[PATCH AUTOSEL 4.14 232/371] net/af_iucv: always register net_device notifier

Sasha Levin
2020-01-16T18:20:33Z

From: Julian Wiedmann <jwi@linux.ibm.com>

[ Upstream commit 06996c1d4088a0d5f3e7789d7f96b4653cc947cc ]

Even when running as VM guest (ie pr_iucv != NULL), af_iucv can still
open HiperTransport-based connections. For robust operation these
connections require the af_iucv_netdev_notifier, so register it
unconditionally.

Also handle any error that register_netdevice_notifier() returns.

Fixes: 9fbd87d41392 ("af_iucv: handle netdev events")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/iucv/af_iucv.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index ca98276c2709..7a9cbc9502d9 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -2446,6 +2446,13 @@ static int afiucv_iucv_init(void)
return err;
}

+static void afiucv_iucv_exit(void)
+{
+ device_unregister(af_iucv_dev);
+ driver_unregister(&af_iucv_driver);
+ pr_iucv->iucv_unregister(&af_iucv_handler, 0);
+}
+
static int __init afiucv_init(void)
{
int err;
@@ -2479,11 +2486,18 @@ static int __init afiucv_init(void)
err = afiucv_iucv_init();
if (err)
goto out_sock;
- } else
- register_netdevice_notifier(&afiucv_netdev_notifier);
+ }
+
+ err = register_netdevice_notifier(&afiucv_netdev_notifier);
+ if (err)
+ goto out_notifier;
+
dev_add_pack(&iucv_packet_type);
return 0;

+out_notifier:
+ if (pr_iucv)
+ afiucv_iucv_exit();
out_sock:
sock_unregister(PF_IUCV);
out_proto:
@@ -2497,12 +2511,11 @@ static int __init afiucv_init(void)
static void __exit afiucv_exit(void)
{
if (pr_iucv) {
- device_unregister(af_iucv_dev);
- driver_unregister(&af_iucv_driver);
- pr_iucv->iucv_unregister(&af_iucv_handler, 0);
+ afiucv_iucv_exit();
symbol_put(iucv_if);
- } else
- unregister_netdevice_notifier(&afiucv_netdev_notifier);
+ }
+
+ unregister_netdevice_notifier(&afiucv_netdev_notifier);
dev_remove_pack(&iucv_packet_type);
sock_unregister(PF_IUCV);
proto_unregister(&iucv_proto);
--
2.20.1