Subject: Re: [PATCH net v3 1/4] octeon_ep: fix race conditions in ndo_get_stats64

From: Jakub Kicinski <[email-masked]>
Date: Thu, 19 Dec 2024 19:21:23 -0800

On Wed, 18 Dec 2024 03:51:08 -0800 Shinas Rasheed wrote:
> ndo_get_stats64() can race with ndo_stop(), which frees input and
> output queue resources. Call synchronize_net() to avoid such races.

synchronize_rcu() acts as a barrier.
What are the two operations you are separating with this barrier?

> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> index 549436efc204..941bbaaa67b5 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> @@ -757,6 +757,7 @@ static int octep_stop(struct net_device *netdev)
>  {
>  	struct octep_device *oct = netdev_priv(netdev);
>  
> +	synchronize_net();
>  	netdev_info(netdev, "Stopping the device ...\n");