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36 hoursinit: fix early boot crash with bare hostname parameterThorsten Blum
When a bare hostname parameter is specified on the kernel command line without the '=' separator, early parameter parsing passes NULL to early_hostname(), which dereferences it in strscpy() and can crash the system during early boot. Reject NULL values in early_hostname() and return -EINVAL instead. Link: https://lore.kernel.org/20260826100904.296151-2-blum@kernel.org Fixes: 5a704629f2c1 ("init: add "hostname" kernel parameter") Signed-off-by: Thorsten Blum <blum@kernel.org> Cc: Dan Moulding <dmoulding@me.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
4 daysMerge tag 'bootconfig-v7.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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
9 daysMerge tag 'mm-stable-2026-08-18-18-39' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 ...
9 daysMerge tag 'sched_ext-for-7.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext updates from Tejun Heo: "Most of this cycle completes the enqueue-path support for hierarchical sub-scheduling, which makes sub-scheduler support feature complete: a root BPF scheduler can now hand a cgroup subtree over to a nested sub-scheduler together with revocable CPU grants, and the sub-scheduler owns all scheduling decisions for its tasks on those CPUs. Development volume was high and a number of changes plugging holes in the new support landed late in the cycle. Also included are core scheduling fixes that were completed too late for the v7.2 release and are routed through this pull request. Sub-scheduler CPU delegation: - Parent schedulers now grant and revoke per-CPU capabilities (enqueueing, preemption, CPU frequency control) on their children, enforced on every path a scheduler can reach a CPU through. Previously only dispatching could be delegated; this lets sub-schedulers fully schedule their CPUs. - Rescue execution: a task whose scheduler doesn't have access to the CPUs the task needs to run on starved until the watchdog ejected the whole scheduler. The kernel now runs such tasks directly on a small bandwidth budget, turning a scheduler-killing failure into bounded degradation. - Cgroup integration: tasks migrating across a sub-scheduler boundary weren't re-homed to the new owner, causing wrong-scheduler scheduling and a use-after-free. Sub-schedulers now take over their cgroup subtree and receive its cgroup callbacks. - Arena objects now cross the kernel/BPF boundary as typed pointer arguments, translated transparently by the BPF tree's new arena argument support, replacing untyped arguments with manual translation. - scx_qmap now demonstrates full hierarchical sub-scheduling. Other fixes and updates: - Robustness improvements: the abort path is now NMI-safe, fixing deadlocks when errors are raised from NMI context and making hardlockup recovery direct. Reenqueue loops that could monopolize a CPU ahead of the watchdog now eject the offending scheduler, and stalls are blamed on the scheduler actually responsible. - Hardening: BPF-writable arena memory is validated before kernel use, and task slice and vtime writes got explicit synchronization rules, closing corruption vectors open to buggy or malicious schedulers. - Core scheduling: sched_ext dispatching can drop the rq lock inside the core-wide pick, which let interleaving selections corrupt each other's state and hard-hang the machine. The selection now restarts when the lock was released. The task ordering callback was also invoked with its arguments swapped, and the default ordering is updated to work across sub-scheduler boundaries. The fixes are marked for stable. - Other fixes headed for stable: a task init leak on fork failure during enable, tooling compat macros that silently failed to detect newer kernels, and a crash on reenqueueing against a destroyed dispatch queue. - Tooling: scx_pair moves off deprecated callbacks, and the deprecated scx_bpf_cpu_rq() kfunc is removed" * tag 'sched_ext-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (144 commits) sched_ext: Drop the dead SCX_DEQ_CORE_SCHED_EXEC test in dequeue_task_scx() sched_ext: Make core-sched task ordering hierarchy-aware sched_ext: Use runnable_at for the default core-sched task ordering sched_ext: Fix inverted ops.core_sched_before() invocation sched_ext: Move the config-off sub-cap kfunc stubs into sub.c sched_ext: Rename balance-era identifiers to dispatch terms sched_ext: Drop the stale keep_prev fixup in dispatch_pick() sched_ext: Keep kick_sync waiting on the rq's own CPU sched_ext: Make SCHED_CLASS_EXT select GENERIC_ALLOCATOR sched_ext/scx_flatcg: Fix cvtime true-up on slice expiry sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users sched_ext: Fix scx_bpf_dsq_move_to_local___v2 compat detection sched_ext: Make scx_bpf_events() read the calling scheduler's counters sched_ext: Drop unlocked scx_rq_clock_invalidate() from scx_root_disable() selftests/sched_ext: Fix flaky ddsp failure tests on busy systems selftests/sched_ext: Make numa idle validation race-free sched_ext: Fix scx_bpf_dsq_reenq___compat kfunc extern prototype sched_ext/scx_flatcg: expire cached hweights on weight changes sched_ext: Fix exit_task leak on fork failure during enable sched_ext: fix stale references in doc comments ...
9 daysMerge tag 'sysctl-7.03-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl 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
11 daysMerge tag 'timers-vdso-2026-08-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull VDSO updates from Thomas Gleixner: - Consolidate the VDSO datastore further and provide support for mlock_all() and prefaulting. - Provide 32-bit legacy time related functionality only if CONFIG_COMPAT_32BIT_TIME is enabled. The config switch exists, but architecture code still exposes the legacy functionality even disabled. Clean this up by adding the missing guards and validating at build time that the VDSO is legacy free if disabled. - Consolidate the VDSO related config options in core and drivers, which removes some non-sensical dependencies and quite an amount of #ifdeffery. - Clean up the PAGE_SIZE definition maze * tag 'timers-vdso-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits) random: vDSO: Drop custom PAGE_SIZE definitions LoongArch: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery clocksource/drivers/timer-riscv: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery clocksource/drivers/arm_arch_timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery clocksource/drivers/mips-gic-timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery MIPS: csrc-r4k: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery vDSO: Make clockmode constants available without CONFIG_GENERIC_GETTIMEOFDAY kbuild: Support generated asm-headers in subdirectories vdso: Rename HAVE_GENERIC_VDSO to VDSO_DATASTORE vdso: Drop HAVE_GENERIC_VDSO from architecture kconfig files vdso: Automatically select HAVE_GENERIC_VDSO if necessary MIPS: vdso: Stop using CONFIG_HAVE_GENERIC_VDSO vdso: Remove the dependency on HAVE_GENERIC_VDSO from ARCH_HAS_VDSO_ARCH_DATA futex: Remove dependency on HAVE_GENERIC_VDSO from FUTEX_ROBUST_UNLOCK vdso/gettimeofday: Verify COMPAT_32BIT_TIME interactions sparc: vdso: Respect COMPAT_32BIT_TIME MIPS: VDSO: Respect COMPAT_32BIT_TIME powerpc/vdso: Respect COMPAT_32BIT_TIME ARM: VDSO: Respect COMPAT_32BIT_TIME arm64: vdso32: Respect COMPAT_32BIT_TIME ...
11 daysMerge tag 'timers-core-2026-08-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer and timekeeping core updates from Thomas Gleixner: - Fix a subtly inconsistency in the timekeeping code, which fails to account for the monotonicity adjustment in ntp_error. For small changes of the clocksource multiplicator (+/-1) which are typically used by the NTP PLL this is hard to observe. But for larger adjustments, e.g. caused by a direct frequency setting through adjtimex() the one-time uncompensated offset is significant. Cure this by adjusting ntp_error with the resulting offset so that the discrepancy is smoothed away over time - Make tick length calculations correct in NTP. The timekeeping core takes the quantisation of the clocksource into account when calculating the tick length to compensate for the deviation of the nominal NTP_INTERVAL_LENGTH. While timekeeping gets this right, NTP is not aware of that, which means it operates on the nominal value and not on the actual value which is determined by the clock source frequency. The rounding of a coarse clocksource like the ACPI PM timer results in a +127 PPM deviation. Cure this by exposing the deviation to the NTP code so that it can operate on the same data as the timekeeping core. This is purely kernel internal. User space still sees the nominal tick lenght via adjtimex(). - The accuracy of the NTP adjustments is fairly approximate as the code assumes that the invocations are precisely in NTP interval frequency ticks and the final adjustment can over and under-run. Cure this by adjusting ntp_error by the intended skew on each tick to achieve the desired rate. - Handle the two competing skews of time offset and time adjustment correctly by calculating the conflict portion between the skews and adjusting both accordingly. - A set of updates and improvements for the selftests - The usual small fixes and improvements all over the place * tag 'timers-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits) selftests: timers: nsleep-lat: Check all calls to clock_nanosleep() and clock_gettime() selftests: timers: nsleep-lat: Reuse kselftest error numbers selftests: timers: nsleep-lat: Explicitly list the tested clocks selftests: timers: nsleep-lat: Use NSEC_PER_MSEC define for unreasonable latency selftests: timers: nanosleep: Report each test separately selftests: timers: nanosleep: Explicitly handle timer_delete() failure selftests: timers: nanosleep: Move all single clock tests out of the loop in main() selftests: timers: nanosleep: Reuse kselftest error numbers selftests: timers: nanosleep: Explicitly list the tested clocks selftests: timers: nanosleep: Drop output alignment selftests: timers: Use clock_name() and constants from clock-helpers.h selftests: Add clock-helpers.h timer_list: Use ktime_t over nanoseconds timer_list: Use standard 'long long' format placeholders hrtimer: Add a lockdep assertion to hrtimer_update_base() timekeeping: Use u32 for clock_was_set_seq timekeeping: Rename clockid_aux_valid() to clockid_is_aux_clock() hrtimer: Account nr_retries on recovered interrupt retries timers/itimer: Zero-init old itimerval before copy to userspace nohz: Replace dead select with choice default ...
