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2025-12-23selftests/mm: fix thread state check in uffd-unit-testsWake Liu
In the thread_state_get() function, the logic to find the thread's state character was using `sizeof(header) - 1` to calculate the offset from the "State:\t" string. The `header` variable is a `const char *` pointer. `sizeof()` on a pointer returns the size of the pointer itself, not the length of the string literal it points to. This makes the code's behavior dependent on the architecture's pointer size. This bug was identified on a 32-bit ARM build (`gsi_tv_arm`) for Android, running on an ARMv8-based device, compiled with Clang 19.0.1. On this 32-bit architecture, `sizeof(char *)` is 4. The expression `sizeof(header) - 1` resulted in an incorrect offset of 3, causing the test to read the wrong character from `/proc/[tid]/status` and fail. On 64-bit architectures, `sizeof(char *)` is 8, so the expression coincidentally evaluates to 7, which matches the length of "State:\t". This is why the bug likely remained hidden on 64-bit builds. To fix this and make the code portable and correct across all architectures, this patch replaces `sizeof(header) - 1` with `strlen(header)`. The `strlen()` function correctly calculates the string's length, ensuring the correct offset is always used. Link: https://lkml.kernel.org/r/20251210091408.3781445-1-wakel@google.com Fixes: f60b6634cd88 ("mm/selftests: add a test to verify mmap_changing race with -EAGAIN") Signed-off-by: Wake Liu <wakel@google.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Bill Wendling <morbo@google.com> Cc: Justin Stitt <justinstitt@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-12-06Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko) fixes a build issue and does some cleanup in ib/sys_info.c - "Implement mul_u64_u64_div_u64_roundup()" (David Laight) enhances the 64-bit math code on behalf of a PWM driver and beefs up the test module for these library functions - "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich) makes BPF symbol names, sizes, and line numbers available to the GDB debugger - "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang) adds a sysctl which can be used to cause additional info dumping when the hung-task and lockup detectors fire - "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu) adds a general base64 encoder/decoder to lib/ and migrates several users away from their private implementations - "rbree: inline rb_first() and rb_last()" (Eric Dumazet) makes TCP a little faster - "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin) reworks the KEXEC Handover interfaces in preparation for Live Update Orchestrator (LUO), and possibly for other future clients - "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin) increases the flexibility of KEXEC Handover. Also preparation for LUO - "Live Update Orchestrator" (Pasha Tatashin) is a major new feature targeted at cloud environments. Quoting the cover letter: This series introduces the Live Update Orchestrator, a kernel subsystem designed to facilitate live kernel updates using a kexec-based reboot. This capability is critical for cloud environments, allowing hypervisors to be updated with minimal downtime for running virtual machines. LUO achieves this by preserving the state of selected resources, such as memory, devices and their dependencies, across the kernel transition. As a key feature, this series includes support for preserving memfd file descriptors, which allows critical in-memory data, such as guest RAM or any other large memory region, to be maintained in RAM across the kexec reboot. Mike Rappaport merits a mention here, for his extensive review and testing work. - "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain) moves the kexec and kdump sysfs entries from /sys/kernel/ to /sys/kernel/kexec/ and adds back-compatibility symlinks which can hopefully be removed one day - "kho: fixes for vmalloc restoration" (Mike Rapoport) fixes a BUG which was being hit during KHO restoration of vmalloc() regions * tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits) calibrate: update header inclusion Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()" vmcoreinfo: track and log recoverable hardware errors kho: fix restoring of contiguous ranges of order-0 pages kho: kho_restore_vmalloc: fix initialization of pages array MAINTAINERS: TPM DEVICE DRIVER: update the W-tag init: replace simple_strtoul with kstrtoul to improve lpj_setup KHO: fix boot failure due to kmemleak access to non-PRESENT pages Documentation/ABI: new kexec and kdump sysfs interface Documentation/ABI: mark old kexec sysfs deprecated kexec: move sysfs entries to /sys/kernel/kexec test_kho: always print restore status kho: free chunks using free_page() instead of kfree() selftests/liveupdate: add kexec test for multiple and empty sessions selftests/liveupdate: add simple kexec-based selftest for LUO selftests/liveupdate: add userspace API selftests docs: add documentation for memfd preservation via LUO mm: memfd_luo: allow preserving memfd liveupdate: luo_file: add private argument to store runtime state mm: shmem: export some functions to internal.h ...
