Re: [dpdk-dev] [PATCH] librte_ether: fix crashes in rte_ethdev functions.

["Qiu, Michael" <michael.qiu@intel.com>]

On 2015/12/18 1:24, Bernard Iremonger wrote:
> The nb_rx_queues and nb_tx_queues are initialised before
> the tx_queue and rx_queue arrays are allocated. The arrays
> are allocated when the ethdev port is started.
>
> If any of the following functions are called before the ethdev
> port is started there is a segmentation fault:
>
> rte_eth_stats_get
> rte_eth_stats_reset
> rte_eth_xstats_get
> rte_eth_xstats_reset
>
> Fixes: af75078fece3 ("first public release")
> Fixes: ce757f5c9a4d ("ethdev: new method to retrieve extended statistics")
> Fixes: d4fef8b0d5e5 ("ethdev: expose generic and driver specific stats in xstats")
> Signed-off-by: Bernard Iremonger <bernard.iremonger@intel.com>
> ---
>  lib/librte_ether/rte_ethdev.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index ed971b4..a0ee84d 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -1441,7 +1441,10 @@ rte_eth_stats_get(uint8_t port_id, struct rte_eth_stats *stats)
>  	memset(stats, 0, sizeof(*stats));
>  
>  	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->stats_get, -ENOTSUP);
> -	(*dev->dev_ops->stats_get)(dev, stats);
> +
> +	if (dev->data->dev_started)
> +		(*dev->dev_ops->stats_get)(dev, stats);
> +

My question is should we mark an error or a warning here and return an
error so that the caller knows what happens?

Thanks,
Michael

>  	stats->rx_nombuf = dev->data->rx_mbuf_alloc_failed;
>  	return 0;
>  }
> @@ -1455,7 +1458,10 @@ rte_eth_stats_reset(uint8_t port_id)
>  	dev = &rte_eth_devices[port_id];
>  
>  	RTE_FUNC_PTR_OR_RET(*dev->dev_ops->stats_reset);
> -	(*dev->dev_ops->stats_reset)(dev);
> +
> +	if (dev->data->dev_started)
> +		(*dev->dev_ops->stats_reset)(dev);
> +
>  	dev->data->rx_mbuf_alloc_failed = 0;
>  }
>  
> @@ -1479,7 +1485,8 @@ rte_eth_xstats_get(uint8_t port_id, struct rte_eth_xstats *xstats,
>  		(dev->data->nb_tx_queues * RTE_NB_TXQ_STATS);
>  
>  	/* implemented by the driver */
> -	if (dev->dev_ops->xstats_get != NULL) {
> +	if ((dev->dev_ops->xstats_get != NULL) &&
> +		(dev->data->dev_started)) {
>  		/* Retrieve the xstats from the driver at the end of the
>  		 * xstats struct.
>  		 */
> @@ -1548,7 +1555,8 @@ rte_eth_xstats_reset(uint8_t port_id)
>  	dev = &rte_eth_devices[port_id];
>  
>  	/* implemented by the driver */
> -	if (dev->dev_ops->xstats_reset != NULL) {
> +	if ((dev->dev_ops->xstats_reset != NULL) &&
> +		(dev->data->dev_started)) {
>  		(*dev->dev_ops->xstats_reset)(dev);
>  		return;
>  	}