FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_mmap.c
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: releng/10.1/sys/vm/vm_mmap.c 267901 2014-06-26 08:30:08Z kib $");
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/capability.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
94 int old_mlock = 0;
95 SYSCTL_INT(_vm, OID_AUTO, old_mlock, CTLFLAG_RW | CTLFLAG_TUN, &old_mlock, 0,
96 "Do not apply RLIMIT_MEMLOCK on mlockall");
97 TUNABLE_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
103 static 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 *);
105 static 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 *);
107 static 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_
111 struct sbrk_args {
112 int incr;
113 };
114 #endif
115
116 /*
117 * MPSAFE
118 */
119 /* ARGSUSED */
120 int
121 sys_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_
130 struct sstk_args {
131 int incr;
132 };
133 #endif
134
135 /*
136 * MPSAFE
137 */
138 /* ARGSUSED */
139 int
140 sys_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_
150 struct getpagesize_args {
151 int dummy;
152 };
153 #endif
154
155 int
156 ogetpagesize(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_
181 struct 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 */
195 int
196 sys_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 }
416 map:
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);
433 done:
434 if (fp)
435 fdrop(fp, td);
436
437 return (error);
438 }
439
440 int
441 freebsd6_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_
456 struct ommap_args {
457 caddr_t addr;
458 int len;
459 int prot;
460 int flags;
461 int fd;
462 long pos;
463 };
464 #endif
465 int
466 ommap(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_
516 struct msync_args {
517 void *addr;
518 size_t len;
519 int flags;
520 };
521 #endif
522 /*
523 * MPSAFE
524 */
525 int
526 sys_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_
572 struct munmap_args {
573 void *addr;
574 size_t len;
575 };
576 #endif
577 /*
578 * MPSAFE
579 */
580 int
581 sys_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_
647 struct mprotect_args {
648 const void *addr;
649 size_t len;
650 int prot;
651 };
652 #endif
653 /*
654 * MPSAFE
655 */
656 int
657 sys_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_
689 struct minherit_args {
690 void *addr;
691 size_t len;
692 int inherit;
693 };
694 #endif
695 /*
696 * MPSAFE
697 */
698 int
699 sys_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_
729 struct madvise_args {
730 void *addr;
731 size_t len;
732 int behav;
733 };
734 #endif
735
736 /*
737 * MPSAFE
738 */
739 int
740 sys_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_
787 struct mincore_args {
788 const void *addr;
789 size_t len;
790 char *vec;
791 };
792 #endif
793
794 /*
795 * MPSAFE
796 */
797 int
798 sys_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);
837 RestartScan:
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);
1043 done2:
1044 return (error);
1045 }
1046
1047 #ifndef _SYS_SYSPROTO_H_
1048 struct mlock_args {
1049 const void *addr;
1050 size_t len;
1051 };
1052 #endif
1053 /*
1054 * MPSAFE
1055 */
1056 int
1057 sys_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
1065 int
1066 vm_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_
1118 struct mlockall_args {
1119 int how;
1120 };
1121 #endif
1122
1123 /*
1124 * MPSAFE
1125 */
1126 int
1127 sys_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_
1193 struct munlockall_args {
1194 register_t dummy;
1195 };
1196 #endif
1197
1198 /*
1199 * MPSAFE
1200 */
1201 int
1202 sys_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_
1234 struct munlock_args {
1235 const void *addr;
1236 size_t len;
1237 };
1238 #endif
1239 /*
1240 * MPSAFE
1241 */
1242 int
1243 sys_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 */
1287 int
1288 vm_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 mount *mp;
1297 struct ucred *cred;
1298 int error, flags, locktype;
1299
1300 mp = vp->v_mount;
1301 cred = td->td_ucred;
1302 if ((*maxprotp & VM_PROT_WRITE) && (*flagsp & MAP_SHARED))
1303 locktype = LK_EXCLUSIVE;
1304 else
1305 locktype = LK_SHARED;
1306 if ((error = vget(vp, locktype, td)) != 0)
1307 return (error);
1308 foff = *foffp;
1309 flags = *flagsp;
1310 obj = vp->v_object;
1311 if (vp->v_type == VREG) {
1312 /*
1313 * Get the proper underlying object
1314 */
1315 if (obj == NULL) {
1316 error = EINVAL;
1317 goto done;
1318 }
1319 if (obj->type == OBJT_VNODE && obj->handle != vp) {
1320 vput(vp);
1321 vp = (struct vnode *)obj->handle;
1322 /*
1323 * Bypass filesystems obey the mpsafety of the
1324 * underlying fs. Tmpfs never bypasses.
