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2810
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Linus Torvalds
|
18fbf5151d |
Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton: - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff" (Lorenzo Stoakes) Index MAP_PRIVATE file-backed folios by their anonymous page offset to resolve confusion around reverse mapping for zeroed and CoW'd file-backed memory. Use this new VMA anonymous page offset tracking to eliminate index conflicts and lay the foundation for scalable CoW performance improvements. - "promote mapped executable folios after first usage for MGLRU" (Baolin Wang) Make MGLRU's protection of mapped executable file folios more reliable. Follow the classical LRU's logic, promoting mapped executable file folios after their first usage to give executable code a better chance to stay in memory and improve workload performance. - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen) Fix per-node proactive reclaim interface's ignoring the swappiness parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness() into a single function that checks proactive_swappiness regardless of kernel configuration. - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance cost" (Usama Arif) Reduce lru_lock contention in the reclaim path by deriving scan-balance costs from vmstat counters rather than lock-acquired producer updates. Read and decay these cost signals on the reclaim side under a dedicated per-lruvec lock, reducing total LRU lock wait time by over 60% without impacting scan throughput. - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky) Fix two low-risk zram bugs which Sashiko spotted in drive-by review. - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's memcg" (Zi Yan) Fix xas_split_alloc() by enabling target folio memcg charging during splits and adding the missing __GFP_ACCOUNT flag for proper XArray node memory accounting. - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick) Replace hardcoded binary names in selftests/mm/.gitignore with a generic pattern-matching rule to automatically ignore generated test files and avoid manual updates when adding new tests. - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon) Make the incompatibility between FLATMEM and NUMA explicit in mm/Kconfig and remove the unused pgdat_page_ext_init() function. - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang) Clean up zram compression backends by removing redundant error cleanup, adding parameter and dictionary validation, auto-prefixing algorithm error logs, and resetting parameters prior to reinitialization. - "zram: fix stale scan bounds after reinitialization" (Longlong Xia) Prevent out-of-bounds slot accesses during concurrent zram resets by moving table scan bound calculations under dev_lock in writeback_store() and read_block_state(). - "add anon mTHP collapse test cases" (Baolin Wang) Extend selftests helper functions to support arbitrary page orders and add new test cases and options for mTHP collapse in khugepaged. - "selftests/mm: Handle unsupported and transient test conditions" (Muhammad Usama Anjum) Update MM selftests to report a SKIP status instead of a failure when required kernel or filesystem features are unsupported, while adding retry logic for transient page migration errors. - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia) Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled and extend shrink_memcg() to support batch writeback for improved writeback efficiency. - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan) Introduce an IOCTL-based binary interface for memory allocation profiling that enables kernel-side filtering before per-CPU counter aggregation. This eliminates the text-parsing overhead of /proc/allocinfo and provides up to a 20x speedup by transferring only filtered allocation data to userspace. - "better block swap batching and a different take on swap_ops v5" (Christoph Hellwig) Refactor block swap I/O to use swap_iocb for batching instead of single-bio requests and rebase the swap_ops interface, achieving faster swap throughput during kernel builds. - "mm: kmemleak: reduce transient false positives by confirming leaks" (Catalin Marinas) Reduce false-positive kmemleak reports by combining two kmemleak enhancements that add a second confirmation scan and a configurable minimum unreferenced scan count module parameter. - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels" (Breno Leitao) Auto-scanning kernels can generate false-positive memory leak reports on single scans, so this patch defaults min_unref_scans to 2 when CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming scan. - "swap_ops updates" (Christoph Hellwig) Batching I/O for synchronous swap devices causes performance regressions and filesystem-based swap suffers from double-indirection overhead. This series resolves both issues by reintroducing per-folio writes for synchronous swap and allowing filesystems to directly export their own swap_ops. - "mm/khugepaged: several cleanups" (Nico Pache) khugepaged accumulated redundant state-checking patterns and outdated comments following mTHP integration. Introduce dedicated helpers for PTE validation and event counting while refreshing the internal documentation. - "maple_tree: lock checking and clean ups" (Liam Howlett) Syzbot reports incorrectly blame memory management exit paths for locking bugs, maple tree erase operations risk allocation failures without gfp flags and internal documentation lacks clarity. Improve lock error detection, update docs, fix race and allocation edge cases and optimize erase allocations using a fallback to GFP_KERNEL | GFP_NOFAIL. * tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits) selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC memcg: move LRU size accounting on reparenting instead of copying it mm/vmscan: fix comment logic in balance_pgdat maple_tree: add helper mas_make_walkable() maple_tree: avoid extra gap calculation maple_tree: fix argument name in header maple_tree: change two GFP flags in tests maple_tree: document erase and allocations better maple_tree: avoid mas_erase() and mtree_erase() failures maple_tree: document that erase may use GFP_KERNEL for allocations maple_tree: catch race in mas_alloc_cyclic() maple_tree: add bulk parent set helper maple_tree: micro optimisation of mas_wr_store_type() maple_tree: optimise mas_wr_node_store() when not in rcu mode maple_tree: use prefetched value in mas_wr_store_type() maple_tree: clarify comments on mas_nomem() maple_tree: drop MAPLE_ALLOC_SLOTS maple_tree: drop dead code from mas_extend_spanning_null() maple_tree: documentation fix maple_tree: add write lock checking with lockdep sequence numbers ... |
||
|
Lorenzo Stoakes (ARM)
|
51943a18ad |
mm: provide vma_[flags_]is_cow_mapping() and remove is_cow_mapping()
All remaining callers of is_cow_mapping() are invoking it in the form of is_cow_mapping(vma->vm_flags) or an indirected version of this. Therefore, provide a helper - vma_is_cow_mapping() to directly test the VMA. Additionally provide a new helper vma_flags_is_cow_mapping() which performs the check using the new vma_flags_t type, and share this logic between vma_is_cow_mapping() and vma_desc_is_cow_mapping(). With these changes, no callers of is_cow_mapping() remain, so remove it. Also update the userland VMA tests to reflect the change. No functional change intended. [[email protected]: fix kerneldoc comment typo, per Lorenzo] Link: https://lore.kernel.org/aob1goSSPH6sTN9y@gremlin Link: https://lore.kernel.org/[email protected] Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]> Acked-by: David Hildenbrand (Arm) <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Deucher <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Baolin Wang <[email protected]> Cc: Baoquan He <[email protected]> Cc: Barry Song <[email protected]> Cc: Boris Brezillon <[email protected]> Cc: Byungchul Park <[email protected]> Cc: Chengming Zhou <[email protected]> Cc: Chris Li <[email protected]> Cc: Christan König <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Claudio Imbrenda <[email protected]> Cc: Dave Airlie <[email protected]> Cc: Dev Jain <[email protected]> Cc: Gerald Schaefer <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Gregory Price (Meta) <[email protected]> Cc: Harry Yoo <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Huang Ray <[email protected]> Cc: "Huang, Ying" <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: James Clark <[email protected]> Cc: Jan Kara <[email protected]> Cc: Jann Horn <[email protected]> Cc: Janosch Frank <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: John Hubbard <[email protected]> Cc: Joshua Hahn <[email protected]> Cc: Kairui Song <[email protected]> Cc: Kees Cook <[email protected]> Cc: Kemeng Shi <[email protected]> Cc: Lance Yang <[email protected]> Cc: Liam R. Howlett <[email protected]> Cc: Liviu Dudau <[email protected]> Cc: Maarten Lankhorst <[email protected]> Cc: Marc Rutland <[email protected]> Cc: "Masami Hiramatsu (Google)" <[email protected]> Cc: Matthew Auld <[email protected]> Cc: Matthew Brost <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Maxime Ripard <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Muchun Song <[email protected]> Cc: Namhyung kim <[email protected]> Cc: Naoya Horiguchi <[email protected]> Cc: Nhat Pham <[email protected]> Cc: Nico Pache <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Pedro Falcato <[email protected]> Cc: Peter Xu <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rakie Kim <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Rodrigo Vivi <[email protected]> Cc: Ryan Roberts <[email protected]> Cc: Steven Price <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Thomas Hellström <[email protected]> Cc: Thomas Zimemrmann <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: xu xin <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
||
|
Linus Torvalds
|
ed3b875bea |
Merge tag 'mm-stable-2026-08-18-18-39' of 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
...
|
||
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Linus Torvalds
|
9d2ed026f0 |
Merge tag 'sysctl-7.03-rc1' of 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
|
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Linus Torvalds
|
fff0150b02 |
Merge tag 'vfs-7.3-rc1.kthread' of 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 ... |
||
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Jinjiang Tu
|
39e9b8aeaa |
fs: stable_page_flags(): simplify KPF_IDLE handling
For KPF_IDLE, folio_test_idle() check in set_ps_flags() already handles all config cases, so remove the duplicate code in stable_page_flags() that deals with CONFIG_PAGE_IDLE_FLAG for the 64‑bit case. No functional change is intended. Link: https://lore.kernel.org/[email protected] Signed-off-by: Jinjiang Tu <[email protected]> Acked-by: David Hildenbrand (Arm) <[email protected]> Cc: Chengming Zhou <[email protected]> Cc: Kefeng Wang <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Nanyong Sun <[email protected]> Cc: Svetly Todorov <[email protected]> Cc: xu xin <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
||
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Jinjiang Tu
|
c52faf27a9 |
fs: stable_page_flags(): use folio_test_*() helpers
Since commit |
||
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Jinjiang Tu
|
e984520724 |
fs: stable_page_flags(): use BIT_ULL() for KPF flags
Patch series "cleanup for stable_page_flags()", v2. This series cleans up stable_page_flags(), see the details in the commit messages. This patch (of 3): The stable_page_flags() function currently sets page flag bits using "1 << KPF_xxx" for various KPF_* definitions. KPF_* may be larger than 32, which will trigger -Wshift-count-overflow warning. All KPF_* values currently used in "1 << KPF_xxx" are smaller than 33, so no warning is triggered with current code. Replace all occurrences of "1 << KPF_*" with the BIT_ULL() macro to ensure all shifts are performed on a 64-bit unsigned type. This makes the code robust, and safe for future extension. No functional change is intended. Link: https://lore.kernel.org/[email protected] Link: https://lore.kernel.org/[email protected] Signed-off-by: Jinjiang Tu <[email protected]> Acked-by: David Hildenbrand (Arm) <[email protected]> Acked-by: Zi Yan <[email protected]> Cc: Chengming Zhou <[email protected]> Cc: Kefeng Wang <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Nanyong Sun <[email protected]> Cc: Svetly Todorov <[email protected]> Cc: xu xin <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
||
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Oleg Nesterov
|
8d75c338f0 |
sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL
CONFIG_SYSCTL used to make sense as a separate hidden bool before commit
|
||
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Kiryl Shutsemau (Meta)
|
3389648819 |
mm/pagemap: add PAGE_IS_ACCESSED for RWP tracking
PAGEMAP_SCAN already reports PAGE_IS_WRITTEN from the inverted uffd PTE bit, targeting the UFFDIO_WRITEPROTECT workflow. UFFDIO_RWPROTECT reuses the same PTE bit as a marker for read-write protection, but "has been written" and "has been accessed" are distinct semantic signals — they happen to share one PTE bit today only because the two implementations share infrastructure. Give RWP its own pagemap category so the UAPI does not conflate them: PAGE_IS_WRITTEN reported on VM_UFFD_WP VMAs, !pte_uffd(pte) PAGE_IS_ACCESSED reported on VM_UFFD_RWP VMAs, !pte_uffd(pte) Both still read the same PTE bit today, but each is scoped to the VMA whose registered mode makes the bit meaningful. If a future implementation moves RWP to a separate PTE bit, only PAGE_IS_ACCESSED switches over. This is a UAPI narrowing. Outside VM_UFFD_WP VMAs the uffd bit is always clear, so PAGEMAP_SCAN used to flag PAGE_IS_WRITTEN on every present PTE there — a meaningless duplicate of PAGE_IS_PRESENT. Now PAGE_IS_WRITTEN fires only inside VM_UFFD_WP VMAs. pagemap_hugetlb_category() now takes the vma like its PTE/PMD peers. Link: https://lore.kernel.org/[email protected] Signed-off-by: Kiryl Shutsemau <[email protected]> Assisted-by: Claude:claude-opus-4-6 Acked-by: Mike Rapoport (Microsoft) <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: James Houghton <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Lorenzo Stoakes <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Peter Xu <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: SeongJae Park <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
||
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Kiryl Shutsemau (Meta)
|
134c1d031a |
mm: add VM_UFFD_RWP VMA flag
Preparatory patch for userfaultfd read-write protection (RWP). RWP extends userfaultfd protection from plain write-protection (WP) to full read-write protection: accesses to an RWP-protected range -- reads as well as writes -- trap through userfaultfd. Reserve VM_UFFD_RWP, add the userfaultfd_rwp() and userfaultfd_protected() helpers, and wire up the smaps "ur" entry and the trace-flag table the rest of the series will use. The flag is gated on CONFIG_USERFAULTFD_RWP, which is introduced together with the UAPI in a later patch; until then VM_UFFD_RWP aliases VM_NONE and every downstream check folds to dead code. Nothing sets or queries the flag yet. Link: https://lore.kernel.org/[email protected] Signed-off-by: Kiryl Shutsemau <[email protected]> Assisted-by: Claude:claude-opus-4-6 Reviewed-by: Mike Rapoport (Microsoft) <[email protected]> Reviewed-by: SeongJae Park <[email protected]> Reviewed-by: Lorenzo Stoakes <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: James Houghton <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Peter Xu <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
||
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Kiryl Shutsemau (Meta)
|
c0ffe79eed |
mm: rename uffd-wp PTE accessors to uffd
Userfaultfd RWP will reuse the uffd-wp PTE bit to mark access-tracking PTEs, alongside the write-protected ones it already marks. The bit's meaning now depends on the VMA flag (WP or RWP), not on its name. Rename the kernel-internal names that describe the bit: - pte/pmd/huge_pte accessors (and swap variants) - pgtable_supports_uffd() capability query - SCAN_PTE_UFFD khugepaged enum The ftrace string emitted by mm_khugepaged_scan_pmd for this enum is kept as "pte_uffd_wp" so existing trace-based tooling keeps matching. Pure mechanical rename -- no behavior change. Link: https://lore.kernel.org/[email protected] Signed-off-by: Kiryl Shutsemau <[email protected]> Assisted-by: Claude:claude-opus-4-6 Reviewed-by: Mike Rapoport (Microsoft) <[email protected]> Reviewed-by: SeongJae Park <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: James Houghton <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Lorenzo Stoakes <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Peter Xu <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
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Usama Arif
|
eecd06034b |
fs/proc: use softleaf_has_pfn() in pagemap PMD walker
pagemap_pmd_range_thp() assumes that every non-present PMD is a migration entry and unconditionally calls softleaf_to_page(). This will crash on any non-present PMD type that does not encode a PFN, such as the upcoming PMD-level swap entries. Guard the page lookup with softleaf_has_pfn(), matching how pte_to_pagemap_entry() already handles non-present PTEs. Link: https://lore.kernel.org/[email protected] Signed-off-by: Usama Arif <[email protected]> Acked-by: David Hildenbrand (Arm) <[email protected]> Reviewed-by: Zi Yan <[email protected]> Cc: Alexandre Ghiti <[email protected]> Cc: Baolin Wang <[email protected]> Cc: Baoquan He <[email protected]> Cc: Barry Song <[email protected]> Cc: Chris Li <[email protected]> Cc: Dev Jain <[email protected]> Cc: "Huang, Ying" <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Kairui Song <[email protected]> Cc: Kemeng Shi <[email protected]> Cc: Kiryl Shutsemau <[email protected]> Cc: Lance Yang <[email protected]> Cc: Liam R. Howlett <[email protected]> Cc: Lorenzo Stoakes <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Nhat Pham <[email protected]> Cc: Nico Pache <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Ryan Roberts <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
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Linus Torvalds
|
62cc902415 |
Merge tag 'mm-hotfixes-stable-2026-07-27-14-18' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton: "13 hotfixes. All are cc:stable. 11 are for MM. All are singletons - please see the changelogs for details" * tag 'mm-hotfixes-stable-2026-07-27-14-18' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: fs/proc/task_mmu: fix PAGEMAP_SCAN written state for PMD holes mm/hugetlb: fix list corruption in allocate_file_region_entries() mm: mglru: fix stale batch updates after memcg reparenting selftest: fix headers in fclog.c ocfs2: fix boundary check in ocfs2_check_dir_entry() to use buffer offset mm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk() mm/util: don't read __page_2 for order-1 folios in snapshot_page() mm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork() mm: migrate_device: fix pte_pfn/pte_dirty called on non-present PTE fs/proc/task_mmu: fix PAGEMAP_SCAN written state for unpopulated ptes userfaultfd: wait on source PMD during UFFDIO_MOVE lib: test_hmm: use device devt for coherent device range selection mm/vmstat: fold stranded per-cpu node stats when a node comes online |
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Jann Horn
|
425224c2d7 |
proc: Fix broken error paths for namespace links
Don't return the return value of down_read_killable() (0) when a ptrace
access check fails, return -EACCES as intended.
Reported-by: Magnus Lindholm <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]
Fixes:
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Kiryl Shutsemau (Meta)
|
40de8160ca |
fs/proc/task_mmu: fix PAGEMAP_SCAN written state for PMD holes
PAGEMAP_SCAN reports an unpopulated PTE in a uffd-wp VMA as written, but a
range with no page table at all -- a PMD hole -- is skipped:
pagemap_scan_pte_hole() tests p->cur_vma_category, which never carries
PAGE_IS_WRITTEN, so the hole is neither reported nor (under
PM_SCAN_WP_MATCHING) armed.
In a uffd-wp VMA, WP_UNPOPULATED installs uffd-wp markers when protecting
a range, allocating page tables as needed, so an unpopulated slot is
treated as written -- see the pte_none() handling in
pagemap_page_category(). A missing marker therefore means the range was
zapped, e.g. via MADV_DONTNEED. This applies to anon and shmem VMAs.
An anonymous THP is write-protected in place as a huge PMD, so a full-PMD
MADV_DONTNEED clears it to pmd_none -- a hole with no page table -- and
pagemap_scan_pte_hole() misses it. For a MAP_PRIVATE|MAP_ANON mapping
MADV_DONTNEED has fill-with-zeros semantics, so a write-tracking
checkpoint/migration tool (e.g. CRIU) treats the range as unchanged and
keeps its previous contents; after restore or live migration the process
reads stale data instead of zeroes -- data corruption.
Report a hole in a non-hugetlb uffd-wp VMA as written, matching the
pte_none handling in pagemap_page_category(); the existing
PM_SCAN_WP_MATCHING path then arms it via uffd_wp_range().
hugetlb is excluded: pagemap_hugetlb_category() reports an empty hugetlb
entry (huge_pte_none) as not-written, unlike pagemap_page_category(),
which reports pte_none as written. pagemap_scan_pte_hole() fires for a
hugetlb slot only when it has no page table; keeping that not-written
matches how an allocated-but-empty hugetlb entry reads, so the hole and
the empty-entry cases agree within the VMA.
Link: https://lore.kernel.org/[email protected]
Fixes:
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||
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Kiryl Shutsemau (Meta)
|
07b4377bdb |
fs/proc/task_mmu: fix PAGEMAP_SCAN written state for unpopulated ptes
PAGEMAP_SCAN reports an unpopulated pte differently depending on which
path serves the request. The PAGE_IS_WRITTEN fast path in
pagemap_scan_pmd_entry() reports a pte_none as written (and, under
PM_SCAN_WP_MATCHING, arms a marker); pagemap_page_category() returns 0 for
the same pte_none. A request that cannot take the fast path (an extra
category bit, category_anyof_mask or category_inverted) therefore reports
the pte as clean and skips arming it.
A range that was populated and then MADV_DONTNEED'd reads as written via
one mask and clean via another, and in the latter case is not re-armed for
the next round -- an incremental-dump consumer (e.g. CRIU) using a richer
mask drops the zapped range and stops tracking writes to it.
Report pte_none as written in pagemap_page_category() too. A pte_none
carries no uffd-wp marker, i.e. it is not write-protected -- the same
condition under which the present and swap cases already report
PAGE_IS_WRITTEN. The fast path applies no VMA test, so neither does this.
The hugetlb and fully-unpopulated-PMD (no page table) scans have no
PAGE_IS_WRITTEN fast path, so they do not exhibit the per-entry divergence
and are left unchanged.
Add a pagemap_ioctl selftest that populates a range, drops it with
MADV_DONTNEED, and checks that the fast path and the generic
(category_anyof_mask) path both report every page written.
Link: https://lore.kernel.org/[email protected]
Fixes:
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||
|
Linus Torvalds
|
0e35b9b6ec |
Merge tag 'mm-hotfixes-stable-2026-07-06-17-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton: "20 hotfixes. 17 are for MM. 12 are cc:stable and the remaining 8 address post-7.1 issues or aren't considered suitable for backporting. Two patches from SJ addresses a couple of quite old DAMON issues. And two patches from Yichong Chen fixes tools/virtio build issues. The remaining patches are singletons" * tag 'mm-hotfixes-stable-2026-07-06-17-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: tools/include: include stdint.h for SIZE_MAX in overflow.h tools/virtio: add missing compat definitions for vhost_net_test mm: do file ownership checks with the proper mount idmap samples/damon/mtier: fail early if address range parameters are invalid mm: a second pagecache maintainer mm/damon: add a kernel-doc comment for damon_ctx->rnd_state mm/damon: add a kernel-doc comment for damon_ctx->probes mailmap: add entries for Radu Rendec selftests/mm: hmm-tests: include linux/mman.h to access MADV_COLLAPSE selftests/mm: pagemap_ioctl: use the correct page size for transact_test() fs/proc: fix KPF_KSM reported for all anonymous pages mm: page_ext: add count limit to page_ext_iter_next to prevent invalid PFN access mm/damon/ops-common: handle extreme intervals in damon_hot_score() MAINTAINERS: add Lance as an rmap reviewer mm/compaction: handle free_pages_prepare() properly in compaction_free() mm/damon/sysfs-schemes: put stats for scheme_add_dirs() internal error mm/damon/sysfs-schemes: fix dir put orders in access_pattern_add_dirs() mm: shrinker: fix NULL pointer dereference in debugfs mm: shrinker: fix shrinker_info teardown race with expansion selftests/mm: fix ksft_process_madv.sh test category |
||
|
Jinjiang Tu
|
81401cebfc |
fs/proc: fix KPF_KSM reported for all anonymous pages
Reading /proc/kpageflags for any anonymous page returns KPF_KSM set, even
when KSM is not in use. As a result, tools misclassify all anonymous
pages as KSM merged.
In stable_page_flags(), if the page is anonymous, then use (mapping &
FOLIO_MAPPING_KSM) check to identify if the anonymous page is KSM page.
However, FOLIO_MAPPING_KSM is FOLIO_MAPPING_ANON | FOLIO_MAPPING_ANON_KSM,
(mapping & FOLIO_MAPPING_KSM) check returns true for all anonymous pages.
To fix it, use FOLIO_MAPPING_ANON_KSM instead.
