NTSTATUS DumpKernelMemory(PVOID DstAddr, PVOID SrcAddr, ULONG Size)
{
    PMDL  pSrcMdl, pDstMdl;
    PUCHAR pAddress, pDstAddress;
    NTSTATUS st = STATUS_UNSUCCESSFUL;
    ULONG r;

	// Создаем MDL для буфера-источника
    pSrcMdl = IoAllocateMdl(SrcAddr, Size, FALSE, FALSE, NULL);

	if (pSrcMdl)
	{
		// Построение MDL
		MmBuildMdlForNonPagedPool(pSrcMdl);
		// Получение адреса из MDL
		pAddress = (PUCHAR)MmGetSystemAddressForMdlSafe(pSrcMdl, NormalPagePriority);
		zDbgPrint("pAddress = %x", pAddress);
		if (pAddress != NULL)
		{
			pDstMdl = IoAllocateMdl(DstAddr, Size, FALSE, FALSE, NULL);
			zDbgPrint("pDstMdl = %x", pDstMdl);
			if (pDstMdl != NULL)
			{
				__try
				{
					MmProbeAndLockPages(pDstMdl, KernelMode, IoWriteAccess);
					pDstAddress = (PUCHAR)MmGetSystemAddressForMdlSafe(pDstMdl, NormalPagePriority);
					zDbgPrint("pDstAddress = %x", pDstAddress);
					if (pDstAddress != NULL)
					{
						memset(pDstAddress, 0, Size);
						zDbgPrint("Copy block");
						for (r = 1; r < Size; r++)
						{
							if (MmIsAddressValid(pAddress)) 
								*pDstAddress = *pAddress;
							else
								*pDstAddress = 0;
							pAddress++;
							pDstAddress++;
						}

						st = STATUS_SUCCESS;
					}

					MmUnlockPages(pDstMdl);
				}
				__except(EXCEPTION_EXECUTE_HANDLER)
				{    
					zDbgPrint("Copy block exception");
				}
				IoFreeMdl(pDstMdl);
			}
		}            

PMDL
Ext2CreateMdl (
    IN PVOID Buffer,
    IN BOOLEAN bPaged,
    IN ULONG Length,
    IN LOCK_OPERATION Operation
)
{
    NTSTATUS Status;
    PMDL Mdl = NULL;

    ASSERT (Buffer != NULL);
    Mdl = IoAllocateMdl (Buffer, Length, FALSE, FALSE, NULL);
    if (Mdl == NULL) {
        Status = STATUS_INSUFFICIENT_RESOURCES;
    } else {
        __try {
            if (bPaged) {
                MmProbeAndLockPages(Mdl, KernelMode, Operation);
            } else {
                MmBuildMdlForNonPagedPool (Mdl);
            }
            Status = STATUS_SUCCESS;
        } __except (EXCEPTION_EXECUTE_HANDLER) {
            IoFreeMdl (Mdl);
            Mdl = NULL;
            DbgBreak();
            Status = STATUS_INVALID_USER_BUFFER;
        }
    }
    return Mdl;
}

NTSTATUS
Ext2LockUserBuffer (IN PIRP     Irp,
                    IN ULONG            Length,
                    IN LOCK_OPERATION   Operation)
{
    NTSTATUS Status;
    ASSERT(Irp != NULL);

    if (Irp->MdlAddress != NULL) {
        return STATUS_SUCCESS;
    }

    IoAllocateMdl(Irp->UserBuffer, Length, FALSE, FALSE, Irp);
    if (Irp->MdlAddress == NULL) {
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    __try {

        MmProbeAndLockPages(Irp->MdlAddress, Irp->RequestorMode, Operation);
        Status = STATUS_SUCCESS;

    } __except (EXCEPTION_EXECUTE_HANDLER) {

        DbgBreak();
        IoFreeMdl(Irp->MdlAddress);
        Irp->MdlAddress = NULL;
        Status = STATUS_INVALID_USER_BUFFER;
    }

    return Status;
}

NTSTATUS
	TdiQueryAddress(
		PFILE_OBJECT		AddressObject, 
		PTDI_ADDRESS_INFO	AddressInfo,
		PULONG				pInfoLength
		)
{
	NTSTATUS	ntStatus;
	PIRP		Irp;
	PMDL		Mdl;
    PDEVICE_OBJECT	DeviceObject = IoGetRelatedDeviceObject(AddressObject);
    IO_STATUS_BLOCK IoStatus;

    if (!(Irp = TdiBuildInternalDeviceControlIrp(TDI_QUERY_INFORMATION, DeviceObject, FileObject, NULL, &IoStatus)))
		return STATUS_INSUFFICIENT_RESOURCES;

	if (!(Mdl = IoAllocateMdl(AddressInfo, *pInfoLength, FALSE, FALSE, Irp)))
	{
		IoFreeIrp(Irp);
		return STATUS_INSUFFICIENT_RESOURCES;
	}

	MmProbeAndLockPages(Mdl, KernelMode, IoModifyAccess);

    TdiBuildQueryInformation(Irp, DeviceObject, AddressObject, NULL, NULL, TDI_QUERY_ADDRESS_INFO, Mdl);

    ntStatus = IoCallDriver(DeviceObject, Irp);

    return(ntStatus == STATUS_SUCCESS ? IoStatus.Status : ntStatus);

}

//
// file local helper functions.
//
NTSTATUS
InitScratchpad(
    IN PUSB_FDO_CONTEXT fdoContext)
{
    NTSTATUS status;
    KeInitializeEvent(&fdoContext->ScratchPad.CompletionEvent, NotificationEvent, FALSE);
    
    fdoContext->ScratchPad.Buffer = ExAllocatePoolWithTag(NonPagedPool, PAGE_SIZE, XVU1);
    if (!fdoContext->ScratchPad.Buffer)
    {
            status =  STATUS_NO_MEMORY;
            TraceEvents(TRACE_LEVEL_ERROR, TRACE_DEVICE,
                __FUNCTION__": Device %p ExAllocatePoolWithTag failed\n",
                fdoContext->WdfDevice);
            return status;
    }
    RtlZeroMemory(fdoContext->ScratchPad.Buffer, PAGE_SIZE);

    fdoContext->ScratchPad.Mdl = IoAllocateMdl(fdoContext->ScratchPad.Buffer,
        PAGE_SIZE,
        FALSE,
        FALSE,
        NULL);
    if (!fdoContext->ScratchPad.Mdl)
    {
        status =  STATUS_NO_MEMORY;
        TraceEvents(TRACE_LEVEL_ERROR, TRACE_DEVICE,
            __FUNCTION__": device %p IoAllocateMdl failed\n",
            fdoContext->WdfDevice);
        return status;
    }
    MmBuildMdlForNonPagedPool(fdoContext->ScratchPad.Mdl);

    return STATUS_SUCCESS;
}

NTSTATUS ChangeServiceTableMemoryFlags()
{
	// Map the memory into our domain and change the permissions on the memory page by using a MDL
	g_MappedSystemCallTableMDL = IoAllocateMdl(	KeServiceDescriptorTable.ServiceTableBase,		// starting virtual address
												KeServiceDescriptorTable.NumberOfServices*4,	// size of buffer
												FALSE,											// not associated with an IRP
												FALSE,											// charge quota, should be FALSE
												NULL											// IRP * should be NULL
												);
	if(!g_MappedSystemCallTableMDL)
	{
		DbgPrint("MDL could not be allocated...");
		return STATUS_UNSUCCESSFUL;
	}
	else
	{
		DbgPrint("The MDL is at 0x%x\n", g_MappedSystemCallTableMDL);
	}

	// MmBuildMdlForNonPagedPool fills in the corresponding physical page array 
	// of a given MDL for a buffer in nonpaged system space (pool).
	MmBuildMdlForNonPagedPool(g_MappedSystemCallTableMDL);
	// MDL's are supposed to be opaque, but this is the only way we know of getting to these flags...
	g_MappedSystemCallTableMDL->MdlFlags = g_MappedSystemCallTableMDL->MdlFlags | MDL_MAPPED_TO_SYSTEM_VA;
	// finish off the mapping...
	g_MappedSystemCallTable = MmMapLockedPages(g_MappedSystemCallTableMDL, KernelMode);

	return STATUS_SUCCESS;
}

NTSTATUS tdi_recv_stream(PFILE_OBJECT connectionFileObject, char *buf, int len, ULONG flags)
{
    PDEVICE_OBJECT  devObj;
    KEVENT          event;
    PIRP            irp;
    PMDL            mdl;
    IO_STATUS_BLOCK iosb;
    NTSTATUS        status;

    devObj = IoGetRelatedDeviceObject(connectionFileObject);

