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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Ujwal Kundur , Brendan Jackman Cc: kernel-team@android.com, linux-kernel@vger.kernel.org, Carlos Llamas , stable@vger.kernel.org, "open list:MEMORY MANAGEMENT - USERFAULTFD" , "open list:KERNEL SELFTEST FRAMEWORK" Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Commit 4dfd4bba8578 ("selftests/mm/uffd: refactor non-composite global vars into struct") moved some of the operations previously implemented in uffd_setup_environment() earlier in the main test loop. The calculation of nr_pages, which involves a division by page_size, now occurs before checking that default_huge_page_size() returns a non-zero This leads to a division-by-zero error on systems with !CONFIG_HUGETLB. Fix this by relocating the non-zero page_size check before the nr_pages calculation, as it was originally implemented. Cc: stable@vger.kernel.org Fixes: 4dfd4bba8578 ("selftests/mm/uffd: refactor non-composite global vars= into struct") Signed-off-by: Carlos Llamas Acked-by: David Hildenbrand (Red Hat) Reviewed-by: Lorenzo Stoakes Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Ujwal Kundur --- tools/testing/selftests/mm/uffd-unit-tests.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/s= elftests/mm/uffd-unit-tests.c index 9e3be2ee7f1b..f917b4c4c943 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -1758,10 +1758,15 @@ int main(int argc, char *argv[]) uffd_test_ops =3D mem_type->mem_ops; uffd_test_case_ops =3D test->test_case_ops; =20 - if (mem_type->mem_flag & (MEM_HUGETLB_PRIVATE | MEM_HUGETLB)) + if (mem_type->mem_flag & (MEM_HUGETLB_PRIVATE | MEM_HUGETLB)) { gopts.page_size =3D default_huge_page_size(); - else + if (gopts.page_size =3D=3D 0) { + uffd_test_skip("huge page size is 0, feature missing?"); + continue; + } + } else { gopts.page_size =3D psize(); + } =20 /* Ensure we have at least 2 pages */ gopts.nr_pages =3D MAX(UFFD_TEST_MEM_SIZE, gopts.page_size * 2) @@ -1776,12 +1781,6 @@ int main(int argc, char *argv[]) continue; =20 uffd_test_start("%s on %s", test->name, mem_type->name); - if ((mem_type->mem_flag =3D=3D MEM_HUGETLB || - mem_type->mem_flag =3D=3D MEM_HUGETLB_PRIVATE) && - (default_huge_page_size() =3D=3D 0)) { - uffd_test_skip("huge page size is 0, feature missing?"); - continue; - } if (!uffd_feature_supported(test)) { uffd_test_skip("feature missing"); continue; --=20 2.51.2.1041.gc1ab5b90ca-goog