extern int arp_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt);
extern int arp_find(unsigned char *haddr, struct sk_buff *skb);
-extern int arp_ioctl(unsigned int cmd, void *arg);
+extern int arp_ioctl(unsigned int cmd, void __user *arg);
extern void arp_send(int type, int ptype, u32 dest_ip,
struct net_device *dev, u32 src_ip,
unsigned char *dest_hw, unsigned char *src_hw, unsigned char *th);