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192112b74f
freebsd-skq/sys/vm/vm_map.c
Konstantin Belousov 192112b74f Add pgo_getvp method 
This eliminates the staircase of conditions in vm_map_entry_set_vnode_text().

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D30070
2021-05-07 17:08:03 +03:00

5366 lines
149 KiB
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/*-
* SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
*
* 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 Mach Operating System project at Carnegie-Mellon University.
*
* 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: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Virtual memory mapping module.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/elf.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/vmmeter.h>
#include <sys/mman.h>
#include <sys/vnode.h>
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/file.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/shm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_object.h>
#include <vm/vm_pager.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/vnode_pager.h>
#include <vm/swap_pager.h>
#include <vm/uma.h>
/*
* Virtual memory maps provide for the mapping, protection,
* and sharing of virtual memory objects. In addition,
* this module provides for an efficient virtual copy of
* memory from one map to another.
*
* Synchronization is required prior to most operations.
*
* Maps consist of an ordered doubly-linked list of simple
* entries; a self-adjusting binary search tree of these
* entries is used to speed up lookups.
*
* Since portions of maps are specified by start/end addresses,
* which may not align with existing map entries, all
* routines merely "clip" entries to these start/end values.
* [That is, an entry is split into two, bordering at a
* start or end value.] Note that these clippings may not
* always be necessary (as the two resulting entries are then
* not changed); however, the clipping is done for convenience.
*
* As mentioned above, virtual copy operations are performed
* by copying VM object references from one map to
* another, and then marking both regions as copy-on-write.
*/
static struct mtx map_sleep_mtx;
static uma_zone_t mapentzone;
static uma_zone_t kmapentzone;
static uma_zone_t vmspace_zone;
static int vmspace_zinit(void *mem, int size, int flags);
static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min,
vm_offset_t max);
static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map);
static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry);
static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry);
static int vm_map_growstack(vm_map_t map, vm_offset_t addr,
vm_map_entry_t gap_entry);
static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags);
#ifdef INVARIANTS
static void vmspace_zdtor(void *mem, int size, void *arg);
#endif
static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos,
vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max,
int cow);
static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
vm_offset_t failed_addr);
#define ENTRY_CHARGED(e) ((e)->cred != NULL || \
((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \
!((e)->eflags & MAP_ENTRY_NEEDS_COPY)))
/*
* PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type
* stable.
*/
#define PROC_VMSPACE_LOCK(p) do { } while (0)
#define PROC_VMSPACE_UNLOCK(p) do { } while (0)
/*
* VM_MAP_RANGE_CHECK: [ internal use only ]
*
* Asserts that the starting and ending region
* addresses fall within the valid range of the map.
*/
#define VM_MAP_RANGE_CHECK(map, start, end) \
{ \
if (start < vm_map_min(map)) \
start = vm_map_min(map); \
if (end > vm_map_max(map)) \
end = vm_map_max(map); \
if (start > end) \
start = end; \
}
#ifndef UMA_MD_SMALL_ALLOC
/*
* Allocate a new slab for kernel map entries. The kernel map may be locked or
* unlocked, depending on whether the request is coming from the kernel map or a
* submap. This function allocates a virtual address range directly from the
* kernel map instead of the kmem_* layer to avoid recursion on the kernel map
* lock and also to avoid triggering allocator recursion in the vmem boundary
* tag allocator.
*/
static void *
kmapent_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
vm_offset_t addr;
int error, locked;
*pflag = UMA_SLAB_PRIV;
if (!(locked = vm_map_locked(kernel_map)))
vm_map_lock(kernel_map);
addr = vm_map_findspace(kernel_map, vm_map_min(kernel_map), bytes);
if (addr + bytes < addr || addr + bytes > vm_map_max(kernel_map))
panic("%s: kernel map is exhausted", __func__);
error = vm_map_insert(kernel_map, NULL, 0, addr, addr + bytes,
VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
if (error != KERN_SUCCESS)
panic("%s: vm_map_insert() failed: %d", __func__, error);
if (!locked)
vm_map_unlock(kernel_map);
error = kmem_back_domain(domain, kernel_object, addr, bytes, M_NOWAIT |
M_USE_RESERVE | (wait & M_ZERO));
if (error == KERN_SUCCESS) {
return ((void *)addr);
} else {
if (!locked)
vm_map_lock(kernel_map);
vm_map_delete(kernel_map, addr, bytes);
if (!locked)
vm_map_unlock(kernel_map);
return (NULL);
}
}
static void
kmapent_free(void *item, vm_size_t size, uint8_t pflag)
{
vm_offset_t addr;
int error;
if ((pflag & UMA_SLAB_PRIV) == 0)
/* XXX leaked */
return;
addr = (vm_offset_t)item;
kmem_unback(kernel_object, addr, size);
error = vm_map_remove(kernel_map, addr, addr + size);
KASSERT(error == KERN_SUCCESS,
("%s: vm_map_remove failed: %d", __func__, error));
}
/*
* The worst-case upper bound on the number of kernel map entries that may be
* created before the zone must be replenished in _vm_map_unlock().
*/
#define KMAPENT_RESERVE 1
#endif /* !UMD_MD_SMALL_ALLOC */
/*
* vm_map_startup:
*
* Initialize the vm_map module. Must be called before any other vm_map
* routines.
*
* User map and entry structures are allocated from the general purpose
* memory pool. Kernel maps are statically defined. Kernel map entries
* require special handling to avoid recursion; see the comments above
* kmapent_alloc() and in vm_map_entry_create().
*/
void
vm_map_startup(void)
{
mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF);
/*
* Disable the use of per-CPU buckets: map entry allocation is
* serialized by the kernel map lock.
*/
kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
UMA_ZONE_VM | UMA_ZONE_NOBUCKET);
#ifndef UMA_MD_SMALL_ALLOC
/* Reserve an extra map entry for use when replenishing the reserve. */
uma_zone_reserve(kmapentzone, KMAPENT_RESERVE + 1);
uma_prealloc(kmapentzone, KMAPENT_RESERVE + 1);
uma_zone_set_allocf(kmapentzone, kmapent_alloc);
uma_zone_set_freef(kmapentzone, kmapent_free);
#endif
mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL,
#ifdef INVARIANTS
vmspace_zdtor,
#else
NULL,
#endif
vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
}
static int
vmspace_zinit(void *mem, int size, int flags)
{
struct vmspace *vm;
vm_map_t map;
vm = (struct vmspace *)mem;
map = &vm->vm_map;
memset(map, 0, sizeof(*map));
mtx_init(&map->system_mtx, "vm map (system)", NULL,
MTX_DEF | MTX_DUPOK);
sx_init(&map->lock, "vm map (user)");
PMAP_LOCK_INIT(vmspace_pmap(vm));
return (0);
}
#ifdef INVARIANTS
static void
vmspace_zdtor(void *mem, int size, void *arg)
{
struct vmspace *vm;
vm = (struct vmspace *)mem;
KASSERT(vm->vm_map.nentries == 0,
("vmspace %p nentries == %d on free", vm, vm->vm_map.nentries));
KASSERT(vm->vm_map.size == 0,
("vmspace %p size == %ju on free", vm, (uintmax_t)vm->vm_map.size));
}
#endif /* INVARIANTS */
/*
* Allocate a vmspace structure, including a vm_map and pmap,
* and initialize those structures. The refcnt is set to 1.
*/
struct vmspace *
vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit)
{
struct vmspace *vm;
vm = uma_zalloc(vmspace_zone, M_WAITOK);
KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL"));
if (!pinit(vmspace_pmap(vm))) {
uma_zfree(vmspace_zone, vm);
return (NULL);
}
CTR1(KTR_VM, "vmspace_alloc: %p", vm);
_vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max);
refcount_init(&vm->vm_refcnt, 1);
vm->vm_shm = NULL;
vm->vm_swrss = 0;
vm->vm_tsize = 0;
vm->vm_dsize = 0;
vm->vm_ssize = 0;
vm->vm_taddr = 0;
vm->vm_daddr = 0;
vm->vm_maxsaddr = 0;
return (vm);
}
#ifdef RACCT
static void
vmspace_container_reset(struct proc *p)
{
PROC_LOCK(p);
racct_set(p, RACCT_DATA, 0);
racct_set(p, RACCT_STACK, 0);
racct_set(p, RACCT_RSS, 0);
racct_set(p, RACCT_MEMLOCK, 0);
racct_set(p, RACCT_VMEM, 0);
PROC_UNLOCK(p);
}
#endif
static inline void
vmspace_dofree(struct vmspace *vm)
{
CTR1(KTR_VM, "vmspace_free: %p", vm);
/*
* Make sure any SysV shm is freed, it might not have been in
* exit1().
*/
shmexit(vm);
/*
* Lock the map, to wait out all other references to it.
* Delete all of the mappings and pages they hold, then call
* the pmap module to reclaim anything left.
*/
(void)vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map),
vm_map_max(&vm->vm_map));
pmap_release(vmspace_pmap(vm));
vm->vm_map.pmap = NULL;
uma_zfree(vmspace_zone, vm);
}
void
vmspace_free(struct vmspace *vm)
{
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"vmspace_free() called");
if (refcount_release(&vm->vm_refcnt))
vmspace_dofree(vm);
}
void
vmspace_exitfree(struct proc *p)
{
struct vmspace *vm;
PROC_VMSPACE_LOCK(p);
vm = p->p_vmspace;
p->p_vmspace = NULL;
PROC_VMSPACE_UNLOCK(p);
KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace"));
vmspace_free(vm);
}
void
vmspace_exit(struct thread *td)
{
struct vmspace *vm;
struct proc *p;
bool released;
p = td->td_proc;
vm = p->p_vmspace;
/*
* Prepare to release the vmspace reference. The thread that releases
* the last reference is responsible for tearing down the vmspace.
* However, threads not releasing the final reference must switch to the
* kernel's vmspace0 before the decrement so that the subsequent pmap
* deactivation does not modify a freed vmspace.
*/
refcount_acquire(&vmspace0.vm_refcnt);
if (!(released = refcount_release_if_last(&vm->vm_refcnt))) {
if (p->p_vmspace != &vmspace0) {
PROC_VMSPACE_LOCK(p);
p->p_vmspace = &vmspace0;
PROC_VMSPACE_UNLOCK(p);
pmap_activate(td);
}
released = refcount_release(&vm->vm_refcnt);
}
if (released) {
/*
* pmap_remove_pages() expects the pmap to be active, so switch
* back first if necessary.
*/
if (p->p_vmspace != vm) {
PROC_VMSPACE_LOCK(p);
p->p_vmspace = vm;
PROC_VMSPACE_UNLOCK(p);
pmap_activate(td);
}
pmap_remove_pages(vmspace_pmap(vm));
PROC_VMSPACE_LOCK(p);
p->p_vmspace = &vmspace0;
PROC_VMSPACE_UNLOCK(p);
pmap_activate(td);
vmspace_dofree(vm);
}
#ifdef RACCT
if (racct_enable)
vmspace_container_reset(p);
#endif
}
/* Acquire reference to vmspace owned by another process. */
struct vmspace *
vmspace_acquire_ref(struct proc *p)
{
struct vmspace *vm;
PROC_VMSPACE_LOCK(p);
vm = p->p_vmspace;
if (vm == NULL || !refcount_acquire_if_not_zero(&vm->vm_refcnt)) {
PROC_VMSPACE_UNLOCK(p);
return (NULL);
}
if (vm != p->p_vmspace) {
PROC_VMSPACE_UNLOCK(p);
vmspace_free(vm);
return (NULL);
}
PROC_VMSPACE_UNLOCK(p);
return (vm);
}
/*
* Switch between vmspaces in an AIO kernel process.
*
* The new vmspace is either the vmspace of a user process obtained
* from an active AIO request or the initial vmspace of the AIO kernel
* process (when it is idling). Because user processes will block to
* drain any active AIO requests before proceeding in exit() or
* execve(), the reference count for vmspaces from AIO requests can
* never be 0. Similarly, AIO kernel processes hold an extra
* reference on their initial vmspace for the life of the process. As
* a result, the 'newvm' vmspace always has a non-zero reference
* count. This permits an additional reference on 'newvm' to be
* acquired via a simple atomic increment rather than the loop in
* vmspace_acquire_ref() above.
*/
void
vmspace_switch_aio(struct vmspace *newvm)
{
struct vmspace *oldvm;
/* XXX: Need some way to assert that this is an aio daemon. */
KASSERT(refcount_load(&newvm->vm_refcnt) > 0,
("vmspace_switch_aio: newvm unreferenced"));
oldvm = curproc->p_vmspace;
if (oldvm == newvm)
return;
/*
* Point to the new address space and refer to it.
*/
curproc->p_vmspace = newvm;
refcount_acquire(&newvm->vm_refcnt);
/* Activate the new mapping. */
pmap_activate(curthread);
vmspace_free(oldvm);
}
void
_vm_map_lock(vm_map_t map, const char *file, int line)
{
if (map->system_map)
mtx_lock_flags_(&map->system_mtx, 0, file, line);
else
sx_xlock_(&map->lock, file, line);
map->timestamp++;
}
void
vm_map_entry_set_vnode_text(vm_map_entry_t entry, bool add)
{
vm_object_t object;
struct vnode *vp;
bool vp_held;
if ((entry->eflags & MAP_ENTRY_VN_EXEC) == 0)
return;
KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
("Submap with execs"));
object = entry->object.vm_object;
KASSERT(object != NULL, ("No object for text, entry %p", entry));
if ((object->flags & OBJ_ANON) != 0)
object = object->handle;
else
KASSERT(object->backing_object == NULL,
("non-anon object %p shadows", object));
KASSERT(object != NULL, ("No content object for text, entry %p obj %p",
entry, entry->object.vm_object));
/*
* Mostly, we do not lock the backing object. It is
* referenced by the entry we are processing, so it cannot go
* away.
*/
vm_pager_getvp(object, &vp, &vp_held);
if (vp != NULL) {
if (add) {
VOP_SET_TEXT_CHECKED(vp);
} else {
vn_lock(vp, LK_SHARED | LK_RETRY);
VOP_UNSET_TEXT_CHECKED(vp);
VOP_UNLOCK(vp);
}
if (vp_held)
vdrop(vp);
}
}
/*
* Use a different name for this vm_map_entry field when it's use
* is not consistent with its use as part of an ordered search tree.
*/
#define defer_next right
static void
vm_map_process_deferred(void)
{
struct thread *td;
vm_map_entry_t entry, next;
vm_object_t object;
td = curthread;
entry = td->td_map_def_user;
td->td_map_def_user = NULL;
while (entry != NULL) {
next = entry->defer_next;
MPASS((entry->eflags & (MAP_ENTRY_WRITECNT |
MAP_ENTRY_VN_EXEC)) != (MAP_ENTRY_WRITECNT |
MAP_ENTRY_VN_EXEC));
if ((entry->eflags & MAP_ENTRY_WRITECNT) != 0) {
/*
* Decrement the object's writemappings and
* possibly the vnode's v_writecount.
*/
KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
("Submap with writecount"));
object = entry->object.vm_object;
KASSERT(object != NULL, ("No object for writecount"));
vm_pager_release_writecount(object, entry->start,
entry->end);
}
vm_map_entry_set_vnode_text(entry, false);
vm_map_entry_deallocate(entry, FALSE);
entry = next;
}
}
#ifdef INVARIANTS
static void
_vm_map_assert_locked(vm_map_t map, const char *file, int line)
{
if (map->system_map)
mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
else
sx_assert_(&map->lock, SA_XLOCKED, file, line);
}
#define VM_MAP_ASSERT_LOCKED(map) \
_vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE)
enum { VMMAP_CHECK_NONE, VMMAP_CHECK_UNLOCK, VMMAP_CHECK_ALL };
#ifdef DIAGNOSTIC
static int enable_vmmap_check = VMMAP_CHECK_UNLOCK;
#else
static int enable_vmmap_check = VMMAP_CHECK_NONE;
#endif
SYSCTL_INT(_debug, OID_AUTO, vmmap_check, CTLFLAG_RWTUN,
&enable_vmmap_check, 0, "Enable vm map consistency checking");
static void _vm_map_assert_consistent(vm_map_t map, int check);
#define VM_MAP_ASSERT_CONSISTENT(map) \
_vm_map_assert_consistent(map, VMMAP_CHECK_ALL)
#ifdef DIAGNOSTIC
#define VM_MAP_UNLOCK_CONSISTENT(map) do { \
if (map->nupdates > map->nentries) { \
_vm_map_assert_consistent(map, VMMAP_CHECK_UNLOCK); \
map->nupdates = 0; \
} \
} while (0)
#else
#define VM_MAP_UNLOCK_CONSISTENT(map)
#endif
#else
#define VM_MAP_ASSERT_LOCKED(map)
#define VM_MAP_ASSERT_CONSISTENT(map)
#define VM_MAP_UNLOCK_CONSISTENT(map)
#endif /* INVARIANTS */
void
_vm_map_unlock(vm_map_t map, const char *file, int line)
{
VM_MAP_UNLOCK_CONSISTENT(map);
if (map->system_map) {
#ifndef UMA_MD_SMALL_ALLOC
if (map == kernel_map && (map->flags & MAP_REPLENISH) != 0) {
uma_prealloc(kmapentzone, 1);
map->flags &= ~MAP_REPLENISH;
}
#endif
mtx_unlock_flags_(&map->system_mtx, 0, file, line);
} else {
sx_xunlock_(&map->lock, file, line);
vm_map_process_deferred();
}
}
void
_vm_map_lock_read(vm_map_t map, const char *file, int line)
{
if (map->system_map)
mtx_lock_flags_(&map->system_mtx, 0, file, line);
else
sx_slock_(&map->lock, file, line);
}
void
_vm_map_unlock_read(vm_map_t map, const char *file, int line)
{
if (map->system_map) {
KASSERT((map->flags & MAP_REPLENISH) == 0,
("%s: MAP_REPLENISH leaked", __func__));
mtx_unlock_flags_(&map->system_mtx, 0, file, line);
} else {
sx_sunlock_(&map->lock, file, line);
vm_map_process_deferred();
}
}
int
_vm_map_trylock(vm_map_t map, const char *file, int line)
{
int error;
error = map->system_map ?
!mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
!sx_try_xlock_(&map->lock, file, line);
if (error == 0)
map->timestamp++;
return (error == 0);
}
int
_vm_map_trylock_read(vm_map_t map, const char *file, int line)
{
int error;
error = map->system_map ?
!mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
!sx_try_slock_(&map->lock, file, line);
return (error == 0);
}
/*
* _vm_map_lock_upgrade: [ internal use only ]
*
* Tries to upgrade a read (shared) lock on the specified map to a write
* (exclusive) lock. Returns the value "0" if the upgrade succeeds and a
* non-zero value if the upgrade fails. If the upgrade fails, the map is
* returned without a read or write lock held.
*
* Requires that the map be read locked.
*/
int
_vm_map_lock_upgrade(vm_map_t map, const char *file, int line)
{
unsigned int last_timestamp;
if (map->system_map) {
mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
} else {
if (!sx_try_upgrade_(&map->lock, file, line)) {
last_timestamp = map->timestamp;
sx_sunlock_(&map->lock, file, line);
vm_map_process_deferred();
/*
* If the map's timestamp does not change while the
* map is unlocked, then the upgrade succeeds.
*/
sx_xlock_(&map->lock, file, line);
if (last_timestamp != map->timestamp) {
sx_xunlock_(&map->lock, file, line);
return (1);
}
}
}
map->timestamp++;
return (0);
}
void
_vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
{
if (map->system_map) {
KASSERT((map->flags & MAP_REPLENISH) == 0,
("%s: MAP_REPLENISH leaked", __func__));
mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
} else {
VM_MAP_UNLOCK_CONSISTENT(map);
sx_downgrade_(&map->lock, file, line);
}
}
/*
* vm_map_locked:
*
* Returns a non-zero value if the caller holds a write (exclusive) lock
* on the specified map and the value "0" otherwise.
*/
int
vm_map_locked(vm_map_t map)
{
if (map->system_map)
return (mtx_owned(&map->system_mtx));
else
return (sx_xlocked(&map->lock));
}
/*
* _vm_map_unlock_and_wait:
*
* Atomically releases the lock on the specified map and puts the calling
* thread to sleep. The calling thread will remain asleep until either
* vm_map_wakeup() is performed on the map or the specified timeout is
* exceeded.
*
* WARNING! This function does not perform deferred deallocations of
* objects and map entries. Therefore, the calling thread is expected to
* reacquire the map lock after reawakening and later perform an ordinary
* unlock operation, such as vm_map_unlock(), before completing its
* operation on the map.
*/
int
_vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line)
{
VM_MAP_UNLOCK_CONSISTENT(map);
mtx_lock(&map_sleep_mtx);
if (map->system_map) {
KASSERT((map->flags & MAP_REPLENISH) == 0,
("%s: MAP_REPLENISH leaked", __func__));
mtx_unlock_flags_(&map->system_mtx, 0, file, line);
} else {
sx_xunlock_(&map->lock, file, line);
}
return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps",
timo));
}
/*
* vm_map_wakeup:
*
* Awaken any threads that have slept on the map using
* vm_map_unlock_and_wait().
*/
void
vm_map_wakeup(vm_map_t map)
{
/*
* Acquire and release map_sleep_mtx to prevent a wakeup()
* from being performed (and lost) between the map unlock
* and the msleep() in _vm_map_unlock_and_wait().
*/
mtx_lock(&map_sleep_mtx);
mtx_unlock(&map_sleep_mtx);
wakeup(&map->root);
}
void
vm_map_busy(vm_map_t map)
{
VM_MAP_ASSERT_LOCKED(map);
map->busy++;
}
void
vm_map_unbusy(vm_map_t map)
{
VM_MAP_ASSERT_LOCKED(map);
KASSERT(map->busy, ("vm_map_unbusy: not busy"));
if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) {
vm_map_modflags(map, 0, MAP_BUSY_WAKEUP);
wakeup(&map->busy);
}
}
void
vm_map_wait_busy(vm_map_t map)
{
VM_MAP_ASSERT_LOCKED(map);
while (map->busy) {
vm_map_modflags(map, MAP_BUSY_WAKEUP, 0);
if (map->system_map)
msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0);
else
sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0);
}
map->timestamp++;
}
long
vmspace_resident_count(struct vmspace *vmspace)
{
return pmap_resident_count(vmspace_pmap(vmspace));
}
/*
* Initialize an existing vm_map structure
* such as that in the vmspace structure.
*/
static void
_vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
{
map->header.eflags = MAP_ENTRY_HEADER;
map->needs_wakeup = FALSE;
map->system_map = 0;
map->pmap = pmap;
map->header.end = min;
map->header.start = max;
map->flags = 0;
map->header.left = map->header.right = &map->header;
map->root = NULL;
map->timestamp = 0;
map->busy = 0;
map->anon_loc = 0;
#ifdef DIAGNOSTIC
map->nupdates = 0;
#endif
}
void
vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
{
_vm_map_init(map, pmap, min, max);
mtx_init(&map->system_mtx, "vm map (system)", NULL,
MTX_DEF | MTX_DUPOK);
sx_init(&map->lock, "vm map (user)");
}
/*
* vm_map_entry_dispose: [ internal use only ]
*
* Inverse of vm_map_entry_create.
*/
static void
vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry)
{
uma_zfree(map->system_map ? kmapentzone : mapentzone, entry);
}
/*
* vm_map_entry_create: [ internal use only ]
*
* Allocates a VM map entry for insertion.
* No entry fields are filled in.
*/
static vm_map_entry_t
vm_map_entry_create(vm_map_t map)
{
vm_map_entry_t new_entry;
#ifndef UMA_MD_SMALL_ALLOC
if (map == kernel_map) {
VM_MAP_ASSERT_LOCKED(map);
/*
* A new slab of kernel map entries cannot be allocated at this
* point because the kernel map has not yet been updated to
* reflect the caller's request. Therefore, we allocate a new
* map entry, dipping into the reserve if necessary, and set a
* flag indicating that the reserve must be replenished before
* the map is unlocked.
*/
new_entry = uma_zalloc(kmapentzone, M_NOWAIT | M_NOVM);
if (new_entry == NULL) {
new_entry = uma_zalloc(kmapentzone,
M_NOWAIT | M_NOVM | M_USE_RESERVE);
kernel_map->flags |= MAP_REPLENISH;
}
} else
#endif
if (map->system_map) {
new_entry = uma_zalloc(kmapentzone, M_NOWAIT);
} else {
new_entry = uma_zalloc(mapentzone, M_WAITOK);
}
KASSERT(new_entry != NULL,
("vm_map_entry_create: kernel resources exhausted"));
return (new_entry);
}
/*
* vm_map_entry_set_behavior:
*
* Set the expected access behavior, either normal, random, or
* sequential.
*/
static inline void
vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior)
{
entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) |
(behavior & MAP_ENTRY_BEHAV_MASK);
}
/*
* vm_map_entry_max_free_{left,right}:
*
* Compute the size of the largest free gap between two entries,
* one the root of a tree and the other the ancestor of that root
* that is the least or greatest ancestor found on the search path.
*/
static inline vm_size_t
vm_map_entry_max_free_left(vm_map_entry_t root, vm_map_entry_t left_ancestor)
{
return (root->left != left_ancestor ?
root->left->max_free : root->start - left_ancestor->end);
}
static inline vm_size_t
vm_map_entry_max_free_right(vm_map_entry_t root, vm_map_entry_t right_ancestor)
{
return (root->right != right_ancestor ?
root->right->max_free : right_ancestor->start - root->end);
}
/*
* vm_map_entry_{pred,succ}:
*
* Find the {predecessor, successor} of the entry by taking one step
* in the appropriate direction and backtracking as much as necessary.
* vm_map_entry_succ is defined in vm_map.h.
*/
static inline vm_map_entry_t
vm_map_entry_pred(vm_map_entry_t entry)
{
vm_map_entry_t prior;
prior = entry->left;
if (prior->right->start < entry->start) {
do
prior = prior->right;
while (prior->right != entry);
}
return (prior);
}
static inline vm_size_t
vm_size_max(vm_size_t a, vm_size_t b)
{
return (a > b ? a : b);
}
#define SPLAY_LEFT_STEP(root, y, llist, rlist, test) do { \
vm_map_entry_t z; \
vm_size_t max_free; \
\
/* \
* Infer root->right->max_free == root->max_free when \
* y->max_free < root->max_free || root->max_free == 0. \
* Otherwise, look right to find it. \
*/ \
y = root->left; \
max_free = root->max_free; \
KASSERT(max_free == vm_size_max( \
vm_map_entry_max_free_left(root, llist), \
vm_map_entry_max_free_right(root, rlist)), \
("%s: max_free invariant fails", __func__)); \
if (max_free - 1 < vm_map_entry_max_free_left(root, llist)) \
max_free = vm_map_entry_max_free_right(root, rlist); \
if (y != llist && (test)) { \
/* Rotate right and make y root. */ \
z = y->right; \
if (z != root) { \
root->left = z; \
y->right = root; \
if (max_free < y->max_free) \
root->max_free = max_free = \
vm_size_max(max_free, z->max_free); \
} else if (max_free < y->max_free) \
root->max_free = max_free = \
vm_size_max(max_free, root->start - y->end);\
root = y; \
y = root->left; \
} \
/* Copy right->max_free. Put root on rlist. */ \
root->max_free = max_free; \
KASSERT(max_free == vm_map_entry_max_free_right(root, rlist), \
("%s: max_free not copied from right", __func__)); \
root->left = rlist; \
rlist = root; \
root = y != llist ? y : NULL; \
} while (0)
#define SPLAY_RIGHT_STEP(root, y, llist, rlist, test) do { \
vm_map_entry_t z; \
vm_size_t max_free; \
\
/* \
* Infer root->left->max_free == root->max_free when \
* y->max_free < root->max_free || root->max_free == 0. \
* Otherwise, look left to find it. \
*/ \
y = root->right; \
max_free = root->max_free; \
KASSERT(max_free == vm_size_max( \
vm_map_entry_max_free_left(root, llist), \
vm_map_entry_max_free_right(root, rlist)), \
("%s: max_free invariant fails", __func__)); \
if (max_free - 1 < vm_map_entry_max_free_right(root, rlist)) \
max_free = vm_map_entry_max_free_left(root, llist); \
if (y != rlist && (test)) { \
/* Rotate left and make y root. */ \
z = y->left; \
if (z != root) { \
root->right = z; \
y->left = root; \
if (max_free < y->max_free) \
root->max_free = max_free = \
vm_size_max(max_free, z->max_free); \
} else if (max_free < y->max_free) \
root->max_free = max_free = \
vm_size_max(max_free, y->start - root->end);\
root = y; \
y = root->right; \
} \
/* Copy left->max_free. Put root on llist. */ \
root->max_free = max_free; \
KASSERT(max_free == vm_map_entry_max_free_left(root, llist), \
("%s: max_free not copied from left", __func__)); \
root->right = llist; \
llist = root; \
root = y != rlist ? y : NULL; \
} while (0)
/*
* Walk down the tree until we find addr or a gap where addr would go, breaking
* off left and right subtrees of nodes less than, or greater than addr. Treat
* subtrees with root->max_free < length as empty trees. llist and rlist are
* the two sides in reverse order (bottom-up), with llist linked by the right
* pointer and rlist linked by the left pointer in the vm_map_entry, and both
* lists terminated by &map->header. This function, and the subsequent call to
* vm_map_splay_merge_{left,right,pred,succ}, rely on the start and end address
* values in &map->header.
*/
static __always_inline vm_map_entry_t
vm_map_splay_split(vm_map_t map, vm_offset_t addr, vm_size_t length,
vm_map_entry_t *llist, vm_map_entry_t *rlist)
{
vm_map_entry_t left, right, root, y;
left = right = &map->header;
root = map->root;
while (root != NULL && root->max_free >= length) {
KASSERT(left->end <= root->start &&
root->end <= right->start,
("%s: root not within tree bounds", __func__));
if (addr < root->start) {
SPLAY_LEFT_STEP(root, y, left, right,
y->max_free >= length && addr < y->start);
} else if (addr >= root->end) {
SPLAY_RIGHT_STEP(root, y, left, right,
y->max_free >= length && addr >= y->end);
} else
break;
}
*llist = left;
*rlist = right;
return (root);
}
static __always_inline void
vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *rlist)
{
vm_map_entry_t hi, right, y;
right = *rlist;
hi = root->right == right ? NULL : root->right;
if (hi == NULL)
return;
do
SPLAY_LEFT_STEP(hi, y, root, right, true);
while (hi != NULL);
*rlist = right;
}
static __always_inline void
vm_map_splay_findprev(vm_map_entry_t root, vm_map_entry_t *llist)
{
vm_map_entry_t left, lo, y;
left = *llist;
lo = root->left == left ? NULL : root->left;
if (lo == NULL)
return;
do
SPLAY_RIGHT_STEP(lo, y, left, root, true);
while (lo != NULL);
*llist = left;
}
static inline void
vm_map_entry_swap(vm_map_entry_t *a, vm_map_entry_t *b)
{
vm_map_entry_t tmp;
tmp = *b;
*b = *a;
*a = tmp;
}
/*
* Walk back up the two spines, flip the pointers and set max_free. The
* subtrees of the root go at the bottom of llist and rlist.
*/
static vm_size_t
vm_map_splay_merge_left_walk(vm_map_entry_t header, vm_map_entry_t root,
vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t llist)
{
do {
/*
* The max_free values of the children of llist are in
* llist->max_free and max_free. Update with the
* max value.
*/
llist->max_free = max_free =
vm_size_max(llist->max_free, max_free);
vm_map_entry_swap(&llist->right, &tail);
vm_map_entry_swap(&tail, &llist);
} while (llist != header);
root->left = tail;
return (max_free);
}
/*
* When llist is known to be the predecessor of root.
*/
static inline vm_size_t
vm_map_splay_merge_pred(vm_map_entry_t header, vm_map_entry_t root,
vm_map_entry_t llist)
{
vm_size_t max_free;
max_free = root->start - llist->end;
if (llist != header) {
max_free = vm_map_splay_merge_left_walk(header, root,
root, max_free, llist);
} else {
root->left = header;
header->right = root;
}
return (max_free);
}
/*
* When llist may or may not be the predecessor of root.
*/
static inline vm_size_t
vm_map_splay_merge_left(vm_map_entry_t header, vm_map_entry_t root,
vm_map_entry_t llist)
{
vm_size_t max_free;
max_free = vm_map_entry_max_free_left(root, llist);
if (llist != header) {
max_free = vm_map_splay_merge_left_walk(header, root,
root->left == llist ? root : root->left,
max_free, llist);
}
return (max_free);
}
static vm_size_t
vm_map_splay_merge_right_walk(vm_map_entry_t header, vm_map_entry_t root,
vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t rlist)
{
do {
/*
* The max_free values of the children of rlist are in
* rlist->max_free and max_free. Update with the
* max value.
*/
rlist->max_free = max_free =
vm_size_max(rlist->max_free, max_free);
vm_map_entry_swap(&rlist->left, &tail);
vm_map_entry_swap(&tail, &rlist);
} while (rlist != header);
root->right = tail;
return (max_free);
}
/*
* When rlist is known to be the succecessor of root.
*/
static inline vm_size_t
vm_map_splay_merge_succ(vm_map_entry_t header, vm_map_entry_t root,
vm_map_entry_t rlist)
{
vm_size_t max_free;
max_free = rlist->start - root->end;
if (rlist != header) {
max_free = vm_map_splay_merge_right_walk(header, root,
root, max_free, rlist);
} else {
root->right = header;
header->left = root;
}
return (max_free);
}
/*
* When rlist may or may not be the succecessor of root.
*/
static inline vm_size_t
vm_map_splay_merge_right(vm_map_entry_t header, vm_map_entry_t root,
vm_map_entry_t rlist)
{
vm_size_t max_free;
max_free = vm_map_entry_max_free_right(root, rlist);
if (rlist != header) {
max_free = vm_map_splay_merge_right_walk(header, root,
root->right == rlist ? root : root->right,
max_free, rlist);
}
return (max_free);
}
/*
* vm_map_splay:
*
* The Sleator and Tarjan top-down splay algorithm with the
* following variation. Max_free must be computed bottom-up, so
* on the downward pass, maintain the left and right spines in
* reverse order. Then, make a second pass up each side to fix
* the pointers and compute max_free. The time bound is O(log n)
* amortized.
*
* The tree is threaded, which means that there are no null pointers.
* When a node has no left child, its left pointer points to its
* predecessor, which the last ancestor on the search path from the root
* where the search branched right. Likewise, when a node has no right
* child, its right pointer points to its successor. The map header node
* is the predecessor of the first map entry, and the successor of the
* last.
*
* The new root is the vm_map_entry containing "addr", or else an
* adjacent entry (lower if possible) if addr is not in the tree.
*
* The map must be locked, and leaves it so.
*
* Returns: the new root.
*/
static vm_map_entry_t
vm_map_splay(vm_map_t map, vm_offset_t addr)
{
vm_map_entry_t header, llist, rlist, root;
vm_size_t max_free_left, max_free_right;
header = &map->header;
root = vm_map_splay_split(map, addr, 0, &llist, &rlist);
if (root != NULL) {
max_free_left = vm_map_splay_merge_left(header, root, llist);
max_free_right = vm_map_splay_merge_right(header, root, rlist);
} else if (llist != header) {
/*
* Recover the greatest node in the left
* subtree and make it the root.
*/
root = llist;
llist = root->right;
max_free_left = vm_map_splay_merge_left(header, root, llist);
max_free_right = vm_map_splay_merge_succ(header, root, rlist);
} else if (rlist != header) {
/*
* Recover the least node in the right
* subtree and make it the root.
*/
root = rlist;
rlist = root->left;
max_free_left = vm_map_splay_merge_pred(header, root, llist);
max_free_right = vm_map_splay_merge_right(header, root, rlist);
} else {
/* There is no root. */
return (NULL);
}
root->max_free = vm_size_max(max_free_left, max_free_right);
map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
return (root);
}
/*
* vm_map_entry_{un,}link:
*
* Insert/remove entries from maps. On linking, if new entry clips
* existing entry, trim existing entry to avoid overlap, and manage
* offsets. On unlinking, merge disappearing entry with neighbor, if
* called for, and manage offsets. Callers should not modify fields in
* entries already mapped.
*/
static void
vm_map_entry_link(vm_map_t map, vm_map_entry_t entry)
{
vm_map_entry_t header, llist, rlist, root;
vm_size_t max_free_left, max_free_right;
CTR3(KTR_VM,
"vm_map_entry_link: map %p, nentries %d, entry %p", map,
map->nentries, entry);
VM_MAP_ASSERT_LOCKED(map);
map->nentries++;
header = &map->header;
root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
if (root == NULL) {
/*
* The new entry does not overlap any existing entry in the
* map, so it becomes the new root of the map tree.
*/
max_free_left = vm_map_splay_merge_pred(header, entry, llist);
max_free_right = vm_map_splay_merge_succ(header, entry, rlist);
} else if (entry->start == root->start) {
/*
* The new entry is a clone of root, with only the end field
* changed. The root entry will be shrunk to abut the new
* entry, and will be the right child of the new root entry in
* the modified map.
*/
KASSERT(entry->end < root->end,
("%s: clip_start not within entry", __func__));
vm_map_splay_findprev(root, &llist);
root->offset += entry->end - root->start;
root->start = entry->end;
max_free_left = vm_map_splay_merge_pred(header, entry, llist);
max_free_right = root->max_free = vm_size_max(
vm_map_splay_merge_pred(entry, root, entry),
vm_map_splay_merge_right(header, root, rlist));
} else {
/*
* The new entry is a clone of root, with only the start field
* changed. The root entry will be shrunk to abut the new
* entry, and will be the left child of the new root entry in
* the modified map.
*/
KASSERT(entry->end == root->end,
("%s: clip_start not within entry", __func__));
vm_map_splay_findnext(root, &rlist);
entry->offset += entry->start - root->start;
root->end = entry->start;
max_free_left = root->max_free = vm_size_max(
vm_map_splay_merge_left(header, root, llist),
vm_map_splay_merge_succ(entry, root, entry));
max_free_right = vm_map_splay_merge_succ(header, entry, rlist);
}
entry->max_free = vm_size_max(max_free_left, max_free_right);
map->root = entry;
VM_MAP_ASSERT_CONSISTENT(map);
}
enum unlink_merge_type {
UNLINK_MERGE_NONE,
UNLINK_MERGE_NEXT
};
static void
vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry,
enum unlink_merge_type op)
{
vm_map_entry_t header, llist, rlist, root;
vm_size_t max_free_left, max_free_right;
VM_MAP_ASSERT_LOCKED(map);
header = &map->header;
root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
KASSERT(root != NULL,
("vm_map_entry_unlink: unlink object not mapped"));
vm_map_splay_findprev(root, &llist);
vm_map_splay_findnext(root, &rlist);
if (op == UNLINK_MERGE_NEXT) {
rlist->start = root->start;
rlist->offset = root->offset;
}
if (llist != header) {
root = llist;
llist = root->right;
max_free_left = vm_map_splay_merge_left(header, root, llist);
max_free_right = vm_map_splay_merge_succ(header, root, rlist);
} else if (rlist != header) {
root = rlist;
rlist = root->left;
max_free_left = vm_map_splay_merge_pred(header, root, llist);
max_free_right = vm_map_splay_merge_right(header, root, rlist);
} else {
header->left = header->right = header;
root = NULL;
}
if (root != NULL)
root->max_free = vm_size_max(max_free_left, max_free_right);
map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
map->nentries--;
CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map,
map->nentries, entry);
}
/*
* vm_map_entry_resize:
*
* Resize a vm_map_entry, recompute the amount of free space that
* follows it and propagate that value up the tree.
*
* The map must be locked, and leaves it so.
*/
static void
vm_map_entry_resize(vm_map_t map, vm_map_entry_t entry, vm_size_t grow_amount)
{
vm_map_entry_t header, llist, rlist, root;
VM_MAP_ASSERT_LOCKED(map);
header = &map->header;
root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
KASSERT(root != NULL, ("%s: resize object not mapped", __func__));
vm_map_splay_findnext(root, &rlist);
entry->end += grow_amount;
root->max_free = vm_size_max(
vm_map_splay_merge_left(header, root, llist),
vm_map_splay_merge_succ(header, root, rlist));
map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
CTR4(KTR_VM, "%s: map %p, nentries %d, entry %p",
__func__, map, map->nentries, entry);
}
/*
* vm_map_lookup_entry: [ internal use only ]
*
* Finds the map entry containing (or
* immediately preceding) the specified address
* in the given map; the entry is returned
* in the "entry" parameter. The boolean
* result indicates whether the address is
* actually contained in the map.
*/
boolean_t
vm_map_lookup_entry(
vm_map_t map,
vm_offset_t address,
vm_map_entry_t *entry) /* OUT */
{
vm_map_entry_t cur, header, lbound, ubound;
boolean_t locked;
/*
* If the map is empty, then the map entry immediately preceding
* "address" is the map's header.
*/
header = &map->header;
cur = map->root;
if (cur == NULL) {
*entry = header;
return (FALSE);
}
if (address >= cur->start && cur->end > address) {
*entry = cur;
return (TRUE);
}
if ((locked = vm_map_locked(map)) ||
sx_try_upgrade(&map->lock)) {
/*
* Splay requires a write lock on the map. However, it only
* restructures the binary search tree; it does not otherwise
* change the map. Thus, the map's timestamp need not change
* on a temporary upgrade.
*/
cur = vm_map_splay(map, address);
if (!locked) {
VM_MAP_UNLOCK_CONSISTENT(map);
sx_downgrade(&map->lock);
}
/*
* If "address" is contained within a map entry, the new root
* is that map entry. Otherwise, the new root is a map entry
* immediately before or after "address".
*/
if (address < cur->start) {
*entry = header;
return (FALSE);
}
*entry = cur;
return (address < cur->end);
}
/*
* Since the map is only locked for read access, perform a
* standard binary search tree lookup for "address".
*/
lbound = ubound = header;
for (;;) {
if (address < cur->start) {
ubound = cur;
cur = cur->left;
if (cur == lbound)
break;
} else if (cur->end <= address) {
lbound = cur;
cur = cur->right;
if (cur == ubound)
break;
} else {
*entry = cur;
return (TRUE);
}
}
*entry = lbound;
return (FALSE);
}
/*
* vm_map_insert:
*
* Inserts the given whole VM object into the target
* map at the specified address range. The object's
* size should match that of the address range.
*
* Requires that the map be locked, and leaves it so.
*
* If object is non-NULL, ref count must be bumped by caller
* prior to making call to account for the new entry.
*/
int
vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow)
{
vm_map_entry_t new_entry, next_entry, prev_entry;
struct ucred *cred;
vm_eflags_t protoeflags;
vm_inherit_t inheritance;
u_long bdry;
u_int bidx;
VM_MAP_ASSERT_LOCKED(map);
KASSERT(object != kernel_object ||
(cow & MAP_COPY_ON_WRITE) == 0,
("vm_map_insert: kernel object and COW"));
KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0 ||
(cow & MAP_SPLIT_BOUNDARY_MASK) != 0,
("vm_map_insert: paradoxical MAP_NOFAULT request, obj %p cow %#x",
object, cow));
KASSERT((prot & ~max) == 0,
("prot %#x is not subset of max_prot %#x", prot, max));
/*
* Check that the start and end points are not bogus.
*/
if (start == end || !vm_map_range_valid(map, start, end))
return (KERN_INVALID_ADDRESS);
if ((map->flags & MAP_WXORX) != 0 && (prot & (VM_PROT_WRITE |
VM_PROT_EXECUTE)) == (VM_PROT_WRITE | VM_PROT_EXECUTE))
return (KERN_PROTECTION_FAILURE);
/*
* Find the entry prior to the proposed starting address; if it's part
* of an existing entry, this range is bogus.
*/
if (vm_map_lookup_entry(map, start, &prev_entry))
return (KERN_NO_SPACE);
/*
* Assert that the next entry doesn't overlap the end point.
*/
next_entry = vm_map_entry_succ(prev_entry);
if (next_entry->start < end)
return (KERN_NO_SPACE);
if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL ||
max != VM_PROT_NONE))
return (KERN_INVALID_ARGUMENT);
protoeflags = 0;
if (cow & MAP_COPY_ON_WRITE)
protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY;
if (cow & MAP_NOFAULT)
protoeflags |= MAP_ENTRY_NOFAULT;
if (cow & MAP_DISABLE_SYNCER)
protoeflags |= MAP_ENTRY_NOSYNC;
if (cow & MAP_DISABLE_COREDUMP)
protoeflags |= MAP_ENTRY_NOCOREDUMP;
if (cow & MAP_STACK_GROWS_DOWN)
protoeflags |= MAP_ENTRY_GROWS_DOWN;
if (cow & MAP_STACK_GROWS_UP)
protoeflags |= MAP_ENTRY_GROWS_UP;
if (cow & MAP_WRITECOUNT)
protoeflags |= MAP_ENTRY_WRITECNT;
if (cow & MAP_VN_EXEC)
protoeflags |= MAP_ENTRY_VN_EXEC;
if ((cow & MAP_CREATE_GUARD) != 0)
protoeflags |= MAP_ENTRY_GUARD;
if ((cow & MAP_CREATE_STACK_GAP_DN) != 0)
protoeflags |= MAP_ENTRY_STACK_GAP_DN;
if ((cow & MAP_CREATE_STACK_GAP_UP) != 0)
protoeflags |= MAP_ENTRY_STACK_GAP_UP;
if (cow & MAP_INHERIT_SHARE)
inheritance = VM_INHERIT_SHARE;
else
inheritance = VM_INHERIT_DEFAULT;
if ((cow & MAP_SPLIT_BOUNDARY_MASK) != 0) {
/* This magically ignores index 0, for usual page size. */
bidx = (cow & MAP_SPLIT_BOUNDARY_MASK) >>
MAP_SPLIT_BOUNDARY_SHIFT;
if (bidx >= MAXPAGESIZES)
return (KERN_INVALID_ARGUMENT);
bdry = pagesizes[bidx] - 1;
if ((start & bdry) != 0 || (end & bdry) != 0)
return (KERN_INVALID_ARGUMENT);
protoeflags |= bidx << MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
}
cred = NULL;
if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0)
goto charged;
if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) &&
((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) {
if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start))
return (KERN_RESOURCE_SHORTAGE);
KASSERT(object == NULL ||
(protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 ||
object->cred == NULL,
("overcommit: vm_map_insert o %p", object));
cred = curthread->td_ucred;
}
charged:
/* Expand the kernel pmap, if necessary. */
if (map == kernel_map && end > kernel_vm_end)
pmap_growkernel(end);
if (object != NULL) {
/*
* OBJ_ONEMAPPING must be cleared unless this mapping
* is trivially proven to be the only mapping for any
* of the object's pages. (Object granularity
* reference counting is insufficient to recognize
* aliases with precision.)
*/
if ((object->flags & OBJ_ANON) != 0) {
VM_OBJECT_WLOCK(object);
if (object->ref_count > 1 || object->shadow_count != 0)
vm_object_clear_flag(object, OBJ_ONEMAPPING);
VM_OBJECT_WUNLOCK(object);
}
} else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) ==
protoeflags &&
(cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP |
MAP_VN_EXEC)) == 0 &&
prev_entry->end == start && (prev_entry->cred == cred ||
(prev_entry->object.vm_object != NULL &&
prev_entry->object.vm_object->cred == cred)) &&
vm_object_coalesce(prev_entry->object.vm_object,
prev_entry->offset,
(vm_size_t)(prev_entry->end - prev_entry->start),
(vm_size_t)(end - prev_entry->end), cred != NULL &&
(protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) {
/*
* We were able to extend the object. Determine if we
* can extend the previous map entry to include the
* new range as well.
*/
if (prev_entry->inheritance == inheritance &&
prev_entry->protection == prot &&
prev_entry->max_protection == max &&
prev_entry->wired_count == 0) {
KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) ==
0, ("prev_entry %p has incoherent wiring",
prev_entry));
if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0)
map->size += end - prev_entry->end;
vm_map_entry_resize(map, prev_entry,
end - prev_entry->end);
vm_map_try_merge_entries(map, prev_entry, next_entry);
return (KERN_SUCCESS);
}
/*
* If we can extend the object but cannot extend the
* map entry, we have to create a new map entry. We
* must bump the ref count on the extended object to
* account for it. object may be NULL.
*/
object = prev_entry->object.vm_object;
offset = prev_entry->offset +
(prev_entry->end - prev_entry->start);
vm_object_reference(object);
if (cred != NULL && object != NULL && object->cred != NULL &&
!(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
/* Object already accounts for this uid. */
cred = NULL;
}
}
if (cred != NULL)
crhold(cred);
/*
* Create a new entry
*/
new_entry = vm_map_entry_create(map);
new_entry->start = start;
new_entry->end = end;
new_entry->cred = NULL;
new_entry->eflags = protoeflags;
new_entry->object.vm_object = object;
new_entry->offset = offset;
new_entry->inheritance = inheritance;
new_entry->protection = prot;
new_entry->max_protection = max;
new_entry->wired_count = 0;
new_entry->wiring_thread = NULL;
new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT;
new_entry->next_read = start;
KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry),
("overcommit: vm_map_insert leaks vm_map %p", new_entry));
new_entry->cred = cred;
/*
* Insert the new entry into the list
*/
vm_map_entry_link(map, new_entry);
if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0)
map->size += new_entry->end - new_entry->start;
/*
* Try to coalesce the new entry with both the previous and next
* entries in the list. Previously, we only attempted to coalesce
* with the previous entry when object is NULL. Here, we handle the
* other cases, which are less common.
*/
vm_map_try_merge_entries(map, prev_entry, new_entry);
vm_map_try_merge_entries(map, new_entry, next_entry);
if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) {
vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset),
end - start, cow & MAP_PREFAULT_PARTIAL);
}
return (KERN_SUCCESS);
}
/*
* vm_map_findspace:
*
* Find the first fit (lowest VM address) for "length" free bytes
* beginning at address >= start in the given map.
*
* In a vm_map_entry, "max_free" is the maximum amount of
* contiguous free space between an entry in its subtree and a
* neighbor of that entry. This allows finding a free region in
* one path down the tree, so O(log n) amortized with splay
* trees.
*
* The map must be locked, and leaves it so.
*
* Returns: starting address if sufficient space,
* vm_map_max(map)-length+1 if insufficient space.
*/
vm_offset_t
vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length)
{
vm_map_entry_t header, llist, rlist, root, y;
vm_size_t left_length, max_free_left, max_free_right;
vm_offset_t gap_end;
VM_MAP_ASSERT_LOCKED(map);
/*
* Request must fit within min/max VM address and must avoid
* address wrap.
*/
start = MAX(start, vm_map_min(map));
if (start >= vm_map_max(map) || length > vm_map_max(map) - start)
return (vm_map_max(map) - length + 1);
/* Empty tree means wide open address space. */
if (map->root == NULL)
return (start);
/*
* After splay_split, if start is within an entry, push it to the start
* of the following gap. If rlist is at the end of the gap containing
* start, save the end of that gap in gap_end to see if the gap is big
* enough; otherwise set gap_end to start skip gap-checking and move
* directly to a search of the right subtree.
*/
header = &map->header;
root = vm_map_splay_split(map, start, length, &llist, &rlist);
gap_end = rlist->start;
if (root != NULL) {
start = root->end;
if (root->right != rlist)
gap_end = start;
max_free_left = vm_map_splay_merge_left(header, root, llist);
max_free_right = vm_map_splay_merge_right(header, root, rlist);
} else if (rlist != header) {
root = rlist;
rlist = root->left;
max_free_left = vm_map_splay_merge_pred(header, root, llist);
max_free_right = vm_map_splay_merge_right(header, root, rlist);
} else {
root = llist;
llist = root->right;
max_free_left = vm_map_splay_merge_left(header, root, llist);
max_free_right = vm_map_splay_merge_succ(header, root, rlist);
}
root->max_free = vm_size_max(max_free_left, max_free_right);
map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
if (length <= gap_end - start)
return (start);
/* With max_free, can immediately tell if no solution. */
if (root->right == header || length > root->right->max_free)
return (vm_map_max(map) - length + 1);
/*
* Splay for the least large-enough gap in the right subtree.
*/
llist = rlist = header;
for (left_length = 0;;
left_length = vm_map_entry_max_free_left(root, llist)) {
if (length <= left_length)
SPLAY_LEFT_STEP(root, y, llist, rlist,
length <= vm_map_entry_max_free_left(y, llist));
else
SPLAY_RIGHT_STEP(root, y, llist, rlist,
length > vm_map_entry_max_free_left(y, root));
if (root == NULL)
break;
}
root = llist;
llist = root->right;
max_free_left = vm_map_splay_merge_left(header, root, llist);
if (rlist == header) {
root->max_free = vm_size_max(max_free_left,
vm_map_splay_merge_succ(header, root, rlist));
} else {
y = rlist;
rlist = y->left;
y->max_free = vm_size_max(
vm_map_splay_merge_pred(root, y, root),
vm_map_splay_merge_right(header, y, rlist));
root->max_free = vm_size_max(max_free_left, y->max_free);
}
map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
return (root->end);
}
int
vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
vm_offset_t start, vm_size_t length, vm_prot_t prot,
vm_prot_t max, int cow)
{
vm_offset_t end;
int result;
end = start + length;
KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
object == NULL,
("vm_map_fixed: non-NULL backing object for stack"));
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if ((cow & MAP_CHECK_EXCL) == 0) {
result = vm_map_delete(map, start, end);
if (result != KERN_SUCCESS)
goto out;
}
if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
result = vm_map_stack_locked(map, start, length, sgrowsiz,
prot, max, cow);
} else {
result = vm_map_insert(map, object, offset, start, end,
prot, max, cow);
}
out:
vm_map_unlock(map);
return (result);
}
static const int aslr_pages_rnd_64[2] = {0x1000, 0x10};
static const int aslr_pages_rnd_32[2] = {0x100, 0x4};
static int cluster_anon = 1;
SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW,
&cluster_anon, 0,
"Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always");
static bool
clustering_anon_allowed(vm_offset_t addr)
{
switch (cluster_anon) {
case 0:
return (false);
case 1:
return (addr == 0);
case 2:
default:
return (true);
}
}
static long aslr_restarts;
SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD,
&aslr_restarts, 0,
"Number of aslr failures");
/*
* Searches for the specified amount of free space in the given map with the
* specified alignment. Performs an address-ordered, first-fit search from
* the given address "*addr", with an optional upper bound "max_addr". If the
* parameter "alignment" is zero, then the alignment is computed from the
* given (object, offset) pair so as to enable the greatest possible use of
* superpage mappings. Returns KERN_SUCCESS and the address of the free space
* in "*addr" if successful. Otherwise, returns KERN_NO_SPACE.
*
* The map must be locked. Initially, there must be at least "length" bytes
* of free space at the given address.
*/
static int
vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr,
vm_offset_t alignment)
{
vm_offset_t aligned_addr, free_addr;
VM_MAP_ASSERT_LOCKED(map);
free_addr = *addr;
KASSERT(free_addr == vm_map_findspace(map, free_addr, length),
("caller failed to provide space %#jx at address %p",
(uintmax_t)length, (void *)free_addr));
for (;;) {
/*
* At the start of every iteration, the free space at address
* "*addr" is at least "length" bytes.
*/
if (alignment == 0)
pmap_align_superpage(object, offset, addr, length);
else if ((*addr & (alignment - 1)) != 0) {
*addr &= ~(alignment - 1);
*addr += alignment;
}
aligned_addr = *addr;
if (aligned_addr == free_addr) {
/*
* Alignment did not change "*addr", so "*addr" must
* still provide sufficient free space.
*/
return (KERN_SUCCESS);
}
/*
* Test for address wrap on "*addr". A wrapped "*addr" could
* be a valid address, in which case vm_map_findspace() cannot
* be relied upon to fail.
*/
if (aligned_addr < free_addr)
return (KERN_NO_SPACE);
*addr = vm_map_findspace(map, aligned_addr, length);
if (*addr + length > vm_map_max(map) ||
(max_addr != 0 && *addr + length > max_addr))
return (KERN_NO_SPACE);
free_addr = *addr;
if (free_addr == aligned_addr) {
/*
* If a successful call to vm_map_findspace() did not
* change "*addr", then "*addr" must still be aligned
* and provide sufficient free space.
*/
return (KERN_SUCCESS);
}
}
}
int
vm_map_find_aligned(vm_map_t map, vm_offset_t *addr, vm_size_t length,
vm_offset_t max_addr, vm_offset_t alignment)
{
/* XXXKIB ASLR eh ? */
*addr = vm_map_findspace(map, *addr, length);
if (*addr + length > vm_map_max(map) ||
(max_addr != 0 && *addr + length > max_addr))
return (KERN_NO_SPACE);
return (vm_map_alignspace(map, NULL, 0, addr, length, max_addr,
alignment));
}
/*
* vm_map_find finds an unallocated region in the target address
* map with the given length. The search is defined to be
* first-fit from the specified address; the region found is
* returned in the same parameter.
*
* If object is non-NULL, ref count must be bumped by caller
* prior to making call to account for the new entry.
*/
int
vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
vm_offset_t *addr, /* IN/OUT */
vm_size_t length, vm_offset_t max_addr, int find_space,
vm_prot_t prot, vm_prot_t max, int cow)
{
vm_offset_t alignment, curr_min_addr, min_addr;
int gap, pidx, rv, try;
bool cluster, en_aslr, update_anon;
KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
object == NULL,
("vm_map_find: non-NULL backing object for stack"));
MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE &&
(cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0));
if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL ||
(object->flags & OBJ_COLORED) == 0))
find_space = VMFS_ANY_SPACE;
if (find_space >> 8 != 0) {
KASSERT((find_space & 0xff) == 0, ("bad VMFS flags"));
alignment = (vm_offset_t)1 << (find_space >> 8);
} else
alignment = 0;
en_aslr = (map->flags & MAP_ASLR) != 0;
update_anon = cluster = clustering_anon_allowed(*addr) &&
(map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 &&
find_space != VMFS_NO_SPACE && object == NULL &&
(cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP |
MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE;
curr_min_addr = min_addr = *addr;
if (en_aslr && min_addr == 0 && !cluster &&
find_space != VMFS_NO_SPACE &&
(map->flags & MAP_ASLR_IGNSTART) != 0)
curr_min_addr = min_addr = vm_map_min(map);
try = 0;
vm_map_lock(map);
if (cluster) {
curr_min_addr = map->anon_loc;
if (curr_min_addr == 0)
cluster = false;
}
if (find_space != VMFS_NO_SPACE) {
KASSERT(find_space == VMFS_ANY_SPACE ||
find_space == VMFS_OPTIMAL_SPACE ||
find_space == VMFS_SUPER_SPACE ||
alignment != 0, ("unexpected VMFS flag"));
again:
/*
* When creating an anonymous mapping, try clustering
* with an existing anonymous mapping first.
*
* We make up to two attempts to find address space
* for a given find_space value. The first attempt may
* apply randomization or may cluster with an existing
* anonymous mapping. If this first attempt fails,
* perform a first-fit search of the available address
* space.
*
* If all tries failed, and find_space is
* VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE.
* Again enable clustering and randomization.
*/
try++;
MPASS(try <= 2);
if (try == 2) {
/*
* Second try: we failed either to find a
* suitable region for randomizing the
* allocation, or to cluster with an existing
* mapping. Retry with free run.
*/
curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ?
vm_map_min(map) : min_addr;
atomic_add_long(&aslr_restarts, 1);
}
if (try == 1 && en_aslr && !cluster) {
/*
* Find space for allocation, including
* gap needed for later randomization.
*/
pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 &&
(find_space == VMFS_SUPER_SPACE || find_space ==
VMFS_OPTIMAL_SPACE) ? 1 : 0;
gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR &&
(max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ?
aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx];
*addr = vm_map_findspace(map, curr_min_addr,
length + gap * pagesizes[pidx]);
if (*addr + length + gap * pagesizes[pidx] >
vm_map_max(map))
goto again;
/* And randomize the start address. */
*addr += (arc4random() % gap) * pagesizes[pidx];
if (max_addr != 0 && *addr + length > max_addr)
goto again;
} else {
*addr = vm_map_findspace(map, curr_min_addr, length);
if (*addr + length > vm_map_max(map) ||
(max_addr != 0 && *addr + length > max_addr)) {
if (cluster) {
cluster = false;
MPASS(try == 1);
goto again;
}
rv = KERN_NO_SPACE;
goto done;
}
}
if (find_space != VMFS_ANY_SPACE &&
(rv = vm_map_alignspace(map, object, offset, addr, length,
max_addr, alignment)) != KERN_SUCCESS) {
if (find_space == VMFS_OPTIMAL_SPACE) {
find_space = VMFS_ANY_SPACE;
curr_min_addr = min_addr;
cluster = update_anon;
try = 0;
goto again;
}
goto done;
}
} else if ((cow & MAP_REMAP) != 0) {
if (!vm_map_range_valid(map, *addr, *addr + length)) {
rv = KERN_INVALID_ADDRESS;
goto done;
}
rv = vm_map_delete(map, *addr, *addr + length);
if (rv != KERN_SUCCESS)
goto done;
}
if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot,
max, cow);
} else {
rv = vm_map_insert(map, object, offset, *addr, *addr + length,
prot, max, cow);
}
if (rv == KERN_SUCCESS && update_anon)
map->anon_loc = *addr + length;
done:
vm_map_unlock(map);
return (rv);
}
/*
* vm_map_find_min() is a variant of vm_map_find() that takes an
* additional parameter (min_addr) and treats the given address
* (*addr) differently. Specifically, it treats *addr as a hint
* and not as the minimum address where the mapping is created.
*
* This function works in two phases. First, it tries to
* allocate above the hint. If that fails and the hint is
* greater than min_addr, it performs a second pass, replacing
* the hint with min_addr as the minimum address for the
* allocation.
*/
int
vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr,
vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max,
int cow)
{
vm_offset_t hint;
int rv;
hint = *addr;
for (;;) {
rv = vm_map_find(map, object, offset, addr, length, max_addr,
find_space, prot, max, cow);
if (rv == KERN_SUCCESS || min_addr >= hint)
return (rv);
*addr = hint = min_addr;
}
}
/*
* A map entry with any of the following flags set must not be merged with
* another entry.
*/
#define MAP_ENTRY_NOMERGE_MASK (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \
MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_VN_EXEC)
static bool
vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry)
{
KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 ||
(entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0,
("vm_map_mergeable_neighbors: neither %p nor %p are mergeable",
prev, entry));
return (prev->end == entry->start &&
prev->object.vm_object == entry->object.vm_object &&
(prev->object.vm_object == NULL ||
prev->offset + (prev->end - prev->start) == entry->offset) &&
prev->eflags == entry->eflags &&
prev->protection == entry->protection &&
prev->max_protection == entry->max_protection &&
prev->inheritance == entry->inheritance &&
prev->wired_count == entry->wired_count &&
prev->cred == entry->cred);
}
static void
vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry)
{
/*
* If the backing object is a vnode object, vm_object_deallocate()
* calls vrele(). However, vrele() does not lock the vnode because
* the vnode has additional references. Thus, the map lock can be
* kept without causing a lock-order reversal with the vnode lock.
*
* Since we count the number of virtual page mappings in
* object->un_pager.vnp.writemappings, the writemappings value
* should not be adjusted when the entry is disposed of.
*/
if (entry->object.vm_object != NULL)
vm_object_deallocate(entry->object.vm_object);
if (entry->cred != NULL)
crfree(entry->cred);
vm_map_entry_dispose(map, entry);
}
/*
* vm_map_try_merge_entries:
*
* Compare the given map entry to its predecessor, and merge its precessor
* into it if possible. The entry remains valid, and may be extended.
* The predecessor may be deleted.
*
* The map must be locked.
*/
void
vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev_entry,
vm_map_entry_t entry)
{
VM_MAP_ASSERT_LOCKED(map);
if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 &&
vm_map_mergeable_neighbors(prev_entry, entry)) {
vm_map_entry_unlink(map, prev_entry, UNLINK_MERGE_NEXT);
vm_map_merged_neighbor_dispose(map, prev_entry);
}
}
/*
* vm_map_entry_back:
*
* Allocate an object to back a map entry.
*/
static inline void
vm_map_entry_back(vm_map_entry_t entry)
{
vm_object_t object;
KASSERT(entry->object.vm_object == NULL,
("map entry %p has backing object", entry));
KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
("map entry %p is a submap", entry));
object = vm_object_allocate_anon(atop(entry->end - entry->start), NULL,
entry->cred, entry->end - entry->start);
entry->object.vm_object = object;
entry->offset = 0;
entry->cred = NULL;
}
/*
* vm_map_entry_charge_object
*
* If there is no object backing this entry, create one. Otherwise, if
* the entry has cred, give it to the backing object.
*/
static inline void
vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry)
{
VM_MAP_ASSERT_LOCKED(map);
KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
("map entry %p is a submap", entry));
if (entry->object.vm_object == NULL && !map->system_map &&
(entry->eflags & MAP_ENTRY_GUARD) == 0)
vm_map_entry_back(entry);
else if (entry->object.vm_object != NULL &&
((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
entry->cred != NULL) {
VM_OBJECT_WLOCK(entry->object.vm_object);
KASSERT(entry->object.vm_object->cred == NULL,
("OVERCOMMIT: %s: both cred e %p", __func__, entry));
entry->object.vm_object->cred = entry->cred;
entry->object.vm_object->charge = entry->end - entry->start;
VM_OBJECT_WUNLOCK(entry->object.vm_object);
entry->cred = NULL;
}
}
/*
* vm_map_entry_clone
*
* Create a duplicate map entry for clipping.
*/
static vm_map_entry_t
vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry)
{
vm_map_entry_t new_entry;
VM_MAP_ASSERT_LOCKED(map);
/*
* Create a backing object now, if none exists, so that more individual
* objects won't be created after the map entry is split.
*/
vm_map_entry_charge_object(map, entry);
/* Clone the entry. */
new_entry = vm_map_entry_create(map);
*new_entry = *entry;
if (new_entry->cred != NULL)
crhold(entry->cred);
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
vm_object_reference(new_entry->object.vm_object);
vm_map_entry_set_vnode_text(new_entry, true);
/*
* The object->un_pager.vnp.writemappings for the object of
* MAP_ENTRY_WRITECNT type entry shall be kept as is here. The
* virtual pages are re-distributed among the clipped entries,
* so the sum is left the same.
*/
}
return (new_entry);
}
/*
* vm_map_clip_start: [ internal use only ]
*
* Asserts that the given entry begins at or after
* the specified address; if necessary,
* it splits the entry into two.
*/
static int
vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t startaddr)
{
vm_map_entry_t new_entry;
int bdry_idx;
if (!map->system_map)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"%s: map %p entry %p start 0x%jx", __func__, map, entry,
(uintmax_t)startaddr);
if (startaddr <= entry->start)
return (KERN_SUCCESS);
VM_MAP_ASSERT_LOCKED(map);
KASSERT(entry->end > startaddr && entry->start < startaddr,
("%s: invalid clip of entry %p", __func__, entry));
bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
if (bdry_idx != 0) {
if ((startaddr & (pagesizes[bdry_idx] - 1)) != 0)
return (KERN_INVALID_ARGUMENT);
}
new_entry = vm_map_entry_clone(map, entry);
/*
* Split off the front portion. Insert the new entry BEFORE this one,
* so that this entry has the specified starting address.
*/
new_entry->end = startaddr;
vm_map_entry_link(map, new_entry);
return (KERN_SUCCESS);
}
/*
* vm_map_lookup_clip_start:
*
* Find the entry at or just after 'start', and clip it if 'start' is in
* the interior of the entry. Return entry after 'start', and in
* prev_entry set the entry before 'start'.
*/
static int
vm_map_lookup_clip_start(vm_map_t map, vm_offset_t start,
vm_map_entry_t *res_entry, vm_map_entry_t *prev_entry)
{
vm_map_entry_t entry;
int rv;
if (!map->system_map)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"%s: map %p start 0x%jx prev %p", __func__, map,
(uintmax_t)start, prev_entry);
if (vm_map_lookup_entry(map, start, prev_entry)) {
entry = *prev_entry;
rv = vm_map_clip_start(map, entry, start);
if (rv != KERN_SUCCESS)
return (rv);
*prev_entry = vm_map_entry_pred(entry);
} else
entry = vm_map_entry_succ(*prev_entry);
*res_entry = entry;
return (KERN_SUCCESS);
}
/*
* vm_map_clip_end: [ internal use only ]
*
* Asserts that the given entry ends at or before
* the specified address; if necessary,
* it splits the entry into two.
*/
static int
vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t endaddr)
{
vm_map_entry_t new_entry;
int bdry_idx;
if (!map->system_map)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"%s: map %p entry %p end 0x%jx", __func__, map, entry,
(uintmax_t)endaddr);
if (endaddr >= entry->end)
return (KERN_SUCCESS);
VM_MAP_ASSERT_LOCKED(map);
KASSERT(entry->start < endaddr && entry->end > endaddr,
("%s: invalid clip of entry %p", __func__, entry));
bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
if (bdry_idx != 0) {
if ((endaddr & (pagesizes[bdry_idx] - 1)) != 0)
return (KERN_INVALID_ARGUMENT);
}
new_entry = vm_map_entry_clone(map, entry);
/*
* Split off the back portion. Insert the new entry AFTER this one,
* so that this entry has the specified ending address.
*/
new_entry->start = endaddr;
vm_map_entry_link(map, new_entry);
return (KERN_SUCCESS);
}
/*
* vm_map_submap: [ kernel use only ]
*
* Mark the given range as handled by a subordinate map.
*
* This range must have been created with vm_map_find,
* and no other operations may have been performed on this
* range prior to calling vm_map_submap.
*
* Only a limited number of operations can be performed
* within this rage after calling vm_map_submap:
* vm_fault
* [Don't try vm_map_copy!]
*
* To remove a submapping, one must first remove the
* range from the superior map, and then destroy the
* submap (if desired). [Better yet, don't try it.]
*/
int
vm_map_submap(
vm_map_t map,
vm_offset_t start,
vm_offset_t end,
vm_map_t submap)
{
vm_map_entry_t entry;
int result;
result = KERN_INVALID_ARGUMENT;
vm_map_lock(submap);
submap->flags |= MAP_IS_SUB_MAP;
vm_map_unlock(submap);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (vm_map_lookup_entry(map, start, &entry) && entry->end >= end &&
(entry->eflags & MAP_ENTRY_COW) == 0 &&
entry->object.vm_object == NULL) {
result = vm_map_clip_start(map, entry, start);
if (result != KERN_SUCCESS)
goto unlock;
result = vm_map_clip_end(map, entry, end);
if (result != KERN_SUCCESS)
goto unlock;
entry->object.sub_map = submap;
entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
result = KERN_SUCCESS;
}
unlock:
vm_map_unlock(map);
if (result != KERN_SUCCESS) {
vm_map_lock(submap);
submap->flags &= ~MAP_IS_SUB_MAP;
vm_map_unlock(submap);
}
return (result);
}
/*
* The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified
*/
#define MAX_INIT_PT 96
/*
* vm_map_pmap_enter:
*
* Preload the specified map's pmap with mappings to the specified
* object's memory-resident pages. No further physical pages are
* allocated, and no further virtual pages are retrieved from secondary
* storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a
* limited number of page mappings are created at the low-end of the
* specified address range. (For this purpose, a superpage mapping
* counts as one page mapping.) Otherwise, all resident pages within
* the specified address range are mapped.
*/
static void
vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags)
{
vm_offset_t start;
vm_page_t p, p_start;
vm_pindex_t mask, psize, threshold, tmpidx;
if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL)
return;
if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
VM_OBJECT_WLOCK(object);
if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
pmap_object_init_pt(map->pmap, addr, object, pindex,
size);
VM_OBJECT_WUNLOCK(object);
return;
}
VM_OBJECT_LOCK_DOWNGRADE(object);
} else
VM_OBJECT_RLOCK(object);
psize = atop(size);
if (psize + pindex > object->size) {
if (pindex >= object->size) {
VM_OBJECT_RUNLOCK(object);
return;
}
psize = object->size - pindex;
}
start = 0;
p_start = NULL;
threshold = MAX_INIT_PT;
p = vm_page_find_least(object, pindex);
/*
* Assert: the variable p is either (1) the page with the
* least pindex greater than or equal to the parameter pindex
* or (2) NULL.
*/
for (;
p != NULL && (tmpidx = p->pindex - pindex) < psize;
p = TAILQ_NEXT(p, listq)) {
/*
* don't allow an madvise to blow away our really
* free pages allocating pv entries.
*/
if (((flags & MAP_PREFAULT_MADVISE) != 0 &&
vm_page_count_severe()) ||
((flags & MAP_PREFAULT_PARTIAL) != 0 &&
tmpidx >= threshold)) {
psize = tmpidx;
break;
}
if (vm_page_all_valid(p)) {
if (p_start == NULL) {
start = addr + ptoa(tmpidx);
p_start = p;
}
/* Jump ahead if a superpage mapping is possible. */
if (p->psind > 0 && ((addr + ptoa(tmpidx)) &
(pagesizes[p->psind] - 1)) == 0) {
mask = atop(pagesizes[p->psind]) - 1;
if (tmpidx + mask < psize &&
vm_page_ps_test(p, PS_ALL_VALID, NULL)) {
p += mask;
threshold += mask;
}
}
} else if (p_start != NULL) {
pmap_enter_object(map->pmap, start, addr +
ptoa(tmpidx), p_start, prot);
p_start = NULL;
}
}
if (p_start != NULL)
pmap_enter_object(map->pmap, start, addr + ptoa(psize),
p_start, prot);
VM_OBJECT_RUNLOCK(object);
}
/*
* vm_map_protect:
*
* Sets the protection and/or the maximum protection of the
* specified address region in the target map.
*/
int
vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
vm_prot_t new_prot, vm_prot_t new_maxprot, int flags)
{
vm_map_entry_t entry, first_entry, in_tran, prev_entry;
vm_object_t obj;
struct ucred *cred;
vm_prot_t old_prot;
int rv;
if (start == end)
return (KERN_SUCCESS);
if ((flags & (VM_MAP_PROTECT_SET_PROT | VM_MAP_PROTECT_SET_MAXPROT)) ==
(VM_MAP_PROTECT_SET_PROT | VM_MAP_PROTECT_SET_MAXPROT) &&
(new_prot & new_maxprot) != new_prot)
return (KERN_OUT_OF_BOUNDS);
again:
in_tran = NULL;
vm_map_lock(map);
if ((map->flags & MAP_WXORX) != 0 &&
(flags & VM_MAP_PROTECT_SET_PROT) != 0 &&
(new_prot & (VM_PROT_WRITE | VM_PROT_EXECUTE)) == (VM_PROT_WRITE |
VM_PROT_EXECUTE)) {
vm_map_unlock(map);
return (KERN_PROTECTION_FAILURE);
}
/*
* Ensure that we are not concurrently wiring pages. vm_map_wire() may
* need to fault pages into the map and will drop the map lock while
* doing so, and the VM object may end up in an inconsistent state if we
* update the protection on the map entry in between faults.
*/
vm_map_wait_busy(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (!vm_map_lookup_entry(map, start, &first_entry))
first_entry = vm_map_entry_succ(first_entry);
/*
* Make a first pass to check for protection violations.
*/
for (entry = first_entry; entry->start < end;
entry = vm_map_entry_succ(entry)) {
if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
continue;
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
vm_map_unlock(map);
return (KERN_INVALID_ARGUMENT);
}
if ((flags & VM_MAP_PROTECT_SET_PROT) == 0)
new_prot = entry->protection;
if ((flags & VM_MAP_PROTECT_SET_MAXPROT) == 0)
new_maxprot = entry->max_protection;
if ((new_prot & entry->max_protection) != new_prot ||
(new_maxprot & entry->max_protection) != new_maxprot) {
vm_map_unlock(map);
return (KERN_PROTECTION_FAILURE);
}
if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0)
in_tran = entry;
}
/*
* Postpone the operation until all in-transition map entries have
* stabilized. An in-transition entry might already have its pages
* wired and wired_count incremented, but not yet have its
* MAP_ENTRY_USER_WIRED flag set. In which case, we would fail to call
* vm_fault_copy_entry() in the final loop below.
*/
if (in_tran != NULL) {
in_tran->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
vm_map_unlock_and_wait(map, 0);
goto again;
}
/*
* Before changing the protections, try to reserve swap space for any
* private (i.e., copy-on-write) mappings that are transitioning from
* read-only to read/write access. If a reservation fails, break out
* of this loop early and let the next loop simplify the entries, since
* some may now be mergeable.
*/
rv = vm_map_clip_start(map, first_entry, start);
if (rv != KERN_SUCCESS) {
vm_map_unlock(map);
return (rv);
}
for (entry = first_entry; entry->start < end;
entry = vm_map_entry_succ(entry)) {
rv = vm_map_clip_end(map, entry, end);
if (rv != KERN_SUCCESS) {
vm_map_unlock(map);
return (rv);
}
if ((flags & VM_MAP_PROTECT_SET_PROT) == 0 ||
((new_prot & ~entry->protection) & VM_PROT_WRITE) == 0 ||
ENTRY_CHARGED(entry) ||
(entry->eflags & MAP_ENTRY_GUARD) != 0)
continue;
cred = curthread->td_ucred;
obj = entry->object.vm_object;
if (obj == NULL ||
(entry->eflags & MAP_ENTRY_NEEDS_COPY) != 0) {
if (!swap_reserve(entry->end - entry->start)) {
rv = KERN_RESOURCE_SHORTAGE;
end = entry->end;
break;
}
crhold(cred);
entry->cred = cred;
continue;
}
if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP)
continue;
VM_OBJECT_WLOCK(obj);
if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) {
VM_OBJECT_WUNLOCK(obj);
continue;
}
/*
* Charge for the whole object allocation now, since
* we cannot distinguish between non-charged and
* charged clipped mapping of the same object later.
*/
KASSERT(obj->charge == 0,
("vm_map_protect: object %p overcharged (entry %p)",
obj, entry));
if (!swap_reserve(ptoa(obj->size))) {
VM_OBJECT_WUNLOCK(obj);
rv = KERN_RESOURCE_SHORTAGE;
end = entry->end;
break;
}
crhold(cred);
obj->cred = cred;
obj->charge = ptoa(obj->size);
VM_OBJECT_WUNLOCK(obj);
}
/*
* If enough swap space was available, go back and fix up protections.
* Otherwise, just simplify entries, since some may have been modified.
* [Note that clipping is not necessary the second time.]
*/
for (prev_entry = vm_map_entry_pred(first_entry), entry = first_entry;
entry->start < end;
vm_map_try_merge_entries(map, prev_entry, entry),
prev_entry = entry, entry = vm_map_entry_succ(entry)) {
if (rv != KERN_SUCCESS ||
(entry->eflags & MAP_ENTRY_GUARD) != 0)
continue;
old_prot = entry->protection;
if ((flags & VM_MAP_PROTECT_SET_MAXPROT) != 0) {
entry->max_protection = new_maxprot;
entry->protection = new_maxprot & old_prot;
}
if ((flags & VM_MAP_PROTECT_SET_PROT) != 0)
entry->protection = new_prot;
/*
* For user wired map entries, the normal lazy evaluation of
* write access upgrades through soft page faults is
* undesirable. Instead, immediately copy any pages that are
* copy-on-write and enable write access in the physical map.
*/
if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0 &&
(entry->protection & VM_PROT_WRITE) != 0 &&
(old_prot & VM_PROT_WRITE) == 0)
vm_fault_copy_entry(map, map, entry, entry, NULL);
/*
* When restricting access, update the physical map. Worry
* about copy-on-write here.
*/
if ((old_prot & ~entry->protection) != 0) {
#define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
VM_PROT_ALL)
pmap_protect(map->pmap, entry->start,
entry->end,
entry->protection & MASK(entry));
#undef MASK
}
}
vm_map_try_merge_entries(map, prev_entry, entry);
vm_map_unlock(map);
return (rv);
}
/*
* vm_map_madvise:
*
* This routine traverses a processes map handling the madvise
* system call. Advisories are classified as either those effecting
* the vm_map_entry structure, or those effecting the underlying
* objects.
*/
int
vm_map_madvise(
vm_map_t map,
vm_offset_t start,
vm_offset_t end,
int behav)
{
vm_map_entry_t entry, prev_entry;
int rv;
bool modify_map;
/*
* Some madvise calls directly modify the vm_map_entry, in which case
* we need to use an exclusive lock on the map and we need to perform
* various clipping operations. Otherwise we only need a read-lock
* on the map.
*/
switch(behav) {
case MADV_NORMAL:
case MADV_SEQUENTIAL:
case MADV_RANDOM:
case MADV_NOSYNC:
case MADV_AUTOSYNC:
case MADV_NOCORE:
case MADV_CORE:
if (start == end)
return (0);
modify_map = true;
vm_map_lock(map);
break;
case MADV_WILLNEED:
case MADV_DONTNEED:
case MADV_FREE:
if (start == end)
return (0);
modify_map = false;
vm_map_lock_read(map);
break;
default:
return (EINVAL);
}
/*
* Locate starting entry and clip if necessary.
*/
VM_MAP_RANGE_CHECK(map, start, end);
if (modify_map) {
/*
* madvise behaviors that are implemented in the vm_map_entry.
*
* We clip the vm_map_entry so that behavioral changes are
* limited to the specified address range.
*/
rv = vm_map_lookup_clip_start(map, start, &entry, &prev_entry);
if (rv != KERN_SUCCESS) {
vm_map_unlock(map);
return (vm_mmap_to_errno(rv));
}
for (; entry->start < end; prev_entry = entry,
entry = vm_map_entry_succ(entry)) {
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
continue;
rv = vm_map_clip_end(map, entry, end);
if (rv != KERN_SUCCESS) {
vm_map_unlock(map);
return (vm_mmap_to_errno(rv));
}
switch (behav) {
case MADV_NORMAL:
vm_map_entry_set_behavior(entry,
MAP_ENTRY_BEHAV_NORMAL);
break;
case MADV_SEQUENTIAL:
vm_map_entry_set_behavior(entry,
MAP_ENTRY_BEHAV_SEQUENTIAL);
break;
case MADV_RANDOM:
vm_map_entry_set_behavior(entry,
MAP_ENTRY_BEHAV_RANDOM);
break;
case MADV_NOSYNC:
entry->eflags |= MAP_ENTRY_NOSYNC;
break;
case MADV_AUTOSYNC:
entry->eflags &= ~MAP_ENTRY_NOSYNC;
break;
case MADV_NOCORE:
entry->eflags |= MAP_ENTRY_NOCOREDUMP;
break;
case MADV_CORE:
entry->eflags &= ~MAP_ENTRY_NOCOREDUMP;
break;
default:
break;
}
vm_map_try_merge_entries(map, prev_entry, entry);
}
vm_map_try_merge_entries(map, prev_entry, entry);
vm_map_unlock(map);
} else {
vm_pindex_t pstart, pend;
/*
* madvise behaviors that are implemented in the underlying
* vm_object.
*
* Since we don't clip the vm_map_entry, we have to clip
* the vm_object pindex and count.
*/
if (!vm_map_lookup_entry(map, start, &entry))
entry = vm_map_entry_succ(entry);
for (; entry->start < end;
entry = vm_map_entry_succ(entry)) {
vm_offset_t useEnd, useStart;
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
continue;
/*
* MADV_FREE would otherwise rewind time to
* the creation of the shadow object. Because
* we hold the VM map read-locked, neither the
* entry's object nor the presence of a
* backing object can change.
*/
if (behav == MADV_FREE &&
entry->object.vm_object != NULL &&
entry->object.vm_object->backing_object != NULL)
continue;
pstart = OFF_TO_IDX(entry->offset);
pend = pstart + atop(entry->end - entry->start);
useStart = entry->start;
useEnd = entry->end;
if (entry->start < start) {
pstart += atop(start - entry->start);
useStart = start;
}
if (entry->end > end) {
pend -= atop(entry->end - end);
useEnd = end;
}
if (pstart >= pend)
continue;
/*
* Perform the pmap_advise() before clearing
* PGA_REFERENCED in vm_page_advise(). Otherwise, a
* concurrent pmap operation, such as pmap_remove(),
* could clear a reference in the pmap and set
* PGA_REFERENCED on the page before the pmap_advise()
* had completed. Consequently, the page would appear
* referenced based upon an old reference that
* occurred before this pmap_advise() ran.
*/
if (behav == MADV_DONTNEED || behav == MADV_FREE)
pmap_advise(map->pmap, useStart, useEnd,
behav);
vm_object_madvise(entry->object.vm_object, pstart,
pend, behav);
/*
* Pre-populate paging structures in the
* WILLNEED case. For wired entries, the
* paging structures are already populated.
*/
if (behav == MADV_WILLNEED &&
entry->wired_count == 0) {
vm_map_pmap_enter(map,
useStart,
entry->protection,
entry->object.vm_object,
pstart,
ptoa(pend - pstart),
MAP_PREFAULT_MADVISE
);
}
}
vm_map_unlock_read(map);
}
return (0);
}
/*
* vm_map_inherit:
*
* Sets the inheritance of the specified address
* range in the target map. Inheritance
* affects how the map will be shared with
* child maps at the time of vmspace_fork.
*/
int
vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
vm_inherit_t new_inheritance)
{
vm_map_entry_t entry, lentry, prev_entry, start_entry;
int rv;
switch (new_inheritance) {
case VM_INHERIT_NONE:
case VM_INHERIT_COPY:
case VM_INHERIT_SHARE:
case VM_INHERIT_ZERO:
break;
default:
return (KERN_INVALID_ARGUMENT);
}
if (start == end)
return (KERN_SUCCESS);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
rv = vm_map_lookup_clip_start(map, start, &start_entry, &prev_entry);
if (rv != KERN_SUCCESS)
goto unlock;
if (vm_map_lookup_entry(map, end - 1, &lentry)) {
rv = vm_map_clip_end(map, lentry, end);
if (rv != KERN_SUCCESS)
goto unlock;
}
if (new_inheritance == VM_INHERIT_COPY) {
for (entry = start_entry; entry->start < end;
prev_entry = entry, entry = vm_map_entry_succ(entry)) {
if ((entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK)
!= 0) {
rv = KERN_INVALID_ARGUMENT;
goto unlock;
}
}
}
for (entry = start_entry; entry->start < end; prev_entry = entry,
entry = vm_map_entry_succ(entry)) {
KASSERT(entry->end <= end, ("non-clipped entry %p end %jx %jx",
entry, (uintmax_t)entry->end, (uintmax_t)end));
if ((entry->eflags & MAP_ENTRY_GUARD) == 0 ||
new_inheritance != VM_INHERIT_ZERO)
entry->inheritance = new_inheritance;
vm_map_try_merge_entries(map, prev_entry, entry);
}
vm_map_try_merge_entries(map, prev_entry, entry);
unlock:
vm_map_unlock(map);
return (rv);
}
/*
* vm_map_entry_in_transition:
*
* Release the map lock, and sleep until the entry is no longer in
* transition. Awake and acquire the map lock. If the map changed while
* another held the lock, lookup a possibly-changed entry at or after the
* 'start' position of the old entry.
*/
static vm_map_entry_t
vm_map_entry_in_transition(vm_map_t map, vm_offset_t in_start,
vm_offset_t *io_end, bool holes_ok, vm_map_entry_t in_entry)
{
vm_map_entry_t entry;
vm_offset_t start;
u_int last_timestamp;
VM_MAP_ASSERT_LOCKED(map);
KASSERT((in_entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
("not in-tranition map entry %p", in_entry));
/*
* We have not yet clipped the entry.
*/
start = MAX(in_start, in_entry->start);
in_entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
last_timestamp = map->timestamp;
if (vm_map_unlock_and_wait(map, 0)) {
/*
* Allow interruption of user wiring/unwiring?
*/
}
vm_map_lock(map);
if (last_timestamp + 1 == map->timestamp)
return (in_entry);
/*
* Look again for the entry because the map was modified while it was
* unlocked. Specifically, the entry may have been clipped, merged, or
* deleted.
*/
if (!vm_map_lookup_entry(map, start, &entry)) {
if (!holes_ok) {
*io_end = start;
return (NULL);
}
entry = vm_map_entry_succ(entry);
}
return (entry);
}
/*
* vm_map_unwire:
*
* Implements both kernel and user unwiring.
*/
int
vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
int flags)
{
vm_map_entry_t entry, first_entry, next_entry, prev_entry;
int rv;
bool holes_ok, need_wakeup, user_unwire;
if (start == end)
return (KERN_SUCCESS);
holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
user_unwire = (flags & VM_MAP_WIRE_USER) != 0;
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (!vm_map_lookup_entry(map, start, &first_entry)) {
if (holes_ok)
first_entry = vm_map_entry_succ(first_entry);
else {
vm_map_unlock(map);
return (KERN_INVALID_ADDRESS);
}
}
rv = KERN_SUCCESS;
for (entry = first_entry; entry->start < end; entry = next_entry) {
if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
/*
* We have not yet clipped the entry.
*/
next_entry = vm_map_entry_in_transition(map, start,
&end, holes_ok, entry);
if (next_entry == NULL) {
if (entry == first_entry) {
vm_map_unlock(map);
return (KERN_INVALID_ADDRESS);
}
rv = KERN_INVALID_ADDRESS;
break;
}
first_entry = (entry == first_entry) ?
next_entry : NULL;
continue;
}
rv = vm_map_clip_start(map, entry, start);
if (rv != KERN_SUCCESS)
break;
rv = vm_map_clip_end(map, entry, end);
if (rv != KERN_SUCCESS)
break;
/*
* Mark the entry in case the map lock is released. (See
* above.)
*/
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
entry->wiring_thread == NULL,
("owned map entry %p", entry));
entry->eflags |= MAP_ENTRY_IN_TRANSITION;
entry->wiring_thread = curthread;
next_entry = vm_map_entry_succ(entry);
/*
* Check the map for holes in the specified region.
* If holes_ok, skip this check.
*/
if (!holes_ok &&
entry->end < end && next_entry->start > entry->end) {
end = entry->end;
rv = KERN_INVALID_ADDRESS;
break;
}
/*
* If system unwiring, require that the entry is system wired.
*/
if (!user_unwire &&
vm_map_entry_system_wired_count(entry) == 0) {
end = entry->end;
rv = KERN_INVALID_ARGUMENT;
break;
}
}
need_wakeup = false;
if (first_entry == NULL &&
!vm_map_lookup_entry(map, start, &first_entry)) {
KASSERT(holes_ok, ("vm_map_unwire: lookup failed"));
prev_entry = first_entry;
entry = vm_map_entry_succ(first_entry);
} else {
prev_entry = vm_map_entry_pred(first_entry);
entry = first_entry;
}
for (; entry->start < end;
prev_entry = entry, entry = vm_map_entry_succ(entry)) {
/*
* If holes_ok was specified, an empty
* space in the unwired region could have been mapped
* while the map lock was dropped for draining
* MAP_ENTRY_IN_TRANSITION. Moreover, another thread
* could be simultaneously wiring this new mapping
* entry. Detect these cases and skip any entries
* marked as in transition by us.
*/
if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
entry->wiring_thread != curthread) {
KASSERT(holes_ok,
("vm_map_unwire: !HOLESOK and new/changed entry"));
continue;
}
if (rv == KERN_SUCCESS && (!user_unwire ||
(entry->eflags & MAP_ENTRY_USER_WIRED))) {
if (entry->wired_count == 1)
vm_map_entry_unwire(map, entry);
else
entry->wired_count--;
if (user_unwire)
entry->eflags &= ~MAP_ENTRY_USER_WIRED;
}
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
("vm_map_unwire: in-transition flag missing %p", entry));
KASSERT(entry->wiring_thread == curthread,
("vm_map_unwire: alien wire %p", entry));
entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
entry->wiring_thread = NULL;
if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
need_wakeup = true;
}
vm_map_try_merge_entries(map, prev_entry, entry);
}
vm_map_try_merge_entries(map, prev_entry, entry);
vm_map_unlock(map);
if (need_wakeup)
vm_map_wakeup(map);
return (rv);
}
static void
vm_map_wire_user_count_sub(u_long npages)
{
atomic_subtract_long(&vm_user_wire_count, npages);
}
static bool
vm_map_wire_user_count_add(u_long npages)
{
u_long wired;
wired = vm_user_wire_count;
do {
if (npages + wired > vm_page_max_user_wired)
return (false);
} while (!atomic_fcmpset_long(&vm_user_wire_count, &wired,
npages + wired));
return (true);
}
/*
* vm_map_wire_entry_failure:
*
* Handle a wiring failure on the given entry.
*
* The map should be locked.
*/
static void
vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
vm_offset_t failed_addr)
{
VM_MAP_ASSERT_LOCKED(map);
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 &&
entry->wired_count == 1,
("vm_map_wire_entry_failure: entry %p isn't being wired", entry));
KASSERT(failed_addr < entry->end,
("vm_map_wire_entry_failure: entry %p was fully wired", entry));
/*
* If any pages at the start of this entry were successfully wired,
* then unwire them.
*/
if (failed_addr > entry->start) {
pmap_unwire(map->pmap, entry->start, failed_addr);
vm_object_unwire(entry->object.vm_object, entry->offset,
failed_addr - entry->start, PQ_ACTIVE);
}
/*
* Assign an out-of-range value to represent the failure to wire this
* entry.
*/
entry->wired_count = -1;
}
int
vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
{
int rv;
vm_map_lock(map);
rv = vm_map_wire_locked(map, start, end, flags);
vm_map_unlock(map);
return (rv);
}
/*
* vm_map_wire_locked:
*
* Implements both kernel and user wiring. Returns with the map locked,
* the map lock may be dropped.
*/
int
vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
{
vm_map_entry_t entry, first_entry, next_entry, prev_entry;
vm_offset_t faddr, saved_end, saved_start;
u_long incr, npages;
u_int bidx, last_timestamp;
int rv;
bool holes_ok, need_wakeup, user_wire;
vm_prot_t prot;
VM_MAP_ASSERT_LOCKED(map);
if (start == end)
return (KERN_SUCCESS);
prot = 0;
if (flags & VM_MAP_WIRE_WRITE)
prot |= VM_PROT_WRITE;
holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
user_wire = (flags & VM_MAP_WIRE_USER) != 0;
VM_MAP_RANGE_CHECK(map, start, end);
if (!vm_map_lookup_entry(map, start, &first_entry)) {
if (holes_ok)
first_entry = vm_map_entry_succ(first_entry);
else
return (KERN_INVALID_ADDRESS);
}
for (entry = first_entry; entry->start < end; entry = next_entry) {
if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
/*
* We have not yet clipped the entry.
*/
next_entry = vm_map_entry_in_transition(map, start,
&end, holes_ok, entry);
if (next_entry == NULL) {
if (entry == first_entry)
return (KERN_INVALID_ADDRESS);
rv = KERN_INVALID_ADDRESS;
goto done;
}
first_entry = (entry == first_entry) ?
next_entry : NULL;
continue;
}
rv = vm_map_clip_start(map, entry, start);
if (rv != KERN_SUCCESS)
goto done;
rv = vm_map_clip_end(map, entry, end);
if (rv != KERN_SUCCESS)
goto done;
/*
* Mark the entry in case the map lock is released. (See
* above.)
*/
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
entry->wiring_thread == NULL,
("owned map entry %p", entry));
entry->eflags |= MAP_ENTRY_IN_TRANSITION;
entry->wiring_thread = curthread;
if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0
|| (entry->protection & prot) != prot) {
entry->eflags |= MAP_ENTRY_WIRE_SKIPPED;
if (!holes_ok) {
end = entry->end;
rv = KERN_INVALID_ADDRESS;
goto done;
}
} else if (entry->wired_count == 0) {
entry->wired_count++;
npages = atop(entry->end - entry->start);
if (user_wire && !vm_map_wire_user_count_add(npages)) {
vm_map_wire_entry_failure(map, entry,
entry->start);
end = entry->end;
rv = KERN_RESOURCE_SHORTAGE;
goto done;
}
/*
* Release the map lock, relying on the in-transition
* mark. Mark the map busy for fork.
*/
saved_start = entry->start;
saved_end = entry->end;
last_timestamp = map->timestamp;
bidx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK)
>> MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
incr = pagesizes[bidx];
vm_map_busy(map);
vm_map_unlock(map);
for (faddr = saved_start; faddr < saved_end;
faddr += incr) {
/*
* Simulate a fault to get the page and enter
* it into the physical map.
*/
rv = vm_fault(map, faddr, VM_PROT_NONE,
VM_FAULT_WIRE, NULL);
if (rv != KERN_SUCCESS)
break;
}
vm_map_lock(map);
vm_map_unbusy(map);
if (last_timestamp + 1 != map->timestamp) {
/*
* Look again for the entry because the map was
* modified while it was unlocked. The entry
* may have been clipped, but NOT merged or
* deleted.
*/
if (!vm_map_lookup_entry(map, saved_start,
&next_entry))
KASSERT(false,
("vm_map_wire: lookup failed"));
first_entry = (entry == first_entry) ?
next_entry : NULL;
for (entry = next_entry; entry->end < saved_end;
entry = vm_map_entry_succ(entry)) {
/*
* In case of failure, handle entries
* that were not fully wired here;
* fully wired entries are handled
* later.
*/
if (rv != KERN_SUCCESS &&
faddr < entry->end)
vm_map_wire_entry_failure(map,
entry, faddr);
}
}
if (rv != KERN_SUCCESS) {
vm_map_wire_entry_failure(map, entry, faddr);
if (user_wire)
vm_map_wire_user_count_sub(npages);
end = entry->end;
goto done;
}
} else if (!user_wire ||
(entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
entry->wired_count++;
}
/*
* Check the map for holes in the specified region.
* If holes_ok was specified, skip this check.
*/
next_entry = vm_map_entry_succ(entry);
if (!holes_ok &&
entry->end < end && next_entry->start > entry->end) {
end = entry->end;
rv = KERN_INVALID_ADDRESS;
goto done;
}
}
rv = KERN_SUCCESS;
done:
need_wakeup = false;
if (first_entry == NULL &&
!vm_map_lookup_entry(map, start, &first_entry)) {
KASSERT(holes_ok, ("vm_map_wire: lookup failed"));
prev_entry = first_entry;
entry = vm_map_entry_succ(first_entry);
} else {
prev_entry = vm_map_entry_pred(first_entry);
entry = first_entry;
}
for (; entry->start < end;
prev_entry = entry, entry = vm_map_entry_succ(entry)) {
/*
* If holes_ok was specified, an empty
* space in the unwired region could have been mapped
* while the map lock was dropped for faulting in the
* pages or draining MAP_ENTRY_IN_TRANSITION.
* Moreover, another thread could be simultaneously
* wiring this new mapping entry. Detect these cases
* and skip any entries marked as in transition not by us.
*
* Another way to get an entry not marked with
* MAP_ENTRY_IN_TRANSITION is after failed clipping,
* which set rv to KERN_INVALID_ARGUMENT.
*/
if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
entry->wiring_thread != curthread) {
KASSERT(holes_ok || rv == KERN_INVALID_ARGUMENT,
("vm_map_wire: !HOLESOK and new/changed entry"));
continue;
}
if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) {
/* do nothing */
} else if (rv == KERN_SUCCESS) {
if (user_wire)
entry->eflags |= MAP_ENTRY_USER_WIRED;
} else if (entry->wired_count == -1) {
/*
* Wiring failed on this entry. Thus, unwiring is
* unnecessary.
*/
entry->wired_count = 0;
} else if (!user_wire ||
(entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
/*
* Undo the wiring. Wiring succeeded on this entry
* but failed on a later entry.
*/
if (entry->wired_count == 1) {
vm_map_entry_unwire(map, entry);
if (user_wire)
vm_map_wire_user_count_sub(
atop(entry->end - entry->start));
} else
entry->wired_count--;
}
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
("vm_map_wire: in-transition flag missing %p", entry));
KASSERT(entry->wiring_thread == curthread,
("vm_map_wire: alien wire %p", entry));
entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION |
MAP_ENTRY_WIRE_SKIPPED);
entry->wiring_thread = NULL;
if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
need_wakeup = true;
}
vm_map_try_merge_entries(map, prev_entry, entry);
}
vm_map_try_merge_entries(map, prev_entry, entry);
if (need_wakeup)
vm_map_wakeup(map);
return (rv);
}
/*
* vm_map_sync
*
* Push any dirty cached pages in the address range to their pager.
* If syncio is TRUE, dirty pages are written synchronously.
* If invalidate is TRUE, any cached pages are freed as well.
*
* If the size of the region from start to end is zero, we are
* supposed to flush all modified pages within the region containing
* start. Unfortunately, a region can be split or coalesced with
* neighboring regions, making it difficult to determine what the
* original region was. Therefore, we approximate this requirement by
* flushing the current region containing start.
*
* Returns an error if any part of the specified range is not mapped.
*/
int
vm_map_sync(
vm_map_t map,
vm_offset_t start,
vm_offset_t end,
boolean_t syncio,
boolean_t invalidate)
{
vm_map_entry_t entry, first_entry, next_entry;
vm_size_t size;
vm_object_t object;
vm_ooffset_t offset;
unsigned int last_timestamp;
int bdry_idx;
boolean_t failed;
vm_map_lock_read(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (!vm_map_lookup_entry(map, start, &first_entry)) {
vm_map_unlock_read(map);
return (KERN_INVALID_ADDRESS);
} else if (start == end) {
start = first_entry->start;
end = first_entry->end;
}
/*
* Make a first pass to check for user-wired memory, holes,
* and partial invalidation of largepage mappings.
*/
for (entry = first_entry; entry->start < end; entry = next_entry) {
if (invalidate) {
if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0) {
vm_map_unlock_read(map);
return (KERN_INVALID_ARGUMENT);
}
bdry_idx = (entry->eflags &
MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
if (bdry_idx != 0 &&
((start & (pagesizes[bdry_idx] - 1)) != 0 ||
(end & (pagesizes[bdry_idx] - 1)) != 0)) {
vm_map_unlock_read(map);
return (KERN_INVALID_ARGUMENT);
}
}
next_entry = vm_map_entry_succ(entry);
if (end > entry->end &&
entry->end != next_entry->start) {
vm_map_unlock_read(map);
return (KERN_INVALID_ADDRESS);
}
}
if (invalidate)
pmap_remove(map->pmap, start, end);
failed = FALSE;
/*
* Make a second pass, cleaning/uncaching pages from the indicated
* objects as we go.
*/
for (entry = first_entry; entry->start < end;) {
offset = entry->offset + (start - entry->start);
size = (end <= entry->end ? end : entry->end) - start;
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
vm_map_t smap;
vm_map_entry_t tentry;
vm_size_t tsize;
smap = entry->object.sub_map;
vm_map_lock_read(smap);
(void) vm_map_lookup_entry(smap, offset, &tentry);
tsize = tentry->end - offset;
if (tsize < size)
size = tsize;
object = tentry->object.vm_object;
offset = tentry->offset + (offset - tentry->start);
vm_map_unlock_read(smap);
} else {
object = entry->object.vm_object;
}
vm_object_reference(object);
last_timestamp = map->timestamp;
vm_map_unlock_read(map);
if (!vm_object_sync(object, offset, size, syncio, invalidate))
failed = TRUE;
start += size;
vm_object_deallocate(object);
vm_map_lock_read(map);
if (last_timestamp == map->timestamp ||
!vm_map_lookup_entry(map, start, &entry))
entry = vm_map_entry_succ(entry);
}
vm_map_unlock_read(map);
return (failed ? KERN_FAILURE : KERN_SUCCESS);
}
/*
* vm_map_entry_unwire: [ internal use only ]
*
* Make the region specified by this entry pageable.
*
* The map in question should be locked.
* [This is the reason for this routine's existence.]
*/
static void
vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
{
vm_size_t size;
VM_MAP_ASSERT_LOCKED(map);
KASSERT(entry->wired_count > 0,
("vm_map_entry_unwire: entry %p isn't wired", entry));
size = entry->end - entry->start;
if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0)
vm_map_wire_user_count_sub(atop(size));
pmap_unwire(map->pmap, entry->start, entry->end);
vm_object_unwire(entry->object.vm_object, entry->offset, size,
PQ_ACTIVE);
entry->wired_count = 0;
}
static void
vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map)
{
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
vm_object_deallocate(entry->object.vm_object);
uma_zfree(system_map ? kmapentzone : mapentzone, entry);
}
/*
* vm_map_entry_delete: [ internal use only ]
*
* Deallocate the given entry from the target map.
*/
static void
vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
{
vm_object_t object;
vm_pindex_t offidxstart, offidxend, size1;
vm_size_t size;
vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE);
object = entry->object.vm_object;
if ((entry->eflags & MAP_ENTRY_GUARD) != 0) {
MPASS(entry->cred == NULL);
MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0);
MPASS(object == NULL);
vm_map_entry_deallocate(entry, map->system_map);
return;
}
size = entry->end - entry->start;
map->size -= size;
if (entry->cred != NULL) {
swap_release_by_cred(size, entry->cred);
crfree(entry->cred);
}
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) {
entry->object.vm_object = NULL;
} else if ((object->flags & OBJ_ANON) != 0 ||
object == kernel_object) {
KASSERT(entry->cred == NULL || object->cred == NULL ||
(entry->eflags & MAP_ENTRY_NEEDS_COPY),
("OVERCOMMIT vm_map_entry_delete: both cred %p", entry));
offidxstart = OFF_TO_IDX(entry->offset);
offidxend = offidxstart + atop(size);
VM_OBJECT_WLOCK(object);
if (object->ref_count != 1 &&
((object->flags & OBJ_ONEMAPPING) != 0 ||
object == kernel_object)) {
vm_object_collapse(object);
/*
* The option OBJPR_NOTMAPPED can be passed here
* because vm_map_delete() already performed
* pmap_remove() on the only mapping to this range
* of pages.
*/
vm_object_page_remove(object, offidxstart, offidxend,
OBJPR_NOTMAPPED);
if (offidxend >= object->size &&
offidxstart < object->size) {
size1 = object->size;
object->size = offidxstart;
if (object->cred != NULL) {
size1 -= object->size;
KASSERT(object->charge >= ptoa(size1),
("object %p charge < 0", object));
swap_release_by_cred(ptoa(size1),
object->cred);
object->charge -= ptoa(size1);
}
}
}
VM_OBJECT_WUNLOCK(object);
}
if (map->system_map)
vm_map_entry_deallocate(entry, TRUE);
else {
entry->defer_next = curthread->td_map_def_user;
curthread->td_map_def_user = entry;
}
}
/*
* vm_map_delete: [ internal use only ]
*
* Deallocates the given address range from the target
* map.
*/
int
vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
{
vm_map_entry_t entry, next_entry, scratch_entry;
int rv;
VM_MAP_ASSERT_LOCKED(map);
if (start == end)
return (KERN_SUCCESS);
/*
* Find the start of the region, and clip it.
* Step through all entries in this region.
*/
rv = vm_map_lookup_clip_start(map, start, &entry, &scratch_entry);
if (rv != KERN_SUCCESS)
return (rv);
for (; entry->start < end; entry = next_entry) {
/*
* Wait for wiring or unwiring of an entry to complete.
* Also wait for any system wirings to disappear on
* user maps.
*/
if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 ||
(vm_map_pmap(map) != kernel_pmap &&
vm_map_entry_system_wired_count(entry) != 0)) {
unsigned int last_timestamp;
vm_offset_t saved_start;
saved_start = entry->start;
entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
last_timestamp = map->timestamp;
(void) vm_map_unlock_and_wait(map, 0);
vm_map_lock(map);
if (last_timestamp + 1 != map->timestamp) {
/*
* Look again for the entry because the map was
* modified while it was unlocked.
* Specifically, the entry may have been
* clipped, merged, or deleted.
*/
rv = vm_map_lookup_clip_start(map, saved_start,
&next_entry, &scratch_entry);
if (rv != KERN_SUCCESS)
break;
} else
next_entry = entry;
continue;
}
/* XXXKIB or delete to the upper superpage boundary ? */
rv = vm_map_clip_end(map, entry, end);
if (rv != KERN_SUCCESS)
break;
next_entry = vm_map_entry_succ(entry);
/*
* Unwire before removing addresses from the pmap; otherwise,
* unwiring will put the entries back in the pmap.
*/
if (entry->wired_count != 0)
vm_map_entry_unwire(map, entry);
/*
* Remove mappings for the pages, but only if the
* mappings could exist. For instance, it does not
* make sense to call pmap_remove() for guard entries.
*/
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 ||
entry->object.vm_object != NULL)
pmap_remove(map->pmap, entry->start, entry->end);
if (entry->end == map->anon_loc)
map->anon_loc = entry->start;
/*
* Delete the entry only after removing all pmap
* entries pointing to its pages. (Otherwise, its
* page frames may be reallocated, and any modify bits
* will be set in the wrong object!)
*/
vm_map_entry_delete(map, entry);
}
return (rv);
}
/*
* vm_map_remove:
*
* Remove the given address range from the target map.
* This is the exported form of vm_map_delete.
*/
int
vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
{
int result;
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
result = vm_map_delete(map, start, end);
vm_map_unlock(map);
return (result);
}
/*
* vm_map_check_protection:
*
* Assert that the target map allows the specified privilege on the
* entire address region given. The entire region must be allocated.
*
* WARNING! This code does not and should not check whether the
* contents of the region is accessible. For example a smaller file
* might be mapped into a larger address space.
*
* NOTE! This code is also called by munmap().
*
* The map must be locked. A read lock is sufficient.
*/
boolean_t
vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
vm_prot_t protection)
{
vm_map_entry_t entry;
vm_map_entry_t tmp_entry;
if (!vm_map_lookup_entry(map, start, &tmp_entry))
return (FALSE);
entry = tmp_entry;
while (start < end) {
/*
* No holes allowed!
*/
if (start < entry->start)
return (FALSE);
/*
* Check protection associated with entry.
*/
if ((entry->protection & protection) != protection)
return (FALSE);
/* go to next entry */
start = entry->end;
entry = vm_map_entry_succ(entry);
}
return (TRUE);
}
/*
*
* vm_map_copy_swap_object:
*
* Copies a swap-backed object from an existing map entry to a
* new one. Carries forward the swap charge. May change the
* src object on return.
*/
static void
vm_map_copy_swap_object(vm_map_entry_t src_entry, vm_map_entry_t dst_entry,
vm_offset_t size, vm_ooffset_t *fork_charge)
{
vm_object_t src_object;
struct ucred *cred;
int charged;
src_object = src_entry->object.vm_object;
charged = ENTRY_CHARGED(src_entry);
if ((src_object->flags & OBJ_ANON) != 0) {
VM_OBJECT_WLOCK(src_object);
vm_object_collapse(src_object);
if ((src_object->flags & OBJ_ONEMAPPING) != 0) {
vm_object_split(src_entry);
src_object = src_entry->object.vm_object;
}
vm_object_reference_locked(src_object);
vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
VM_OBJECT_WUNLOCK(src_object);
} else
vm_object_reference(src_object);
if (src_entry->cred != NULL &&
!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
KASSERT(src_object->cred == NULL,
("OVERCOMMIT: vm_map_copy_anon_entry: cred %p",
src_object));
src_object->cred = src_entry->cred;
src_object->charge = size;
}
dst_entry->object.vm_object = src_object;
if (charged) {
cred = curthread->td_ucred;
crhold(cred);
dst_entry->cred = cred;
*fork_charge += size;
if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
crhold(cred);
src_entry->cred = cred;
*fork_charge += size;
}
}
}
/*
* vm_map_copy_entry:
*
* Copies the contents of the source entry to the destination
* entry. The entries *must* be aligned properly.
*/
static void
vm_map_copy_entry(
vm_map_t src_map,
vm_map_t dst_map,
vm_map_entry_t src_entry,
vm_map_entry_t dst_entry,
vm_ooffset_t *fork_charge)
{
vm_object_t src_object;
vm_map_entry_t fake_entry;
vm_offset_t size;
VM_MAP_ASSERT_LOCKED(dst_map);
if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP)
return;
if (src_entry->wired_count == 0 ||
(src_entry->protection & VM_PROT_WRITE) == 0) {
/*
* If the source entry is marked needs_copy, it is already
* write-protected.
*/
if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 &&
(src_entry->protection & VM_PROT_WRITE) != 0) {
pmap_protect(src_map->pmap,
src_entry->start,
src_entry->end,
src_entry->protection & ~VM_PROT_WRITE);
}
/*
* Make a copy of the object.
*/
size = src_entry->end - src_entry->start;
if ((src_object = src_entry->object.vm_object) != NULL) {
if (src_object->type == OBJT_DEFAULT ||
src_object->type == OBJT_SWAP) {
vm_map_copy_swap_object(src_entry, dst_entry,
size, fork_charge);
/* May have split/collapsed, reload obj. */
src_object = src_entry->object.vm_object;
} else {
vm_object_reference(src_object);
dst_entry->object.vm_object = src_object;
}
src_entry->eflags |= MAP_ENTRY_COW |
MAP_ENTRY_NEEDS_COPY;
dst_entry->eflags |= MAP_ENTRY_COW |
MAP_ENTRY_NEEDS_COPY;
dst_entry->offset = src_entry->offset;
if (src_entry->eflags & MAP_ENTRY_WRITECNT) {
/*
* MAP_ENTRY_WRITECNT cannot
* indicate write reference from
* src_entry, since the entry is
* marked as needs copy. Allocate a
* fake entry that is used to
* decrement object->un_pager writecount
* at the appropriate time. Attach
* fake_entry to the deferred list.
*/
fake_entry = vm_map_entry_create(dst_map);
fake_entry->eflags = MAP_ENTRY_WRITECNT;
src_entry->eflags &= ~MAP_ENTRY_WRITECNT;
vm_object_reference(src_object);
fake_entry->object.vm_object = src_object;
fake_entry->start = src_entry->start;
fake_entry->end = src_entry->end;
fake_entry->defer_next =
curthread->td_map_def_user;
curthread->td_map_def_user = fake_entry;
}
pmap_copy(dst_map->pmap, src_map->pmap,
dst_entry->start, dst_entry->end - dst_entry->start,
src_entry->start);
} else {
dst_entry->object.vm_object = NULL;
dst_entry->offset = 0;
if (src_entry->cred != NULL) {
dst_entry->cred = curthread->td_ucred;
crhold(dst_entry->cred);
*fork_charge += size;
}
}
} else {
/*
* We don't want to make writeable wired pages copy-on-write.
* Immediately copy these pages into the new map by simulating
* page faults. The new pages are pageable.
*/
vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry,
fork_charge);
}
}
/*
* vmspace_map_entry_forked:
* Update the newly-forked vmspace each time a map entry is inherited
* or copied. The values for vm_dsize and vm_tsize are approximate
* (and mostly-obsolete ideas in the face of mmap(2) et al.)
*/
static void
vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2,
vm_map_entry_t entry)
{
vm_size_t entrysize;
vm_offset_t newend;
if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
return;
entrysize = entry->end - entry->start;
vm2->vm_map.size += entrysize;
if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) {
vm2->vm_ssize += btoc(entrysize);
} else if (entry->start >= (vm_offset_t)vm1->vm_daddr &&
entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) {
newend = MIN(entry->end,
(vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize));
vm2->vm_dsize += btoc(newend - entry->start);
} else if (entry->start >= (vm_offset_t)vm1->vm_taddr &&
entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) {
newend = MIN(entry->end,
(vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize));
vm2->vm_tsize += btoc(newend - entry->start);
}
}
/*
* vmspace_fork:
* Create a new process vmspace structure and vm_map
* based on those of an existing process. The new map
* is based on the old map, according to the inheritance
* values on the regions in that map.
*
* XXX It might be worth coalescing the entries added to the new vmspace.
*
* The source map must not be locked.
*/
struct vmspace *
vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
{
struct vmspace *vm2;
vm_map_t new_map, old_map;
vm_map_entry_t new_entry, old_entry;
vm_object_t object;
int error, locked;
vm_inherit_t inh;
old_map = &vm1->vm_map;
/* Copy immutable fields of vm1 to vm2. */
vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map),
pmap_pinit);
if (vm2 == NULL)
return (NULL);
vm2->vm_taddr = vm1->vm_taddr;
vm2->vm_daddr = vm1->vm_daddr;
vm2->vm_maxsaddr = vm1->vm_maxsaddr;
vm_map_lock(old_map);
if (old_map->busy)
vm_map_wait_busy(old_map);
new_map = &vm2->vm_map;
locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */
KASSERT(locked, ("vmspace_fork: lock failed"));
error = pmap_vmspace_copy(new_map->pmap, old_map->pmap);
if (error != 0) {
sx_xunlock(&old_map->lock);
sx_xunlock(&new_map->lock);
vm_map_process_deferred();
vmspace_free(vm2);
return (NULL);
}
new_map->anon_loc = old_map->anon_loc;
new_map->flags |= old_map->flags & (MAP_ASLR | MAP_ASLR_IGNSTART |
MAP_WXORX);
VM_MAP_ENTRY_FOREACH(old_entry, old_map) {
if ((old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
panic("vm_map_fork: encountered a submap");
inh = old_entry->inheritance;
if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 &&
inh != VM_INHERIT_NONE)
inh = VM_INHERIT_COPY;
switch (inh) {
case VM_INHERIT_NONE:
break;
case VM_INHERIT_SHARE:
/*
* Clone the entry, creating the shared object if
* necessary.
*/
object = old_entry->object.vm_object;
if (object == NULL) {
vm_map_entry_back(old_entry);
object = old_entry->object.vm_object;
}
/*
* Add the reference before calling vm_object_shadow
* to insure that a shadow object is created.
*/
vm_object_reference(object);
if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
vm_object_shadow(&old_entry->object.vm_object,
&old_entry->offset,
old_entry->end - old_entry->start,
old_entry->cred,
/* Transfer the second reference too. */
true);
old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
old_entry->cred = NULL;
/*
* As in vm_map_merged_neighbor_dispose(),
* the vnode lock will not be acquired in
* this call to vm_object_deallocate().
*/
vm_object_deallocate(object);
object = old_entry->object.vm_object;
} else {
VM_OBJECT_WLOCK(object);
vm_object_clear_flag(object, OBJ_ONEMAPPING);
if (old_entry->cred != NULL) {
KASSERT(object->cred == NULL,
("vmspace_fork both cred"));
object->cred = old_entry->cred;
object->charge = old_entry->end -
old_entry->start;
old_entry->cred = NULL;
}
/*
* Assert the correct state of the vnode
* v_writecount while the object is locked, to
* not relock it later for the assertion
* correctness.
*/
if (old_entry->eflags & MAP_ENTRY_WRITECNT &&
object->type == OBJT_VNODE) {
KASSERT(((struct vnode *)object->
handle)->v_writecount > 0,
("vmspace_fork: v_writecount %p",
object));
KASSERT(object->un_pager.vnp.
writemappings > 0,
("vmspace_fork: vnp.writecount %p",
object));
}
VM_OBJECT_WUNLOCK(object);
}
/*
* Clone the entry, referencing the shared object.
*/
new_entry = vm_map_entry_create(new_map);
*new_entry = *old_entry;
new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
MAP_ENTRY_IN_TRANSITION);
new_entry->wiring_thread = NULL;
new_entry->wired_count = 0;
if (new_entry->eflags & MAP_ENTRY_WRITECNT) {
vm_pager_update_writecount(object,
new_entry->start, new_entry->end);
}
vm_map_entry_set_vnode_text(new_entry, true);
/*
* Insert the entry into the new map -- we know we're
* inserting at the end of the new map.
*/
vm_map_entry_link(new_map, new_entry);
vmspace_map_entry_forked(vm1, vm2, new_entry);
/*
* Update the physical map
*/
pmap_copy(new_map->pmap, old_map->pmap,
new_entry->start,
(old_entry->end - old_entry->start),
old_entry->start);
break;
case VM_INHERIT_COPY:
/*
* Clone the entry and link into the map.
*/
new_entry = vm_map_entry_create(new_map);
*new_entry = *old_entry;
/*
* Copied entry is COW over the old object.
*/
new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WRITECNT);
new_entry->wiring_thread = NULL;
new_entry->wired_count = 0;
new_entry->object.vm_object = NULL;
new_entry->cred = NULL;
vm_map_entry_link(new_map, new_entry);
vmspace_map_entry_forked(vm1, vm2, new_entry);
vm_map_copy_entry(old_map, new_map, old_entry,
new_entry, fork_charge);
vm_map_entry_set_vnode_text(new_entry, true);
break;
case VM_INHERIT_ZERO:
/*
* Create a new anonymous mapping entry modelled from
* the old one.
*/
new_entry = vm_map_entry_create(new_map);
memset(new_entry, 0, sizeof(*new_entry));
new_entry->start = old_entry->start;
new_entry->end = old_entry->end;
new_entry->eflags = old_entry->eflags &
~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION |
MAP_ENTRY_WRITECNT | MAP_ENTRY_VN_EXEC |
MAP_ENTRY_SPLIT_BOUNDARY_MASK);
new_entry->protection = old_entry->protection;
new_entry->max_protection = old_entry->max_protection;
new_entry->inheritance = VM_INHERIT_ZERO;
vm_map_entry_link(new_map, new_entry);
vmspace_map_entry_forked(vm1, vm2, new_entry);
new_entry->cred = curthread->td_ucred;
crhold(new_entry->cred);
*fork_charge += (new_entry->end - new_entry->start);
break;
}
}
/*
* Use inlined vm_map_unlock() to postpone handling the deferred
* map entries, which cannot be done until both old_map and
* new_map locks are released.
*/
sx_xunlock(&old_map->lock);
sx_xunlock(&new_map->lock);
vm_map_process_deferred();
return (vm2);
}
/*
* Create a process's stack for exec_new_vmspace(). This function is never
* asked to wire the newly created stack.
*/
int
vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
vm_prot_t prot, vm_prot_t max, int cow)
{
vm_size_t growsize, init_ssize;
rlim_t vmemlim;
int rv;
MPASS((map->flags & MAP_WIREFUTURE) == 0);
growsize = sgrowsiz;
init_ssize = (max_ssize < growsize) ? max_ssize : growsize;
vm_map_lock(map);
vmemlim = lim_cur(curthread, RLIMIT_VMEM);
/* If we would blow our VMEM resource limit, no go */
if (map->size + init_ssize > vmemlim) {
rv = KERN_NO_SPACE;
goto out;
}
rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot,
max, cow);
out:
vm_map_unlock(map);
return (rv);
}
static int stack_guard_page = 1;
SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN,
&stack_guard_page, 0,
"Specifies the number of guard pages for a stack that grows");
static int
vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow)
{
vm_map_entry_t new_entry, prev_entry;
vm_offset_t bot, gap_bot, gap_top, top;
vm_size_t init_ssize, sgp;
int orient, rv;
/*
* The stack orientation is piggybacked with the cow argument.
* Extract it into orient and mask the cow argument so that we
* don't pass it around further.
*/
orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP);
KASSERT(orient != 0, ("No stack grow direction"));
KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP),
("bi-dir stack"));
if (max_ssize == 0 ||
!vm_map_range_valid(map, addrbos, addrbos + max_ssize))
return (KERN_INVALID_ADDRESS);
sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
(curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
(vm_size_t)stack_guard_page * PAGE_SIZE;
if (sgp >= max_ssize)
return (KERN_INVALID_ARGUMENT);
init_ssize = growsize;
if (max_ssize < init_ssize + sgp)
init_ssize = max_ssize - sgp;
/* If addr is already mapped, no go */
if (vm_map_lookup_entry(map, addrbos, &prev_entry))
return (KERN_NO_SPACE);
/*
* If we can't accommodate max_ssize in the current mapping, no go.
*/
if (vm_map_entry_succ(prev_entry)->start < addrbos + max_ssize)
return (KERN_NO_SPACE);
/*
* We initially map a stack of only init_ssize. We will grow as
* needed later. Depending on the orientation of the stack (i.e.
* the grow direction) we either map at the top of the range, the
* bottom of the range or in the middle.
*
* Note: we would normally expect prot and max to be VM_PROT_ALL,
* and cow to be 0. Possibly we should eliminate these as input
* parameters, and just pass these values here in the insert call.
*/
if (orient == MAP_STACK_GROWS_DOWN) {
bot = addrbos + max_ssize - init_ssize;
top = bot + init_ssize;
gap_bot = addrbos;
gap_top = bot;
} else /* if (orient == MAP_STACK_GROWS_UP) */ {
bot = addrbos;
top = bot + init_ssize;
gap_bot = top;
gap_top = addrbos + max_ssize;
}
rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow);
if (rv != KERN_SUCCESS)
return (rv);
new_entry = vm_map_entry_succ(prev_entry);
KASSERT(new_entry->end == top || new_entry->start == bot,
("Bad entry start/end for new stack entry"));
KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 ||
(new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0,
("new entry lacks MAP_ENTRY_GROWS_DOWN"));
KASSERT((orient & MAP_STACK_GROWS_UP) == 0 ||
(new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0,
("new entry lacks MAP_ENTRY_GROWS_UP"));
if (gap_bot == gap_top)
return (KERN_SUCCESS);
rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE,
VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ?
MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP));
if (rv == KERN_SUCCESS) {
/*
* Gap can never successfully handle a fault, so
* read-ahead logic is never used for it. Re-use
* next_read of the gap entry to store
* stack_guard_page for vm_map_growstack().
*/
if (orient == MAP_STACK_GROWS_DOWN)
vm_map_entry_pred(new_entry)->next_read = sgp;
else
vm_map_entry_succ(new_entry)->next_read = sgp;
} else {
(void)vm_map_delete(map, bot, top);
}
return (rv);
}
/*
* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we
* successfully grow the stack.
*/
static int
vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
{
vm_map_entry_t stack_entry;
struct proc *p;
struct vmspace *vm;
struct ucred *cred;
vm_offset_t gap_end, gap_start, grow_start;
vm_size_t grow_amount, guard, max_grow;
rlim_t lmemlim, stacklim, vmemlim;
int rv, rv1;
bool gap_deleted, grow_down, is_procstack;
#ifdef notyet
uint64_t limit;
#endif
#ifdef RACCT
int error;
#endif
p = curproc;
vm = p->p_vmspace;
/*
* Disallow stack growth when the access is performed by a
* debugger or AIO daemon. The reason is that the wrong
* resource limits are applied.
*/
if (p != initproc && (map != &p->p_vmspace->vm_map ||
p->p_textvp == NULL))
return (KERN_FAILURE);
MPASS(!map->system_map);
lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK);
stacklim = lim_cur(curthread, RLIMIT_STACK);
vmemlim = lim_cur(curthread, RLIMIT_VMEM);
retry:
/* If addr is not in a hole for a stack grow area, no need to grow. */
if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry))
return (KERN_FAILURE);
if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0)
return (KERN_SUCCESS);
if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) {
stack_entry = vm_map_entry_succ(gap_entry);
if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 ||
stack_entry->start != gap_entry->end)
return (KERN_FAILURE);
grow_amount = round_page(stack_entry->start - addr);
grow_down = true;
} else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) {
stack_entry = vm_map_entry_pred(gap_entry);
if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 ||
stack_entry->end != gap_entry->start)
return (KERN_FAILURE);
grow_amount = round_page(addr + 1 - stack_entry->end);
grow_down = false;
} else {
return (KERN_FAILURE);
}
guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
(curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
gap_entry->next_read;
max_grow = gap_entry->end - gap_entry->start;
if (guard > max_grow)
return (KERN_NO_SPACE);
max_grow -= guard;
if (grow_amount > max_grow)
return (KERN_NO_SPACE);
/*
* If this is the main process stack, see if we're over the stack
* limit.
*/
is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr &&
addr < (vm_offset_t)p->p_sysent->sv_usrstack;
if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim))
return (KERN_NO_SPACE);
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(p);
if (is_procstack && racct_set(p, RACCT_STACK,
ctob(vm->vm_ssize) + grow_amount)) {
PROC_UNLOCK(p);
return (KERN_NO_SPACE);
}
PROC_UNLOCK(p);
}
#endif
grow_amount = roundup(grow_amount, sgrowsiz);
if (grow_amount > max_grow)
grow_amount = max_grow;
if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) {
grow_amount = trunc_page((vm_size_t)stacklim) -
ctob(vm->vm_ssize);
}
#ifdef notyet
PROC_LOCK(p);
limit = racct_get_available(p, RACCT_STACK);
PROC_UNLOCK(p);
if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit))
grow_amount = limit - ctob(vm->vm_ssize);
#endif
if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) {
if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) {
rv = KERN_NO_SPACE;
goto out;
}
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(p);
if (racct_set(p, RACCT_MEMLOCK,
ptoa(pmap_wired_count(map->pmap)) + grow_amount)) {
PROC_UNLOCK(p);
rv = KERN_NO_SPACE;
goto out;
}
PROC_UNLOCK(p);
}
#endif
}
/* If we would blow our VMEM resource limit, no go */
if (map->size + grow_amount > vmemlim) {
rv = KERN_NO_SPACE;
goto out;
}
#ifdef RACCT
if (racct_enable) {
PROC_LOCK(p);
if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) {
PROC_UNLOCK(p);
rv = KERN_NO_SPACE;
goto out;
}
PROC_UNLOCK(p);
}
#endif
if (vm_map_lock_upgrade(map)) {
gap_entry = NULL;
vm_map_lock_read(map);
goto retry;
}
if (grow_down) {
grow_start = gap_entry->end - grow_amount;
if (gap_entry->start + grow_amount == gap_entry->end) {
gap_start = gap_entry->start;
gap_end = gap_entry->end;
vm_map_entry_delete(map, gap_entry);
gap_deleted = true;
} else {
MPASS(gap_entry->start < gap_entry->end - grow_amount);
vm_map_entry_resize(map, gap_entry, -grow_amount);
gap_deleted = false;
}
rv = vm_map_insert(map, NULL, 0, grow_start,
grow_start + grow_amount,
stack_entry->protection, stack_entry->max_protection,
MAP_STACK_GROWS_DOWN);
if (rv != KERN_SUCCESS) {
if (gap_deleted) {
rv1 = vm_map_insert(map, NULL, 0, gap_start,
gap_end, VM_PROT_NONE, VM_PROT_NONE,
MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN);
MPASS(rv1 == KERN_SUCCESS);
} else
vm_map_entry_resize(map, gap_entry,
grow_amount);
}
} else {
grow_start = stack_entry->end;
cred = stack_entry->cred;
if (cred == NULL && stack_entry->object.vm_object != NULL)
cred = stack_entry->object.vm_object->cred;
if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred))
rv = KERN_NO_SPACE;
/* Grow the underlying object if applicable. */
else if (stack_entry->object.vm_object == NULL ||
vm_object_coalesce(stack_entry->object.vm_object,
stack_entry->offset,
(vm_size_t)(stack_entry->end - stack_entry->start),
grow_amount, cred != NULL)) {
if (gap_entry->start + grow_amount == gap_entry->end) {
vm_map_entry_delete(map, gap_entry);
vm_map_entry_resize(map, stack_entry,
grow_amount);
} else {
gap_entry->start += grow_amount;
stack_entry->end += grow_amount;
}
map->size += grow_amount;
rv = KERN_SUCCESS;
} else
rv = KERN_FAILURE;
}
if (rv == KERN_SUCCESS && is_procstack)
vm->vm_ssize += btoc(grow_amount);
/*
* Heed the MAP_WIREFUTURE flag if it was set for this process.
*/
if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) {
rv = vm_map_wire_locked(map, grow_start,
grow_start + grow_amount,
VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
}
vm_map_lock_downgrade(map);
out:
#ifdef RACCT
if (racct_enable && rv != KERN_SUCCESS) {
PROC_LOCK(p);
error = racct_set(p, RACCT_VMEM, map->size);
KASSERT(error == 0, ("decreasing RACCT_VMEM failed"));
if (!old_mlock) {
error = racct_set(p, RACCT_MEMLOCK,
ptoa(pmap_wired_count(map->pmap)));
KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed"));
}
error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize));
KASSERT(error == 0, ("decreasing RACCT_STACK failed"));
PROC_UNLOCK(p);
}
#endif
return (rv);
}
/*
* Unshare the specified VM space for exec. If other processes are
* mapped to it, then create a new one. The new vmspace is null.
*/
int
vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser)
{
struct vmspace *oldvmspace = p->p_vmspace;
struct vmspace *newvmspace;
KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0,
("vmspace_exec recursed"));
newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit);
if (newvmspace == NULL)
return (ENOMEM);
newvmspace->vm_swrss = oldvmspace->vm_swrss;
/*
* This code is written like this for prototype purposes. The
* goal is to avoid running down the vmspace here, but let the
* other process's that are still using the vmspace to finally
* run it down. Even though there is little or no chance of blocking
* here, it is a good idea to keep this form for future mods.
*/
PROC_VMSPACE_LOCK(p);
p->p_vmspace = newvmspace;
PROC_VMSPACE_UNLOCK(p);
if (p == curthread->td_proc)
pmap_activate(curthread);
curthread->td_pflags |= TDP_EXECVMSPC;
return (0);
}
/*
* Unshare the specified VM space for forcing COW. This
* is called by rfork, for the (RFMEM|RFPROC) == 0 case.
*/
int
vmspace_unshare(struct proc *p)
{
struct vmspace *oldvmspace = p->p_vmspace;
struct vmspace *newvmspace;
vm_ooffset_t fork_charge;
if (refcount_load(&oldvmspace->vm_refcnt) == 1)
return (0);
fork_charge = 0;
newvmspace = vmspace_fork(oldvmspace, &fork_charge);
if (newvmspace == NULL)
return (ENOMEM);
if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) {
vmspace_free(newvmspace);
return (ENOMEM);
}
PROC_VMSPACE_LOCK(p);
p->p_vmspace = newvmspace;
PROC_VMSPACE_UNLOCK(p);
if (p == curthread->td_proc)
pmap_activate(curthread);
vmspace_free(oldvmspace);
return (0);
}
/*
* vm_map_lookup:
*
* Finds the VM object, offset, and
* protection for a given virtual address in the
* specified map, assuming a page fault of the
* type specified.
*
* Leaves the map in question locked for read; return
* values are guaranteed until a vm_map_lookup_done
* call is performed. Note that the map argument
* is in/out; the returned map must be used in
* the call to vm_map_lookup_done.
*
* A handle (out_entry) is returned for use in
* vm_map_lookup_done, to make that fast.
*
* If a lookup is requested with "write protection"
* specified, the map may be changed to perform virtual
* copying operations, although the data referenced will
* remain the same.
*/
int
vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
vm_offset_t vaddr,
vm_prot_t fault_typea,
vm_map_entry_t *out_entry, /* OUT */
vm_object_t *object, /* OUT */
vm_pindex_t *pindex, /* OUT */
vm_prot_t *out_prot, /* OUT */
boolean_t *wired) /* OUT */
{
vm_map_entry_t entry;
vm_map_t map = *var_map;
vm_prot_t prot;
vm_prot_t fault_type;
vm_object_t eobject;
vm_size_t size;
struct ucred *cred;
RetryLookup:
vm_map_lock_read(map);
RetryLookupLocked:
/*
* Lookup the faulting address.
*/
if (!vm_map_lookup_entry(map, vaddr, out_entry)) {
vm_map_unlock_read(map);
return (KERN_INVALID_ADDRESS);
}
entry = *out_entry;
/*
* Handle submaps.
*/
if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
vm_map_t old_map = map;
*var_map = map = entry->object.sub_map;
vm_map_unlock_read(old_map);
goto RetryLookup;
}
/*
* Check whether this task is allowed to have this page.
*/
prot = entry->protection;
if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) {
fault_typea &= ~VM_PROT_FAULT_LOOKUP;
if (prot == VM_PROT_NONE && map != kernel_map &&
(entry->eflags & MAP_ENTRY_GUARD) != 0 &&
(entry->eflags & (MAP_ENTRY_STACK_GAP_DN |
MAP_ENTRY_STACK_GAP_UP)) != 0 &&
vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS)
goto RetryLookupLocked;
}
fault_type = fault_typea & VM_PROT_ALL;
if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) {
vm_map_unlock_read(map);
return (KERN_PROTECTION_FAILURE);
}
KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags &
(MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) !=
(MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY),
("entry %p flags %x", entry, entry->eflags));
if ((fault_typea & VM_PROT_COPY) != 0 &&
(entry->max_protection & VM_PROT_WRITE) == 0 &&
(entry->eflags & MAP_ENTRY_COW) == 0) {
vm_map_unlock_read(map);
return (KERN_PROTECTION_FAILURE);
}
/*
* If this page is not pageable, we have to get it for all possible
* accesses.
*/
*wired = (entry->wired_count != 0);
if (*wired)
fault_type = entry->protection;
size = entry->end - entry->start;
/*
* If the entry was copy-on-write, we either ...
*/
if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
/*
* If we want to write the page, we may as well handle that
* now since we've got the map locked.
*
* If we don't need to write the page, we just demote the
* permissions allowed.
*/
if ((fault_type & VM_PROT_WRITE) != 0 ||
(fault_typea & VM_PROT_COPY) != 0) {
/*
* Make a new object, and place it in the object
* chain. Note that no new references have appeared
* -- one just moved from the map to the new
* object.
*/
if (vm_map_lock_upgrade(map))
goto RetryLookup;
if (entry->cred == NULL) {
/*
* The debugger owner is charged for
* the memory.
*/
cred = curthread->td_ucred;
crhold(cred);
if (!swap_reserve_by_cred(size, cred)) {
crfree(cred);
vm_map_unlock(map);
return (KERN_RESOURCE_SHORTAGE);
}
entry->cred = cred;
}
eobject = entry->object.vm_object;
vm_object_shadow(&entry->object.vm_object,
&entry->offset, size, entry->cred, false);
if (eobject == entry->object.vm_object) {
/*
* The object was not shadowed.
*/
swap_release_by_cred(size, entry->cred);
crfree(entry->cred);
}
entry->cred = NULL;
entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
vm_map_lock_downgrade(map);
} else {
/*
* We're attempting to read a copy-on-write page --
* don't allow writes.
*/
prot &= ~VM_PROT_WRITE;
}
}
/*
* Create an object if necessary.
*/
if (entry->object.vm_object == NULL && !map->system_map) {
if (vm_map_lock_upgrade(map))
goto RetryLookup;
entry->object.vm_object = vm_object_allocate_anon(atop(size),
NULL, entry->cred, entry->cred != NULL ? size : 0);
entry->offset = 0;
entry->cred = NULL;
vm_map_lock_downgrade(map);
}
/*
* Return the object/offset from this entry. If the entry was
* copy-on-write or empty, it has been fixed up.
*/
*pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
*object = entry->object.vm_object;
*out_prot = prot;
return (KERN_SUCCESS);
}
/*
* vm_map_lookup_locked:
*
* Lookup the faulting address. A version of vm_map_lookup that returns
* KERN_FAILURE instead of blocking on map lock or memory allocation.
*/
int
vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */
vm_offset_t vaddr,
vm_prot_t fault_typea,
vm_map_entry_t *out_entry, /* OUT */
vm_object_t *object, /* OUT */
vm_pindex_t *pindex, /* OUT */
vm_prot_t *out_prot, /* OUT */
boolean_t *wired) /* OUT */
{
vm_map_entry_t entry;
vm_map_t map = *var_map;
vm_prot_t prot;
vm_prot_t fault_type = fault_typea;
/*
* Lookup the faulting address.
*/
if (!vm_map_lookup_entry(map, vaddr, out_entry))
return (KERN_INVALID_ADDRESS);
entry = *out_entry;
/*
* Fail if the entry refers to a submap.
*/
if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
return (KERN_FAILURE);
/*
* Check whether this task is allowed to have this page.
*/
prot = entry->protection;
fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
if ((fault_type & prot) != fault_type)
return (KERN_PROTECTION_FAILURE);
/*
* If this page is not pageable, we have to get it for all possible
* accesses.
*/
*wired = (entry->wired_count != 0);
if (*wired)
fault_type = entry->protection;
if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
/*
* Fail if the entry was copy-on-write for a write fault.
*/
if (fault_type & VM_PROT_WRITE)
return (KERN_FAILURE);
/*
* We're attempting to read a copy-on-write page --
* don't allow writes.
*/
prot &= ~VM_PROT_WRITE;
}
/*
* Fail if an object should be created.
*/
if (entry->object.vm_object == NULL && !map->system_map)
return (KERN_FAILURE);
/*
* Return the object/offset from this entry. If the entry was
* copy-on-write or empty, it has been fixed up.
*/
*pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
*object = entry->object.vm_object;
*out_prot = prot;
return (KERN_SUCCESS);
}
/*
* vm_map_lookup_done:
*
* Releases locks acquired by a vm_map_lookup
* (according to the handle returned by that lookup).
*/
void
vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry)
{
/*
* Unlock the main-level map
*/
vm_map_unlock_read(map);
}
vm_offset_t
vm_map_max_KBI(const struct vm_map *map)
{
return (vm_map_max(map));
}
vm_offset_t
vm_map_min_KBI(const struct vm_map *map)
{
return (vm_map_min(map));
}
pmap_t
vm_map_pmap_KBI(vm_map_t map)
{
return (map->pmap);
}
bool
vm_map_range_valid_KBI(vm_map_t map, vm_offset_t start, vm_offset_t end)
{
return (vm_map_range_valid(map, start, end));
}
#ifdef INVARIANTS
static void
_vm_map_assert_consistent(vm_map_t map, int check)
{
vm_map_entry_t entry, prev;
vm_map_entry_t cur, header, lbound, ubound;
vm_size_t max_left, max_right;
#ifdef DIAGNOSTIC
++map->nupdates;
#endif
if (enable_vmmap_check != check)
return;
header = prev = &map->header;
VM_MAP_ENTRY_FOREACH(entry, map) {
KASSERT(prev->end <= entry->start,
("map %p prev->end = %jx, start = %jx", map,
(uintmax_t)prev->end, (uintmax_t)entry->start));
KASSERT(entry->start < entry->end,
("map %p start = %jx, end = %jx", map,
(uintmax_t)entry->start, (uintmax_t)entry->end));
KASSERT(entry->left == header ||
entry->left->start < entry->start,
("map %p left->start = %jx, start = %jx", map,
(uintmax_t)entry->left->start, (uintmax_t)entry->start));
KASSERT(entry->right == header ||
entry->start < entry->right->start,
("map %p start = %jx, right->start = %jx", map,
(uintmax_t)entry->start, (uintmax_t)entry->right->start));
cur = map->root;
lbound = ubound = header;
for (;;) {
if (entry->start < cur->start) {
ubound = cur;
cur = cur->left;
KASSERT(cur != lbound,
("map %p cannot find %jx",
map, (uintmax_t)entry->start));
} else if (cur->end <= entry->start) {
lbound = cur;
cur = cur->right;
KASSERT(cur != ubound,
("map %p cannot find %jx",
map, (uintmax_t)entry->start));
} else {
KASSERT(cur == entry,
("map %p cannot find %jx",
map, (uintmax_t)entry->start));
break;
}
}
max_left = vm_map_entry_max_free_left(entry, lbound);
max_right = vm_map_entry_max_free_right(entry, ubound);
KASSERT(entry->max_free == vm_size_max(max_left, max_right),
("map %p max = %jx, max_left = %jx, max_right = %jx", map,
(uintmax_t)entry->max_free,
(uintmax_t)max_left, (uintmax_t)max_right));
prev = entry;
}
KASSERT(prev->end <= entry->start,
("map %p prev->end = %jx, start = %jx", map,
(uintmax_t)prev->end, (uintmax_t)entry->start));
}
#endif
#include "opt_ddb.h"
#ifdef DDB
#include <sys/kernel.h>
#include <ddb/ddb.h>
static void
vm_map_print(vm_map_t map)
{
vm_map_entry_t entry, prev;
db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
(void *)map,
(void *)map->pmap, map->nentries, map->timestamp);
db_indent += 2;
prev = &map->header;
VM_MAP_ENTRY_FOREACH(entry, map) {
db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n",
(void *)entry, (void *)entry->start, (void *)entry->end,
entry->eflags);
{
static const char * const inheritance_name[4] =
{"share", "copy", "none", "donate_copy"};
db_iprintf(" prot=%x/%x/%s",
entry->protection,
entry->max_protection,
inheritance_name[(int)(unsigned char)
entry->inheritance]);
if (entry->wired_count != 0)
db_printf(", wired");
}
if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
db_printf(", share=%p, offset=0x%jx\n",
(void *)entry->object.sub_map,
(uintmax_t)entry->offset);
if (prev == &map->header ||
prev->object.sub_map !=
entry->object.sub_map) {
db_indent += 2;
vm_map_print((vm_map_t)entry->object.sub_map);
db_indent -= 2;
}
} else {
if (entry->cred != NULL)
db_printf(", ruid %d", entry->cred->cr_ruid);
db_printf(", object=%p, offset=0x%jx",
(void *)entry->object.vm_object,
(uintmax_t)entry->offset);
if (entry->object.vm_object && entry->object.vm_object->cred)
db_printf(", obj ruid %d charge %jx",
entry->object.vm_object->cred->cr_ruid,
(uintmax_t)entry->object.vm_object->charge);
if (entry->eflags & MAP_ENTRY_COW)
db_printf(", copy (%s)",
(entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
db_printf("\n");
if (prev == &map->header ||
prev->object.vm_object !=
entry->object.vm_object) {
db_indent += 2;
vm_object_print((db_expr_t)(intptr_t)
entry->object.vm_object,
0, 0, (char *)0);
db_indent -= 2;
}
}
prev = entry;
}
db_indent -= 2;
}
DB_SHOW_COMMAND(map, map)
{
if (!have_addr) {
db_printf("usage: show map <addr>\n");
return;
}
vm_map_print((vm_map_t)addr);
}
DB_SHOW_COMMAND(procvm, procvm)
{
struct proc *p;
if (have_addr) {
p = db_lookup_proc(addr);
} else {
p = curproc;
}
db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
(void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
(void *)vmspace_pmap(p->p_vmspace));
vm_map_print((vm_map_t)&p->p_vmspace->vm_map);
}
#endif /* DDB */
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