vm_mmap.c revision 281776
1/*-
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
35 *
36 *	@(#)vm_mmap.c	8.4 (Berkeley) 1/12/94
37 */
38
39/*
40 * Mapped file (mmap) interface to VM
41 */
42
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD: stable/10/sys/vm/vm_mmap.c 281776 2015-04-20 17:36:43Z alc $");
45
46#include "opt_compat.h"
47#include "opt_hwpmc_hooks.h"
48
49#include <sys/param.h>
50#include <sys/systm.h>
51#include <sys/capsicum.h>
52#include <sys/kernel.h>
53#include <sys/lock.h>
54#include <sys/mutex.h>
55#include <sys/sysproto.h>
56#include <sys/filedesc.h>
57#include <sys/priv.h>
58#include <sys/proc.h>
59#include <sys/procctl.h>
60#include <sys/racct.h>
61#include <sys/resource.h>
62#include <sys/resourcevar.h>
63#include <sys/rwlock.h>
64#include <sys/sysctl.h>
65#include <sys/vnode.h>
66#include <sys/fcntl.h>
67#include <sys/file.h>
68#include <sys/mman.h>
69#include <sys/mount.h>
70#include <sys/conf.h>
71#include <sys/stat.h>
72#include <sys/syscallsubr.h>
73#include <sys/sysent.h>
74#include <sys/vmmeter.h>
75
76#include <security/mac/mac_framework.h>
77
78#include <vm/vm.h>
79#include <vm/vm_param.h>
80#include <vm/pmap.h>
81#include <vm/vm_map.h>
82#include <vm/vm_object.h>
83#include <vm/vm_page.h>
84#include <vm/vm_pager.h>
85#include <vm/vm_pageout.h>
86#include <vm/vm_extern.h>
87#include <vm/vm_page.h>
88#include <vm/vnode_pager.h>
89
90#ifdef HWPMC_HOOKS
91#include <sys/pmckern.h>
92#endif
93
94int old_mlock = 0;
95SYSCTL_INT(_vm, OID_AUTO, old_mlock, CTLFLAG_RW | CTLFLAG_TUN, &old_mlock, 0,
96    "Do not apply RLIMIT_MEMLOCK on mlockall");
97TUNABLE_INT("vm.old_mlock", &old_mlock);
98
99#ifdef MAP_32BIT
100#define	MAP_32BIT_MAX_ADDR	((vm_offset_t)1 << 31)
101#endif
102
103static int vm_mmap_vnode(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
104    int *, struct vnode *, vm_ooffset_t *, vm_object_t *, boolean_t *);
105static int vm_mmap_cdev(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
106    int *, struct cdev *, vm_ooffset_t *, vm_object_t *);
107static int vm_mmap_shm(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
108    int *, struct shmfd *, vm_ooffset_t, vm_object_t *);
109
110#ifndef _SYS_SYSPROTO_H_
111struct sbrk_args {
112	int incr;
113};
114#endif
115
116/*
117 * MPSAFE
118 */
119/* ARGSUSED */
120int
121sys_sbrk(td, uap)
122	struct thread *td;
123	struct sbrk_args *uap;
124{
125	/* Not yet implemented */
126	return (EOPNOTSUPP);
127}
128
129#ifndef _SYS_SYSPROTO_H_
130struct sstk_args {
131	int incr;
132};
133#endif
134
135/*
136 * MPSAFE
137 */
138/* ARGSUSED */
139int
140sys_sstk(td, uap)
141	struct thread *td;
142	struct sstk_args *uap;
143{
144	/* Not yet implemented */
145	return (EOPNOTSUPP);
146}
147
148#if defined(COMPAT_43)
149#ifndef _SYS_SYSPROTO_H_
150struct getpagesize_args {
151	int dummy;
152};
153#endif
154
155int
156ogetpagesize(td, uap)
157	struct thread *td;
158	struct getpagesize_args *uap;
159{
160	/* MP SAFE */
161	td->td_retval[0] = PAGE_SIZE;
162	return (0);
163}
164#endif				/* COMPAT_43 */
165
166
167/*
168 * Memory Map (mmap) system call.  Note that the file offset
169 * and address are allowed to be NOT page aligned, though if
170 * the MAP_FIXED flag it set, both must have the same remainder
171 * modulo the PAGE_SIZE (POSIX 1003.1b).  If the address is not
172 * page-aligned, the actual mapping starts at trunc_page(addr)
173 * and the return value is adjusted up by the page offset.
174 *
175 * Generally speaking, only character devices which are themselves
176 * memory-based, such as a video framebuffer, can be mmap'd.  Otherwise
177 * there would be no cache coherency between a descriptor and a VM mapping
178 * both to the same character device.
179 */
180#ifndef _SYS_SYSPROTO_H_
181struct mmap_args {
182	void *addr;
183	size_t len;
184	int prot;
185	int flags;
186	int fd;
187	long pad;
188	off_t pos;
189};
190#endif
191
192/*
193 * MPSAFE
194 */
195int
196sys_mmap(td, uap)
197	struct thread *td;
198	struct mmap_args *uap;
199{
200#ifdef HWPMC_HOOKS
201	struct pmckern_map_in pkm;
202#endif
203	struct file *fp;
204	struct vnode *vp;
205	vm_offset_t addr;
206	vm_size_t size, pageoff;
207	vm_prot_t cap_maxprot, prot, maxprot;
208	void *handle;
209	objtype_t handle_type;
210	int align, error, flags;
211	off_t pos;
212	struct vmspace *vms = td->td_proc->p_vmspace;
213	cap_rights_t rights;
214
215	addr = (vm_offset_t) uap->addr;
216	size = uap->len;
217	prot = uap->prot & VM_PROT_ALL;
218	flags = uap->flags;
219	pos = uap->pos;
220
221	fp = NULL;
222
223	/*
224	 * Enforce the constraints.
225	 * Mapping of length 0 is only allowed for old binaries.
226	 * Anonymous mapping shall specify -1 as filedescriptor and
227	 * zero position for new code. Be nice to ancient a.out
228	 * binaries and correct pos for anonymous mapping, since old
229	 * ld.so sometimes issues anonymous map requests with non-zero
230	 * pos.
231	 */
232	if (!SV_CURPROC_FLAG(SV_AOUT)) {
233		if ((uap->len == 0 && curproc->p_osrel >= P_OSREL_MAP_ANON) ||
234		    ((flags & MAP_ANON) != 0 && (uap->fd != -1 || pos != 0)))
235			return (EINVAL);
236	} else {
237		if ((flags & MAP_ANON) != 0)
238			pos = 0;
239	}
240
241	if (flags & MAP_STACK) {
242		if ((uap->fd != -1) ||
243		    ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
244			return (EINVAL);
245		flags |= MAP_ANON;
246		pos = 0;
247	}
248	if ((flags & (MAP_EXCL | MAP_FIXED)) == MAP_EXCL)
249		return (EINVAL);
250
251	/*
252	 * Align the file position to a page boundary,
253	 * and save its page offset component.
254	 */
255	pageoff = (pos & PAGE_MASK);
256	pos -= pageoff;
257
258	/* Adjust size for rounding (on both ends). */
259	size += pageoff;			/* low end... */
260	size = (vm_size_t) round_page(size);	/* hi end */
261
262	/* Ensure alignment is at least a page and fits in a pointer. */
263	align = flags & MAP_ALIGNMENT_MASK;
264	if (align != 0 && align != MAP_ALIGNED_SUPER &&
265	    (align >> MAP_ALIGNMENT_SHIFT >= sizeof(void *) * NBBY ||
266	    align >> MAP_ALIGNMENT_SHIFT < PAGE_SHIFT))
267		return (EINVAL);
268
269	/*
270	 * Check for illegal addresses.  Watch out for address wrap... Note
271	 * that VM_*_ADDRESS are not constants due to casts (argh).
272	 */
273	if (flags & MAP_FIXED) {
274		/*
275		 * The specified address must have the same remainder
276		 * as the file offset taken modulo PAGE_SIZE, so it
277		 * should be aligned after adjustment by pageoff.
278		 */
279		addr -= pageoff;
280		if (addr & PAGE_MASK)
281			return (EINVAL);
282
283		/* Address range must be all in user VM space. */
284		if (addr < vm_map_min(&vms->vm_map) ||
285		    addr + size > vm_map_max(&vms->vm_map))
286			return (EINVAL);
287		if (addr + size < addr)
288			return (EINVAL);
289#ifdef MAP_32BIT
290		if (flags & MAP_32BIT && addr + size > MAP_32BIT_MAX_ADDR)
291			return (EINVAL);
292	} else if (flags & MAP_32BIT) {
293		/*
294		 * For MAP_32BIT, override the hint if it is too high and
295		 * do not bother moving the mapping past the heap (since
296		 * the heap is usually above 2GB).
297		 */
298		if (addr + size > MAP_32BIT_MAX_ADDR)
299			addr = 0;
300#endif
301	} else {
302		/*
303		 * XXX for non-fixed mappings where no hint is provided or
304		 * the hint would fall in the potential heap space,
305		 * place it after the end of the largest possible heap.
306		 *
307		 * There should really be a pmap call to determine a reasonable
308		 * location.
309		 */
310		PROC_LOCK(td->td_proc);
311		if (addr == 0 ||
312		    (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
313		    addr < round_page((vm_offset_t)vms->vm_daddr +
314		    lim_max(td->td_proc, RLIMIT_DATA))))
315			addr = round_page((vm_offset_t)vms->vm_daddr +
316			    lim_max(td->td_proc, RLIMIT_DATA));
317		PROC_UNLOCK(td->td_proc);
318	}
319	if (flags & MAP_ANON) {
320		/*
321		 * Mapping blank space is trivial.
322		 */
323		handle = NULL;
324		handle_type = OBJT_DEFAULT;
325		maxprot = VM_PROT_ALL;
326		cap_maxprot = VM_PROT_ALL;
327	} else {
328		/*
329		 * Mapping file, get fp for validation and don't let the
330		 * descriptor disappear on us if we block. Check capability
331		 * rights, but also return the maximum rights to be combined
332		 * with maxprot later.
333		 */
334		cap_rights_init(&rights, CAP_MMAP);
335		if (prot & PROT_READ)
336			cap_rights_set(&rights, CAP_MMAP_R);
337		if ((flags & MAP_SHARED) != 0) {
338			if (prot & PROT_WRITE)
339				cap_rights_set(&rights, CAP_MMAP_W);
340		}
341		if (prot & PROT_EXEC)
342			cap_rights_set(&rights, CAP_MMAP_X);
343		error = fget_mmap(td, uap->fd, &rights, &cap_maxprot, &fp);
344		if (error != 0)
345			goto done;
346		if (fp->f_type == DTYPE_SHM) {
347			handle = fp->f_data;
348			handle_type = OBJT_SWAP;
349			maxprot = VM_PROT_NONE;
350
351			/* FREAD should always be set. */
352			if (fp->f_flag & FREAD)
353				maxprot |= VM_PROT_EXECUTE | VM_PROT_READ;
354			if (fp->f_flag & FWRITE)
355				maxprot |= VM_PROT_WRITE;
356			goto map;
357		}
358		if (fp->f_type != DTYPE_VNODE) {
359			error = ENODEV;
360			goto done;
361		}
362#if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
363    defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
364		/*
365		 * POSIX shared-memory objects are defined to have
366		 * kernel persistence, and are not defined to support
367		 * read(2)/write(2) -- or even open(2).  Thus, we can
368		 * use MAP_ASYNC to trade on-disk coherence for speed.
369		 * The shm_open(3) library routine turns on the FPOSIXSHM
370		 * flag to request this behavior.
371		 */
372		if (fp->f_flag & FPOSIXSHM)
373			flags |= MAP_NOSYNC;
374#endif
375		vp = fp->f_vnode;
376		/*
377		 * Ensure that file and memory protections are
378		 * compatible.  Note that we only worry about
379		 * writability if mapping is shared; in this case,
380		 * current and max prot are dictated by the open file.
381		 * XXX use the vnode instead?  Problem is: what
382		 * credentials do we use for determination? What if
383		 * proc does a setuid?
384		 */
385		if (vp->v_mount != NULL && vp->v_mount->mnt_flag & MNT_NOEXEC)
386			maxprot = VM_PROT_NONE;
387		else
388			maxprot = VM_PROT_EXECUTE;
389		if (fp->f_flag & FREAD) {
390			maxprot |= VM_PROT_READ;
391		} else if (prot & PROT_READ) {
392			error = EACCES;
393			goto done;
394		}
395		/*
396		 * If we are sharing potential changes (either via
397		 * MAP_SHARED or via the implicit sharing of character
398		 * device mappings), and we are trying to get write
399		 * permission although we opened it without asking
400		 * for it, bail out.
