From: Julien Thierry <jthierry@xxxxxxxxxx> [ Upstream commit 7170cf47d16f1ba29eca07fd818870b7af0a93a5 ] The .alternatives section can contain entries with no original instructions. Objtool will currently crash when handling such an entry. Just skip that entry, but still give a warning to discourage useless entries. Signed-off-by: Julien Thierry <jthierry@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Reviewed-by: Miroslav Benes <mbenes@xxxxxxx> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/objtool/check.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index fcc6cd404f56..48b234d8f251 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -865,6 +865,12 @@ static int add_special_section_alts(struct objtool_file *file) } if (special_alt->group) { + if (!special_alt->orig_len) { + WARN_FUNC("empty alternative entry", + orig_insn->sec, orig_insn->offset); + continue; + } + ret = handle_group_alt(file, special_alt, orig_insn, &new_insn); if (ret) -- 2.25.1