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uvm_mmap.c revision 1.162.6.1
      1 /*	$NetBSD: uvm_mmap.c,v 1.162.6.1 2017/05/02 03:19:22 pgoyette 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. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
     39  *      @(#)vm_mmap.c   8.5 (Berkeley) 5/19/94
     40  * from: Id: uvm_mmap.c,v 1.1.2.14 1998/01/05 21:04:26 chuck Exp
     41  */
     42 
     43 /*
     44  * uvm_mmap.c: system call interface into VM system, plus kernel vm_mmap
     45  * function.
     46  */
     47 
     48 #include <sys/cdefs.h>
     49 __KERNEL_RCSID(0, "$NetBSD: uvm_mmap.c,v 1.162.6.1 2017/05/02 03:19:22 pgoyette Exp $");
     50 
     51 #include "opt_compat_netbsd.h"
     52 #include "opt_pax.h"
     53 
     54 #include <sys/types.h>
     55 #include <sys/file.h>
     56 #include <sys/filedesc.h>
     57 #include <sys/resourcevar.h>
     58 #include <sys/mman.h>
     59 #include <sys/pax.h>
     60 
     61 #include <sys/syscallargs.h>
     62 
     63 #include <uvm/uvm.h>
     64 #include <uvm/uvm_device.h>
     65 
     66 static int uvm_mmap(struct vm_map *, vaddr_t *, vsize_t, vm_prot_t, vm_prot_t,
     67     int, int, struct uvm_object *, voff_t, vsize_t);
     68 
     69 static int
     70 range_test(struct vm_map *map, vaddr_t addr, vsize_t size, bool ismmap)
     71 {
     72 	vaddr_t vm_min_address = vm_map_min(map);
     73 	vaddr_t vm_max_address = vm_map_max(map);
     74 	vaddr_t eaddr = addr + size;
     75 	int res = 0;
     76 
     77 	if (addr < vm_min_address)
     78 		return EINVAL;
     79 	if (eaddr > vm_max_address)
     80 		return ismmap ? EFBIG : EINVAL;
     81 	if (addr > eaddr) /* no wrapping! */
     82 		return ismmap ? EOVERFLOW : EINVAL;
     83 
     84 #ifdef MD_MMAP_RANGE_TEST
     85 	res = MD_MMAP_RANGE_TEST(addr, eaddr);
     86 #endif
     87 
     88 	return res;
     89 }
     90 
     91 /*
     92  * unimplemented VM system calls:
     93  */
     94 
     95 /*
     96  * sys_sbrk: sbrk system call.
     97  */
     98 
     99 /* ARGSUSED */
    100 int
    101 sys_sbrk(struct lwp *l, const struct sys_sbrk_args *uap, register_t *retval)
    102 {
    103 	/* {
    104 		syscallarg(intptr_t) incr;
    105 	} */
    106 
    107 	return ENOSYS;
    108 }
    109 
    110 /*
    111  * sys_sstk: sstk system call.
    112  */
    113 
    114 /* ARGSUSED */
    115 int
    116 sys_sstk(struct lwp *l, const struct sys_sstk_args *uap, register_t *retval)
    117 {
    118 	/* {
    119 		syscallarg(int) incr;
    120 	} */
    121 
    122 	return ENOSYS;
    123 }
    124 
    125 /*
    126  * sys_mincore: determine if pages are in core or not.
    127  */
    128 
    129 /* ARGSUSED */
    130 int
    131 sys_mincore(struct lwp *l, const struct sys_mincore_args *uap,
    132     register_t *retval)
    133 {
    134 	/* {
    135 		syscallarg(void *) addr;
    136 		syscallarg(size_t) len;
    137 		syscallarg(char *) vec;
    138 	} */
    139 	struct proc *p = l->l_proc;
    140 	struct vm_page *pg;
    141 	char *vec, pgi;
    142 	struct uvm_object *uobj;
    143 	struct vm_amap *amap;
    144 	struct vm_anon *anon;
    145 	struct vm_map_entry *entry;
    146 	vaddr_t start, end, lim;
    147 	struct vm_map *map;
    148 	vsize_t len;
    149 	int error = 0, npgs;
    150 
    151 	map = &p->p_vmspace->vm_map;
    152 
    153 	start = (vaddr_t)SCARG(uap, addr);
    154 	len = SCARG(uap, len);
    155 	vec = SCARG(uap, vec);
    156 
    157 	if (start & PAGE_MASK)
    158 		return EINVAL;
    159 	len = round_page(len);
    160 	end = start + len;
    161 	if (end <= start)
    162 		return EINVAL;
    163 
    164 	/*
    165 	 * Lock down vec, so our returned status isn't outdated by
    166 	 * storing the status byte for a page.
