Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition

[Michael Ellerman <mpe@ellerman.id.au>]

On Tue, 2015-09-22 at 18:15 +0100, Andre Przywara wrote:
> On 22/09/15 15:06, Andrea Arcangeli wrote:
> > Andre, could you see if linux-next (which includes -mm) works for you
> > by just running "cd tools/testing/selftests/vm/ && make"? If there's
> > any further change required could you diff it against linux-next?
> 
> This doesn't compile now for me, because it looks into
> /usr/include/asm/unistd.h, which I keep to the distribution copy of it.
> Also linux/userfaultfd.h is missing, because it's brand new.
...
> I guess the right solution would be to hack the Makefile to set the
> include path to the kernel's copy of include/uapi, though I am not sure
> this works cleanly for different architectures and separate build
> directories. I will give this a try ...

Not that's not the right solution.

The right solution is to export the kernel headers, the Makefile will pick them
up (at least in linux-next):

  $ cd linux
  $ make headers_install
  $ ls usr/include/
  asm/  asm-generic/  drm/  linux/  misc/  mtd/  rdma/  scsi/  sound/  uapi/  video/  xen/
  $ make -C tools/testing/selftests TARGETS=vm
  ...
  $ ls tools/testing/selftests/vm/userfaultfd
  tools/testing/selftests/vm/userfaultfd*

cheers