Linux kernel stable tree https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=master 2026-08-25T18:48:04+00:00 2026-08-25T18:48:04+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-25T18:48:04+00:00 urn:sha1:7bb6284aa7b3c369b41e7f33fcbe193161f008e7 Pull kvm updates from Paolo Bonzini: "ARM64: - Add support for 'slot' based PMU events, paired with new UAPI that compels the user to select a specific PMU implementation - Lazy save/restore of vCPU state for pKVM, along with various fixes and cleanups to the management of vCPU state between the untrusted host and pKVM hypervisor - Disable traps of EL1 registers for nested hypervisors when FEAT_NV2p1 is present, guaranteeing that EL2-specific register bits are stateful in the EL1 counterpart - Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the scope of those instructions remains 'in host' (i.e. L1 kernel/userspace) - Pile of fixes for the management of the VNCR pseudo-TLB, such as under-invalidations and races with concurrent TLBIs on other vCPUs - Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a runtime-patched constant, allowing the same data to be shared with pKVM prior to dropping host privileges - Considerable pile of LLM-assisted fixes around the shop but mostly in the VGIC, our in-kernel generator of bugs (and sometimes interrupts) LoongArch: - Advertise already-supported capabilities - Some bug fixes about timer and MMIO - Some hardening about interrupt injection - Replace kvm_err() with kvm_pr_unimpl() - Add FPU/LSX/LASX test cases for selftests RISC-V: - Svadu/Zicfiss/Zicfilp FWFT support for Guest - Use try_cmpxchg for IMSIC MRIF RMW - More arch-specific tracepoints in KVM RISC-V - Eager page splitting when enabling dirty logging - Optimize hfence request handling for SMP Guests - Improve dirty log clearing by skipping zero bits in mask - Guard HFENCE range loops against overflow - CPU PM notifiers in KVM RISC-V for non-retentive idle states - Fix kernel-mode vector context save/restore for Guest s390: - Fixes for vfio-ap - Fixes for the gmap rework - Fixes for vsie - AI triggered fixes all over - diag9c tracing - code move preparation for the additional arm64 support - enable CONTEXT_ANALYSIS x86: - Perform spring cleaning on x86.{c,h} and asm/kvm_host.h, by adding regs.c (the kvm_cache_regs.h => regs.h is already applied) and msrs.{c,h}, and moving relevant code out of x86.c - Split kvm_mmu in three parts, respectively to describe the format of page tables, walking the guest page tables and building the page tables. Always use the same page table walker kvm->arch.gva_walk as the entry point to convert a guest's virtual address, where the previous code used two different kvm_mmu structs depending on whether the walk included nested EPT/NPT or not. Make page fault vmexits reuse the permission checking machinery that is used for guest page faults. This is both a cleanup and a baby step towards supporting XS/XU memory permissions - Document some of the "fun" gotchas with the APIC base when creating IRQCHIPs on x86 - Remove a defunct masterclock update from kvm_xen_shared_info_init(). It could result in incorrect kvmclock due to triggering an unnecessary switch to/from masterclock mode - Skip Xen runstate time updates if time has effectively gone backwards, so that the guest doesn't report 100% steal time for a very, very long time - Drop KVM's runtime updates of the Xen PV timing CPUID leaf, as KVM was updating the wrong sub-leaf, and upstream KVM will soon provide all the information needed by userspace to populate the CPUID field itself - Fix a bug where KVM would walk a newly created rmap without holding the rmap lock (or mmu_lock) during aging - Fix a bug where aging TDP MMU SPTEs could clobber FROZEN SPTEs - Fix a variety of #DB priority bugs - Fix a class of races related to enabling Hyper-V emulation on a vCPU after the vCPU is visible to the rest of KVM - Use static calls for nested virtualization ops - Move more KVM-internal code out of x86's kvm_host.h - Enumerate support for a variety of Zhaoxin instructions that don't require explicit virtualization - Fix missing EFER validation bugs, including in the KVM_SET_SREGS* path - Harden kvm_vcpu_map() against double-mapping and thus leaking references - Misc fixes and cleanups, e.g. for largely benign syzkaller splats x86 (Intel): - Zero a vCPU's entry in VMX's Posted Interrupt Descriptor table used for IPI virtualization when the vCPU is freed, to fix a use-after-free where hardware will write to a freed vCPU's PID - Service local TLB flushes on a failed nested VM-Enter to fix a bug where KVM could miss a TLB on a future, successful VM-Enter with the same L2 VPID - Cap the maximum value shoved into the VMX Preemption Timer to workaround an erratum that affects all existing Intel CPUs that support CPUID 0x15 - Fix VPID virtualization bugs where KVM would fail to flush hardware TLBs - Harden the TDX "populate" ioctls against bad input, and to prepare for supporting in-place private<=>shared conversion x86 (AMD): - Forcefully invalidate SNP VMSA pages if their backing guest_memfd page is zapped/invalidated, e.g. due to a PUNCH_HOLE in response to a Page-State Change request - Remove a dying VM from the GA Log notifier list before the VM is actually destroyed, to fix a potential use-after-free - While FOLL_WRITE was needed in the past to trigger CoW unsharing, nowadays FOLL_LONGTERM