如何得到pdo设备的设备指针

NTSTATUSntStatus = STATUS_SUCCESS;PDEVICE_OBJECTDeviceObject = NULL;PFILE_OBJECTFileObject = NULL; ntStatus = IoGetDeviceObjectPointer(pObjectName,FILE_ALL_ACCESS,&FileObject,&DeviceObject);if(!NT_SUCCESS(ntStatus)){KdPrint(("IoGetDeviceObjectPointer Failed,ntStatus = 0x%08lX/n",ntStatus));goto _EXIT0_;}KdPrint(("IoGetDeviceObjectPointer succeed!/n"));DeviceObject = IoGetLowerDeviceObject(DeviceObject);if(!DeviceObject){KdPrint(("IoGetLowerDeviceObject Failed,ntStatus = 0x%08lX!/n",ntStatus));ntStatus = STATUS_UNSUCCESSFUL;goto _EXIT1_;}while(!(DeviceObject->Flags & DO_BUS_ENUMERATED_DEVICE)){ObDereferenceObject(DeviceObject);DeviceObject = IoGetLowerDeviceObject(DeviceObject);if(!DeviceObject){ObDereferenceObject(FileObject);ntStatus = STATUS_UNSUCCESSFUL;goto _EXIT1_;} }