1325 */
1326 error = vget(vp, locktype, td);
1327 if (error != 0)
1328 return (error);
1329 }
1330 if (locktype == LK_EXCLUSIVE) {
1331 *writecounted = TRUE;
1332 vnode_pager_update_writecount(obj, 0, objsize);
1333 }
1334 } else if (vp->v_type == VCHR) {
1335 error = vm_mmap_cdev(td, objsize, prot, maxprotp, flagsp,
1336 vp->v_rdev, foffp, objp);
1337 if (error == 0)
1338 goto mark_atime;
1339 goto done;
1340 } else {
1341 error = EINVAL;
1342 goto done;
1343 }
1344 if ((error = VOP_GETATTR(vp, &va, cred)))
1345 goto done;
1346 #ifdef MAC
1347 error = mac_vnode_check_mmap(cred, vp, prot, flags);
1348 if (error != 0)
1349 goto done;
1350 #endif
1351 if ((flags & MAP_SHARED) != 0) {
1352 if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) != 0) {
1353 if (prot & PROT_WRITE) {
1354 error = EPERM;
1355 goto done;
1356 }
1357 *maxprotp &= ~VM_PROT_WRITE;
1358 }
1359 }
1360 /*
1361 * If it is a regular file without any references
1362 * we do not need to sync it.
1363 * Adjust object size to be the size of actual file.
1364 */
1365 objsize = round_page(va.va_size);
1366 if (va.va_nlink == 0)
1367 flags |= MAP_NOSYNC;
1368 if (obj->type == OBJT_VNODE)
1369 obj = vm_pager_allocate(OBJT_VNODE, vp, objsize, prot, foff,
1370 cred);
1371 else {
1372 KASSERT(obj->type == OBJT_DEFAULT || obj->type == OBJT_SWAP,
1373 ("wrong object type"));
1374 vm_object_reference(obj);
1375 }
1376 if (obj == NULL) {
1377 error = ENOMEM;
1378 goto done;
1379 }
1380 *objp = obj;
1381 *flagsp = flags;
1382
1383 mark_atime:
1384 vfs_mark_atime(vp, cred);
1385
1386 done:
1387 if (error != 0 && *writecounted) {
1388 *writecounted = FALSE;
1389 vnode_pager_update_writecount(obj, objsize, 0);
1390 }
1391 vput(vp);
1392 return (error);
1393 }
1394
1395 /*
1396 * vm_mmap_cdev()
1397 *
1398 * MPSAFE
1399 *
1400 * Helper function for vm_mmap. Perform sanity check specific for mmap
1401 * operations on cdevs.
1402 */
1403 int
1404 vm_mmap_cdev(struct thread *td, vm_size_t objsize,
1405 vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1406 struct cdev *cdev, vm_ooffset_t *foff, vm_object_t *objp)
1407 {
1408 vm_object_t obj;
1409 struct cdevsw *dsw;
1410 int error, flags, ref;
1411
1412 flags = *flagsp;
1413
1414 dsw = dev_refthread(cdev, &ref);
1415 if (dsw == NULL)
1416 return (ENXIO);
1417 if (dsw->d_flags & D_MMAP_ANON) {
1418 dev_relthread(cdev, ref);
1419 *maxprotp = VM_PROT_ALL;
1420 *flagsp |= MAP_ANON;
1421 return (0);
1422 }
1423 /*
1424 * cdevs do not provide private mappings of any kind.
1425 */
1426 if ((*maxprotp & VM_PROT_WRITE) == 0 &&
1427 (prot & PROT_WRITE) != 0) {
1428 dev_relthread(cdev, ref);
1429 return (EACCES);
1430 }
1431 if (flags & (MAP_PRIVATE|MAP_COPY)) {
1432 dev_relthread(cdev, ref);
1433 return (EINVAL);
1434 }
1435 /*
1436 * Force device mappings to be shared.
1437 */
1438 flags |= MAP_SHARED;
1439 #ifdef MAC_XXX
1440 error = mac_cdev_check_mmap(td->td_ucred, cdev, prot);
1441 if (error != 0) {
1442 dev_relthread(cdev, ref);
1443 return (error);
1444 }
1445 #endif
1446 /*
1447 * First, try d_mmap_single(). If that is not implemented
1448 * (returns ENODEV), fall back to using the device pager.
1449 * Note that d_mmap_single() must return a reference to the
1450 * object (it needs to bump the reference count of the object
1451 * it returns somehow).