Link: https://lore.kernel.org/[email protected]
Link: https://lore.kernel.org/[email protected]
Fixes:
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||
|
Krzysztof Wilczyński
|
16b02eb4b9 |
proc: only bump parent nlink when registering directories
proc_register() increments the parent directory's link count for every entry it registers, while remove_proc_entry() and remove_proc_subtree() decrement it only when the removed entry is a directory. Regular files thus inflate the parent's count while they exist, and leak one link permanently on every create and remove cycle. For example, /proc/bus/pci/00 with twenty-two device files and no subdirectories reports nlink 24 instead of 2, and SR-IOV VF enable and disable cycles, each creating and removing the VF config space entries under /proc/bus/pci/<bus>, inflate the link count of that directory without bound. Before commit |
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|
Christian Brauner
|
1d4ee94a51 |
fs: add real_fs to track task's actual fs_struct
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/[email protected] Signed-off-by: Christian Brauner (Amutable) <[email protected]> |
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Linus Torvalds
|
2e05544060 |
Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of 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()
...
|
||
|
Linus Torvalds
|
a552c81ff4 |
Merge tag 'mm-stable-2026-06-18-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "selftests/mm: clean up build output and verbosity" (Li Wang)
Remove some noise from the MM selftests build
- "mm: Free contiguous order-0 pages efficiently" (Ryan Roberts)
Speed up the freeing of a batch of 0-order pages by first scanning
them for coalescing opportunities. This is applicable to vfree() and
to the releasing of frozen pages
- "mm/damon: introduce DAMOS failed region quota charge ratio"
(SeongJae Park)
Address a DAMOS usability issue: The DAMOS quota often exhausts
prematurely because it charges for all memory attempted, causing slow
and inconsistent performance when actions fail on unreclaimable
memory.
To fix this, a new feature lets users set a smaller, flexible quota
charge ratio (via a numerator and denominator) for failed regions.
Since failed actions cause less overhead, reducing their quota cost
ensures more predictable and efficient DAMOS processing
- "selftests/cgroup: improve zswap tests robustness and support large
page sizes" (Li Wang)
Fix various spurious failures and improves the overall robustness of
the cgroup zswap selftests
- "fix MAP_DROPPABLE not supported errno" (Anthony Yznaga)
Fix an issue in the mlock selftests on arm32
- "mm: huge_memory: clean up defrag sysfs with shared" (Breno Leitao)
Some maintenance work in the huge_memory code
- "treewide: fixup gfp_t printks" (Brendan Jackman)
Use the special vprintf() gfp_t conversion in various places
- "mm: Fix vmemmap optimization accounting and initialization" (Muchun
Song)
Fix several bugs in the vmemmap optimization, mainly around incorrect
page accounting and memmap initialization in the DAX and memory
hotplug paths. It also fixes pageblock migratetype initialization and
struct page initialization for ZONE_DEVICE compound pages
- "mm/damon: repost non-hotfix reviewed patches in damon/next tree"
A sprinkle of unrelated minor bugfixes for DAMON
- "mm: remove page_mapped()" (David Hildenbrand)
Remove this function from the tree, replacing it with folio_mapped()
- "mm/damon: let DAMON be paused and resumed" (SeongJae Park)
Allow DAMON to be paused and resumed without losing its current state
- "kasan: hw_tags: Disable tagging for stack and page-tables" (Muhammad
Usama Anjum)
Simplify and speed up kasan by removing its ineffective tagging of
stacks and page tables
- "mm/damon/reclaim,lru_sort: monitor all system rams by default"
(SeongJae Park)
Simplify deployment on diverse hardware like NUMA systems by updating
DAMON_RECLAIM and DAMON_LRU_SORT to automatically monitor the
physical address range covering all System RAM areas by default,
replacing the overly restrictive behavior that only targeted the
single largest memory block to save on negligible overhead
- "mm/damon/sysfs: document filters/ directory as deprecated" (SeongJae
Park)
Update some DAMON docs
- "mm: use spinlock guards for zone lock" (Dmitry Ilvokhin)
Switch zone->lock handling over to using the guard() mechanisms
- "mm/filemap: tighten mmap_miss hit accounting" (fujunjie)
Fix a flaw where the mmap_miss counter over-credited page cache hits
during fault-arounds and page-fault retries. This results in
significant reduction of redundant synchronous mmap readahead I/O,
drastically cutting down execution time and gigabytes read for sparse
random or strided memory access workloads
- "selftests/cgroup: Fix false positive failures in test_percpu_basic"
(Li Wang)
Fix a couple of false-positives in the cgroup kmem selftests
- "mm/damon/reclaim: support monitoring intervals auto-tuning"
(SeongJae Park)
Add a new parameter to DAMON permitting DAMON_RECLAIM to
automatically tune DAMON's sampling and aggregation intervals
- "mm/damon/stat: add kdamond_pid parameter" (SeongJae Park)
Change DAMON_STAT to provide the pid of its kdamond
- "mm/kmemleak: dedupe verbose scan output" (Breno Leitao)
Remove large amounts of duplicated backtraces from the verbose-mode
kmemleak output
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 1)" (David
Hildenbrand)
Reduce our use of CONFIG_HAVE_BOOTMEM_INFO_NODE, with a view to
removing it entirely in a later series
- "mm/damon: validate min_region_size to be power of 2" (Liew Rui Yan)
Prevent users from passing a non-power-of-2 value of `addr_unit', as
this later results in undesirable behavior
- "mm: document read_pages and simplify usage" (Frederick Mayle)
- "tools/mm/page-types: Fix misc bugs" (Ye Liu)
Fix three issues in tools/mm/page-types.c
- "mm: misc cleanups from __GFP_UNMAPPED series" (Brendan Jackman)
Implement several cleanups in the page allocator and related code
- "mm, swap: swap table phase IV: unify allocation" (Kairui Song)
Unify the allocation and charging of anon and shmem swap in folios,
provides better synchronization, consolidates the metadata
management, hence dropping the static array and map, and improves
performance
- "mm/damon: introduce data attributes monitoring" (SeongJae Park(
Extend DAMON to monitor general data attributes other than accesses
- "mm/vmalloc: free unused pages on vrealloc() shrink" (Shivam Kalra)
Implement the TODO in vrealloc() to unmap and free unused pages when
shrinking across a page boundary
- "mm/damon: documentation and comment fixes" (niecheng)
- "remove mmap_action success, error hooks" (Lorenzo Stoakes)
Eliminate custom hooks from mmap_action by removing the problematic
success_hook which allowed drivers to improperly access uninitialized
VMAs. It replaces the error_hook with a simple error-code field and
updates the memory char driver accordingly
- "mm/damon: minor improvements for code readability and tests"
(SeongJae Park)
- "mm/damon: fix macro arguments and clarify quota goals doc" (Maksym
Shcherba)
- "userfaultfd: merge fs/userfaultfd.c into mm/userfaultfd.c" (Mike
Rapoport)
- "mm/mglru: improve reclaim loop and dirty folio" (Kairui Song and
others)
Clean up and slightly improves MGLRU's reclaim loop and dirty
writeback handling. Large performance improvements are measured
- "use vma locks for proc/pid/{smaps|numa_maps} reads" (Suren
Baghdasaryan)
Use per-vma locks when reading /proc/pid/smaps and numa_maps similar
to reduce contention on central mmap_lock
- "refactors thpsize_shmem_enabled_store() and thpsize_shmem_enabled_show()"
(Ran Xiaokai)
Some cleanup work in the THP code
- "selftests/memfd: fix compilation warnings" (Konstantin Khorenko)
Fix a few build glitches in the memfd selftest code.
- "memcg: shrink obj_stock_pcp and cache multiple objcgs" (Shakeel
Butt)
Resolve a 68% performance regression caused by NUMA-node cache
thrashing around struct obj_stock_pcp by shrinking its existing
fields and expanding it into a multi-slot array that caches up to
five obj_cgroup pointers per CPU, allowing per-node variants of the
same memcg to coexist within a single 64-byte cache line.
- "zram: writeback fixes" (Sergey Senozhatsky)
address a couple of unrelated zram writeback issues
- "mm: switch THP shrinker to list_lru" (Johannes Weiner)
Resolve NUMA-awareness issues and streamlines callsite interaction by
refactoring and extending the list_lru API to completely replace the
complex, open-coded deferred split queue for Transparent Huge Pages
- "mm: improve large folio readahead for exec memory" (Usama Arif)
Improve large-folio readahead on systems like 64K-page arm64 by
preventing the mmap_miss check from permanently disabling
target-oriented VM_EXEC readahead, and by generalizing the
force_thp_readahead gate to support mappings with any usefully large
maximum folio order under the cache cap.
- "userfaultfd/pagemap: pre-existing fixes" (Kiryl Shutsemau)
Fix a bunch of minor issues in the userfaultfd/pagemap, all of which
were flagged by Sashiko review of proposed new material
- "mm/sparse-vmemmap: Provide generic vmemmap_set_pmd() and
vmemmap_check_pmd()" (Muchun Song)
Provide generic versions of these two functions so the four
arch-specific implementations can be removed.
- "mm/swap, PM: hibernate: fix swapoff race in uswsusp by pinning swap
device" (Youngjun Park)
Address a uswsusp-vs-swapoff race and reduces the swap device
reference taking/releasing frequency.
- "mm/hmm: A fix and a selftest" (Dev Jain)
* tag 'mm-stable-2026-06-18-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
selftests/mm/hmm-tests: test pagemap reads of PMD device-private entries
fs/proc/task_mmu: do not warn on seeing non-migration pmd entry
lib/test_hmm: check alloc_page_vma() return value and handle OOM
mm/compaction: cap compact_gap() at COMPACT_CLUSTER_MAX
mm/swap: remove redundant swap device reference in alloc/free
mm/swap, PM: hibernate: fix swapoff race in uswsusp by pinning swap device
mm/filemap: use folio_next_index() for start
vmalloc: fix NULL pointer dereference in is_vm_area_hugepages()
sparc/mm: drop vmemmap_check_pmd helper and use generic code
loongarch/mm: drop vmemmap_check_pmd helper and use generic code
riscv/mm: drop vmemmap_pmd helpers and use generic code
arm64/mm: drop vmemmap_pmd helpers and use generic code
mm/sparse-vmemmap: provide generic vmemmap_set_pmd() and vmemmap_check_pmd()
rust: page: mark Page::nid as inline
userfaultfd: build __VMA_UFFD_FLAGS from config-gated masks
userfaultfd: gate must_wait writability check on pte_present()
mm/huge_memory: preserve pmd_swp_uffd_wp on device-private PMD downgrade
fs/proc/task_mmu: fix hugetlb self-deadlock in pagemap_scan_pte_hole()
fs/proc/task_mmu: use huge_page_size() in pagemap_scan_hugetlb_entry()
fs/proc/task_mmu: fix make_uffd_wp_huge_pte() prot-update race
...
|
||
|
Linus Torvalds
|
a53fcff8fc |
Merge tag 'timers-nohz-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull NOHZ updates from Thomas Gleixner: - Fix a long standing TOCTOU in get_cpu_sleep_time_us() - Make the CPU offline NOHZ handling more robust by disabling NOHZ on the outgoing CPU early instead of creating unneeded state which needs to be undone. - Unify idle CPU time accounting instead of having two different accounting mechanisms. These two different mechanisms are not really independent, but the different properties can in the worst case cause that gloabl idle time can be observed going backwards. - Consolidate the idle/iowait time retrieval interfaces instead of converting back and forth between them. - Make idle interrupt time accounting more robust. The original code assumes that interrupt time accouting is enabled and therefore stops elapsing idle time while an interrupt is handled in NOHZ dyntick state. That assumption is not correct as interrupt time accounting can be disabled at compile and runtime. - Fix an accounting error between dyntick idle time and dyntick idle steal time. The stolen time is not accounted and therefore idle time becomes inaccurate. The stolen time is now accounted after the fact as there is no way to predict the steal time upfront. * tag 'timers-nohz-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: sched/cputime: Handle dyntick-idle steal time correctly sched/cputime: Handle idle irqtime gracefully sched/cputime: Provide get_cpu_[idle|iowait]_time_us() off-case tick/sched: Consolidate idle time fetching APIs tick/sched: Account tickless idle cputime only when tick is stopped tick/sched: Remove unused fields tick/sched: Move dyntick-idle cputime accounting to cputime code tick/sched: Remove nohz disabled special case in cputime fetch tick/sched: Unify idle cputime accounting s390/time: Prepare to stop elapsing in dynticks-idle powerpc/time: Prepare to stop elapsing in dynticks-idle sched/cputime: Correctly support generic vtime idle time sched/cputime: Remove superfluous and error prone kcpustat_field() parameter sched/idle: Handle offlining first in idle loop tick/sched: Fix TOCTOU in nohz idle time fetch |
||
|
Linus Torvalds
|
13e1a6d6a1 |
Merge tag 'irq-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull interrupt core updates from Thomas Gleixner:
- Rework of /proc/interrupt handling:
/proc/interrupts was subject to micro optimizations for a long time,
but most of the low hanging fruit was left on the table. This rework
addresses the major time consuming issues:
- Printing a long series of zeros one by one via a format string
instead of counting subsequent zeros and emitting a string
constant.
- Simplify and cache the conditions whether interrupts should be
printed
- Use a proper iteration over the interrupt descriptor xarray
instead of walking and testing one by one.
- Provide helper functions for the architecture code to emit the
architecture specific counters
- Convert the counter structure in x86 to an array, which
simplifies the output and add mechanisms to suppress unused
architecture interrupts, which just occupy space for nothing.
Adopt the new core mechanisms.
This adjusts the gdb scripts related to interrupt counter statistics
to work with the new mechanisms.
- Prevent a string overflow in the /proc/irq/$N/ directory name
creation code.
* tag 'irq-core-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
x86/irq: Add missing 's' back to thermal event printout
genirq/proc: Speed up /proc/interrupts iteration
genirq/proc: Runtime size the chip name
genirq: Expose irq_find_desc_at_or_after() in core code
genirq: Add rcuref count to struct irq_desc
genirq/proc: Increase default interrupt number precision to four
genirq: Calculate precision only when required
genirq: Cache the condition for /proc/interrupts exposure
genirq/manage: Make NMI cleanup RT safe
genirq: Expose nr_irqs in core code
scripts/gdb: Update x86 interrupts to the array based storage
x86/irq: Move IOAPIC misrouted and PIC/APIC error counts into irq_stats
x86/irq: Suppress unlikely interrupt stats by default
x86/irq: Make irqstats array based
genirq/proc: Utilize irq_desc::tot_count to avoid evaluation
genirq/proc: Avoid formatting zero counts in /proc/interrupts
x86/irq: Optimize interrupts decimals printing
genirq/proc: Size interrupt directory names for 10-digit interrupt numbers
|
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|
Linus Torvalds
|
e8a56d6fc8 |
Merge tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dcache updates from Al Viro:
- d_alloc_parallel() API change (Neil's with my changes)
- NORCU fixes
- Reorganization and simplification of dentry eviction logic
- Simplifying rcu_read_lock() scopes in fs/dcache.c
- Secondary roots work - getting rid of NFS fake root dentries and
dealing with remaining shrink_dcache_for_umount() and
shrink_dentry_list() races
- making cursors NORCU (surprisingly easy)
* tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (22 commits)
make cursors NORCU
nfs: get rid of fake root dentries
wind ->s_roots via ->d_sib instead of ->d_hash
shrink_dentry_tree(): unify the calls of shrink_dentry_list()
shrinking rcu_read_lock() scope in d_alloc_parallel()
d_walk(): shrink rcu_read_lock() scope
document dentry_kill()
adjust calling conventions of lock_for_kill(), fold __dentry_kill() into dentry_kill()
Document rcu_read_lock() use in select_collect2()
Shift rcu_read_{,un}lock() inside fast_dput()
simplify safety for lock_for_kill() slowpath
fold lock_for_kill() and __dentry_kill() into common helper
fold lock_for_kill() into shrink_kill()
shrink_dentry_list(): start with removing from shrink list
d_prune_aliases(): make sure to skip NORCU aliases
kill d_dispose_if_unused()
make to_shrink_list() return whether it has moved dentry to list
select_collect(): ignore dentries on shrink lists if they have positive refcounts
find_acceptable_alias(): skip NORCU aliases with zero refcount
fix a race between d_find_any_alias() and final dput() of NORCU dentries
...
