[dpdk-dev] [PATCH 2/2] net/mlx5: fix crash in dev_info_get in secondary process

[Stephen Hemminger <stephen@networkplumber.org>]

mlx5_dev_info_get calls mlx5_get_ifname, but mlx5_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.

Fixes: e60fbd5b24fc ("mlx5: add device configure/start/stop")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/mlx5/mlx5.c        | 17 ++++++++---------
 drivers/net/mlx5/mlx5.h        |  1 +
 drivers/net/mlx5/mlx5_ethdev.c |  4 +---
 3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index d93f92db56b5..27c5ef9b1763 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -1105,6 +1105,7 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
 	int own_domain_id = 0;
 	uint16_t port_id;
 	unsigned int i;
+	char ifname[IF_NAMESIZE];
 
 	/* Determine if this port representor is supposed to be spawned. */
 	if (switch_info->representor && dpdk_dev->devargs) {
@@ -1479,18 +1480,16 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
 		mac.addr_bytes[0], mac.addr_bytes[1],
 		mac.addr_bytes[2], mac.addr_bytes[3],
 		mac.addr_bytes[4], mac.addr_bytes[5]);
-#ifndef NDEBUG
-	{
-		char ifname[IF_NAMESIZE];
 
-		if (mlx5_get_ifname(eth_dev, &ifname) == 0)
-			DRV_LOG(DEBUG, "port %u ifname is \"%s\"",
+	if (mlx5_get_ifname(eth_dev, &ifname) == 0) {
+		priv->if_index = if_nametoindex(ifname);
+		DRV_LOG(DEBUG, "port %u ifname is \"%s\"",
 				eth_dev->data->port_id, ifname);
-		else
-			DRV_LOG(DEBUG, "port %u ifname is unknown",
-				eth_dev->data->port_id);
+	} else {
+		DRV_LOG(DEBUG, "port %u ifname is unknown",
+			eth_dev->data->port_id);
 	}
-#endif
+
 	/* Get actual MTU if possible. */
 	err = mlx5_get_mtu(eth_dev, &priv->mtu);
 	if (err) {
diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 5af3f413cdcb..a06ffd444255 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -342,6 +342,7 @@ struct mlx5_priv {
 	uint16_t vlan_filter[MLX5_MAX_VLAN_IDS]; /* VLAN filters table. */
 	unsigned int vlan_filter_n; /* Number of configured VLAN filters. */
 	/* Device properties. */
+	unsigned int if_index; /* Associated kernel network device index. */
 	uint16_t mtu; /* Configured MTU. */
 	unsigned int isolated:1; /* Whether isolated mode is enabled. */
 	unsigned int representor:1; /* Device is a port representor. */
diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index eeefe4df3cd4..41e58db5e573 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -605,7 +605,6 @@ mlx5_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	struct mlx5_priv *priv = dev->data->dev_private;
 	struct mlx5_dev_config *config = &priv->config;
 	unsigned int max;
-	char ifname[IF_NAMESIZE];
 
 	/* FIXME: we should ask the device for these values. */
 	info->min_rx_bufsize = 32;
@@ -626,8 +625,7 @@ mlx5_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	info->rx_offload_capa = (mlx5_get_rx_port_offloads() |
 				 info->rx_queue_offload_capa);
 	info->tx_offload_capa = mlx5_get_tx_port_offloads(dev);
-	if (mlx5_get_ifname(dev, &ifname) == 0)
-		info->if_index = if_nametoindex(ifname);
+	info->if_index = priv->if_index;
 	info->reta_size = priv->reta_idx_n ?
 		priv->reta_idx_n : config->ind_table_max_size;
 	info->hash_key_size = MLX5_RSS_HASH_KEY_LEN;
-- 
2.20.1