[PATCH 03/13] objtool: Improve __noreturn annotation warning
From: Josh Poimboeuf
Date: Fri Mar 14 2025 - 15:31:58 EST
Clarify what needs to be done to resolve the missing __noreturn warning.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/Documentation/objtool.txt | 12 +++++-------
tools/objtool/check.c | 2 +-
2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt
index 7c3ee959b63c..87950a7aaa17 100644
--- a/tools/objtool/Documentation/objtool.txt
+++ b/tools/objtool/Documentation/objtool.txt
@@ -319,14 +319,12 @@ the objtool maintainers.
a just a bad person, you can tell objtool to ignore it. See the
"Adding exceptions" section below.
- If it's not actually in a callable function (e.g. kernel entry code),
- change ENDPROC to END.
+3. file.o: warning: objtool: foo+0x48c: bar() missing __noreturn in .c/.h or NORETURN() in noreturns.h
-3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn annotation
-
- The call from foo() to bar() doesn't return, but bar() is missing the
- __noreturn annotation. NOTE: In addition to annotating the function
- with __noreturn, please also add it to tools/objtool/noreturns.h.
+ The call from foo() to bar() doesn't return, but bar() is incorrectly
+ annotated. A noreturn function must be marked __noreturn in both its
+ declaration and its definition, and must have a NORETURN() annotation
+ in tools/objtool/noreturns.h.
4. file.o: warning: objtool: func(): can't find starting instruction
or
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 2b5249af7b0f..6b9ad3afe389 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4458,7 +4458,7 @@ static int validate_reachable_instructions(struct objtool_file *file)
if (prev_insn && prev_insn->dead_end) {
call_dest = insn_call_dest(prev_insn);
if (call_dest) {
- WARN_INSN(insn, "%s() is missing a __noreturn annotation",
+ WARN_INSN(insn, "%s() missing __noreturn in .c/.h or NORETURN() in noreturns.h",
call_dest->name);
warnings++;
continue;
--
2.48.1