@@ -24,6 +24,18 @@ struct switch_table_info {
void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
{
+ if (alt->orig_len && !alt->new_len) {
+ /*
+ * ARM64_CB_PATCH has no alternative instruction.
+ * a callback is called at alternative replacement time
+ * to dynamically change the original instructions.
+ *
+ * ARM64_CB_PATCH is the last ARM64 feature, it's value changes
+ * every time a new feature is added. So the orig/alt region
+ * length are used to detect those alternatives
+ */
+ alt->skip_alt = true;
+ }
}
bool arch_support_alt_relocation(struct special_alt *special_alt,
@@ -1182,6 +1182,9 @@ static int add_special_section_alts(struct objtool_file *file)
continue;
}
+ if (special_alt->skip_alt && !special_alt->new_len)
+ continue;
+
ret = handle_group_alt(file, special_alt, orig_insn,
&new_insn);
if (ret)
ARM64_CB_PATCH doesn't have static replacement instructions. Skip trying to validate the alternative section. Signed-off-by: Julien Thierry <jthierry@redhat.com> --- tools/objtool/arch/arm64/special.c | 12 ++++++++++++ tools/objtool/check.c | 3 +++ 2 files changed, 15 insertions(+)