[PATCH v2 20/62] objtool: Fix "unexpected end of section" warning for alternatives

[Josh Poimboeuf]

Due to the short circuiting logic in next_insn_to_validate(), control
flow may silently transition from .altinstr_replacement to .text without
a corresponding nested call to validate_branch().

As a result the validate_branch() 'sec' variable doesn't get
reinitialized, which can trigger a confusing "unexpected end of section"
warning which blames .altinstr_replacement rather than the offending
fallthrough function.

Fix that by not caching the section.  There's no point in doing that
anyway.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 tools/objtool/check.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ea4e0facd21b..53793b9ea974 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3545,15 +3545,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 {
 	struct alternative *alt;
 	struct instruction *next_insn, *prev_insn = NULL;
-	struct section *sec;
 	u8 visited;
 	int ret;
 
 	if (func && func->ignore)
 		return 0;
 
-	sec = insn->sec;
-
 	while (1) {
 		next_insn = next_insn_to_validate(file, insn);
 
@@ -3791,7 +3788,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 			WARN("%s%sunexpected end of section %s",
 			     func ? func->name : "", func ? "(): " : "",
-			     sec->name);
+			     insn->sec->name);
 			return 1;
 		}
 
-- 
2.49.0