Commit Graph

287 Commits

Author SHA1 Message Date
Li Wang
51d54ff2b7 selftests/mm/charge_reserved_hugetlb: drop mount size for hugetlbfs
[ Upstream commit 1aa1dd9cc5 ]

charge_reserved_hugetlb.sh mounts a hugetlbfs instance at /mnt/huge with a
fixed size of 256M.  On systems with large base hugepages (e.g.  512MB),
this is smaller than a single hugepage, so the hugetlbfs mount ends up
with zero capacity (often visible as size=0 in mount output).

As a result, write_to_hugetlbfs fails with ENOMEM and the test can hang
waiting for progress.

=== Error log ===
  # uname -r
  6.12.0-xxx.el10.aarch64+64k

  #./charge_reserved_hugetlb.sh -cgroup-v2
  # -----------------------------------------
  ...
  # nr hugepages = 10
  # writing cgroup limit: 5368709120
  # writing reseravation limit: 5368709120
  ...
  # write_to_hugetlbfs: Error mapping the file: Cannot allocate memory
  # Waiting for hugetlb memory reservation to reach size 2684354560.
  # 0
  # Waiting for hugetlb memory reservation to reach size 2684354560.
  # 0
  ...

  # mount |grep /mnt/huge
  none on /mnt/huge type hugetlbfs (rw,relatime,seclabel,pagesize=512M,size=0)

  # grep -i huge /proc/meminfo
  ...
  HugePages_Total:      10
  HugePages_Free:       10
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:     524288 kB
  Hugetlb:         5242880 kB

Drop the mount args with 'size=256M', so the filesystem capacity is sufficient
regardless of HugeTLB page size.

Link: https://lkml.kernel.org/r/20251221122639.3168038-3-liwang@redhat.com
Fixes: 29750f71a9 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: Li Wang <liwang@redhat.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:21:46 -05:00
Siddarth G
a4720c30ea selftests/mm: convert page_size to unsigned long
[ Upstream commit 0bf19a357e ]

Cppcheck warning:
int result is assigned to long long variable. If the variable is long long
to avoid loss of information, then you have loss of information.

This patch changes the type of page_size from 'unsigned int' to
'unsigned long' instead of using ULL suffixes. Changing hpage_size to
'unsigned long' was considered, but since gethugepage() expects an int,
this change was avoided.

Link: https://lkml.kernel.org/r/20250403101345.29226-1-siddarthsgml@gmail.com
Signed-off-by: Siddarth G <siddarthsgml@gmail.com>
Reported-by: David Binderman <dcb314@hotmail.com>
Closes: https://lore.kernel.org/all/AS8PR02MB10217315060BBFDB21F19643E9CA62@AS8PR02MB10217.eurprd02.prod.outlook.com/
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 7e938f00b0 ("selftests/mm: fix faulting-in code in pagemap_ioctl test")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:20:07 -05:00
Muhammad Usama Anjum
306c11e7b8 selftests/mm: pagemap_ioctl: Fix types mismatches shown by compiler options
[ Upstream commit 43448e5bbb ]

Fix following warnings caught by compiler:

- There are several type mismatches among different variables.
- Remove unused variable warnings.

Link: https://lkml.kernel.org/r/20241209185624.2245158-3-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 7e938f00b0 ("selftests/mm: fix faulting-in code in pagemap_ioctl test")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04 07:20:07 -05:00
Lance Yang
394ad21319 selftests/mm: skip soft-dirty tests when CONFIG_MEM_SOFT_DIRTY is disabled
commit 0389c305ef upstream.

The madv_populate and soft-dirty kselftests currently fail on systems
where CONFIG_MEM_SOFT_DIRTY is disabled.

Introduce a new helper softdirty_supported() into vm_util.c/h to ensure
tests are properly skipped when the feature is not enabled.

Link: https://lkml.kernel.org/r/20250917133137.62802-1-lance.yang@linux.dev
Fixes: 9f3265db6a ("selftests: vm: add test for Soft-Dirty PTE bit")
Signed-off-by: Lance Yang <lance.yang@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19 16:34:00 +02:00
Nysal Jan K.A.
5156f7c484 selftests/mm: fix a build failure on powerpc
commit 8cf6ecb18b upstream.

The compiler is unaware of the size of code generated by the ".rept"
assembler directive.  This results in the compiler emitting branch
instructions where the offset to branch to exceeds the maximum allowed
value, resulting in build failures like the following:

  CC       protection_keys
  /tmp/ccypKWAE.s: Assembler messages:
  /tmp/ccypKWAE.s:2073: Error: operand out of range (0x0000000000020158
  is not between 0xffffffffffff8000 and 0x0000000000007ffc)
  /tmp/ccypKWAE.s:2509: Error: operand out of range (0x0000000000020130
  is not between 0xffffffffffff8000 and 0x0000000000007ffc)

Fix the issue by manually adding nop instructions using the preprocessor.

Link: https://lkml.kernel.org/r/20250428131937.641989-2-nysal@linux.ibm.com
Fixes: 46036188ea ("selftests/mm: build with -O2")
Reported-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Nysal Jan K.A. <nysal@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Donet Tom <donettom@linux.ibm.com>
Tested-by: Donet Tom <donettom@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-18 08:24:52 +02:00
Feng Tang
b21ec0726a selftests/mm: compaction_test: support platform with huge mount of memory
commit ab00ddd802 upstream.

When running mm selftest to verify mm patches, 'compaction_test' case
failed on an x86 server with 1TB memory.  And the root cause is that it
has too much free memory than what the test supports.