11 daysMerge tag 'timers-cleanups-2026-08-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
12 daysMerge tag 'vfs-7.3-rc1.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Bigger cleanups: - The lockref dead-count handling is tidied up. The open-coded check for a count below zero as the dead marker relies on information the caller should not have. - make put_mnt_ns() leave mounts connected. Destroying a mount namespace disconnected its mounts from their mount points. So a file descriptor still open on the parent of a mount point could be used to peek under it. Locked mounts were already kept connected to prevent exactly that. But a mount is only locked when its tree is copied across a user namespace boundary. So a mount namespace set up by a privileged component had no locked mounts and its mounts were disconnected. Passing UMOUNT_CONNECTED keeps every mount connected and prevents that bug. - vfs_prepare_mode() passes S_IFDIR for directories. I meant to fix that ago but didn't get to it. So now someone finally did it. This kills the exception where the mode could be 0 when a directory was created whereas every other creation operation passed it explicitly already. - move long delayed work for ufs, jffs2, hfsplus, hfs and affs from the per-cpu system_long_wq to the new unbound system_dfl_long_wq. None of that work relies on per-cpu state and the work item is enqueued with queue_delayed_work() whose timer is global anyway. So it may as well benefit from scheduler task placement. Smaller fixes and cleanups: - unlock_buffer() and journal_end_buffer_io_sync() use clear_and_wake_up_bit() - the pipe page pools are unified into a single per-pipe pool and the extra wake_up(rd_wait) is limited to EPOLLET consumers - eventpoll now computes its timer slack lazily in ep_poll() - shrink_dcache_for_umount() keeps making progress on busy roots - excess xarray nodes are freed in clear_inode() - romfs detects hard link cycles - the user path of nested backing files is fixed - pidfd holds exec_update_lock around the namespace ioctl - non-memcg-aware nr_cached_objects is skipped during memcg slab shrink - iomap_write_iter() always returns status - mangle_path() is renamed to seq_mangle_path() - inode timestamp accessors are annotated - new regression test for pipe->poll_usage. - a few documentation, kernel-doc and selftest fixes" * tag 'vfs-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (67 commits) selftests/namespaces: Fix racy pipe handshake in timens and pidns_separate selftests/epoll: add a regression test for pipe->poll_usage pipe: only enable the extra wake_up(rd_wait) for EPOLLET consumers pidfd: hold exec_update_lock around namespace ioctl fs: fix user path of nested backing files fs: remove stale inode_insert5() kernel-doc parameter fs: fix switch/case indentation in sysfs() syscall fs: document semantics of kstat::{uid,gid} fields dcache: keep shrink_dcache_for_umount() making progress on busy roots seq_file: rename mangle_path to seq_mangle_path nstree: add/fix struct ns_id_req kernel-doc member fields dcache: use lockref routines for dead count checks lockref: tidy up dead count handling initramfs: fix typo in reserve_initrd_mem comment fs/pipe: unify the page pools into a single per-pipe pool fs: annotate inode timestamp accessors eventpoll: compute timer slack lazily in ep_poll() selftests/filesystems: add mntns cleanup test put_mnt_ns(): leave mounts connected affs: Move long delayed work on system_dfl_long_wq ...
12 daysMerge tag 'vfs-7.3-rc1.kthread' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull kthread vfs updates from Christian Brauner: "This stops kernel threads from sharing filesystem state with userspace. This work is about 3 cycles old and has been in -next for about that time. When the kernel boots init_task creates PID 1 and then kthreadd. From that point every kthread and PID 1 share the same fs_struct. That is why pivot_root() has to rewrite the fs_struct of all kthreads. The rewriting exists so that kthreads can use init's filesystem state when they want to. It also means userspace can move the ground out from under the kernel. PID 1 now gets a completely separate fs_struct. All kthreads are anchored in a private SB_KERNMOUNT instance of nullfs that cannot be mounted on and cannot be used to follow other mounts. Userspace init can no longer affect kthread filesystem state and kthreads can no longer affect userspace fs state without explicit opting in to that. Path lookup from a kthread now fails by default. It makes it deliberately hard to offload security sensitive operations into init's filesystem state from a kthread. Places that legitimately need to look something up there opt in through the new scoped_with_init_fs() which temporarily overrides the caller's fs_struct with init's. usermodehelpers remain the only kernel tasks that genuinely share init's filesystem state, since they execute random binaries in the root filesystem (excellent...). The visible result is that /proc/2/root is a nullfs with an empty mountinfo while /proc/1/root is the real root" * tag 'vfs-7.3-rc1.kthread' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits) initramfs_test: use test init/exit hooks to override init fs fs: stop rewriting paths for PF_EXITING | PF_DUMPCORE fs: stop rewriting kthread fs structs fs: start all kthreads in nullfs nullfs: make nullfs multi-instance devtmpfs: create private mount namespace fs: add umh argument to struct kernel_clone_args fs: stop sharing fs_struct between init_task and pid 1 af_unix: use scoped_with_init_fs() for coredump socket lookup initramfs: use scoped_with_init_fs() for rootfs unpacking pnfs/blocklayout: use scoped_with_init_fs() for SCSI device lookup ksmbd: use scoped_with_init_fs() for VFS path operations ksmbd: use scoped_with_init_fs() for filesystem info path lookup ksmbd: use scoped_with_init_fs() for share path resolution fs: use scoped_with_init_fs() for kernel_read_file_from_path_initns() coredump: use scoped_with_init_fs() for coredump path resolution btrfs: use scoped_with_init_fs() for update_dev_time() scsi: target: use scoped_with_init_fs() for APTPL metadata scsi: target: use scoped_with_init_fs() for ALUA metadata crypto: ccp: use scoped_with_init_fs() for SEV file access ...
2026-08-11nohz: Replace dead select with choice defaultJulian Braha
'select' does not work on config options in a 'choice', so currently the 'select VIRT_CPU_ACCOUNTING_GEN' for NO_HZ_FULL is dead, with the choice option VIRT_CPU_ACCOUNTING_GEN only being enabled when NO_HZ_FULL=y because the other choice members depend on NO_HZ_FULL=n. Remove the dead select, and encode this relationship as a default of the choice, instead. This dead select was found by kconfirm, a static analysis tool for Kconfig. Signed-off-by: Julian Braha <julianbraha@gmail.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Bradley Morgan <include@grrlz.net> Reviewed-by: Nicolas Schier <nsc@kernel.org> Link: https://patch.msgid.link/20260801160140.2391000-1-julianbraha@gmail.com
2026-08-10Merge branch 'master' of ↵Tejun Heo
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next into for-7.3-arena-args Pull bpf-next d114bb989367 ("Merge branch 'add-arena-argument-support-to-kfuncs-and-struct_ops'") to make the __arena and __arena__nullable kfunc and struct_ops argument suffixes available. The suffixed arguments will be used to convert sched_ext kfuncs and struct_ops callbacks that currently pass arena pointers as scalars and rebase them by hand.
2026-08-06mm/mseal: fix mseal documentation for 32-bit kernelsLeon Hwang
mseal.o is built only for 64-bit kernels, so 32-bit kernels fall back to sys_ni_syscall() and return -ENOSYS rather than -EPERM. Drop architecture description in mseal.rst, since the arch feature doc has the latest state of mseal for each architecture. Fix the CONFIG_MSEAL_SYSTEM_MAPPINGS typo in init/Kconfig. Link: https://lore.kernel.org/20260715131258.55499-1-leon.hwang@linux.dev Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Acked-by: Lance Yang <lance.yang@linux.dev> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Anand Moon <linux.amoon@gmail.com> Cc: Doug Anderson <dianders@chromium.org> Cc: Gary Guo <gary@garyguo.net> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leon Hwang <leon.hwang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-05sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTLOleg Nesterov
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: decouple protnone helpers from CONFIG_NUMA_BALANCINGKiryl Shutsemau (Meta)
Patch series "userfaultfd: working set tracking for VM guest memory", v10. This series adds 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. This patch (of 15): pte_protnone() and pmd_protnone() detect present-but-inaccessible page table entries. This capability is useful beyond NUMA balancing -- for example, userfaultfd working set tracking uses protnone PTEs to track page access without unmapping pages. Introduce CONFIG_ARCH_HAS_PTE_PROTNONE to decouple the protnone PTE infrastructure from CONFIG_NUMA_BALANCING. The six architectures that support protnone PTEs (x86_64, arm64, powerpc, s390, riscv, loongarch) now select this option, and CONFIG_NUMA_BALANCING depends on it. No functional change -- the same set of architectures continues to have working protnone support, but the infrastructure is now available independently of NUMA balancing. Link: https://lore.kernel.org/20260708111417.173443-1-kirill@shutemov.name Link: https://lore.kernel.org/20260708111417.173443-2-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org> Assisted-by: Claude:claude-opus-4-6 Acked-by: SeongJae Park <sj@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@kernel.org> Cc: James Houghton <jthoughton@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-31initramfs_test: use test init/exit hooks to override init fsChristian Brauner
Most initramfs kunit tests interact with initramfs via unpack_to_rootfs() and subsequently init_stat(), init_unlink(), etc. It's cleaner and less error-prone to override current->fs with userspace_init_fs for all initramfs_test_suite tests. Link: https://patch.msgid.link/20260701-work-kunit-nullfs-v1-1-dfa60270434f@kernel.org [1] Link: https://patch.msgid.link/20260729151320.21001-2-ddiss@suse.de # folded into [1] Fixes: 32750c77e811 ("fs: start all kthreads in nullfs") Reported-by: Mark Brown <broonie@kernel.org> Closes: https://lore.kernel.org/r/akOrbOsKUqgZarGw@sirena.org.uk Signed-off-by: David Disseldorp <ddiss@suse.de> Co-developed-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-31initramfs: fix typo in reserve_initrd_mem commentShivank Sharma
Fix a minor typo in the comment inside reserve_initrd_mem. Change "virtul" to "virtual". Signed-off-by: Shivank Sharma <shivanksharma2376543@gmail.com> Link: https://patch.msgid.link/20260716160944.1331096-1-shivanksharma2376543@gmail.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-15calibrate: Rework delay timer calibrationThomas Gleixner
The header define in asm/timex,h and the naming of the function to read the delay timer are confusing at best. Convert it to a config switch selected by the archictures which provide the functionality and rename the function to delay_read_timer(), which makes the purpose clear. Move the declaration to linux/delay.h where it belongs. Remove the resulting empty asm/timex.h files as well. No functional change. Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20260410120317.978403520@kernel.org
2026-07-15futex: Remove dependency on HAVE_GENERIC_VDSO from FUTEX_ROBUST_UNLOCKThomas Weißschuh
The robust futex unlock functionality has no relation to the generic vDSO functionality. Remove the dependency. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://patch.msgid.link/20260709-vdso-have_generic_vdso-v1-1-d2e1061f268b@linutronix.de
2026-07-13sched_ext: Track the cpu a task is runnable onTejun Heo
Add p->scx.runnable_cpu, the cpu @p is runnable on, or -1 when it is not. It is stamped as @p joins the runnable_list (set_task_runnable()) and cleared as it leaves (clr_task_runnable()), both under the rq lock. task_cpu() can't answer "is @p on this rq" reliably: a remote wakeup changes it under @p's pi_lock alone, without the source rq lock, so it can read as the locked rq while @p is really elsewhere. runnable_cpu changes only under the rq lock, so a caller holding an rq lock can compare against it to know whether that is @p's current rq. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-02init/main.c: use bootconfig_cmdline_requested() for the runtime opt-inBreno Leitao
setup_boot_config() open-coded the same "is bootconfig requested on the kernel command line?" check that setup_arch() performs via the shared bootconfig_cmdline_requested() helper. Switch it to the helper so the early (setup_arch) and late (setup_boot_config) paths use one parser and cannot disagree on what counts as opt-in. The helper also reports the offset of the init arguments following a "--" separator, which is exactly what initargs_offs needs, so the local parse_args() call, its bootconfig_params() callback and the tmp_cmdline copy are removed. No functional change intended. Link: https://lore.kernel.org/all/20260626-bootconfig_using_tools-v7-9-24ab72139c29@debian.org/ Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-02bootconfig: skip runtime kernel.* render once prepended earlyBreno Leitao
setup_boot_config() folds the embedded bootconfig "kernel" subtree into the command line via xbc_make_cmdline("kernel"). A subsequent patch lets an architecture prepend the build-time-rendered embedded "kernel" keys to boot_command_line early in setup_arch(); rendering them again here would then duplicate every key in saved_command_line and make accumulating handlers (console=, earlycon=, ...) re-register the same value. Track whether the bootconfig data came from the embedded source (from_embedded) and skip the runtime render only when the early prepend actually happened, as reported by xbc_embedded_cmdline_applied(). On architectures that do not select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG that helper is a stub returning false, so this path is unchanged and the embedded "kernel" keys still reach the cmdline via the runtime parser exactly as before. Link: https://lore.kernel.org/all/20260626-bootconfig_using_tools-v7-8-24ab72139c29@debian.org/ Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-02bootconfig: render embedded bootconfig as a kernel cmdline at build timeBreno Leitao
Add the build-time pipeline that renders the "kernel" subtree of CONFIG_BOOT_CONFIG_EMBED_FILE into a flat cmdline string and stashes it in .init.rodata as embedded_kernel_cmdline[]. A follow-up patch adds the runtime helper that prepends this string to boot_command_line during early architecture setup so parse_early_param() sees the values. The build wires up: tools/bootconfig -C kernel - userspace tool already shared with lib/bootconfig.c, used here in -C mode to render a bootconfig file to a cmdline lib/embedded-cmdline.S - .incbin's the rendered text plus a NUL (listed under the EXTRA BOOT CONFIG MAINTAINERS entry) lib/Makefile rule - runs tools/bootconfig at build time Makefile prepare dep - ensures tools/bootconfig is built first, same pattern as tools/objtool and tools/bpf/resolve_btfids Drop the test target from tools/bootconfig/Makefile's default 'all' recipe so that hooking the binary into the kernel build does not run test-bootconfig.sh on every prepare. The tests stay available as 'make -C tools/bootconfig test', matching the convention of tools/objtool and tools/bpf/resolve_btfids whose 'all' targets only build the binary. Require BOOT_CONFIG_EMBED_FILE to be non-empty before the new option can be enabled, otherwise tools/bootconfig -C runs against an empty file and prints a parse error on every kernel build. The feature gates on CONFIG_ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG, a silent symbol arches select once they've wired the prepend call into setup_arch(). No arch selects it in this patch, so the user-visible CONFIG_CMDLINE_FROM_BOOTCONFIG is not yet enableable; when an arch later opts in, the runtime behavior is added by the follow-up patches. tools/bootconfig also installs on target systems, so its own Makefile keeps $(CC) and stays cross-buildable as a standalone tool. The kernel build, which runs the tool on the build host during prepare, instead forces CC=$(HOSTCC) from a dedicated tools/bootconfig rule and clears CROSS_COMPILE= in the sub-make. Without that clear, an LLVM=1 cross build would inherit CROSS_COMPILE and tools/scripts/Makefile.include would inject --target=/--sysroot= flags into the host clang invocation, producing a target binary that fails to exec ("Exec format error"). embedded-cmdline.S places the rendered string in its own .init.rodata subsection (.init.rodata.embed_cmdline) with the "a" (allocatable, read-only) flag and %progbits. lib/bootconfig-data.S already places the embedded bootconfig blob in .init.rodata with the "aw" flag (xbc_init() rewrites separators in place, so that data must be writable). Using a distinct subsection name avoids the ld.lld section- type mismatch that would otherwise arise from mixing "a" and "aw" under the same name; the linker's "*(.init.rodata .init.rodata.*)" glob still folds both into the init image and frees them after boot. A follow-up patch wires the build-time tools/bootconfig into the top-level clean target. Link: https://lore.kernel.org/all/20260626-bootconfig_using_tools-v7-3-24ab72139c29@debian.org/ Reviewed-by: Nicolas Schier <n.schier@fritz.com> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-06-29rust: allow `suspicious_runtime_symbol_definitions` lint for Rust >= 1.98Miguel Ojeda
