Re: [dpdk-stable] [PATCH] net/mlx5: fix xstats reset reinitialization

[Raslan Darawsheh <rasland@nvidia.com>]

Hi,

> -----Original Message-----
> From: Shiri Kuzin <shirik@nvidia.com>
> Sent: Monday, October 19, 2020 9:37 AM
> To: dev@dpdk.org
> Cc: matan@mellanox.com; rasland@mellanox.com;
> viacheslavo@mellanox.com; stable@dpdk.org
> Subject: [PATCH] net/mlx5: fix xstats reset reinitialization
> 
> The mlx5_xstats_reset clears the device extended statistics.
> In this function the driver may reinitialize the structures
> that are used to read device counters.
> 
> In case of reinitialization, the number of counters may
> change, which wouldn't be taken into account by the
> reset API callback and can cause a segmentation fault.
> 
> This issue is fixed by allocating the counters size after
> the reinitialization.
> 
> Fixes: a4193ae3bc4f ("net/mlx5: support extended statistics")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Shiri Kuzin <shirik@nvidia.com>
> Acked-by: Matan Azrad <matan@nvidia.com>
> ---
>  drivers/net/mlx5/mlx5_stats.c | 18 +++++++++++++++---
>  1 file changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_stats.c b/drivers/net/mlx5/mlx5_stats.c
> index e30542e..82d4d4a 100644
> --- a/drivers/net/mlx5/mlx5_stats.c
> +++ b/drivers/net/mlx5/mlx5_stats.c
> @@ -17,6 +17,7 @@
>  #include "mlx5_defs.h"
>  #include "mlx5.h"
>  #include "mlx5_rxtx.h"
> +#include "mlx5_malloc.h"
> 
>  /**
>   * DPDK callback to get extended device statistics.
> @@ -216,8 +217,7 @@
>  	struct mlx5_xstats_ctrl *xstats_ctrl = &priv->xstats_ctrl;
>  	int stats_n;
>  	unsigned int i;
> -	unsigned int n = xstats_ctrl->mlx5_stats_n;
> -	uint64_t counters[n];
> +	uint64_t *counters;
>  	int ret;
> 
>  	stats_n = mlx5_os_get_stats_n(dev);
> @@ -228,17 +228,29 @@
>  	}
>  	if (xstats_ctrl->stats_n != stats_n)
>  		mlx5_os_stats_init(dev);
> +	counters =  mlx5_malloc(MLX5_MEM_SYS, sizeof(*counters) *
> +			xstats_ctrl->mlx5_stats_n, 0,
> +			SOCKET_ID_ANY);
> +	if (!counters) {
> +		DRV_LOG(WARNING, "port %u unable to allocate memory
> for xstats "
> +				"counters",
> +		     dev->data->port_id);
> +		rte_errno = ENOMEM;
> +		return -rte_errno;
> +	}
>  	ret = mlx5_os_read_dev_counters(dev, counters);
>  	if (ret) {
>  		DRV_LOG(ERR, "port %u cannot read device counters: %s",
>  			dev->data->port_id, strerror(rte_errno));
> +		mlx5_free(counters);
>  		return ret;
>  	}
> -	for (i = 0; i != n; ++i) {
> +	for (i = 0; i != xstats_ctrl->mlx5_stats_n; ++i) {
>  		xstats_ctrl->base[i] = counters[i];
>  		xstats_ctrl->hw_stats[i] = 0;
>  	}
>  	mlx5_txpp_xstats_reset(dev);
> +	mlx5_free(counters);
>  	return 0;
>  }
> 
> --
> 1.8.3.1

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh