net: partially revert dynamic lockdep key changes

This patch reverts the folowing commits:

commit 064ff66e2bef84f1153087612032b5b9eab005bd
"bonding: add missing netdev_update_lockdep_key()"

commit 53d374979ef147ab51f5d632dfe20b14aebeccd0
"net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()"

commit 1f26c0d3d24125992ab0026b0dab16c08df947c7
"net: fix kernel-doc warning in <linux/netdevice.h>"

commit ab92d68fc22f9afab480153bd82a20f6e2533769
"net: core: add generic lockdep keys"

but keeps the addr_list_lock_key because we still lock
addr_list_lock nestedly on stack devices, unlikely xmit_lock
this is safe because we don't take addr_list_lock on any fast
path.

Reported-and-tested-by: syzbot+aaa6fa4949cc5d9b7b25@syzkaller.appspotmail.com
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 0 deletions

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 5f05a728f347..822af540b854 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -739,6 +739,34 @@ static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
 	return 0;
 }
 
+/* batman-adv network devices have devices nesting below it and are a special
+ * "super class" of normal network devices; split their locks off into a
+ * separate class since they always nest.
+ */
+static struct lock_class_key batadv_netdev_xmit_lock_key;
+
+/**
+ * batadv_set_lockdep_class_one() - Set lockdep class for a single tx queue
+ * @dev: device which owns the tx queue
+ * @txq: tx queue to modify
+ * @_unused: always NULL
+ */
+static void batadv_set_lockdep_class_one(struct net_device *dev,
+					 struct netdev_queue *txq,
+					 void *_unused)
+{
+	lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
+}
+
+/**
+ * batadv_set_lockdep_class() - Set txq and addr_list lockdep class
+ * @dev: network device to modify
+ */
+static void batadv_set_lockdep_class(struct net_device *dev)
+{
+	netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
+}
+
 /**
  * batadv_softif_init_late() - late stage initialization of soft interface
  * @dev: registered network device to modify
@@ -752,6 +780,8 @@ static int batadv_softif_init_late(struct net_device *dev)
 	int ret;
 	size_t cnt_len = sizeof(u64) * BATADV_CNT_NUM;
 
+	batadv_set_lockdep_class(dev);
+
 	bat_priv = netdev_priv(dev);
 	bat_priv->soft_iface = dev;