freebsd-nq/sys/vm/vm_mmap.c
Peter Wemm 249645144d Checkpoint of a new physical memory backed object type, that does not
have pv_entries.  This is intended for very special circumstances,
eg: a certain database that has a 1GB shm segment mapped into 300
processes.  That would consume 2GB of kvm just to hold the pv_entries
alone.  This would not be used on systems unless the physical ram was
available, as it's not pageable.

This is a work-in-progress, but is a useful and functional checkpoint.
Matt has got some more fixes for it that will be committed soon.

Reviewed by:	dillon
2000-05-21 13:41:29 +00:00

1163 lines
26 KiB
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.
*
* 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
* $FreeBSD$
*/
/*
* Mapped file (mmap) interface to VM
*/
#include "opt_compat.h"
#include "opt_rlimit.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/filedesc.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/mman.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/vmmeter.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vm_pageout.h>
#include <vm/vm_extern.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#ifndef _SYS_SYSPROTO_H_
struct sbrk_args {
int incr;
};
#endif
static int max_proc_mmap;
SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, "");
/*
* Set the maximum number of vm_map_entry structures per process. Roughly
* speaking vm_map_entry structures are tiny, so allowing them to eat 1/100
* of our KVM malloc space still results in generous limits. We want a
* default that is good enough to prevent the kernel running out of resources
* if attacked from compromised user account but generous enough such that
* multi-threaded processes are not unduly inconvenienced.
*/
static void vmmapentry_rsrc_init __P((void *));
SYSINIT(vmmersrc, SI_SUB_KVM_RSRC, SI_ORDER_FIRST, vmmapentry_rsrc_init, NULL)
static void
vmmapentry_rsrc_init(dummy)
void *dummy;
{
max_proc_mmap = vm_kmem_size / sizeof(struct vm_map_entry);
max_proc_mmap /= 100;
}
/* ARGSUSED */
int
sbrk(p, uap)
struct proc *p;
struct sbrk_args *uap;
{
/* Not yet implemented */
return (EOPNOTSUPP);
}
#ifndef _SYS_SYSPROTO_H_
struct sstk_args {
int incr;
};
#endif
/* ARGSUSED */
int
sstk(p, uap)
struct proc *p;
struct sstk_args *uap;
{
/* Not yet implemented */
return (EOPNOTSUPP);
}
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#ifndef _SYS_SYSPROTO_H_
struct getpagesize_args {
int dummy;
};
#endif
/* ARGSUSED */
int
ogetpagesize(p, uap)
struct proc *p;
struct getpagesize_args *uap;
{
p->p_retval[0] = PAGE_SIZE;
return (0);
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
/*
* 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.
*
* Generally speaking, only character devices which are themselves
* memory-based, such as a video framebuffer, can be mmap'd. Otherwise
* there would be no cache coherency between a descriptor and a VM mapping
* both to the same character device.
*
* Block devices can be mmap'd no matter what they represent. Cache coherency
* is maintained as long as you do not write directly to the underlying
* character device.
*/
#ifndef _SYS_SYSPROTO_H_
struct mmap_args {
void *addr;
size_t len;
int prot;
int flags;
int fd;
long pad;
off_t pos;
};
#endif
int
mmap(p, uap)
struct proc *p;
register struct mmap_args *uap;
{
register struct filedesc *fdp = p->p_fd;
register struct file *fp;
struct vnode *vp;
vm_offset_t addr;
vm_size_t size, pageoff;
vm_prot_t prot, maxprot;
void *handle;
int flags, error;
int disablexworkaround;
off_t pos;
struct vmspace *vms = p->p_vmspace;
addr = (vm_offset_t) uap->addr;
size = uap->len;
prot = uap->prot & VM_PROT_ALL;
flags = uap->flags;
pos = uap->pos;
/* make sure mapping fits into numeric range etc */
if ((ssize_t) uap->len < 0 ||
((flags & MAP_ANON) && uap->fd != -1))
return (EINVAL);
if (flags & MAP_STACK) {
if ((uap->fd != -1) ||
((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
return (EINVAL);
flags |= MAP_ANON;
pos = 0;
}
/*
* 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 */
/*
* 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);
#ifndef i386
if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
return (EINVAL);
#endif
if (addr + size < addr)
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 == 0 ||
(addr >= round_page((vm_offset_t)vms->vm_taddr) &&
addr < round_page((vm_offset_t)vms->vm_daddr + MAXDSIZ)))
addr = round_page((vm_offset_t)vms->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);
/*
* POSIX shared-memory objects are defined to have
* kernel persistence, and are not defined to support
* read(2)/write(2) -- or even open(2). Thus, we can
* use MAP_ASYNC to trade on-disk coherence for speed.
