2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
34 * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
36 * @(#)vm_mmap.c 8.4 (Berkeley) 1/12/94
40 * Mapped file (mmap) interface to VM
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
46 #include "opt_compat.h"
47 #include "opt_hwpmc_hooks.h"
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/capsicum.h>
52 #include <sys/kernel.h>
54 #include <sys/mutex.h>
55 #include <sys/sysproto.h>
56 #include <sys/filedesc.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>
69 #include <sys/mount.h>
72 #include <sys/syscallsubr.h>
73 #include <sys/sysent.h>
74 #include <sys/vmmeter.h>
76 #include <security/mac/mac_framework.h>
79 #include <vm/vm_param.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>
91 #include <sys/pmckern.h>
95 SYSCTL_INT(_vm, OID_AUTO, old_mlock, CTLFLAG_RWTUN, &old_mlock, 0,
96 "Do not apply RLIMIT_MEMLOCK on mlockall");
99 #define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31)
102 static int vm_mmap_vnode(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
103 int *, struct vnode *, vm_ooffset_t *, vm_object_t *, boolean_t *);
104 static int vm_mmap_cdev(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
105 int *, struct cdev *, vm_ooffset_t *, vm_object_t *);
106 static int vm_mmap_shm(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
107 int *, struct shmfd *, vm_ooffset_t, vm_object_t *);
109 #ifndef _SYS_SYSPROTO_H_
122 struct sbrk_args *uap;
124 /* Not yet implemented */
128 #ifndef _SYS_SYSPROTO_H_
141 struct sstk_args *uap;
143 /* Not yet implemented */
147 #if defined(COMPAT_43)
148 #ifndef _SYS_SYSPROTO_H_
149 struct getpagesize_args {
155 ogetpagesize(td, uap)
157 struct getpagesize_args *uap;
160 td->td_retval[0] = PAGE_SIZE;
163 #endif /* COMPAT_43 */
167 * Memory Map (mmap) system call. Note that the file offset
168 * and address are allowed to be NOT page aligned, though if
169 * the MAP_FIXED flag it set, both must have the same remainder
170 * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not
171 * page-aligned, the actual mapping starts at trunc_page(addr)
172 * and the return value is adjusted up by the page offset.
174 * Generally speaking, only character devices which are themselves
175 * memory-based, such as a video framebuffer, can be mmap'd. Otherwise
176 * there would be no cache coherency between a descriptor and a VM mapping
177 * both to the same character device.
179 #ifndef _SYS_SYSPROTO_H_
197 struct mmap_args *uap;
200 struct pmckern_map_in pkm;
205 vm_size_t size, pageoff;
206 vm_prot_t cap_maxprot, prot, maxprot;
208 objtype_t handle_type;
209 int align, error, flags;
211 struct vmspace *vms = td->td_proc->p_vmspace;
214 addr = (vm_offset_t) uap->addr;
216 prot = uap->prot & VM_PROT_ALL;
223 * Enforce the constraints.
224 * Mapping of length 0 is only allowed for old binaries.
225 * Anonymous mapping shall specify -1 as filedescriptor and
226 * zero position for new code. Be nice to ancient a.out
227 * binaries and correct pos for anonymous mapping, since old
228 * ld.so sometimes issues anonymous map requests with non-zero
231 if (!SV_CURPROC_FLAG(SV_AOUT)) {
232 if ((uap->len == 0 && curproc->p_osrel >= P_OSREL_MAP_ANON) ||
233 ((flags & MAP_ANON) != 0 && (uap->fd != -1 || pos != 0)))
236 if ((flags & MAP_ANON) != 0)
240 if (flags & MAP_STACK) {
241 if ((uap->fd != -1) ||
242 ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
247 if ((flags & (MAP_EXCL | MAP_FIXED)) == MAP_EXCL)
251 * Align the file position to a page boundary,
252 * and save its page offset component.
254 pageoff = (pos & PAGE_MASK);
257 /* Adjust size for rounding (on both ends). */
258 size += pageoff; /* low end... */
259 size = (vm_size_t) round_page(size); /* hi end */
261 /* Ensure alignment is at least a page and fits in a pointer. */
262 align = flags & MAP_ALIGNMENT_MASK;
263 if (align != 0 && align != MAP_ALIGNED_SUPER &&
264 (align >> MAP_ALIGNMENT_SHIFT >= sizeof(void *) * NBBY ||
265 align >> MAP_ALIGNMENT_SHIFT < PAGE_SHIFT))
269 * Check for illegal addresses. Watch out for address wrap... Note
270 * that VM_*_ADDRESS are not constants due to casts (argh).
