Re: [PATCH 11/12] selftests/mm: fix missing UFFDIO_CONTINUE_MODE_WP and similar build failures

From: David Hildenbrand <david@redhat.com>
To: John Hubbard <jhubbard@nvidia.com>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Xu <peterx@redhat.com>, Shuah Khan <shuah@kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 11/12] selftests/mm: fix missing UFFDIO_CONTINUE_MODE_WP and similar build failures
Date: Fri, 2 Jun 2023 12:23:28 +0200	[thread overview]
Message-ID: <7a999b80-e266-2b7e-f198-869b1ac7cde7@redhat.com> (raw)
In-Reply-To: <20230602013358.900637-12-jhubbard@nvidia.com>

On 02.06.23 03:33, John Hubbard wrote:
> UFFDIO_CONTINUE_MODE_WP, UFFD_FEATURE_WP_UNPOPULATED, USERFAULTFD_IOC,
> and USERFAULTFD_IOC_NEW are needed lately, but they are not in my host
> (Arch Linux) distro's userfaultfd.h yet. So put them in here.
> 
> A better approach would be to include the uapi version of userfaultfd.h
> from the kernel tree, but that currently fails with rather difficult
> linker problems (__packed is defined multiple times, ugg), so defer that
> to another day and just fix the build for now.
> 
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> ---
>   tools/testing/selftests/mm/uffd-common.h | 17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
> 
> diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
> index a1cdb78c0762..98847e41ecf9 100644
> --- a/tools/testing/selftests/mm/uffd-common.h
> +++ b/tools/testing/selftests/mm/uffd-common.h
> @@ -36,6 +36,23 @@
>   
>   #define UFFD_FLAGS	(O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY)
>   
> +#ifndef UFFDIO_CONTINUE_MODE_WP
> +#define UFFDIO_CONTINUE_MODE_WP			((__u64)1<<1)
> +#endif
> +
> +#ifndef UFFD_FEATURE_WP_UNPOPULATED
> +#define UFFD_FEATURE_WP_UNPOPULATED		(1<<13)
> +#endif
> +
> +/* ioctls for /dev/userfaultfd */
> +#ifndef USERFAULTFD_IOC
> +#define USERFAULTFD_IOC 0xAA
> +#endif
> +
> +#ifndef USERFAULTFD_IOC_NEW
> +#define USERFAULTFD_IOC_NEW _IO(USERFAULTFD_IOC, 0x00)
> +#endif
> +
>   #define _err(fmt, ...)						\
>   	do {							\
>   		int ret = errno;				\

Unfortunately, that seems to be the ugly way to handle this because
including the in-tree headers seems to not work and I yet haven't
figured out why (there were some changes back and forth so I lost track).

CFLAGS = -Wall -I $(top_srcdir) -I $(top_srcdir)/tools/include/uapi $(EXTRA_CFLAGS) $(KHDR_INCLUDES)

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb