RDMA/netdev: Fix netlink support in IPoIB

IPoIB netlink support was broken by the below commit since integrating
the rdma_netdev support relies on an allocation flow for netdevs that
was controlled by the ipoib driver while netdev's rtnl_newlink
implementation assumes that the netdev will be allocated by netlink.
Such situation leads to crash in __ipoib_device_add, once trying to
reuse netlink device.

This patch fixes the kernel oops for both mlx4 and mlx5
devices triggered by the following command:

Fixes: cd565b4b51e5 ("IB/IPoIB: Support acceleration options callbacks")
Signed-off-by: Denis Drozdov <denisd@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 21 insertions, 7 deletions

diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index 2f34d3412097..8ec7418e99f0 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -2643,13 +2643,27 @@ struct net_device *rdma_alloc_netdev(struct ib_device *device, u8 port_num,
 	if (!netdev)
 		return ERR_PTR(-ENOMEM);
 
-	rc = params.initialize_rdma_netdev(device, port_num, netdev,
-					   params.param);
-	if (rc) {
-		free_netdev(netdev);
-		return ERR_PTR(rc);
-	}
-
 	return netdev;
 }
 EXPORT_SYMBOL(rdma_alloc_netdev);
+
+int rdma_init_netdev(struct ib_device *device, u8 port_num,
+		     enum rdma_netdev_t type, const char *name,
+		     unsigned char name_assign_type,
+		     void (*setup)(struct net_device *),
+		     struct net_device *netdev)
+{
+	struct rdma_netdev_alloc_params params;
+	int rc;
+
+	if (!device->rdma_netdev_get_params)
+		return -EOPNOTSUPP;
+
+	rc = device->rdma_netdev_get_params(device, port_num, type, &params);
+	if (rc)
+		return rc;
+
+	return params.initialize_rdma_netdev(device, port_num,
+					     netdev, params.param);
+}
+EXPORT_SYMBOL(rdma_init_netdev);