initial import of NetBSD tree

1 files changed, 981 insertions, 0 deletions

diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
new file mode 100644
index 00000000000..ea205439963
--- /dev/null
+++ b/sys/vm/vm_mmap.c
@@ -0,0 +1,981 @@
+/*	$NetBSD: vm_mmap.c,v 1.42 1995/10/10 01:27:11 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1988 University of Utah.
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * the Systems Programming Group of the University of Utah Computer
+ * Science Department.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
+ *
+ *	@(#)vm_mmap.c	8.5 (Berkeley) 5/19/94
+ */
+
+/*
+ * Mapped file (mmap) interface to VM
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/filedesc.h>
+#include <sys/resourcevar.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/file.h>
+#include <sys/mman.h>
+#include <sys/conf.h>
+
+#include <sys/mount.h>
+#include <sys/syscallargs.h>
+
+#include <miscfs/specfs/specdev.h>
+
+#include <vm/vm.h>
+#include <vm/vm_pager.h>
+#include <vm/vm_prot.h>
+
+#ifdef DEBUG
+int mmapdebug = 0;
+#define MDB_FOLLOW	0x01
+#define MDB_SYNC	0x02
+#define MDB_MAPIT	0x04
+#endif
+
+/* ARGSUSED */
+int
+sys_sbrk(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_sbrk_args /* {
+		syscallarg(int) incr;
+	} */ *uap = v;
+
+	/* Not yet implemented */
+	return (EOPNOTSUPP);
+}
+
+/* ARGSUSED */
+int
+sys_sstk(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_sstk_args /* {
+		syscallarg(int) incr;
+	} */ *uap = v;
+
+	/* Not yet implemented */
+	return (EOPNOTSUPP);
+}
+
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_OSF1) || \
+    defined(COMPAT_FREEBSD)
+/* ARGSUSED */
+int
+compat_43_sys_getpagesize(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+
+	*retval = PAGE_SIZE;
+	return (0);
+}
+#endif /* COMPAT_43 || COMPAT_SUNOS || COMPAT_OSF1 || COMPAT_FREEBSD */
+
+#if defined(COMPAT_43) || defined(COMPAT_FREEBSD)
+int
+compat_43_sys_mmap(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	register struct compat_43_sys_mmap_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+		syscallarg(int) prot;
+		syscallarg(int) flags;
+		syscallarg(int) fd;
+		syscallarg(long) pos;
+	} */ *uap = v;
+	struct sys_mmap_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+		syscallarg(int) prot;
+		syscallarg(int) flags;
+		syscallarg(int) fd;
+		syscallarg(long) pad;
+		syscallarg(off_t) pos;
+	} */ nargs;
+	static const char cvtbsdprot[8] = {
+		0,
+		PROT_EXEC,
+		PROT_WRITE,
+		PROT_EXEC|PROT_WRITE,
+		PROT_READ,
+		PROT_EXEC|PROT_READ,
+		PROT_WRITE|PROT_READ,
+		PROT_EXEC|PROT_WRITE|PROT_READ,
+	};
+#define	OMAP_ANON	0x0002
+#define	OMAP_COPY	0x0020
+#define	OMAP_SHARED	0x0010
+#define	OMAP_FIXED	0x0100
+#define	OMAP_INHERIT	0x0800
+
+	SCARG(&nargs, addr) = SCARG(uap, addr);
+	SCARG(&nargs, len) = SCARG(uap, len);
+	SCARG(&nargs, prot) = cvtbsdprot[SCARG(uap, prot)&0x7];
+	SCARG(&nargs, flags) = 0;
+	if (SCARG(uap, flags) & OMAP_ANON)
+		SCARG(&nargs, flags) |= MAP_ANON;
+	if (SCARG(uap, flags) & OMAP_COPY)
+		SCARG(&nargs, flags) |= MAP_COPY;
+	if (SCARG(uap, flags) & OMAP_SHARED)
+		SCARG(&nargs, flags) |= MAP_SHARED;
+	else
+		SCARG(&nargs, flags) |= MAP_PRIVATE;
+	if (SCARG(uap, flags) & OMAP_FIXED)
+		SCARG(&nargs, flags) |= MAP_FIXED;
+	if (SCARG(uap, flags) & OMAP_INHERIT)
+		SCARG(&nargs, flags) |= MAP_INHERIT;
+	SCARG(&nargs, fd) = SCARG(uap, fd);
+	SCARG(&nargs, pos) = SCARG(uap, pos);
+	return (sys_mmap(p, &nargs, retval));
+}
+#endif
+
+/*
+ * Memory Map (mmap) system call.  Note that the file offset
+ * and address are allowed to be NOT page aligned, though if
+ * the MAP_FIXED flag it set, both must have the same remainder
+ * modulo the PAGE_SIZE (POSIX 1003.1b).  If the address is not
+ * page-aligned, the actual mapping starts at trunc_page(addr)
+ * and the return value is adjusted up by the page offset.
+ */
+int
+sys_mmap(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	register struct sys_mmap_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+		syscallarg(int) prot;
+		syscallarg(int) flags;
+		syscallarg(int) fd;
+		syscallarg(long) pad;
+		syscallarg(off_t) pos;
+	} */ *uap = v;
+	register struct filedesc *fdp = p->p_fd;
+	register struct file *fp;
+	struct vnode *vp;
+	vm_offset_t addr, pos;
+	vm_size_t size, pageoff;
+	vm_prot_t prot, maxprot;
+	caddr_t handle;
+	int fd, flags, error;
+
+	addr = (vm_offset_t) SCARG(uap, addr);
+	size = (vm_size_t) SCARG(uap, len);
+	prot = SCARG(uap, prot) & VM_PROT_ALL;
+	flags = SCARG(uap, flags);
+	fd = SCARG(uap, fd);
+	pos = (vm_offset_t) SCARG(uap, pos);
+
+#ifdef DEBUG
+	if (mmapdebug & MDB_FOLLOW)
+		printf("mmap(%d): addr %x len %x pro %x flg %x fd %d pos %x\n",
+		       p->p_pid, addr, size, prot, flags, fd, pos);
+#endif
+
+	/*
+	 * Align the file position to a page boundary,
+	 * and save its page offset component.
+	 */
+	pageoff = (pos & PAGE_MASK);
+	pos  -= pageoff;
+
+	/* Adjust size for rounding (on both ends). */
+	size += pageoff;	/* low end... */
+	size = (vm_size_t) round_page(size); /* hi end */
+
+	/* Do not allow mappings that cause address wrap... */
+	if ((ssize_t)size < 0)
+		return (EINVAL);
+
+	/*
+	 * Check for illegal addresses.  Watch out for address wrap...
+	 * Note that VM_*_ADDRESS are not constants due to casts (argh).
+	 */
+	if (flags & MAP_FIXED) {
+		/*
+		 * The specified address must have the same remainder
+		 * as the file offset taken modulo PAGE_SIZE, so it
+		 * should be aligned after adjustment by pageoff.
+		 */
+		addr -= pageoff;
+		if (addr & PAGE_MASK)
+			return (EINVAL);
+		/* Address range must be all in user VM space. */
+		if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
+			return (EINVAL);
+		if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
+			return (EINVAL);
+		if (addr > addr + size)
+			return (EINVAL);
+	}
+	/*
+	 * XXX for non-fixed mappings where no hint is provided or
+	 * the hint would fall in the potential heap space,
+	 * place it after the end of the largest possible heap.
+	 *
+	 * There should really be a pmap call to determine a reasonable
+	 * location.  (To avoid VA cache alias problems, for example!)
+	 */
+	else if (addr < round_page(p->p_vmspace->vm_daddr + MAXDSIZ))
+		addr = round_page(p->p_vmspace->vm_daddr + MAXDSIZ);
+
+	if ((flags & MAP_ANON) == 0) {
+		/*
+		 * Mapping file, get fp for validation.
+		 * Obtain vnode and make sure it is of appropriate type.
+		 */
+		if (((unsigned)fd) >= fdp->fd_nfiles ||
+		    (fp = fdp->fd_ofiles[fd]) == NULL)
+			return (EBADF);
+		if (fp->f_type != DTYPE_VNODE)
+			return (EINVAL);
+		vp = (struct vnode *)fp->f_data;
+		if (vp->v_type != VREG && vp->v_type != VCHR)
+			return (EINVAL);
+		/*
+		 * XXX hack to handle use of /dev/zero to map anon
+		 * memory (ala SunOS).
+		 */
+		if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
+			flags |= MAP_ANON;
+			goto is_anon;
+		}
+		/*
+		 * Ensure that file and memory protections are
+		 * compatible.  Note that we only worry about
+		 * writability if mapping is shared; in this case,
+		 * current and max prot are dictated by the open file.
+		 * XXX use the vnode instead?  Problem is: what
+		 * credentials do we use for determination?
+		 * What if proc does a setuid?
+		 */
+		maxprot = VM_PROT_EXECUTE;	/* ??? */
+		if (fp->f_flag & FREAD)
+			maxprot |= VM_PROT_READ;
+		else if (prot & PROT_READ)
+			return (EACCES);
+		if (flags & MAP_SHARED) {
+			if (fp->f_flag & FWRITE)
+				maxprot |= VM_PROT_WRITE;
+			else if (prot & PROT_WRITE)
+				return (EACCES);
+		} else
+			maxprot |= VM_PROT_WRITE;
+		handle = (caddr_t)vp;
+	} else {
+		/*
+		 * (flags & MAP_ANON) == TRUE
+		 * Mapping blank space is trivial.
+		 */
+		if (fd != -1)
+			return (EINVAL);
+	is_anon:
+		handle = NULL;
+		maxprot = VM_PROT_ALL;
+		pos = 0;
+	}
+	error = vm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
+	    flags, handle, pos);
+	if (error == 0)
+		*retval = (register_t)(addr + pageoff);
+	return (error);
+}
+
+int
+sys_msync(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_msync_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+	} */ *uap = v;
+	vm_offset_t addr;
+	vm_size_t size, pageoff;
+	vm_map_t map;
+	int rv;
+	boolean_t syncio, invalidate;
+
+	addr = (vm_offset_t)SCARG(uap, addr);
+	size = (vm_size_t)SCARG(uap, len);
+#ifdef DEBUG
+	if (mmapdebug & (MDB_FOLLOW|MDB_SYNC))
+		printf("msync(%d): addr %x len %x\n",
+		       p->p_pid, addr, size);
+#endif
+
+	/*
+	 * Align the address to a page boundary,
+	 * and adjust the size accordingly.
+	 */
+	pageoff = (addr & PAGE_MASK);
+	addr -= pageoff;
+	size += pageoff;
+	size = (vm_size_t) round_page(size);
+
+	/* Disallow wrap-around. */
+	if (addr + (int)size < addr)
+		return (EINVAL);
+
+	map = &p->p_vmspace->vm_map;
+	/*
+	 * XXX Gak!  If size is zero we are supposed to sync "all modified
+	 * pages with the region containing addr".  Unfortunately, we
+	 * don't really keep track of individual mmaps so we approximate
+	 * by flushing the range of the map entry containing addr.
+	 * This can be incorrect if the region splits or is coalesced
+	 * with a neighbor.
+	 */
+	if (size == 0) {
+		vm_map_entry_t entry;
+
+		vm_map_lock_read(map);
+		rv = vm_map_lookup_entry(map, addr, &entry);
+		vm_map_unlock_read(map);
+		if (rv == FALSE)
+			return (EINVAL);
+		addr = entry->start;
+		size = entry->end - entry->start;
+	}
+#ifdef DEBUG
+	if (mmapdebug & MDB_SYNC)
+		printf("msync: cleaning/flushing address range [%x-%x)\n",
+		       addr, addr+size);
+#endif
+	/*
+	 * Could pass this in as a third flag argument to implement
+	 * Sun's MS_ASYNC.
+	 */
+	syncio = TRUE;
+	/*
+	 * XXX bummer, gotta flush all cached pages to ensure
+	 * consistency with the file system cache.  Otherwise, we could
+	 * pass this in to implement Sun's MS_INVALIDATE.
+	 */
+	invalidate = TRUE;
+	/*
+	 * Clean the pages and interpret the return value.
