Commit f3bdb54f authored Aug 23, 2023 by Andrii Nakryiko Committed by Martin KaFai Lau Aug 23, 2023

libbpf: fix signedness determination in CO-RE relo handling logic

Extracting btf_int_encoding() is only meaningful for BTF_KIND_INT, so we
need to check that first before inferring signedness.

Closes: https://github.com/libbpf/libbpf/issues/704


Reported-by: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230824000016.2658017-2-andrii@kernel.org


Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

parent a182e641

tools/lib/bpf/relo_core.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -776,7 +776,7 @@ static int bpf_core_calc_field_relo(const char *prog_name,
	break;		break;
	case BPF_CORE_FIELD_SIGNED:		case BPF_CORE_FIELD_SIGNED:
	*val = (btf_is_any_enum(mt) && BTF_INFO_KFLAG(mt->info)) \|\|		*val = (btf_is_any_enum(mt) && BTF_INFO_KFLAG(mt->info)) \|\|
	(btf_int_encoding(mt) & BTF_INT_SIGNED);		(btf_is_int(mt) && (btf_int_encoding(mt) & BTF_INT_SIGNED));
	if (validate)		if (validate)
	validate = true; / signedness is never ambiguous */		validate = true; / signedness is never ambiguous */
	break;		break;