Commit 435bc9df authored Feb 07, 2008 by Ursula Braun Committed by David S. Miller Feb 07, 2008

[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>

parent a219994b

net/iucv/iucv.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);

Admin message