diff options
| author | Sabrina Dubroca <sd@queasysnail.net> | 2016-08-12 16:10:33 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-08-14 00:15:54 +0200 |
| commit | 952fcfd08c8109951622579d0ae7b9cd6cafd688 (patch) | |
| tree | 16e787138d3da28899e3a0028962928c79a4af07 /net | |
| parent | macsec: fix lockdep splats when nesting devices (diff) | |
| download | linux-952fcfd08c8109951622579d0ae7b9cd6cafd688.tar.xz linux-952fcfd08c8109951622579d0ae7b9cd6cafd688.zip | |
net: remove type_check from dev_get_nest_level()
The idea for type_check in dev_get_nest_level() was to count the number
of nested devices of the same type (currently, only macvlan or vlan
devices).
This prevented the false positive lockdep warning on configurations such
as:
eth0 <--- macvlan0 <--- vlan0 <--- macvlan1
However, this doesn't prevent a warning on a configuration such as:
eth0 <--- macvlan0 <--- vlan0
eth1 <--- vlan1 <--- macvlan1
In this case, all the locks end up with a nesting subclass of 1, so
lockdep thinks that there is still a deadlock:
- in the first case we have (macvlan_netdev_addr_lock_key, 1) and then
take (vlan_netdev_xmit_lock_key, 1)
- in the second case, we have (vlan_netdev_xmit_lock_key, 1) and then
take (macvlan_netdev_addr_lock_key, 1)
By removing the linktype check in dev_get_nest_level() and always
incrementing the nesting depth, lockdep considers this configuration
valid.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/8021q/vlan.c | 2 | ||||
| -rw-r--r-- | net/core/dev.c | 10 |
2 files changed, 4 insertions, 8 deletions
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 82a116ba590e..8de138d3306b 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -169,7 +169,7 @@ int register_vlan_dev(struct net_device *dev) if (err < 0) goto out_uninit_mvrp; - vlan->nest_level = dev_get_nest_level(real_dev, is_vlan_dev) + 1; + vlan->nest_level = dev_get_nest_level(real_dev) + 1; err = register_netdevice(dev); if (err < 0) goto out_uninit_mvrp; diff --git a/net/core/dev.c b/net/core/dev.c index 4ce07dc25573..dd6ce598de89 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6045,8 +6045,7 @@ void *netdev_lower_dev_get_private(struct net_device *dev, EXPORT_SYMBOL(netdev_lower_dev_get_private); -int dev_get_nest_level(struct net_device *dev, - bool (*type_check)(const struct net_device *dev)) +int dev_get_nest_level(struct net_device *dev) { struct net_device *lower = NULL; struct list_head *iter; @@ -6056,15 +6055,12 @@ int dev_get_nest_level(struct net_device *dev, ASSERT_RTNL(); netdev_for_each_lower_dev(dev, lower, iter) { - nest = dev_get_nest_level(lower, type_check); + nest = dev_get_nest_level(lower); if (max_nest < nest) max_nest = nest; } - if (type_check(dev)) - max_nest++; - - return max_nest; + return max_nest + 1; } EXPORT_SYMBOL(dev_get_nest_level); |