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NetBSD/sys/uvm/uvm_mmap.c
thorpej 1da427a80a Change the pmap_enter() API slightly; pmap_enter() now returns an error 
value (KERN_SUCCESS or KERN_RESOURCE_SHORTAGE) indicating if it succeeded
or failed.  Change the `wired' and `access_type' arguments to a single
`flags' argument, which includes the access type, and flags:

	PMAP_WIRED	the old `wired' boolean
	PMAP_CANFAIL	pmap_enter() is allowed to fail

If PMAP_CANFAIL is not specified, the pmap should behave as it always
has in the face of a drastic resource shortage: fall over dead.

Change the fault handler to deal with failure (which indicates resource
shortage) by unlocking everything, waiting for the pagedaemon to free
more memory, then retrying the fault.
1999-11-13 00:24:38 +00:00

1307 lines
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/* $NetBSD: uvm_mmap.c,v 1.36 1999/11/13 00:24:38 thorpej Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* Copyright (c) 1991, 1993 The Regents of the University of California.
* Copyright (c) 1988 University of Utah.
*
* 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 Charles D. Cranor,
* Washington University, 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
* from: Id: uvm_mmap.c,v 1.1.2.14 1998/01/05 21:04:26 chuck Exp
*/
/*
* uvm_mmap.c: system call interface into VM system, plus kernel vm_mmap
* function.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/resourcevar.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/vnode.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <miscfs/specfs/specdev.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#include <sys/syscallargs.h>
#include <uvm/uvm.h>
#include <uvm/uvm_device.h>
#include <uvm/uvm_vnode.h>
/*
* unimplemented VM system calls:
*/
/*
* sys_sbrk: sbrk system call.
*/
/* ARGSUSED */
int
sys_sbrk(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
#if 0
struct sys_sbrk_args /* {
syscallarg(intptr_t) incr;
} */ *uap = v;
#endif
return (ENOSYS);
}
/*
* sys_sstk: sstk system call.
*/
/* ARGSUSED */
int
sys_sstk(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
#if 0
struct sys_sstk_args /* {
syscallarg(int) incr;
} */ *uap = v;
#endif
return (ENOSYS);
}
/*
* sys_mincore: determine if pages are in core or not.
*/
/* ARGSUSED */
int
sys_mincore(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct sys_mincore_args /* {
syscallarg(void *) addr;
syscallarg(size_t) len;
syscallarg(char *) vec;
} */ *uap = v;
vm_page_t m;
char *vec, pgi;
struct uvm_object *uobj;
struct vm_amap *amap;
struct vm_anon *anon;
vm_map_entry_t entry;
vaddr_t start, end, lim;
vm_map_t map;
vsize_t len;
int error = 0, npgs;
map = &p->p_vmspace->vm_map;
start = (vaddr_t)SCARG(uap, addr);
len = SCARG(uap, len);
vec = SCARG(uap, vec);
if (start & PAGE_MASK)
return (EINVAL);
len = round_page(len);
end = start + len;
if (end <= start)
return (EINVAL);
npgs = len >> PAGE_SHIFT;
if (uvm_useracc(vec, npgs, B_WRITE) == FALSE)
return (EFAULT);
/*
* Lock down vec, so our returned status isn't outdated by
* storing the status byte for a page.
*/
uvm_vslock(p, vec, npgs, VM_PROT_WRITE);
vm_map_lock_read(map);
if (uvm_map_lookup_entry(map, start, &entry) == FALSE) {
error = ENOMEM;
goto out;
}
for (/* nothing */;
entry != &map->header && entry->start < end;
entry = entry->next) {
#ifdef DIAGNOSTIC
if (UVM_ET_ISSUBMAP(entry))
panic("mincore: user map has submap");
if (start < entry->start)
panic("mincore: hole");
#endif
/* Make sure there are no holes. */
if (entry->end < end &&
(entry->next == &map->header ||
entry->next->start > entry->end)) {
error = ENOMEM;
goto out;
}
lim = end < entry->end ? end : entry->end;
/*
* Special case for objects with no "real" pages. Those
* are always considered resident (mapped devices).