+	 */
+	rv = vm_map_clean(map, addr, addr+size, syncio, invalidate);
+	switch (rv) {
+	case KERN_SUCCESS:
+		break;
+	case KERN_INVALID_ADDRESS:
+		return (EINVAL);	/* Sun returns ENOMEM? */
+	case KERN_FAILURE:
+		return (EIO);
+	default:
+		return (EINVAL);
+	}
+	return (0);
+}
+
+int
+sys_munmap(p, v, retval)
+	register struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	register struct sys_munmap_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+	} */ *uap = v;
+	vm_offset_t addr;
+	vm_size_t size, pageoff;
+	vm_map_t map;
+
+	addr = (vm_offset_t) SCARG(uap, addr);
+	size = (vm_size_t) SCARG(uap, len);
+#ifdef DEBUG
+	if (mmapdebug & MDB_FOLLOW)
+		printf("munmap(%d): addr %x len %x\n",
+		       p->p_pid, addr, size);
+#endif
+
+	/*
+	 * Align the address to a page boundary,
+	 * and adjust the size accordingly.
+	 */
+	pageoff = (addr & PAGE_MASK);
+	addr -= pageoff;
+	size += pageoff;
+	size = (vm_size_t) round_page(size);
+	if ((int)size < 0)
+		return(EINVAL);
+	if (size == 0)
+		return(0);
+	/*
+	 * Check for illegal addresses.  Watch out for address wrap...
+	 * Note that VM_*_ADDRESS are not constants due to casts (argh).
+	 */
+	if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
+		return (EINVAL);
+	if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
+		return (EINVAL);
+	if (addr > addr + size)
+		return (EINVAL);
+	map = &p->p_vmspace->vm_map;
+	/*
+	 * Make sure entire range is allocated.
+	 */
+	if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE))
+		return(EINVAL);
+	/* returns nothing but KERN_SUCCESS anyway */
+	(void) vm_map_remove(map, addr, addr+size);
+	return(0);
+}
+
+void
+munmapfd(p, fd)
+	struct proc *p;
+	int fd;
+{
+#ifdef DEBUG
+	if (mmapdebug & MDB_FOLLOW)
+		printf("munmapfd(%d): fd %d\n", p->p_pid, fd);
+#endif
+
+	/*
+	 * XXX should vm_deallocate any regions mapped to this file
+	 */
+	p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
+}
+
+int
+sys_mprotect(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_mprotect_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(int) len;
+		syscallarg(int) prot;
+	} */ *uap = v;
+	vm_offset_t addr;
+	vm_size_t size, pageoff;
+	register vm_prot_t prot;
+
+	addr = (vm_offset_t)SCARG(uap, addr);
+	size = (vm_size_t)SCARG(uap, len);
+	prot = SCARG(uap, prot) & VM_PROT_ALL;
+#ifdef DEBUG
+	if (mmapdebug & MDB_FOLLOW)
+		printf("mprotect(%d): addr %x len %x prot %d\n", p->p_pid,
+		    addr, size, prot);
+#endif
+	/*
+	 * Align the address to a page boundary,
+	 * and adjust the size accordingly.
+	 */
+	pageoff = (addr & PAGE_MASK);
+	addr -= pageoff;
+	size += pageoff;
+	size = (vm_size_t) round_page(size);
+	if ((int)size < 0)
+		return(EINVAL);
+
+	switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr+size, prot,
+	    FALSE)) {
+	case KERN_SUCCESS:
+		return (0);
+	case KERN_PROTECTION_FAILURE:
+		return (EACCES);
+	}
+	return (EINVAL);
+}
+
+/* ARGSUSED */
+int
+sys_madvise(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_madvise_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+		syscallarg(int) behav;
+	} */ *uap = v;
+
+	/* Not yet implemented */
+	return (EOPNOTSUPP);
+}
+
+/* ARGSUSED */
+int
+sys_mincore(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_mincore_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+		syscallarg(char *) vec;
+	} */ *uap = v;
+
+	/* Not yet implemented */
+	return (EOPNOTSUPP);
+}
+
+int
+sys_mlock(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_mlock_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+	} */ *uap = v;
+	vm_offset_t addr;
+	vm_size_t size, pageoff;
+	int error;
+	extern int vm_page_max_wired;
+
+	addr = (vm_offset_t)SCARG(uap, addr);
+	size = (vm_size_t)SCARG(uap, len);
+#ifdef DEBUG
+	if (mmapdebug & MDB_FOLLOW)
+		printf("mlock(%d): addr %x len %x\n",
+		       p->p_pid, addr, size);
+#endif
+	/*
+	 * Align the address to a page boundary,
+	 * and adjust the size accordingly.
