From 81b1e3f91d77564611ab10d2c61774cf6a46ec78 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 19 May 2023 12:27:21 +0200 Subject: [PATCH] selftests/mm: factor out detection of hugetlb page sizes into vm_util Patch series "selftests/mm: new test for FOLL_LONGTERM on file mappings". Let's add some selftests to make sure that: * R/O long-term pinning always works of file mappings * R/W long-term pinning always works in MAP_PRIVATE file mappings * R/W long-term pinning only works in MAP_SHARED mappings with special filesystems (shmem, hugetlb) and fails with other filesystems (ext4, btrfs, xfs). The tests make use of the gup_test kernel module to trigger ordinary GUP and GUP-fast, and liburing (similar to our COW selftests). Test with memfd, memfd hugetlb, tmpfile() and mkstemp(). The latter usually gives us a "real" filesystem (ext4, btrfs, xfs) where long-term pinning is expected to fail. Note that these selftests don't contain any actual reproducers for data corruptions in case R/W long-term pinning on problematic filesystems "would" work. Maybe we can later come up with a racy !FOLL_LONGTERM reproducer that can reuse an existing interface to trigger short-term pinning (I'll look into that next). On current mm/mm-unstable: # ./gup_longterm # [INFO] detected hugetlb page size: 2048 KiB # [INFO] detected hugetlb page size: 1048576 KiB TAP version 13 1..50 # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with memfd ok 1 Should have worked # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with tmpfile ok 2 Should have worked # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with local tmpfile ok 3 Should have failed # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 4 Should have worked # [RUN] R/W longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 5 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd ok 6 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with tmpfile ok 7 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with local tmpfile ok 8 Should have failed # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 9 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 10 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with memfd ok 11 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with tmpfile ok 12 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with local tmpfile ok 13 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 14 Should have worked # [RUN] R/O longterm GUP pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 15 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd ok 16 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with tmpfile ok 17 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with local tmpfile ok 18 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 19 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 20 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with memfd ok 21 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with tmpfile ok 22 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with local tmpfile ok 23 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 24 Should have worked # [RUN] R/W longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 25 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd ok 26 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with tmpfile ok 27 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with local tmpfile ok 28 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 29 Should have worked # [RUN] R/W longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 30 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with memfd ok 31 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with tmpfile ok 32 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with local tmpfile ok 33 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 34 Should have worked # [RUN] R/O longterm GUP pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 35 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd ok 36 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with tmpfile ok 37 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with local tmpfile ok 38 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 39 Should have worked # [RUN] R/O longterm GUP-fast pin in MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 40 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with memfd ok 41 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with tmpfile ok 42 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with local tmpfile ok 43 Should have failed # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with memfd hugetlb (2048 kB) ok 44 Should have worked # [RUN] io_uring fixed buffer with MAP_SHARED file mapping ... with memfd hugetlb (1048576 kB) ok 45 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with memfd ok 46 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with tmpfile ok 47 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with local tmpfile ok 48 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with memfd hugetlb (2048 kB) ok 49 Should have worked # [RUN] io_uring fixed buffer with MAP_PRIVATE file mapping ... with memfd hugetlb (1048576 kB) ok 50 Should have worked # Totals: pass:50 fail:0 xfail:0 xpass:0 skip:0 error:0 This patch (of 3): Let's factor detection out into vm_util, to be reused by a new test. Link: https://lkml.kernel.org/r/20230519102723.185721-1-david@redhat.com Link: https://lkml.kernel.org/r/20230519102723.185721-2-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jens Axboe Cc: John Hubbard Cc: Peter Xu Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/cow.c | 29 ++-------------------------- tools/testing/selftests/mm/vm_util.c | 27 ++++++++++++++++++++++++++ tools/testing/selftests/mm/vm_util.h | 1 + 3 files changed, 30 insertions(+), 27 deletions(-) diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c index dc9d6fe86028..7f3b620d9cb7 100644 --- a/tools/testing/selftests/mm/cow.c +++ b/tools/testing/selftests/mm/cow.c @@ -14,7 +14,6 @@ #include #include #include -#include #include #include #include @@ -70,31 +69,6 @@ static void detect_huge_zeropage(void) close(fd); } -static void detect_hugetlbsizes(void) -{ - DIR *dir = opendir("/sys/kernel/mm/hugepages/"); - - if (!dir) - return; - - while (nr_hugetlbsizes < ARRAY_SIZE(hugetlbsizes)) { - struct dirent *entry = readdir(dir); - size_t kb; - - if (!entry) - break; - if (entry->d_type != DT_DIR) - continue; - if (sscanf(entry->d_name, "hugepages-%zukB", &kb) != 1) - continue; - hugetlbsizes[nr_hugetlbsizes] = kb * 1024; - nr_hugetlbsizes++; - ksft_print_msg("[INFO] detected hugetlb size: %zu KiB\n", - kb); - } - closedir(dir); -} - static bool range_is_swapped(void *addr, size_t size) { for (; size; addr += pagesize, size -= pagesize) @@ -1717,7 +1691,8 @@ int main(int argc, char **argv) if (thpsize) ksft_print_msg("[INFO] detected THP size: %zu KiB\n", thpsize / 1024); - detect_hugetlbsizes(); + nr_hugetlbsizes = detect_hugetlb_page_sizes(hugetlbsizes, + ARRAY_SIZE(hugetlbsizes)); detect_huge_zeropage(); ksft_print_header(); diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index 9b06a5034808..5cf84d860076 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include #include +#include #include #include #include @@ -198,6 +199,32 @@ unsigned long default_huge_page_size(void) return hps; } +int detect_hugetlb_page_sizes(size_t sizes[], int max) +{ + DIR *dir = opendir("/sys/kernel/mm/hugepages/"); + int count = 0; + + if (!dir) + return 0; + + while (count < max) { + struct dirent *entry = readdir(dir); + size_t kb; + + if (!entry) + break; + if (entry->d_type != DT_DIR) + continue; + if (sscanf(entry->d_name, "hugepages-%zukB", &kb) != 1) + continue; + sizes[count++] = kb * 1024; + ksft_print_msg("[INFO] detected hugetlb page size: %zu KiB\n", + kb); + } + closedir(dir); + return count; +} + /* If `ioctls' non-NULL, the allowed ioctls will be returned into the var */ int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len, bool miss, bool wp, bool minor, uint64_t *ioctls) diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index b950bd16083a..99b795528716 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -44,6 +44,7 @@ bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size); bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size); int64_t allocate_transhuge(void *ptr, int pagemap_fd); unsigned long default_huge_page_size(void); +int detect_hugetlb_page_sizes(size_t sizes[], int max); int uffd_register(int uffd, void *addr, uint64_t len, bool miss, bool wp, bool minor); -- 2.39.5