kernel/linux.git/mm/memory-failure.c, branch v7.2-rc1

mm/memory-failure: use zone_pcp_disable() for poison handling

2026-06-02T22:22:33+00:00

__page_handle_poison() used drain_all_pages() instead of zone_pcp_disable() because dissolve_free_hugetlb_folio() could restore HVO vmemmap pages and decrement hugetlb_optimize_vmemmap_key. That static key update took cpu_hotplug_lock through static_key_slow_dec(), while zone_pcp_disable() holds pcp_batch_high_lock. CPU hotplug takes the locks in the opposite order through page_alloc_cpu_online/dead(), so the combination could deadlock. That dependency no longer exists. Commit da3e2d1ca43d ("mm/hugetlb: remove hugetlb_optimize_vmemmap_key static key") removed the HVO static key and the static_branch_dec() from hugetlb_vmemmap_restore_folio(). The dissolve_free_hugetlb_folio() path no longer reaches static_key_slow_dec(). Use zone_pcp_disable() again while dissolving the hugetlb folio and taking the target page off the buddy allocator. This prevents the drained PCP lists from being refilled before take_page_off_buddy() runs, making the page isolation deterministic. Link: https://lore.kernel.org/20260514085754.84097-1-kaitao.cheng@linux.dev Signed-off-by: Kaitao Cheng Reviewed-by: Oscar Salvador Acked-by: Miaohe Lin Cc: Naoya Horiguchi Signed-off-by: Andrew Morton

mm/memory-failure: remove hugetlb output parameter from try_memory_failure_hugetlb()

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

Use -ENOENT return value to distinguish "not a hugetlb page" from "hugetlb handled", instead of carrying an extra output parameter. Link: https://lore.kernel.org/20260515020144.164941-1-ye.liu@linux.dev Signed-off-by: Ye Liu Suggested-by: Oscar Salvador Acked-by: Miaohe Lin Acked-by: Oscar Salvador (SUSE) Cc: Naoya Horiguchi Signed-off-by: Andrew Morton

Merge branch 'mm-hotfixes-stable' into mm-stable to pick up the series

2026-06-02T22:06:49+00:00

"userfaultfd: verify VMA state across UFFDIO_COPY retry", which is a prerequisite for mm-unnstable's series "userfaultfd: merge fs/userfaultfd.c into mm/userfaultfd.c".

mm/memory-failure: replace magic number 3 with GET_PAGE_MAX_RETRY_NUM

2026-05-29T04:04:51+00:00

Replace the hardcoded magic number 3 in get_any_page() with the existing GET_PAGE_MAX_RETRY_NUM macro for code consistency and maintainability. This change has no functional impact, only improves code readability and unifies the retry limit configuration. Link: https://lore.kernel.org/20260402064946.1124250-1-18810879172@163.com Signed-off-by: wangxuewen Acked-by: SeongJae Park Acked-by: Miaohe Lin Cc: Naoya Horiguchi Signed-off-by: Andrew Morton

mm/memory-failure: use bool for forcekill state

2026-05-29T04:04:49+00:00

'forcekill' is used as a boolean flag to control whether processes should be forcibly killed. It is only assigned from boolean expressions and never used in arithmetic or bitmask operations. Convert it from int to bool. No functional change intended. Link: https://lore.kernel.org/20260410074740.2524718-1-ye.liu@linux.dev Signed-off-by: Ye Liu Reviewed-by: SeongJae Park Acked-by: Miaohe Lin Cc: Liu Ye Cc: Naoya Horiguchi Signed-off-by: Andrew Morton

mm/memory-failure: fix hugetlb_lock AA deadlock in get_huge_page_for_hwpoison

2026-05-29T03:50:34+00:00

Two concurrent madvise(MADV_HWPOISON) calls on the same hugetlb page can trigger a recursive spinlock self-deadlock (AA deadlock) on hugetlb_lock when racing with a concurrent unmap: thread#0 thread#1 -------- -------- madvise(folio, MADV_HWPOISON) -> poisons the folio successfully madvise(folio, MADV_HWPOISON) unmap(folio) try_memory_failure_hugetlb get_huge_page_for_hwpoison spin_lock_irq(&hugetlb_lock) <- held __get_huge_page_for_hwpoison hugetlb_update_hwpoison() -> MF_HUGETLB_FOLIO_PRE_POISONED goto out: folio_put() refcount: 1 -> 0 free_huge_folio() spin_lock_irqsave(&hugetlb_lock) -> AA DEADLOCK! The out: path in __get_huge_page_for_hwpoison() calls folio_put() to drop the GUP reference while the hugetlb_lock is still held by the hugetlb.c wrapper get_huge_page_for_hwpoison(). If concurrent unmap has released the page table mapping reference, folio_put() drops the folio refcount to zero, triggering free_huge_folio() which attempts to re-acquire the non-recursive hugetlb_lock. Fix this by moving hugetlb_lock acquisition from the hugetlb.c wrapper into get_huge_page_for_hwpoison(). Place spin_unlock_irq() before the folio_put() at the out: label so the folio is always released outside the lock. [akpm@linux-foundation.org: fix race, rename label per Miaohe] Link: https://sashiko.dev/#/patchset/20260522010305.4099834-1-mawupeng1@huawei.com Link: https://lore.kernel.org/f39f405e-4b4b-8f79-70fe-a2b5b62114eb@huawei.com Link: https://lore.kernel.org/20260522010305.4099834-1-mawupeng1@huawei.com Fixes: 405ce051236c ("mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb()") Signed-off-by: Wupeng Ma Acked-by: Oscar Salvador (SUSE) Acked-by: Muchun Song Reviewed-by: Kefeng Wang Acked-by: Miaohe Lin Cc: David Hildenbrand Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Naoya Horiguchi Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-12T19:32:37+00:00

Pull MM updates from Andrew Morton: - "powerpc/64s: do not re-activate batched TLB flush" makes arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev) It adds a generic enter/leave layer and switches architectures to use it. Various hacks were removed in the process. - "zram: introduce compressed data writeback" implements data compression for zram writeback (Richard Chang and Sergey Senozhatsky) - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous page ranges for hugepages. Large improvements during demand faulting are demonstrated (David Hildenbrand) - "memcg cleanups" tidies up some memcg code (Chen Ridong) - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats" improves DAMOS stat's provided information, deterministic control, and readability (SeongJae Park) - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few issues in the hugetlb cgroup charging selftests (Li Wang) - "Fix va_high_addr_switch.sh test failure - again" addresses several issues in the va_high_addr_switch test (Chunyu Hu) - "mm/damon/tests/core-kunit: extend existing test scenarios" improves the KUnit test coverage for DAMON (Shu Anzai) - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN (Shivank Garg) - "arch, mm: consolidate hugetlb early reservation" reworks and consolidates a pile of straggly code related to reservation of hugetlb memory from bootmem and creation of CMA areas for hugetlb (Mike Rapoport) - "mm: clean up anon_vma implementation" cleans up the anon_vma implementation in various ways (Lorenzo Stoakes) - "tweaks for __alloc_pages_slowpath()" does a little streamlining of the page allocator's slowpath code (Vlastimil Babka) - "memcg: separate private and public ID namespaces" cleans up the memcg ID code and prevents the internal-only private IDs from being exposed to userspace (Shakeel Butt) - "mm: hugetlb: allocate frozen gigantic folio" cleans up the allocation of frozen folios and avoids some atomic refcount operations (Kefeng Wang) - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement of memory betewwn the active and inactive LRUs and adds auto-tuning of the ratio-based quotas and of monitoring intervals (SeongJae Park) - "Support page table check on PowerPC" makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan) - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes nodes_and() and nodes_andnot() propagate the return values from the underlying bit operations, enabling some cleanup in calling code (Yury Norov) - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up some DAMON internal interfaces (SeongJae Park) - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work in khupaged and fixes a scan limit accounting issue (Shivank Garg) - "mm: balloon infrastructure cleanups" goes to town on the balloon infrastructure and its page migration function. Mainly cleanups, also some locking simplification (David Hildenbrand) - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds additional tracepoints to the page reclaim code (Jiayuan Chen) - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is part of Marco's kernel-wide migration from the legacy workqueue APIs over to the preferred unbound workqueues (Marco Crivellari) - "Various mm kselftests improvements/fixes" provides various unrelated improvements/fixes for the mm kselftests (Kevin Brodsky) - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic folio allocation, mainly by avoiding unnecessary work in pfn_range_valid_contig() (Kefeng Wang) - "selftests/damon: improve leak detection and wss estimation reliability" improves the reliability of two of the DAMON selftests (SeongJae Park) - "mm/damon: cleanup kdamond, damon_call(), damos filter and DAMON_MIN_REGION" does some cleanup work in the core DAMON code (SeongJae Park) - "Docs/mm/damon: update intro, modules, maintainer profile, and misc" performs maintenance work on the DAMON documentation (SeongJae Park) - "mm: add and use vma_assert_stabilised() helper" refactors and cleans up the core VMA code. The main aim here is to be able to use the mmap write lock's lockdep state to perform various assertions regarding the locking which the VMA code requires (Lorenzo Stoakes) - "mm, swap: swap table phase II: unify swapin use" removes some old swap code (swap cache bypassing and swap synchronization) which wasn't working very well. Various other cleanups and simplifications were made. The end result is a 20% speedup in one benchmark (Kairui Song) - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM available on 64-bit alpha, loongarch, mips, parisc, and um. Various cleanups were performed along the way (Qi Zheng) * tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits) mm/memory: handle non-split locks correctly in zap_empty_pte_table() mm: move pte table reclaim code to memory.c mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config um: mm: enable MMU_GATHER_RCU_TABLE_FREE parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE mips: mm: enable MMU_GATHER_RCU_TABLE_FREE LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles zsmalloc: make common caches global mm: add SPDX id lines to some mm source files mm/zswap: use %pe to print error pointers mm/vmscan: use %pe to print error pointers mm/readahead: fix typo in comment mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file() mm: refactor vma_map_pages to use vm_insert_pages mm/damon: unify address range representation with damon_addr_range mm/cma: replace snprintf with strscpy in cma_new_area ...

mm/memory-failure: reject unsupported non-folio compound page

2026-02-05T22:10:00+00:00

When !CONFIG_TRANSPARENT_HUGEPAGE, a non-folio compound page can appear in a userspace mapping via either vm_insert_*() functions or vm_operatios_struct->fault(). They are not folios, thus should not be considered for folio operations like split. To reject these pages, make sure get_hwpoison_page() is always called as HWPoisonHandlable() will do the right work. [Some commit log borrowed from Zi Yan. Thanks.] Link: https://lkml.kernel.org/r/20260205075328.523211-1-linmiaohe@huawei.com Fixes: 689b8986776c ("mm/memory-failure: improve large block size folio handling") Signed-off-by: Miaohe Lin Reported-by: 是参差 Closes: https://lore.kernel.org/all/PS1PPF7E1D7501F1E4F4441E7ECD056DEADAB98A@PS1PPF7E1D7501F.apcprd02.prod.outlook.com/ Reviewed-by: Zi Yan Tested-by: Zi Yan Cc: David Hildenbrand Cc: Jane Chu Cc: Miaohe Lin Cc: Naoya Horiguchi Signed-off-by: Andrew Morton

Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm/shmem,

2026-01-31T22:20:03+00:00

swap: fix race of truncate and swap entry split", needed for merging "mm, swap: cleanup swap entry management workflow".