The test case tries to allocate 100000 huge pages, which is about 200 GB
for that x86 server, and when it succeeds, it expects it's large than 1/3
of 80% of the free memory in system.  This logic only works for platform
with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false
alarm for others.

Fix it by changing the fixed page number to self-adjustable number
according to the real number of free memory.

Link: https://lkml.kernel.org/r/20250423103645.2758-1-feng.tang@linux.alibaba.com
Fixes: bd67d5c15c ("Test compaction of mlocked memory")
Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
Acked-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@inux.alibaba.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sri Jayaramappa <sjayaram@akamai.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-18 08:24:52 +02:00
Mark Brown
824b7ad9cf selftests/mm: generate a temporary mountpoint for cgroup filesystem
commit 9c02223e2d upstream.

Currently if the filesystem for the cgroups version it wants to use is not
mounted charge_reserved_hugetlb.sh and hugetlb_reparenting_test.sh tests
will attempt to mount it on the hard coded path /dev/cgroup/memory,
deleting that directory when the test finishes.  This will fail if there
is not a preexisting directory at that path, and since the directory is
deleted subsequent runs of the test will fail.  Instead of relying on this
hard coded directory name use mktemp to generate a temporary directory to
use as a mountpoint, fixing both the assumption and the disruption caused
by deleting a preexisting directory.

This means that if the relevant cgroup filesystem is not already mounted
then we rely on having coreutils (which provides mktemp) installed.  I
suspect that many current users are relying on having things automounted
by default, and given that the script relies on bash it's probably not an
unreasonable requirement.

Link: https://lkml.kernel.org/r/20250404-kselftest-mm-cgroup2-detection-v1-1-3dba6d32ba8c@kernel.org
Fixes: 209376ed2a ("selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25 10:47:54 +02:00
Cyan Yang
0d8ba0ed03 selftests/mm/cow: fix the incorrect error handling
[ Upstream commit f841ad9ca5 ]

Error handling doesn't check the correct return value.  This patch will
fix it.

Link: https://lkml.kernel.org/r/20250312043840.71799-1-cyan.yang@sifive.com
Fixes: f4b5fd6946 ("selftests/vm: anon_cow: THP tests")
Signed-off-by: Cyan Yang <cyan.yang@sifive.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10 14:39:25 +02:00
Rafael Aquini
baa3782905 selftests/mm: run_vmtests.sh: fix half_ufd_size_MB calculation
commit 67a2f86846 upstream.

We noticed that uffd-stress test was always failing to run when invoked
for the hugetlb profiles on x86_64 systems with a processor count of 64 or
bigger:

  ...
  # ------------------------------------
  # running ./uffd-stress hugetlb 128 32
  # ------------------------------------
  # ERROR: invalid MiB (errno=9, @uffd-stress.c:459)
  ...
  # [FAIL]
  not ok 3 uffd-stress hugetlb 128 32 # exit=1
  ...

The problem boils down to how run_vmtests.sh (mis)calculates the size of
the region it feeds to uffd-stress.  The latter expects to see an amount
of MiB while the former is just giving out the number of free hugepages
halved down.  This measurement discrepancy ends up violating uffd-stress'
assertion on number of hugetlb pages allocated per CPU, causing it to bail
out with the error above.

This commit fixes that issue by adjusting run_vmtests.sh's
half_ufd_size_MB calculation so it properly renders the region size in
MiB, as expected, while maintaining all of its original constraints in
place.

Link: https://lkml.kernel.org/r/20250218192251.53243-1-aquini@redhat.com
Fixes: 2e47a445d7 ("selftests/mm: run_vmtests.sh: fix hugetlb mem size calculation")
Signed-off-by: Rafael Aquini <raquini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-28 22:03:30 +01:00
John Hubbard
3e710bac68 Revert "selftests/mm: remove local __NR_* definitions"
commit 0a7565ee6e upstream.

This reverts commit a5c6bc5900.

The general approach described in commit e076eaca59 ("selftests: break
the dependency upon local header files") was taken one step too far here:
it should not have been extended to include the syscall numbers.  This is
because doing so would require per-arch support in tools/include/uapi, and
no such support exists.

This revert fixes two separate reports of test failures, from Dave
Hansen[1], and Li Wang[2].  An excerpt of Dave's report:

Before this commit (a5c6bc5900) things are
fine.  But after, I get:

	running PKEY tests for unsupported CPU/OS

An excerpt of Li's report:

    I just found that mlock2_() return a wrong value in mlock2-test

[1] https://lore.kernel.org/dc585017-6740-4cab-a536-b12b37a7582d@intel.com
[2] https://lore.kernel.org/CAEemH2eW=UMu9+turT2jRie7+6ewUazXmA6kL+VBo3cGDGU6RA@mail.gmail.com

Link: https://lkml.kernel.org/r/20250214033850.235171-1-jhubbard@nvidia.com
Fixes: a5c6bc5900 ("selftests/mm: remove local __NR_* definitions")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Li Wang <liwang@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Andrei Vagin <avagin@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:54 +01:00
Kevin Brodsky
54dba9d5ae selftests/mm: build with -O2
commit 46036188ea upstream.

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.

[kevin.brodsky@arm.com: silence unused-result warnings]
  Link: https://lkml.kernel.org/r/20250107170110.2819685-1-kevin.brodsky@arm.com
Link: https://lkml.kernel.org/r/20241209095019.1732120-6-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Yifei: This commit also fix the failure of pkey_sighandler_tests_64,
  which is also in linux-6.12.y, thus backport this commit. ]
Signed-off-by: Yifei Liu <yifei.l.liu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-27 04:30:24 -08:00
Ryan Roberts
6f8a91d9ae selftests/mm: set allocated memory to non-zero content in cow test
commit a32bf5bb79 upstream.

After commit b1f202060a ("mm: remap unused subpages to shared zeropage
when splitting isolated thp"), cow test cases involving swapping out THPs
via madvise(MADV_PAGEOUT) started to be skipped due to the subsequent
check via pagemap determining that the memory was not actually swapped
out.  Logs similar to this were emitted:

   ...

   # [RUN] Basic COW after fork() ... with swapped-out, PTE-mapped THP (16 kB)
   ok 2 # SKIP MADV_PAGEOUT did not work, is swap enabled?
   # [RUN] Basic COW after fork() ... with single PTE of swapped-out THP (16 kB)
   ok 3 # SKIP MADV_PAGEOUT did not work, is swap enabled?
   # [RUN] Basic COW after fork() ... with swapped-out, PTE-mapped THP (32 kB)
   ok 4 # SKIP MADV_PAGEOUT did not work, is swap enabled?

   ...

The commit in question introduces the behaviour of scanning THPs and if
their content is predominantly zero, it splits them and replaces the pages
which are wholly zero with the zero page.  These cow test cases were
getting caught up in this.

So let's avoid that by filling the contents of all allocated memory with
a non-zero value. With this in place, the tests are passing again.

Link: https://lkml.kernel.org/r/20250107142555.1870101-1-ryan.roberts@arm.com
Fixes: b1f202060a ("mm: remap unused subpages to shared zeropage when splitting isolated thp")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-23 17:23:01 +01:00
Mark Brown
ed9132d038 selftest: hugetlb_dio: fix test naming
commit 4ae132c693 upstream.

The string logged when a test passes or fails is used by the selftest
framework to identify which test is being reported.  The hugetlb_dio test
not only uses the same strings for every test that is run but it also uses
different strings for test passes and failures which means that test
automation is unable to follow what the test is doing at all.

Pull the existing duplicated logging of the number of free huge pages
before and after the test out of the conditional and replace that and the
logging of the result with a single ksft_print_result() which incorporates
the parameters passed into the test into the output.

Link: https://lkml.kernel.org/r/20241127-kselftest-mm-hugetlb-dio-names-v1-1-22aab01bf550@kernel.org
Fixes: fae1980347 ("selftests: hugetlb_dio: fixup check for initial conditions to skip in the start")
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14 20:03:27 +01:00
Donet Tom
fae1980347 selftests: hugetlb_dio: fixup check for initial conditions to skip in the start
This test verifies that a hugepage, used as a user buffer for DIO
operations, is correctly freed upon unmapping.  To test this, we read the
count of free hugepages before and after the mmap, DIO, and munmap
operations, then check if the free hugepage count is the same.

Reading free hugepages before the test was removed by commit 0268d45799
('selftests: hugetlb_dio: check for initial conditions to skip at the
start'), causing the test to always fail.

This patch adds back reading the free hugepages before starting the test. 
With this patch, the tests are now passing.

Test results without this patch:

./tools/testing/selftests/mm/hugetlb_dio
TAP version 13
1..4
 # No. Free pages before allocation : 0
 # No. Free pages after munmap : 100
not ok 1 : Huge pages not freed!
 # No. Free pages before allocation : 0
 # No. Free pages after munmap : 100
not ok 2 : Huge pages not freed!
 # No. Free pages before allocation : 0
 # No. Free pages after munmap : 100
not ok 3 : Huge pages not freed!
 # No. Free pages before allocation : 0
 # No. Free pages after munmap : 100
not ok 4 : Huge pages not freed!
 # Totals: pass:0 fail:4 xfail:0 xpass:0 skip:0 error:0

Test results with this patch:

/tools/testing/selftests/mm/hugetlb_dio
TAP version 13
1..4
# No. Free pages before allocation : 100
# No. Free pages after munmap : 100
ok 1 : Huge pages freed successfully !
# No. Free pages before allocation : 100
# No. Free pages after munmap : 100
ok 2 : Huge pages freed successfully !
# No. Free pages before allocation : 100
# No. Free pages after munmap : 100
ok 3 : Huge pages freed successfully !
# No. Free pages before allocation : 100
# No. Free pages after munmap : 100
ok 4 : Huge pages freed successfully !

# Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0

Link: https://lkml.kernel.org/r/20241110064903.23626-1-donettom@linux.ibm.com
Fixes: 0268d45799 ("selftests: hugetlb_dio: check for initial conditions to skip in the start")
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-12 10:14:00 -08:00
Muhammad Usama Anjum
0268d45799 selftests: hugetlb_dio: check for initial conditions to skip in the start
The test should be skipped if initial conditions aren't fulfilled in the
start instead of failing and outputting non-compliant TAP logs.  This kind
of failure pollutes the results.  The initial conditions are:

- The test should only execute if /tmp file can be allocated.
- The test should only execute if huge pages are free.

Before:
TAP version 13
1..4
Bail out! Error opening file
: Read-only file system (30)
 # Planned tests != run tests (4 != 0)
 # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0

After:
TAP version 13
1..0 # SKIP Unable to allocate file: Read-only file system

Link: https://lkml.kernel.org/r/20241101141557.3159432-1-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Fixes: 3a103b5315 ("selftest: mm: Test if hugepage does not get leaked during __bio_release_pages()")
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:14:59 -08:00
Edward Liaw
f2330b650e selftests/mm: fix deadlock for fork after pthread_create with atomic_bool
Some additional synchronization is needed on Android ARM64; we see a
deadlock with pthread_create when the parent thread races forward before
the child has a chance to start doing work.

Link: https://lkml.kernel.org/r/20241018171734.2315053-4-edliaw@google.com
Fixes: cff2945827 ("selftests/mm: extend and rename uffd pagemap test")
Signed-off-by: Edward Liaw <edliaw@google.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-28 21:40:41 -07:00
Edward Liaw
3673167a3a Revert "selftests/mm: replace atomic_bool with pthread_barrier_t"
This reverts commit e61ef21e27.

uffd_poll_thread may be called by other tests that do not initialize the
pthread_barrier, so this approach is not correct.  This will revert to
using atomic_bool instead.

Link: https://lkml.kernel.org/r/20241018171734.2315053-3-edliaw@google.com
Fixes: e61ef21e27 ("selftests/mm: replace atomic_bool with pthread_barrier_t")
Signed-off-by: Edward Liaw <edliaw@google.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-28 21:40:41 -07:00
Edward Liaw
5bb1f4c934 Revert "selftests/mm: fix deadlock for fork after pthread_create on ARM"
Patch series "selftests/mm: revert pthread_barrier change"

On Android arm, pthread_create followed by a fork caused a deadlock in
the case where the fork required work to be completed by the created
thread.

The previous patches incorrectly assumed that the parent would
always initialize the pthread_barrier for the child thread.  This
reverts the change and replaces the fix for wp-fork-with-event with the
original use of atomic_bool.


This patch (of 3):

This reverts commit e142cc87ac.

fork_event_consumer may be called by other tests that do not initialize
the pthread_barrier, so this approach is not correct.  The subsequent
patch will revert to using atomic_bool instead.

Link: https://lkml.kernel.org/r/20241018171734.2315053-1-edliaw@google.com
Link: https://lkml.kernel.org/r/20241018171734.2315053-2-edliaw@google.com
Fixes: e142cc87ac ("fix deadlock for fork after pthread_create on ARM")
Signed-off-by: Edward Liaw <edliaw@google.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-28 21:40:40 -07:00
Nanyong Sun
3e822bed2f selftests: mm: fix the incorrect usage() info of khugepaged
The mount option of tmpfs should be huge=advise, not madvise which is not
supported and may mislead the users.

Link: https://lkml.kernel.org/r/20241015020257.139235-1-sunnanyong@huawei.com
Fixes: 1b03d0d558 ("selftests/vm: add thp collapse file and tmpfs testing")
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-17 00:28:11 -07:00
Edward Liaw
e142cc87ac selftests/mm: fix deadlock for fork after pthread_create on ARM
On Android with arm, there is some synchronization needed to avoid a
deadlock when forking after pthread_create.

Link: https://lkml.kernel.org/r/20241003211716.371786-3-edliaw@google.com
Fixes: cff2945827 ("selftests/mm: extend and rename uffd pagemap test")
Signed-off-by: Edward Liaw <edliaw@google.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-17 00:28:06 -07:00
Edward Liaw
e61ef21e27 selftests/mm: replace atomic_bool with pthread_barrier_t
Patch series "selftests/mm: fix deadlock after pthread_create".

On Android arm, pthread_create followed by a fork caused a deadlock in the
case where the fork required work to be completed by the created thread.

Update the synchronization primitive to use pthread_barrier instead of
atomic_bool.

Apply the same fix to the wp-fork-with-event test.


This patch (of 2):

Swap synchronization primitive with pthread_barrier, so that stdatomic.h
does not need to be included.

The synchronization is needed on Android ARM64; we see a deadlock with
pthread_create when the parent thread races forward before the child has a
chance to start doing work.

Link: https://lkml.kernel.org/r/20241003211716.371786-1-edliaw@google.com
Link: https://lkml.kernel.org/r/20241003211716.371786-2-edliaw@google.com
Fixes: cff2945827 ("selftests/mm: extend and rename uffd pagemap test")
Signed-off-by: Edward Liaw <edliaw@google.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-17 00:28:06 -07:00
Donet Tom
76503e1fa1 selftests/mm: fix incorrect buffer->mirror size in hmm2 double_map test
The hmm2 double_map test was failing due to an incorrect buffer->mirror
size.  The buffer->mirror size was 6, while buffer->ptr size was 6 *
PAGE_SIZE.  The test failed because the kernel's copy_to_user function was
attempting to copy a 6 * PAGE_SIZE buffer to buffer->mirror.  Since the
size of buffer->mirror was incorrect, copy_to_user failed.

This patch corrects the buffer->mirror size to 6 * PAGE_SIZE.

