xref: /dragonfly/sys/vm/vm_mmap.c (revision 73610d44)
1 /*
2  * (MPSAFE)
3  *
4  * Copyright (c) 1988 University of Utah.
5  * Copyright (c) 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * the Systems Programming Group of the University of Utah Computer
10  * Science Department.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
37  *
38  *	@(#)vm_mmap.c	8.4 (Berkeley) 1/12/94
39  * $FreeBSD: src/sys/vm/vm_mmap.c,v 1.108.2.6 2002/07/02 20:06:19 dillon Exp $
40  */
41 
42 /*
43  * Mapped file (mmap) interface to VM
44  */
45 
46 #include <sys/param.h>
47 #include <sys/kernel.h>
48 #include <sys/systm.h>
49 #include <sys/sysproto.h>
50 #include <sys/filedesc.h>
51 #include <sys/kern_syscall.h>
52 #include <sys/proc.h>
53 #include <sys/priv.h>
54 #include <sys/resource.h>
55 #include <sys/resourcevar.h>
56 #include <sys/vnode.h>
57 #include <sys/fcntl.h>
58 #include <sys/file.h>
59 #include <sys/mman.h>
60 #include <sys/conf.h>
61 #include <sys/stat.h>
62 #include <sys/vmmeter.h>
63 #include <sys/sysctl.h>
64 
65 #include <vm/vm.h>
66 #include <vm/vm_param.h>
67 #include <sys/lock.h>
68 #include <vm/pmap.h>
69 #include <vm/vm_map.h>
70 #include <vm/vm_object.h>
71 #include <vm/vm_page.h>
72 #include <vm/vm_pager.h>
73 #include <vm/vm_pageout.h>
74 #include <vm/vm_extern.h>
75 #include <vm/vm_kern.h>
76 
77 #include <sys/file2.h>
78 #include <sys/thread.h>
79 #include <sys/thread2.h>
80 #include <vm/vm_page2.h>
81 
82 static int max_proc_mmap;
83 SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, "");
84 int vkernel_enable;
85 SYSCTL_INT(_vm, OID_AUTO, vkernel_enable, CTLFLAG_RW, &vkernel_enable, 0, "");
86 
87 /*
88  * Set the maximum number of vm_map_entry structures per process.  Roughly
89  * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100
90  * of our KVM malloc space still results in generous limits.  We want a
91  * default that is good enough to prevent the kernel running out of resources
92  * if attacked from compromised user account but generous enough such that
93  * multi-threaded processes are not unduly inconvenienced.
94  */
95 
96 static void vmmapentry_rsrc_init (void *);
97 SYSINIT(vmmersrc, SI_BOOT1_POST, SI_ORDER_ANY, vmmapentry_rsrc_init, NULL);
98 
99 static void
100 vmmapentry_rsrc_init(void *dummy)
101 {
102     max_proc_mmap = KvaSize / sizeof(struct vm_map_entry);
103     max_proc_mmap /= 100;
104 }
105 
106 /*
107  * MPSAFE
108  */
109 int
110 sys_sbrk(struct sbrk_args *uap)
111 {
112 	/* Not yet implemented */
113 	return (EOPNOTSUPP);
114 }
115 
116 /*
117  * sstk_args(int incr)
118  *
119  * MPSAFE
120  */
121 int
122 sys_sstk(struct sstk_args *uap)
123 {
124 	/* Not yet implemented */
125 	return (EOPNOTSUPP);
126 }
127 
128 /*
129  * mmap_args(void *addr, size_t len, int prot, int flags, int fd,
130  *		long pad, off_t pos)
131  *
132  * Memory Map (mmap) system call.  Note that the file offset
133  * and address are allowed to be NOT page aligned, though if
134  * the MAP_FIXED flag it set, both must have the same remainder
135  * modulo the PAGE_SIZE (POSIX 1003.1b).  If the address is not
136  * page-aligned, the actual mapping starts at trunc_page(addr)
137  * and the return value is adjusted up by the page offset.
138  *
139  * Generally speaking, only character devices which are themselves
140  * memory-based, such as a video framebuffer, can be mmap'd.  Otherwise
141  * there would be no cache coherency between a descriptor and a VM mapping
142  * both to the same character device.
143  *
144  * Block devices can be mmap'd no matter what they represent.  Cache coherency
145  * is maintained as long as you do not write directly to the underlying
146  * character device.
147  *
148  * No requirements
149  */
150 int
151 kern_mmap(struct vmspace *vms, caddr_t uaddr, size_t ulen,
152 	  int uprot, int uflags, int fd, off_t upos, void **res)
153 {
154 	struct thread *td = curthread;
155  	struct proc *p = td->td_proc;
156 	struct file *fp = NULL;
157 	struct vnode *vp;
158 	vm_offset_t addr;
159 	vm_offset_t tmpaddr;
160 	vm_size_t size, pageoff;
161 	vm_prot_t prot, maxprot;
162 	void *handle;
163 	int flags, error;
164 	off_t pos;
165 	vm_object_t obj;
166 
167 	KKASSERT(p);
168 
169 	addr = (vm_offset_t) uaddr;
170 	size = ulen;
171 	prot = uprot & VM_PROT_ALL;
172 	flags = uflags;
173 	pos = upos;
174 
175 	/*
176 	 * Make sure mapping fits into numeric range etc.
177 	 *
178 	 * NOTE: We support the full unsigned range for size now.
179 	 */
180 	if (((flags & MAP_ANON) && (fd != -1 || pos != 0)))
181 		return (EINVAL);
182 
183 	if (size == 0)
184 		return (EINVAL);
185 
186 	if (flags & MAP_STACK) {
187 		if ((fd != -1) ||
188 		    ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
189 			return (EINVAL);
190 		flags |= MAP_ANON;
191 		pos = 0;
192 	}
193 
194 	/*
195 	 * Virtual page tables cannot be used with MAP_STACK.  Apart from
196 	 * it not making any sense, the aux union is used by both
197 	 * types.
198 	 *
199 	 * Because the virtual page table is stored in the backing object
200 	 * and might be updated by the kernel, the mapping must be R+W.
201 	 */
202 	if (flags & MAP_VPAGETABLE) {
203 		if (vkernel_enable == 0)
204 			return (EOPNOTSUPP);
205 		if (flags & MAP_STACK)
206 			return (EINVAL);
207 		if ((prot & (PROT_READ|PROT_WRITE)) != (PROT_READ|PROT_WRITE))
208 			return (EINVAL);
209 	}
210 
211 	/*
212 	 * Align the file position to a page boundary,
213 	 * and save its page offset component.
214 	 */
215 	pageoff = (pos & PAGE_MASK);
216 	pos -= pageoff;
217 
218 	/* Adjust size for rounding (on both ends). */
219 	size += pageoff;			/* low end... */
220 	size = (vm_size_t) round_page(size);	/* hi end */
221 	if (size < ulen)			/* wrap */
222 		return(EINVAL);
223 
224 	/*
225 	 * Check for illegal addresses.  Watch out for address wrap... Note
226 	 * that VM_*_ADDRESS are not constants due to casts (argh).
227 	 */
228 	if (flags & (MAP_FIXED | MAP_TRYFIXED)) {
229 		/*
230 		 * The specified address must have the same remainder
231 		 * as the file offset taken modulo PAGE_SIZE, so it
232 		 * should be aligned after adjustment by pageoff.
233 		 */
234 		addr -= pageoff;
235 		if (addr & PAGE_MASK)
236 			return (EINVAL);
237 
238 		/*
239 		 * Address range must be all in user VM space and not wrap.
240 		 */
241 		tmpaddr = addr + size;
242 		if (tmpaddr < addr)
243 			return (EINVAL);
244 		if (VM_MAX_USER_ADDRESS > 0 && tmpaddr > VM_MAX_USER_ADDRESS)
245 			return (EINVAL);
246 		if (VM_MIN_USER_ADDRESS > 0 && addr < VM_MIN_USER_ADDRESS)
247 			return (EINVAL);
248 	} else {
249 		/*
250 		 * Get a hint of where to map. It also provides mmap offset
251 		 * randomization if enabled.
252 		 */
253 		addr = vm_map_hint(p, addr, prot);
254 	}
255 
256 	if (flags & MAP_ANON) {
257 		/*
258 		 * Mapping blank space is trivial.
259 		 */
260 		handle = NULL;
261 		maxprot = VM_PROT_ALL;
262 	} else {
263 		/*
264 		 * Mapping file, get fp for validation. Obtain vnode and make
265 		 * sure it is of appropriate type.
266 		 */
267 		fp = holdfp(p->p_fd, fd, -1);
268 		if (fp == NULL)
269 			return (EBADF);
270 		if (fp->f_type != DTYPE_VNODE) {
271 			error = EINVAL;
272 			goto done;
273 		}
274 		/*
275 		 * POSIX shared-memory objects are defined to have
276 		 * kernel persistence, and are not defined to support
277 		 * read(2)/write(2) -- or even open(2).  Thus, we can
278 		 * use MAP_ASYNC to trade on-disk coherence for speed.
279 		 * The shm_open(3) library routine turns on the FPOSIXSHM
280 		 * flag to request this behavior.
281 		 */
282 		if (fp->f_flag & FPOSIXSHM)
283 			flags |= MAP_NOSYNC;
284 		vp = (struct vnode *) fp->f_data;
285 
286 		/*
287 		 * Validate the vnode for the operation.
288 		 */
289 		switch(vp->v_type) {
290 		case VREG:
291 			/*
292 			 * Get the proper underlying object
293 			 */
294 			if ((obj = vp->v_object) == NULL) {
295 				error = EINVAL;
296 				goto done;
297 			}
298 			KKASSERT((struct vnode *)obj->handle == vp);
299 			break;
300 		case VCHR:
301 			/*
302 			 * Make sure a device has not been revoked.
303 			 * Mappability is handled by the device layer.
304 			 */
305 			if (vp->v_rdev == NULL) {
306 				error = EBADF;
307 				goto done;
308 			}
309 			break;
310 		default:
311 			/*
312 			 * Nothing else is mappable.
313 			 */
314 			error = EINVAL;
315 			goto done;
316 		}
317 
318 		/*
319 		 * XXX hack to handle use of /dev/zero to map anon memory (ala
320 		 * SunOS).
321 		 */
322 		if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
323 			handle = NULL;
324 			maxprot = VM_PROT_ALL;
325 			flags |= MAP_ANON;
326 			pos = 0;
327 		} else {
328 			/*
329 			 * cdevs does not provide private mappings of any kind.
330 			 */
331 			if (vp->v_type == VCHR &&
332 			    (flags & (MAP_PRIVATE|MAP_COPY))) {
333 				error = EINVAL;
334 				goto done;
335 			}
336 			/*
337 			 * Ensure that file and memory protections are
338 			 * compatible.  Note that we only worry about
339 			 * writability if mapping is shared; in this case,
340 			 * current and max prot are dictated by the open file.
341 			 * XXX use the vnode instead?  Problem is: what
342 			 * credentials do we use for determination? What if
343 			 * proc does a setuid?
344 			 */
345 			maxprot = VM_PROT_EXECUTE;	/* ??? */
346 			if (fp->f_flag & FREAD) {
347 				maxprot |= VM_PROT_READ;
348 			} else if (prot & PROT_READ) {
349 				error = EACCES;
350 				goto done;
351 			}
352 			/*
353 			 * If we are sharing potential changes (either via
354 			 * MAP_SHARED or via the implicit sharing of character
355 			 * device mappings), and we are trying to get write
356 			 * permission although we opened it without asking
357 			 * for it, bail out.  Check for superuser, only if
358 			 * we're at securelevel < 1, to allow the XIG X server
359 			 * to continue to work.
360 			 */
361 			if ((flags & MAP_SHARED) != 0 || vp->v_type == VCHR) {
362 				if ((fp->f_flag & FWRITE) != 0) {
363 					struct vattr va;
364 					if ((error = VOP_GETATTR(vp, &va))) {
365 						goto done;
366 					}
367 					if ((va.va_flags &
368 					    (IMMUTABLE|APPEND)) == 0) {
369 						maxprot |= VM_PROT_WRITE;
370 					} else if (prot & PROT_WRITE) {
371 						error = EPERM;
372 						goto done;
373 					}
374 				} else if ((prot & PROT_WRITE) != 0) {
375 					error = EACCES;
376 					goto done;
377 				}
378 			} else {
379 				maxprot |= VM_PROT_WRITE;
380 			}
381 			handle = (void *)vp;
382 		}
383 	}
384 
385 	lwkt_gettoken(&vms->vm_map.token);
386 
387 	/*
388 	 * Do not allow more then a certain number of vm_map_entry structures
389 	 * per process.  Scale with the number of rforks sharing the map
390 	 * to make the limit reasonable for threads.
