2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
40 * @(#)vm_mmap.c 8.4 (Berkeley) 1/12/94
41 * $FreeBSD: src/sys/vm/vm_mmap.c,v 1.108.2.6 2002/07/02 20:06:19 dillon Exp $
42 * $DragonFly: src/sys/vm/vm_mmap.c,v 1.19 2004/03/23 22:54:32 dillon Exp $
46 * Mapped file (mmap) interface to VM
49 #include <sys/param.h>
50 #include <sys/kernel.h>
51 #include <sys/systm.h>
52 #include <sys/sysproto.h>
53 #include <sys/filedesc.h>
54 #include <sys/kern_syscall.h>
56 #include <sys/resource.h>
57 #include <sys/resourcevar.h>
58 #include <sys/vnode.h>
59 #include <sys/fcntl.h>
64 #include <sys/vmmeter.h>
65 #include <sys/sysctl.h>
68 #include <vm/vm_param.h>
71 #include <vm/vm_map.h>
72 #include <vm/vm_object.h>
73 #include <vm/vm_page.h>
74 #include <vm/vm_pager.h>
75 #include <vm/vm_pageout.h>
76 #include <vm/vm_extern.h>
77 #include <vm/vm_page.h>
78 #include <vm/vm_kern.h>
80 #include <sys/file2.h>
82 static int max_proc_mmap;
83 SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, "");
86 * Set the maximum number of vm_map_entry structures per process. Roughly
87 * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100
88 * of our KVM malloc space still results in generous limits. We want a
89 * default that is good enough to prevent the kernel running out of resources
90 * if attacked from compromised user account but generous enough such that
91 * multi-threaded processes are not unduly inconvenienced.
94 static void vmmapentry_rsrc_init (void *);
95 SYSINIT(vmmersrc, SI_SUB_KVM_RSRC, SI_ORDER_FIRST, vmmapentry_rsrc_init, NULL)
98 vmmapentry_rsrc_init(void *dummy)
100 max_proc_mmap = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
101 sizeof(struct vm_map_entry);
102 max_proc_mmap /= 100;
107 sbrk(struct sbrk_args *uap)
109 /* Not yet implemented */
114 * sstk_args(int incr)
118 sstk(struct sstk_args *uap)
120 /* Not yet implemented */
125 * mmap_args(void *addr, size_t len, int prot, int flags, int fd,
126 * long pad, off_t pos)
128 * Memory Map (mmap) system call. Note that the file offset
129 * and address are allowed to be NOT page aligned, though if
130 * the MAP_FIXED flag it set, both must have the same remainder
131 * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not
132 * page-aligned, the actual mapping starts at trunc_page(addr)
133 * and the return value is adjusted up by the page offset.
135 * Generally speaking, only character devices which are themselves
136 * memory-based, such as a video framebuffer, can be mmap'd. Otherwise
137 * there would be no cache coherency between a descriptor and a VM mapping
138 * both to the same character device.
140 * Block devices can be mmap'd no matter what they represent. Cache coherency
141 * is maintained as long as you do not write directly to the underlying
146 kern_mmap(caddr_t uaddr, size_t ulen, int uprot, int uflags, int fd,
147 off_t upos, void **res)
149 struct thread *td = curthread;
150 struct proc *p = td->td_proc;
151 struct filedesc *fdp = p->p_fd;
152 struct file *fp = NULL;
155 vm_size_t size, pageoff;
156 vm_prot_t prot, maxprot;
159 int disablexworkaround;
161 struct vmspace *vms = p->p_vmspace;
166 addr = (vm_offset_t) uaddr;
168 prot = uprot & VM_PROT_ALL;
172 /* make sure mapping fits into numeric range etc */
173 if ((ssize_t) ulen < 0 ||
174 ((flags & MAP_ANON) && fd != -1))
177 if (flags & MAP_STACK) {
179 ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
186 * Align the file position to a page boundary,
187 * and save its page offset component.
189 pageoff = (pos & PAGE_MASK);
192 /* Adjust size for rounding (on both ends). */
193 size += pageoff; /* low end... */
194 size = (vm_size_t) round_page(size); /* hi end */
197 * Check for illegal addresses. Watch out for address wrap... Note
198 * that VM_*_ADDRESS are not constants due to casts (argh).
