> On Nov 8, 2019, at 11:13 AM, Alexei Starovoitov <ast@xxxxxx> wrote:
>
> On 11/8/19 10:57 AM, Song Liu wrote:
>>
>>
>>> On Nov 7, 2019, at 10:40 PM, Alexei Starovoitov <ast@xxxxxxxxxx> wrote:
>>>
>>> Extend libbpf api to pass attach_prog_fd into bpf_object__open.
>>>
>>> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
>>> ---
>>
>> [...]
>>
>>> +static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
>>> +{
>>> + struct bpf_prog_info_linear *info_linear;
>>> + struct bpf_prog_info *info;
>>> + struct btf *btf = NULL;
>>> + int err = -EINVAL;
>>> +
>>> + info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);
>>> + if (IS_ERR_OR_NULL(info_linear)) {
>>> + pr_warn("failed get_prog_info_linear for FD %d\n",
>>> + attach_prog_fd);
>>> + return -EINVAL;
>>> + }
>>> + info = &info_linear->info;
>>> + if (!info->btf_id) {
>>> + pr_warn("The target program doesn't have BTF\n");
>>> + goto out;
>>> + }
>>> + if (btf__get_from_id(info->btf_id, &btf)) {
>>> + pr_warn("Failed to get BTF of the program\n");
>>> + goto out;
>>> + }
>>> + err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
>>> + btf__free(btf);
>>> + if (err <= 0) {
>>> + pr_warn("%s is not found in prog's BTF\n", name);
>>> + goto out;
>> ^^^ This goto doesn't really do much.
>
> yeah. it does look a bit weird.
> I wanted to keep uniform error handling, but can remove it
> if you insist.
I think it is good as-is.
Thanks,
Song
