From 56d806222ace4c3aeae516cd7a855340fb2839d8 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Tue, 24 Jan 2017 21:49:41 -0500 Subject: tcp: correct memory barrier usage in tcp_check_space() sock_reset_flag() maps to __clear_bit() not the atomic version clear_bit(). Thus, we need smp_mb(), smp_mb__after_atomic() is not sufficient. Fixes: 3c7151275c0c ("tcp: add memory barriers to write space paths") Cc: Eric Dumazet Cc: Oleg Nesterov Signed-off-by: Jason Baron Acked-by: Eric Dumazet Reported-by: Oleg Nesterov Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 6c790754ae3e..41dcbd568cbe 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5078,7 +5078,7 @@ 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(); + smp_mb(); if (sk->sk_socket && test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { tcp_new_space(sk); -- cgit v1.2.3-59-g8ed1b