401		 */
402		if ((flags & MAP_SHARED) != 0) {
403			if ((fp->f_flag & FWRITE) != 0) {
404				maxprot |= VM_PROT_WRITE;
405			} else if ((prot & PROT_WRITE) != 0) {
406				error = EACCES;
407				goto done;
408			}
409		} else if (vp->v_type != VCHR || (fp->f_flag & FWRITE) != 0) {
410			maxprot |= VM_PROT_WRITE;
411			cap_maxprot |= VM_PROT_WRITE;
412		}
413		handle = (void *)vp;
414		handle_type = OBJT_VNODE;
415	}
416map:
417	td->td_fpop = fp;
418	maxprot &= cap_maxprot;
419	error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
420	    flags, handle_type, handle, pos);
421	td->td_fpop = NULL;
422#ifdef HWPMC_HOOKS
423	/* inform hwpmc(4) if an executable is being mapped */
424	if (error == 0 && handle_type == OBJT_VNODE &&
425	    (prot & PROT_EXEC)) {
426		pkm.pm_file = handle;
427		pkm.pm_address = (uintptr_t) addr;
428		PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm);
429	}
430#endif
431	if (error == 0)
432		td->td_retval[0] = (register_t) (addr + pageoff);
433done:
434	if (fp)
435		fdrop(fp, td);
436
437	return (error);
438}
439
440int
441freebsd6_mmap(struct thread *td, struct freebsd6_mmap_args *uap)
442{
443	struct mmap_args oargs;
444
445	oargs.addr = uap->addr;
446	oargs.len = uap->len;
447	oargs.prot = uap->prot;
448	oargs.flags = uap->flags;
449	oargs.fd = uap->fd;
450	oargs.pos = uap->pos;
451	return (sys_mmap(td, &oargs));
452}
453
454#ifdef COMPAT_43
455#ifndef _SYS_SYSPROTO_H_
456struct ommap_args {
457	caddr_t addr;
458	int len;
459	int prot;
460	int flags;
461	int fd;
462	long pos;
463};
464#endif
465int
466ommap(td, uap)
467	struct thread *td;
468	struct ommap_args *uap;
469{
470	struct mmap_args nargs;
471	static const char cvtbsdprot[8] = {
472		0,
473		PROT_EXEC,
474		PROT_WRITE,
475		PROT_EXEC | PROT_WRITE,
476		PROT_READ,
477		PROT_EXEC | PROT_READ,
478		PROT_WRITE | PROT_READ,
479		PROT_EXEC | PROT_WRITE | PROT_READ,
480	};
481
482#define	OMAP_ANON	0x0002
483#define	OMAP_COPY	0x0020
484#define	OMAP_SHARED	0x0010
485#define	OMAP_FIXED	0x0100
486
487	nargs.addr = uap->addr;
488	nargs.len = uap->len;
489	nargs.prot = cvtbsdprot[uap->prot & 0x7];
490#ifdef COMPAT_FREEBSD32
491#if defined(__amd64__) || defined(__ia64__)
492	if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32) &&
493	    nargs.prot != 0)
494		nargs.prot |= PROT_EXEC;
495#endif
496#endif
497	nargs.flags = 0;
498	if (uap->flags & OMAP_ANON)
499		nargs.flags |= MAP_ANON;
500	if (uap->flags & OMAP_COPY)
501		nargs.flags |= MAP_COPY;
502	if (uap->flags & OMAP_SHARED)
503		nargs.flags |= MAP_SHARED;
504	else
505		nargs.flags |= MAP_PRIVATE;
506	if (uap->flags & OMAP_FIXED)
507		nargs.flags |= MAP_FIXED;
508	nargs.fd = uap->fd;
509	nargs.pos = uap->pos;
510	return (sys_mmap(td, &nargs));
511}
512#endif				/* COMPAT_43 */
513
514
515#ifndef _SYS_SYSPROTO_H_
516struct msync_args {
517	void *addr;
518	size_t len;
519	int flags;
520};
521#endif
522/*
523 * MPSAFE
524 */
525int
526sys_msync(td, uap)
527	struct thread *td;
528	struct msync_args *uap;
529{
530	vm_offset_t addr;
531	vm_size_t size, pageoff;
532	int flags;
533	vm_map_t map;
534	int rv;
535
536	addr = (vm_offset_t) uap->addr;
537	size = uap->len;
538	flags = uap->flags;
539
540	pageoff = (addr & PAGE_MASK);
541	addr -= pageoff;
542	size += pageoff;
543	size = (vm_size_t) round_page(size);
544	if (addr + size < addr)
545		return (EINVAL);
546
547	if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
548		return (EINVAL);
549
550	map = &td->td_proc->p_vmspace->vm_map;
551
552	/*
553	 * Clean the pages and interpret the return value.
554	 */
555	rv = vm_map_sync(map, addr, addr + size, (flags & MS_ASYNC) == 0,
556	    (flags & MS_INVALIDATE) != 0);
557	switch (rv) {
558	case KERN_SUCCESS:
559		return (0);
560	case KERN_INVALID_ADDRESS:
561		return (ENOMEM);
562	case KERN_INVALID_ARGUMENT:
563		return (EBUSY);
564	case KERN_FAILURE:
565		return (EIO);
566	default:
567		return (EINVAL);
568	}
569}
570
571#ifndef _SYS_SYSPROTO_H_
572struct munmap_args {
573	void *addr;
574	size_t len;
575};
576#endif
577/*
578 * MPSAFE
579 */
580int
581sys_munmap(td, uap)
582	struct thread *td;
583	struct munmap_args *uap;
584{
585#ifdef HWPMC_HOOKS
586	struct pmckern_map_out pkm;
587	vm_map_entry_t entry;
588#endif
589	vm_offset_t addr;
590	vm_size_t size, pageoff;
591	vm_map_t map;
592
593	addr = (vm_offset_t) uap->addr;
594	size = uap->len;
595	if (size == 0)
596		return (EINVAL);
597
598	pageoff = (addr & PAGE_MASK);
599	addr -= pageoff;
600	size += pageoff;
601	size = (vm_size_t) round_page(size);
602	if (addr + size < addr)
603		return (EINVAL);
604
605	/*
606	 * Check for illegal addresses.  Watch out for address wrap...
607	 */
608	map = &td->td_proc->p_vmspace->vm_map;
609	if (addr < vm_map_min(map) || addr + size > vm_map_max(map))
610		return (EINVAL);
611	vm_map_lock(map);
612#ifdef HWPMC_HOOKS
613	/*
614	 * Inform hwpmc if the address range being unmapped contains
615	 * an executable region.
