Linux-libre 4.3.2-gnu

1 files changed, 10 insertions, 4 deletions

diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 4f0c402a1..448c2615f 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -154,14 +154,20 @@ static void bictcp_init(struct sock *sk)
 static void bictcp_cwnd_event(struct sock *sk, enum tcp_ca_event event)
 {
 	if (event == CA_EVENT_TX_START) {
-		s32 delta = tcp_time_stamp - tcp_sk(sk)->lsndtime;
 		struct bictcp *ca = inet_csk_ca(sk);
+		u32 now = tcp_time_stamp;
+		s32 delta;
+
+		delta = now - tcp_sk(sk)->lsndtime;
 
 		/* We were application limited (idle) for a while.
 		 * Shift epoch_start to keep cwnd growth to cubic curve.
 		 */
-		if (ca->epoch_start && delta > 0)
+		if (ca->epoch_start && delta > 0) {
 			ca->epoch_start += delta;
+			if (after(ca->epoch_start, now))
+				ca->epoch_start = now;
+		}
 		return;
 	}
 }
@@ -335,7 +341,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
 	if (!tcp_is_cwnd_limited(sk))
 		return;
 
-	if (tp->snd_cwnd <= tp->snd_ssthresh) {
+	if (tcp_in_slow_start(tp)) {
 		if (hystart && after(ack, ca->end_seq))
 			bictcp_hystart_reset(sk);
 		acked = tcp_slow_start(tp, acked);
@@ -454,7 +460,7 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us)
 		ca->delay_min = delay;
 
 	/* hystart triggers when cwnd is larger than some threshold */
-	if (hystart && tp->snd_cwnd <= tp->snd_ssthresh &&
+	if (hystart && tcp_in_slow_start(tp) &&
 	    tp->snd_cwnd >= hystart_low_window)
 		hystart_update(sk, delay);
 }