From 3c7151275c0c9a80c3375f9874b1c7129a105eea Mon Sep 17 00:00:00 2001 From: "jbaron@akamai.com" Date: Mon, 20 Apr 2015 20:05:07 +0000 Subject: tcp: add memory barriers to write space paths Ensure that we either see that the buffer has write space in tcp_poll() or that we perform a wakeup from the input side. Did not run into any actual problem here, but thought that we should make things explicit. Signed-off-by: Jason Baron Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a7ef679dd3ea..3a4d9b34bed4 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4845,6 +4845,8 @@ static void tcp_check_space(struct sock *sk) { if (sock_flag(sk, SOCK_QUEUE_SHRUNK)) { sock_reset_flag(sk, SOCK_QUEUE_SHRUNK); + /* pairs with tcp_poll() */ + smp_mb__after_atomic(); if (sk->sk_socket && test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) tcp_new_space(sk); -- cgit v1.2.1