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>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index e645778..5e773ea 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -791,6 +791,7 @@
{
struct ifinfomsg *ifm;
struct nlmsghdr *nlh;
+ struct rtnl_link_stats64 temp;
const struct rtnl_link_stats64 *stats;
struct nlattr *attr;
@@ -847,7 +848,7 @@
if (attr == NULL)
goto nla_put_failure;
- stats = dev_get_stats(dev);
+ stats = dev_get_stats(dev, &temp);
copy_rtnl_link_stats(nla_data(attr), stats);
attr = nla_reserve(skb, IFLA_STATS64,