On Mon, Jul 8, 2019 at 4:13 PM Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> clang warns:
>
> drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c:251:2:
> warning: variable 'rec_seq_sz' is used uninitialized whenever switch
> default is taken [-Wsometimes-uninitialized]
> default:
> ^~~~~~~
> drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c:255:46: note:
> uninitialized use occurs here
> skip_static_post = !memcmp(rec_seq, &rn_be, rec_seq_sz);
> ^~~~~~~~~~
> drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c:239:16: note:
> initialize the variable 'rec_seq_sz' to silence this warning
> u16 rec_seq_sz;
> ^
> = 0
> 1 warning generated.
>
> This case statement was clearly designed to be one that should not be
> hit during runtime because of the WARN_ON statement so just return early
> to prevent copying uninitialized memory up into rn_be.
>
> Fixes: d2ead1f360e8 ("net/mlx5e: Add kTLS TX HW offload support")
> Link: https://github.com/ClangBuiltLinux/linux/issues/590
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
> index 3f5f4317a22b..5c08891806f0 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
> @@ -250,6 +250,7 @@ tx_post_resync_params(struct mlx5e_txqsq *sq,
> }
> default:
> WARN_ON(1);
> + return;
> }
hmm...a switch statement with a single case is a code smell. How
about a single conditional with early return? Then the "meat" of the
happy path doesn't need an additional level of indentation.
--
Thanks,
~Nick Desaulniers