200 if (flags & MAP_FIXED) {
202 * The specified address must have the same remainder
203 * as the file offset taken modulo PAGE_SIZE, so it
204 * should be aligned after adjustment by pageoff.
207 if (addr & PAGE_MASK)
209 /* Address range must be all in user VM space. */
210 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
213 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
216 if (addr + size < addr)
220 * XXX for non-fixed mappings where no hint is provided or
221 * the hint would fall in the potential heap space,
222 * place it after the end of the largest possible heap.
224 * There should really be a pmap call to determine a reasonable
227 else if (addr == 0 ||
228 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
229 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz)))
230 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
232 if (flags & MAP_ANON) {
234 * Mapping blank space is trivial.
237 maxprot = VM_PROT_ALL;
241 * Mapping file, get fp for validation. Obtain vnode and make
242 * sure it is of appropriate type.
244 if (((unsigned) fd) >= fdp->fd_nfiles ||
245 (fp = fdp->fd_ofiles[fd]) == NULL)
247 if (fp->f_type != DTYPE_VNODE)
250 * POSIX shared-memory objects are defined to have
251 * kernel persistence, and are not defined to support
252 * read(2)/write(2) -- or even open(2). Thus, we can
253 * use MAP_ASYNC to trade on-disk coherence for speed.
254 * The shm_open(3) library routine turns on the FPOSIXSHM
255 * flag to request this behavior.
257 if (fp->f_flag & FPOSIXSHM)
259 vp = (struct vnode *) fp->f_data;
260 if (vp->v_type != VREG && vp->v_type != VCHR)
262 if (vp->v_type == VREG) {
264 * Get the proper underlying object
266 if (VOP_GETVOBJECT(vp, &obj) != 0)
268 vp = (struct vnode*)obj->handle;
272 * don't let the descriptor disappear on us if we block
277 * XXX hack to handle use of /dev/zero to map anon memory (ala
280 if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
282 maxprot = VM_PROT_ALL;
287 * cdevs does not provide private mappings of any kind.
290 * However, for XIG X server to continue to work,
291 * we should allow the superuser to do it anyway.
292 * We only allow it at securelevel < 1.
293 * (Because the XIG X server writes directly to video
294 * memory via /dev/mem, it should never work at any
296 * XXX this will have to go
298 if (securelevel >= 1)
299 disablexworkaround = 1;
301 disablexworkaround = suser(td);
302 if (vp->v_type == VCHR && disablexworkaround &&
303 (flags & (MAP_PRIVATE|MAP_COPY))) {
308 * Ensure that file and memory protections are
309 * compatible. Note that we only worry about
310 * writability if mapping is shared; in this case,
311 * current and max prot are dictated by the open file.
312 * XXX use the vnode instead? Problem is: what
313 * credentials do we use for determination? What if
314 * proc does a setuid?
316 maxprot = VM_PROT_EXECUTE; /* ??? */
317 if (fp->f_flag & FREAD) {
318 maxprot |= VM_PROT_READ;
319 } else if (prot & PROT_READ) {
324 * If we are sharing potential changes (either via
325 * MAP_SHARED or via the implicit sharing of character
326 * device mappings), and we are trying to get write
327 * permission although we opened it without asking
328 * for it, bail out. Check for superuser, only if
329 * we're at securelevel < 1, to allow the XIG X server
330 * to continue to work.
333 if ((flags & MAP_SHARED) != 0 ||
334 (vp->v_type == VCHR && disablexworkaround)) {
335 if ((fp->f_flag & FWRITE) != 0) {
337 if ((error = VOP_GETATTR(vp, &va, td))) {
341 (IMMUTABLE|APPEND)) == 0) {
342 maxprot |= VM_PROT_WRITE;
343 } else if (prot & PROT_WRITE) {
347 } else if ((prot & PROT_WRITE) != 0) {
352 maxprot |= VM_PROT_WRITE;
359 * Do not allow more then a certain number of vm_map_entry structures
360 * per process. Scale with the number of rforks sharing the map
361 * to make the limit reasonable for threads.