2025-11-29selftests/mm/uffd: initialize char variable to NullAnkit Khushwaha
In "uffd-stress.c" & "uffd-unit-tests.c". address of char variable having garbage value (uninitialized) is passed to 'write' syscall triggers warning. uffd-stress.c:246:39: warning: variable 'c' is uninitialized when passed as a const pointer argument here [-Wuninitialized-const-pointer] uffd-unit-tests.c:581:31: warning: variable 'c' is uninitialized when passed as a const pointer argument here [-Wuninitialized-const-pointer] so the fix is to assign char variable to '\0' to prevent writing of garbage value. Link: https://lkml.kernel.org/r/20251126160830.52124-1-ankitkhushwaha.linux@gmail.com Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux@gmail.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Bill Wendling <morbo@google.com> Cc: Justin Stitt <justinstitt@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27selftests: complete kselftest include centralizationBala-Vignesh-Reddy
This follow-up patch completes centralization of kselftest.h and ksefltest_harness.h includes in remaining seltests files, replacing all relative paths with a non-relative paths using shared -I include path in lib.mk Tested with gcc-13.3 and clang-18.1, and cross-compiled successfully on riscv, arm64, x86_64 and powerpc arch. [reddybalavignesh9979@gmail.com: add selftests include path for kselftest.h] Link: https://lkml.kernel.org/r/20251017090201.317521-1-reddybalavignesh9979@gmail.com Link: https://lkml.kernel.org/r/20251016104409.68985-1-reddybalavignesh9979@gmail.com Signed-off-by: Bala-Vignesh-Reddy <reddybalavignesh9979@gmail.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/ Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Günther Noack <gnoack@google.com> Cc: Jakub Kacinski <kuba@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mickael Salaun <mic@digikod.net> Cc: Ming Lei <ming.lei@redhat.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Simon Horman <horms@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24selftests/mm: gup_test: fix comment regarding origin of FOLL_WRITEPeng Li
The 'FOLL_WRITE' of the copied source is located in mm_types.h of mm, not mm.h, so fix it. Link: https://lkml.kernel.org/r/20251117154012.197499-2-peng8420.li@gmail.com Signed-off-by: Peng Li <peng8420.li@gmail.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24selftests/mm: gup_test: stop testing FOLL_TOUCHPeng Li
commit 0f20bba1688b ("mm/gup: explicitly define and check internal GUP flags, disallow FOLL_TOUCH") marked FOLL_TOUCH as a GUP-internal flag. This causes a warning to fire when running gup_test, for example: $ ./gup_test -L -r 100 -z dmesg: WARNING: CPU: 1 PID: 117 at mm/gup.c:2512 is_valid_gup_args+0x66/0x8c Therefore, remove the "FOLL_TOUCH" test code from gup_test.c. Link: https://lkml.kernel.org/r/20251117154012.197499-1-peng8420.li@gmail.com Signed-off-by: Peng Li <peng8420.li@gmail.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24selftests/mm/hmm-tests: new throughput tests including THPBalbir Singh
Add new benchmark style support to test transfer bandwidth for zone device memory operations. Link: https://lkml.kernel.org/r/20251001065707.920170-16-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24selftests/mm/hmm-tests: partial unmap, mremap and anon_write testsMatthew Brost
Add partial unmap test case which munmaps memory while in the device. Add tests exercising mremap on faulted-in memory (CPU and GPU) at various offsets and verify correctness. Update anon_write_child to read device memory after fork verifying this flow works in the kernel. Both THP and non-THP cases are updated. Link: https://lkml.kernel.org/r/20251001065707.920170-15-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Signed-off-by: Matthew Brost <matthew.brost@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24selftests/mm/hmm-tests: new tests for zone device THP migrationBalbir Singh
Add new tests for migrating anon THP pages, including anon_huge, anon_huge_zero and error cases involving forced splitting of pages during migration. Link: https://lkml.kernel.org/r/20251001065707.920170-14-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24Merge branch 'mm-hotfixes-stable' into mm-stable in order to mergeAndrew Morton
"mm/huge_memory: only get folio_order() once during __folio_split()" into mm-stable.
2025-11-24selftests/mm: fix division-by-zero in uffd-unit-testsCarlos Llamas
Commit 4dfd4bba8578 ("selftests/mm/uffd: refactor non-composite global vars into struct") moved some of the operations previously implemented in uffd_setup_environment() earlier in the main test loop. The calculation of nr_pages, which involves a division by page_size, now occurs before checking that default_huge_page_size() returns a non-zero This leads to a division-by-zero error on systems with !CONFIG_HUGETLB. Fix this by relocating the non-zero page_size check before the nr_pages calculation, as it was originally implemented. Link: https://lkml.kernel.org/r/20251113034623.3127012-1-cmllamas@google.com Fixes: 4dfd4bba8578 ("selftests/mm/uffd: refactor non-composite global vars into struct") Signed-off-by: Carlos Llamas <cmllamas@google.com> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Ujwal Kundur <ujwal.kundur@gmail.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20testing/selftests/mm: add soft-dirty merge self-testLorenzo Stoakes
Assert that we correctly merge VMAs containing VM_SOFTDIRTY flags now that we correctly handle these as sticky. In order to do so, we have to account for the fact the pagemap interface checks soft dirty PTEs and additionally that newly merged VMAs are marked VM_SOFTDIRTY. We do this by using use unfaulted anon VMAs, establishing one and clearing references on that one, before establishing another and merging the two before checking that soft-dirty is propagated as expected. We check that this functions correctly with mremap() and mprotect() as sample cases, because VMA merge of adjacent newly mapped VMAs will automatically be made soft-dirty due to existing logic which does so. We are therefore exercising other means of merging VMAs. Link: https://lkml.kernel.org/r/d5a0f735783fb4f30a604f570ede02ccc5e29be9.1763399675.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Andrey Vagin <avagin@gmail.com> Cc: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20selftests/mm/uffd: remove static address usage in shmem_allocate_area()Mehdi Ben Hadj Khelifa
