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NetBSD/sys/uvm/uvm_mmap.c
enami 332c98526a - Move the comment, which describes that calling the function 
uvm_map_pageable(map, ...) implies unlocking passed map, just before the
  function call.
- If we bail out before calling the uvm_map_pageable, unlock the map
  by ourself to prevent a panic ``locking against myself''.  The panic is,
  for example, caused when cdrecord is invoked with too large fifo size.
2000-05-23 02:19:20 +00:00

1288 lines
28 KiB
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/* $NetBSD: uvm_mmap.c,v 1.41 2000/05/23 02:19:20 enami 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;
{
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;
struct filedesc *fdp = p->p_fd;
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);
/*
* 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((vaddr_t)p->p_vmspace->vm_daddr+MAXDSIZ))
addr = round_page((vaddr_t)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 */
if (vp->v_type == VREG && (pos + size) < pos)
return (EOVERFLOW); /* no offset wrapping */
/* 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)
struct proc *p;
void *v;
register_t *retval;
{
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;
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? */
voff_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) {
foff = UVM_UNKNOWN_OFFSET;
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) {
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;
vm_map_unlock(map);
/* unmap the region! */
(void) uvm_unmap(map, *addr, *addr + size);
goto bad;
}
/*
* uvm_map_pageable() always returns the map
* unlocked.
*/
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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