364 vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) {
369 error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
372 *res = (void *)(addr + pageoff);
380 mmap(struct mmap_args *uap)
384 error = kern_mmap(uap->addr, uap->len, uap->prot, uap->flags,
385 uap->fd, uap->pos, &uap->sysmsg_resultp);
391 * msync_args(void *addr, int len, int flags)
394 msync(struct msync_args *uap)
396 struct proc *p = curproc;
398 vm_size_t size, pageoff;
403 addr = (vm_offset_t) uap->addr;
407 pageoff = (addr & PAGE_MASK);
410 size = (vm_size_t) round_page(size);
411 if (addr + size < addr)
414 if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
417 map = &p->p_vmspace->vm_map;
420 * XXX Gak! If size is zero we are supposed to sync "all modified
421 * pages with the region containing addr". Unfortunately, we don't
422 * really keep track of individual mmaps so we approximate by flushing
423 * the range of the map entry containing addr. This can be incorrect
424 * if the region splits or is coalesced with a neighbor.
427 vm_map_entry_t entry;
429 vm_map_lock_read(map);
430 rv = vm_map_lookup_entry(map, addr, &entry);
431 vm_map_unlock_read(map);
435 size = entry->end - entry->start;
439 * Clean the pages and interpret the return value.
441 rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0,
442 (flags & MS_INVALIDATE) != 0);
447 case KERN_INVALID_ADDRESS:
448 return (EINVAL); /* Sun returns ENOMEM? */
459 * munmap_args(void *addr, size_t len)
462 munmap(struct munmap_args *uap)
464 struct proc *p = curproc;
466 vm_size_t size, pageoff;
469 addr = (vm_offset_t) uap->addr;
472 pageoff = (addr & PAGE_MASK);
475 size = (vm_size_t) round_page(size);
476 if (addr + size < addr)
483 * Check for illegal addresses. Watch out for address wrap... Note
484 * that VM_*_ADDRESS are not constants due to casts (argh).
486 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
489 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
492 map = &p->p_vmspace->vm_map;
494 * Make sure entire range is allocated.
496 if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE))
498 /* returns nothing but KERN_SUCCESS anyway */
499 (void) vm_map_remove(map, addr, addr + size);
510 * XXX should unmap any regions mapped to this file
512 p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
517 * mprotect_args(const void *addr, size_t len, int prot)
520 mprotect(struct mprotect_args *uap)
522 struct proc *p = curproc;
524 vm_size_t size, pageoff;
527 addr = (vm_offset_t) uap->addr;
529 prot = uap->prot & VM_PROT_ALL;
530 #if defined(VM_PROT_READ_IS_EXEC)
531 if (prot & VM_PROT_READ)
532 prot |= VM_PROT_EXECUTE;
535 pageoff = (addr & PAGE_MASK);
538 size = (vm_size_t) round_page(size);
539 if (addr + size < addr)
542 switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot,
546 case KERN_PROTECTION_FAILURE:
553 * minherit_args(void *addr, size_t len, int inherit)
556 minherit(struct minherit_args *uap)
558 struct proc *p = curproc;
560 vm_size_t size, pageoff;
561 vm_inherit_t inherit;
563 addr = (vm_offset_t)uap->addr;
565 inherit = uap->inherit;
567 pageoff = (addr & PAGE_MASK);
570 size = (vm_size_t) round_page(size);
571 if (addr + size < addr)
574 switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
578 case KERN_PROTECTION_FAILURE:
585 * madvise_args(void *addr, size_t len, int behav)
589 madvise(struct madvise_args *uap)
591 struct proc *p = curproc;
592 vm_offset_t start, end;
595 * Check for illegal behavior
597 if (uap->behav < 0 || uap->behav > MADV_CORE)
600 * Check for illegal addresses. Watch out for address wrap... Note
601 * that VM_*_ADDRESS are not constants due to casts (argh).