1452 *
1453 * XXX assumes VM_PROT_* == PROT_*
1454 */
1455 error = dsw->d_mmap_single(cdev, foff, objsize, objp, (int)prot);
1456 dev_relthread(cdev, ref);
1457 if (error != ENODEV)
1458 return (error);
1459 obj = vm_pager_allocate(OBJT_DEVICE, cdev, objsize, prot, *foff,
1460 td->td_ucred);
1461 if (obj == NULL)
1462 return (EINVAL);
1463 *objp = obj;
1464 *flagsp = flags;
1465 return (0);
1466 }
1467
1468 /*
1469 * vm_mmap_shm()
1470 *
1471 * MPSAFE
1472 *
1473 * Helper function for vm_mmap. Perform sanity check specific for mmap
1474 * operations on shm file descriptors.
1475 */
1476 int
1477 vm_mmap_shm(struct thread *td, vm_size_t objsize,
1478 vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1479 struct shmfd *shmfd, vm_ooffset_t foff, vm_object_t *objp)
1480 {
1481 int error;
1482
1483 if ((*flagsp & MAP_SHARED) != 0 &&
1484 (*maxprotp & VM_PROT_WRITE) == 0 &&
1485 (prot & PROT_WRITE) != 0)
1486 return (EACCES);
1487 #ifdef MAC
1488 error = mac_posixshm_check_mmap(td->td_ucred, shmfd, prot, *flagsp);
1489 if (error != 0)
1490 return (error);
1491 #endif
1492 error = shm_mmap(shmfd, objsize, foff, objp);
1493 if (error)
1494 return (error);
1495 return (0);
1496 }
1497
1498 /*
1499 * vm_mmap()
1500 *
1501 * MPSAFE
1502 *
1503 * Internal version of mmap. Currently used by mmap, exec, and sys5
1504 * shared memory. Handle is either a vnode pointer or NULL for MAP_ANON.
1505 */
1506 int
1507 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
1508 vm_prot_t maxprot, int flags,
1509 objtype_t handle_type, void *handle,
1510 vm_ooffset_t foff)
1511 {
1512 boolean_t fitit;
1513 vm_object_t object = NULL;
1514 struct thread *td = curthread;
1515 int docow, error, findspace, rv;
1516 boolean_t writecounted;
1517
1518 if (size == 0)
1519 return (0);
1520
1521 size = round_page(size);
1522
1523 if (map == &td->td_proc->p_vmspace->vm_map) {
1524 PROC_LOCK(td->td_proc);
1525 if (map->size + size > lim_cur(td->td_proc, RLIMIT_VMEM)) {
1526 PROC_UNLOCK(td->td_proc);
1527 return (ENOMEM);
1528 }
1529 if (racct_set(td->td_proc, RACCT_VMEM, map->size + size)) {
1530 PROC_UNLOCK(td->td_proc);
1531 return (ENOMEM);
1532 }
1533 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
1534 if (ptoa(pmap_wired_count(map->pmap)) + size >
1535 lim_cur(td->td_proc, RLIMIT_MEMLOCK)) {
1536 racct_set_force(td->td_proc, RACCT_VMEM,
1537 map->size);
1538 PROC_UNLOCK(td->td_proc);
1539 return (ENOMEM);
1540 }
1541 error = racct_set(td->td_proc, RACCT_MEMLOCK,
1542 ptoa(pmap_wired_count(map->pmap)) + size);
1543 if (error != 0) {
1544 racct_set_force(td->td_proc, RACCT_VMEM,
1545 map->size);
1546 PROC_UNLOCK(td->td_proc);
1547 return (error);
1548 }
1549 }
1550 PROC_UNLOCK(td->td_proc);
1551 }
1552
1553 /*
1554 * We currently can only deal with page aligned file offsets.
1555 * The check is here rather than in the syscall because the
1556 * kernel calls this function internally for other mmaping
1557 * operations (such as in exec) and non-aligned offsets will
1558 * cause pmap inconsistencies...so we want to be sure to
1559 * disallow this in all cases.
1560 */
1561 if (foff & PAGE_MASK)
1562 return (EINVAL);
1563
1564 if ((flags & MAP_FIXED) == 0) {
1565 fitit = TRUE;
1566 *addr = round_page(*addr);
1567 } else {
1568 if (*addr != trunc_page(*addr))
1569 return (EINVAL);
1570 fitit = FALSE;
1571 }
1572 writecounted = FALSE;
1573
1574 /*
1575 * Lookup/allocate object.
1576 */
1577 switch (handle_type) {
1578 case OBJT_DEVICE:
1579 error = vm_mmap_cdev(td, size, prot, &maxprot, &flags,
1580 handle, &foff, &object);
1581 break;
1582 case OBJT_VNODE:
1583 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags,
1584 handle, &foff, &object, &writecounted);
1585 break;
1586 case OBJT_SWAP:
1587 error = vm_mmap_shm(td, size, prot, &maxprot, &flags,
1588 handle, foff, &object);
1589 break;
1590 case OBJT_DEFAULT:
1591 if (handle == NULL) {
1592 error = 0;
1593 break;
1594 }
1595 /* FALLTHROUGH */
1596 default:
1597 error = EINVAL;
1598 break;
1599 }
1600 if (error)
1601 return (error);
1602 if (flags & MAP_ANON) {
1603 object = NULL;
1604 docow = 0;
1605 /*
1606 * Unnamed anonymous regions always start at 0.
1607 */
1608 if (handle == 0)
1609 foff = 0;
1610 } else if (flags & MAP_PREFAULT_READ)
1611 docow = MAP_PREFAULT;
1612 else
1613 docow = MAP_PREFAULT_PARTIAL;
1614
1615 if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1616 docow |= MAP_COPY_ON_WRITE;
1617 if (flags & MAP_NOSYNC)
1618 docow |= MAP_DISABLE_SYNCER;
1619 if (flags & MAP_NOCORE)
1620 docow |= MAP_DISABLE_COREDUMP;
1621 /* Shared memory is also shared with children. */
1622 if (flags & MAP_SHARED)
1623 docow |= MAP_INHERIT_SHARE;
1624 if (writecounted)
1625 docow |= MAP_VN_WRITECOUNT;
1626 if (flags & MAP_STACK) {
1627 if (object != NULL)
1628 return (EINVAL);
1629 docow |= MAP_STACK_GROWS_DOWN;
1630 }
1631 if ((flags & MAP_EXCL) != 0)
1632 docow |= MAP_CHECK_EXCL;
1633
1634 if (fitit) {
1635 if ((flags & MAP_ALIGNMENT_MASK) == MAP_ALIGNED_SUPER)
1636 findspace = VMFS_SUPER_SPACE;
1637 else if ((flags & MAP_ALIGNMENT_MASK) != 0)
1638 findspace = VMFS_ALIGNED_SPACE(flags >>
1639 MAP_ALIGNMENT_SHIFT);
1640 else
1641 findspace = VMFS_OPTIMAL_SPACE;
1642 rv = vm_map_find(map, object, foff, addr, size,
1643 #ifdef MAP_32BIT
1644 flags & MAP_32BIT ? MAP_32BIT_MAX_ADDR :
1645 #endif
1646 0, findspace, prot, maxprot, docow);
1647 } else {
1648 rv = vm_map_fixed(map, object, foff, *addr, size,
1649 prot, maxprot, docow);
1650 }
1651
1652 if (rv == KERN_SUCCESS) {
1653 /*
1654 * If the process has requested that all future mappings
1655 * be wired, then heed this.
1656 */
1657 if (map->flags & MAP_WIREFUTURE) {
1658 vm_map_wire(map, *addr, *addr + size,
1659 VM_MAP_WIRE_USER | ((flags & MAP_STACK) ?
1660 VM_MAP_WIRE_HOLESOK : VM_MAP_WIRE_NOHOLES));
1661 }
1662 } else {
1663 /*
1664 * If this mapping was accounted for in the vnode's
1665 * writecount, then undo that now.
1666 */
1667 if (writecounted)
1668 vnode_pager_release_writecount(object, 0, size);
1669 /*
1670 * Lose the object reference. Will destroy the
1671 * object if it's an unnamed anonymous mapping
1672 * or named anonymous without other references.
1673 */
1674 vm_object_deallocate(object);
1675 }
1676 return (vm_mmap_to_errno(rv));
1677 }
1678
1679 /*
1680 * Translate a Mach VM return code to zero on success or the appropriate errno
1681 * on failure.
1682 */
1683 int
1684 vm_mmap_to_errno(int rv)
1685 {
1686
1687 switch (rv) {
1688 case KERN_SUCCESS:
1689 return (0);
1690 case KERN_INVALID_ADDRESS:
1691 case KERN_NO_SPACE:
1692 return (ENOMEM);
1693 case KERN_PROTECTION_FAILURE:
1694 return (EACCES);
1695 default:
1696 return (EINVAL);
1697 }
1698 }
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