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fix munmapfd's arguments; it takes a struct proc _then_ an int.
[unix-history] / usr / src / sys / vm / vm_mmap.c
/*
* 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.
*
* %sccs.include.redist.c%
*
* from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
*
* @(#)vm_mmap.c 8.9 (Berkeley) %G%
*/
/*
* 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, pos;
vm_size_t size;
vm_prot_t prot, maxprot;
caddr_t handle;
int flags, error;
prot = uap->prot & VM_PROT_ALL;
flags = uap->flags;
pos = 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, uap->addr, uap->len, prot,
flags, uap->fd, pos);
#endif
/*
* Address (if FIXED) must be page aligned.
* Size is implicitly rounded to a page boundary.
*
* XXX most (all?) vendors require that the file offset be
* page aligned as well. However, we already have applications
* (e.g. nlist) that rely on unrestricted alignment. Since we
* support it, let it happen.
*/
addr = (vm_offset_t) uap->addr;
if (((flags & MAP_FIXED) && (addr & PAGE_MASK)) ||
#if 0
((flags & MAP_ANON) == 0 && (pos & PAGE_MASK)) ||
#endif
(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 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.
*/
else if (addr < round_page(p->p_vmspace->vm_daddr + MAXDSIZ))
addr = round_page(p->p_vmspace->vm_daddr + MAXDSIZ);
if (flags & MAP_ANON) {
/*
* Mapping blank space is trivial.
*/
handle = NULL;
maxprot = VM_PROT_ALL;
pos = 0;
} 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, 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.
* XXX this seemed overly restrictive, so we relaxed it.
*/
#if 0
if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE))
return(EINVAL);
#endif
/* 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;
}
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);
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.