3.16.48-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Dominik Heidler <dheidler@xxxxxxx>
commit 9b3dc0a17d7388c4fb83736ca45253a93e994ce4 upstream.
This fixes a counter problem on 32bit systems:
When the rx_bytes counter reached 2 GiB, it jumpd to (2^64 Bytes - 2GiB) Bytes.
rtnl_link_stats64 has __u64 type and atomic_long_read returns
atomic_long_t which is signed. Due to the conversation
we get an incorrect value on 32bit systems if the MSB of
the atomic_long_t value is set.
CC: Tom Parkin <tparkin@xxxxxxxxxxx>
Fixes: 7b7c0719cd7a ("l2tp: avoid deadlock in l2tp stats update")
Signed-off-by: Dominik Heidler <dheidler@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
net/l2tp/l2tp_eth.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -111,12 +111,13 @@ static struct rtnl_link_stats64 *l2tp_et
{
struct l2tp_eth *priv = netdev_priv(dev);
- stats->tx_bytes = atomic_long_read(&priv->tx_bytes);
- stats->tx_packets = atomic_long_read(&priv->tx_packets);
- stats->tx_dropped = atomic_long_read(&priv->tx_dropped);
- stats->rx_bytes = atomic_long_read(&priv->rx_bytes);
- stats->rx_packets = atomic_long_read(&priv->rx_packets);
- stats->rx_errors = atomic_long_read(&priv->rx_errors);
+ stats->tx_bytes = (unsigned long) atomic_long_read(&priv->tx_bytes);
+ stats->tx_packets = (unsigned long) atomic_long_read(&priv->tx_packets);
+ stats->tx_dropped = (unsigned long) atomic_long_read(&priv->tx_dropped);
+ stats->rx_bytes = (unsigned long) atomic_long_read(&priv->rx_bytes);
+ stats->rx_packets = (unsigned long) atomic_long_read(&priv->rx_packets);
+ stats->rx_errors = (unsigned long) atomic_long_read(&priv->rx_errors);
+
return stats;
}