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 1.30 2006/06/05 07:26:11 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>
81 #include <sys/thread2.h>
83 static int max_proc_mmap;
84 SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, "");
87 * Set the maximum number of vm_map_entry structures per process. Roughly
88 * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100
89 * of our KVM malloc space still results in generous limits. We want a
90 * default that is good enough to prevent the kernel running out of resources
91 * if attacked from compromised user account but generous enough such that
92 * multi-threaded processes are not unduly inconvenienced.
95 static void vmmapentry_rsrc_init (void *);
96 SYSINIT(vmmersrc, SI_SUB_KVM_RSRC, SI_ORDER_FIRST, vmmapentry_rsrc_init, NULL)
99 vmmapentry_rsrc_init(void *dummy)
101 max_proc_mmap = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
102 sizeof(struct vm_map_entry);
103 max_proc_mmap /= 100;
108 sys_sbrk(struct sbrk_args *uap)
110 /* Not yet implemented */
115 * sstk_args(int incr)
119 sys_sstk(struct sstk_args *uap)
121 /* Not yet implemented */
126 * mmap_args(void *addr, size_t len, int prot, int flags, int fd,
127 * long pad, off_t pos)
129 * Memory Map (mmap) system call. Note that the file offset
130 * and address are allowed to be NOT page aligned, though if
131 * the MAP_FIXED flag it set, both must have the same remainder
132 * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not
133 * page-aligned, the actual mapping starts at trunc_page(addr)
134 * and the return value is adjusted up by the page offset.
136 * Generally speaking, only character devices which are themselves
137 * memory-based, such as a video framebuffer, can be mmap'd. Otherwise
138 * there would be no cache coherency between a descriptor and a VM mapping
139 * both to the same character device.
141 * Block devices can be mmap'd no matter what they represent. Cache coherency
142 * is maintained as long as you do not write directly to the underlying
147 kern_mmap(caddr_t uaddr, size_t ulen, int uprot, int uflags, int fd,
148 off_t upos, void **res)
150 struct thread *td = curthread;
151 struct proc *p = td->td_proc;
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 fp = holdfp(p->p_fd, fd, -1);
247 if (fp->f_type != DTYPE_VNODE) {
252 * POSIX shared-memory objects are defined to have
253 * kernel persistence, and are not defined to support
254 * read(2)/write(2) -- or even open(2). Thus, we can
255 * use MAP_ASYNC to trade on-disk coherence for speed.
256 * The shm_open(3) library routine turns on the FPOSIXSHM
257 * flag to request this behavior.
259 if (fp->f_flag & FPOSIXSHM)
261 vp = (struct vnode *) fp->f_data;
262 if (vp->v_type != VREG && vp->v_type != VCHR) {
266 if (vp->v_type == VREG) {
268 * Get the proper underlying object
270 if ((obj = vp->v_object) == NULL) {
274 KKASSERT(vp == (struct vnode *)obj->handle);
278 * XXX hack to handle use of /dev/zero to map anon memory (ala
281 if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
283 maxprot = VM_PROT_ALL;
288 * cdevs does not provide private mappings of any kind.
291 * However, for XIG X server to continue to work,
292 * we should allow the superuser to do it anyway.
293 * We only allow it at securelevel < 1.
294 * (Because the XIG X server writes directly to video
295 * memory via /dev/mem, it should never work at any
297 * XXX this will have to go
299 if (securelevel >= 1)
300 disablexworkaround = 1;
302 disablexworkaround = suser(td);
303 if (vp->v_type == VCHR && disablexworkaround &&
304 (flags & (MAP_PRIVATE|MAP_COPY))) {
309 * Ensure that file and memory protections are
310 * compatible. Note that we only worry about
311 * writability if mapping is shared; in this case,
312 * current and max prot are dictated by the open file.
313 * XXX use the vnode instead? Problem is: what
314 * credentials do we use for determination? What if
315 * proc does a setuid?
317 maxprot = VM_PROT_EXECUTE; /* ??? */
318 if (fp->f_flag & FREAD) {
319 maxprot |= VM_PROT_READ;
320 } else if (prot & PROT_READ) {
325 * If we are sharing potential changes (either via
326 * MAP_SHARED or via the implicit sharing of character
327 * device mappings), and we are trying to get write
328 * permission although we opened it without asking
329 * for it, bail out. Check for superuser, only if
330 * we're at securelevel < 1, to allow the XIG X server
331 * to continue to work.