    KeInitializeEvent(&event, NotificationEvent, FALSE);

    irp = TdiBuildInternalDeviceControlIrp(TDI_RECEIVE, devObj, connectionFileObject, &event, &iosb);

    if (irp == NULL)
    {
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    if (len)
    {
        mdl = IoAllocateMdl((void*) buf, len, FALSE, FALSE, NULL);

        if (mdl == NULL)
        {
            IoFreeIrp(irp);
            return STATUS_INSUFFICIENT_RESOURCES;
        }

        __try
        {
            MmProbeAndLockPages(mdl, KernelMode, IoWriteAccess);
            status = STATUS_SUCCESS;
        }
        __except (EXCEPTION_EXECUTE_HANDLER)
        {
            IoFreeMdl(mdl);
            IoFreeIrp(irp);
            status = STATUS_INVALID_USER_BUFFER;
        }

        if (!NT_SUCCESS(status))
        {
            return status;
        }
    }

    TdiBuildReceive(irp, devObj, connectionFileObject, NULL, NULL, len ? mdl : 0, flags, len);

    status = IoCallDriver(devObj, irp);

    if (status == STATUS_PENDING)
    {
        KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);
        status = iosb.Status;
    }

    return NT_SUCCESS(status) ? iosb.Information : status;
}

/*
* TsmiHandleMemWrite
*
* Purpose:
*
* Patch vbox dll in memory.
*
* Warning: potential BSOD-generator due to nonstandard way of loading, take care with patch offsets.
*
*/
NTSTATUS TsmiHandleMemWrite(
    _In_ PVOID SrcAddress,
    _In_ PVOID DestAddress,
    _In_ ULONG Size
)
{
    PMDL        mdl;
    NTSTATUS    status = STATUS_SUCCESS;

    PAGED_CODE();

    mdl = IoAllocateMdl(DestAddress, Size, FALSE, FALSE, NULL);
    if (mdl == NULL) {
        return STATUS_INSUFFICIENT_RESOURCES;
    }
    if (DestAddress >= MmSystemRangeStart)
        if (!MmIsAddressValid(DestAddress)) {
            return STATUS_ACCESS_VIOLATION;
        }
    MmProbeAndLockPages(mdl, KernelMode, IoReadAccess);
    DestAddress = MmGetSystemAddressForMdlSafe(mdl, HighPagePriority);
    if (DestAddress != NULL) {
        status = MmProtectMdlSystemAddress(mdl, PAGE_EXECUTE_READWRITE);
        __movsb((PUCHAR)DestAddress, (const UCHAR *)SrcAddress, Size);
        MmUnmapLockedPages(DestAddress, mdl);
        MmUnlockPages(mdl);
    }
    else {
        status = STATUS_ACCESS_VIOLATION;
    }

    IoFreeMdl(mdl);
    return status;
}

NTSTATUS
InitWskBuffer(
	__in  PVOID		Buffer,
	__in  ULONG		BufferSize,
	__out PWSK_BUF	WskBuffer
)
{
	NTSTATUS Status = STATUS_SUCCESS;

	ASSERT(Buffer);
	ASSERT(BufferSize);
	ASSERT(WskBuffer);

	WskBuffer->Offset = 0;
	WskBuffer->Length = BufferSize;

	WskBuffer->Mdl = IoAllocateMdl(Buffer, BufferSize, FALSE, FALSE, NULL);
	if (!WskBuffer->Mdl) {
		return STATUS_INSUFFICIENT_RESOURCES;
	}

    try {
	    MmProbeAndLockPages(WskBuffer->Mdl, KernelMode, IoWriteAccess);
    } except(EXCEPTION_EXECUTE_HANDLER) {
        if (WskBuffer->Mdl != NULL) {
            IoFreeMdl(WskBuffer->Mdl);
        }
        WDRBD_ERROR("MmProbeAndLockPages failed. exception code=0x%x\n", GetExceptionCode());
        return STATUS_INSUFFICIENT_RESOURCES;
    }
	return Status;
}

static
PVOID
MapAndLockUserBuffer(
    _In_ _Out_ PIRP Irp,
    _In_ ULONG BufferLength)
{
    PMDL Mdl;

    if (Irp->MdlAddress == NULL)
    {
        Mdl = IoAllocateMdl(Irp->UserBuffer, BufferLength, FALSE, FALSE, Irp);
        if (Mdl == NULL)
        {
            return NULL;
        }

        _SEH2_TRY
        {
            MmProbeAndLockPages(Mdl, Irp->RequestorMode, IoWriteAccess);
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            IoFreeMdl(Mdl);
            Irp->MdlAddress = NULL;
            _SEH2_YIELD(return NULL);
        }
        _SEH2_END;
    }

int hax_pin_user_pages(uint64 start_uva, uint64 size, hax_memdesc_user *memdesc)
{
    PMDL pmdl = NULL;

    if (!memdesc) {
        hax_error("%s: memdesc == NULL\n", __func__);
        return -EINVAL;
    }

    // TODO: Check whether [start_uva, start_uva + size) is a valid UVA range

    pmdl = IoAllocateMdl((PVOID)start_uva, size, FALSE, FALSE, NULL);
    if (!pmdl) {
        hax_error("Failed to allocate MDL for va: 0x%llx, size: 0x%llx.\n",
                  start_uva, size);
        return -EFAULT;
    }

    try {
        MmProbeAndLockPages(pmdl, UserMode, IoWriteAccess);
    } except (EXCEPTION_EXECUTE_HANDLER) {
        hax_error("Failed to probe pages for guest's memory! va: 0x%llx\n",
                  start_uva);
        IoFreeMdl(pmdl);
        return -ENOMEM;
    }

    memdesc->pmdl = pmdl;
    return 0;
}

NTSTATUS SafeCopyMemory(PVOID SrcAddr, PVOID DstAddr, ULONG Size)
{
	PMDL  pSrcMdl, pDstMdl;
	PUCHAR pSrcAddress, pDstAddress;
	NTSTATUS st = STATUS_UNSUCCESSFUL;
	ULONG r;
	BOOL bInit = FALSE;

	pSrcMdl = IoAllocateMdl(SrcAddr, Size, FALSE, FALSE, NULL);
	if (MmIsAddressValidEx(pSrcMdl))
	{
		MmBuildMdlForNonPagedPool(pSrcMdl);
		pSrcAddress = (PUCHAR)MmGetSystemAddressForMdlSafe(pSrcMdl, NormalPagePriority);
		if (MmIsAddressValidEx(pSrcAddress))
		{
			pDstMdl = IoAllocateMdl(DstAddr, Size, FALSE, FALSE, NULL);
			if (MmIsAddressValidEx(pDstMdl))
			{
				__try
				{
					MmProbeAndLockPages(pDstMdl, KernelMode, IoWriteAccess);
					pDstAddress = (PUCHAR)MmGetSystemAddressForMdlSafe(pDstMdl, NormalPagePriority);
					if (MmIsAddressValidEx(pDstAddress))
					{
						RtlZeroMemory(pDstAddress,Size);
						RtlCopyMemory(pDstAddress, pSrcAddress, Size);
						st = STATUS_SUCCESS;
					}
					MmUnlockPages(pDstMdl);
				}
				__except(EXCEPTION_EXECUTE_HANDLER)
				{                 
					if (pDstMdl) MmUnlockPages(pDstMdl);

					if (pDstMdl) IoFreeMdl(pDstMdl);

					if (pSrcMdl) IoFreeMdl(pSrcMdl);

					return GetExceptionCode();
				}
				IoFreeMdl(pDstMdl);
			}
		}            
		IoFreeMdl(pSrcMdl);
	}
	return st;
}

NTSTATUS
NTAPI
USBPORT_ValidateTransferParametersURB(IN PURB Urb)
{
    struct _URB_CONTROL_TRANSFER *UrbRequest;
    PMDL Mdl;

    DPRINT_URB("USBPORT_ValidateTransferParametersURB: Urb - %p\n", Urb);

    UrbRequest = &Urb->UrbControlTransfer;

    if (UrbRequest->TransferBuffer == NULL &&
        UrbRequest->TransferBufferMDL == NULL &&
        UrbRequest->TransferBufferLength > 0)
    {
        DPRINT1("USBPORT_ValidateTransferParametersURB: Not valid parameter\n");
        USBPORT_DumpingURB(Urb);
        return STATUS_INVALID_PARAMETER;
    }

    if ((UrbRequest->TransferBuffer != NULL) &&
        (UrbRequest->TransferBufferMDL != NULL) &&
        UrbRequest->TransferBufferLength == 0)
    {
        DPRINT1("USBPORT_ValidateTransferParametersURB: Not valid parameter\n");
        USBPORT_DumpingURB(Urb);
        return STATUS_INVALID_PARAMETER;
    }

    if (UrbRequest->TransferBuffer != NULL &&
        UrbRequest->TransferBufferMDL == NULL &&
        UrbRequest->TransferBufferLength != 0)
    {
        DPRINT_URB("USBPORT_ValidateTransferParametersURB: TransferBuffer - %p, TransferBufferLength - %x\n",
                   UrbRequest->TransferBuffer,
                   UrbRequest->TransferBufferLength);

        Mdl = IoAllocateMdl(UrbRequest->TransferBuffer,
                            UrbRequest->TransferBufferLength,
                            FALSE,
                            FALSE,
                            NULL);

        if (!Mdl)
        {
            DPRINT1("USBPORT_ValidateTransferParametersURB: Not allocated Mdl\n");
            return STATUS_INSUFFICIENT_RESOURCES;
        }

        MmBuildMdlForNonPagedPool(Mdl);

        UrbRequest->TransferBufferMDL = Mdl;
        Urb->UrbHeader.UsbdFlags |= USBD_FLAG_ALLOCATED_MDL;

        DPRINT_URB("USBPORT_ValidateTransferParametersURB: Mdl - %p\n", Mdl);
    }

    return STATUS_SUCCESS;
}

//------------------------------------------------------------------------------
tOplkError drv_mapPdoMem(UINT8** ppKernelMem_p, UINT8** ppUserMem_p,
                         size_t* pMemSize_p)
{
    tOplkError      ret;

    // Get PDO memory
    ret = pdokcal_getPdoMemRegion((UINT8**)&pdoMemInfo_l.pKernelVa,
                                  &pdoMemInfo_l.memSize);

    if (ret != kErrorOk || pdoMemInfo_l.pKernelVa == NULL)
        return kErrorNoResource;

    if (*pMemSize_p > pdoMemInfo_l.memSize)
    {
        DEBUG_LVL_ERROR_TRACE("%s() Higher Memory requested (Kernel-%d User-%d) !\n",
                              __func__, pdoMemInfo_l.memSize, *pMemSize_p);
        *pMemSize_p = 0;
        return kErrorNoResource;
    }

    // Allocate new MDL pointing to PDO memory
    pdoMemInfo_l.pMdl = IoAllocateMdl(pdoMemInfo_l.pKernelVa, pdoMemInfo_l.memSize, FALSE, FALSE,
                                      NULL);

    if (pdoMemInfo_l.pMdl == NULL)
    {
        DEBUG_LVL_ERROR_TRACE("%s() Error allocating MDL !\n", __func__);
        return kErrorNoResource;
    }

    // Update the MDL with physical addresses
    MmBuildMdlForNonPagedPool(pdoMemInfo_l.pMdl);

    // Map the memory in user space and get the address
    pdoMemInfo_l.pUserVa = MmMapLockedPagesSpecifyCache(pdoMemInfo_l.pMdl,    // MDL
                                                        UserMode,             // Mode
                                                        MmCached,             // Caching
                                                        NULL,                 // Address
                                                        FALSE,                // Bug-check?
                                                        NormalPagePriority);  // Priority

    if (pdoMemInfo_l.pUserVa == NULL)
    {
        MmUnmapLockedPages(pdoMemInfo_l.pUserVa, pdoMemInfo_l.pMdl);
        IoFreeMdl(pdoMemInfo_l.pMdl);
        DEBUG_LVL_ERROR_TRACE("%s() Error mapping MDL !\n", __func__);
        return kErrorNoResource;
    }

    *ppKernelMem_p = pdoMemInfo_l.pKernelVa;
    *ppUserMem_p = pdoMemInfo_l.pUserVa;
    *pMemSize_p = pdoMemInfo_l.memSize;

    TRACE("Mapped memory info U:%p K:%p size %x", pdoMemInfo_l.pUserVa,
                                                 (UINT8*)pdoMemInfo_l.pKernelVa,
                                                 pdoMemInfo_l.memSize);
    return kErrorOk;
}

//-----------------------------------------------------------------------------
// MAIN
//-----------------------------------------------------------------------------
NTSTATUS DriverEntry(PDRIVER_OBJECT driver_object, 
	                 PUNICODE_STRING registry_path)
{
	NTSTATUS ret;

	if (!driver_object)
	{
		DbgPrint("\n!!! ERROR: invalid driver_object in DriverEntry()\n");
		return STATUS_UNSUCCESSFUL;
	}
	driver_object->DriverUnload  = OnUnload;

	DbgPrint("---------------- Driver Loaded\n");

	// routine allocates a memory descriptor list (MDL) 
	mdl_sys_call = IoAllocateMdl(KeServiceDescriptorTable.ServiceTableBase, 
		                         KeServiceDescriptorTable.NumberOfServices * 4, 
								 FALSE, FALSE, NULL);
	if (!mdl_sys_call )
	{
		DbgPrint("\n!!! ERROR: invalid mdl in DriverEntry()\n");
		return STATUS_UNSUCCESSFUL;
	}

	MmBuildMdlForNonPagedPool(mdl_sys_call);

	mdl_sys_call->MdlFlags = mdl_sys_call->MdlFlags | MDL_MAPPED_TO_SYSTEM_VA;

	// map the physical pages 
    syscall_tbl = MmMapLockedPagesSpecifyCache(mdl_sys_call, KernelMode,
											   MmNonCached, NULL, FALSE,
											   HighPagePriority);

	if (!syscall_tbl)
	{
		DbgPrint("\n!!! ERROR: invalid mapped syscall table in DriverEntry()\n");
		return STATUS_UNSUCCESSFUL;
	}

	hook_syscalls();

	debug("register our callback for when our target proc is loaded:\n %ws\n\n",
		     target_file_loc);

#if BREAK_POINT
	// register a callback func that is invoked when our target proc is loaded
	ret = PsSetLoadImageNotifyRoutine(add_one_time_bp);
#endif

#if DATA_MINING
	ret = PsSetLoadImageNotifyRoutine(add_hooks_for_data_mining);
#endif

	if (ret != STATUS_SUCCESS)
		DbgPrint("\n!!! ERROR: PsSetLoadImageNotifyRoutine()\n\n");

	return STATUS_SUCCESS;
}

CMdl::CMdl(
	__in void* virtualAddress, 
	__in size_t size
	) : m_locked(false),
		m_mem(NULL)
{
	m_lockOperation = IoModifyAccess;
	m_mdl = IoAllocateMdl(virtualAddress, (ULONG)size, FALSE, FALSE, NULL);
}

NTSTATUS
AsyncReadWriteSec(
    IN PDEVICE_OBJECT DeviceObject,
	IN PIRP	 ParentIrp,
	IN ULONG ulStartSec,
	IN ULONG ulSectors,
	IN PVOID pBuffer,
    IN UCHAR MajorFunction
)
{
	PMDL				MDL;
    KEVENT				event;
    PIRP				Irp;
	ULONG				ulBytes;
    LARGE_INTEGER		Start;
    IO_STATUS_BLOCK		ioStatus;
	NTSTATUS			status = STATUS_SUCCESS;
    PIO_STACK_LOCATION	NextIrpStack;
	PDEVICE_EXTENSION	deviceExtension = DeviceObject->DeviceExtension;

	ulBytes = ulSectors * SECTOR_SIZE;
	Start.QuadPart = ((LONGLONG)ulStartSec)*SECTOR_SIZE;

	Irp = IoAllocateIrp(LOBYTE(LOWORD(deviceExtension->TargetDeviceObject->StackSize+1)),FALSE);
	//Irp = IoBuildSynchronousFsdRequest( MajorFunction,
	//	                                deviceExtension->TargetDeviceObject,
	//	                                pBuffer,ulBytes,
	//	                                &Start,&event,
	//	                                &ioStatus );

	ASSERT(Irp);
	if (!Irp)
	{
	    return STATUS_INSUFFICIENT_RESOURCES;
	}

	MDL = IoAllocateMdl(pBuffer,ulBytes,FALSE,FALSE,Irp);
	if (!MDL)
		return STATUS_INSUFFICIENT_RESOURCES;

	MmBuildMdlForNonPagedPool(MDL);
	IoSetNextIrpStackLocation(Irp);
	NextIrpStack = IoGetNextIrpStackLocation(Irp);

	NextIrpStack->DeviceObject  = deviceExtension->TargetDeviceObject;
	NextIrpStack->MajorFunction = MajorFunction;
	NextIrpStack->MinorFunction = 0;

	NextIrpStack->Parameters.Read.Length = ulBytes;
	NextIrpStack->Parameters.Read.Key		 = 0;
	NextIrpStack->Parameters.Read.ByteOffset.QuadPart = Start.QuadPart;

	RtlCopyMemory(&(NextIrpStack->Parameters.Write),&(NextIrpStack->Parameters.Read),sizeof(NextIrpStack->Parameters.Read));
	IoSetCompletionRoutine(Irp,AsyncCompletion,ParentIrp,TRUE,TRUE,TRUE);
	status = IoCallDriver(deviceExtension->TargetDeviceObject,Irp);
	return status;
} // end SyncReadWriteSec()

int dump_hook_init(PDRIVER_OBJECT drv_obj)
{
	PLDR_DATA_TABLE_ENTRY table;
	PHYSICAL_ADDRESS      high_addr;
	PLIST_ENTRY           entry;
	NTSTATUS              status;
	int                   resl = 0;

	ExInitializeFastMutex(&dump_sync);

	ExAcquireFastMutex(&dump_sync);

	/* find PsLoadedModuleListHead */
	entry = ((PLIST_ENTRY)(drv_obj->DriverSection))->Flink;

	while (entry != drv_obj->DriverSection)
	{
		table = CONTAINING_RECORD(entry, LDR_DATA_TABLE_ENTRY, InLoadOrderLinks);
		entry = entry->Flink;

		if ( (table->BaseDllName.Length == 0x18) && 
			 (p32(table->BaseDllName.Buffer)[0] == 0x0074006E) )
		{
			ps_loaded_mod_list = pv(table->InLoadOrderLinks.Blink);
			break;
		}
	}

	ExReleaseFastMutex(&dump_sync);

	do
	{
		if (ps_loaded_mod_list == NULL) break;

		status = PsSetLoadImageNotifyRoutine(load_img_routine);
		if (NT_SUCCESS(status) == FALSE) break;

		high_addr.HighPart = 0;
		high_addr.LowPart  = 0xFFFFFFFF;

		dump_mem = MmAllocateContiguousMemory(DUMP_MEM_SIZE, high_addr);
		if (dump_mem == NULL) break;
		dump_mdl = IoAllocateMdl(dump_mem, DUMP_MEM_SIZE, FALSE, FALSE, NULL); 
		if (dump_mdl == NULL) break;

		MmBuildMdlForNonPagedPool(dump_mdl);
		memset(dump_mem, 0, DUMP_MEM_SIZE);
		resl = 1;
	} while (0);

	if (resl == 0) {
		if (dump_mdl != NULL) IoFreeMdl(dump_mdl);
		if (dump_mem != NULL) MmFreeContiguousMemory(dump_mem);
	}
	return resl;	
}

