net: Statically initialize init_net.dev_base_head

This change eliminates an initialization-order hazard most
recently seen when netprio_cgroup is built into the kernel.

With thanks to Eric Dumazet for catching a bug.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 5 insertions, 2 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 0f28a9e0b8ad..1cb0d8a6aa6c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6283,7 +6283,8 @@ static struct hlist_head *netdev_create_hash(void)
 /* Initialize per network namespace state */
 static int __net_init netdev_init(struct net *net)
 {
-        INIT_LIST_HEAD(&net->dev_base_head);
+        if (net != &init_net)
+                INIT_LIST_HEAD(&net->dev_base_head);
 
         net->dev_name_head = netdev_create_hash();
         if (net->dev_name_head == NULL)
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index dddbacb8f28c..42f1e1c7514f 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -27,7 +27,9 @@ static DEFINE_MUTEX(net_mutex);
 LIST_HEAD(net_namespace_list);
 EXPORT_SYMBOL_GPL(net_namespace_list);
 
-struct net init_net;
+struct net init_net = {
+        .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
+};
 EXPORT_SYMBOL(init_net);
 
 #define INITIAL_NET_GEN_PTRS    13 /* +1 for len +2 for rcu_head */