391 	 */
392 	if (max_proc_mmap &&
393 	    vms->vm_map.nentries >= max_proc_mmap * vmspace_getrefs(vms)) {
394 		error = ENOMEM;
395 		lwkt_reltoken(&vms->vm_map.token);
396 		goto done;
397 	}
398 
399 	error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
400 			flags, handle, pos);
401 	if (error == 0)
402 		*res = (void *)(addr + pageoff);
403 
404 	lwkt_reltoken(&vms->vm_map.token);
405 done:
406 	if (fp)
407 		fdrop(fp);
408 
409 	return (error);
410 }
411 
412 /*
413  * mmap system call handler
414  *
415  * No requirements.
416  */
417 int
418 sys_mmap(struct mmap_args *uap)
419 {
420 	int error;
421 
422 	error = kern_mmap(curproc->p_vmspace, uap->addr, uap->len,
423 			  uap->prot, uap->flags,
424 			  uap->fd, uap->pos, &uap->sysmsg_resultp);
425 
426 	return (error);
427 }
428 
429 /*
430  * msync system call handler
431  *
432  * msync_args(void *addr, size_t len, int flags)
433  *
434  * No requirements
435  */
436 int
437 sys_msync(struct msync_args *uap)
438 {
439 	struct proc *p = curproc;
440 	vm_offset_t addr;
441 	vm_offset_t tmpaddr;
442 	vm_size_t size, pageoff;
443 	int flags;
444 	vm_map_t map;
445 	int rv;
446 
447 	addr = (vm_offset_t) uap->addr;
448 	size = uap->len;
449 	flags = uap->flags;
450 
451 	pageoff = (addr & PAGE_MASK);
452 	addr -= pageoff;
453 	size += pageoff;
454 	size = (vm_size_t) round_page(size);
455 	if (size < uap->len)		/* wrap */
456 		return(EINVAL);
457 	tmpaddr = addr + size;		/* workaround gcc4 opt */
458 	if (tmpaddr < addr)		/* wrap */
459 		return(EINVAL);
460 
461 	if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
462 		return (EINVAL);
463 
464 	map = &p->p_vmspace->vm_map;
465 
466 	/*
467 	 * map->token serializes extracting the address range for size == 0
468 	 * msyncs with the vm_map_clean call; if the token were not held
469 	 * across the two calls, an intervening munmap/mmap pair, for example,
470 	 * could cause msync to occur on a wrong region.
471 	 */
472 	lwkt_gettoken(&map->token);
473 
474 	/*
475 	 * XXX Gak!  If size is zero we are supposed to sync "all modified
476 	 * pages with the region containing addr".  Unfortunately, we don't
477 	 * really keep track of individual mmaps so we approximate by flushing
478 	 * the range of the map entry containing addr. This can be incorrect
479 	 * if the region splits or is coalesced with a neighbor.
480 	 */
481 	if (size == 0) {
482 		vm_map_entry_t entry;
483 
484 		vm_map_lock_read(map);
485 		rv = vm_map_lookup_entry(map, addr, &entry);
486 		if (rv == FALSE) {
487 			vm_map_unlock_read(map);
488 			rv = KERN_INVALID_ADDRESS;
489 			goto done;
490 		}
491 		addr = entry->start;
492 		size = entry->end - entry->start;
493 		vm_map_unlock_read(map);
494 	}
495 
496 	/*
497 	 * Clean the pages and interpret the return value.
498 	 */
499 	rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0,
500 			  (flags & MS_INVALIDATE) != 0);
501 done:
502 	lwkt_reltoken(&map->token);
503 
504 	switch (rv) {
505 	case KERN_SUCCESS:
506 		break;
507 	case KERN_INVALID_ADDRESS:
508 		return (EINVAL);	/* Sun returns ENOMEM? */
509 	case KERN_FAILURE:
510 		return (EIO);
511 	default:
512 		return (EINVAL);
513 	}
514 
515 	return (0);
516 }
517 
518 /*
519  * munmap system call handler
520  *
521  * munmap_args(void *addr, size_t len)
522  *
523  * No requirements
524  */
525 int
526 sys_munmap(struct munmap_args *uap)
527 {
528 	struct proc *p = curproc;
529 	vm_offset_t addr;
530 	vm_offset_t tmpaddr;
531 	vm_size_t size, pageoff;
532 	vm_map_t map;
533 
534 	addr = (vm_offset_t) uap->addr;
535 	size = uap->len;
536 
537 	pageoff = (addr & PAGE_MASK);
538 	addr -= pageoff;
539 	size += pageoff;
540 	size = (vm_size_t) round_page(size);
541 	if (size < uap->len)		/* wrap */
542 		return(EINVAL);
543 	tmpaddr = addr + size;		/* workaround gcc4 opt */
544 	if (tmpaddr < addr)		/* wrap */
545 		return(EINVAL);
546 
547 	if (size == 0)
548 		return (0);
549 
550 	/*
551 	 * Check for illegal addresses.  Watch out for address wrap... Note
552 	 * that VM_*_ADDRESS are not constants due to casts (argh).
553 	 */
554 	if (VM_MAX_USER_ADDRESS > 0 && tmpaddr > VM_MAX_USER_ADDRESS)
555 		return (EINVAL);
556 	if (VM_MIN_USER_ADDRESS > 0 && addr < VM_MIN_USER_ADDRESS)
557 		return (EINVAL);
558 
559 	map = &p->p_vmspace->vm_map;
560 
561 	/* map->token serializes between the map check and the actual unmap */
562 	lwkt_gettoken(&map->token);
563 
564 	/*
565 	 * Make sure entire range is allocated.
566 	 */
567 	if (!vm_map_check_protection(map, addr, addr + size,
568 				     VM_PROT_NONE, FALSE)) {
569 		lwkt_reltoken(&map->token);
570 		return (EINVAL);
571 	}
572 	/* returns nothing but KERN_SUCCESS anyway */
573 	vm_map_remove(map, addr, addr + size);
574 	lwkt_reltoken(&map->token);
575 	return (0);
576 }
577 
578 /*
579  * mprotect_args(const void *addr, size_t len, int prot)
580  *
581  * No requirements.
582  */
583 int
584 sys_mprotect(struct mprotect_args *uap)
585 {
586 	struct proc *p = curproc;
587 	vm_offset_t addr;
588 	vm_offset_t tmpaddr;
589 	vm_size_t size, pageoff;
590 	vm_prot_t prot;
591 	int error;
592 
593 	addr = (vm_offset_t) uap->addr;
594 	size = uap->len;
595 	prot = uap->prot & VM_PROT_ALL;
596 #if defined(VM_PROT_READ_IS_EXEC)
597 	if (prot & VM_PROT_READ)
598 		prot |= VM_PROT_EXECUTE;
599 #endif
600 
601 	pageoff = (addr & PAGE_MASK);
602 	addr -= pageoff;
603 	size += pageoff;
604 	size = (vm_size_t) round_page(size);
605 	if (size < uap->len)		/* wrap */
606 		return(EINVAL);
607 	tmpaddr = addr + size;		/* workaround gcc4 opt */
608 	if (tmpaddr < addr)		/* wrap */
609 		return(EINVAL);
610 
611 	switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size,
612 			       prot, FALSE)) {
613 	case KERN_SUCCESS:
614 		error = 0;
615 		break;
616 	case KERN_PROTECTION_FAILURE:
617 		error = EACCES;
618 		break;
619 	default:
620 		error = EINVAL;
621 		break;
622 	}
623 	return (error);
624 }
625 
626 /*
627  * minherit system call handler
628  *
629  * minherit_args(void *addr, size_t len, int inherit)
630  *
631  * No requirements.
632  */
633 int
634 sys_minherit(struct minherit_args *uap)
635 {
636 	struct proc *p = curproc;
637 	vm_offset_t addr;
638 	vm_offset_t tmpaddr;
639 	vm_size_t size, pageoff;
640 	vm_inherit_t inherit;
641 	int error;
642 
643 	addr = (vm_offset_t)uap->addr;
644 	size = uap->len;
645 	inherit = uap->inherit;
646 
647 	pageoff = (addr & PAGE_MASK);
648 	addr -= pageoff;
649 	size += pageoff;
650 	size = (vm_size_t) round_page(size);
651 	if (size < uap->len)		/* wrap */
652 		return(EINVAL);
653 	tmpaddr = addr + size;		/* workaround gcc4 opt */
654 	if (tmpaddr < addr)		/* wrap */
655 		return(EINVAL);
656 
657 	switch (vm_map_inherit(&p->p_vmspace->vm_map, addr,
658 			       addr + size, inherit)) {
659 	case KERN_SUCCESS:
660 		error = 0;
661 		break;
662 	case KERN_PROTECTION_FAILURE:
663 		error = EACCES;
664 		break;
665 	default:
666 		error = EINVAL;
667 		break;
668 	}
669 	return (error);
670 }
671 
672 /*
673  * madvise system call handler
674  *
675  * madvise_args(void *addr, size_t len, int behav)
676  *
677  * No requirements.
678  */
679 int
680 sys_madvise(struct madvise_args *uap)
681 {
682 	struct proc *p = curproc;
683 	vm_offset_t start, end;
684 	vm_offset_t tmpaddr = (vm_offset_t)uap->addr + uap->len;
685 	int error;
686 
687 	/*
688 	 * Check for illegal behavior
689 	 */
690 	if (uap->behav < 0 || uap->behav >= MADV_CONTROL_END)
691 		return (EINVAL);
692 	/*
693 	 * Check for illegal addresses.  Watch out for address wrap... Note
694 	 * that VM_*_ADDRESS are not constants due to casts (argh).
695 	 */
696 	if (tmpaddr < (vm_offset_t)uap->addr)
697 		return (EINVAL);
698 	if (VM_MAX_USER_ADDRESS > 0 && tmpaddr > VM_MAX_USER_ADDRESS)
699 		return (EINVAL);
700 	if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS)
701 		return (EINVAL);
702 
703 	/*
704 	 * Since this routine is only advisory, we default to conservative
705 	 * behavior.
706 	 */
707 	start = trunc_page((vm_offset_t)uap->addr);
708 	end = round_page(tmpaddr);
709 
710 	error = vm_map_madvise(&p->p_vmspace->vm_map, start, end,
711 			       uap->behav, 0);
712 	return (error);
713 }
714 
715 /*
716  * mcontrol system call handler
717  *
718  * mcontrol_args(void *addr, size_t len, int behav, off_t value)
719  *
720  * No requirements
721  */
722 int
723 sys_mcontrol(struct mcontrol_args *uap)
724 {
725 	struct proc *p = curproc;
726 	vm_offset_t start, end;
727 	vm_offset_t tmpaddr = (vm_offset_t)uap->addr + uap->len;
728 	int error;
729 
730 	/*
731 	 * Check for illegal behavior
732 	 */
733 	if (uap->behav < 0 || uap->behav > MADV_CONTROL_END)
734 		return (EINVAL);
735 	/*
736 	 * Check for illegal addresses.  Watch out for address wrap... Note
737 	 * that VM_*_ADDRESS are not constants due to casts (argh).
738 	 */
739 	if (tmpaddr < (vm_offset_t) uap->addr)
740 		return (EINVAL);
741 	if (VM_MAX_USER_ADDRESS > 0 && tmpaddr > VM_MAX_USER_ADDRESS)
742 		return (EINVAL);
743 	if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS)
744 		return (EINVAL);
745 
746 	/*
747 	 * Since this routine is only advisory, we default to conservative
748 	 * behavior.
749 	 */
750 	start = trunc_page((vm_offset_t)uap->addr);
751 	end = round_page(tmpaddr);
752 
753 	error = vm_map_madvise(&p->p_vmspace->vm_map, start, end,
754 			       uap->behav, uap->value);
755 	return (error);
756 }
757 
758 
759 /*
760  * mincore system call handler
761  *
762  * mincore_args(const void *addr, size_t len, char *vec)
763  *
764  * No requirements
765  */
766 int
767 sys_mincore(struct mincore_args *uap)
768 {
769 	struct proc *p = curproc;
770 	vm_offset_t addr, first_addr;
771 	vm_offset_t end, cend;
772 	pmap_t pmap;
773 	vm_map_t map;
774 	char *vec;
775 	int error;
776 	int vecindex, lastvecindex;
777 	vm_map_entry_t current;
778 	vm_map_entry_t entry;
779 	int mincoreinfo;
780 	unsigned int timestamp;
781 
782 	/*
783 	 * Make sure that the addresses presented are valid for user
784 	 * mode.