Test Result without this patch
==============================
 #  RUN           hmm2.hmm2_device_private.double_map ...
 # hmm-tests.c:1680:double_map:Expected ret (-14) == 0 (0)
 # double_map: Test terminated by assertion
 #          FAIL  hmm2.hmm2_device_private.double_map
 not ok 53 hmm2.hmm2_device_private.double_map

Test Result with this patch
===========================
 #  RUN           hmm2.hmm2_device_private.double_map ...
 #            OK  hmm2.hmm2_device_private.double_map
 ok 53 hmm2.hmm2_device_private.double_map

Link: https://lkml.kernel.org/r/20240927050752.51066-1-donettom@linux.ibm.com
Fixes: fee9f6d1b8 ("mm/hmm/test: add selftests for HMM")
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-09 12:47:19 -07:00
Muhammad Usama Anjum
f30beffd97 kselftests: mm: fix wrong __NR_userfaultfd value
grep -rnIF "#define __NR_userfaultfd"
tools/include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282
arch/x86/include/generated/uapi/asm/unistd_32.h:374:#define
__NR_userfaultfd 374
arch/x86/include/generated/uapi/asm/unistd_64.h:327:#define
__NR_userfaultfd 323
arch/x86/include/generated/uapi/asm/unistd_x32.h:282:#define
__NR_userfaultfd (__X32_SYSCALL_BIT + 323)
arch/arm/include/generated/uapi/asm/unistd-eabi.h:347:#define
__NR_userfaultfd (__NR_SYSCALL_BASE + 388)
arch/arm/include/generated/uapi/asm/unistd-oabi.h:359:#define
__NR_userfaultfd (__NR_SYSCALL_BASE + 388)
include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282

The number is dependent on the architecture. The above data shows that:
x86	374
x86_64	323

The value of __NR_userfaultfd was changed to 282 when asm-generic/unistd.h
was included.  It makes the test to fail every time as the correct number
of this syscall on x86_64 is 323.  Fix the header to asm/unistd.h.

Link: https://lkml.kernel.org/r/20240923053836.3270393-1-usama.anjum@collabora.com
Fixes: a5c6bc5900 ("selftests/mm: remove local __NR_* definitions")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-26 14:01:44 -07:00
Linus Torvalds
617a814f14 Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Linus Torvalds
70f43ea3a3 Merge tag 'x86-mm-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 memory management updates from Thomas Gleixner:

 - Make LAM enablement safe vs. kernel threads using a process mm
   temporarily as switching back to the process would not update CR3 and
   therefore not enable LAM causing faults in user space when using
   tagged pointers. Cure it by synchronizing LAM enablement via IPIs to
   all CPUs which use the related mm.

 - Cure a LAM harmless inconsistency between CR3 and the state during
   context switch. It's both confusing and prone to lead to real bugs

 - Handle alt stack handling for threads which run with a non-zero
   protection key. The non-zero key prevents the kernel to access the
   alternate stack. Cure it by temporarily enabling all protection keys
   for the alternate stack setup/restore operations.

 - Provide a EFI config table identity mapping for kexec kernel to
   prevent kexec fails because the new kernel cannot access the config
   table array

 - Use GB pages only when a full GB is mapped in the identity map as
   otherwise the CPU can speculate into reserved areas after the end of
   memory which causes malfunction on UV systems.

 - Remove the noisy and pointless SRAT table dump during boot

 - Use is_ioremap_addr() for iounmap() address range checks instead of
   high_memory. is_ioremap_addr() is more precise.

* tag 'x86-mm-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioremap: Improve iounmap() address range checks
  x86/mm: Remove duplicate check from build_cr3()
  x86/mm: Remove unused NX related declarations
  x86/mm: Remove unused CR3_HW_ASID_BITS
  x86/mm: Don't print out SRAT table information
  x86/mm/ident_map: Use gbpages only where full GB page should be mapped.
  x86/kexec: Add EFI config table identity mapping for kexec kernel
  selftests/mm: Add new testcases for pkeys
  x86/pkeys: Restore altstack access in sigreturn()
  x86/pkeys: Update PKRU to enable all pkeys before XSAVE
  x86/pkeys: Add helper functions to update PKRU on the sigframe
  x86/pkeys: Add PKRU as a parameter in signal handling functions
  x86/mm: Cleanup prctl_enable_tagged_addr() nr_bits error checking
  x86/mm: Fix LAM inconsistency during context switch
  x86/mm: Use IPIs to synchronize LAM enablement
2024-09-17 15:03:01 +02:00
Linus Torvalds
114143a595 Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
 "The highlights are support for Arm's "Permission Overlay Extension"
  using memory protection keys, support for running as a protected guest
  on Android as well as perf support for a bunch of new interconnect
  PMUs.

  Summary:

  ACPI:
   - Enable PMCG erratum workaround for HiSilicon HIP10 and 11
     platforms.
   - Ensure arm64-specific IORT header is covered by MAINTAINERS.

  CPU Errata:
   - Enable workaround for hardware access/dirty issue on Ampere-1A
     cores.

  Memory management:
   - Define PHYSMEM_END to fix a crash in the amdgpu driver.
   - Avoid tripping over invalid kernel mappings on the kexec() path.
   - Userspace support for the Permission Overlay Extension (POE) using
     protection keys.

  Perf and PMUs:
   - Add support for the "fixed instruction counter" extension in the
     CPU PMU architecture.
   - Extend and fix the event encodings for Apple's M1 CPU PMU.
   - Allow LSM hooks to decide on SPE permissions for physical
     profiling.
   - Add support for the CMN S3 and NI-700 PMUs.

  Confidential Computing:
   - Add support for booting an arm64 kernel as a protected guest under
     Android's "Protected KVM" (pKVM) hypervisor.

  Selftests:
   - Fix vector length issues in the SVE/SME sigreturn tests
   - Fix build warning in the ptrace tests.

  Timers:
   - Add support for PR_{G,S}ET_TSC so that 'rr' can deal with
     non-determinism arising from the architected counter.

  Miscellaneous:
   - Rework our IPI-based CPU stopping code to try NMIs if regular IPIs
     don't succeed.
   - Minor fixes and cleanups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits)
  perf: arm-ni: Fix an NULL vs IS_ERR() bug
  arm64: hibernate: Fix warning for cast from restricted gfp_t
  arm64: esr: Define ESR_ELx_EC_* constants as UL
  arm64: pkeys: remove redundant WARN
  perf: arm_pmuv3: Use BR_RETIRED for HW branch event if enabled
  MAINTAINERS: List Arm interconnect PMUs as supported
  perf: Add driver for Arm NI-700 interconnect PMU
  dt-bindings/perf: Add Arm NI-700 PMU
  perf/arm-cmn: Improve format attr printing
  perf/arm-cmn: Clean up unnecessary NUMA_NO_NODE check
  arm64/mm: use lm_alias() with addresses passed to memblock_free()
  mm: arm64: document why pte is not advanced in contpte_ptep_set_access_flags()
  arm64: Expose the end of the linear map in PHYSMEM_END
  arm64: trans_pgd: mark PTEs entries as valid to avoid dead kexec()
  arm64/mm: Delete __init region from memblock.reserved
  perf/arm-cmn: Support CMN S3
  dt-bindings: perf: arm-cmn: Add CMN S3
  perf/arm-cmn: Refactor DTC PMU register access
  perf/arm-cmn: Make cycle counts less surprising
  perf/arm-cmn: Improve build-time assertion
  ...
2024-09-16 06:55:07 +02:00
Dev Jain
536ab838a5 selftests/mm: relax test to fail after 100 migration failures
It was recently observed at [1] that during the folio unmapping stage of
migration, when the PTEs are cleared, a racing thread faulting on that
folio may increase the refcount of the folio, sleep on the folio lock (the
migration path has the lock), and migration ultimately fails when
asserting the actual refcount against the expected.  Thereby, the
migration selftest fails on shared-anon mappings.  The above enforces the
fact that migration is a best-effort service, therefore, it is wrong to
fail the test for just a single failure; hence, fail the test after 100
consecutive failures (where 100 is still a subjective choice).  Note that,
this has no effect on the execution time of the test since that is
controlled by a timeout.

[1] https://lore.kernel.org/all/20240801081657.1386743-1-dev.jain@arm.com/

Link: https://lkml.kernel.org/r/20240830051609.4037834-1-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@gentwo.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <yang@os.amperecomputing.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:05 -07:00
Alexander Zhu
391e869711 mm: selftest to verify zero-filled pages are mapped to zeropage
When a THP is split, any subpage that is zero-filled will be mapped to the
shared zeropage, hence saving memory.  Add selftest to verify this by
allocating zero-filled THP and comparing RssAnon before and after split.

Link: https://lkml.kernel.org/r/20240830100438.3623486-4-usamaarif642@gmail.com
Signed-off-by: Alexander Zhu <alexlzhu@fb.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuang Zhai <zhais@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Shuang Zhai <szhai2@cs.rochester.edu>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:03 -07:00
Joey Gouly
f5b5ea51f7 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 <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20240822151113.1479789-27-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2024-09-04 12:54:06 +01:00
Joey Gouly
41bbcf7b4b selftests: mm: move fpregs printing
arm64's fpregs are not at a constant offset from sigcontext. Since this is
not an important part of the test, don't print the fpregs pointer on arm64.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20240822151113.1479789-26-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2024-09-04 12:54:06 +01:00
David Hildenbrand
c41a701d18 selftests/mm: fix charge_reserved_hugetlb.sh test
Currently, running the charge_reserved_hugetlb.sh selftest we can
sometimes observe something like:

  $ ./charge_reserved_hugetlb.sh -cgroup-v2
  ...
  write_result is 0
  After write:
  hugetlb_usage=0
  reserved_usage=10485760
  killing write_to_hugetlbfs
  Received 2.
  Deleting the memory
  Detach failure: Invalid argument
  umount: /mnt/huge: target is busy.

Both cases are issues in the test.

While the unmount error seems to be racy, it will make the test fail:
	$ ./run_vmtests.sh -t hugetlb
	...
	# [FAIL]
	not ok 10 charge_reserved_hugetlb.sh -cgroup-v2 # exit=32

The issue is that we are not waiting for the write_to_hugetlbfs process to
quit.  So it might still have a hugetlbfs file open, about which umount is
not happy.  Fix that by making "killall" wait for the process to quit.

The other error ("Detach failure: Invalid argument") does not seem to
result in a test error, but is misleading.  Turns out write_to_hugetlbfs.c
unconditionally tries to cleanup using shmdt(), even when we only
mmap()'ed a hugetlb file.  Even worse, shmaddr is never even set for the
SHM case.  Fix that as well.

With this change it seems to work as expected.

Link: https://lkml.kernel.org/r/20240821123115.2068812-1-david@redhat.com
Fixes: 29750f71a9 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:46 -07:00
Pedro Falcato
f28bdd1b17 selftests/mm: add more mseal traversal tests
Add more mseal traversal tests across VMAs, where we could possibly screw
up sealing checks.  These test more across-vma traversal for mprotect,
munmap and madvise.  Particularly, we test for the case where a regular
VMA is followed by a sealed VMA.

[akpm@linux-foundation.org: remove incorrect comment, per review]
[akpm@linux-foundation.org: remove the correct comment, per Pedro]
[pedro.falcato@gmail.com: fix mseal's length]
  Link: https://lkml.kernel.org/r/vc4czyuemmu3kylqb4ctaga6y5yvondlyabimx6jvljlw2fkea@djawlllf45xa
Link: https://lkml.kernel.org/r/20240817-mseal-depessimize-v3-7-d8d2e037df30@gmail.com
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:42 -07:00
Baolin Wang
2e6d88e9d4 selftests: mm: support shmem mTHP collapse testing
Add shmem mTHP collpase testing.  Similar to the anonymous page, users can
use the '-s' parameter to specify the shmem mTHP size for testing.

Link: https://lkml.kernel.org/r/fa44bfa20ca5b9fd6f9163a048f3d3c1e53cd0a8.1724140601.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:39 -07:00
Jinjiang Tu
2f4db28610 selftests/mm: remove unnecessary ia64 code and comment
IA64 has gone with commit cf8e865810 ("arch: Remove Itanium (IA-64)
architecture"), so remove unnecessary ia64 special mm code and comment in
selftests too.

Link: https://lkml.kernel.org/r/20240819130609.3386195-1-tujinjiang@huawei.com
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:38 -07:00
Jeff Xu
072cd213b7 selftest mm/mseal: fix test_seal_mremap_move_dontunmap_anyaddr
the syscall remap accepts following:

mremap(src, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP, dst)

when the src is sealed, the call will fail with error code:
EPERM

Previously, the test uses hard-coded 0xdeaddead as dst, and it
will fail on the system with newer glibc installed.

This patch removes test's dependency on glibc for mremap(), also
fix the test and remove the hardcoded address.

Link: https://lkml.kernel.org/r/20240807212320.2831848-1-jeffxu@chromium.org
Fixes: 4926c7a52d ("selftest mm/mseal memory sealing")
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reported-by: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:05 -07:00
Pedro Falcato
67203f3f2a selftests/mm: add mseal test for no-discard madvise
Add an mseal test for madvise() operations that aren't considered
"discard" (e.g purely advisory ops such as MADV_RANDOM).

[pedro.falcato@gmail.com: adjust the mseal test's plan]
  Link: https://lkml.kernel.org/r/20240807203724.2686144-1-pedro.falcato@gmail.com
Link: https://lkml.kernel.org/r/20240807173336.2523757-3-pedro.falcato@gmail.com
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
Tested-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Jeff Xu <jeffxu@chromium.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:03 -07:00
Muhammad Usama Anjum
b808f62921 selftests: mm: fix build errors on armhf
The __NR_mmap isn't found on armhf.  The mmap() is commonly available
system call and its wrapper is present on all architectures.  So it should
be used directly.  It solves problem for armhf and doesn't create problem
for other architectures.

Remove sys_mmap() functions as they aren't doing anything else other than
calling mmap().  There is no need to set errno = 0 manually as glibc
always resets it.

For reference errors are as following:

  CC       seal_elf
seal_elf.c: In function 'sys_mmap':
seal_elf.c:39:33: error: '__NR_mmap' undeclared (first use in this function)
   39 |         sret = (void *) syscall(__NR_mmap, addr, len, prot,
      |                                 ^~~~~~~~~

mseal_test.c: In function 'sys_mmap':
mseal_test.c:90:33: error: '__NR_mmap' undeclared (first use in this function)
   90 |         sret = (void *) syscall(__NR_mmap, addr, len, prot,
      |                                 ^~~~~~~~~

Link: https://lkml.kernel.org/r/20240809082511.497266-1-usama.anjum@collabora.com
Fixes: 4926c7a52d ("selftest mm/mseal memory sealing")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 17:58:59 -07:00
Muhammad Usama Anjum
7c5e8d212d 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/20240812061522.1933054-1-usama.anjum@collabora.com
Link: https://lore.kernel.org/all/20210518072034.31572-7-rppt@kernel.org/ [1]
Link: https://lkml.kernel.org/r/20240809075642.403247-1-usama.anjum@collabora.com
Fixes: 76fe17ef58 ("secretmem: test: add basic selftest for memfd_secret(2)")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-15 22:16:15 -07:00
Dan Carpenter
af3b7d09a9 selftests/mm: compaction_test: fix off by one in check_compaction()
The "initial_nr_hugepages" variable is unsigned long so it takes up to 20
characters to print, plus 1 more character for the NUL terminator. 
Unfortunately, this buffer is not quite large enough for the terminator to
fit.  Also use snprintf() for a belt and suspenders approach.

Link: https://lkml.kernel.org/r/87470c06-b45a-4e83-92ff-aac2e7b9c6ba@stanley.mountain
Fixes: fb9293b6b0 ("selftests/mm: compaction_test: fix bogus test success and reduce probability of OOM-killer invocation")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-15 22:16:15 -07:00
Linus Torvalds
660e4b18a7 Merge tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
 "Nine hotfixes. Five are cc:stable, the others either pertain to
  post-6.10 material or aren't considered necessary for earlier kernels.

  Five are MM and four are non-MM. No identifiable theme here - please
  see the individual changelogs"

* tag 'mm-hotfixes-stable-2024-08-07-18-32' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  padata: Fix possible divide-by-0 panic in padata_mt_helper()
  mailmap: update entry for David Heidelberg
  memcg: protect concurrent access to mem_cgroup_idr
  mm: shmem: fix incorrect aligned index when checking conflicts
  mm: shmem: avoid allocating huge pages larger than MAX_PAGECACHE_ORDER for shmem
  mm: list_lru: fix UAF for memory cgroup
  kcov: properly check for softirq context
  MAINTAINERS: Update LTP members and web
  selftests: mm: add s390 to ARCH check
2024-08-08 07:32:20 -07:00
Nico Pache
30b651c8bc selftests: mm: add s390 to ARCH check
commit 0518dbe97f ("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/20240724213517.23918-1-npache@redhat.com
Fixes: 0518dbe97f ("selftests/mm: fix cross compilation with LLVM")
Signed-off-by: Nico Pache <npache@redhat.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-07 18:33:55 -07:00
Keith Lucas
6998a73efb 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 <keith.lucas@oracle.com>
Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240802061318.2140081-6-aruna.ramakrishna@oracle.com
2024-08-02 14:12:21 +02:00
Linus Torvalds
1a251f52cf minmax: make generic MIN() and MAX() macros available everywhere
This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics.  The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.

These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:

 - trivial duplicated macro definitions have been removed

   Note that 'trivial' here means that it's obviously kernel code that
   already included all the major kernel headers, and thus gets the new
   generic MIN/MAX macros automatically.

 - non-trivial duplicated macro definitions are guarded with #ifndef

   This is the "yes, they define their own versions, but no, the include
   situation is not entirely obvious, and maybe they don't get the
   generic version automatically" case.

 - strange use case #1

   A couple of drivers decided that the way they want to describe their
   versioning is with

	#define MAJ 1
	#define MIN 2
	#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)

   which adds zero value and I just did my Alexander the Great
   impersonation, and rewrote that pointless Gordian knot as

	#define DRV_VERSION "1.2"

   instead.

 - strange use case #2

   A couple of drivers thought that it's a good idea to have a random
   'MIN' or 'MAX' define for a value or index into a table, rather than
   the traditional macro that takes arguments.

   These values were re-written as C enum's instead. The new
   function-line macros only expand when followed by an open
   parenthesis, and thus don't clash with enum use.

Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.

Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-28 15:49:18 -07:00
Dev Jain
f556acc2fa selftests/mm: skip test for non-LPA2 and non-LVA systems
Post my improvement of the test in e4a4ba4154 ("selftests/mm:
va_high_addr_switch: dynamically initialize testcases to enable LPA2
testing"):

The test begins to fail on 4k and 16k pages, on non-LPA2 systems.  To
reduce noise in the CI systems, let us skip the test when higher address
space is not implemented.

Link: https://lkml.kernel.org/r/20240718052504.356517-1-dev.jain@arm.com
Fixes: e4a4ba4154 ("selftests/mm: va_high_addr_switch: dynamically initialize testcases to enable LPA2 testing")
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-26 14:33:10 -07:00
Linus Torvalds
7a3fad30fd 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
2024-07-24 10:29:50 -07:00
Jason A. Donenfeld
9651fcedf7 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>
2024-07-19 20:22:12 +02:00
Edward Liaw
cc937dad85 selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk
Centralize the _GNU_SOURCE definition to CFLAGS in lib.mk.  Remove
redundant defines from Makefiles that import lib.mk.  Convert any usage of
"#define _GNU_SOURCE 1" to "#define _GNU_SOURCE".

This uses the form "-D_GNU_SOURCE=", which is equivalent to
"#define _GNU_SOURCE".

Otherwise using "-D_GNU_SOURCE" is equivalent to "-D_GNU_SOURCE=1" and
"#define _GNU_SOURCE 1", which is less commonly seen in source code and
would require many changes in selftests to avoid redefinition warnings.

Link: https://lkml.kernel.org/r/20240625223454.1586259-2-edliaw@google.com
Signed-off-by: Edward Liaw <edliaw@google.com>
Suggested-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: André Almeida <andrealmeid@igalia.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <kees@kernel.org>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10 12:14:51 -07:00
Jiaqi Yan
72ead83dad 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.

[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>
2024-07-04 18:06:00 -07:00
Audra Mitchell
a591d35c40 mm: turn off test_uffdio_wp if CONFIG_PTE_MARKER_UFFD_WP is not configured.
If CONFIG_PTE_MARKER_UFFD_WP is disabled, then we turn off three features
in userfaultfd_api (UFFD_FEATURE_WP_HUGETLBFS_SHMEM,
UFFD_FEATURE_WP_UNPOPULATED, and UFFD_FEATURE_WP_ASYNC).

Currently this test always will call uffdio_regsiter with the flag
UFFDIO_REGISTER_MODE_WP.  However, the kernel ensures in vma_can_userfault
that if the feature UFFD_FEATURE_WP_HUGETLBFS_SHMEM is disabled, only
allow the VM_UFFD_WP on anonymous vmas, meaning our call to
uffdio_regsiter will fail.

We still want to be able to run the test even if we have
CONFIG_PTE_MARKER_UFFD_WP disabled, so check to see if the feature
UFFD_FEATURE_WP_HUGETLBFS_SHMEM has been turned off in the test and if so,
disable us from calling uffdio_regsiter with the flag
UFFDIO_REGISTER_MODE_WP.

Link: https://lkml.kernel.org/r/20240626130513.120193-3-audra@redhat.com
Signed-off-by: Audra Mitchell <audra@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Rafael Aquini <raquini@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:58 -07:00
Audra Mitchell
a47a7af9b5 mm: update uffd-stress to handle EINVAL for unset config features
Now that we have updated userfaultfd_api to correctly return EINVAL when a
feature is requested but not available, let's fix the uffd-stress test to
only set the UFFD_FEATURE_WP_UNPOPULATED feature when the config is set. 
In addition, still run the test if the CONFIG_PTE_MARKER_UFFD_WP is not
set, just dont use the corresponding UFFD_FEATURE_WP_UNPOPULATED feature.

Link: https://lkml.kernel.org/r/20240626130513.120193-2-audra@redhat.com
Signed-off-by: Audra Mitchell <audra@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rafael Aquini <raquini@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:58 -07:00