On Tue, Apr 19, 2022 at 9:04 AM grantseltzer <grantseltzer@xxxxxxxxx> wrote:
>
> From: Grant Seltzer <grantseltzer@xxxxxxxxx>
>
> This adds an error return to the following API functions:
>
> - bpf_program__set_expected_attach_type()
> - bpf_program__set_type()
>
> In both cases, the error occurs when the BPF object has
> already been loaded when the function is called. In this
> case -EBUSY is returned.
>
> Signed-off-by: Grant Seltzer <grantseltzer@xxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index bf4f7ac54ebf..0ed1a8c9c398 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -8551,8 +8551,11 @@ enum bpf_prog_type bpf_program__type(const struct bpf_program *prog)
> return prog->type;
> }
>
> -void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
> +int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
> {
> + if (prog->obj->loaded)
> + return libbpf_err(-EBUSY);
> +
> prog->type = type;
return 0;
> }
>
> @@ -8598,10 +8601,14 @@ enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program
> return prog->expected_attach_type;
> }
>
> -void bpf_program__set_expected_attach_type(struct bpf_program *prog,
> +int bpf_program__set_expected_attach_type(struct bpf_program *prog,
> enum bpf_attach_type type)
> {
> + if (prog->obj->loaded)
> + return libbpf_err(-EBUSY);
> +
> prog->expected_attach_type = type;
> + return 0;
> }
>
> __u32 bpf_program__flags(const struct bpf_program *prog)
> --
> 2.34.1
>
