From: Eric Dumazet eric.dumazet@gmail.com

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 [sven.eckelmann@gmx.de: Added compat.h defines for pre-2.6.36 kernels] Signed-off-by: Sven Eckelmann sven.eckelmann@gmx.de --- This patch entered net-next-2.6 today. It is also part of maint and must be applied in trunk too.

The original commit can be found using its SHA1 28172739f0a276eb8d6ca917b3974c2edb036da3.

batman-adv/compat.h | 8 ++++++++ batman-adv/hard-interface.c | 3 ++- 2 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/batman-adv/compat.h b/batman-adv/compat.h index 09016c8..103593d 100644 --- a/batman-adv/compat.h +++ b/batman-adv/compat.h @@ -249,4 +249,12 @@ static inline struct net_device_stats *dev_get_stats(struct net_device *dev)

#endif /* < KERNEL_VERSION(2, 6, 29) */

+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36) + +#define dev_get_stats(x, y) dev_get_stats(x) + +#define rtnl_link_stats64 rtnl_link_stats __attribute__((unused)) + +#endif /* < KERNEL_VERSION(2, 6, 36) */ + #endif /* _NET_BATMAN_ADV_COMPAT_H_ */ diff --git a/batman-adv/hard-interface.c b/batman-adv/hard-interface.c index 5ff9dcb..6a37c33 100644 --- a/batman-adv/hard-interface.c +++ b/batman-adv/hard-interface.c @@ -445,6 +445,7 @@ int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, struct batman_packet *batman_packet; struct batman_if *batman_if; struct net_device_stats *stats; + struct rtnl_link_stats64 temp; int ret;

skb = skb_share_check(skb, GFP_ATOMIC); @@ -480,7 +481,7 @@ int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, if (batman_if->if_status != IF_ACTIVE) goto err_free;

- stats = (struct net_device_stats *)dev_get_stats(skb->dev); + stats = (struct net_device_stats *)dev_get_stats(skb->dev, &temp); if (stats) { stats->rx_packets++; stats->rx_bytes += skb->len;