+	 */
+	pageoff = (addr & PAGE_MASK);
+	addr -= pageoff;
+	size += pageoff;
+	size = (vm_size_t) round_page(size);
+
+	/* Disallow wrap-around. */
+	if (addr + (int)size < addr)
+		return (EINVAL);
+
+	if (atop(size) + cnt.v_wire_count > vm_page_max_wired)
+		return (EAGAIN);
+#ifdef pmap_wired_count
+	if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
+	    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
+		return (EAGAIN);
+#else
+	if (error = suser(p->p_ucred, &p->p_acflag))
+		return (error);
+#endif
+
+	error = vm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, FALSE);
+	return (error == KERN_SUCCESS ? 0 : ENOMEM);
+}
+
+int
+sys_munlock(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_munlock_args /* {
+		syscallarg(caddr_t) addr;
+		syscallarg(size_t) len;
+	} */ *uap = v;
+	vm_offset_t addr;
+	vm_size_t size, pageoff;
+	int error;
+
+	addr = (vm_offset_t)SCARG(uap, addr);
+	size = (vm_size_t)SCARG(uap, len);
+#ifdef DEBUG
+	if (mmapdebug & MDB_FOLLOW)
+		printf("munlock(%d): addr %x len %x\n",
+		       p->p_pid, addr, size);
+#endif
+	/*
+	 * Align the address to a page boundary,
+	 * and adjust the size accordingly.
+	 */
+	pageoff = (addr & PAGE_MASK);
+	addr -= pageoff;
+	size += pageoff;
+	size = (vm_size_t) round_page(size);
+
+	/* Disallow wrap-around. */
+	if (addr + (int)size < addr)
+		return (EINVAL);
+
+#ifndef pmap_wired_count
+	if (error = suser(p->p_ucred, &p->p_acflag))
+		return (error);
+#endif
+
+	error = vm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, TRUE);
+	return (error == KERN_SUCCESS ? 0 : ENOMEM);
+}
+
+/*
+ * Internal version of mmap.
+ * Currently used by mmap, exec, and sys5 shared memory.
+ * Handle is either a vnode pointer or NULL for MAP_ANON.
+ * This (internal) interface requires the file offset to be
+ * page-aligned by the caller.  (Also addr, if MAP_FIXED).
+ */
+int
+vm_mmap(map, addr, size, prot, maxprot, flags, handle, foff)
+	register vm_map_t map;
+	register vm_offset_t *addr;
+	register vm_size_t size;
+	vm_prot_t prot, maxprot;
+	register int flags;
+	caddr_t handle;		/* XXX should be vp */
+	vm_offset_t foff;
+{
+	register vm_pager_t pager;
+	boolean_t fitit;
+	vm_object_t object;
+	struct vnode *vp = NULL;
+	int type;
+	int rv = KERN_SUCCESS;
+
+	if (size == 0)
+		return (0);
+
+	/* The file offset must be page aligned. */
+	if (foff & PAGE_MASK)
+		return (EINVAL);
+
+	if ((flags & MAP_FIXED) == 0) {
+		/* The address is just a hint */
+		fitit = TRUE;
+		*addr = round_page(*addr);
+	} else {
+		/*
+		 * Use the specified address exactly
+		 * (but check alignment first).
+		 */
+		fitit = FALSE;
+		if (*addr & PAGE_MASK)
+			return (EINVAL);
+		(void)vm_deallocate(map, *addr, size);
+	}
+
+	/*
+	 * Lookup/allocate pager.  All except an unnamed anonymous lookup
+	 * gain a reference to ensure continued existance of the object.
+	 * (XXX the exception is to appease the pageout daemon)
+	 */
+	if (flags & MAP_ANON) {
+		type = PG_DFLT;
+		foff = 0;
+	} else {
+		vp = (struct vnode *)handle;
+		if (vp->v_type == VCHR) {
+			type = PG_DEVICE;
+			handle = (caddr_t)(long)vp->v_rdev;
+		} else
+			type = PG_VNODE;
+	}
+	pager = vm_pager_allocate(type, handle, size, prot, foff);
+	if (pager == NULL)
+		return (type == PG_DEVICE ? EINVAL : ENOMEM);
+	/*
+	 * Find object and release extra reference gained by lookup
+	 */
+	object = vm_object_lookup(pager);
+	vm_object_deallocate(object);
+
+	/*
+	 * Anonymous memory.
+	 */
+	if (flags & MAP_ANON) {
+		rv = vm_allocate_with_pager(map, addr, size, fitit,
+					    pager, foff, TRUE);
+		if (rv != KERN_SUCCESS) {
+			if (handle == NULL)
+				vm_pager_deallocate(pager);
+			else
+				vm_object_deallocate(object);
+			goto out;
+		}
+		/*
+		 * Don't cache anonymous objects.
+		 * Loses the reference gained by vm_pager_allocate.
+		 * Note that object will be NULL when handle == NULL,
+		 * this is ok since vm_allocate_with_pager has made
+		 * sure that these objects are uncached.
+		 */
+		(void) pager_cache(object, FALSE);
+#ifdef DEBUG
+		if (mmapdebug & MDB_MAPIT)
+			printf("vm_mmap(%d): ANON *addr %x size %x pager %x\n",
+			       curproc->p_pid, *addr, size, pager);
+#endif
+	}
+	/*
+	 * Must be a mapped file.
+	 * Distinguish between character special and regular files.
+	 */
+	else if (vp->v_type == VCHR) {
+		rv = vm_allocate_with_pager(map, addr, size, fitit,
+					    pager, foff, FALSE);
+		/*
+		 * Uncache the object and lose the reference gained
+		 * by vm_pager_allocate().  If the call to
+		 * vm_allocate_with_pager() was sucessful, then we
+		 * gained an additional reference ensuring the object
+		 * will continue to exist.  If the call failed then
+		 * the deallocate call below will terminate the
+		 * object which is fine.
+		 */
+		(void) pager_cache(object, FALSE);
+		if (rv != KERN_SUCCESS)
+			goto out;
+	}
+	/*
+	 * A regular file
+	 */
+	else {
+#ifdef DEBUG
+		if (object == NULL)
+			printf("vm_mmap: no object: vp %x, pager %x\n",
+			       vp, pager);
+#endif
+		/*
+		 * Map it directly.
+		 * Allows modifications to go out to the vnode.
+		 */
+		if (flags & MAP_SHARED) {
+			rv = vm_allocate_with_pager(map, addr, size,
+						    fitit, pager,
+						    foff, FALSE);
+			if (rv != KERN_SUCCESS) {
+				vm_object_deallocate(object);
+				goto out;
+			}
+			/*
+			 * Don't cache the object.  This is the easiest way
+			 * of ensuring that data gets back to the filesystem
+			 * because vnode_pager_deallocate() will fsync the
+			 * vnode.  pager_cache() will lose the extra ref.
+			 */
+			if (prot & VM_PROT_WRITE)
+				pager_cache(object, FALSE);
+			else
+				vm_object_deallocate(object);
+		}
+		/*
+		 * Copy-on-write of file.  Two flavors.
+		 * MAP_COPY is true COW, you essentially get a snapshot of
+		 * the region at the time of mapping.  MAP_PRIVATE means only
+		 * that your changes are not reflected back to the object.
+		 * Changes made by others will be seen.
+		 */
+		else {
+			vm_map_t tmap;
+			vm_offset_t off;
+
+			/* locate and allocate the target address space */
+			if (fitit) {
+				/*
+				 * We cannot call vm_map_find() because
+				 * a proposed address may be vetoed by
+				 * the pmap module.
+				 * So we look for space ourselves, validate
+				 * it and insert it into the map. 
+				 */
+				vm_map_lock(map);
+			again:
+				if (vm_map_findspace(map, *addr, size,
+						     addr) == 1) {
+					rv = KERN_NO_SPACE;
+				} else {
+					vm_object_prefer(object, foff, addr);
+					rv = vm_map_insert(map, NULL,
+							(vm_offset_t)0,
+							*addr, *addr+size);
+					if (rv == KERN_NO_SPACE)
+						/*
+						 * Modified address didn't fit
+						 * after all, the gap must
+						 * have been to small.
