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freebsd-nq/sys/vm/vm_mmap.c
Konstantin Belousov 5dc7e31a09 Control implicit PROT_MAX() using procctl(2) and the FreeBSD note 
feature bit.

In particular, allocate the bit to opt-out the image from implicit
PROTMAX enablement.  Provide procctl(2) verbs to set and query
implicit PROTMAX handling.  The knobs mimic the same per-image flag
and per-process controls for ASLR.

Reviewed by:	emaste, markj (previous version)
Discussed with:	brooks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D20795
2019-07-02 19:07:17 +00:00

1648 lines
39 KiB
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Raw Blame History

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
*
* @(#)vm_mmap.c 8.4 (Berkeley) 1/12/94
*/
/*
* Mapped file (mmap) interface to VM
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_hwpmc_hooks.h"
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capsicum.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysproto.h>
#include <sys/elf.h>
#include <sys/filedesc.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/procctl.h>
#include <sys/racct.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/vmmeter.h>
#if defined(__amd64__) || defined(__i386__) /* for i386_read_exec */
#include <machine/md_var.h>
#endif
#include <security/audit/audit.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vm_pageout.h>
#include <vm/vm_extern.h>
#include <vm/vm_page.h>
#include <vm/vnode_pager.h>
#ifdef HWPMC_HOOKS
#include <sys/pmckern.h>
#endif
int old_mlock = 0;
SYSCTL_INT(_vm, OID_AUTO, old_mlock, CTLFLAG_RWTUN, &old_mlock, 0,
"Do not apply RLIMIT_MEMLOCK on mlockall");
static int mincore_mapped = 1;
SYSCTL_INT(_vm, OID_AUTO, mincore_mapped, CTLFLAG_RWTUN, &mincore_mapped, 0,
"mincore reports mappings, not residency");
static int imply_prot_max = 0;
SYSCTL_INT(_vm, OID_AUTO, imply_prot_max, CTLFLAG_RWTUN, &imply_prot_max, 0,
"Imply maximum page permissions in mmap() when none are specified");
#ifdef MAP_32BIT
#define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31)
#endif
#ifndef _SYS_SYSPROTO_H_
struct sbrk_args {
int incr;
};
#endif
int
sys_sbrk(struct thread *td, struct sbrk_args *uap)
{
/* Not yet implemented */
return (EOPNOTSUPP);
}
#ifndef _SYS_SYSPROTO_H_
struct sstk_args {
int incr;
};
#endif
int
sys_sstk(struct thread *td, struct sstk_args *uap)
{
/* Not yet implemented */
return (EOPNOTSUPP);
}
#if defined(COMPAT_43)
int
ogetpagesize(struct thread *td, struct ogetpagesize_args *uap)
{
td->td_retval[0] = PAGE_SIZE;
return (0);
}
#endif /* COMPAT_43 */
/*
* Memory Map (mmap) system call. Note that the file offset
* and address are allowed to be NOT page aligned, though if
* the MAP_FIXED flag it set, both must have the same remainder
* modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not
* page-aligned, the actual mapping starts at trunc_page(addr)
* and the return value is adjusted up by the page offset.
*
* Generally speaking, only character devices which are themselves
* memory-based, such as a video framebuffer, can be mmap'd. Otherwise
* there would be no cache coherency between a descriptor and a VM mapping
* both to the same character device.
*/
#ifndef _SYS_SYSPROTO_H_
struct mmap_args {
void *addr;
size_t len;
int prot;
int flags;
int fd;
long pad;
off_t pos;
};
#endif
int
sys_mmap(struct thread *td, struct mmap_args *uap)
{
return (kern_mmap(td, (uintptr_t)uap->addr, uap->len, uap->prot,
uap->flags, uap->fd, uap->pos));
}
int
kern_mmap_maxprot(struct proc *p, int prot)
{
if ((p->p_flag2 & P2_PROTMAX_DISABLE) != 0 ||
(p->p_fctl0 & NT_FREEBSD_FCTL_PROTMAX_DISABLE) != 0)
return (_PROT_ALL);
if (((p->p_flag2 & P2_PROTMAX_ENABLE) != 0 || imply_prot_max) &&
prot != PROT_NONE)
return (prot);
return (_PROT_ALL);
}
int
kern_mmap(struct thread *td, uintptr_t addr0, size_t len, int prot, int flags,
int fd, off_t pos)
{
struct vmspace *vms;
struct file *fp;
struct proc *p;
vm_offset_t addr;
vm_size_t pageoff, size;
vm_prot_t cap_maxprot;
int align, error, max_prot;
cap_rights_t rights;
if ((prot & ~(_PROT_ALL | PROT_MAX(_PROT_ALL))) != 0)
return (EINVAL);
max_prot = PROT_MAX_EXTRACT(prot);
prot = PROT_EXTRACT(prot);
if (max_prot != 0 && (max_prot & prot) != prot)
return (EINVAL);
p = td->td_proc;
/*
* Always honor PROT_MAX if set. If not, default to all
* permissions unless we're implying maximum permissions.
*/
if (max_prot == 0)
max_prot = kern_mmap_maxprot(p, prot);
vms = p->p_vmspace;
fp = NULL;
AUDIT_ARG_FD(fd);
addr = addr0;
/*
* Ignore old flags that used to be defined but did not do anything.
*/
flags &= ~(MAP_RESERVED0020 | MAP_RESERVED0040);
/*
* Enforce the constraints.
* Mapping of length 0 is only allowed for old binaries.
* Anonymous mapping shall specify -1 as filedescriptor and
* zero position for new code. Be nice to ancient a.out
* binaries and correct pos for anonymous mapping, since old
* ld.so sometimes issues anonymous map requests with non-zero
* pos.
*/
if (!SV_CURPROC_FLAG(SV_AOUT)) {
if ((len == 0 && p->p_osrel >= P_OSREL_MAP_ANON) ||
((flags & MAP_ANON) != 0 && (fd != -1 || pos != 0)))
return (EINVAL);
} else {
if ((flags & MAP_ANON) != 0)
pos = 0;
}
if (flags & MAP_STACK) {
if ((fd != -1) ||
((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
return (EINVAL);
flags |= MAP_ANON;
pos = 0;
}
if ((flags & ~(MAP_SHARED | MAP_PRIVATE | MAP_FIXED | MAP_HASSEMAPHORE |
MAP_STACK | MAP_NOSYNC | MAP_ANON | MAP_EXCL | MAP_NOCORE |
MAP_PREFAULT_READ | MAP_GUARD |
#ifdef MAP_32BIT
MAP_32BIT |
#endif
MAP_ALIGNMENT_MASK)) != 0)
return (EINVAL);
if ((flags & (MAP_EXCL | MAP_FIXED)) == MAP_EXCL)
return (EINVAL);
if ((flags & (MAP_SHARED | MAP_PRIVATE)) == (MAP_SHARED | MAP_PRIVATE))
return (EINVAL);
if (prot != PROT_NONE &&
(prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) != 0)
return (EINVAL);
if ((flags & MAP_GUARD) != 0 && (prot != PROT_NONE || fd != -1 ||
pos != 0 || (flags & ~(MAP_FIXED | MAP_GUARD | MAP_EXCL |
#ifdef MAP_32BIT
MAP_32BIT |
#endif
MAP_ALIGNMENT_MASK)) != 0))
return (EINVAL);
/*
* Align the file position to a page boundary,
* and save its page offset component.
*/
pageoff = (pos & PAGE_MASK);
pos -= pageoff;
/* Compute size from len by rounding (on both ends). */
size = len + pageoff; /* low end... */
size = round_page(size); /* hi end */
/* Check for rounding up to zero. */
if (len > size)
return (ENOMEM);
/* Ensure alignment is at least a page and fits in a pointer. */
align = flags & MAP_ALIGNMENT_MASK;
if (align != 0 && align != MAP_ALIGNED_SUPER &&
(align >> MAP_ALIGNMENT_SHIFT >= sizeof(void *) * NBBY ||
align >> MAP_ALIGNMENT_SHIFT < PAGE_SHIFT))
return (EINVAL);
/*
* Check for illegal addresses. Watch out for address wrap... Note
* that VM_*_ADDRESS are not constants due to casts (argh).
*/
if (flags & MAP_FIXED) {
/*
* The specified address must have the same remainder
* as the file offset taken modulo PAGE_SIZE, so it
* should be aligned after adjustment by pageoff.
*/
addr -= pageoff;
if (addr & PAGE_MASK)
return (EINVAL);
/* Address range must be all in user VM space. */
if (addr < vm_map_min(&vms->vm_map) ||
addr + size > vm_map_max(&vms->vm_map))
return (EINVAL);
if (addr + size < addr)
return (EINVAL);
#ifdef MAP_32BIT
if (flags & MAP_32BIT && addr + size > MAP_32BIT_MAX_ADDR)
return (EINVAL);
} else if (flags & MAP_32BIT) {
/*
* For MAP_32BIT, override the hint if it is too high and
* do not bother moving the mapping past the heap (since
* the heap is usually above 2GB).
*/
if (addr + size > MAP_32BIT_MAX_ADDR)
addr = 0;
#endif
} else {
/*
* XXX for non-fixed mappings where no hint is provided or
* the hint would fall in the potential heap space,
* place it after the end of the largest possible heap.
*
* There should really be a pmap call to determine a reasonable
* location.
*/
if (addr == 0 ||
(addr >= round_page((vm_offset_t)vms->vm_taddr) &&
addr < round_page((vm_offset_t)vms->vm_daddr +
lim_max(td, RLIMIT_DATA))))
addr = round_page((vm_offset_t)vms->vm_daddr +
lim_max(td, RLIMIT_DATA));
}
if (len == 0) {
/*
* Return success without mapping anything for old
* binaries that request a page-aligned mapping of
* length 0. For modern binaries, this function
* returns an error earlier.
*/
error = 0;
} else if ((flags & MAP_GUARD) != 0) {
error = vm_mmap_object(&vms->vm_map, &addr, size, VM_PROT_NONE,
VM_PROT_NONE, flags, NULL, pos, FALSE, td);
} else if ((flags & MAP_ANON) != 0) {
/*
* Mapping blank space is trivial.
*
* This relies on VM_PROT_* matching PROT_*.
*/
error = vm_mmap_object(&vms->vm_map, &addr, size, prot,
max_prot, flags, NULL, pos, FALSE, td);
} else {
/*
* Mapping file, get fp for validation and don't let the
* descriptor disappear on us if we block. Check capability
* rights, but also return the maximum rights to be combined
* with maxprot later.
*/
cap_rights_init(&rights, CAP_MMAP);
if (prot & PROT_READ)
cap_rights_set(&rights, CAP_MMAP_R);
if ((flags & MAP_SHARED) != 0) {
if (prot & PROT_WRITE)
cap_rights_set(&rights, CAP_MMAP_W);
}
if (prot & PROT_EXEC)
cap_rights_set(&rights, CAP_MMAP_X);
error = fget_mmap(td, fd, &rights, &cap_maxprot, &fp);
if (error != 0)
goto done;
if ((flags & (MAP_SHARED | MAP_PRIVATE)) == 0 &&
p->p_osrel >= P_OSREL_MAP_FSTRICT) {
error = EINVAL;
goto done;
}
/* This relies on VM_PROT_* matching PROT_*. */
error = fo_mmap(fp, &vms->vm_map, &addr, size, prot,
max_prot & cap_maxprot, flags, pos, td);
}
if (error == 0)
td->td_retval[0] = (register_t) (addr + pageoff);
done:
if (fp)
fdrop(fp, td);
return (error);
}
#if defined(COMPAT_FREEBSD6)
int
freebsd6_mmap(struct thread *td, struct freebsd6_mmap_args *uap)
{
return (kern_mmap(td, (uintptr_t)uap->addr, uap->len, uap->prot,
uap->flags, uap->fd, uap->pos));
}
#endif
#ifdef COMPAT_43
#ifndef _SYS_SYSPROTO_H_
struct ommap_args {
caddr_t addr;
int len;
int prot;
int flags;
int fd;
long pos;
};
#endif
int
ommap(struct thread *td, struct ommap_args *uap)
{
static const char cvtbsdprot[8] = {
0,
PROT_EXEC,
PROT_WRITE,
PROT_EXEC | PROT_WRITE,
PROT_READ,
PROT_EXEC | PROT_READ,
PROT_WRITE | PROT_READ,
PROT_EXEC | PROT_WRITE | PROT_READ,
};
int flags, prot;
#define OMAP_ANON 0x0002
#define OMAP_COPY 0x0020
#define OMAP_SHARED 0x0010
#define OMAP_FIXED 0x0100
prot = cvtbsdprot[uap->prot & 0x7];
#if (defined(COMPAT_FREEBSD32) && defined(__amd64__)) || defined(__i386__)
if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32) &&
prot != 0)
prot |= PROT_EXEC;
#endif
flags = 0;
if (uap->flags & OMAP_ANON)
flags |= MAP_ANON;
if (uap->flags & OMAP_COPY)
flags |= MAP_COPY;
if (uap->flags & OMAP_SHARED)
flags |= MAP_SHARED;
else
flags |= MAP_PRIVATE;
if (uap->flags & OMAP_FIXED)
flags |= MAP_FIXED;
return (kern_mmap(td, (uintptr_t)uap->addr, uap->len, prot, flags,
uap->fd, uap->pos));
}
#endif /* COMPAT_43 */
#ifndef _SYS_SYSPROTO_H_
struct msync_args {
void *addr;
size_t len;
int flags;
};
#endif
int
sys_msync(struct thread *td, struct msync_args *uap)
{
return (kern_msync(td, (uintptr_t)uap->addr, uap->len, uap->flags));
}
int
kern_msync(struct thread *td, uintptr_t addr0, size_t size, int flags)
{
vm_offset_t addr;
vm_size_t pageoff;
vm_map_t map;
int rv;
addr = addr0;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
return (EINVAL);
if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
return (EINVAL);
map = &td->td_proc->p_vmspace->vm_map;
/*
* Clean the pages and interpret the return value.
*/
rv = vm_map_sync(map, addr, addr + size, (flags & MS_ASYNC) == 0,
(flags & MS_INVALIDATE) != 0);
switch (rv) {
case KERN_SUCCESS:
return (0);
case KERN_INVALID_ADDRESS:
return (ENOMEM);
case KERN_INVALID_ARGUMENT:
return (EBUSY);
case KERN_FAILURE:
return (EIO);
default:
return (EINVAL);
}
}
#ifndef _SYS_SYSPROTO_H_
struct munmap_args {
void *addr;
size_t len;
};
#endif
int
sys_munmap(struct thread *td, struct munmap_args *uap)
{
return (kern_munmap(td, (uintptr_t)uap->addr, uap->len));
}
int
kern_munmap(struct thread *td, uintptr_t addr0, size_t size)
{
#ifdef HWPMC_HOOKS
struct pmckern_map_out pkm;
vm_map_entry_t entry;
bool pmc_handled;
#endif
vm_offset_t addr;
vm_size_t pageoff;
vm_map_t map;
if (size == 0)
return (EINVAL);
addr = addr0;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
return (EINVAL);
/*
* Check for illegal addresses. Watch out for address wrap...
*/
map = &td->td_proc->p_vmspace->vm_map;
if (addr < vm_map_min(map) || addr + size > vm_map_max(map))
return (EINVAL);
vm_map_lock(map);
#ifdef HWPMC_HOOKS
pmc_handled = false;
if (PMC_HOOK_INSTALLED(PMC_FN_MUNMAP)) {
pmc_handled = true;
/*
* Inform hwpmc if the address range being unmapped contains
* an executable region.
*/
pkm.pm_address = (uintptr_t) NULL;
if (vm_map_lookup_entry(map, addr, &entry)) {
for (; entry->start < addr + size;
entry = entry->next) {
if (vm_map_check_protection(map, entry->start,
entry->end, VM_PROT_EXECUTE) == TRUE) {
pkm.pm_address = (uintptr_t) addr;
pkm.pm_size = (size_t) size;
break;
}
}
}
}
#endif
vm_map_delete(map, addr, addr + size);
#ifdef HWPMC_HOOKS
if (__predict_false(pmc_handled)) {
/* downgrade the lock to prevent a LOR with the pmc-sx lock */
vm_map_lock_downgrade(map);
if (pkm.pm_address != (uintptr_t) NULL)
PMC_CALL_HOOK(td, PMC_FN_MUNMAP, (void *) &pkm);
vm_map_unlock_read(map);
} else
#endif
vm_map_unlock(map);
/* vm_map_delete returns nothing but KERN_SUCCESS anyway */
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct mprotect_args {
const void *addr;
size_t len;
int prot;
};
#endif
int
sys_mprotect(struct thread *td, struct mprotect_args *uap)
{
return (kern_mprotect(td, (uintptr_t)uap->addr, uap->len, uap->prot));
}
int
kern_mprotect(struct thread *td, uintptr_t addr0, size_t size, int prot)
{
vm_offset_t addr;
vm_size_t pageoff;
int vm_error, max_prot;
addr = addr0;
if ((prot & ~(_PROT_ALL | PROT_MAX(_PROT_ALL))) != 0)
return (EINVAL);
max_prot = PROT_MAX_EXTRACT(prot);
prot = PROT_EXTRACT(prot);
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
#ifdef COMPAT_FREEBSD32
if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
if (((addr + size) & 0xffffffff) < addr)
return (EINVAL);
} else
#endif
if (addr + size < addr)
return (EINVAL);
vm_error = KERN_SUCCESS;
if (max_prot != 0) {
if ((max_prot & prot) != prot)
return (EINVAL);
vm_error = vm_map_protect(&td->td_proc->p_vmspace->vm_map,
addr, addr + size, max_prot, TRUE);
}
if (vm_error == KERN_SUCCESS)
vm_error = vm_map_protect(&td->td_proc->p_vmspace->vm_map,
addr, addr + size, prot, FALSE);
switch (vm_error) {
case KERN_SUCCESS:
return (0);
case KERN_PROTECTION_FAILURE:
return (EACCES);
case KERN_RESOURCE_SHORTAGE:
return (ENOMEM);
}
return (EINVAL);
}
#ifndef _SYS_SYSPROTO_H_
struct minherit_args {
void *addr;
size_t len;
int inherit;
};
#endif
int
sys_minherit(struct thread *td, struct minherit_args *uap)
{
vm_offset_t addr;
vm_size_t size, pageoff;
vm_inherit_t inherit;
addr = (vm_offset_t)uap->addr;
size = uap->len;
inherit = uap->inherit;
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
return (EINVAL);
switch (vm_map_inherit(&td->td_proc->p_vmspace->vm_map, addr,
addr + size, inherit)) {
case KERN_SUCCESS:
return (0);
case KERN_PROTECTION_FAILURE:
return (EACCES);
}
return (EINVAL);
}
#ifndef _SYS_SYSPROTO_H_
struct madvise_args {
void *addr;
size_t len;
int behav;
};
#endif
int
sys_madvise(struct thread *td, struct madvise_args *uap)
{
return (kern_madvise(td, (uintptr_t)uap->addr, uap->len, uap->behav));
}
int
kern_madvise(struct thread *td, uintptr_t addr0, size_t len, int behav)
{
vm_map_t map;
vm_offset_t addr, end, start;
int flags;
/*
* Check for our special case, advising the swap pager we are
* "immortal."
*/
if (behav == MADV_PROTECT) {
flags = PPROT_SET;
return (kern_procctl(td, P_PID, td->td_proc->p_pid,
PROC_SPROTECT, &flags));
}
/*
* Check for illegal addresses. Watch out for address wrap... Note
* that VM_*_ADDRESS are not constants due to casts (argh).
*/
map = &td->td_proc->p_vmspace->vm_map;
addr = addr0;
if (addr < vm_map_min(map) || addr + len > vm_map_max(map))
return (EINVAL);
if ((addr + len) < addr)
return (EINVAL);
/*
* Since this routine is only advisory, we default to conservative
* behavior.
*/
start = trunc_page(addr);
end = round_page(addr + len);
/*
* vm_map_madvise() checks for illegal values of behav.
*/
return (vm_map_madvise(map, start, end, behav));
}
#ifndef _SYS_SYSPROTO_H_
struct mincore_args {
const void *addr;
size_t len;
char *vec;
};
#endif
int
sys_mincore(struct thread *td, struct mincore_args *uap)
{
return (kern_mincore(td, (uintptr_t)uap->addr, uap->len, uap->vec));
}
int
kern_mincore(struct thread *td, uintptr_t addr0, size_t len, char *vec)
{
vm_offset_t addr, first_addr;
vm_offset_t end, cend;
pmap_t pmap;
vm_map_t map;
int error = 0;
int vecindex, lastvecindex;
vm_map_entry_t current;
vm_map_entry_t entry;
vm_object_t object;
vm_paddr_t locked_pa;
vm_page_t m;
vm_pindex_t pindex;
int mincoreinfo;
unsigned int timestamp;
boolean_t locked;
/*
* Make sure that the addresses presented are valid for user
* mode.
*/
first_addr = addr = trunc_page(addr0);
end = addr + (vm_size_t)round_page(len);
map = &td->td_proc->p_vmspace->vm_map;
if (end > vm_map_max(map) || end < addr)
return (ENOMEM);
pmap = vmspace_pmap(td->td_proc->p_vmspace);
vm_map_lock_read(map);
RestartScan:
timestamp = map->timestamp;
if (!vm_map_lookup_entry(map, addr, &entry)) {
vm_map_unlock_read(map);
return (ENOMEM);
}
/*
* Do this on a map entry basis so that if the pages are not
* in the current processes address space, we can easily look
* up the pages elsewhere.
*/
lastvecindex = -1;
for (current = entry; current->start < end; current = current->next) {
/*
* check for contiguity
*/
if (current->end < end && current->next->start > current->end) {
vm_map_unlock_read(map);
return (ENOMEM);
}
/*
* ignore submaps (for now) or null objects
*/
if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
current->object.vm_object == NULL)
continue;
/*
* limit this scan to the current map entry and the
* limits for the mincore call
*/
if (addr < current->start)
addr = current->start;
cend = current->end;
if (cend > end)
cend = end;
/*
* scan this entry one page at a time
*/
while (addr < cend) {
/*
* Check pmap first, it is likely faster, also
* it can provide info as to whether we are the
* one referencing or modifying the page.
*/
object = NULL;
locked_pa = 0;
retry:
m = NULL;
mincoreinfo = pmap_mincore(pmap, addr, &locked_pa);
if (mincore_mapped) {
/*
* We only care about this pmap's
* mapping of the page, if any.
*/
if (locked_pa != 0) {
vm_page_unlock(PHYS_TO_VM_PAGE(
locked_pa));
}
} else if (locked_pa != 0) {
/*
* The page is mapped by this process but not
* both accessed and modified. It is also
* managed. Acquire the object lock so that
* other mappings might be examined.
*/
m = PHYS_TO_VM_PAGE(locked_pa);
if (m->object != object) {
if (object != NULL)
VM_OBJECT_WUNLOCK(object);
object = m->object;
locked = VM_OBJECT_TRYWLOCK(object);
vm_page_unlock(m);
if (!locked) {
VM_OBJECT_WLOCK(object);
vm_page_lock(m);
goto retry;
}
} else
vm_page_unlock(m);
KASSERT(m->valid == VM_PAGE_BITS_ALL,
("mincore: page %p is mapped but invalid",
m));
} else if (mincoreinfo == 0) {
/*
* The page is not mapped by this process. If
* the object implements managed pages, then
* determine if the page is resident so that
* the mappings might be examined.
*/
if (current->object.vm_object != object) {
if (object != NULL)
VM_OBJECT_WUNLOCK(object);
object = current->object.vm_object;
VM_OBJECT_WLOCK(object);
}
if (object->type == OBJT_DEFAULT ||
object->type == OBJT_SWAP ||
object->type == OBJT_VNODE) {
pindex = OFF_TO_IDX(current->offset +
(addr - current->start));
m = vm_page_lookup(object, pindex);
if (m != NULL && m->valid == 0)
m = NULL;
if (m != NULL)
mincoreinfo = MINCORE_INCORE;
}
}
if (m != NULL) {
/* Examine other mappings to the page. */
if (m->dirty == 0 && pmap_is_modified(m))
vm_page_dirty(m);
if (m->dirty != 0)
mincoreinfo |= MINCORE_MODIFIED_OTHER;
/*
* The first test for PGA_REFERENCED is an
* optimization. The second test is
* required because a concurrent pmap
* operation could clear the last reference
* and set PGA_REFERENCED before the call to
* pmap_is_referenced().
*/
if ((m->aflags & PGA_REFERENCED) != 0 ||
pmap_is_referenced(m) ||
(m->aflags & PGA_REFERENCED) != 0)
mincoreinfo |= MINCORE_REFERENCED_OTHER;
}
if (object != NULL)
VM_OBJECT_WUNLOCK(object);
/*
* subyte may page fault. In case it needs to modify
* the map, we release the lock.
*/
vm_map_unlock_read(map);
/*
* calculate index into user supplied byte vector
*/
vecindex = atop(addr - first_addr);
/*
* If we have skipped map entries, we need to make sure that
* the byte vector is zeroed for those skipped entries.
*/
while ((lastvecindex + 1) < vecindex) {
++lastvecindex;
error = subyte(vec + lastvecindex, 0);
if (error) {
error = EFAULT;
goto done2;
}
}
/*
* Pass the page information to the user
*/
error = subyte(vec + vecindex, mincoreinfo);
if (error) {
error = EFAULT;
goto done2;
}
/*
* If the map has changed, due to the subyte, the previous
* output may be invalid.
*/
vm_map_lock_read(map);
if (timestamp != map->timestamp)
goto RestartScan;
lastvecindex = vecindex;
addr += PAGE_SIZE;
}
}
/*
* subyte may page fault. In case it needs to modify
* the map, we release the lock.
*/
vm_map_unlock_read(map);
/*
* Zero the last entries in the byte vector.
*/
vecindex = atop(end - first_addr);
while ((lastvecindex + 1) < vecindex) {
++lastvecindex;
error = subyte(vec + lastvecindex, 0);
if (error) {
error = EFAULT;
goto done2;
}
}
/*
* If the map has changed, due to the subyte, the previous
* output may be invalid.
*/
vm_map_lock_read(map);
if (timestamp != map->timestamp)
goto RestartScan;
vm_map_unlock_read(map);
done2:
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct mlock_args {
const void *addr;
size_t len;
};
#endif
int
sys_mlock(struct thread *td, struct mlock_args *uap)
{
return (kern_mlock(td->td_proc, td->td_ucred,
__DECONST(uintptr_t, uap->addr), uap->len));
}
int
kern_mlock(struct proc *proc, struct ucred *cred, uintptr_t addr0, size_t len)
{
vm_offset_t addr, end, last, start;
vm_size_t npages, size;
vm_map_t map;
unsigned long nsize;
int error;
error = priv_check_cred(cred, PRIV_VM_MLOCK);
if (error)
return (error);
addr = addr0;
size = len;
last = addr + size;
start = trunc_page(addr);
end = round_page(last);
if (last < addr || end < addr)
return (EINVAL);
npages = atop(end - start);
if (npages > vm_page_max_user_wired)
return (ENOMEM);
map = &proc->p_vmspace->vm_map;
PROC_LOCK(proc);
nsize = ptoa(npages + pmap_wired_count(map->pmap));
if (nsize > lim_cur_proc(proc, RLIMIT_MEMLOCK)) {
PROC_UNLOCK(proc);
return (ENOMEM);
}
PROC_UNLOCK(proc);
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(proc);
error = racct_set(proc, RACCT_MEMLOCK, nsize);
PROC_UNLOCK(proc);
if (error != 0)
return (ENOMEM);
}
#endif
error = vm_map_wire(map, start, end,
VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
#ifdef RACCT
if (racct_enable && error != KERN_SUCCESS) {
PROC_LOCK(proc);
racct_set(proc, RACCT_MEMLOCK,
ptoa(pmap_wired_count(map->pmap)));
PROC_UNLOCK(proc);
}
#endif
return (error == KERN_SUCCESS ? 0 : ENOMEM);
}
#ifndef _SYS_SYSPROTO_H_
struct mlockall_args {
int how;
};
#endif
int
sys_mlockall(struct thread *td, struct mlockall_args *uap)
{
vm_map_t map;
int error;
map = &td->td_proc->p_vmspace->vm_map;
error = priv_check(td, PRIV_VM_MLOCK);
if (error)
return (error);
if ((uap->how == 0) || ((uap->how & ~(MCL_CURRENT|MCL_FUTURE)) != 0))
return (EINVAL);
/*
* If wiring all pages in the process would cause it to exceed
* a hard resource limit, return ENOMEM.
*/
if (!old_mlock && uap->how & MCL_CURRENT) {
if (map->size > lim_cur(td, RLIMIT_MEMLOCK))
return (ENOMEM);
}
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(td->td_proc);
error = racct_set(td->td_proc, RACCT_MEMLOCK, map->size);
PROC_UNLOCK(td->td_proc);
if (error != 0)
return (ENOMEM);
}
#endif
if (uap->how & MCL_FUTURE) {
vm_map_lock(map);
vm_map_modflags(map, MAP_WIREFUTURE, 0);
vm_map_unlock(map);
error = 0;
}
if (uap->how & MCL_CURRENT) {
/*
* P1003.1-2001 mandates that all currently mapped pages
* will be memory resident and locked (wired) upon return
* from mlockall(). vm_map_wire() will wire pages, by
* calling vm_fault_wire() for each page in the region.
*/
error = vm_map_wire(map, vm_map_min(map), vm_map_max(map),
VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
if (error == KERN_SUCCESS)
error = 0;
else if (error == KERN_RESOURCE_SHORTAGE)
error = ENOMEM;
else
error = EAGAIN;
}
#ifdef RACCT
if (racct_enable && error != KERN_SUCCESS) {
PROC_LOCK(td->td_proc);
racct_set(td->td_proc, RACCT_MEMLOCK,
ptoa(pmap_wired_count(map->pmap)));
PROC_UNLOCK(td->td_proc);
}
#endif
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct munlockall_args {
register_t dummy;
};
#endif
int
sys_munlockall(struct thread *td, struct munlockall_args *uap)
{
vm_map_t map;
int error;
map = &td->td_proc->p_vmspace->vm_map;
error = priv_check(td, PRIV_VM_MUNLOCK);
if (error)
return (error);
/* Clear the MAP_WIREFUTURE flag from this vm_map. */
vm_map_lock(map);
vm_map_modflags(map, 0, MAP_WIREFUTURE);
vm_map_unlock(map);
/* Forcibly unwire all pages. */
error = vm_map_unwire(map, vm_map_min(map), vm_map_max(map),
VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
#ifdef RACCT
if (racct_enable && error == KERN_SUCCESS) {
PROC_LOCK(td->td_proc);
racct_set(td->td_proc, RACCT_MEMLOCK, 0);
PROC_UNLOCK(td->td_proc);
}
#endif
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct munlock_args {
const void *addr;
size_t len;
};
#endif
int
sys_munlock(struct thread *td, struct munlock_args *uap)
{
return (kern_munlock(td, (uintptr_t)uap->addr, uap->len));
}
int
kern_munlock(struct thread *td, uintptr_t addr0, size_t size)
{
vm_offset_t addr, end, last, start;
#ifdef RACCT
vm_map_t map;
#endif
int error;
error = priv_check(td, PRIV_VM_MUNLOCK);
if (error)
return (error);
addr = addr0;
last = addr + size;
start = trunc_page(addr);
end = round_page(last);
if (last < addr || end < addr)
return (EINVAL);
error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, start, end,
VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
#ifdef RACCT
if (racct_enable && error == KERN_SUCCESS) {
PROC_LOCK(td->td_proc);
map = &td->td_proc->p_vmspace->vm_map;
racct_set(td->td_proc, RACCT_MEMLOCK,
ptoa(pmap_wired_count(map->pmap)));
PROC_UNLOCK(td->td_proc);
}
#endif
return (error == KERN_SUCCESS ? 0 : ENOMEM);
}
/*
* vm_mmap_vnode()
*
* Helper function for vm_mmap. Perform sanity check specific for mmap
* operations on vnodes.
*/
int
vm_mmap_vnode(struct thread *td, vm_size_t objsize,
vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
struct vnode *vp, vm_ooffset_t *foffp, vm_object_t *objp,
boolean_t *writecounted)
{
struct vattr va;
vm_object_t obj;
vm_ooffset_t foff;
struct ucred *cred;
int error, flags;
bool writex;
cred = td->td_ucred;
writex = (*maxprotp & VM_PROT_WRITE) != 0 &&
(*flagsp & MAP_SHARED) != 0;
if ((error = vget(vp, LK_SHARED, td)) != 0)
return (error);
AUDIT_ARG_VNODE1(vp);
foff = *foffp;
flags = *flagsp;
obj = vp->v_object;
if (vp->v_type == VREG) {
/*
* Get the proper underlying object
*/
if (obj == NULL) {
error = EINVAL;
goto done;
}
if (obj->type == OBJT_VNODE && obj->handle != vp) {
vput(vp);
vp = (struct vnode *)obj->handle;
/*
* Bypass filesystems obey the mpsafety of the
* underlying fs. Tmpfs never bypasses.
*/
error = vget(vp, LK_SHARED, td);
if (error != 0)
return (error);
}
if (writex) {
*writecounted = TRUE;
vnode_pager_update_writecount(obj, 0, objsize);
}
} else {
error = EINVAL;
goto done;
}
if ((error = VOP_GETATTR(vp, &va, cred)))
goto done;
#ifdef MAC
/* This relies on VM_PROT_* matching PROT_*. */
error = mac_vnode_check_mmap(cred, vp, (int)prot, flags);
if (error != 0)
goto done;
#endif
if ((flags & MAP_SHARED) != 0) {
if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) != 0) {
if (prot & VM_PROT_WRITE) {
error = EPERM;
goto done;
}
*maxprotp &= ~VM_PROT_WRITE;
}
}
/*
* If it is a regular file without any references
* we do not need to sync it.
* Adjust object size to be the size of actual file.
*/
objsize = round_page(va.va_size);
if (va.va_nlink == 0)
flags |= MAP_NOSYNC;
if (obj->type == OBJT_VNODE) {
obj = vm_pager_allocate(OBJT_VNODE, vp, objsize, prot, foff,
cred);
if (obj == NULL) {
error = ENOMEM;
goto done;
}
} else {
KASSERT(obj->type == OBJT_DEFAULT || obj->type == OBJT_SWAP,
("wrong object type"));
VM_OBJECT_WLOCK(obj);
vm_object_reference_locked(obj);
#if VM_NRESERVLEVEL > 0
vm_object_color(obj, 0);
#endif
VM_OBJECT_WUNLOCK(obj);
}
*objp = obj;
*flagsp = flags;
vfs_mark_atime(vp, cred);
done:
if (error != 0 && *writecounted) {
*writecounted = FALSE;
vnode_pager_update_writecount(obj, objsize, 0);
}
vput(vp);
return (error);
}
/*
* vm_mmap_cdev()
*
* Helper function for vm_mmap. Perform sanity check specific for mmap
* operations on cdevs.
*/
int
vm_mmap_cdev(struct thread *td, vm_size_t objsize, vm_prot_t prot,
vm_prot_t *maxprotp, int *flagsp, struct cdev *cdev, struct cdevsw *dsw,
vm_ooffset_t *foff, vm_object_t *objp)
{
vm_object_t obj;
int error, flags;
flags = *flagsp;
if (dsw->d_flags & D_MMAP_ANON) {
*objp = NULL;
*foff = 0;
*maxprotp = VM_PROT_ALL;
*flagsp |= MAP_ANON;
return (0);
}
/*
* cdevs do not provide private mappings of any kind.
*/
if ((*maxprotp & VM_PROT_WRITE) == 0 &&
(prot & VM_PROT_WRITE) != 0)
return (EACCES);
if (flags & (MAP_PRIVATE|MAP_COPY))
return (EINVAL);
/*
* Force device mappings to be shared.
*/
flags |= MAP_SHARED;
#ifdef MAC_XXX
error = mac_cdev_check_mmap(td->td_ucred, cdev, (int)prot);
if (error != 0)
return (error);
#endif
/*
* First, try d_mmap_single(). If that is not implemented
* (returns ENODEV), fall back to using the device pager.
* Note that d_mmap_single() must return a reference to the
* object (it needs to bump the reference count of the object
* it returns somehow).
*
* XXX assumes VM_PROT_* == PROT_*
*/
error = dsw->d_mmap_single(cdev, foff, objsize, objp, (int)prot);
if (error != ENODEV)
return (error);
obj = vm_pager_allocate(OBJT_DEVICE, cdev, objsize, prot, *foff,
td->td_ucred);
if (obj == NULL)
return (EINVAL);
*objp = obj;
*flagsp = flags;
return (0);
}
/*
* vm_mmap()
*
* Internal version of mmap used by exec, sys5 shared memory, and
* various device drivers. Handle is either a vnode pointer, a
* character device, or NULL for MAP_ANON.
*/
int
vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
vm_prot_t maxprot, int flags,
objtype_t handle_type, void *handle,
vm_ooffset_t foff)
{
vm_object_t object;
struct thread *td = curthread;
int error;
boolean_t writecounted;
if (size == 0)
return (EINVAL);
size = round_page(size);
object = NULL;
writecounted = FALSE;
/*
* Lookup/allocate object.
*/
switch (handle_type) {
case OBJT_DEVICE: {
struct cdevsw *dsw;
struct cdev *cdev;
int ref;
cdev = handle;
dsw = dev_refthread(cdev, &ref);
if (dsw == NULL)
return (ENXIO);
error = vm_mmap_cdev(td, size, prot, &maxprot, &flags, cdev,
dsw, &foff, &object);
dev_relthread(cdev, ref);
break;
}
case OBJT_VNODE:
error = vm_mmap_vnode(td, size, prot, &maxprot, &flags,
handle, &foff, &object, &writecounted);
break;
case OBJT_DEFAULT:
if (handle == NULL) {
error = 0;
break;
}
/* FALLTHROUGH */
default:
error = EINVAL;
break;
}
if (error)
return (error);
error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
foff, writecounted, td);
if (error != 0 && object != NULL) {
/*
* If this mapping was accounted for in the vnode's
* writecount, then undo that now.
*/
if (writecounted)
vnode_pager_release_writecount(object, 0, size);
vm_object_deallocate(object);
}
return (error);
}
/*
* Internal version of mmap that maps a specific VM object into an
* map. Called by mmap for MAP_ANON, vm_mmap, shm_mmap, and vn_mmap.
*/
int
vm_mmap_object(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
vm_prot_t maxprot, int flags, vm_object_t object, vm_ooffset_t foff,
boolean_t writecounted, struct thread *td)
{
boolean_t curmap, fitit;
vm_offset_t max_addr;
int docow, error, findspace, rv;
curmap = map == &td->td_proc->p_vmspace->vm_map;
if (curmap) {
RACCT_PROC_LOCK(td->td_proc);
if (map->size + size > lim_cur(td, RLIMIT_VMEM)) {
RACCT_PROC_UNLOCK(td->td_proc);
return (ENOMEM);
}
if (racct_set(td->td_proc, RACCT_VMEM, map->size + size)) {
RACCT_PROC_UNLOCK(td->td_proc);
return (ENOMEM);
}
if (!old_mlock && map->flags & MAP_WIREFUTURE) {
if (ptoa(pmap_wired_count(map->pmap)) + size >
lim_cur(td, RLIMIT_MEMLOCK)) {
racct_set_force(td->td_proc, RACCT_VMEM,
map->size);
RACCT_PROC_UNLOCK(td->td_proc);
return (ENOMEM);
}
error = racct_set(td->td_proc, RACCT_MEMLOCK,
ptoa(pmap_wired_count(map->pmap)) + size);
if (error != 0) {
racct_set_force(td->td_proc, RACCT_VMEM,
map->size);
RACCT_PROC_UNLOCK(td->td_proc);
return (error);
}
}
RACCT_PROC_UNLOCK(td->td_proc);
}
/*
* We currently can only deal with page aligned file offsets.
* The mmap() system call already enforces this by subtracting
* the page offset from the file offset, but checking here
* catches errors in device drivers (e.g. d_single_mmap()
* callbacks) and other internal mapping requests (such as in
* exec).
*/
if (foff & PAGE_MASK)
return (EINVAL);
if ((flags & MAP_FIXED) == 0) {
fitit = TRUE;
*addr = round_page(*addr);
} else {
if (*addr != trunc_page(*addr))
return (EINVAL);
fitit = FALSE;
}
if (flags & MAP_ANON) {
if (object != NULL || foff != 0)
return (EINVAL);
docow = 0;
} else if (flags & MAP_PREFAULT_READ)
docow = MAP_PREFAULT;
else
docow = MAP_PREFAULT_PARTIAL;
if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
docow |= MAP_COPY_ON_WRITE;
if (flags & MAP_NOSYNC)
docow |= MAP_DISABLE_SYNCER;
if (flags & MAP_NOCORE)
docow |= MAP_DISABLE_COREDUMP;
/* Shared memory is also shared with children. */
if (flags & MAP_SHARED)
docow |= MAP_INHERIT_SHARE;
if (writecounted)
docow |= MAP_VN_WRITECOUNT;
if (flags & MAP_STACK) {
if (object != NULL)
return (EINVAL);
docow |= MAP_STACK_GROWS_DOWN;
}
if ((flags & MAP_EXCL) != 0)
docow |= MAP_CHECK_EXCL;
if ((flags & MAP_GUARD) != 0)
docow |= MAP_CREATE_GUARD;
if (fitit) {
if ((flags & MAP_ALIGNMENT_MASK) == MAP_ALIGNED_SUPER)
findspace = VMFS_SUPER_SPACE;
else if ((flags & MAP_ALIGNMENT_MASK) != 0)
findspace = VMFS_ALIGNED_SPACE(flags >>
MAP_ALIGNMENT_SHIFT);
else
findspace = VMFS_OPTIMAL_SPACE;
max_addr = 0;
#ifdef MAP_32BIT
if ((flags & MAP_32BIT) != 0)
max_addr = MAP_32BIT_MAX_ADDR;
#endif
if (curmap) {
rv = vm_map_find_min(map, object, foff, addr, size,
round_page((vm_offset_t)td->td_proc->p_vmspace->
vm_daddr + lim_max(td, RLIMIT_DATA)), max_addr,
findspace, prot, maxprot, docow);
} else {
rv = vm_map_find(map, object, foff, addr, size,
max_addr, findspace, prot, maxprot, docow);
}
} else {
rv = vm_map_fixed(map, object, foff, *addr, size,
prot, maxprot, docow);
}
if (rv == KERN_SUCCESS) {
/*
* If the process has requested that all future mappings
* be wired, then heed this.
*/
if ((map->flags & MAP_WIREFUTURE) != 0) {
vm_map_lock(map);
if ((map->flags & MAP_WIREFUTURE) != 0)
(void)vm_map_wire_locked(map, *addr,
*addr + size, VM_MAP_WIRE_USER |
((flags & MAP_STACK) ? VM_MAP_WIRE_HOLESOK :
VM_MAP_WIRE_NOHOLES));
vm_map_unlock(map);
}
}
return (vm_mmap_to_errno(rv));
}
/*
* Translate a Mach VM return code to zero on success or the appropriate errno
* on failure.
*/
int
vm_mmap_to_errno(int rv)
{
switch (rv) {
case KERN_SUCCESS:
return (0);
case KERN_INVALID_ADDRESS:
case KERN_NO_SPACE:
return (ENOMEM);
case KERN_PROTECTION_FAILURE:
return (EACCES);
default:
return (EINVAL);
}
}
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