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2026-08-26Merge tag 'hyperv-next-signed-20260826' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linuxLinus Torvalds1-6/+19
Pull hyperv updates from Wei Liu: - Decrypt netvsc buffer on contiguous direct-map addresses (Kameron Carr) - Drop WS2012/2012R2 & Win8/8.1 Hyper-V support (Michael Kelley) - Use more meaningful errnos for hypercall status code (Hardik Garg) - Fix lost interrupts on CPU hot-unplug for Hyper-V PCI/MSI (Naman Jain) - Reserve more MSHV vectors for Linux root partition (Wei Liu) * tag 'hyperv-next-signed-20260826' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: clocksource: hyper-v: Remove support for stimer interrupts in message mode scsi: storvsc: Remove support for storvsc protocol of old Hyper-V hosts hv_netvsc: Remove GPADL teardown special case for old Hyper-V hosts hv_sock: Remove check for old Hyper-V hosts Drivers: hv: Remove support for WS2012/2012R2 & Win8/8.1 version of Hyper-V hv_netvsc: Allocate send/receive buffers using vmbus_alloc_buffer() Drivers: hv: vmbus: Add vmbus_alloc_buffer()/vmbus_free_buffer() for CoCo VMs Drivers: hv: vmbus: add vmbus_establish_gpadl_caller_decrypted() Drivers: hv: vmbus: Skip VMBus module cleanup for non-nested root partition x86/hyperv: reserve more vectors PCI: hv: Set irq_retrigger callback for the Hyper-V PCI MSI irqchip Drivers: hv: Use meaningful errnos for hypercall status codes
2026-08-25Merge tag 'bootconfig-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds1-1/+13
Pull bootconfig updates from Masami Hiramatsu: - Support build-time command line building for embedded bootconfig - Fix xbc_snprint_cmdline() to render descendant keys when the root has both a value and subkeys, and treats empty subtrees correctly. - Add build-time pipeline using tools/bootconfig -C to render the embedded bootconfig "kernel" subtree into .init.rodata as a cmdline string. - Clean build-time tools/bootconfig from make clean - Add helper to prepend embedded bootconfig cmdline into boot_command_line early before parse_early_param() - Wire early prepend helper in x86 setup_arch() so early_param handlers see values from the embedded bootconfig (currently x86 only) - Avoid duplicating "kernel" keys in setup_boot_config() - Refactor setup_boot_config() to share bootconfig_cmdline_requested() - Document CONFIG_CMDLINE_FROM_BOOTCONFIG usage, requirements, and precedence * tag 'bootconfig-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: init/main.c: use bootconfig_cmdline_requested() for the runtime opt-in bootconfig: skip runtime kernel.* render once prepended early x86/setup: prepend embedded bootconfig cmdline before parse_early_param Documentation: bootconfig: document build-time cmdline rendering bootconfig: add xbc_prepend_embedded_cmdline() helper bootconfig: clean build-time tools/bootconfig from make clean bootconfig: render embedded bootconfig as a kernel cmdline at build time bootconfig: render descendant keys when xbc_snprint_cmdline() root has a value
2026-08-24Merge tags 'dma-mapping-7.3-2026-08-24' and 'dma-mapping-7.3-2026-08-24-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linuxLinus Torvalds2-17/+17
Pull dma-mapping updates from Marek Szyprowski: - swiotlb: - new configuration option for the default pool size (Jagadeesh Pagadala) - reduce overhead for high watermark tracking (chenhuguanshen) - minor code cleanups and improvements (Vova Sharaienko, Honglei Huang and Marek Szyprowski) - add proper tracking of the shared DMA state through direct, pool and swiotlb paths (Aneesh Kumar K.V) This is important for confidential-computing * tag 'dma-mapping-7.3-2026-08-24' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: dma/swiotlb: decouple high watermark tracking from CONFIG_DEBUG_FS MAINTAINERS: update tree for DMA MAPPING HELPERS dma/swiotlb: introduce Kconfig option for compile-time default pool size dma-direct: Improve readability of the dma_direct_map_sg() for P2PDMA case iommu/dma: simplify dma_iova_destroy() and drop the free_iova helper dma-coherent: use KiB in DMA allocation logs dma-coherent: fix spacing coding style issue * tag 'dma-mapping-7.3-2026-08-24-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: (23 commits) swiotlb: remove unused SWIOTLB_FORCE flag dma: swiotlb: handle set_memory_decrypted() failures dma: swiotlb: free dynamic pools from process context dma-direct: rename ret to cpu_addr in alloc helpers dma-direct: select DMA address encoding from __DMA_ATTR_ALLOC_CC_SHARED dma-direct: set decrypted flag for remapped DMA allocations dma-direct: make dma_direct_map_phys() honor DMA_ATTR_CC_SHARED dma-direct: Move dma_direct_map_phys() to dma/direct.c dma-direct: pass attrs to dma_capable() for DMA_ATTR_CC_SHARED checks dma-mapping: make dma_pgprot() honor __DMA_ATTR_ALLOC_CC_SHARED dma: swiotlb: track pool encryption state and honor DMA_ATTR_CC_SHARED dma: swiotlb: pass mapping attributes by reference dma-pool: track decrypted atomic pools and select them via attrs dma-direct: use __DMA_ATTR_ALLOC_CC_SHARED in alloc/free paths dma-mapping: Add internal shared allocation attribute coco: arm64: s390: powerpc: Mark secure guests with CC_ATTR_GUEST_MEM_ENCRYPT dma-direct: swiotlb: handle swiotlb alloc/free outside __dma_direct_alloc_pages s390: Expose protected virtualization through cc_platform_has() swiotlb: Preserve allocation virtual address for dynamic pools dma: free atomic pool pages by physical address ...
2026-08-24clocksource: hyper-v: Remove support for stimer interrupts in message modeMichael Kelley1-3/+1
In Hyper-V versions prior to WS2016/Win10, Hyper-V synthetic timers interrupt the guest by delivering a message that is initially handled by the Linux VMBus driver. Starting with WS2016/Win10, Hyper-V can deliver stimer interrupts directly to an assigned interrupt vector without involving the VMBus driver. This is called "Direct Mode". With the overall removal of Linux support for running on Hyper-V hosts earlier than WS2016 and Windows 10, it's no longer necessary to support the legacy message-based delivery. Remove that delivery mechanism and always use Direct Mode. If for some reason, the Hyper-V host does not enumerate Direct Mode, output an error message but continue to run using the LAPIC timer instead of an stimer. With these changes, the VMBus driver no longer calls the stimer interrupt service routine. This removal has a broader benefit in unblocking the disentangling of VMBus code and stimer code, as they should be independent of each other. The final disentangling will come as a follow-on patch set. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-24x86/hyperv: reserve more vectorsWei Liu1-3/+18
Microsoft Hypervisor delivers three vectors to the NT HAL running in the root partition and refuses to map a device interrupt to any of them when interrupt remapping is not available in the system. As of writing, the nested MSHV setup has no interrupt remapping capability. The three vectors are: HAL_NT_APC_VECTOR 0x1F HAL_NT_DPC_VECTOR 0x2F HAL_NT_CLOCK_IPI_VECTOR 0xD2 0x1F is below FIRST_EXTERNAL_VECTOR so the vector allocator never hands it out, but 0x2F and 0xD2 are both inside the allocatable range and are handed out once enough vectors are in use. Mapping such an interrupt then fails with HV_STATUS_INVALID_PARAMETER, and the interrupt is never delivered. Reserve all three next to the hypervisor debug vectors that are already kept out of the allocator's hands. Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-23Merge tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linuxLinus Torvalds1-0/+1
Pull more liveupdate updates from Mike Rapoport: "Make boot time huge page allocation work nicely with kexec handover. Today allocation of gigantic pages in HugeTLB cannot work reliably with kexec handover (KHO): - HugeTLB allocates gigantic pages using memblock and autoscaling of KHO scratch accounts for these allocations. When gigantic pages occupy half of the memory of more, KHO fails to allocate its scratch memory. - After kexec handover, memblock allocations exclusively use KHO scratch that is not supposed to contain preserved memory. This essentially blocks preservation of HugeTLB with gigantic pages. Extend early memory pools available for KHO kernel with areas that are guaranteed not to contain preserved memory" * tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (21 commits) kho: exclude hugetlb memory from scratch size calculation memblock: add memblock_reserved_hugetlb_size() memblock: make HugeTLB bootmem allocation work with KHO memblock: always include KHO headers kho: extend scratch mm/mm_init: don't rely on memblock to get KHO scratch migratetype kho: initialize preserved memory map radix tree earlier kho: initialize kho_scratch pointer earlier in boot kho: expose kho_scratch_overlap() to kexec_handover.h kho: add kho_radix_init_tree() kho: allow destroying KHO radix tree kho: allow early-boot usage of the KHO radix tree kho: add data argument to radix walk callback kho: add callback for table pages kho: add a struct for radix callbacks kho: move all memory retrieval logic to kho_mem_retrieve() kho: store incoming radix tree in kho_in kho: disallow wide keys in radix tree kho: make radix max key width more obvious kho: generalize radix tree APIs ...
2026-08-20Merge tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-1/+2
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 ...
2026-08-20Merge tag 'sysctl-7.03-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctlLinus Torvalds1-1/+1
Pull sysctl updates from Joel Granados: - Fix kernel-doc warnings by adjusting in file documentation - Consolidate do_proc_* function into do_proc_vec Consolidate three slightly different implementations of applying a converter on all elements of a vector. Fixes to this function now propagate to the three types. - Replace CONFIG_PROC_SYSCTL with CONFIG_SYSCTL (they were the same) and restrict cad_pid modifications to global root (GLOBAL_ROOT_UID) * tag 'sysctl-7.03-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL sysctl: move the "cad_pid" entry from pid_table[] to kern_reboot_table[] sysctl: repair some kernel-doc comments sysctl: add Returns: kernel-doc for all functions sysctl: Update API function documentation sysctl: Rename proc_doulongvec_minmax_conv to proc_doulongvec_conv sysctl: Group proc_handler declarations and document sysctl: Replace do_proc_do{int,ulong,uint}vec with do_proc_vec sysctl: Add negp parameter to douintvec converter functions sysctl: Move default converter assignment out of do_proc_dointvec
2026-08-18Merge tag 'x86_cpu_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds22-119/+109
Pull x86 cpuid updates from Borislav Petkov: - Get rid of static_cpu_has() - one less API to care about testing CPU features - Unify the handling of CPU core types (performance, efficient, etc) by mapping the vendor-specific types to Linux ones - Continuation of the work of Ahmed Darwish to centralize CPUID leaf representation * tag 'x86_cpu_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU: Rename struct cpuid_read_output to struct cpuid_output x86/cpu/scattered: Sort it properly x86/cpu: Use parsed CPUID(0x1) x86/lib: Add CPUID(0x1) family and model calculation x86/cpu: Use parsed CPUID(0x0) x86/cpu/transmeta: Rescan CPUID(0x1) after modifying capabilities x86/topology: Add TOPO_CPU_TYPE_LOW_POWER x86/topology: Name the AMD core-type values x86/topo: Map vendor CPU types to generic Linux such types x86/bugs: Don't use cpu-type matching in cpu_vuln_blacklist x86/cpu: Hide and rename static_cpu_has()
2026-08-18Merge tag 'x86_cleanups_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds11-65/+59
Pull x86 cleanups from Borislav Petkov: - The usual pile of smallish cleanups and fixlets all over the place * tag 'x86_cleanups_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Remove unnecessary __maybe_unused annotations x86/msr: Document the I/O-like write semantics in the msr driver x86/apic: Ensure ICR register write value is handled as 32 bits x86/boot/compressed/head_64.S: Clean up SEV-related comments Documentation/arch/x86/amd-memory-encryption.rst: Fix typo x86/platform/quark: Fix kernel-doc warnings in imr.c x86/ras: Move contents from arch/x86/ras/Kconfig into drivers/ras/Kconfig x86/cpu: Move intel_get_platform_id() to cpu/intel.c x86/mm: Fix typo in comment x86/fpu: Fix kernel-doc formatting above fpu_enable_guest_xfd_features() x86/cfi: Use symmetric SYM_START and SYM_END in __CFI_TYPE() x86/cfi: Add __init_or_module annotations for fineibt
2026-08-18Merge tag 'x86_cache_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds5-20/+19
Pull x86 resource control updates from Borislav Petkov: - How refreshing: no new features but a whole pile of fixes to more or less serious issues reported by Sashiko along with miscellaneous cleanups all over the place. All except one by Reinette Chatre, the one by Tony Luck. * tag 'x86_cache_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: fs/resctrl: Inform user space when status buffer overflowed fs/resctrl: Communicate resource group deleted error via last_cmd_status fs/resctrl: Add last_cmd_status support for writes to max_threshold_occupancy fs/resctrl: Change last_cmd_status custom during input parsing fs/resctrl: Use accurate and symmetric exit flows fs/resctrl: Pass error reading event through to user space fs/resctrl: Use accurate type for rdt_resource::rid fs/resctrl: Change pattern used to track number of entries in enum resctrl_conf_type x86/resctrl: Protect against bad shift fs/resctrl: Use correct format specifier for printing error pointers fs/resctrl: Fix UAF from worker threads when domains are removed x86/resctrl: Ensure domain fully initialized before placed on RCU list fs/resctrl: Prevent deadlock and use-after-free in info file handlers fs/resctrl: Prevent use-after-free in rdtgroup_kn_put() fs/resctrl: Fix deadlock on errors during mount fs/resctrl: Move functions to avoid forward references in subsequent fixes x86,fs/resctrl: Document safe RCU list traversal
2026-08-18Merge tag 'x86_alternatives_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds6-221/+1
Pull x86 alternatives update from Borislav Petkov: - Remove the smp_locks alternatives machinery which was used to patch out lock prefixes when running a SMP kernel on a uniprocessor machine * tag 'x86_alternatives_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternative: Drop smp_locks glue
2026-08-18Merge tag 'x86_mm_for_7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+3
Pull x86 mm updates from Dave Hansen: "There are two things in here of note. First, there are fixes to reduce the time that the TLB flushing code sits around with interrupts disabled. It should be well tested, but it's certainly something to keep an eye on. Second is a little back-and-forth in the interactions between the set_memory*() locking and DEBUG_PAGEALLOC. There was a slightly painful re-discovery of why DEBUG_PAGEALLOC has special locking rules, but the code did end up better for it. Summary: - Fix pkey_alloc() return value when pkeys are not supported - Allow preemption during IPI completion waiting to improve wakeup latency - Convert more x86 page table code to ptdescs - Fixes and cleanups for set_memory*() locking, mostly around large pages" * tag 'x86_mm_for_7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pkeys: Fix pkey_alloc() return value when pkeys are not supported x86/mm: Fix and document DEBUG_PAGEALLOC x86/mm: Use guard() for pgd_lock x86/mm: Use guard() in cpa_collapse_large_pages() x86/mm: Re-enable preemption before flush_tlb_multi() x86/kvm: Disable preemption in kvm_flush_tlb_multi() x86/mm: Move flush_tlb_info back to the stack x86/mm: Cap flush_tlb_info alignment at 64 bytes x86/mm: Factor out flush_tlb_info initialization x86/mm/pat: Take cpa_lock around large-page collapse x86/mm/pat: Don't gate cpa_lock on debug_pagealloc_enabled() x86/xen: Convert xen_mm_unpin_all() to ptdescs x86/xen: Convert xen_mm_pin_all() to ptdescs x86/mm: Convert pgd_page_get_mm() to ptdescs x86/mm: Convert sync_global_pgds_l4() to ptdescs x86/mm: Convert sync_global_pgds_l5() to ptdescs x86/mm: Convert arch_sync_kernel_mappings() to ptdescs x86/mm/pat: Convert collapse_pmd_page() to ptdescs x86/mm/pat: Convert __set_pmd_pte() to ptdescs x86/mm/pat: Use IS_ENABLED() instead of ifdef
2026-08-18Merge tag 'timers-cleanups-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
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
2026-08-18Merge tag 'x86-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-3/+29
Pull x86 core updates from Ingo Molnar: - Optimize the kcfi call sequence (Peter Zijlstra) - Use sfence for wmb() if SSE is available (Yao Zi) * tag 'x86-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/locking: Use sfence for wmb() if SSE is available x86/kcfi: Optimize call sequence
2026-08-18Merge tag 'x86-build-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+6
Pull x86 build update from Ingo Molnar: - Only align ENTRY_TEXT to PMD_SIZE if necessary (Hamza Mahfooz) * tag 'x86-build-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build: Only align ENTRY_TEXT to PMD_SIZE if necessary
2026-08-18Merge tag 'x86-boot-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-3/+2
Pull x86 boot updates from Ingo Molnar: - Misc simplifications and cleanups (Thorsten Blum) * tag 'x86-boot-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Use bool and IS_ENABLED() to simplify query_edd() x86/boot: Use IS_ENABLED() to simplify built-in-or-module checks x86/purgatory: Return bool from verify_sha256_digest()
2026-08-18Merge tag 'x86-msr-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds24-258/+291
Pull x86 MSR updates from Ingo Molnar: - Streamline the x86 MSR handling APIs along the 64-bit variants, simplifying the interfaces. Removal of the old APIs is planned for the next cycle, to reduce churn & integration pain (Juergen Gross) * tag 'x86-msr-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) x86/mce: Work around build warning after MSR-interface switch cpufreq: Stop using 32-bit MSR interfaces x86/featctl: Stop using 32-bit MSR interfaces KVM/x86: Stop using 32-bit MSR interfaces x86/mtrr: Stop using 32-bit MSR interfaces acpi: Stop using 32-bit MSR interfaces powercap: Stop using 32-bit MSR interfaces thermal/intel: Stop using 32-bit MSR interfaces x86/olpc: Stop using 32-bit MSR interfaces x86/hyperv: Stop using 32-bit MSR interfaces hwmon: Stop using 32-bit MSR interfaces EDAC: Stop using 32-bit MSR interfaces x86/cpu: Stop using 32-bit MSR interfaces x86/apic: Stop using 32-bit MSR interfaces x86/resctrl: Stop using 32-bit MSR interfaces x86/tsc: Stop using 32-bit MSR interfaces x86/amd: Stop using 32-bit MSR interfaces x86/pci: Stop using 32-bit MSR interfaces x86/hygon: Stop using 32-bit MSR interfaces x86/mce: Stop using 32-bit MSR interfaces ...
2026-08-18Merge tag 'locking-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds4-11/+86
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 ...
2026-08-18Merge tag 'perf-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-159/+245
Pull performance events updates from Ingo Molnar: "uprobes updates: - Fix a category of bugs with optimized uprobes that can clobber the redzone area with call instruction storing return address on stack where user code may keep temporary data without adjusting RSP. Fix this by moving the optimized uprobes on top of 10-bytes NOP instruction, so we can squeeze another instruction to escape the redzone area before doing the call (Jiri Olsa, Andrii Nakryiko) - Switch uretprobes_srcu to SRCU-fast-updown, to improve performance (Puranjay Mohan) Intel CPU PMU driver updates: - Optimize ACR handling in match_prev_assignment() (Dapeng Mi) - Fix various PMU driver bugs and data leaks (Dapeng Mi) - Fix Intel PT stop/start with no update (Adrian Hunter) Intel uncore PMU driver updates: - Fix various uncore PMU setup robustness bugs (Zide Chen) AMD uncore PMU driver updates: - Add group validation (Sandipan Das) .. and misc fixes and updates by Dapeng Mi, Randy Dunlap and Zide Chen" * tag 'perf-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) perf/x86: Optimize ACR handling in match_prev_assignment() perf/x86/intel: Fix intel_cap handling on hybrid PMUs perf/x86: Remove stale fixed counter helper and fix hybrid PMU access perf/x86/intel: Unwind cpuc state if PEBS buffer setup fails perf/x86: Guard intel_pmu_cpu_dead() against invalid hybrid PMU casts perf/x86: Free hybrid state on PMU init failure perf/x86: Unregister PMI handler on PMU init failure perf/x86/intel/pt: Fix stop/start with no update perf/x86/intel/pt: Use bitwise access for PERF_HES_STOPPED perf/x86/intel/pt: Factor out pt_config_enable() uprobes: Switch uretprobes_srcu to SRCU-fast-updown srcu: Add lock guard for srcu_fast_updown flavor perf/x86/intel/pt: Drop kernel-doc for deleted struct members perf/x86/amd/uncore: Add group validation selftests/bpf: Add tests for forked/cloned optimized uprobes selftests/bpf: Add tests for uprobe nop10 red zone clobbering selftests/bpf: Add reattach tests for uprobe syscall selftests/bpf: Change uprobe/usdt trigger bench code to use nop10 selftests/bpf: Change uprobe syscall tests to use nop10 selftests/bpf: Emit nop,nop10 instructions combo for x86_64 arch ...
2026-08-18Merge tag 'for-linus-7.3-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds1-1/+1
Pull xen updates from Juergen Gross: - Small cleanups for the Xen ACPI pad driver and the gnttab driver - Fix an issue with Xen PV device initialization seen with QubesOS tests - Fixes for the Xen balloon driver and the xenbus driver - Simplify Xen related kernel configuration * tag 'for-linus-7.3-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xenbus: Unregister reboot notifier on init failure x86/xen: Drop CONFIG_XEN_PVHVM_SMP xen: Drop CONFIG_XEN_AUTO_XLATE xen: Drop CONFIG_XEN_PVHVM x86/xen: Remove redundant config dependency on X86_LOCAL_APIC x86/xen: fix init of balloon stats again xen/xenbus: check otherend_id only after it has been initialized xen/xenbus: log more information when device state got reset Xen/gnttab: adjust two uses of sizeof() ACPI: PAD: xen: Stop setting acpi_device_name/class()
2026-08-18Merge tag 'kexec-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linuxLinus Torvalds1-78/+11
Pull kexec updates from Mike Rapoport: - Deduplicate crash memory allocation and the exclusion of reserved crash kernel regions from architecture specific code into a generic crash_prepare_headers() and enable crashkernel CMA reservation on arm64 and riscv reservation on arm64 and riscv. - Skip purgatory checksum verification when the kexec segments cannot be corrupted by DMA, which saves about 250ms on kexec. - Replace __ASSEMBLY__ with the compiler provided __ASSEMBLER__ in include/linux/kexec.h. - Fix a keyring refcount imbalance in the kdump kernel's dm-crypt key restore path, which over-dropped the user keyring reference when more than one key was restored. * tag 'kexec-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: crash_dump: release keyring reference at the correct time kexec: Replace __ASSEMBLY__ with __ASSEMBLER__ in header file kexec_file: skip checksum verification when safe riscv: kexec_file: Add support for crashkernel CMA reservation arm64: kexec_file: Add support for crashkernel CMA reservation powerpc/kexec_file: Use crash_exclude_core_ranges() helper LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code riscv: kexec_file: Use crash_prepare_headers() helper to simplify code x86/crash: Use crash_prepare_headers() helper to simplify code arm64: kexec_file: Use crash_prepare_headers() helper to simplify code crash: Add crash_prepare_headers() to exclude crash kernel memory powerpc/crash: sort crash memory ranges before preparing elfcorehdr riscv: kexec_file: Fix crashk_low_res not exclude bug
2026-08-10x86/CPU: Add a tlbi= cmdline switchRik van Riel1-0/+10
With the recently found INVLPGB / TLBSYNC issue, there has been some interest in disabling INVLPGB-based TLB flushing, in order to rule out that CPU issue as a cause of userspace crashes. Add a kernel command line option to control the TLB flushing behavior. If the need arises, we will add a "tlbi=broadcast" for the case when TLB invalidation broadcasts need to be explicitly selected, but this is not needed now yet. [ bp: Rewrite commit message, move to cpu/common.c, add documentation. ] Fixes: 767ae437a32d ("x86/mm: Add INVLPGB feature and Kconfig entry") Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://patch.msgid.link/20260729204341.3eb0b5ea@fangorn
2026-08-10preempt: Introduce HAS_SEPARATE_PREEMPT_RESCHED_BITSBoqun Feng1-1/+1
With the changes that enable preempt count to track IRQ disabling nesting, we don't have enough bits in 32-bit preempt count implementation, as a result we move NMI nesting bits out of the 32-bit preempt count. However on the architectures that can support 64-bit preempt count implementation, we can keep the NMI nesting bits in the 32-bit preempt count and avoid maintaining NMI nesting bits outside of the same cache line. Therefore HAS_SEPARATE_PREEMPT_RESCHED_BITS is introduced to allow architectures to select this. Note that under this Kconfig, preempt count is maintained in a 64-bit word however preempt_count() still remains as an int because all the effective bits still fit in (previously we mask out NEED_RESCHED bit in preempt_count()). This should make no functional changes for existing preempt_count() users. Enable this for x86_64 along with the introduction of the Kconfig. [boqun: Undo the __preempt_count_{add,sub}() optimization in 32-bit preempt count since it may introduce {over,under}flow] Originally-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260804161447.84806-11-boqun@kernel.org
2026-08-08Merge tag 'x86-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull x86 fix from Ingo Molnar: - Fix MCE CMCI discovery initialization ordering bug (Breno Leitao) * tag 'x86-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Set up the polling timer before CMCI discovery
2026-08-07x86/paravirt: Trace contended_release on unlockDmitry Ilvokhin1-2/+51
On PARAVIRT_SPINLOCKS=y kernels queued_spin_unlock() is dispatched through a static_call(). Those PARAVIRT_SPINLOCKS=y kernels are quite popular. Gating contended_release behind a static branch would leave a NOP on the unlock hot path even, when the tracepoint is disabled. Since the static_call() is already present, swap its target to a traced unlock, when the tracepoint is enabled instead. When contended_release tracepoint is disabled the target is the plain unlock (an inline store on native x86_64), so the unlock path is unchanged and the tracepoint is truly zero-cost. Provide two traced variants, native_queued_spin_unlock_traced() and pv_queued_spin_unlock_traced(), so each tail-calls its own base unlock directly rather than recursing through the now-traced static_call(). Teach pv_is_native_spin_unlock() that the traced native variant still counts as native. Only PARAVIRT_SPINLOCKS=y is affected. PARAVIRT_SPINLOCKS=n keeps the generic static-branch path. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juergen Gross <jgross@suse.com> Link: https://patch.msgid.link/17fa67f9fa4cf93f1150725e89f5f916e41a9b6f.1785778551.git.d@ilvokhin.com
2026-08-07x86/paravirt: Use static_call() for the paravirt spinlock opsPeter Zijlstra3-9/+35
queued_spin_lock_slowpath() and queued_spin_unlock() are dispatched through pv_ops_lock via the paravirt-ops ALTERNATIVE machinery, which picks the target (native inline store / hypervisor call) once at boot and cannot change at runtime. Convert both to static_call(). The site becomes a direct call patched in place (one byte smaller), and on native the unlock still collapses to the inline "movb $0, (%rdi)" store, so the fast path is unchanged. Unlike the ALTERNATIVE mechanism, a static_call() target can also be updated at runtime via static_call_update(). This is a prerequisite for the contended_release tracepoint, which has to swap in a traced unlock while the system is running. [ ilvokhin: commit message; fix PARAVIRT_SPINLOCKS=n build; teach __static_call_validate() about the inline unlock insn; make the slowpath site module-safe: static_call_mod() + EXPORT_STATIC_CALL_TRAMP(); pass @lock to the callee-save unlock, fixing a boot hang under CALL_DEPTH_TRACKING. Boot tested native + KVM PV guest. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Dmitry Ilvokhin <d@ilvokhin.com> Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/all/20260603120811.GW3493090@noisy.programming.kicks-ass.net/ Link: https://patch.msgid.link/9a32ae399eb804a02a31af04dcabe7e7ee4f3fdf.1785778551.git.d@ilvokhin.com
2026-08-06xen: Drop CONFIG_XEN_PVHVMJuergen Gross1-1/+1
On x86 CONFIG_XEN_PVHVM is now a synonym of CONFIG_XEN. In Xen specific x86 code it can be just dropped, in non-Xen specific x86 code it can be replaced with CONFIG_XEN. In architecture independent code it is used only where CONFIG_XEN is defined, so it can be replaced with CONFIG_X86 there. Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com> Message-ID: <20260805082137.1214967-3-jgross@suse.com>
2026-08-05Merge tag 'x86_bugs_saferet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+39
- Add a mitigation for the attack vector of interrupting the saferet sequence used in the SRSO mitigation and still poisoning the RSB. Do that by emulating the saferet sequence and thus avoiding executing a RET instruction. * tag 'x86_bugs_saferet' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/bugs: Make Safe-RET robust against interrupt injection
2026-08-05x86/CPU: Rename struct cpuid_read_output to struct cpuid_outputBorislav Petkov (AMD)2-33/+29
There's no CPUID "write" operation so there's no need to have a cpuid_read_output thing - cpuid_output is perfectly clear. And shortens the code just fine. Remove the funky function signature line breaks while at it. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20260805025323.GCanKlox0DF7Gwhpf1@fat_crate.local
2026-08-05sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTLOleg Nesterov1-1/+1
CONFIG_SYSCTL used to make sense as a separate hidden bool before commit 61a47c1ad3a4 ("sysctl: Remove the sysctl system call"); it was selected by both CONFIG_SYSCTL_SYSCALL and CONFIG_PROC_SYSCTL. Today CONFIG_PROC_SYSCTL is the only selector, so the two are always equal. Kill the hidden bool, rename the PROC_SYSCTL prompt to SYSCTL, and s/CONFIG_PROC_SYSCTL/CONFIG_SYSCTL/ tree-wide. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2026-08-04mm: use linear_page_[index, delta]() consistentlyLorenzo Stoakes1-1/+2
There are a number of places where we open code what linear_page_index() and linear_page_delta() calculate. Replace this code with the appropriate functions for consistency. No functional change intended. Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-21-2a5aa403d977@kernel.org Signed-off-by: Lorenzo Stoakes <ljs@kernel.org> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> [DRM] Acked-by: Kai Huang <kai.huang@intel.com> # for sgx Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Pedro Falcato <pfalcato@suse.de> # for mm Reviewed-by: Ackerley Tng <ackerleytng@google.com> [guest_memfd] Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: David Hildenbrand (Arm) <david@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: SJ Park <sj@kernel.org> Cc: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04x86/mce: Set up the polling timer before CMCI discoveryBreno Leitao1-1/+1
I hit the following on one of my machines: mce: CPU0 BANK15 CMCI inherited storm ------------[ cut here ]------------ ODEBUG: assert_init not available (active state 0) object: (____ptrval____) object type: timer_list hint: 0x0 WARNING: lib/debugobjects.c:632 at debug_object_assert_init+0x178/0x230, CPU#0: swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc5 #3 PREEMPTLAZY RIP: 0010:debug_object_assert_init+0x18f/0x230 Call Trace: <TASK> __mod_timer mce_timer_kick cmci_discover intel_init_cmci mce_intel_feature_init mcheck_cpu_init identify_cpu identify_boot_cpu arch_cpu_finalize_init start_kernel A second splat follows right after, from timer_setup() finding that same timer already queued: ODEBUG: init active (active state 0) object: (____ptrval____) object type: timer_list hint: stub_timer+0x0/0x10 This is happening because CMCI storm detection is trying to modify the timer before latter was properly set up. Set up the timer first. __mcheck_cpu_setup_timer() only calls timer_setup(), and depends on neither the generic nor the vendor init. [ bp: Massage commit message. ] Fixes: 1f68ce2a0272 ("x86/mce: Handle Intel threshold interrupt storms") Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260803-mce_timer_init-v1-1-9539db424330@debian.org
2026-08-04x86/boot: Use IS_ENABLED() to simplify built-in-or-module checksThorsten Blum1-3/+2
Replace open-coded built-in-or-module checks for CONFIG_APM, CONFIG_EDD, and CONFIG_X86_SPEEDSTEP_SMI with IS_ENABLED(). No change in functionality intended. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://patch.msgid.link/20260804115227.62158-4-thorsten.blum@linux.dev
2026-07-31x86/cpu/scattered: Sort it properlyBorislav Petkov (AMD)1-2/+2
Sort it according to the following precedence of struct cpuid_bit fields: (level) -> (sub_leaf) -> (reg) -> (bit). No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2026-07-31x86/cpu: Use parsed CPUID(0x1)Ahmed S. Darwish1-11/+11
On early boot CPU detection, use parsed CPUID(0x1) instead of a direct CPUID query. Beside the parser's centralization benefits, use the auto generated CPUID data types, and their C99 bitfields, instead of doing ugly bitwise operations. [ bp: - Use a common code pattern for l1 of fetching and checking it right after that - flip the check to save an indentation level - align assignments vertically. ] Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20260528153923.403473-12-darwi@linutronix.de
2026-07-31x86/cpu: Use parsed CPUID(0x0)Ahmed S. Darwish1-5/+6
Use parsed CPUID(0x0) instead of a direct CPUID query. [ bp: Drop the unnecessary NULL check. ] Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20260528153923.403473-10-darwi@linutronix.de
2026-07-31Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar3-6/+50
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2026-07-31dma-direct: make dma_direct_map_phys() honor DMA_ATTR_CC_SHAREDAneesh Kumar K.V (Arm)1-3/+1
Teach dma_direct_map_phys() to select the DMA address encoding based on DMA_ATTR_CC_SHARED. Use phys_to_dma_unencrypted() for decrypted mappings and phys_to_dma_encrypted() otherwise. If a device requires unencrypted DMA but the source physical address is still encrypted, force the mapping through swiotlb so the DMA address and backing memory attributes remain consistent. Update the arm64, x86, s390 and powerpc secure-guest setup to not use swiotlb force option Tested-by: Jiri Pirko <jiri@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Mostafa Saleh <smostafa@google.com> Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Link: https://lore.kernel.org/r/20260717180442.110954-18-aneesh.kumar@kernel.org [mszyprow: rebased onto latest changes in arch/arm64/mm/init.c] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2026-07-31dma-direct: pass attrs to dma_capable() for DMA_ATTR_CC_SHARED checksAneesh Kumar K.V (Arm)1-14/+16
Teach dma_capable() about DMA_ATTR_CC_SHARED so the capability check can reject encrypted DMA addresses for devices that require unencrypted/shared DMA. Also propagate DMA_ATTR_CC_SHARED in swiotlb_map() when the selected SWIOTLB pool is decrypted so the capability check sees the correct DMA address attribute. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Jiri Pirko <jiri@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Mostafa Saleh <smostafa@google.com> Reviewed-by: Petr Tesarik <ptesarik@suse.com> Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Link: https://lore.kernel.org/r/20260717180442.110954-16-aneesh.kumar@kernel.org Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2026-07-30x86/kcfi: Optimize call sequencePeter Zijlstra2-3/+29
As noted in commit 85a2d4a890dc ("x86,ibt: Use UDB instead of 0xEA") Jcc should be assumed not-taken, however the normal kCFI (ABI) emits the following sequence: movl $(-hash), %r10d addl -15(%r11), %r10d je 1f ud2 1: cs call __x86_indirect_thunk_r11 (when used in conjunction with -mretpoline-external-thunk). Notably, the Jcc here is always taken, resulting in lower throughput than would be ideal. Replace it with the following sequence on boot: movl $(-hash), %r10d addl -15(%r11), %r10d jne . + 3 test $0xd6, %al cs call __x86_indirect_thunk_r11 This jumps to the UDB instruction used as an immediate byte in the test instruction. The test instruction will clobber eflags, but that is immaterial, eflags is already changed by the preceding addl. Intel recommends the FineIBT sequence on platforms that support IBT; older platforms are still widely used and would benefit from this. An earlier PoC was benchmarked by Scott: Indirect branch miss rate (br_misp_retired.indirect:k / br_inst_retired.indirect:k) BHI_DIS_S=1 Benchmark Baseline IBT kCFI kCFI-opt ----------------------------------------------------------------------------- iperf3 UDP 0.103764 0.103180 0.104311 0.102945 hackbench 0.000885 0.000876 0.001996 0.000826 lmbench syscall 0.005089 0.004486 0.016990 0.005852 lmbench fork+exit 0.018454 0.019176 0.031085 0.015153 lmbench fork+exec 0.017147 0.021613 0.029129 0.016337 redis 0.032220 0.032655 0.045540 0.027946 nginx+wrk 0.109033 0.112765 0.132557 0.102417 fio randread 0.009704 0.009620 0.008548 0.000962 fio seqwrite 0.006927 0.006707 0.019372 0.004590 kbuild 0.056748 0.057324 0.064640 0.048136 BHI_DIS_S=0 Benchmark Baseline IBT kCFI kCFI-opt ----------------------------------------------------------------------------- iperf3 UDP 0.000077 0.000106 0.000186 0.000073 hackbench 0.000123 0.000132 0.000367 0.000097 lmbench syscall 0.023259 0.018319 0.040903 0.012772 lmbench fork+exit 0.011494 0.011887 0.029079 0.016415 lmbench fork+exec 0.037782 0.038994 0.055378 0.026381 redis 0.002481 0.003152 0.017073 0.000184 nginx+wrk 0.015478 0.016266 0.033637 0.000268 fio randread 0.009836 0.007949 0.007096 0.000143 fio seqwrite 0.014587 0.014165 0.041792 0.002157 kbuild 0.055774 0.055249 0.062590 0.046546 Suggested-by: Scott D Constable <scott.d.constable@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://patch.msgid.link/20260612071506.GQ187714%40noisy.programming.kicks-ass.net
2026-07-30Merge branch 'mm-stable-6d098029de09' of https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm into kho-scratchMike Rapoport (Microsoft)4-14/+68
2026-07-29x86/CPU/AMD: Carve out a Zen5 models rangePratik Vishwakarma1-1/+3
Family 0x1a, model 0xd0..0xd7 belongs to the Zen5 generation. Carve it out from the larger, Zen6 range where former doesn't belong. [ bp: Rewrite commit message, add tags. ] Fixes: b5f53e6d3d32 ("x86/CPU/AMD: Add more Zen6 models") Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://patch.msgid.link/20260729055459.15904-1-Pratik.Vishwakarma@amd.com
2026-07-27x86/cpu/transmeta: Rescan CPUID(0x1) after modifying capabilitiesAhmed S. Darwish1-0/+1
Transmeta CPUs allow masking CPUID(0x1).EDX feature flags via MSR writes. If a bit is cleared in the 0x80860004 MSR, its corresponding feature flag is not reported by CPUID. Refresh the CPUID parser's CPUID(0x1) cache after all MSR bits are unmasked. Note, the MSR 0x80860004 semantics are documented in the "BIOS Programmer's Guide: Transmeta Crusoe Processor" document, dated June 14, 2002. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20260528153923.403473-9-darwi@linutronix.de
2026-07-26x86/bugs: Make Safe-RET robust against interrupt injectionBorislav Petkov (AMD)1-0/+39
An attacker injecting interrupts while the Safe-RET mitigation executes on machines affected by SRSO can neutralize the safe return sequence, potentially leading to data leakage through speculative execution. Fixup register state as if the Safe-RET sequence executed successfully by "emulating" it, in a manner of speaking, and avoid executing a RET instruction after returning from the interrupt. Co-developed-by: David Kaplan <David.Kaplan@amd.com> Signed-off-by: David Kaplan <David.Kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2026-07-23x86/topology: Add TOPO_CPU_TYPE_LOW_POWERVishal Badole2-1/+5
AMD heterogeneous parts report a third core type via CPUID Fn0x80000026 EBX[31:28] (Extended CPU Topology, Core Type): 0 - Performance 1 - Efficiency 2 - Low Power get_topology_cpu_type() only translates the first two, so on parts that ship low-power cores the third type falls through to TOPO_CPU_TYPE_UNKNOWN. Add TOPO_CPU_TYPE_LOW_POWER which takes care of this new type. [ bp: Massage commit message, zap the "what" explanation. ] Signed-off-by: Vishal Badole <Vishal.Badole@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20260721154514.2506972-4-Vishal.Badole@amd.com
2026-07-23x86/topology: Name the AMD core-type valuesVishal Badole1-2/+2
Replace the bare 0/1 in get_topology_cpu_type() with named constants that mirror what the AMD APM publishes for CPUID Fn0x80000026 EBX[31:28] (Extended CPU Topology, Core Type): 0 - Performance core 1 - Efficient core 2 - Low-power core (used by a follow-up) No functional change. Suggested-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Vishal Badole <Vishal.Badole@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20260721154514.2506972-3-Vishal.Badole@amd.com
2026-07-23x86/topo: Map vendor CPU types to generic Linux such typesBorislav Petkov (AMD)5-35/+14
Sashiko reported¹ that a confusion could ensue if a vendor-specific CPU type 0 (performance) gets attempted to be used in a x86_cpu_id match table. The current logic treats 0 as the wildcard X86_CPU_TYPE_ANY and such a thing would end up matching the wrong CPUs. This is all backwards because we started using the vendor-specific CPU type number instead of using a Linux-defined, generic CPU type which is agnostic. Convert the current logic to it before users start appearing. ¹https://sashiko.dev/#/patchset/20260629094349.533301-1-Vishal.Badole%40amd.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Vishal Badole <Vishal.Badole@amd.com> Link: https://patch.msgid.link/20260721154514.2506972-2-Vishal.Badole@amd.com
2026-07-23x86/kvm: Disable preemption in kvm_flush_tlb_multi()Chuyi Zhou1-1/+3
kvm_flush_tlb_multi() is installed as an x86 PV TLB flush backend, so flush_tlb_multi() can reach it through pv_ops when running as a KVM guest. kvm_flush_tlb_multi() uses the per-CPU scratch cpumask __pv_cpu_mask. That buffer must remain tied to the current CPU until the mask has been copied, filtered, and consumed by native_flush_tlb_multi(). The x86/mm callers currently enter flush_tlb_multi() while pinned to a CPU. To let those callers drop CPU pinning before issuing the remote TLB flush, each PV backend must protect its own CPU-local scratch state. Make the KVM backend protect its per-CPU scratch cpumask by disabling preemption locally. This is harmless with the current callers, where the preemption disable is nested, and makes the KVM pv_ops dependency explicit before changing the x86/mm call sites. Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20260709122933.4021501-14-zhouchuyi@bytedance.com
2026-07-22x86/resctrl: Protect against bad shiftReinette Chatre1-1/+5
The size of the bandwidth field is enumerated from AMD hardware. resctrl uses this field width to determine the maximum bandwidth supported that is stored in resctrl_membw::max_bw. User space allocation requests ("control values") are compared against this maximum for validity before being programmed to hardware. resctrl filesystem and resctrl x86 architecture code only support u32 control values: resctrl_membw::max_bw is a u32, the control value provided by user space is parsed into u32 local variables, and after validity checks, the control value is staged into the u32 resctrl_staged_config::new_ctrl for architecture consumption. The resctrl x86 architecture code in turn caches the new control value into the u32 array rdt_hw_ctrl_domain::ctrl_val[]. The AMD bandwidth field to which control values are written can be up to 64 bits wide. While not an issue with current hardware (bandwidths that require more than a u32, more than 536870911.875 GB/s, seem unreasonable today), it is theoretically possible that enumeration of maximum bandwidth field width will return values that are according to specification but cannot be supported by resctrl. Static checkers complain about this size mismatch. Fix the static checker complaint by explicitly encoding the fact that resctrl is unable to support all values that the hardware specification allows. Switch to BIT() instead of open-coding the bitshift to avoid signed integer overflow if the number of bits is a valid 31. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://patch.msgid.link/dd9fc3505c0ed250c5f14898b0ed6d7460a3cb82.1784753375.git.reinette.chatre@intel.com