    167 	 */
    168 
    169 	npgs = len >> PAGE_SHIFT;
    170 	error = uvm_vslock(p->p_vmspace, vec, npgs, VM_PROT_WRITE);
    171 	if (error) {
    172 		return error;
    173 	}
    174 	vm_map_lock_read(map);
    175 
    176 	if (uvm_map_lookup_entry(map, start, &entry) == false) {
    177 		error = ENOMEM;
    178 		goto out;
    179 	}
    180 
    181 	for (/* nothing */;
    182 	     entry != &map->header && entry->start < end;
    183 	     entry = entry->next) {
    184 		KASSERT(!UVM_ET_ISSUBMAP(entry));
    185 		KASSERT(start >= entry->start);
    186 
    187 		/* Make sure there are no holes. */
    188 		if (entry->end < end &&
    189 		     (entry->next == &map->header ||
    190 		      entry->next->start > entry->end)) {
    191 			error = ENOMEM;
    192 			goto out;
    193 		}
    194 
    195 		lim = end < entry->end ? end : entry->end;
    196 
    197 		/*
    198 		 * Special case for objects with no "real" pages.  Those
    199 		 * are always considered resident (mapped devices).
    200 		 */
    201 
    202 		if (UVM_ET_ISOBJ(entry)) {
    203 			KASSERT(!UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj));
    204 			if (UVM_OBJ_IS_DEVICE(entry->object.uvm_obj)) {
    205 				for (/* nothing */; start < lim;
    206 				     start += PAGE_SIZE, vec++)
    207 					subyte(vec, 1);
    208 				continue;
    209 			}
    210 		}
    211 
    212 		amap = entry->aref.ar_amap;	/* upper layer */
    213 		uobj = entry->object.uvm_obj;	/* lower layer */
    214 
    215 		if (amap != NULL)
    216 			amap_lock(amap);
    217 		if (uobj != NULL)
    218 			mutex_enter(uobj->vmobjlock);
    219 
    220 		for (/* nothing */; start < lim; start += PAGE_SIZE, vec++) {
    221 			pgi = 0;
    222 			if (amap != NULL) {
    223 				/* Check the upper layer first. */
    224 				anon = amap_lookup(&entry->aref,
    225 				    start - entry->start);
    226 				/* Don't need to lock anon here. */
    227 				if (anon != NULL && anon->an_page != NULL) {
    228 
    229 					/*
    230 					 * Anon has the page for this entry
    231 					 * offset.
    232 					 */
    233 
    234 					pgi = 1;
    235 				}
    236 			}
    237 			if (uobj != NULL && pgi == 0) {
    238 				/* Check the lower layer. */
    239 				pg = uvm_pagelookup(uobj,
    240 				    entry->offset + (start - entry->start));
    241 				if (pg != NULL) {
    242 
    243 					/*
    244 					 * Object has the page for this entry
    245 					 * offset.
    246 					 */
    247 
    248 					pgi = 1;
    249 				}
    250 			}
    251 			(void) subyte(vec, pgi);
    252 		}
    253 		if (uobj != NULL)
    254 			mutex_exit(uobj->vmobjlock);
    255 		if (amap != NULL)
    256 			amap_unlock(amap);
    257 	}
    258 
    259  out:
    260 	vm_map_unlock_read(map);
    261 	uvm_vsunlock(p->p_vmspace, SCARG(uap, vec), npgs);
    262 	return error;
    263 }
    264 
    265 /*
    266  * sys_mmap: mmap system call.
    267  *
    268  * => file offset and address may not be page aligned
    269  *    - if MAP_FIXED, offset and address must have remainder mod PAGE_SIZE
    270  *    - if address isn't page aligned the mapping starts at trunc_page(addr)
    271  *      and the return value is adjusted up by the page offset.
    272  */
    273 
    274 int
    275 sys_mmap(struct lwp *l, const struct sys_mmap_args *uap, register_t *retval)
    276 {
    277 	/* {
    278 		syscallarg(void *) addr;
    279 		syscallarg(size_t) len;
    280 		syscallarg(int) prot;
    281 		syscallarg(int) flags;
    282 		syscallarg(int) fd;
    283 		syscallarg(long) pad;
    284 		syscallarg(off_t) pos;
    285 	} */
    286 	struct proc *p = l->l_proc;
    287 	vaddr_t addr;
    288 	off_t pos;
    289 	vsize_t size, pageoff, newsize;
    290 	vm_prot_t prot, maxprot;
    291 	int flags, fd, advice;
    292 	vaddr_t defaddr;
    293 	struct file *fp = NULL;
    294 	struct uvm_object *uobj;
    295 	int error;
    296 #ifdef PAX_ASLR
    297 	vaddr_t orig_addr;
    298 #endif /* PAX_ASLR */
    299 
    300 	/*
    301 	 * first, extract syscall args from the uap.
