Re: [bug report] net/mlx5: DR, Add STEv1 setters and getters

[Yevgeny Kliteynik <kliteyn@nvidia.com>]

On 05-Feb-21 15:02, Dan Carpenter wrote:
> 
> Hello Yevgeny Kliteynik,
> 
> The patch a6098129c781: "net/mlx5: DR, Add STEv1 setters and getters"
> from Sep 22, 2020, leads to the following static checker warning:
> 
>          drivers/net/ethernet/mellanox/mlx5/core/steering/dr_ste_v1.c:268 dr_ste_v1_get_miss_addr()
>          warn: potential shift truncation.  '0xff (0-255) << 26'
> 
> drivers/net/ethernet/mellanox/mlx5/core/steering/dr_ste_v1.c
>     264  static u64 dr_ste_v1_get_miss_addr(u8 *hw_ste_p)
>     265  {
>     266          u64 index =
>     267                  (MLX5_GET(ste_match_bwc_v1, hw_ste_p, miss_address_31_6) |
>                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>     268                   MLX5_GET(ste_match_bwc_v1, hw_ste_p, miss_address_39_32) << 26);
>                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> index is a u64 but the right side is a two u32s.  The << 26 can shift
> wrap potentially according to Smatch.

Thanks Dan, will send a fix shortly.

-- YK

>     269
>     270          return index << 6;
>     271  }
> 
> regards,
> dan carpenter
>