sctp: use time_before or time_after for comparing jiffies

The functions time_before or time_after are more robust
for comparing jiffies against other values.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 4 deletions

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index bc411c896216..a367d15a21aa 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -428,7 +428,8 @@ void sctp_retransmit_mark(struct sctp_outq *q,
                          * retransmitting due to T3 timeout.
                          */
                         if (reason == SCTP_RTXR_T3_RTX &&
-                            (jiffies - chunk->sent_at) < transport->last_rto)
+                            time_before(jiffies, chunk->sent_at +
+                                                 transport->last_rto))
                                 continue;
 
                         /* RFC 2960 6.2.1 Processing a Received SACK
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 5c29b14ee9af..e5dde45c79d3 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -543,8 +543,8 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
                  * congestion indications more than once every window of
                  * data (or more loosely more than once every round-trip time).
                  */
-                if ((jiffies - transport->last_time_ecne_reduced) >
-                    transport->rtt) {
+                if (time_after(jiffies, transport->last_time_ecne_reduced +
+                                        transport->rtt)) {
                         transport->ssthresh = max(transport->cwnd/2,
                                                   4*transport->asoc->pathmtu);
                         transport->cwnd = transport->ssthresh;
@@ -561,7 +561,8 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
                  * to be done every RTO interval, we do it every hearbeat
                  * interval.
                  */
-                if ((jiffies - transport->last_time_used) > transport->rto)
+                if (time_after(jiffies, transport->last_time_used +
+                                        transport->rto))
                         transport->cwnd = max(transport->cwnd/2,
                                                  4*transport->asoc->pathmtu);
                 break;