603 if (VM_MAXUSER_ADDRESS > 0 &&
604 ((vm_offset_t) uap->addr + uap->len) > VM_MAXUSER_ADDRESS)
607 if (VM_MIN_ADDRESS > 0 && uap->addr < VM_MIN_ADDRESS)
610 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
614 * Since this routine is only advisory, we default to conservative
617 start = trunc_page((vm_offset_t) uap->addr);
618 end = round_page((vm_offset_t) uap->addr + uap->len);
620 if (vm_map_madvise(&p->p_vmspace->vm_map, start, end, uap->behav))
626 * mincore_args(const void *addr, size_t len, char *vec)
630 mincore(struct mincore_args *uap)
632 struct proc *p = curproc;
633 vm_offset_t addr, first_addr;
634 vm_offset_t end, cend;
639 int vecindex, lastvecindex;
640 vm_map_entry_t current;
641 vm_map_entry_t entry;
643 unsigned int timestamp;
646 * Make sure that the addresses presented are valid for user
649 first_addr = addr = trunc_page((vm_offset_t) uap->addr);
650 end = addr + (vm_size_t)round_page(uap->len);
651 if (VM_MAXUSER_ADDRESS > 0 && end > VM_MAXUSER_ADDRESS)
657 * Address of byte vector
661 map = &p->p_vmspace->vm_map;
662 pmap = vmspace_pmap(p->p_vmspace);
664 vm_map_lock_read(map);
666 timestamp = map->timestamp;
668 if (!vm_map_lookup_entry(map, addr, &entry))
672 * Do this on a map entry basis so that if the pages are not
673 * in the current processes address space, we can easily look
674 * up the pages elsewhere.
678 (current != &map->header) && (current->start < end);
679 current = current->next) {
682 * ignore submaps (for now) or null objects
684 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
685 current->object.vm_object == NULL)
689 * limit this scan to the current map entry and the
690 * limits for the mincore call
692 if (addr < current->start)
693 addr = current->start;
699 * scan this entry one page at a time
703 * Check pmap first, it is likely faster, also
704 * it can provide info as to whether we are the
705 * one referencing or modifying the page.
707 mincoreinfo = pmap_mincore(pmap, addr);
713 * calculate the page index into the object
715 offset = current->offset + (addr - current->start);
716 pindex = OFF_TO_IDX(offset);
717 m = vm_page_lookup(current->object.vm_object,
720 * if the page is resident, then gather information about
724 mincoreinfo = MINCORE_INCORE;
727 mincoreinfo |= MINCORE_MODIFIED_OTHER;
728 if ((m->flags & PG_REFERENCED) ||
729 pmap_ts_referenced(m)) {
730 vm_page_flag_set(m, PG_REFERENCED);
731 mincoreinfo |= MINCORE_REFERENCED_OTHER;
737 * subyte may page fault. In case it needs to modify
738 * the map, we release the lock.
740 vm_map_unlock_read(map);
743 * calculate index into user supplied byte vector
745 vecindex = OFF_TO_IDX(addr - first_addr);
748 * If we have skipped map entries, we need to make sure that
749 * the byte vector is zeroed for those skipped entries.
751 while((lastvecindex + 1) < vecindex) {
752 error = subyte( vec + lastvecindex, 0);
760 * Pass the page information to the user
762 error = subyte( vec + vecindex, mincoreinfo);
768 * If the map has changed, due to the subyte, the previous
769 * output may be invalid.
771 vm_map_lock_read(map);
772 if (timestamp != map->timestamp)
775 lastvecindex = vecindex;
781 * subyte may page fault. In case it needs to modify
782 * the map, we release the lock.
784 vm_map_unlock_read(map);
787 * Zero the last entries in the byte vector.
789 vecindex = OFF_TO_IDX(end - first_addr);
790 while((lastvecindex + 1) < vecindex) {
791 error = subyte( vec + lastvecindex, 0);
799 * If the map has changed, due to the subyte, the previous
800 * output may be invalid.
802 vm_map_lock_read(map);
803 if (timestamp != map->timestamp)
805 vm_map_unlock_read(map);
811 * mlock_args(const void *addr, size_t len)
814 mlock(struct mlock_args *uap)
817 vm_size_t size, pageoff;
819 struct proc *p = curproc;
821 addr = (vm_offset_t) uap->addr;
824 pageoff = (addr & PAGE_MASK);
827 size = (vm_size_t) round_page(size);
829 /* disable wrap around */
830 if (addr + size < addr)
833 if (atop(size) + vmstats.v_wire_count > vm_page_max_wired)
836 #ifdef pmap_wired_count
837 if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
838 p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
841 error = suser_cred(p->p_ucred, 0);
846 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, FALSE);
847 return (error == KERN_SUCCESS ? 0 : ENOMEM);
851 * mlockall_args(int how)
854 mlockall(struct mlockall_args *uap)
860 * munlockall_args(void)
863 munlockall(struct munlockall_args *uap)
869 * munlock_args(const void *addr, size_t len)
872 munlock(struct munlock_args *uap)
874 struct thread *td = curthread;
875 struct proc *p = td->td_proc;
877 vm_size_t size, pageoff;
880 addr = (vm_offset_t) uap->addr;
883 pageoff = (addr & PAGE_MASK);
886 size = (vm_size_t) round_page(size);
888 /* disable wrap around */
889 if (addr + size < addr)
892 #ifndef pmap_wired_count
898 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, TRUE);
899 return (error == KERN_SUCCESS ? 0 : ENOMEM);
903 * Internal version of mmap.
