[PATCH 3.14 12/44] udp: fix behavior of wrong checksums
3.14-stable review patch. If anyone has any objections, please let me know. -- From: Eric Dumazet [ Upstream commit beb39db59d14990e401e235faf66a6b9b31240b0 ] We have two problems in UDP stack related to bogus checksums : 1) We return -EAGAIN to application even if receive queue is not empty. This breaks applications using edge trigger epoll() 2) Under UDP flood, we can loop forever without yielding to other processes, potentially hanging the host, especially on non SMP. This patch is an attempt to make things better. We might in the future add extra support for rt applications wanting to better control time spent doing a recv() in a hostile environment. For example we could validate checksums before queuing packets in socket receive queue. Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/udp.c |6 ++ net/ipv6/udp.c |6 ++ 2 files changed, 4 insertions(+), 8 deletions(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1317,10 +1317,8 @@ csum_copy_err: } unlock_sock_fast(sk, slow); - if (noblock) - return -EAGAIN; - - /* starting over for a new packet */ + /* starting over for a new packet, but check if we need to yield */ + cond_resched(); msg->msg_flags &= ~MSG_TRUNC; goto try_again; } --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -515,10 +515,8 @@ csum_copy_err: } unlock_sock_fast(sk, slow); - if (noblock) - return -EAGAIN; - - /* starting over for a new packet */ + /* starting over for a new packet, but check if we need to yield */ + cond_resched(); msg->msg_flags &= ~MSG_TRUNC; goto try_again; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3.14 12/44] udp: fix behavior of wrong checksums
3.14-stable review patch. If anyone has any objections, please let me know. -- From: Eric Dumazet eduma...@google.com [ Upstream commit beb39db59d14990e401e235faf66a6b9b31240b0 ] We have two problems in UDP stack related to bogus checksums : 1) We return -EAGAIN to application even if receive queue is not empty. This breaks applications using edge trigger epoll() 2) Under UDP flood, we can loop forever without yielding to other processes, potentially hanging the host, especially on non SMP. This patch is an attempt to make things better. We might in the future add extra support for rt applications wanting to better control time spent doing a recv() in a hostile environment. For example we could validate checksums before queuing packets in socket receive queue. Signed-off-by: Eric Dumazet eduma...@google.com Cc: Willem de Bruijn will...@google.com Signed-off-by: David S. Miller da...@davemloft.net Signed-off-by: Greg Kroah-Hartman gre...@linuxfoundation.org --- net/ipv4/udp.c |6 ++ net/ipv6/udp.c |6 ++ 2 files changed, 4 insertions(+), 8 deletions(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1317,10 +1317,8 @@ csum_copy_err: } unlock_sock_fast(sk, slow); - if (noblock) - return -EAGAIN; - - /* starting over for a new packet */ + /* starting over for a new packet, but check if we need to yield */ + cond_resched(); msg-msg_flags = ~MSG_TRUNC; goto try_again; } --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -515,10 +515,8 @@ csum_copy_err: } unlock_sock_fast(sk, slow); - if (noblock) - return -EAGAIN; - - /* starting over for a new packet */ + /* starting over for a new packet, but check if we need to yield */ + cond_resched(); msg-msg_flags = ~MSG_TRUNC; goto try_again; } -- To unsubscribe from this list: send the line unsubscribe linux-kernel in Please read the FAQ at http://www.tux.org/lkml/
