Commit Graph

4198 Commits

Author SHA1 Message Date
Mikhail Gavrilov
e3ee38c1bc x86/mm: Drop unnecessary PMD page copy when freeing
On a box with a discrete GPU, lockdep reports a possible deadlock as
soon as kswapd shrinks the TTM page pool. The immediate cause is an
x86 commit that added an mmap_read_lock() to kernel page protection
munging code.

The huge vmap code holds the same lock over a GFP_KERNEL allocation,
which is a no-no now that reclaim can take it. That allocation is in a
page table *free* path and ends up being for dubious purposes[1].
Basically, it tries to avoid hardware setting Accessed=1 in page table
entries that are unreachable by the hardware, a non-issue.

Remove the PMD copy. Detach the original PMD page at the PUD, flush
the mid-level caches, and free the PTE tables straight from the
detached PMD page. With no allocation left, the locking issue is gone.

Lockdep splat/analysis:

  WARNING: possible circular locking dependency detected
  7.3.0-rc3-f6e7b42bf05b+ #183 Tainted: G     U
  ------------------------------------------------------
  kswapd0/269 is trying to acquire lock:
  ((init_mm).mmap_lock){++++}-{4:4}, at: change_page_attr_set_clr+0x29a/0x4a0
  but task is already holding lock:
  (pool_shrink_rwsem){.+.+}-{4:4}, at: ttm_pool_shrink+0xb2/0x330 [ttm]
  Chain exists of:
    (init_mm).mmap_lock --> fs_reclaim --> pool_shrink_rwsem

The cycle is built from three edges:

  1) pool_shrink_rwsem -> (init_mm).mmap_lock

     The TTM shrinker restores the caching attribute of every page it
     frees, while holding pool_shrink_rwsem:

       ttm_pool_shrink()
       -> ttm_pool_dispose_list()
       -> ttm_pool_free_page()
       -> set_pages_wb()
       -> change_page_attr_set_clr()   [ init_mm mmap read lock ]

  2) fs_reclaim -> pool_shrink_rwsem

     The same shrinker, called from reclaim.

  3) (init_mm).mmap_lock -> fs_reclaim

     ioremap() installing a huge PUD mapping over an existing PMD table:

       ioremap_page_range()
       -> vmap_range_noflush()
       -> vmap_try_huge_pud()          [ init_mm mmap read lock ]
       -> pud_free_pmd_page()
       -> __get_free_page(GFP_KERNEL)  [ enters reclaim ]

[ dhansen: Lots of changelog munging/trimming and merged comments from my
	   version of the fix. ]

Fixes: d5d8b8662e ("x86/mm/pat: Acquire init_mm read lock on attribute changes to avoid UAF")
Suggested-by: Pedro Falcato <pfalcato@suse.de>
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Link: https://lore.kernel.org/20260916062222.27347-1-mikhail.v.gavrilov@gmail.com
Link: https://lore.kernel.org/all/e11449f0-d9ad-4d1b-ab21-2be7d71fe335@intel.com/ [1]
Link: https://patch.msgid.link/20260923223116.20090-1-mikhail.v.gavrilov@gmail.com
Cc: stable@vger.kernel.org
2026-09-28 08:08:16 -07:00
Linus Torvalds
4aec9ad1c6 dma-mapping fixes for Linux 7.3
A few fixes for the DMA-mapping code:
 - resolved regression in accessing encrypted memory by IOMMU-backed
 devices (Aneesh Kumar K.V),
 - improved failure handling and removed rare bug in swiotlb/highmem
 (Donggeun Yoo).
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQSrngzkoBtlA8uaaJ+Jp1EFxbsSRAUCaquwMwAKCRCJp1EFxbsS
 RMT6AP0elpdaZXNY0KwUBTwU95H604J+donqriepHABIBhIDEQD9GWZqNf/m1gEI
 tR5lHQ3+NGs0Q7Vd2ed1vSe82HQSsgU=
 =QxUC
 -----END PGP SIGNATURE-----

Merge tag 'dma-mapping-7.3-2026-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

Pull dma-mapping fixes from Marek Szyprowski:
 "A few fixes for the DMA-mapping code:

   - resolved regression in accessing encrypted memory by IOMMU-backed
     devices (Aneesh Kumar K.V)

   - improved failure handling and removed rare bug in swiotlb/highmem
     (Donggeun Yoo)"

* tag 'dma-mapping-7.3-2026-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  x86/mm: Don't force unencrypted DMA for IOMMU-backed devices
  dma-mapping: don't trace the DMA address when the allocation fails
  swiotlb: use the adjusted address for the highmem page lookup
  dma-coherent: report a failed reserved memory assignment
2026-09-17 08:03:37 -07:00
Aneesh Kumar K.V (Arm)
55a8e14518 x86/mm: Don't force unencrypted DMA for IOMMU-backed devices
Commit 8277a12d0d ("dma-pool: track decrypted atomic pools and select
them via attrs") exposed an issue with force_dma_unencrypted() on
systems using host memory encryption.

force_dma_unencrypted() checks whether the device DMA mask can address
the encryption bit and, if not, requires DMA allocations to use
unencrypted memory. However, this check is not applicable when the
device is using the IOMMU. In that case, the device DMA mask constrains
the IOVA seen by the device, not the backing physical address, so it
does not need to cover the C-bit.

This currently causes dma_alloc_attrs() to set
__DMA_ATTR_ALLOC_CC_SHARED for such devices. iommu_dma_alloc() does not
support that attribute and rejects the allocation, causing DMA
allocations to fail.

Do not force DMA allocations to be unencrypted when the device is using
the IOMMU. This allows the IOMMU to map the encrypted physical pages as
before and avoids incorrectly requesting CC_SHARED allocations.

Fixes: 8277a12d0d ("dma-pool: track decrypted atomic pools and select them via attrs")
Reported-by: Timo Witte <timo.witte@gmail.com>
Closes: https://lore.kernel.org/all/CANB4YXS=Nf-co3t8eMHtqrW4sn=1BDcP6o=EoTrgZm0WYMYTyw@mail.gmail.com/
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Link: https://lore.kernel.org/r/20260908113232.247457-1-aneesh.kumar@kernel.org
[mszyprow: adjusted url and changed 'link' tag to the 'closes' one]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2026-09-11 10:30:50 +02:00
Lorenzo Stoakes (ARM)
9e4a3ec341 x86/mm/pat: Allocate split page tables as kernel page tables
A PTE is allocated directly without going through the standard page table
allocation routines (such as pte_alloc_one_kernel()) when the CPA code
splits a large page (__split_large_page()).

This means the page table constructor is never called nor is the page table
marked as a kernel page table.

The former results in the folio associated with the page table not being
marked as a page table (__pagetable_ctor() is never called thus neither is
__folio_set_pgtable()) nor are statistics updated to reflect
it (lruvec_stat_add_folio() is never called).

The latter issue of failing to mark the page table as a kernel page
table (ptdesc_set_kernel() is never called) is far more problematic.

Since commit:

  5ba2f0a155 ("mm: introduce deferred freeing for kernel page tables")

kernel page table freeing has been batched and since the
subsequent commit:

  e37d5a2d60 ("iommu/sva: invalidate stale IOTLB entries for kernel address space")

IOTLB cache entries for kernel page tables have been invalidated upon
being freed.

Since split page tables are freed without this invalidation, the IOTLB
can contain stale entries for them.

Resolve the issue by using the ordinary PTE allocation API at split time.

This results in these kernel page tables invoking a page table constructor,
and thus requires a page table destructor.

Destructors are not always present, like for early allocated direct map
page tables). Conditionally call pagetable_dtor_free() if the PG_table
folio flag for the ptdesc is set, otherwise we free the page table via
pagetable_free().

Regardless of which path is taken page tables marked as kernel page tables,
which now includes split page tables, take the correct route through
pagetable_free_kernel().

There is a user-visible side effect in that split page tables will appear
in nr_page_table_pages in /proc/vmstat (as do other kernel page tables
allocated after early boot), however this is a positive change.

This issue started being markedly problematic after commit:

  5ba2f0a155 ("mm: introduce deferred freeing for kernel page tables")

so choose this as the Fixes target.

[ dhansen: rephrase in imperative mood ]

Fixes: 5ba2f0a155 ("mm: introduce deferred freeing for kernel page tables")
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Vishal Moola <vishal.moola@gmail.com>
Tested-by: Atish Patra <atishp@meta.com>
Tested-by: Nikunj A Dadhania <nikunj@amd.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260813-cpa-fixes-v2-4-39b4ff90f91d@kernel.org
2026-09-09 08:39:11 +02:00
Lorenzo Stoakes (ARM)
d5d8b8662e x86/mm/pat: Acquire init_mm read lock on attribute changes to avoid UAF
A previous commit protected against races between ptdump and CPA collapse,
however one still exists between attribute changes and collapse as reported
by Denis V. Lunev (linked).

When an attribute change arises, a lockless page table walker obtains a PTE
entry, which is later written to via set_pte_atomic():

  ...
  -> change_page_attr_set_clr()
  -> __change_page_attr_set_clr()
  -> __change_page_attr()
	-> _lookup_address_cpa()
	-> lookup_address_in_pgd_attr()
	-> [ lockless page table walker ]
  -> set_pte_atomic()

There is nothing preventing a concurrent CPA collapse which can free the
PTE that was retrieved here, resulting in a use-after-free.

With the mmap write lock taken on init_mm over CPA collapse, resolve this
race by acquiring an mmap read lock on init_mm over
__change_page_attr_set_clr().

This locks across the whole operation over which the walk and the PTE
entry write occurs, solving the race.

It is safe to do this here, as no spinlocks are held upon entry to
__change_page_attr_set_clr().

However, the lock must not be held over an allocation, as allocation can
trigger reclaim and shrinkers may call into CPA recursively, making
deadlocks possible (init_mm -> ... -> fs_reclaim -> init_mm).

A page table is allocated when a huge page needs to be split:

  -> change_page_attr_set_clr()
  -> __change_page_attr_set_clr()
  -> __change_page_attr()
  -> split_large_page()
  [ pagetable_alloc() ]
  -> __split_large_page()

Avoid deadlocks by dropping the mmap lock across pagetable_alloc() in
split_large_page() and track whether this is needed by adding a new
'init_mm_read_locked' flag to struct cpa_data.

This is safe as __split_large_page() (called with locks re-established)
revalidates that the page table entry is the same as it was prior to the
locks being dropped and __change_page_attr() repeats the entire page table
walk whenever a split occurs, so concurrent split and collapse are
accounted for.

Concurrent ptdump is also safe as the lock is only dropped over page table
allocation during which time the page table has not yet been modified.

The CPA_COLLAPSE flag is only set by set_memory_rox(), which exclusively
operates upon vmalloc ranges, and on x86 only within the module mapping
space.

This is important, because some callers directly invoke
__change_page_attr_set_clr(), bypassing this lock. However, none of these
operate within the module mapping space.

  * cpa_process_alias() - a recursive helper called by
    __change_page_attr_set_clr().
  * __set_memory_enc_pgtable() - operates on the direct mapping and (via
    __vmbus_establish_gpadl()) the vmalloc mapping space.
  * __set_pages_[n]p() - called by set_direct_map_[invalid, default,
    valid]_noflush(), __kernel_map_pages() - operates on the direct map.
  * kernel_[un]map_pages_in_pgd() - operates on EFI ranges.

This work is based upon Denis V. Lunev's excellent analysis of the bug
with gratitude.

[ dhansen: move to imperative voice in changelog ]

Fixes: 41d88484c7 ("x86/mm/pat: restore large ROX pages after fragmentation")
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Atish Patra <atishp@meta.com>
Tested-by: Nikunj A Dadhania <nikunj@amd.com>
Link: https://lore.kernel.org/all/20260626163213.2284080-1-den@openvz.org/
Cc:stable@vger.kernel.org
Link: https://patch.msgid.link/20260813-cpa-fixes-v2-2-39b4ff90f91d@kernel.org
2026-09-09 08:39:04 +02:00
Lorenzo Stoakes (ARM)
a1c7570ced x86/mm/pat: Acquire init_mm write lock on collapse to avoid UAF
x86 implements page attribute modification using its Change Page
Attributes (CPA) mechanism.

This tracks properties of ranges such as cache mode through x86 page
attributes, and as part of that logic manipulates kernel page tables.

Since commit:

  41d88484c7 ("x86/mm/pat: restore large ROX pages after fragmentation")

ranges of kernel page table entries can be collapsed into
huge page table entries as part of this logic.

As part of this collapse, it frees the page tables which the collapsed
entries previously pointed to, and it does so without any relevant locks
being held to preclude concurrent kernel page table walkers.

The only way this code can be reached is if CPA_COLLAPSE is specified, and
this is only set in set_memory_rox() via:

set_memory_rox()
-> change_page_attr_set_clr()
-> cpa_flush()
-> cpa_collapse_large_pages()

Notable users of this are execmem and BPF when manipulating executable
mappings.

However, this is problematic for ptdump as it walks ranges it does not own
and thus runs the risk of a use-after-free on page tables freed underneath
it.

In addition, concurrent CPA collapse operations are possible which can also
cause races.

Resolve the issue by acquiring the mmap write lock on init_mm across the
whole operation.

It is safe to acquire a sleeping lock as all the callers invoke
set_memory_rox() from process context and in any case,
change_page_attr_set_clr() calls vm_unmap_alias() which ultimately takes a
mutex, disallowing atomic context here.

Fixes: 41d88484c7 ("x86/mm/pat: restore large ROX pages after fragmentation")
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Will Deacon <will@kernel.org>
Reviewed-by: David Carlier <devnexen@gmail.com>
Tested-by: Atish Patra <atishp@meta.com>
Tested-by: Nikunj A Dadhania <nikunj@amd.com>
Cc:stable@vger.kernel.org
Link: https://patch.msgid.link/20260813-cpa-fixes-v2-1-39b4ff90f91d@kernel.org
2026-09-09 08:38:56 +02:00
Linus Torvalds
ed3b875bea mm.git review status for mm-hotfixes-stable..mm-stable
Everything:
 
 Total patches:       501
 Reviews/patch:       1.66
 Reviewed rate:       70%
 
 Excluding DAMON:
 
 Total patches:       356
 Reviews/patch:       2.26
 Reviewed rate:       90%
 
 Excluding DAMON and selftests:
 
 Total patches:       329
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Excluding DAMON, selftests and maple_tree:
 
 Total patches:       328
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Summary of patch series in this merge:
 
 - The 2 patch series "mm: drop "sub" prefix from various places" from
   Dev Jain implements some page->folio conversion and a naming cleanup.
 
 - The 2 patch series "mm/kasan: remove redundant initialization for
   kasan_flag_write_only" from Igor Putko provides some KASAN cleanup work.
 
 - The 2 patch series "mm/filemap: reduce unnecessary xarray lookups"
   from Chi Zhiling provides a small speedup in the pagecaache read code.
 
 - The 4 patch series "mm/percpu: Fix possible NOFS/NOIO reclaim
   recursion" from Kaitao Cheng improves a few things in the vmalloc code -
   mainly the avoidance of GFP_KERNEL allocations when the caller asked for
   GFP_NOFS or GFP_NOIO.
 
 - The 3 patch series "mm/kmemleak: avoid soft lockup when scanning task
   stacks" from Breno Leitao avoids a soft lockup watchdog trigger from the
   kmemleak scanning code in extreme situations.
 
 - The 6 patch series "mm/page_owner: misc cleanups" from Ye Liu is a
   collection of unrelated cleanups to the page_owner code.  For some
   reason lots of people have been working on the page_owner code this
   cycle.
 
 - The 4 patch series "mm: convert to walk_page_range_vma() to eliminate
   find_vma()" from Kefeng Wang simplifies and accelerates the page walking
   library function.
 
 - The 3 patch series "mm/migrate: preparatory cleanups for batch copy
   and offload" from Shivank Garg implements cleanups in the migration
   code.
 
 - The 4 patch series "mm/page_owner: add per-fd filter infrastructure
   for print_mode and NUMA filtering" from Zhen Ni provides per-fd
   filtering to page_owner in order to reduce the sometimes vast amount of
   output it can produce.
 
 - The 19 patch series "mm: Refactor bootmem gigantic hugepage
   allocation" from Muchun Song is a "set of fixes and preparatory cleanups
   around bootmem HugeTLB handling, sparse initialization ordering, and
   related vmemmap setup".
 
 - The 4 patch series "mm/zsmalloc: reduce lock contention in zs_free()"
   from Wenchao Hao reduces 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.
 
 - The 2 patch series "move alloc_tag.c file under mm/" from Suren
   Baghdasaryan does that.
 
 - The 6 patch series "samples/damon: handle damon_{start,stop}()
   failures" from SJ Park fixes 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.
 
 - The 11 patch series "mm/damon/sysfs: kobject_del() directories that
   users can create/remove" from SJ Park resolves an issue where delayed
   sysfs directory removal under CONFIG_DEBUG_KOBJECT_RELEASE causes
   creation failures due to duplicate directory names by adding missing
   kobject_del() calls before creating new directories.
 
 - The 3 patch series "mm: cleanup clear_not_present_full_ptes()" from
   David Hildenbrand cleans up the core pte handling code.
 
 - The 3 patch series "selftests/damon: misc fixes for test bugs" from
   Kunwu Chan fixes several bugs in the DAMON selftests.
 
 - The 2 patch series "selftests/damon: fix memcg_path staging handling"
   from Cheng Nie fixes a bug in _damon_sysfs.py for damos_filter
   memcg_path setup, and adds a test case for it in sysfs.py.
 
 - The 2 patch series "selftests/damon: test kdamond refresh_ms" from
   Ruslan Valiyev introduces 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.
 
 - The 5 patch series "mm/damon: five misc fixups" from Akinobu Mita
   contains miscellaneous DAMON fixups.
 
 - The 2 patch series "mm/damon/core: detect internal variation above
   max_nr_regions/2" from Jiayuan Chen fixes 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 adds corresponding
   KUnit test coverage.
 
 - The 6 patch series "mm: preparatory patches for PMD level swap
   entries" from Usama Arif refactors and cleans 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.
 
 - The 11 patch series "mm/damon: update, optimize, and clean up doc,
   tests, and code" from SJ Park updates DAMON design and ABI
   documentation, expands unit and selftest coverage, optimizes
   damon_commit_target_regions(), and cleans up recently added sysfs
   interface code for better readability.
 
 - The 2 patch series "mm/vmpressure: reduce CPU, memory and code
   overhead on cgroup v2" from Usama Arif optimizes vmpressure() by
   skipping unnecessary work on cgroup v2 for userspace event notifications
   and refactors v1-only eventfd handling into mm/memcontrol-v1.c to reduce
   memory overhead and code complexity.
 
 - The 10 patch series "selftests/mm: refactor pkey helpers and fix mmap
   error handling" from Hongfu Li refactors pkeys shared tracing and
   assertion helpers into a common file, unifies protection key selftests
   to use consistent diagnostic logging and assertions, and enforces
   standardized MAP_FAILED return checks for mmap() calls across the tests.
 
 - The 18 patch series "mm/damon: optimize out nr_accesses_bp" from SJ
   Park replaces the error-prone, continuously updated nr_accesses_bp field
   in damon_region with an on-demand moving sum function
   (damon_nr_accesses_mvsum()), reducing structure memory overhead and
   avoiding state corruption bugs.
 
 - The 6 patch series "Open HugeTLB allocation routine for more generic
   use" from Ackerley Tng decouples 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.
 
 - The 3 patch series "mm/damon: provide pseudo moving sum probe_hits"
   from SJ Park integrates DAMON's probe_hits attribute counter into the
   pseudo moving sum infrastructure, enabling real-time, online monitoring
   without waiting for full aggregation intervals.
 
 - The 18 patch series "mm: Some cleanups for page allocator APIs" from
   Brendan Jackman simplifies and refactors the page allocator entry points
   and flags by unifying allocation paths, adding internal alloc_flags
   arguments, and eliminating redundant __ prefixed alloc_pages variants.
 
 - The 5 patch series "Fix incorrect access of hugetlb pte entries" from
   Dev Jain enforces 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.
 
 - The 8 patch series "mm/damon: validate all parameters in the core"
   from SJ Park consolidates 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.
 
 - The 3 patch series "tools/mm/page_owner_sort: fix filtering and
   cleanup issues" from Yichong Chen renames is_need() to filter_record()
   for clearer return semantics, fixes per-record allocation memory leaks
   and bounds output copies in search_pattern() to address an existing
   buffer issue.
 
 - The 4 patch series "memcg: bail out reclaim when memcg is dying" from
   Jiayuan Chen mitigates a system-wide stall which occurs when a cgroup is
   removed while one of its memory control files is doing synchronous
   reclaim.
 
 - The 5 patch series "mm/memory-failure: add panic option for
   unrecoverable pages" from Breno Leitao introduces 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.
 
 - The 11 patch series "mm/damon: refactor damon_{start,stop,commit}()
   for simple error handling" from SJ Park refactors 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.
 
 - The 5 patch series "Keep tail page private zero at free and folio
   split" from Zi Yan adds 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().
 
 - The 4 patch series "mm: drop redundant lru_add_drain in anon folio
   reuse paths" from Barry Song eliminates 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.
 
 - The 3 patch series "mm: clean up folio LRU and swap declarations" from
   Jianyue Wu reorganizes 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.
 
 - The 15 patch series "userfaultfd: working set tracking for VM guest
   memory" from Kiryl Shutsemau adds userfaultfd support for tracking the
   working set of VM guest memory, so a VMM can identify hot pages and
   reclaim cold ones to tiered or remote storage.
 
 - The 10 patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part
   2)" from David Hildenbrand removes the remaining pieces of
   CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around
   freeing of reserved vmemmap pages on the way.
 
 - The 7 patch series "mm/damon: update probe hits for runtime parameter
   commits" from SJ Park ensures 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.
 
 - The 3 patch series "KSM: performance optimizations for rmap_walk_ksm"
   from xu xin resolves 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.
 
 - The 3 patch series "mm: split a couple of headers from internal.h"
   from Mike Rapoport splits declarations related to mm_init, memblock,
   vmalloc and sparse into new headers.
 
 - The 2 patch series "KSM: use linear_page_index in collect_procs_ksm()"
   from xu xin applies 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.
 
 - The 3 patch series "selftests/mm: avoid false failures in hugetlb and
   KSM tests" from Sayali Patil fixes issues in the hugetlb and KSM MM
   selftest categories that can report failures when the prerequisites for
   the tests are not satisfied.
 
 - The 19 patch series "mm/damon: introduce data attributes only
   monitoring" from SJ Park introduces 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.
 
 - The 8 patch series "mm/hmm: Add mmap lock-drop support for
   userfaultfd-backed mappings" from Stanislav Kinsburskii extends
   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.
 
 - The 33 patch series "mm: make VMA page offset handling more
   consistent" from Lorenzo Stoakes cleans up and standardizes 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.
 
 - The 3 patch series "mm: handle device-private PMDs in walk callbacks"
   from Usama Arif addresses 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.
 
 - The 5 patch series "mm/rmap: Refactor try_to_unmap_one" from Dev Jain
   refactors 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.
 
 - The 4 patch series "Docs/ABI/damon: sysfs ABI document fixes and
   additions" from Song Hu fixes typos and fills in missing entries in the
   DAMON sysfs ABI document.
 
 - The 10 patch series "dax/kmem: atomic whole-device hotplug via sysfs"
   from Gregory Price introduces 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.
 
 - The 13 patch series "mm: convert more vm_flags_t users to vma_flags_t"
   from Lorenzo Stoakes continues 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.
 
 - The 2 patch series "Two small patches to clean up mm/mm_slot.h" from
   xu xin refactors 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.
 
 - The 10 patch series "mm/damon/core: hide core-private struct fields"
   from SJ Park cleans 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.
 
 - The 6 patch series "mm/damon: unurgent fixes for infinite loop, NULL
   de-ref and races" from SJ Park addresses 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.
 
 - The 2 patch series "mm/page_alloc: fixes for free_pages_nolock() on
   RT/UP" from Brendan Jackman fixes 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.
 
 - The 4 patch series "mm/page_alloc: couple of followups for recent
   cleanups" from Brendan Jackman cleans up and updates 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.
 
 - The 3 patch series "mm/mseal: further cleanups" from Lorenzo Stoakes
   refactors and simplifies 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.
 
 - The 4 patch series "mm/vmscan: fix swappiness=max and clean up
   per-node proactive reclaim" from Ridong Chen resolves reclaim behavior
   bugs and cleans 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().
 
 - The 6 patch series "mm: mincore: misc cleanups" from Kefeng Wang
   cleans up and simplifies the mincore code.  Most importantly, it removes
   the historical special behavior that always reports VM_PFNMAP pages as
   non-resident.
 
 - The 2 patch series "mm/huge_memory: drop dead split helper variants"
   from Kiryl Shutsemau implements two trivial cleanups in the folio split
   API.
 
 - The 7 patch series "mm/damon: fix uninitialized DAMOS field and kunit
   exec expectation bugs" from SJ Park resolves 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.
 
 - The 3 patch series "cleanup for stable_page_flags()" from Jinjiang Tu
   cleans up and refactors 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.
 
 - The 3 patch series "Batch unmap of uffd-wp file folios" from Dev Jain
   extends 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.
 
 - The 3 patch series "mm/early_ioremap: clarify and clean up
   early_ioremap_reset()" from Sang-Heon Jeon clarifies and cleans 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.
 
 - The 4 patch series "mm: fix reclaim storms in defrag_mode" from
   Johannes Weiner addresses 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.
 
 - The 2 patch series "zram: lockmap tweaks" from Sebastian Siewior
   optimizes and fixes lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolating lock classes across multiple instances.
 
   It 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.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaoUJbQAKCRDdBJ7gKXxA
 jqrzAP9WoPU0hiK4qS/kSjhtoZxhjpS5eLSUCy/utKuEvZbfGgEAu1zA+LH+X9Tm
 THK5ex4iUZxiFbXpWfLMxE/Q9PmQYQ8=
 =QTyb
 -----END PGP SIGNATURE-----

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
  ...
2026-08-20 18:17:08 -07:00
Linus Torvalds
5a8cd539ac Major changes:
- Redesign the verifier error reporting: failures now carry source and
   instruction annotations along with the causal event history that led
   to them, making program rejections far easier to debug and repair
   (Kumar Kartikeya Dwivedi)
 
 - Add arena argument support to kfuncs and struct_ops through the new
   __arena and __arena__nullable suffixes (Tejun Heo, Puranjay Mohan,
   Kumar Kartikeya Dwivedi, Ihor Solodrai)
 
 - Signed BPF program loader rework to accommodate both BPF and security
   community needs where the kernel runs the signature verification at
   BPF_PROG_LOAD time before the LSM admission hook (Daniel Borkmann)
 
 - Add a set of ksock kfuncs which let BPF LSM and syscall programs
   create, connect and send on UDP sockets in order to emit telemetry
   data (Mahe Tardy)
 
 - Unify helper and kfunc call argument verification and classify kfunc
   arguments purely from BTF into a generated bpf_func_proto which is
   computed once at add-call time (Amery Hung)
 
 Other features and fixes:
 
 - Enable EXECMEM_ROX_CACHE for BPF allocations on x86 (Mike Rapoport)
 
 - Add bidirectional VLAN support to bpf_fib_lookup() through the new
   BPF_FIB_LOOKUP_VLAN and BPF_FIB_LOOKUP_VLAN_INPUT flags
   (Avinash Duduskar)
 
 - Infer zext_dst from static register liveness analysis to fix 32-bit
   zero-extension semantics, and remove the artificial limitations on
   pointer types eligible for spilling (Eduard Zingerman)
 
 - Inline the numeric open-coded iterator kfuncs so that bpf_for() loops
   no longer pay a kfunc call on every iteration (Puranjay Mohan)
 
 - Add an arena-based bitmap data structure to libarena along with
   serial and parallel selftests (Emil Tsalapatis)
 
 - Teach resolve_btfids to discover kfuncs from the kernel's BTF ID sets
   and to emit kfunc BTF decl tags, reducing the kernel build's
   dependency on pahole features (Ihor Solodrai)
 
 - Add BPF_F_ADJ_ROOM_DECAP_* flags to bpf_skb_adjust_room() so that
   tunnel decapsulation can update the GSO and encapsulation state of
   the skb (Nick Hudson)
 
 - Fix the ring buffer pending_pos walk and the available-data
   accounting on 32-bit position wrap (Israel Téllez García)
 
 - Add memory usage accounting for arena maps and fix an mmap_lock
   deadlock on arena lock failure (Jiayuan Chen)
 
 - Add tracing_multi link info support to the kernel UAPI and bpftool,
   and refactor the stack map code to run with preemption disabled
   (Jiri Olsa)
 
 - Support BPF_F_EGRESS in bpf_redirect_peer() to emit the skb in the
   egress direction of the target's peer device (Jordan Rife)
 
 - Add a KF_SPINLOCK_SAFE kfunc flag so that providers, in particular
   modules, can declare kfuncs safe to call under bpf_spin_lock instead
   of relying on the verifier's hard-coded allowlist (Kaitao Cheng)
 
 - Introduce global percpu data for BPF programs with libbpf probing
   and bpftool skeleton support, and stop exposing uninitialized kernel
   heap memory when copying per-CPU map values (Leon Hwang)
 
 - Add s390 JIT support for load-acquire and store-release instructions
   (Maxim Khmelevskii)
 
 - Fix a CFI mismatch in the task work callback and an arm64 KASAN
   false positive after bpf_throw() (Mykyta Yatsenko)
 
 - Reject writes through untrusted BTF pointers and bound the
   rdonly/rdwr_buf_size kfunc arguments (Nicholas Dudar)
 
 - Invalidate RCU pointers only after the final spin unlock and account
   for preempt and IRQ disabled regions as overlapping RCU protection
   (Ning Ding)
 
 - Support mixing bpf2bpf calls and tail calls on RV64, add signed
   operations and 32-bit atomics to the RV32 JIT, and add timed may_goto
   support (Pu Lehui, Kuan-Wei Chiu, Feng Jiang)
 
 - Fix a use-after-free on mm_struct in bpf_find_vma() for foreign tasks
   and an mmap_lock leak in the irq_work path (Sanghyun Park)
 
 - Populate mmap-able BPF array map memory lazily which makes mmap() O(1)
   instead of proportional to the map size (Song Liu)
 
 - Introduce a jit_required flag and reject programs with inlined
   helpers when no JIT is available, where the interpreter would
   otherwise jump into an invalid address (Tiezhu Yang)
 
 - Fix the x86 JIT per-CPU address resolution into an extended register
   where the REX prefix dropped the high destination register bit
   (Vineet Gupta)
 
 - Reject MEM_ALLOC BTF accesses past object bounds, arena frees below
   the arena base, and mixed arena and ordinary atomic paths
   (Yiyang Chen)
 
 - Fix the trampoline handling of 128-bit arguments and of return values
   larger than 8 bytes (Yonghong Song)
 
 - Ensure that any fault prone load is rewritten with exception table
   handling, and fix the arena load-acquire and atomic fetch handling
   in the x86, arm64, riscv and s390 JITs (Daniel Borkmann)
 
 - Many more fixes and cleanups across the verifier, arena, trampolines,
   sockmap, cgroup, ring buffer, x86/arm64/riscv/s390 JITs, libbpf,
   bpftool, resolve_btfids and selftests.
 
 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
 -----BEGIN PGP SIGNATURE-----
 
 iIsEABYKADMWIQTFp0I1jqZrAX+hPRXbK58LschIgwUCaoNzBBUcZGFuaWVsQGlv
 Z2VhcmJveC5uZXQACgkQ2yufC7HISIOb3QEAy5cyrLXY+VWofhsC9wULkHyETOdj
 oTkdohQomZp4VhEA/1RZXdHVS1ANFgreWv0fMorUOHEKv2ZuNokfk3LWgW4L
 =VRyL
 -----END PGP SIGNATURE-----

Merge tag 'bpf-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Daniel Borkmann:
 "Major changes:

   - Redesign the verifier error reporting: failures now carry source
     and instruction annotations along with the causal event history
     that led to them, making program rejections far easier to debug and
     repair (Kumar Kartikeya Dwivedi)

   - Add arena argument support to kfuncs and struct_ops through the new
     __arena and __arena__nullable suffixes (Tejun Heo, Puranjay Mohan,
     Kumar Kartikeya Dwivedi, Ihor Solodrai)

   - Signed BPF program loader rework to accommodate both BPF and
     security community needs where the kernel runs the signature
     verification at BPF_PROG_LOAD time before the LSM admission hook
     (Daniel Borkmann)

   - Add a set of ksock kfuncs which let BPF LSM and syscall programs
     create, connect and send on UDP sockets in order to emit telemetry
     data (Mahe Tardy)

   - Unify helper and kfunc call argument verification and classify
     kfunc arguments purely from BTF into a generated bpf_func_proto
     which is computed once at add-call time (Amery Hung)

  Other features and fixes:

   - Enable EXECMEM_ROX_CACHE for BPF allocations on x86 (Mike Rapoport)

   - Add bidirectional VLAN support to bpf_fib_lookup() through the new
     BPF_FIB_LOOKUP_VLAN and BPF_FIB_LOOKUP_VLAN_INPUT flags (Avinash
     Duduskar)

   - Infer zext_dst from static register liveness analysis to fix 32-bit
     zero-extension semantics, and remove the artificial limitations on
     pointer types eligible for spilling (Eduard Zingerman)

   - Inline the numeric open-coded iterator kfuncs so that bpf_for()
     loops no longer pay a kfunc call on every iteration (Puranjay
     Mohan)

   - Add an arena-based bitmap data structure to libarena along with
     serial and parallel selftests (Emil Tsalapatis)

   - Teach resolve_btfids to discover kfuncs from the kernel's BTF ID
     sets and to emit kfunc BTF decl tags, reducing the kernel build's
     dependency on pahole features (Ihor Solodrai)

   - Add BPF_F_ADJ_ROOM_DECAP_* flags to bpf_skb_adjust_room() so that
     tunnel decapsulation can update the GSO and encapsulation state of
     the skb (Nick Hudson)

   - Fix the ring buffer pending_pos walk and the available-data
     accounting on 32-bit position wrap (Israel Téllez García)

   - Add memory usage accounting for arena maps and fix an mmap_lock
     deadlock on arena lock failure (Jiayuan Chen)

   - Add tracing_multi link info support to the kernel UAPI and bpftool,
     and refactor the stack map code to run with preemption disabled
     (Jiri Olsa)

   - Support BPF_F_EGRESS in bpf_redirect_peer() to emit the skb in the
     egress direction of the target's peer device (Jordan Rife)

   - Add a KF_SPINLOCK_SAFE kfunc flag so that providers, in particular
     modules, can declare kfuncs safe to call under bpf_spin_lock
     instead of relying on the verifier's hard-coded allowlist (Kaitao
     Cheng)

   - Introduce global percpu data for BPF programs with libbpf probing
     and bpftool skeleton support, and stop exposing uninitialized
     kernel heap memory when copying per-CPU map values (Leon Hwang)

   - Add s390 JIT support for load-acquire and store-release
     instructions (Maxim Khmelevskii)

   - Fix a CFI mismatch in the task work callback and an arm64 KASAN
     false positive after bpf_throw() (Mykyta Yatsenko)

   - Reject writes through untrusted BTF pointers and bound the
     rdonly/rdwr_buf_size kfunc arguments (Nicholas Dudar)

   - Invalidate RCU pointers only after the final spin unlock and
     account for preempt and IRQ disabled regions as overlapping RCU
     protection (Ning Ding)

   - Support mixing bpf2bpf calls and tail calls on RV64, add signed
     operations and 32-bit atomics to the RV32 JIT, and add timed
     may_goto support (Pu Lehui, Kuan-Wei Chiu, Feng Jiang)

   - Fix a use-after-free on mm_struct in bpf_find_vma() for foreign
     tasks and an mmap_lock leak in the irq_work path (Sanghyun Park)

   - Populate mmap-able BPF array map memory lazily which makes mmap()
     O(1) instead of proportional to the map size (Song Liu)

   - Introduce a jit_required flag and reject programs with inlined
     helpers when no JIT is available, where the interpreter would
     otherwise jump into an invalid address (Tiezhu Yang)

   - Fix the x86 JIT per-CPU address resolution into an extended
     register where the REX prefix dropped the high destination register
     bit (Vineet Gupta)

   - Reject MEM_ALLOC BTF accesses past object bounds, arena frees below
     the arena base, and mixed arena and ordinary atomic paths (Yiyang
     Chen)

   - Fix the trampoline handling of 128-bit arguments and of return
     values larger than 8 bytes (Yonghong Song)

   - Ensure that any fault prone load is rewritten with exception table
     handling, and fix the arena load-acquire and atomic fetch handling
     in the x86, arm64, riscv and s390 JITs (Daniel Borkmann)

   - Many more fixes and cleanups across the verifier, arena,
     trampolines, sockmap, cgroup, ring buffer, x86/arm64/riscv/s390
     JITs, libbpf, bpftool, resolve_btfids and selftests"

* tag 'bpf-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (373 commits)
  selftests/bpf: Add tests for a store on a fault prone qdisc pointer
  selftests/bpf: Add tests for fault prone loads out of RCU pointers
  selftests/bpf: Add tests for pointer type merge at a shared load
  selftests/bpf: Remove duplicate copies of the arena spinlock qnodes
  selftests/bpf: Retry stat generation in cgroup_iter_memcg
  selftests/bpf: Test pseudo-function policy diagnostics
  bpf: Distinguish function references in policy diagnostics
  bpf: Preserve source attribution without source text
  selftests/bpf: Test kfunc argument diagnostics
  bpf: Correct kfunc argument diagnostics
  bpf: Use canonical stack argument names in diagnostics
  bpf: Preserve R0 lineage across helper calls
  selftests/bpf: Exercise negative optlen in cgroup getsockopt hook
  bpf: Reject negative optlen in cgroup getsockopt hook
  selftests/bpf: tc_tunnel - validate decap GSO and encapsulation state
  bpf: Clear decap state on skb_adjust_room shrink path
  bpf: Allow new DECAP flags and add guard rails
  bpf: Add BPF_F_ADJ_ROOM_DECAP_* flags for tunnel decapsulation
  bpf: Refactor masks for ADJ_ROOM flags and encap validation
  bpf: Name the enum for BPF_FUNC_skb_adjust_room flags
  ...
2026-08-20 07:36:20 -07:00
Linus Torvalds
5808ac1889 - Get rid of static_cpu_has() - one less API to care about testing CPU
features
 
 - Unify the handling of CPU core types (performance, efficient, etc) by
   mapping the vendor-specific types to Linux ones
 
 - Continuation of the work of Ahmed Darwish to centralize CPUID leafs
   representation
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmqEomYACgkQEsHwGGHe
 VUqrVhAAmN1E0HRaRm2zUcJqDS2TVz9a//LTWI/i9pNtlhPrdGrPtaHfps89TGj3
 1TBiFPE6I4xbuTlumFBToqfPbJ8mw41s3ZnlAUk/QVkf0J7Qkra/tZ9dRsWpjwqJ
 y/PqzgW7qTtpye881VX0fNaOlV4CRAQiGv6StALRo9fXn1lWRfwCfFBjYeuMHS0H
 e8r0shF0petS7JdHyTWmzS3E50ETrGI6XNbkKjWFyMjolaeP3r4YP1ucj/B5KY1E
 CFjdBkgXM3PQ0K4Nax96PA15VoMorIuGhpjiv0phiA9itBay3x6EQfOhXoMWtgiE
 9gbgUfWUCx/n+U5tXwOaZnFBd8gnyT0QOENmojEf8GCIBoGgeff0g6djNAm36QlF
 Zyfq7EOMBCfkooddWEz6qhZdeP7SwKz0i0dHyJ6OroQKXVjnCXAUveyA3/1venYb
 HT/xP/BNDQc4+GpO1ZPCuottpC6CVPclWsVOrcnU4jBtZJRhvNTWQMbDpZUFUefO
 FIJi40u1cnHw1hk7t5dVACJAME5p4hUz9hlfZFMETbkxjFH7cJEKaGFO2JXhSsui
 NaLkCJQWgnJynnhNhdycRsdbC6+pAiayoajGe80hiwYrr3j0YhG5UKSrgUwD6uiq
 CxuFt7C8jLEsAcWBILVB5+S6vh+3peHRAm9m9LtgiDpRAM4vGGI=
 =IKxX
 -----END PGP SIGNATURE-----

Merge tag 'x86_cpu_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpuid updates from Borislav Petkov:

 - Get rid of static_cpu_has() - one less API to care about testing CPU
   features

 - Unify the handling of CPU core types (performance, efficient, etc) by
   mapping the vendor-specific types to Linux ones

 - Continuation of the work of Ahmed Darwish to centralize CPUID leaf
   representation

* tag 'x86_cpu_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU: Rename struct cpuid_read_output to struct cpuid_output
  x86/cpu/scattered: Sort it properly
  x86/cpu: Use parsed CPUID(0x1)
  x86/lib: Add CPUID(0x1) family and model calculation
  x86/cpu: Use parsed CPUID(0x0)
  x86/cpu/transmeta: Rescan CPUID(0x1) after modifying capabilities
  x86/topology: Add TOPO_CPU_TYPE_LOW_POWER
  x86/topology: Name the AMD core-type values
  x86/topo: Map vendor CPU types to generic Linux such types
  x86/bugs: Don't use cpu-type matching in cpu_vuln_blacklist
  x86/cpu: Hide and rename static_cpu_has()
2026-08-18 19:09:42 -07:00
Linus Torvalds
bbd0571269 - The usual pile of smallish cleanups and fixlets all over the place
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmqEj4IACgkQEsHwGGHe
 VUoFdRAAvbLBiy7GJixnL2RqNuJ2AoScR09VsFeZ5yKO5y9T7dycZ6Ahkp2/CZVw
 aWTuFctTTcjF8B8nv/phw9RBnT1bSU3y+t/6w2kPgrCnjq8OZ3vH3VRsUyYLUhcN
 fxd45445bIWgbc9Jv6F8tyOdS/l9Lkc3NXTkHWKvDBru/XH4+UGU0tcNcvOiXoWi
 5UXmjm3Wj9DqsFxUkGAzFJVKXq+BD+3vqByNPqudo7HV+SY5jeGs921lgcfJtZwe
 lD3Sz8F7/eVH8Kb5pZt1uYHlorqy1SoZDIp559W9O0jmi3BLY4RmeTcvSu7fYGpT
 n5lV9n6aZDwBe45pbeoICHyRGnJP8fN2BygGNblL6Cfdh8Wx4U3UWqiAYsDKwOAi
 336bRp611RLStOBV8+mEmpTJ0KfK/HIhPxIvuk49zqHffVniRvMSbbr5DxF2iWbU
 21yRBrEtzqsWMI9c4GgZnHPSLw4pE2cznEd/xId6eAX4aBF/03y0IUvqJX9q85Lj
 9Swd2wdyZysetXN6Ibk8R7BqQqsW6gZtm+k7bdkdxN3MqDMy3rCk66bz00t2kVey
 OIfTtP8Ai1TAh7Y3mFXTT6S6y5RK4vM2L41QJalVLklhyBruYzhrpOz2RcafXm4n
 b5ebossw9TF4hRKdoxULLdNfVrnhgT+akNG6MS3ekZctrWULyt4=
 =/jsH
 -----END PGP SIGNATURE-----

Merge tag 'x86_cleanups_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cleanups from Borislav Petkov:

 - The usual pile of smallish cleanups and fixlets all over the place

* tag 'x86_cleanups_for_v7.3_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Remove unnecessary __maybe_unused annotations
  x86/msr: Document the I/O-like write semantics in the msr driver
  x86/apic: Ensure ICR register write value is handled as 32 bits
  x86/boot/compressed/head_64.S: Clean up SEV-related comments
  Documentation/arch/x86/amd-memory-encryption.rst: Fix typo
  x86/platform/quark: Fix kernel-doc warnings in imr.c
  x86/ras: Move contents from arch/x86/ras/Kconfig into drivers/ras/Kconfig
  x86/cpu: Move intel_get_platform_id() to cpu/intel.c
  x86/mm: Fix typo in comment
  x86/fpu: Fix kernel-doc formatting above fpu_enable_guest_xfd_features()
  x86/cfi: Use symmetric SYM_START and SYM_END in __CFI_TYPE()
  x86/cfi: Add __init_or_module annotations for fineibt
2026-08-18 18:34:58 -07:00
Linus Torvalds
b126f6f594 * Fix pkey_alloc() return value when pkeys are not supported
* Allow preemption during IPI completion waiting to improve wakeup latency
  * Convert more x86 page table code to ptdescs
  * Fixes and cleanups for set_memory*() locking, mostly around large pages
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmqEeS8ACgkQaDWVMHDJ
 krDQmRAAqGxk8Wma2fmxe4eZlSmauJSgoPYGt5eBI1nNCwVH323hKXanjOZ0zQ6Z
 vF6IDxk2MqvBh3TXLOkbDtOi2A7IIvb+g7SEqvfEnmrv5PSaiBzZdcE6+zfkyq51
 BGg5TWQdaM5psiyS8D33OUmcYS1H0B9+x/dHU5nGDYRbQBeEXVwT8rL8MOYTQP8e
 Drjvk2gru7wwaXiDk6go26momhVAFMCGgVZKUlHfdi1jSschjEJhOl1YTvtMoQp9
 PukZ+gwgJfsZTBnfPTZwatWbUAb8ishUeIBOpLhMamoenScA7Cylh4zz/LKtedXy
 +jxt1VPN0J3kxHlCwV6X/bGNhiIpGWQIZgYVPwwWEPjFvBIzersuoPMOZAPG6ZB0
 pBnMg6fhu/dpUmHaKHLpRr/qsx19zzW2ftRLFyp4FY4i3o2fnhc4icPk/xBENETh
 luo9ETLLCa5zJWTN3y2cNzNFrizpHFrRTuRy3c0B512gaIh0gW1tmMom1Tl3meEj
 oaf2vOlRoW4S2PP60LWKtyl6H8wjzylqzKVGNpSkzBIC0a1+ln4jQhcfLMuigQwF
 DSA8tOFNL1DGC9MVQTHV0r799QJWs4lPt9lM1d/OzUeIzgWaDQ4aqTV5ni+zhwF8
 ZWYttRMWAceL4RwGEDsdVWuGay6mtIna8HTEDkG5/co+jmwoehw=
 =e5mx
 -----END PGP SIGNATURE-----

Merge tag 'x86_mm_for_7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 mm updates from Dave Hansen:
 "There are two things in here of note. First, there are fixes to reduce
  the time that the TLB flushing code sits around with interrupts
  disabled. It should be well tested, but it's certainly something to
  keep an eye on.

  Second is a little back-and-forth in the interactions between the
  set_memory*() locking and DEBUG_PAGEALLOC. There was a slightly
  painful re-discovery of why DEBUG_PAGEALLOC has special locking rules,
  but the code did end up better for it.

  Summary:

   - Fix pkey_alloc() return value when pkeys are not supported

   - Allow preemption during IPI completion waiting to improve wakeup
     latency

   - Convert more x86 page table code to ptdescs

   - Fixes and cleanups for set_memory*() locking, mostly around large
     pages"

* tag 'x86_mm_for_7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pkeys: Fix pkey_alloc() return value when pkeys are not supported
  x86/mm: Fix and document DEBUG_PAGEALLOC
  x86/mm: Use guard() for pgd_lock
  x86/mm: Use guard() in cpa_collapse_large_pages()
  x86/mm: Re-enable preemption before flush_tlb_multi()
  x86/kvm: Disable preemption in kvm_flush_tlb_multi()
  x86/mm: Move flush_tlb_info back to the stack
  x86/mm: Cap flush_tlb_info alignment at 64 bytes
  x86/mm: Factor out flush_tlb_info initialization
  x86/mm/pat: Take cpa_lock around large-page collapse
  x86/mm/pat: Don't gate cpa_lock on debug_pagealloc_enabled()
  x86/xen: Convert xen_mm_unpin_all() to ptdescs
  x86/xen: Convert xen_mm_pin_all() to ptdescs
  x86/mm: Convert pgd_page_get_mm() to ptdescs
  x86/mm: Convert sync_global_pgds_l4() to ptdescs
  x86/mm: Convert sync_global_pgds_l5() to ptdescs
  x86/mm: Convert arch_sync_kernel_mappings() to ptdescs
  x86/mm/pat: Convert collapse_pmd_page() to ptdescs
  x86/mm/pat: Convert __set_pmd_pte() to ptdescs
  x86/mm/pat: Use IS_ENABLED() instead of ifdef
2026-08-18 17:44:09 -07:00
Peter Zijlstra
7da514d819 x86/mm: Fix and document DEBUG_PAGEALLOC
It turns out that commit 5fce67641a ("x86/mm/pat: Don't gate
cpa_lock on debug_pagealloc_enabled()") was a little too quick to
remove the debug_pagealloc exception for cpa_lock.

Notably __kernel_map_pages() is used by the page-allocator from any
context the page-allocator itself is used, which violates the cpa_lock
rules.

Re-instate the exception, except make it specific to the
__kernel_map_pages() such that any other cpa() usage is still fully
serialized by cpa_lock. Also note that since cpa() should not be used
on memory that isn't allocated, the page-allocator locking and cpa are
infact mutually exclusive and all cpa usage in fully serialized.

Add a comment explaining this and other 'funnies' surrounding
DEBUG_PAGEALLOC, including how pgd_lock is not affected and the TLB
trickery.

Fixes: 5fce67641a ("x86/mm/pat: Don't gate cpa_lock on debug_pagealloc_enabled()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260729111119.604452135@infradead.org
2026-08-05 14:19:35 +02:00
Peter Zijlstra
7558828805 x86/mm: Use guard() for pgd_lock
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260729111119.488154104@infradead.org
2026-08-05 14:19:35 +02:00
Peter Zijlstra
c980eafc5b x86/mm: Use guard() in cpa_collapse_large_pages()
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260729111119.375614011@infradead.org
2026-08-05 14:19:35 +02:00
David Hildenbrand (Arm)
ea963eab11 x86/mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE
CONFIG_HAVE_BOOTMEM_INFO_NODE now essentially doesn't do anything.

So let's remove support for CONFIG_HAVE_BOOTMEM_INFO_NODE.

Link: https://lore.kernel.org/20260716-bootmem_info_part2-v2-7-4afc76c73d61@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04 19:18:42 -07:00
David Hildenbrand (Arm)
f20e92095f x86/mm: stop marking page tables as MIX_SECTION_INFO
There is no good reason to mark boot page tables as MIX_SECTION_INFO: we
only free boot page tables when they are completely empty, and memory
offlining/hotunplug doesn't benefit from it in any way.

So just stop marking page tables as MIX_SECTION_INFO.  In
free_pagetable(), we can now simply free reserved pages directly.

Link: https://lore.kernel.org/20260716-bootmem_info_part2-v2-6-4afc76c73d61@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04 19:18:41 -07:00
David Hildenbrand (Arm)
7bfc04d6bd x86/mm: stop marking vmemmap as SECTION_INFO
We added the whole bootmem registration machinery in commit 0475327876
("memory hotplug: register section/node id to free").

The main use case was to remember to which memory section memmap pages
belonged, so the memmap could be handled accordingly when freeing memory.

However, all that machinery is not required anymore: a memory section can
only get offlined if *all* pages can get offlined; and it can only get
unplugged once offline.  If some of these pages are unmovable memmap
pages: bad luck, doesn't work.  Offlining will fail.

Further, a lot of this machinery was required for pre-vmemmap support. 
Now we only support the vmemmap with memory hotplug.

So the whole machinery is useless today.  Let's start by removing the last
pieces by first stopping to mark vmemmap pages as SECTION_INFO.  In
free_vmemmap_pages(), we can now always just free the reserved pages
directly.

Link: https://lore.kernel.org/20260716-bootmem_info_part2-v2-5-4afc76c73d61@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04 19:18:41 -07:00
David Hildenbrand (Arm)
d79db3f396 mm: provide free_reserved_pages(), removing x86 variant
Let's extend free_reserved_page() in page_alloc.c to
free_reserved_pages(), dropping the custom x86 variant.  The common-code
variant will consume an order, so adjust the x86 callers accordingly.

Make free_reserved_pages() assume that we are freeing ordinary high-order
pages, just with the special "reserved" flavor.  The target use case for
now is freeing vmemmap PMD pages.

Set the refcount directly to 0 (instead of 1) and call
__free_frozen_pages().  Set the page count to 0 before clearing
PG_reserved, so someone checking PG_reserved (and not finding it set) to
then try grabbing a ref would not suddenly have that ref be dropped.  That
is arguably cleaner and safer than the old way of doing it.

Add some kerneldoc.  Use a single adjust_managed_page_count() call.

Link: https://lore.kernel.org/20260716-bootmem_info_part2-v2-2-4afc76c73d61@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04 19:18:40 -07:00
David Hildenbrand (Arm)
5e83b4944d x86/mm: drop order parameter from free_pagetable()
Patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)", v2.

Let's remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap pages
on the way.


This patch (of 10):

All callers pass 0, so let's drop the parameter.

Link: https://lore.kernel.org/20260716-bootmem_info_part2-v2-0-4afc76c73d61@kernel.org
Link: https://lore.kernel.org/20260716-bootmem_info_part2-v2-1-4afc76c73d61@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04 19:18:40 -07:00
Chuyi Zhou
a5a162fe1a x86/mm: Re-enable preemption before flush_tlb_multi()
flush_tlb_mm_range() and arch_tlbbatch_flush() pin the current CPU while
they decide whether the flush can be handled locally or must be sent to
remote CPUs. The CPU pinning is needed for the current CPU number and for
the local TLB flush path, which reads per-CPU TLB state.

The caller does not need to remain pinned while waiting for a remote TLB
flush to complete. After the remote-flush path has been selected,
flush_tlb_info is caller-private stack storage, so the caller no longer
has to stay on the same CPU to protect a shared per-CPU flush_tlb_info
object.

flush_tlb_multi() may also route through x86 PV backends. Those backends
must protect their own CPU-local scratch state instead of relying on the
caller to stay pinned. Hyper-V already does this by disabling interrupts
while using hyperv_pcpu_input_arg, and Xen's multicall path brackets its
per-CPU multicall buffer with xen_mc_batch() and xen_mc_issue().
kvm_flush_tlb_multi() also disables preemption while using __pv_cpu_mask.

Remote TLB flushes may synchronously wait for many CPUs, and the wait can
take tens of milliseconds when remote CPUs have interrupts disabled or
when many CPUs are involved. Keeping preemption disabled for that whole
wait unnecessarily increases scheduling latency on the initiating CPU.

Drop the CPU pinning before calling flush_tlb_multi() in the remote paths
of flush_tlb_mm_range() and arch_tlbbatch_flush(). Keep the local paths
inside the pinned section because they still access this CPU's TLB state.

Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20260709122933.4021501-15-zhouchuyi@bytedance.com
2026-07-23 12:30:31 +02:00
Chuyi Zhou
ed15468787 x86/mm: Move flush_tlb_info back to the stack
flush_tlb_info benefits from cacheline alignment, but using
cacheline-aligned stack storage directly can grow stack usage too much on
configurations with large SMP_CACHE_BYTES values. Commit 515ab7c413
("x86/mm: Align TLB invalidation info") attempted to align stack storage,
and commit 780e0106d4 ("x86/mm/tlb: Revert "x86/mm: Align TLB
invalidation info"") reverted it because using SMP_CACHE_BYTES led to 320
bytes of stack consumption. Commit 3db6d5a5ec ("x86/mm/tlb: Remove
'struct flush_tlb_info' from the stack") moved flush_tlb_info to per-CPU
storage, which avoided the stack growth problem while preserving
cacheline alignment. That was a good fit while the callers kept
preemption disabled for the whole flush operation.

However, a single per-CPU flush_tlb_info also requires all flush_tlb*()
operations to keep preemption disabled while the object is in use, so
that it cannot be overwritten by another flush on the same CPU.
flush_tlb*() may send IPIs to remote CPUs and synchronously wait for all
remote CPUs to complete their local TLB flushes. That wait can take tens
of milliseconds when interrupts are disabled on a remote CPU or when a
large number of remote CPUs are involved.

To shorten the CPU-pinned and preemption-disabled section around those
remote TLB flush waits, move flush_tlb_info back to caller-private stack
storage. The caller then does not have to stay on the same CPU until the
remote flush completes.

The type alignment is capped at 64 bytes. This keeps the alignment
benefit for stack objects without reintroducing the old large-cacheline
stack usage problem.

To evaluate the performance impact, use the following script to reproduce
the microbenchmark mentioned in commit 3db6d5a5ec ("x86/mm/tlb: Remove
'struct flush_tlb_info' from the stack"). The test environment is an Ice
Lake system (Intel(R) Xeon(R) Platinum 8336C) with 128 CPUs and 2 NUMA
nodes. During the test, the threads were bound to specific CPUs, and both
pti and mitigations were disabled:

    #include <stdio.h>
    #include <stdlib.h>
    #include <pthread.h>
    #include <sys/mman.h>
    #include <sys/time.h>
    #include <unistd.h>

    #define NUM_OPS 1000000
    #define NUM_THREADS 3
    #define NUM_RUNS 5
    #define PAGE_SIZE 4096

    volatile int stop_threads = 0;

    void *busy_wait_thread(void *arg) {
        while (!stop_threads) {
            __asm__ volatile ("nop");
        }
        return NULL;
    }

    long long get_usec() {
        struct timeval tv;
        gettimeofday(&tv, NULL);
        return tv.tv_sec * 1000000LL + tv.tv_usec;
    }

    int main() {
        pthread_t threads[NUM_THREADS];
        char *addr;
        int i, r;
        addr = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE
                | MAP_ANONYMOUS, -1, 0);

        if (addr == MAP_FAILED) {
            perror("mmap");
            exit(1);
        }

        for (i = 0; i < NUM_THREADS; i++) {
            if (pthread_create(&threads[i], NULL, busy_wait_thread, NULL))
                exit(1);
        }

        printf("Running benchmark: %d runs, %d ops each, %d background\n"
               "threads\n", NUM_RUNS, NUM_OPS, NUM_THREADS);

        for (r = 0; r < NUM_RUNS; r++) {
            long long start, end;
            start = get_usec();
            for (i = 0; i < NUM_OPS; i++) {
                addr[0] = 1;
                if (madvise(addr, PAGE_SIZE, MADV_DONTNEED)) {
                    perror("madvise");
                    exit(1);
                }
            }
            end = get_usec();
            double duration = (double)(end - start);
            double avg_lat = duration / NUM_OPS;
            printf("Run %d: Total time %.2f us, Avg latency %.4f us/op\n",
                   r + 1, duration, avg_lat);
        }
        stop_threads = 1;
        for (i = 0; i < NUM_THREADS; i++)
            pthread_join(threads[i], NULL);
        munmap(addr, PAGE_SIZE);
        return 0;
    }

                   base   on-stack-aligned  on-stack-not-aligned
                   ----       ---------      -----------
avg (usec/op)     2.5278       2.5261         2.5508
stddev            0.0007       0.0027         0.0023

The benchmark results show that the average latency difference between
the baseline (base) and the properly aligned stack variable
(on-stack-aligned) is within the standard deviation (stddev). This
indicates that the variations are caused by testing noise, and reverting
to a stack variable with proper alignment causes no performance
regression compared to the per-CPU implementation. The unaligned version
(on-stack-not-aligned) shows a minor performance drop. The
CPU-pinned/preemption-disabled section can therefore be shortened without
sacrificing performance.

With caller-private storage there is no shared per-CPU object to protect,
so remove the DEBUG_VM reentrancy counter as well.

Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Nadav Amit <nadav.amit@gmail.com>
Link: https://patch.msgid.link/20260709122933.4021501-13-zhouchuyi@bytedance.com
2026-07-23 12:30:31 +02:00
Chuyi Zhou
33c179b502 x86/mm: Factor out flush_tlb_info initialization
get_flush_tlb_info() has two responsibilities: it reserves the per-CPU
flush_tlb_info storage and it initializes the fields that describe the
flush operation. The per-CPU storage also carries the DEBUG_VM
reentrancy check and the matching put_flush_tlb_info() lifetime rules.

Moving flush_tlb_info back to caller-provided storage requires the same
field initialization without tying the caller to the per-CPU object.
Leaving the field setup embedded in get_flush_tlb_info() would either
keep those callers tied to the per-CPU object or duplicate the
initialization logic.

Split the field setup into init_flush_tlb_info(). Keep the per-CPU
storage selection, DEBUG_VM reentrancy check and put_flush_tlb_info()
lifetime rules in get_flush_tlb_info().

No functional change intended.

Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20260709122933.4021501-11-zhouchuyi@bytedance.com
2026-07-23 12:30:31 +02:00
Mike Rapoport (Microsoft)
6b88aaec81
x86/bpf: Enable EXECMEM_ROX_CACHE for BPF allocations
BPF core and x86 JIT use text poking and temporary writable buffers and
thus can handle ROX memory.

Enable ROX cache for EXECMEM_BPF when configuration and CPU features allow
that.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20260716-execmem-x86-rox-bpf-v0-v3-5-4e76158c01c5@kernel.org
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-07-22 17:27:15 +02:00
Denis V. Lunev
1aac65f3e6 x86/mm/pat: Take cpa_lock around large-page collapse
Loading and unloading modules concurrently on several CPUs on a KASAN
build, with a short delay injected at the CPA page-table lookup to
widen the window, faults within minutes:

  BUG: KASAN: use-after-free in __change_page_attr+0x7cc/0x7e0
  Write of size 8 at addr ffff888181139718 by task modprobe
  ...
  The buggy address belongs to the physical page:
   pfn:0x181139 ... page_type: f2(table)

cpa_collapse_large_pages() rebuilds a leaf PMD from its 4K PTEs and
frees the old PTE-table pages, while __change_page_attr() fetches a
PTE pointer from a lockless lookup_address_in_pgd_attr() and writes
it with set_pte_atomic() only later. When module text is served from
a shared large ROX mapping the two run on the same PMD:

  CPU A (module load)              CPU B (module finalize)
  -------------------              -----------------------
  execmem_make_temp_rw
   set_memory_nx
    __change_page_attr
     split 2M -> 4K table P
     kpte = &P[i]  (lockless)
                                   execmem_restore_rox
                                    set_memory_rox (CPA_COLLAPSE)
                                     cpa_collapse_large_pages
                                      rebuild leaf PMD
                                      flush_tlb_all
                                      pagetable_free(P)
     set_pte_atomic(kpte, ...)
       -> writes into freed P

P is a page-table page (page_type: table), reused at once, so the
write corrupts whatever got the page next: a bad-pte or bad-page
splat, or a fatal fault once P has been turned into read-only text.

The flush_tlb_all() before the free does not close this: its IPI only
serializes against page-table walkers that run with interrupts off
(e.g. GUP-fast); the walk in __change_page_attr() runs with interrupts
on, so nothing stops it from holding a stale pointer into P.

Serialize the collapse - the PMD rebuild, TLB flush and PTE-table
free - under cpa_lock, the same lock __change_page_attr() now takes
unconditionally since commit ("x86/mm/pat: stop gating cpa_lock on
debug_pagealloc_enabled()"), so a concurrent walker can no longer
hold a pointer into a table the collapse is about to free.

Fixes: 41d88484c7 ("x86/mm/pat: restore large ROX pages after fragmentation")
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Link: https://patch.msgid.link/20260715183453.2381141-1-den@openvz.org
2026-07-15 13:06:55 -07:00
Mike Rapoport (Microsoft)
5fce67641a x86/mm/pat: Don't gate cpa_lock on debug_pagealloc_enabled()
The splitting and merging of kernel page table mappings between small and
large is protected by cpa_lock. The merging is relatively new but the
splitting is ancient.

The splitting has a locking optimization: since DEBUG_PAGEALLOC forces all
mappings to 4k, there are no large pages to split. So the code that *might*
cause a split can just skip the locking (and a few other things).

This is entertaining, but it adds complexity and makes for weird locking
rules. Plus it's all for a debugging feature which makes the kernel super
slow in the first place. Optimizing something which is already super slow
and not used in production is not the best way to spend our complexity
budget.

Stop gating cpa_lock on debug_pagealloc_enabled() to simplify the code
and the locking rules.

[ dhansen: flesh out changelog ]

Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20260715144519.934289-1-rppt@kernel.org
Link: https://lore.kernel.org/all/aab44f08-89f8-47fe-bee4-0ab6b25968c6@intel.com/
2026-07-15 08:00:49 -07:00
Vishal Moola
dd9850c916 x86/mm: Convert pgd_page_get_mm() to ptdescs
Convert pgd_page_get_mm() to ptdescs. Define struct ptdesc in our
pgtable_types so that our declarations recognize ptdesc as an
appropriate page table type.

Now that all callers are using ptdescs, we can pass in that
ptdesc to get the underlying mm_struct.

Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-8-vishal.moola@gmail.com
2026-07-13 15:55:10 -07:00
Vishal Moola
9c453f8784 x86/mm: Convert sync_global_pgds_l4() to ptdescs
Convert sync_global_pgds_l4() to ptdescs in preparation for the
eventual splitting of ptdescs from struct page.

Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-7-vishal.moola@gmail.com
2026-07-13 15:55:10 -07:00
Vishal Moola
90c881895f x86/mm: Convert sync_global_pgds_l5() to ptdescs
Convert sync_global_pgds_l5() to ptdescs in preparation for the
eventual splitting of ptdescs from struct page.

Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-6-vishal.moola@gmail.com
2026-07-13 15:55:10 -07:00
Vishal Moola
46ee485bb9 x86/mm: Convert arch_sync_kernel_mappings() to ptdescs
Convert arch_sync_kernel_mappings() to ptdescs in preparation for
the eventual splitting of ptdescs from struct page.

Following this patch, we can successfully boot a 32-bit x86 kernel with
separately allocated ptdescs.

Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-5-vishal.moola@gmail.com
2026-07-13 15:55:10 -07:00
Vishal Moola
5fcb2abffe x86/mm/pat: Convert collapse_pmd_page() to ptdescs
Convert collapse_pmd_page() to ptdescs in preparation for the
eventual splitting of ptdescs from struct page.

Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-4-vishal.moola@gmail.com
2026-07-13 15:55:10 -07:00
Vishal Moola
e27d938b0d x86/mm/pat: Convert __set_pmd_pte() to ptdescs
Convert __set_pmd_pte() to ptdescs in preparation for the eventual
splitting of ptdescs from struct page.

Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-3-vishal.moola@gmail.com
2026-07-13 15:55:10 -07:00
Vishal Moola
e7616bb5ef x86/mm/pat: Use IS_ENABLED() instead of ifdef
Use IS_ENABLED() to check if we are on 32 bit. This standardizes this
check with the other 32 bit check in the file. No functional changes.

Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-2-vishal.moola@gmail.com
2026-07-13 15:55:09 -07:00
Borislav Petkov (AMD)
3eaa50e1e2 x86/cpu: Hide and rename static_cpu_has()
cpu_feature_enabled() is the one to use to test feature flags so hide
the static thing which doesn't pay attention to disabled mask bits
anyway.

Use the following command to do the replacement:

  $ git grep --files-with-matches -w static_cpu_has -- ':(exclude)*cpufeature.h' \
  | xargs sed -i 's/static_cpu_has(/cpu_feature_enabled\(/g'

There should be no functional changes resulting from this.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Link: https://patch.msgid.link/20260620015041.336288-1-bp@kernel.org
2026-07-06 21:34:26 -07:00
Sang-Heon Jeon
63fa742bae x86/numa: remove redundant numa_nodes_parsed node_set()
numa_add_memblk() now sets the node in numa_nodes_parsed itself, so the
caller's own node_set() is redundant.  Remove it.

No functional change.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Link: https://patch.msgid.link/20260703041329.2797584-5-ekffu200098@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-07-03 11:16:27 +03:00
You-Li Lin
324549c06e x86/mm: Fix typo in comment
Fix "begining" to "beginning" in a code comment.

Signed-off-by: You-Li Lin <lhu540507@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260627051343.51326-1-lhu540507@gmail.com
2026-07-01 12:43:45 -07:00
Linus Torvalds
a552c81ff4 mm.git review status for mm-hotfixes-stable..mm-stable
Everything:
 
 Total patches:       321
 Reviews/patch:       1.52
 Reviewed rate:       68%
 
 Excluding DAMON:
 
 Total patches:       227
 Reviews/patch:       2.07
 Reviewed rate:       90%
 
 Excluding DAMON and selftests:
 
 Total patches:       203
 Reviews/patch:       2.14
 Reviewed rate:       91%
 
 Patchsets in this merge:
 
 - The 2 patch series "selftests/mm: clean up build output and verbosity"
   from Li Wang removes some noise from the MM selftests build out.
 
 - The 3 patch series "mm: Free contiguous order-0 pages efficiently"
   from Ryan Roberts speeds 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.
 
 - The 11 patch series "mm/damon: introduce DAMOS failed region quota
   charge ratio" from SeongJae Park addresses 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
 
 - The 8 patch series "selftests/cgroup: improve zswap tests robustness
   and support large page sizes" from Li Wang fixes various spurious
   failures and improves the overall robustness of the cgroup zswap
   selftests.
 
 - The 3 patch series "fix MAP_DROPPABLE not supported errno" from
   Anthony Yznaga fixes an issue in the mlock selftests on arm32.
 
 - The 2 patch series "mm: huge_memory: clean up defrag sysfs with
   shared" from Breno Leitao does some maintenance work in the huge_memory
   code.
 
 - The 3 patch series "treewide: fixup gfp_t printks" from Brendan
   Jackman uses the special vprintf() gfp_t conversion in various places.
 
 - The 6 patch series "mm: Fix vmemmap optimization accounting and
   initialization" from Muchun Song fixes 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.
 
 - The 4 patch series "mm/damon: repost non-hotfix reviewed patches in
   damon/next tree" from is a sprinkle of unrelated minor bugfixes for
   DAMON.
 
 - The 3 patch series "mm: remove page_mapped()" from David Hildenbrand
   remove this function from the tree, replacing it with folio_mapped().
 
 - The 10 patch series "mm/damon: let DAMON be paused and resumed" from
   SeongJae Park permits DAMON to be paused and resumed without losing its
   current state.
 
 - The 3 patch series "kasan: hw_tags: Disable tagging for stack and
   page-tables" from Muhammad Usama Anjum simplifies and speeds up kasan by
   removing its ineffective tagging of stacks and page tables.
 
 - The 7 patch series "mm/damon/reclaim,lru_sort: monitor all system rams
   by default" from SeongJae Park simplifies 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.
 
 - The 2 patch series "mm/damon/sysfs: document filters/ directory as
   deprecated" from SeongJae Park updates some DAMON docs.
 
 - The 8 patch series "mm: use spinlock guards for zone lock" from Dmitry
   Ilvokhin switches zone->lock handling over to using the guard()
   mechanisms.
 
 - The 2 patch series "mm/filemap: tighten mmap_miss hit accounting" from
   fujunjie fixes 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.
 
 - The 2 patch series "selftests/cgroup: Fix false positive failures in
   test_percpu_basic" from Li Wang fixes a couple of false-positives in the
   cgroup kmem selftests.
 
 - The 2 patch series "mm/damon/reclaim: support monitoring intervals
   auto-tuning" from SeongJae Park adds a new parameter to DAMON permitting
   DAMON_RECLAIM to automatically tune DAMON's sampling and aggregation
   intervals.
 
 - The 2 patch series "mm/damon/stat: add kdamond_pid parameter" from
   SeongJae Park chnges DAMON_STAT to provide the pid of its kdamond.
 
 - The 2 patch series "mm/kmemleak: dedupe verbose scan output" from
   Breno Leitao removes large amounts of duplicated backtraces from the
   verbose-mode kmemleak output.
 
 - The 8 patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 1)"
   from David Hildenbrand reduces our use of CONFIG_HAVE_BOOTMEM_INFO_NODE,
   with a view to removing it entirely in a later series.
 
 - The 2 patch series "mm/damon: validate min_region_size to be power of
   2" from Liew Rui Yan prevents users from passing a non-power-of-2 value
   of `addr_unit', as this later results in undesirable behavior.
 
 - The 2 patch series "mm: document read_pages and simplify usage" from
   Frederick Mayle does as claimed.
 
 - The 3 patch series "tools/mm/page-types: Fix misc bugs" from Ye Liu
   fixes three issues in tools/mm/page-types.c.
 
 - The 4 patch series "mm: misc cleanups from __GFP_UNMAPPED series" from
   Brendan Jackman implements several cleanups in the page allocator and
   related code.
 
 - The 12 patch series "mm, swap: swap table phase IV: unify allocation"
   from Kairui Song unifies 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.
 
 - The 28 patch series "mm/damon: introduce data attributes monitoring"
   from SeongJae Park extends DAMON for monitoring general data attributes
   other than accesses.
 
 - The 5 patch series "mm/vmalloc: free unused pages on vrealloc()
   shrink" from Shivam Kalra implements the TODO in vrealloc() to unmap and
   free unused pages when shrinking across a page boundary.
 
 - The 3 patch series "mm/damon: documentation and comment fixes" from
   niecheng does as advertised.
 
 - The 3 patch series "remove mmap_action success, error hooks" from
   Lorenzo Stoakes eliminates 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.
 
 - The 14 patch series "mm/damon: minor improvements for code readability
   and tests" from SeongJae Park implements minor improvements in code
   readability and tests for DAMON.
 
 - The 2 patch series "mm/damon: fix macro arguments and clarify quota
   goals doc" from Maksym Shcherba does those things.
 
 - The 2 patch series "userfaultfd: merge fs/userfaultfd.c into
   mm/userfaultfd.c" from Mike Rapoport performs that code movement.
 
 - The 15 patch series "mm/mglru: improve reclaim loop and dirty folio"
   from Kairui Song and others cleans up and slightly improves MGLRU's
   reclaim loop and dirty writeback handling.  Large performance
   improvements are measured.
 
 - The 3 patch series "use vma locks for proc/pid/{smaps|numa_maps}
   reads" from Suren Baghdasaryan uses per-vma locks when reading
   /proc/pid/smaps and /proc/pid/numa_maps similar to reduce contention on
   central mmap_lock.
 
 - The 2 patch series "refactors thpsize_shmem_enabled_store() and
   thpsize_shmem_enabled_show()" from Ran Xiaokai provides some cleanup
   work in the THP code.
 
 - The 2 patch series "selftests/memfd: fix compilation warnings" from
   Konstantin Khorenko fixes a few build glitches in the memfd selftest
   code.
 
 - The 4 patch series "memcg: shrink obj_stock_pcp and cache multiple
   objcgs" from Shakeel Butt resolves 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.
 
 - The 2 patch series "zram: writeback fixes" from Sergey Senozhatsky
   addresses a couple of unrelated zram writeback issues.
 
 - The 9 patch series "mm: switch THP shrinker to list_lru" from Johannes
   Weiner resolves 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 (THPs).
 
 - The 2 patch series "mm: improve large folio readahead for exec memory"
   from Usama Arif improves 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.
 
 - The 6 patch series "userfaultfd/pagemap: pre-existing fixes" from
   Kiryl Shutsemau fixes a bunch of minor issues in the
   userfaultfd/pagemap, all of which were flagged by Sashiko review of
   proposed new material.
 
 - The 5 patch series "mm/sparse-vmemmap: Provide generic
   vmemmap_set_pmd() and vmemmap_check_pmd()" from Muchun Song provides
   generic versions of these two functions so the four arch-specific
   implementations can be removed.
 
 - The 2 patch series "mm/swap, PM: hibernate: fix swapoff race in
   uswsusp by pinning swap device" from Youngjun Park addresses a
   uswsusp-vs-swapoff race and reduces the swap device reference
   taking/releasing frequency.
 
 - The 2 patch series "mm/hmm: A fix and a selftest" from Dev Jain does
   as claimed.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCajQcWQAKCRDdBJ7gKXxA
 jkjFAQD14ZCAS7c/lsNHPRpOARR2zrCJiIp+vhZDEx5V+d8u0QD+I4ca11CnQ+OA
 dKCeabWWYuTR1GDtTHbLVCRfpGexBwM=
 =cWPO
 -----END PGP SIGNATURE-----

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
  ...
2026-06-19 10:14:34 -07:00
Linus Torvalds
59a6c7ac0a bitmap updates for v7.2
- new handy helper FIELD_GET_SIGNED() (Yury);
  - arch test_and_set_bit_lock() and clear_bit_unlock() cleanup (Randy);
  - __bf_shf() simplification (Yury);
  - bitmap_print_to_pagebuf() removal (Yury);
  - RISCV/bitrev conditional support (Jindie, Yury);
 -----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEEi8GdvG6xMhdgpu/4sUSA/TofvsgFAmowS0sACgkQsUSA/Tof
 vshqLgwAw2RkV8ZHAniyPgz4noGztto+fcD70UbMgkh48n46PSKIUPCUvOj4RGHc
 Nzcjg6VkHLlypb7U3fHoXOHhkt+nTt+OeVDtZCmr8OzlRYmWXAo9TptfalDAlH1A
 OucRocjYSkwl/nbuYk0EQ/0+AcTFlfVTeyyus6wUYt7Nj1ncCNjKF2K5EjtF4aoQ
 JiA4d9LKWCIN4qFodP/9aFDzLX5MvqHgvOmBPSSFZKkMAer9HHCa/V3jHH3JMh21
 bMPjZvaPUCI9oywLL+pDe0RRhP1CYFevxJ/Tnpcx0elV+CekrzuSsM3zpRbPt6hR
 0P+8VVzUuoI8yth5mSH1gvUn9ZDvDeognTpKpXR574lB83A8Ub/Gu/NGMXO3TY0q
 mtuVbI5ZG0dCqahjEZvJQJmZ/qqbmwDhQDBtPS0x3S9XyzhNAga+JFpr6FXhULx8
 b8ZrDPc5BGLtTt5aBOAgpN10CeFM8JHxku1B489sqRXQWaeKW++GkVfVTZ9UOK1E
 8c3l/1Bl
 =z8f4
 -----END PGP SIGNATURE-----

Merge tag 'bitmap-for-7.2' of https://github.com/norov/linux

Pull bitmap updates from Yury Norov:
 "This includes the new FIELD_GET_SIGNED() helper,
  bitmap_print_to_pagebuf() removal, RISCV/bitrev support, and a couple
  cleanups.

   - new handy helper FIELD_GET_SIGNED() (Yury)

   - arch test_and_set_bit_lock() and clear_bit_unlock() cleanup (Randy)

   - __bf_shf() simplification (Yury)

   - bitmap_print_to_pagebuf() removal (Yury)

   - RISCV/bitrev conditional support (Jindie, Yury)"

* tag 'bitmap-for-7.2' of https://github.com/norov/linux:
  MAINTAINERS: BITOPS: include bitrev.[ch]
  arch/riscv: Add bitrev.h file to support rev8 and brev8
  bitops: Define generic___bitrev8/16/32 for reuse
  lib/bitrev: Introduce GENERIC_BITREVERSE
  arch: select HAVE_ARCH_BITREVERSE conditionally on BITREVERSE
  bitmap: fix find helper documentation
  bitmap: drop bitmap_print_to_pagebuf()
  cpumask: switch cpumap_print_to_pagebuf() to using scnprintf()
  bitfield: wire __bf_shf to __builtin_ctzll
  bitops: use common function parameter names
  ptp: switch to using FIELD_GET_SIGNED()
  rtc: rv3032: switch to using FIELD_GET_SIGNED()
  wifi: rtw89: switch to using FIELD_GET_SIGNED()
  iio: mcp9600: switch to using FIELD_GET_SIGNED()
  iio: pressure: bmp280: switch to using FIELD_GET_SIGNED()
  iio: magnetometer: yas530: switch to using FIELD_GET_SIGNED()
  iio: intel_dc_ti_adc: switch to using FIELD_GET_SIGNED()
  x86/extable: switch to using FIELD_GET_SIGNED()
  bitfield: add FIELD_GET_SIGNED()
2026-06-17 11:38:38 +01:00
Linus Torvalds
9c87e61e3c bpf-next-7.2
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE+soXsSLHKoYyzcli6rmadz2vbToFAmowIHwACgkQ6rmadz2v
 bTqRog/+KIO6wpvuizt8N+vzgKeEYR/KlEPEyV5dGAopIk1Ct5Ahzti1/V6zg7hk
 oddWhPewF7QncVLdnL6zRCRahXCHOi30148acG8pj3Fwj/iYw/zVihVkppVt9qRU
 REAvFj0/hYJOGzttSt9UfQ78ZftrZNhXFCRIK/zUWj72IVMJD04Vbawo8iIixVtu
 I+fCB3A1kv+RMlZ/3TWk11z3Fko4lK/jKpujegIzv6s+n+0lAraF0aw0cWMwNpUj
 mtJx2PktPHYbjA5CwE1Fyxf6EhV4OhV5gwyET7gzqITG5zjUo45pMNcA7EAxDyiC
 NvTGIZMsAC+9iSSLNSfdjBWExXFYHHuCkeoxkw9ei05Qrye/7lYzwwtgImuyhBZG
 xNXrnSNCG5BPl+DCLy09LzzwNdRoP7zYZV3QH/ZU0uMTS6foegYoSM8jSa2skmM+
 mR8a4qrMeZTv+XWvScduOqtFMBOv3mSPkZMkoyqReLaMIPse5NuUOTxOGn5REu4X
 tQLW0GLa6ad/7udv7DYrSfmwK1dihyOPmZl/GMuGroXm4rW4jNojljNBdTFEWjCQ
 Rd9qArq1Z1z/g8mWjTdiRRGa/QzF5rmJRLgjjUKIzUlQ5/77t96ls0jLexsRZQx5
 hCdu/HoK+pIRIUy20NtdqA8ykowsfUkyEBjYR28GV4RHvtmgW5k=
 =rtQD
 -----END PGP SIGNATURE-----

Merge tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:
 "Major changes:

   - Recover from BPF arena page faults using a scratch page and add
     ptep_try_set() for lockless empty-slot installs on x86 and arm64.

     This allows BPF kfuncs to access arena pointers directly.

     The 'arena_direct_access' stable branch was created for this work
     and was pulled into sched-ext and bpf-next trees (Tejun Heo, Kumar
     Kartikeya Dwivedi)

   - Lift old restriction and support 6+ arguments in BPF programs and
     kfuncs on x86 and arm64 (Yonghong Song, Puranjay Mohan)

  Other features and fixes:

   - Add 24-bit BTF vlen and reclaim unused bits in the BTF UAPI to ease
     addition of new BTF kinds (Alan Maguire)

   - Raise the maximum BPF call chain depth from 8 to 16 frames (Alexei
     Starovoitov)

   - Refactor object relationship tracking in the verifier and fix a
     dynptr use-after-free bug (Amery Hung)

   - Harden the signed program loader and reject exclusive maps as inner
     maps (Daniel Borkmann)

   - Replace the verifier min/max bounds fields with a circular number
     (cnum) representation and improve 32->64 bit range refinements
     (Eduard Zingerman)

   - Introduce the arena library and runtime (libarena) with a buddy
     allocator, rbtree and SPMC queue data structures, ASAN support and
     a parallel test harness. Allow subprograms to return arena pointers
     and switch to a BTF type-tag based __arena annotation (Emil
     Tsalapatis)

   - Cache build IDs in the sleepable stackmap path and avoid faultable
     build ID reads under mm locks (Ihor Solodrai)

   - Introduce the tracing_multi link to attach a single BPF program to
     many kernel functions at once. Allow specifying the uprobe_multi
     target via FD (Jiri Olsa)

   - Extend the bpf_list family of kfuncs with bpf_list_add/del(), and
     bpf_list_is_first/is_last/empty() (Kaitao Cheng)

   - Extend the BPF syscall with common attributes support for
     prog_load, btf_load and map_create (Leon Hwang)

   - Wrap rhashtable as BPF map (Mykyta Yatsenko, Herbert Xu)

   - Add sleepable support for tracepoint programs and fix deadlocks in
     LRU map due to NMI reentry (Mykyta Yatsenko)

   - Fix OOB access in bpf_flow_keys, fix nullness analysis of inner
     arrays, enforce write checks for global subprograms (Nuoqi Gui)

   - Report the maximum combined stack depth and print a breakdown of
     instructions processed per subprogram (Paul Chaignon)

   - Add an XDP load-balancer benchmark and arm64 JIT support for stack
     arguments (Puranjay Mohan)

   - Add kfuncs to traverse over wakeup_sources (Samuel Wu)

   - Allow sleepable BPF programs to use LPM trie maps directly (Vlad
     Poenaru)

   - Many more fixes and cleanups across the verifier, BTF, sockmap,
     devmap, bpffs, security hooks, s390/riscv/loongarch JITs,
     rqspinlock, libbpf, bpftool, selftests"

* tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (336 commits)
  selftests/bpf: Work around llvm stack overflow in crypto progs
  selftests/bpf: add test for bpf_msg_pop_data() overflow
  bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check
  sockmap: Fix use-after-free in udp_bpf_recvmsg()
  bpf, sockmap: keep sk_msg copy state in sync
  bpf, sockmap: Fix wrong rsge offset in bpf_msg_push_data()
  bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data()
  selftsets/bpf: Retry map update on helper_fill_hashmap()
  selftests/bpf: Add test for sleepable lsm_cgroup rejection
  selftests/bpf: Add test to verify the fix for bpf_setsockopt() helper
  bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket
  selftests/bpf: Avoid static LLVM linking for cross builds
  selftests/bpf: Use common CFLAGS for urandom_read
  selftests/bpf: Initialize operation name before use
  tools/bpf: build: Append extra cflags
  libbpf: Initialize CFLAGS before including Makefile.include
  bpftool: Append extra host flags
  bpftool: Avoid adding EXTRA_CFLAGS to HOST_CFLAGS
  bpftool: Pass host flags to bootstrap libbpf
  selftests/bpf: correct CONFIG_PPC64 macro name in comment
  ...
2026-06-17 09:18:14 +01:00
Linus Torvalds
7d36844ae7 * Fix freeing of PMD-sized vmemmap pages
* Update comment about pgd_list
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmowVdwACgkQaDWVMHDJ
 krARXA//c+FCH86tcGuZndWmebCP5ZuPFDkZMQuK53cg2hZq6OHUSxDL989iq/AO
 YMfKR+CFJtpMd3fiLiASbks+mctWLJYjX1eWFvjtGaZPsH4u0CdlbPkYsfY5OKcA
 NYeZ9Pbag/DYDu/SvSylDaYR0P1VgncaF4fhP5gH3YbhEU4rzNyrf6T+HBPz0B1h
 iXWre0QAkXLrx2pkKRx8h55uy+hNLjLfExD6tbMMxnOHtOVaBL+JHG8czBgv6P7F
 VrQ2vu8BKBqq8+rPGFVuolvGri2iM+hpddemKzc/wFHxP9oW7bLj9bieuoQk3R3p
 1ILhDF0rfwoTzgzw2wD3yJpzP5BNB+tqlOqnN+KUFK8w1l01I1dbzfz/Ib/ozH3O
 fAOLCAC9nlZ0VFozzPvpe3YHGI2feK/sW0Wh3X7YcfibmofpCHn8BkSgCo0cEjXs
 JkcMqyCPEyYQUwWvbV39yeMKUnfi447UQdr95q4QNxi8stozQewLN6r/Y4DnGuEi
 qZWzOSBGr3wCK25Tn0MF4vv0oVWb+4UFhF/79FkJBPZq78390XcmyYBC/tiWx8KJ
 qQPhpfk3TIga2mmQsq1qwr4am7XXwjmB6sZHaprV7LDq/YLFnJTsmhIsq0nicrYZ
 88S+XF94z/woCEUMaYjcp7E+bBUu5n4i2yWocu5yHwFd0pmuDGo=
 =tM/K
 -----END PGP SIGNATURE-----

Merge tag 'x86_mm_for_7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull x86 mm updates from Dave Hansen:
 "There's a small comment fixup, followed by an actual bug fix. The bug
  fix is slightly new territory for us. It fixes a real regression, but
  it is from ~6.18 not a _new_ regression. It was mostly only biting
  folks doing hotplug memory testing. So, it was queued in here and held
  for the merge window instead of going via x86/urgent.

   - Fix freeing of PMD-sized vmemmap pages

   - Update comment about pgd_list"

* tag 'x86_mm_for_7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix freeing of PMD-sized vmemmap pages
  x86: Update comment about pgd_list
2026-06-16 06:17:23 +05:30
Linus Torvalds
454761e121 - The usual pile of cleanups and fixlets the cat dragged in
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmowF/UACgkQEsHwGGHe
 VUqPFQ//WJ62+aEsmuuZZ/HWuU/Warawn3R5Hm0DxgXAssUviuyOKBJhoP9ApaCK
 SfyNxSqcu2QJed0tZXfJsF+qH8OrNf/FjkenWpgrBJDtl+qiRRT/WRekVtzUR5WO
 HFemO+vnR5lgKKPwPlDFGs3/rARHPWs8HEl984PrjZJajwWnQujhkdZA88Hj8ehH
 hglS780Uitdp/8aqYB8mlsDdb1JPL2m3Ajoagij7nX9FjLz4fayMjiQW+w/XfYTw
 VP9vJtwXsVHP8inFLJPctKx2XRNYKU4g6WOGd2j3tIIeE9pvOpRbLJopeFgWAzbU
 zhxCMMlW30KmuBIRAUQAG6B2xlJxAqsZbH7om7QPXRNLYJ8wMlqPqZ5Q3WW52cmo
 YLbFDtcrHSn79Gukn0RZIN66xc6h1zKakhByZ5IPAB4GK2aJcS1f6OJCMIVknZUy
 FlkCH+YiRSWn3yJVUgeVK8QbG0+n4r+a2QhnT/ems2nVzmBvLYHbV9QtKEdfxTj8
 aD8Nwjh40mYvzOkbzCVyPO7QR/7SxIumaT/LsDvxMMMKBzuzS6BEy8WBtztxhhsU
 yTABDf8WInRwTPe8P8jCArpFRlRbLeXkkBqzvQlWMJEty1Md1Id+LdAF+hCEOTip
 jEYPWnmsaEnIFcJUQ/Am9f+ST8sq91kR92fLadxiWIuLjyQA1bo=
 =sSrt
 -----END PGP SIGNATURE-----

Merge tag 'x86_cleanups_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull x86 cleanups from Borislav Petkov:

 - The usual pile of cleanups and fixlets the cat dragged in

* tag 'x86_cleanups_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Remove obsolete aperfmperf_get_khz() declaration
  x86/pmem: Check for platform_device_alloc() retval
  x86/platform/uv: Use str_enabled_disabled() in uv_nmi_setup_hubless_intr()
  x86/cpu: Keep the PROCESSOR_SELECT menu together
  x86/tlb: Convert copy_from_user() + kstrtouint() to kstrtouint_from_user()
  x86/purgatory: Fix #endif comment
  x86/boot: Get rid of kstrtoull()
  x86/boot/compressed: Use boot_kstrtoul() for hugepages= parsing
2026-06-16 05:41:22 +05:30
Linus Torvalds
ff5ccdb8d5 x86/cpu updates for v7.2:
- CPUID API updates (Ahmed S. Darwish):
 
    - Introduce a centralized CPUID parser
    - Introduce a centralized CPUID data model
    - Introduce <asm/cpuid/leaf_types.h>
    - Rename cpuid_leaf()/cpuid_subleaf() APIs
    - treewide: Explicitly include the x86 CPUID headers
 
  - Update to x86-cpuid-db v3.1 (Maciej Wieczor-Retman)
 
  - Continued removal of pre-i586 support and related
    simplifications (Ingo Molnar)
 
  - Add Intel CPU model number for rugged Panther Lake
    (Tony Luck)
 
  - Misc fixes, updates and cleanups by Arnd Bergmann, Chao Gao,
    Lukas Bulwahn, Sohil Mehta, Maciej Wieczor-Retman.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmou1LcRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1h16Q/9GvxrQDX13qd7/XrjOKNYtoLIGh1GhvHM
 2ZdbYh80LX36bDOg7Mhoy0bvElwmzaz2x1Zrb5SAIqpQXYqjfuRCe7a1SPQxYtCK
 A6j1YeD/CJMm36jaQITYkuCYxwaw5LQ62u0ShpEvyzZzarEJt8c8COWJjbE57FN2
 qusr+6K1sBwpEUl5mLabbJWXqhpPRYCz+nl2GF9BCHe6z7Nw7Q8VZf4w1weONJOy
 lMpC2X08w5TE2f4OwvnRbZLelyROz6pr1c3osUoQSVtBkprO9TsYHgd9yBva1E2E
 KxdWm+uSSUXM7cFBzY3RLBzKpG6iLtqircoDFBVdxOlT8I8KFggzbYy4JPlDEHQS
 FqUwWL+2duoRciOncnZn9hydxlg5So4w7OscvTVNp94/Pb2pMdpOB+bsN05WTpXc
 VMQVxrfsmwT1rV1oppzRizTMnb6yGg8BQvZPE+wrMDdH+/wwhzok4GdZzKVCzUoD
 nDFhJL7t8ikRwwuq5RAl1EcT7qLFJx3ba77B5REf2Uos2liTExO/XzcmQnzSV1M1
 RXpajQ1ikEBtJPAD3Zy0ASm/QPjB27o+6Kj6hW3NLlPoi5l0Lu6xQzH3wNrpQpst
 02NCWEn2X00YUQt2ukNcDFJiMHJzXAnBQDBSrWwwd97wol3sKnT9RR2NZVFzn7ls
 GOF8yJ0Wuec=
 =tpai
 -----END PGP SIGNATURE-----

Merge tag 'x86-cpu-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull x86 cpuid updates from Ingo Molnar:

 - CPUID API updates (Ahmed S. Darwish):
    - Introduce a centralized CPUID parser
    - Introduce a centralized CPUID data model
    - Introduce <asm/cpuid/leaf_types.h>
    - Rename cpuid_leaf()/cpuid_subleaf() APIs
    - treewide: Explicitly include the x86 CPUID headers

 - Update to x86-cpuid-db v3.1 (Maciej Wieczor-Retman)

 - Continued removal of pre-i586 support and related simplifications
   (Ingo Molnar)

 - Add Intel CPU model number for rugged Panther Lake (Tony Luck)

 - Misc fixes, updates and cleanups by Arnd Bergmann, Chao Gao, Lukas
   Bulwahn, Sohil Mehta, Maciej Wieczor-Retman.

* tag 'x86-cpu-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (25 commits)
  x86/cpu: Make CONFIG_X86_CX8 unconditional
  x86/cpu: Remove unused !CONFIG_X86_TSC code
  x86/cpuid: Update bitfields to x86-cpuid-db v3.1
  tools/x86/kcpuid: Update bitfields to x86-cpuid-db v3.1
  x86/cpu: Make CONFIG_X86_TSC unconditional
  MAINTAINERS: Drop obsolete FPU EMULATOR section
  x86/cpu: Fix a F00F bug warning and clean up surrounding code
  x86/cpu: Add Intel CPU model number for rugged Panther Lake
  x86/cpuid: Introduce a centralized CPUID parser
  x86/cpu: Introduce a centralized CPUID data model
  x86/cpuid: Introduce <asm/cpuid/leaf_types.h>
  x86/cpuid: Rename cpuid_leaf()/cpuid_subleaf() APIs
  x86/cpu: Do not include the CPUID API header in asm/processor.h
  Documentation: core-api/cpu_hotplug: Remove stale cpu0_hotplug docs
  x86/cpu, cpufreq: Remove AMD ELAN support
  x86/fpu: Remove the math-emu/ FPU emulation library
  x86/fpu: Remove the 'no387' boot option
  x86/fpu: Remove MATH_EMULATION and related glue code
  treewide: Explicitly include the x86 CPUID headers
  x86/cpu: Remove the CONFIG_X86_INVD_BUG quirk
  ...
2026-06-15 15:25:17 +05:30
Linus Torvalds
13e1a6d6a1 Interrupt core code changes:
- 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 statitics
       to work with the new mechanisms.
 
     - Prevent a string overflow in the /proc/irq/$N/ directory name
       creation code.
 -----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCgAuFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmoths8QHHRnbHhAa2Vy
 bmVsLm9yZwAKCRCmGPVMDXSYoSoMEACRODwHjNfULjgD2heHbiPKsmPMRZvwO1Ud
 xu5XAoNT1gwxnLo4D+KrGCZeyxka+byRpby6eNg7HdRJuu3DUf8umwt/Q472I9a9
 ck8OGFp8ntbxnueISKfzxY/O2eXHYxSKmmfZMv3wdOKbvn5OUlFT6eHPjb8PzVUM
 7DiXsBL8s3MNHwdJ3grG5lBh60pt5fujzURwYAqvh/i8jlDHxsFRTMGuhR710knr
 YZrgZ4/7ffnEbDsn98xezPewRomIbhhEijgfjkkbnYYUub6Y2RHJqOzZhlp6zNgi
 vTsU/suW3ryVuzG34rL2uHvsxOcJY1HNA+ING7fkRmPuKxRGKOMBQfPmLQcWqP69
 GxwGIlBvNbAEYievgTCS7GNHTy3t0JbxTGhHcBvX3oMtnnOSTttqH9XzvrTwGxjj
 fMUykfvB+40Fp47D+t0JDhgyNNEkixSBjW8/gogZFQ0OdMFX6BQZNT/DLhMMC0LR
 JbqMpfsffp5+gYam/wixv3sPlxajMpQ2w8ocgyUHVAeFMo1LOY1spUuO3+Tq7nSj
 xt95xVg6HQDr+L+8QmZmnRq27uG276CxPpLotbPMsrn0Ax5PL+fymfmVsFmJFjAR
 ZHKK3tSD6M94GtklfKlB/yBJGNRafH4MVZbMa0iUxGI6UyAFr/Yror3mfDK9NsIA
 WTwwaqI8qw==
 =z6vj
 -----END PGP SIGNATURE-----

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
2026-06-15 13:19:41 +05:30
Muchun Song
3bbc54dd1b mm/sparse-vmemmap: pass @pgmap argument to memory deactivation paths
Currently, the memory hot-remove call chain -- arch_remove_memory(),
__remove_pages(), sparse_remove_section() and section_deactivate() -- does
not carry the struct dev_pagemap pointer.  This prevents the lower levels
from knowing whether the section was originally populated with vmemmap
optimizations (e.g., DAX with vmemmap optimization enabled).

Without this information, we cannot call vmemmap_can_optimize() to
determine if the vmemmap pages were optimized.  As a result, the vmemmap
page accounting during teardown will mistakenly assume a non-optimized
allocation, leading to incorrect memmap statistics.

To lay the groundwork for fixing the vmemmap page accounting, we need to
pass the @pgmap pointer down to the deactivation location.  Plumb the
@pgmap argument through the APIs of arch_remove_memory(), __remove_pages()
and sparse_remove_section(), mirroring the corresponding *_activate()
paths.

Link: https://lore.kernel.org/20260428081855.1249045-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Liam R. Howlett <liam@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-05-28 21:04:54 -07:00
David Hildenbrand (Arm)
39406c05f8 x86/mm: Fix freeing of PMD-sized vmemmap pages
Commit bf9e4e30f3 ("x86/mm: use pagetable_free()"), switched from
freeing non-boot page tables through __free_pages() to
pagetable_free().

However, the function is also called to free vmemmap pages.

Given that vmemmap pages are not page tables, already the page_ptdesc(page)
is wrong. But worse, pagetable_free() calls:

	__free_pages(page, compound_order(page));

Since vmemmap pages are not compound pages (see vmemmap_alloc_block())
-- except for HVO, which doesn't apply here -- only first page of a
PMD-sized vmemmap page is freed, leaking the other ones.

Fix it by properly decoupling pagetable and vmemmap freeing.
free_pagetable() no longer has to mess with SECTION_INFO, as only the
vmemmap is marked like that in register_page_bootmem_memmap().

The indentation in remove_pmd_table() is messed up. Fix that while
touching it.

Bootmem info handling will soon be fixed up. For now, handle it
similar to free_pagetable(), just avoiding the ifdef.

[ dhansen: changelog munging. More imperative voice ]

Fixes: bf9e4e30f3 ("x86/mm: use pagetable_free()")
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: Lance Yang <lance.yang@linux.dev>
Link: https://lore.kernel.org/20260429-vmemmap-v2-1-8dfcacffd877@kernel.org
Link: https://patch.msgid.link/20260429-vmemmap-v2-1-8dfcacffd877@kernel.org
Cc: stable@vger.kernel.org
2026-05-27 11:39:38 -07:00
Thomas Gleixner
2b57c69917 x86/irq: Make irqstats array based
Having the x86 specific interrupt statistics as a data structure with
individual members instead of an array is just stupid as it requires
endless copy and paste in arch_show_interrupts() and arch_irq_stat_cpu(),
where the latter does not even take the latest interrupt additions into
account. The resulting #ifdef orgy is just disgusting.

Convert it to an array of counters, which does not make a difference in the
actual interrupt hotpath increment as the array index is constant and
therefore not any different than the member based access.

But in arch_show_interrupts() and arch_irq_stat_cpu() this just turns into
a loop, which reduces the text size by ~2k (~12%):

   text	   data	    bss	    dec	    hex	filename
  19643	  15250	    904	  35797	   8bd5	../build/arch/x86/kernel/irq.o
  17355	  15250	    904	  33509	   82e5	../build/arch/x86/kernel/irq.o

Adding a new vector or software counter only requires to update the table
and everything just works. Using the core provided emit function which
speeds up 0 outputs makes it significantly faster.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Radu Rendec <radu@rendec.net>
Link: https://patch.msgid.link/20260517194931.196070643@kernel.org
2026-05-26 16:21:12 +02:00
Fushuai Wang
648fb97ee9 x86/tlb: Convert copy_from_user() + kstrtouint() to kstrtouint_from_user()
Using kstrtouint_from_user() instead of copy_from_user() + kstrtouint() makes
the code simpler and less error-prone.

No functional changes.

  [ bp: Align function args on opening brace, while at it. ]

Suggested-by: Yury Norov <ynorov@nvidia.com>
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Yury Norov <ynorov@nvidia.com>
Link: https://patch.msgid.link/20260117145615.53455-3-fushuai.wang@linux.dev
2026-05-24 16:08:38 -07:00
Kumar Kartikeya Dwivedi
dc11a4dba2 bpf: Recover arena kernel faults with scratch page
BPF arena usage is becoming more prevalent, but kernel <-> BPF communication
over arena memory is awkward today. Data has to be staged through a trusted
kernel pointer with extra code and copying on the BPF side. While reads
through arena pointers can use a fault-safe helper, writes don't have a good
solution. The in-line alternative would need instruction emulation or asm
fixup labels.

Enable direct kernel-side reads and writes within GUARD_SZ / 2 of any
handed-in arena pointer, without bounds checking. A per-arena scratch page
is installed by the arch fault path into empty arena kernel PTEs - x86 from
page_fault_oops() for not-present faults, arm64 from __do_kernel_fault() for
translation faults, both after the existing exception-table and KFENCE
handling. The faulting instruction retries and the access is also reported
through the program's BPF stream, preserving error reporting.

bpf_prog_find_from_stack() resolves the current BPF program (and its arena)
from the kernel stack - no new bpf_run_ctx state is added. Recovery covers
the 4 GiB arena plus the upper half-guard (GUARD_SZ / 2). The lower
half-guard is excluded because well-behaved kfuncs only access forward from
arena pointers. The kfunc-author contract - access at most GUARD_SZ / 2 past
a handed-in pointer - is documented in Documentation/bpf/kfuncs.rst.

The install is lock-free via ptep_try_set(). On race-loss the winning
installer's PTE is already valid, so the access retry succeeds. The arena
clear path uses ptep_get_and_clear() so installer and clearer race through
atomic accessors. No flush_tlb_kernel_range() afterwards. Stale "not mapped"
entries just cause one extra re-fault, cheaper than a global IPI on every
install.

Scratch exists only to keep the kernel from oopsing on an in-line arena
access. Its presence at a PTE means the BPF program has already
malfunctioned, and the violation is reported through the program's BPF
stream. The only requirement for behavior on a scratched PTE is that the
kernel doesn't crash. In particular, any user-side access through such a PTE
may segfault. The shared scratch page is freed once during map destruction.

BPF instruction faults continue to use the existing JIT exception-table
path. This patch changes only the kernel-text fault path. No UAPI flag is
added. The new behavior is the default.

v2: Use ptep_get_and_clear() in apply_range_clear_cb(). (David)
v3: Stub bpf_arena_handle_page_fault() for !CONFIG_BPF_SYSCALL. (lkp)

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Cc: David Hildenbrand <david@kernel.org>
Link: https://lore.kernel.org/r/20260522172219.1423324-3-tj@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-05-23 01:50:33 -07:00
Yury Norov
d3d4233c7c x86/extable: switch to using FIELD_GET_SIGNED()
The EX_DATA register is laid out such that EX_DATA_IMM occupied MSB.
It's done to make sure that FIELD_GET() will sign-extend the IMM
field during extraction.

To enforce that, all EX_DATA masks are made signed integers. This
works, but relies on the particular implementation of FIELD_GET(),
i.e. masking then shifting, not vice versa; and the particular
placement of the fields in the register.

Switch to using the dedicated FIELD_GET_SIGNED(), and relax those
limitations.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Yury Norov <ynorov@nvidia.com>
2026-05-20 11:18:27 -04:00
Brendan Jackman
952ac097ce x86: Update comment about pgd_list
This venerable comment got detached from its context when the code moved
in commit 394158559d ("x86: move all the pgd_list handling to one
place"). Put it back next to its context. It was originally on
pgd_list_add() but it actually describes pgd_list so put it there.

While moving it, update it to strip away stale and superfluous info.
pageattr.c doesn't exist any more. pgd_list is now required
for all x86 architectures. Also be slightly more precise about what PGDs
are in this list.

[ dhansen: tweak and trim the updated comment a bit ]

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20260323-pgd_list-comment-v2-1-77ccf2dc77e8@google.com
2026-05-11 11:26:33 -07:00
Ahmed S. Darwish
7b49a3fb69 treewide: Explicitly include the x86 CPUID headers
Modify all CPUID call sites which implicitly include any of the CPUID
headers to explicitly include them instead.

For KVM's reverse_cpuid.h, just include <asm/cpuid/types.h> since it
references the CPUID_EAX..EDX symbols without using the CPUID APIs.

Note, this allows removing the inclusion of <asm/cpuid/api.h> from within
<asm/processor.h> next.  That allows the CPUID API headers to include
<asm/processor.h> without introducing a circular dependency.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20260327021645.555257-1-darwi@linutronix.de
2026-05-06 14:29:59 +02:00