616	 */
617	pkm.pm_address = (uintptr_t) NULL;
618	if (vm_map_lookup_entry(map, addr, &entry)) {
619		for (;
620		     entry != &map->header && entry->start < addr + size;
621		     entry = entry->next) {
622			if (vm_map_check_protection(map, entry->start,
623				entry->end, VM_PROT_EXECUTE) == TRUE) {
624				pkm.pm_address = (uintptr_t) addr;
625				pkm.pm_size = (size_t) size;
626				break;
627			}
628		}
629	}
630#endif
631	vm_map_delete(map, addr, addr + size);
632
633#ifdef HWPMC_HOOKS
634	/* downgrade the lock to prevent a LOR with the pmc-sx lock */
635	vm_map_lock_downgrade(map);
636	if (pkm.pm_address != (uintptr_t) NULL)
637		PMC_CALL_HOOK(td, PMC_FN_MUNMAP, (void *) &pkm);
638	vm_map_unlock_read(map);
639#else
640	vm_map_unlock(map);
641#endif
642	/* vm_map_delete returns nothing but KERN_SUCCESS anyway */
643	return (0);
644}
645
646#ifndef _SYS_SYSPROTO_H_
647struct mprotect_args {
648	const void *addr;
649	size_t len;
650	int prot;
651};
652#endif
653/*
654 * MPSAFE
655 */
656int
657sys_mprotect(td, uap)
658	struct thread *td;
659	struct mprotect_args *uap;
660{
661	vm_offset_t addr;
662	vm_size_t size, pageoff;
663	vm_prot_t prot;
664
665	addr = (vm_offset_t) uap->addr;
666	size = uap->len;
667	prot = uap->prot & VM_PROT_ALL;
668
669	pageoff = (addr & PAGE_MASK);
670	addr -= pageoff;
671	size += pageoff;
672	size = (vm_size_t) round_page(size);
673	if (addr + size < addr)
674		return (EINVAL);
675
676	switch (vm_map_protect(&td->td_proc->p_vmspace->vm_map, addr,
677	    addr + size, prot, FALSE)) {
678	case KERN_SUCCESS:
679		return (0);
680	case KERN_PROTECTION_FAILURE:
681		return (EACCES);
682	case KERN_RESOURCE_SHORTAGE:
683		return (ENOMEM);
684	}
685	return (EINVAL);
686}
687
688#ifndef _SYS_SYSPROTO_H_
689struct minherit_args {
690	void *addr;
691	size_t len;
692	int inherit;
693};
694#endif
695/*
696 * MPSAFE
697 */
698int
699sys_minherit(td, uap)
700	struct thread *td;
701	struct minherit_args *uap;
702{
703	vm_offset_t addr;
704	vm_size_t size, pageoff;
705	vm_inherit_t inherit;
706
707	addr = (vm_offset_t)uap->addr;
708	size = uap->len;
709	inherit = uap->inherit;
710
711	pageoff = (addr & PAGE_MASK);
712	addr -= pageoff;
713	size += pageoff;
714	size = (vm_size_t) round_page(size);
715	if (addr + size < addr)
716		return (EINVAL);
717
718	switch (vm_map_inherit(&td->td_proc->p_vmspace->vm_map, addr,
719	    addr + size, inherit)) {
720	case KERN_SUCCESS:
721		return (0);
722	case KERN_PROTECTION_FAILURE:
723		return (EACCES);
724	}
725	return (EINVAL);
726}
727
728#ifndef _SYS_SYSPROTO_H_
729struct madvise_args {
730	void *addr;
731	size_t len;
732	int behav;
733};
734#endif
735
736/*
737 * MPSAFE
738 */
739int
740sys_madvise(td, uap)
741	struct thread *td;
742	struct madvise_args *uap;
743{
744	vm_offset_t start, end;
745	vm_map_t map;
746	int flags;
747
748	/*
749	 * Check for our special case, advising the swap pager we are
750	 * "immortal."
751	 */
752	if (uap->behav == MADV_PROTECT) {
753		flags = PPROT_SET;
754		return (kern_procctl(td, P_PID, td->td_proc->p_pid,
755		    PROC_SPROTECT, &flags));
756	}
757
758	/*
759	 * Check for illegal behavior
760	 */
761	if (uap->behav < 0 || uap->behav > MADV_CORE)
762		return (EINVAL);
763	/*
764	 * Check for illegal addresses.  Watch out for address wrap... Note
765	 * that VM_*_ADDRESS are not constants due to casts (argh).
766	 */
767	map = &td->td_proc->p_vmspace->vm_map;
768	if ((vm_offset_t)uap->addr < vm_map_min(map) ||
769	    (vm_offset_t)uap->addr + uap->len > vm_map_max(map))
770		return (EINVAL);
771	if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
772		return (EINVAL);
773
774	/*
775	 * Since this routine is only advisory, we default to conservative
776	 * behavior.
777	 */
778	start = trunc_page((vm_offset_t) uap->addr);
779	end = round_page((vm_offset_t) uap->addr + uap->len);
780
781	if (vm_map_madvise(map, start, end, uap->behav))
782		return (EINVAL);
783	return (0);
784}
785
786#ifndef _SYS_SYSPROTO_H_
787struct mincore_args {
788	const void *addr;
789	size_t len;
790	char *vec;
791};
792#endif
793
794/*
795 * MPSAFE
796 */
797int
798sys_mincore(td, uap)
799	struct thread *td;
800	struct mincore_args *uap;
801{
802	vm_offset_t addr, first_addr;
803	vm_offset_t end, cend;
804	pmap_t pmap;
805	vm_map_t map;
806	char *vec;
807	int error = 0;
808	int vecindex, lastvecindex;
809	vm_map_entry_t current;
810	vm_map_entry_t entry;
811	vm_object_t object;
812	vm_paddr_t locked_pa;
813	vm_page_t m;
814	vm_pindex_t pindex;
815	int mincoreinfo;
816	unsigned int timestamp;
817	boolean_t locked;
818
819	/*
820	 * Make sure that the addresses presented are valid for user
821	 * mode.
822	 */
823	first_addr = addr = trunc_page((vm_offset_t) uap->addr);
824	end = addr + (vm_size_t)round_page(uap->len);
825	map = &td->td_proc->p_vmspace->vm_map;
826	if (end > vm_map_max(map) || end < addr)
827		return (ENOMEM);
828
829	/*
830	 * Address of byte vector
831	 */
832	vec = uap->vec;
833
834	pmap = vmspace_pmap(td->td_proc->p_vmspace);
835
836	vm_map_lock_read(map);
837RestartScan:
838	timestamp = map->timestamp;
839
840	if (!vm_map_lookup_entry(map, addr, &entry)) {
841		vm_map_unlock_read(map);
842		return (ENOMEM);
843	}
844
845	/*
846	 * Do this on a map entry basis so that if the pages are not
847	 * in the current processes address space, we can easily look
848	 * up the pages elsewhere.
849	 */
850	lastvecindex = -1;
851	for (current = entry;
852	    (current != &map->header) && (current->start < end);
853	    current = current->next) {
854
855		/*
856		 * check for contiguity
857		 */
858		if (current->end < end &&
859		    (entry->next == &map->header ||
860		     current->next->start > current->end)) {
861			vm_map_unlock_read(map);
862			return (ENOMEM);
863		}
864
865		/*
866		 * ignore submaps (for now) or null objects
867		 */
868		if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
869			current->object.vm_object == NULL)
870			continue;
871
872		/*
873		 * limit this scan to the current map entry and the
874		 * limits for the mincore call
875		 */
876		if (addr < current->start)
877			addr = current->start;
878		cend = current->end;
879		if (cend > end)
880			cend = end;
881
882		/*
883		 * scan this entry one page at a time
884		 */
885		while (addr < cend) {
886			/*
887			 * Check pmap first, it is likely faster, also
888			 * it can provide info as to whether we are the
889			 * one referencing or modifying the page.
890			 */
891			object = NULL;
892			locked_pa = 0;
893		retry:
894			m = NULL;
895			mincoreinfo = pmap_mincore(pmap, addr, &locked_pa);
896			if (locked_pa != 0) {
897				/*
898				 * The page is mapped by this process but not
899				 * both accessed and modified.  It is also
900				 * managed.  Acquire the object lock so that
901				 * other mappings might be examined.
902				 */
903				m = PHYS_TO_VM_PAGE(locked_pa);
904				if (m->object != object) {
905					if (object != NULL)
906						VM_OBJECT_WUNLOCK(object);
907					object = m->object;
908					locked = VM_OBJECT_TRYWLOCK(object);
909					vm_page_unlock(m);
910					if (!locked) {
911						VM_OBJECT_WLOCK(object);
912						vm_page_lock(m);
913						goto retry;
914					}
915				} else
916					vm_page_unlock(m);
917				KASSERT(m->valid == VM_PAGE_BITS_ALL,
918				    ("mincore: page %p is mapped but invalid",
919				    m));
920			} else if (mincoreinfo == 0) {
921				/*
922				 * The page is not mapped by this process.  If
923				 * the object implements managed pages, then
924				 * determine if the page is resident so that
925				 * the mappings might be examined.
926				 */
927				if (current->object.vm_object != object) {
928					if (object != NULL)
929						VM_OBJECT_WUNLOCK(object);
930					object = current->object.vm_object;
931					VM_OBJECT_WLOCK(object);
932				}
933				if (object->type == OBJT_DEFAULT ||
934				    object->type == OBJT_SWAP ||
935				    object->type == OBJT_VNODE) {
936					pindex = OFF_TO_IDX(current->offset +
937					    (addr - current->start));
938					m = vm_page_lookup(object, pindex);
939					if (m == NULL &&
940					    vm_page_is_cached(object, pindex))
941						mincoreinfo = MINCORE_INCORE;
942					if (m != NULL && m->valid == 0)
943						m = NULL;
944					if (m != NULL)
945						mincoreinfo = MINCORE_INCORE;
946				}
947			}
948			if (m != NULL) {
949				/* Examine other mappings to the page. */
950				if (m->dirty == 0 && pmap_is_modified(m))
951					vm_page_dirty(m);
952				if (m->dirty != 0)
953					mincoreinfo |= MINCORE_MODIFIED_OTHER;
954				/*
955				 * The first test for PGA_REFERENCED is an
956				 * optimization.  The second test is
957				 * required because a concurrent pmap
958				 * operation could clear the last reference
959				 * and set PGA_REFERENCED before the call to
960				 * pmap_is_referenced().
961				 */
962				if ((m->aflags & PGA_REFERENCED) != 0 ||
963				    pmap_is_referenced(m) ||
964				    (m->aflags & PGA_REFERENCED) != 0)
965					mincoreinfo |= MINCORE_REFERENCED_OTHER;
966			}
967			if (object != NULL)
968				VM_OBJECT_WUNLOCK(object);
969
970			/*
971			 * subyte may page fault.  In case it needs to modify
972			 * the map, we release the lock.
973			 */
974			vm_map_unlock_read(map);
975
976			/*
977			 * calculate index into user supplied byte vector
978			 */
979			vecindex = OFF_TO_IDX(addr - first_addr);
980
981			/*
982			 * If we have skipped map entries, we need to make sure that
983			 * the byte vector is zeroed for those skipped entries.
984			 */
985			while ((lastvecindex + 1) < vecindex) {
986				++lastvecindex;
987				error = subyte(vec + lastvecindex, 0);
988				if (error) {
989					error = EFAULT;
990					goto done2;
991				}
992			}
993
994			/*
995			 * Pass the page information to the user
996			 */
997			error = subyte(vec + vecindex, mincoreinfo);
998			if (error) {
999				error = EFAULT;
1000				goto done2;
1001			}
1002
1003			/*
1004			 * If the map has changed, due to the subyte, the previous
1005			 * output may be invalid.
1006			 */
1007			vm_map_lock_read(map);
1008			if (timestamp != map->timestamp)
1009				goto RestartScan;
1010
1011			lastvecindex = vecindex;
1012			addr += PAGE_SIZE;
1013		}
1014	}
1015
1016	/*
1017	 * subyte may page fault.  In case it needs to modify
1018	 * the map, we release the lock.
1019	 */
1020	vm_map_unlock_read(map);
1021
1022	/*
1023	 * Zero the last entries in the byte vector.
1024	 */
1025	vecindex = OFF_TO_IDX(end - first_addr);
1026	while ((lastvecindex + 1) < vecindex) {
1027		++lastvecindex;
1028		error = subyte(vec + lastvecindex, 0);
1029		if (error) {
1030			error = EFAULT;
1031			goto done2;
1032		}
1033	}
1034
1035	/*
1036	 * If the map has changed, due to the subyte, the previous
1037	 * output may be invalid.
1038	 */
1039	vm_map_lock_read(map);
1040	if (timestamp != map->timestamp)
1041		goto RestartScan;
1042	vm_map_unlock_read(map);
1043done2:
1044	return (error);
1045}
1046
1047#ifndef _SYS_SYSPROTO_H_
1048struct mlock_args {
1049	const void *addr;
1050	size_t len;
1051};
1052#endif
1053/*
1054 * MPSAFE
1055 */
1056int
1057sys_mlock(td, uap)
1058	struct thread *td;
1059	struct mlock_args *uap;
1060{
1061
1062	return (vm_mlock(td->td_proc, td->td_ucred, uap->addr, uap->len));
1063}
1064
1065int
1066vm_mlock(struct proc *proc, struct ucred *cred, const void *addr0, size_t len)
1067{
1068	vm_offset_t addr, end, last, start;
1069	vm_size_t npages, size;
1070	vm_map_t map;
1071	unsigned long nsize;
1072	int error;
1073
1074	error = priv_check_cred(cred, PRIV_VM_MLOCK, 0);
1075	if (error)
1076		return (error);
1077	addr = (vm_offset_t)addr0;
1078	size = len;
1079	last = addr + size;
1080	start = trunc_page(addr);
1081	end = round_page(last);
1082	if (last < addr || end < addr)
1083		return (EINVAL);
1084	npages = atop(end - start);
1085	if (npages > vm_page_max_wired)
1086		return (ENOMEM);
1087	map = &proc->p_vmspace->vm_map;
1088	PROC_LOCK(proc);
1089	nsize = ptoa(npages + pmap_wired_count(map->pmap));
1090	if (nsize > lim_cur(proc, RLIMIT_MEMLOCK)) {
1091		PROC_UNLOCK(proc);
1092		return (ENOMEM);
1093	}
1094	PROC_UNLOCK(proc);
1095	if (npages + cnt.v_wire_count > vm_page_max_wired)
1096		return (EAGAIN);
1097#ifdef RACCT
1098	PROC_LOCK(proc);
1099	error = racct_set(proc, RACCT_MEMLOCK, nsize);
1100	PROC_UNLOCK(proc);
1101	if (error != 0)
1102		return (ENOMEM);
1103#endif
1104	error = vm_map_wire(map, start, end,
1105	    VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
1106#ifdef RACCT
1107	if (error != KERN_SUCCESS) {
1108		PROC_LOCK(proc);
1109		racct_set(proc, RACCT_MEMLOCK,
1110		    ptoa(pmap_wired_count(map->pmap)));
1111		PROC_UNLOCK(proc);
1112	}
1113#endif
1114	return (error == KERN_SUCCESS ? 0 : ENOMEM);
1115}
1116
1117#ifndef _SYS_SYSPROTO_H_
1118struct mlockall_args {
1119	int	how;
1120};
1121#endif
1122
1123/*
1124 * MPSAFE
1125 */
1126int
1127sys_mlockall(td, uap)
1128	struct thread *td;
1129	struct mlockall_args *uap;
1130{
1131	vm_map_t map;
1132	int error;
1133
1134	map = &td->td_proc->p_vmspace->vm_map;
1135	error = priv_check(td, PRIV_VM_MLOCK);
1136	if (error)
1137		return (error);
1138
1139	if ((uap->how == 0) || ((uap->how & ~(MCL_CURRENT|MCL_FUTURE)) != 0))
1140		return (EINVAL);
1141
1142	/*
1143	 * If wiring all pages in the process would cause it to exceed
1144	 * a hard resource limit, return ENOMEM.
1145	 */
1146	if (!old_mlock && uap->how & MCL_CURRENT) {
1147		PROC_LOCK(td->td_proc);
1148		if (map->size > lim_cur(td->td_proc, RLIMIT_MEMLOCK)) {
1149			PROC_UNLOCK(td->td_proc);
1150			return (ENOMEM);
1151		}
1152		PROC_UNLOCK(td->td_proc);
1153	}
1154#ifdef RACCT
1155	PROC_LOCK(td->td_proc);
1156	error = racct_set(td->td_proc, RACCT_MEMLOCK, map->size);
1157	PROC_UNLOCK(td->td_proc);
1158	if (error != 0)
1159		return (ENOMEM);
1160#endif
1161
1162	if (uap->how & MCL_FUTURE) {
1163		vm_map_lock(map);
1164		vm_map_modflags(map, MAP_WIREFUTURE, 0);
1165		vm_map_unlock(map);
1166		error = 0;
1167	}
1168
1169	if (uap->how & MCL_CURRENT) {
1170		/*
1171		 * P1003.1-2001 mandates that all currently mapped pages
1172		 * will be memory resident and locked (wired) upon return
1173		 * from mlockall(). vm_map_wire() will wire pages, by
1174		 * calling vm_fault_wire() for each page in the region.
1175		 */
1176		error = vm_map_wire(map, vm_map_min(map), vm_map_max(map),
1177		    VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
1178		error = (error == KERN_SUCCESS ? 0 : EAGAIN);
1179	}
1180#ifdef RACCT
1181	if (error != KERN_SUCCESS) {
1182		PROC_LOCK(td->td_proc);
1183		racct_set(td->td_proc, RACCT_MEMLOCK,
1184		    ptoa(pmap_wired_count(map->pmap)));
1185		PROC_UNLOCK(td->td_proc);
1186	}
1187#endif
1188
1189	return (error);
1190}
1191
1192#ifndef _SYS_SYSPROTO_H_
1193struct munlockall_args {
1194	register_t dummy;
1195};
1196#endif
1197
1198/*
1199 * MPSAFE
1200 */
1201int
1202sys_munlockall(td, uap)
1203	struct thread *td;
1204	struct munlockall_args *uap;
1205{
1206	vm_map_t map;
1207	int error;
1208
1209	map = &td->td_proc->p_vmspace->vm_map;
1210	error = priv_check(td, PRIV_VM_MUNLOCK);
1211	if (error)
1212		return (error);
1213
1214	/* Clear the MAP_WIREFUTURE flag from this vm_map. */
1215	vm_map_lock(map);
1216	vm_map_modflags(map, 0, MAP_WIREFUTURE);
1217	vm_map_unlock(map);
1218
1219	/* Forcibly unwire all pages. */
1220	error = vm_map_unwire(map, vm_map_min(map), vm_map_max(map),
1221	    VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
1222#ifdef RACCT
1223	if (error == KERN_SUCCESS) {
1224		PROC_LOCK(td->td_proc);
1225		racct_set(td->td_proc, RACCT_MEMLOCK, 0);
1226		PROC_UNLOCK(td->td_proc);
1227	}
1228#endif
1229
1230	return (error);
1231}
1232
1233#ifndef _SYS_SYSPROTO_H_
1234struct munlock_args {
1235	const void *addr;
1236	size_t len;
1237};
1238#endif
1239/*
1240 * MPSAFE
1241 */
1242int
1243sys_munlock(td, uap)
1244	struct thread *td;
1245	struct munlock_args *uap;
1246{
1247	vm_offset_t addr, end, last, start;
1248	vm_size_t size;
1249#ifdef RACCT
1250	vm_map_t map;
1251#endif
1252	int error;
1253
1254	error = priv_check(td, PRIV_VM_MUNLOCK);
1255	if (error)
1256		return (error);
1257	addr = (vm_offset_t)uap->addr;
1258	size = uap->len;
1259	last = addr + size;
1260	start = trunc_page(addr);
1261	end = round_page(last);
1262	if (last < addr || end < addr)
1263		return (EINVAL);
1264	error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, start, end,
1265	    VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
1266#ifdef RACCT
1267	if (error == KERN_SUCCESS) {
1268		PROC_LOCK(td->td_proc);
1269		map = &td->td_proc->p_vmspace->vm_map;
1270		racct_set(td->td_proc, RACCT_MEMLOCK,
1271		    ptoa(pmap_wired_count(map->pmap)));
1272		PROC_UNLOCK(td->td_proc);
1273	}
1274#endif
1275	return (error == KERN_SUCCESS ? 0 : ENOMEM);
1276}
1277
1278/*
1279 * vm_mmap_vnode()
1280 *
1281 * Helper function for vm_mmap.  Perform sanity check specific for mmap
1282 * operations on vnodes.
1283 *
1284 * For VCHR vnodes, the vnode lock is held over the call to
1285 * vm_mmap_cdev() to keep vp->v_rdev valid.
1286 */
1287int
1288vm_mmap_vnode(struct thread *td, vm_size_t objsize,
1289    vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1290    struct vnode *vp, vm_ooffset_t *foffp, vm_object_t *objp,
1291    boolean_t *writecounted)
1292{
1293	struct vattr va;
1294	vm_object_t obj;
1295	vm_offset_t foff;
1296	struct ucred *cred;
1297	int error, flags, locktype;
1298
1299	cred = td->td_ucred;
1300	if ((*maxprotp & VM_PROT_WRITE) && (*flagsp & MAP_SHARED))
1301		locktype = LK_EXCLUSIVE;
1302	else
1303		locktype = LK_SHARED;
1304	if ((error = vget(vp, locktype, td)) != 0)
1305		return (error);
1306	foff = *foffp;
1307	flags = *flagsp;
1308	obj = vp->v_object;
1309	if (vp->v_type == VREG) {
1310		/*
1311		 * Get the proper underlying object
1312		 */
1313		if (obj == NULL) {
1314			error = EINVAL;
1315			goto done;
1316		}
1317		if (obj->type == OBJT_VNODE && obj->handle != vp) {
1318			vput(vp);
1319			vp = (struct vnode *)obj->handle;
1320			/*
1321			 * Bypass filesystems obey the mpsafety of the
1322			 * underlying fs.  Tmpfs never bypasses.
1323			 */
1324			error = vget(vp, locktype, td);
1325			if (error != 0)
1326				return (error);
1327		}
1328		if (locktype == LK_EXCLUSIVE) {
1329			*writecounted = TRUE;
1330			vnode_pager_update_writecount(obj, 0, objsize);
1331		}
1332	} else if (vp->v_type == VCHR) {
1333		error = vm_mmap_cdev(td, objsize, prot, maxprotp, flagsp,
1334		    vp->v_rdev, foffp, objp);
1335		if (error == 0)
1336			goto mark_atime;
1337		goto done;
1338	} else {
1339		error = EINVAL;
1340		goto done;
1341	}
1342	if ((error = VOP_GETATTR(vp, &va, cred)))
1343		goto done;
1344#ifdef MAC
1345	error = mac_vnode_check_mmap(cred, vp, prot, flags);
1346	if (error != 0)
1347		goto done;
1348#endif
1349	if ((flags & MAP_SHARED) != 0) {
1350		if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) != 0) {
1351			if (prot & PROT_WRITE) {
1352				error = EPERM;
1353				goto done;
1354			}
1355			*maxprotp &= ~VM_PROT_WRITE;
1356		}
1357	}
1358	/*
1359	 * If it is a regular file without any references
1360	 * we do not need to sync it.
1361	 * Adjust object size to be the size of actual file.
1362	 */
1363	objsize = round_page(va.va_size);
1364	if (va.va_nlink == 0)
1365		flags |= MAP_NOSYNC;
1366	if (obj->type == OBJT_VNODE)
1367		obj = vm_pager_allocate(OBJT_VNODE, vp, objsize, prot, foff,
1368		    cred);
1369	else {
1370		KASSERT(obj->type == OBJT_DEFAULT || obj->type == OBJT_SWAP,
1371		    ("wrong object type"));
1372		vm_object_reference(obj);
1373	}
1374	if (obj == NULL) {
1375		error = ENOMEM;
1376		goto done;
1377	}
1378	*objp = obj;
1379	*flagsp = flags;
1380
1381mark_atime:
1382	vfs_mark_atime(vp, cred);
1383
1384done:
1385	if (error != 0 && *writecounted) {
1386		*writecounted = FALSE;
1387		vnode_pager_update_writecount(obj, objsize, 0);
1388	}
1389	vput(vp);
1390	return (error);
1391}
1392
1393/*
1394 * vm_mmap_cdev()
1395 *
1396 * MPSAFE
1397 *
1398 * Helper function for vm_mmap.  Perform sanity check specific for mmap
1399 * operations on cdevs.
1400 */
1401int
1402vm_mmap_cdev(struct thread *td, vm_size_t objsize,
1403    vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1404    struct cdev *cdev, vm_ooffset_t *foff, vm_object_t *objp)
1405{
1406	vm_object_t obj;
1407	struct cdevsw *dsw;
1408	int error, flags, ref;
1409
1410	flags = *flagsp;
1411
1412	dsw = dev_refthread(cdev, &ref);
1413	if (dsw == NULL)
1414		return (ENXIO);
1415	if (dsw->d_flags & D_MMAP_ANON) {
1416		dev_relthread(cdev, ref);
1417		*maxprotp = VM_PROT_ALL;
1418		*flagsp |= MAP_ANON;
1419		return (0);
1420	}
1421	/*
1422	 * cdevs do not provide private mappings of any kind.
1423	 */
1424	if ((*maxprotp & VM_PROT_WRITE) == 0 &&
1425	    (prot & PROT_WRITE) != 0) {
1426		dev_relthread(cdev, ref);
1427		return (EACCES);
1428	}
1429	if (flags & (MAP_PRIVATE|MAP_COPY)) {
1430		dev_relthread(cdev, ref);
1431		return (EINVAL);
1432	}
1433	/*
1434	 * Force device mappings to be shared.
1435	 */
1436	flags |= MAP_SHARED;
1437#ifdef MAC_XXX
1438	error = mac_cdev_check_mmap(td->td_ucred, cdev, prot);
1439	if (error != 0) {
1440		dev_relthread(cdev, ref);
1441		return (error);
1442	}
1443#endif
1444	/*
1445	 * First, try d_mmap_single().  If that is not implemented
1446	 * (returns ENODEV), fall back to using the device pager.
1447	 * Note that d_mmap_single() must return a reference to the
1448	 * object (it needs to bump the reference count of the object
1449	 * it returns somehow).
1450	 *
1451	 * XXX assumes VM_PROT_* == PROT_*
1452	 */
1453	error = dsw->d_mmap_single(cdev, foff, objsize, objp, (int)prot);
1454	dev_relthread(cdev, ref);
1455	if (error != ENODEV)
1456		return (error);
1457	obj = vm_pager_allocate(OBJT_DEVICE, cdev, objsize, prot, *foff,
1458	    td->td_ucred);
1459	if (obj == NULL)
1460		return (EINVAL);
1461	*objp = obj;
1462	*flagsp = flags;
1463	return (0);
1464}
1465
1466/*
1467 * vm_mmap_shm()
1468 *
1469 * MPSAFE
1470 *
1471 * Helper function for vm_mmap.  Perform sanity check specific for mmap
1472 * operations on shm file descriptors.
1473 */
1474int
1475vm_mmap_shm(struct thread *td, vm_size_t objsize,
1476    vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1477    struct shmfd *shmfd, vm_ooffset_t foff, vm_object_t *objp)
1478{
1479	int error;
1480
1481	if ((*flagsp & MAP_SHARED) != 0 &&
1482	    (*maxprotp & VM_PROT_WRITE) == 0 &&
1483	    (prot & PROT_WRITE) != 0)
1484		return (EACCES);
1485#ifdef MAC
1486	error = mac_posixshm_check_mmap(td->td_ucred, shmfd, prot, *flagsp);
1487	if (error != 0)
1488		return (error);
1489#endif
1490	error = shm_mmap(shmfd, objsize, foff, objp);
1491	if (error)
1492		return (error);
1493	return (0);
1494}
1495
1496/*
1497 * vm_mmap()
1498 *
1499 * MPSAFE
1500 *
1501 * Internal version of mmap.  Currently used by mmap, exec, and sys5
1502 * shared memory.  Handle is either a vnode pointer or NULL for MAP_ANON.
1503 */
1504int
1505vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
1506	vm_prot_t maxprot, int flags,
1507	objtype_t handle_type, void *handle,
1508	vm_ooffset_t foff)
1509{
1510	boolean_t fitit;
1511	vm_object_t object = NULL;
1512	struct thread *td = curthread;
1513	int docow, error, findspace, rv;
1514	boolean_t writecounted;
1515
1516	if (size == 0)
1517		return (0);
1518
1519	size = round_page(size);
1520
1521	if (map == &td->td_proc->p_vmspace->vm_map) {
1522		PROC_LOCK(td->td_proc);
1523		if (map->size + size > lim_cur(td->td_proc, RLIMIT_VMEM)) {
1524			PROC_UNLOCK(td->td_proc);
1525			return (ENOMEM);
1526		}
1527		if (racct_set(td->td_proc, RACCT_VMEM, map->size + size)) {
1528			PROC_UNLOCK(td->td_proc);
1529			return (ENOMEM);
1530		}
1531		if (!old_mlock && map->flags & MAP_WIREFUTURE) {
1532			if (ptoa(pmap_wired_count(map->pmap)) + size >
1533			    lim_cur(td->td_proc, RLIMIT_MEMLOCK)) {
1534				racct_set_force(td->td_proc, RACCT_VMEM,
1535				    map->size);
1536				PROC_UNLOCK(td->td_proc);
1537				return (ENOMEM);
1538			}
1539			error = racct_set(td->td_proc, RACCT_MEMLOCK,
1540			    ptoa(pmap_wired_count(map->pmap)) + size);
1541			if (error != 0) {
1542				racct_set_force(td->td_proc, RACCT_VMEM,
1543				    map->size);
1544				PROC_UNLOCK(td->td_proc);
1545				return (error);
1546			}
1547		}
1548		PROC_UNLOCK(td->td_proc);
1549	}
1550
1551	/*
1552	 * We currently can only deal with page aligned file offsets.
1553	 * The check is here rather than in the syscall because the
1554	 * kernel calls this function internally for other mmaping
1555	 * operations (such as in exec) and non-aligned offsets will
1556	 * cause pmap inconsistencies...so we want to be sure to
1557	 * disallow this in all cases.
1558	 */
1559	if (foff & PAGE_MASK)
1560		return (EINVAL);
1561
1562	if ((flags & MAP_FIXED) == 0) {
1563		fitit = TRUE;
1564		*addr = round_page(*addr);
1565	} else {
1566		if (*addr != trunc_page(*addr))
1567			return (EINVAL);
1568		fitit = FALSE;
1569	}
1570	writecounted = FALSE;
1571
1572	/*
1573	 * Lookup/allocate object.
1574	 */
1575	switch (handle_type) {
1576	case OBJT_DEVICE:
1577		error = vm_mmap_cdev(td, size, prot, &maxprot, &flags,
1578		    handle, &foff, &object);
1579		break;
1580	case OBJT_VNODE:
1581		error = vm_mmap_vnode(td, size, prot, &maxprot, &flags,
1582		    handle, &foff, &object, &writecounted);
1583		break;
1584	case OBJT_SWAP:
1585		error = vm_mmap_shm(td, size, prot, &maxprot, &flags,
1586		    handle, foff, &object);
1587		break;
1588	case OBJT_DEFAULT:
1589		if (handle == NULL) {
1590			error = 0;
1591			break;
1592		}
1593		/* FALLTHROUGH */
1594	default:
1595		error = EINVAL;
1596		break;
1597	}
1598	if (error)
1599		return (error);
1600	if (flags & MAP_ANON) {
1601		object = NULL;
1602		docow = 0;
1603		/*
1604		 * Unnamed anonymous regions always start at 0.
1605		 */
1606		if (handle == 0)
1607			foff = 0;
1608	} else if (flags & MAP_PREFAULT_READ)
1609		docow = MAP_PREFAULT;
1610	else
1611		docow = MAP_PREFAULT_PARTIAL;
1612
1613	if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1614		docow |= MAP_COPY_ON_WRITE;
1615	if (flags & MAP_NOSYNC)
1616		docow |= MAP_DISABLE_SYNCER;
1617	if (flags & MAP_NOCORE)
1618		docow |= MAP_DISABLE_COREDUMP;
1619	/* Shared memory is also shared with children. */
1620	if (flags & MAP_SHARED)
1621		docow |= MAP_INHERIT_SHARE;
1622	if (writecounted)
1623		docow |= MAP_VN_WRITECOUNT;
1624	if (flags & MAP_STACK) {
1625		if (object != NULL)
1626			return (EINVAL);
1627		docow |= MAP_STACK_GROWS_DOWN;
1628	}
1629	if ((flags & MAP_EXCL) != 0)
1630		docow |= MAP_CHECK_EXCL;
1631
1632	if (fitit) {
1633		if ((flags & MAP_ALIGNMENT_MASK) == MAP_ALIGNED_SUPER)
1634			findspace = VMFS_SUPER_SPACE;
1635		else if ((flags & MAP_ALIGNMENT_MASK) != 0)
1636			findspace = VMFS_ALIGNED_SPACE(flags >>
1637			    MAP_ALIGNMENT_SHIFT);
1638		else
1639			findspace = VMFS_OPTIMAL_SPACE;
1640		rv = vm_map_find(map, object, foff, addr, size,
1641#ifdef MAP_32BIT
1642		    flags & MAP_32BIT ? MAP_32BIT_MAX_ADDR :
1643#endif
1644		    0, findspace, prot, maxprot, docow);
1645	} else {
1646		rv = vm_map_fixed(map, object, foff, *addr, size,
1647		    prot, maxprot, docow);
1648	}
1649
1650	if (rv == KERN_SUCCESS) {
1651		/*
1652		 * If the process has requested that all future mappings
1653		 * be wired, then heed this.
1654		 */
1655		if (map->flags & MAP_WIREFUTURE) {
1656			vm_map_wire(map, *addr, *addr + size,
1657			    VM_MAP_WIRE_USER | ((flags & MAP_STACK) ?
1658			    VM_MAP_WIRE_HOLESOK : VM_MAP_WIRE_NOHOLES));
1659		}
1660	} else {
1661		/*
1662		 * If this mapping was accounted for in the vnode's
1663		 * writecount, then undo that now.
1664		 */
1665		if (writecounted)
1666			vnode_pager_release_writecount(object, 0, size);
1667		/*
1668		 * Lose the object reference.  Will destroy the
1669		 * object if it's an unnamed anonymous mapping
1670		 * or named anonymous without other references.
1671		 */
1672		vm_object_deallocate(object);
1673	}
1674	return (vm_mmap_to_errno(rv));
1675}
1676
1677/*
1678 * Translate a Mach VM return code to zero on success or the appropriate errno
1679 * on failure.
1680 */
1681int
1682vm_mmap_to_errno(int rv)
1683{
1684
1685	switch (rv) {
1686	case KERN_SUCCESS:
1687		return (0);
1688	case KERN_INVALID_ADDRESS:
1689	case KERN_NO_SPACE:
1690		return (ENOMEM);
1691	case KERN_PROTECTION_FAILURE:
1692		return (EACCES);
1693	default:
1694		return (EINVAL);
1695	}
1696}
1697