272 if (flags & MAP_FIXED) {
274 * The specified address must have the same remainder
275 * as the file offset taken modulo PAGE_SIZE, so it
276 * should be aligned after adjustment by pageoff.
279 if (addr & PAGE_MASK)
282 /* Address range must be all in user VM space. */
283 if (addr < vm_map_min(&vms->vm_map) ||
284 addr + size > vm_map_max(&vms->vm_map))
286 if (addr + size < addr)
289 if (flags & MAP_32BIT && addr + size > MAP_32BIT_MAX_ADDR)
291 } else if (flags & MAP_32BIT) {
293 * For MAP_32BIT, override the hint if it is too high and
294 * do not bother moving the mapping past the heap (since
295 * the heap is usually above 2GB).
297 if (addr + size > MAP_32BIT_MAX_ADDR)
302 * XXX for non-fixed mappings where no hint is provided or
303 * the hint would fall in the potential heap space,
304 * place it after the end of the largest possible heap.
306 * There should really be a pmap call to determine a reasonable
309 PROC_LOCK(td->td_proc);
311 (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
312 addr < round_page((vm_offset_t)vms->vm_daddr +
313 lim_max(td->td_proc, RLIMIT_DATA))))
314 addr = round_page((vm_offset_t)vms->vm_daddr +
315 lim_max(td->td_proc, RLIMIT_DATA));
316 PROC_UNLOCK(td->td_proc);
318 if (flags & MAP_ANON) {
320 * Mapping blank space is trivial.
323 handle_type = OBJT_DEFAULT;
324 maxprot = VM_PROT_ALL;
325 cap_maxprot = VM_PROT_ALL;
328 * Mapping file, get fp for validation and don't let the
329 * descriptor disappear on us if we block. Check capability
330 * rights, but also return the maximum rights to be combined
331 * with maxprot later.
333 cap_rights_init(&rights, CAP_MMAP);
334 if (prot & PROT_READ)
335 cap_rights_set(&rights, CAP_MMAP_R);
336 if ((flags & MAP_SHARED) != 0) {
337 if (prot & PROT_WRITE)
338 cap_rights_set(&rights, CAP_MMAP_W);
340 if (prot & PROT_EXEC)
341 cap_rights_set(&rights, CAP_MMAP_X);
342 error = fget_mmap(td, uap->fd, &rights, &cap_maxprot, &fp);
345 if (fp->f_type == DTYPE_SHM) {
347 handle_type = OBJT_SWAP;
348 maxprot = VM_PROT_NONE;
350 /* FREAD should always be set. */
351 if (fp->f_flag & FREAD)
352 maxprot |= VM_PROT_EXECUTE | VM_PROT_READ;
353 if (fp->f_flag & FWRITE)
354 maxprot |= VM_PROT_WRITE;
357 if (fp->f_type != DTYPE_VNODE) {
361 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
362 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
364 * POSIX shared-memory objects are defined to have
365 * kernel persistence, and are not defined to support
366 * read(2)/write(2) -- or even open(2). Thus, we can
367 * use MAP_ASYNC to trade on-disk coherence for speed.
368 * The shm_open(3) library routine turns on the FPOSIXSHM
369 * flag to request this behavior.
371 if (fp->f_flag & FPOSIXSHM)
376 * Ensure that file and memory protections are
377 * compatible. Note that we only worry about
378 * writability if mapping is shared; in this case,
379 * current and max prot are dictated by the open file.
380 * XXX use the vnode instead? Problem is: what
381 * credentials do we use for determination? What if
382 * proc does a setuid?