* The shm_open(3) library routine turns on the FPOSIXSHM
* flag to request this behavior.
*/
if (fp->f_flag & FPOSIXSHM)
flags |= MAP_NOSYNC;
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;
pos = 0;
} else {
/*
* cdevs does not provide private mappings of any kind.
*/
/*
* However, for XIG X server to continue to work,
* we should allow the superuser to do it anyway.
* We only allow it at securelevel < 1.
* (Because the XIG X server writes directly to video
* memory via /dev/mem, it should never work at any
* other securelevel.
* XXX this will have to go
*/
if (securelevel >= 1)
disablexworkaround = 1;
else
disablexworkaround = suser(p);
if (vp->v_type == VCHR && disablexworkaround &&
(flags & (MAP_PRIVATE|MAP_COPY)))
return (EINVAL);
/*
* 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 we are sharing potential changes (either via
* MAP_SHARED or via the implicit sharing of character
* device mappings), and we are trying to get write
* permission although we opened it without asking
* for it, bail out. Check for superuser, only if
* we're at securelevel < 1, to allow the XIG X server
* to continue to work.
*/
if ((flags & MAP_SHARED) != 0 ||
(vp->v_type == VCHR && disablexworkaround)) {
if ((fp->f_flag & FWRITE) != 0) {
struct vattr va;
if ((error =
VOP_GETATTR(vp, &va,
p->p_ucred, p)))
return (error);
if ((va.va_flags &
(IMMUTABLE|APPEND)) == 0)
maxprot |= VM_PROT_WRITE;
else if (prot & PROT_WRITE)
return (EPERM);
} else if ((prot & PROT_WRITE) != 0)
return (EACCES);
} else
maxprot |= VM_PROT_WRITE;
handle = (void *)vp;
}
}
/*
* Do not allow more then a certain number of vm_map_entry structures
* per process. Scale with the number of rforks sharing the map
* to make the limit reasonable for threads.
*/
if (max_proc_mmap &&
vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) {
return (ENOMEM);
}
error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
flags, handle, pos);
if (error == 0)
p->p_retval[0] = (register_t) (addr + pageoff);
return (error);
}
#ifdef COMPAT_43
#ifndef _SYS_SYSPROTO_H_
struct ommap_args {
caddr_t addr;
int len;
int prot;
int flags;
int fd;
long pos;
};
#endif
int
ommap(p, uap)
struct proc *p;
register struct ommap_args *uap;
{
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));
}
#endif /* COMPAT_43 */
#ifndef _SYS_SYSPROTO_H_
struct msync_args {
void *addr;
int len;
int flags;
};
#endif
int
msync(p, uap)
struct proc *p;
struct msync_args *uap;
{
vm_offset_t addr;
vm_size_t size, pageoff;
int flags;
vm_map_t map;
int rv;
addr = (vm_offset_t) uap->addr;
size = uap->len;
flags = uap->flags;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
return(EINVAL);
if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
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;
}
/*
* Clean the pages and interpret the return value.
