The pidfd selftests run in userspace and include both userspace and kernel header files. On some distros (for example, CentOS), this results in duplicate-symbol warnings in allmodconfig builds, while on other distros (for example, Ubuntu) it does not. (This happens in recent -next trees, including next-20250714.)

Therefore, use #undef to get rid of the userspace definitions in favor of the kernel definitions.

Other ways of handling this include splitting up the selftest code so that the userspace definitions go into one translation unit and the kernel definitions into another (which might or might not be feasible) or to adjust compiler command-line options to suppress the warnings (which might or might not be desirable).

Signed-off-by: Paul E. McKenney paulmck@kernel.org Cc: Christian Brauner brauner@kernel.org Cc: Shuah Khan shuah@kernel.org Cc: linux-kselftest@vger.kernel.org

--- pidfd.h | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index efd74063126eb..6ff495398e872 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -16,6 +16,10 @@ #include <sys/types.h> #include <sys/wait.h>

+#undef SCHED_NORMAL +#undef SCHED_FLAG_KEEP_ALL +#undef SCHED_FLAG_UTIL_CLAMP + #include "../kselftest.h" #include "../clone3/clone3_selftests.h"