Commit db089c91 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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libbpf: never interpret subprogs in .text as entry programs 



Libbpf pre-1.0 had a legacy logic of allowing singular non-annotated
(i.e., not having explicit SEC() annotation) function to be treated as
sole entry BPF program (unless there were other explicit entry
programs).

This behavior was dropped during libbpf 1.0 transition period (unless
LIBBPF_STRICT_SEC_NAME flag was unset in libbpf_mode). When 1.0 was
released and all the legacy behavior was removed, the bug slipped
through leaving this legacy behavior around.

Fix this for good, as it actually causes very confusing behavior if BPF
object file only has subprograms, but no entry programs.

Fixes: bd054102 ("libbpf: enforce strict libbpf 1.0 behaviors")
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241010211731.4121837-1-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 59972544

tools/lib/bpf/libbpf.c

+1 −1
Original line number Diff line number Diff line
@@ -4417,7 +4417,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj) 


static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog)

{

	return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1;

	return prog->sec_idx == obj->efile.text_shndx;

}



struct bpf_program *