On Tue, Jun 02, 2020 at 03:28:37PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
>
> Clang warns:
>
> drivers/net/ethernet/mellanox/mlx5/core/main.c:1278:6: warning: variable
> 'err' is used uninitialized whenever 'if' condition is true
> [-Wsometimes-uninitialized]
> if (!priv->dbg_root) {
> ^~~~~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlx5/core/main.c:1303:9: note:
> uninitialized use occurs here
> return err;
> ^~~
> drivers/net/ethernet/mellanox/mlx5/core/main.c:1278:2: note: remove the
> 'if' if its condition is always false
> if (!priv->dbg_root) {
> ^~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlx5/core/main.c:1259:9: note: initialize
> the variable 'err' to silence this warning
> int err;
> ^
> = 0
> 1 warning generated.
>
> The check of returned value of debugfs_create_dir() is wrong because
> by the design debugfs failures should never fail the driver and the
> check itself was wrong too. The kernel compiled without CONFIG_DEBUG_FS
> will return ERR_PTR(-ENODEV) and not NULL as expected.
>
> Fixes: 11f3b84d7068 ("net/mlx5: Split mdev init and pci init")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1042
> Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Thanks! That's what I figured it should be.
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> ---
> Original discussion:
> https://lore.kernel.org/lkml/20200530055447.1028004-1-natechancellor@xxxxxxxxx
> ---
> drivers/net/ethernet/mellanox/mlx5/core/main.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c
> index df46b1fce3a7..110e8d277d15 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
> @@ -1275,11 +1275,6 @@ static int mlx5_mdev_init(struct mlx5_core_dev *dev, int profile_idx)
>
> priv->dbg_root = debugfs_create_dir(dev_name(dev->device),
> mlx5_debugfs_root);
> - if (!priv->dbg_root) {
> - dev_err(dev->device, "mlx5_core: error, Cannot create debugfs dir, aborting\n");
> - goto err_dbg_root;
> - }
> -
> err = mlx5_health_init(dev);
> if (err)
> goto err_health_init;
> --
> 2.26.2
>