The current shmem_allocate_area() implementation uses a hardcoded virtual base address (BASE_PMD_ADDR) as a hint for mmap() when creating shmem-backed test areas. This approach is fragile and may fail on systems with ASLR or different virtual memory layouts, where the chosen address is unavailable. Replace the static base address with a dynamically reserved address range obtained via mmap(NULL, ..., PROT_NONE). The memfd-backed areas and their alias are then mapped into that reserved region using MAP_FIXED, preserving the original layout and aliasing semantics while avoiding collisions with unrelated mappings. This change improves robustness and portability of the test suite without altering its behavior or coverage. [mehdi.benhadjkhelifa@gmail.com: make cleanup code more clear, per Mike] Link: https://lkml.kernel.org/r/20251113142050.108638-1-mehdi.benhadjkhelifa@gmail.com Link: https://lkml.kernel.org/r/20251111205739.420009-1-mehdi.benhadjkhelifa@gmail.com Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com> Suggested-by: Mike Rapoport <rppt@kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Hunter <david.hunter.linux@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20tools/testing/selftests/mm: add smaps visibility guard region testLorenzo Stoakes
Assert that we observe guard regions appearing in /proc/$pid/smaps as expected, and when split/merge is performed too (with expected sticky behaviour). Also add handling for file systems which don't sanely handle mmap() VMA merging so we don't incorrectly encounter a test failure in this situation. Link: https://lkml.kernel.org/r/059e62b8c67e55e6d849878206a95ea1d7c1e885.1763460113.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20tools/testing/selftests/mm: add MADV_COLLAPSE test caseLorenzo Stoakes
To ensure the retract_page_tables() logic functions correctly with the introduction of VM_MAYBE_GUARD, add a test to assert that madvise collapse fails when guard regions are established in the collapsed range in all cases. Unfortunately we cannot differentiate between e.g. CONFIG_READ_ONLY_THP_FOR_FS not being set vs. a file-backed VMA having collapse correctly disallowed, so in each instance we will get an assert pass here. We add an additional check to see whether guard regions are preserved across collapse in case of a bug causing the collapse to succeed, which will give us more data to debug with should this occur in future. Link: https://lkml.kernel.org/r/0748beeb864525b8ddfa51adad7128dd32eb3ac4.1763460113.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand (Red Hat) <david@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20selftest/mm: fix pointer comparison in mremap_testAnkit Khushwaha
Pointer arthemitic with 'void * addr' and 'ulong dest_alignment' triggers following warning: mremap_test.c:1035:31: warning: pointer comparison always evaluates to false [-Wtautological-compare] 1035 | if (addr + c.dest_alignment < addr) { | ^ this warning is raised from clang version 20.1.8 (Fedora 20.1.8-4.fc42). use 'void *tmp_addr' to do the pointer arthemitic. Link: https://lkml.kernel.org/r/20251108161829.25105-1-ankitkhushwaha.linux@gmail.com Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux@gmail.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16selftests: update ksm inheritance tests for prctl fork/execxu xin
To reproduce the issue mentioned by [1], this add a setting of pages_to_scan and sleep_millisecs at the start of test_prctl_fork_exec(). The main change is just raise the scanning frequency of ksmd. [1] https://lore.kernel.org/all/202510012256278259zrhgATlLA2C510DMD3qI@zte.com.cn/ Link: https://lkml.kernel.org/r/20251007182935207jm31wCIgLpZg5XbXQY64S@zte.com.cn Signed-off-by: xu xin <xu.xin16@zte.com.cn> Cc: David Hildenbrand <david@redhat.com> Cc: Jinjiang Tu <tujinjiang@huawei.com> Cc: Stefan Roesch <shr@devkernel.io> Cc: Wang Yaxin <wang.yaxin@zte.com.cn> Cc: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-28selftests/mm: add fork inheritance test for ksm_merging_pages counterDonet Tom
Add a new selftest to verify whether the `ksm_merging_pages` counter in `mm_struct` is not inherited by a child process after fork. This helps ensure correctness of KSM accounting across process creation. Link: https://lkml.kernel.org/r/e7bb17d374133bd31a3e423aa9e46e1122e74971.1758648700.git.donettom@linux.ibm.com Signed-off-by: Donet Tom <donettom@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Aboorva Devarajan <aboorvad@linux.ibm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-23selftests/mm: skip soft-dirty tests when CONFIG_MEM_SOFT_DIRTY is disabledLance Yang
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: 9f3265db6ae8 ("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>
2025-09-21selftests/mm: protection_keys: fix dead codeMuhammad Usama Anjum
The while loop doesn't execute and following warning gets generated: protection_keys.c:561:15: warning: code will never be executed [-Wunreachable-code] int rpkey = alloc_random_pkey(); Let's enable the while loop such that it gets executed nr_iterations times. Simplify the code a bit as well. Link: https://lkml.kernel.org/r/20250912123025.1271051-3-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: add -Wunreachable-code and fix warningsMuhammad Usama Anjum
Patch series "selftests/mm: Add -Wunreachable-code and fix warnings". Add -Wunreachable-code to selftests and remove dead code from generated warnings. This patch (of 2): Enable -Wunreachable-code flag to catch dead code and fix them. 1. Remove the dead code and write a comment instead: hmm-tests.c:2033:3: warning: code will never be executed [-Wunreachable-code] perror("Should not reach this\n"); ^~~~~~ 2. ksft_exit_fail_msg() calls exit(). So cleanup isn't done. Replace it with ksft_print_msg(). split_huge_page_test.c:301:3: warning: code will never be executed [-Wunreachable-code] goto cleanup; ^~~~~~~~~~~~ 3. Remove duplicate inline. pkey_sighandler_tests.c:44:15: warning: duplicate 'inline' declaration specifier [-Wduplicate-decl-specifier] static inline __always_inline Link: https://lkml.kernel.org/r/20250912123025.1271051-1-usama.anjum@collabora.com Link: https://lkml.kernel.org/r/20250912123025.1271051-2-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: centralize the __always_unused macroMuhammad Usama Anjum
This macro gets used in different tests. Add it to kselftest.h which is central location and tests use this header. Then use this new macro. Link: https://lkml.kernel.org/r/20250912125102.1309796-1-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Antonio Quartulli <antonio@openvpn.net> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kacinski <kuba@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: "Sabrina Dubroca" <sd@queasysnail.net> Cc: Shuah Khan <shuah@kernel.org> Cc: Simon Horman <horms@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: gup_tests: option to GUP all pages in a single callDavid Hildenbrand
We recently missed detecting an issue during early testing because the default (!all) tests would not trigger it and even when running "all" tests it only would happen sometimes because of races. So let's allow for an easy way to specify "GUP all pages in a single call", extend the test matrix and extend our default (!all) tests. By GUP'ing all pages in a single call, with the default size of 128MiB we'll cover multiple leaf page tables / PMDs on architectures with sane THP sizes. Link: https://lkml.kernel.org/r/20250910093051.1693097-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: remove PROT_EXEC req from file-collapse testsZach O'Keefe
As of v6.8 commit 7fbb5e188248 ("mm: remove VM_EXEC requirement for THP eligibility") thp collapse no longer requires file-backed mappings be created with PROT_EXEC. Remove the overly-strict dependency from thp collapse tests so we test the least-strict requirement for success. Link: https://lkml.kernel.org/r/20250909190534.512801-1-zokeefe@google.com Signed-off-by: Zach O'Keefe <zokeefe@google.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: fix va_high_addr_switch.sh failure on x86_64Chunyu Hu
The test will fail as below on x86_64 with cpu la57 support (will skip if no la57 support). Note, the test requries nr_hugepages to be set first. # running bash ./va_high_addr_switch.sh # ------------------------------------- # mmap(addr_switch_hint - pagesize, pagesize): 0x7f55b60fa000 - OK # mmap(addr_switch_hint - pagesize, (2 * pagesize)): 0x7f55b60f9000 - OK # mmap(addr_switch_hint, pagesize): 0x800000000000 - OK # mmap(addr_switch_hint, 2 * pagesize, MAP_FIXED): 0x800000000000 - OK # mmap(NULL): 0x7f55b60f9000 - OK # mmap(low_addr): 0x40000000 - OK # mmap(high_addr): 0x1000000000000 - OK # mmap(high_addr) again: 0xffff55b6136000 - OK # mmap(high_addr, MAP_FIXED): 0x1000000000000 - OK # mmap(-1): 0xffff55b6134000 - OK # mmap(-1) again: 0xffff55b6132000 - OK # mmap(addr_switch_hint - pagesize, pagesize): 0x7f55b60fa000 - OK # mmap(addr_switch_hint - pagesize, 2 * pagesize): 0x7f55b60f9000 - OK # mmap(addr_switch_hint - pagesize/2 , 2 * pagesize): 0x7f55b60f7000 - OK # mmap(addr_switch_hint, pagesize): 0x800000000000 - OK # mmap(addr_switch_hint, 2 * pagesize, MAP_FIXED): 0x800000000000 - OK # mmap(NULL, MAP_HUGETLB): 0x7f55b5c00000 - OK # mmap(low_addr, MAP_HUGETLB): 0x40000000 - OK # mmap(high_addr, MAP_HUGETLB): 0x1000000000000 - OK # mmap(high_addr, MAP_HUGETLB) again: 0xffff55b5e00000 - OK # mmap(high_addr, MAP_FIXED | MAP_HUGETLB): 0x1000000000000 - OK # mmap(-1, MAP_HUGETLB): 0x7f55b5c00000 - OK # mmap(-1, MAP_HUGETLB) again: 0x7f55b5a00000 - OK # mmap(addr_switch_hint - pagesize, 2*hugepagesize, MAP_HUGETLB): 0x800000000000 - FAILED # mmap(addr_switch_hint , 2*hugepagesize, MAP_FIXED | MAP_HUGETLB): 0x800000000000 - OK # [FAIL] addr_switch_hint is defined as DFEFAULT_MAP_WINDOW in the failed test (for x86_64, DFEFAULT_MAP_WINDOW is defined as (1UL<<47) - pagesize) in 64 bit. Before commit cc92882ee218 ("mm: drop hugetlb_get_unmapped_area{_*} functions"), for x86_64 hugetlb_get_unmapped_area() is handled in arch code arch/x86/mm/hugetlbpage.c and addr is checked with map_address_hint_valid() after align with 'addr &= huge_page_mask(h)' which is a round down way, and it will fail the check because the addr is within the DEFAULT_MAP_WINDOW but (addr + len) is above the DFEFAULT_MAP_WINDOW. So it wil go through the hugetlb_get_unmmaped_area_top_down() to find an area within the DFEFAULT_MAP_WINDOW. After commit cc92882ee218 ("mm: drop hugetlb_get_unmapped_area{_*} functions"). The addr hint for hugetlb_get_unmmaped_area() will be rounded up and aligned to hugepage size with ALIGN() for all arches. And after the align, the addr will be above the default MAP_DEFAULT_WINDOW, and the map_addresshint_valid() check will pass because both aligned addr (addr0) and (addr + len) are above the DEFAULT_MAP_WINDOW, and the aligned hint address (0x800000000000) is returned as an suitable gap is found there, in arch_get_unmapped_area_topdown(). To still cover the case that addr is within the DEFAULT_MAP_WINDOW, and addr + len is above the DFEFAULT_MAP_WINDOW, change to choose the last hugepage aligned address within the DEFAULT_MAP_WINDOW as the hint addr, and the addr + len (2 hugepages) will be one hugepage above the DEFAULT_MAP_WINDOW. An aligned address won't be affected by the page round up or round down from kernel, so it's determistic. Link: https://lkml.kernel.org/r/20250912013711.3002969-4-chuhu@redhat.com Fixes: cc92882ee218 ("mm: drop hugetlb_get_unmapped_area{_*} functions") Signed-off-by: Chunyu Hu <chuhu@redhat.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: alloc hugepages in va_high_addr_switch testChunyu Hu
Alloc hugepages in the test internally, so we don't fully rely on the run_vmtests.sh. If run_vmtests.sh does that great, free hugepages is enough for being used to run the test, leave it as it is, otherwise setup the hugepages in the test. Save the original nr_hugepages value and restore it after test finish, so leave a stable test envronment. Link: https://lkml.kernel.org/r/20250912013711.3002969-3-chuhu@redhat.com Signed-off-by: Chunyu Hu <chuhu@redhat.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: fix hugepages cleanup too earlyChunyu Hu
Patch series "Fix va_high_addr_switch.sh test failure", v3. These three patches fix the va_high_addr_switch.sh test failure on x86_64. Patch 1 fixes the hugepage setup issue that nr_hugepages is reset too early in run_vmtests.sh and break the later va_high_addr_switch testing. Patch 2 adds hugepage setup in va_high_addr_switch test, so that it can still work if vm_runtests.sh changes the hugepage setup someday. Patch 3 fixes the test failure caused by the hint addr align method change in hugetlb_get_unmapped_area(). This patch (of 3): The nr_hugepgs variable is used to keep the original nr_hugepages at the hugepage setup step at test beginning. After userfaultfd test, a cleaup is executed, both /sys/kernel/mm/hugepages/hugepages-*/nr_hugepages and /proc/sys//vm/nr_hugepages are reset to 'original' value before userfaultfd test starts. Issue here is the value used to restore /proc/sys/vm/nr_hugepages is nr_hugepgs which is the initial value before the vm_runtests.sh runs, not the value before userfaultfd test starts. 'va_high_addr_swith.sh' tests runs after that will possibly see no hugepages available for test, and got EINVAL when mmap(HUGETLB), making the result invalid. And before pkey tests, nr_hugepgs is changed to be used as a temp variable to save nr_hugepages before pkey test, and restore it after pkey tests finish. The original nr_hugepages value is not tracked anymore, so no way to restore it after all tests finish. Add a new variable orig_nr_hugepgs to save the original nr_hugepages, and and restore it to nr_hugepages after all tests finish. And change to use the nr_hugepgs variable to save the /proc/sys/vm/nr_hugeages after hugepage setup, it's also the value before userfaultfd test starts, and the correct value to be restored after userfaultfd finishes. The va_high_addr_switch.sh broken will be resolved. Link: https://lkml.kernel.org/r/20250912013711.3002969-1-chuhu@redhat.com Link: https://lkml.kernel.org/r/20250912013711.3002969-2-chuhu@redhat.com Signed-off-by: Chunyu Hu <chuhu@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: split_huge_page_test: cleanups for split_pte_mapped_thp testDavid Hildenbrand
There is room for improvement, so let's clean up a bit: (1) Define "4" as a constant. (2) SKIP if we fail to allocate all THPs (e.g., fragmented) and add recovery code for all other failure cases: no need to exit the test. (3) Rename "len" to thp_area_size, and "one_page" to "thp_area". (4) Allocate a new area "page_area" into which we will mremap the pages; add "page_area_size". Now we can easily merge the two mremap instances into a single one. (5) Iterate THPs instead of bytes when checking for missed THPs after mremap. (6) Rename "pte_mapped2" to "tmp", used to verify mremap(MAP_FIXED) result. (7) Split the corruption test from the failed-split test, so we can just iterate bytes vs. thps naturally. (8) Extend comments and clarify why we are using mremap in the first place. Link: https://lkml.kernel.org/r/20250903070253.34556-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm: split_huge_page_test: fix occasional is_backed_by_folio() ↵David Hildenbrand
wrong results Patch series "selftests/mm: split_huge_page_test: split_pte_mapped_thp improvements", v2. One fix for occasional failures I found while testing and a bunch of cleanups that should make that test easier to digest. This patch (of 2): When checking for actual tail or head pages of a folio, we must make sure that the KPF_COMPOUND_HEAD/KPF_COMPOUND_TAIL flag is paired with KPF_THP. For example, if we have another large folio after our large folio in physical memory, our "pfn_flags & (KPF_THP | KPF_COMPOUND_TAIL)" would trigger even though it's actually a head page of the next folio. If is_backed_by_folio() returns a wrong result, split_pte_mapped_thp() can fail with "Some THPs are missing during mremap". Fix it by checking for head/tail pages of folios properly. Add folio_tail_flags/folio_head_flags to improve readability and use these masks also when just testing for any compound page. Link: https://lkml.kernel.org/r/20250903070253.34556-1-david@redhat.com Link: https://lkml.kernel.org/r/20250903070253.34556-2-david@redhat.com Fixes: 169b456b0162 ("selftests/mm: reimplement is_backed_by_thp() with more precise check") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21selftests/mm/uffd: refactor non-composite global vars into structUjwal Kundur
Refactor macros and non-composite global variable definitions into a struct that is defined at the start of a test and is passed around instead of relying on global vars. Link: https://lkml.kernel.org/r/20250829155600.2000-1-ujwal.kundur@gmail.com Signed-off-by: Ujwal Kundur <ujwal.kundur@gmail.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm/uffd-stress: stricten constraint on free hugepages needed ↵Dev Jain
before the test The test requires at least 2 * (bytes/page_size) hugetlb memory, since we require identical number of hugepages for src and dst location. Fix this. Along with the above, as explained in patch "selftests/mm/uffd-stress: Make test operate on less hugetlb memory", the racy nature of the test requires that we have some extra number of hugepages left beyond what is required. Therefore, stricten this constraint. Link: https://lkml.kernel.org/r/20250909061531.57272-3-dev.jain@arm.com Fixes: 5a6aa60d1823 ("selftests/mm: skip uffd hugetlb tests with insufficient hugepages") Signed-off-by: Dev Jain <dev.jain@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm/uffd-stress: make test operate on less hugetlb memoryDev Jain
Patch series "selftests/mm: uffd-stress fixes", v2. This patchset ensures that the number of hugepages is correctly set in the system so that the uffd-stress test does not fail due to the racy nature of the test. Patch 1 changes the hugepage constraint in the run_vmtests.sh script, whereas patch 2 changes the constraint in the test itself. This patch (of 2): We observed uffd-stress selftest failure on arm64 and intermittent failures on x86 too: running ./uffd-stress hugetlb-private 128 32 bounces: 17, mode: rnd read, ERROR: UFFDIO_COPY error: -12 (errno=12, @uffd-common.c:617) [FAIL] not ok 18 uffd-stress hugetlb-private 128 32 # exit=1 For this particular case, the number of free hugepages from run_vmtests.sh will be 128, and the test will allocate 64 hugepages in the source location. The stress() function will start spawning threads which will operate on the destination location, triggering uffd-operations like UFFDIO_COPY from src to dst, which means that we will require 64 more hugepages for the dst location. Let us observe the locking_thread() function. It will lock the mutex kept at dst, triggering uffd-copy. Suppose that 127 (64 for src and 63 for dst) hugepages have been reserved. In case of BOUNCE_RANDOM, it may happen that two threads trying to lock the mutex at dst, try to do so at the same hugepage number. If one thread succeeds in reserving the last hugepage, then the other thread may fail in alloc_hugetlb_folio(), returning -ENOMEM. I can confirm that this is indeed the case by this hacky patch: :--- a/mm/hugetlb.c ; +++ b/mm/hugetlb.c ; @@ -6929,6 +6929,11 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, ; ; folio = alloc_hugetlb_folio(dst_vma, dst_addr, false); ; if (IS_ERR(folio)) { ; + pte_t *actual_pte = hugetlb_walk(dst_vma, dst_addr, PMD_SIZE); ; + if (actual_pte) { ; + ret = -EEXIST; ; + goto out; ; + } ; ret = -ENOMEM; ; goto out; ; } This code path gets triggered indicating that the PMD at which one thread is trying to map a hugepage, gets filled by a racing thread. Therefore, instead of using freepgs to compute the amount of memory, use freepgs - (min(32, nr_cpus) - 1), so that the test still has some extra hugepages to use. The adjustment is a function of min(32, nr_cpus) - the value of nr_parallel in the test - because in the worst case, nr_parallel number of threads will try to map a hugepage on the same PMD, one will win the allocation race, and the other nr_parallel - 1 threads will fail, so we need extra nr_parallel - 1 hugepages to satisfy this request. Note that, in case the adjusted value underflows, there is a check for the number of free hugepages in the test itself, which will fail: get_free_hugepages() < bytes / page_size A negative value will be passed on to bytes which is of type size_t, thus the RHS will become a large value and the check will fail, so we are safe. Link: https://lkml.kernel.org/r/20250909061531.57272-1-dev.jain@arm.com Link: https://lkml.kernel.org/r/20250909061531.57272-2-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: use calloc instead of malloc in pagemap_ioctl.cI Viswanath
As per Documentation/process/deprecated.rst, dynamic size calculations should not be performed in memory allocator arguments due to possible overflows. Replace malloc with calloc to avoid open-ended arithmetic and prevent possible overflows. Link: https://lkml.kernel.org/r/20250825170643.63174-1-viswanathiyyappan@gmail.com Signed-off-by: I Viswanath <viswanathiyyappan@gmail.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed by: Donet Tom <donettom@linux.ibm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests: centralise maybe-unused definition in kselftest.hBala-Vignesh-Reddy
Several selftests subdirectories duplicated the define __maybe_unused, leading to redundant code. Move to kselftest.h header and remove other definitions. This addresses the duplication noted in the proc-pid-vm warning fix Link: https://lkml.kernel.org/r/20250821101159.2238-1-reddybalavignesh9979@gmail.com Signed-off-by: Bala-Vignesh-Reddy <reddybalavignesh9979@gmail.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Link:https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/ Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Acked-by: Mickal Salan <mic@digikod.net> [landlock] Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13kselftest: mm: fix typos in test_vmalloc.shally heev
Fix simple typos in function name and console message. Link: https://lkml.kernel.org/r/20250823170208.184149-1-allyheev@gmail.com Signed-off-by: ally heev <allyheev@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: test that rmap behaves as expectedWei Yang
As David suggested, currently we don't have a high level test case to verify the behavior of rmap. This patch introduce the verification on rmap by migration. The general idea is if migrate one shared page between processes, this would be reflected in all related processes. Otherwise, we have problem in rmap. Currently it covers following four scenarios: * anonymous page * shmem page * pagecache page * ksm page Link: https://lkml.kernel.org/r/20250819080047.10063-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Suggested-by: David Hildenbrand <david@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Rik van Riel <riel@surriel.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: put general ksm operation into vm_utilWei Yang
Patch series "test that rmap behaves as expected", v4. As David suggested, currently we don't have a high level test case to verify the behavior of rmap. This patch set introduce the verification on rmap by migration. Patch 1 is a preparation to move ksm related operations into vm_util. Patch 2 is the new test case for rmap. Currently it covers following four scenarios: * anonymous page * shmem page * pagecache page * ksm page This patch (of 2): There are some general ksm operations could be used by other related test cases. Put them into vm_util for common use. This is a preparation patch for later use. Link: https://lkml.kernel.org/r/20250819080047.10063-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20250819080047.10063-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Suggested-by: David Hildenbrand <david@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Rik van Riel <riel@surriel.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: check after-split folio orders in split_huge_page_testZi Yan
Instead of just checking the existence of PMD folios before and after folio split tests, use check_folio_orders() to check after-split folio orders. The split ranges in split_thp_in_pagecache_to_order_at() are changed to [addr, addr + pagesize) for every pmd_pagesize. It prevents folios within the range being split multiple times due to debugfs split function always perform splits with a pagesize step for a given range. The following tests are not changed: 1. split_pte_mapped_thp: the test already uses kpageflags to check; 2. split_file_backed_thp: no vaddr available. Link: https://lkml.kernel.org/r/20250818184622.1521620-6-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: wang lian <lianux.mm@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: add check_after_split_folio_orders() helperZi Yan
The helper gathers a folio order statistics of folios within a virtual address range and checks it against a given order list. It aims to provide a more precise folio order check instead of just checking the existence of PMD folios. The helper will be used the upcoming commit. Link: https://lkml.kernel.org/r/20250818184622.1521620-5-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: wang lian <lianux.mm@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: reimplement is_backed_by_thp() with more precise checkZi Yan
and rename it to is_backed_by_folio(). is_backed_by_folio() checks if the given vaddr is backed a folio with a given order. It does so by: 1. getting the pfn of the vaddr; 2. checking kpageflags of the pfn; if order is greater than 0: 3. checking kpageflags of the head pfn; 4. checking kpageflags of all tail pfns. pmd_order is added to split_huge_page_test.c and replaces max_order. [ziy@nvidia.com: reduce code duplication, per David] Link: https://lkml.kernel.org/r/F54782D6-65A3-4D35-AE03-8ADE636EE258@nvidia.com Link: https://lkml.kernel.org/r/20250818184622.1521620-4-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: wang lian <lianux.mm@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: mark all functions static in split_huge_page_test.cZi Yan
All functions are only used within the file. Link: https://lkml.kernel.org/r/20250818184622.1521620-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: wang lian <lianux.mm@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Donet Tom <donettom@linux.ibm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests: prctl: introduce tests for disabling THPs except for madviseUsama Arif
The test will set the global system THP setting to never, madvise or always depending on the fixture variant and the 2M setting to inherit before it starts (and reset to original at teardown). The fixture setup will also test if PR_SET_THP_DISABLE prctl call can be made with PR_THP_DISABLE_EXCEPT_ADVISED and skip if it fails. This tests if the process can: - successfully get the policy to disable THPs expect for madvise. - get hugepages only on MADV_HUGE and MADV_COLLAPSE if the global policy is madvise/always and only with MADV_COLLAPSE if the global policy is never. - successfully reset the policy of the process. - after reset, only get hugepages with: - MADV_COLLAPSE when policy is set to never. - MADV_HUGE and MADV_COLLAPSE when policy is set to madvise. - always when policy is set to "always". - never get a THP with MADV_NOHUGEPAGE. - repeat the above tests in a forked process to make sure the policy is carried across forks. Test results: ./prctl_thp_disable TAP version 13 1..12 ok 1 prctl_thp_disable_completely.never.nofork ok 2 prctl_thp_disable_completely.never.fork ok 3 prctl_thp_disable_completely.madvise.nofork ok 4 prctl_thp_disable_completely.madvise.fork ok 5 prctl_thp_disable_completely.always.nofork ok 6 prctl_thp_disable_completely.always.fork ok 7 prctl_thp_disable_except_madvise.never.nofork ok 8 prctl_thp_disable_except_madvise.never.fork ok 9 prctl_thp_disable_except_madvise.madvise.nofork ok 10 prctl_thp_disable_except_madvise.madvise.fork ok 11 prctl_thp_disable_except_madvise.always.nofork ok 12 prctl_thp_disable_except_madvise.always.fork [usamaarif642@gmail.com: return after executing test in child process] Link: https://lkml.kernel.org/r/3dca2de4-9a6a-4efe-a86c-83f9509831fc@gmail.com Link: https://lkml.kernel.org/r/20250815135549.130506-8-usamaarif642@gmail.com Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yafang <laoar.shao@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests: prctl: introduce tests for disabling THPs completelyUsama Arif
The test will set the global system THP setting to never, madvise or always depending on the fixture variant and the 2M setting to inherit before it starts (and reset to original at teardown). The fixture setup will also test if PR_SET_THP_DISABLE prctl call can be made to disable all THPs and skip if it fails. This tests if the process can: - successfully get the policy to disable THPs completely. - never get a hugepage when the THPs are completely disabled with the prctl, including with MADV_HUGE and MADV_COLLAPSE. - successfully reset the policy of the process. - after reset, only get hugepages with: - MADV_COLLAPSE when policy is set to never. - MADV_HUGE and MADV_COLLAPSE when policy is set to madvise. - always when policy is set to "always". - never get a THP with MADV_NOHUGEPAGE. - repeat the above tests in a forked process to make sure the policy is carried across forks. [usamaarif642@gmail.com: return after executing test in child process] Link: https://lkml.kernel.org/r/2d0ea708-ecba-4021-b6ca-e93f1413d60a@gmail.com [usamaarif642@gmail.com: include linux/mman.h for prctl_thp_disable] Link: https://lkml.kernel.org/r/20250910204609.1720498-1-usamaarif642@gmail.com Link: https://lore.kernel.org/all/c8249725-e91d-4c51-b9bb-40305e61e20d@sirena.org.uk/ Link: https://lkml.kernel.org/r/20250815135549.130506-7-usamaarif642@gmail.com Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yafang <laoar.shao@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftest/mm: extract sz2ord function into vm_util.hUsama Arif
The function already has 2 uses and will have a 3rd one in prctl selftests. The pagesize argument is added into the function, as it's not a global variable anymore. No functional change intended with this patch. Link: https://lkml.kernel.org/r/20250815135549.130506-6-usamaarif642@gmail.com Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Usama Arif <usamaarif642@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yafang <laoar.shao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: skip hugepage-mremap test if userfaultfd unavailableAboorva Devarajan
Gracefully skip test if userfaultfd is not supported (ENOSYS) or not permitted (EPERM), instead of failing. This avoids misleading failures with clear skip messages. -------------- Before Patch -------------- ~ running ./hugepage-mremap ... ~ Bail out! userfaultfd: Function not implemented ~ Planned tests != run tests (1 != 0) ~ Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0 ~ [FAIL] not ok 4 hugepage-mremap # exit=1 -------------- After Patch -------------- ~ running ./hugepage-mremap ... ~ ok 2 # SKIP userfaultfd is not supported/not enabled. ~ 1 skipped test(s) detected. ~ Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0 ~ [SKIP] ok 4 hugepage-mremap # SKIP Link: https://lkml.kernel.org/r/20250816040113.760010-8-aboorvad@linux.ibm.com Co-developed-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: skip thuge-gen test if system is not setup properlyAboorva Devarajan
Make thuge-gen skip instead of fail when it can't run due to system settings. If shmmax is too small or no 1G huge pages are available, the test now prints a warning and is marked as skipped. ------------------- Before Patch: ------------------- ~ running ./thuge-gen ~ Bail out! Please do echo 262144 > /proc/sys/kernel/shmmax ~ Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0 ~ [FAIL] not ok 28 thuge-gen ~ exit=1 ------------------- After Patch: ------------------- ~ running ./thuge-gen ~ ~ WARNING: shmmax is too small to run this test. ~ ~ Please run the following command to increase shmmax: ~ ~ echo 262144 > /proc/sys/kernel/shmmax ~ 1..0 ~ SKIP Test skipped due to insufficient shmmax value. ~ [SKIP] ok 29 thuge-gen ~ SKIP Link: https://lkml.kernel.org/r/20250816040113.760010-7-aboorvad@linux.ibm.com Co-developed-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: fix child process exit codes in ksm_functional_testsAboorva Devarajan
In ksm_functional_tests, test_child_ksm() returned negative values to indicate errors. However, when passed to exit(), these were interpreted as large unsigned values (e.g, -2 became 254), leading to incorrect handling in the parent process. As a result, some tests appeared to be skipped or silently failed. This patch changes test_child_ksm() to return positive error codes (1, 2, 3) and updates test_child_ksm_err() to interpret them correctly. Additionally, test_prctl_fork_exec() now uses exit(4) after a failed execv() to clearly signal exec failures. This ensures the parent accurately detects and reports child process failures. -------------- Before patch: -------------- - [RUN] test_unmerge ok 1 Pages were unmerged ... - [RUN] test_prctl_fork - No pages got merged - [RUN] test_prctl_fork_exec ok 7 PR_SET_MEMORY_MERGE value is inherited ... Bail out! 1 out of 8 tests failed - Planned tests != run tests (9 != 8) - Totals: pass:7 fail:1 xfail:0 xpass:0 skip:0 error:0 -------------- After patch: -------------- - [RUN] test_unmerge ok 1 Pages were unmerged ... - [RUN] test_prctl_fork - No pages got merged not ok 7 Merge in child failed - [RUN] test_prctl_fork_exec ok 8 PR_SET_MEMORY_MERGE value is inherited ... Bail out! 2 out of 9 tests failed - Totals: pass:7 fail:2 xfail:0 xpass:0 skip:0 error:0 Link: https://lkml.kernel.org/r/20250816040113.760010-6-aboorvad@linux.ibm.com Fixes: 6c47de3be3a0 ("selftest/mm: ksm_functional_tests: extend test case for ksm fork/exec") Co-developed-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13mm/selftests: fix split_huge_page_test failure on systems with 64KB page sizeDonet Tom
The split_huge_page_test fails on systems with a 64KB base page size. This is because the order of a 2MB huge page is different: On 64KB systems, the order is 5. On 4KB systems, it's 9. The test currently assumes a maximum huge page order of 9, which is only valid for 4KB base page systems. On systems with 64KB pages, attempting to split huge pages beyond their actual order (5) causes the test to fail. In this patch, we calculate the huge page order based on the system's base page size. With this change, the tests now run successfully on both 64KB and 4KB page size systems. Link: https://lkml.kernel.org/r/20250816040113.760010-5-aboorvad@linux.ibm.com Fixes: fa6c02315f74 ("mm: huge_memory: a new debugfs interface for splitting THP tests") Co-developed-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftest/mm: fix ksm_funtional_test failuresDonet Tom
This patch fixes 2 issues. 1) After fork() in test_prctl_fork, the child process uses the file descriptors from the parent process to read ksm_stat and ksm_merging_pages. This results in incorrect values being read (parent process ksm_stat and ksm_merging_pages will be read in child), causing the test to fail. This patch calls init_global_file_handles() in the child process to ensure that the current process's file descriptors are used to read ksm_stat and ksm_merging_pages. 2) All tests currently call ksm_merge to trigger page merging. To ensure the system remains in a consistent state for subsequent tests, it is better to call ksm_unmerge during the test cleanup phase In the test_prctl_fork test, after a fork(), reading ksm_merging_pages in the child process returns a non-zero value because a previous test performed a merge, and the child's memory state is inherited from the parent. Although the child process calls ksm_unmerge, the ksm_merging_pages counter in the parent is reset to zero, while the child's counter remains unchanged. This discrepancy causes the test to fail. To avoid this issue, each test should call ksm_unmerge during cleanup to ensure the counter is reset and the system is in a clean state for subsequent tests. execv argument is an array of pointers to null-terminated strings. In this patch we also added NULL in the execv argument. Link: https://lkml.kernel.org/r/20250816040113.760010-4-aboorvad@linux.ibm.com Fixes: 6c47de3be3a0 ("selftest/mm: ksm_functional_tests: extend test case for ksm fork/exec") Co-developed-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13selftests/mm: add support to test 4PB VA on PPC64Donet Tom
PowerPC64 supports a 4PB virtual address space, but this test was previously limited to 512TB. This patch extends the coverage up to the full 4PB VA range on PowerPC64. Memory from 0 to 128TB is allocated without an address hint, while allocations from 128TB to 4PB use a hint address. Link: https://lkml.kernel.org/r/20250816040113.760010-3-aboorvad@linux.ibm.com Co-developed-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
generated by cgit (git 2.34.1) at 2026-01-09 11:26:41 +0000