On Fri, May 22, 2026 at 02:38:54PM +0100, Kiryl Shutsemau wrote: > From: "Kiryl Shutsemau (Meta)" <[email protected]> > > Coverage for UFFDIO_REGISTER_MODE_RWP and UFFDIO_RWPROTECT: > > rwp-async async mode — touch pages, verify permissions are > auto-restored without a message > rwp-sync sync mode — access blocks, handler resolves via > UFFDIO_RWPROTECT > rwp-pagemap PAGEMAP_SCAN reports still-cold pages via > inverted PAGE_IS_ACCESSED > rwp-mprotect RWP survives mprotect(PROT_NONE) -> > mprotect(PROT_READ|PROT_WRITE) round-trip > rwp-gup GUP walks through a protnone RWP PTE (pipe > write/read drives the GUP path) > rwp-async-toggle UFFDIO_SET_MODE flips between sync and async > without re-registering > rwp-close closing the uffd restores page permissions > rwp-fork RWP survives fork() with EVENT_FORK; child's > PTEs keep the uffd bit > rwp-fork-pin RWP survives fork() on an RO-longterm-pinned > anon page (forces copy_present_page()); child > read auto-resolves and clears the bit, proving > PAGE_NONE was in place > rwp-wp-exclusive register with MODE_WP|MODE_RWP returns -EINVAL > > All tests run against anon, shmem, shmem-private, hugetlb, and > hugetlb-private memory, except rwp-fork-pin which is anon-only — > copy_present_page() is the private-anon pinned-exclusive fork path. > > Signed-off-by: Kiryl Shutsemau <[email protected]> > Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) <[email protected]> > --- > tools/testing/selftests/mm/uffd-unit-tests.c | 766 +++++++++++++++++++ > 1 file changed, 766 insertions(+) -- Sincerely yours, Mike.