*/
rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0,
(flags & MS_INVALIDATE) != 0);
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);
}
#ifndef _SYS_SYSPROTO_H_
struct munmap_args {
void *addr;
size_t len;
};
#endif
int
munmap(p, uap)
register struct proc *p;
register struct munmap_args *uap;
{
vm_offset_t addr;
vm_size_t size, pageoff;
vm_map_t map;
addr = (vm_offset_t) uap->addr;
size = uap->len;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
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);
#ifndef i386
if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
return (EINVAL);
#endif
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;
{
/*
* XXX should unmap any regions mapped to this file
*/
p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
}
#ifndef _SYS_SYSPROTO_H_
struct mprotect_args {
const void *addr;
size_t len;
int prot;
};
#endif
int
mprotect(p, uap)
struct proc *p;
struct mprotect_args *uap;
{
vm_offset_t addr;
vm_size_t size, pageoff;
register vm_prot_t prot;
addr = (vm_offset_t) uap->addr;
size = uap->len;
prot = uap->prot & VM_PROT_ALL;
#if defined(VM_PROT_READ_IS_EXEC)
if (prot & VM_PROT_READ)
prot |= VM_PROT_EXECUTE;
#endif
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
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);
}
#ifndef _SYS_SYSPROTO_H_
struct minherit_args {
void *addr;
size_t len;
int inherit;
};
#endif
int
minherit(p, uap)
struct proc *p;
struct minherit_args *uap;
{
vm_offset_t addr;
vm_size_t size, pageoff;
register vm_inherit_t inherit;
addr = (vm_offset_t)uap->addr;
size = uap->len;
inherit = uap->inherit;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
return(EINVAL);
switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
inherit)) {
case KERN_SUCCESS:
return (0);
case KERN_PROTECTION_FAILURE:
return (EACCES);
}
return (EINVAL);
}
#ifndef _SYS_SYSPROTO_H_
struct madvise_args {
void *addr;
size_t len;
int behav;
};
#endif
/* ARGSUSED */
int
madvise(p, uap)
struct proc *p;
struct madvise_args *uap;
{
vm_offset_t start, end;
/*
* Check for illegal behavior
*/
if (uap->behav < 0 || uap->behav > MADV_CORE)
return (EINVAL);
/*
* 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 &&
((vm_offset_t) uap->addr + uap->len) > VM_MAXUSER_ADDRESS)
return (EINVAL);
#ifndef i386
if (VM_MIN_ADDRESS > 0 && uap->addr < VM_MIN_ADDRESS)
return (EINVAL);
#endif
if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
return (EINVAL);
/*
* Since this routine is only advisory, we default to conservative
* behavior.
*/
start = trunc_page((vm_offset_t) uap->addr);
end = round_page((vm_offset_t) uap->addr + uap->len);
if (vm_map_madvise(&p->p_vmspace->vm_map, start, end, uap->behav))
return (EINVAL);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct mincore_args {
const void *addr;
size_t len;
char *vec;
};
#endif
/* ARGSUSED */
int
mincore(p, uap)
struct proc *p;
struct mincore_args *uap;
{
vm_offset_t addr, first_addr;
vm_offset_t end, cend;
pmap_t pmap;
vm_map_t map;
char *vec;
int error;
int vecindex, lastvecindex;
register vm_map_entry_t current;
vm_map_entry_t entry;
int mincoreinfo;
unsigned int timestamp;
/*
* Make sure that the addresses presented are valid for user
* mode.
*/
first_addr = addr = trunc_page((vm_offset_t) uap->addr);
end = addr + (vm_size_t)round_page(uap->len);
if (VM_MAXUSER_ADDRESS > 0 && end > VM_MAXUSER_ADDRESS)
return (EINVAL);
if (end < addr)
return (EINVAL);
/*
* Address of byte vector
*/
vec = uap->vec;
map = &p->p_vmspace->vm_map;
pmap = vmspace_pmap(p->p_vmspace);
vm_map_lock_read(map);
RestartScan:
timestamp = map->timestamp;
if (!vm_map_lookup_entry(map, addr, &entry))
entry = entry->next;
/*
* Do this on a map entry basis so that if the pages are not
* in the current processes address space, we can easily look
* up the pages elsewhere.