384 if (vp->v_mount != NULL && vp->v_mount->mnt_flag & MNT_NOEXEC)
385 maxprot = VM_PROT_NONE;
387 maxprot = VM_PROT_EXECUTE;
388 if (fp->f_flag & FREAD) {
389 maxprot |= VM_PROT_READ;
390 } else if (prot & PROT_READ) {
395 * If we are sharing potential changes (either via
396 * MAP_SHARED or via the implicit sharing of character
397 * device mappings), and we are trying to get write
398 * permission although we opened it without asking
401 if ((flags & MAP_SHARED) != 0) {
402 if ((fp->f_flag & FWRITE) != 0) {
403 maxprot |= VM_PROT_WRITE;
404 } else if ((prot & PROT_WRITE) != 0) {
408 } else if (vp->v_type != VCHR || (fp->f_flag & FWRITE) != 0) {
409 maxprot |= VM_PROT_WRITE;
410 cap_maxprot |= VM_PROT_WRITE;
413 handle_type = OBJT_VNODE;
417 maxprot &= cap_maxprot;
418 error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
419 flags, handle_type, handle, pos);
422 /* inform hwpmc(4) if an executable is being mapped */
423 if (error == 0 && handle_type == OBJT_VNODE &&
424 (prot & PROT_EXEC)) {
425 pkm.pm_file = handle;
426 pkm.pm_address = (uintptr_t) addr;
427 PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm);
431 td->td_retval[0] = (register_t) (addr + pageoff);
440 freebsd6_mmap(struct thread *td, struct freebsd6_mmap_args *uap)
442 struct mmap_args oargs;
444 oargs.addr = uap->addr;
445 oargs.len = uap->len;
446 oargs.prot = uap->prot;
447 oargs.flags = uap->flags;
449 oargs.pos = uap->pos;
450 return (sys_mmap(td, &oargs));
454 #ifndef _SYS_SYSPROTO_H_
467 struct ommap_args *uap;
469 struct mmap_args nargs;
470 static const char cvtbsdprot[8] = {
474 PROT_EXEC | PROT_WRITE,
476 PROT_EXEC | PROT_READ,
477 PROT_WRITE | PROT_READ,
478 PROT_EXEC | PROT_WRITE | PROT_READ,
481 #define OMAP_ANON 0x0002
482 #define OMAP_COPY 0x0020
483 #define OMAP_SHARED 0x0010
484 #define OMAP_FIXED 0x0100
486 nargs.addr = uap->addr;
487 nargs.len = uap->len;
488 nargs.prot = cvtbsdprot[uap->prot & 0x7];
489 #ifdef COMPAT_FREEBSD32
490 #if defined(__amd64__) || defined(__ia64__)
491 if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32) &&
493 nargs.prot |= PROT_EXEC;
497 if (uap->flags & OMAP_ANON)
498 nargs.flags |= MAP_ANON;
499 if (uap->flags & OMAP_COPY)
500 nargs.flags |= MAP_COPY;
501 if (uap->flags & OMAP_SHARED)
502 nargs.flags |= MAP_SHARED;
504 nargs.flags |= MAP_PRIVATE;
505 if (uap->flags & OMAP_FIXED)
506 nargs.flags |= MAP_FIXED;
508 nargs.pos = uap->pos;
509 return (sys_mmap(td, &nargs));
511 #endif /* COMPAT_43 */
514 #ifndef _SYS_SYSPROTO_H_
527 struct msync_args *uap;
530 vm_size_t size, pageoff;
535 addr = (vm_offset_t) uap->addr;
539 pageoff = (addr & PAGE_MASK);
542 size = (vm_size_t) round_page(size);
543 if (addr + size < addr)
546 if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
549 map = &td->td_proc->p_vmspace->vm_map;
552 * Clean the pages and interpret the return value.
554 rv = vm_map_sync(map, addr, addr + size, (flags & MS_ASYNC) == 0,
555 (flags & MS_INVALIDATE) != 0);
559 case KERN_INVALID_ADDRESS:
561 case KERN_INVALID_ARGUMENT:
570 #ifndef _SYS_SYSPROTO_H_
582 struct munmap_args *uap;
585 struct pmckern_map_out pkm;
586 vm_map_entry_t entry;
589 vm_size_t size, pageoff;
592 addr = (vm_offset_t) uap->addr;
597 pageoff = (addr & PAGE_MASK);
600 size = (vm_size_t) round_page(size);
601 if (addr + size < addr)
605 * Check for illegal addresses. Watch out for address wrap...
607 map = &td->td_proc->p_vmspace->vm_map;
608 if (addr < vm_map_min(map) || addr + size > vm_map_max(map))
613 * Inform hwpmc if the address range being unmapped contains
614 * an executable region.
616 pkm.pm_address = (uintptr_t) NULL;
617 if (vm_map_lookup_entry(map, addr, &entry)) {
619 entry != &map->header && entry->start < addr + size;
620 entry = entry->next) {
621 if (vm_map_check_protection(map, entry->start,
622 entry->end, VM_PROT_EXECUTE) == TRUE) {
623 pkm.pm_address = (uintptr_t) addr;
624 pkm.pm_size = (size_t) size;
630 vm_map_delete(map, addr, addr + size);
633 /* downgrade the lock to prevent a LOR with the pmc-sx lock */
634 vm_map_lock_downgrade(map);
635 if (pkm.pm_address != (uintptr_t) NULL)
636 PMC_CALL_HOOK(td, PMC_FN_MUNMAP, (void *) &pkm);
637 vm_map_unlock_read(map);
641 /* vm_map_delete returns nothing but KERN_SUCCESS anyway */
645 #ifndef _SYS_SYSPROTO_H_
646 struct mprotect_args {
656 sys_mprotect(td, uap)
658 struct mprotect_args *uap;
661 vm_size_t size, pageoff;
664 addr = (vm_offset_t) uap->addr;
666 prot = uap->prot & VM_PROT_ALL;
668 pageoff = (addr & PAGE_MASK);
671 size = (vm_size_t) round_page(size);
672 if (addr + size < addr)
675 switch (vm_map_protect(&td->td_proc->p_vmspace->vm_map, addr,
676 addr + size, prot, FALSE)) {
679 case KERN_PROTECTION_FAILURE:
681 case KERN_RESOURCE_SHORTAGE:
687 #ifndef _SYS_SYSPROTO_H_
688 struct minherit_args {
698 sys_minherit(td, uap)
700 struct minherit_args *uap;
703 vm_size_t size, pageoff;
704 vm_inherit_t inherit;
706 addr = (vm_offset_t)uap->addr;
708 inherit = uap->inherit;
710 pageoff = (addr & PAGE_MASK);
713 size = (vm_size_t) round_page(size);
714 if (addr + size < addr)
717 switch (vm_map_inherit(&td->td_proc->p_vmspace->vm_map, addr,
718 addr + size, inherit)) {
721 case KERN_PROTECTION_FAILURE:
727 #ifndef _SYS_SYSPROTO_H_
728 struct madvise_args {
741 struct madvise_args *uap;
743 vm_offset_t start, end;
748 * Check for our special case, advising the swap pager we are
751 if (uap->behav == MADV_PROTECT) {
753 return (kern_procctl(td, P_PID, td->td_proc->p_pid,
754 PROC_SPROTECT, &flags));
758 * Check for illegal behavior
760 if (uap->behav < 0 || uap->behav > MADV_CORE)
763 * Check for illegal addresses. Watch out for address wrap... Note
764 * that VM_*_ADDRESS are not constants due to casts (argh).
766 map = &td->td_proc->p_vmspace->vm_map;
767 if ((vm_offset_t)uap->addr < vm_map_min(map) ||
768 (vm_offset_t)uap->addr + uap->len > vm_map_max(map))
770 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
774 * Since this routine is only advisory, we default to conservative
777 start = trunc_page((vm_offset_t) uap->addr);
778 end = round_page((vm_offset_t) uap->addr + uap->len);
780 if (vm_map_madvise(map, start, end, uap->behav))
785 #ifndef _SYS_SYSPROTO_H_
786 struct mincore_args {
799 struct mincore_args *uap;
801 vm_offset_t addr, first_addr;
802 vm_offset_t end, cend;
807 int vecindex, lastvecindex;
808 vm_map_entry_t current;
809 vm_map_entry_t entry;
811 vm_paddr_t locked_pa;
815 unsigned int timestamp;
819 * Make sure that the addresses presented are valid for user
822 first_addr = addr = trunc_page((vm_offset_t) uap->addr);
823 end = addr + (vm_size_t)round_page(uap->len);
824 map = &td->td_proc->p_vmspace->vm_map;
825 if (end > vm_map_max(map) || end < addr)
829 * Address of byte vector
833 pmap = vmspace_pmap(td->td_proc->p_vmspace);
835 vm_map_lock_read(map);
837 timestamp = map->timestamp;
839 if (!vm_map_lookup_entry(map, addr, &entry)) {
840 vm_map_unlock_read(map);
845 * Do this on a map entry basis so that if the pages are not
846 * in the current processes address space, we can easily look
847 * up the pages elsewhere.
850 for (current = entry;
851 (current != &map->header) && (current->start < end);
852 current = current->next) {
855 * check for contiguity
857 if (current->end < end &&
858 (entry->next == &map->header ||
859 current->next->start > current->end)) {
860 vm_map_unlock_read(map);
865 * ignore submaps (for now) or null objects
867 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
868 current->object.vm_object == NULL)
872 * limit this scan to the current map entry and the
873 * limits for the mincore call
875 if (addr < current->start)
876 addr = current->start;
882 * scan this entry one page at a time
884 while (addr < cend) {
886 * Check pmap first, it is likely faster, also
887 * it can provide info as to whether we are the
888 * one referencing or modifying the page.
894 mincoreinfo = pmap_mincore(pmap, addr, &locked_pa);
895 if (locked_pa != 0) {
897 * The page is mapped by this process but not
898 * both accessed and modified. It is also
899 * managed. Acquire the object lock so that
900 * other mappings might be examined.
902 m = PHYS_TO_VM_PAGE(locked_pa);
903 if (m->object != object) {
905 VM_OBJECT_WUNLOCK(object);
907 locked = VM_OBJECT_TRYWLOCK(object);
910 VM_OBJECT_WLOCK(object);
916 KASSERT(m->valid == VM_PAGE_BITS_ALL,
917 ("mincore: page %p is mapped but invalid",
919 } else if (mincoreinfo == 0) {
921 * The page is not mapped by this process. If
922 * the object implements managed pages, then
923 * determine if the page is resident so that
924 * the mappings might be examined.
926 if (current->object.vm_object != object) {
928 VM_OBJECT_WUNLOCK(object);
929 object = current->object.vm_object;
930 VM_OBJECT_WLOCK(object);
932 if (object->type == OBJT_DEFAULT ||
933 object->type == OBJT_SWAP ||
934 object->type == OBJT_VNODE) {
935 pindex = OFF_TO_IDX(current->offset +
936 (addr - current->start));
937 m = vm_page_lookup(object, pindex);
939 vm_page_is_cached(object, pindex))
940 mincoreinfo = MINCORE_INCORE;
941 if (m != NULL && m->valid == 0)
944 mincoreinfo = MINCORE_INCORE;
948 /* Examine other mappings to the page. */
949 if (m->dirty == 0 && pmap_is_modified(m))
952 mincoreinfo |= MINCORE_MODIFIED_OTHER;
954 * The first test for PGA_REFERENCED is an
955 * optimization. The second test is
956 * required because a concurrent pmap
957 * operation could clear the last reference
958 * and set PGA_REFERENCED before the call to
959 * pmap_is_referenced().
961 if ((m->aflags & PGA_REFERENCED) != 0 ||
962 pmap_is_referenced(m) ||
963 (m->aflags & PGA_REFERENCED) != 0)
964 mincoreinfo |= MINCORE_REFERENCED_OTHER;
967 VM_OBJECT_WUNLOCK(object);
970 * subyte may page fault. In case it needs to modify
971 * the map, we release the lock.
973 vm_map_unlock_read(map);
976 * calculate index into user supplied byte vector
978 vecindex = OFF_TO_IDX(addr - first_addr);
981 * If we have skipped map entries, we need to make sure that
982 * the byte vector is zeroed for those skipped entries.
984 while ((lastvecindex + 1) < vecindex) {
986 error = subyte(vec + lastvecindex, 0);
994 * Pass the page information to the user
996 error = subyte(vec + vecindex, mincoreinfo);
1003 * If the map has changed, due to the subyte, the previous
1004 * output may be invalid.
1006 vm_map_lock_read(map);
1007 if (timestamp != map->timestamp)
1010 lastvecindex = vecindex;
1016 * subyte may page fault. In case it needs to modify
1017 * the map, we release the lock.
1019 vm_map_unlock_read(map);
1022 * Zero the last entries in the byte vector.
1024 vecindex = OFF_TO_IDX(end - first_addr);
1025 while ((lastvecindex + 1) < vecindex) {
1027 error = subyte(vec + lastvecindex, 0);
1035 * If the map has changed, due to the subyte, the previous
1036 * output may be invalid.
1038 vm_map_lock_read(map);
1039 if (timestamp != map->timestamp)
1041 vm_map_unlock_read(map);
1046 #ifndef _SYS_SYSPROTO_H_
1058 struct mlock_args *uap;
1061 return (vm_mlock(td->td_proc, td->td_ucred, uap->addr, uap->len));
1065 vm_mlock(struct proc *proc, struct ucred *cred, const void *addr0, size_t len)
1067 vm_offset_t addr, end, last, start;
1068 vm_size_t npages, size;
1070 unsigned long nsize;
1073 error = priv_check_cred(cred, PRIV_VM_MLOCK, 0);
1076 addr = (vm_offset_t)addr0;
1079 start = trunc_page(addr);
1080 end = round_page(last);
1081 if (last < addr || end < addr)
1083 npages = atop(end - start);
1084 if (npages > vm_page_max_wired)
1086 map = &proc->p_vmspace->vm_map;
1088 nsize = ptoa(npages + pmap_wired_count(map->pmap));
1089 if (nsize > lim_cur(proc, RLIMIT_MEMLOCK)) {
1094 if (npages + vm_cnt.v_wire_count > vm_page_max_wired)
1098 error = racct_set(proc, RACCT_MEMLOCK, nsize);
1103 error = vm_map_wire(map, start, end,
1104 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
1106 if (error != KERN_SUCCESS) {
1108 racct_set(proc, RACCT_MEMLOCK,
1109 ptoa(pmap_wired_count(map->pmap)));
1113 return (error == KERN_SUCCESS ? 0 : ENOMEM);
1116 #ifndef _SYS_SYSPROTO_H_
1117 struct mlockall_args {
1126 sys_mlockall(td, uap)
1128 struct mlockall_args *uap;
1133 map = &td->td_proc->p_vmspace->vm_map;
1134 error = priv_check(td, PRIV_VM_MLOCK);
1138 if ((uap->how == 0) || ((uap->how & ~(MCL_CURRENT|MCL_FUTURE)) != 0))
1142 * If wiring all pages in the process would cause it to exceed
1143 * a hard resource limit, return ENOMEM.
1145 if (!old_mlock && uap->how & MCL_CURRENT) {
1146 PROC_LOCK(td->td_proc);
1147 if (map->size > lim_cur(td->td_proc, RLIMIT_MEMLOCK)) {
1148 PROC_UNLOCK(td->td_proc);
1151 PROC_UNLOCK(td->td_proc);
1154 PROC_LOCK(td->td_proc);
1155 error = racct_set(td->td_proc, RACCT_MEMLOCK, map->size);
1156 PROC_UNLOCK(td->td_proc);
1161 if (uap->how & MCL_FUTURE) {
1163 vm_map_modflags(map, MAP_WIREFUTURE, 0);
1168 if (uap->how & MCL_CURRENT) {
1170 * P1003.1-2001 mandates that all currently mapped pages
1171 * will be memory resident and locked (wired) upon return
1172 * from mlockall(). vm_map_wire() will wire pages, by
1173 * calling vm_fault_wire() for each page in the region.
1175 error = vm_map_wire(map, vm_map_min(map), vm_map_max(map),
1176 VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
1177 error = (error == KERN_SUCCESS ? 0 : EAGAIN);
1180 if (error != KERN_SUCCESS) {
1181 PROC_LOCK(td->td_proc);
1182 racct_set(td->td_proc, RACCT_MEMLOCK,
1183 ptoa(pmap_wired_count(map->pmap)));
1184 PROC_UNLOCK(td->td_proc);
1191 #ifndef _SYS_SYSPROTO_H_
1192 struct munlockall_args {
1201 sys_munlockall(td, uap)
1203 struct munlockall_args *uap;
1208 map = &td->td_proc->p_vmspace->vm_map;
1209 error = priv_check(td, PRIV_VM_MUNLOCK);
1213 /* Clear the MAP_WIREFUTURE flag from this vm_map. */
1215 vm_map_modflags(map, 0, MAP_WIREFUTURE);
1218 /* Forcibly unwire all pages. */
1219 error = vm_map_unwire(map, vm_map_min(map), vm_map_max(map),
1220 VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
1222 if (error == KERN_SUCCESS) {
1223 PROC_LOCK(td->td_proc);
1224 racct_set(td->td_proc, RACCT_MEMLOCK, 0);
1225 PROC_UNLOCK(td->td_proc);
1232 #ifndef _SYS_SYSPROTO_H_
1233 struct munlock_args {
1242 sys_munlock(td, uap)
1244 struct munlock_args *uap;
1246 vm_offset_t addr, end, last, start;
1253 error = priv_check(td, PRIV_VM_MUNLOCK);
1256 addr = (vm_offset_t)uap->addr;
1259 start = trunc_page(addr);
1260 end = round_page(last);
1261 if (last < addr || end < addr)
1263 error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, start, end,
1264 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
1266 if (error == KERN_SUCCESS) {
1267 PROC_LOCK(td->td_proc);
1268 map = &td->td_proc->p_vmspace->vm_map;
1269 racct_set(td->td_proc, RACCT_MEMLOCK,
1270 ptoa(pmap_wired_count(map->pmap)));
1271 PROC_UNLOCK(td->td_proc);
1274 return (error == KERN_SUCCESS ? 0 : ENOMEM);
1280 * Helper function for vm_mmap. Perform sanity check specific for mmap
1281 * operations on vnodes.
1283 * For VCHR vnodes, the vnode lock is held over the call to
1284 * vm_mmap_cdev() to keep vp->v_rdev valid.
1287 vm_mmap_vnode(struct thread *td, vm_size_t objsize,
1288 vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1289 struct vnode *vp, vm_ooffset_t *foffp, vm_object_t *objp,
1290 boolean_t *writecounted)
1297 int error, flags, locktype;
1300 cred = td->td_ucred;
1301 if ((*maxprotp & VM_PROT_WRITE) && (*flagsp & MAP_SHARED))
1302 locktype = LK_EXCLUSIVE;
1304 locktype = LK_SHARED;
1305 if ((error = vget(vp, locktype, td)) != 0)
1310 if (vp->v_type == VREG) {
1312 * Get the proper underlying object
1318 if (obj->type == OBJT_VNODE && obj->handle != vp) {
1320 vp = (struct vnode *)obj->handle;
1322 * Bypass filesystems obey the mpsafety of the
1323 * underlying fs. Tmpfs never bypasses.
1325 error = vget(vp, locktype, td);
1329 if (locktype == LK_EXCLUSIVE) {
1330 *writecounted = TRUE;
1331 vnode_pager_update_writecount(obj, 0, objsize);
1333 } else if (vp->v_type == VCHR) {
1334 error = vm_mmap_cdev(td, objsize, prot, maxprotp, flagsp,
1335 vp->v_rdev, foffp, objp);
1343 if ((error = VOP_GETATTR(vp, &va, cred)))
1346 error = mac_vnode_check_mmap(cred, vp, prot, flags);
1350 if ((flags & MAP_SHARED) != 0) {
1351 if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) != 0) {
1352 if (prot & PROT_WRITE) {
1356 *maxprotp &= ~VM_PROT_WRITE;
1360 * If it is a regular file without any references
1361 * we do not need to sync it.
1362 * Adjust object size to be the size of actual file.
1364 objsize = round_page(va.va_size);
1365 if (va.va_nlink == 0)
1366 flags |= MAP_NOSYNC;
1367 if (obj->type == OBJT_VNODE)
1368 obj = vm_pager_allocate(OBJT_VNODE, vp, objsize, prot, foff,
1371 KASSERT(obj->type == OBJT_DEFAULT || obj->type == OBJT_SWAP,
1372 ("wrong object type"));
1373 vm_object_reference(obj);
1383 vfs_mark_atime(vp, cred);
1386 if (error != 0 && *writecounted) {
1387 *writecounted = FALSE;
1388 vnode_pager_update_writecount(obj, objsize, 0);
1399 * Helper function for vm_mmap. Perform sanity check specific for mmap
1400 * operations on cdevs.
1403 vm_mmap_cdev(struct thread *td, vm_size_t objsize,
1404 vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1405 struct cdev *cdev, vm_ooffset_t *foff, vm_object_t *objp)
1409 int error, flags, ref;
1413 dsw = dev_refthread(cdev, &ref);
1416 if (dsw->d_flags & D_MMAP_ANON) {
1417 dev_relthread(cdev, ref);
1418 *maxprotp = VM_PROT_ALL;
1419 *flagsp |= MAP_ANON;
1423 * cdevs do not provide private mappings of any kind.
1425 if ((*maxprotp & VM_PROT_WRITE) == 0 &&
1426 (prot & PROT_WRITE) != 0) {
1427 dev_relthread(cdev, ref);
1430 if (flags & (MAP_PRIVATE|MAP_COPY)) {
1431 dev_relthread(cdev, ref);
1435 * Force device mappings to be shared.
1437 flags |= MAP_SHARED;
1439 error = mac_cdev_check_mmap(td->td_ucred, cdev, prot);
1441 dev_relthread(cdev, ref);
1446 * First, try d_mmap_single(). If that is not implemented
1447 * (returns ENODEV), fall back to using the device pager.
1448 * Note that d_mmap_single() must return a reference to the
1449 * object (it needs to bump the reference count of the object
1450 * it returns somehow).
1452 * XXX assumes VM_PROT_* == PROT_*
1454 error = dsw->d_mmap_single(cdev, foff, objsize, objp, (int)prot);
1455 dev_relthread(cdev, ref);
1456 if (error != ENODEV)
1458 obj = vm_pager_allocate(OBJT_DEVICE, cdev, objsize, prot, *foff,
1472 * Helper function for vm_mmap. Perform sanity check specific for mmap
1473 * operations on shm file descriptors.
1476 vm_mmap_shm(struct thread *td, vm_size_t objsize,
1477 vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1478 struct shmfd *shmfd, vm_ooffset_t foff, vm_object_t *objp)
1482 if ((*flagsp & MAP_SHARED) != 0 &&
1483 (*maxprotp & VM_PROT_WRITE) == 0 &&
1484 (prot & PROT_WRITE) != 0)
1487 error = mac_posixshm_check_mmap(td->td_ucred, shmfd, prot, *flagsp);
1491 error = shm_mmap(shmfd, objsize, foff, objp);
1502 * Internal version of mmap. Currently used by mmap, exec, and sys5
1503 * shared memory. Handle is either a vnode pointer or NULL for MAP_ANON.