does that already even without FOLL_WRITE, and in fact, get_user_pages() actually disallows FOLL_WRITE together with FOLL_LONGTERM. So don't pass FOLL_WRITE when registering encrypted memory regions, i.e. when pinning SEV/SEV-ES guest memory, to fix a regression with file-backed memory introduced by KVM's (correct) usage of long-term pins (This was reviewed by mm maintainers; for more information, see commit ee1a586dd1fa "KVM: SEV: Drop FOLL_WRITE for encrypted region registration") - Allocate full pages for SEV/SEV-ES {DE,EN}CRYPT ops on SNP-enabled hosts to fix a data corruption issue due to the PSP driver assigning to-be-written pages to firmware (as required by the SNP specs) - Unconditionally intercept ICBEP so that KVM generates the correct guest RIP when handling an ICEBP-induced TASK_SWITCH #VMEXIT - Harden the SNP "populate" ioctls against bad input, and to prepare for supporting in-place private<=>shared conversion Generic: - Remove kvm_debugfs_dir if kvm_init() fails after creating KVM's debugfs - Add a per-VM bitmap to track which vCPU IDs have been "claimed" but for which the vCPU isn't yet online, and use the bitmap to reject duplicate IDs before calling into arch code. This allows arch code to consume vcpu_id without having to worry about cross-vCPU clobbering (at least s390 and x86 have had related bugs) - Rework the so called "prepare" and "invalidate" guest_memfd hooks to prepare for in-place private<=>shared conversion, and clean up a few warts along the way Selftests: - Automatically allocate a full page for L2 guest stacks on x86 instead of requiring test-specific L1 guest code to carve out a portion of the L1 stack for L2 usage, and to ensure the L2 stack also adheres to the x86-64 calling convention ABI - Add a selftest to verify {Guest,Host}-Only behavior in x86's mediated PMU - Clean up nested SVM's handling of GPRs on L2<=>L1 transitions, reuse the functionality for nested VMX, and drop the ucall hack that was fudging around the lack of GPR switching on nVMX - Add a stress test to verify KVM doesn't clobber/drop #PF state, e.g. CR2, across save/restore, including when L2 is active - Add a test to verify KVM_CREATE_VM accepts exactly what is reported by KVM_CAP_VM_TYPES - Misc selftests fixes and cleanups - Fix several issues with seeding the pRNG, and rework the pRNG APIs to that the pRNG can be sanely used in host code, not just guest code - Add an IRQ test to validate virtual IRQ deliverty for IRQs wired up via KVM_IRQFD + KVM_SET_GSI_ROUTING, with optional support for triggering IRQs via writes to an assigned VFIO device - Add syscall wrappers to assert success on a variety of pthreads and CPU affinity APIs - Set vCPU pthread affinity as early as possible to reduce contention issues that were surfaced by PREEMPT_LAZY, which result in runtimes of over a minute on large hosts, versus the expected ~5 seconds - Rework the PMU counters test to run each testcase using a single VM with many vCPUs for each sub-testcase, instead of using a unique VM for each sub-testcase. This cuts the runtime by ~20x Miscellaneous: - MAINTAINERS updates for vfio-ap, guest_memfd, kvm-x86. Mostly representing the status quo more accurately, but also... welcome David Hildenbrand as guest_memfd reviewer!" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (413 commits) KVM: arm64: Validate GICv5 timer PPIs before claiming ownership KVM: arm64: vgic: Reject out-of-range GICv5 PPI IDs KVM: arm64: vgic: Prevent speculative SPI array underflow KVM: arm64: vgic: Free gic_kvm_info on initialization failure KVM: arm64: Avoid mismatched accesses to 'struct kvm_nvhe_init_params' s390/vfio-ap: Fix NULL deref in status_show() during queue probe s390/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain removed s390/vfio-ap: fix potential use of uninitialized apm_filtered bitmap s390/vfio-ap: Fix control domain removal in vfio_ap_mdev_cfg_remove s390/vfio-ap: Fix required lock not held during update of ap_matrix_mdev object s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects s390/vfio-ap: Fix dereference matrix_mdev->kvm without checking for NULL s390/vfio-ap: Fix stale do_remove flag across iterations in vfio_ap_mdev_cfg_remove RISC-V: KVM: fix vcpu vector context handling for kernel-mode vector riscv: vector: allow non-preemptible kernel-mode vector with IRQs off riscv: vector: refactor riscv_v_start_kernel_context KVM: s390: gmap: Make prefix handling optional KVM: s390: gmap: Make CMMA optional KVM: s390: gmap: Make storage keys optional KVM: s390: Prepare gmap for a second KVM implementation ... 2026-08-21T01:17:08+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-21T01:17:08+00:00 urn:sha1:ed3b875bea55a3ec4837113356df2ead11115af9 Pull MM updates from Andrew Morton: - "mm: drop "sub" prefix from various places" (Dev Jain) page->folio conversion and a naming cleanup - "mm/kasan: remove redundant initialization for kasan_flag_write_only" (Igor Putko) KASAN cleanup work - "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling) Small speedup in the pagecaache read code - "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng) Improve the vmalloc code - mainly the avoidance of GFP_KERNEL allocations when the caller asked for GFP_NOFS or GFP_NOIO - "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno Leitao) Avoid a soft lockup watchdog trigger from the kmemleak scanning code in extreme situations - "mm/page_owner: misc cleanups" (Ye Liu) Cleanups to the page_owner code. For some reason lots of people have been working on the page_owner code this cycle. - "mm: convert to walk_page_range_vma() to eliminate find_vma()" (Kefeng Wang) Simplify and accelerate the page walking library function - "mm/migrate: preparatory cleanups for batch copy and offload" (Shivank Garg) Cleanups in the migration code - "mm/page_owner: add per-fd filter infrastructure for print_mode and NUMA filtering" (Zhen Ni) Per-fd filtering to page_owner in order to reduce the sometimes vast amount of output it can produce - "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song) Fixes and preparatory cleanups around bootmem HugeTLB handling, sparse initialization ordering, and related vmemmap setup - "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao) Reduce lock contention in zs_free(), which dominates the unmap path under memory pressure on Android (LMK kills) and on x86 servers running zswap-heavy workloads. Up to 1.83x improvement in microbenchmarking. - "move alloc_tag.c file under mm/" (Suren Baghdasaryan) - "samples/damon: handle damon_{start,stop}() failures" (SJ Park) Fix improper handling of damon_start(), damon_stop(), and damon_call() failures across DAMON sample modules to prevent potential memory leaks, operation disruptions and use-after-free bugs - "mm/damon/sysfs: kobject_del() directories that users can create/remove" (SJ Park) Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE causeing creation failures due to duplicate directory names by adding missing kobject_del() calls before creating new directories - "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand) Clean up the core pte handling code - "selftests/damon: misc fixes for test bugs" (Kunwu Chan) Fix several bugs in the DAMON selftests - "selftests/damon: fix memcg_path staging handling" (Cheng Nie) Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and add a test case for it in sysfs.py. - "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev) Selftest coverage for DAMON's refresh_ms sysfs feature by updating the test control module and verifying that scheme stats update automatically without manual intervention - "mm/damon: five misc fixups" (Akinobu Mita) Miscellaneous DAMON fixups. - "mm/damon/core: detect internal variation above max_nr_regions/2" (Jiayuan Chen) Fix DAMON's region splitting behavior when region counts exceed half the maximum budget by dynamically scaling down the split fraction as the limit approaches, preventing large regions from staying un-split, and add corresponding KUnit test coverage - "mm: preparatory patches for PMD level swap entries" (Usama Arif) Refactor and clean up PMD softleaf helpers, call sites, and architecture flags to lay the groundwork for a follow-up series that introduces PMD page table swap entries - "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ Park) Update DAMON design and ABI documentation, expands unit and selftest coverage, optimize damon_commit_target_regions(), and clean up recently added sysfs interface code for better readability - "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2" (Usama Arif) Optimize vmpressure() by skipping unnecessary work on cgroup v2 for userspace event notifications and refactor v1-only eventfd handling into mm/memcontrol-v1.c to reduce memory overhead and code complexity - "selftests/mm: refactor pkey helpers and fix mmap error handling" (Hongfu Li) Refactor pkeys shared tracing and assertion helpers into a common file, unify protection key selftests to use consistent diagnostic logging and assertions, and enforce standardized MAP_FAILED return checks for mmap() calls across the tests - "mm/damon: optimize out nr_accesses_bp" (SJ Park) Replace the error-prone, continuously updated nr_accesses_bp field in damon_region with an on-demand moving sum function, reducing structure memory overhead and avoiding state corruption bugs - "Open HugeTLB allocation routine for more generic use" (Ackerley Tng) Decouple HugeTLB folio allocation from VMA dependencies by introducing hugetlb_alloc_folio(), enabling subsystems like guest_memfd to allocate HugeTLB folios without standard VMA reservations or pseudo-VMAs - "mm/damon: provide pseudo moving sum probe_hits" (SJ Park) Integrate DAMON's probe_hits attribute counter into the pseudo moving sum infrastructure, enabling real-time, online monitoring without waiting for full aggregation intervals - "mm: Some cleanups for page allocator APIs" (Brendan Jackman) Simplify and refactor the page allocator entry points and flags by unifying allocation paths, adding internal alloc_flags arguments, and eliminating redundant __ prefixed alloc_pages variants. - "Fix incorrect access of hugetlb pte entries" (Dev Jain) Enforce the consistent use of huge_ptep_get() instead of ptep_get() for HugeTLB entries and fixes an unaligned address issue in arm64's huge_ptep_get() implementation - "mm/damon: validate all parameters in the core" (SJ Park) Consolidate parameter validation into the DAMON core specifically within damon_start() and damon_commit_ctx() to centralize error checking, eliminate caller-side redundant checks and to improve maintenance efficiency - "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong Chen) Rename is_need() to filter_record() for clearer return semantics, fix per-record allocation memory leaks and bound output copies in search_pattern() to address an existing buffer issue - "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen) Mitigate a system-wide stall which occurs when a cgroup is removed while one of its memory control files is doing synchronous reclaim - "mm/memory-failure: add panic option for unrecoverable pages" (Breno Leitao) Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics the kernel on unrecoverable memory errors in kernel-owned pages to preserve error context and prevent delayed, silent data corruption - "mm/damon: refactor damon_{start,stop,commit}() for simple error handling" (SJ Park) Refactor the DAMON core API functions to guarantee that all contexts are fully stopped when damon_start(), damon_stop(), or damon_commit() fail, eliminating the need for complex and error-prone caller-side cleanup code - "Keep tail page private zero at free and folio split" (Zi Yan) Add checks to ensure tail_page->private is zero when freeing compound or high-order pages and when promoting tail pages during large folio splits. By validating these fields at free and split time, it allows the removal of redundant private field clearing inside prep_compound_tail() - "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry Song) Eliminate redundant lru_add_drain() calls in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock contention and system overhead By validating folio refcounts against the LRU cache before draining and removing unnecessary drains in the swap path, it achieves up to a 30.5% reduction in drain calls during heavy swap workloads - "mm: clean up folio LRU and swap declarations" (Jianyue Wu) Reorganize folio LRU and swap code by relocating page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving MM-internal reclaim declarations into mm/internal.h. - "userfaultfd: working set tracking for VM guest memory" (Kiryl Shutsemau) Add userfaultfd support for tracking the working set of VM guest memory, so a VMM can identify hot pages and reclaim cold ones to tiered or remote storage - "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David Hildenbrand) Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around freeing of reserved vmemmap pages on the way. - "mm/damon: update probe hits for runtime parameter commits" (SJ Park) Ensure that DAMON's probe_hits attribute counter is properly updated when monitoring intervals are changed at runtime, matching the behavior of nr_accesses. To achieve this, it refactors and renames existing helper functions for shared use, applies the updates to probe_hits, and handles edge cases in damon_probe_hits_mvsum() to maintain measurement accuracy. - "KSM: performance optimizations for rmap_walk_ksm" (xu xin) Resolve a severe KSM reverse-mapping performance bottleneck where thousands of split VMAs sharing a single anon_vma cause extended lock contention. By adding an interval-filtering check during the rmap walk, it reduces worst-case anon_vma lock hold times from over 500ms down to under 2ms, preventing application freezes and latency spikes under memory pressure. - "mm: split a couple of headers from internal.h" (Mike Rapoport) Split declarations related to mm_init, memblock, vmalloc and sparse into new headers - "KSM: use linear_page_index in collect_procs_ksm()" (xu xin) Apply the interval tree optimization from rmap_walk_ksm() to collect_procs_ksm() to avoid iterating over non-matching VMAs during KSM memory error handling. It hoists loop-invariant address initialization and restricts the anon_vma_interval_tree_foreach walk to a targeted page offset range, reducing redundant checks and improving lookup efficiency. - "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali Patil) Fix issues in the hugetlb and KSM MM selftest categories that can report failures when the prerequisites for the tests are not satisfied - "mm/damon: introduce data attributes only monitoring" (SJ Park) Introduce attribute-weighted region management in DAMON, allowing users to prioritize specific data attributes (such as page sizes or cgroups) over or instead of access monitoring. By assigning weights to attribute probes, DAMON can completely disable access tracking and adjust monitoring regions based on weighted probe-hit counters to optimize monitoring quality for attribute-focused workloads. - "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings" (Stanislav Kinsburskii) Extend hmm_range_fault() to support userfaultfd-backed regions by allowing the mmap lock to be dropped during fault handling via a new hmm_range_fault_locked() helper. By accepting a locked pointer and signaling retry status when lock release occurs, it enables page fault resolution in userfaultfd regions while preserving backward compatibility for existing callers. - "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes) Clean up and standardize how vma->vm_pgoff is accessed and manipulated across file-backed and anonymous mappings in the kernel It introduces dedicated helper functions such as vma_start_pgoff(), vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming rmap interval tree helpers to better reflect their functionality. These changes establish a cleaner foundation for future work that will unify virtual page offset indexing for all anonymous and CoW'd folios. - "mm: handle device-private PMDs in walk callbacks" (Usama Arif) Address kernel panics and state corruption caused by MM walk callbacks reaching non-present device-private PMD swap entries created during HMM migrations It ensures that functions which acquire pmd_trans_huge_lock() properly recognize device-private PMDs instead of assuming a present THP or a standard migration entry. - "mm/rmap: Refactor try_to_unmap_one" (Dev Jain) Refactor try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree, and anonymous-swapbacked logic into dedicated functions, laying the structural groundwork for batched anonymous large folio unmapping. - "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu) Fix typos and fills in missing entries in the DAMON sysfs ABI document - "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price) Introduce an atomic sysfs state attribute and supporting DAX/MM infrastructure to prevent userland races when offlining and removing entire memory regions By adding an unplugged state alongside standard online modes, it enables whole-device atomic hotplug control while preserving backward compatibility. - "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes) Continue transitioning the kernel from the deprecated vm_flags_t type to vma_flags_t across core memory management infrastructure. It replaces legacy type usage in core functions such as do_mmap(), unmapped area allocation, mm->def_vma_flags, and VMA operations like mlock, mprotect, and mremap. - "Two small patches to clean up mm/mm_slot.h" (xu xin) Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate slot deletion sequences in khugepaged and KSM. It also adds code documentation explaining why mm_slot_lookup and mm_slot_insert must remain as preprocessor macros rather than static inline functions. - "mm/damon/core: hide core-private struct fields" (SJ Park) Clean up DAMON core structures by consistently marking internal-only fields with private: comment tags to prevent improper direct access from outer layers. It enforces encapsulation across core structures including damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to interact through approved access APIs instead of exposing raw struct members. - "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races" (SJ Park) Address potential infinite loops, NULL dereferences, and race conditions identified in DAMON It fixes an infinite loop triggered by extreme user configurations, a NULL pointer dereference within unit tests and minor monitoring accuracy degradation caused by subtle runtime races. - "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan Jackman) Fix an NMI safety flaw in __free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks via non-PCP or isolated migration paths. It also resolves potential kernel crashes and privilege escalation risks triggered when BPF tracing runs in NMI context alongside memory hotplug or large allocation frees. - "mm/page_alloc: couple of followups for recent cleanups" (Brendan Jackman) Clean up and update page allocator nomenclature, documentation, and debug assertions. It aligns internal FPI_ flags with the public "nolock" naming convention, removes outdated internal implementation details from high-level page allocator comments, and eliminates obsolete VM_BUG_ON() assertions in allocation paths. - "mm/mseal: further cleanups" (Lorenzo Stoakes) Refactor and simplify the mseal implementation by clarifying API boundaries and removing unnecessary code complexity. It replaces generic do_mseal() usage outside the syscall with a dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates mm_struct parameters to enforce that sealing applies only to current->mm, and streamlines overall logic and comments with no functional changes intended. - "mm/vmscan: fix swappiness=max and clean up per-node proactive reclaim" (Ridong Chen) Resolve reclaim behavior bugs and clean up function parameters across memory reclaim paths It fixes swappiness=max in both standard reclaim and MGLRU so unswappable anonymous memory no longer falls back to evicting page cache, ensures reclaim_store() returns accurate error codes instead of collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask parameter from __node_reclaim(). - "mm: mincore: misc cleanups" (Kefeng Wang) Clean up and simplifies the mincore code. Most importantly, it removes the historical special behavior that always reports VM_PFNMAP pages as non-resident. - "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau) Two trivial cleanups in the folio split API - "mm/damon: fix uninitialized DAMOS field and kunit exec expectation bugs" (SJ Park) Resolve minor operational and testing bugs in DAMON identified by Sashiko. It initializes the damos->last_applied field to prevent occasional efficiency degradation and fixes invalid memory accesses in DAMON KUnit tests during test failure handling. - "cleanup for stable_page_flags()" (Jinjiang Tu) Clean up and refactor stable_page_flags() used by /proc/kpageflags without altering functionality. It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag bits, converts folio-specific flag checks to standard folio_test_*() helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling. - "Batch unmap of uffd-wp file folios" (Dev Jain) Extend batched folio unmapping support to file folios within userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities to pte_install_uffd_wp_if_needed(). This removes special-case restrictions on uffd-wp VMAs in try_to_unmap_one(), significantly simplifying the function's control flow and complexity. - "mm/early_ioremap: clarify and clean up early_ioremap_reset()" (Sang-Heon Jeon) Clarify and clean up the architecture-specific usage of __late_set_fixmap() and __late_clear_fixmap() after early_ioremap_reset() It adds explicit documentation regarding when early_ioremap_reset() must be called and removes redundant macro definitions and reset calls in the RISC-V and ARM64 architectures. - "mm: fix reclaim storms in defrag_mode" (Johannes Weiner) Address severe performance regressions, swap storms, and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta production It updates the page allocator slowpath so non-movable allocation requests actively trigger direct reclaim and direct compaction at pageblock_order scale, allowing them to claim whole pageblocks rather than spinning unproductively. - "zram: lockmap tweaks" (Sebastian Siewior) Optimize and fix lockdep tracking for zram devices by consolidating per-entry lockmaps and isolate lock classes across multiple instances This reduces memory overhead by replacing per-entry lockdep_map instances with a single map per struct zram, and assigns a dynamic lock_class_key to each instance to prevent false deadlock reports when different zram devices are backed by distinct filesystems. * tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits) selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check selftests/mm: unpoison pages in memory-failure teardown mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn() mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro mm/zsmalloc: fix release order of locks in zs_page_migrate() Documentation: zram: remove sections numbering ksm: stop iterating VMAs when ksm_test_exit returns true mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch() zram: use a custom key for each zram object zram: move lockmap to be per-zram instead per table selftests/mm: fix gup_longterm EINVAL error message mm: page_alloc: fix non-movable reclaim storm in defrag_mode mm: page_alloc: move capture_control to the page allocator mm: compaction: support non-movable compaction for pageblock requests mm: page_alloc: __GFP_FS lockdep annotation for direct compaction hugetlb: evaluate subpool free state while locked mm/damon: remove trailing semicolons after function definitions mm/damon/ops-common: prevent migration fallback to non-target nodes mm/damon: update outdated comment about DAMOS filter handling ... 2026-08-20T21:53:54+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-20T21:53:54+00:00 urn:sha1:073e62fd33fe9cec754cb89e60c0ebbab781a50a Pull RISC-V updates from Paul Walmsley - Add initial definitions and discovery for the Smcsrind, Sscsrind, Smcntrpmf, Ssccfg, Smcdeleg, Zicclsm, Ziccamoa, Ziccif, Ziccrse, Za64rs, and Ssqosid RISC-V ISA extensions - Improve the RISC-V update_mmu_cache_range() implementation by using flush-by-ASID, enabling performance improvements on microarchitectures that support related optimizations; and by taking advantage of the Svinval RISC-V ISA extension on microarchitectures that support it - Shrink CFI shadow stack allocation further (to 512MB) to save virtual address space (and physical memory on systems with strict overcommit policies) - Add initial CPU context switch support for QoS tagging (Ssqosid) - Change our vector misaligned access speed test code to be synchronous, avoiding a bunch of bugs related to unnecessary asynchronicity - Enable ARCH_HAS_ACPI_TABLE_UPGRADE for RISC-V to help with ACPI table debugging (similar to ARM64 and x86) - Extract vDSO section offsets at build time, rather than run time, to avoid the boot time overhead - Use assembler directives to control the use of instructions from the RISC-V ISA extensions Zacas and Zabha, rather than compiler -march flags that could affect the whole kernel (similar to ARM64) - Add a kselftest for kprobes support for the c.jal instruction on RISC-V - When UEFI runtime services are available, use them to restart and power off - Fix ARCH_HAS_ACPI_TABLE_UPGRADE for RISC-V by adding a missing include file to the ACPI code - Move contiguous DMA memory reservation later in the boot, to ensure that the correct global and per-node pools are allocated when CONFIG_CMA_SIZE_PERNUMA is enabled - Disallow probes on breakpoint handlers to avoid recursing indefinitely into do_trap_break() - Patch the compat vDSO during runtime alternatives processing, not only the standard vDSO - Remove some leftover XIP support elements missed by commit 9b3a2be84803 ("riscv: Remove support for XIP kernel") - Fix broadcast timer switching in ACPI LPI power states by implementing a RISC-V version of arch_get_idle_state_flags() - Miscellaneous fixes, including: vDSO makefile simplification; marking our default_power_off() as __noreturn; error path fixes in the PMU SBI perf driver; RISC-V extension capitalization consistency; the use of BIT() macros in one of our include files; and some documentation fixes * tag 'riscv-for-linus-7.3-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (39 commits) RISC-V: hwprobe: Use BIT macro to avoid warnings riscv: alternative: Also patch the compat vDSO riscv: alternative: Use the statically extracted vDSO section offsets riscv: vdso: Add symbols for the alternative section boundaries riscv: Add Ziccamoa, Ziccif, Ziccrse, and Za64rs to cpufeature and hwprobe riscv: Add Zicclsm to cpufeature and hwprobe riscv: cpufeature: Clarify ISA spec version for canonical order riscv: Standardize extension capitalization riscv: kprobes: Prevent probes in breakpoint handlers riscv: cmpxchg: Use .option arch for Zacas and Zabha riscv: acpi: Handle LPI architectural context loss flags riscv: further remove XIP riscv: Add support for srmcfg CSR from Ssqosid extension riscv: Detect the Ssqosid extension dt-bindings: riscv: Add Ssqosid extension description dt-bindings: riscv: add Counter delegation ISA extensions description RISC-V: Add Ssccfg/Smcdeleg ISA extension definition and parsing RISC-V: Add Ssccfg extension CSR definition dt-bindings: riscv: add Smcntrpmf ISA extension description RISC-V: Add Smcntrpmf extension parsing ... 2026-08-18T22:58:29+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-18T22:58:29+00:00 urn:sha1:030c9f813b8e48d2b066983c94cf6294968f9496 Pull treewide timer related cleanups from Thomas Gleixner: - Remove the leftover CLOCK_TICK_RATE which has been scheduled for removal more than a decade ago along with some now empty asm/timex.h files. - Consolidate delay timer calibration The construct of having a define in a header requires that architectures provided asm/timex.h for no reason. Also the function name for reading the delay timer is confusing at best. Use a config switch to enable that functionality and rename the function to delay_read_timer() to make the purpose clear. This removes some more now empty asm/timex.h files as well. * tag 'timers-cleanups-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: calibrate: Rework delay timer calibration treewide: Remove CLOCK_TICK_RATE x86: Use PIT_TICK_RATE instead of CLOCK_TICK_RATE 2026-08-18T22:00:56+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-18T22:00:56+00:00 urn:sha1:3424d8c18a7da1010d03391a22e728b857d0d5c5 Pull generic entry code updates from Thomas Gleixner: - Make syscall user dispatching configurable Not all architectures can makes use of syscall user dispatching. Allow them to disable the feature completely. - Consolidate stack randomization for the generic entry code and the architectures using it. Stack randomization on syscall entry was sprinkled throughout the architecture specific low level entry code and in some cases at the wrong points, e.g. before establishing state, which violates the non-instrumentable constraints of that code. Clean this up by integrating stack randomization into the generic entry code helpers so that it is invoked at the earliest possible point right after establishing state and converting all generic entry code using architecture over. - Clean up the syscall number handling in the generic entry code. It works correctly for architectures which have a separate return value storage in pt_regs, but fails to distinguish the case where user space handed in -1 as syscall number from the case where the entry code rejects it by returning -1 to the callers. Aside of that the return value functionality of those interfaces is not really intuitive. Fix this by separating the decision to reject a syscall (user dispatch, ptrace, seccomp ...) from the potential modification of the syscall number through these mechanisms. This solves most of the problems for architectures which do not have a separate return value storage in pt_regs except for the case where a tracepoint has a BPF script or a probe attached which overwrite both the syscall number and the return value. But that's a problem which cannot be solved in the generic code, that only can be addressed by separating the storage model in the affected architectures. * tag 'core-entry-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) entry, treewide: Make syscall_enter_from_user_mode[_work]() indicate syscall execution entry: Make return type of syscall_trace_enter() bool entry: Rework trace_syscall_enter() entry: Rework syscall_audit_enter() syscall_user_dispatch: Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH entry: Fix seccomp bypass after ptrace with TSYNC x86/entry: Simplify the syscall number logic x86/entry: Get rid of the sys_ni_syscall() indirection x86/entry: Make syscall functions static ptrace, treewide: Rename ptrace_report_syscall_entry() to ptrace_report_syscall_permit_entry() seccomp, treewide: Rename and convert __secure_computing() to return boolean entry: Use syscall number instead of rereading it entry: Remove syscall_enter_from_user_mode() x86/syscall: Use [syscall_]enter_from_user_mode_randomize_stack() s390/syscall: Use enter_from_user_mode_randomize_stack() riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack() powerpc/syscall: Use syscall_enter_from_user_mode_randomize_stack() loongarch/syscall: Use syscall_enter_from_user_mode_randomize_stack() entry: Provide [syscall_]enter_from_user_mode_randomize_stack() randomize_kstack: Provide add_random_kstack_offset_irqsoff() ... 2026-08-18T20:07:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-18T20:07:17+00:00 urn:sha1:dfa35434d7f20142fedd7120277b1044a0a2bb64 Pull locking updates from Ingo Molnar: "Futexes: - Use runtime constants for futex_hash computation (K Prateek Nayak, Peter Zijlstra) - Optimise the size check get_futex_key() (Sebastian Andrzej Siewior) - Avoid private hash use-after-free on final put (Felix Hoffmann) - Tell kmemleak we're not leaking __futex_queues (Peter Zijlstra) Rust integration updates: - Implement refcounted interrupt disable and SpinLockIrq for Rust (Boqun Feng, Heiko Carstens, Joel Fernandes, Lyude Paul) - Rust sync: add helpers for mb, dma_mb and friends; add generic memory barriers and use LKMM atomics instead of Rust atomics in the revocable code (Gary Guo) - Add abstraction and integrate synchronize_rcu() (Philipp Stanner) Lock debugging: - Add qspinlock contended_release tracepoint (Dmitry Ilvokhin, Peter Zijlstra) - Enable the printing of held locks of remote running tasks and print task CPU (Ingo Molnar) - percpu-rwsem: Annotate intentional data race in readers_active_check() (Sun Shaojie) Misc fixes and updates by Boqun Feng, Peter Zijlstra, Fangrui Song, Naveen Kumar Chaudhary and Thomas Huth" * tag 'locking-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) rust: sync: Introduce SpinLockIrq::lock_with() and friends rust: sync: Add SpinLockIrq rust: sync: Use super::* in spinlock.rs rust: helper: Add spin_{un,}lock_irq_{enable,disable}() helpers rust: Introduce interrupt module s390/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS arm64: sched/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS preempt: Introduce HAS_SEPARATE_PREEMPT_RESCHED_BITS sched: Avoid signed comparison of preempt_count() in __cant_migrate() sched: Remove the unused preempt_offset parameter of __cant_sleep() locking: Switch to _irq_{disable,enable}() variants in cleanup guards irq: Add KUnit test for refcounted interrupt enable/disable irq,spin_lock: Add counted interrupt disabling/enabling openrisc: Include <linux/cpumask.h> in smp.h preempt: Introduce __preempt_count_{sub,add}_return() preempt: Introduce HARDIRQ_DISABLE_BITS preempt: Track NMI nesting to separate per-CPU counter futex: Tell kmemleak we're not leaking __futex_queues x86/paravirt: Trace contended_release on unlock tracing/lock: Use TRACE_EVENT_FN() for contended_release ... 2026-08-18T11:11:45+00:00 Paolo Bonzini pbonzini@redhat.com 2026-08-18T11:11:45+00:00 urn:sha1:41362886881f6af28fdf416be662c02968c37d81 LoongArch KVM changes for v7.3 1. Advertise already-supported capabilities. 2. Some bug fixes about timer and MMIO. 3. Some hardening about interrupt injection. 4. Replace kvm_err() with kvm_pr_unimpl(). 5. Add FPU/LSX/LASX test cases for selftests. 2026-08-13T07:50:02+00:00 Andy Chiu tchiu@tenstorrent.com 2026-08-03T21:52:42+00:00 urn:sha1:b5060a4aa33d7d78a8c1837ab08ef0c81ea96650 Running vector workloads like perf + mcf on KVM can result in an unexpected termination due to a vtype corruption. This happens because the kernel-mode vector (KMV) misattributes the guest's vcpu context as the user's context and source from a wrong status.VS. The simplified call chain that results in this problem is shown as follow: __riscv_sys_ioctl() kvm_arch_vcpu_ioctl_run() kvm_riscv_vcpu_exit() kvm_riscv_vcpu_sbi_ecall() kvm_riscv_vcpu_pmu_ctr_stop() kvm_vcpu_write_guest() __copy_to_user() enter_vector_usercopy() kernel_vector_begin() kernel_vector_begin() should use the sstatus.VS from guest's vcpu context instead of task_pt_reg(current). Also, it should not save guest's v-reg into the user's context memory. To resolve this, the vcpu context must be correctly saved when KMV is serving a guest. However, invoking KVM functions directly from generic RISC-V architecture code introduces a reverse dependency, breaking builds when KVM is configured as N or M. Address this by registering an RCU-protected callback for context flushing. KVM registers this callback at module initialization and unregisters it on exit. When KMV starts a kernel context, it can now safely flush the vector context via the callback. Fixes: ecd2ada8a5e0 ("riscv: Add support for kernel mode vector") Signed-off-by: Andy Chiu <tchiu@tenstorrent.com> Reviewed-by: Yong-Xuan Wang <yongxuan.wang@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20260803215250.824417-4-tchiu@tenstorrent.com Signed-off-by: Anup Patel <anup@brainfault.org> 2026-08-13T07:50:02+00:00 Andy Chiu tchiu@tenstorrent.com 2026-08-03T21:52:41+00:00 urn:sha1:848a973c5f368c6c4f8e76bb6ccb5371c6566b51 Similar to commit 7137a203b251 ("arm64/fpsimd: Permit kernel mode NEON with IRQs off"), we are upgrading get/put_cpu_vector_context such that kvm_arch_vcpu_load/put can be safely called under both irq off and regular process context. Also, export both symbols so the kvm module can call into it. Signed-off-by: Andy Chiu <tchiu@tenstorrent.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20260803215250.824417-3-tchiu@tenstorrent.com Signed-off-by: Anup Patel <anup@brainfault.org> 2026-08-12T16:37:07+00:00 Yong-Xuan Wang yongxuan.wang@sifive.com 2026-08-10T10:18:50+00:00 urn:sha1:df81f80c35bce3f9d3b275b91d2f5aabc2312241 Register a CPU_PM notifier to restore hypervisor CSR content during CPU non-retention idle states. When a CPU enters a deep idle state that powers off the CPU domain, hypervisor CSRs and VS CSRs lose their state and must be saved before entry and restored after exit. This completes KVM's power management coverage for RISC-V: - CPU hotplug: handled by kvm_online_cpu/kvm_offline_cpu (cpuhp callbacks) - System suspend: handled by kvm_suspend/kvm_resume (syscore ops) - CPU idle (retention): no action needed, CSRs are retained - CPU idle (non-retention): handled by this CPU_PM notifier Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20260810-kvm-cpu-pm-v5-1-6c9e4c95caf5@sifive.com Signed-off-by: Anup Patel <anup@brainfault.org>