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uvm_mmap.c revision 1.26
      1 /*	$NetBSD: uvm_mmap.c,v 1.26 1999/06/19 00:11:17 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997 Charles D. Cranor and Washington University.
      5  * Copyright (c) 1991, 1993 The Regents of the University of California.
      6  * Copyright (c) 1988 University of Utah.
      7  *
      8  * All rights reserved.
      9  *
     10  * This code is derived from software contributed to Berkeley by
     11  * the Systems Programming Group of the University of Utah Computer
     12  * Science Department.
     13  *
     14  * Redistribution and use in source and binary forms, with or without
     15  * modification, are permitted provided that the following conditions
     16  * are met:
     17  * 1. Redistributions of source code must retain the above copyright
     18  *    notice, this list of conditions and the following disclaimer.
     19  * 2. Redistributions in binary form must reproduce the above copyright
     20  *    notice, this list of conditions and the following disclaimer in the
     21  *    documentation and/or other materials provided with the distribution.
     22  * 3. All advertising materials mentioning features or use of this software
     23  *    must display the following acknowledgement:
     24  *      This product includes software developed by the Charles D. Cranor,
     25  *	Washington University, University of California, Berkeley and
     26  *	its contributors.
     27  * 4. Neither the name of the University nor the names of its contributors
     28  *    may be used to endorse or promote products derived from this software
     29  *    without specific prior written permission.
     30  *
     31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     41  * SUCH DAMAGE.
     42  *
     43  * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
     44  *      @(#)vm_mmap.c   8.5 (Berkeley) 5/19/94
     45  * from: Id: uvm_mmap.c,v 1.1.2.14 1998/01/05 21:04:26 chuck Exp
     46  */
     47 
     48 /*
     49  * uvm_mmap.c: system call interface into VM system, plus kernel vm_mmap
     50  * function.
     51  */
     52 #include <sys/param.h>
     53 #include <sys/systm.h>
     54 #include <sys/file.h>
     55 #include <sys/filedesc.h>
     56 #include <sys/resourcevar.h>
     57 #include <sys/mman.h>
     58 #include <sys/mount.h>
     59 #include <sys/proc.h>
     60 #include <sys/malloc.h>
     61 #include <sys/vnode.h>
     62 #include <sys/conf.h>
     63 #include <sys/stat.h>
     64 
     65 #include <miscfs/specfs/specdev.h>
     66 
     67 #include <vm/vm.h>
     68 #include <vm/vm_page.h>
     69 #include <vm/vm_kern.h>
     70 
     71 #include <sys/syscallargs.h>
     72 
     73 #include <uvm/uvm.h>
     74 #include <uvm/uvm_device.h>
     75 #include <uvm/uvm_vnode.h>
     76 
     77 
     78 /*
     79  * unimplemented VM system calls:
     80  */
     81 
     82 /*
     83  * sys_sbrk: sbrk system call.
     84  */
     85 
     86 /* ARGSUSED */
     87 int
     88 sys_sbrk(p, v, retval)
     89 	struct proc *p;
     90 	void *v;
     91 	register_t *retval;
     92 {
     93 #if 0
     94 	struct sys_sbrk_args /* {
     95 		syscallarg(int) incr;
     96 	} */ *uap = v;
     97 #endif
     98 
     99 	return (ENOSYS);
    100 }
    101 
    102 /*
    103  * sys_sstk: sstk system call.
    104  */
    105 
    106 /* ARGSUSED */
    107 int
    108 sys_sstk(p, v, retval)
    109 	struct proc *p;
    110 	void *v;
    111 	register_t *retval;
    112 {
    113 #if 0
    114 	struct sys_sstk_args /* {
    115 		syscallarg(int) incr;
    116 	} */ *uap = v;
    117 #endif
    118 
    119 	return (ENOSYS);
    120 }
    121 
    122 /*
    123  * sys_mincore: determine if pages are in core or not.
    124  */
    125 
    126 /* ARGSUSED */
    127 int
    128 sys_mincore(p, v, retval)
    129 	struct proc *p;
    130 	void *v;
    131 	register_t *retval;
    132 {
    133 	struct sys_mincore_args /* {
    134 		syscallarg(void *) addr;
    135 		syscallarg(size_t) len;
    136 		syscallarg(char *) vec;
    137 	} */ *uap = v;
    138 	vm_page_t m;
    139 	char *vec, pgi;
    140 	struct uvm_object *uobj;
    141 	struct vm_amap *amap;
    142 	struct vm_anon *anon;
    143 	vm_map_entry_t entry;
    144 	vaddr_t start, end, lim;
    145 	vm_map_t map;
    146 	vsize_t len;
    147 	int error = 0, npgs;
    148 
    149 	map = &p->p_vmspace->vm_map;
    150 
    151 	start = (vaddr_t)SCARG(uap, addr);
    152 	len = SCARG(uap, len);
    153 	vec = SCARG(uap, vec);
    154 
    155 	if (start & PAGE_MASK)
    156 		return (EINVAL);
    157 	len = round_page(len);
    158 	end = start + len;
    159 	if (end <= start)
    160 		return (EINVAL);
    161 
    162 	npgs = len >> PAGE_SHIFT;
    163 
    164 	if (uvm_useracc(vec, npgs, B_WRITE) == FALSE)
    165 		return (EFAULT);
    166 
    167 	/*
    168 	 * Lock down vec, so our returned status isn't outdated by
    169 	 * storing the status byte for a page.
    170 	 */
    171 	uvm_vslock(p, vec, npgs, VM_PROT_WRITE);
    172 
    173 	vm_map_lock_read(map);
    174 
    175 	if (uvm_map_lookup_entry(map, start, &entry) == FALSE) {
    176 		error = ENOMEM;
    177 		goto out;
    178 	}
    179 
    180 	for (/* nothing */;
    181 	     entry != &map->header && entry->start < end;
    182 	     entry = entry->next) {
    183 #ifdef DIAGNOSTIC
    184 		if (UVM_ET_ISSUBMAP(entry))
    185 			panic("mincore: user map has submap");
    186 		if (start < entry->start)
    187 			panic("mincore: hole");
    188 #endif
    189 		/* Make sure there are no holes. */
    190 		if (entry->end < end &&
    191 		     (entry->next == &map->header ||
    192 		      entry->next->start > entry->end)) {
    193 			error = ENOMEM;
    194 			goto out;
    195 		}
    196 
    197 		lim = end < entry->end ? end : entry->end;
    198 
    199 		/*
    200 		 * Special case for mapped devices; these are always
    201 		 * considered resident.
    202 		 */
    203 		if (UVM_ET_ISOBJ(entry)) {
    204 			extern struct uvm_pagerops uvm_deviceops; /* XXX */
    205 #ifdef DIAGNOSTIC
    206 			if (UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj))
    207 				panic("mincore: user map has kernel object");
    208 #endif
    209 			if (entry->object.uvm_obj->pgops == &uvm_deviceops) {
    210 				for (/* nothing */; start < lim;
    211 				     start += PAGE_SIZE, vec++)
    212 					subyte(vec, 1);
    213 				continue;
    214 			}
    215 		}
    216 
    217 		uobj = entry->object.uvm_obj;	/* top layer */
    218 		amap = entry->aref.ar_amap;	/* bottom layer */
    219 
    220 		if (amap != NULL)
    221 			amap_lock(amap);
    222 		if (uobj != NULL)
    223 			simple_lock(&uobj->vmobjlock);
    224 
    225 		for (/* nothing */; start < lim; start += PAGE_SIZE, vec++) {
    226 			pgi = 0;
    227 			if (amap != NULL) {
    228 				/* Check the top layer first. */
    229 				anon = amap_lookup(&entry->aref,
    230 				    start - entry->start);
    231 				/* Don't need to lock anon here. */
    232 				if (anon != NULL && anon->u.an_page != NULL) {
    233 					/*
    234 					 * Anon has the page for this entry
    235 					 * offset.
    236 					 */
    237 					pgi = 1;
    238 				}
    239 			}
    240 
    241 			if (uobj != NULL && pgi == 0) {
    242 				/* Check the bottom layer. */
    243 				m = uvm_pagelookup(uobj,
    244 				    entry->offset + (start - entry->start));
    245 				if (m != NULL) {
    246 					/*
    247 					 * Object has the page for this entry
    248 					 * offset.
    249 					 */
    250 					pgi = 1;
    251 				}
    252 			}
    253 
    254 			(void) subyte(vec, pgi);
    255 		}
    256 
    257 		if (uobj != NULL)
    258 			simple_unlock(&obj->vmobjlock);
    259 		if (amap != NULL)
    260 			amap_unlock(amap);
    261 	}
    262 
    263  out:
    264 	vm_map_unlock_read(map);
    265 	uvm_vsunlock(p, SCARG(uap, vec), npgs);
    266 	return (error);
    267 }
    268 
    269 #if 0
    270 /*
    271  * munmapfd: unmap file descriptor
    272  *
    273  * XXX: is this acutally a useful function?   could it be useful?
    274  */
    275 
    276 void
    277 munmapfd(p, fd)
    278 	struct proc *p;
    279 	int fd;
    280 {
    281 
    282 	/*
    283 	 * XXX should vm_deallocate any regions mapped to this file
    284 	 */
    285 	p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
    286 }
    287 #endif
    288 
    289 /*
    290  * sys_mmap: mmap system call.
    291  *
    292  * => file offest and address may not be page aligned
    293  *    - if MAP_FIXED, offset and address must have remainder mod PAGE_SIZE
    294  *    - if address isn't page aligned the mapping starts at trunc_page(addr)
    295  *      and the return value is adjusted up by the page offset.
    296  */
    297 
    298 int
    299 sys_mmap(p, v, retval)
    300 	struct proc *p;
    301 	void *v;
    302 	register_t *retval;
    303 {
    304 	register struct sys_mmap_args /* {
    305 		syscallarg(caddr_t) addr;
    306 		syscallarg(size_t) len;
    307 		syscallarg(int) prot;
    308 		syscallarg(int) flags;
    309 		syscallarg(int) fd;
    310 		syscallarg(long) pad;
    311 		syscallarg(off_t) pos;
    312 	} */ *uap = v;
    313 	vaddr_t addr;
    314 	struct vattr va;
    315 	off_t pos;
    316 	vsize_t size, pageoff;
    317 	vm_prot_t prot, maxprot;
    318 	int flags, fd;
    319 	vaddr_t vm_min_address = VM_MIN_ADDRESS;
    320 	register struct filedesc *fdp = p->p_fd;
    321 	register struct file *fp;
    322 	struct vnode *vp;
    323 	caddr_t handle;
    324 	int error;
    325 
    326 	/*
    327 	 * first, extract syscall args from the uap.
    328 	 */
    329 
    330 	addr = (vaddr_t) SCARG(uap, addr);
    331 	size = (vsize_t) SCARG(uap, len);
    332 	prot = SCARG(uap, prot) & VM_PROT_ALL;
    333 	flags = SCARG(uap, flags);
    334 	fd = SCARG(uap, fd);
    335 	pos = SCARG(uap, pos);
    336 
    337 	/*
    338 	 * Fixup the old deprecated MAP_COPY into MAP_PRIVATE, and
    339 	 * validate the flags.
    340 	 */
    341 	if (flags & MAP_COPY)
    342 		flags = (flags & ~MAP_COPY) | MAP_PRIVATE;
    343 	if ((flags & (MAP_SHARED|MAP_PRIVATE)) == (MAP_SHARED|MAP_PRIVATE))
    344 		return (EINVAL);
    345 
    346 	/*
    347 	 * make sure that the newsize fits within a vaddr_t
    348 	 * XXX: need to revise addressing data types
    349 	 */
    350 	if (pos + size > (vaddr_t)-PAGE_SIZE) {
    351 #ifdef DEBUG
    352 		printf("mmap: pos=%qx, size=%lx too big\n", (long long)pos,
    353 		       (long)size);
    354 #endif
    355 		return (EINVAL);
    356 	}
    357 
    358 	/*
    359 	 * align file position and save offset.  adjust size.
    360 	 */
    361 
    362 	pageoff = (pos & PAGE_MASK);
    363 	pos  -= pageoff;
    364 	size += pageoff;			/* add offset */
    365 	size = (vsize_t) round_page(size);	/* round up */
    366 	if ((ssize_t) size < 0)
    367 		return (EINVAL);			/* don't allow wrap */
    368 
    369 	/*
    370 	 * now check (MAP_FIXED) or get (!MAP_FIXED) the "addr"
    371 	 */
    372 
    373 	if (flags & MAP_FIXED) {
    374 
    375 		/* ensure address and file offset are aligned properly */
    376 		addr -= pageoff;
    377 		if (addr & PAGE_MASK)
    378 			return (EINVAL);
    379 
    380 		if (VM_MAXUSER_ADDRESS > 0 &&
    381 		    (addr + size) > VM_MAXUSER_ADDRESS)
    382 			return (EINVAL);
    383 		if (vm_min_address > 0 && addr < vm_min_address)
    384 			return (EINVAL);
    385 		if (addr > addr + size)
    386 			return (EINVAL);		/* no wrapping! */
    387 
    388 	} else {
    389 
    390 		/*
    391 		 * not fixed: make sure we skip over the largest possible heap.
    392 		 * we will refine our guess later (e.g. to account for VAC, etc)
    393 		 */
    394 		if (addr < round_page(p->p_vmspace->vm_daddr + MAXDSIZ))
    395 			addr = round_page(p->p_vmspace->vm_daddr + MAXDSIZ);
    396 	}
    397 
    398 	/*
    399 	 * check for file mappings (i.e. not anonymous) and verify file.
    400 	 */
    401 
    402 	if ((flags & MAP_ANON) == 0) {
    403 
    404 		if (fd < 0 || fd >= fdp->fd_nfiles)
    405 			return(EBADF);		/* failed range check? */
    406 		fp = fdp->fd_ofiles[fd];	/* convert to file pointer */
    407 		if (fp == NULL)
    408 			return(EBADF);
    409 
    410 		if (fp->f_type != DTYPE_VNODE)
    411 			return (ENODEV);		/* only mmap vnodes! */
    412 		vp = (struct vnode *)fp->f_data;	/* convert to vnode */
    413 
    414 		if (vp->v_type != VREG && vp->v_type != VCHR &&
    415 		    vp->v_type != VBLK)
    416 			return (ENODEV);  /* only REG/CHR/BLK support mmap */
    417 
    418 		/* special case: catch SunOS style /dev/zero */
    419 		if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
    420 			flags |= MAP_ANON;
    421 			goto is_anon;
    422 		}
    423 
    424 		/*
    425 		 * Old programs may not select a specific sharing type, so
    426 		 * default to an appropriate one.
    427 		 *
    428 		 * XXX: how does MAP_ANON fit in the picture?
    429 		 */
    430 		if ((flags & (MAP_SHARED|MAP_PRIVATE)) == 0) {
    431 #if defined(DEBUG)
    432 			printf("WARNING: defaulted mmap() share type to "
    433 			   "%s (pid %d comm %s)\n", vp->v_type == VCHR ?
    434 			   "MAP_SHARED" : "MAP_PRIVATE", p->p_pid,
    435 			    p->p_comm);
    436 #endif
    437 			if (vp->v_type == VCHR)
    438 				flags |= MAP_SHARED;	/* for a device */
    439 			else
    440 				flags |= MAP_PRIVATE;	/* for a file */
    441 		}
    442 
    443 		/*
    444 		 * MAP_PRIVATE device mappings don't make sense (and aren't
    445 		 * supported anyway).  However, some programs rely on this,
    446 		 * so just change it to MAP_SHARED.