334 if ((flags & MAP_SHARED) != 0 ||
335 (vp->v_type == VCHR && disablexworkaround)) {
336 if ((fp->f_flag & FWRITE) != 0) {
338 if ((error = VOP_GETATTR(vp, &va))) {
342 (IMMUTABLE|APPEND)) == 0) {
343 maxprot |= VM_PROT_WRITE;
344 } else if (prot & PROT_WRITE) {
348 } else if ((prot & PROT_WRITE) != 0) {
353 maxprot |= VM_PROT_WRITE;
360 * Do not allow more then a certain number of vm_map_entry structures
361 * per process. Scale with the number of rforks sharing the map
362 * to make the limit reasonable for threads.
365 vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) {
370 error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
373 *res = (void *)(addr + pageoff);
381 sys_mmap(struct mmap_args *uap)
385 error = kern_mmap(uap->addr, uap->len, uap->prot, uap->flags,
386 uap->fd, uap->pos, &uap->sysmsg_resultp);
392 * msync_args(void *addr, int len, int flags)
395 sys_msync(struct msync_args *uap)
397 struct proc *p = curproc;
399 vm_size_t size, pageoff;
404 addr = (vm_offset_t) uap->addr;
408 pageoff = (addr & PAGE_MASK);
411 size = (vm_size_t) round_page(size);
412 if (addr + size < addr)
415 if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
418 map = &p->p_vmspace->vm_map;
421 * XXX Gak! If size is zero we are supposed to sync "all modified
422 * pages with the region containing addr". Unfortunately, we don't
423 * really keep track of individual mmaps so we approximate by flushing
424 * the range of the map entry containing addr. This can be incorrect
425 * if the region splits or is coalesced with a neighbor.
428 vm_map_entry_t entry;
430 vm_map_lock_read(map);
431 rv = vm_map_lookup_entry(map, addr, &entry);
432 vm_map_unlock_read(map);
436 size = entry->end - entry->start;
440 * Clean the pages and interpret the return value.
442 rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0,
443 (flags & MS_INVALIDATE) != 0);
448 case KERN_INVALID_ADDRESS:
449 return (EINVAL); /* Sun returns ENOMEM? */
460 * munmap_args(void *addr, size_t len)
463 sys_munmap(struct munmap_args *uap)
465 struct proc *p = curproc;
467 vm_size_t size, pageoff;
470 addr = (vm_offset_t) uap->addr;
473 pageoff = (addr & PAGE_MASK);
476 size = (vm_size_t) round_page(size);
477 if (addr + size < addr)
484 * Check for illegal addresses. Watch out for address wrap... Note
485 * that VM_*_ADDRESS are not constants due to casts (argh).
487 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
490 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
493 map = &p->p_vmspace->vm_map;
495 * Make sure entire range is allocated.
497 if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE))
499 /* returns nothing but KERN_SUCCESS anyway */
500 vm_map_remove(map, addr, addr + size);
505 * mprotect_args(const void *addr, size_t len, int prot)
508 sys_mprotect(struct mprotect_args *uap)
510 struct proc *p = curproc;
512 vm_size_t size, pageoff;
515 addr = (vm_offset_t) uap->addr;
517 prot = uap->prot & VM_PROT_ALL;
518 #if defined(VM_PROT_READ_IS_EXEC)
519 if (prot & VM_PROT_READ)
520 prot |= VM_PROT_EXECUTE;
523 pageoff = (addr & PAGE_MASK);
526 size = (vm_size_t) round_page(size);
527 if (addr + size < addr)
530 switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot,
534 case KERN_PROTECTION_FAILURE:
541 * minherit_args(void *addr, size_t len, int inherit)
544 sys_minherit(struct minherit_args *uap)
546 struct proc *p = curproc;
548 vm_size_t size, pageoff;
549 vm_inherit_t inherit;
551 addr = (vm_offset_t)uap->addr;
553 inherit = uap->inherit;
555 pageoff = (addr & PAGE_MASK);
558 size = (vm_size_t) round_page(size);
559 if (addr + size < addr)
562 switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
566 case KERN_PROTECTION_FAILURE:
573 * madvise_args(void *addr, size_t len, int behav)
577 sys_madvise(struct madvise_args *uap)
579 struct proc *p = curproc;
580 vm_offset_t start, end;
583 * Check for illegal behavior
585 if (uap->behav < 0 || uap->behav > MADV_CORE)
588 * Check for illegal addresses. Watch out for address wrap... Note
589 * that VM_*_ADDRESS are not constants due to casts (argh).
