kernel/linux.git/tools/testing/selftests/mm, branch v6.19.11

selftests/mm/charge_reserved_hugetlb: drop mount size for hugetlbfs

2026-03-04T12:21:20+00:00

[ Upstream commit 1aa1dd9cc595917882fb6db67725442956f79607 ] 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: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests") Signed-off-by: Li Wang Acked-by: David Hildenbrand (Red Hat) Acked-by: Waiman Long Cc: Mark Brown Cc: Shuah Khan Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

selftests/mm: fix usage of FORCE_READ() in cow tests

2026-02-26T23:01:09+00:00

[ Upstream commit bce1dabd310e87fefe0645fec9ba98b84d37e418 ] Commit 5bbc2b785e63 ("selftests/mm: fix FORCE_READ to read input value correctly") modified FORCE_READ() to take a value instead of a pointer. It also changed most of the call sites accordingly, but missed many of them in cow.c. In those cases, we ended up with the pointer itself being read, not the memory it points to. No failure occurred as a result, so it looks like the tests work just fine without faulting in. However, the huge_zeropage tests explicitly check that pages are populated, so those became skipped. Convert all the remaining FORCE_READ() to fault in the mapped page, as was originally intended. This allows the huge_zeropage tests to run again (3 tests in total). Link: https://lkml.kernel.org/r/20260122170224.4056513-5-kevin.brodsky@arm.com Fixes: 5bbc2b785e63 ("selftests/mm: fix FORCE_READ to read input value correctly") Signed-off-by: Kevin Brodsky Acked-by: SeongJae Park Reviewed-by: wang lian Acked-by: David Hildenbrand (Red Hat) Reviewed-by: Dev Jain Cc: Jason Gunthorpe Cc: John Hubbard Cc: Lorenzo Stoakes Cc: Mark Brown Cc: Paolo Abeni Cc: Ryan Roberts Cc: Shuah Khan Cc: Usama Anjum Cc: Yunsheng Lin Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

tools/testing/selftests: fix gup_longterm for unknown fs

2026-01-15T06:16:26+00:00

Commit 66bce7afbaca ("selftests/mm: fix test result reporting in gup_longterm") introduced a small bug causing unknown filesystems to always result in a test failure. This is because do_test() was updated to use a common reporting path, but this case appears to have been missed. This is problematic for e.g. virtme-ng which uses an overlayfs file system, causing gup_longterm to appear to fail each time due to a test count mismatch: # Planned tests != run tests (50 != 46) # Totals: pass:24 fail:0 xfail:0 xpass:0 skip:22 error:0 The fix is to simply change the return into a break. Link: https://lkml.kernel.org/r/20260106154547.214907-1-lorenzo.stoakes@oracle.com Fixes: 66bce7afbaca ("selftests/mm: fix test result reporting in gup_longterm") Signed-off-by: Lorenzo Stoakes Reviewed-by: David Hildenbrand (Red Hat) Cc: Jason Gunthorpe Cc: John Hubbard Cc: Liam Howlett Cc: "Liam R. Howlett" Cc: Mark Brown Cc: Michal Hocko Cc: Mike Rapoport Cc: Peter Xu Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton

tools/testing/selftests: add forked (un)/faulted VMA merge tests

2026-01-15T06:16:25+00:00

Now we correctly handle forked faulted/unfaulted merge on mremap(), exhaustively assert that we handle this correctly. Do this in the less duplicative way by adding a new merge_with_fork fixture and forked/unforked variants, and abstract the forking logic as necessary to avoid code duplication with this also. Link: https://lkml.kernel.org/r/1daf76d89fdb9d96f38a6a0152d8f3c2e9e30ac7.1767638272.git.lorenzo.stoakes@oracle.com Fixes: 879bca0a2c4f ("mm/vma: fix incorrectly disallowed anonymous VMA merges") Signed-off-by: Lorenzo Stoakes Cc: David Hildenbrand (Red Hat) Cc: Jann Horn Cc: Jeongjun Park Cc: Liam Howlett Cc: Pedro Falcato Cc: Rik van Riel Cc: Vlastimil Babka Cc: Yeoreum Yun Cc: Harry Yoo Cc: Signed-off-by: Andrew Morton

tools/testing/selftests: add tests for !tgt, src mremap() merges

2026-01-15T06:16:24+00:00

Test that mremap()'ing a VMA into a position such that the target VMA on merge is unfaulted and the source faulted is correctly performed. We cover 4 cases: 1. Previous VMA unfaulted: copied -----| v |-----------|.............| | unfaulted |(faulted VMA)| |-----------|.............| prev target = prev, expand prev to cover. 2. Next VMA unfaulted: copied -----| v |.............|-----------| |(faulted VMA)| unfaulted | |.............|-----------| next target = next, expand next to cover. 3. Both adjacent VMAs unfaulted: copied -----| v |-----------|.............|-----------| | unfaulted |(faulted VMA)| unfaulted | |-----------|.............|-----------| prev next target = prev, expand prev to cover. 4. prev unfaulted, next faulted: copied -----| v |-----------|.............|-----------| | unfaulted |(faulted VMA)| faulted | |-----------|.............|-----------| prev next target = prev, expand prev to cover. Essentially equivalent to 3, but with additional requirement that next's anon_vma is the same as the copied VMA's. Each of these are performed with MREMAP_DONTUNMAP set, which will cause a KASAN assert for UAF or an assert on zero refcount anon_vma if a bug exists with correctly propagating anon_vma state in each scenario. Link: https://lkml.kernel.org/r/f903af2930c7c2c6e0948c886b58d0f42d8e8ba3.1767638272.git.lorenzo.stoakes@oracle.com Fixes: 879bca0a2c4f ("mm/vma: fix incorrectly disallowed anonymous VMA merges") Signed-off-by: Lorenzo Stoakes Cc: David Hildenbrand (Red Hat) Cc: Jann Horn Cc: Jeongjun Park Cc: Liam Howlett Cc: Pedro Falcato Cc: Rik van Riel Cc: Vlastimil Babka Cc: Yeoreum Yun Cc: Harry Yoo Cc: Signed-off-by: Andrew Morton

selftests/mm: fix thread state check in uffd-unit-tests

2025-12-23T19:23:14+00:00

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 Acked-by: Peter Xu Reviewed-by: Mike Rapoport (Microsoft) Cc: Bill Wendling Cc: Justin Stitt Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Nathan Chancellor Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-12-06T22:01:20+00:00

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 ...

selftests/mm/uffd: initialize char variable to Null

2025-11-29T18:41:09+00:00

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 Reviewed-by: Mike Rapoport (Microsoft) Cc: Bill Wendling Cc: Justin Stitt Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Nathan Chancellor Cc: Peter Xu Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests: complete kselftest include centralization

2025-11-27T22:24:31+00:00

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 Suggested-by: Andrew Morton Link: https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/ Reviewed-by: Wei Yang Cc: David Hildenbrand Cc: David S. Miller Cc: Eric Dumazet Cc: Günther Noack Cc: Jakub Kacinski Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mickael Salaun Cc: Ming Lei Cc: Paolo Abeni Cc: Shuah Khan Cc: Simon Horman Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/mm: gup_test: fix comment regarding origin of FOLL_WRITE

2025-11-24T23:08:53+00:00

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 Reviewed-by: John Hubbard Reviewed-by: David Hildenbrand (Red Hat) Cc: Dan Williams Cc: Jason Gunthorpe Cc: Oscar Salvador Cc: Peter Xu Signed-off-by: Andrew Morton