net: restore gnet_stats_basic to previous definition

In 5e140dfc1fe87eae27846f193086724806b33c7d "net: reorder struct Qdisc
for better SMP performance" the definition of struct gnet_stats_basic
changed incompatibly, as copies of this struct are shipped to
userland via netlink.

Restoring old behavior is not welcome, for performance reason.

Fix is to use a private structure for kernel, and
teach gnet_stats_copy_basic() to convert from kernel to user land,
using legacy structure (struct gnet_stats_basic)

Based on a report and initial patch from Michael Spang.

Reported-by: Michael Spang <mspang@csclub.uwaterloo.ca>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/act_api.h b/include/net/act_api.h
index 565eed8fe496..c05fd717c588 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -16,7 +16,7 @@ struct tcf_common {
         u32                             tcfc_capab;
         int                             tcfc_action;
         struct tcf_t                    tcfc_tm;
-        struct gnet_stats_basic         tcfc_bstats;
+        struct gnet_stats_basic_packed  tcfc_bstats;
         struct gnet_stats_queue         tcfc_qstats;
         struct gnet_stats_rate_est      tcfc_rate_est;
         spinlock_t                      tcfc_lock;