rtnl/do_setlink(): set modified when IFLA_LINKMODE is updated

The only effect of this patch is to print a warning if IFLA_LINKMODE is updated
and a following change fails.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 1 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 5bbaf74bf457..2bd9fb15b987 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1624,8 +1624,12 @@ static int do_setlink(const struct sk_buff *skb,
                 set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
 
         if (tb[IFLA_LINKMODE]) {
+                unsigned char value = nla_get_u8(tb[IFLA_LINKMODE]);
+
                 write_lock_bh(&dev_base_lock);
-                dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
+                if (dev->link_mode ^ value)
+                        modified = 1;
+                dev->link_mode = value;
                 write_unlock_bh(&dev_base_lock);
         }