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freebsd-skq/sys/vm/vm_mmap.c
Konstantin Belousov 6a97a3f756 Treat the addr argument for mmap(2) request without MAP_FIXED flag as 
a hint.

Right now, for non-fixed mmap(2) calls, addr is de-facto interpreted
as the absolute minimal address of the range where the mapping is
created.  The VA allocator only allocates in the range [addr,
VM_MAXUSER_ADDRESS].  This is too restrictive, the mmap(2) call might
unduly fail if there is no free addresses above addr but a lot of
usable space below it.

Lift this implementation limitation by allocating VA in two passes.
First, try to allocate above addr, as before.  If that fails, do the
second pass with less restrictive constraints for the start of
allocation by specifying minimal allocation address at the max bss
end, if this limit is less than addr.

One important case where this change makes a difference is the
allocation of the stacks for new threads in libthr.  Under some
configuration conditions, libthr tries to hint kernel to reuse the
main thread stack grow area for the new stacks.  This cannot work by
design now after grow area is converted to stack, and there is no
unallocated VA above the main stack.  Interpreting requested stack
base address as the hint provides compatibility with old libthr and
with (mis-)configured current libthr.

Reviewed by:	alc
Tested by:	dim (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-06-28 04:02:36 +00:00

1587 lines
37 KiB
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/*-
* 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_compat.h"
#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/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>
#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");
#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)
#ifndef _SYS_SYSPROTO_H_
struct getpagesize_args {
int dummy;
};
#endif
int
ogetpagesize(struct thread *td, struct getpagesize_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(struct thread *td, uintptr_t addr0, size_t size, int prot, int flags,
int fd, off_t pos)
{
struct vmspace *vms;
struct file *fp;
vm_offset_t addr;
vm_size_t pageoff;
vm_prot_t cap_maxprot;
int align, error;
cap_rights_t rights;
vms = td->td_proc->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 ((size == 0 && curproc->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_SHARED | MAP_PRIVATE | MAP_PREFAULT |
MAP_PREFAULT_READ | MAP_ANON | MAP_STACK)) != 0))
return (EINVAL);
/*
* Align the file position to a page boundary,
* and save its page offset component.
*/
pageoff = (pos & PAGE_MASK);
pos -= pageoff;
/* Adjust size for rounding (on both ends). */
size += pageoff; /* low end... */
size = (vm_size_t) round_page(size); /* hi end */
/* 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 (size == 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,
VM_PROT_ALL, 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 &&
td->td_proc->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,
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];
#ifdef COMPAT_FREEBSD32
#if defined(__amd64__)
if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32) &&
prot != 0)
prot |= PROT_EXEC;
#endif
#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 != &map->header && 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;
addr = addr0;
prot = (prot & VM_PROT_ALL);
pageoff = (addr & PAGE_MASK);
addr -= pageoff;
size += pageoff;
size = (vm_size_t) round_page(size);
if (addr + size < addr)
return (EINVAL);
switch (vm_map_protect(&td->td_proc->p_vmspace->vm_map, addr,
addr + size, prot, FALSE)) {
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 behavior
*/
if (behav < 0 || behav > MADV_CORE)
return (EINVAL);
/*
* 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);
if (vm_map_madvise(map, start, end, behav))
return (EINVAL);
return (0);
}
#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 != &map->header) && (current->start < end);
current = current->next) {
/*
* check for contiguity
*/
if (current->end < end &&
(entry->next == &map->header ||
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 (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, 0);
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_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);
if (npages + vm_cnt.v_wire_count > vm_page_max_wired)
return (EAGAIN);
#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) {
PROC_LOCK(td->td_proc);
if (map->size > lim_cur(td, RLIMIT_MEMLOCK)) {
PROC_UNLOCK(td->td_proc);
return (ENOMEM);
}
PROC_UNLOCK(td->td_proc);
}
#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);
error = (error == KERN_SUCCESS ? 0 : 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_offset_t foff;
struct ucred *cred;
int error, flags, locktype;
cred = td->td_ucred;
if ((*maxprotp & VM_PROT_WRITE) && (*flagsp & MAP_SHARED))
locktype = LK_EXCLUSIVE;
else
locktype = LK_SHARED;
if ((error = vget(vp, locktype, 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, locktype, td);
if (error != 0)
return (error);
}
if (locktype == LK_EXCLUSIVE) {
*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) {
PROC_LOCK(td->td_proc);
if (map->size + size > lim_cur_proc(td->td_proc, RLIMIT_VMEM)) {
PROC_UNLOCK(td->td_proc);
return (ENOMEM);
}
if (racct_set(td->td_proc, RACCT_VMEM, map->size + size)) {
PROC_UNLOCK(td->td_proc);
return (ENOMEM);
}
if (!old_mlock && map->flags & MAP_WIREFUTURE) {
if (ptoa(pmap_wired_count(map->pmap)) + size >
lim_cur_proc(td->td_proc, RLIMIT_MEMLOCK)) {
racct_set_force(td->td_proc, RACCT_VMEM,
map->size);
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);
PROC_UNLOCK(td->td_proc);
return (error);
}
}
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) {
vm_map_wire(map, *addr, *addr + size,
VM_MAP_WIRE_USER | ((flags & MAP_STACK) ?
VM_MAP_WIRE_HOLESOK : VM_MAP_WIRE_NOHOLES));
}
}
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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