void gs_put_char(struct tty_struct *tty, unsigned char ch);
-int gs_write(struct tty_struct *tty,
+int gs_write(struct tty_struct *tty, int from_user,
const unsigned char *buf, int count);
int gs_write_room(struct tty_struct *tty);
int gs_chars_in_buffer(struct tty_struct *tty);