net: fix 64 bit counters on 32 bit arches

There is a small possibility that a reader gets incorrect values on 32
bit arches. SNMP applications could catch incorrect counters when a
32bit high part is changed by another stats consumer/provider.

One way to solve this is to add a rtnl_link_stats64 param to all
ndo_get_stats64() methods, and also add such a parameter to
dev_get_stats().

Rule is that we are not allowed to use dev->stats64 as a temporary
storage for 64bit stats, but a caller provided area (usually on stack)

Old drivers (only providing get_stats() method) need no changes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index e6d626e78515..6112f1498940 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -431,12 +431,12 @@ static void macvlan_uninit(struct net_device *dev)
         free_percpu(vlan->rx_stats);
 }
 
-static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev)
+static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev,
+                                                         struct rtnl_link_stats64 *stats)
 {
-        struct rtnl_link_stats64 *stats = &dev->stats64;
         struct macvlan_dev *vlan = netdev_priv(dev);
 
-        dev_txq_stats_fold(dev, &dev->stats);
+        dev_txq_stats_fold(dev, (struct net_device_stats *)stats);
 
         if (vlan->rx_stats) {
                 struct macvlan_rx_stats *p, accum = {0};