net/mlx4: fix crash on info query in secondary process

[ upstream commit 164cad7 ]

mlx4_dev_info_get calls mlx4_get_ifname, but mlx4_get_ifname
uses priv->ctx which is not a valid pointer in a secondary
process. The fix is to cache the value in primary.

In the primary process, get and store the interface index of
the device so that secondary process can see it.

Bugzilla ID: 320
Fixes: 61cbdd4 ("net/mlx4: separate device control functions")

Reported-by: Suyang Ju <sju@paloaltonetworks.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Matan Azrad <matan@mellanox.com>

drivers/net/mlx4/mlx4.c

@@ -520,6 +520,7 @@ mlx4_pci_probe(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 	};
 	unsigned int vf;
 	int i;
+	char ifname[IF_NAMESIZE];
 
 	(void)pci_drv;
 	assert(pci_drv == &mlx4_driver);
@@ -703,17 +704,15 @@ mlx4_pci_probe(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 		     mac.addr_bytes[4], mac.addr_bytes[5]);
 		/* Register MAC address. */
 		priv->mac[0] = mac;
-#ifndef NDEBUG
-		{
-			char ifname[IF_NAMESIZE];
 
-			if (mlx4_get_ifname(priv, &ifname) == 0)
-				DEBUG("port %u ifname is \"%s\"",
-				      priv->port, ifname);
-			else
-				DEBUG("port %u ifname is unknown", priv->port);
+		if (mlx4_get_ifname(priv, &ifname) == 0) {
+			DEBUG("port %u ifname is \"%s\"",
+			      priv->port, ifname);
+			priv->if_index = if_nametoindex(ifname);
+		} else {
+			DEBUG("port %u ifname is unknown", priv->port);
 		}
-#endif
+
 		/* Get actual MTU if possible. */
 		mlx4_mtu_get(priv, &priv->mtu);
 		DEBUG("port %u MTU is %u", priv->port, priv->mtu);

drivers/net/mlx4/mlx4.h

@@ -84,6 +84,7 @@ struct mlx4_priv {
 	struct ibv_device_attr device_attr; /**< Device properties. */
 	struct ibv_pd *pd; /**< Protection Domain. */
 	/* Device properties. */
+	unsigned int if_index;	/**< Associated network device index */
 	uint16_t mtu; /**< Configured MTU. */
 	uint8_t port; /**< Physical port number. */
 	uint32_t started:1; /**< Device started, flows enabled. */

drivers/net/mlx4/mlx4_ethdev.c

@@ -559,7 +559,6 @@ mlx4_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 {
 	struct mlx4_priv *priv = dev->data->dev_private;
 	unsigned int max;
-	char ifname[IF_NAMESIZE];
 
 	/* FIXME: we should ask the device for these values. */
 	info->min_rx_bufsize = 32;
@@ -580,8 +579,7 @@ mlx4_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	info->rx_queue_offload_capa = mlx4_get_rx_queue_offloads(priv);
 	info->rx_offload_capa = (mlx4_get_rx_port_offloads(priv) |
 				 info->rx_queue_offload_capa);
-	if (mlx4_get_ifname(priv, &ifname) == 0)
-		info->if_index = if_nametoindex(ifname);
+	info->if_index = priv->if_index;
 	info->hash_key_size = MLX4_RSS_HASH_KEY_SIZE;
 	info->speed_capa =
 			ETH_LINK_SPEED_1G |