path: root/include/linux/netdevice.h
diff options
authorEric Dumazet <eric.dumazet@gmail.com>2011-01-26 18:08:02 +0000
committerDavid S. Miller <davem@davemloft.net>2011-01-27 15:02:56 -0800
commitccf434380d1a67df2dcb9113206b77d0cb0a1cef (patch)
tree1e1a36691f42ed7448f27f71a9ca9445e88ab5f1 /include/linux/netdevice.h
parentnet: Store ipv4/ipv6 COW'd metrics in inetpeer cache. (diff)
net: fix dev_seq_next()
Commit c6d14c84566d (net: Introduce for_each_netdev_rcu() iterator) added a race in dev_seq_next(). The rcu_dereference() call should be done _before_ testing the end of list, or we might return a wrong net_device if a concurrent thread changes net_device list under us. Note : discovered thanks to a sparse warning : net/core/dev.c:3919:9: error: incompatible types in comparison expression (different address spaces) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/netdevice.h')
1 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8858422c5c5d..c7d707452228 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1447,7 +1447,7 @@ static inline struct net_device *next_net_device_rcu(struct net_device *dev)
struct net *net;
net = dev_net(dev);
- lh = rcu_dereference(dev->dev_list.next);
+ lh = rcu_dereference(list_next_rcu(&dev->dev_list));
return lh == &net->dev_base_head ? NULL : net_device_entry(lh);
@@ -1457,6 +1457,13 @@ static inline struct net_device *first_net_device(struct net *net)
+static inline struct net_device *first_net_device_rcu(struct net *net)
+ struct list_head *lh = rcu_dereference(list_next_rcu(&net->dev_base_head));
+ return lh == &net->dev_base_head ? NULL : net_device_entry(lh);
extern int netdev_boot_setup_check(struct net_device *dev);
extern unsigned long netdev_boot_base(const char *prefix, int unit);
extern struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,