Add tests for process_madvise(), focusing on verifying behavior under
various conditions including valid usage and error cases.
[lianux.mm@gmail.com: v7]
Link: https://lkml.kernel.org/r/20250729113109.12272-1-lianux.mm@gmail.com
Link: https://lkml.kernel.org/r/20250729113109.12272-1-lianux.mm@gmail.com
Link: https://lkml.kernel.org/r/20250721114614.40996-1-lianux.mm@gmail.com
Signed-off-by: wang lian <lianux.mm@gmail.com>
Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Zi Yan <ziy@nvidia.com>
Suggested-by: Mark Brown <broonie@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Tested-by: Zi Yan <ziy@nvidia.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Let's test some basic functionality using /dev/mem. These tests will
implicitly cover some PAT (Page Attribute Handling) handling on x86.
These tests will only run when /dev/mem access to the first two pages in
physical address space is possible and allowed; otherwise, the tests are
skipped.
On current x86-64 with PAT inside a VM, all tests pass:
TAP version 13
1..6
# Starting 6 tests from 1 test cases.
# RUN pfnmap.madvise_disallowed ...
# OK pfnmap.madvise_disallowed
ok 1 pfnmap.madvise_disallowed
# RUN pfnmap.munmap_split ...
# OK pfnmap.munmap_split
ok 2 pfnmap.munmap_split
# RUN pfnmap.mremap_fixed ...
# OK pfnmap.mremap_fixed
ok 3 pfnmap.mremap_fixed
# RUN pfnmap.mremap_shrink ...
# OK pfnmap.mremap_shrink
ok 4 pfnmap.mremap_shrink
# RUN pfnmap.mremap_expand ...
# OK pfnmap.mremap_expand
ok 5 pfnmap.mremap_expand
# RUN pfnmap.fork ...
# OK pfnmap.fork
ok 6 pfnmap.fork
# PASSED: 6 / 6 tests passed.
# Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0
However, we are able to trigger:
[ 27.888251] x86/PAT: pfnmap:1790 freeing invalid memtype [mem 0x00000000-0x00000fff]
There are probably more things worth testing in the future, such as
MAP_PRIVATE handling. But this set of tests is sufficient to cover most
of the things we will rework regarding PAT handling.
Link: https://lkml.kernel.org/r/20250509153033.952746-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Prior to the recently applied commit that permits this merge,
mprotect()'ing a faulted VMA, adjacent to an unfaulted VMA, such that the
two share characteristics would fail to merge due to what appear to be
unintended consequences of commit 965f55dea0 ("mmap: avoid merging
cloned VMAs").
Now we have fixed this bug, assert that we can indeed merge anonymous VMAs
this way.
Also assert that forked source/target VMAs are equally rejected.
Previously, all empty target anon merges with one VMA faulted and the
other unfaulted would be rejected incorrectly, now we ensure that unforked
merge, but forked do not.
Additionally, add the new test file to the MEMORY MAPPING section in
MAINTAINERS, as these tests are explicitly memory mapping related.
Link: https://lkml.kernel.org/r/2b69330274a3b71721f7042c5eabe91143934415.1744104124.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The feature formerly referred to as guard pages is more correctly referred
to as 'guard regions', as in fact no pages are ever allocated in the
process of installing the regions.
To avoid confusion, rename the tests accordingly.
[lorenzo.stoakes@oracle.com: fix guard regions invocation]
Link: https://lkml.kernel.org/r/13426c71-d069-4407-9340-b227ff8b8736@lucifer.local
Link: https://lkml.kernel.org/r/1c3cd04a3f69b5756b94bda701ac88325a9be18b.1739469950.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce a test that registers a range of memory for
UFFDIO_WRITEPROTECT_MODE_WP without UFFD_FEATURE_EVENT_REMAP. First check
that the uffd-wp bit is set for every PTE in the range. Then mremap() the
range to a new location and check that the uffd-wp bit is clear for every
PTE in the range.
Run the test for small folios, all supported THP sizes and all supported
hugetlb sizes, and for swapped out memory, shared and private.
There was previously a bug in the kernel where the uffd-wp bits remained
set in all PTEs for this case, after fixing the kernel, the tests all
pass.
Link: https://lkml.kernel.org/r/20250107144755.1871363-3-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Compiled binary files should be added to .gitignore
'git status' complains:
Untracked files:
(use "git add <file>..." to include in what will be committed)
mm/hugetlb_dio
mm/pkey_sighandler_tests_32
mm/pkey_sighandler_tests_64
Link: https://lkml.kernel.org/r/20241125064036.413536-1-lizhijian@fujitsu.com
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Utilise the kselftest harmness to implement tests for the guard page
implementation.
We start by implement basic tests asserting that guard pages can be
installed, removed and that touching guard pages result in SIGSEGV. We
also assert that, in removing guard pages from a range, non-guard pages
remain intact.
We then examine different operations on regions containing guard markers
behave to ensure correct behaviour:
* Operations over multiple VMAs operate as expected.
* Invoking MADV_GUARD_INSTALL / MADV_GUARD_REMOVE via process_madvise() in
batches works correctly.
* Ensuring that munmap() correctly tears down guard markers.
* Using mprotect() to adjust protection bits does not in any way override
or cause issues with guard markers.
* Ensuring that splitting and merging VMAs around guard markers causes no
issue - i.e. that a marker which 'belongs' to one VMA can function just
as well 'belonging' to another.
* Ensuring that madvise(..., MADV_DONTNEED) and madvise(..., MADV_FREE)
do not remove guard markers.
* Ensuring that mlock()'ing a range containing guard markers does not
cause issues.
* Ensuring that mremap() can move a guard range and retain guard markers.
* Ensuring that mremap() can expand a guard range and retain guard
markers (perhaps moving the range).
* Ensuring that mremap() can shrink a guard range and retain guard markers.
* Ensuring that forking a process correctly retains guard markers.
* Ensuring that forking a VMA with VM_WIPEONFORK set behaves sanely.
* Ensuring that lazyfree simply clears guard markers.
* Ensuring that userfaultfd can co-exist with guard pages.
* Ensuring that madvise(..., MADV_POPULATE_READ) and
madvise(..., MADV_POPULATE_WRITE) error out when encountering
guard markers.
* Ensuring that madvise(..., MADV_COLD) and madvise(..., MADV_PAGEOUT) do
not remove guard markers.
If any test is unable to be run due to lack of permissions, that test is
skipped.
Link: https://lkml.kernel.org/r/c3dcca76b736bac0aeaf1dc085927536a253ac94.1730123433.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Jann Horn <jannh@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabkba@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 6998a73efb ("selftests/mm: Add new testcases for pkeys") and
commit 3a103b5315 ("selftest: mm: Test if hugepage does not get leaked
during __bio_release_pages()") generate test binaries hugetlb_dio,
pkey_sighandler_tests_32 and pkey_sighandler_tests_64 but did not add
these to .gitignore. Correct this.
Link: https://lkml.kernel.org/r/20240924185911.117937-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Merge tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator updates from Jason Donenfeld:
"This adds getrandom() support to the vDSO.
First, it adds a new kind of mapping to mmap(2), MAP_DROPPABLE, which
lets the kernel zero out pages anytime under memory pressure, which
enables allocating memory that never gets swapped to disk but also
doesn't count as being mlocked.
Then, the vDSO implementation of getrandom() is introduced in a
generic manner and hooked into random.c.
Next, this is implemented on x86. (Also, though it's not ready for
this pull, somebody has begun an arm64 implementation already)
Finally, two vDSO selftests are added.
There are also two housekeeping cleanup commits"
* tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
MAINTAINERS: add random.h headers to RNG subsection
random: note that RNDGETPOOL was removed in 2.6.9-rc2
selftests/vDSO: add tests for vgetrandom
x86: vdso: Wire up getrandom() vDSO implementation
random: introduce generic vDSO getrandom() implementation
mm: add MAP_DROPPABLE for designating always lazily freeable mappings
The vDSO getrandom() implementation works with a buffer allocated with a
new system call that has certain requirements:
- It shouldn't be written to core dumps.
* Easy: VM_DONTDUMP.
- It should be zeroed on fork.
* Easy: VM_WIPEONFORK.
- It shouldn't be written to swap.
* Uh-oh: mlock is rlimited.
* Uh-oh: mlock isn't inherited by forks.
- It shouldn't reserve actual memory, but it also shouldn't crash when
page faulting in memory if none is available
* Uh-oh: VM_NORESERVE means segfaults.
It turns out that the vDSO getrandom() function has three really nice
characteristics that we can exploit to solve this problem:
1) Due to being wiped during fork(), the vDSO code is already robust to
having the contents of the pages it reads zeroed out midway through
the function's execution.
2) In the absolute worst case of whatever contingency we're coding for,
we have the option to fallback to the getrandom() syscall, and
everything is fine.
3) The buffers the function uses are only ever useful for a maximum of
60 seconds -- a sort of cache, rather than a long term allocation.
These characteristics mean that we can introduce VM_DROPPABLE, which
has the following semantics:
a) It never is written out to swap.
b) Under memory pressure, mm can just drop the pages (so that they're
zero when read back again).
c) It is inherited by fork.
d) It doesn't count against the mlock budget, since nothing is locked.
e) If there's not enough memory to service a page fault, it's not fatal,
and no signal is sent.
This way, allocations used by vDSO getrandom() can use:
VM_DROPPABLE | VM_DONTDUMP | VM_WIPEONFORK | VM_NORESERVE
And there will be no problem with OOMing, crashing on overcommitment,
using memory when not in use, not wiping on fork(), coredumps, or
writing out to swap.
In order to let vDSO getrandom() use this, expose these via mmap(2) as
MAP_DROPPABLE.
Note that this involves removing the MADV_FREE special case from
sort_folio(), which according to Yu Zhao is unnecessary and will simply
result in an extra call to shrink_folio_list() in the worst case. The
chunk removed reenables the swapbacked flag, which we don't want for
VM_DROPPABLE, and we can't conditionalize it here because there isn't a
vma reference available.
Finally, the provided self test ensures that this is working as desired.
Cc: linux-mm@kvack.org
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Add regression and new tests when hugepage has correctable memory errors,
and how userspace wants to deal with it:
* if enable_soft_offline=1, mapped hugepage is soft offlined
* if enable_soft_offline=0, mapped hugepage is intact
Free hugepages case is not explicitly covered by the tests.
Hugepage having corrected memory errors is emulated with
MADV_SOFT_OFFLINE.
[jiaqiyan@google.com: v7]
Link: https://lkml.kernel.org/r/20240628205958.2845610-4-jiaqiyan@google.com
Link: https://lkml.kernel.org/r/20240626050818.2277273-4-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This test stresses the race between of madvise(DONTNEED), a page fault
and a parallel huge page mmap, which should fail due to lack of
available page available for mapping.
This test case must run on a system with one and only one huge page
available.
# echo 1 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
During setup, the test allocates the only available page, and starts
three threads:
- thread 1:
* madvise(MADV_DONTNEED) on the allocated huge page
- thread 2:
* Write to the allocated huge page
- thread 3:
* Tries to allocated (steal) an extra huge page (which is not
available)
thread 3 should never succeed in the allocation, since the only huge
page was never unmapped, and should be reserved.
Touching the old page after thread3 allocation will raise a SIGBUS.
Link: https://lkml.kernel.org/r/20240105155419.1939484-2-leitao@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add pagemap ioctl tests. Add several different types of tests to judge
the correction of the interface.
Link: https://lkml.kernel.org/r/20230821141518.870589-7-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Miroslaw <emmir@google.com>
Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Paul Gofman <pgofman@codeweavers.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: Yang Shi <shy828301@gmail.com>
Cc: Yun Zhou <yun.zhou@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add tests for the improvement made to read operation on HWPOISON
hugetlb page with different read granularities. For each chunk size,
three read scenarios are tested:
1. Simple regression test on read without HWPOISON.
2. Sequential read page by page should succeed until encounters the 1st
raw HWPOISON subpage.
3. After skip a raw HWPOISON subpage by lseek, read()s always succeed.
Link: https://lkml.kernel.org/r/20230713001833.3778937-5-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
These new build products were left out of .gitignore, so add them now.
Link: https://lkml.kernel.org/r/20230606071637.267103-6-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.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>
Let's add a new test for checking whether GUP long-term page pinning works
as expected (R/O vs. R/W, MAP_PRIVATE vs. MAP_SHARED, GUP vs.
GUP-fast). Note that COW handling with long-term R/O pinning in private
mappings, and pinning of anonymous memory in general, is tested by the COW
selftest. This test, therefore, focuses on page pinning in file mappings.
The most interesting case is probably the "local tmpfile" case, as that
will likely end up on a "real" filesystem such as ext4 or xfs, not on a
virtual one like tmpfs or hugetlb where any long-term page pinning is
always expected to succeed.
For now, only add tests that use the "/sys/kernel/debug/gup_test"
interface. We'll add tests based on liburing separately next.
[akpm@linux-foundation.org: update .gitignore for gup_longterm, per Peter]
Link: https://lkml.kernel.org/r/20230519102723.185721-3-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>
In many ways it's weird and unwanted to keep all the tests in the same
userfaultfd.c at least when still in the current way.
For example, it doesn't make much sense to run the stress test for each
method we can create an userfaultfd handle (either via syscall or /dev/
node). It's a waste of time running this twice for the whole stress as
the stress paths are the same, only the open path is different.
It's also just weird to need to manually specify different types of memory
to run all unit tests for the userfaultfd interface. We should be able to
just run a single program and that should go through all functional uffd
tests without running the stress test at all. The stress test was more
for torturing and finding race conditions. We don't want to wait for
stress to finish just to regress test a functional test.
When we start to pile up more things on top of the same file and same
functions, things start to go a bit chaos and the code is just harder to
maintain too with tons of global variables.
This patch creates a new test uffd-unit-tests to keep userfaultfd unit
tests in the future, currently empty.
Meanwhile rename the old userfaultfd.c test to uffd-stress.c.
Link: https://lkml.kernel.org/r/20230412164244.328270-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/mm: Split / Refactor userfault test", v2.
This patchset splits userfaultfd.c into two tests:
- uffd-stress: the "vanilla", old and powerful stress test
- uffd-unit-tests: all the unit tests will be moved here
This is on my todo list for a long time but I never did it for real. The
uffd test is growing into a small and cute monster. I start to notice it's
going harder to maintain such a test and make it useful.
A few issues I found when looking at userfaultfd test:
- We have a bunch of unit tests in userfaultfd.c, but they always need to
be run only after a stress type. No way to not do it.
- We can only run an unit test for one memory type only, if we want to
do a quick smoke test to check regressions, there's no good way. The
best to come currently is "bash ./run_vmtests.sh -t userfaultfd" thanks
to the most recent changes to run_vmtests.sh on tagging. Still, that
needs to run the stress tests always and hard to see what's wrong.
- It's hard to add a new unit test to userfaultfd.c, we don't really know
what's happening, not until we mostly read the whole file.
- We did a bunch of useless tests, e.g. we run twice the whole suite of
stress test just to verify both syscall and /dev/userfaultfd. They're
all using userfaultfd_new() to create the handle, everything should
really be the same underneath. One simple unit test should cover that!
- We have tens of global variables in one file but shared with all the
tests. Some of them are not suitable to be a global var from
maintainance pov. It enforces every unit test to consider how these
vars affects the stress test and vice versa, but that's logically not
necessary.
- Userfaultfd test is not friendly to old kernels. Mostly it only works
on the latest kernel tree. It's preferrable to be run on all kernels
and properly report what's missing.
I'll stop here, I feel like I can still list some..
This patchset should resolve all issues above, and actually we can do even
more on top. I stopped doing that until I found I already got 29 patches
and 2000+ LOC changes. That's already a patchset terrible enough so we
should move in small steps.
After the whole set applied, "./run_vmtests.sh -t userfaultfd" looks like
this:
===8<===
vm.nr_hugepages = 1024
-------------------------
running ./uffd-unit-tests
-------------------------
Testing UFFDIO_API (with syscall)... done
Testing UFFDIO_API (with /dev/userfaultfd)... done
Testing register-ioctls on anon... done
Testing register-ioctls on shmem... done
Testing register-ioctls on shmem-private... done
Testing register-ioctls on hugetlb... done
Testing register-ioctls on hugetlb-private... done
Testing zeropage on anon... done
Testing zeropage on shmem... done
Testing zeropage on shmem-private... done
Testing zeropage on hugetlb... done
Testing zeropage on hugetlb-private... done
Testing pagemap on anon... done
Testing wp-unpopulated on anon... done
Testing minor on shmem... done
Testing minor on hugetlb... done
Testing minor-wp on shmem... done
Testing minor-wp on hugetlb... done
Testing minor-collapse on shmem... done
Testing sigbus on anon... done
Testing sigbus on shmem... done
Testing sigbus on shmem-private... done
Testing sigbus on hugetlb... done
Testing sigbus on hugetlb-private... done
Testing sigbus-wp on anon... done
Testing sigbus-wp on shmem... done
Testing sigbus-wp on shmem-private... done
Testing sigbus-wp on hugetlb... done
Testing sigbus-wp on hugetlb-private... done
Testing events on anon... done
Testing events on shmem... done
Testing events on shmem-private... done
Testing events on hugetlb... done
Testing events on hugetlb-private... done
Testing events-wp on anon... done
Testing events-wp on shmem... done
Testing events-wp on shmem-private... done
Testing events-wp on hugetlb... done
Testing events-wp on hugetlb-private... done
Userfaults unit tests: pass=39, skip=0, fail=0 (total=39)
[PASS]
--------------------------------
running ./uffd-stress anon 20 16
--------------------------------
nr_pages: 5120, nr_pages_per_cpu: 640
bounces: 15, mode: rnd racing ver poll, userfaults: 345 missing (26+48+61+102+30+12+59+7) 1596 wp (120+139+317+346+215+67+306+86)
[...]
[PASS]
------------------------------------
running ./uffd-stress hugetlb 128 32
------------------------------------
nr_pages: 64, nr_pages_per_cpu: 8
bounces: 31, mode: rnd racing ver poll, userfaults: 29 missing (6+6+6+5+4+2+0+0) 104 wp (20+19+22+18+7+12+5+1)
[...]
[PASS]
--------------------------------------------
running ./uffd-stress hugetlb-private 128 32
--------------------------------------------
nr_pages: 64, nr_pages_per_cpu: 8
bounces: 31, mode: rnd racing ver poll, userfaults: 33 missing (12+9+7+0+5+0+0+0) 111 wp (24+25+14+14+11+17+5+1)
[...]
[PASS]
---------------------------------
running ./uffd-stress shmem 20 16
---------------------------------
nr_pages: 5120, nr_pages_per_cpu: 640
bounces: 15, mode: rnd racing ver poll, userfaults: 247 missing (15+17+34+60+81+37+3+0) 2038 wp (180+114+276+400+381+318+165+204)
[...]
[PASS]
-----------------------------------------
running ./uffd-stress shmem-private 20 16
-----------------------------------------
nr_pages: 5120, nr_pages_per_cpu: 640
bounces: 15, mode: rnd racing ver poll, userfaults: 235 missing (52+29+55+56+13+9+16+5) 2849 wp (218+406+461+531+328+284+430+191)
[...]
[PASS]
SUMMARY: PASS=6 SKIP=0 FAIL=0
===8<===
The output may be different if we miss some features (e.g., hugetlb not
allocated, old kernel, less privilege of uffd handle), but they should show
up with good reasons. E.g., I tried to run the unit test on my Fedora
kernel and it gives me:
===8<===
UFFDIO_API (with syscall)... failed [reason: UFFDIO_API should fail with wrong api but didn't]
UFFDIO_API (with /dev/userfaultfd)... skipped [reason: cannot open userfaultfd handle]
zeropage on anon... done
zeropage on shmem... done
zeropage on shmem-private... done
zeropage-hugetlb on hugetlb... done
zeropage-hugetlb on hugetlb-private... done
pagemap on anon... pagemap on anon... pagemap on anon... done
wp-unpopulated on anon... skipped [reason: feature missing]
minor on shmem... done
minor on hugetlb... done
minor-wp on shmem... skipped [reason: feature missing]
minor-wp on hugetlb... skipped [reason: feature missing]
minor-collapse on shmem... done
sigbus on anon... skipped [reason: possible lack of priviledge]
sigbus on shmem... skipped [reason: possible lack of priviledge]
sigbus on shmem-private... skipped [reason: possible lack of priviledge]
sigbus on hugetlb... skipped [reason: possible lack of priviledge]
sigbus on hugetlb-private... skipped [reason: possible lack of priviledge]
sigbus-wp on anon... skipped [reason: possible lack of priviledge]
sigbus-wp on shmem... skipped [reason: possible lack of priviledge]
sigbus-wp on shmem-private... skipped [reason: possible lack of priviledge]
sigbus-wp on hugetlb... skipped [reason: possible lack of priviledge]
sigbus-wp on hugetlb-private... skipped [reason: possible lack of priviledge]
events on anon... skipped [reason: possible lack of priviledge]
events on shmem... skipped [reason: possible lack of priviledge]
events on shmem-private... skipped [reason: possible lack of priviledge]
events on hugetlb... skipped [reason: possible lack of priviledge]
events on hugetlb-private... skipped [reason: possible lack of priviledge]
events-wp on anon... skipped [reason: possible lack of priviledge]
events-wp on shmem... skipped [reason: possible lack of priviledge]
events-wp on shmem-private... skipped [reason: possible lack of priviledge]
events-wp on hugetlb... skipped [reason: possible lack of priviledge]
events-wp on hugetlb-private... skipped [reason: possible lack of priviledge]
Userfaults unit tests: pass=9, skip=24, fail=1 (total=34)
===8<===
Patch layout:
- Revert "userfaultfd: don't fail on unrecognized features"
Something I found when I got the UFFDIO_API test below. Axel, I still
propose to revert it as a whole, but feel free to continue the discussion
from the original patch thread.
- selftests/mm: Update .gitignore with two missing tests
- selftests/mm: Dump a summary in run_vmtests.sh
- selftests/mm: Merge util.h into vm_util.h
- selftests/mm: Use TEST_GEN_PROGS where proper
- selftests/mm: Link vm_util.c always
- selftests/mm: Merge default_huge_page_size() into one
- selftests/mm: Use PM_* macros in vm_utils.h
- selftests/mm: Reuse pagemap_get_entry() in vm_util.h
- selftests/mm: Test UFFDIO_ZEROPAGE only when !hugetlb
- selftests/mm: Drop test_uffdio_zeropage_eexist
Until here, all cleanups here and there. I wanted to keep going, but I
found that maybe it'll take a few more days to split the test. Hence I
did a split starting from the next one, so we have a working thing first.
- selftests/mm: Create uffd-common.[ch]
- selftests/mm: Split uffd tests into uffd-stress and uffd-unit-tests
This did the major brute force split of common codes into
uffd-common.[ch]. That'll be the so far common base for stress and unit
tests. Then a new unit test is created.
- selftests/mm: uffd_[un]register()
- selftests/mm: uffd_open_{dev|sys}()
- selftests/mm: UFFDIO_API test
This patch hides here to start writting the 1st unit test with
UFFDIO_API, also detection of userfaultfd privileges.
- selftests/mm: Drop global mem_fd in uffd tests
- selftests/mm: Drop global hpage_size in uffd tests
- selftests/mm: Rename uffd_stats to uffd_args
- selftests/mm: Let uffd_handle_page_fault() takes wp parameter
- selftests/mm: Allow allocate_area() to fail properly
Some further cleanup that I noticed otherwise hard to move the tests.
- selftests/mm: Add framework for uffd-unit-test
The major patch provides the framework for most of the rest unit tests.
- selftests/mm: Move uffd pagemap test to unit test
- selftests/mm: Move uffd minor test to unit test
- selftests/mm: Move uffd sig/events tests into uffd unit tests
- selftests/mm: Move zeropage test into uffd unit tests
Move unit tests and suite them into the new file.
- selftests/mm: Workaround no way to detect uffd-minor + wp
- selftests/mm: Allow uffd test to skip properly with no privilege
- selftests/mm: Drop sys/dev test in uffd-stress test
- selftests/mm: Add shmem-private test to uffd-stress
A bunch of changes to do better on error reportings, and add
shmem-private to the stress test which was long missing.
- selftests/mm: Add uffdio register ioctls test
One more patch to test uffdio_register.ioctls.
This patch (of 30):
Update .gitignore with two missing tests.
Link: https://lkml.kernel.org/r/20230412163922.327282-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20230412164114.327709-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>