ARM64_CB_PATCH doesn't have static replacement instructions. Skip
trying to validate the alternative section.
Signed-off-by: Julien Thierry <jthie...@redhat.com>
---
tools/objtool/arch/arm64/special.c | 12 ++++++++++++
tools/objtool/check.c | 3 +++
2 files changed, 15 insertions(+)
diff --git a/tools/objtool/arch/arm64/special.c
b/tools/objtool/arch/arm64/special.c
index a70b91e8bd7d..ed642bd6f886 100644
--- a/tools/objtool/arch/arm64/special.c
+++ b/tools/objtool/arch/arm64/special.c
@@ -4,6 +4,18 @@
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,
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 7750f6342855..1999d1f1967a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1293,6 +1293,9 @@ 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)
--
2.25.4
