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 1.15 2003/10/19 00:23:30 dillon Exp $
46 * Mapped file (mmap) interface to VM
49 #include "opt_compat.h"
51 #include <sys/param.h>
52 #include <sys/kernel.h>
53 #include <sys/systm.h>
54 #include <sys/sysproto.h>
55 #include <sys/filedesc.h>
57 #include <sys/resource.h>
58 #include <sys/resourcevar.h>
59 #include <sys/vnode.h>
60 #include <sys/fcntl.h>
65 #include <sys/vmmeter.h>
66 #include <sys/sysctl.h>
69 #include <vm/vm_param.h>
72 #include <vm/vm_map.h>
73 #include <vm/vm_object.h>
74 #include <vm/vm_page.h>
75 #include <vm/vm_pager.h>
76 #include <vm/vm_pageout.h>
77 #include <vm/vm_extern.h>
78 #include <vm/vm_page.h>
79 #include <vm/vm_kern.h>
81 #include <sys/file2.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(dummy)
102 max_proc_mmap = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
103 sizeof(struct vm_map_entry);
104 max_proc_mmap /= 100;
109 sbrk(struct sbrk_args *uap)
111 /* Not yet implemented */
116 * sstk_args(int incr)
120 sstk(struct sstk_args *uap)
122 /* Not yet implemented */
126 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
129 * getpagesize_args(int dummy)
133 ogetpagesize(struct getpagesize_args *uap)
135 uap->sysmsg_result = PAGE_SIZE;
138 #endif /* COMPAT_43 || COMPAT_SUNOS */
142 * mmap_args(void *addr, size_t len, int prot, int flags, int fd,
143 * long pad, off_t pos)
145 * Memory Map (mmap) system call. Note that the file offset
146 * and address are allowed to be NOT page aligned, though if
147 * the MAP_FIXED flag it set, both must have the same remainder
148 * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not
149 * page-aligned, the actual mapping starts at trunc_page(addr)
150 * and the return value is adjusted up by the page offset.
152 * Generally speaking, only character devices which are themselves
153 * memory-based, such as a video framebuffer, can be mmap'd. Otherwise
154 * there would be no cache coherency between a descriptor and a VM mapping
155 * both to the same character device.
157 * Block devices can be mmap'd no matter what they represent. Cache coherency
158 * is maintained as long as you do not write directly to the underlying
163 mmap(struct mmap_args *uap)
165 struct thread *td = curthread;
166 struct proc *p = td->td_proc;
167 struct filedesc *fdp = p->p_fd;
168 struct file *fp = NULL;
171 vm_size_t size, pageoff;
172 vm_prot_t prot, maxprot;
175 int disablexworkaround;
177 struct vmspace *vms = p->p_vmspace;
182 addr = (vm_offset_t) uap->addr;
184 prot = uap->prot & VM_PROT_ALL;
188 /* make sure mapping fits into numeric range etc */
189 if ((ssize_t) uap->len < 0 ||
190 ((flags & MAP_ANON) && uap->fd != -1))
193 if (flags & MAP_STACK) {
194 if ((uap->fd != -1) ||
195 ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
202 * Align the file position to a page boundary,
203 * and save its page offset component.
205 pageoff = (pos & PAGE_MASK);
208 /* Adjust size for rounding (on both ends). */
209 size += pageoff; /* low end... */
210 size = (vm_size_t) round_page(size); /* hi end */
213 * Check for illegal addresses. Watch out for address wrap... Note
214 * that VM_*_ADDRESS are not constants due to casts (argh).
216 if (flags & MAP_FIXED) {
218 * The specified address must have the same remainder
219 * as the file offset taken modulo PAGE_SIZE, so it
220 * should be aligned after adjustment by pageoff.
223 if (addr & PAGE_MASK)
225 /* Address range must be all in user VM space. */
226 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
229 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
232 if (addr + size < addr)
236 * XXX for non-fixed mappings where no hint is provided or
237 * the hint would fall in the potential heap space,
238 * place it after the end of the largest possible heap.
240 * There should really be a pmap call to determine a reasonable
243 else if (addr == 0 ||
244 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
245 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz)))
246 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
248 if (flags & MAP_ANON) {
250 * Mapping blank space is trivial.
253 maxprot = VM_PROT_ALL;
257 * Mapping file, get fp for validation. Obtain vnode and make
258 * sure it is of appropriate type.
