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.
>> + }
>> +out:
>> + free(info_linear);
>> + return err;
>> +}
>
> Otherwise
>
> Acked-by: Song Liu <songliubraving@xxxxxx>
>
