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-ee4dd525713... 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];