[IUCV]: wrong irq-disabling locking at module load time

Linux may hang when running af_iucv socket programs concurrently
with a load of module netiucv. iucv_register() tries to take the
iucv_table_lock with spin_lock_irq. This conflicts with
iucv_connect() which has a need for an smp_call_function while
holding the iucv_table_lock.
Solution: use bh-disabling locking in iucv_register()

Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index f13fe8821cbd7bf7817c6eacb85709aaca134492..2753b0c448f374f3f27c26f991e97d94c43459ad 100644 (file)
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -693,9 +693,9 @@ int iucv_register(struct iucv_handler *handler, int smp)
                iucv_setmask_up();
        INIT_LIST_HEAD(&handler->paths);
 
-       spin_lock_irq(&iucv_table_lock);
+       spin_lock_bh(&iucv_table_lock);
        list_add_tail(&handler->list, &iucv_handler_list);
-       spin_unlock_irq(&iucv_table_lock);
+       spin_unlock_bh(&iucv_table_lock);
        rc = 0;
 out_mutex:
        mutex_unlock(&iucv_register_mutex);