s390: avoid inconsistent lock state in qeth

ipv6_regen_rndid in net/ipv6/addrconf.c makes use of "write_lock_bh"
for its inet6_dev->lock. It may run in softirq-context.
qeth makes use of "read_lock" for the same inet6_dev->lock.
To avoid a potential deadlock situation, qeth should make use of
"read_lock_bh" for its usages of inet6_dev->lock.

Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/s390/net/qeth_main.c b/drivers/s390/net/qeth_main.c
index c5a9507..79b7379 100644 (file)
--- a/drivers/s390/net/qeth_main.c
+++ b/drivers/s390/net/qeth_main.c
@@ -5850,9 +5850,9 @@ qeth_add_vlan_mc6(struct qeth_card *card)
                in_dev = in6_dev_get(netdev);
                if (!in_dev)
                        continue;
-               read_lock(&in_dev->lock);
+               read_lock_bh(&in_dev->lock);
                qeth_add_mc6(card,in_dev);
-               read_unlock(&in_dev->lock);
+               read_unlock_bh(&in_dev->lock);
                in6_dev_put(in_dev);
        }
 #endif /* CONFIG_QETH_VLAN */
@@ -5869,10 +5869,10 @@ qeth_add_multicast_ipv6(struct qeth_card *card)
        in6_dev = in6_dev_get(card->dev);
        if (in6_dev == NULL)
                return;
-       read_lock(&in6_dev->lock);
+       read_lock_bh(&in6_dev->lock);
        qeth_add_mc6(card, in6_dev);
        qeth_add_vlan_mc6(card);
-       read_unlock(&in6_dev->lock);
+       read_unlock_bh(&in6_dev->lock);
        in6_dev_put(in6_dev);
 }
 #endif /* CONFIG_QETH_IPV6 */