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, 2 insertions, 1 deletions

diff --git a/drivers/usb/gadget/rndis.c b/drivers/usb/gadget/rndis.c
index fb69b01c8f3a..020fa5a25fda 100644
--- a/drivers/usb/gadget/rndis.c
+++ b/drivers/usb/gadget/rndis.c
@@ -171,6 +171,7 @@ gen_ndis_query_resp (int configNr, u32 OID, u8 *buf, unsigned buf_len,
         int                     i, count;
         rndis_query_cmplt_type  *resp;
         struct net_device       *net;
+        struct rtnl_link_stats64 temp;
         const struct rtnl_link_stats64 *stats;
 
         if (!r) return -ENOMEM;
@@ -194,7 +195,7 @@ gen_ndis_query_resp (int configNr, u32 OID, u8 *buf, unsigned buf_len,
         resp->InformationBufferOffset = cpu_to_le32 (16);
 
         net = rndis_per_dev_params[configNr].dev;
-        stats = dev_get_stats(net);
+        stats = dev_get_stats(net, &temp);
 
         switch (OID) {