if (skb->ip_summed == CHECKSUM_HW) return csum_tcpudp_magic( saddr, daddr, ulen, IPPROTO_UDP, skb->csum); 
psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0); 
static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,			     unsigned short ulen, u32 saddr, u32 daddr){	if (uh->check == 0)		return 0;	if (skb->ip_summed == CHECKSUM_HW)		return csum_tcpudp_magic(			saddr, daddr, ulen, IPPROTO_UDP, skb->csum);	skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);	return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/fb286bb2990a107009dbf25f6ffebeb7df77f9be/netpoll.c/buggy/net/core/netpoll.c