selftests/mm/cow: add tests for anonymous multi-size THP

Add tests similar to the existing PMD-sized THP tests, but which operate
on memory backed by (PTE-mapped) multi-size THP. This reuses all the
existing infrastructure. If the test suite detects that multi-size THP is
not supported by the kernel, the new tests are skipped.

Link: https://lkml.kernel.org/r/20231207161211.2374093-11-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Itaru Kitayama <itaru.kitayama@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests/mm/cow: generalize do_run_with_thp() helper

do_run_with_thp() prepares (PMD-sized) THP memory into different states
before running tests. With the introduction of multi-size THP, we would
like to reuse this logic to also test those smaller THP sizes. So let's
add a thpsize parameter which tells the function what size THP it should
operate on.

A separate commit will utilize this change to add new tests for multi-size
THP, where available.

Link: https://lkml.kernel.org/r/20231207161211.2374093-10-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Itaru Kitayama <itaru.kitayama@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests/mm: cow: print ksft header before printing anything else

Doing a ksft_print_msg() before the ksft_print_header() seems to confuse
the ksft framework in a strange way: running the test on the cmdline
results in the expected output.

But piping the output somewhere else, results in some odd output,
whereby we repeatedly get the same info printed:
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
TAP version 13
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
TAP version 13
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
ok 1 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped out base page
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled

Doing the ksft_print_header() first seems to resolve that and gives us
the output we expect:
TAP version 13
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
ok 1 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped out base page
ok 2 No leak from parent into child
# [RUN] Basic COW after fork() ... with THP
ok 3 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped-out THP
ok 4 No leak from parent into child
# [RUN] Basic COW after fork() ... with PTE-mapped THP
ok 5 No leak from parent into child

Link: https://lkml.kernel.org/r/20231206103558.38040-1-david@redhat.com
Fixes: f4b5fd6946e2 ("selftests/vm: anon_cow: THP tests")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Nico Pache <npache@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests: mm: remove duplicate unneeded defines

Remove all defines which aren't needed after correctly including the
kernel header files.

Link: https://lkml.kernel.org/r/20230612095347.996335-2-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stefan Roesch <shr@devkernel.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests/mm: fix build failures due to missing MADV_COLLAPSE

MADV_PAGEOUT, MADV_POPULATE_READ, MADV_COLLAPSE are conditionally
defined as necessary. However, that was being done in .c files, and a
new build failure came up that would have been automatically avoided had
these been in a common header file.

So consolidate and move them all to vm_util.h, which fixes the build
failure.

An alternative approach from Muhammad Usama Anjum was: rely on "make
headers" being required, and include asm-generic/mman-common.h. This
works in the sense that it builds, but it still generates warnings about
duplicate MADV_* symbols, and the goal here is to get a fully clean (no
warnings) build here.

Link: https://lkml.kernel.org/r/20230606071637.267103-9-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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 <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests/mm: reuse read_pmd_pagesize() in COW selftest

Patch series "mm: (pte|pmd)_mkdirty() should not unconditionally allow for
write access".

This is the follow-up on [1], adding selftests (testing for known issues
we added workarounds for and other issues that haven't been fixed yet),
fixing sparc64, reverting the workarounds, and perform one cleanup.

The patch from [1] was modified slightly (updated/extended patch
description, dropped one unnecessary NOP instruction from the ASM in
__pte_mkhwwrite()).

Retested on x86_64 and sparc64 (sun4u in QEMU).

I scanned most architectures to make sure their (pte|pmd)_mkdirty()
handling is correct. To be sure, we can run the selftests and find out if
other architectures are still affectes (loongarch was fixed recently as
well).

Based on master for now. I don't expect surprises regarding mm-tress, but
I can rebase if there are any problems.


This patch (of 6):

The COW selftest can deal with THP not being configured. So move error
handling of read_pmd_pagesize() into the callers such that we can reuse it
in the COW selftest.

Link: https://lkml.kernel.org/r/20230411142512.438404-1-david@redhat.com
Link: https://lkml.kernel.org/r/20221212130213.136267-1-david@redhat.com [1]
Link: https://lkml.kernel.org/r/20230411142512.438404-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests/mm: define MADV_PAGEOUT to fix compilation issues

If MADV_PAGEOUT is not defined (e.g., on AlmaLinux 8), compilation will
fail. Let's fix that like khugepaged.c does by conditionally defining
MADV_PAGEOUT.

Link: https://lkml.kernel.org/r/20230109171255.488749-1-david@redhat.com
Fixes: 69c66add5663 ("selftests/vm: anon_cow: test COW handling of anonymous memory")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests/vm: rename selftests/vm to selftests/mm

Rename selftets/vm to selftests/mm for being more consistent with the
code, documentation, and tools directories, and won't be confused with
virtual machines.

[sj@kernel.org: convert missing vm->mm changes]
Link: https://lkml.kernel.org/r/20230107230643.252273-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230103180754.129637-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>