*/
lastvecindex = -1;
for(current = entry;
(current != &map->header) && (current->start < end);
current = current->next) {
/*
* ignore submaps (for now) or null objects
*/
if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
current->object.vm_object == NULL)
continue;
/*
* limit this scan to the current map entry and the
* limits for the mincore call
*/
if (addr < current->start)
addr = current->start;
cend = current->end;
if (cend > end)
cend = end;
/*
* scan this entry one page at a time
*/
while(addr < cend) {
/*
* Check pmap first, it is likely faster, also
* it can provide info as to whether we are the
* one referencing or modifying the page.
*/
mincoreinfo = pmap_mincore(pmap, addr);
if (!mincoreinfo) {
vm_pindex_t pindex;
vm_ooffset_t offset;
vm_page_t m;
/*
* calculate the page index into the object
*/
offset = current->offset + (addr - current->start);
pindex = OFF_TO_IDX(offset);
m = vm_page_lookup(current->object.vm_object,
pindex);
/*
* if the page is resident, then gather information about
* it.
*/
if (m) {
mincoreinfo = MINCORE_INCORE;
if (m->dirty ||
pmap_is_modified(m))
mincoreinfo |= MINCORE_MODIFIED_OTHER;
if ((m->flags & PG_REFERENCED) ||
pmap_ts_referenced(m)) {
vm_page_flag_set(m, PG_REFERENCED);
mincoreinfo |= MINCORE_REFERENCED_OTHER;
}
}
}
/*
* subyte may page fault. In case it needs to modify
* the map, we release the lock.
*/
vm_map_unlock_read(map);
/*
* calculate index into user supplied byte vector
*/
vecindex = OFF_TO_IDX(addr - first_addr);
/*
* If we have skipped map entries, we need to make sure that
* the byte vector is zeroed for those skipped entries.
*/
while((lastvecindex + 1) < vecindex) {
error = subyte( vec + lastvecindex, 0);
if (error) {
return (EFAULT);
}
++lastvecindex;
}
/*
* Pass the page information to the user
*/
error = subyte( vec + vecindex, mincoreinfo);
if (error) {
return (EFAULT);
}
/*
* If the map has changed, due to the subyte, the previous
* output may be invalid.
*/
vm_map_lock_read(map);
if (timestamp != map->timestamp)
goto RestartScan;
lastvecindex = vecindex;
addr += PAGE_SIZE;
}
}
/*
* subyte may page fault. In case it needs to modify
* the map, we release the lock.
*/
vm_map_unlock_read(map);
/*
* Zero the last entries in the byte vector.
*/
vecindex = OFF_TO_IDX(end - first_addr);
while((lastvecindex + 1) < vecindex) {
error = subyte( vec + lastvecindex, 0);
if (error) {
return (EFAULT);
}
++lastvecindex;
}
/*
* If the map has changed, due to the subyte, the previous
* output may be invalid.
*/
vm_map_lock_read(map);
if (timestamp != map->timestamp)
goto RestartScan;
vm_map_unlock_read(map);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct mlock_args {
const void *addr;
size_t len;
};
#endif
int
mlock(p, uap)
struct proc *p;
struct mlock_args *uap;
{
vm_offset_t addr;
vm_size_t size, pageoff;
int error;
addr = (vm_offset_t) uap->addr;
size = uap->len;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
/* disable wrap around */
if (addr + 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 (ENOMEM);
#else
error = suser(p);
if (error)
return (error);
#endif
error = vm_map_user_pageable(&p->p_vmspace->vm_map, addr, addr + size, FALSE);
return (error == KERN_SUCCESS ? 0 : ENOMEM);
}
#ifndef _SYS_SYSPROTO_H_
struct mlockall_args {
int how;
};
#endif
int
mlockall(p, uap)
struct proc *p;
struct mlockall_args *uap;
{
return 0;
}
#ifndef _SYS_SYSPROTO_H_
struct mlockall_args {
int how;
};
#endif
int
munlockall(p, uap)
struct proc *p;
struct munlockall_args *uap;
{
return 0;
}
#ifndef _SYS_SYSPROTO_H_
struct munlock_args {
const void *addr;
size_t len;
};
#endif
int
munlock(p, uap)
struct proc *p;
struct munlock_args *uap;
{
vm_offset_t addr;
vm_size_t size, pageoff;
int error;
addr = (vm_offset_t) uap->addr;
size = uap->len;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
/* disable wrap around */
if (addr + size < addr)
return (EINVAL);
#ifndef pmap_wired_count
error = suser(p);
if (error)
return (error);
#endif
error = vm_map_user_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(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
vm_prot_t maxprot, int flags,
void *handle,
vm_ooffset_t foff)
{
boolean_t fitit;
vm_object_t object;
struct vnode *vp = NULL;
objtype_t type;
int rv = KERN_SUCCESS;
vm_ooffset_t objsize;
int docow;
struct proc *p = curproc;
if (size == 0)
return (0);
objsize = size = round_page(size);
/*
* We currently can only deal with page aligned file offsets.