260 if (((unsigned) uap->fd) >= fdp->fd_nfiles ||
261 (fp = fdp->fd_ofiles[uap->fd]) == NULL)
263 if (fp->f_type != DTYPE_VNODE)
266 * POSIX shared-memory objects are defined to have
267 * kernel persistence, and are not defined to support
268 * read(2)/write(2) -- or even open(2). Thus, we can
269 * use MAP_ASYNC to trade on-disk coherence for speed.
270 * The shm_open(3) library routine turns on the FPOSIXSHM
271 * flag to request this behavior.
273 if (fp->f_flag & FPOSIXSHM)
275 vp = (struct vnode *) fp->f_data;
276 if (vp->v_type != VREG && vp->v_type != VCHR)
278 if (vp->v_type == VREG) {
280 * Get the proper underlying object
282 if (VOP_GETVOBJECT(vp, &obj) != 0)
284 vp = (struct vnode*)obj->handle;
288 * don't let the descriptor disappear on us if we block
293 * XXX hack to handle use of /dev/zero to map anon memory (ala
296 if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
298 maxprot = VM_PROT_ALL;
303 * cdevs does not provide private mappings of any kind.
306 * However, for XIG X server to continue to work,
307 * we should allow the superuser to do it anyway.
308 * We only allow it at securelevel < 1.
309 * (Because the XIG X server writes directly to video
310 * memory via /dev/mem, it should never work at any
312 * XXX this will have to go
314 if (securelevel >= 1)
315 disablexworkaround = 1;
317 disablexworkaround = suser(td);
318 if (vp->v_type == VCHR && disablexworkaround &&
319 (flags & (MAP_PRIVATE|MAP_COPY))) {
324 * Ensure that file and memory protections are
325 * compatible. Note that we only worry about
326 * writability if mapping is shared; in this case,
327 * current and max prot are dictated by the open file.
328 * XXX use the vnode instead? Problem is: what
329 * credentials do we use for determination? What if
330 * proc does a setuid?
332 maxprot = VM_PROT_EXECUTE; /* ??? */
333 if (fp->f_flag & FREAD) {
334 maxprot |= VM_PROT_READ;
335 } else if (prot & PROT_READ) {
340 * If we are sharing potential changes (either via
341 * MAP_SHARED or via the implicit sharing of character
342 * device mappings), and we are trying to get write
343 * permission although we opened it without asking
344 * for it, bail out. Check for superuser, only if
345 * we're at securelevel < 1, to allow the XIG X server
346 * to continue to work.
349 if ((flags & MAP_SHARED) != 0 ||
350 (vp->v_type == VCHR && disablexworkaround)) {
351 if ((fp->f_flag & FWRITE) != 0) {
353 if ((error = VOP_GETATTR(vp, &va, td))) {
357 (IMMUTABLE|APPEND)) == 0) {
358 maxprot |= VM_PROT_WRITE;
359 } else if (prot & PROT_WRITE) {
363 } else if ((prot & PROT_WRITE) != 0) {
368 maxprot |= VM_PROT_WRITE;
375 * Do not allow more then a certain number of vm_map_entry structures
376 * per process. Scale with the number of rforks sharing the map
377 * to make the limit reasonable for threads.
380 vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) {
385 error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
388 uap->sysmsg_resultp = (void *)(addr + pageoff);
397 * ommap_args(caddr_t addr, int len, int prot, int flags, int fd, long pos)
400 ommap(struct ommap_args *uap)
402 struct mmap_args nargs;
403 static const char cvtbsdprot[8] = {
407 PROT_EXEC | PROT_WRITE,
409 PROT_EXEC | PROT_READ,
410 PROT_WRITE | PROT_READ,
411 PROT_EXEC | PROT_WRITE | PROT_READ,
414 #define OMAP_ANON 0x0002
415 #define OMAP_COPY 0x0020
416 #define OMAP_SHARED 0x0010
417 #define OMAP_FIXED 0x0100
418 #define OMAP_INHERIT 0x0800
420 nargs.addr = uap->addr;
421 nargs.len = uap->len;
422 nargs.prot = cvtbsdprot[uap->prot & 0x7];
424 if (uap->flags & OMAP_ANON)
425 nargs.flags |= MAP_ANON;
426 if (uap->flags & OMAP_COPY)
427 nargs.flags |= MAP_COPY;
428 if (uap->flags & OMAP_SHARED)
429 nargs.flags |= MAP_SHARED;
431 nargs.flags |= MAP_PRIVATE;
432 if (uap->flags & OMAP_FIXED)
433 nargs.flags |= MAP_FIXED;
434 if (uap->flags & OMAP_INHERIT)
435 nargs.flags |= MAP_INHERIT;
437 nargs.pos = uap->pos;
438 return (mmap(&nargs));
440 #endif /* COMPAT_43 */
444 * msync_args(void *addr, int len, int flags)
447 msync(struct msync_args *uap)
449 struct proc *p = curproc;
451 vm_size_t size, pageoff;
456 addr = (vm_offset_t) uap->addr;
460 pageoff = (addr & PAGE_MASK);
463 size = (vm_size_t) round_page(size);
464 if (addr + size < addr)
467 if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
470 map = &p->p_vmspace->vm_map;
473 * XXX Gak! If size is zero we are supposed to sync "all modified
474 * pages with the region containing addr". Unfortunately, we don't
475 * really keep track of individual mmaps so we approximate by flushing
476 * the range of the map entry containing addr. This can be incorrect
477 * if the region splits or is coalesced with a neighbor.
480 vm_map_entry_t entry;
482 vm_map_lock_read(map);
483 rv = vm_map_lookup_entry(map, addr, &entry);
484 vm_map_unlock_read(map);
488 size = entry->end - entry->start;
492 * Clean the pages and interpret the return value.
494 rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0,
495 (flags & MS_INVALIDATE) != 0);
500 case KERN_INVALID_ADDRESS:
501 return (EINVAL); /* Sun returns ENOMEM? */
512 * munmap_args(void *addr, size_t len)
515 munmap(struct munmap_args *uap)
517 struct proc *p = curproc;
519 vm_size_t size, pageoff;
522 addr = (vm_offset_t) uap->addr;
525 pageoff = (addr & PAGE_MASK);
528 size = (vm_size_t) round_page(size);
529 if (addr + size < addr)
536 * Check for illegal addresses. Watch out for address wrap... Note
537 * that VM_*_ADDRESS are not constants due to casts (argh).
539 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
542 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
545 map = &p->p_vmspace->vm_map;
547 * Make sure entire range is allocated.
549 if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE))
551 /* returns nothing but KERN_SUCCESS anyway */
552 (void) vm_map_remove(map, addr, addr + size);
563 * XXX should unmap any regions mapped to this file
565 p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
570 * mprotect_args(const void *addr, size_t len, int prot)
573 mprotect(struct mprotect_args *uap)
575 struct proc *p = curproc;
577 vm_size_t size, pageoff;
580 addr = (vm_offset_t) uap->addr;
582 prot = uap->prot & VM_PROT_ALL;
583 #if defined(VM_PROT_READ_IS_EXEC)
584 if (prot & VM_PROT_READ)
585 prot |= VM_PROT_EXECUTE;
588 pageoff = (addr & PAGE_MASK);
591 size = (vm_size_t) round_page(size);
592 if (addr + size < addr)
595 switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot,
599 case KERN_PROTECTION_FAILURE:
606 * minherit_args(void *addr, size_t len, int inherit)
609 minherit(struct minherit_args *uap)
611 struct proc *p = curproc;
613 vm_size_t size, pageoff;
614 vm_inherit_t inherit;
616 addr = (vm_offset_t)uap->addr;
618 inherit = uap->inherit;
620 pageoff = (addr & PAGE_MASK);
623 size = (vm_size_t) round_page(size);
624 if (addr + size < addr)
627 switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
631 case KERN_PROTECTION_FAILURE:
638 * madvise_args(void *addr, size_t len, int behav)
642 madvise(struct madvise_args *uap)
644 struct proc *p = curproc;
645 vm_offset_t start, end;
648 * Check for illegal behavior
650 if (uap->behav < 0 || uap->behav > MADV_CORE)
653 * Check for illegal addresses. Watch out for address wrap... Note
654 * that VM_*_ADDRESS are not constants due to casts (argh).
656 if (VM_MAXUSER_ADDRESS > 0 &&
657 ((vm_offset_t) uap->addr + uap->len) > VM_MAXUSER_ADDRESS)
660 if (VM_MIN_ADDRESS > 0 && uap->addr < VM_MIN_ADDRESS)
663 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
667 * Since this routine is only advisory, we default to conservative
670 start = trunc_page((vm_offset_t) uap->addr);
671 end = round_page((vm_offset_t) uap->addr + uap->len);
673 if (vm_map_madvise(&p->p_vmspace->vm_map, start, end, uap->behav))
679 * mincore_args(const void *addr, size_t len, char *vec)
683 mincore(struct mincore_args *uap)
685 struct proc *p = curproc;
686 vm_offset_t addr, first_addr;
687 vm_offset_t end, cend;
692 int vecindex, lastvecindex;
693 vm_map_entry_t current;
694 vm_map_entry_t entry;
696 unsigned int timestamp;
699 * Make sure that the addresses presented are valid for user
702 first_addr = addr = trunc_page((vm_offset_t) uap->addr);
703 end = addr + (vm_size_t)round_page(uap->len);
704 if (VM_MAXUSER_ADDRESS > 0 && end > VM_MAXUSER_ADDRESS)
710 * Address of byte vector
714 map = &p->p_vmspace->vm_map;
715 pmap = vmspace_pmap(p->p_vmspace);
717 vm_map_lock_read(map);
719 timestamp = map->timestamp;
721 if (!vm_map_lookup_entry(map, addr, &entry))
725 * Do this on a map entry basis so that if the pages are not
726 * in the current processes address space, we can easily look
727 * up the pages elsewhere.
731 (current != &map->header) && (current->start < end);
732 current = current->next) {
735 * ignore submaps (for now) or null objects
737 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
738 current->object.vm_object == NULL)
742 * limit this scan to the current map entry and the
743 * limits for the mincore call
745 if (addr < current->start)
746 addr = current->start;
752 * scan this entry one page at a time
756 * Check pmap first, it is likely faster, also
757 * it can provide info as to whether we are the
758 * one referencing or modifying the page.
760 mincoreinfo = pmap_mincore(pmap, addr);
766 * calculate the page index into the object
768 offset = current->offset + (addr - current->start);
769 pindex = OFF_TO_IDX(offset);
770 m = vm_page_lookup(current->object.vm_object,
773 * if the page is resident, then gather information about
777 mincoreinfo = MINCORE_INCORE;
780 mincoreinfo |= MINCORE_MODIFIED_OTHER;
781 if ((m->flags & PG_REFERENCED) ||
782 pmap_ts_referenced(m)) {
783 vm_page_flag_set(m, PG_REFERENCED);
784 mincoreinfo |= MINCORE_REFERENCED_OTHER;
790 * subyte may page fault. In case it needs to modify
791 * the map, we release the lock.
793 vm_map_unlock_read(map);
796 * calculate index into user supplied byte vector
798 vecindex = OFF_TO_IDX(addr - first_addr);
801 * If we have skipped map entries, we need to make sure that
802 * the byte vector is zeroed for those skipped entries.
804 while((lastvecindex + 1) < vecindex) {
805 error = subyte( vec + lastvecindex, 0);
813 * Pass the page information to the user
815 error = subyte( vec + vecindex, mincoreinfo);
821 * If the map has changed, due to the subyte, the previous
822 * output may be invalid.
824 vm_map_lock_read(map);
825 if (timestamp != map->timestamp)
828 lastvecindex = vecindex;
834 * subyte may page fault. In case it needs to modify
835 * the map, we release the lock.
837 vm_map_unlock_read(map);
840 * Zero the last entries in the byte vector.
842 vecindex = OFF_TO_IDX(end - first_addr);
843 while((lastvecindex + 1) < vecindex) {
844 error = subyte( vec + lastvecindex, 0);
852 * If the map has changed, due to the subyte, the previous
853 * output may be invalid.
855 vm_map_lock_read(map);
856 if (timestamp != map->timestamp)
858 vm_map_unlock_read(map);
864 * mlock_args(const void *addr, size_t len)
867 mlock(struct mlock_args *uap)
870 vm_size_t size, pageoff;
872 struct proc *p = curproc;
874 addr = (vm_offset_t) uap->addr;
877 pageoff = (addr & PAGE_MASK);
880 size = (vm_size_t) round_page(size);
882 /* disable wrap around */
883 if (addr + size < addr)
886 if (atop(size) + vmstats.v_wire_count > vm_page_max_wired)
889 #ifdef pmap_wired_count
890 if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
891 p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
894 error = suser_cred(p->p_ucred, 0);
899 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, FALSE);
900 return (error == KERN_SUCCESS ? 0 : ENOMEM);
904 * mlockall_args(int how)
907 mlockall(struct mlockall_args *uap)
913 * mlockall_args(int how)
916 munlockall(struct munlockall_args *uap)
922 * munlock_args(const void *addr, size_t len)
925 munlock(struct munlock_args *uap)
927 struct thread *td = curthread;
928 struct proc *p = td->td_proc;
930 vm_size_t size, pageoff;
933 addr = (vm_offset_t) uap->addr;
936 pageoff = (addr & PAGE_MASK);
939 size = (vm_size_t) round_page(size);
941 /* disable wrap around */
942 if (addr + size < addr)
945 #ifndef pmap_wired_count
951 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, TRUE);
952 return (error == KERN_SUCCESS ? 0 : ENOMEM);
956 * Internal version of mmap.
