From 4df9cefa9419718c32259c105ac8fbbc680410f7 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Wed, 12 Apr 2023 12:45:17 -0400 Subject: [PATCH] selftests/mm: workaround no way to detect uffd-minor + wp Userfaultfd minor+wp mode was very recently added. The test will fail on the old kernels at ioctl(UFFDIO_CONTINUE) which is misterious. Unfortunately there's no feature bit to detect for this support. Add a hack to leverage WP_UNPOPULATED to detect whether that feature existed, since WP_UNPOPULATED was merged right after minor+wp. Link: https://lkml.kernel.org/r/20230412164517.329152-1-peterx@redhat.com Signed-off-by: Peter Xu Cc: Axel Rasmussen Cc: David Hildenbrand Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Mike Kravetz Cc: Mike Rapoport (IBM) Cc: Zach O'Keefe Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/uffd-unit-tests.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 160bd8ccda55..a33d6c928eeb 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -780,7 +780,13 @@ uffd_test_case_t uffd_tests[] = { .mem_targets = MEM_SHMEM | MEM_HUGETLB, .uffd_feature_required = UFFD_FEATURE_MINOR_HUGETLBFS | UFFD_FEATURE_MINOR_SHMEM | - UFFD_FEATURE_PAGEFAULT_FLAG_WP, + UFFD_FEATURE_PAGEFAULT_FLAG_WP | + /* + * HACK: here we leveraged WP_UNPOPULATED to detect whether + * minor mode supports wr-protect. There's no feature flag + * for it so this is the best we can test against. + */ + UFFD_FEATURE_WP_UNPOPULATED, }, { .name = "minor-collapse",