904 * Currently used by mmap, exec, and sys5 shared memory.
905 * Handle is either a vnode pointer or NULL for MAP_ANON.
908 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
909 vm_prot_t maxprot, int flags,
915 struct vnode *vp = NULL;
917 int rv = KERN_SUCCESS;
918 vm_ooffset_t objsize;
920 struct thread *td = curthread; /* XXX */
921 struct proc *p = td->td_proc;
928 objsize = size = round_page(size);
930 if (p->p_vmspace->vm_map.size + size >
931 p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
936 * We currently can only deal with page aligned file offsets.
937 * The check is here rather than in the syscall because the
938 * kernel calls this function internally for other mmaping
939 * operations (such as in exec) and non-aligned offsets will
940 * cause pmap inconsistencies...so we want to be sure to
941 * disallow this in all cases.
943 if (foff & PAGE_MASK)
946 if ((flags & MAP_FIXED) == 0) {
948 *addr = round_page(*addr);
950 if (*addr != trunc_page(*addr))
953 (void) vm_map_remove(map, *addr, *addr + size);
957 * Lookup/allocate object.
959 if (flags & MAP_ANON) {
962 * Unnamed anonymous regions always start at 0.
967 vp = (struct vnode *) handle;
968 if (vp->v_type == VCHR) {
970 handle = (void *)(intptr_t)vp->v_rdev;
975 error = VOP_GETATTR(vp, &vat, td);
978 objsize = round_page(vat.va_size);
981 * if it is a regular file without any references
982 * we do not need to sync it.
984 if (vp->v_type == VREG && vat.va_nlink == 0) {
990 if (handle == NULL) {
994 object = vm_pager_allocate(type,
995 handle, objsize, prot, foff);
997 return (type == OBJT_DEVICE ? EINVAL : ENOMEM);
998 docow = MAP_PREFAULT_PARTIAL;
1002 * Force device mappings to be shared.
1004 if (type == OBJT_DEVICE || type == OBJT_PHYS) {
1005 flags &= ~(MAP_PRIVATE|MAP_COPY);
1006 flags |= MAP_SHARED;
1009 if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1010 docow |= MAP_COPY_ON_WRITE;
1011 if (flags & MAP_NOSYNC)
1012 docow |= MAP_DISABLE_SYNCER;
1013 if (flags & MAP_NOCORE)
1014 docow |= MAP_DISABLE_COREDUMP;
1016 #if defined(VM_PROT_READ_IS_EXEC)
1017 if (prot & VM_PROT_READ)
1018 prot |= VM_PROT_EXECUTE;
1020 if (maxprot & VM_PROT_READ)
1021 maxprot |= VM_PROT_EXECUTE;
1025 *addr = pmap_addr_hint(object, *addr, size);
1028 if (flags & MAP_STACK)
1029 rv = vm_map_stack (map, *addr, size, prot,
1032 rv = vm_map_find(map, object, foff, addr, size, fitit,
1033 prot, maxprot, docow);
1035 if (rv != KERN_SUCCESS) {
1037 * Lose the object reference. Will destroy the
1038 * object if it's an unnamed anonymous mapping
1039 * or named anonymous without other references.
1041 vm_object_deallocate(object);
1046 * Shared memory is also shared with children.
1048 if (flags & (MAP_SHARED|MAP_INHERIT)) {
1049 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE);
1050 if (rv != KERN_SUCCESS) {
1051 (void) vm_map_remove(map, *addr, *addr + size);
1059 case KERN_INVALID_ADDRESS:
1062 case KERN_PROTECTION_FAILURE: