vm_shared_region_pager.c [plain text]
#include <sys/errno.h>
#include <mach/mach_types.h>
#include <mach/mach_traps.h>
#include <mach/host_priv.h>
#include <mach/kern_return.h>
#include <mach/memory_object_control.h>
#include <mach/memory_object_types.h>
#include <mach/port.h>
#include <mach/policy.h>
#include <mach/upl.h>
#include <mach/thread_act.h>
#include <mach/mach_vm.h>
#include <kern/host.h>
#include <kern/kalloc.h>
#include <kern/queue.h>
#include <kern/thread.h>
#include <kern/ipc_kobject.h>
#include <ipc/ipc_port.h>
#include <ipc/ipc_space.h>
#include <vm/memory_object.h>
#include <vm/vm_kern.h>
#include <vm/vm_fault.h>
#include <vm/vm_map.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pageout.h>
#include <vm/vm_protos.h>
#include <vm/vm_shared_region.h>
void shared_region_pager_reference(memory_object_t mem_obj);
void shared_region_pager_deallocate(memory_object_t mem_obj);
kern_return_t shared_region_pager_init(memory_object_t mem_obj,
memory_object_control_t control,
memory_object_cluster_size_t pg_size);
kern_return_t shared_region_pager_terminate(memory_object_t mem_obj);
kern_return_t shared_region_pager_data_request(memory_object_t mem_obj,
memory_object_offset_t offset,
memory_object_cluster_size_t length,
vm_prot_t protection_required,
memory_object_fault_info_t fault_info);
kern_return_t shared_region_pager_data_return(memory_object_t mem_obj,
memory_object_offset_t offset,
memory_object_cluster_size_t data_cnt,
memory_object_offset_t *resid_offset,
int *io_error,
boolean_t dirty,
boolean_t kernel_copy,
int upl_flags);
kern_return_t shared_region_pager_data_initialize(memory_object_t mem_obj,
memory_object_offset_t offset,
memory_object_cluster_size_t data_cnt);
kern_return_t shared_region_pager_data_unlock(memory_object_t mem_obj,
memory_object_offset_t offset,
memory_object_size_t size,
vm_prot_t desired_access);
kern_return_t shared_region_pager_synchronize(memory_object_t mem_obj,
memory_object_offset_t offset,
memory_object_size_t length,
vm_sync_t sync_flags);
kern_return_t shared_region_pager_map(memory_object_t mem_obj,
vm_prot_t prot);
kern_return_t shared_region_pager_last_unmap(memory_object_t mem_obj);
const struct memory_object_pager_ops shared_region_pager_ops = {
shared_region_pager_reference,
shared_region_pager_deallocate,
shared_region_pager_init,
shared_region_pager_terminate,
shared_region_pager_data_request,
shared_region_pager_data_return,
shared_region_pager_data_initialize,
shared_region_pager_data_unlock,
shared_region_pager_synchronize,
shared_region_pager_map,
shared_region_pager_last_unmap,
NULL,
"shared_region"
};
typedef struct shared_region_pager {
struct memory_object sc_pgr_hdr;
queue_chain_t pager_queue;
unsigned int ref_count;
boolean_t is_ready;
boolean_t is_mapped;
vm_object_t backing_object;
vm_object_offset_t backing_offset;
struct vm_shared_region_slide_info *scp_slide_info;
} *shared_region_pager_t;
#define SHARED_REGION_PAGER_NULL ((shared_region_pager_t) NULL)
int shared_region_pager_count = 0;
int shared_region_pager_count_mapped = 0;
queue_head_t shared_region_pager_queue;
decl_lck_mtx_data(, shared_region_pager_lock)
int shared_region_pager_cache_limit = 0;
int shared_region_pager_count_max = 0;
int shared_region_pager_count_unmapped_max = 0;
int shared_region_pager_num_trim_max = 0;
int shared_region_pager_num_trim_total = 0;
lck_grp_t shared_region_pager_lck_grp;
lck_grp_attr_t shared_region_pager_lck_grp_attr;
lck_attr_t shared_region_pager_lck_attr;
uint64_t shared_region_pager_copied = 0;
uint64_t shared_region_pager_slid = 0;
uint64_t shared_region_pager_slid_error = 0;
uint64_t shared_region_pager_reclaimed = 0;
shared_region_pager_t shared_region_pager_create(
vm_object_t backing_object,
vm_object_offset_t backing_offset,
struct vm_shared_region_slide_info *slide_info);
shared_region_pager_t shared_region_pager_lookup(memory_object_t mem_obj);
void shared_region_pager_dequeue(shared_region_pager_t pager);
void shared_region_pager_deallocate_internal(shared_region_pager_t pager,
boolean_t locked);
void shared_region_pager_terminate_internal(shared_region_pager_t pager);
void shared_region_pager_trim(void);
#if DEBUG
int shared_region_pagerdebug = 0;
#define PAGER_ALL 0xffffffff
#define PAGER_INIT 0x00000001
#define PAGER_PAGEIN 0x00000002
#define PAGER_DEBUG(LEVEL, A) \
MACRO_BEGIN \
if ((shared_region_pagerdebug & (LEVEL)) == (LEVEL)) { \
printf A; \
} \
MACRO_END
#else
#define PAGER_DEBUG(LEVEL, A)
#endif
void
shared_region_pager_bootstrap(void)
{
lck_grp_attr_setdefault(&shared_region_pager_lck_grp_attr);
lck_grp_init(&shared_region_pager_lck_grp, "shared_region", &shared_region_pager_lck_grp_attr);
lck_attr_setdefault(&shared_region_pager_lck_attr);
lck_mtx_init(&shared_region_pager_lock, &shared_region_pager_lck_grp, &shared_region_pager_lck_attr);
queue_init(&shared_region_pager_queue);
}
kern_return_t
shared_region_pager_init(
memory_object_t mem_obj,
memory_object_control_t control,
#if !DEBUG
__unused
#endif
memory_object_cluster_size_t pg_size)
{
shared_region_pager_t pager;
kern_return_t kr;
memory_object_attr_info_data_t attributes;
PAGER_DEBUG(PAGER_ALL,
("shared_region_pager_init: %p, %p, %x\n",
mem_obj, control, pg_size));
if (control == MEMORY_OBJECT_CONTROL_NULL) {
return KERN_INVALID_ARGUMENT;
}
pager = shared_region_pager_lookup(mem_obj);
memory_object_control_reference(control);
pager->sc_pgr_hdr.mo_control = control;
attributes.copy_strategy = MEMORY_OBJECT_COPY_DELAY;
attributes.cluster_size = (1 << (PAGE_SHIFT));
attributes.may_cache_object = FALSE;
attributes.temporary = TRUE;
kr = memory_object_change_attributes(
control,
MEMORY_OBJECT_ATTRIBUTE_INFO,
(memory_object_info_t) &attributes,
MEMORY_OBJECT_ATTR_INFO_COUNT);
if (kr != KERN_SUCCESS) {
panic("shared_region_pager_init: "
"memory_object_change_attributes() failed");
}
#if CONFIG_SECLUDED_MEMORY
if (secluded_for_filecache) {
#if 00
memory_object_mark_eligible_for_secluded(control, TRUE);
#endif
}
#endif
return KERN_SUCCESS;
}
kern_return_t
shared_region_pager_data_return(
__unused memory_object_t mem_obj,
__unused memory_object_offset_t offset,
__unused memory_object_cluster_size_t data_cnt,
__unused memory_object_offset_t *resid_offset,
__unused int *io_error,
__unused boolean_t dirty,
__unused boolean_t kernel_copy,
__unused int upl_flags)
{
panic("shared_region_pager_data_return: should never get called");
return KERN_FAILURE;
}
kern_return_t
shared_region_pager_data_initialize(
__unused memory_object_t mem_obj,
__unused memory_object_offset_t offset,
__unused memory_object_cluster_size_t data_cnt)
{
panic("shared_region_pager_data_initialize: should never get called");
return KERN_FAILURE;
}
kern_return_t
shared_region_pager_data_unlock(
__unused memory_object_t mem_obj,
__unused memory_object_offset_t offset,
__unused memory_object_size_t size,
__unused vm_prot_t desired_access)
{
return KERN_FAILURE;
}
int shared_region_pager_data_request_debug = 0;
kern_return_t
shared_region_pager_data_request(
memory_object_t mem_obj,
memory_object_offset_t offset,
memory_object_cluster_size_t length,
#if !DEBUG
__unused
#endif
vm_prot_t protection_required,
memory_object_fault_info_t mo_fault_info)
{
shared_region_pager_t pager;
memory_object_control_t mo_control;
upl_t upl;
int upl_flags;
upl_size_t upl_size;
upl_page_info_t *upl_pl;
unsigned int pl_count;
vm_object_t src_top_object, src_page_object, dst_object;
kern_return_t kr, retval;
vm_offset_t src_vaddr, dst_vaddr;
vm_offset_t cur_offset;
vm_offset_t offset_in_page;
kern_return_t error_code;
vm_prot_t prot;
vm_page_t src_page, top_page;
int interruptible;
struct vm_object_fault_info fault_info;
mach_vm_offset_t slide_start_address;
PAGER_DEBUG(PAGER_ALL, ("shared_region_pager_data_request: %p, %llx, %x, %x\n", mem_obj, offset, length, protection_required));
retval = KERN_SUCCESS;
src_top_object = VM_OBJECT_NULL;
src_page_object = VM_OBJECT_NULL;
upl = NULL;
upl_pl = NULL;
fault_info = *((struct vm_object_fault_info *)(uintptr_t)mo_fault_info);
fault_info.stealth = TRUE;
fault_info.io_sync = FALSE;
fault_info.mark_zf_absent = FALSE;
fault_info.batch_pmap_op = FALSE;
interruptible = fault_info.interruptible;
pager = shared_region_pager_lookup(mem_obj);
assert(pager->is_ready);
assert(pager->ref_count > 1);
PAGER_DEBUG(PAGER_PAGEIN, ("shared_region_pager_data_request: %p, %llx, %x, %x, pager %p\n", mem_obj, offset, length, protection_required, pager));
mo_control = pager->sc_pgr_hdr.mo_control;
upl_size = length;
upl_flags =
UPL_RET_ONLY_ABSENT |
UPL_SET_LITE |
UPL_NO_SYNC |
UPL_CLEAN_IN_PLACE |
UPL_SET_INTERNAL;
pl_count = 0;
kr = memory_object_upl_request(mo_control,
offset, upl_size,
&upl, NULL, NULL, upl_flags, VM_KERN_MEMORY_SECURITY);
if (kr != KERN_SUCCESS) {
retval = kr;
goto done;
}
dst_object = mo_control->moc_object;
assert(dst_object != VM_OBJECT_NULL);
src_top_object = pager->backing_object;
assert(src_top_object != VM_OBJECT_NULL);
vm_object_reference(src_top_object);
slide_start_address = pager->scp_slide_info->slid_address;
fault_info.lo_offset += pager->backing_offset;
fault_info.hi_offset += pager->backing_offset;
upl_pl = UPL_GET_INTERNAL_PAGE_LIST(upl);
pl_count = length / PAGE_SIZE;
for (cur_offset = 0;
retval == KERN_SUCCESS && cur_offset < length;
cur_offset += PAGE_SIZE) {
ppnum_t dst_pnum;
if (!upl_page_present(upl_pl, (int)(cur_offset / PAGE_SIZE))) {
continue;
}
retry_src_fault:
vm_object_lock(src_top_object);
vm_object_paging_begin(src_top_object);
error_code = 0;
prot = VM_PROT_READ;
src_page = VM_PAGE_NULL;
kr = vm_fault_page(src_top_object,
pager->backing_offset + offset + cur_offset,
VM_PROT_READ,
FALSE,
FALSE,
&prot,
&src_page,
&top_page,
NULL,
&error_code,
FALSE,
FALSE,
&fault_info);
switch (kr) {
case VM_FAULT_SUCCESS:
break;
case VM_FAULT_RETRY:
goto retry_src_fault;
case VM_FAULT_MEMORY_SHORTAGE:
if (vm_page_wait(interruptible)) {
goto retry_src_fault;
}
case VM_FAULT_INTERRUPTED:
retval = MACH_SEND_INTERRUPTED;
goto done;
case VM_FAULT_SUCCESS_NO_VM_PAGE:
vm_object_paging_end(src_top_object);
vm_object_unlock(src_top_object);
case VM_FAULT_MEMORY_ERROR:
if (error_code) {
retval = error_code;
} else {
retval = KERN_MEMORY_ERROR;
}
goto done;
default:
panic("shared_region_pager_data_request: "
"vm_fault_page() unexpected error 0x%x\n",
kr);
}
assert(src_page != VM_PAGE_NULL);
assert(src_page->vmp_busy);
if (src_page->vmp_q_state != VM_PAGE_ON_SPECULATIVE_Q) {
vm_page_lockspin_queues();
if (src_page->vmp_q_state != VM_PAGE_ON_SPECULATIVE_Q) {
vm_page_speculate(src_page, FALSE);
}
vm_page_unlock_queues();
}
dst_pnum = (ppnum_t)
upl_phys_page(upl_pl, (int)(cur_offset / PAGE_SIZE));
assert(dst_pnum != 0);
#if __x86_64__
src_vaddr = (vm_map_offset_t)
PHYSMAP_PTOV((pmap_paddr_t)VM_PAGE_GET_PHYS_PAGE(src_page)
<< PAGE_SHIFT);
dst_vaddr = (vm_map_offset_t)
PHYSMAP_PTOV((pmap_paddr_t)dst_pnum << PAGE_SHIFT);
#elif __arm__ || __arm64__
src_vaddr = (vm_map_offset_t)
phystokv((pmap_paddr_t)VM_PAGE_GET_PHYS_PAGE(src_page)
<< PAGE_SHIFT);
dst_vaddr = (vm_map_offset_t)
phystokv((pmap_paddr_t)dst_pnum << PAGE_SHIFT);
#else
#error "vm_paging_map_object: no 1-to-1 kernel mapping of physical memory..."
src_vaddr = 0;
dst_vaddr = 0;
#endif
src_page_object = VM_PAGE_OBJECT(src_page);
if (src_page_object->code_signed) {
vm_page_validate_cs_mapped(
src_page,
(const void *) src_vaddr);
}
UPL_SET_CS_VALIDATED(upl_pl, cur_offset / PAGE_SIZE,
src_page->vmp_cs_validated);
UPL_SET_CS_TAINTED(upl_pl, cur_offset / PAGE_SIZE,
src_page->vmp_cs_tainted);
UPL_SET_CS_NX(upl_pl, cur_offset / PAGE_SIZE,
src_page->vmp_cs_nx);
assert(src_page->vmp_busy);
assert(src_page_object->paging_in_progress > 0);
vm_object_unlock(src_page_object);
for (offset_in_page = 0;
offset_in_page < PAGE_SIZE;
offset_in_page += PAGE_SIZE_FOR_SR_SLIDE) {
vm_object_offset_t chunk_offset;
vm_object_offset_t offset_in_backing_object;
vm_object_offset_t offset_in_sliding_range;
chunk_offset = offset + cur_offset + offset_in_page;
bcopy((const char *)(src_vaddr +
offset_in_page),
(char *)(dst_vaddr + offset_in_page),
PAGE_SIZE_FOR_SR_SLIDE);
offset_in_backing_object = (chunk_offset +
pager->backing_offset);
if ((offset_in_backing_object < pager->scp_slide_info->start) ||
(offset_in_backing_object >= pager->scp_slide_info->end)) {
shared_region_pager_copied++;
continue;
}
offset_in_sliding_range =
(offset_in_backing_object -
pager->scp_slide_info->start);
kr = vm_shared_region_slide_page(
pager->scp_slide_info,
dst_vaddr + offset_in_page,
(mach_vm_offset_t) (offset_in_sliding_range +
slide_start_address),
(uint32_t) (offset_in_sliding_range /
PAGE_SIZE_FOR_SR_SLIDE));
if (shared_region_pager_data_request_debug) {
printf("shared_region_data_request"
"(%p,0x%llx+0x%llx+0x%04llx): 0x%llx "
"in sliding range [0x%llx:0x%llx]: "
"SLIDE offset 0x%llx="
"(0x%llx+0x%llx+0x%llx+0x%04llx)"
"[0x%016llx 0x%016llx] "
"code_signed=%d "
"cs_validated=%d "
"cs_tainted=%d "
"cs_nx=%d "
"kr=0x%x\n",
pager,
offset,
(uint64_t) cur_offset,
(uint64_t) offset_in_page,
chunk_offset,
pager->scp_slide_info->start,
pager->scp_slide_info->end,
(pager->backing_offset +
offset +
cur_offset +
offset_in_page),
pager->backing_offset,
offset,
(uint64_t) cur_offset,
(uint64_t) offset_in_page,
*(uint64_t *)(dst_vaddr + offset_in_page),
*(uint64_t *)(dst_vaddr + offset_in_page + 8),
src_page_object->code_signed,
src_page->vmp_cs_validated,
src_page->vmp_cs_tainted,
src_page->vmp_cs_nx,
kr);
}
if (kr != KERN_SUCCESS) {
shared_region_pager_slid_error++;
break;
}
shared_region_pager_slid++;
}
assert(VM_PAGE_OBJECT(src_page) == src_page_object);
assert(src_page->vmp_busy);
assert(src_page_object->paging_in_progress > 0);
vm_object_lock(src_page_object);
PAGE_WAKEUP_DONE(src_page);
src_page = VM_PAGE_NULL;
vm_object_paging_end(src_page_object);
vm_object_unlock(src_page_object);
if (top_page != VM_PAGE_NULL) {
assert(VM_PAGE_OBJECT(top_page) == src_top_object);
vm_object_lock(src_top_object);
VM_PAGE_FREE(top_page);
vm_object_paging_end(src_top_object);
vm_object_unlock(src_top_object);
}
}
done:
if (upl != NULL) {
upl_clear_dirty(upl, TRUE);
if (retval != KERN_SUCCESS) {
upl_abort(upl, 0);
} else {
boolean_t empty;
upl_commit_range(upl, 0, upl->size,
UPL_COMMIT_CS_VALIDATED | UPL_COMMIT_WRITTEN_BY_KERNEL,
upl_pl, pl_count, &empty);
}
upl_deallocate(upl);
upl = NULL;
}
if (src_top_object != VM_OBJECT_NULL) {
vm_object_deallocate(src_top_object);
}
return retval;
}
void
shared_region_pager_reference(
memory_object_t mem_obj)
{
shared_region_pager_t pager;
pager = shared_region_pager_lookup(mem_obj);
lck_mtx_lock(&shared_region_pager_lock);
assert(pager->ref_count > 0);
pager->ref_count++;
lck_mtx_unlock(&shared_region_pager_lock);
}
void
shared_region_pager_dequeue(
shared_region_pager_t pager)
{
assert(!pager->is_mapped);
queue_remove(&shared_region_pager_queue,
pager,
shared_region_pager_t,
pager_queue);
pager->pager_queue.next = NULL;
pager->pager_queue.prev = NULL;
shared_region_pager_count--;
}
void
shared_region_pager_terminate_internal(
shared_region_pager_t pager)
{
assert(pager->is_ready);
assert(!pager->is_mapped);
if (pager->backing_object != VM_OBJECT_NULL) {
vm_object_deallocate(pager->backing_object);
pager->backing_object = VM_OBJECT_NULL;
}
memory_object_destroy(pager->sc_pgr_hdr.mo_control, 0);
}
void
shared_region_pager_deallocate_internal(
shared_region_pager_t pager,
boolean_t locked)
{
boolean_t needs_trimming;
int count_unmapped;
if (!locked) {
lck_mtx_lock(&shared_region_pager_lock);
}
count_unmapped = (shared_region_pager_count -
shared_region_pager_count_mapped);
if (count_unmapped > shared_region_pager_cache_limit) {
needs_trimming = TRUE;
} else {
needs_trimming = FALSE;
}
pager->ref_count--;
if (pager->ref_count == 1) {
shared_region_pager_dequeue(pager);
lck_mtx_unlock(&shared_region_pager_lock);
shared_region_pager_terminate_internal(pager);
} else if (pager->ref_count == 0) {
lck_mtx_unlock(&shared_region_pager_lock);
if (pager->sc_pgr_hdr.mo_control != MEMORY_OBJECT_CONTROL_NULL) {
memory_object_control_deallocate(pager->sc_pgr_hdr.mo_control);
pager->sc_pgr_hdr.mo_control = MEMORY_OBJECT_CONTROL_NULL;
}
kfree(pager, sizeof(*pager));
pager = SHARED_REGION_PAGER_NULL;
} else {
lck_mtx_unlock(&shared_region_pager_lock);
}
if (needs_trimming) {
shared_region_pager_trim();
}
}
void
shared_region_pager_deallocate(
memory_object_t mem_obj)
{
shared_region_pager_t pager;
PAGER_DEBUG(PAGER_ALL, ("shared_region_pager_deallocate: %p\n", mem_obj));
pager = shared_region_pager_lookup(mem_obj);
shared_region_pager_deallocate_internal(pager, FALSE);
}
kern_return_t
shared_region_pager_terminate(
#if !DEBUG
__unused
#endif
memory_object_t mem_obj)
{
PAGER_DEBUG(PAGER_ALL, ("shared_region_pager_terminate: %p\n", mem_obj));
return KERN_SUCCESS;
}
kern_return_t
shared_region_pager_synchronize(
__unused memory_object_t mem_obj,
__unused memory_object_offset_t offset,
__unused memory_object_size_t length,
__unused vm_sync_t sync_flags)
{
panic("shared_region_pager_synchronize: memory_object_synchronize no longer supported\n");
return KERN_FAILURE;
}
kern_return_t
shared_region_pager_map(
memory_object_t mem_obj,
__unused vm_prot_t prot)
{
shared_region_pager_t pager;
PAGER_DEBUG(PAGER_ALL, ("shared_region_pager_map: %p\n", mem_obj));
pager = shared_region_pager_lookup(mem_obj);
lck_mtx_lock(&shared_region_pager_lock);
assert(pager->is_ready);
assert(pager->ref_count > 0);
if (pager->is_mapped == FALSE) {
pager->is_mapped = TRUE;
pager->ref_count++;
shared_region_pager_count_mapped++;
}
lck_mtx_unlock(&shared_region_pager_lock);
return KERN_SUCCESS;
}
kern_return_t
shared_region_pager_last_unmap(
memory_object_t mem_obj)
{
shared_region_pager_t pager;
int count_unmapped;
PAGER_DEBUG(PAGER_ALL,
("shared_region_pager_last_unmap: %p\n", mem_obj));
pager = shared_region_pager_lookup(mem_obj);
lck_mtx_lock(&shared_region_pager_lock);
if (pager->is_mapped) {
shared_region_pager_count_mapped--;
count_unmapped = (shared_region_pager_count -
shared_region_pager_count_mapped);
if (count_unmapped > shared_region_pager_count_unmapped_max) {
shared_region_pager_count_unmapped_max = count_unmapped;
}
pager->is_mapped = FALSE;
shared_region_pager_deallocate_internal(pager, TRUE);
} else {
lck_mtx_unlock(&shared_region_pager_lock);
}
return KERN_SUCCESS;
}
shared_region_pager_t
shared_region_pager_lookup(
memory_object_t mem_obj)
{
shared_region_pager_t pager;
assert(mem_obj->mo_pager_ops == &shared_region_pager_ops);
pager = (shared_region_pager_t)(uintptr_t) mem_obj;
assert(pager->ref_count > 0);
return pager;
}
shared_region_pager_t
shared_region_pager_create(
vm_object_t backing_object,
vm_object_offset_t backing_offset,
struct vm_shared_region_slide_info *slide_info)
{
shared_region_pager_t pager;
memory_object_control_t control;
kern_return_t kr;
pager = (shared_region_pager_t) kalloc(sizeof(*pager));
if (pager == SHARED_REGION_PAGER_NULL) {
return SHARED_REGION_PAGER_NULL;
}
pager->sc_pgr_hdr.mo_ikot = IKOT_MEMORY_OBJECT;
pager->sc_pgr_hdr.mo_pager_ops = &shared_region_pager_ops;
pager->sc_pgr_hdr.mo_control = MEMORY_OBJECT_CONTROL_NULL;
pager->is_ready = FALSE;
pager->ref_count = 1;
pager->ref_count++;
pager->is_mapped = FALSE;
pager->backing_object = backing_object;
pager->backing_offset = backing_offset;
pager->scp_slide_info = slide_info;
vm_object_reference(backing_object);
lck_mtx_lock(&shared_region_pager_lock);
queue_enter_first(&shared_region_pager_queue,
pager,
shared_region_pager_t,
pager_queue);
shared_region_pager_count++;
if (shared_region_pager_count > shared_region_pager_count_max) {
shared_region_pager_count_max = shared_region_pager_count;
}
lck_mtx_unlock(&shared_region_pager_lock);
kr = memory_object_create_named((memory_object_t) pager,
0,
&control);
assert(kr == KERN_SUCCESS);
lck_mtx_lock(&shared_region_pager_lock);
pager->is_ready = TRUE;
lck_mtx_unlock(&shared_region_pager_lock);
thread_wakeup(&pager->is_ready);
return pager;
}
memory_object_t
shared_region_pager_setup(
vm_object_t backing_object,
vm_object_offset_t backing_offset,
struct vm_shared_region_slide_info *slide_info)
{
shared_region_pager_t pager;
pager = shared_region_pager_create(
backing_object,
backing_offset,
slide_info);
if (pager == SHARED_REGION_PAGER_NULL) {
return MEMORY_OBJECT_NULL;
}
lck_mtx_lock(&shared_region_pager_lock);
while (!pager->is_ready) {
lck_mtx_sleep(&shared_region_pager_lock,
LCK_SLEEP_DEFAULT,
&pager->is_ready,
THREAD_UNINT);
}
lck_mtx_unlock(&shared_region_pager_lock);
return (memory_object_t) pager;
}
void
shared_region_pager_trim(void)
{
shared_region_pager_t pager, prev_pager;
queue_head_t trim_queue;
int num_trim;
int count_unmapped;
lck_mtx_lock(&shared_region_pager_lock);
queue_init(&trim_queue);
num_trim = 0;
for (pager = (shared_region_pager_t)
queue_last(&shared_region_pager_queue);
!queue_end(&shared_region_pager_queue,
(queue_entry_t) pager);
pager = prev_pager) {
prev_pager = (shared_region_pager_t)
queue_prev(&pager->pager_queue);
if (pager->ref_count == 2 &&
pager->is_ready &&
!pager->is_mapped) {
num_trim++;
shared_region_pager_dequeue(pager);
queue_enter_first(&trim_queue,
pager,
shared_region_pager_t,
pager_queue);
count_unmapped = (shared_region_pager_count -
shared_region_pager_count_mapped);
if (count_unmapped <= shared_region_pager_cache_limit) {
break;
}
}
}
if (num_trim > shared_region_pager_num_trim_max) {
shared_region_pager_num_trim_max = num_trim;
}
shared_region_pager_num_trim_total += num_trim;
lck_mtx_unlock(&shared_region_pager_lock);
while (!queue_empty(&trim_queue)) {
queue_remove_first(&trim_queue,
pager,
shared_region_pager_t,
pager_queue);
pager->pager_queue.next = NULL;
pager->pager_queue.prev = NULL;
assert(pager->ref_count == 2);
pager->ref_count--;
shared_region_pager_terminate_internal(pager);
}
}