From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>
Cc: Lawrence Brakmo <brakmo@fb.com>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH] tcp_nv: fix division by zero in tcpnv_acked()
Date: Wed, 01 Nov 2017 16:32:15 +0300 [thread overview]
Message-ID: <150954313588.153848.10192893966808917578.stgit@buzz> (raw)
Average RTT could become zero. This happened in real life at least twice.
This patch treats zero as 1us.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
net/ipv4/tcp_nv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_nv.c b/net/ipv4/tcp_nv.c
index 1ff73982e28c..125fc1450b01 100644
--- a/net/ipv4/tcp_nv.c
+++ b/net/ipv4/tcp_nv.c
@@ -252,7 +252,7 @@ static void tcpnv_acked(struct sock *sk, const struct ack_sample *sample)
/* rate in 100's bits per second */
rate64 = ((u64)sample->in_flight) * 8000000;
- rate = (u32)div64_u64(rate64, (u64)(avg_rtt * 100));
+ rate = (u32)div64_u64(rate64, (u64)(avg_rtt ?: 1) * 100);
/* Remember the maximum rate seen during this RTT
* Note: It may be more than one RTT. This function should be
next reply other threads:[~2017-11-01 13:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-01 13:32 Konstantin Khlebnikov [this message]
2017-11-01 13:47 ` Lawrence Brakmo
2017-11-01 14:13 ` Stephen Hemminger
2017-11-01 14:17 ` Eric Dumazet
2017-11-02 7:17 ` David Miller
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