* The check is here rather than in the syscall because the
* kernel calls this function internally for other mmaping
* operations (such as in exec) and non-aligned offsets will
* cause pmap inconsistencies...so we want to be sure to
* disallow this in all cases.
*/
if (foff & PAGE_MASK)
return (EINVAL);
if ((flags & MAP_FIXED) == 0) {
fitit = TRUE;
*addr = round_page(*addr);
} else {
if (*addr != trunc_page(*addr))
return (EINVAL);
fitit = FALSE;
(void) vm_map_remove(map, *addr, *addr + size);
}
/*
* Lookup/allocate object.
*/
if (flags & MAP_ANON) {
type = OBJT_DEFAULT;
/*
* Unnamed anonymous regions always start at 0.
*/
if (handle == 0)
foff = 0;
} else {
vp = (struct vnode *) handle;
if (vp->v_type == VCHR) {
type = OBJT_DEVICE;
handle = (void *)(intptr_t)vp->v_rdev;
} else {
struct vattr vat;
int error;
error = VOP_GETATTR(vp, &vat, p->p_ucred, p);
if (error)
return (error);
objsize = round_page(vat.va_size);
type = OBJT_VNODE;
/*
* if it is a regular file without any references
* we do not need to sync it.
*/
if (vp->v_type == VREG && vat.va_nlink == 0) {
flags |= MAP_NOSYNC;
}
}
}
if (handle == NULL) {
object = NULL;
docow = 0;
} else {
object = vm_pager_allocate(type,
handle, objsize, prot, foff);
if (object == NULL)
return (type == OBJT_DEVICE ? EINVAL : ENOMEM);
docow = MAP_PREFAULT_PARTIAL;
}
/*
* Force device mappings to be shared.
*/
if (type == OBJT_DEVICE || type == OBJT_PHYS) {
flags &= ~(MAP_PRIVATE|MAP_COPY);
flags |= MAP_SHARED;
}
if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
docow |= MAP_COPY_ON_WRITE;
if (flags & MAP_NOSYNC)
docow |= MAP_DISABLE_SYNCER;
if (flags & MAP_NOCORE)
docow |= MAP_DISABLE_COREDUMP;
#if defined(VM_PROT_READ_IS_EXEC)
if (prot & VM_PROT_READ)
prot |= VM_PROT_EXECUTE;
if (maxprot & VM_PROT_READ)
maxprot |= VM_PROT_EXECUTE;
#endif
if (fitit) {
*addr = pmap_addr_hint(object, *addr, size);
}
if (flags & MAP_STACK)
rv = vm_map_stack (map, *addr, size, prot,
maxprot, docow);
else
rv = vm_map_find(map, object, foff, addr, size, fitit,
prot, maxprot, docow);
if (rv != KERN_SUCCESS) {
/*
* Lose the object reference. Will destroy the
* object if it's an unnamed anonymous mapping
* or named anonymous without other references.
*/
vm_object_deallocate(object);
goto out;
}
/*
* Shared memory is also shared with children.
*/
if (flags & (MAP_SHARED|MAP_INHERIT)) {
rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE);
if (rv != KERN_SUCCESS) {
(void) vm_map_remove(map, *addr, *addr + size);
goto out;
}
}
out:
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);
}
}