/*
* TsmiHandleMemWrite
*
* Purpose:
*
* Patch vbox dll in memory.
*
* Warning: If compiled not in ReleaseSigned configuration this function is a
* potential BSOD-generator due to nonstandard way of loading, take care with patch offsets.
*
*/
NTSTATUS TsmiHandleMemWrite(
    _In_ PVOID SrcAddress,
    _In_ PVOID DestAddress,
    _In_ ULONG Size
)
{
    PMDL        mdl;
    NTSTATUS    status = STATUS_SUCCESS;

    PAGED_CODE();

    mdl = IoAllocateMdl(DestAddress, Size, FALSE, FALSE, NULL);
    if (mdl == NULL) {
#ifdef _DEBUGMSG
        DbgPrint("[TSMI] Failed to create MDL at write\n");
#endif
        return STATUS_INSUFFICIENT_RESOURCES;
    }

#ifdef _SIGNED_BUILD
    __try {
#endif //_SIGNED_BUILD

        if (DestAddress >= MmSystemRangeStart)
            if (!MmIsAddressValid(DestAddress)) {
#ifdef _DEBUGMSG
                DbgPrint("[TSMI] Invalid address\n");
#endif //_DEBUGMSG
                return STATUS_ACCESS_VIOLATION;
            }
        MmProbeAndLockPages(mdl, KernelMode, IoReadAccess);
        DestAddress = MmGetSystemAddressForMdlSafe(mdl, HighPagePriority);
        if (DestAddress != NULL) {
            status = MmProtectMdlSystemAddress(mdl, PAGE_EXECUTE_READWRITE);
            __movsb((PUCHAR)DestAddress, (const UCHAR *)SrcAddress, Size);
            MmUnmapLockedPages(DestAddress, mdl);
            MmUnlockPages(mdl);
        }
        else {
            status = STATUS_ACCESS_VIOLATION;
        }

#ifdef _SIGNED_BUILD
    }
    __except (EXCEPTION_EXECUTE_HANDLER) {
        status = STATUS_ACCESS_VIOLATION;
#ifdef _DEBUGMSG
        DbgPrint("[TSMI] MmProbeAndLockPages failed at write DestAddress = %p\n", DestAddress);
#endif //_DEBUGMSG
    }
#endif //_SIGNED_BUILD

    IoFreeMdl(mdl);
    return status;
}

NTSTATUS 
xixfs_PinCallersBuffer(
	PIRP				PtrIrp,
	BOOLEAN			IsReadOperation,
	uint32			Length
)
{
	NTSTATUS			RC = STATUS_SUCCESS;
	PMDL				PtrMdl = NULL;

	PAGED_CODE();
	DebugTrace(DEBUG_LEVEL_TRACE, (DEBUG_TARGET_READ|DEBUG_TARGET_WRITE),
		("Enter xixfs_PinCallersBuffer \n"));

	ASSERT(PtrIrp);
	
	try {
		
		// Is a MDL already present in the IRP
		if (!(PtrIrp->MdlAddress)) {
				DebugTrace(DEBUG_LEVEL_ERROR, DEBUG_TARGET_ALL,
						("PtrIrp->MdlAddress is NULL!!!\n"));
			// Allocate a MDL
			if (!(PtrMdl = IoAllocateMdl(PtrIrp->UserBuffer, Length, FALSE, FALSE, PtrIrp))) {
				DebugTrace(DEBUG_LEVEL_ERROR, DEBUG_TARGET_ALL,
						("Fail Allocate Mdl!!!\n"));
				
				RC = STATUS_INSUFFICIENT_RESOURCES;
				try_return(RC);
			}

			// Probe and lock the pages described by the MDL
			// We could encounter an exception doing so, swallow the exception
			// NOTE: The exception could be due to an unexpected (from our
			// perspective), invalidation of the virtual addresses that comprise
			// the passed in buffer
			try {
				MmProbeAndLockPages(PtrMdl, PtrIrp->RequestorMode, (IsReadOperation ? IoReadAccess : IoWriteAccess));
			} except(EXCEPTION_EXECUTE_HANDLER) {
				DebugTrace(DEBUG_LEVEL_ERROR, DEBUG_TARGET_ALL,
						("Fail Mdl Lock Page Fail!!!\n"));

				RC = STATUS_INVALID_USER_BUFFER;
			}


		}
		


		;
	} finally {