kernel/git/stable/linux.git/lib/test_hmm.c, branch master

Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-08-27T16:17:06+00:00

Pull more MM updates from Andrew Morton: - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff" (Lorenzo Stoakes) Index MAP_PRIVATE file-backed folios by their anonymous page offset to resolve confusion around reverse mapping for zeroed and CoW'd file-backed memory. Use this new VMA anonymous page offset tracking to eliminate index conflicts and lay the foundation for scalable CoW performance improvements. - "promote mapped executable folios after first usage for MGLRU" (Baolin Wang) Make MGLRU's protection of mapped executable file folios more reliable. Follow the classical LRU's logic, promoting mapped executable file folios after their first usage to give executable code a better chance to stay in memory and improve workload performance. - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen) Fix per-node proactive reclaim interface's ignoring the swappiness parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness() into a single function that checks proactive_swappiness regardless of kernel configuration. - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance cost" (Usama Arif) Reduce lru_lock contention in the reclaim path by deriving scan-balance costs from vmstat counters rather than lock-acquired producer updates. Read and decay these cost signals on the reclaim side under a dedicated per-lruvec lock, reducing total LRU lock wait time by over 60% without impacting scan throughput. - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky) Fix two low-risk zram bugs which Sashiko spotted in drive-by review. - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's memcg" (Zi Yan) Fix xas_split_alloc() by enabling target folio memcg charging during splits and adding the missing __GFP_ACCOUNT flag for proper XArray node memory accounting. - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick) Replace hardcoded binary names in selftests/mm/.gitignore with a generic pattern-matching rule to automatically ignore generated test files and avoid manual updates when adding new tests. - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon) Make the incompatibility between FLATMEM and NUMA explicit in mm/Kconfig and remove the unused pgdat_page_ext_init() function. - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang) Clean up zram compression backends by removing redundant error cleanup, adding parameter and dictionary validation, auto-prefixing algorithm error logs, and resetting parameters prior to reinitialization. - "zram: fix stale scan bounds after reinitialization" (Longlong Xia) Prevent out-of-bounds slot accesses during concurrent zram resets by moving table scan bound calculations under dev_lock in writeback_store() and read_block_state(). - "add anon mTHP collapse test cases" (Baolin Wang) Extend selftests helper functions to support arbitrary page orders and add new test cases and options for mTHP collapse in khugepaged. - "selftests/mm: Handle unsupported and transient test conditions" (Muhammad Usama Anjum) Update MM selftests to report a SKIP status instead of a failure when required kernel or filesystem features are unsupported, while adding retry logic for transient page migration errors. - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia) Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled and extend shrink_memcg() to support batch writeback for improved writeback efficiency. - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan) Introduce an IOCTL-based binary interface for memory allocation profiling that enables kernel-side filtering before per-CPU counter aggregation. This eliminates the text-parsing overhead of /proc/allocinfo and provides up to a 20x speedup by transferring only filtered allocation data to userspace. - "better block swap batching and a different take on swap_ops v5" (Christoph Hellwig) Refactor block swap I/O to use swap_iocb for batching instead of single-bio requests and rebase the swap_ops interface, achieving faster swap throughput during kernel builds. - "mm: kmemleak: reduce transient false positives by confirming leaks" (Catalin Marinas) Reduce false-positive kmemleak reports by combining two kmemleak enhancements that add a second confirmation scan and a configurable minimum unreferenced scan count module parameter. - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels" (Breno Leitao) Auto-scanning kernels can generate false-positive memory leak reports on single scans, so this patch defaults min_unref_scans to 2 when CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming scan. - "swap_ops updates" (Christoph Hellwig) Batching I/O for synchronous swap devices causes performance regressions and filesystem-based swap suffers from double-indirection overhead. This series resolves both issues by reintroducing per-folio writes for synchronous swap and allowing filesystems to directly export their own swap_ops. - "mm/khugepaged: several cleanups" (Nico Pache) khugepaged accumulated redundant state-checking patterns and outdated comments following mTHP integration. Introduce dedicated helpers for PTE validation and event counting while refreshing the internal documentation. - "maple_tree: lock checking and clean ups" (Liam Howlett) Syzbot reports incorrectly blame memory management exit paths for locking bugs, maple tree erase operations risk allocation failures without gfp flags and internal documentation lacks clarity. Improve lock error detection, update docs, fix race and allocation edge cases and optimize erase allocations using a fallback to GFP_KERNEL | GFP_NOFAIL. * tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits) selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC memcg: move LRU size accounting on reparenting instead of copying it mm/vmscan: fix comment logic in balance_pgdat maple_tree: add helper mas_make_walkable() maple_tree: avoid extra gap calculation maple_tree: fix argument name in header maple_tree: change two GFP flags in tests maple_tree: document erase and allocations better maple_tree: avoid mas_erase() and mtree_erase() failures maple_tree: document that erase may use GFP_KERNEL for allocations maple_tree: catch race in mas_alloc_cyclic() maple_tree: add bulk parent set helper maple_tree: micro optimisation of mas_wr_store_type() maple_tree: optimise mas_wr_node_store() when not in rcu mode maple_tree: use prefetched value in mas_wr_store_type() maple_tree: clarify comments on mas_nomem() maple_tree: drop MAPLE_ALLOC_SLOTS maple_tree: drop dead code from mas_extend_spanning_null() maple_tree: documentation fix maple_tree: add write lock checking with lockdep sequence numbers ...

