Kernel2

UNICODE_STRING     uniName;
	OBJECT_ATTRIBUTES  objAttr;

	RtlInitUnicodeString(&uniName, L"\\DosDevices\\C:\\Users\\rainb\\source\\repos\\testAppForKernel\\x64\\Debug\\usermode.txt");  // or L"\\SystemRoot\\example.txt"
	InitializeObjectAttributes(&objAttr, &uniName,
		OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE,
		NULL, NULL);

	HANDLE   handle;
	NTSTATUS ntstatus;
	IO_STATUS_BLOCK    ioStatusBlock;

	if (KeGetCurrentIrql() != PASSIVE_LEVEL)
		return STATUS_INVALID_DEVICE_STATE;

	ntstatus = ZwCreateFile(&handle,
		GENERIC_WRITE,
		&objAttr, &ioStatusBlock, NULL,
		FILE_ATTRIBUTE_NORMAL,
		0,
		FILE_OVERWRITE_IF,
		FILE_SYNCHRONOUS_IO_NONALERT,
		NULL, 0);

	LARGE_INTEGER      byteOffset;
	#define  BUFFER_SIZE 30
	CHAR     buffer[BUFFER_SIZE];

	ntstatus = ZwCreateFile(&handle,
		GENERIC_READ,
		&objAttr, &ioStatusBlock,
		NULL,
		FILE_ATTRIBUTE_NORMAL,
		0,
		FILE_OPEN,
		FILE_SYNCHRONOUS_IO_NONALERT,
		NULL, 0);
	if (NT_SUCCESS(ntstatus)) {
		byteOffset.LowPart = byteOffset.HighPart = 0;
		ntstatus = ZwReadFile(handle, NULL, NULL, NULL, &ioStatusBlock,
			buffer, BUFFER_SIZE, &byteOffset, NULL);
		if (NT_SUCCESS(ntstatus)) {
			buffer[BUFFER_SIZE - 1] = '\0';
			DbgPrint("%s\n", buffer);
		}
		ZwClose(handle);
	}