785 	 */
786 	first_addr = addr = trunc_page((vm_offset_t) uap->addr);
787 	end = addr + (vm_size_t)round_page(uap->len);
788 	if (end < addr)
789 		return (EINVAL);
790 	if (VM_MAX_USER_ADDRESS > 0 && end > VM_MAX_USER_ADDRESS)
791 		return (EINVAL);
792 
793 	/*
794 	 * Address of byte vector
795 	 */
796 	vec = uap->vec;
797 
798 	map = &p->p_vmspace->vm_map;
799 	pmap = vmspace_pmap(p->p_vmspace);
800 
801 	lwkt_gettoken(&map->token);
802 	vm_map_lock_read(map);
803 RestartScan:
804 	timestamp = map->timestamp;
805 
806 	if (!vm_map_lookup_entry(map, addr, &entry))
807 		entry = entry->next;
808 
809 	/*
810 	 * Do this on a map entry basis so that if the pages are not
811 	 * in the current processes address space, we can easily look
812 	 * up the pages elsewhere.
813 	 */
814 	lastvecindex = -1;
815 	for(current = entry;
816 		(current != &map->header) && (current->start < end);
817 		current = current->next) {
818 
819 		/*
820 		 * ignore submaps (for now) or null objects
821 		 */
822 		if (current->maptype != VM_MAPTYPE_NORMAL &&
823 		    current->maptype != VM_MAPTYPE_VPAGETABLE) {
824 			continue;
825 		}
826 		if (current->object.vm_object == NULL)
827 			continue;
828 
829 		/*
830 		 * limit this scan to the current map entry and the
831 		 * limits for the mincore call
832 		 */
833 		if (addr < current->start)
834 			addr = current->start;
835 		cend = current->end;
836 		if (cend > end)
837 			cend = end;
838 
839 		/*
840 		 * scan this entry one page at a time
841 		 */
842 		while (addr < cend) {
843 			/*
844 			 * Check pmap first, it is likely faster, also
845 			 * it can provide info as to whether we are the
846 			 * one referencing or modifying the page.
847 			 *
848 			 * If we have to check the VM object, only mess
849 			 * around with normal maps.  Do not mess around
850 			 * with virtual page tables (XXX).
851 			 */
852 			mincoreinfo = pmap_mincore(pmap, addr);
853 			if (mincoreinfo == 0 &&
854 			    current->maptype == VM_MAPTYPE_NORMAL) {
855 				vm_pindex_t pindex;
856 				vm_ooffset_t offset;
857 				vm_page_t m;
858 
859 				/*
860 				 * calculate the page index into the object
861 				 */
862 				offset = current->offset + (addr - current->start);
863 				pindex = OFF_TO_IDX(offset);
864 
865 				/*
866 				 * if the page is resident, then gather
867 				 * information about it.  spl protection is
868 				 * required to maintain the object
869 				 * association.  And XXX what if the page is
870 				 * busy?  What's the deal with that?
871 				 *
872 				 * XXX vm_token - legacy for pmap_ts_referenced
873 				 *     in i386 and vkernel pmap code.
874 				 */
875 				lwkt_gettoken(&vm_token);
876 				vm_object_hold(current->object.vm_object);
877 				m = vm_page_lookup(current->object.vm_object,
878 						    pindex);
879 				if (m && m->valid) {
880 					mincoreinfo = MINCORE_INCORE;
881 					if (m->dirty ||
882 						pmap_is_modified(m))
883 						mincoreinfo |= MINCORE_MODIFIED_OTHER;
884 					if ((m->flags & PG_REFERENCED) ||
885 						pmap_ts_referenced(m)) {
886 						vm_page_flag_set(m, PG_REFERENCED);
887 						mincoreinfo |= MINCORE_REFERENCED_OTHER;
888 					}
889 				}
890 				vm_object_drop(current->object.vm_object);
891 				lwkt_reltoken(&vm_token);
892 			}
893 
894 			/*
895 			 * subyte may page fault.  In case it needs to modify
896 			 * the map, we release the lock.
897 			 */
898 			vm_map_unlock_read(map);
899 
900 			/*
901 			 * calculate index into user supplied byte vector
902 			 */
903 			vecindex = OFF_TO_IDX(addr - first_addr);
904 
905 			/*
906 			 * If we have skipped map entries, we need to make sure that
907 			 * the byte vector is zeroed for those skipped entries.
908 			 */
909 			while((lastvecindex + 1) < vecindex) {
910 				error = subyte( vec + lastvecindex, 0);
911 				if (error) {
912 					error = EFAULT;
913 					goto done;
914 				}
915 				++lastvecindex;
916 			}
917 
918 			/*
919 			 * Pass the page information to the user
920 			 */
921 			error = subyte( vec + vecindex, mincoreinfo);
922 			if (error) {
923 				error = EFAULT;
924 				goto done;
925 			}
926 
927 			/*
928 			 * If the map has changed, due to the subyte, the previous
929 			 * output may be invalid.
930 			 */
931 			vm_map_lock_read(map);
932 			if (timestamp != map->timestamp)
933 				goto RestartScan;
934 
935 			lastvecindex = vecindex;
936 			addr += PAGE_SIZE;
937 		}
938 	}
939 
940 	/*
941 	 * subyte may page fault.  In case it needs to modify
942 	 * the map, we release the lock.
943 	 */
944 	vm_map_unlock_read(map);
945 
946 	/*
947 	 * Zero the last entries in the byte vector.
948 	 */
949 	vecindex = OFF_TO_IDX(end - first_addr);
950 	while((lastvecindex + 1) < vecindex) {
951 		error = subyte( vec + lastvecindex, 0);
952 		if (error) {
953 			error = EFAULT;
954 			goto done;
955 		}
956 		++lastvecindex;
957 	}
958 
959 	/*
960 	 * If the map has changed, due to the subyte, the previous
961 	 * output may be invalid.
