge %jx",
4522 entry->object.vm_object->cred->cr_ruid,
4523 (uintmax_t)entry->object.vm_object->charge);
4524 if (entry->eflags & MAP_ENTRY_COW)
4525 db_printf(", copy (%s)",
4526 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
4529 if ((entry->prev == &map->header) ||
4530 (entry->prev->object.vm_object !=
4531 entry->object.vm_object)) {
4533 vm_object_print((db_expr_t)(intptr_t)
4534 entry->object.vm_object,
4543 DB_SHOW_COMMAND(map, map)
4547 db_printf("usage: show map <addr>\n");
4550 vm_map_print((vm_map_t)addr);
4553 DB_SHOW_COMMAND(procvm, procvm)
4558 p = db_lookup_proc(addr);
4563 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
4564 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
4565 (void *)vmspace_pmap(p->p_vmspace));
4567 vm_map_print((vm_map_t)&p->p_vmspace->vm_map);