+						 */
+						goto again;
+				}
+				vm_map_unlock(map);
+			} else {
+				rv = vm_map_find(map, NULL, (vm_offset_t)0,
+					 addr, size, 0);
+
+				/*
+				 * Check against PMAP preferred address. If
+				 * there's a mismatch, these pages should not
+				 * be shared with others. <howto?>
+				 */
+				if (rv == KERN_SUCCESS) {
+					vm_offset_t	paddr = *addr;
+					vm_object_prefer(object, foff, &paddr);
+					if (paddr != *addr)
+						printf("vm_mmap: pmap botch!\n");
+				}
+			}
+
+			if (rv != KERN_SUCCESS) {
+				vm_object_deallocate(object);
+				goto out;
+			}
+			tmap = vm_map_create(pmap_create(size), VM_MIN_ADDRESS,
+					     VM_MIN_ADDRESS+size, TRUE);
+			off = VM_MIN_ADDRESS;
+			rv = vm_allocate_with_pager(tmap, &off, size,
+						    TRUE, pager,
+						    foff, FALSE);
+			if (rv != KERN_SUCCESS) {
+				vm_object_deallocate(object);
+				vm_map_deallocate(tmap);
+				goto out;
+			}
+			/*
+			 * (XXX)
+			 * MAP_PRIVATE implies that we see changes made by
+			 * others.  To ensure that we need to guarentee that
+			 * no copy object is created (otherwise original
+			 * pages would be pushed to the copy object and we
+			 * would never see changes made by others).  We
+			 * totally sleeze it right now by marking the object
+			 * internal temporarily.
+			 */
+			if ((flags & MAP_COPY) == 0)
+				object->flags |= OBJ_INTERNAL;
+			rv = vm_map_copy(map, tmap, *addr, size, off,
+					 FALSE, FALSE);
+			object->flags &= ~OBJ_INTERNAL;
+			/*
+			 * (XXX)
+			 * My oh my, this only gets worse...
+			 * Force creation of a shadow object so that
+			 * vm_map_fork will do the right thing.
+			 */
+			if ((flags & MAP_COPY) == 0) {
+				vm_map_t tmap;
+				vm_map_entry_t tentry;
+				vm_object_t tobject;
+				vm_offset_t toffset;
+				vm_prot_t tprot;
+				boolean_t twired, tsu;
+
+				tmap = map;
+				vm_map_lookup(&tmap, *addr, VM_PROT_WRITE,
+					      &tentry, &tobject, &toffset,
+					      &tprot, &twired, &tsu);
+				vm_map_lookup_done(tmap, tentry);
+			}
+			/*
+			 * (XXX)
+			 * Map copy code cannot detect sharing unless a
+			 * sharing map is involved.  So we cheat and write
+			 * protect everything ourselves.
+			 */
+			vm_object_pmap_copy(object, foff, foff + size);
+			vm_object_deallocate(object);
+			vm_map_deallocate(tmap);
+			if (rv != KERN_SUCCESS)
+				goto out;
+		}
+#ifdef DEBUG
+		if (mmapdebug & MDB_MAPIT)
+			printf("vm_mmap(%d): FILE *addr %x size %x pager %x\n",
+			       curproc->p_pid, *addr, size, pager);
+#endif
+	}
+	/*
+	 * Correct protection (default is VM_PROT_ALL).
+	 * If maxprot is different than prot, we must set both explicitly.
+	 */
+	rv = KERN_SUCCESS;
+	if (maxprot != VM_PROT_ALL)
+		rv = vm_map_protect(map, *addr, *addr+size, maxprot, TRUE);
+	if (rv == KERN_SUCCESS && prot != maxprot)
+		rv = vm_map_protect(map, *addr, *addr+size, prot, FALSE);
+	if (rv != KERN_SUCCESS) {
+		(void) vm_deallocate(map, *addr, size);
+		goto out;
+	}
+	/*
+	 * Shared memory is also shared with children.
+	 */
+	if (flags & MAP_SHARED) {
+		rv = vm_map_inherit(map, *addr, *addr+size, VM_INHERIT_SHARE);
+		if (rv != KERN_SUCCESS) {
+			(void) vm_deallocate(map, *addr, size);
+			goto out;
+		}
+	}
+out:
+#ifdef DEBUG
+	if (mmapdebug & MDB_MAPIT)
+		printf("vm_mmap: rv %d\n", rv);
+#endif
+	switch (rv) {
+	case KERN_SUCCESS:
+		return (0);
+	case KERN_INVALID_ADDRESS:
+	case KERN_NO_SPACE:
+		return (ENOMEM);
+	case KERN_PROTECTION_FAILURE:
+		return (EACCES);
+	default:
+		return (EINVAL);
+	}
+}