Starting with Rust 1.98.0 (expected 2026-08-20), Rust is introducing a couple new lints, `invalid_runtime_symbol_definitions` (deny-by-default) and `suspicious_runtime_symbol_definitions` (warn-by-default), which check the signature of items whose symbol name is a runtime symbol expected by `core`. Our build hits the second one, i.e. the warning: error: suspicious definition of the runtime `strlen` symbol used by the standard library --> rust/bindings/bindings_generated.rs:20018:5 | 20018 | pub fn strlen(s: *const ffi::c_char) -> usize; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: expected `unsafe extern "C" fn(*const i8) -> usize` found `unsafe extern "C" fn(*const u8) -> usize` = help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]` = help: allow this lint if the signature is compatible = note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]` error: suspicious definition of the runtime `strlen` symbol used by the standard library --> rust/uapi/uapi_generated.rs:14236:5 | 14236 | pub fn strlen(s: *const ffi::c_char) -> usize; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: expected `unsafe extern "C" fn(*const i8) -> usize` found `unsafe extern "C" fn(*const u8) -> usize` = help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]` = help: allow this lint if the signature is compatible = note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]` Thus `allow` the lint in `bindings` and `uapi`. A more targeted alternative to avoid `allow`ing it would be to pass `--blocklist-function strlen` to `bindgen`, but we would perhaps need to adjust if other C headers end up adding more (or Rust checking more). Since it is just the less critical one that we hit, and since eventually this should be properly fixed by getting upstream Rust to provide a flag like GCC/Clang's `-funsigned-char` [2][3], just `allow` it for now. Cc: Urgau <urgau@numericable.fr> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Link: https://github.com/rust-lang/rust/pull/155521 [1] Link: https://github.com/rust-lang/rust/issues/138446 [2] Link: https://github.com/Rust-for-Linux/linux/issues/355 [3] Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Tamir Duberstein <tamird@kernel.org> Link: https://patch.msgid.link/20260615143225.471756-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-29fs: stop sharing fs_struct between init_task and pid 1Christian Brauner
Spawn kernel_init (PID 1) via kernel_clone() directly instead of user_mode_thread(), without CLONE_FS. This gives PID 1 its own private copy of init_task's fs_struct rather than sharing it. This is a prerequisite for isolating kthreads in nullfs: when init_task's fs is later pointed at nullfs, PID 1 must not share it or init_userspace_fs() would modify init_task's fs as well, defeating the isolation. At this stage PID 1 still gets rootfs (a private copy rather than a shared reference), so there is no functional change. Link: https://patch.msgid.link/20260601-work-kthread-nullfs-v4-19-77ee053060e0@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-29initramfs: use scoped_with_init_fs() for rootfs unpackingChristian Brauner
Extract the initramfs unpacking code into a separate unpack_initramfs() function and wrap its invocation from do_populate_rootfs() with scoped_with_init_fs(). This ensures all file operations during initramfs unpacking (including filp_open() calls in do_name() and populate_initrd_image()) happen in init's filesystem context. Note that security_initramfs_populated() needs the scope as well since it does use current->fs to derive the initramfs superblock. do_populate_rootfs() ← async_schedule_domain() ← kworker (async workqueue) May also run synchronously from PID 1 in case async workqueue is considered full. Overriding in that case is fine as well. Link: https://patch.msgid.link/20260601-work-kthread-nullfs-v4-17-77ee053060e0@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-29fs: make userspace_init_fs a dynamically-initialized pointerChristian Brauner
Change userspace_init_fs from a declared-but-unused extern struct to a dynamically initialized pointer. Add init_userspace_fs() which is called early in kernel_init() (PID 1) to record PID 1's fs_struct as the canonical userspace filesystem state. Wire up __override_init_fs() and __revert_init_fs() to actually swap current->fs to/from userspace_init_fs. Previously these were no-ops that stored current->fs back to itself. Fix nullfs_userspace_init() to compare against userspace_init_fs instead of &init_fs. When PID 1 unshares its filesystem state, revert userspace_init_fs to init_fs's root (nullfs) so that stale filesystem state is not silently inherited by kworkers and usermodehelpers. At this stage PID 1's fs still points to rootfs (set by init_mount_tree), so userspace_init_fs points to rootfs and scoped_with_init_fs() is functionally equivalent to its previous no-op behavior. Link: https://patch.msgid.link/20260601-work-kthread-nullfs-v4-5-77ee053060e0@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-29fs: add real_fs to track task's actual fs_structChristian Brauner
Add a real_fs field to task_struct that always mirrors the fs field. This lays the groundwork for distinguishing between a task's permanent fs_struct and one that is temporarily overridden via scoped_with_init_fs(). When a kthread temporarily overrides current->fs for path lookup, we need to know the original fs_struct for operations like exit_fs() and unshare_fs_struct() that must operate on the real, permanent fs. For now real_fs is always equal to fs. It is maintained alongside fs in all the relevant paths: exit_fs(), unshare_fs_struct(), switch_fs_struct(), and copy_fs(). Link: https://patch.msgid.link/20260601-work-kthread-nullfs-v4-4-77ee053060e0@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-21Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen) Fix a taskstats TGID aggregation bug where fields added in the TGID query path were not preserved after thread exit, and adds a kselftest covering the regression. - "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko) Improve lib/tests/string_helpers_kunit.c a little - "lib/base64: decode fixes" (Josh Law) Address minor issues in lib/base64.c - "selftests/filelock: Make output more kselftestish" (Mark Brown) Make the output from the ofdlocks test a bit easier for tooling to work with. Also ignore the generated file - "uaccess: unify inline vs outline copy_{from,to}_user() selection" (Yury Norov) Simplify the usercopy code by removing the selectability of inlining copy_{from,to}_user(). - "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang) Fix a number of possible issues in the ocfs2 xattr code - "lib and lib/cmdline enhancements" (Dmitry Antipov) Provide additional robustness checking in the cmdline handling code and its in-kernel testing and selftests - "cleanup the RAID6 P/Q library" (Christoph Hellwig) Clean up the RAID6 P/Q library to match the recent updates to the RAID 5 XOR library and other CRC/crypto libraries - "ocfs2: harden inode validators against forged metadata" (Michael Bommarito) Add three structural checks to OCFS2 dinode validation so malformed on-disk fields are rejected before ocfs2_populate_inode() copies them into the in-core inode - "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike Rapoport) Clean up the lib/raid code by using kmalloc() in more places * tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits) ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits lib: interval_tree_test: validate benchmark parameters ocfs2: avoid moving extents to occupied clusters treewide: fix transposed "sign" typos and update spelling.txt ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec fat: reject BPB volumes whose data area starts beyond total sectors selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems lib/test_firmware: allocate the configured into_buf size fs: efs: remove unneeded debug prints checkpatch: cuppress warnings when Reported-by: is followed by Link: MAINTAINERS: add Alexander as a kcov reviewer mailmap: update Alexander Sverdlin's Email addresses fs: fat: inode: replace sprintf() with scnprintf() ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release() ocfs2/dlm: require a ref for locking_state debugfs open ocfs2: reject FITRIM ranges shorter than a cluster ocfs2: validate fast symlink target during inode read ocfs2: add journal NULL check in ocfs2_checkpoint_inode() ...
2026-06-16Merge tag 'bootconfig-v7.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull bootconfig updates from Masami Hiramatsu: - bootconfig: move xbc_snprint_cmdline() to lib/bootconfig.c Move the xbc_snprint_cmdline() function and its buffer from main.c to the shared lib/bootconfig.c parser library so it can be reused by userspace tools. - render kernel.* subtree as cmdline string with -C Add a new -C option to print the kernel.* subtree as a flat command-line string at build time, allowing early parameter injection without runtime parsing. * tag 'bootconfig-v7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tools/bootconfig: render kernel.* subtree as cmdline string with -C bootconfig: move xbc_snprint_cmdline() to lib/bootconfig.c
2026-06-16Merge tag 'slab-for-7.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - Support for "allocation tokens" (currently available in Clang 22+) for smarter partitioning of kmalloc caches based on the allocated object type, which can be enabled instead of the "random" per-caller-address-hash partitioning. It should be able to deterministically separate types containing a pointer from those that do not (Marco Elver) - Improvements and simplification of the kmem_cache_alloc_bulk() and mempool_alloc_bulk() API. This includes adaptation of callers (Christoph Hellwig) - Performance improvements and cleanups related mostly to sheaves refill (Hao Li, Shengming Hu, Vlastimil Babka) - Several fixups for the slabinfo tool (Xuewen Wang) * tag 'slab-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slab: do not limit zeroing to orig_size when only red zoning is enabled mm/slub: preserve original size in _kmalloc_nolock_noprof retry path mm: simplify the mempool_alloc_bulk API mm/slab: improve kmem_cache_alloc_bulk mm/slub: detach and reattach partial slabs in batch mm/slub: introduce helpers for node partial slab state mm/slub: use empty sheaf helpers for oversized sheaves tools/mm/slabinfo: remove redundant slab->partial assignment tools/mm/slabinfo: remove dead assignment in get_obj_and_str() tools/mm/slabinfo: Fix trace disable logic inversion MAINTAINERS: add slab-related scripts and tools to SLAB ALLOCATOR mm/slub: fix typo in sheaves comment mm, slab: simplify returning slab in __refill_objects_node() mm, slab: add an optimistic __slab_try_return_freelist() slab: fix kernel-docs for mm-api slab: improve KMALLOC_PARTITION_RANDOM randomness slab: support for compiler-assisted type-based slab cache partitioning mm/slub: defer freelist construction until after bulk allocation from a new slab
2026-06-15Merge tag 'sched-core-2026-06-14' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "SMP load-balancing updates: - A large series to introduce infrastructure for cache-aware load balancing, with the goal of co-locating tasks that share data within the same Last Level Cache (LLC) domain. By improving cache locality, the scheduler can reduce cache bouncing and cache misses, ultimately improving data access efficiency. Implemented by Chen Yu and Tim Chen, based on early prototype work by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and Shrikanth Hegde. - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde) Fair scheduler updates: - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing SMT awareness (Andrea Righi, K Prateek Nayak) - A series to optimize cfs_rq and sched_entity allocation for better data locality (Zecheng Li) - A preparatory series to change fair/cgroup scheduling to a single runqueue, without the final change (Peter Zijlstra) - Auto-manage ext/fair dl_server bandwidth (Andrea Righi) - Fix cpu_util runnable_avg arithmetic (Hongyan Xia) - Optimize update_tg_load_avg()'s rate-limiting code (Rik van Riel) - Allow account_cfs_rq_runtime() to throttle current hierarchy (K Prateek Nayak) - Update util_est after updating util_avg during dequeue, to fix the util signal update logic, which reduces signal noise (Vincent Guittot) Scheduler topology updates: - Allow multiple domains to claim sched_domain_shared (K Prateek Nayak) - Add parameter to split LLC (Peter Zijlstra) Core scheduler updates: - Use trace_call__<tp>() to save a static branch (Gabriele Monaco) Scheduler statistics updates: - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation guard (Nicolas Pitre) Deadline scheduler updates: - Reject debugfs dl_server writes for offline CPUs (Andrea Righi) - Fix replenishment logic for non-deferred servers (Yuri Andriaccio) RT scheduling updates: - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt) - Update default bandwidth for real-time tasks to 1.0 (Yuri Andriaccio) Proxy scheduling updates: - A series to implement Optimized Donor Migration for Proxy Execution (John Stultz, Peter Zijlstra) - Various proxy scheduling cleanups and fixes (Peter Zijlstra, K Prateek Nayak) Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi, Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde, Peter Zijlstra, Liang Luo and Yiyang Chen" * tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (91 commits) sched/fair: Fix newidle vs core-sched sched/deadline: Use task_on_rq_migrating() helper sched/core: Combine separate 'else' and 'if' statements sched/fair: Fix cpu_util runnable_avg arithmetic sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime() sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up() sched/fair: Call update_curr() before unthrottling the hierarchy sched/fair: Use throttled_csd_list for local unthrottle sched/fair: Convert cfs bandwidth throttling to use guards sched/fair: Allocate cfs_tg_state with percpu allocator sched/fair: Remove task_group->se pointer array sched/fair: Co-locate cfs_rq and sched_entity in cfs_tg_state sched: restore timer_slack_ns when resetting RT policy on fork MAINTAINERS: Fix spelling mistake in Peter's name sched: Simplify ttwu_runnable() sched/proxy: Remove superfluous clear_task_blocked_in() sched/proxy: Remove PROXY_WAKING sched/proxy: Switch proxy to use p->is_blocked sched/proxy: Only return migrate when needed sched: Be more strict about p->is_blocked ...
2026-06-15Merge tag 'locking-core-2026-06-14' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Futex updates: - Optimize futex hash bucket access patterns (Peter Zijlstra) - Large series to address the robust futex unlock race for real, by Thomas Gleixner: "The robust futex unlock mechanism is racy in respect to the clearing of the robust_list_head::list_op_pending pointer because unlock and clearing the pointer are not atomic. The race window is between the unlock and clearing the pending op pointer. If the task is forced to exit in this window, exit will access a potentially invalid pending op pointer when cleaning up the robust list. That happens if another task manages to unmap the object containing the lock before the cleanup, which results in an UAF. In the worst case this UAF can lead to memory corruption when unrelated content has been mapped to the same address by the time the access happens. User space can't solve this problem without help from the kernel. This series provides the kernel side infrastructure to help it along: 1) Combined unlock, pointer clearing, wake-up for the contended case 2) VDSO based unlock and pointer clearing helpers with a fix-up function in the kernel when user space was interrupted within the critical section. ... with help by André Almeida: - Add a note about robust list race condition (André Almeida) - Add self-tests for robust release operations (André Almeida) Context analysis updates: - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche) - Bump required Clang version to 23 (Marco Elver) Guard infrastructure updates: - Series to remove NULL check from unconditional guards (Dmitry Ilvokhin) Lockdep updates: - Restore self-test migrate_disable() and sched_rt_mutex state on PREEMPT_RT (Karl Mehltretter) Membarriers updates: - Use per-CPU mutexes for targeted commands (Aniket Gattani) - Modernize membarrier_global_expedited with cleanup guards (Aniket Gattani) - Add rseq stress test for CFS throttle interactions (Aniket Gattani) percpu-rwsems updates: - Extract __percpu_up_read() to optimize inlining overhead (Dmitry Ilvokhin) Seqlocks updates: - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens) Lock tracing: - Add contended_release tracepoint to sleepable locks such as mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry Ilvokhin) MAINTAINERS updates: - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng) Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra, Dmitry Ilvokhin and Peter Zijlstra" * tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits) locking: Add contended_release tracepoint to sleepable locks locking/percpu-rwsem: Extract __percpu_up_read() tracing/lock: Remove unnecessary linux/sched.h include futex: Optimize futex hash bucket access patterns rust: sync: completion: Mark inline complete_all and wait_for_completion MAINTAINERS: Add RUST [SYNC] entry cleanup: Specify nonnull argument index selftests: futex: Add tests for robust release operations Documentation: futex: Add a note about robust list race condition x86/vdso: Implement __vdso_futex_robust_try_unlock() x86/vdso: Prepare for robust futex unlock support futex: Provide infrastructure to plug the non contended robust futex unlock race futex: Add robust futex unlock IP range futex: Add support for unlocking robust futexes futex: Cleanup UAPI defines x86: Select ARCH_MEMORY_ORDER_TSO uaccess: Provide unsafe_atomic_store_release_user() futex: Provide UABI defines for robust list entry modifiers futex: Move futex related mm_struct data into a struct futex: Make futex_mm_init() void ...
2026-06-15Merge tag 'rust-7.2' of gitolite.kernel.org:pub/scm/linux/kernel/git/ojeda/linuxLinus Torvalds
Pull Rust updates from Miguel Ojeda: "This one is big due to the vendoring of the `zerocopy` library, which allows us to replace a bunch of `unsafe` code dealing with conversions between byte sequences and other types with safe alternatives. More details on that below (and in its merge commit). Toolchain and infrastructure: - Introduce support for the 'zerocopy' library [1][2]: Fast, safe, compile error. Pick two. Zerocopy makes zero-cost memory manipulation effortless. We write `unsafe` so you don't have to. It essentially provides derivable traits (e.g. 'FromBytes') and macros (e.g. 'transmute!') for safely converting between byte sequences and other types. Having such support allows us to remove some 'unsafe' code. It is among the most downloaded Rust crates and it is also used by the Rust compiler itself. It is licensed under "BSD-2-Clause OR Apache-2.0 OR MIT". The crates are imported essentially as-is (only +2/-3 lines needed to be adapted), plus SPDX identifiers. Upstream has since added the SPDX identifiers as well as one of the tweaks at my request, thus reducing our future diffs on updates -- I keep the details in one of our usual live lists [3]. In total, it is about ~39k lines added, ~32k without counting 'benches/' which are just for documentation purposes. The series includes a few Kbuild and rust-analyzer improvements and an example patch using it in Nova, removing one 'unsafe impl'. I checked that the codegen of an isolated example function (similar to the Nova patch on top) is essentially identical. It also turns out that (for that particular case) the 'zerocopy' version, even with 'debug-assertions' enabled, has no remaining panics, unlike a few in the current code (since the compiler can prove the remaining 'ub_checks' statically). So their "fast, safe" does indeed check out -- at least in that case. - Support AutoFDO. This allows Rust code to be profiled and optimized based on the profile. Tested with Rust Binder: ~13% slower without AutoFDO in the binderAddInts benchmark (using an app-launch benchmark for the profile). - Support Software Tag-Based KASAN. In addition, fix KASAN Kconfig by requiring Clang. - Add Kconfig options for each existing Rust KUnit test suite, such as 'CONFIG_RUST_BITMAP_KUNIT_TEST'. They are placed within a new menu, 'CONFIG_RUST_KUNIT_TESTS', in the new 'rust/kernel/Kconfig.test' file. - Support the upcoming Rust 1.98.0 release (expected 2026-08-20): lint cleanups and an unstable flag rename. - Disable 'rustdoc' documentation inlining for all prelude items, which bloats the generated documentation. - Ignore (in Git) and clean (in Kbuild) the (rarely) 'rustc'-generated '*.long-type-*.txt' files. 'kernel' crate: - Add new 'bitfield' module with the 'bitfield!' macro (extracted from the existing 'register!' one), which declares integer types that are split into distinct bit fields of arbitrary length. Each field is a 'Bounded' of the appropriate bit width (ensuring values are properly validated and avoiding implicit data loss) and gets several generated getters and setters (infallible, 'const' and fallible) as well as associated constants ('_MASK', '_SHIFT' and '_RANGE'). It also supports fields that can be converted from/to custom types, either fallibly ('?=>') or infallibly ('=>'). For instance: bitfield! { struct Rgb(u16) { 15:11 blue; 10:5 green; 4:0 red; } } // Compile-time checks. let color = Rgb::zeroed().with_const_green::<0x1f>(); assert_eq!(color.green(), 0x1f); assert_eq!(color.into_raw(), 0x1f << Rgb::GREEN_SHIFT); Add as well documentation and a test suite for it, as usual; and update the 'register!' macro to use it. It will be maintained by Alexandre Courbot (with Yury Norov as reviewer) under a new 'MAINTAINERS' entry: 'RUST [BITFIELD]'. - 'ptr' module: rework index projection syntax into keyworded syntax and introduce panicking variant. The keyword syntax ('build:', 'try:', 'panic:') is more explicit and paves the way of perhaps adding more flavors in the future, e.g. an 'unsafe' index projection. For instance, projections now look like this: fn f(p: *const [u8; 32]) -> Result { // Ok, within bounds, checked at build time. project!(p, [build: 1]); // Build error. project!(p, [build: 128]); // `OutOfBound` runtime error (convertible to `ERANGE`). project!(p, [try: 128]); // Runtime panic. project!(p, [panic: 128]); Ok(()) } Update as well the users, which now look like e.g. // Pointer to the first entry of the GSP message queue. let data = project!(self.0.as_ptr(), .gspq.msgq.data[build: 0]); - 'build_assert' module: make the module the home of its macros instead of rendering them twice. - 'sync' module: add 'UniqueArc::as_ptr()' associated function. - 'alloc' module: - Fix the 'Vec::reserve()' doctest to properly account for the existing vector length in the capacity assertion. - Fix an incorrect operator in the 'Vec::extend_with()' 'SAFETY' comment; add a doc test demonstrating basic usage and the zero-length case. - Clean imports across several modules to follow the "kernel vertical" import style in order to minimize conflicts. 'pin-init' crate: - User visible changes: - Do not generate 'non_snake_case' warnings for identifiers that are syntactically just users of a field name. This would allow all '#[allow(non_snake_case)]' in nova-core to be removed, which Gary will send to the nova tree next cycle. - Filter non-cfg attributes out properly in derived structs. This improves pin-init compatibility with other derive macros. - Insert projection types' where clause properly. - Other changes: - Bump MSRV to 1.82, plus associated cleanups. - Overhaul how init slots are projected. The new approach is easier to justify with safety comments. - Mark more functions as inline, which should help mitigate the super-long symbol name issue due to lack of inlining. rust-analyzer: - Support '--envs' for passing env vars for crates like 'zerocopy'. 'MAINTAINERS': - Add the following reviewers to the 'RUST' entry: - Daniel Almeida - Tamir Duberstein - Alexandre Courbot - Onur Özkan They have been involved in the Rust for Linux project for about 7 collective years and bring expertise across several domains, which will be very useful to have around in the future. Thanks everyone for stepping up! And some other fixes, cleanups and improvements" Link: https://github.com/google/zerocopy [1] Link: https://docs.rs/zerocopy [2] Link: https://github.com/Rust-for-Linux/linux/issues/1239 [3] * tag 'rust-7.2' of gitolite.kernel.org:pub/scm/linux/kernel/git/ojeda/linux: (86 commits) MAINTAINERS: add Onur Özkan as Rust reviewer MAINTAINERS: add Alexandre Courbot as Rust reviewer MAINTAINERS: add Tamir Duberstein as Rust reviewer MAINTAINERS: add Daniel Almeida as Rust reviewer kbuild: rust: clean `zerocopy-derive` in `mrproper` rust: make `build_assert` module the home of related macros rust: str: clean unused import for Rust >= 1.98 rust: str: use the "kernel vertical" imports style rust: aref: use the "kernel vertical" imports style rust: page: use the "kernel vertical" imports style gpu: nova-core: firmware: parse `FalconUCodeDescV2` via `zerocopy` rust: prelude: add `zerocopy{,_derive}::FromBytes` rust: zerocopy-derive: enable support in kbuild rust: zerocopy-derive: add `README.md` rust: zerocopy-derive: avoid generating non-ASCII identifiers rust: zerocopy-derive: add SPDX License Identifiers rust: zerocopy-derive: import crate rust: zerocopy: enable support in kbuild rust: zerocopy: add `README.md` rust: zerocopy: remove float `Display` support ...
2026-06-15Merge tag 'kbuild-7.2-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild / Kconfig updates from Nathan Chancellor: "Kbuild: - Remove broken module linking exclusion for BTF - Add documentation around how offset header files work - Include unstripped vDSO libraries in pacman packages - Bump minimum version of LLVM for building the kernel to 17.0.1 and clean up unnecessary workarounds - Use a context manager in run-clang-tools - Add dist macro value if present to release tag for RPM packages - Detect and report truncated buf_printf() output in modpost - Add __llvm_covfun and __llvm_covmap to section whitelist in modpost - Support Clang's distributed ThinLTO mode - Remove architecture specific configurations for AutoFDO and Propeller to ease individual architecture maintenance Kconfig: - Add kconfig-sym-check target to look for dangling Kconfig symbol references and invalid tristate literal values - Harden against potential NULL pointer dereference - Fix typo in Kconfig test comment" * tag 'kbuild-7.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (31 commits) kconfig: tests: fix typo in comment kconfig: Remove the architecture specific config for Propeller kconfig: Remove the architecture specific config for AutoFDO modpost: Add __llvm_covfun and __llvm_covmap to section_white_list kconfig: add kconfig-sym-check static checker kbuild: Remove unnecessary 'T' modifier in cmd_ar_builtin_fixup kbuild: distributed build support for Clang ThinLTO kbuild: move vmlinux.a build rule to scripts/Makefile.vmlinux_a scripts: modpost: detect and report truncated buf_printf() output kbuild: rpm-pkg: append %{?dist} macro to Release tag run-clang-tools: run multiprocessing.Pool as context manager compiler-clang.h: Drop explicit version number from "all" diagnostic macro compiler-clang.h: Remove __cleanup -Wunused-variable workaround kbuild: Remove check for broken scoping with clang < 17 in CC_HAS_ASM_GOTO_OUTPUT x86/entry/vdso32: Remove conditional omission of '.cfi_offset eflags' x86/module: Revert "Deal with GOT based stack cookie load on Clang < 17" x86/build: Drop unnecessary '-ffreestanding' addition to KBUILD_CFLAGS scripts/Makefile.warn: Drop -Wformat handling for clang < 16 riscv: Drop tautological condition from TOOLCHAIN_NEEDS_OLD_ISA_SPEC riscv: Remove tautological condition from selection of ARCH_SUPPORTS_CFI ...
2026-06-15Merge tag 'vfs-7.2-rc1.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Features: - Reduce pipe->mutex contention by pre-allocating pages outside the lock in anon_pipe_write(). anon_pipe_write() called alloc_page() once per page while holding pipe->mutex. The allocation can sleep doing direct reclaim and runs memcg charging, which extends the critical section and stalls any concurrent reader on the same mutex. Now up to 8 pages are pre-allocated before the mutex is taken, leftovers are recycled into the per-pipe tmp_page[] cache before unlock, and any remainder is released after unlock, keeping the allocator out of the critical section on both sides. On a writers x readers sweep with 64KB writes against a 1 MB pipe throughput improves 6-28% and average write latency drops 5-22%; under memory pressure - when the cost of holding the mutex across reclaim is highest - throughput improves 21-48% and latency drops 17-33%. The microbenchmark is added to selftests. - uaccess/sockptr: fix the ignored_trailing logic in copy_struct_to_user() to behave as documented and the usize check in copy_struct_from_sockptr() for user pointers, and add copy_struct_{from,to}_bounce_buffer() and copy_struct_to_sockptr() helpers for upcoming users (IPPROTO_SMBDIRECT, IPPROTO_QUIC). - bpf: add a sleepable bpf_real_inode() kfunc that resolves the real inode backing a dentry via d_real_inode(). On overlayfs the inode attached to the dentry doesn't carry the underlying device information; this is used by the filesystem restriction BPF program that was merged into systemd. - docs: add guidelines for submitting new filesystems, motivated by the maintenance burden abandoned and untestable filesystems impose on VFS developers, blocking infrastructure work like folio conversions and iomap migration. Fixes: - libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() and drop the now-redundant assignments in callers. This began as a one-line dma-buf fix for a path_noexec() warning; a pseudo filesystem has no reason not to set SB_I_NOEXEC. All init_pseudo() callers were audited: the only visible effect is on dma-buf where SB_I_NOEXEC silences the warning. - Handle set_blocksize() failures in legacy filesystems (bfs, hpfs, qnx4, jfs, befs, affs, isofs, minix, ntfs3, omfs). Mounting a device with a sector size > PAGE_SIZE crashed roughly half of them; the rest had the same missing error handling pattern. Plus a follow-up releasing the superblock buffer_head when setting the minix v3 block size fails. - mount: honour SB_NOUSER in the new mount API. - fs/fcntl: fix a SOFTIRQ-unsafe lock order in fasync signaling by switching the process-group paths of send_sigio() and send_sigurg() from read_lock(&tasklist_lock) to RCU, matching the single-PID path. - vfs: add an FS_USERNS_DELEGATABLE flag and set it for NFS, fixing delegated NFS mounts (fsopen() in a container with the mount performed by a privileged daemon) that broke when non-init s_user_ns was tied to FS_USERNS_MOUNT. - selftests/namespaces: fix a hang in nsid_test where an unreaped grandchild kept the TAP pipe write-end open, a waitpid(-1) race in listns_efault_test, and a false FAIL on kernels without listns() where the tests should SKIP. - filelock: fix the break_lease() stub signature for CONFIG_FILE_LOCKING=n. - init/initramfs_test: wait for the async initramfs unpacking before running; the test and do_populate_rootfs() share the parser state. - fs/coredump: reduce redundant log noise in validate_coredump_safety(). - iomap: pass the correct length to fserror_report_io() in __iomap_write_begin(). - backing-file: fix the backing_file_open() kerneldoc. Cleanups: - initramfs: refactor the cpio hex header parsing to use hex2bin() instead of the hand-rolled simple_strntoul() which is reverted, and extend the initramfs KUnit tests to cover header fields with 0x prefixes. - Replace __get_free_pages() and friends with kmalloc()/kzalloc() across quota, proc, ocfs2/dlm, nilfs2, nfs, nfsd, libfs, jfs, jbd2, isofs, fuse, select, namespace, configfs, binfmt_misc, bfs, and the do_mounts init code - part of the larger work of replacing page allocator calls with kmalloc(). - Use clear_and_wake_up_bit() in unlock_buffer() and journal_end_buffer_io_sync() instead of open-coding the sequence. - Drop unused VFS exports: unexport drop_super_exclusive(), remove start_removing_user_path_at(), and fold __start_removing_path() into start_removing_path(). - fs/read_write: narrow the __kernel_write() export with EXPORT_SYMBOL_FOR_MODULES(). - vfs: uapi: retire octal and hex constants in favor of (1 << n) for the O_ flags. Finding a free bit for a new flag across the architectures was needlessly hard with the mixed bases. - dcache: add extra sanity checks of dead dentries in dentry_free() via a new DENTRY_WARN_ONCE() that also prints d_flags. - iov_iter: use kmemdup_array() in dup_iter() to harden the allocation against multiplication overflow. - fs/pipe: write to ->poll_usage only once. - vfs: remove an always-taken if-branch in find_next_fd(). - dcache: use kmalloc_flex() for struct external_name in __d_alloc(). - namei: use QSTR() instead of QSTR_INIT() in path_pts(). - sync_file_range: delete dead S_ISLNK code. - Comment fixes: retire a stale comment in fget_task_next() and fix assorted spelling mistakes" * tag 'vfs-7.2-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (73 commits) backing-file: fix backing_file_open() kerneldoc parameter iomap: pass the correct len to fserror_report_io in __iomap_write_begin vfs: add FS_USERNS_DELEGATABLE flag and set it for NFS filelock: fix break_lease() stub signature for CONFIG_FILE_LOCKING=n vfs: uapi: retire octal and hex numbers in favor of (1 << n) for O_ flags bpf: add bpf_real_inode() kfunc fs/read_write: Do not export __kernel_write() to the entire world libfs: drop redundant SB_I_NOEXEC/SB_I_NODEV in init_pseudo() callers libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() mount: honour SB_NOUSER in the new mount API fs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling selftests/pipe: add pipe_bench microbenchmark fs/pipe: pre-allocate pages outside pipe->mutex in anon_pipe_write fs: retire stale comment in fget_task_next() fs: fix spelling mistakes in comment bfs: replace get_zeroed_page() with kzalloc() binfmt_misc: replace __get_free_page() with kmalloc() configfs: replace __get_free_pages() with kzalloc() fs/namespace: use __getname() to allocate mntpath buffer fs/select: replace __get_free_page() with kmalloc() ...
