1 files changed, 5 insertions, 4 deletions

diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 07e839e387db..b10154cc46b6 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -498,10 +498,8 @@ struct eth_init {
         int index;
 };
 
-/* Filled in at boot time.  Will need locking if the transports become
- * modular.
- */
-struct list_head transports = LIST_HEAD_INIT(transports);
+static DEFINE_SPINLOCK(transports_lock);
+static LIST_HEAD(transports);
 
 /* Filled in during early boot */
 struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
@@ -540,7 +538,10 @@ void register_transport(struct transport *new)
         char *mac = NULL;
         int match;
 
+        spin_lock(&transports_lock);
+        BUG_ON(!list_empty(&new->list));
         list_add(&new->list, &transports);
+        spin_unlock(&transports_lock);
 
         list_for_each_safe(ele, next, &eth_cmd_line){
                 eth = list_entry(ele, struct eth_init, list);