[PATCH AUTOSEL 6.15 082/110] selftests: harness: Mark functions without prototypes static

[Sasha Levin <sashal@kernel.org>]

From: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

[ Upstream commit c2bcc8e9577a35f9cf4707f8bb0b58bce30991aa ]

With -Wmissing-prototypes the compiler will warn about non-static
functions which don't have a prototype defined.
As they are not used from a different compilation unit they don't need to
be defined globally.

Avoid the issue by marking the functions static.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250505-nolibc-kselftest-harness-v4-4-ee4dd5257135@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

**YES** This commit should be backported to stable kernel trees.
**Rationale:** 1. **Legitimate Build Fix**: The commit addresses a real
compiler warning issue (`-Wmissing-prototypes`) that affects build
cleanliness and code quality. Modern build systems increasingly use
stricter warning flags, making this fix valuable for stable trees. 2.
**Zero Functional Risk**: The changes are purely cosmetic from a runtime
perspective. Adding `static` to functions that were already internal has
no impact on functionality, memory layout, or behavior - it only affects
compiler symbol visibility and warnings. 3. **Minimal and Contained**:
The diff is extremely small (4 function signatures with `static` added)
and isolated to the kselftest harness framework. There are no complex
logic changes or cross-subsystem impacts. 4. **Testing Infrastructure
Improvement**: While the kselftest framework isn't critical runtime
code, it's important for kernel testing and validation. Improving build
compliance in testing infrastructure benefits stable kernel maintenance.
5. **Standard Practice**: Compiler warning fixes of this nature (adding
missing `static` keywords) are routinely backported to stable trees as
they represent good coding practices without functional risk. 6.
**Different from Similar Commits**: Unlike the referenced similar
commits (all marked "NO") which involved feature additions, API changes,
or structural modifications, this commit is purely a build compliance
fix with no behavioral changes. The commit meets all stable tree
criteria: it fixes an issue (compiler warnings), has minimal risk (no
functional changes), and improves code quality without introducing new
features or architectural changes. Tools like `kselftest_harness.h:241`,
`kselftest_harness.h:290`, `kselftest_harness.h:970`, and
`kselftest_harness.h:1188` are the specific locations where these low-
risk improvements are made.

 tools/testing/selftests/kselftest_harness.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index 666c9fde76da9..7c337b4fa054d 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -258,7 +258,7 @@
  * A bare "return;" statement may be used to return early.
  */
 #define FIXTURE_SETUP(fixture_name) \
-	void fixture_name##_setup( \
+	static void fixture_name##_setup( \
 		struct __test_metadata __attribute__((unused)) *_metadata, \
 		FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \
 		const FIXTURE_VARIANT(fixture_name) \
@@ -307,7 +307,7 @@
 	__FIXTURE_TEARDOWN(fixture_name)
 
 #define __FIXTURE_TEARDOWN(fixture_name) \
-	void fixture_name##_teardown( \
+	static void fixture_name##_teardown( \
 		struct __test_metadata __attribute__((unused)) *_metadata, \
 		FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \
 		const FIXTURE_VARIANT(fixture_name) \
@@ -987,7 +987,7 @@ static void __timeout_handler(int sig, siginfo_t *info, void *ucontext)
 	kill(-(t->pid), SIGKILL);
 }
 
-void __wait_for_test(struct __test_metadata *t)
+static void __wait_for_test(struct __test_metadata *t)
 {
 	struct sigaction action = {
 		.sa_sigaction = __timeout_handler,
@@ -1205,9 +1205,9 @@ static bool test_enabled(int argc, char **argv,
 	return !has_positive;
 }
 
-void __run_test(struct __fixture_metadata *f,
-		struct __fixture_variant_metadata *variant,
-		struct __test_metadata *t)
+static void __run_test(struct __fixture_metadata *f,
+		       struct __fixture_variant_metadata *variant,
+		       struct __test_metadata *t)
 {
 	struct __test_xfail *xfail;
 	char test_name[1024];
-- 
2.39.5