On Wed, Jun 12, 2019 at 11:06 AM Martynas Pumputis <m@xxxxxxxxx> wrote:
>
> Previously, the BPF_FIB_LOOKUP_{DIRECT,OUTPUT} flags were defined
> with the help of BIT macro. This had the following issues:
>
> - In order to user any of the flags, a user was required to depend
> on <linux/bits.h>.
> - No other flag in bpf.h uses the macro, so it seems that an unwritten
> convention is to use (1 << (nr)) to define BPF-related flags.
>
Makes sense!
Acked-by: Andrii Nakryiko <andriin@xxxxxx>
> Signed-off-by: Martynas Pumputis <m@xxxxxxxxx>
> ---
> include/uapi/linux/bpf.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 63e0cf66f01a..a8f17bc86732 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -3376,8 +3376,8 @@ struct bpf_raw_tracepoint_args {
> /* DIRECT: Skip the FIB rules and go to FIB table associated with device
> * OUTPUT: Do lookup from egress perspective; default is ingress
> */
> -#define BPF_FIB_LOOKUP_DIRECT BIT(0)
> -#define BPF_FIB_LOOKUP_OUTPUT BIT(1)
> +#define BPF_FIB_LOOKUP_DIRECT (1U << 0)
> +#define BPF_FIB_LOOKUP_OUTPUT (1U << 1)
>
> enum {
> BPF_FIB_LKUP_RET_SUCCESS, /* lookup successful */
> --
> 2.21.0
>