591 if (VM_MAXUSER_ADDRESS > 0 &&
592 ((vm_offset_t) uap->addr + uap->len) > VM_MAXUSER_ADDRESS)
595 if (VM_MIN_ADDRESS > 0 && uap->addr < VM_MIN_ADDRESS)
598 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
602 * Since this routine is only advisory, we default to conservative
605 start = trunc_page((vm_offset_t) uap->addr);
606 end = round_page((vm_offset_t) uap->addr + uap->len);
608 if (vm_map_madvise(&p->p_vmspace->vm_map, start, end, uap->behav))
614 * mincore_args(const void *addr, size_t len, char *vec)
618 sys_mincore(struct mincore_args *uap)
620 struct proc *p = curproc;
621 vm_offset_t addr, first_addr;
622 vm_offset_t end, cend;
627 int vecindex, lastvecindex;
628 vm_map_entry_t current;
629 vm_map_entry_t entry;
631 unsigned int timestamp;
634 * Make sure that the addresses presented are valid for user
637 first_addr = addr = trunc_page((vm_offset_t) uap->addr);
638 end = addr + (vm_size_t)round_page(uap->len);
639 if (VM_MAXUSER_ADDRESS > 0 && end > VM_MAXUSER_ADDRESS)
645 * Address of byte vector
649 map = &p->p_vmspace->vm_map;
650 pmap = vmspace_pmap(p->p_vmspace);
652 vm_map_lock_read(map);
654 timestamp = map->timestamp;
656 if (!vm_map_lookup_entry(map, addr, &entry))
660 * Do this on a map entry basis so that if the pages are not
661 * in the current processes address space, we can easily look
662 * up the pages elsewhere.
666 (current != &map->header) && (current->start < end);
667 current = current->next) {
670 * ignore submaps (for now) or null objects
672 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
673 current->object.vm_object == NULL)
677 * limit this scan to the current map entry and the
678 * limits for the mincore call
680 if (addr < current->start)
681 addr = current->start;
687 * scan this entry one page at a time
689 while (addr < cend) {
691 * Check pmap first, it is likely faster, also
692 * it can provide info as to whether we are the
693 * one referencing or modifying the page.
695 mincoreinfo = pmap_mincore(pmap, addr);
702 * calculate the page index into the object
704 offset = current->offset + (addr - current->start);
705 pindex = OFF_TO_IDX(offset);
708 * if the page is resident, then gather
709 * information about it. spl protection is
710 * required to maintain the object
711 * association. And XXX what if the page is
712 * busy? What's the deal with that?
715 m = vm_page_lookup(current->object.vm_object,
718 mincoreinfo = MINCORE_INCORE;
721 mincoreinfo |= MINCORE_MODIFIED_OTHER;
722 if ((m->flags & PG_REFERENCED) ||
723 pmap_ts_referenced(m)) {
724 vm_page_flag_set(m, PG_REFERENCED);
725 mincoreinfo |= MINCORE_REFERENCED_OTHER;
732 * subyte may page fault. In case it needs to modify
733 * the map, we release the lock.
735 vm_map_unlock_read(map);
738 * calculate index into user supplied byte vector
740 vecindex = OFF_TO_IDX(addr - first_addr);
743 * If we have skipped map entries, we need to make sure that
744 * the byte vector is zeroed for those skipped entries.
746 while((lastvecindex + 1) < vecindex) {
747 error = subyte( vec + lastvecindex, 0);
755 * Pass the page information to the user
757 error = subyte( vec + vecindex, mincoreinfo);
763 * If the map has changed, due to the subyte, the previous
764 * output may be invalid.
766 vm_map_lock_read(map);
767 if (timestamp != map->timestamp)
770 lastvecindex = vecindex;
776 * subyte may page fault. In case it needs to modify
777 * the map, we release the lock.
779 vm_map_unlock_read(map);
782 * Zero the last entries in the byte vector.
784 vecindex = OFF_TO_IDX(end - first_addr);
785 while((lastvecindex + 1) < vecindex) {
786 error = subyte( vec + lastvecindex, 0);
794 * If the map has changed, due to the subyte, the previous
795 * output may be invalid.
797 vm_map_lock_read(map);
798 if (timestamp != map->timestamp)
800 vm_map_unlock_read(map);
806 * mlock_args(const void *addr, size_t len)
809 sys_mlock(struct mlock_args *uap)
812 vm_size_t size, pageoff;
814 struct proc *p = curproc;
816 addr = (vm_offset_t) uap->addr;
819 pageoff = (addr & PAGE_MASK);
822 size = (vm_size_t) round_page(size);
824 /* disable wrap around */
825 if (addr + size < addr)
828 if (atop(size) + vmstats.v_wire_count > vm_page_max_wired)
831 #ifdef pmap_wired_count
832 if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
833 p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
836 error = suser_cred(p->p_ucred, 0);
841 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, FALSE);
842 return (error == KERN_SUCCESS ? 0 : ENOMEM);
846 * mlockall_args(int how)
849 sys_mlockall(struct mlockall_args *uap)
855 * munlockall_args(void)
858 sys_munlockall(struct munlockall_args *uap)
864 * munlock_args(const void *addr, size_t len)
867 sys_munlock(struct munlock_args *uap)
869 struct thread *td = curthread;
870 struct proc *p = td->td_proc;
872 vm_size_t size, pageoff;
875 addr = (vm_offset_t) uap->addr;
878 pageoff = (addr & PAGE_MASK);
881 size = (vm_size_t) round_page(size);
883 /* disable wrap around */
884 if (addr + size < addr)
887 #ifndef pmap_wired_count
893 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, TRUE);
894 return (error == KERN_SUCCESS ? 0 : ENOMEM);
898 * Internal version of mmap.
899 * Currently used by mmap, exec, and sys5 shared memory.
900 * Handle is either a vnode pointer or NULL for MAP_ANON.
903 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
904 vm_prot_t maxprot, int flags,
910 struct vnode *vp = NULL;
912 int rv = KERN_SUCCESS;
915 struct thread *td = curthread; /* XXX */
916 struct proc *p = td->td_proc;
923 objsize = size = round_page(size);
925 if (p->p_vmspace->vm_map.size + size >
926 p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
931 * We currently can only deal with page aligned file offsets.
932 * The check is here rather than in the syscall because the
933 * kernel calls this function internally for other mmaping
934 * operations (such as in exec) and non-aligned offsets will
935 * cause pmap inconsistencies...so we want to be sure to
936 * disallow this in all cases.
938 if (foff & PAGE_MASK)
941 if ((flags & MAP_FIXED) == 0) {
943 *addr = round_page(*addr);
945 if (*addr != trunc_page(*addr))
948 vm_map_remove(map, *addr, *addr + size);
952 * Lookup/allocate object.
954 if (flags & MAP_ANON) {
957 * Unnamed anonymous regions always start at 0.
962 vp = (struct vnode *) handle;
963 if (vp->v_type == VCHR) {
965 handle = (void *)(intptr_t)vp->v_rdev;
970 error = VOP_GETATTR(vp, &vat);
973 objsize = vat.va_size;
976 * if it is a regular file without any references
977 * we do not need to sync it.
979 if (vp->v_type == VREG && vat.va_nlink == 0) {
985 if (handle == NULL) {
989 object = vm_pager_allocate(type, handle, objsize, prot, foff);
991 return (type == OBJT_DEVICE ? EINVAL : ENOMEM);
992 docow = MAP_PREFAULT_PARTIAL;
996 * Force device mappings to be shared.
998 if (type == OBJT_DEVICE || type == OBJT_PHYS) {
999 flags &= ~(MAP_PRIVATE|MAP_COPY);
1000 flags |= MAP_SHARED;
1003 if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1004 docow |= MAP_COPY_ON_WRITE;
1005 if (flags & MAP_NOSYNC)
1006 docow |= MAP_DISABLE_SYNCER;
1007 if (flags & MAP_NOCORE)
1008 docow |= MAP_DISABLE_COREDUMP;
1010 #if defined(VM_PROT_READ_IS_EXEC)
1011 if (prot & VM_PROT_READ)
1012 prot |= VM_PROT_EXECUTE;
1014 if (maxprot & VM_PROT_READ)
1015 maxprot |= VM_PROT_EXECUTE;
1019 *addr = pmap_addr_hint(object, *addr, size);
1022 if (flags & MAP_STACK)
1023 rv = vm_map_stack (map, *addr, size, prot,
1026 rv = vm_map_find(map, object, foff, addr, size, fitit,
1027 prot, maxprot, docow);
1029 if (rv != KERN_SUCCESS) {
1031 * Lose the object reference. Will destroy the
1032 * object if it's an unnamed anonymous mapping
1033 * or named anonymous without other references.
1035 vm_object_deallocate(object);
1040 * Shared memory is also shared with children.
1042 if (flags & (MAP_SHARED|MAP_INHERIT)) {
1043 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE);
1044 if (rv != KERN_SUCCESS) {
1045 vm_map_remove(map, *addr, *addr + size);
1053 case KERN_INVALID_ADDRESS:
1056 case KERN_PROTECTION_FAILURE: