kernel/linux.git/fs/proc/task_mmu.c, branch v7.0.10

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

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-hotfixes-stable-2026-02-13-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-13T20:13:27+00:00

Pull MM fixes from Andrew Morton: "Three MM hotfixes, all three are cc:stable" * tag 'mm-hotfixes-stable-2026-02-13-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: procfs: fix possible double mmput() in do_procmap_query() mm/page_alloc: skip debug_check_no_{obj,locks}_freed with FPI_TRYLOCK mm/hugetlb: restore failed global reservations to subpool

procfs: fix possible double mmput() in do_procmap_query()

2026-02-12T23:40:16+00:00

When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY we return with -ENAMETOOLONG error. After recent changes this condition happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(), so original goto out is now wrong and will double-mmput() mm_struct. Fix by jumping further to clean up only vm_file and name_buf. Link: https://lkml.kernel.org/r/20260210192738.3041609-1-andrii@kernel.org Fixes: b5cbacd7f86f ("procfs: avoid fetching build ID while holding VMA lock") Signed-off-by: Andrii Nakryiko Reported-by: Ruikai Peng Reported-by: Thomas Gleixner Tested-by: Thomas Gleixner Reviewed-by: Shakeel Butt Reported-by: syzbot+237b5b985b78c1da9600@syzkaller.appspotmail.com Cc: Ruikai Peng Closes: https://lkml.kernel.org/r/CAFD3drOJANTZPuyiqMdqpiRwOKnHwv5QgMNZghCDr-WxdiHvMg@mail.gmail.com Closes: https://lore.kernel.org/all/698aaf3c.050a0220.3b3015.0088.GAE@google.com/T/#u Cc: Signed-off-by: Andrew Morton

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 ...

procfs: avoid fetching build ID while holding VMA lock

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

Fix PROCMAP_QUERY to fetch optional build ID only after dropping mmap_lock or per-VMA lock, whichever was used to lock VMA under question, to avoid deadlock reported by syzbot: -> #1 (&mm->mmap_lock){++++}-{4:4}: __might_fault+0xed/0x170 _copy_to_iter+0x118/0x1720 copy_page_to_iter+0x12d/0x1e0 filemap_read+0x720/0x10a0 blkdev_read_iter+0x2b5/0x4e0 vfs_read+0x7f4/0xae0 ksys_read+0x12a/0x250 do_syscall_64+0xcb/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sb->s_type->i_mutex_key#8){++++}-{4:4}: __lock_acquire+0x1509/0x26d0 lock_acquire+0x185/0x340 down_read+0x98/0x490 blkdev_read_iter+0x2a7/0x4e0 __kernel_read+0x39a/0xa90 freader_fetch+0x1d5/0xa80 __build_id_parse.isra.0+0xea/0x6a0 do_procmap_query+0xd75/0x1050 procfs_procmap_ioctl+0x7a/0xb0 __x64_sys_ioctl+0x18e/0x210 do_syscall_64+0xcb/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&mm->mmap_lock); lock(&sb->s_type->i_mutex_key#8); lock(&mm->mmap_lock); rlock(&sb->s_type->i_mutex_key#8); *** DEADLOCK *** This seems to be exacerbated (as we haven't seen these syzbot reports before that) by the recent: 777a8560fd29 ("lib/buildid: use __kernel_read() for sleepable context") To make this safe, we need to grab file refcount while VMA is still locked, but other than that everything is pretty straightforward. Internal build_id_parse() API assumes VMA is passed, but it only needs the underlying file reference, so just add another variant build_id_parse_file() that expects file passed directly. [akpm@linux-foundation.org: fix up kerneldoc] Link: https://lkml.kernel.org/r/20260129215340.3742283-1-andrii@kernel.org Fixes: ed5d583a88a9 ("fs/procfs: implement efficient VMA querying API for /proc//maps") Signed-off-by: Andrii Nakryiko Reported-by: Reviewed-by: Suren Baghdasaryan Tested-by: Suren Baghdasaryan Reviewed-by: Shakeel Butt Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Eduard Zingerman Cc: Hao Luo Cc: Jiri Olsa Cc: John Fastabend Cc: KP Singh Cc: Martin KaFai Lau Cc: Song Liu Cc: Stanislav Fomichev Cc: Yonghong Song Cc: Signed-off-by: Andrew Morton

mm: introduce generic lazy_mmu helpers

2026-01-21T03:24:33+00:00

The implementation of the lazy MMU mode is currently entirely arch-specific; core code directly calls arch helpers: arch_{enter,leave}_lazy_mmu_mode(). We are about to introduce support for nested lazy MMU sections. As things stand we'd have to duplicate that logic in every arch implementing lazy_mmu - adding to a fair amount of logic already duplicated across lazy_mmu implementations. This patch therefore introduces a new generic layer that calls the existing arch_* helpers. Two pair of calls are introduced: * lazy_mmu_mode_enable() ... lazy_mmu_mode_disable() This is the standard case where the mode is enabled for a given block of code by surrounding it with enable() and disable() calls. * lazy_mmu_mode_pause() ... lazy_mmu_mode_resume() This is for situations where the mode is temporarily disabled by first calling pause() and then resume() (e.g. to prevent any batching from occurring in a critical section). The documentation in will be updated in a subsequent patch. No functional change should be introduced at this stage. The implementation of enable()/resume() and disable()/pause() is currently identical, but nesting support will change that. Most of the call sites have been updated using the following Coccinelle script: @@ @@ { ... - arch_enter_lazy_mmu_mode(); + lazy_mmu_mode_enable(); ... - arch_leave_lazy_mmu_mode(); + lazy_mmu_mode_disable(); ... } @@ @@ { ... - arch_leave_lazy_mmu_mode(); + lazy_mmu_mode_pause(); ... - arch_enter_lazy_mmu_mode(); + lazy_mmu_mode_resume(); ... } A couple of notes regarding x86: * Xen is currently the only case where explicit handling is required for lazy MMU when context-switching. This is purely an implementation detail and using the generic lazy_mmu_mode_* functions would cause trouble when nesting support is introduced, because the generic functions must be called from the current task. For that reason we still use arch_leave() and arch_enter() there. * x86 calls arch_flush_lazy_mmu_mode() unconditionally in a few places, but only defines it if PARAVIRT_XXL is selected, and we are removing the fallback in . Add a new fallback definition to to keep things building. Link: https://lkml.kernel.org/r/20251215150323.2218608-8-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Acked-by: David Hildenbrand Reviewed-by: Anshuman Khandual Reviewed-by: Yeoreum Yun Cc: Alexander Gordeev Cc: Andreas Larsson Cc: Borislav Betkov Cc: Boris Ostrovsky Cc: Catalin Marinas Cc: Christophe Leroy Cc: David Hildenbrand (Red Hat) Cc: David S. Miller Cc: David Woodhouse Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jann Horn Cc: Juegren Gross Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Ritesh Harjani (IBM) Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Thomas Gleinxer Cc: Venkat Rao Bagalkote Cc: Vlastimil Babka Cc: Will Deacon Signed-off-by: Andrew Morton

fs/proc/task_mmu.c: fix make_uffd_wp_huge_pte() huge pte handling

2025-11-29T18:41:10+00:00

make_uffd_wp_huge_pte() should return after handling a huge_pte_none() pte. Link: https://lkml.kernel.org/r/66178124-ebdf-4e23-b8ca-ed3eb8030c81@lucifer.local Fixes: 03bfbc3ad6e4 ("mm: remove is_hugetlb_entry_[migration, hwpoisoned]()") Signed-off-by: Lorenzo Stoakes Reported-by: Vlastimil Babka Closes: https://lkml.kernel.org/r/dc483db3-be4d-45f7-8b40-a28f5d8f5738@suse.cz Signed-off-by: Andrew Morton

mm: declare VMA flags by bit

2025-11-29T18:41:08+00:00

Patch series "initial work on making VMA flags a bitmap", v3. We are in the rather silly situation that we are running out of VMA flags as they are currently limited to a system word in size. This leads to absurd situations where we limit features to 64-bit architectures only because we simply do not have the ability to add a flag for 32-bit ones. This is very constraining and leads to hacks or, in the worst case, simply an inability to implement features we want for entirely arbitrary reasons. This also of course gives us something of a Y2K type situation in mm where we might eventually exhaust all of the VMA flags even on 64-bit systems. This series lays the groundwork for getting away from this limitation by establishing VMA flags as a bitmap whose size we can increase in future beyond 64 bits if required. This is necessarily a highly iterative process given the extensive use of VMA flags throughout the kernel, so we start by performing basic steps. Firstly, we declare VMA flags by bit number rather than by value, retaining the VM_xxx fields but in terms of these newly introduced VMA_xxx_BIT fields. While we are here, we use sparse annotations to ensure that, when dealing with VMA bit number parameters, we cannot be passed values which are not declared as such - providing some useful type safety. We then introduce an opaque VMA flag type, much like the opaque mm_struct flag type introduced in commit bb6525f2f8c4 ("mm: add bitmap mm->flags field"), which we establish in union with vma->vm_flags (but still set at system word size meaning there is no functional or data type size change). We update the vm_flags_xxx() helpers to use this new bitmap, introducing sensible helpers to do so. This series lays the foundation for further work to expand the use of bitmap VMA flags and eventually eliminate these arbitrary restrictions. This patch (of 4): In order to lay the groundwork for VMA flags being a bitmap rather than a system word in size, we need to be able to consistently refer to VMA flags by bit number rather than value. Take this opportunity to do so in an enum which we which is additionally useful for tooling to extract metadata from. This additionally makes it very clear which bits are being used for what at a glance. We use the VMA_ prefix for the bit values as it is logical to do so since these reference VMAs. We consistently suffix with _BIT to make it clear what the values refer to. We declare bit values even when the flags that use them would not be enabled by config options as this is simply clearer and clearly defines what bit numbers are used for what, at no additional cost. We declare a sparse-bitwise type vma_flag_t which ensures that users can't pass around invalid VMA flags by accident and prepares for future work towards VMA flags being a bitmap where we want to ensure bit values are type safe. To make life easier, we declare some macro helpers - DECLARE_VMA_BIT() allows us to avoid duplication in the enum bit number declarations (and maintaining the sparse __bitwise attribute), and INIT_VM_FLAG() is used to assist with declaration of flags. Unfortunately we can't declare both in the enum, as we run into issue with logic in the kernel requiring that flags are preprocessor definitions, and additionally we cannot have a macro which declares another macro so we must define each flag macro directly. Additionally, update the VMA userland testing vma_internal.h header to include these changes. We also have to fix the parameters to the vma_flag_*_atomic() functions since VMA_MAYBE_GUARD_BIT is now of type vma_flag_t and sparse will complain otherwise. We have to update some rather silly if-deffery found in mm/task_mmu.c which would otherwise break. Finally, we update the rust binding helper as now it cannot auto-detect the flags at all. Link: https://lkml.kernel.org/r/cover.1764064556.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/3a35e5a0bcfa00e84af24cbafc0653e74deda64a.1764064556.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Acked-by: Vlastimil Babka Reviewed-by: Pedro Falcato Acked-by: Alice Ryhl [rust] Cc: Alex Gaynor Cc: Alistair Popple Cc: Andreas Hindborg Cc: Axel Rasmussen Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Ben Segall Cc: Björn Roy Baron Cc: Boqun Feng Cc: Byungchul Park Cc: Chengming Zhou Cc: Chris Li Cc: Danilo Krummrich Cc: David Hildenbrand Cc: David Rientjes Cc: Dev Jain Cc: Dietmar Eggemann Cc: Gary Guo Cc: Gregory Price Cc: "Huang, Ying" Cc: Ingo Molnar Cc: Jann Horn Cc: Jason Gunthorpe Cc: Johannes Weiner Cc: John Hubbard Cc: Joshua Hahn Cc: Juri Lelli Cc: Kairui Song Cc: Kees Cook Cc: Kemeng Shi Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam Howlett Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Mel Gorman Cc: Michal Hocko Cc: Miguel Ojeda Cc: Mike Rapoport Cc: Muchun Song Cc: Nhat Pham Cc: Nico Pache Cc: Oscar Salvador Cc: Peter Xu Cc: Peter Zijlstra Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Ryan Roberts Cc: Shakeel Butt Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Trevor Gross Cc: Valentin Schneider Cc: Vincent Guittot Cc: Wei Xu Cc: xu xin Cc: Yuanchu Xie Cc: Zi Yan Signed-off-by: Andrew Morton

mm: softdirty: add pgtable_supports_soft_dirty()

2025-11-24T23:08:54+00:00

Patch series "mm: Add soft-dirty and uffd-wp support for RISC-V", v15. This patchset adds support for Svrsw60t59b [1] extension which is ratified now, also add soft dirty and userfaultfd write protect tracking for RISC-V. The patches 1 and 2 add macros to allow architectures to define their own checks if the soft-dirty / uffd_wp PTE bits are available, in other words for RISC-V, the Svrsw60t59b extension is supported on which device the kernel is running. Also patch1-2 are removing "ifdef CONFIG_MEM_SOFT_DIRTY" "ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP" and "ifdef CONFIG_PTE_MARKER_UFFD_WP" in favor of checks which if not overridden by the architecture, no change in behavior is expected. This patchset has been tested with kselftest mm suite in which soft-dirty, madv_populate, test_unmerge_uffd_wp, and uffd-unit-tests run and pass, and no regressions are observed in any of the other tests. This patch (of 6): Some platforms can customize the PTE PMD entry soft-dirty bit making it unavailable even if the architecture provides the resource. Add an API which architectures can define their specific implementations to detect if soft-dirty bit is available on which device the kernel is running. This patch is removing "ifdef CONFIG_MEM_SOFT_DIRTY" in favor of pgtable_supports_soft_dirty() checks that defaults to IS_ENABLED(CONFIG_MEM_SOFT_DIRTY), if not overridden by the architecture, no change in behavior is expected. We make sure to never set VM_SOFTDIRTY if !pgtable_supports_soft_dirty(), so we will never run into VM_SOFTDIRTY checks. [lorenzo.stoakes@oracle.com: fix VMA selftests] Link: https://lkml.kernel.org/r/dac6ddfe-773a-43d5-8f69-021b9ca4d24b@lucifer.local Link: https://lkml.kernel.org/r/20251113072806.795029-1-zhangchunyan@iscas.ac.cn Link: https://lkml.kernel.org/r/20251113072806.795029-2-zhangchunyan@iscas.ac.cn Link: https://github.com/riscv-non-isa/riscv-iommu/pull/543 [1] Signed-off-by: Chunyan Zhang Acked-by: David Hildenbrand Cc: Albert Ou Cc: Alexandre Ghiti Cc: Al Viro Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Christian Brauner Cc: Conor Dooley Cc: Deepak Gupta Cc: Jan Kara Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Xu Cc: Rob Herring Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yuanchu Xie Cc: Alexandre Ghiti Cc: Andrew Jones Cc: Conor Dooley Signed-off-by: Andrew Morton