    447 		 */
    448 		if (vp->v_type == VCHR && (flags & MAP_PRIVATE) != 0) {
    449 #if defined(DIAGNOSTIC)
    450 			printf("WARNING: converted MAP_PRIVATE device mapping "
    451 			    "to MAP_SHARED (pid %d comm %s)\n", p->p_pid,
    452 			    p->p_comm);
    453 #endif
    454 			flags = (flags & ~MAP_PRIVATE) | MAP_SHARED;
    455 		}
    456 
    457 		/*
    458 		 * now check protection
    459 		 */
    460 
    461 		maxprot = VM_PROT_EXECUTE;
    462 
    463 		/* check read access */
    464 		if (fp->f_flag & FREAD)
    465 			maxprot |= VM_PROT_READ;
    466 		else if (prot & PROT_READ)
    467 			return (EACCES);
    468 
    469 		/* check write access, shared case first */
    470 		if (flags & MAP_SHARED) {
    471 			/*
    472 			 * if the file is writable, only add PROT_WRITE to
    473 			 * maxprot if the file is not immutable, append-only.
    474 			 * otherwise, if we have asked for PROT_WRITE, return
    475 			 * EPERM.
    476 			 */
    477 			if (fp->f_flag & FWRITE) {
    478 				if ((error =
    479 				    VOP_GETATTR(vp, &va, p->p_ucred, p)))
    480 					return (error);
    481 				if ((va.va_flags & (IMMUTABLE|APPEND)) == 0)
    482 					maxprot |= VM_PROT_WRITE;
    483 				else if (prot & PROT_WRITE)
    484 					return (EPERM);
    485 			}
    486 			else if (prot & PROT_WRITE)
    487 				return (EACCES);
    488 		} else {
    489 			/* MAP_PRIVATE mappings can always write to */
    490 			maxprot |= VM_PROT_WRITE;
    491 		}
    492 
    493 		/*
    494 		 * set handle to vnode
    495 		 */
    496 
    497 		handle = (caddr_t)vp;
    498 
    499 	} else {		/* MAP_ANON case */
    500 		/*
    501 		 * XXX What do we do about (MAP_SHARED|MAP_PRIVATE) == 0?
    502 		 */
    503 		if (fd != -1)
    504 			return (EINVAL);
    505 
    506  is_anon:		/* label for SunOS style /dev/zero */
    507 		handle = NULL;
    508 		maxprot = VM_PROT_ALL;
    509 		pos = 0;
    510 	}
    511 
    512 	/*
    513 	 * now let kernel internal function uvm_mmap do the work.
    514 	 */
    515 
    516 	error = uvm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
    517 	    flags, handle, pos, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
    518 
    519 	if (error == 0)
    520 		/* remember to add offset */
    521 		*retval = (register_t)(addr + pageoff);
    522 
    523 	return (error);
    524 }
    525 
    526 /*
    527  * sys___msync13: the msync system call (a front-end for flush)
    528  */
    529 
    530 int
    531 sys___msync13(p, v, retval)
    532 	struct proc *p;
    533 	void *v;
    534 	register_t *retval;
    535 {
    536 	struct sys___msync13_args /* {
    537 		syscallarg(caddr_t) addr;
    538 		syscallarg(size_t) len;
    539 		syscallarg(int) flags;
    540 	} */ *uap = v;
    541 	vaddr_t addr;
    542 	vsize_t size, pageoff;
    543 	vm_map_t map;
    544 	int rv, flags, uvmflags;
    545 
    546 	/*
    547 	 * extract syscall args from the uap
    548 	 */
    549 
    550 	addr = (vaddr_t)SCARG(uap, addr);
    551 	size = (vsize_t)SCARG(uap, len);
    552 	flags = SCARG(uap, flags);
    553 
    554 	/* sanity check flags */
    555 	if ((flags & ~(MS_ASYNC | MS_SYNC | MS_INVALIDATE)) != 0 ||
    556 			(flags & (MS_ASYNC | MS_SYNC | MS_INVALIDATE)) == 0 ||
    557 			(flags & (MS_ASYNC | MS_SYNC)) == (MS_ASYNC | MS_SYNC))
    558 	  return (EINVAL);
    559 	if ((flags & (MS_ASYNC | MS_SYNC)) == 0)
    560 	  flags |= MS_SYNC;
    561 
    562 	/*
    563 	 * align the address to a page boundary, and adjust the size accordingly
    564 	 */
    565 
    566 	pageoff = (addr & PAGE_MASK);
    567 	addr -= pageoff;
    568 	size += pageoff;
    569 	size = (vsize_t) round_page(size);
    570 
    571 	/* disallow wrap-around. */
    572 	if (addr + size < addr)
    573 		return (EINVAL);
    574 
    575 	/*
    576 	 * get map
    577 	 */
    578 
    579 	map = &p->p_vmspace->vm_map;
    580 
    581 	/*
    582 	 * XXXCDC: do we really need this semantic?
    583 	 *
    584 	 * XXX Gak!  If size is zero we are supposed to sync "all modified
    585 	 * pages with the region containing addr".  Unfortunately, we
    586 	 * don't really keep track of individual mmaps so we approximate
    587 	 * by flushing the range of the map entry containing addr.
    588 	 * This can be incorrect if the region splits or is coalesced
    589 	 * with a neighbor.
    590 	 */
    591 	if (size == 0) {
    592 		vm_map_entry_t entry;
    593 
    594 		vm_map_lock_read(map);
    595 		rv = uvm_map_lookup_entry(map, addr, &entry);
    596 		if (rv == TRUE) {
    597 			addr = entry->start;
    598 			size = entry->end - entry->start;
    599 		}
    600 		vm_map_unlock_read(map);
    601 		if (rv == FALSE)
    602 			return (EINVAL);
    603 	}
    604 
    605 	/*
    606 	 * translate MS_ flags into PGO_ flags
    607 	 */
    608 	uvmflags = (flags & MS_INVALIDATE) ? PGO_FREE : 0;
    609 	if (flags & MS_SYNC)
    610 		uvmflags |= PGO_SYNCIO;
    611 	else
    612 		uvmflags |= PGO_SYNCIO;	 /* XXXCDC: force sync for now! */
    613 
    614 	/*
    615 	 * doit!
    616 	 */
    617 	rv = uvm_map_clean(map, addr, addr+size, uvmflags);
    618 
    619 	/*
    620 	 * and return...
    621 	 */
    622 	switch (rv) {
    623 	case KERN_SUCCESS:
    624 		return(0);
    625 	case KERN_INVALID_ADDRESS:
    626 		return (ENOMEM);
    627 	case KERN_FAILURE:
    628 		return (EIO);
    629 	case KERN_PAGES_LOCKED:	/* XXXCDC: uvm doesn't return this */
    630 		return (EBUSY);
    631 	default:
    632 		return (EINVAL);
    633 	}
    634 	/*NOTREACHED*/
    635 }
    636 
    637 /*
    638  * sys_munmap: unmap a users memory
    639  */
    640 
    641 int
    642 sys_munmap(p, v, retval)
    643 	register struct proc *p;
    644 	void *v;
    645 	register_t *retval;
    646 {
    647 	register struct sys_munmap_args /* {
    648 		syscallarg(caddr_t) addr;
    649 		syscallarg(size_t) len;
    650 	} */ *uap = v;
    651 	vaddr_t addr;
    652 	vsize_t size, pageoff;
    653 	vm_map_t map;
    654 	vaddr_t vm_min_address = VM_MIN_ADDRESS;
    655 	struct vm_map_entry *dead_entries;
    656 
    657 	/*
    658 	 * get syscall args...
    659 	 */
    660 
    661 	addr = (vaddr_t) SCARG(uap, addr);
    662 	size = (vsize_t) SCARG(uap, len);
    663 
    664 	/*
    665 	 * align the address to a page boundary, and adjust the size accordingly
    666 	 */
    667 
    668 	pageoff = (addr & PAGE_MASK);
    669 	addr -= pageoff;
    670 	size += pageoff;
    671 	size = (vsize_t) round_page(size);
    672 
    673 	if ((int)size < 0)
    674 		return (EINVAL);
    675 	if (size == 0)
    676 		return (0);
    677 
    678 	/*
    679 	 * Check for illegal addresses.  Watch out for address wrap...
    680 	 * Note that VM_*_ADDRESS are not constants due to casts (argh).
    681 	 */
    682 	if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
    683 		return (EINVAL);
    684 	if (vm_min_address > 0 && addr < vm_min_address)
    685 		return (EINVAL);
    686 	if (addr > addr + size)
    687 		return (EINVAL);
    688 	map = &p->p_vmspace->vm_map;
    689 
    690 
    691 	vm_map_lock(map);	/* lock map so we can checkprot */
    692 
    693 	/*
    694 	 * interesting system call semantic: make sure entire range is
    695 	 * allocated before allowing an unmap.
    696 	 */
    697 
    698 	if (!uvm_map_checkprot(map, addr, addr + size, VM_PROT_NONE)) {
    699 		vm_map_unlock(map);
    700 		return (EINVAL);
    701 	}
    702 
    703 	/*
    704 	 * doit!
    705 	 */
    706 	(void) uvm_unmap_remove(map, addr, addr + size, &dead_entries);
    707 
    708 	vm_map_unlock(map);	/* and unlock */
    709 
    710 	if (dead_entries != NULL)
    711 		uvm_unmap_detach(dead_entries, 0);
    712 
    713 	return (0);
    714 }
    715 
    716 /*
    717  * sys_mprotect: the mprotect system call
    718  */
    719 
    720 int
    721 sys_mprotect(p, v, retval)
    722 	struct proc *p;
    723 	void *v;
    724 	register_t *retval;
    725 {
    726 	struct sys_mprotect_args /* {
    727 		syscallarg(caddr_t) addr;
    728 		syscallarg(int) len;
    729 		syscallarg(int) prot;
    730 	} */ *uap = v;
    731 	vaddr_t addr;
    732 	vsize_t size, pageoff;
    733 	vm_prot_t prot;
    734 	int rv;
    735 
    736 	/*
    737 	 * extract syscall args from uap
    738 	 */
    739 
    740 	addr = (vaddr_t)SCARG(uap, addr);
    741 	size = (vsize_t)SCARG(uap, len);
    742 	prot = SCARG(uap, prot) & VM_PROT_ALL;
    743 
    744 	/*
    745 	 * align the address to a page boundary, and adjust the size accordingly
    746 	 */
    747 	pageoff = (addr & PAGE_MASK);
    748 	addr -= pageoff;
    749 	size += pageoff;
    750 	size = (vsize_t) round_page(size);
    751 	if ((int)size < 0)
    752 		return (EINVAL);
    753 
    754 	/*
    755 	 * doit
    756 	 */
    757 
    758 	rv = uvm_map_protect(&p->p_vmspace->vm_map,
    759 			   addr, addr+size, prot, FALSE);
    760 
    761 	if (rv == KERN_SUCCESS)
    762 		return (0);
    763 	if (rv == KERN_PROTECTION_FAILURE)
    764 		return (EACCES);
    765 	return (EINVAL);
    766 }
    767 
    768 /*
    769  * sys_minherit: the minherit system call
    770  */
    771 
    772 int
    773 sys_minherit(p, v, retval)
    774 	struct proc *p;
    775 	void *v;
    776 	register_t *retval;
    777 {
    778 	struct sys_minherit_args /* {
