selftests/mm: rename guard-pages to guard-regions

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
proc

selftests/mm: rename guard-pages to guard-regions

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.

[[email protected]: fix guard regions invocation]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/1c3cd04a3f69b5756b94bda701ac88325a9be18b.1739469950.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: "Paul E . McKenney" <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests/mm: introduce uffd-wp-mremap regression test

Introduce a test that registers a range of memory for
UFFDIO_WRITEPROTECT_MODE_WP without UFFD_FEATURE_EVENT_REMAP. First check
that the uffd-

selftests/mm: introduce uffd-wp-mremap regression test

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/[email protected]
Signed-off-by: Ryan Roberts <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests/mm: use sys_pkey helpers consistently

sys_pkey_alloc, sys_pkey_free and sys_mprotect_pkey are currently used in
protections_keys.c, while pkey_sighandler_tests.c calls the libc wrappers
di

selftests/mm: use sys_pkey helpers consistently

sys_pkey_alloc, sys_pkey_free and sys_mprotect_pkey are currently used in
protections_keys.c, while pkey_sighandler_tests.c calls the libc wrappers
directly (e.g. pkey_mprotect()). This is probably ok when using glibc
(those symbols appeared a while ago), but Musl does not currently provide
them. The logging in the helpers from pkey-helpers.h can also come in
handy.

Make things more consistent by using the sys_pkey helpers in
pkey_sighandler_tests.c too. To that end their implementation is moved to
a common .c file (pkey_util.c). This also enables calling
is_pkeys_supported() outside of protections_keys.c, since it relies on
sys_pkey_{alloc,free}.

[[email protected]: fix dependency on pkey_util.c]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kevin Brodsky <[email protected]>
Cc: Aruna Ramakrishna <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Joey Gouly <[email protected]>
Cc: Keith Lucas <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests/mm: build with -O2

The mm kselftests are currently built with no optimisation (-O0). It's
unclear why, and besides being obviously suboptimal, this also prevents
the pkeys tests from work

selftests/mm: build with -O2

The mm kselftests are currently built with no optimisation (-O0). It's
unclear why, and besides being obviously suboptimal, this also prevents
the pkeys tests from working as intended. Let's build all the tests with
-O2.

[[email protected]: silence unused-result warnings]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kevin Brodsky <[email protected]>
Cc: Aruna Ramakrishna <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Joey Gouly <[email protected]>
Cc: Keith Lucas <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftest/mm: remove seal_elf

Remove seal_elf, which is a demo of mseal, we no longer need this.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <je

selftest/mm: remove seal_elf

Remove seal_elf, which is a demo of mseal, we no longer need this.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm: page_frag: fix a compile error when kernel is not compiled

page_frag test module is an out of tree module, but built
using KDIR as the main kernel tree, the mm test suite is
just getting skipped

mm: page_frag: fix a compile error when kernel is not compiled

page_frag test module is an out of tree module, but built
using KDIR as the main kernel tree, the mm test suite is
just getting skipped if newly added page_frag test module
fails to compile due to kernel not yet compiled.

Fix the above problem by ensuring both kernel is built first
and a newer kernel which has page_frag_cache.h is used.

CC: Andrew Morton <[email protected]>
CC: Alexander Duyck <[email protected]>
CC: Linux-MM <[email protected]>
Fixes: 7fef0dec415c ("mm: page_frag: add a test module for page_frag")
Fixes: 65941f10caf2 ("mm: move the page fragment allocator from page_alloc into its own file")
Reported-by: Mark Brown <[email protected]>
Signed-off-by: Yunsheng Lin <[email protected]>
Tested-by: Mark Brown <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

show more ...

selftests/mm: skip virtual_address_range tests on riscv

RISC-V doesn't currently have the behavior of restricting the virtual
address space which virtual_address_range tests check, this will
cause t

selftests/mm: skip virtual_address_range tests on riscv

RISC-V doesn't currently have the behavior of restricting the virtual
address space which virtual_address_range tests check, this will
cause the tests fail. So lets disable the whole test suite for riscv64
for now, not build it and run_vmtests.sh will skip it if it is not present.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Chunyan Zhang <[email protected]>
Reviewed-by: Charlie Jenkins <[email protected]>
Acked-by: Palmer Dabbelt <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: page_frag: add a test module for page_frag

The testing is done by ensuring that the fragment allocated
from a frag_frag_cache instance is pushed into a ptr_ring
instance in a kthread binded to a

mm: page_frag: add a test module for page_frag

The testing is done by ensuring that the fragment allocated
from a frag_frag_cache instance is pushed into a ptr_ring
instance in a kthread binded to a specified cpu, and a kthread
binded to a specified cpu will pop the fragment from the
ptr_ring and free the fragment.