2026-06-08rust: tests: add Kconfig for KUnit testYury Norov
There are 6 individual Rust KUnit test suites (plus the doctests one). All the tests are compiled unconditionally now, which adds ~200 kB to the kernel image for me on x86_64. As Rust matures, this bloating will inevitably grow. Add Kconfig.test which includes a RUST_KUNIT_TESTS menu, and all individual tests under it. As usual, new tests are all enabled if KUNIT_ALL_TESTS=y. Suggested-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Yury Norov <ynorov@nvidia.com> Reviewed-by: David Gow <david@davidgow.net> Acked-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260417031531.315281-3-ynorov@nvidia.com [ Fixed capitalization. Used singular for "API" for consistency. Reworded to clarify these are suites and that there exists the doctests one (which is the biggest at the moment by far). - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-03futex: Add robust futex unlock IP rangeThomas Gleixner
There will be a VDSO function to unlock robust futexes in user space. The unlock sequence is racy vs. clearing the list_pending_op pointer in the tasks robust list head. To plug this race the kernel needs to know the instruction window. As the VDSO is per MM the addresses are stored in mm_struct::futex. Architectures which implement support for this have to update these addresses when the VDSO is (re)mapped and indicate the pending op pointer size which is matching the IP. Arguably this could be resolved by chasing mm->context->vdso->image, but that's architecture specific and requires to touch quite some cache lines. Having it in mm::futex reduces the cache line impact and avoids having yet another set of architecture specific functionality. To support multi size robust list applications (gaming) this provides two ranges when COMPAT is enabled. Signed-off-by: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: André Almeida <andrealmeid@igalia.com> Link: https://patch.msgid.link/20260602090535.718926819@kernel.org
2026-06-02sched: Add blocked_donor link to task for smarter mutex handoffsPeter Zijlstra
Add link to the task this task is proxying for, and use it so the mutex owner can do an intelligent hand-off of the mutex to the task that the owner is running on behalf. [jstultz: This patch was split out from larger proxy patch] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260512025635.2840817-8-jstultz@google.com
2026-05-28treewide: fix indentation and whitespace in Kconfig filesAnand Moon
Clean up inconsistent indentation (mixing tabs and spaces) and remove extraneous whitespace in several Kconfig files across the tree. This is a purely cosmetic change to improve readability. Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ /\t/' -i */Kconfig Link: https://lore.kernel.org/20260407053945.14116-1-linux.amoon@gmail.com Signed-off-by: Anand Moon <linux.amoon@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> [fs] Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> [mm] Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> [mm] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-05-27kbuild: Remove check for broken scoping with clang < 17 in ↵Nathan Chancellor
CC_HAS_ASM_GOTO_OUTPUT Now that the minimum supported version of LLVM for building the kernel has been raised to 17.0.1, the check added to CC_HAS_ASM_GOTO_OUTPUT by commit e2ffa15b9baa ("kbuild: Disable CC_HAS_ASM_GOTO_OUTPUT on clang < 17") can be removed, as the issue it detects is guaranteed to be fixed. Acked-by: Nicolas Schier <nsc@kernel.org> Link: https://patch.msgid.link/20260517-bump-minimum-supported-llvm-version-to-17-v2-14-b3b8cda46bdd@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-05-27init/initramfs_test: wait_for_initramfs() before runningJia He
initramfs_test_extract() and friends call unpack_to_rootfs() from a kunit kthread while do_populate_rootfs() may still be running asynchronously from rootfs_initcall. unpack_to_rootfs() keeps its parser state in module-static variables (victim, byte_count, state, this_header, header_buf, name_buf, ...), so the two writers corrupt each other. On arm64 v7.0-rc5+ this oopses early in boot: Unable to handle kernel paging request at virtual address ffff80018f9f0ffc pc : do_reset+0x3c/0x98 Call trace: do_reset initramfs_test_extract kunit_try_run_case Initramfs unpacking failed: junk within compressed archive do_reset() faults because 'victim' was overwritten by the boot-time unpacker; the boot unpacker meanwhile logs the bogus "junk within compressed archive" on the real initrd because the test wrecked its state machine. Add a .suite_init callback that calls wait_for_initramfs() so the async unpack is quiescent before the first case runs. suite_init runs once per suite rather than before every individual test case. Fixes: 83c0b27266ec ("initramfs_test: kunit tests for initramfs unpacking") Signed-off-by: Jia He <justin.he@arm.com> Link: https://patch.msgid.link/20260519093937.1064628-1-justin.he@arm.com Reviewed-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-27rust: kasan: add support for Software Tag-Based KASANAlice Ryhl
This adds support for Software Tag-Based KASAN (KASAN_SW_TAGS) when CONFIG_RUST is enabled. This requires that rustc includes support for the kernel-hwaddress sanitizer, which is available since 1.96.0 [1]. Unlike with clang, we need to pass -Zsanitizer-recover in addition to -Zsanitizer because the option is not implied automatically. The kasan makefile uses different names for the flags depending on whether CC is clang or gcc, but as we require that CC is clang when using KASAN, we do not need to try to handle mixed gcc/llvm builds when Rust is enabled. Link: https://github.com/rust-lang/rust/pull/153049 [1] Reviewed-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260408-kasan-rust-sw-tags-v3-2-e07964d14363@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-05-27rust: kasan: KASAN+RUST requires clangAlice Ryhl
Kernel KASAN involves passing various llvm/gcc specific arguments to the C and Rust compiler. Since these arguments differ between llvm and gcc, it's not safe to mix an llvm-based rustc with a gcc build when kasan is enabled. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Cc: stable@vger.kernel.org Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support") Link: https://patch.msgid.link/20260408-kasan-rust-sw-tags-v3-1-e07964d14363@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-05-26exec_state: relocate dumpable informationChristian Brauner (Amutable)
The dumpable flag captured at execve() is consulted by __ptrace_may_access() and several /proc owner / visibility checks. It lives on mm_struct today, which exit_mm() clears from the task long before the task itself is reaped. exec_state is anchored to the execve() that established the current privilege domain. CLONE_VM siblings refcount-share the parent's exec_state via copy_exec_state(); non-CLONE_VM clones allocate a fresh exec_state inheriting the parent's dumpable mode and user_ns reference via task_exec_state_copy(). execve() allocates a fresh instance (via alloc_task_exec_state() in begin_new_exec()) and installs it under task_lock + exec_update_lock with task_exec_state_replace(). init_task uses a static instance. The dumpable mode now lives on task->exec_state->dumpable. task->mm->flags no longer carries dumpability; MMF_DUMPABLE_MASK is removed, but MMF_DUMPABLE_BITS is reserved so MMF_DUMP_FILTER_* bit positions remain stable for the /proc/<pid>/coredump_filter ABI. The task->user_dumpable cache bit and its assignment in exit_mm() are removed; readers go through get_dumpable(task) directly. coredump_params gains a snapshot field cprm.dumpable, populated from get_dumpable(current) at vfs_coredump() entry, replacing the previous __get_dumpable(cprm->mm_flags) consumers in fs/coredump.c and fs/pidfs.c. The user namespace recorded at execve() is consulted by __ptrace_may_access() and by /proc/PID/* owner derivation. Move the captured user_ns onto task_exec_state, which stays attached to the task past exit_mm() and across exit_files(). bprm grows a user_ns field staged in bprm_mm_init() with the caller's user_ns, narrowed by would_dump() to the closest privileged ancestor, and consumed by exec_mmap() via alloc_task_exec_state(bprm->user_ns). free_bprm() releases the staging reference. mm_struct loses ->user_ns entirely. Initializers in init-mm, efi_mm, and the implicit one in mm_init()/dup_mm()/mm_alloc() are removed; __mmdrop() drops the matching put_user_ns(). The kthread_use_mm() WARN_ON_ONCE(!mm->user_ns) is no longer meaningful and goes too. Reviewed-by: Jann Horn <jannh@google.com> Link: https://patch.msgid.link/20260520-work-task_exec_state-v3-4-69f895bc1385@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-22init: do_mounts: use kmalloc() for allocations of temporary buffersMike Rapoport (Microsoft)
Several places in init/do_mounts.c allocate temporary buffers for filesystem names or options using __get_free_page() or alloc_page(). Usage of alloc_page() APIs is not required there and only creates unnecessary noise with castings or conversion from struct page to void *. kmalloc() is a better API for these uses and it also provides better scalability and more debugging possibilities. Replace use of __get_free_page() and alloc_page() with kmalloc(). While on it, add a check for -ENOMEM condition in mount_root_generic(). Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Link: https://patch.msgid.link/20260520-init-v1-1-aaf2ebac5ad9@kernel.org Reviewed-by: David Disseldorp <ddiss@suse.de> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-21initramfs: Refactor to use hex2bin() instead of custom approachAndy Shevchenko
There is a simple_strntoul() function used solely as a shortcut for hex2bin() with proper endianess conversions. Replace that and drop the unneeded function in the next changes. This implementation will abort if we fail to parse the cpio header, instead of using potentially bogus header values. Co-developed-by: David Disseldorp <ddiss@suse.de> Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20260331070519.5974-5-ddiss@suse.de Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-21initramfs: Sort headers alphabeticallyAndy Shevchenko
Sorting headers alphabetically helps locating duplicates, and makes it easier to figure out where to insert new headers. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20260331070519.5974-4-ddiss@suse.de Reviewed-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-21initramfs_test: test header fields with 0x hex prefixDavid Disseldorp
cpio header fields are 8-byte hex strings, but one "interesting" side-effect of our historic simple_str[n]toul() use means that a "0x" (or "0X") prefixed header field will be successfully processed when coupled alongside a 6-byte hex remainder string. "0x" prefix support is contrary to the initramfs specification at Documentation/driver-api/early-userspace/buffer-format.rst which states: The structure of the cpio_header is as follows (all fields contain hexadecimal ASCII numbers fully padded with '0' on the left to the full width of the field, for example, the integer 4780 is represented by the ASCII string "000012ac"): Test for this corner case by injecting "0x" prefixes into the uid, gid and namesize cpio header fields. Confirm that init_stat() returns matching uid and gid values. This test can be modified in future to expect unpack_to_rootfs() failure when header validation is changed to properly follow the specification. Add some missing struct kstat initializations to account for possible init_stat() failures. Signed-off-by: David Disseldorp <ddiss@suse.de> Link: https://patch.msgid.link/20260331070519.5974-3-ddiss@suse.de Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-21initramfs_test: add fill_cpio() inject_ox parameterDavid Disseldorp
fill_cpio() uses sprintf() to write out the in-memory cpio archive from an array of struct initramfs_test_cpio. This change allows callers to modify the cpio sprintf() format string so that future tests can intentionally corrupt the header with "0x" and "0X" prefixed fields. Signed-off-by: David Disseldorp <ddiss@suse.de> Link: https://patch.msgid.link/20260331070519.5974-2-ddiss@suse.de Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Christian Brauner <brauner@kernel.org>