    779 		syscallarg(caddr_t) addr;
    780 		syscallarg(int) len;
    781 		syscallarg(int) inherit;
    782 	} */ *uap = v;
    783 	vaddr_t addr;
    784 	vsize_t size, pageoff;
    785 	register vm_inherit_t inherit;
    786 
    787 	addr = (vaddr_t)SCARG(uap, addr);
    788 	size = (vsize_t)SCARG(uap, len);
    789 	inherit = SCARG(uap, inherit);
    790 	/*
    791 	 * align the address to a page boundary, and adjust the size accordingly
    792 	 */
    793 
    794 	pageoff = (addr & PAGE_MASK);
    795 	addr -= pageoff;
    796 	size += pageoff;
    797 	size = (vsize_t) round_page(size);
    798 
    799 	if ((int)size < 0)
    800 		return (EINVAL);
    801 
    802 	switch (uvm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
    803 			 inherit)) {
    804 	case KERN_SUCCESS:
    805 		return (0);
    806 	case KERN_PROTECTION_FAILURE:
    807 		return (EACCES);
    808 	}
    809 	return (EINVAL);
    810 }
    811 
    812 /*
    813  * sys_madvise: give advice about memory usage.
    814  */
    815 
    816 /* ARGSUSED */
    817 int
    818 sys_madvise(p, v, retval)
    819 	struct proc *p;
    820 	void *v;
    821 	register_t *retval;
    822 {
    823 	struct sys_madvise_args /* {
    824 		syscallarg(caddr_t) addr;
    825 		syscallarg(size_t) len;
    826 		syscallarg(int) behav;
    827 	} */ *uap = v;
    828 	vaddr_t addr;
    829 	vsize_t size, pageoff;
    830 	int advice;
    831 
    832 	addr = (vaddr_t)SCARG(uap, addr);
    833 	size = (vsize_t)SCARG(uap, len);
    834 	advice = SCARG(uap, behav);
    835 
    836 	/*
    837 	 * align the address to a page boundary, and adjust the size accordingly
    838 	 */
    839 	pageoff = (addr & PAGE_MASK);
    840 	addr -= pageoff;
    841 	size += pageoff;
    842 	size = (vsize_t) round_page(size);
    843 
    844 	if ((int)size < 0)
    845 		return (EINVAL);
    846 
    847 	switch (uvm_map_advice(&p->p_vmspace->vm_map, addr, addr+size,
    848 			 advice)) {
    849 	case KERN_SUCCESS:
    850 		return (0);
    851 	case KERN_PROTECTION_FAILURE:
    852 		return (EACCES);
    853 	}
    854 	return (EINVAL);
    855 }
    856 
    857 /*
    858  * sys_mlock: memory lock
    859  */
    860 
    861 int
    862 sys_mlock(p, v, retval)
    863 	struct proc *p;
    864 	void *v;
    865 	register_t *retval;
    866 {
    867 	struct sys_mlock_args /* {
    868 		syscallarg(const void *) addr;
    869 		syscallarg(size_t) len;
    870 	} */ *uap = v;
    871 	vaddr_t addr;
    872 	vsize_t size, pageoff;
    873 	int error;
    874 
    875 	/*
    876 	 * extract syscall args from uap
    877 	 */
    878 	addr = (vaddr_t)SCARG(uap, addr);
    879 	size = (vsize_t)SCARG(uap, len);
    880 
    881 	/*
    882 	 * align the address to a page boundary and adjust the size accordingly
    883 	 */
    884 	pageoff = (addr & PAGE_MASK);
    885 	addr -= pageoff;
    886 	size += pageoff;
    887 	size = (vsize_t) round_page(size);
    888 
    889 	/* disallow wrap-around. */
    890 	if (addr + (int)size < addr)
    891 		return (EINVAL);
    892 
    893 	if (atop(size) + uvmexp.wired > uvmexp.wiredmax)
    894 		return (EAGAIN);
    895 
    896 #ifdef pmap_wired_count
    897 	if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
    898 			p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
    899 		return (EAGAIN);
    900 #else
    901 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    902 		return (error);
    903 #endif
    904 
    905 	error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, FALSE,
    906 	    FALSE);
    907 	return (error == KERN_SUCCESS ? 0 : ENOMEM);
    908 }
    909 
    910 /*
    911  * sys_munlock: unlock wired pages
    912  */
    913 
    914 int
    915 sys_munlock(p, v, retval)
    916 	struct proc *p;
    917 	void *v;
    918 	register_t *retval;
    919 {
    920 	struct sys_munlock_args /* {
    921 		syscallarg(const void *) addr;
    922 		syscallarg(size_t) len;
    923 	} */ *uap = v;
    924 	vaddr_t addr;
    925 	vsize_t size, pageoff;
    926 	int error;
    927 
    928 	/*
    929 	 * extract syscall args from uap
    930 	 */
    931 
    932 	addr = (vaddr_t)SCARG(uap, addr);
    933 	size = (vsize_t)SCARG(uap, len);
    934 
    935 	/*
    936 	 * align the address to a page boundary, and adjust the size accordingly
    937 	 */
    938 	pageoff = (addr & PAGE_MASK);
    939 	addr -= pageoff;
    940 	size += pageoff;
    941 	size = (vsize_t) round_page(size);
    942 
    943 	/* disallow wrap-around. */
    944 	if (addr + (int)size < addr)
    945 		return (EINVAL);
    946 
    947 #ifndef pmap_wired_count
    948 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    949 		return (error);
    950 #endif
    951 
    952 	error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, TRUE,
    953 	    FALSE);
    954 	return (error == KERN_SUCCESS ? 0 : ENOMEM);
    955 }
    956 
    957 /*
    958  * sys_mlockall: lock all pages mapped into an address space.
    959  */
    960 
    961 int
    962 sys_mlockall(p, v, retval)
    963 	struct proc *p;
    964 	void *v;
    965 	register_t *retval;
    966 {
    967 	struct sys_mlockall_args /* {
    968 		syscallarg(int) flags;
    969 	} */ *uap = v;
    970 	int error, flags;
    971 
    972 	flags = SCARG(uap, flags);
    973 
    974 	if (flags == 0 ||
    975 	    (flags & ~(MCL_CURRENT|MCL_FUTURE)) != 0)
    976 		return (EINVAL);
    977 
    978 #ifndef pmap_wired_count
    979 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
    980 		return (error);
    981 #endif
    982 
    983 	error = uvm_map_pageable_all(&p->p_vmspace->vm_map, flags,
    984 	    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
    985 	switch (error) {
    986 	case KERN_SUCCESS:
    987 		error = 0;
    988 		break;
    989 
    990 	case KERN_NO_SPACE:	/* XXX overloaded */
    991 		error = ENOMEM;
    992 		break;
    993 
    994 	default:
    995 		/*
    996 		 * "Some or all of the memory could not be locked when
    997 		 * the call was made."
    998 		 */
    999 		error = EAGAIN;
   1000 	}
   1001 
   1002 	return (error);
   1003 }
   1004 
   1005 /*
   1006  * sys_munlockall: unlock all pages mapped into an address space.
   1007  */
   1008 
   1009 int
   1010 sys_munlockall(p, v, retval)
   1011 	struct proc *p;
   1012 	void *v;
   1013 	register_t *retval;
   1014 {
   1015 
   1016 	(void) uvm_map_pageable_all(&p->p_vmspace->vm_map, 0, 0);
   1017 	return (0);
   1018 }
   1019 
   1020 /*
   1021  * uvm_mmap: internal version of mmap
   1022  *
   1023  * - used by sys_mmap, exec, and sysv shm
   1024  * - handle is a vnode pointer or NULL for MAP_ANON (XXX: not true,
   1025  *	sysv shm uses "named anonymous memory")
   1026  * - caller must page-align the file offset
   1027  */
   1028 
   1029 int
   1030 uvm_mmap(map, addr, size, prot, maxprot, flags, handle, foff, locklimit)
   1031 	vm_map_t map;
   1032 	vaddr_t *addr;
   1033 	vsize_t size;
   1034 	vm_prot_t prot, maxprot;
   1035 	int flags;
   1036 	caddr_t handle;		/* XXX: VNODE? */
   1037 	vaddr_t foff;
   1038 	vsize_t locklimit;
   1039 {
   1040 	struct uvm_object *uobj;
   1041 	struct vnode *vp;
   1042 	int retval;
   1043 	int advice = UVM_ADV_NORMAL;
   1044 	uvm_flag_t uvmflag = 0;
   1045 
   1046 	/*
   1047 	 * check params
   1048 	 */
   1049 
   1050 	if (size == 0)
   1051 		return(0);
   1052 	if (foff & PAGE_MASK)
   1053 		return(EINVAL);
   1054 	if ((prot & maxprot) != prot)
   1055 		return(EINVAL);
   1056 
   1057 	/*
   1058 	 * for non-fixed mappings, round off the suggested address.
   1059 	 * for fixed mappings, check alignment and zap old mappings.
   1060 	 */
   1061 
   1062 	if ((flags & MAP_FIXED) == 0) {
   1063 		*addr = round_page(*addr);	/* round */
   1064 	} else {
   1065 
   1066 		if (*addr & PAGE_MASK)
   1067 			return(EINVAL);
   1068 		uvmflag |= UVM_FLAG_FIXED;
   1069 		(void) uvm_unmap(map, *addr, *addr + size);	/* zap! */
   1070 	}
   1071 
   1072 	/*
   1073 	 * handle anon vs. non-anon mappings.   for non-anon mappings attach
   1074 	 * to underlying vm object.
   1075 	 */
   1076 
   1077 	if (flags & MAP_ANON) {
   1078 
   1079 		foff = UVM_UNKNOWN_OFFSET;
   1080 		uobj = NULL;
   1081 		if ((flags & MAP_SHARED) == 0)
   1082 			/* XXX: defer amap create */
   1083 			uvmflag |= UVM_FLAG_COPYONW;
   1084 		else
   1085 			/* shared: create amap now */
   1086 			uvmflag |= UVM_FLAG_OVERLAY;
   1087 
   1088 	} else {
   1089 
   1090 		vp = (struct vnode *) handle;	/* get vnode */
   1091 		if (vp->v_type != VCHR) {
   1092 			uobj = uvn_attach((void *) vp, (flags & MAP_SHARED) ?
   1093 			   maxprot : (maxprot & ~VM_PROT_WRITE));
   1094 
   1095 			/*
   1096 			 * XXXCDC: hack from old code
   1097 			 * don't allow vnodes which have been mapped
   1098 			 * shared-writeable to persist [forces them to be
   1099 			 * flushed out when last reference goes].
   1100 			 * XXXCDC: interesting side effect: avoids a bug.
   1101 			 * note that in WRITE [ufs_readwrite.c] that we
   1102 			 * allocate buffer, uncache, and then do the write.
   1103 			 * the problem with this is that if the uncache causes
   1104 			 * VM data to be flushed to the same area of the file
   1105 			 * we are writing to... in that case we've got the
   1106 			 * buffer locked and our process goes to sleep forever.
   1107 			 *
   1108 			 * XXXCDC: checking maxprot protects us from the
   1109 			 * "persistbug" program but this is not a long term
   1110 			 * solution.
   1111 			 *
   1112 			 * XXXCDC: we don't bother calling uncache with the vp
   1113 			 * VOP_LOCKed since we know that we are already
   1114 			 * holding a valid reference to the uvn (from the
   1115 			 * uvn_attach above), and thus it is impossible for
   1116 			 * the uncache to kill the uvn and trigger I/O.
   1117 			 */
   1118 			if (flags & MAP_SHARED) {
   1119 				if ((prot & VM_PROT_WRITE) ||
   1120 				    (maxprot & VM_PROT_WRITE)) {
   1121 					uvm_vnp_uncache(vp);
   1122 				}
   1123 			}
   1124 
   1125 		} else {
   1126 			uobj = udv_attach((void *) &vp->v_rdev,
   1127 			    (flags & MAP_SHARED) ?
   1128 			    maxprot : (maxprot & ~VM_PROT_WRITE), foff, size);
   1129 			advice = UVM_ADV_RANDOM;
   1130 		}
   1131 
   1132 		if (uobj == NULL)
   1133 			return((vp->v_type == VREG) ? ENOMEM : EINVAL);
   1134 
   1135 		if ((flags & MAP_SHARED) == 0)
   1136 			uvmflag |= UVM_FLAG_COPYONW;
   1137 	}
   1138 
   1139 	/*
   1140 	 * set up mapping flags
   1141 	 */
   1142 
   1143 	uvmflag = UVM_MAPFLAG(prot, maxprot,
   1144 			(flags & MAP_SHARED) ? UVM_INH_SHARE : UVM_INH_COPY,
   1145 			advice, uvmflag);
   1146 
   1147 	/*
   1148 	 * do it!
   1149 	 */
   1150 
   1151 	retval = uvm_map(map, addr, size, uobj, foff, uvmflag);
   1152 
   1153 	if (retval == KERN_SUCCESS) {
   1154 		/*
   1155 		 * POSIX 1003.1b -- if our address space was configured
   1156 		 * to lock all future mappings, wire the one we just made.
   1157 		 */
   1158 		if (prot == VM_PROT_NONE) {
   1159 			/*
   1160 			 * No more work to do in this case.
   1161 			 */
   1162 			return (0);
   1163 		}
   1164 
   1165 		vm_map_lock(map);
   1166 
   1167 		if (map->flags & VM_MAP_WIREFUTURE) {
   1168 			/*
   1169 			 * uvm_map_pageable() always returns the map
   1170 			 * unlocked.
   1171 			 */
   1172 			if ((atop(size) + uvmexp.wired) > uvmexp.wiredmax
   1173 #ifdef pmap_wired_count
   1174 			    || (locklimit != 0 && (size +
   1175 			         ptoa(pmap_wired_count(vm_map_pmap(map)))) >
   1176 			        locklimit)
   1177 #endif
   1178 			) {
   1179 				retval = KERN_RESOURCE_SHORTAGE;
   1180 				/* unmap the region! */
   1181 				(void) uvm_unmap(map, *addr, *addr + size);
   1182 				goto bad;
   1183 			}
   1184 			retval = uvm_map_pageable(map, *addr, *addr + size,
   1185 			    FALSE, TRUE);
   1186 			if (retval != KERN_SUCCESS) {
   1187 				/* unmap the region! */
   1188 				(void) uvm_unmap(map, *addr, *addr + size);
   1189 				goto bad;
   1190 			}
   1191 			return (0);
   1192 		}
   1193 
   1194 		vm_map_unlock(map);
   1195 
   1196 		return (0);
   1197 	}
   1198 
   1199 	/*
   1200 	 * errors: first detach from the uobj, if any.
   1201 	 */
   1202 
   1203 	if (uobj)
   1204 		uobj->pgops->pgo_detach(uobj);
   1205 
   1206  bad:
   1207 	switch (retval) {
   1208 	case KERN_INVALID_ADDRESS:
   1209 	case KERN_NO_SPACE:
   1210 		return(ENOMEM);
   1211 	case KERN_RESOURCE_SHORTAGE:
   1212 		return (EAGAIN);
   1213 	case KERN_PROTECTION_FAILURE:
   1214 		return(EACCES);
   1215 	}
   1216 	return(EINVAL);
   1217 }
   1218