NTSTATUS
NtFreeVirtualMemory(
__in HANDLE ProcessHandle,
__inout PVOID *BaseAddress,
__inout PSIZE_T RegionSize,
__in ULONG FreeType
)
/*++
Routine Description:
This function deletes a region of pages within the virtual address
space of a subject process.
Arguments:
ProcessHandle - An open handle to a process object.
BaseAddress - The base address of the region of pages
to be freed. This value is rounded down to the
next host page address boundary.
RegionSize - A pointer to a variable that will receive
the actual size in bytes of the freed region of
pages. The initial value of this argument is
rounded up to the next host page size boundary.
FreeType - A set of flags that describe the type of
free that is to be performed for the specified
region of pages.
FreeType Flags
MEM_DECOMMIT - The specified region of pages is to be decommitted.
MEM_RELEASE - The specified region of pages is to be released.
Return Value:
NTSTATUS.
--*/
{
KAPC_STATE ApcState;
PMMVAD_SHORT Vad;
PMMVAD_SHORT NewVad;
PMMVAD PreviousVad;
PMMVAD NextVad;
PMMVAD ChargedVad;
PEPROCESS Process;
KPROCESSOR_MODE PreviousMode;
PVOID StartingAddress;
PVOID EndingAddress;
NTSTATUS Status;
LOGICAL Attached;
SIZE_T CapturedRegionSize;
PVOID CapturedBase;
PMMPTE StartingPte;
PMMPTE EndingPte;
SIZE_T OldQuota;
SIZE_T QuotaCharge;
SIZE_T CommitReduction;
LOGICAL UserPhysicalPages;
PETHREAD CurrentThread;
PEPROCESS CurrentProcess;
PAGED_CODE();
//
// Check to make sure FreeType is good.
//
if ((FreeType & ~(MEM_DECOMMIT | MEM_RELEASE)) != 0) {
return STATUS_INVALID_PARAMETER_4;
}
//
// One of MEM_DECOMMIT or MEM_RELEASE must be specified, but not both.
//
if (((FreeType & (MEM_DECOMMIT | MEM_RELEASE)) == 0) ||
((FreeType & (MEM_DECOMMIT | MEM_RELEASE)) ==
(MEM_DECOMMIT | MEM_RELEASE))) {
return STATUS_INVALID_PARAMETER_4;
}
CurrentThread = PsGetCurrentThread ();
CurrentProcess = PsGetCurrentProcessByThread (CurrentThread);
PreviousMode = KeGetPreviousModeByThread(&CurrentThread->Tcb);
//
// Establish an exception handler, probe the specified addresses
// for write access and capture the initial values.
//
try {
if (PreviousMode != KernelMode) {
ProbeForWritePointer (BaseAddress);
ProbeForWriteUlong_ptr (RegionSize);
}
//
// Capture the base address.
//
CapturedBase = *BaseAddress;
//
// Capture the region size.
//
CapturedRegionSize = *RegionSize;
}
except (ExSystemExceptionFilter ()) {
//
// If an exception occurs during the probe or capture
// of the initial values, then handle the exception and
// return the exception code as the status value.
//
return GetExceptionCode ();
}
//
// Make sure the specified starting and ending addresses are
// within the user part of the virtual address space.
//
if (CapturedBase > MM_HIGHEST_USER_ADDRESS) {
//
// Invalid base address.
//
return STATUS_INVALID_PARAMETER_2;
}
if ((ULONG_PTR)MM_HIGHEST_USER_ADDRESS - (ULONG_PTR)CapturedBase <
CapturedRegionSize) {
//
// Invalid region size;
//
return STATUS_INVALID_PARAMETER_3;
}
EndingAddress = (PVOID)(((LONG_PTR)CapturedBase + CapturedRegionSize - 1) |
(PAGE_SIZE - 1));
StartingAddress = PAGE_ALIGN(CapturedBase);
Attached = FALSE;
if (ProcessHandle == NtCurrentProcess()) {
Process = CurrentProcess;
}
else {
//
// Reference the specified process handle for VM_OPERATION access.
//
Status = ObReferenceObjectByHandle (ProcessHandle,
PROCESS_VM_OPERATION,
PsProcessType,
PreviousMode,
(PVOID *)&Process,
NULL);
if (!NT_SUCCESS(Status)) {
return Status;
}
//
// If the specified process is not the current process, attach
// to the specified process.
//
if (CurrentProcess != Process) {
KeStackAttachProcess (&Process->Pcb, &ApcState);
Attached = TRUE;
}
}
CommitReduction = 0;
//
// Get the address creation mutex to block multiple threads from
// creating or deleting address space at the same time and
// get the working set mutex so virtual address descriptors can
// be inserted and walked. Block APCs to prevent page faults while
// we own the working set mutex.
//
LOCK_ADDRESS_SPACE (Process);
//
// Make sure the address space was not deleted.
//
if (Process->Flags & PS_PROCESS_FLAGS_VM_DELETED) {
Status = STATUS_PROCESS_IS_TERMINATING;
goto ErrorReturn;
}
Vad = (PMMVAD_SHORT) MiLocateAddress (StartingAddress);
if (Vad == NULL) {
//
// No Virtual Address Descriptor located for Base Address.
//
Status = STATUS_MEMORY_NOT_ALLOCATED;
goto ErrorReturn;
}
//
// Found the associated Virtual Address Descriptor.
//
if (Vad->EndingVpn < MI_VA_TO_VPN (EndingAddress)) {
//
// The entire range to delete is not contained within a single
// virtual address descriptor. Return an error.
//
Status = STATUS_UNABLE_TO_FREE_VM;
goto ErrorReturn;
}
//
// Check to ensure this Vad is deletable. Delete is required
// for both decommit and release.
//
if (((Vad->u.VadFlags.PrivateMemory == 0) &&
(Vad->u.VadFlags.VadType != VadRotatePhysical))
||
(Vad->u.VadFlags.VadType == VadDevicePhysicalMemory)) {
Status = STATUS_UNABLE_TO_DELETE_SECTION;
goto ErrorReturn;
}
if (Vad->u.VadFlags.NoChange == 1) {
//
// An attempt is being made to delete a secured VAD, check
// to see if this deletion is allowed.
//
if (FreeType & MEM_RELEASE) {
//
// Specify the whole range, this solves the problem with
// splitting the VAD and trying to decide where the various
// secure ranges need to go.
//
Status = MiCheckSecuredVad ((PMMVAD)Vad,
MI_VPN_TO_VA (Vad->StartingVpn),
((Vad->EndingVpn - Vad->StartingVpn) << PAGE_SHIFT) +
PAGE_SIZE,
MM_SECURE_DELETE_CHECK);
}
else {
Status = MiCheckSecuredVad ((PMMVAD)Vad,
CapturedBase,
CapturedRegionSize,
MM_SECURE_DELETE_CHECK);
}
if (!NT_SUCCESS (Status)) {
goto ErrorReturn;
}
}
UserPhysicalPages = FALSE;
ChargedVad = NULL;
PreviousVad = MiGetPreviousVad (Vad);
NextVad = MiGetNextVad (Vad);
if (FreeType & MEM_RELEASE) {
//
// *****************************************************************
// MEM_RELEASE was specified.
// *****************************************************************
//
//
// The descriptor for the address range is deletable. Remove or split
// the descriptor.
//
//
// If the region size is zero, remove the whole VAD.
//
if (CapturedRegionSize == 0) {
//
// If the region size is specified as 0, the base address
// must be the starting address for the region.
//
if (MI_VA_TO_VPN (CapturedBase) != Vad->StartingVpn) {
Status = STATUS_FREE_VM_NOT_AT_BASE;
goto ErrorReturn;
}
//
// This Virtual Address Descriptor has been deleted.
//
StartingAddress = MI_VPN_TO_VA (Vad->StartingVpn);
EndingAddress = MI_VPN_TO_VA_ENDING (Vad->EndingVpn);
if (Vad->u.VadFlags.VadType == VadRotatePhysical) {
Status = MiUnmapViewOfSection (Process,
CapturedBase,
UNMAP_ADDRESS_SPACE_HELD | UNMAP_ROTATE_PHYSICAL_OK);
ASSERT (CommitReduction == 0);
Vad = NULL;
CapturedRegionSize = 1 + (PCHAR)EndingAddress - (PCHAR)StartingAddress;
goto AllDone;
}
//
// Free all the physical pages that this VAD might be mapping.
//
if (Vad->u.VadFlags.VadType == VadLargePages) {
MiAweViewRemover (Process, (PMMVAD)Vad);
MiReleasePhysicalCharges (Vad->EndingVpn - Vad->StartingVpn + 1,
Process);
LOCK_WS_UNSAFE (CurrentThread, Process);
MiFreeLargePages (MI_VPN_TO_VA (Vad->StartingVpn),
MI_VPN_TO_VA_ENDING (Vad->EndingVpn),
FALSE);
}
else if (Vad->u.VadFlags.VadType == VadAwe) {
MiAweViewRemover (Process, (PMMVAD)Vad);
MiRemoveUserPhysicalPagesVad (Vad);
UserPhysicalPages = TRUE;
LOCK_WS_UNSAFE (CurrentThread, Process);
}
else if (Vad->u.VadFlags.VadType == VadWriteWatch) {
LOCK_WS_UNSAFE (CurrentThread, Process);
MiPhysicalViewRemover (Process, (PMMVAD)Vad);
}
else {
LOCK_WS_UNSAFE (CurrentThread, Process);
}
ChargedVad = (PMMVAD)Vad;
MiRemoveVad ((PMMVAD)Vad, Process);
//
// Free the VAD pool and release quota after releasing our mutexes
// to reduce contention.
//
}
else {
//
// Region's size was not specified as zero, delete the
// whole VAD or split the VAD.
//
if (MI_VA_TO_VPN (StartingAddress) == Vad->StartingVpn) {
if (MI_VA_TO_VPN (EndingAddress) == Vad->EndingVpn) {
//
// This Virtual Address Descriptor has been deleted.
//
// Free all the physical pages that this VAD might be
// mapping.
//
if (Vad->u.VadFlags.VadType == VadRotatePhysical) {
Status = MiUnmapViewOfSection (Process,
CapturedBase,
UNMAP_ADDRESS_SPACE_HELD | UNMAP_ROTATE_PHYSICAL_OK);
ASSERT (CommitReduction == 0);
Vad = NULL;
CapturedRegionSize = 1 + (PCHAR)EndingAddress - (PCHAR)StartingAddress;
goto AllDone;
}
if (Vad->u.VadFlags.VadType == VadLargePages) {
MiAweViewRemover (Process, (PMMVAD)Vad);
MiReleasePhysicalCharges (Vad->EndingVpn - Vad->StartingVpn + 1,
Process);
LOCK_WS_UNSAFE (CurrentThread, Process);
MiFreeLargePages (MI_VPN_TO_VA (Vad->StartingVpn),
MI_VPN_TO_VA_ENDING (Vad->EndingVpn),
FALSE);
}
else if (Vad->u.VadFlags.VadType == VadAwe) {
MiAweViewRemover (Process, (PMMVAD)Vad);
MiRemoveUserPhysicalPagesVad (Vad);
UserPhysicalPages = TRUE;
LOCK_WS_UNSAFE (CurrentThread, Process);
}
else if (Vad->u.VadFlags.VadType == VadWriteWatch) {
LOCK_WS_UNSAFE (CurrentThread, Process);
MiPhysicalViewRemover (Process, (PMMVAD)Vad);
}
else {
LOCK_WS_UNSAFE (CurrentThread, Process);
}
ChargedVad = (PMMVAD)Vad;
MiRemoveVad ((PMMVAD)Vad, Process);
//
// Free the VAD pool after releasing our mutexes
// to reduce contention.
//
}
else {
if ((Vad->u.VadFlags.VadType == VadAwe) ||
(Vad->u.VadFlags.VadType == VadLargePages) ||
(Vad->u.VadFlags.VadType == VadRotatePhysical) ||
(Vad->u.VadFlags.VadType == VadWriteWatch)) {
//
// Splitting or chopping a physical VAD, large page VAD
// or a write-watch VAD is not allowed.
//
Status = STATUS_FREE_VM_NOT_AT_BASE;
goto ErrorReturn;
}
LOCK_WS_UNSAFE (CurrentThread, Process);
//
// This Virtual Address Descriptor has a new starting
// address.
//
CommitReduction = MiCalculatePageCommitment (
StartingAddress,
EndingAddress,
(PMMVAD)Vad,
Process);
Vad->StartingVpn = MI_VA_TO_VPN ((PCHAR)EndingAddress + 1);
Vad->u.VadFlags.CommitCharge -= CommitReduction;
ASSERT ((SSIZE_T)Vad->u.VadFlags.CommitCharge >= 0);
NextVad = (PMMVAD)Vad;
Vad = NULL;
}
}
else {
if ((Vad->u.VadFlags.VadType == VadAwe) ||
(Vad->u.VadFlags.VadType == VadLargePages) ||
(Vad->u.VadFlags.VadType == VadRotatePhysical) ||
(Vad->u.VadFlags.VadType == VadWriteWatch)) {
//
// Splitting or chopping a physical VAD, large page VAD
// or a write-watch VAD is not allowed.
//
Status = STATUS_FREE_VM_NOT_AT_BASE;
goto ErrorReturn;
}
//
// Starting address is greater than start of VAD.
//
if (MI_VA_TO_VPN (EndingAddress) == Vad->EndingVpn) {
//
// Change the ending address of the VAD.
//
LOCK_WS_UNSAFE (CurrentThread, Process);
CommitReduction = MiCalculatePageCommitment (
StartingAddress,
EndingAddress,
(PMMVAD)Vad,
Process);
Vad->u.VadFlags.CommitCharge -= CommitReduction;
Vad->EndingVpn = MI_VA_TO_VPN ((PCHAR)StartingAddress - 1);
PreviousVad = (PMMVAD)Vad;
}
else {
//
// Split this VAD as the address range is within the VAD.
//
NewVad = ExAllocatePoolWithTag (NonPagedPool,
sizeof(MMVAD_SHORT),
'FdaV');
if (NewVad == NULL) {
Status = STATUS_INSUFFICIENT_RESOURCES;
goto ErrorReturn;
}
*NewVad = *Vad;
NewVad->StartingVpn = MI_VA_TO_VPN ((PCHAR)EndingAddress + 1);
//
// Set the commit charge to zero so MiInsertVad will
// not charge commitment for splitting the VAD.
//
NewVad->u.VadFlags.CommitCharge = 0;
//
// Insert the VAD, this could fail due to quota charges.
//
Status = MiInsertVadCharges ((PMMVAD)NewVad, Process);
if (!NT_SUCCESS(Status)) {
//
// The quota charging failed, free the new VAD
// and return an error.
//
UNLOCK_ADDRESS_SPACE (Process);
ExFreePool (NewVad);
goto ErrorReturn2;
}
LOCK_WS_UNSAFE (CurrentThread, Process);
CommitReduction = MiCalculatePageCommitment (
StartingAddress,
EndingAddress,
(PMMVAD)Vad,
Process);
OldQuota = Vad->u.VadFlags.CommitCharge - CommitReduction;
Vad->EndingVpn = MI_VA_TO_VPN ((PCHAR)StartingAddress - 1);
MiInsertVad ((PMMVAD)NewVad, Process);
//
// As we have split the original VAD into 2 separate VADs
// there is no way of knowing what the commit charge
// is for each VAD. Calculate the charge and reset
// each VAD. Note that we also use the previous value
// to make sure the books stay balanced.
//
QuotaCharge = MiCalculatePageCommitment (MI_VPN_TO_VA (Vad->StartingVpn),
(PCHAR)StartingAddress - 1,
(PMMVAD)Vad,
Process);
Vad->u.VadFlags.CommitCharge = QuotaCharge;
//
// Give the remaining charge to the new VAD.
//
NewVad->u.VadFlags.CommitCharge = OldQuota - QuotaCharge;
PreviousVad = (PMMVAD)Vad;
NextVad = (PMMVAD)NewVad;
}
Vad = NULL;
}
}
if (UserPhysicalPages == TRUE) {
MiDeletePageTablesForPhysicalRange (StartingAddress, EndingAddress);
}
else {
MiDeleteVirtualAddresses (StartingAddress,
EndingAddress,
NULL);
}
UNLOCK_WS_UNSAFE (CurrentThread, Process);
//
// Return commitment for page table pages if possible.
//
MiReturnPageTablePageCommitment (StartingAddress,
EndingAddress,
Process,
PreviousVad,
NextVad);
if (ChargedVad != NULL) {
MiRemoveVadCharges (ChargedVad, Process);
}
CapturedRegionSize = 1 + (PCHAR)EndingAddress - (PCHAR)StartingAddress;
//
// Update the virtual size in the process header.
//
Process->VirtualSize -= CapturedRegionSize;
Process->CommitCharge -= CommitReduction;
Status = STATUS_SUCCESS;
AllDone:
UNLOCK_ADDRESS_SPACE (Process);
if (CommitReduction != 0) {
MI_INCREMENT_TOTAL_PROCESS_COMMIT (0 - CommitReduction);
ASSERT (Vad == NULL);
PsReturnProcessPageFileQuota (Process, CommitReduction);
MiReturnCommitment (CommitReduction);
if (Process->JobStatus & PS_JOB_STATUS_REPORT_COMMIT_CHANGES) {
PsChangeJobMemoryUsage (PS_JOB_STATUS_REPORT_COMMIT_CHANGES, -(SSIZE_T)CommitReduction);
}
MM_TRACK_COMMIT (MM_DBG_COMMIT_RETURN_NTFREEVM1, CommitReduction);
}
else if (Vad != NULL) {
ExFreePool (Vad);
}
if (Attached == TRUE) {
KeUnstackDetachProcess (&ApcState);
}
if (ProcessHandle != NtCurrentProcess ()) {
ObDereferenceObject (Process);
}
//
// Establish an exception handler and write the size and base
// address.
//
try {
*RegionSize = CapturedRegionSize;
*BaseAddress = StartingAddress;
}
except (EXCEPTION_EXECUTE_HANDLER) {
//
// An exception occurred, don't take any action (just handle
// the exception and return success.
}
return Status;
}
//
// **************************************************************
//
// MEM_DECOMMIT was specified.
//
// **************************************************************
//
if (Vad->u.VadFlags.VadType == VadAwe) {
//
// Pages from a physical VAD must be released via
// NtFreeUserPhysicalPages, not this routine.
//
Status = STATUS_MEMORY_NOT_ALLOCATED;
goto ErrorReturn;
}
if ((Vad->u.VadFlags.VadType == VadLargePages) ||
(Vad->u.VadFlags.VadType == VadRotatePhysical)) {
//
// Pages from a large page or rotate physical VAD must be released -
// they cannot be merely decommitted.
//
Status = STATUS_MEMORY_NOT_ALLOCATED;
goto ErrorReturn;
}
//
// Check to ensure the complete range of pages is already committed.
//
if (CapturedRegionSize == 0) {
if (MI_VA_TO_VPN (CapturedBase) != Vad->StartingVpn) {
Status = STATUS_FREE_VM_NOT_AT_BASE;
goto ErrorReturn;
}
EndingAddress = MI_VPN_TO_VA_ENDING (Vad->EndingVpn);
}
//
// The address range is entirely committed, decommit it now.
//
//
// Calculate the initial quotas and commit charges for this VAD.
//
StartingPte = MiGetPteAddress (StartingAddress);
EndingPte = MiGetPteAddress (EndingAddress);
CommitReduction = 1 + EndingPte - StartingPte;
//
// Check to see if the entire range can be decommitted by
// just updating the virtual address descriptor.
//
CommitReduction -= MiDecommitPages (StartingAddress,
EndingPte,
Process,
Vad);
//
// Adjust the quota charges.
//
ASSERT ((LONG)CommitReduction >= 0);
Vad->u.VadFlags.CommitCharge -= CommitReduction;
ASSERT ((LONG)Vad->u.VadFlags.CommitCharge >= 0);
Vad = NULL;
Process->CommitCharge -= CommitReduction;
UNLOCK_ADDRESS_SPACE (Process);
if (CommitReduction != 0) {
MI_INCREMENT_TOTAL_PROCESS_COMMIT (0 - CommitReduction);
PsReturnProcessPageFileQuota (Process, CommitReduction);
MiReturnCommitment (CommitReduction);
if (Process->JobStatus & PS_JOB_STATUS_REPORT_COMMIT_CHANGES) {
PsChangeJobMemoryUsage (PS_JOB_STATUS_REPORT_COMMIT_CHANGES, -(SSIZE_T)CommitReduction);
}
MM_TRACK_COMMIT (MM_DBG_COMMIT_RETURN_NTFREEVM2, CommitReduction);
}
else if (Vad != NULL) {
ExFreePool (Vad);
}
if (Attached == TRUE) {
KeUnstackDetachProcess (&ApcState);
}
if (ProcessHandle != NtCurrentProcess()) {
ObDereferenceObject (Process);
}
//
// Establish an exception handler and write the size and base address.
//
try {
*RegionSize = 1 + (PCHAR)EndingAddress - (PCHAR)StartingAddress;
*BaseAddress = StartingAddress;
}
except (EXCEPTION_EXECUTE_HANDLER) {
NOTHING;
}
return STATUS_SUCCESS;
ErrorReturn:
UNLOCK_ADDRESS_SPACE (Process);
ErrorReturn2:
if (Attached == TRUE) {
KeUnstackDetachProcess (&ApcState);
}
if (ProcessHandle != NtCurrentProcess()) {
ObDereferenceObject (Process);
}
return Status;
}
NTSTATUS
NtFreeVirtualMemory(
IN HANDLE ProcessHandle,
IN OUT PVOID *BaseAddress,
IN OUT PULONG RegionSize,
IN ULONG FreeType
)
/*++
Routine Description:
This function deletes a region of pages within the virtual address
space of a subject process.
Arguments:
ProcessHandle - An open handle to a process object.
BaseAddress - The base address of the region of pages
to be freed. This value is rounded down to the
next host page address boundary.
RegionSize - A pointer to a variable that will receive
the actual size in bytes of the freed region of
pages. The initial value of this argument is
rounded up to the next host page size boundary.
FreeType - A set of flags that describe the type of
free that is to be performed for the specified
region of pages.
FreeType Flags
MEM_DECOMMIT - The specified region of pages is to
be decommitted.
MEM_RELEASE - The specified region of pages is to
be released.
Return Value:
Returns the status
TBS
--*/
{
PMMVAD_SHORT Vad;
PMMVAD_SHORT NewVad;
PMMVAD PreviousVad;
PMMVAD NextVad;
PEPROCESS Process;
KPROCESSOR_MODE PreviousMode;
PVOID StartingAddress;
PVOID EndingAddress;
NTSTATUS Status;
ULONG Attached = FALSE;
ULONG CapturedRegionSize;
PVOID CapturedBase;
PMMPTE StartingPte;
PMMPTE EndingPte;
ULONG OldQuota;
ULONG QuotaCharge;
ULONG CommitReduction;
PVOID OldEnd;
PAGED_CODE();
//
// Check to make sure FreeType is good.
//
if ((FreeType & ~(MEM_DECOMMIT | MEM_RELEASE)) != 0) {
return STATUS_INVALID_PARAMETER_4;
}
//
// One of MEM_DECOMMIT or MEM_RELEASE must be specified, but not both.
//
if (((FreeType & (MEM_DECOMMIT | MEM_RELEASE)) == 0) ||
((FreeType & (MEM_DECOMMIT | MEM_RELEASE)) ==
(MEM_DECOMMIT | MEM_RELEASE))) {
return STATUS_INVALID_PARAMETER_4;
}
PreviousMode = KeGetPreviousMode();
//
// Establish an exception handler, probe the specified addresses
// for write access and capture the initial values.
//
try {
if (PreviousMode != KernelMode) {
ProbeForWriteUlong ((PULONG)BaseAddress);
ProbeForWriteUlong (RegionSize);
}
//
// Capture the base address.
//
CapturedBase = *BaseAddress;
//
// Capture the region size.
//
CapturedRegionSize = *RegionSize;
} except (ExSystemExceptionFilter()) {
//
// If an exception occurs during the probe or capture
// of the initial values, then handle the exception and
// return the exception code as the status value.
//
return GetExceptionCode();
}
#if DBG
if (MmDebug & MM_DBG_SHOW_NT_CALLS) {
if ( !MmWatchProcess ) {
DbgPrint("freevm processhandle %lx base %lx size %lx type %lx\n",
ProcessHandle, CapturedBase, CapturedRegionSize, FreeType);
}
}
#endif
//
// Make sure the specified starting and ending addresses are
// within the user part of the virtual address space.
//
if (CapturedBase > MM_HIGHEST_USER_ADDRESS) {
//
// Invalid base address.
//
return STATUS_INVALID_PARAMETER_2;
}
if ((ULONG)MM_HIGHEST_USER_ADDRESS - (ULONG)CapturedBase <
CapturedRegionSize) {
//
// Invalid region size;
//
return STATUS_INVALID_PARAMETER_3;
}
EndingAddress = (PVOID)(((ULONG)CapturedBase + CapturedRegionSize - 1) |
(PAGE_SIZE - 1));
StartingAddress = (PVOID)PAGE_ALIGN(CapturedBase);
if ( ProcessHandle == NtCurrentProcess() ) {
Process = PsGetCurrentProcess();
} else {
//
// Reference the specified process handle for VM_OPERATION access.
//
Status = ObReferenceObjectByHandle ( ProcessHandle,
PROCESS_VM_OPERATION,
PsProcessType,
PreviousMode,
(PVOID *)&Process,
NULL );
if (!NT_SUCCESS(Status)) {
return Status;
}
}
//
// If the specified process is not the current process, attach
// to the specified process.
//
if (PsGetCurrentProcess() != Process) {
KeAttachProcess (&Process->Pcb);
Attached = TRUE;
}
//
// Get the address creation mutex to block multiple threads from
// creating or deleting address space at the same time and
// get the working set mutex so virtual address descriptors can
// be inserted and walked. Block APCs to prevent page faults while
// we own the working set mutex.
//
LOCK_WS_AND_ADDRESS_SPACE (Process);
//
// Make sure the address space was not deleted.
//
if (Process->AddressSpaceDeleted != 0) {
Status = STATUS_PROCESS_IS_TERMINATING;
goto ErrorReturn;
}
Vad = (PMMVAD_SHORT)MiLocateAddress (StartingAddress);
if (Vad == NULL) {
//
// No Virtual Address Descriptor located for Base Address.
//
Status = STATUS_MEMORY_NOT_ALLOCATED;
goto ErrorReturn;
}
//
// Found the associated Virtual Address Descriptor.
//
if (Vad->EndingVa < EndingAddress) {
//
// The entire range to delete is not contained within a single
// virtual address descriptor. Return an error.
//
Status = STATUS_UNABLE_TO_FREE_VM;
goto ErrorReturn;
}
//
// Check to ensure this Vad is deletable. Delete is required
// for both decommit and release.
//
if ((Vad->u.VadFlags.PrivateMemory == 0) ||
(Vad->u.VadFlags.PhysicalMapping == 1)) {
Status = STATUS_UNABLE_TO_DELETE_SECTION;
goto ErrorReturn;
}
if (Vad->u.VadFlags.NoChange == 1) {
//
// An attempt is being made to delete a secured VAD, check
// to see if this deletion is allowed.
//
if (FreeType & MEM_RELEASE) {
//
// Specifiy the whole range, this solves the problem with
// splitting the VAD and trying to decide where the various
// secure ranges need to go.
//
Status = MiCheckSecuredVad ((PMMVAD)Vad,
Vad->StartingVa,
(PCHAR)Vad->EndingVa - (PCHAR)Vad->StartingVa,
MM_SECURE_DELETE_CHECK);
} else {
Status = MiCheckSecuredVad ((PMMVAD)Vad,
CapturedBase,
CapturedRegionSize,
MM_SECURE_DELETE_CHECK);
}
if (!NT_SUCCESS (Status)) {
goto ErrorReturn;
}
}
PreviousVad = MiGetPreviousVad (Vad);
NextVad = MiGetNextVad (Vad);
if (FreeType & MEM_RELEASE) {
//
// *****************************************************************
// MEM_RELEASE was specified.
// *****************************************************************
//
//
// The descriptor for the address range is deletable. Remove or split
// the descriptor.
//
//
// If the region size is zero, remove the whole VAD.
//
if (CapturedRegionSize == 0) {
//
// If the region size is specified as 0, the base address
// must be the starting address for the region.
//
if (CapturedBase != Vad->StartingVa) {
Status = STATUS_FREE_VM_NOT_AT_BASE;
goto ErrorReturn;
}
//
// This Virtual Address Descriptor has been deleted.
//
StartingAddress = Vad->StartingVa;
EndingAddress = Vad->EndingVa;
MiRemoveVad ((PMMVAD)Vad);
ExFreePool (Vad);
} else {
//
// Regions size was not specified as zero, delete the
// whole VAD or split the VAD.
//
if (StartingAddress == Vad->StartingVa) {
if (EndingAddress == Vad->EndingVa) {
//
// This Virtual Address Descriptor has been deleted.
//
MiRemoveVad ((PMMVAD)Vad);
ExFreePool (Vad);
} else {
//
// This Virtual Address Descriptor has a new starting
// address.
//
CommitReduction = MiCalculatePageCommitment (
StartingAddress,
EndingAddress,
(PMMVAD)Vad,
Process );
Vad->StartingVa = (PVOID)((ULONG)EndingAddress + 1L);
Vad->u.VadFlags.CommitCharge -= CommitReduction;
ASSERT ((LONG)Vad->u.VadFlags.CommitCharge >= 0);
MiReturnPageFileQuota (CommitReduction, Process);
MiReturnCommitment (CommitReduction);
Process->CommitCharge -= CommitReduction;
PreviousVad = (PMMVAD)Vad;
}
} else {
//
// Starting address is greater than start of VAD.
//
if (EndingAddress == Vad->EndingVa) {
//
// Change the ending address of the VAD.
//
CommitReduction = MiCalculatePageCommitment (
StartingAddress,
EndingAddress,
(PMMVAD)Vad,
Process );
Vad->u.VadFlags.CommitCharge -= CommitReduction;
MiReturnPageFileQuota (CommitReduction, Process);
MiReturnCommitment (CommitReduction);
Process->CommitCharge -= CommitReduction;
Vad->EndingVa = (PVOID)((ULONG)StartingAddress - 1L);
PreviousVad = (PMMVAD)Vad;
} else {
//
// Split this VAD as the address range is within the VAD.
//
//
// Allocate an new VAD under an exception handler
// as there may not be enough quota.
//
NewVad = ExAllocatePoolWithTag (NonPagedPool,
sizeof(MMVAD_SHORT),
'SdaV');
if ( NewVad == NULL ) {
Status = STATUS_INSUFFICIENT_RESOURCES;
goto ErrorReturn;
}
CommitReduction = MiCalculatePageCommitment (
StartingAddress,
EndingAddress,
(PMMVAD)Vad,
Process );
OldQuota = Vad->u.VadFlags.CommitCharge - CommitReduction;
OldEnd = Vad->EndingVa;
*NewVad = *Vad;
Vad->EndingVa = (PVOID)((ULONG)StartingAddress - 1L);
NewVad->StartingVa = (PVOID)((ULONG)EndingAddress + 1L);
//
// Set the commit charge to zero so MiInsertVad will
// not charge committment for splitting the VAD.
//
NewVad->u.VadFlags.CommitCharge = 0;
try {
//
// Insert the VAD, this could get an exception
// on charging quota.
//
MiInsertVad ((PMMVAD)NewVad);
} except (EXCEPTION_EXECUTE_HANDLER) {
//
// Inserting the Vad failed, reset the original
// VAD, free new vad and return an error.
//
Vad->EndingVa = OldEnd;
ExFreePool (NewVad);
Status = GetExceptionCode();
goto ErrorReturn;
}
Vad->u.VadFlags.CommitCharge -= CommitReduction;
MiReturnPageFileQuota (CommitReduction, Process);
MiReturnCommitment (CommitReduction);
Process->CommitCharge -= CommitReduction;
//
// As we have split the original VAD into 2 seperate VADs
// there is know way of knowing what the commit charge
// is for each VAD. Calculate the charge and reset
// each VAD. Note that we also use the previous value
// to make sure the books stay balanced.
//
QuotaCharge = MiCalculatePageCommitment (Vad->StartingVa,
Vad->EndingVa,
(PMMVAD)Vad,
Process );
Vad->u.VadFlags.CommitCharge = QuotaCharge;
//
// Give the remaining charge to the new VAD.
//
NewVad->u.VadFlags.CommitCharge = OldQuota - QuotaCharge;
PreviousVad = (PMMVAD)Vad;
NextVad = (PMMVAD)NewVad;
}
}
}
//
// Return commitment for page table pages if possibible.
//
MiReturnPageTablePageCommitment (StartingAddress,
EndingAddress,
Process,
PreviousVad,
NextVad);
//
// Get the PFN mutex so the MiDeleteVirtualAddresses can be called.
//
MiDeleteFreeVm (StartingAddress, EndingAddress);
UNLOCK_WS (Process);
CapturedRegionSize = 1 + (ULONG)EndingAddress - (ULONG)StartingAddress;
//
// Update the virtual size in the process header.
//
Process->VirtualSize -= CapturedRegionSize;
UNLOCK_ADDRESS_SPACE (Process);
if (Attached) {
KeDetachProcess();
}
if ( ProcessHandle != NtCurrentProcess() ) {
ObDereferenceObject (Process);
}
//
// Establish an exception handler and write the size and base
// address.
//
try {
*RegionSize = CapturedRegionSize;
*BaseAddress = StartingAddress;
} except (EXCEPTION_EXECUTE_HANDLER) {
//
// An exception occurred, don't take any action (just handle
// the exception and return success.
}
#if DBG
if (MmDebug & MM_DBG_SHOW_NT_CALLS) {
if ( MmWatchProcess ) {
if ( MmWatchProcess == PsGetCurrentProcess() ) {
DbgPrint("\n--- FREE Type 0x%lx Base %lx Size %lx\n",
FreeType, StartingAddress, CapturedRegionSize);
MmFooBar();
}
}
}
#endif
#if DBG
if (RtlAreLogging( RTL_EVENT_CLASS_VM )) {
RtlLogEvent( MiFreeVmEventId,
RTL_EVENT_CLASS_VM,
StartingAddress,
CapturedRegionSize,
FreeType
);
}
#endif // DBG
return STATUS_SUCCESS;
}
//
// **************************************************************
//
// MEM_DECOMMIT was specified.
//
// **************************************************************
//
//
// Check to ensure the complete range of pages is already committed.
//
if (CapturedRegionSize == 0) {
if (CapturedBase != Vad->StartingVa) {
Status = STATUS_FREE_VM_NOT_AT_BASE;
goto ErrorReturn;
}
EndingAddress = Vad->EndingVa;
}
#if 0
if (FreeType & MEM_CHECK_COMMIT_STATE) {
if ( !MiIsEntireRangeCommitted(StartingAddress,
EndingAddress,
Vad,
Process)) {
//
// The entire range to be decommited is not committed,
// return an errror.
//
Status = STATUS_UNABLE_TO_DECOMMIT_VM;
goto ErrorReturn;
}
}
#endif //0
//
// The address range is entirely committed, decommit it now.
//
//
// Calculate the initial quotas and commit charges for this VAD.
//
StartingPte = MiGetPteAddress (StartingAddress);
EndingPte = MiGetPteAddress (EndingAddress);
CommitReduction = 1 + EndingPte - StartingPte;
//
// Check to see if the entire range can be decommitted by
// just updating the virtual address descriptor.
//
CommitReduction -= MiDecommitPages (StartingAddress,
EndingPte,
Process,
Vad);
//
// Adjust the quota charges.
//
ASSERT ((LONG)CommitReduction >= 0);
MiReturnPageFileQuota (CommitReduction, Process);
MiReturnCommitment (CommitReduction);
Vad->u.VadFlags.CommitCharge -= CommitReduction;
Process->CommitCharge -= CommitReduction;
ASSERT ((LONG)Vad->u.VadFlags.CommitCharge >= 0);
UNLOCK_WS (Process);
UNLOCK_ADDRESS_SPACE (Process);
if (Attached) {
KeDetachProcess();
}
if ( ProcessHandle != NtCurrentProcess() ) {
ObDereferenceObject (Process);
}
//
// Establish an exception handler and write the size and base
// address.
//
try {
*RegionSize = 1 + (ULONG)EndingAddress - (ULONG)StartingAddress;
*BaseAddress = StartingAddress;
} except (EXCEPTION_EXECUTE_HANDLER) {
NOTHING;
}
#if DBG
if (RtlAreLogging( RTL_EVENT_CLASS_VM )) {
RtlLogEvent( MiFreeVmEventId,
RTL_EVENT_CLASS_VM,
StartingAddress,
1 + (ULONG)EndingAddress - (ULONG)StartingAddress,
FreeType
);
}
#endif // DBG
return STATUS_SUCCESS;
ErrorReturn:
UNLOCK_WS (Process);
UNLOCK_ADDRESS_SPACE (Process);
if (Attached) {
KeDetachProcess();
}
if ( ProcessHandle != NtCurrentProcess() ) {
ObDereferenceObject (Process);
}
return Status;
}