Re: [PATCH bpf-next 3/3] bpf/bpftool: handle libbpf_probe_prog_type errors

From: Quentin Monnet
Date: Fri Apr 01 2022 - 12:32:18 EST


2022-03-31 11:45 UTC-0400 ~ Milan Landaverde <milan@xxxxxxxxxxxx>
> Previously [1], we were using bpf_probe_prog_type which returned a
> bool, but the new libbpf_probe_bpf_prog_type can return a negative
> error code on failure. This change decides for bpftool to declare
> a program type is not available on probe failure.
>
> [1] https://lore.kernel.org/bpf/20220202225916.3313522-3-andrii@xxxxxxxxxx/
>
> Signed-off-by: Milan Landaverde <milan@xxxxxxxxxxxx>
> ---
> tools/bpf/bpftool/feature.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c
> index c2f43a5d38e0..b2fbaa7a6b15 100644
> --- a/tools/bpf/bpftool/feature.c
> +++ b/tools/bpf/bpftool/feature.c
> @@ -564,7 +564,7 @@ probe_prog_type(enum bpf_prog_type prog_type, bool *supported_types,
>
> res = probe_prog_type_ifindex(prog_type, ifindex);
> } else {
> - res = libbpf_probe_bpf_prog_type(prog_type, NULL);
> + res = libbpf_probe_bpf_prog_type(prog_type, NULL) > 0;
> }
>
> #ifdef USE_LIBCAP

Reviewed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>

Thanks!