[dpdk-dev] [PATCH v2] net/mlx5: fix potential unreleased lock problem

[Slava Ovsiienko]

Hi, Chengfeng

Thank you for the fix, we can adopt this (ie Upstream ML is not "wrong place" 😊)
I have some minor comment about:
- the problem should be described in past tense (should b e"sh->txpp.mutex WAS not correctly")
- headline should be more specific, like "fix mutex unlock in txpp cleanup")
- "Fixes:" tag should be present
- Cc: stable at dpdk.org  should be present

Could you, please, update and send v3 ?

With best regards,
Slava

> -----Original Message-----
> From: dev <dev-bounces at dpdk.org> On Behalf Of YE Chengfeng
> Sent: Thursday, August 26, 2021 22:06
> To: asomalap at amd.com
> Cc: dev at dpdk.org
> Subject: [dpdk-dev] 回复: [PATCH v2] net/mlx5: fix potential unreleased lock
> problem
> 
> It seems that I send this patch to a wrong place,  please just ignore it.
> 
> Thanks,
> Chengfeng
> ________________________________
> 发件人: YE Chengfeng <cyeaa at connect.ust.hk>
> 发送时间: 2021年8月27日 2:56
> 收件人: asomalap at amd.com <asomalap at amd.com>
> 抄送: dev at dpdk.org <dev at dpdk.org>; YE Chengfeng
> <cyeaa at connect.ust.hk>
> 主题: [PATCH v2] net/mlx5: fix potential unreleased lock problem
> 
> The lock sh->txpp.mutex isn't correctly released if the function return in
> these two branches, which may lead to deadlock if the lock is acquired again.
> 
> Cc: cyeaa at connect.ust.hk
> Bugzilla ID: 774
> 
> Signed-off-by: Chengfeng Ye <cyeaa at connect.ust.hk>
> ---
>  drivers/net/mlx5/mlx5_txpp.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_txpp.c b/drivers/net/mlx5/mlx5_txpp.c
> index 4f6da9f2d1..0ece788a84 100644
> --- a/drivers/net/mlx5/mlx5_txpp.c
> +++ b/drivers/net/mlx5/mlx5_txpp.c
> @@ -961,8 +961,12 @@ mlx5_txpp_stop(struct rte_eth_dev *dev)
>          MLX5_ASSERT(!ret);
>          RTE_SET_USED(ret);
>          MLX5_ASSERT(sh->txpp.refcnt);
> -       if (!sh->txpp.refcnt || --sh->txpp.refcnt)
> +       if (!sh->txpp.refcnt || --sh->txpp.refcnt) {
> +               ret = pthread_mutex_unlock(&sh->txpp.mutex);
> +               MLX5_ASSERT(!ret);
> +               RTE_SET_USED(ret);
>                  return;
> +       }
>          /* No references any more, do actual destroy. */
>          mlx5_txpp_destroy(sh);
>          ret = pthread_mutex_unlock(&sh->txpp.mutex);
> --
> 2.17.1