    302 	 */
    303 
    304 	addr = (vaddr_t)SCARG(uap, addr);
    305 	size = (vsize_t)SCARG(uap, len);
    306 	prot = SCARG(uap, prot) & VM_PROT_ALL;
    307 	flags = SCARG(uap, flags);
    308 	fd = SCARG(uap, fd);
    309 	pos = SCARG(uap, pos);
    310 
    311 #ifdef PAX_ASLR
    312 	orig_addr = addr;
    313 #endif /* PAX_ASLR */
    314 
    315 	if ((flags & (MAP_SHARED|MAP_PRIVATE)) == (MAP_SHARED|MAP_PRIVATE))
    316 		return EINVAL;
    317 
    318 	/*
    319 	 * align file position and save offset.  adjust size.
    320 	 */
    321 
    322 	pageoff = (pos & PAGE_MASK);
    323 	pos    -= pageoff;
    324 	newsize = size + pageoff;		/* add offset */
    325 	newsize = (vsize_t)round_page(newsize);	/* round up */
    326 
    327 	if (newsize < size)
    328 		return ENOMEM;
    329 	size = newsize;
    330 
    331 	/*
    332 	 * now check (MAP_FIXED) or get (!MAP_FIXED) the "addr"
    333 	 */
    334 	if (flags & MAP_FIXED) {
    335 		/* ensure address and file offset are aligned properly */
    336 		addr -= pageoff;
    337 		if (addr & PAGE_MASK)
    338 			return EINVAL;
    339 
    340 		error = range_test(&p->p_vmspace->vm_map, addr, size, true);
    341 		if (error) {
    342 			return error;
    343 		}
    344 	} else if (addr == 0 || !(flags & MAP_TRYFIXED)) {
    345 		/*
    346 		 * not fixed: make sure we skip over the largest
    347 		 * possible heap for non-topdown mapping arrangements.
    348 		 * we will refine our guess later (e.g. to account for
    349 		 * VAC, etc)
    350 		 */
    351 
    352 		defaddr = p->p_emul->e_vm_default_addr(p,
    353 		    (vaddr_t)p->p_vmspace->vm_daddr, size,
    354 		    p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN);
    355 
    356 		if (addr == 0 || !(p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN))
    357 			addr = MAX(addr, defaddr);
    358 		else
    359 			addr = MIN(addr, defaddr);
    360 	}
    361 
    362 	/*
    363 	 * check for file mappings (i.e. not anonymous) and verify file.
    364 	 */
    365 
    366 	advice = UVM_ADV_NORMAL;
    367 	if ((flags & MAP_ANON) == 0) {
    368 		if ((fp = fd_getfile(fd)) == NULL)
    369 			return EBADF;
    370 
    371 		if (fp->f_ops->fo_mmap == NULL) {
    372 			error = ENODEV;
    373 			goto out;
    374 		}
    375 		error = (*fp->f_ops->fo_mmap)(fp, &pos, size, prot, &flags,
    376 		    &advice, &uobj, &maxprot);
    377 		if (error) {
    378 			goto out;
    379 		}
    380 		if (uobj == NULL) {
    381 			flags |= MAP_ANON;
    382 			fd_putfile(fd);
    383 			fp = NULL;
    384 			goto is_anon;
    385 		}
    386 	} else {		/* MAP_ANON case */
    387 		/*
    388 		 * XXX What do we do about (MAP_SHARED|MAP_PRIVATE) == 0?
    389 		 */
    390 		if (fd != -1)
    391 			return EINVAL;
    392 
    393  is_anon:		/* label for SunOS style /dev/zero */
    394 		uobj = NULL;
    395 		maxprot = VM_PROT_ALL;
    396 		pos = 0;
    397 	}
    398 
    399 	PAX_MPROTECT_ADJUST(l, &prot, &maxprot);
    400 
    401 	pax_aslr_mmap(l, &addr, orig_addr, flags);
    402 
    403 	/*
    404 	 * now let kernel internal function uvm_mmap do the work.
    405 	 */
    406 
    407 	error = uvm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
    408 	    flags, advice, uobj, pos, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
    409 
    410 	/* remember to add offset */
    411 	*retval = (register_t)(addr + pageoff);
    412 
    413  out:
    414 	if (fp != NULL)
    415 		fd_putfile(fd);
    416 
    417 	return error;
    418 }
    419 
    420 /*
    421  * sys___msync13: the msync system call (a front-end for flush)
    422  */
    423 
    424 int
    425 sys___msync13(struct lwp *l, const struct sys___msync13_args *uap,
    426     register_t *retval)
    427 {
    428 	/* {
    429 		syscallarg(void *) addr;
    430 		syscallarg(size_t) len;
    431 		syscallarg(int) flags;
    432 	} */
    433 	struct proc *p = l->l_proc;
    434 	vaddr_t addr;
    435 	vsize_t size, pageoff;
    436 	struct vm_map *map;
    437 	int error, flags, uvmflags;
    438 	bool rv;
    439 
    440 	/*
    441 	 * extract syscall args from the uap
    442 	 */
    443 
    444 	addr = (vaddr_t)SCARG(uap, addr);
    445 	size = (vsize_t)SCARG(uap, len);
    446 	flags = SCARG(uap, flags);
    447 
    448 	/* sanity check flags */
    449 	if ((flags & ~(MS_ASYNC | MS_SYNC | MS_INVALIDATE)) != 0 ||
    450 	    (flags & (MS_ASYNC | MS_SYNC | MS_INVALIDATE)) == 0 ||
    451 	    (flags & (MS_ASYNC | MS_SYNC)) == (MS_ASYNC | MS_SYNC))
    452 		return EINVAL;
    453 	if ((flags & (MS_ASYNC | MS_SYNC)) == 0)
    454 		flags |= MS_SYNC;
    455 
    456 	/*
    457 	 * align the address to a page boundary and adjust the size accordingly.
    458 	 */
    459 
    460 	pageoff = (addr & PAGE_MASK);
    461 	addr -= pageoff;
    462 	size += pageoff;
    463 	size = (vsize_t)round_page(size);
    464 
    465 
    466 	/*
    467 	 * get map
    468 	 */
    469 	map = &p->p_vmspace->vm_map;
    470 
    471 	error = range_test(map, addr, size, false);
    472 	if (error)
    473 		return ENOMEM;
    474 
    475 	/*
    476 	 * XXXCDC: do we really need this semantic?
    477 	 *
    478 	 * XXX Gak!  If size is zero we are supposed to sync "all modified
    479 	 * pages with the region containing addr".  Unfortunately, we
    480 	 * don't really keep track of individual mmaps so we approximate
    481 	 * by flushing the range of the map entry containing addr.
    482 	 * This can be incorrect if the region splits or is coalesced
    483 	 * with a neighbor.
    484 	 */
    485 
    486 	if (size == 0) {
    487 		struct vm_map_entry *entry;
    488 
    489 		vm_map_lock_read(map);
    490 		rv = uvm_map_lookup_entry(map, addr, &entry);
    491 		if (rv == true) {
    492 			addr = entry->start;
    493 			size = entry->end - entry->start;
    494 		}
    495 		vm_map_unlock_read(map);
    496 		if (rv == false)
    497 			return EINVAL;
    498 	}
    499 
    500 	/*
    501 	 * translate MS_ flags into PGO_ flags
    502 	 */
    503 
    504 	uvmflags = PGO_CLEANIT;
    505 	if (flags & MS_INVALIDATE)
    506 		uvmflags |= PGO_FREE;
    507 	if (flags & MS_SYNC)
    508 		uvmflags |= PGO_SYNCIO;
    509 
    510 	error = uvm_map_clean(map, addr, addr+size, uvmflags);
    511 	return error;
    512 }
    513 
    514 /*
    515  * sys_munmap: unmap a users memory
    516  */
    517 
    518 int
    519 sys_munmap(struct lwp *l, const struct sys_munmap_args *uap, register_t *retval)
    520 {
    521 	/* {
    522 		syscallarg(void *) addr;
    523 		syscallarg(size_t) len;
    524 	} */
    525 	struct proc *p = l->l_proc;
    526 	vaddr_t addr;
    527 	vsize_t size, pageoff;
    528 	struct vm_map *map;
    529 	struct vm_map_entry *dead_entries;
    530 	int error;
    531 
    532 	/*
    533 	 * get syscall args.
    534 	 */
    535 
    536 	addr = (vaddr_t)SCARG(uap, addr);
    537 	size = (vsize_t)SCARG(uap, len);
    538 
    539 	/*
    540 	 * align the address to a page boundary and adjust the size accordingly.
    541 	 */
    542 
    543 	pageoff = (addr & PAGE_MASK);
    544 	addr -= pageoff;
    545 	size += pageoff;
    546 	size = (vsize_t)round_page(size);
    547 
    548 	if (size == 0)
    549 		return 0;
    550 
    551 	map = &p->p_vmspace->vm_map;
    552 
    553 	error = range_test(map, addr, size, false);
    554 	if (error)
    555 		return EINVAL;
    556 
    557 	vm_map_lock(map);
    558 #if 0
    559 	/*
    560 	 * interesting system call semantic: make sure entire range is
    561 	 * allocated before allowing an unmap.
    562 	 */
    563 	if (!uvm_map_checkprot(map, addr, addr + size, VM_PROT_NONE)) {
    564 		vm_map_unlock(map);
    565 		return EINVAL;
    566 	}
    567 #endif
    568 	uvm_unmap_remove(map, addr, addr + size, &dead_entries, 0);
    569 	vm_map_unlock(map);
    570 	if (dead_entries != NULL)
    571 		uvm_unmap_detach(dead_entries, 0);
    572 	return 0;
    573 }
    574 
    575 /*
    576  * sys_mprotect: the mprotect system call
    577  */
    578 
    579 int
    580 sys_mprotect(struct lwp *l, const struct sys_mprotect_args *uap,
    581     register_t *retval)
    582 {
    583 	/* {
    584 		syscallarg(void *) addr;
    585 		syscallarg(size_t) len;
    586 		syscallarg(int) prot;
    587 	} */
    588 	struct proc *p = l->l_proc;
    589 	vaddr_t addr;
    590 	vsize_t size, pageoff;
    591 	vm_prot_t prot;
    592 	int error;
    593 
    594 	/*
    595 	 * extract syscall args from uap
    596 	 */
    597 
    598 	addr = (vaddr_t)SCARG(uap, addr);
    599 	size = (vsize_t)SCARG(uap, len);
    600 	prot = SCARG(uap, prot) & VM_PROT_ALL;
    601 
    602 	/*
    603 	 * align the address to a page boundary and adjust the size accordingly.
    604 	 */
    605 
    606 	pageoff = (addr & PAGE_MASK);
    607 	addr -= pageoff;
    608 	size += pageoff;
    609 	size = round_page(size);
    610 
    611 	error = range_test(&p->p_vmspace->vm_map, addr, size, false);
    612 	if (error)
    613 		return EINVAL;
    614 
    615 	error = uvm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot,
    616 				false);
    617 	return error;
    618 }
    619 
    620 /*
    621  * sys_minherit: the minherit system call
    622  */
    623 
    624 int
    625 sys_minherit(struct lwp *l, const struct sys_minherit_args *uap,
    626    register_t *retval)
    627 {
    628 	/* {
    629 		syscallarg(void *) addr;
    630 		syscallarg(int) len;
    631 		syscallarg(int) inherit;
    632 	} */
    633 	struct proc *p = l->l_proc;
    634 	vaddr_t addr;
    635 	vsize_t size, pageoff;
    636 	vm_inherit_t inherit;
    637 	int error;
    638 
    639 	addr = (vaddr_t)SCARG(uap, addr);
    640 	size = (vsize_t)SCARG(uap, len);
    641 	inherit = SCARG(uap, inherit);
    642 
    643 	/*
    644 	 * align the address to a page boundary and adjust the size accordingly.
    645 	 */
    646 
    647 	pageoff = (addr & PAGE_MASK);
    648 	addr -= pageoff;
    649 	size += pageoff;
    650 	size = (vsize_t)round_page(size);
    651 
    652 	error = range_test(&p->p_vmspace->vm_map, addr, size, false);
    653 	if (error)
    654 		return EINVAL;
    655 
    656 	error = uvm_map_inherit(&p->p_vmspace->vm_map, addr, addr + size,
    657 	    inherit);
    658 	return error;
    659 }
    660 
    661 /*
    662  * sys_madvise: give advice about memory usage.
    663  */
    664 
    665 /* ARGSUSED */
    666 int
    667 sys_madvise(struct lwp *l, const struct sys_madvise_args *uap,
    668    register_t *retval)
    669 {
    670 	/* {
    671 		syscallarg(void *) addr;
    672 		syscallarg(size_t) len;
    673 		syscallarg(int) behav;
    674 	} */
    675 	struct proc *p = l->l_proc;
    676 	vaddr_t addr;
    677 	vsize_t size, pageoff;
    678 	int advice, error;
    679 
    680 	addr = (vaddr_t)SCARG(uap, addr);
    681 	size = (vsize_t)SCARG(uap, len);
    682 	advice = SCARG(uap, behav);
    683 
    684 	/*
    685 	 * align the address to a page boundary, and adjust the size accordingly
    686 	 */
    687 
    688 	pageoff = (addr & PAGE_MASK);
    689 	addr -= pageoff;
    690 	size += pageoff;
    691 	size = (vsize_t)round_page(size);
    692 
    693 	error = range_test(&p->p_vmspace->vm_map, addr, size, false);
    694 	if (error)
    695 		return EINVAL;
    696 
    697 	switch (advice) {
    698 	case MADV_NORMAL:
    699 	case MADV_RANDOM:
    700 	case MADV_SEQUENTIAL:
    701 		error = uvm_map_advice(&p->p_vmspace->vm_map, addr, addr + size,
    702 		    advice);
    703 		break;
    704 
    705 	case MADV_WILLNEED:
    706 
    707 		/*
    708 		 * Activate all these pages, pre-faulting them in if
    709 		 * necessary.
    710 		 */
    711 		error = uvm_map_willneed(&p->p_vmspace->vm_map,
    712 		    addr, addr + size);
    713 		break;
    714 
    715 	case MADV_DONTNEED:
    716 
    717 		/*
    718 		 * Deactivate all these pages.  We don't need them
    719 		 * any more.  We don't, however, toss the data in
    720 		 * the pages.
    721 		 */
    722 
    723 		error = uvm_map_clean(&p->p_vmspace->vm_map, addr, addr + size,
    724 		    PGO_DEACTIVATE);
    725 		break;
    726 
    727 	case MADV_FREE:
    728 
    729 		/*
    730 		 * These pages contain no valid data, and may be
    731 		 * garbage-collected.  Toss all resources, including
    732 		 * any swap space in use.
    733 		 */
    734 
    735 		error = uvm_map_clean(&p->p_vmspace->vm_map, addr, addr + size,
    736 		    PGO_FREE);
    737 		break;
    738 
    739 	case MADV_SPACEAVAIL:
    740 
    741 		/*
    742 		 * XXXMRG What is this?  I think it's:
    743 		 *
    744 		 *	Ensure that we have allocated backing-store
    745 		 *	for these pages.
    746 		 *
    747 		 * This is going to require changes to the page daemon,
    748 		 * as it will free swap space allocated to pages in core.
    749 		 * There's also what to do for device/file/anonymous memory.
    750 		 */
    751 
    752 		return EINVAL;
    753 
    754 	default:
    755 		return EINVAL;
    756 	}
    757 
    758 	return error;
    759 }
    760 
    761 /*
    762  * sys_mlock: memory lock
    763  */
    764 
    765 int
    766 sys_mlock(struct lwp *l, const struct sys_mlock_args *uap, register_t *retval)
    767 {
    768 	/* {
    769 		syscallarg(const void *) addr;
    770 		syscallarg(size_t) len;
    771 	} */
    772 	struct proc *p = l->l_proc;
    773 	vaddr_t addr;
    774 	vsize_t size, pageoff;
    775 	int error;
    776 
    777 	/*
    778 	 * extract syscall args from uap
    779 	 */
    780 
    781 	addr = (vaddr_t)SCARG(uap, addr);
    782 	size = (vsize_t)SCARG(uap, len);
    783 
    784 	/*
    785 	 * align the address to a page boundary and adjust the size accordingly
    786 	 */
    787 
    788 	pageoff = (addr & PAGE_MASK);
    789 	addr -= pageoff;
    790 	size += pageoff;
    791 	size = (vsize_t)round_page(size);
    792 
    793 	error = range_test(&p->p_vmspace->vm_map, addr, size, false);
    794 	if (error)
    795 		return ENOMEM;
    796 
    797 	if (atop(size) + uvmexp.wired > uvmexp.wiredmax)
    798 		return EAGAIN;
    799 
    800 	if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
    801 	    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
    802 		return EAGAIN;
    803 
    804 	error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, false,
    805 	    0);
    806 	if (error == EFAULT)
    807 		error = ENOMEM;
    808 	return error;
    809 }
    810 
    811 /*
    812  * sys_munlock: unlock wired pages
    813  */
    814 
    815 int
    816 sys_munlock(struct lwp *l, const struct sys_munlock_args *uap,
    817     register_t *retval)
    818 {
    819 	/* {
    820 		syscallarg(const void *) addr;
    821 		syscallarg(size_t) len;
    822 	} */
    823 	struct proc *p = l->l_proc;
    824 	vaddr_t addr;
    825 	vsize_t size, pageoff;
    826 	int error;
    827 
    828 	/*
    829 	 * extract syscall args from uap
    830 	 */
    831 
    832 	addr = (vaddr_t)SCARG(uap, addr);
    833 	size = (vsize_t)SCARG(uap, len);
    834 
    835 	/*
    836 	 * align the address to a page boundary, and adjust the size accordingly
    837 	 */
    838 
    839 	pageoff = (addr & PAGE_MASK);
    840 	addr -= pageoff;
    841 	size += pageoff;
    842 	size = (vsize_t)round_page(size);
    843 
    844 	error = range_test(&p->p_vmspace->vm_map, addr, size, false);
    845 	if (error)
    846 		return ENOMEM;
    847 
    848 	error = uvm_map_pageable(&p->p_vmspace->vm_map, addr, addr+size, true,
    849 	    0);
    850 	if (error)
    851 		return ENOMEM;
    852 
    853 	return 0;
    854 }
    855 
    856 /*
    857  * sys_mlockall: lock all pages mapped into an address space.
