5.10-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 05dc72aba364d374a27de567fac58c199ff5ee97 ]
Both tcp_data_ready() and tcp_stream_is_readable() share the same logic.
Add tcp_epollin_ready() helper to avoid duplication.
Signed-off-by: Eric Dumazet edumazet@google.com Cc: Arjun Roy arjunroy@google.com Cc: Wei Wang weiwan@google.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 2660a544fdc0 ("net: Fix TOCTOU issue in sk_is_readable()") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/tcp.h | 12 ++++++++++++ net/ipv4/tcp.c | 18 +++++------------- net/ipv4/tcp_input.c | 11 ++--------- 3 files changed, 19 insertions(+), 22 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h index 2aad2e79ac6ad..41f535dcaa3f9 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1445,6 +1445,18 @@ static inline bool tcp_rmem_pressure(const struct sock *sk) return atomic_read(&sk->sk_rmem_alloc) > threshold; }
+static inline bool tcp_epollin_ready(const struct sock *sk, int target) +{ + const struct tcp_sock *tp = tcp_sk(sk); + int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); + + if (avail <= 0) + return false; + + return (avail >= target) || tcp_rmem_pressure(sk) || + (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss); +} + extern void tcp_openreq_init_rwin(struct request_sock *req, const struct sock *sk_listener, const struct dst_entry *dst); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 24ebd51c5e0b8..0332fdab942db 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -476,19 +476,11 @@ static void tcp_tx_timestamp(struct sock *sk, u16 tsflags) } }
-static inline bool tcp_stream_is_readable(const struct tcp_sock *tp, - int target, struct sock *sk) +static bool tcp_stream_is_readable(struct sock *sk, int target) { - int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); - - if (avail > 0) { - if (avail >= target) - return true; - if (tcp_rmem_pressure(sk)) - return true; - if (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss) - return true; - } + if (tcp_epollin_ready(sk, target)) + return true; + if (sk->sk_prot->stream_memory_read) return sk->sk_prot->stream_memory_read(sk); return false; @@ -565,7 +557,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait) tp->urg_data) target++;
- if (tcp_stream_is_readable(tp, target, sk)) + if (tcp_stream_is_readable(sk, target)) mask |= EPOLLIN | EPOLLRDNORM;
if (!(shutdown & SEND_SHUTDOWN)) { diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7c2e714527f68..318fdeb1deef3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5028,15 +5028,8 @@ int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
void tcp_data_ready(struct sock *sk) { - const struct tcp_sock *tp = tcp_sk(sk); - int avail = tp->rcv_nxt - tp->copied_seq; - - if (avail < sk->sk_rcvlowat && !tcp_rmem_pressure(sk) && - !sock_flag(sk, SOCK_DONE) && - tcp_receive_window(tp) > inet_csk(sk)->icsk_ack.rcv_mss) - return; - - sk->sk_data_ready(sk); + if (tcp_epollin_ready(sk, sk->sk_rcvlowat)) + sk->sk_data_ready(sk); }
static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)