diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h index 3ebfcc6e56fd..7559020f760c 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -71,7 +71,7 @@ static inline int rtnl_msg_family(const struct nlmsghdr *nlh) /** * struct rtnl_link_ops - rtnetlink link operations * - * @list: Used internally, protected by RTNL and SRCU + * @list: Used internally, protected by link_ops_mutex and SRCU * @srcu: Used internally * @kind: Identifier * @netns_refund: Physical device, move to init_net on netns exit diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index f0246ecec7fa..21154ef0048f 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -466,6 +466,7 @@ void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n) } EXPORT_SYMBOL_GPL(__rtnl_unregister_many); +static DEFINE_MUTEX(link_ops_mutex); static LIST_HEAD(link_ops); static struct rtnl_link_ops *rtnl_link_ops_get(const char *kind, int *srcu_index) @@ -508,14 +509,6 @@ int __rtnl_link_register(struct rtnl_link_ops *ops) struct rtnl_link_ops *tmp; int err; - /* When RTNL is removed, add lock for link_ops. */ - ASSERT_RTNL(); - - list_for_each_entry(tmp, &link_ops, list) { - if (!strcmp(ops->kind, tmp->kind)) - return -EEXIST; - } - /* The check for alloc/setup is here because if ops * does not have that filled up, it is not possible * to use the ops for creating device. So do not @@ -528,9 +521,20 @@ int __rtnl_link_register(struct rtnl_link_ops *ops) if (err) return err; - list_add_tail_rcu(&ops->list, &link_ops); + mutex_lock(&link_ops_mutex); - return 0; + list_for_each_entry(tmp, &link_ops, list) { + if (!strcmp(ops->kind, tmp->kind)) { + err = -EEXIST; + goto unlock; + } + } + + list_add_tail_rcu(&ops->list, &link_ops); +unlock: + mutex_unlock(&link_ops_mutex); + + return err; } EXPORT_SYMBOL_GPL(__rtnl_link_register); @@ -598,14 +602,17 @@ void rtnl_link_unregister(struct rtnl_link_ops *ops) { struct net *net; + mutex_lock(&link_ops_mutex); + list_del_rcu(&ops->list); + mutex_unlock(&link_ops_mutex); + + synchronize_srcu(&ops->srcu); + cleanup_srcu_struct(&ops->srcu); + /* Close the race with setup_net() and cleanup_net() */ down_write(&pernet_ops_rwsem); rtnl_lock_unregistering_all(); - list_del_rcu(&ops->list); - synchronize_srcu(&ops->srcu); - cleanup_srcu_struct(&ops->srcu); - for_each_net(net) __rtnl_kill_links(net, ops);