static ssize_t proc_file_read(struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos);
static ssize_t proc_file_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos);
static loff_t proc_file_lseek(struct file *, loff_t, int);
static ssize_t proc_file_read(struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos);
static ssize_t proc_file_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos);
static loff_t proc_file_lseek(struct file *, loff_t, int);