static ssize_t procfile_read(struct file *file, char *buffer, size_t length, loff_t *offset) {
    static int finished = 0;
    int ret = 0;

    printk(KERN_INFO "procfile_read (/proc/%s) called, len: %zun", procfs_name, length);

    if (finished) {
        printk(KERN_INFO "procfs_read: ENDn");
        finished = 0;
        return 0;
    }

    finished = 1;
    ret = sprintf(buffer, "Hello,world!n");
    return ret;
}