udp: fix busy polling

Generic sk_busy_loop_end() only looks at sk->sk_receive_queue
for presence of packets.

Problem is that for UDP sockets after blamed commit, some packets
could be present in another queue: udp_sk(sk)->reader_queue

In some cases, a busy poller could spin until timeout expiration,
even if some packets are available in udp_sk(sk)->reader_queue.

v3: - make sk_busy_loop_end() nicer (Willem)

v2: - add a READ_ONCE(sk->sk_family) in sk_is_inet() to avoid KCSAN splats.
    - add a sk_is_inet() check in sk_is_udp() (Willem feedback)
    - add a sk_is_inet() check in sk_is_tcp().

Fixes: 2276f58ac5 ("udp: use a separate rx queue for packet reception")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2024-01-18 20:17:49 +00:00
committed by David S. Miller
parent e3f9bed9be
commit a54d51fb2d
4 changed files with 26 additions and 14 deletions

View File

@ -2765,9 +2765,25 @@ static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
&skb_shinfo(skb)->tskey);
}
static inline bool sk_is_inet(const struct sock *sk)
{
int family = READ_ONCE(sk->sk_family);
return family == AF_INET || family == AF_INET6;
}
static inline bool sk_is_tcp(const struct sock *sk)
{
return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP;
return sk_is_inet(sk) &&
sk->sk_type == SOCK_STREAM &&
sk->sk_protocol == IPPROTO_TCP;
}
static inline bool sk_is_udp(const struct sock *sk)
{
return sk_is_inet(sk) &&
sk->sk_type == SOCK_DGRAM &&
sk->sk_protocol == IPPROTO_UDP;
}
static inline bool sk_is_stream_unix(const struct sock *sk)