    858  */
    859 
    860 int
    861 sys_mlockall(struct lwp *l, const struct sys_mlockall_args *uap,
    862     register_t *retval)
    863 {
    864 	/* {
    865 		syscallarg(int) flags;
    866 	} */
    867 	struct proc *p = l->l_proc;
    868 	int error, flags;
    869 
    870 	flags = SCARG(uap, flags);
    871 
    872 	if (flags == 0 || (flags & ~(MCL_CURRENT|MCL_FUTURE)) != 0)
    873 		return EINVAL;
    874 
    875 	error = uvm_map_pageable_all(&p->p_vmspace->vm_map, flags,
    876 	    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
    877 	return error;
    878 }
    879 
    880 /*
    881  * sys_munlockall: unlock all pages mapped into an address space.
    882  */
    883 
    884 int
    885 sys_munlockall(struct lwp *l, const void *v, register_t *retval)
    886 {
    887 	struct proc *p = l->l_proc;
    888 
    889 	(void) uvm_map_pageable_all(&p->p_vmspace->vm_map, 0, 0);
    890 	return 0;
    891 }
    892 
    893 /*
    894  * uvm_mmap: internal version of mmap
    895  *
    896  * - used by sys_mmap and various framebuffers
    897  * - uobj is a struct uvm_object pointer or NULL for MAP_ANON
    898  * - caller must page-align the file offset
    899  */
    900 
    901 int
    902 uvm_mmap(struct vm_map *map, vaddr_t *addr, vsize_t size, vm_prot_t prot,
    903     vm_prot_t maxprot, int flags, int advice, struct uvm_object *uobj,
    904     voff_t foff, vsize_t locklimit)
    905 {
    906 	vaddr_t align = 0;
    907 	int error;
    908 	uvm_flag_t uvmflag = 0;
    909 
    910 	/*
    911 	 * check params
    912 	 */
    913 
    914 	if (size == 0)
    915 		return 0;
    916 	if (foff & PAGE_MASK)
    917 		return EINVAL;
    918 	if ((prot & maxprot) != prot)
    919 		return EINVAL;
    920 
    921 	/*
    922 	 * for non-fixed mappings, round off the suggested address.
    923 	 * for fixed mappings, check alignment and zap old mappings.
    924 	 */
    925 
    926 	if ((flags & MAP_FIXED) == 0) {
    927 		*addr = round_page(*addr);
    928 	} else {
    929 		if (*addr & PAGE_MASK)
    930 			return EINVAL;
    931 		uvmflag |= UVM_FLAG_FIXED;
    932 		(void) uvm_unmap(map, *addr, *addr + size);
    933 	}
    934 
    935 	/*
    936 	 * Try to see if any requested alignment can even be attemped.
    937 	 * Make sure we can express the alignment (asking for a >= 4GB
    938 	 * alignment on an ILP32 architecure make no sense) and the
    939 	 * alignment is at least for a page sized quanitiy.  If the
    940 	 * request was for a fixed mapping, make sure supplied address
    941 	 * adheres to the request alignment.
    942 	 */
    943 	align = (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT;
    944 	if (align) {
    945 		if (align >= sizeof(vaddr_t) * NBBY)
    946 			return EINVAL;
    947 		align = 1L << align;
    948 		if (align < PAGE_SIZE)
    949 			return EINVAL;
    950 		if (align >= vm_map_max(map))
    951 			return ENOMEM;
    952 		if (flags & MAP_FIXED) {
    953 			if ((*addr & (align-1)) != 0)
    954 				return EINVAL;
    955 			align = 0;
    956 		}
    957 	}
    958 
    959 	/*
    960 	 * check resource limits
    961 	 */
    962 
    963 	if (!VM_MAP_IS_KERNEL(map) &&
    964 	    (((rlim_t)curproc->p_vmspace->vm_map.size + (rlim_t)size) >
    965 	    curproc->p_rlimit[RLIMIT_AS].rlim_cur))
    966 		return ENOMEM;
    967 
    968 	/*
    969 	 * handle anon vs. non-anon mappings.   for non-anon mappings attach
    970 	 * to underlying vm object.
