求助在驱动中读写文件时蓝屏

相关代码:
#define DEFAULT_LOG_FILE_NAME L\"\\\\DosDevices\\\\C:\\\\UnScanner.log\"
//---------------------------------------------------------------------
BOOLEAN DVRH_LogMessage(PCHAR szFormat, ...)
{
ULONG Length;
char messagebuf[256];
va_list va;
    IO_STATUS_BLOCK  IoStatus;
OBJECT_ATTRIBUTES objectAttributes;
NTSTATUS status;
HANDLE FileHandle;
    UNICODE_STRING fileName;

//format the string
    va_start(va,szFormat);
vsprintf(messagebuf,szFormat,va);
va_end(va);

//get a handle to the log file object
    fileName.Buffer = NULL;
    fileName.Length = 0;
    fileName.MaximumLength = sizeof(DEFAULT_LOG_FILE_NAME) + sizeof(UNICODE_NULL);
    fileName.Buffer = ExAllocatePool(PagedPool,
                                        fileName.MaximumLength);
    if (!fileName.Buffer)
    {
        //ParDump2(PARERRORS, (\"LogMessage: FAIL. ExAllocatePool Failed.\\n\") );
        return FALSE;
    }
    RtlZeroMemory(fileName.Buffer, fileName.MaximumLength);
    status = RtlAppendUnicodeToString(&fileName, (PWSTR)DEFAULT_LOG_FILE_NAME);

InitializeObjectAttributes (&objectAttributes,
(PUNICODE_STRING)&fileName,
OBJ_CASE_INSENSITIVE,
NULL,
NULL );

status = ZwCreateFile(&FileHandle,
 FILE_APPEND_DATA,
 &objectAttributes,
 &IoStatus,
 0,
 FILE_ATTRIBUTE_NORMAL,
 FILE_SHARE_WRITE,
 FILE_OPEN_IF,
 FILE_SYNCHRONOUS_IO_NONALERT,
 NULL,    
 0 );

if(NT_SUCCESS(status))
{
CHAR buf[300];
LARGE_INTEGER time;
KeQuerySystemTime(&time);

//put a time stamp on the output message
sprintf(buf,\"%10u-%10u  %s\",time.HighPart,time.LowPart,messagebuf);

//format the string to make sure it appends a newline carrage-return to the
//end of the string.
Length=strlen(buf);
if(buf[Length-1]==\'\\n\')
{
buf[Length-1]=\'\\r\';
strcat(buf,\"\\n\");
Length++;
}
else
{
strcat(buf,\"\\r\\n\");
Length+=2;
}

ZwWriteFile(FileHandle,
 NULL,
 NULL,
 NULL,
 &IoStatus,
 buf,
 Length,
 NULL,
 NULL );

ZwClose(FileHandle);
}
    if (fileName.Buffer)
        ExFreePool (fileName.Buffer);

return STATUS_SUCCESS;
}
//---------------------------------------------------------------------
//上面的函数是从DDK例子debug.c中copy过来的
//当执行下面的语句时回导致系统蓝屏
char logMsg[64];
sprintf(logMsg, \"%d\", * (int *)(PacketBuffer + 26));
DVRH_LogMessage(logMsg);
//本人是刚开始学驱动开发,找不到资料
//所以还望高手指点一下

我的函数调用格式是错的

楼主，可否把解决方法贴出来阿

//put a time stamp on the output message
sprintf(buf,"%10u-%10u %s",time.HighPart,time.LowPart,messagebuf);

//format the string to make sure it appends a newline carrage-return to the
//end of the string.
Length=strlen(buf);
if(buf[Length-1]=='\n')
{
buf[Length-1]='\r';
strcat(buf,"\n");
Length++;
}
else
{
strcat(buf,"\r\n");
Length+=2;
}
把上面一段换成内核函数试试！我以前用C库也兰过屏！！
不知对不对