Re: [dpdk-dev] [PATCH] net/bonding: fix crash when stopping mode 4 port

[Chas Williams <3chas3@gmail.com>]

On 11/08/2018 10:26 AM, Radu Nicolau wrote:
> When stopping a bonded port all slaves are deactivated. Attempting
> to deactivate a slave that was never activated will result in a segfault
> when mode 4 is used.
> 
> Fixes: 7486331308f6 ("net/bonding: stop and deactivate slaves on stop")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Radu Nicolau <radu.nicolau@intel.com>

Acked-by: Chas Williams <chas3@att.com>

> ---
>   drivers/net/bonding/rte_eth_bond_pmd.c | 11 ++++++++---
>   1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c b/drivers/net/bonding/rte_eth_bond_pmd.c
> index 1a6d8e4..2661620 100644
> --- a/drivers/net/bonding/rte_eth_bond_pmd.c
> +++ b/drivers/net/bonding/rte_eth_bond_pmd.c
> @@ -2181,9 +2181,14 @@ bond_ethdev_stop(struct rte_eth_dev *eth_dev)
>   
>   	internals->link_status_polling_enabled = 0;
>   	for (i = 0; i < internals->slave_count; i++) {
> -		internals->slaves[i].last_link_status = 0;
> -		rte_eth_dev_stop(internals->slaves[i].port_id);
> -		deactivate_slave(eth_dev, internals->slaves[i].port_id);
> +		uint16_t slave_id = internals->slaves[i].port_id;
> +		if (find_slave_by_id(internals->active_slaves,
> +				internals->active_slave_count, slave_id) !=
> +						internals->active_slave_count) {
> +			internals->slaves[i].last_link_status = 0;
> +			rte_eth_dev_stop(slave_id);
> +			deactivate_slave(eth_dev, slave_id);

Just some commentary. I believe that when this is stopping the bonding
driver is still watching for link status changes. You can't know when
the LSC thread was scheduled to run so something could still activate
a slave after this has deactivated the slaves.

> +		}
>   	}
>   }
>   
>