tcp: ensure proper barriers in lockless contexts

[firefly-linux-kernel-4.4.55.git] / net / ipv4 / tcp_ipv4.c

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 950e28c0cdf25e23658926cdcf37335aed3fb193..ba09016d1bfd2a778d57cdc37f0a7db539f9cb3a 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2158,6 +2158,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
        __u16 destp = ntohs(inet->inet_dport);
        __u16 srcp = ntohs(inet->inet_sport);
        int rx_queue;
+       int state;
 
        if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
            icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
@@ -2175,17 +2176,18 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
                timer_expires = jiffies;
        }
 
-       if (sk->sk_state == TCP_LISTEN)
+       state = sk_state_load(sk);
+       if (state == TCP_LISTEN)
                rx_queue = sk->sk_ack_backlog;
        else
-               /*
-                * because we dont lock socket, we might find a transient negative value
+               /* Because we don't lock the socket,
+                * we might find a transient negative value.
                 */
                rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
 
        seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
                        "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d",
-               i, src, srcp, dest, destp, sk->sk_state,
+               i, src, srcp, dest, destp, state,
                tp->write_seq - tp->snd_una,
                rx_queue,
                timer_active,
@@ -2199,8 +2201,8 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
                jiffies_to_clock_t(icsk->icsk_ack.ato),
                (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
                tp->snd_cwnd,
-               sk->sk_state == TCP_LISTEN ?
-                   (fastopenq ? fastopenq->max_qlen : 0) :
+               state == TCP_LISTEN ?
+                   fastopenq->max_qlen :
                    (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh));
 }