Re: [PATCH v2 09/13] selftests/mm: skip uffd-wp-mremap if UFFD write-protect is unsupported

[Sayali Patil]

On 12/03/26 18:20, David Hildenbrand (Arm) wrote:
> On 3/12/26 13:25, Sayali Patil wrote:
> > The uffd-wp-mremap test requires the UFFD_FEATURE_PAGEFAULT_FLAG_WP
> > capability. On systems where userfaultfd write-protect is
> > not supported, uffd_register() fails and the test reports failures.
> >
> > Check for the required feature at startup and skip the test when the
> > UFFD_FEATURE_PAGEFAULT_FLAG_WP capability is not present,
> > preventing false failures on unsupported configurations.
> >
> > Before patch:
> >   running ./uffd-wp-mremap
> >   ------------------------
> >    [INFO] detected THP size: 256 KiB
> >    [INFO] detected THP size: 512 KiB
> >    [INFO] detected THP size: 1024 KiB
> >    [INFO] detected THP size: 2048 KiB
> >    [INFO] detected hugetlb page size: 2048 KiB
> >    [INFO] detected hugetlb page size: 1048576 KiB
> >   1..24
> >    [RUN] test_one_folio(size=65536, private=false, swapout=false,
> >    hugetlb=false)
> >   not ok 1 uffd_register() failed
> >    [RUN] test_one_folio(size=65536, private=true, swapout=false,
> >    hugetlb=false)
> >   not ok 2 uffd_register() failed
> >    [RUN] test_one_folio(size=65536, private=false, swapout=true,
> >    hugetlb=false)
> >   not ok 3 uffd_register() failed
> >    [RUN] test_one_folio(size=65536, private=true, swapout=true,
> >    hugetlb=false)
> >   not ok 4 uffd_register() failed
> >    [RUN] test_one_folio(size=262144, private=false, swapout=false,
> >    hugetlb=false)
> >   not ok 5 uffd_register() failed
> >    [RUN] test_one_folio(size=524288, private=false, swapout=false,
> >    hugetlb=false)
> >   not ok 6 uffd_register() failed
> >   .
> >   .
> >   .
> >   Bail out! 24 out of 24 tests failed
> >    Totals: pass:0 fail:24 xfail:0 xpass:0 skip:0 error:0
> >   [FAIL]
> > not ok 1 uffd-wp-mremap # exit=1
> >
> > After patch:
> >   running ./uffd-wp-mremap
> >   ------------------------
> >   1..0 # SKIP uffd-wp feature not supported
> >   [SKIP]
> > ok 1 uffd-wp-mremap # SKIP
> >
> > Acked-by: Zi Yan <ziy@xxxxxxxxxx>
> > Signed-off-by: Sayali Patil <sayalip@xxxxxxxxxxxxx>
> > ---
> >   tools/testing/selftests/mm/uffd-wp-mremap.c | 13 +++++++++++++
> >   1 file changed, 13 insertions(+)
> >
> > diff --git a/tools/testing/selftests/mm/uffd-wp-mremap.c b/tools/testing/selftests/mm/uffd-wp-mremap.c
> > index 17186d4a4147..73d53a4da389 100644
> > --- a/tools/testing/selftests/mm/uffd-wp-mremap.c
> > +++ b/tools/testing/selftests/mm/uffd-wp-mremap.c
> > @@ -19,6 +19,17 @@ static size_t thpsizes[20];
> >   static int nr_hugetlbsizes;
> >   static size_t hugetlbsizes[10];
> >   
> > +static void uffd_wp_feature_supported(void)
> Likely that function should be called
>
> "check_uffd_wp_feature_supported()"
>
> Because right now it reads as if it would be returning a bool.
>
> Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
Thanks for the review. I'll rename it to
"check_uffd_wp_feature_supported()" in the next version.