From: Julien Thierry <jthierry@redhat.com>
Date: Fri, 27 Mar 2020 15:28:41 +0000
Subject: objtool: Ignore empty alternatives
Git-commit: 7170cf47d16f1ba29eca07fd818870b7af0a93a5
Patch-mainline: v5.8-rc1
References: bsc#1169514
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@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Miroslav Benes <mbenes@suse.cz>
---
tools/objtool/check.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 5b67d6150a0b..efb964013552 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -905,6 +905,12 @@ 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)