On Fri, Jul 18, 2025 at 03:03:43PM -0600, Shuah Khan wrote:
> On 7/14/25 17:01, Paul E. McKenney wrote:
> > 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 <paul...@kernel.org>
> > Cc: Christian Brauner <brau...@kernel.org>
> > Cc: Shuah Khan <sh...@kernel.org>
> > Cc: <linux-kselft...@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>
>
> Please add comments here about why we are adding this so there
> won't be any confusion later.
Good point, thank you!
Like this?
/*
* 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"
>
> With that change:
>
> Reviewed-by: Shuah Khan <sk...@linuxfoundation.org>
Thank you!
> I am assuming this will go through Christian's tree. If not I can
> take it through mine.
I am of course good either way. ;-)
Thanx, Paul