    971 	 */
    972 
    973 	if (flags & MAP_ANON) {
    974 		KASSERT(uobj == NULL);
    975 		foff = UVM_UNKNOWN_OFFSET;
    976 		if ((flags & MAP_SHARED) == 0)
    977 			/* XXX: defer amap create */
    978 			uvmflag |= UVM_FLAG_COPYONW;
    979 		else
    980 			/* shared: create amap now */
    981 			uvmflag |= UVM_FLAG_OVERLAY;
    982 
    983 	} else {
    984 		KASSERT(uobj != NULL);
    985 		if ((flags & MAP_SHARED) == 0) {
    986 			uvmflag |= UVM_FLAG_COPYONW;
    987 		}
    988 	}
    989 
    990 	uvmflag = UVM_MAPFLAG(prot, maxprot,
    991 	    (flags & MAP_SHARED) ? UVM_INH_SHARE : UVM_INH_COPY, advice,
    992 	    uvmflag);
    993 	error = uvm_map(map, addr, size, uobj, foff, align, uvmflag);
    994 	if (error) {
    995 		if (uobj)
    996 			uobj->pgops->pgo_detach(uobj);
    997 		return error;
    998 	}
    999 
   1000 	/*
   1001 	 * POSIX 1003.1b -- if our address space was configured
   1002 	 * to lock all future mappings, wire the one we just made.
   1003 	 *
   1004 	 * Also handle the MAP_WIRED flag here.
   1005 	 */
   1006 
   1007 	if (prot == VM_PROT_NONE) {
   1008 
   1009 		/*
   1010 		 * No more work to do in this case.
   1011 		 */
   1012 
   1013 		return 0;
   1014 	}
   1015 	if ((flags & MAP_WIRED) != 0 || (map->flags & VM_MAP_WIREFUTURE) != 0) {
   1016 		vm_map_lock(map);
   1017 		if (atop(size) + uvmexp.wired > uvmexp.wiredmax ||
   1018 		    (locklimit != 0 &&
   1019 		     size + ptoa(pmap_wired_count(vm_map_pmap(map))) >
   1020 		     locklimit)) {
   1021 			vm_map_unlock(map);
   1022 			uvm_unmap(map, *addr, *addr + size);
   1023 			return ENOMEM;
   1024 		}
   1025 
   1026 		/*
   1027 		 * uvm_map_pageable() always returns the map unlocked.
   1028 		 */
   1029 
   1030 		error = uvm_map_pageable(map, *addr, *addr + size,
   1031 		    false, UVM_LK_ENTER);
   1032 		if (error) {
   1033 			uvm_unmap(map, *addr, *addr + size);
   1034 			return error;
   1035 		}
   1036 		return 0;
   1037 	}
   1038 	return 0;
   1039 }
   1040 
   1041 vaddr_t
   1042 uvm_default_mapaddr(struct proc *p, vaddr_t base, vsize_t sz, int topdown)
   1043 {
   1044 
   1045 	if (topdown)
   1046 		return VM_DEFAULT_ADDRESS_TOPDOWN(base, sz);
   1047 	else
   1048 		return VM_DEFAULT_ADDRESS_BOTTOMUP(base, sz);
   1049 }
   1050 
   1051 int
   1052 uvm_mmap_dev(struct proc *p, void **addrp, size_t len, dev_t dev,
   1053     off_t off)
   1054 {
   1055 	struct uvm_object *uobj;
   1056 	int error, flags, prot;
   1057 
   1058 	flags = MAP_SHARED;
   1059 	prot = VM_PROT_READ | VM_PROT_WRITE;
   1060 	if (*addrp)
   1061 		flags |= MAP_FIXED;
   1062 	else
   1063 		*addrp = (void *)p->p_emul->e_vm_default_addr(p,
   1064 		    (vaddr_t)p->p_vmspace->vm_daddr, len,
   1065 		    p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN);
   1066 
   1067 	uobj = udv_attach(dev, prot, off, len);
   1068 	if (uobj == NULL)
   1069 		return EINVAL;
   1070 
   1071 	error = uvm_mmap(&p->p_vmspace->vm_map, (vaddr_t *)addrp,
   1072 	    (vsize_t)len, prot, prot, flags, UVM_ADV_RANDOM, uobj, off,
   1073 	    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
   1074 	return error;
   1075 }
   1076 
   1077 int
   1078 uvm_mmap_anon(struct proc *p, void **addrp, size_t len)
   1079 {
   1080 	int error, flags, prot;
   1081 
   1082 	flags = MAP_PRIVATE | MAP_ANON;
   1083 	prot = VM_PROT_READ | VM_PROT_WRITE;
   1084 	if (*addrp)
   1085 		flags |= MAP_FIXED;
   1086 	else
   1087 		*addrp = (void *)p->p_emul->e_vm_default_addr(p,
   1088 		    (vaddr_t)p->p_vmspace->vm_daddr, len,
   1089 		    p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN);
   1090 
   1091 	error = uvm_mmap(&p->p_vmspace->vm_map, (vaddr_t *)addrp,
   1092 	    (vsize_t)len, prot, prot, flags, UVM_ADV_NORMAL, NULL, 0,
   1093 	    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
   1094 	return error;
   1095 }
   1096