|
||
|
Linus Torvalds
|
79169a1624 |
Merge tag 'vfs-7.2-rc1.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull procfs updates from Christian Brauner:
- Revamp fs/filesystems.c
The file was a mess with a hand-rolled linked list in desperate need
of a cleanup. The filesystems list is now RCU-ified, /proc files can
be marked permanent from outside fs/proc/, and the string emitted
when reading /proc/filesystems is pre-generated and cached instead of
pointer-chasing and printfing entry by entry on every read.
The file is read frequently because libselinux reads it and is linked
into numerous frequently used programs (even ones you would not
suspect, like sed!). Scalability also improves since reference
maintenance on open/close is bypassed.
open+read+close cycle single-threaded (ops/s):
before: 442732
after: 1063462 (+140%)
open+read+close cycle with 20 processes (ops/s):
before: 606177
after:
|
||
|
Linus Torvalds
|
7e0e7bd60d |
Merge tag 'vfs-7.2-rc1.misc' of 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()
...
|
||
|
Dev Jain
|
cd1fc0e3c1 |
fs/proc/task_mmu: do not warn on seeing non-migration pmd entry
Patch series "mm/hmm: A fix and a selftest", v3.
Patch 1 fixes a stale warning present from the time when only migration
softleaf entries were supported at the PMD level.
Patch 2 adds some code into hmm-tests.c which exercises the pagemap path
for PMD device-private entries.
This patch (of 2):
pagemap_pmd_range_thp() warns if a non-present PMD is not a migration
entry. This became false once device-private entries at the PMD level
were added.
Therefore, remove the stale migration-only assertion.
Link: https://lore.kernel.org/[email protected]
Link: https://lore.kernel.org/[email protected]
Fixes:
|
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|
Kiryl Shutsemau (Meta)
|
e92d92bbaf |
fs/proc/task_mmu: fix hugetlb self-deadlock in pagemap_scan_pte_hole()
A PAGEMAP_SCAN ioctl requesting PM_SCAN_WP_MATCHING on a hugetlb VMA hangs
the calling thread, unkillably, as soon as the scan reaches an unpopulated
part of the range:
do_pagemap_scan()
walk_page_range()
walk_hugetlb_range()
hugetlb_vma_lock_read() # take the vma lock for read ...
pagemap_scan_pte_hole() # ... ->pte_hole() for a hole
uffd_wp_range()
change_protection()
hugetlb_change_protection()
hugetlb_vma_lock_write() # ... and block taking it for write
walk_hugetlb_range() holds the hugetlb vma lock for read across the whole
walk. A present entry goes to ->hugetlb_entry(); an unpopulated one goes
to ->pte_hole(), i.e. pagemap_scan_pte_hole(). To write-protect the hole
that handler calls uffd_wp_range(), which on a hugetlb VMA reaches
hugetlb_change_protection() and takes the same vma lock for write. The
thread then blocks in down_write() waiting for the read lock it is itself
holding.
The populated path avoids this: pagemap_scan_hugetlb_entry()
write-protects the entry inline under the page-table lock and never enters
hugetlb_change_protection().
Do the same for holes. Fault in the page table and install the uffd-wp
marker directly with make_uffd_wp_huge_pte() under the page-table lock,
rather than routing through uffd_wp_range(). That is the same sequence
hugetlb_change_protection() runs for an unpopulated entry, minus the vma
write lock -- which is safe to skip because PMD sharing is disabled on
uffd-wp VMAs (hugetlb_unshare_all_pmds() runs at registration), leaving
nothing for that lock to serialise against.
Link: https://lore.kernel.org/[email protected]
Fixes:
|
||
|
Kiryl Shutsemau (Meta)
|
1b074e3270 |
fs/proc/task_mmu: use huge_page_size() in pagemap_scan_hugetlb_entry()
The partial-page check compares against HPAGE_SIZE (PMD_SIZE), which is
wrong for gigantic hugetlb hstates (e.g. 1G). The walker hands the
callback a huge_page_size()-sized range, never start + HPAGE_SIZE, so the
comparison always declares it partial and aborts the WP. Compare against
the actual hstate's page size.
Link: https://lore.kernel.org/[email protected]
Fixes:
|
||
|
Kiryl Shutsemau (Meta)
|
04718f7c92 |
fs/proc/task_mmu: fix make_uffd_wp_huge_pte() prot-update race
Patch series "userfaultfd/pagemap: pre-existing fixes".
These are pre-existing bug fixes that were carried at the front of the
userfaultfd RWP working-set-tracking series up to v5 [1]. Per review
feedback that fixes should not sit in the middle of a feature series, they
are split out and sent on their own; the RWP series is reposted rebased on
top of this.
All six were flagged by the Sashiko AI review of the RWP series and carry
Reported-by: Sashiko AI review <[email protected]>. They are
independent of RWP, apply to mm-new directly, and carry Cc: stable@.
1: fs/proc/task_mmu: a missing huge_ptep_modify_prot_start() in
make_uffd_wp_huge_pte() can lose hardware Dirty/Accessed updates
when PAGEMAP_SCAN write-protects a hugetlb PTE.
2: fs/proc/task_mmu: pagemap_scan_hugetlb_entry() compares the range
against HPAGE_SIZE rather than the hstate page size, so it never
write-protects gigantic hugetlb pages.
3: fs/proc/task_mmu: PAGEMAP_SCAN with PM_SCAN_WP_MATCHING over an
unpopulated hugetlb range self-deadlocks -- pagemap_scan_pte_hole()
calls uffd_wp_range() while walk_hugetlb_range() holds the hugetlb
vma lock for read, and hugetlb_change_protection() then takes it
for write. Install the marker inline instead.
4: mm/huge_memory: change_non_present_huge_pmd() drops pmd_swp_uffd_wp
on a device-private PMD permission downgrade, silently losing the
uffd-wp marker.
5: userfaultfd: must_wait() applies pte_write() to a locklessly read
PTE without checking pte_present(), so swap/migration entries
decode random offset bits and a thread can stay parked on a stale
fault.
6: userfaultfd: __VMA_UFFD_FLAGS feeds VMA_UFFD_MINOR_BIT (41) to
mk_vma_flags() unconditionally, an out-of-bounds write into the
single-word vma_flags_t on 32-bit. Build the mask from config-gated
per-mode masks so an unavailable bit is never materialised.
This patch (of 6):
make_uffd_wp_huge_pte() arms the UFFD_WP bit on a present HugeTLB PTE by
calling huge_ptep_modify_prot_commit() with a ptent snapshot that was
fetched without the corresponding huge_ptep_modify_prot_start(). The
start helper is what atomically clears the entry so the kernel-owned
snapshot stays consistent until the commit; without it, the hardware may
set Dirty or Accessed in the live PTE between the original read and the
commit, and huge_ptep_modify_prot_commit() (whose generic implementation
just calls set_huge_pte_at()) then writes the stale snapshot back over the
live hardware bits, losing the update.
The non-hugetlb sibling make_uffd_wp_pte() does this correctly via
ptep_modify_prot_start() / ptep_modify_prot_commit(). Mirror that pattern
for the present-PTE branch. The migration case stays as-is -- migration
entries are non-present, so there's no hardware update to race against.
