[PATCH] net/mlx5: fix build with clang 14

[David Marchand]

On Wed, May 11, 2022 at 3:59 PM Ali Alnubani <alialnu at nvidia.com> wrote:
>
> Use fgets instead of fscanf to resolve the following warning
> reported by clang 14.0.0 in Fedora 37 (Rawhide):
>
> drivers/net/mlx5/linux/mlx5_ethdev_os.c:1137:52: error:
>   'fscanf' may overflow; destination buffer in argument 3 has size 16,
>   but the corresponding specifier may require size 17
>   [-Werror,-Wfortify-source]
>   ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);
>
> Fixes: 63d1db710fbc ("net/mlx5: fix unlimited parsing of switch info")
> Cc: michaelba at mellanox.com
> Cc: stable at dpdk.org
>
> Signed-off-by: Ali Alnubani <alialnu at nvidia.com>
> ---
>  drivers/net/mlx5/linux/mlx5_ethdev_os.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/mlx5/linux/mlx5_ethdev_os.c b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
> index 8fe73f1adb..3d28597e7b 100644
> --- a/drivers/net/mlx5/linux/mlx5_ethdev_os.c
> +++ b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
> @@ -1118,7 +1118,7 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
>         bool port_switch_id_set = false;
>         bool device_dir = false;
>         char c;
> -       int ret;
> +       char *ret;
>
>         if (!if_indextoname(ifindex, ifname)) {
>                 rte_errno = errno;
> @@ -1134,9 +1134,9 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
>
>         file = fopen(phys_port_name, "rb");
>         if (file != NULL) {
> -               ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);
> +               ret = fgets(port_name, IF_NAMESIZE, file);
>                 fclose(file);
> -               if (ret == 1)
> +               if (ret != NULL)
>                         mlx5_translate_port_name(port_name, &data);

You can directly check fgets return value and remove (misleading)
variable ret from the global scope of this function.


>         }
>         file = fopen(phys_switch_id, "rb");



-- 
David Marchand