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authorrgrimes <rgrimes@FreeBSD.org>1994-05-24 10:09:53 +0000
committerrgrimes <rgrimes@FreeBSD.org>1994-05-24 10:09:53 +0000
commit8fb65ce818b3e3c6f165b583b910af24000768a5 (patch)
treeba751e4f2166aefec707c9d7401c7ff432506642 /sys/vm/vm_mmap.c
parenta6ce65d368e623088a4c1a29865889f431b15420 (diff)
downloadFreeBSD-src-8fb65ce818b3e3c6f165b583b910af24000768a5.zip
FreeBSD-src-8fb65ce818b3e3c6f165b583b910af24000768a5.tar.gz
BSD 4.4 Lite Kernel Sources
Diffstat (limited to 'sys/vm/vm_mmap.c')
-rw-r--r--sys/vm/vm_mmap.c832
1 files changed, 832 insertions, 0 deletions
diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
new file mode 100644
index 0000000..340cded
--- /dev/null
+++ b/sys/vm/vm_mmap.c
@@ -0,0 +1,832 @@
+/*
+ * 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 8.4 (Berkeley) 1/12/94
+ */
+
+/*
+ * 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 <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
+
+struct sbrk_args {
+ int incr;
+};
+/* ARGSUSED */
+int
+sbrk(p, uap, retval)
+ struct proc *p;
+ struct sbrk_args *uap;
+ int *retval;
+{
+
+ /* Not yet implemented */
+ return (EOPNOTSUPP);
+}
+
+struct sstk_args {
+ int incr;
+};
+/* ARGSUSED */
+int
+sstk(p, uap, retval)
+ struct proc *p;
+ struct sstk_args *uap;
+ int *retval;
+{
+
+ /* Not yet implemented */
+ return (EOPNOTSUPP);
+}
+
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+struct getpagesize_args {
+ int dummy;
+};
+/* ARGSUSED */
+int
+ogetpagesize(p, uap, retval)
+ struct proc *p;
+ struct getpagesize_args *uap;
+ int *retval;
+{
+
+ *retval = PAGE_SIZE;
+ return (0);
+}
+#endif /* COMPAT_43 || COMPAT_SUNOS */
+
+struct mmap_args {
+ caddr_t addr;
+ size_t len;
+ int prot;
+ int flags;
+ int fd;
+ long pad;
+ off_t pos;
+};
+
+#ifdef COMPAT_43
+struct ommap_args {
+ caddr_t addr;
+ int len;
+ int prot;
+ int flags;
+ int fd;
+ long pos;
+};
+int
+ommap(p, uap, retval)
+ struct proc *p;
+ register struct ommap_args *uap;
+ int *retval;
+{
+ struct mmap_args 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
+
+ nargs.addr = uap->addr;
+ nargs.len = uap->len;
+ nargs.prot = cvtbsdprot[uap->prot&0x7];
+ nargs.flags = 0;
+ if (uap->flags & OMAP_ANON)
+ nargs.flags |= MAP_ANON;
+ if (uap->flags & OMAP_COPY)
+ nargs.flags |= MAP_COPY;
+ if (uap->flags & OMAP_SHARED)
+ nargs.flags |= MAP_SHARED;
+ else
+ nargs.flags |= MAP_PRIVATE;
+ if (uap->flags & OMAP_FIXED)
+ nargs.flags |= MAP_FIXED;
+ if (uap->flags & OMAP_INHERIT)
+ nargs.flags |= MAP_INHERIT;
+ nargs.fd = uap->fd;
+ nargs.pos = uap->pos;
+ return (mmap(p, &nargs, retval));
+}
+#endif
+
+int
+mmap(p, uap, retval)
+ struct proc *p;
+ register struct mmap_args *uap;
+ int *retval;
+{
+ register struct filedesc *fdp = p->p_fd;
+ register struct file *fp;
+ struct vnode *vp;
+ vm_offset_t addr;
+ vm_size_t size;
+ vm_prot_t prot, maxprot;
+ caddr_t handle;
+ int flags, error;
+
+ prot = uap->prot & VM_PROT_ALL;
+ flags = uap->flags;
+#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, uap->addr, uap->len, prot,
+ flags, uap->fd, (vm_offset_t)uap->pos);
+#endif
+ /*
+ * Address (if FIXED) must be page aligned.
+ * Size is implicitly rounded to a page boundary.
+ */
+ addr = (vm_offset_t) uap->addr;
+ if (((flags & MAP_FIXED) && (addr & PAGE_MASK)) ||
+ (ssize_t)uap->len < 0 || ((flags & MAP_ANON) && uap->fd != -1))
+ return (EINVAL);
+ size = (vm_size_t) round_page(uap->len);
+ /*
+ * Check for illegal addresses. Watch out for address wrap...
+ * Note that VM_*_ADDRESS are not constants due to casts (argh).
+ */
+ if (flags & MAP_FIXED) {
+ 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 if no hint provided for a non-fixed mapping place it after
+ * the end of the largest possible heap.
+ *
+ * There should really be a pmap call to determine a reasonable
+ * location.
+ */
+ if (addr == 0 && (flags & MAP_FIXED) == 0)
+ addr = round_page(p->p_vmspace->vm_daddr + MAXDSIZ);
+ if (flags & MAP_ANON) {
+ /*
+ * Mapping blank space is trivial.
+ */
+ handle = NULL;
+ maxprot = VM_PROT_ALL;
+ } else {
+ /*
+ * Mapping file, get fp for validation.
+ * Obtain vnode and make sure it is of appropriate type.
+ */
+ if (((unsigned)uap->fd) >= fdp->fd_nfiles ||
+ (fp = fdp->fd_ofiles[uap->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)) {
+ handle = NULL;
+ maxprot = VM_PROT_ALL;
+ flags |= MAP_ANON;
+ } else {
+ /*
+ * 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;
+ }
+ }
+ error = vm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
+ flags, handle, (vm_offset_t)uap->pos);
+ if (error == 0)
+ *retval = (int)addr;
+ return (error);
+}
+
+struct msync_args {
+ caddr_t addr;
+ int len;
+};
+int
+msync(p, uap, retval)
+ struct proc *p;
+ struct msync_args *uap;
+ int *retval;
+{
+ vm_offset_t addr;
+ vm_size_t size;
+ vm_map_t map;
+ int rv;
+ boolean_t syncio, invalidate;
+
+#ifdef DEBUG
+ if (mmapdebug & (MDB_FOLLOW|MDB_SYNC))
+ printf("msync(%d): addr %x len %x\n",
+ p->p_pid, uap->addr, uap->len);
+#endif
+ if (((int)uap->addr & PAGE_MASK) || uap->addr + uap->len < uap->addr)
+ return (EINVAL);
+ map = &p->p_vmspace->vm_map;
+ addr = (vm_offset_t)uap->addr;
+ size = (vm_size_t)uap->len;
+ /*
+ * 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)
+ 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);
+}
+
+struct munmap_args {
+ caddr_t addr;
+ int len;
+};
+int
+munmap(p, uap, retval)
+ register struct proc *p;
+ register struct munmap_args *uap;
+ int *retval;
+{
+ vm_offset_t addr;
+ vm_size_t size;
+ vm_map_t map;
+
+#ifdef DEBUG
+ if (mmapdebug & MDB_FOLLOW)
+ printf("munmap(%d): addr %x len %x\n",
+ p->p_pid, uap->addr, uap->len);
+#endif
+
+ addr = (vm_offset_t) uap->addr;
+ if ((addr & PAGE_MASK) || uap->len < 0)
+ return(EINVAL);
+ size = (vm_size_t) round_page(uap->len);
+ 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(fd)
+ int fd;
+{
+#ifdef DEBUG
+ if (mmapdebug & MDB_FOLLOW)
+ printf("munmapfd(%d): fd %d\n", curproc->p_pid, fd);
+#endif
+
+ /*
+ * XXX should vm_deallocate any regions mapped to this file
+ */
+ curproc->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
+}
+
+struct mprotect_args {
+ caddr_t addr;
+ int len;
+ int prot;
+};
+int
+mprotect(p, uap, retval)
+ struct proc *p;
+ struct mprotect_args *uap;
+ int *retval;
+{
+ vm_offset_t addr;
+ vm_size_t size;
+ register vm_prot_t prot;
+
+#ifdef DEBUG
+ if (mmapdebug & MDB_FOLLOW)
+ printf("mprotect(%d): addr %x len %x prot %d\n",
+ p->p_pid, uap->addr, uap->len, uap->prot);
+#endif
+
+ addr = (vm_offset_t)uap->addr;
+ if ((addr & PAGE_MASK) || uap->len < 0)
+ return(EINVAL);
+ size = (vm_size_t)uap->len;
+ prot = uap->prot & VM_PROT_ALL;
+
+ 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);
+}
+
+struct madvise_args {
+ caddr_t addr;
+ int len;
+ int behav;
+};
+/* ARGSUSED */
+int
+madvise(p, uap, retval)
+ struct proc *p;
+ struct madvise_args *uap;
+ int *retval;
+{
+
+ /* Not yet implemented */
+ return (EOPNOTSUPP);
+}
+
+struct mincore_args {
+ caddr_t addr;
+ int len;
+ char *vec;
+};
+/* ARGSUSED */
+int
+mincore(p, uap, retval)
+ struct proc *p;
+ struct mincore_args *uap;
+ int *retval;
+{
+
+ /* Not yet implemented */
+ return (EOPNOTSUPP);
+}
+
+struct mlock_args {
+ caddr_t addr;
+ size_t len;
+};
+int
+mlock(p, uap, retval)
+ struct proc *p;
+ struct mlock_args *uap;
+ int *retval;
+{
+ vm_offset_t addr;
+ vm_size_t size;
+ int error;
+ extern int vm_page_max_wired;
+
+#ifdef DEBUG
+ if (mmapdebug & MDB_FOLLOW)
+ printf("mlock(%d): addr %x len %x\n",
+ p->p_pid, uap->addr, uap->len);
+#endif
+ addr = (vm_offset_t)uap->addr;
+ if ((addr & PAGE_MASK) || uap->addr + uap->len < uap->addr)
+ return (EINVAL);
+ size = round_page((vm_size_t)uap->len);
+ 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);
+}
+
+struct munlock_args {
+ caddr_t addr;
+ size_t len;
+};
+int
+munlock(p, uap, retval)
+ struct proc *p;
+ struct munlock_args *uap;
+ int *retval;
+{
+ vm_offset_t addr;
+ vm_size_t size;
+ int error;
+
+#ifdef DEBUG
+ if (mmapdebug & MDB_FOLLOW)
+ printf("munlock(%d): addr %x len %x\n",
+ p->p_pid, uap->addr, uap->len);
+#endif
+ addr = (vm_offset_t)uap->addr;
+ if ((addr & PAGE_MASK) || uap->addr + uap->len < uap->addr)
+ return (EINVAL);
+#ifndef pmap_wired_count
+ if (error = suser(p->p_ucred, &p->p_acflag))
+ return (error);
+#endif
+ size = round_page((vm_size_t)uap->len);
+
+ 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.
+ */
+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);
+
+ if ((flags & MAP_FIXED) == 0) {
+ fitit = TRUE;
+ *addr = round_page(*addr);
+ } else {
+ fitit = FALSE;
+ (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;
+ else {
+ vp = (struct vnode *)handle;
+ if (vp->v_type == VCHR) {
+ type = PG_DEVICE;
+ handle = (caddr_t)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 */
+ rv = vm_map_find(map, NULL, (vm_offset_t)0,
+ addr, size, fitit);
+ 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);
+ }
+}
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