Commit dafe58fc authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

bpf: Remove recursion call in btf_struct_access 



Andrii suggested we can simply jump to again label
instead of making recursion call.

Suggested-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-7-jolsa@kernel.org
parent 887c31a3

kernel/bpf/btf.c

+5 −6
Original line number Diff line number Diff line
@@ -3931,14 +3931,13 @@ int btf_struct_access(struct bpf_verifier_log *log, 
		/* Only allow structure for now, can be relaxed for

		 * other types later.

		 */

		elem_type = btf_type_skip_modifiers(btf_vmlinux,

						    array_elem->type, NULL);

		if (!btf_type_is_struct(elem_type))

		t = btf_type_skip_modifiers(btf_vmlinux, array_elem->type,

					    NULL);

		if (!btf_type_is_struct(t))

			goto error;



		off = (off - moff) % elem_type->size;

		return btf_struct_access(log, elem_type, off, size, atype,

					 next_btf_id);

		off = (off - moff) % t->size;

		goto again;



error:

		bpf_log(log, "access beyond struct %s at off %u size %u\n",