1506 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
1507 vm_prot_t maxprot, int flags,
1508 objtype_t handle_type, void *handle,
1512 vm_object_t object = NULL;
1513 struct thread *td = curthread;
1514 int docow, error, findspace, rv;
1515 boolean_t writecounted;
1520 size = round_page(size);
1522 if (map == &td->td_proc->p_vmspace->vm_map) {
1523 PROC_LOCK(td->td_proc);
1524 if (map->size + size > lim_cur(td->td_proc, RLIMIT_VMEM)) {
1525 PROC_UNLOCK(td->td_proc);
1528 if (racct_set(td->td_proc, RACCT_VMEM, map->size + size)) {
1529 PROC_UNLOCK(td->td_proc);
1532 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
1533 if (ptoa(pmap_wired_count(map->pmap)) + size >
1534 lim_cur(td->td_proc, RLIMIT_MEMLOCK)) {
1535 racct_set_force(td->td_proc, RACCT_VMEM,
1537 PROC_UNLOCK(td->td_proc);
1540 error = racct_set(td->td_proc, RACCT_MEMLOCK,
1541 ptoa(pmap_wired_count(map->pmap)) + size);
1543 racct_set_force(td->td_proc, RACCT_VMEM,
1545 PROC_UNLOCK(td->td_proc);
1549 PROC_UNLOCK(td->td_proc);
1553 * We currently can only deal with page aligned file offsets.
1554 * The check is here rather than in the syscall because the
1555 * kernel calls this function internally for other mmaping
1556 * operations (such as in exec) and non-aligned offsets will
1557 * cause pmap inconsistencies...so we want to be sure to
1558 * disallow this in all cases.
1560 if (foff & PAGE_MASK)
1563 if ((flags & MAP_FIXED) == 0) {
1565 *addr = round_page(*addr);
1567 if (*addr != trunc_page(*addr))
1571 writecounted = FALSE;
1574 * Lookup/allocate object.
1576 switch (handle_type) {
1578 error = vm_mmap_cdev(td, size, prot, &maxprot, &flags,
1579 handle, &foff, &object);
1582 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags,
1583 handle, &foff, &object, &writecounted);
1586 error = vm_mmap_shm(td, size, prot, &maxprot, &flags,
1587 handle, foff, &object);
1590 if (handle == NULL) {
1601 if (flags & MAP_ANON) {
1605 * Unnamed anonymous regions always start at 0.
1609 } else if (flags & MAP_PREFAULT_READ)
1610 docow = MAP_PREFAULT;
1612 docow = MAP_PREFAULT_PARTIAL;
1614 if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1615 docow |= MAP_COPY_ON_WRITE;
1616 if (flags & MAP_NOSYNC)
1617 docow |= MAP_DISABLE_SYNCER;
1618 if (flags & MAP_NOCORE)
1619 docow |= MAP_DISABLE_COREDUMP;
1620 /* Shared memory is also shared with children. */
1621 if (flags & MAP_SHARED)
1622 docow |= MAP_INHERIT_SHARE;
1624 docow |= MAP_VN_WRITECOUNT;
1625 if (flags & MAP_STACK) {
1628 docow |= MAP_STACK_GROWS_DOWN;
1630 if ((flags & MAP_EXCL) != 0)
1631 docow |= MAP_CHECK_EXCL;
1634 if ((flags & MAP_ALIGNMENT_MASK) == MAP_ALIGNED_SUPER)
1635 findspace = VMFS_SUPER_SPACE;
1636 else if ((flags & MAP_ALIGNMENT_MASK) != 0)
1637 findspace = VMFS_ALIGNED_SPACE(flags >>
1638 MAP_ALIGNMENT_SHIFT);
1640 findspace = VMFS_OPTIMAL_SPACE;
1641 rv = vm_map_find(map, object, foff, addr, size,
1643 flags & MAP_32BIT ? MAP_32BIT_MAX_ADDR :
1645 0, findspace, prot, maxprot, docow);
1647 rv = vm_map_fixed(map, object, foff, *addr, size,
1648 prot, maxprot, docow);
1651 if (rv == KERN_SUCCESS) {
1653 * If the process has requested that all future mappings
1654 * be wired, then heed this.
1656 if (map->flags & MAP_WIREFUTURE) {
1657 vm_map_wire(map, *addr, *addr + size,
1658 VM_MAP_WIRE_USER | ((flags & MAP_STACK) ?
1659 VM_MAP_WIRE_HOLESOK : VM_MAP_WIRE_NOHOLES));
1663 * If this mapping was accounted for in the vnode's
1664 * writecount, then undo that now.
1667 vnode_pager_release_writecount(object, 0, size);
1669 * Lose the object reference. Will destroy the
1670 * object if it's an unnamed anonymous mapping
1671 * or named anonymous without other references.
1673 vm_object_deallocate(object);
1675 return (vm_mmap_to_errno(rv));
1679 * Translate a Mach VM return code to zero on success or the appropriate errno
1683 vm_mmap_to_errno(int rv)
1689 case KERN_INVALID_ADDRESS:
1692 case KERN_PROTECTION_FAILURE: