On Tue, Apr 19, 2022 at 9:04 AM grantseltzer <grantseltzer@xxxxxxxxx> wrote:
>
> From: Grant Seltzer <grantseltzer@xxxxxxxxx>
>
> This updates usage of the following API functions within
> libbpf so their newly added error return is checked:
>
> - bpf_program__set_expected_attach_type()
> - bpf_program__set_type()
>
> Signed-off-by: Grant Seltzer <grantseltzer@xxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 29 +++++++++++++++++++++++------
> 1 file changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 0ed1a8c9c398..7635c50a05c6 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -7005,9 +7005,19 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
> continue;
> }
>
> - bpf_program__set_type(prog, prog->sec_def->prog_type);
> - bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type);
> + err = bpf_program__set_type(prog, prog->sec_def->prog_type);
> + if (err) {
> + pr_warn("prog '%s': failed to initialize: %d, could not set program type\n",
> + prog->name, err);
> + return err;
> + }
>
> + err = bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type);
> + if (err) {
> + pr_warn("prog '%s': failed to initialize: %d, could not set expected attach type\n",
> + prog->name, err);
> + return err;
> + }
this is too paranoid, we know that this will succeed. We can just do:
prog->type = prog->sec_def->prog_type;
prog->expected_attach_type = prog->sec_def->expected_attach_type;
to make this very clear
> #pragma GCC diagnostic push
> #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
> if (prog->sec_def->prog_type == BPF_PROG_TYPE_TRACING ||
> @@ -8570,8 +8580,7 @@ int bpf_program__set_##NAME(struct bpf_program *prog) \
> { \
> if (!prog) \
> return libbpf_err(-EINVAL); \
> - bpf_program__set_type(prog, TYPE); \
> - return 0; \
> + return bpf_program__set_type(prog, TYPE); \
> } \
> \
> bool bpf_program__is_##NAME(const struct bpf_program *prog) \
> @@ -9678,9 +9687,17 @@ static int bpf_prog_load_xattr2(const struct bpf_prog_load_attr *attr,
> * bpf_object__open guessed
> */
> if (attr->prog_type != BPF_PROG_TYPE_UNSPEC) {
> - bpf_program__set_type(prog, attr->prog_type);
> - bpf_program__set_expected_attach_type(prog,
> + err = bpf_program__set_type(prog, attr->prog_type);
> + if (err) {
> + pr_warn("could not set program type\n");
> + return libbpf_err(err);
> + }
> + err = bpf_program__set_expected_attach_type(prog,
> attach_type);
> + if (err) {
> + pr_warn("could not set expected attach type\n");
> + return libbpf_err(err);
> + }
same as above, no need to add unnecessary checks and pr_warns
> }
> if (bpf_program__type(prog) == BPF_PROG_TYPE_UNSPEC) {
> /*
> --
> 2.34.1
>