lib/test_hmm: fix garbage pfn and wrong direction in devmem fault debug

2026-08-25T01:43:24+00:00

Move pr_debug() inside the `if (dpage)` block to avoid printing garbage pfn for NULL dpage, and correct the direction label from "sys to dev" to "dev to sys". Link: https://lore.kernel.org/20260812092856.55296-1-liuqiangneo@163.com Signed-off-by: Qiang Liu Assisted-by: Qoder:Qwen-3.8-MAX-Preview Cc: Jason Gunthorpe Cc: Leon Romanovsky Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2026-08-22-16-57' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-08-23T15:07:11+00:00

Pull non-MM updates from Andrew Morton: - "ocfs2/dlm: bound peer-controlled lengths in the o2dlm" (Bryam Vargas) Validate and bound all input lengths and count fields in the o2dlm migration and recovery receive handlers to prevent memory corruption and kernel panics from malformed cluster messages - "ocfs2: validate xattr entry bounds" (Cen Zhang) Validate OCFS2 extended attribute entry name and value bounds during metadata reads to prevent out-of-range memory accesses during retrieval or listing operations. - "taskstats: fix cgroupstats invalid fd handling and add selftests" (Yiyang Chen) Return -EBADF when cgroupstats receives an invalid file descriptor to prevent caller hangs and misleading success ACKs. Add a kselftest to validate valid cgroup v1 queries and verify proper error handling across different Netlink flag combinations. - "misc lib/raid/ improvements v2" (Christoph Hellwig) Improve benchmark-based algorithm selection for the XOR and RAID6 libraries, add KUnit benchmark tests, and cleanup minor implementation details. - "ocfs2: cluster: o2hb_region_pin() fixes" (Joseph Qi) Fix sleeping-in-atomic, lock order inversion and error-path cleanup bugs in o2hb_region_pin() by releasing o2hb_live_lock across sleeping configfs_depend_item() calls and using unlocked variants from callback context. Ensure failed pin attempts properly decrement user counts and unpin partially initialized heartbeat regions to prevent memory leaks and unprotected states. - "lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()" (Vincent Mailhol) Fix an off-by-one which could cause an out-of-bounds read. - "ocfs2: harden heartbeat teardown races" (Cen Zhang) Fix two OCFS2 heartbeat/o2net teardown races found by KASAN. - "taskstats: tidy up the cpumask command path" *Bradley Morgan) make two small cleanups in kernel/taskstats.c. - "ocfs2: validate active orphan slots during inode read" (ZhengYuan Huang) Validate active ordinary and append-DIO orphan slots read from OCFS2 dinodes at the metadata boundary to prevent corrupted slot indices from causing out-of-bounds array accesses. - "ocfs2: bound-check both readdir re-validation scans" (Zhan Xusheng) Enforce strict boundary checks on directory entry record lengths and offset calculations during OCFS2 directory re-scans to prevent out-of-bounds memory reads and directory position corruption. * tag 'mm-nonmm-stable-2026-08-22-16-57' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (95 commits) mailmap: fix bouncing address for Taniya Das ocfs2: bound-check dir entries in the inline-data re-validation scan ocfs2: bound-check dir entries in the readdir re-validation scan squashfs: avoid thundering-herd cache wakeups prctl: fix PR_SET_MM_AUXV losing the forced AT_NULL terminator mailmap: update email address for Linfeng Sun lib/interval_tree: fix allocation warning messages checkpatch: add NOKPROBE_SYMBOL to the whitelist of lines that can occur immediately after functions Squashfs: check block offset is not negative signal: factor out the kernel reserved si_code check ocfs2: fix readdir position truncation on 32-bit kernels ocfs2: fix cached cluster count after suballocator reclaim ocfs2: fix circular locking dependency in ocfs2_init_acl() ocfs2: validate DIO orphan slot during inode read ocfs2: validate orphan slot during inode read selftests/prctl: fix non-anonymous VMA mapping in set-anon-vma-name test MAINTAINERS: add IRC and patchwork for LTP include/linux/list.h: mark list_add and __list_add as __always_inline tools/mm: prevent page_owner_sort from truncating input hung_task: update DETECT_HUNG_TASK_BLOCKER Kconfig help ...

