1 files changed, 27 insertions, 25 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2ea3d63e1d4c..25e68f56b4ba 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -530,33 +530,35 @@ static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 {
         struct net_device *dev;
         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
+        struct ethtool_cmd ecmd;
+        int err;
 
-        dev = dev_get_by_index(sock_net(&po->sk), po->ifindex);
-        if (unlikely(dev == NULL))
+        rtnl_lock();
+        dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
+        if (unlikely(!dev)) {
+                rtnl_unlock();
                 return DEFAULT_PRB_RETIRE_TOV;
-
-        if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
-                struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
-
-                if (!dev->ethtool_ops->get_settings(dev, &ecmd)) {
-                        switch (ecmd.speed) {
-                        case SPEED_10000:
-                                msec = 1;
-                                div = 10000/1000;
-                                break;
-                        case SPEED_1000:
-                                msec = 1;
-                                div = 1000/1000;
-                                break;
-                        /*
-                         * If the link speed is so slow you don't really
-                         * need to worry about perf anyways
-                         */
-                        case SPEED_100:
-                        case SPEED_10:
-                        default:
-                                return DEFAULT_PRB_RETIRE_TOV;
-                        }
+        }
+        err = __ethtool_get_settings(dev, &ecmd);
+        rtnl_unlock();
+        if (!err) {
+                switch (ecmd.speed) {
+                case SPEED_10000:
+                        msec = 1;
+                        div = 10000/1000;
+                        break;
+                case SPEED_1000:
+                        msec = 1;
+                        div = 1000/1000;
+                        break;
+                /*
+                 * If the link speed is so slow you don't really
+                 * need to worry about perf anyways
+                 */
+                case SPEED_100:
+                case SPEED_10:
+                default:
+                        return DEFAULT_PRB_RETIRE_TOV;
                 }
         }