diff options
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 5 | ||||
| -rw-r--r-- | net/core/fib_notifier.c | 2 | ||||
| -rw-r--r-- | net/core/net_namespace.c | 18 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 5 |
4 files changed, 25 insertions, 5 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index e13807b5c84d..eca5458b2753 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1629,6 +1629,7 @@ int register_netdevice_notifier(struct notifier_block *nb) goto unlock; if (dev_boot_phase) goto unlock; + down_read(&net_rwsem); for_each_net(net) { for_each_netdev(net, dev) { err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev); @@ -1642,6 +1643,7 @@ int register_netdevice_notifier(struct notifier_block *nb) call_netdevice_notifier(nb, NETDEV_UP, dev); } } + up_read(&net_rwsem); unlock: rtnl_unlock(); @@ -1664,6 +1666,7 @@ rollback: } outroll: + up_read(&net_rwsem); raw_notifier_chain_unregister(&netdev_chain, nb); goto unlock; } @@ -1694,6 +1697,7 @@ int unregister_netdevice_notifier(struct notifier_block *nb) if (err) goto unlock; + down_read(&net_rwsem); for_each_net(net) { for_each_netdev(net, dev) { if (dev->flags & IFF_UP) { @@ -1704,6 +1708,7 @@ int unregister_netdevice_notifier(struct notifier_block *nb) call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev); } } + up_read(&net_rwsem); unlock: rtnl_unlock(); return err; diff --git a/net/core/fib_notifier.c b/net/core/fib_notifier.c index 0c048bdeb016..614b985c92a4 100644 --- a/net/core/fib_notifier.c +++ b/net/core/fib_notifier.c @@ -33,6 +33,7 @@ static unsigned int fib_seq_sum(void) struct net *net; rtnl_lock(); + down_read(&net_rwsem); for_each_net(net) { rcu_read_lock(); list_for_each_entry_rcu(ops, &net->fib_notifier_ops, list) { @@ -43,6 +44,7 @@ static unsigned int fib_seq_sum(void) } rcu_read_unlock(); } + up_read(&net_rwsem); rtnl_unlock(); return fib_seq; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index b5796d17a302..7fdf321d4997 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -33,6 +33,10 @@ static struct list_head *first_device = &pernet_list; LIST_HEAD(net_namespace_list); EXPORT_SYMBOL_GPL(net_namespace_list); +/* Protects net_namespace_list. Nests iside rtnl_lock() */ +DECLARE_RWSEM(net_rwsem); +EXPORT_SYMBOL_GPL(net_rwsem); + struct net init_net = { .count = REFCOUNT_INIT(1), .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), @@ -309,9 +313,9 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) if (error < 0) goto out_undo; } - rtnl_lock(); + down_write(&net_rwsem); list_add_tail_rcu(&net->list, &net_namespace_list); - rtnl_unlock(); + up_write(&net_rwsem); out: return error; @@ -450,7 +454,7 @@ static void unhash_nsid(struct net *net, struct net *last) * and this work is the only process, that may delete * a net from net_namespace_list. So, when the below * is executing, the list may only grow. Thus, we do not - * use for_each_net_rcu() or rtnl_lock(). + * use for_each_net_rcu() or net_rwsem. */ for_each_net(tmp) { int id; @@ -485,7 +489,7 @@ static void cleanup_net(struct work_struct *work) down_read(&pernet_ops_rwsem); /* Don't let anyone else find us. */ - rtnl_lock(); + down_write(&net_rwsem); llist_for_each_entry(net, net_kill_list, cleanup_list) list_del_rcu(&net->list); /* Cache last net. After we unlock rtnl, no one new net @@ -499,7 +503,7 @@ static void cleanup_net(struct work_struct *work) * useless anyway, as netns_ids are destroyed there. */ last = list_last_entry(&net_namespace_list, struct net, list); - rtnl_unlock(); + up_write(&net_rwsem); llist_for_each_entry(net, net_kill_list, cleanup_list) { unhash_nsid(net, last); @@ -900,6 +904,9 @@ static int __register_pernet_operations(struct list_head *list, list_add_tail(&ops->list, list); if (ops->init || (ops->id && ops->size)) { + /* We held write locked pernet_ops_rwsem, and parallel + * setup_net() and cleanup_net() are not possible. + */ for_each_net(net) { error = ops_init(ops, net); if (error) @@ -923,6 +930,7 @@ static void __unregister_pernet_operations(struct pernet_operations *ops) LIST_HEAD(net_exit_list); list_del(&ops->list); + /* See comment in __register_pernet_operations() */ for_each_net(net) list_add_tail(&net->exit_list, &net_exit_list); ops_exit_list(ops, &net_exit_list); diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 2d3949789cef..e86b28482ca7 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -418,9 +418,11 @@ void __rtnl_link_unregister(struct rtnl_link_ops *ops) { struct net *net; + down_read(&net_rwsem); for_each_net(net) { __rtnl_kill_links(net, ops); } + up_read(&net_rwsem); list_del(&ops->list); } EXPORT_SYMBOL_GPL(__rtnl_link_unregister); @@ -438,6 +440,9 @@ static void rtnl_lock_unregistering_all(void) for (;;) { unregistering = false; rtnl_lock(); + /* We held write locked pernet_ops_rwsem, and parallel + * setup_net() and cleanup_net() are not possible. + */ for_each_net(net) { if (net->dev_unreg_count > 0) { unregistering = true; |