957 * Currently used by mmap, exec, and sys5 shared memory.
958 * Handle is either a vnode pointer or NULL for MAP_ANON.
961 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
962 vm_prot_t maxprot, int flags,
968 struct vnode *vp = NULL;
970 int rv = KERN_SUCCESS;
971 vm_ooffset_t objsize;
973 struct thread *td = curthread; /* XXX */
974 struct proc *p = td->td_proc;
981 objsize = size = round_page(size);
983 if (p->p_vmspace->vm_map.size + size >
984 p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
989 * We currently can only deal with page aligned file offsets.
990 * The check is here rather than in the syscall because the
991 * kernel calls this function internally for other mmaping
992 * operations (such as in exec) and non-aligned offsets will
993 * cause pmap inconsistencies...so we want to be sure to
994 * disallow this in all cases.
996 if (foff & PAGE_MASK)
999 if ((flags & MAP_FIXED) == 0) {
1001 *addr = round_page(*addr);
1003 if (*addr != trunc_page(*addr))
1006 (void) vm_map_remove(map, *addr, *addr + size);
1010 * Lookup/allocate object.
1012 if (flags & MAP_ANON) {
1013 type = OBJT_DEFAULT;
1015 * Unnamed anonymous regions always start at 0.
1020 vp = (struct vnode *) handle;
1021 if (vp->v_type == VCHR) {
1023 handle = (void *)(intptr_t)vp->v_rdev;
1028 error = VOP_GETATTR(vp, &vat, td);
1031 objsize = round_page(vat.va_size);
1034 * if it is a regular file without any references
1035 * we do not need to sync it.
1037 if (vp->v_type == VREG && vat.va_nlink == 0) {
1038 flags |= MAP_NOSYNC;
1043 if (handle == NULL) {
1047 object = vm_pager_allocate(type,
1048 handle, objsize, prot, foff);
1050 return (type == OBJT_DEVICE ? EINVAL : ENOMEM);
1051 docow = MAP_PREFAULT_PARTIAL;
1055 * Force device mappings to be shared.
1057 if (type == OBJT_DEVICE || type == OBJT_PHYS) {
1058 flags &= ~(MAP_PRIVATE|MAP_COPY);
1059 flags |= MAP_SHARED;
1062 if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1063 docow |= MAP_COPY_ON_WRITE;
1064 if (flags & MAP_NOSYNC)
1065 docow |= MAP_DISABLE_SYNCER;
1066 if (flags & MAP_NOCORE)
1067 docow |= MAP_DISABLE_COREDUMP;
1069 #if defined(VM_PROT_READ_IS_EXEC)
1070 if (prot & VM_PROT_READ)
1071 prot |= VM_PROT_EXECUTE;
1073 if (maxprot & VM_PROT_READ)
1074 maxprot |= VM_PROT_EXECUTE;
1078 *addr = pmap_addr_hint(object, *addr, size);
1081 if (flags & MAP_STACK)
1082 rv = vm_map_stack (map, *addr, size, prot,
1085 rv = vm_map_find(map, object, foff, addr, size, fitit,
1086 prot, maxprot, docow);
1088 if (rv != KERN_SUCCESS) {
1090 * Lose the object reference. Will destroy the
1091 * object if it's an unnamed anonymous mapping
1092 * or named anonymous without other references.
1094 vm_object_deallocate(object);
1099 * Shared memory is also shared with children.
1101 if (flags & (MAP_SHARED|MAP_INHERIT)) {
1102 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE);
1103 if (rv != KERN_SUCCESS) {
1104 (void) vm_map_remove(map, *addr, *addr + size);
1112 case KERN_INVALID_ADDRESS:
1115 case KERN_PROTECTION_FAILURE: