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Message-ID: <7d99e58d5a0bbd46ccfe4ece125c72815e99e205.1746821544.git.jpoimboe@kernel.org>
Date: Fri, 9 May 2025 13:16:44 -0700
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: x86@...nel.org
Cc: linux-kernel@...r.kernel.org,
Petr Mladek <pmladek@...e.com>,
Miroslav Benes <mbenes@...e.cz>,
Joe Lawrence <joe.lawrence@...hat.com>,
live-patching@...r.kernel.org,
Song Liu <song@...nel.org>,
laokz <laokz@...mail.com>,
Jiri Kosina <jikos@...nel.org>,
Marcos Paulo de Souza <mpdesouza@...e.com>,
Weinan Liu <wnliu@...gle.com>,
Fazla Mehrab <a.mehrab@...edance.com>,
Chen Zhongjin <chenzhongjin@...wei.com>,
Puranjay Mohan <puranjay@...nel.org>
Subject: [PATCH v2 20/62] objtool: Fix "unexpected end of section" warning for alternatives
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@...nel.org>
---
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
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