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>

drivers/parisc/led.c

@@ -355,12 +355,13 @@ static __inline__ int led_get_net_activity(void)
 	rcu_read_lock();
 	for_each_netdev_rcu(&init_net, dev) {
 	    const struct net_device_stats *stats;
+	    struct rtnl_link_stats64 temp;
 	    struct in_device *in_dev = __in_dev_get_rcu(dev);
 	    if (!in_dev || !in_dev->ifa_list)
 		continue;
 	    if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
 		continue;
-	    stats = dev_get_stats(dev);
+	    stats = dev_get_stats(dev, &temp);
 	    rx_total += stats->rx_packets;
 	    tx_total += stats->tx_packets;
 	}