CC: Andrew Morton <[email protected]>
CC: Linux-MM <[email protected]>
Signed-off-by: Yunsheng Lin <[email protected]>
Reviewed-by: Alexander Duyck <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

show more ...

selftests/mm: add self tests for guard page feature

Utilise the kselftest harmness to implement tests for the guard page
implementation.

We start by implement basic tests asserting that guard pages

selftests/mm: add self tests for guard page feature

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 <[email protected]>
Reviewed-by: Shuah Khan <[email protected]>
Suggested-by: Vlastimil Babka <[email protected]>
Suggested-by: Jann Horn <[email protected]>
Suggested-by: David Hildenbrand <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: James E.J. Bottomley <[email protected]>
Cc: Jeff Xu <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Sidhartha Kumar <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests/mm: Enable pkey_sighandler_tests on arm64

pkey_sighandler_tests.c makes raw syscalls using its own helper,
syscall_raw(). One of those syscalls is clone, which is problematic
as every arch

selftests/mm: Enable pkey_sighandler_tests on arm64

pkey_sighandler_tests.c makes raw syscalls using its own helper,
syscall_raw(). One of those syscalls is clone, which is problematic
as every architecture has a different opinion on the order of its
arguments.

To complete arm64 support, we therefore add an appropriate
implementation in syscall_raw(), and introduce a clone_raw() helper
that shuffles arguments as needed for each arch.

Having done this, we enable building pkey_sighandler_tests for arm64
in the Makefile.

Signed-off-by: Kevin Brodsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

show more ...

selftests: mm: make protection_keys test work on arm64

The encoding of the pkey register differs on arm64, than on x86/ppc. On those
platforms, a bit in the register is used to disable permissions,

selftests: mm: make protection_keys test work on arm64

The encoding of the pkey register differs on arm64, than on x86/ppc. On those
platforms, a bit in the register is used to disable permissions, for arm64, a
bit enabled in the register indicates that the permission is allowed.

This drops two asserts of the form:
assert(read_pkey_reg() <= orig_pkey_reg);
Because on arm64 this doesn't hold, due to the encoding.

The pkey must be reset to both access allow and write allow in the signal
handler. pkey_access_allow() works currently for PowerPC as the
PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE have overlapping bits set.

Access to the uc_mcontext is abstracted, as arm64 has a different structure.

Signed-off-by: Joey Gouly <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Acked-by: Dave Hansen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

show more ...

selftests/mm: remove unnecessary ia64 code and comment

IA64 has gone with commit cf8e8658100d ("arch: Remove Itanium (IA-64)
architecture"), so remove unnecessary ia64 special mm code and comment in

selftests/mm: remove unnecessary ia64 code and comment

IA64 has gone with commit cf8e8658100d ("arch: Remove Itanium (IA-64)
architecture"), so remove unnecessary ia64 special mm code and comment in
selftests too.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jinjiang Tu <[email protected]>
Cc: Kefeng Wang <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Nanyong Sun <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests: memfd_secret: don't build memfd_secret test on unsupported arches

[1] mentions that memfd_secret is only supported on arm64, riscv, x86 and
x86_64 for now. It doesn't support other archi

selftests: memfd_secret: don't build memfd_secret test on unsupported arches

[1] mentions that memfd_secret is only supported on arm64, riscv, x86 and
x86_64 for now. It doesn't support other architectures. I found the
build error on arm and decided to send the fix as it was creating noise on
KernelCI:

memfd_secret.c: In function 'memfd_secret':
memfd_secret.c:42:24: error: '__NR_memfd_secret' undeclared (first use in this function);
did you mean 'memfd_secret'?
42 | return syscall(__NR_memfd_secret, flags);
| ^~~~~~~~~~~~~~~~~
| memfd_secret

Hence I'm adding condition that memfd_secret should only be compiled on
supported architectures.

Also check in run_vmtests script if memfd_secret binary is present before
executing it.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/[email protected]/ [1]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 76fe17ef588a ("secretmem: test: add basic selftest for memfd_secret(2)")
Signed-off-by: Muhammad Usama Anjum <[email protected]>
Reviewed-by: Shuah Khan <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Mike Rapoport (Microsoft) <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests: mm: add s390 to ARCH check

commit 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
changed the env variable for the architecture from MACHINE to ARCH.

This is preventing 3

selftests: mm: add s390 to ARCH check

commit 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
changed the env variable for the architecture from MACHINE to ARCH.

This is preventing 3 required TEST_GEN_FILES from being included when
cross compiling s390x and errors when trying to run the test suite. This
is due to the ARCH variable already being set and the arch folder name
being s390.

Add "s390" to the filtered list to cover this case and have the 3 files
included in the build.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
Signed-off-by: Nico Pache <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests/mm: Add new testcases for pkeys

Add a few new tests to exercise the signal handler flow, especially with
PKEY 0 disabled:

- Verify that the SIGSEGV handler is invoked when pkey 0 is disa

selftests/mm: Add new testcases for pkeys

Add a few new tests to exercise the signal handler flow, especially with
PKEY 0 disabled:

- Verify that the SIGSEGV handler is invoked when pkey 0 is disabled.

- Verify that a thread which disables PKEY 0 segfaults with PKUERR when
accessing the stack.

- Verify that the SIGSEGV handler that uses an alternate signal stack is
correctly invoked when the thread disabled PKEY 0

- Verify that the PKRU value set by the application is correctly restored
upon return from signal handling.

- Verify that sigreturn() is able to restore the altstack even if the
thread had PKEY 0 disabled

[ Aruna: Adapted to upstream ]
[ tglx: Made it actually compile. Restored protection_keys compile. Added
useful info to the changelog instead of bare function names. ]

Signed-off-by: Keith Lucas <[email protected]>
Signed-off-by: Aruna Ramakrishna <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/all/[email protected]

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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 sh

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: [email protected]
Acked-by: David Hildenbrand <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

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selftest/mm: test enable_soft_offline behaviors

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

selftest/mm: test enable_soft_offline behaviors

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.

[[email protected]: v7]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jiaqi Yan <[email protected]>
Acked-by: Miaohe Lin <[email protected]>
Acked-by: David Rientjes <[email protected]>
Cc: Frank van der Linden <[email protected]>
Cc: Jane Chu <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests/mm: mseal, self_elf: factor out test macros and other duplicated items

Clean up and move some copy-pasted items into a new mseal_helpers.h.

1. The test macros can be made safer and simple

selftests/mm: mseal, self_elf: factor out test macros and other duplicated items

Clean up and move some copy-pasted items into a new mseal_helpers.h.

1. The test macros can be made safer and simpler, by observing that
they are invariably called when about to return. This means that the
macros do not need an intrusive label to goto; they can simply return.

2. PKEY* items. We cannot, unfortunately use pkey-helpers.h. The
best we can do is to factor out these few items into mseal_helpers.h.

3. These tests still need their own definition of u64, so also move
that to the header file.

4. Be sure to include the new mseal_helpers.h in the Makefile
dependencies.

[[email protected]: include the new mseal_helpers.h in Makefile dependencies]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Jeff Xu <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftest: mm: Test if hugepage does not get leaked during __bio_release_pages()

Commit 1b151e2435fc ("block: Remove special-casing of compound pages")
caused a change in behaviour when releasing the

selftest: mm: Test if hugepage does not get leaked during __bio_release_pages()

Commit 1b151e2435fc ("block: Remove special-casing of compound pages")
caused a change in behaviour when releasing the pages if the buffer does
not start at the beginning of the page. This was because the calculation
of the number of pages to release was incorrect. This was fixed by commit
38b43539d64b ("block: Fix page refcounts for unaligned buffers in
__bio_release_pages()").

We pin the user buffer during direct I/O writes. If this buffer is a
hugepage, bio_release_page() will unpin it and decrement all references
and pin counts at ->bi_end_io. However, if any references to the hugepage
remain post-I/O, the hugepage will not be freed upon unmap, leading to a
memory leak.

This patch verifies that a hugepage, used as a user buffer for DIO
operations, is correctly freed upon unmapping, regardless of whether the
offsets are aligned or unaligned w.r.t page boundary.

Test Result Fail Scenario (Without the fix)
--------------------------------------------------------
[]# ./hugetlb_dio
TAP version 13
1..4
No. Free pages before allocation : 7
No. Free pages after munmap : 7
ok 1 : Huge pages freed successfully !
No. Free pages before allocation : 7
No. Free pages after munmap : 7
ok 2 : Huge pages freed successfully !
No. Free pages before allocation : 7
No. Free pages after munmap : 7
ok 3 : Huge pages freed successfully !
No. Free pages before allocation : 7
No. Free pages after munmap : 6
not ok 4 : Huge pages not freed!
Totals: pass:3 fail:1 xfail:0 xpass:0 skip:0 error:0

Test Result PASS Scenario (With the fix)
---------------------------------------------------------
[]#./hugetlb_dio
TAP version 13
1..4
No. Free pages before allocation : 7
No. Free pages after munmap : 7
ok 1 : Huge pages freed successfully !
No. Free pages before allocation : 7
No. Free pages after munmap : 7
ok 2 : Huge pages freed successfully !
No. Free pages before allocation : 7
No. Free pages after munmap : 7
ok 3 : Huge pages freed successfully !
No. Free pages before allocation : 7
No. Free pages after munmap : 7
ok 4 : Huge pages freed successfully !
Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0

