[PATCH 4/4] objtool: Fix function fallthrough detection for vmlinux

From: Josh Poimboeuf
Date: Mon Apr 11 2022 - 19:11:24 EST


Objtool's function fallthrough detection only works on C objects.
The distinction between C and assembly objects no longer makes sense
with objtool running on vmlinux.o.

Now that copy_user_64.S has been fixed up, and an objtool sibling call
detection bug has been fixed, the asm code is in "compliance" and this
hack is no longer needed. Remove it.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/check.c | 2 +-
tools/objtool/include/objtool/objtool.h | 2 +-
tools/objtool/objtool.c | 1 -
3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 0f5d3de30e0d..5f10653eb5c2 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3310,7 +3310,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
while (1) {
next_insn = next_insn_to_validate(file, insn);

- if (file->c_file && func && insn->func && func != insn->func->pfunc) {
+ if (func && insn->func && func != insn->func->pfunc) {
WARN("%s() falls through to next function %s()",
func->name, insn->func->name);
return 1;
diff --git a/tools/objtool/include/objtool/objtool.h b/tools/objtool/include/objtool/objtool.h
index 7a5c13a78f87..a6e72d916807 100644
--- a/tools/objtool/include/objtool/objtool.h
+++ b/tools/objtool/include/objtool/objtool.h
@@ -27,7 +27,7 @@ struct objtool_file {
struct list_head static_call_list;
struct list_head mcount_loc_list;
struct list_head endbr_list;
- bool ignore_unreachables, c_file, hints, rodata;
+ bool ignore_unreachables, hints, rodata;

unsigned int nr_endbr;
unsigned int nr_endbr_int;
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index b09946f4e1d6..843ff3c2f28e 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -129,7 +129,6 @@ struct objtool_file *objtool_open_read(const char *_objname)
INIT_LIST_HEAD(&file.static_call_list);
INIT_LIST_HEAD(&file.mcount_loc_list);
INIT_LIST_HEAD(&file.endbr_list);
- file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
file.ignore_unreachables = no_unreachable;
file.hints = false;

--
2.34.1