The quilt patch titled Subject: selftests/mm: fix division-by-zero in uffd-unit-tests has been removed from the -mm tree. Its filename was selftests-mm-fix-division-by-zero-in-uffd-unit-tests.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------ From: Carlos Llamas cmllamas@google.com Subject: selftests/mm: fix division-by-zero in uffd-unit-tests Date: Thu, 13 Nov 2025 03:46:22 +0000
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.
Link: https://lkml.kernel.org/r/20251113034623.3127012-1-cmllamas@google.com Fixes: 4dfd4bba8578 ("selftests/mm/uffd: refactor non-composite global vars into struct") Signed-off-by: Carlos Llamas cmllamas@google.com Acked-by: David Hildenbrand (Red Hat) david@kernel.org Reviewed-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com Reviewed-by: Mike Rapoport (Microsoft) rppt@kernel.org Reviewed-by: Ujwal Kundur ujwal.kundur@gmail.com Cc: Brendan Jackman jackmanb@google.com Cc: Liam Howlett liam.howlett@oracle.com Cc: Michal Hocko mhocko@suse.com Cc: Peter Xu peterx@redhat.com Cc: Shuah Khan shuah@kernel.org Cc: Suren Baghdasaryan surenb@google.com Cc: Vlastimil Babka vbabka@suse.cz Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
tools/testing/selftests/mm/uffd-unit-tests.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)
--- a/tools/testing/selftests/mm/uffd-unit-tests.c~selftests-mm-fix-division-by-zero-in-uffd-unit-tests +++ a/tools/testing/selftests/mm/uffd-unit-tests.c @@ -1758,10 +1758,15 @@ int main(int argc, char *argv[]) uffd_test_ops = mem_type->mem_ops; uffd_test_case_ops = test->test_case_ops;
- if (mem_type->mem_flag & (MEM_HUGETLB_PRIVATE | MEM_HUGETLB)) + if (mem_type->mem_flag & (MEM_HUGETLB_PRIVATE | MEM_HUGETLB)) { gopts.page_size = default_huge_page_size(); - else + if (gopts.page_size == 0) { + uffd_test_skip("huge page size is 0, feature missing?"); + continue; + } + } else { gopts.page_size = psize(); + }
/* Ensure we have at least 2 pages */ gopts.nr_pages = MAX(UFFD_TEST_MEM_SIZE, gopts.page_size * 2) @@ -1776,12 +1781,6 @@ int main(int argc, char *argv[]) continue;
uffd_test_start("%s on %s", test->name, mem_type->name); - if ((mem_type->mem_flag == MEM_HUGETLB || - mem_type->mem_flag == MEM_HUGETLB_PRIVATE) && - (default_huge_page_size() == 0)) { - uffd_test_skip("huge page size is 0, feature missing?"); - continue; - } if (!uffd_feature_supported(test)) { uffd_test_skip("feature missing"); continue; _
Patches currently in -mm which might be from cmllamas@google.com are