macsec: fix lockdep splats when nesting devices

Currently, trying to setup a vlan over a macsec device, or other
combinations of devices, triggers a lockdep warning.

Use netdev_lockdep_set_classes and ndo_get_lock_subclass, similar to
what macvlan does.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 2 deletions

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index dbd590a8177f..2043e8c97a81 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -270,6 +270,7 @@ struct macsec_dev {
         struct pcpu_secy_stats __percpu *stats;
         struct list_head secys;
         struct gro_cells gro_cells;
+        unsigned int nest_level;
 };
 
 /**
@@ -2699,6 +2700,8 @@ static netdev_tx_t macsec_start_xmit(struct sk_buff *skb,
 
 #define MACSEC_FEATURES \
         (NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST)
+static struct lock_class_key macsec_netdev_addr_lock_key;
+
 static int macsec_dev_init(struct net_device *dev)
 {
         struct macsec_dev *macsec = macsec_priv(dev);
@@ -2910,6 +2913,13 @@ static int macsec_get_iflink(const struct net_device *dev)
         return macsec_priv(dev)->real_dev->ifindex;
 }
 
+
+static int macsec_get_nest_level(struct net_device *dev)
+{
+        return macsec_priv(dev)->nest_level;
+}
+
+
 static const struct net_device_ops macsec_netdev_ops = {
         .ndo_init               = macsec_dev_init,
         .ndo_uninit             = macsec_dev_uninit,
@@ -2923,6 +2933,7 @@ static const struct net_device_ops macsec_netdev_ops = {
         .ndo_start_xmit         = macsec_start_xmit,
         .ndo_get_stats64        = macsec_get_stats64,
         .ndo_get_iflink         = macsec_get_iflink,
+        .ndo_get_lock_subclass  = macsec_get_nest_level,
 };
 
 static const struct device_type macsec_type = {
@@ -3050,10 +3061,12 @@ static void macsec_del_dev(struct macsec_dev *macsec)
 static void macsec_common_dellink(struct net_device *dev, struct list_head *head)
 {
         struct macsec_dev *macsec = macsec_priv(dev);
+        struct net_device *real_dev = macsec->real_dev;
 
         unregister_netdevice_queue(dev, head);
         list_del_rcu(&macsec->secys);
         macsec_del_dev(macsec);
+        netdev_upper_dev_unlink(real_dev, dev);
 
         macsec_generation++;
 }
@@ -3188,6 +3201,16 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 
         dev_hold(real_dev);
 
+        macsec->nest_level = dev_get_nest_level(real_dev, netif_is_macsec) + 1;
+        netdev_lockdep_set_classes(dev);
+        lockdep_set_class_and_subclass(&dev->addr_list_lock,
+                                       &macsec_netdev_addr_lock_key,
+                                       macsec_get_nest_level(dev));
+
+        err = netdev_upper_dev_link(real_dev, dev);
+        if (err < 0)
+                goto unregister;
+
         /* need to be already registered so that ->init has run and
          * the MAC addr is set
          */
@@ -3200,12 +3223,12 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 
         if (rx_handler && sci_exists(real_dev, sci)) {
                 err = -EBUSY;
-                goto unregister;
+                goto unlink;
         }
 
         err = macsec_add_dev(dev, sci, icv_len);
         if (err)
-                goto unregister;
+                goto unlink;
 
         if (data)
                 macsec_changelink_common(dev, data);
@@ -3220,6 +3243,8 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 
 del_dev:
         macsec_del_dev(macsec);
+unlink:
+        netdev_upper_dev_unlink(real_dev, dev);
 unregister:
         unregister_netdevice(dev);
         return err;