2021-10-27 21:29:27

by Nathan Chancellor

Subject: [PATCH net-next] net/mlx5: Add esw assignment back in mlx5e_tc_sample_unoffload()

Clang warns:

drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c:635:34: error: variable 'esw' is uninitialized when used here [-Werror,-Wuninitialized]
mlx5_eswitch_del_offloaded_rule(esw, sample_flow->pre_rule, sample_flow->pre_attr);
^~~
drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c:626:26: note: initialize the variable 'esw' to silence this warning
struct mlx5_eswitch *esw;
^
= NULL
1 error generated.

It appears that the assignment should have been shuffled instead of
removed outright like in mlx5e_tc_sample_offload(). Add it back so there
is no use of esw uninitialized.

Fixes: a64c5edbd20e ("net/mlx5: Remove unnecessary checks for slow path flag")
Link: https://github.com/ClangBuiltLinux/linux/issues/1494
Signed-off-by: Nathan Chancellor <[email protected]>
---
drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c
index 1046b7ea5c88..df6888c4793c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c
@@ -631,6 +631,7 @@ mlx5e_tc_sample_unoffload(struct mlx5e_tc_psample *tc_psample,
/* The following delete order can't be changed, otherwise,
* will hit fw syndromes.
*/
+ esw = tc_psample->esw;
sample_flow = attr->sample_attr->sample_flow;
mlx5_eswitch_del_offloaded_rule(esw, sample_flow->pre_rule, sample_flow->pre_attr);


base-commit: 6487c819393ed1678ef847fd260ea86edccc0bb3
--
2.33.1.637.gf443b226ca

2021-10-28 05:31:50

by Saeed Mahameed

Subject: Re: [PATCH net-next] net/mlx5: Add esw assignment back in mlx5e_tc_sample_unoffload()

On Wed, 2021-10-27 at 08:31 -0700, Nathan Chancellor wrote:
> Clang warns:
>
> drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c:635:34: error:
> variable 'esw' is uninitialized when used here [-Werror,-
> Wuninitialized]
>         mlx5_eswitch_del_offloaded_rule(esw, sample_flow->pre_rule,
> sample_flow->pre_attr);
>                                         ^~~
> drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c:626:26: note:
> initialize the variable 'esw' to silence this warning
>         struct mlx5_eswitch *esw;
>                                 ^
>                                  = NULL
> 1 error generated.
>
> It appears that the assignment should have been shuffled instead of
> removed outright like in mlx5e_tc_sample_offload(). Add it back so
> there
> is no use of esw uninitialized.
>
> Fixes: a64c5edbd20e ("net/mlx5: Remove unnecessary checks for slow
> path flag")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1494
> Signed-off-by: Nathan Chancellor <[email protected]>

Nice catch !
applied to net-next-mlx5, 
Thanks !