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.
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).
[ paulmck: Apply Shuah Khan feedback. ]
Signed-off-by: Paul E. McKenney paulmck@kernel.org Reviewed-by: Shuah Khan skhan@linuxfoundation.org Cc: Christian Brauner brauner@kernel.org Cc: linux-kselftest@vger.kernel.org
--- pidfd.h | 9 +++++++++ 1 file changed, 9 insertions(+)
Changes since v1 (RFC):
o Added comment explaining the purpose of the #undef calls per Shuah Khan feedback.
diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index efd74063126eb..254eaa6cc4dfa 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -16,6 +16,15 @@ #include <sys/types.h> #include <sys/wait.h>
+/* + * Remove the userspace definitions of the following preprocessor symbols + * to avoid duplicate-definition warnings from the subsequent in-kernel + * definitions. + */ +#undef SCHED_NORMAL +#undef SCHED_FLAG_KEEP_ALL +#undef SCHED_FLAG_UTIL_CLAMP + #include "../kselftest.h" #include "../clone3/clone3_selftests.h"