[[email protected]: address review comments from Muhammad]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: add this test to run_vmtests.sh]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 38b43539d64b ("block: Fix page refcounts for unaligned buffers in __bio_release_pages()")
Signed-off-by: Donet Tom <[email protected]>
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
Co-developed-by: Ritesh Harjani (IBM) <[email protected]>
Reviewed-by: Muhammad Usama Anjum <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Ritesh Harjani (IBM) <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Tony Battersby <[email protected]>
Cc: Jens Axboe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftest mm/mseal read-only elf memory segment

Sealing read-only of elf mapping so it can't be changed by mprotect.

[[email protected]: style change]
Link: https://lkml.kernel.org/r/20240416220

selftest mm/mseal read-only elf memory segment

Sealing read-only of elf mapping so it can't be changed by mprotect.

[[email protected]: style change]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix linker error for inline function]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix compile warning]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix arm build]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <[email protected]>
Signed-off-by: Amer Al Shanawany <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jeff Xu <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Jorge Lucangeli Obes <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Stephen Röttger <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Amer Al Shanawany <[email protected]>
Cc: Javier Carrasco <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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selftest mm/mseal memory sealing

selftest for memory sealing change in mmap() and mseal().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <jeffxu

selftest mm/mseal memory sealing

selftest for memory sealing change in mmap() and mseal().

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jeff Xu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jeff Xu <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Jorge Lucangeli Obes <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Stephen Röttger <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Amer Al Shanawany <[email protected]>
Cc: Javier Carrasco <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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selftests/mm: fix powerpc ARCH check

In commit 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
the logic to detect the machine architecture in the Makefile was changed
to use ARCH, an

selftests/mm: fix powerpc ARCH check

In commit 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
the logic to detect the machine architecture in the Makefile was changed
to use ARCH, and only fallback to uname -m if ARCH is unset. However the
tests of ARCH were not updated to account for the fact that ARCH is
"powerpc" for powerpc builds, not "ppc64".

Fix it by changing the checks to look for "powerpc", and change the
uname -m logic to convert "ppc64.*" into "powerpc".

With that fixed the following tests now build for powerpc again:
* protection_keys
* va_high_addr_switch
* virtual_address_range
* write_to_hugetlbfs

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
Signed-off-by: Michael Ellerman <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: <[email protected]> [6.4+]
Signed-off-by: Andrew Morton <[email protected]>

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selftests: break the dependency upon local header files

Patch series "Fix selftests/mm build without requiring "make headers"".

As mentioned in each patch, this implements the solution that we disc

selftests: break the dependency upon local header files

Patch series "Fix selftests/mm build without requiring "make headers"".

As mentioned in each patch, this implements the solution that we discussed
in December 2023, in [1]. This turned out to be very clean and easy. It
should also be quite easy to maintain.

This should also make Peter Zijlstra happy, because it directly addresses
the root cause of his "NAK NAK NAK" reply [2]. :)

[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/lkml/[email protected]/


This patch (of 2):

Use tools/include/uapi/ files instead. These are obtained by taking a
snapshot: run "make headers" at the top level, then copy the desired
header file into the appropriate subdir in tools/uapi/.

This was discussed and solved in [1].

However, even before copying any additional files there, there are already
quite a few in tools/include/uapi already. And these will immediately fix
a number of selftests/mm build failures.

So this patch:

a) Adds TOOLS_INCLUDES to selftests/lib.mk, so that all selftests can
immediately and easily include the snapshotted header files.

b) Uses $(TOOLS_INCLUDES) in the selftests/mm build. On today's Arch
Linux, this already fixes all build errors except for a few
userfaultfd.h (those will be addressed in a subsequent patch).

[1] https://lore.kernel.org/all/[email protected]/

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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selftests/mm: run_vmtests.sh: add missing tests

Add missing tests to run_vmtests.sh. The mm kselftests are run through
run_vmtests.sh. If a test isn't present in this script, it'll not run
with ru

selftests/mm: run_vmtests.sh: add missing tests

Add missing tests to run_vmtests.sh. The mm kselftests are run through
run_vmtests.sh. If a test isn't present in this script, it'll not run
with run_tests or `make -C tools/testing/selftests/mm run_tests`.

[[email protected]: use correct flag in the code]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Cc: Ryan Roberts <[email protected]>
Signed-off-by: Muhammad Usama Anjum <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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selftests/mm: new test that steals pages

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 availab

selftests/mm: new test that steals pages

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/[email protected]
Signed-off-by: Breno Leitao <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Vegard Nossum <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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