RE: [PATCH] net/iavf: fix core dump when exiting testpmd

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Kaiwen Deng <kaiwenx.deng@intel.com>
> Sent: Thursday, October 26, 2023 4:55 PM
> To: dev@dpdk.org
> Cc: Yang, Qiming <qiming.yang@intel.com>; Zhou, YidingX
> <yidingx.zhou@intel.com>; Deng, KaiwenX <kaiwenx.deng@intel.com>; Wu,
> Jingjing <jingjing.wu@intel.com>; Xing, Beilei <beilei.xing@intel.com>; Lu,
> Wenzhuo <wenzhuo.lu@intel.com>; Richardson, Bruce
> <bruce.richardson@intel.com>
> Subject: [PATCH] net/iavf: fix core dump when exiting testpmd
> 
> release null mbuf results coredump.
> This commit adding mbuf check before releasing.
> 
> Fixes: 12016895fcf3 ("net/iavf: fix buffer leak on Tx queue stop")
> 
> Signed-off-by: Kaiwen Deng <kaiwenx.deng@intel.com>
> ---
>  drivers/net/iavf/iavf_rxtx_vec_common.h | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/iavf/iavf_rxtx_vec_common.h
> b/drivers/net/iavf/iavf_rxtx_vec_common.h
> index e18cdc3f11..f50a500536 100644
> --- a/drivers/net/iavf/iavf_rxtx_vec_common.h
> +++ b/drivers/net/iavf/iavf_rxtx_vec_common.h
> @@ -187,8 +187,11 @@ _iavf_tx_queue_release_mbufs_vec(struct
> iavf_tx_queue *txq)
> 
>  	i = txq->next_dd - txq->rs_thresh + 1;
>  	while (i != txq->tx_tail) {
> -		rte_pktmbuf_free_seg(txq->sw_ring[i].mbuf);
> -		txq->sw_ring[i].mbuf = NULL;
> +		if (txq->sw_ring[i].mbuf) {
> +			rte_pktmbuf_free_seg(txq->sw_ring[i].mbuf);
> +			txq->sw_ring[i].mbuf = NULL;
> +		}

Could you explain how to reproduce this issue in the commit log.

Looks like it is to fix the scenario that queue stop and start again and some mbuf will be double free at some time?

> +
>  		if (++i == txq->nb_tx_desc)
>  			i = 0;
>  	}
> --
> 2.34.1