path: root/drivers/net/hamradio/bpqether.c
diff options
authorCong Wang <xiyou.wangcong@gmail.com>2020-06-08 14:53:01 -0700
committerDavid S. Miller <davem@davemloft.net>2020-06-09 12:59:45 -0700
commit845e0ebb4408d4473cf60d21224a897037e9a77a (patch)
tree053282d21248269b50668f920d39ba07b7a0277d /drivers/net/hamradio/bpqether.c
parentselftests/net: in timestamping, strncpy needs to preserve null byte (diff)
net: change addr_list_lock back to static key
The dynamic key update for addr_list_lock still causes troubles, for example the following race condition still exists: CPU 0: CPU 1: (RCU read lock) (RTNL lock) dev_mc_seq_show() netdev_update_lockdep_key() -> lockdep_unregister_key() -> netif_addr_lock_bh() because lockdep doesn't provide an API to update it atomically. Therefore, we have to move it back to static keys and use subclass for nest locking like before. In commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key changes"), I already reverted most parts of commit ab92d68fc22f ("net: core: add generic lockdep keys"). This patch reverts the rest and also part of commit f3b0a18bb6cb ("net: remove unnecessary variables and callback"). After this patch, addr_list_lock changes back to using static keys and subclasses to satisfy lockdep. Thanks to dev->lower_level, we do not have to change back to ->ndo_get_lock_subclass(). And hopefully this reduces some syzbot lockdep noises too. Reported-by: syzbot+f3a0e80c34b3fc28ac5e@syzkaller.appspotmail.com Cc: Taehee Yoo <ap420073@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c
index 60dcaf2a04a9..1ad6085994b1 100644
--- a/drivers/net/hamradio/bpqether.c
+++ b/drivers/net/hamradio/bpqether.c
@@ -113,6 +113,7 @@ static LIST_HEAD(bpq_devices);
* off into a separate class since they always nest.
static struct lock_class_key bpq_netdev_xmit_lock_key;
+static struct lock_class_key bpq_netdev_addr_lock_key;
static void bpq_set_lockdep_class_one(struct net_device *dev,
struct netdev_queue *txq,
@@ -123,6 +124,7 @@ static void bpq_set_lockdep_class_one(struct net_device *dev,
static void bpq_set_lockdep_class(struct net_device *dev)
+ lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);