bpf: Use proper target btf when exporting attach_btf_obj_id

When attaching to program, the program itself might not be attached
to anything (and, hence, might not have attach_btf), so we can't
unconditionally use 'prog->aux->dst_prog->aux->attach_btf'.

Instead, use bpf_prog_get_target_btf to pick proper target BTF:

  * when attached to dst_prog, use dst_prog->aux->btf
  * when attached to kernel btf, use prog->aux->attach_btf

Fixes: b79c9fc9551b ("bpf: implement BPF_PROG_QUERY for BPF_LSM_CGROUP")
Signed-off-by: Stanislav Fomichev <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Hao Luo <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

0 files changed, 0 insertions, 0 deletions