*/
if (UVM_ET_ISOBJ(entry)) {
#ifdef DIAGNOSTIC
if (UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj))
panic("mincore: user map has kernel object");
#endif
if (entry->object.uvm_obj->pgops->pgo_releasepg
== NULL) {
for (/* nothing */; start < lim;
start += PAGE_SIZE, vec++)
subyte(vec, 1);
continue;
}
}
amap = entry->aref.ar_amap; /* top layer */
uobj = entry->object.uvm_obj; /* bottom layer */
if (amap != NULL)
amap_lock(amap);
if (uobj != NULL)
simple_lock(&uobj->vmobjlock);
for (/* nothing */; start < lim; start += PAGE_SIZE, vec++) {
pgi = 0;
if (amap != NULL) {
/* Check the top layer first. */
anon = amap_lookup(&entry->aref,
start - entry->start);
/* Don't need to lock anon here. */
if (anon != NULL && anon->u.an_page != NULL) {
/*
* Anon has the page for this entry
* offset.
*/
pgi = 1;
}
}
if (uobj != NULL && pgi == 0) {
/* Check the bottom layer. */
m = uvm_pagelookup(uobj,
entry->offset + (start - entry->start));
if (m != NULL) {
/*
* Object has the page for this entry
* offset.
*/
pgi = 1;
}
}
(void) subyte(vec, pgi);
}
if (uobj != NULL)
simple_unlock(&uobj->vmobjlock);
if (amap != NULL)
amap_unlock(amap);
}
out:
vm_map_unlock_read(map);
uvm_vsunlock(p, SCARG(uap, vec), npgs);
return (error);
}
#if 0
/*
* munmapfd: unmap file descriptor
*
* XXX: is this acutally a useful function? could it be useful?
*/
void
munmapfd(p, fd)
struct proc *p;
int fd;
{
/*
* XXX should vm_deallocate any regions mapped to this file
*/
p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
}
#endif
/*
* sys_mmap: mmap system call.
*
* => file offest and address may not be page aligned
* - if MAP_FIXED, offset and address must have remainder mod PAGE_SIZE
* - if address isn't page aligned the 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;
vaddr_t addr;
struct vattr va;
off_t pos;
vsize_t size, pageoff;
vm_prot_t prot, maxprot;
int flags, fd;
vaddr_t vm_min_address = VM_MIN_ADDRESS;
register struct filedesc *fdp = p->p_fd;
register struct file *fp;
struct vnode *vp;
caddr_t handle;
int error;
/*
* first, extract syscall args from the uap.
*/
addr = (vaddr_t) SCARG(uap, addr);
size = (vsize_t) SCARG(uap, len);
prot = SCARG(uap, prot) & VM_PROT_ALL;
flags = SCARG(uap, flags);
fd = SCARG(uap, fd);
pos = SCARG(uap, pos);
/*
* Fixup the old deprecated MAP_COPY into MAP_PRIVATE, and
* validate the flags.
*/
if (flags & MAP_COPY)
flags = (flags & ~MAP_COPY) | MAP_PRIVATE;
if ((flags & (MAP_SHARED|MAP_PRIVATE)) == (MAP_SHARED|MAP_PRIVATE))
return (EINVAL);
/*
* make sure that the newsize fits within a vaddr_t
* XXX: need to revise addressing data types
*/
if (pos + size > (vaddr_t)-PAGE_SIZE) {
#ifdef DEBUG
printf("mmap: pos=%qx, size=%lx too big\n", (long long)pos,
(long)size);
#endif
return (EINVAL);
}
/*
* align file position and save offset. adjust size.
*/
pageoff = (pos & PAGE_MASK);
pos -= pageoff;
size += pageoff; /* add offset */
size = (vsize_t) round_page(size); /* round up */
if ((ssize_t) size < 0)
return (EINVAL); /* don't allow wrap */
/*
* now check (MAP_FIXED) or get (!MAP_FIXED) the "addr"
*/
if (flags & MAP_FIXED) {
/* ensure address and file offset are aligned properly */
addr -= pageoff;
if (addr & PAGE_MASK)
return (EINVAL);
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); /* no wrapping! */
} else {
/*
* not fixed: make sure we skip over the largest possible heap.
* we will refine our guess later (e.g. to account for VAC, etc)
*/
if (addr < round_page(p->p_vmspace->vm_daddr + MAXDSIZ))
addr = round_page(p->p_vmspace->vm_daddr + MAXDSIZ);
}
/*
* check for file mappings (i.e. not anonymous) and verify file.
*/
if ((flags & MAP_ANON) == 0) {
if (fd < 0 || fd >= fdp->fd_nfiles)
return(EBADF); /* failed range check? */
fp = fdp->fd_ofiles[fd]; /* convert to file pointer */
if (fp == NULL)
return(EBADF);
if (fp->f_type != DTYPE_VNODE)
return (ENODEV); /* only mmap vnodes! */
vp = (struct vnode *)fp->f_data; /* convert to vnode */
if (vp->v_type != VREG && vp->v_type != VCHR &&
vp->v_type != VBLK)
return (ENODEV); /* only REG/CHR/BLK support mmap */
/* special case: catch SunOS style /dev/zero */
if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
flags |= MAP_ANON;
goto is_anon;
}
/*
* Old programs may not select a specific sharing type, so
* default to an appropriate one.
*
* XXX: how does MAP_ANON fit in the picture?
*/
if ((flags & (MAP_SHARED|MAP_PRIVATE)) == 0) {
#if defined(DEBUG)
printf("WARNING: defaulted mmap() share type to "
"%s (pid %d comm %s)\n", vp->v_type == VCHR ?
"MAP_SHARED" : "MAP_PRIVATE", p->p_pid,
p->p_comm);
#endif
if (vp->v_type == VCHR)
flags |= MAP_SHARED; /* for a device */
else
flags |= MAP_PRIVATE; /* for a file */
}
/*
* MAP_PRIVATE device mappings don't make sense (and aren't
* supported anyway). However, some programs rely on this,
* so just change it to MAP_SHARED.
*/
if (vp->v_type == VCHR && (flags & MAP_PRIVATE) != 0) {
#if defined(DIAGNOSTIC)
printf("WARNING: converted MAP_PRIVATE device mapping "
"to MAP_SHARED (pid %d comm %s)\n", p->p_pid,
p->p_comm);
#endif
flags = (flags & ~MAP_PRIVATE) | MAP_SHARED;
}
/*
* now check protection
*/
maxprot = VM_PROT_EXECUTE;
/* check read access */
if (fp->f_flag & FREAD)
maxprot |= VM_PROT_READ;
else if (prot & PROT_READ)
return (EACCES);
/* check write access, shared case first */
if (flags & MAP_SHARED) {
/*
* if the file is writable, only add PROT_WRITE to
* maxprot if the file is not immutable, append-only.
* otherwise, if we have asked for PROT_WRITE, return
* EPERM.
*/
if (fp->f_flag & FWRITE) {
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)
return (EACCES);
} else {
/* MAP_PRIVATE mappings can always write to */
maxprot |= VM_PROT_WRITE;
}
/*
* set handle to vnode
*/
handle = (caddr_t)vp;
} else { /* MAP_ANON case */
/*
* XXX What do we do about (MAP_SHARED|MAP_PRIVATE) == 0?
*/
if (fd != -1)
return (EINVAL);
is_anon: /* label for SunOS style /dev/zero */
handle = NULL;
maxprot = VM_PROT_ALL;
pos = 0;
}
/*
* XXX (in)sanity check. We don't do proper datasize checking
* XXX for anonymous (or private writable) mmap(). However,
* XXX know that if we're trying to allocate more than the amount
* XXX remaining under our current data size limit, _that_ should
* XXX be disallowed.
*/
if ((flags & MAP_ANON) != 0 ||
((flags & MAP_PRIVATE) != 0 && (prot & PROT_WRITE) != 0)) {
if (size >
(p->p_rlimit[RLIMIT_DATA].rlim_cur - ctob(p->p_vmspace->vm_dsize))) {
return (ENOMEM);
}
}
/*
* now let kernel internal function uvm_mmap do the work.
*/
error = uvm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
flags, handle, pos, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
if (error == 0)
/* remember to add offset */
*retval = (register_t)(addr + pageoff);
return (error);
}
/*
* sys___msync13: the msync system call (a front-end for flush)
*/
int
sys___msync13(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct sys___msync13_args /* {
syscallarg(caddr_t) addr;
syscallarg(size_t) len;
syscallarg(int) flags;
} */ *uap = v;
vaddr_t addr;
vsize_t size, pageoff;
vm_map_t map;
int rv, flags, uvmflags;
/*
* extract syscall args from the uap
*/
addr = (vaddr_t)SCARG(uap, addr);
size = (vsize_t)SCARG(uap, len);
flags = SCARG(uap, flags);
/* sanity check flags */
if ((flags & ~(MS_ASYNC | MS_SYNC | MS_INVALIDATE)) != 0 ||
(flags & (MS_ASYNC | MS_SYNC | MS_INVALIDATE)) == 0 ||
(flags & (MS_ASYNC | MS_SYNC)) == (MS_ASYNC | MS_SYNC))
return (EINVAL);
if ((flags & (MS_ASYNC | MS_SYNC)) == 0)
flags |= MS_SYNC;
/*
* align the address to a page boundary, and adjust the size accordingly
*/
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vsize_t) round_page(size);
/* disallow wrap-around. */
if (addr + size < addr)
return (EINVAL);
/*
* get map
*/
map = &p->p_vmspace->vm_map;
/*
* XXXCDC: do we really need this semantic?
*
* 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 = uvm_map_lookup_entry(map, addr, &entry);
if (rv == TRUE) {
addr = entry->start;
size = entry->end - entry->start;
}
vm_map_unlock_read(map);
if (rv == FALSE)
return (EINVAL);
}
/*
* translate MS_ flags into PGO_ flags
*/
uvmflags = PGO_CLEANIT;
if (flags & MS_INVALIDATE)
uvmflags |= PGO_FREE;
if (flags & MS_SYNC)
uvmflags |= PGO_SYNCIO;
else
uvmflags |= PGO_SYNCIO; /* XXXCDC: force sync for now! */
/*
* doit!
*/
rv = uvm_map_clean(map, addr, addr+size, uvmflags);
/*
* and return...
*/
switch (rv) {
case KERN_SUCCESS:
return(0);
case KERN_INVALID_ADDRESS:
return (ENOMEM);
case KERN_FAILURE:
return (EIO);
case KERN_PAGES_LOCKED: /* XXXCDC: uvm doesn't return this */
return (EBUSY);
default:
return (EINVAL);
}
/*NOTREACHED*/
}
/*
* sys_munmap: unmap a users memory
*/
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;
vaddr_t addr;
vsize_t size, pageoff;
vm_map_t map;
vaddr_t vm_min_address = VM_MIN_ADDRESS;
struct vm_map_entry *dead_entries;
/*
* get syscall args...
*/
addr = (vaddr_t) SCARG(uap, addr);
size = (vsize_t) SCARG(uap, len);
/*
* align the address to a page boundary, and adjust the size accordingly
*/
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vsize_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;
vm_map_lock(map); /* lock map so we can checkprot */
/*
* interesting system call semantic: make sure entire range is
* allocated before allowing an unmap.
*/
if (!uvm_map_checkprot(map, addr, addr + size, VM_PROT_NONE)) {
vm_map_unlock(map);
return (EINVAL);
}
/*
* doit!
*/
(void) uvm_unmap_remove(map, addr, addr + size, &dead_entries);
vm_map_unlock(map); /* and unlock */
if (dead_entries != NULL)
uvm_unmap_detach(dead_entries, 0);
return (0);
}
/*
* sys_mprotect: the mprotect system call
*/
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;
vaddr_t addr;
vsize_t size, pageoff;
vm_prot_t prot;
int rv;
/*
* extract syscall args from uap
*/
addr = (vaddr_t)SCARG(uap, addr);
size = (vsize_t)SCARG(uap, len);
prot = SCARG(uap, prot) & VM_PROT_ALL;
/*
* align the address to a page boundary, and adjust the size accordingly
*/
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vsize_t) round_page(size);
if ((int)size < 0)
return (EINVAL);
/*
* doit
*/
rv = uvm_map_protect(&p->p_vmspace->vm_map,
addr, addr+size, prot, FALSE);
if (rv == KERN_SUCCESS)
return (0);
if (rv == KERN_PROTECTION_FAILURE)
return (EACCES);
return (EINVAL);
}
/*
* sys_minherit: the minherit system call
*/
int
sys_minherit(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct sys_minherit_args /* {
syscallarg(caddr_t) addr;
syscallarg(int) len;
syscallarg(int) inherit;
} */ *uap = v;
vaddr_t addr;
vsize_t size, pageoff;
register vm_inherit_t inherit;
addr = (vaddr_t)SCARG(uap, addr);
size = (vsize_t)SCARG(uap, len);
inherit = SCARG(uap, inherit);
/*
* align the address to a page boundary, and adjust the size accordingly
*/
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vsize_t) round_page(size);
if ((int)size < 0)
return (EINVAL);
switch (uvm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
inherit)) {
case KERN_SUCCESS:
return (0);
case KERN_PROTECTION_FAILURE:
return (EACCES);
}
return (EINVAL);
}
/*
* sys_madvise: give advice about memory usage.
*/
/* 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;
vaddr_t addr;
vsize_t size, pageoff;
int advice, rv;;
addr = (vaddr_t)SCARG(uap, addr);
size = (vsize_t)SCARG(uap, len);
advice = SCARG(uap, behav);
/*
* align the address to a page boundary, and adjust the size accordingly
*/
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vsize_t) round_page(size);
if ((ssize_t)size <= 0)
return (EINVAL);
switch (advice) {
case MADV_NORMAL:
case MADV_RANDOM:
case MADV_SEQUENTIAL:
rv = uvm_map_advice(&p->p_vmspace->vm_map, addr, addr + size,
advice);
break;
case MADV_WILLNEED:
/*
* Activate all these pages, pre-faulting them in if
* necessary.
*/
/*
* XXX IMPLEMENT ME.
* Should invent a "weak" mode for uvm_fault()
* which would only do the PGO_LOCKED pgo_get().
*/
return (0);
case MADV_DONTNEED:
/*
* Deactivate all these pages. We don't need them
* any more. We don't, however, toss the data in
* the pages.
*/
rv = uvm_map_clean(&p->p_vmspace->vm_map, addr, addr + size,
PGO_DEACTIVATE);
break;
case MADV_FREE:
/*
* These pages contain no valid data, and may be
* grbage-collected. Toss all resources, including
* any swap space in use.
*/
rv = uvm_map_clean(&p->p_vmspace->vm_map, addr, addr + size,
PGO_FREE);
break;
case MADV_SPACEAVAIL:
/*
* XXXMRG What is this? I think it's:
*
* Ensure that we have allocated backing-store
* for these pages.
*
* This is going to require changes to the page daemon,
* as it will free swap space allocated to pages in core.
* There's also what to do for device/file/anonymous memory.
*/
return (EINVAL);
default:
return (EINVAL);
}
switch (rv) {
case KERN_SUCCESS:
return (0);
case KERN_NO_SPACE:
return (EAGAIN);
case KERN_INVALID_ADDRESS:
return (ENOMEM);
case KERN_FAILURE:
return (EIO);
}
return (EINVAL);
}
/*
* sys_mlock: memory lock
*/
int
sys_mlock(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct sys_mlock_args /* {
syscallarg(const void *) addr;
syscallarg(size_t) len;
} */ *uap = v;
vaddr_t addr;
vsize_t size, pageoff;
int error;
/*
* extract syscall args from uap
*/
addr = (vaddr_t)SCARG(uap, addr);
size = (vsize_t)SCARG(uap, len);
/*
* align the address to a page boundary and adjust the size accordingly
*/
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vsize_t) round_page(size);
/* disallow wrap-around. */
if (addr + (int)size < addr)
return (EINVAL);
if (atop(size) + uvmexp.wired > uvmexp.wiredmax)
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)) != 0)
return (error);
#endif
error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, FALSE,
0);
return (error == KERN_SUCCESS ? 0 : ENOMEM);
}
/*
* sys_munlock: unlock wired pages
*/
int
sys_munlock(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct sys_munlock_args /* {
syscallarg(const void *) addr;
syscallarg(size_t) len;
} */ *uap = v;
vaddr_t addr;
vsize_t size, pageoff;
int error;
/*
* extract syscall args from uap
*/
addr = (vaddr_t)SCARG(uap, addr);
size = (vsize_t)SCARG(uap, len);
/*
* align the address to a page boundary, and adjust the size accordingly
*/
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vsize_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)) != 0)
return (error);
#endif
error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, TRUE,
0);
return (error == KERN_SUCCESS ? 0 : ENOMEM);
}
/*
* sys_mlockall: lock all pages mapped into an address space.
*/
int
sys_mlockall(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct sys_mlockall_args /* {
syscallarg(int) flags;
} */ *uap = v;
int error, flags;
flags = SCARG(uap, flags);
if (flags == 0 ||
(flags & ~(MCL_CURRENT|MCL_FUTURE)) != 0)
return (EINVAL);
#ifndef pmap_wired_count
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
return (error);
#endif
error = uvm_map_pageable_all(&p->p_vmspace->vm_map, flags,
p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
switch (error) {
case KERN_SUCCESS:
error = 0;
break;
case KERN_NO_SPACE: /* XXX overloaded */
error = ENOMEM;
break;
default:
/*
* "Some or all of the memory could not be locked when
* the call was made."
*/
error = EAGAIN;
}
return (error);
}
/*
* sys_munlockall: unlock all pages mapped into an address space.
*/
int
sys_munlockall(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
(void) uvm_map_pageable_all(&p->p_vmspace->vm_map, 0, 0);
return (0);
}
/*
* uvm_mmap: internal version of mmap
*
* - used by sys_mmap, exec, and sysv shm
* - handle is a vnode pointer or NULL for MAP_ANON (XXX: not true,
* sysv shm uses "named anonymous memory")
* - caller must page-align the file offset
*/
int
uvm_mmap(map, addr, size, prot, maxprot, flags, handle, foff, locklimit)
vm_map_t map;
vaddr_t *addr;
vsize_t size;
vm_prot_t prot, maxprot;
int flags;
caddr_t handle; /* XXX: VNODE? */
vaddr_t foff;
vsize_t locklimit;
{
struct uvm_object *uobj;
struct vnode *vp;
int retval;
int advice = UVM_ADV_NORMAL;
uvm_flag_t uvmflag = 0;
/*
* check params
*/
if (size == 0)
return(0);
if (foff & PAGE_MASK)
return(EINVAL);
if ((prot & maxprot) != prot)
return(EINVAL);
/*
* for non-fixed mappings, round off the suggested address.
* for fixed mappings, check alignment and zap old mappings.
*/
if ((flags & MAP_FIXED) == 0) {
*addr = round_page(*addr); /* round */
} else {
if (*addr & PAGE_MASK)
return(EINVAL);
uvmflag |= UVM_FLAG_FIXED;
(void) uvm_unmap(map, *addr, *addr + size); /* zap! */
}
/*
* handle anon vs. non-anon mappings. for non-anon mappings attach
* to underlying vm object.
*/
if (flags & MAP_ANON) {
#if 1
/*
* Specify an offset of 0 so that uvm_map_findspace() via.
* uvm_map() will PMAP_PREFER the address for us. This
* prevents alias problems if the following occurs:
*
* - Anon region mapped.
* - File mapped over anon region (using MAP_FIXED).
*/
foff = 0;
#else
foff = UVM_UNKNOWN_OFFSET;
#endif
uobj = NULL;
if ((flags & MAP_SHARED) == 0)
/* XXX: defer amap create */
uvmflag |= UVM_FLAG_COPYONW;
else
/* shared: create amap now */
uvmflag |= UVM_FLAG_OVERLAY;
} else {
vp = (struct vnode *) handle; /* get vnode */
if (vp->v_type != VCHR) {
uobj = uvn_attach((void *) vp, (flags & MAP_SHARED) ?
maxprot : (maxprot & ~VM_PROT_WRITE));
/*
* XXXCDC: hack from old code
* don't allow vnodes which have been mapped
* shared-writeable to persist [forces them to be
* flushed out when last reference goes].
* XXXCDC: interesting side effect: avoids a bug.
* note that in WRITE [ufs_readwrite.c] that we
* allocate buffer, uncache, and then do the write.
* the problem with this is that if the uncache causes
* VM data to be flushed to the same area of the file
* we are writing to... in that case we've got the
* buffer locked and our process goes to sleep forever.
*
* XXXCDC: checking maxprot protects us from the
* "persistbug" program but this is not a long term
* solution.
*
* XXXCDC: we don't bother calling uncache with the vp
* VOP_LOCKed since we know that we are already
* holding a valid reference to the uvn (from the
* uvn_attach above), and thus it is impossible for
* the uncache to kill the uvn and trigger I/O.
*/
if (flags & MAP_SHARED) {
if ((prot & VM_PROT_WRITE) ||
(maxprot & VM_PROT_WRITE)) {
uvm_vnp_uncache(vp);
}
}
} else {
uobj = udv_attach((void *) &vp->v_rdev,
(flags & MAP_SHARED) ?
maxprot : (maxprot & ~VM_PROT_WRITE), foff, size);
advice = UVM_ADV_RANDOM;
}
if (uobj == NULL)
return((vp->v_type == VREG) ? ENOMEM : EINVAL);
if ((flags & MAP_SHARED) == 0)
uvmflag |= UVM_FLAG_COPYONW;
}
/*
* set up mapping flags
*/
uvmflag = UVM_MAPFLAG(prot, maxprot,
(flags & MAP_SHARED) ? UVM_INH_SHARE : UVM_INH_COPY,
advice, uvmflag);
/*
* do it!
*/
retval = uvm_map(map, addr, size, uobj, foff, uvmflag);
if (retval == KERN_SUCCESS) {
/*
* POSIX 1003.1b -- if our address space was configured
* to lock all future mappings, wire the one we just made.
*/
if (prot == VM_PROT_NONE) {
/*
* No more work to do in this case.
*/
return (0);
}
vm_map_lock(map);
if (map->flags & VM_MAP_WIREFUTURE) {
/*
* uvm_map_pageable() always returns the map
* unlocked.
*/
if ((atop(size) + uvmexp.wired) > uvmexp.wiredmax
#ifdef pmap_wired_count
|| (locklimit != 0 && (size +
ptoa(pmap_wired_count(vm_map_pmap(map)))) >
locklimit)
#endif
) {
retval = KERN_RESOURCE_SHORTAGE;
/* unmap the region! */
(void) uvm_unmap(map, *addr, *addr + size);
goto bad;
}
retval = uvm_map_pageable(map, *addr, *addr + size,
FALSE, UVM_LK_ENTER);
if (retval != KERN_SUCCESS) {
/* unmap the region! */
(void) uvm_unmap(map, *addr, *addr + size);
goto bad;
}
return (0);
}
vm_map_unlock(map);
return (0);
}
/*
* errors: first detach from the uobj, if any.
*/
if (uobj)
uobj->pgops->pgo_detach(uobj);
bad:
switch (retval) {
case KERN_INVALID_ADDRESS:
case KERN_NO_SPACE:
return(ENOMEM);
case KERN_RESOURCE_SHORTAGE:
return (EAGAIN);
case KERN_PROTECTION_FAILURE:
return(EACCES);
}
return(EINVAL);
}
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