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

Hi Michael,

On 23/09/15 10:55, Michael Ellerman wrote:

On Tue, 2015-09-22 at 18:15 +0100, Andre Przywara wrote:

quoted

On 22/09/15 15:06, Andrea Arcangeli wrote:

quoted

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.

...

quoted

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):

Actually that was I was hoping for, I just missed the possibility of
headers_install to put the files back into the kernel tree (I usually
use it with INSTALL_HDR_PATH for packaging).

  $ 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*

Yes, that works. Now I have just to figure out how to arrange this with
out-of-tree build directories.

Cheers,
Andre.