296f7ea75b
This patch adds a tracepoint to __udp_queue_rcv_skb to get the return value of ip_queue_rcv_skb. It indicates why kernel drops a packet at this point. ip_queue_rcv_skb returns following values in the packet drop case: rcvbuf is full : -ENOMEM sk_filter returns error : -EINVAL, -EACCESS, -ENOMEM, etc. __sk_mem_schedule returns error: -ENOBUF Signed-off-by: Satoru Moriya <satoru.moriya@hds.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>