Re: [PATCH v3 3/3] selftests: pidfd: add tests for PIDFD_SELF_*

[Lorenzo Stoakes <lorenzo.stoakes@oracle.com>]

On Thu, Oct 17, 2024 at 10:17:54AM -0700, John Hubbard wrote:
> On 10/17/24 5:06 AM, Lorenzo Stoakes wrote:
> > +cc John, sorry I forgot to cc you on other replies!!
> >
> > On Thu, Oct 17, 2024 at 09:08:19AM +0100, Lorenzo Stoakes wrote:
> > [snip]
> > >
> > > In any case I think copying the header to the tools/ directory with this
> > > linux/fcntl.h in some way stubbed out (we could even stub out fcntl.h
> > > there?) is the sensible way forward.
> > >
> > > A 'just include the header' is simply not an option as it breaks the tests.
>
> I should have read this one first, this morning, but I missed it initially.
> :)

No worries easily done! :)

>
> >
> > Ohhh ok I think maybe we could have a good compromise that should (hopefully!)
> > satisfy both you and John.
> >
> > I can introduce tools/include/linux/pidfd.h that is a stub wrapper around
> > the pidfd.h file.
> >
> > So it can be something like:
> >
> >
> > 	#ifndef __TOOLS_LINUX_PIDFD_H
> > 	#define __TOOLS_LINUX_PIDFD_H
> >
> > 	/*
> > 	 * Some systems have issues with the linux/fcntl.h import in linux/pidfd.h, so
> > 	 * work around this by setting the header guard.
> > 	 */
> > 	#define _LINUX_FCNTL_H
> > 	#include "../../../include/uapi/linux/pidfd.h"
> > 	#undef _LINUX_FCNTL_H
> >
> > 	#endif /* __TOOLS_LINUX_PIDFD_H */
> >
> >
> > Then the test code needs only to update the pidfd.h file to #include
> > <linux/pidfd.h> and add a simple $(TOOLS_INCLUDES) to the CFLAGS += line in
> > the pidfd self tests Makefile and we should be all good.
>
> Yes.
>
> >
> > That way we always import everything in this header correctly, we directly
> > document this issue, we include the header as you would in userland and we
> > should cover off all the issues?
>
> Very nice!

Thanks!

I saw from your other thread the idea was to take snapshots and to run scripts
to compare etc. but I suppose putting this into the known-stub directory
tools/include/linux rather than tools/include/uapi/linux would avoid a conflict
here.

Or would you say the wrapper should regardless be in the uapi/linux directory?

Thanks!

>
>
> thanks,
> --
> John Hubbard
>