On Sun, Apr 24, 2022 at 03:23:23AM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   e7d6987e09a328d4a949701db40ef63fbb970670
> commit: 70a8da53f7cb7368776f9d2790ecbb4f8bc53ba5 [5085/5845] mm: teach core mm about pte markers
> config: x86_64-randconfig-a002-20210928 (https://download.01.org/0day-ci/archive/20220424/202204240320.TGDuGcsL-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.2.0-20) 11.2.0
> reproduce (this is a W=1 build):
>         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=70a8da53f7cb7368776f9d2790ecbb4f8bc53ba5
>         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
>         git fetch --no-tags linux-next master
>         git checkout 70a8da53f7cb7368776f9d2790ecbb4f8bc53ba5
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> Note: the linux-next/master HEAD e7d6987e09a328d4a949701db40ef63fbb970670 builds fine.
>       It may have been fixed somewhere.
> 
> All errors (new ones prefixed by >>):
> 
>    fs/userfaultfd.c: In function 'userfaultfd_must_wait':
> >> fs/userfaultfd.c:337:13: error: implicit declaration of function 'pte_none_mostly' [-Werror=implicit-function-declaration]
>      337 |         if (pte_none_mostly(*pte))
>          |             ^~~~~~~~~~~~~~~
>    cc1: some warnings being treated as errors

Ah, userfaultfd.c may need explicit inclusion for swapops.h now..  Expected
fix attached to be squashed into "mm: Teach core mm about pte markers", I think.

Thanks,

-- 
Peter Xu