962 	 */
963 	vm_map_lock_read(map);
964 	if (timestamp != map->timestamp)
965 		goto RestartScan;
966 	vm_map_unlock_read(map);
967 
968 	error = 0;
969 done:
970 	lwkt_reltoken(&map->token);
971 	return (error);
972 }
973 
974 /*
975  * mlock system call handler
976  *
977  * mlock_args(const void *addr, size_t len)
978  *
979  * No requirements
980  */
981 int
982 sys_mlock(struct mlock_args *uap)
983 {
984 	vm_offset_t addr;
985 	vm_offset_t tmpaddr;
986 	vm_size_t size, pageoff;
987 	struct thread *td = curthread;
988 	struct proc *p = td->td_proc;
989 	int error;
990 
991 	addr = (vm_offset_t) uap->addr;
992 	size = uap->len;
993 
994 	pageoff = (addr & PAGE_MASK);
995 	addr -= pageoff;
996 	size += pageoff;
997 	size = (vm_size_t) round_page(size);
998 	if (size < uap->len)		/* wrap */
999 		return(EINVAL);
1000 	tmpaddr = addr + size;		/* workaround gcc4 opt */
1001 	if (tmpaddr < addr)		/* wrap */
1002 		return (EINVAL);
1003 
1004 	if (atop(size) + vmstats.v_wire_count > vm_page_max_wired)
1005 		return (EAGAIN);
1006 
1007 	/*
1008 	 * We do not need to synchronize against other threads updating ucred;
1009 	 * they update p->ucred, which is synchronized into td_ucred ourselves.
1010 	 */
1011 #ifdef pmap_wired_count
1012 	if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
1013 	    p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur) {
1014 		return (ENOMEM);
1015 	}
1016 #else
1017 	error = priv_check_cred(td->td_ucred, PRIV_ROOT, 0);
1018 	if (error) {
1019 		return (error);
1020 	}
1021 #endif
1022 	error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, FALSE);
1023 	return (error == KERN_SUCCESS ? 0 : ENOMEM);
1024 }
1025 
1026 /*
1027  * mlockall(int how)
1028  *
1029  * No requirements
1030  */
1031 int
1032 sys_mlockall(struct mlockall_args *uap)
1033 {
1034 	struct thread *td = curthread;
1035 	struct proc *p = td->td_proc;
1036 	vm_map_t map = &p->p_vmspace->vm_map;
1037 	vm_map_entry_t entry;
1038 	int how = uap->how;
1039 	int rc = KERN_SUCCESS;
1040 
1041 	if (((how & MCL_CURRENT) == 0) && ((how & MCL_FUTURE) == 0))
1042 		return (EINVAL);
1043 
1044 	rc = priv_check_cred(td->td_ucred, PRIV_ROOT, 0);
1045 	if (rc)
1046 		return (rc);
1047 
1048 	vm_map_lock(map);
1049 	do {
1050 		if (how & MCL_CURRENT) {
1051 			for(entry = map->header.next;
1052 			    entry != &map->header;
1053 			    entry = entry->next);
1054 
1055 			rc = ENOSYS;
1056 			break;
1057 		}
1058 
1059 		if (how & MCL_FUTURE)
1060 			map->flags |= MAP_WIREFUTURE;
1061 	} while(0);
1062 	vm_map_unlock(map);
1063 
1064 	return (rc);
1065 }
1066 
1067 /*
1068  * munlockall(void)
1069  *
1070  *	Unwire all user-wired map entries, cancel MCL_FUTURE.
1071  *
1072  * No requirements
1073  */
1074 int
1075 sys_munlockall(struct munlockall_args *uap)
1076 {
1077 	struct thread *td = curthread;
1078 	struct proc *p = td->td_proc;
1079 	vm_map_t map = &p->p_vmspace->vm_map;
1080 	vm_map_entry_t entry;
1081 	int rc = KERN_SUCCESS;
1082 
1083 	vm_map_lock(map);
1084 
1085 	/* Clear MAP_WIREFUTURE to cancel mlockall(MCL_FUTURE) */
1086 	map->flags &= ~MAP_WIREFUTURE;
1087 
1088 retry:
1089 	for (entry = map->header.next;
1090 	     entry != &map->header;
1091 	     entry = entry->next) {
1092 		if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0)
1093 			continue;
1094 
1095 		/*
1096 		 * If we encounter an in-transition entry, we release the
1097 		 * map lock and retry the scan; we do not decrement any
1098 		 * wired_count more than once because we do not touch
1099 		 * any entries with MAP_ENTRY_USER_WIRED not set.
1100 		 *
1101  		 * There is a potential interleaving with concurrent
1102 		 * mlockall()s here -- if we abort a scan, an mlockall()
1103 		 * could start, wire a number of entries before our
1104 		 * current position in, and then stall itself on this
1105 		 * or any other in-transition entry. If that occurs, when
1106 		 * we resume, we will unwire those entries.
1107  		 */
1108 		if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1109 			entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1110 			++mycpu->gd_cnt.v_intrans_coll;
1111 			++mycpu->gd_cnt.v_intrans_wait;
1112 			vm_map_transition_wait(map);
1113 			goto retry;
1114 		}
1115 
1116 		KASSERT(entry->wired_count > 0,
1117 			("wired_count was 0 with USER_WIRED set! %p", entry));
1118 
1119 		/* Drop wired count, if it hits zero, unwire the entry */
1120 		entry->eflags &= ~MAP_ENTRY_USER_WIRED;
1121 		entry->wired_count--;
1122 		if (entry->wired_count == 0)
1123 			vm_fault_unwire(map, entry);
1124 	}
1125 
1126 	map->timestamp++;
1127 	vm_map_unlock(map);
1128 
1129 	return (rc);
1130 }
1131 
1132 /*
1133  * munlock system call handler
1134  *
1135  * munlock_args(const void *addr, size_t len)
1136  *
1137  * No requirements
1138  */
1139 int
1140 sys_munlock(struct munlock_args *uap)
1141 {
1142 	struct thread *td = curthread;
1143 	struct proc *p = td->td_proc;
1144 	vm_offset_t addr;
1145 	vm_offset_t tmpaddr;
1146 	vm_size_t size, pageoff;
1147 	int error;
1148 
1149 	addr = (vm_offset_t) uap->addr;
1150 	size = uap->len;
1151 
1152 	pageoff = (addr & PAGE_MASK);
1153 	addr -= pageoff;
1154 	size += pageoff;
1155 	size = (vm_size_t) round_page(size);
1156 
1157 	tmpaddr = addr + size;
1158 	if (tmpaddr < addr)		/* wrap */
1159 		return (EINVAL);
1160 
1161 #ifndef pmap_wired_count
1162 	error = priv_check(td, PRIV_ROOT);
1163 	if (error)
1164 		return (error);
1165 #endif
1166 
1167 	error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, TRUE);
1168 	return (error == KERN_SUCCESS ? 0 : ENOMEM);
1169 }
1170 
1171 /*
1172  * Internal version of mmap.
