The lock sh->txpp.mutex was not correctly released if the function returned in these two branches, which may led to deadlock if the function was acquired again. Fixes: d133f4cdb7 ("net/mlx5: create clock queue for packet pacing") Cc: stable@dpdk.org Signed-off-by: Chengfeng Ye <cyeaa@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
The lock sh->txpp.mutex was not correctly released if the function returned in these two branches, which may led to deadlock if the function was acquired again. Fixes: d133f4cdb7 ("net/mlx5: create clock queue for packet pacing") Cc: stable@dpdk.org Signed-off-by: Chengfeng Ye <cyeaa@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
Hi, Chengfeng
Good catch, thank you.
Could we polish the commit message a bit?
"The lock sh->txpp.mutex was not correctly released on all pathes
of cleanup function return, potentially causing the deadlock."
With best regards,
Slava
> in these two branches, which may led to deadlock if the function was
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Chengfeng Ye
> Sent: Friday, September 3, 2021 11:44
> To: david.marchand@redhat.com
> Cc: dev@dpdk.org; Chengfeng Ye <cyeaa@connect.ust.hk>;
> stable@dpdk.org
> Subject: [dpdk-dev] [PATCH v4] net/mlx5: fix mutex unlock in txpp cleanup
>
> The lock sh->txpp.mutex was not correctly released if the function returned
> in these two branches, which may led to deadlock if the function was
> acquired again.
>
> Fixes: d133f4cdb7 ("net/mlx5: create clock queue for packet pacing")
> Cc: stable@dpdk.org
>
> Signed-off-by: Chengfeng Ye <cyeaa@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