From 47fba2b6d5bae89df5b1434bfdad4a56c7e88059 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 9 Mar 2023 17:37:11 -0500 Subject: [PATCH] selftests/mm: smoke test UFFD_FEATURE_WP_UNPOPULATED Enable it by default on the stress test, and add some smoke tests for the pte markers on anonymous. Link: https://lkml.kernel.org/r/20230309223711.823547-3-peterx@redhat.com Signed-off-by: Peter Xu Cc: Andrea Arcangeli Cc: Axel Rasmussen Cc: David Hildenbrand Cc: Mike Rapoport Cc: Muhammad Usama Anjum Cc: Nadav Amit Cc: Paul Gofman Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/userfaultfd.c | 45 ++++++++++++++++++++++++++++++-- 1 file changed, 43 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/userfaultfd.c b/tools/testing/selftests/mm/userfaultfd.c index 7f22844ed704..e030d63c031a 100644 --- a/tools/testing/selftests/mm/userfaultfd.c +++ b/tools/testing/selftests/mm/userfaultfd.c @@ -1444,6 +1444,43 @@ static int pagemap_test_fork(bool present) return result; } +static void userfaultfd_wp_unpopulated_test(int pagemap_fd) +{ + uint64_t value; + + /* Test applying pte marker to anon unpopulated */ + wp_range(uffd, (uint64_t)area_dst, page_size, true); + value = pagemap_read_vaddr(pagemap_fd, area_dst); + pagemap_check_wp(value, true); + + /* Test unprotect on anon pte marker */ + wp_range(uffd, (uint64_t)area_dst, page_size, false); + value = pagemap_read_vaddr(pagemap_fd, area_dst); + pagemap_check_wp(value, false); + + /* Test zap on anon marker */ + wp_range(uffd, (uint64_t)area_dst, page_size, true); + if (madvise(area_dst, page_size, MADV_DONTNEED)) + err("madvise(MADV_DONTNEED) failed"); + value = pagemap_read_vaddr(pagemap_fd, area_dst); + pagemap_check_wp(value, false); + + /* Test fault in after marker removed */ + *area_dst = 1; + value = pagemap_read_vaddr(pagemap_fd, area_dst); + pagemap_check_wp(value, false); + /* Drop it to make pte none again */ + if (madvise(area_dst, page_size, MADV_DONTNEED)) + err("madvise(MADV_DONTNEED) failed"); + + /* Test read-zero-page upon pte marker */ + wp_range(uffd, (uint64_t)area_dst, page_size, true); + *(volatile char *)area_dst; + /* Drop it to make pte none again */ + if (madvise(area_dst, page_size, MADV_DONTNEED)) + err("madvise(MADV_DONTNEED) failed"); +} + static void userfaultfd_pagemap_test(unsigned int test_pgsize) { struct uffdio_register uffdio_register; @@ -1462,7 +1499,7 @@ static void userfaultfd_pagemap_test(unsigned int test_pgsize) /* Flush so it doesn't flush twice in parent/child later */ fflush(stdout); - uffd_test_ctx_init(0); + uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED); if (test_pgsize > page_size) { /* This is a thp test */ @@ -1482,6 +1519,10 @@ static void userfaultfd_pagemap_test(unsigned int test_pgsize) pagemap_fd = pagemap_open(); + /* Smoke test WP_UNPOPULATED first when it's still empty */ + if (test_pgsize == page_size) + userfaultfd_wp_unpopulated_test(pagemap_fd); + /* Touch the page */ *area_dst = 1; wp_range(uffd, (uint64_t)area_dst, test_pgsize, true); @@ -1526,7 +1567,7 @@ static int userfaultfd_stress(void) struct uffdio_register uffdio_register; struct uffd_stats uffd_stats[nr_cpus]; - uffd_test_ctx_init(0); + uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED); if (posix_memalign(&area, page_size, page_size)) err("out of memory"); -- 2.11.0