1173  * Currently used by mmap, exec, and sys5 shared memory.
1174  * Handle is either a vnode pointer or NULL for MAP_ANON.
1175  *
1176  * No requirements
1177  */
1178 int
1179 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
1180 	vm_prot_t maxprot, int flags, void *handle, vm_ooffset_t foff)
1181 {
1182 	boolean_t fitit;
1183 	vm_object_t object;
1184 	vm_offset_t eaddr;
1185 	vm_size_t   esize;
1186 	vm_size_t   align;
1187 	int (*uksmap)(cdev_t dev, vm_page_t fake);
1188 	struct vnode *vp;
1189 	struct thread *td = curthread;
1190 	struct proc *p;
1191 	int rv = KERN_SUCCESS;
1192 	off_t objsize;
1193 	int docow;
1194 	int error;
1195 
1196 	if (size == 0)
1197 		return (0);
1198 
1199 	objsize = round_page(size);
1200 	if (objsize < size)
1201 		return (EINVAL);
1202 	size = objsize;
1203 
1204 	lwkt_gettoken(&map->token);
1205 
1206 	/*
1207 	 * XXX messy code, fixme
1208 	 *
1209 	 * NOTE: Overflow checks require discrete statements or GCC4
1210 	 * will optimize it out.
1211 	 */
1212 	if ((p = curproc) != NULL && map == &p->p_vmspace->vm_map) {
1213 		esize = map->size + size;	/* workaround gcc4 opt */
1214 		if (esize < map->size ||
1215 		    esize > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
1216 			lwkt_reltoken(&map->token);
1217 			return(ENOMEM);
1218 		}
1219 	}
1220 
1221 	/*
1222 	 * We currently can only deal with page aligned file offsets.
1223 	 * The check is here rather than in the syscall because the
1224 	 * kernel calls this function internally for other mmaping
1225 	 * operations (such as in exec) and non-aligned offsets will
1226 	 * cause pmap inconsistencies...so we want to be sure to
1227 	 * disallow this in all cases.
1228 	 *
1229 	 * NOTE: Overflow checks require discrete statements or GCC4
1230 	 * will optimize it out.
1231 	 */
1232 	if (foff & PAGE_MASK) {
1233 		lwkt_reltoken(&map->token);
1234 		return (EINVAL);
1235 	}
1236 
1237 	/*
1238 	 * Handle alignment.  For large memory maps it is possible
1239 	 * that the MMU can optimize the page table so align anything
1240 	 * that is a multiple of SEG_SIZE to SEG_SIZE.
1241 	 *
1242 	 * Also align any large mapping (bigger than 16x SG_SIZE) to a
1243 	 * SEG_SIZE address boundary.
1244 	 */
1245 	if (flags & MAP_SIZEALIGN) {
1246 		align = size;
1247 		if ((align ^ (align - 1)) != (align << 1) - 1) {
1248 			lwkt_reltoken(&map->token);
1249 			return (EINVAL);
1250 		}
1251 	} else if ((flags & MAP_FIXED) == 0 &&
1252 		   ((size & SEG_MASK) == 0 || size > SEG_SIZE * 16)) {
1253 		align = SEG_SIZE;
1254 	} else {
1255 		align = PAGE_SIZE;
1256 	}
1257 
1258 	if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
1259 		fitit = TRUE;
1260 		*addr = round_page(*addr);
1261 	} else {
1262 		if (*addr != trunc_page(*addr)) {
1263 			lwkt_reltoken(&map->token);
1264 			return (EINVAL);
1265 		}
1266 		eaddr = *addr + size;
1267 		if (eaddr < *addr) {
1268 			lwkt_reltoken(&map->token);
1269 			return (EINVAL);
1270 		}
1271 		fitit = FALSE;
1272 		if ((flags & MAP_TRYFIXED) == 0)
1273 			vm_map_remove(map, *addr, *addr + size);
1274 	}
1275 
1276 	uksmap = NULL;
1277 
1278 	/*
1279 	 * Lookup/allocate object.
1280 	 */
1281 	if (flags & MAP_ANON) {
1282 		/*
1283 		 * Unnamed anonymous regions always start at 0.
1284 		 */
1285 		if (handle) {
1286 			/*
1287 			 * Default memory object
1288 			 */
1289 			object = default_pager_alloc(handle, objsize,
1290 						     prot, foff);
1291 			if (object == NULL) {
1292 				lwkt_reltoken(&map->token);
1293 				return(ENOMEM);
1294 			}
1295 			docow = MAP_PREFAULT_PARTIAL;
1296 		} else {
1297 			/*
1298 			 * Implicit single instance of a default memory
1299 			 * object, so we don't need a VM object yet.
1300 			 */
1301 			foff = 0;
1302 			object = NULL;
1303 			docow = 0;
1304 		}
1305 		vp = NULL;
1306 	} else {
1307 		vp = (struct vnode *)handle;
1308 
1309 		/*
1310 		 * Non-anonymous mappings of VCHR (aka not /dev/zero)
1311 		 * cannot specify MAP_STACK or MAP_VPAGETABLE.
1312 		 */
1313 		if (vp->v_type == VCHR) {
1314 			if (flags & (MAP_STACK | MAP_VPAGETABLE)) {
1315 				lwkt_reltoken(&map->token);
1316 				return(EINVAL);
1317 			}
1318 		}
1319 
1320 		if (vp->v_type == VCHR && vp->v_rdev->si_ops->d_uksmap) {
1321 			/*
1322 			 * Device mappings without a VM object, typically
1323 			 * sharing permanently allocated kernel memory or
1324 			 * process-context-specific (per-process) data.
1325 			 *
1326 			 * Force them to be shared.
1327 			 */
1328 			uksmap = vp->v_rdev->si_ops->d_uksmap;
1329 			object = NULL;
1330 			docow = MAP_PREFAULT_PARTIAL;
1331 			flags &= ~(MAP_PRIVATE|MAP_COPY);
1332 			flags |= MAP_SHARED;
1333 		} else if (vp->v_type == VCHR) {
1334 			/*
1335 			 * Device mappings (device size unknown?).
1336 			 * Force them to be shared.
1337 			 */
1338 			error = dev_dmmap_single(vp->v_rdev, &foff, objsize,
1339 						&object, prot, NULL);
1340 
1341 			if (error == ENODEV) {
1342 				handle = (void *)(intptr_t)vp->v_rdev;
1343 				object = dev_pager_alloc(handle, objsize, prot, foff);
1344 				if (object == NULL) {
1345 					lwkt_reltoken(&map->token);
1346 					return(EINVAL);
1347 				}
1348 			} else if (error) {
1349 				lwkt_reltoken(&map->token);
1350 				return(error);
1351 			}
1352 
1353 			docow = MAP_PREFAULT_PARTIAL;
1354 			flags &= ~(MAP_PRIVATE|MAP_COPY);
1355 			flags |= MAP_SHARED;
1356 		} else {
1357 			/*
1358 			 * Regular file mapping (typically).  The attribute
1359 			 * check is for the link count test only.  mmapable
1360 			 * vnodes must already have a VM object assigned.
1361 			 */
1362 			struct vattr vat;
1363 			int error;
1364 
1365 			error = VOP_GETATTR(vp, &vat);
1366 			if (error) {
1367 				lwkt_reltoken(&map->token);
1368 				return (error);
1369 			}
1370 			docow = MAP_PREFAULT_PARTIAL;
1371 			object = vnode_pager_reference(vp);
1372 			if (object == NULL && vp->v_type == VREG) {
1373 				lwkt_reltoken(&map->token);
1374 				kprintf("Warning: cannot mmap vnode %p, no "
1375 					"object\n", vp);
1376 				return(EINVAL);
1377 			}
1378 
1379 			/*
1380 			 * If it is a regular file without any references
1381 			 * we do not need to sync it.
1382 			 */
1383 			if (vp->v_type == VREG && vat.va_nlink == 0) {
1384 				flags |= MAP_NOSYNC;
1385 			}
1386 		}
1387 	}
1388 
1389 	/*
1390 	 * Deal with the adjusted flags
1391 	 */
1392 	if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1393 		docow |= MAP_COPY_ON_WRITE;
1394 	if (flags & MAP_NOSYNC)
1395 		docow |= MAP_DISABLE_SYNCER;
1396 	if (flags & MAP_NOCORE)
1397 		docow |= MAP_DISABLE_COREDUMP;
1398 
1399 #if defined(VM_PROT_READ_IS_EXEC)
1400 	if (prot & VM_PROT_READ)
1401 		prot |= VM_PROT_EXECUTE;
1402 
1403 	if (maxprot & VM_PROT_READ)
1404 		maxprot |= VM_PROT_EXECUTE;
1405 #endif
1406 
1407 	/*
1408 	 * This may place the area in its own page directory if (size) is
1409 	 * large enough, otherwise it typically returns its argument.
1410 	 *
1411 	 * (object can be NULL)
1412 	 */
1413 	if (fitit) {
1414 		*addr = pmap_addr_hint(object, *addr, size);
1415 	}
1416 
1417 	/*
1418 	 * Stack mappings need special attention.
1419 	 *
1420 	 * Mappings that use virtual page tables will default to storing
1421 	 * the page table at offset 0.
1422 	 */
1423 	if (uksmap) {
1424 		rv = vm_map_find(map, uksmap, vp->v_rdev,
1425 				 foff, addr, size,
1426 				 align,
1427 				 fitit, VM_MAPTYPE_UKSMAP,
1428 				 prot, maxprot, docow);
1429 	} else if (flags & MAP_STACK) {
1430 		rv = vm_map_stack(map, *addr, size, flags,
1431 				  prot, maxprot, docow);
1432 	} else if (flags & MAP_VPAGETABLE) {
1433 		rv = vm_map_find(map, object, NULL,
1434 				 foff, addr, size,
1435 				 align,
1436 				 fitit, VM_MAPTYPE_VPAGETABLE,
1437 				 prot, maxprot, docow);
1438 	} else {
1439 		rv = vm_map_find(map, object, NULL,
1440 				 foff, addr, size,
1441 				 align,
1442 				 fitit, VM_MAPTYPE_NORMAL,
1443 				 prot, maxprot, docow);
1444 	}
1445 
1446 	if (rv != KERN_SUCCESS) {
1447 		/*
1448 		 * Lose the object reference. Will destroy the
1449 		 * object if it's an unnamed anonymous mapping
1450 		 * or named anonymous without other references.
1451 		 *
1452 		 * (NOTE: object can be NULL)
1453 		 */
1454 		vm_object_deallocate(object);
1455 		goto out;
1456 	}
1457 
1458 	/*
1459 	 * Shared memory is also shared with children.
1460 	 */
1461 	if (flags & (MAP_SHARED|MAP_INHERIT)) {
1462 		rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE);
1463 		if (rv != KERN_SUCCESS) {
1464 			vm_map_remove(map, *addr, *addr + size);
1465 			goto out;
1466 		}
1467 	}
1468 
1469 	/* If a process has marked all future mappings for wiring, do so */
1470 	if ((rv == KERN_SUCCESS) && (map->flags & MAP_WIREFUTURE))
1471 		vm_map_unwire(map, *addr, *addr + size, FALSE);
1472 
1473 	/*
1474 	 * Set the access time on the vnode
1475 	 */
1476 	if (vp != NULL)
1477 		vn_mark_atime(vp, td);
1478 out:
1479 	lwkt_reltoken(&map->token);
1480 
1481 	switch (rv) {
1482 	case KERN_SUCCESS:
1483 		return (0);
1484 	case KERN_INVALID_ADDRESS:
1485 	case KERN_NO_SPACE:
1486 		return (ENOMEM);
1487 	case KERN_PROTECTION_FAILURE:
1488 		return (EACCES);
1489 	default:
1490 		return (EINVAL);
1491 	}
1492 }
1493 
1494 /*
1495  * Translate a Mach VM return code to zero on success or the appropriate errno
1496  * on failure.
1497  */
1498 int
1499 vm_mmap_to_errno(int rv)
1500 {
1501 
1502 	switch (rv) {
1503 	case KERN_SUCCESS:
1504 		return (0);
1505 	case KERN_INVALID_ADDRESS:
1506 	case KERN_NO_SPACE:
1507 		return (ENOMEM);
1508 	case KERN_PROTECTION_FAILURE:
1509 		return (EACCES);
1510 	default:
1511 		return (EINVAL);
1512 	}
1513 }
1514