Re: [dpdk-stable] [PATCH 1/2] net/mlx4: fix crash in dev_info_get in secondary process

[Matan Azrad <matan@mellanox.com>]

Hi Stephen

 From: Stephen Hemminger
> 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: 61cbdd419478 ("net/mlx4: separate device control functions")
> Cc: stable@dpdk.org
> Reported-by: Suyang Ju <sju@paloaltonetworks.com>
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Matan Azrad <matan@mellanox.com>

Thanks for the fix.

> ---
>  drivers/net/mlx4/mlx4.c        | 19 +++++++++----------
>  drivers/net/mlx4/mlx4.h        |  1 +
>  drivers/net/mlx4/mlx4_ethdev.c |  4 +---
>  3 files changed, 11 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c index
> 2e169b0887a7..bab2cadbe519 100644
> --- a/drivers/net/mlx4/mlx4.c
> +++ b/drivers/net/mlx4/mlx4.c
> @@ -763,6 +763,7 @@ 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;
>  	err = mlx4_init_once();
> @@ -1002,17 +1003,15 @@ 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); diff --git
> a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h index
> cd0d637ac2bf..81b529ee8030 100644
> --- a/drivers/net/mlx4/mlx4.h
> +++ b/drivers/net/mlx4/mlx4.h
> @@ -159,6 +159,7 @@ 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. */ diff --git
> a/drivers/net/mlx4/mlx4_ethdev.c b/drivers/net/mlx4/mlx4_ethdev.c index
> ceef921620a8..5d28c0116d21 100644
> --- a/drivers/net/mlx4/mlx4_ethdev.c
> +++ b/drivers/net/mlx4/mlx4_ethdev.c
> @@ -616,7 +616,6 @@ 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;
> @@ -637,8 +636,7 @@ 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 |
> --
> 2.20.1