On 11/11/2021 7:06 AM, Slava Ovsiienko wrote:
Hi, Ferruh
-----Original Message-----
From: Ferruh Yigit <[email protected]>
Sent: Wednesday, November 10, 2021 18:57
To: Chengfeng Ye <[email protected]>; [email protected];
Slava Ovsiienko <[email protected]>; Shahaf Shuler
<[email protected]>; Matan Azrad <[email protected]>
Cc: [email protected]; [email protected]
Subject: Re: [dpdk-dev] [PATCH v5] net/mlx5: fix mutex unlock in txpp
cleanup
On 10/12/2021 11:02 AM, Chengfeng Ye wrote:
The lock sh->txpp.mutex was not correctly released on one path of
cleanup function return, potentially causing the deadlock.
Fixes: d133f4cdb7 ("net/mlx5: create clock queue for packet pacing")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
---
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);
Is this 'RTE_SET_USED()' need to be used multiple times for same variable?
mmm, It seems "claim_zero()" macro would be better here:
claim_zero(pthread_mutex_lock(&sh->txpp.mutex));
I will provide the cleanup patch, thank you for noticing that
This usage looks ugly, I can see why it is used but I wonder if this can be
solved differently, what about something like following:
#ifdef RTE_LIBRTE_MLX5_DEBUG
#define MLX5_ASSERT(exp) RTE_VERIFY(exp)
#else
#ifdef RTE_ENABLE_ASSERT
#define MLX5_ASSERT(exp) RTE_ASSERT(exp)
#else
#define MLX5_ASSERT(exp) RTE_SET_USED(exp)
#endif
#endif
It would directly replace MLX5_ASSERT(exp) with RTE_SET_USED(exp)
if there is neither RTE_ENABLE_ASSERT nor RTE_LIBRTE_MLX5_DEBUG.
We would not like to drop the "not used" check functionality at all , right?
The suggestion was to prevent following kind of usage:
MLX5_ASSERT(!ret);
RTE_SET_USED(ret);
I assume you need above usage when a variable is used only in the 'MLX5_ASSERT',
if there is a way to prevent warning in that case without 'RTE_SET_USED' that
may be better.