Link: https://lore.kernel.org/[email protected]
Link: https://lore.kernel.org/[email protected]
Link: https://lore.kernel.org/all/[email protected]/ [1]
Fixes:
|
||
|
Jann Horn
|
6255da28d4 |
proc: protect ptrace_may_access() with exec_update_lock (FD links)
proc_pid_get_link() and proc_pid_readlink() currently look up the task from
the pid once, then do the ptrace access check on that task, then look up
the task from the pid a second time to do the actual access.
That's racy in several ways.
To fix it, pass the task to the ->proc_get_link() handler, and instead of
proc_fd_access_allowed(), introduce a new helper call_proc_get_link() that
looks up and locks the task, does the access check, and calls
->proc_get_link().
Fixes:
|
||
|
Jann Horn
|
6650527444 |
proc: protect ptrace_may_access() with exec_update_lock (part 1)
Fix the easy cases where procfs currently calls ptrace_may_access() without
exec_update_lock protection, where the fix is to simply add the extra lock
or use mm_access():
- do_task_stat(): grab exec_update_lock
- proc_pid_wchan(): grab exec_update_lock
- proc_map_files_lookup(): use mm_access() instead of get_task_mm()
- proc_map_files_readdir(): use mm_access() instead of get_task_mm()
- proc_ns_get_link(): grab exec_update_lock
- proc_ns_readlink(): grab exec_update_lock
Fixes:
|
||
|
NeilBrown
|
0e0e490f5d |
VFS: use wait_var_event for waiting in d_alloc_parallel()
Parallel lookup starts with a call of d_alloc_parallel(). That primitive
either returns a matching hashed dentry or allocates a new one in the
in-lookup state and returns it to the caller. Once the caller is done
with lookup, it indicates so either by call of d_{splice_alias,add}()
or by call of d_done_lookup(); at that point dentry leaves the in-lookup
state.
If d_alloc_parallel() finds a matching in-lookup dentry, it must wait for
that dentry to leave the in-lookup state, one way or another. Currently
by supplying wait_queue_head to d_alloc_parallel(). If d_alloc_parallel()
creates a new in-lookup dentry, the address of that wait_queue_head is stored
in ->d_wait of new dentry and stays there while it's in the in-lookup;
subsequent d_alloc_parallel() will wait on the queue found in the matching
in-lookup dentry. Transition out of in-lookup state wakes waiters on that
queue (if any).
That works, but the calling conventions are inconvenient - the caller must
supply wait_queue_head and make sure that it survives at least until the new
in-lookup dentry leaves the in-lookup state. That amounts to boilerplate
in the d_alloc_parallel() callers that are followed by a call of d_lookup_done()
in the same function; in cases like nfs asynchronous unlink it gets worse than
that.
This patch changes d_alloc_parallel() to use wake_up_var_locked() to
wake up waiters, and wait_var_event_spinlock() to wait. dentry->d_lock
is used for synchronisation as it is already held and the relevant
times.
That eliminates the need of caller-supplied wait_queue_head, simplifying
the calling conventions. Better yet, we only need one bit of information
stored in dentry itself: whether there are any waiters to be woken up,
and that can be easily stored in ->d_flags; ->d_wait goes away.
The reason we need that bit (DCACHE_LOOKUP_WAITERS) is that with wait_var
machinery the queues are shared with all kinds of stuff and there's
no way tell if any of the waiters have anything to do with our dentry;
most of the time none of them will be relevant, so we need to avoid the
pointless wakeups.
Another benefit of the new scheme comes from the fact that wakeups
have to be done outside of write-side critical areas of ->i_dir_seq;
with the old scheme we need to carry the value picked from ->d_wait from
__d_lookup_unhash() to the place where we actually wake the waiters up.
Now we can just leave DCACHE_LOOKUP_WAITERS in ->d_flags until we get
to doing wakeups - that's done within the same ->d_lock scope, so we
are fine; new bit is accessed only under ->d_lock and it's seen only
on dentries with DCACHE_PAR_LOOKUP in ->d_flags.
__d_lookup_unhash() no longer needs to re-init ->d_lru. That was
previously shared (in a union) with ->d_wait but ->d_wait is now gone
so it no longer corrupts ->d_lru.
Co-developed-by: Al Viro <[email protected]> # saner handling of flags
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: Al Viro <[email protected]>
|
||
|
Suren Baghdasaryan
|
ea3085dd7a |
fs/proc/task_mmu: read proc/pid/{smaps|numa_maps} under per-vma lock
Patch series "use vma locks for proc/pid/{smaps|numa_maps} reads", v2.
Use per-vma locks when reading /proc/pid/smaps and /proc/pid/numa_maps
similar to /proc/pid/maps to reduce contention on central mmap_lock. One
major difference between maps and smaps/numa_maps reading is that the
latter executes page table walk which can't be done under RCU due to a
possibility of sleeping. Therefore we drop RCU read lock before this walk
while keeping the VMA locked. After the walk we retake RCU read lock,
reset VMA iterator and proceed with the next VMA.
The last two patches extend /proc/pid/maps test to cover /proc/pid/smaps
reading during concurrent address space modification.
This patch (of 3):
proc/pid/{smaps|numa_maps} can be read using the combination of RCU and
VMA read locks, similar to proc/pid/maps. RCU is required to safely
traverse the VMA tree and VMA lock stabilizes the VMA being processed and
the pagetable walk.
Link: https://lore.kernel.org/[email protected]
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Suren Baghdasaryan <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: "Paul E . McKenney" <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
||
|
Frederic Weisbecker
|
127b2eb44f |
tick/sched: Consolidate idle time fetching APIs
Fetching the idle cputime is available through a variety of accessors all
over the place depending on the different accounting flavours and needs:
- idle vtime generic accounting can be accessed by kcpustat_field(),
kcpustat_cpu_fetch(), get_idle/iowait_time() and
get_cpu_idle/iowait_time_us()
- dynticks-idle accounting can only be accessed by get_idle/iowait_time()
or get_cpu_idle/iowait_time_us()
- CONFIG_NO_HZ_COMMON=n idle accounting can be accessed by kcpustat_field()
kcpustat_cpu_fetch(), or get_idle/iowait_time() but not by
get_cpu_idle/iowait_time_us()
Moreover get_idle/iowait_time() relies on get_cpu_idle/iowait_time_us()
with a non-sensical conversion to microseconds and back to nanoseconds on
the way.
Start consolidating the APIs with removing get_idle/iowait_time() and make
kcpustat_field() and kcpustat_cpu_fetch() work for all cases.
Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Shrikanth Hegde <[email protected]>
Link: https://patch.msgid.link/[email protected]
|
||
|
Thorsten Blum
|
de5d0652d0 |
proc: use strnlen() for name validation in __proc_create
Replace strlen(fn) with strnlen(fn, NAME_MAX + 1) when validating the final path component in __proc_create(). This preserves the existing name limit while bounding the length scan to one byte past the maximum name length. Handle empty names separately, and treat names longer than NAME_MAX as too long. Link: https://lore.kernel.org/[email protected] Signed-off-by: Thorsten Blum <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Al Viro <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Thorsten Blum <[email protected]> Cc: wangzijie <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
||
|
Alexey Dobriyan
|
f7027ed76d |
proc: rewrite next_tgid()
* deduplicate "iter.tgid += 1" line,
Right now it is done once inside next_tgid() itself and second time
inside "for" loop.
* deduplicate next_tgid() call itself with different loop style:
auto it = make_tgid_iter();
while (next_tgid(&it)) {
...
}
gcc seems to inline it twice:
$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
add/remove: 0/1 grow/shrink: 1/0 up/down: 100/-245 (-145)
Function old new delta
proc_pid_readdir 531 631 +100
next_tgid 245 - -245
* make tgid_iter.pid_ns const
it never changes during readdir anyway
[[email protected]: remove newline]
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
||
|
Alexey Dobriyan
|
9794de4500 |
proc: add tgid_iter.pid_ns member
next_tgid() accepts pid namespace as an argument, but it never changes during readdir (which would be unthinkable thing to do anyway). Move it inside iterator type and hide from direct usage. Link: https://lore.kernel.org/[email protected] Signed-off-by: Alexey Dobriyan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> |
||
|
Mike Rapoport (Microsoft)
|
cb7907e36c |
proc: replace __get_free_page() with kmalloc()
A few functions in fs/proc/base.c use __get_free_page() to allocate a temporary buffer. kmalloc() is a better API for such use and it also provides better scalability and more debugging possibilities. Replace use of __get_free_page() with kmalloc(). Signed-off-by: Mike Rapoport (Microsoft) <[email protected]> Link: https://patch.msgid.link/[email protected] Reviewed-by: Jan Kara <[email protected]> Signed-off-by: Christian Brauner (Amutable) <[email protected]> |
||
|
Thomas Gleixner
|
171cc0d9ee |
genirq/proc: Speed up /proc/interrupts iteration
Reading /proc/interrupts iterates over the interrupt number space one by one and looks up the descriptors one by one. That's just a waste of time. When CONFIG_GENERIC_IRQ_SHOW is enabled this can utilize the maple tree and cache the descriptor pointer efficiently for the sequence file operations. Implement a CONFIG_GENERIC_IRQ_SHOW specific version in the core code and leave the fs/proc/ variant for the legacy architectures which ignore generic code. This reduces the time wasted for looking up the next record significantly. Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Michael Kelley <[email protected]> Reviewed-by: Dmitry Ilvokhin <[email protected]> Link: https://patch.msgid.link/[email protected] |
||
|
Thomas Gleixner
|
d6b70b16b4 |
x86/irq: Move IOAPIC misrouted and PIC/APIC error counts into irq_stats
The special treatment of these counts is just adding extra code for no real value. The irq_stats mechanism allows to suppress output of counters, which should never happen by default and provides a mechanism to enable them for the rare case that they occur. Move the IOAPIC misrouted and the PIC/APIC error counts into irq_stats, mark them suppressed by default and update the sites which increment them. This changes the output format of 'ERR' and 'MIS' in case there are events to the regular per CPU display format and otherwise suppresses them completely. As a side effect this removes the arch_cpu_stat() mechanism from proc/stat which was only there to account for the error interrupts on x86 and missed to take the misrouted ones into account. Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Michael Kelley <[email protected]> Reviewed-by: Radu Rendec <[email protected]> Link: https://patch.msgid.link/[email protected] |
||
|
Christian Brauner (Amutable)
|
6b1c66c9cc |
exec_state: relocate dumpable information
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 <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Christian Brauner (Amutable) <[email protected]> |
||
|
Christian Brauner (Amutable)
|
4f365e7a5d |
sched/coredump: introduce enum task_dumpable
Replace the SUID_DUMP_DISABLE/USER/ROOT preprocessor constants with enum task_dumpable. Numeric values are preserved (kernel.suid_dumpable sysctl and prctl(PR_SET_DUMPABLE) ABI), so this is a pure rename with no behavioral change. Subsequent commits relocate dumpability onto a per-task structure where the enum type will allow stronger type-checking on the new API. Reviewed-by: Jann Horn <[email protected]> Reviewed-by: David Hildenbrand (arm) <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Christian Brauner (Amutable) <[email protected]> |
||
|
Alexey Gladkov
|
05dab768fc |
proc: handle subset=pid separately in userns visibility checks
When procfs is mounted with subset=pid, only the dynamic process-related part of the filesystem remains visible. That part cannot be hidden by overmounts, so checking whether an existing procfs mount is fully visible does not make sense for this mode. At the same time, a subset=pid procfs mount must not be used as evidence that a later procfs mount would not reveal additional information. It provides a restricted view of procfs, not the full filesystem view. Mark subset=pid procfs instances as restricted variants. Ignore restricted variants when looking for an already-visible mount, and allow new restricted variants without consulting mnt_already_visible(). Signed-off-by: Alexey Gladkov <[email protected]> Link: https://patch.msgid.link/4d5e760c3d534dd2e05578d119cc408450053a98.1777278334.git.legion@kernel.org Reviewed-by: Aleksa Sarai <[email protected]> Signed-off-by: Christian Brauner <[email protected]> |
||
|
Alexey Gladkov
|
1991a8f693 |
proc: prevent reconfiguring subset=pid
Changing subset=pid on an existing procfs instance is not safe. If a full procfs mount has entries hidden by overmounts, switching it to subset=pid would hide the top-level procfs entries from lookup and readdir while leaving the existing overmounts reachable. Reject attempts to change the subset=pid state during reconfigure before applying any other procfs mount options, so a failed reconfigure cannot partially update the instance. Signed-off-by: Alexey Gladkov <[email protected]> Link: https://patch.msgid.link/13295f40f642af5d6e7038d681d43132ad80f7b2.1777278334.git.legion@kernel.org Reviewed-by: Aleksa Sarai <[email protected]> Signed-off-by: Christian Brauner <[email protected]> |
||
|
Alexey Gladkov
|
a2a5eb6323 |
proc: subset=pid: Show /proc/self/net only for CAP_NET_ADMIN
Cache the mounters credentials and allow access to the net directories contingent of the permissions of the mounter of proc. Do not show /proc/self/net when proc is mounted with subset=pid option and the mounter does not have CAP_NET_ADMIN. To avoid inadvertently allowing access to /proc/<pid>/net, updating mounter credentials is not supported. Signed-off-by: Alexey Gladkov <[email protected]> Link: https://patch.msgid.link/d2466fe9085367f1e24693c437ecb8cff2789660.1777278334.git.legion@kernel.org Reviewed-by: Aleksa Sarai <[email protected]> Signed-off-by: Christian Brauner <[email protected]> |
||
|
Christian Brauner
|
dc4edae7f4 |
fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED
Whether a filesystem's mounts need to undergo a visibility check in user namespaces is a static property of the filesystem type, not a runtime property of each superblock instance. Both proc and sysfs always set SB_I_USERNS_VISIBLE on their superblocks unconditionally (sysfs does so on first creation, and subsequent mounts reuse the same superblock). Move this flag from sb->s_iflags (SB_I_USERNS_VISIBLE) to file_system_type->fs_flags (FS_USERNS_MOUNT_RESTRICTED) so the intent is expressed at the filesystem type level where it belongs. All check sites are updated to test sb->s_type->fs_flags instead of sb->s_iflags. The SB_I_NOEXEC and SB_I_NODEV flags remain on the superblock as they are runtime properties set during fill_super. Link: https://patch.msgid.link/72887c5b6204dc3adf5a53104f0be6bd8bc4f6cd.1777278334.git.legion@kernel.org Reviewed-by: Aleksa Sarai <[email protected]> Signed-off-by: Christian Brauner <[email protected]> |
||
|
Alexey Dobriyan
|
912289ee83 |
proc: allow to mark /proc files permanent outside of fs/proc/
Add proc_make_permanent() function to mark PDE as permanent to speed up
open/read/close (one alloc/free and lock/unlock less).
Enable it for built-in code and for compiled-in modules.
This function becomes nop magically in modular code.
Note, note, note!
If built-in code creates and deletes PDEs dynamically (not in init
hook), then proc_make_permanent() must not be used.
It is intended for simple code:
static int __init xxx_module_init(void)
{
g_pde = proc_create_single();
proc_make_permanent(g_pde);
return 0;
}
static void __exit xxx_module_exit(void)
{
remove_proc_entry(g_pde);
}
If module is built-in then exit hook never executed and PDE is
permanent so it is OK to mark it as such.
If module is module then rmmod will yank PDE, but proc_make_permanent()
is nop and core /proc code will do everything right.
Signed-off-by: Alexey Dobriyan <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Christian Brauner <[email protected]>
|