lib/test_hmm: remove dead NULL checks after GFP_NOFAIL allocations

2026-08-05T18:20:13+00:00

kvcalloc with the __GFP_NOFAIL flag will never return NULL, so the subsequent NULL checks are unreachable dead code. Remove them. Link: https://lore.kernel.org/20260724022851.466017-6-gouhao@uniontech.com Signed-off-by: Gou Hao Reviewed-by: Alistair Popple Cc: Bharat Potnuri Cc: Cédric Le Goater Cc: Dave Airlie Cc: Jason Gunthorpe Cc: jiazhenyuan Cc: Leon Romanovsky Cc: Maarten Lankhorst Cc: Madhavan Srinivasan Cc: Maxime Ripard Cc: Michael Ellerman Cc: Nam Cao Cc: Nicholas Piggin Cc: Nilay Shroff Cc: Shrikanth Hegde Cc: Thomas Zimemrmann Cc: Wentao Guan Signed-off-by: Andrew Morton

selftests/mm: add HMM test for mmap lock-dropping faults

2026-08-05T02:18:54+00:00

Add test_hmm coverage for the HMM lock-dropping fault path. The test module gets a new HMM_DMIRROR_READ_UNLOCKED ioctl that calls hmm_range_fault_unlocked_timeout() with a timeout of 0, exercising the unbounded retry mode while allowing the mmap lock to be dropped during fault handling. Add a userfaultfd_read selftest that registers an anonymous mapping with UFFDIO_REGISTER_MODE_MISSING, services the faults from a handler thread with UFFDIO_COPY, and verifies that HMM can read back the data supplied by the handler. This exercises the path where handle_mm_fault() drops mmap_lock and hmm_range_fault_unlocked_timeout() restarts the walk internally. Assisted-by: GitHub-Copilot:claude-opus-4.6 Link: https://lore.kernel.org/20260723-hmm-v10-v11-3-c55b003a4b61@gmail.com Signed-off-by: Stanislav Kinsburskii Cc: Danilo Krummrich Cc: Dave Airlie Cc: David Hildenbrand Cc: Dexuan Cui Cc: Haiyang Zhang Cc: Jason Gunthorpe Cc: Jonathan Corbet Cc: K. Y. Srinivasan Cc: Leon Romanovsky Cc: Liam R. Howlett Cc: Lizhi Hou Cc: Long Li Cc: Lorenzo Stoakes Cc: Lyude Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Michal Hocko Cc: Mike Rapoport Cc: Oded Gabbay Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Thomas Zimemrmann Cc: Vlastimil Babka Cc: Wei Liu Signed-off-by: Andrew Morton

lib/test_hmm: fail dmirror_fault() when the mirrored mm is gone

2026-07-31T02:40:31+00:00

dmirror_fault() is called from the dmirror_read() and dmirror_write() retry loops after dmirror_do_read() or dmirror_do_write() finds a missing device page table entry. If the mirrored mm has already exited, mmget_not_zero() fails. The current code returns 0 in that case, which tells the caller that faulting succeeded even though no page was faulted and no device page table entry was installed. The caller then retries the same address, hits -ENOENT again, and can loop forever without making progress. Return -EFAULT instead, so the ioctl fails when the mirrored mm is no longer faultable. Link: https://lore.kernel.org/178294308408.327222.3319445682023999403.stgit@skinsburskii Fixes: b2ef9f5a5cb37 ("mm/hmm/test: add selftest driver for HMM") Signed-off-by: Stanislav Kinsburskii Cc: Jason Gunthorpe Cc: Leon Romanovsky Cc: Ralph Campbell Signed-off-by: Andrew Morton

lib: test_hmm: use device devt for coherent device range selection

2026-07-21T00:41:26+00:00

Commit af69016dab96 ("lib: test_hmm: implement a device release method") moved the initial dmirror_allocate_chunk() call before cdev_device_add(). That means the struct cdev has not been added yet, so cdev_add() has not initialized mdevice->cdevice.dev. The coherent-device range selection uses the device minor to choose between spm_addr_dev0 and spm_addr_dev1. Reading MINOR(mdevice->cdevice.dev) before cdev_add() therefore always sees an uninitialized dev_t. As a result, both coherent devices select the same physical range, and adding the second device fails due to the overlapping dev_pagemap range. Use mdevice->device.devt instead. It is initialized in dmirror_device_init() before dmirror_allocate_chunk() is called and is the same dev_t later passed to cdev_device_add(). Link: https://lore.kernel.org/178277581197.172200.16265155329935822153.stgit@skinsburskii Fixes: af69016dab96 ("lib: test_hmm: implement a device release method") Signed-off-by: Stanislav Kinsburskii Reviewed-by: Alistair Popple Cc: Balbir Singh Cc: Zenghui Yu (Huawei) Cc: Jason Gunthorpe Cc: Leon Romanovsky Cc: Signed-off-by: Andrew Morton

lib/test_hmm: check alloc_page_vma() return value and handle OOM

2026-06-09T01:21:32+00:00

Check alloc_page_vma() return status for page allocation failures, free allocated pages and return VM_FAULT_OOM on error. Handle return codes of dmirror_devmem_fault_alloc_and_copy(), call migrate_vma_finalize() to remove migration entries from migrate_vma_setup(). Link: https://lore.kernel.org/20260521021858.21511-1-liuqiangneo@163.com Signed-off-by: Qiang Liu Cc: Alistair Popple Cc: Jason Gunthorpe Cc: Leon Romanovsky [akpm@linux-foundation.org: fix dmirror_devmem_fault_alloc_and_copy() retval handling] Link: https://lore.kernel.org/oe-kbuild-all/202606011329.zWs2BKy4-lkp@intel.com/ Signed-off-by: Andrew Morton

lib/test_hmm: fix memory leak in dmirror_migrate_to_system()

2026-06-09T01:21:27+00:00

Move the kvcalloc() calls after the early return checks to avoid leaking src_pfns and dst_pfns when end < start or mmget_not_zero() fails. Link: https://lore.kernel.org/20260528011336.20797-1-hao.ge@linux.dev Fixes: 775465fd26a3 ("lib/test_hmm: add zone device private THP test infrastructure") Signed-off-by: Hao Ge Reviewed-by: Alistair Popple Reported-by: Sashiko Reviewed-by: Balbir Singh Cc: Jason Gunthorpe Cc: Leon Romanovsky Signed-off-by: Andrew Morton

lib/test_hmm: fix error path in dmirror_devmem_fault()

2026-06-02T22:22:24+00:00

Handle migrate_vma_setup() failure via goto err for unified cleanup. Link: https://lore.kernel.org/20260515070312.130435-1-liuqiangneo@163.com Signed-off-by: Qiang Liu Reviewed-by: Alistair Popple Cc: Jason Gunthorpe Cc: Leon Romanovsky Signed-off-by: Andrew Morton