#include <linux/module.h>
#include <linux/init.h>
#include <linux/moduleparam.h>

MODULE_LICENSE("GPL");

#define param_check_even(name, p)

int param_set_even(const char *pbuf, struct kernel_param *kp)
{
  int number;

  number = simple_strtoul(pbuf, NULL, 0);
  if(number % 2) // ungerade?
    return -EINVAL;
  *(int *)kp->arg = number;
  return 0;
}

int param_get_even(char *pbuf, struct kernel_param *kp)
{
  return sprintf((char *)pbuf, "%d", *(int *)kp->arg);
}

static int para;
module_param(para, even, 0666);

static int __init mod_init(void)
{
  printk("para = %d\n", para );
  return 0;
}

static void __exit mod_exit(void)
{
}
module_init( mod_init );
module_exit( mod_exit );