Commit Graph

7763 Commits

Author SHA1 Message Date
Aboorva Devarajan
11ae2e1dc5 powerpc/entry: Fix double accounting of user time on interrupt entry
Since the switch to generic entry, an interrupt from user mode
accounts user time twice: once in arch_interrupt_enter_prepare()
and again in arch_enter_from_user_mode(), which irqentry_enter()
invokes for the same interrupt:

	arch_interrupt_enter_prepare()
	  account_cpu_user_entry()		/* first */
	irqentry_enter()
	  arch_enter_from_user_mode()
	    account_cpu_user_entry()		/* second */

The second call charges the same interval again, because
account_cpu_user_entry() accumulates the time spent in user mode
since the last return to user space.

The two calls come from the GENERIC_ENTRY preparation series,
where each step was a no-op on its own. Commit 09a9d3a849
("powerpc: introduce arch_enter_from_user_mode") added the hook
with the user-time accounting in it, but nothing called it yet.
Commit 893082ac76 ("powerpc: Prepare for IRQ entry exit")
copied interrupt_enter_prepare() verbatim into entry-common.h as
arch_interrupt_enter_prepare(); that copy was equally unused, as
handlers still called interrupt_enter_prepare().

Commit bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
made both live. On the syscall side it did the full conversion:
system_call_exception() now accounts once through the hook via
syscall_enter_from_user_mode(), rather than calling
account_cpu_user_entry() directly. On the interrupt side it
switched the handler macros to arch_interrupt_enter_prepare()
followed by irqentry_enter(), which also runs the hook, but the
accounting in arch_interrupt_enter_prepare() was not removed to
match. The double accounting starts with that commit.

With CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y this roughly doubles the
reported user time of any workload that takes interrupts. The
other accounting modes compile account_cpu_user_entry() to an
empty stub, so they are not affected.

Remove the accounting from arch_interrupt_enter_prepare() and rely
on arch_enter_from_user_mode(), which already runs for both
syscalls and interrupts. The duplicate account_stolen_time() call
is removed the same way.

On a pseries LPAR a busy loop reports 6s user time in 3s elapsed
(~210% CPU) before the fix, and 3s (~105% CPU) after it:

  $ python3 -c 'while True: pass' &
  $ sleep 3; ps -p $! -o etime,time,pcpu

            ELAPSED     TIME  %CPU
  Before      00:03 00:00:06   210
  After       00:03 00:00:03   105

A 50% load reports ~70% usr / 30% idle before the fix, and
~49% usr / 51% idle after it:

  $ taskset -c 6 stress-ng --cpu 1 --cpu-load 50 &
  $ mpstat -P 6 1

            CPU    %usr   %idle
  Before      6   69.74   30.26
  After       6   48.51   50.50

Fixes: bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260904025831.3439809-1-aboorvad@linux.ibm.com
2026-09-10 08:58:10 +05:30
Mukesh Kumar Chaurasiya (IBM)
63a7531ca3 powerpc/entry: Fix irq_soft_mask corruption on replayed interrupt exit
When __replay_soft_interrupts() replays a pending interrupt (e.g.
PACA_IRQ_DEC -> timer_interrupt), it calls the handler directly with a
synthetic pt_regs. The DEFINE_INTERRUPT_HANDLER_ASYNC wrapper around
each handler calls arch_interrupt_async_exit_prepare() on the way out,
which calls arch_interrupt_exit_prepare() -> local_irq_disable() ->
arch_local_irq_disable(), which does:

    irq_soft_mask_set(IRQS_DISABLED)   /* 0x1 */

This unconditionally overwrites irq_soft_mask with IRQS_DISABLED (0x1),
stripping the IRQS_PMI_DISABLED (0x2) bit. The result is that
irq_soft_mask is 0x1 instead of IRQS_ALL_DISABLED (0x3) when the
handler returns to __replay_soft_interrupts().

For a normally-taken interrupt this is harmless: the next interrupt
always enters through arch_interrupt_enter_prepare() which
unconditionally sets irq_soft_mask to IRQS_ALL_DISABLED. But during
replay, next_interrupt() is called directly between replayed handlers
without going back through arch_interrupt_enter_prepare(), so the
stripped bit is never restored. next_interrupt() then fires a WARNING:

    WARNING: arch/powerpc/kernel/irq_64.c:75
    WARN_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED)

The warning was observed early in boot on a POWER10 pseries guest
during kmem_cache_init_late(), where a spinlock release triggers
interrupt replay that processes a pending timer interrupt.

Debugger state confirming the bug:
  Before timer_interrupt(&regs):
    irq_soft_mask = 0x3 (IRQS_ALL_DISABLED)   correct
    irq_happened  = 0x41 (HARD_DIS|REPLAYING)  correct
  After timer_interrupt(&regs) returns:
    irq_soft_mask = 0x1 (IRQS_DISABLED)        WRONG - PMI bit stripped
    irq_happened  = 0x41                        unchanged

The fix is to replace local_irq_disable() with hard_irq_disable().

hard_irq_disable() is the right primitive here for two reasons:

1. On PPC64 (hw_irq.h:301) it calls irq_soft_mask_set_return(IRQS_ALL_DISABLED),
   setting the soft mask to 0x3 (both IRQS_DISABLED and IRQS_PMI_DISABLED),
   which preserves the PMI bit and fixes the WARNING. The additional
   work it does (__hard_irq_disable(), PACA_IRQ_HARD_DIS |=) is
   redundant but safe since both are already set at this point in the
   exit path; the trace_hardirqs_off() inside is guarded by
   if (!arch_irqs_disabled_flags(flags)) so it will not double-fire.

2. On PPC32 (hw_irq.h:467) hard_irq_disable() maps to
   arch_local_irq_disable() -> __hard_irq_disable(), which clears
   MSR[EE] in hardware. This is exactly correct: PPC32 has no soft-mask
   PACA mechanism, so the hardware disable is the right way to satisfy
   irqentry_exit()'s requirement. This also fixes a build error on PPC32
   where irq_soft_mask_set() is only defined under CONFIG_PPC64:

       arch/powerpc/include/asm/entry-common.h:273: error: implicit
       declaration of function 'irq_soft_mask_set'

   Using hard_irq_disable() requires no #ifdef and is consistent with
   how the rest of the entry code (e.g. entry-common.h:463) handles the
   same PPC32/PPC64 split.

Fixes: 334f3f6d7a ("powerpc/entry: Disable interrupts before irqentry_exit")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/6f9bfb0f-b14c-468e-bb9f-c157d120d0dc@linux.ibm.com/
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260904090858.128563-1-mkchauras@gmail.com
2026-09-05 17:39:36 +05:30
Ritesh Harjani (IBM)
c2549d7495 powerpc: Do not restore KUAP in arch_exit_to_user_mode_prepare()
KUAP means kernel cannot touch user memory unless it explicitly is
enabled. In the kernel it should stay AMR_KUAP_BLOCKED. While returning
to userspace just before RFI, kernel should restore the user AMR value
back.

Looks like GENERIC_ENTRY might be treating arch_exit_to_user_mode_prepare()
as the last architecture step before returning to userspace.
commit bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
therefore called kuap_user_restore() from that hook. But on PowerPC that
is too early. After irqentry_exit() / syscall_exit_to_user_mode() we
still run platform specific exit routines.

e.g. code snippets showing both exception handling and system call
handling as the callers of function arch_exit_to_user_mode_prepare()
which does kuap_user_restore(). The below path shows that calling
kuap_user_restore() is too early when called from
arch_exit_to_user_mode_prepare().

Exception handling in exceptions-64s.S
=======================================

bl	CFUNC(do_page_fault)
	  ..DEFINE_INTERRUPT_HANDLER_ASYNC(do_page_fault)
	      arch_interrupt_async_enter_prepare(regs);
	      state = irqentry_enter(regs);
	      instrumentation_begin();
	      irq_enter_rcu();
	      handler(regs);
	      nap_adjust_return(regs);
	      irq_exit_rcu();
	      instrumentation_end();
	      arch_interrupt_async_exit_prepare(regs);
	      irqentry_exit(regs, state); 		   <<< too early
	        irqentry_exit_to_user_mode()
		  __exit_to_user_mode_prepare(regs, EXIT_TO_USER_MODE_WORK_IRQ);
		    arch_exit_to_user_mode_prepare(regs, ti_work);  <<< too early
b	interrupt_return_srr
		.. bl	CFUNC(interrupt_exit_user_prepare) <<< already calls kuap_user_restore

prep_irq_for_enabled_exit() retry can run kernel code with IRQs on. So
only when that routine is fully finished is when the user KUAP should be
fully restored which interrupt_exit_user_prepare() already takes care of
before returning.

Similarly for system call handling in interrupt_64.S
======================================================

	bl	CFUNC(system_call_exception)

.Lsyscall_exit:
	addi	r4,r1,STACK_INT_FRAME_REGS
	li	r5,0 /* !scv */
	bl	CFUNC(syscall_exit_prepare)
		  .. kuap_assert_locked();
		     syscall_exit_to_user_mode(regs); <<< too early
		       syscall_exit_to_user_mode_prepare(regs);  <<< too early
 		     kuap_user_restore(regs);         <<< already calls

syscall_exit_prepare(), which can enable IRQs, replay a pending
interrupt, and only then rfi. Those functions already restore KUAP
immediately before rfi.

Note that if we restore the user AMR too early like in the current code
as shown from the code snippets above, then we get the following warning
when CONFIG_PPC_KUAP_DEBUG is enabled:
  WARNING: arch/powerpc/include/asm/book3s/64/kup.h:293 at interrupt_exit_user_prepare+0x1a0/0x1c0
  Hardware name: IBM pSeries (emulated by qemu) POWER10 (architected)
  TRAP: 0700
  LR: c00000000000d8d4 CTR: c0000000021fe500
  MSR: <SF,EE,ME,IR,DR,RI,LE>  CR: 44000804  XER: 20040000
  interrupt_exit_user_prepare+0x1a0/0x1c0
  interrupt_return_srr_user+0x8/0x12c

Fixes: bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
Fixes: 02565a782c ("powerpc: Introduce syscall exit arch functions")
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/52fee44fd23acf8e1c024ace668728e626a783a8.1788101609.git.ritesh.list@gmail.com
2026-09-03 15:10:03 +05:30
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.
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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
030c9f813b Treewide timer related cleanups:
- Remove the leftover CLOCK_TICK_RATE which has been scheduled for
     removal more than a decade ago along with some now empty asm/timex.h
     files.
 
   - Consolidate delay timer calibration
 
     The construct of having a define in a header requires that
     architectures provided asm/timex.h for no reason. Also the function
     name for reading the delay timer is confusing at best.
 
     Use a config switch to enable that functionality and rename the
     function to delay_read_timer() to make the purpose clear.
 
     This removes some more now empty asm/timex.h files as well.
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Merge tag 'timers-cleanups-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull treewide timer related cleanups from Thomas Gleixner:

 - Remove the leftover CLOCK_TICK_RATE which has been scheduled for
   removal more than a decade ago along with some now empty asm/timex.h
   files.

 - Consolidate delay timer calibration

   The construct of having a define in a header requires that
   architectures provided asm/timex.h for no reason. Also the function
   name for reading the delay timer is confusing at best.

   Use a config switch to enable that functionality and rename the
   function to delay_read_timer() to make the purpose clear.

   This removes some more now empty asm/timex.h files as well.

* tag 'timers-cleanups-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  calibrate: Rework delay timer calibration
  treewide: Remove CLOCK_TICK_RATE
  x86: Use PIT_TICK_RATE instead of CLOCK_TICK_RATE
2026-08-18 15:58:29 -07:00
Linus Torvalds
3424d8c18a Generic entry code updates:
- Make syscall user dispatching configurable
 
     Not all architectures can makes use of syscall user dispatching. Allow
     them to disable the feature completely.
 
   - Consolidate stack randomization for the generic entry code and the
     architectures using it.
 
     Stack randomization on syscall entry was sprinkled throughout the
     architecture specific low level entry code and in some cases at the
     wrong points, e.g. before establishing state, which violates the
     non-instrumentable constraints of that code.
 
     Clean this up by integrating stack randomization into the generic entry
     code helpers so that it is invoked at the earliest possible point right
     after establishing state and converting all generic entry code using
     architecture over.
 
   - Clean up the syscall number handling in the generic entry code. It
     works correctly for architectures which have a separate return value
     storage in pt_regs, but fails to distinguish the case where user space
     handed in -1 as syscall number from the case where the entry code
     rejects it by returning -1 to the callers. Aside of that the return
     value functionality of those interfaces is not really intuitive.
 
     Fix this by separating the decision to reject a syscall (user dispatch,
     ptrace, seccomp ...) from the potential modification of the syscall
     number through these mechanisms.
 
     This solves most of the problems for architectures which do not have a
     separate return value storage in pt_regs except for the case where a
     tracepoint has a BPF script or a probe attached which overwrite both
     the syscall number and the return value. But that's a problem which
     cannot be solved in the generic code, that only can be addressed by
     separating the storage model in the affected architectures.
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Merge tag 'core-entry-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull generic entry code updates from Thomas Gleixner:

 - Make syscall user dispatching configurable

   Not all architectures can makes use of syscall user dispatching.
   Allow them to disable the feature completely.

 - Consolidate stack randomization for the generic entry code and the
   architectures using it.

   Stack randomization on syscall entry was sprinkled throughout the
   architecture specific low level entry code and in some cases at the
   wrong points, e.g. before establishing state, which violates the
   non-instrumentable constraints of that code.

   Clean this up by integrating stack randomization into the generic
   entry code helpers so that it is invoked at the earliest possible
   point right after establishing state and converting all generic entry
   code using architecture over.

 - Clean up the syscall number handling in the generic entry code. It
   works correctly for architectures which have a separate return value
   storage in pt_regs, but fails to distinguish the case where user
   space handed in -1 as syscall number from the case where the entry
   code rejects it by returning -1 to the callers. Aside of that the
   return value functionality of those interfaces is not really
   intuitive.

   Fix this by separating the decision to reject a syscall (user
   dispatch, ptrace, seccomp ...) from the potential modification of the
   syscall number through these mechanisms.

   This solves most of the problems for architectures which do not have
   a separate return value storage in pt_regs except for the case where
   a tracepoint has a BPF script or a probe attached which overwrite
   both the syscall number and the return value. But that's a problem
   which cannot be solved in the generic code, that only can be
   addressed by separating the storage model in the affected
   architectures.

* tag 'core-entry-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  entry, treewide: Make syscall_enter_from_user_mode[_work]() indicate syscall execution
  entry: Make return type of syscall_trace_enter() bool
  entry: Rework trace_syscall_enter()
  entry: Rework syscall_audit_enter()
  syscall_user_dispatch: Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH
  entry: Fix seccomp bypass after ptrace with TSYNC
  x86/entry: Simplify the syscall number logic
  x86/entry: Get rid of the sys_ni_syscall() indirection
  x86/entry: Make syscall functions static
  ptrace, treewide: Rename ptrace_report_syscall_entry() to ptrace_report_syscall_permit_entry()
  seccomp, treewide: Rename and convert __secure_computing() to return boolean
  entry: Use syscall number instead of rereading it
  entry: Remove syscall_enter_from_user_mode()
  x86/syscall: Use [syscall_]enter_from_user_mode_randomize_stack()
  s390/syscall: Use enter_from_user_mode_randomize_stack()
  riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack()
  powerpc/syscall: Use syscall_enter_from_user_mode_randomize_stack()
  loongarch/syscall: Use syscall_enter_from_user_mode_randomize_stack()
  entry: Provide [syscall_]enter_from_user_mode_randomize_stack()
  randomize_kstack: Provide add_random_kstack_offset_irqsoff()
  ...
2026-08-18 15:00:56 -07:00
Linus Torvalds
1200d84f4c powerpc updates for 7.3
- powerpc: Enable Rust for ppc64le
 
  - ppc4xx gpio driver updates
 
  - Add power12 base enablement support
 
  - Validate arch_compat against host compatibility mode
 
  - Simplify bootx_scan_dt_build_struct() in powermac platform
 
  - powerpc: implement get_direction() in cpm2
 
  - Use cpu_relax() in ps3_create_spu()
 
  - Add NULL guard for cause_ipi in smp_muxed_ipi_message_pass
 
  - fixes to handle pseries watchdogs in kdump path
 
  - powerpc/irq: Fix missing r2 clobber in PCREL inline assembly
 
  - ppc44x: Set GPIO chip parent
 
  - KVM: PPC: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl BY: Amit Machhiwal
 
  - KVM: powerpc: Use generic xfer to guest work function
 
  - Enable to run posix cpu timers in task context
 
  - misc fixes and cleanups
 
 Thanks to:
 Aditya Gupta, Alice Ryhl, Amit Machhiwal, Andrew Morton, Anushree Mathur,
 Athira Rajeev, Bartosz Golaszewski, Cédric Le Goater, Christian König,
 Christophe Leroy (CS GROUP), Gary Guo, Gaurav Batra, Gautam Menghani, Gou Hao,
 Hari Bathini, Harsh Prateek Bora, jiazhenyuan, Jinjie Ruan, Link Mauve, Linus
 Walleij, Mahesh Kumar G Mahesh Salgaonkar, Michael Walle, Michal Suchánek,
 Mukesh Kumar Chaurasiya (IBM), Nicholas Piggin, Nikhil Kumar Singh, Praveen K
 Pandey, Ritesh Harjani (IBM), Rosen Penev, Saket Kumar Bhaskar, Shrikanth
 Hegde, Sourabh Jain, Thorsten Blum, Vaibhav Jain, Venkat Rao Bagalkote, Vishal
 Chourasia, Wentao Guan, Yanfei Xu
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Merge tag 'powerpc-7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Madhavan Srinivasan:

 - Enable Rust for ppc64le

 - ppc4xx gpio driver updates

 - Add power12 base enablement support

 - Validate arch_compat against host compatibility mode

 - Simplify bootx_scan_dt_build_struct() in powermac platform

 - Implement get_direction() in cpm2

 - Use cpu_relax() in ps3_create_spu()

 - Add NULL guard for cause_ipi in smp_muxed_ipi_message_pass

 - Fixes to handle pseries watchdogs in kdump path

 - Fix missing r2 clobber in PCREL inline assembly

 - Set GPIO chip parent on ppc44x

 - KVM: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl

 - KVM: Use generic xfer to guest work function

 - Enable to run posix cpu timers in task context

 - Misc fixes and cleanups

Thanks to Aditya Gupta, Alice Ryhl, Amit Machhiwal, Andrew Morton,
Anushree Mathur, Athira Rajeev, Bartosz Golaszewski, Cédric Le Goater,
Christian König, Christophe Leroy (CS GROUP), Gary Guo, Gaurav Batra,
Gautam Menghani, Gou Hao, Hari Bathini, Harsh Prateek Bora, jiazhenyuan,
Jinjie Ruan, Link Mauve, Linus Walleij, Mahesh Kumar G Mahesh
Salgaonkar, Michael Walle, Michal Suchánek, Mukesh Kumar Chaurasiya
(IBM), Nicholas Piggin, Nikhil Kumar Singh, Praveen K Pandey, Ritesh
Harjani (IBM), Rosen Penev, Saket Kumar Bhaskar, Shrikanth Hegde,
Sourabh Jain, Thorsten Blum, Vaibhav Jain, Venkat Rao Bagalkote, Vishal
Chourasia, Wentao Guan, and Yanfei Xu.

* tag 'powerpc-7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (62 commits)
  powerpc/pseries/iommu: switch to Default DMA window during kdump
  powerpc/configs: enable CONFIG_RAS to fix EDAC support
  KVM: PPC: Document KVM_PPC_GET_COMPAT_CAPS ioctl
  KVM: PPC: Book3S HV: Add support for compat CPU capabilities for KVM on PowerNV
  KVM: PPC: Book3S HV: Implement compat CPU capability retrieval for KVM on PowerVM
  KVM: PPC: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl
  gpio: ppc44x: use dev_name() for chip label
  gpio: ppc44x: fix undefined behavior in GPIO_MASK2 macro
  gpio: ppc44x: drop PPC-specific IO helpers
  gpio: ppc44x: Convert GPIO to generic MMIO
  gpio: ppc44x: Use platform resource helper for GPIO MMIO
  gpio: ppc44x: Use module platform driver helper for GPIO
  gpio: ppc44x: update all 4xx to 44x
  gpio: move ppc4xx gpio driver from arch/powerpc to drivers/gpio
  KVM: PPC: Use min() in kvm_vm_ioctl_check_extension()
  KVM: PPC: booke: Use min() in watchdog_next_timeout()
  powerpc/perf: Add power12 Base Performance Monitoring support
  powerpc: Add Power12 architected mode
  powerpc: Add Power12 raw mode
  powerpc/pseries: Limit PVR list to 16 entries for CAS negotiation
  ...
2026-08-18 12:08:13 -07:00
Linus Torvalds
ba24659b1d kexec: updates for v7.3-rc1
* Deduplicate crash memory allocation and the exclusion of reserved crash
   kernel regions from architecture specific code into a generic
   crash_prepare_headers() and enable crashkernel CMA reservation on arm64 and
   riscv reservation on arm64 and riscv.
 * Skip purgatory checksum verification when the kexec segments cannot be
   corrupted by DMA, which saves about 250ms on kexec.
 * Replace __ASSEMBLY__ with the compiler provided __ASSEMBLER__ in
   include/linux/kexec.h.
 * Fix a keyring refcount imbalance in the kdump kernel's dm-crypt key restore
   path, which over-dropped the user keyring reference when more than one key
   was restored.
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Merge tag 'kexec-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux

Pull kexec updates from Mike Rapoport:

 - Deduplicate crash memory allocation and the exclusion of reserved
   crash kernel regions from architecture specific code into a generic
   crash_prepare_headers() and enable crashkernel CMA reservation on
   arm64 and riscv reservation on arm64 and riscv.

 - Skip purgatory checksum verification when the kexec segments cannot
   be corrupted by DMA, which saves about 250ms on kexec.

 - Replace __ASSEMBLY__ with the compiler provided __ASSEMBLER__ in
   include/linux/kexec.h.

 - Fix a keyring refcount imbalance in the kdump kernel's dm-crypt key
   restore path, which over-dropped the user keyring reference when
   more than one key was restored.

* tag 'kexec-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux:
  crash_dump: release keyring reference at the correct time
  kexec: Replace __ASSEMBLY__ with __ASSEMBLER__ in header file
  kexec_file: skip checksum verification when safe
  riscv: kexec_file: Add support for crashkernel CMA reservation
  arm64: kexec_file: Add support for crashkernel CMA reservation
  powerpc/kexec_file: Use crash_exclude_core_ranges() helper
  LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
  riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
  x86/crash: Use crash_prepare_headers() helper to simplify code
  arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
  crash: Add crash_prepare_headers() to exclude crash kernel memory
  powerpc/crash: sort crash memory ranges before preparing elfcorehdr
  riscv: kexec_file: Fix crashk_low_res not exclude bug
2026-08-18 10:28:28 -07:00
Amit Machhiwal
b76fb087ef KVM: PPC: Book3S HV: Implement compat CPU capability retrieval for KVM on PowerVM
On POWER systems, the host CPU may run in a compatibility mode (e.g., a
Power11 processor operating in Power10 compatibility mode). In such
cases, the effective CPU level exposed to guests differs from the
physical processor generation.

When running nested KVM guests, QEMU derives the host CPU type using
mfpvr(), which reflects the physical processor version. This can result
in a mismatch between the CPU model selected by QEMU and the
compatibility mode enforced by the host, leading to guest boot failures.

For example, booting a nested guest on a Power11 LPAR configured in
Power10 compatibility mode fails with:

  KVM-NESTEDv2: couldn't set guest wide elements
  [..KVM reg dump..]

This occurs because QEMU selects a CPU model corresponding to the
physical processor (via mfpvr()), while the host operates in a lower
compatibility mode. As a result, KVM rejects the requested compatibility
level during guest initialization.

On pseries nestedv2 systems, add support for retrieving host CPU
compatibility capabilities for nested guests on PowerVM. The capability
bitmap reflects the processor modes negotiated between the Power
hypervisor (L0) and the host partition (L1) via the
H_GUEST_GET_CAPABILITIES hcall, but is retrieved from the cached
nested_capabilities value populated during module initialization,
avoiding repeated hypervisor calls. A WARN_ON_ONCE() flags the
unexpected case where nested_capabilities is zero on a nestedv2 system.
The implementation defines KVM-specific capability constants
(KVM_PPC_COMPAT_CAP_POWER9/10/11), masks unsupported bits, and exposes
the result through the KVM_PPC_GET_COMPAT_CAPS ioctl.

Hook the implementation into the Book3S HV kvmppc_ops so that it can be
invoked by the generic KVM ioctl handling code.

Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-3-amachhiw@linux.ibm.com
2026-08-09 20:26:43 +05:30
Amit Machhiwal
ac3e65dddd KVM: PPC: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl
Introduce a new capability and ioctl to expose CPU compatibility modes
supported by the host processor for nested guests.

On IBM POWER systems, newer processor generations (N) can operate in
compatibility modes corresponding to earlier generations, like (N-1) and
(N-2). This is particularly relevant for nested virtualization, where
nested KVM guests may need to run with a specific processor compatibility
level.

Introduce KVM_CAP_PPC_COMPAT_CAPS capability and the corresponding
KVM_PPC_GET_COMPAT_CAPS vm ioctl. The ioctl returns a bitmap describing
the compatibility modes supported by the host in respective bit numbers,
allowing userspace (e.g., QEMU) to select an appropriate compatibility
level when configuring nested KVM guests.

The ioctl handling is added in kvm_arch_vm_ioctl() and retrieves host
CPU compatibility capabilities via a PowerPC-specific backend
implementation when available.

The struct kvm_ppc_compat_caps places the 'size' field first so it can
be read alone via get_user() before copy_struct_from_user() is called,
avoiding pointer arithmetic to locate the size field.

The ioctl is defined using _IO so the ioctl number remains stable even if
the struct grows in future versions. It uses copy_struct_from_user() and
copy_struct_to_user() to provide forward- and backward-compatible
extensibility: older userspace passing a smaller struct to a newer kernel
gets zero-padded trailing fields. Newer userspace passing a larger struct to
an older kernel (usize > ksize) succeeds if trailing bytes are zero (the
kernel reports back min(usize, ksize) as the filled size); if trailing bytes
are non-zero, the kernel writes back ksize into host_caps.size and returns
-E2BIG so userspace can retry with the correct size.

KVM_PPC_COMPAT_CAPS_SIZE_VER0 is defined as a frozen integer constant
(24) marking the size of the initial struct version, used as the
minimum floor for size field validation, similar to other versioned
struct interfaces in the kernel.

The 'flags' field is reserved for future use. The kernel rejects any
call where flags is non-zero with -EINVAL, preventing garbage values
from being baked into ABI permanently.

The ioctl returns appropriate error codes: E2BIG if usize exceeds
PAGE_SIZE, or if new userspace provides a larger struct with non-zero
trailing bytes (with ksize written back into host_caps.size for the
retry); EINVAL for an invalid size or non-zero reserved fields; EFAULT
for failed copy operations; and ENOTTY if the backend doesn't implement
get_compat_caps.

Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-2-amachhiw@linux.ibm.com
2026-08-09 20:26:43 +05:30
Ritesh Harjani (IBM)
287df870bf powerpc: Add Power12 architected mode
PVR value of 0x0f000008 means we are arch v3.2 compliant (i.e.
Power12). This is used by phyp and kvm when booting as a pseries guest
to detect the presence of new Power12 features and to enable the
appropriate hwcap and facility bits.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260806051120.3703698-4-mahesh@linux.ibm.com
2026-08-06 11:00:55 +05:30
Nicholas Piggin
e671e147ea powerpc: Add Power12 raw mode
Add CPU table entries for raw mode.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260806051120.3703698-3-mahesh@linux.ibm.com
2026-08-06 11:00:55 +05:30
Kiryl Shutsemau (Meta)
c6f11553c0 mm: decouple protnone helpers from CONFIG_NUMA_BALANCING
Patch series "userfaultfd: working set tracking for VM guest memory", v10.

This series adds userfaultfd support for tracking the working set of VM
guest memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage.


This patch (of 15):

pte_protnone() and pmd_protnone() detect present-but-inaccessible page
table entries.  This capability is useful beyond NUMA balancing -- for
example, userfaultfd working set tracking uses protnone PTEs to track page
access without unmapping pages.

Introduce CONFIG_ARCH_HAS_PTE_PROTNONE to decouple the protnone PTE
infrastructure from CONFIG_NUMA_BALANCING.  The six architectures that
support protnone PTEs (x86_64, arm64, powerpc, s390, riscv, loongarch) now
select this option, and CONFIG_NUMA_BALANCING depends on it.

No functional change -- the same set of architectures continues to have
working protnone support, but the infrastructure is now available
independently of NUMA balancing.

Link: https://lore.kernel.org/20260708111417.173443-1-kirill@shutemov.name
Link: https://lore.kernel.org/20260708111417.173443-2-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Assisted-by: Claude:claude-opus-4-6
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: James Houghton <jthoughton@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04 19:18:36 -07:00
Mukesh Kumar Chaurasiya (IBM)
69cb2be898 powerpc/syscall: Fix syscall skip handling for seccomp and ptrace
After enabling GENERIC_ENTRY on PowerPC, syscall_enter_from_user_mode()
returns -1 as a sentinel to signal that seccomp or ptrace has intercepted
the syscall and already set a return value via syscall_set_return_value().
system_call_exception() was not handling this sentinel, and since -1UL
is >= NR_syscalls, the code fell into the out-of-range path and returned
-ENOSYS, overwriting the errno already placed in regs->gpr[3].

The naive fix of checking r0 == -1L before the NR_syscalls bounds check
is ambiguous: a user legitimately calling syscall(-1) also produces r0 ==
-1L, and a tracer intercepting such a call would have its injected return
value silently discarded.

Fix this by introducing a thread flag that is set whenever
syscall_set_return_value() explicitly updates the return value. In
system_call_exception(), check and clear this flag before dispatching
the syscall, and return the preset value directly when it is present.
This ensures that an explicitly supplied return value always suppresses
syscall execution, regardless of the syscall number.

This handles all seccomp actions correctly:

  - SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE (no tracer), SECCOMP_RET_USER_NOTIF:
    all call syscall_set_return_value(), flag is set, injected value returned.
  - SECCOMP_RET_TRAP, SECCOMP_RET_KILL: call syscall_rollback() and deliver
    a signal; flag is not set, but the process is dying so the return value
    is irrelevant.

The fix covers both ppc32 and ppc64 with no #ifdefs.

Fixes: bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
Reported-by: Michal Suchánek <msuchanek@suse.de>
Closes: https://lore.kernel.org/all/ajpp-_XnbF3UTM_E@kunlun.suse.cz/
Tested-by: Michal Suchánek <msuchanek@suse.de>
Reviewed-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260731081521.1852133-1-mkchauras@gmail.com
2026-08-03 14:09:14 +05:30
Sourabh Jain
fb43ba4256 powerpc/crash: stop watchdogs before booting kdump kernel
On pseries LPAR systems, watchdog timers configured from userspace can
remain active after a kernel panic. When a panic triggers kdump, the
crashing kernel jumps directly to the kdump kernel without stopping
active watchdogs. As a result, the watchdogs remain active after the
kdump kernel starts.

If dump capture takes longer than the watchdog timeout, PHYP resets the
LPAR before the dump is fully captured, causing dump capture to fail.

Fix this by issuing the `H_WATCHDOG` hcall during the crash shutdown
sequence to stop all active watchdogs before booting the kdump kernel.

Cc: stable@vger.kernel.org
Fixes: 69472ffa65 ("watchdog/pseries-wdt: initial support for H_WATCHDOG-based watchdog timers")
Reported-by: Mahesh Kumar G <mahe657@linux.ibm.com>
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727053416.276317-4-sourabhjain@linux.ibm.com
2026-08-03 14:05:55 +05:30
Sourabh Jain
516a254918 powerpc/pseries: Move H_WATCHDOG definitions to a common header
The H_WATCHDOG input and output definitions are currently local to the
pseries watchdog driver. The next patch in this series also needs these
definitions to issue H_WATCHDOG hypercalls outside the watchdog driver.

Move the H_WATCHDOG definitions to a new common header,
asm/papr-watchdog.h, so they can be shared without duplicating the
PAPR watchdog definitions.

No functional changes.

Cc: stable@vger.kernel.org
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727053416.276317-2-sourabhjain@linux.ibm.com
2026-08-03 14:05:55 +05:30
Amit Machhiwal
884ea0283f KVM: PPC: Book3S HV: Validate arch_compat against host compatibility mode
On IBM POWER systems, newer processor generations can operate in
compatibility modes corresponding to earlier generations. This becomes
relevant for nested virtualization, where nested KVM guests may need to
run with a specific processor compatibility level.

Currently, when running a nested KVM guest (L2) inside a Power11 pSeries
logical partition (L1) booted in Power10 compatibility mode, the guest
fails to boot while setting 'arch_compat'. This happens because the CPU
class is derived from the hardware PVR (via mfspr()), which reflects the
physical processor generation (Power11), rather than the effective
compatibility mode (Power10).

As a result, userspace may request a Power11 arch_compat for the L2
guest. However, the L1 partition, running in Power10 compatibility, has
only negotiated support up to Power10 with the Power Hypervisor (L0).
When H_GUEST_SET_STATE is invoked with a Power11 Logical PVR, the
hypervisor rejects the request, leading to a late guest boot failure:

  KVM-NESTEDv2: couldn't set guest wide elements
  [..KVM reg dump..]

This situation should be detected earlier and rejected by KVM. Without
proper validation, if userspace ignores the error, the guest may continue
to boot in Power11 raw mode on a Power10 compatibility host, which should
not be allowed.

Introduce a validation mechanism that detects unsupported arch_compat
values early in the guest initialization path. When an unsupported
arch_compat is requested (e.g., Power11 on a Power10 compatibility mode
host), kvmppc_set_arch_compat() uses cpu_has_feature(CPU_FTR_P11_PVR) to
detect the mismatch and sets arch_compat to PVR_ARCH_INVALID (0xffffffff).
This sentinel value is architecturally safe: PAPR specifies that valid
logical PVR values must have 0x0f as the first byte, ensuring 0xffffffff
lies permanently outside the specification-defined range. Setting this
value triggers kvmppc_sanity_check() to mark the vCPU as invalid by
setting vcpu->arch.sane to false. On the next vCPU run, kvmppc_vcpu_run_hv()
checks this flag and returns -EINVAL, preventing the guest from running
with an invalid processor compatibility configuration.

With this, when a Power11 arch_compat is requested on a Power10
compatibility mode host, the guest fails early during boot with:

  error: kvm run failed Invalid argument

This provides a much clearer failure mode compared to the previous
behavior where the guest could boot in Power11 raw mode (if userspace
ignored the error) or fail late during H_GUEST_SET_STATE.

Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Acked-by: Gautam Menghani <gautam@linux.ibm.com>
Cc: stable@vger.kernel.org # v6.13+
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260714175432.86388-1-amachhiw@linux.ibm.com
2026-08-03 14:00:51 +05:30
Gou Hao
ab5ae5dceb powerpc/xive: add error return value to xive_smp_probe()
xive_smp_probe() calls xive_init_ipis() which can fail, but its
return value is currently ignored.  Change xive_smp_probe() to
return int so that errors can be propagated to callers.

This is a preparatory patch for the next one.

No functional change yet; the return value is always 0 at this point.

Signed-off-by: Gou Hao <gouhao@uniontech.com>
Reviewed-by: Wentao Guan <guanwentao@uniontech.com>
Reviewed-by: jiazhenyuan <jiazhenyuan@uniontech.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727104215.184786-3-gouhao@uniontech.com
2026-08-03 13:55:59 +05:30
Thorsten Blum
be57ed7694 powerpc/serial: Use generic BASE_BAUD in asm/serial.h
Include asm-generic/serial.h and use the generic BASE_BAUD definition
instead of redefining it.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260729223807.570178-3-thorsten.blum@linux.dev
2026-07-31 17:07:41 +05:30
Mukesh Kumar Chaurasiya (IBM)
13244c0a40 powerpc/jump_label: adjust inline asm to be consistent
Added support for a new macro ARCH_STATIC_BRANCH_ASM in powerpc
to avoid duplication of inline asm between C and Rust. This is
inline with 'commit aecaf18165 ("jump_label: adjust inline asm to be consistent")'

Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://github.com/Rust-for-Linux/linux/issues/105
Link: https://github.com/linuxppc/issues/issues/451
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260708082454.1254320-4-mkchauras@gmail.com
2026-07-31 16:57:48 +05:30
Usama Arif
d547b10017 mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVES
CONFIG_ARCH_ENABLE_THP_MIGRATION gates PMD-level migration entries. 
PMD-level device-private entries use the same migration mechanism and
therefore require the same architecture support.

Upcoming PMD-level swap entries can use the same PMD softleaf helpers
without depending on page migration, so rename the architecture gate to
CONFIG_ARCH_HAS_PMD_SOFTLEAVES.  This describes the PMD entry capability
rather than one current user of it.

This is a pure rename: the set of selecting architectures (x86, arm64,
s390, riscv, loongarch, and powerpc on PPC_BOOK3S_64) and the gating
semantics are unchanged.

No functional change intended.

Link: https://lore.kernel.org/20260706114320.1643046-7-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-30 19:40:25 -07:00
Thorsten Blum
86f057c19f powerpc/serial: Fix include guard comment
Replace _PPC64_SERIAL_H with _ASM_POWERPC_SERIAL_H to match the actual
macro name. Remove an empty comment while at it.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260623153825.403819-2-thorsten.blum@linux.dev
2026-07-28 10:23:32 +05:30
Mukesh Kumar Chaurasiya (IBM)
263e5159e0 powerpc: Fix exit_flags field placement in pt_regs for ptrace
Commit d7a6797e0b ("powerpc: add exit_flags field in pt_regs") added
the exit_flags field to struct pt_regs to pass internal exit control
flags (e.g. _TIF_RESTOREALL) from syscall_exit_prepare() to the
low-level assembly exit path.

However, the field was placed in a way that was visible to userspace
tools such as strace via PTRACE_GETREGS, or caused a struct layout or
size regression observable through ptrace. The field is purely
kernel-internal and must not be exposed beyond the user_pt_regs
boundary.

Move exit_flags into struct thread_info where it is only accessible to
the kernel, and keep it out of the ptrace-visible register window
entirely.

Fixes: d7a6797e0b ("powerpc: add exit_flags field in pt_regs")
Reported-by: Dmitry V. Levin <ldv@strace.io>
Closes: https://lore.kernel.org/all/20260722070155.GA11808@strace.io/
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260723194809.4046600-1-mkchauras@gmail.com
2026-07-28 10:23:31 +05:30
Mukesh Kumar Chaurasiya (IBM)
bddf754009 powerpc/970: fix nap return address corruption on async interrupt exit
On PowerMac G5 (PPC970, CONFIG_PPC_970_NAP) the system panics shortly
after boot with symptoms including instruction fetch faults, kernel data
access faults, and stack corruption, predominantly on SMP and always
somewhere inside softirq processing.

The PPC970 idle path works by setting _TLF_NAPPING in the current
thread's local flags before entering the MSR_POW nap loop.  When any
async interrupt wakes the CPU, nap_adjust_return() is expected to detect
_TLF_NAPPING, clear it, and rewrite regs->NIP to power4_idle_nap_return
so that the interrupt returns cleanly to the caller of power4_idle_nap()
rather than back into the nap spin loop.

DEFINE_INTERRUPT_HANDLER_ASYNC generates the following sequence:

    irq_enter_rcu();
    ____func(regs);           /* timer_interrupt / do_IRQ body */
    irq_exit_rcu();           /* softirqs run here, irqs re-enabled */
    arch_interrupt_async_exit_prepare(regs); /* nap_adjust_return was here */
    irqentry_exit(regs, state);

irq_exit_rcu() calls invoke_softirq() -> do_softirq_own_stack(), which
runs softirqs with hardware interrupts re-enabled.  A nested async
interrupt can therefore arrive while _TLF_NAPPING is still set.  That
nested interrupt reaches nap_adjust_return() in its own
arch_interrupt_async_exit_prepare() call, finds _TLF_NAPPING set, and
redirects *its own* regs->NIP to power4_idle_nap_return.  Returning via
that blr with an unrelated LR on the softirq stack jumps to a garbage
address, causing the observed crashes.

The comment that previously lived in arch_interrupt_async_exit_prepare()
even described this exact hazard ("must come before irq_exit()"), but
nap_adjust_return() was placed after irq_exit_rcu() in the macro, so
the protection was never effective.

Fix this by calling nap_adjust_return() inside DEFINE_INTERRUPT_HANDLER_ASYNC
immediately before irq_exit_rcu(), ensuring _TLF_NAPPING is cleared and
regs->NIP is adjusted before any code that can re-enable interrupts or
invoke softirqs runs.  Move the explanatory comment into
nap_adjust_return() itself and remove it from arch_interrupt_async_exit_prepare().

Fixes: bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
Closes: https://lore.kernel.org/all/87wlvazrdy.fsf@igel.home/
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Tested-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260707172430.790040-1-mkchauras@gmail.com
2026-07-28 10:23:31 +05:30
Thomas Gleixner
3ed403bbc9 treewide: Remove CLOCK_TICK_RATE
This has been scheduled for removal more than a decade ago and the comments
related to it have been dutifully ignored. The last dependencies are gone.

Remove it along with various now empty asm/timex.h files.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://patch.msgid.link/20260410120317.910770161@kernel.org
2026-07-15 15:04:55 +02:00
Christophe Leroy (CS GROUP)
a2c02aa0c6 powerpc: Remove dead non-preemption code
Since commit 7dadeaa6e8 ("sched: Further restrict the preemption
modes"), powerpc always has CONFIG_PREEMPTION because only
CONFIG_PREEMPT and CONFIG_PREEMPT_LAZY are possible, even in
dynamic preemption mode (see sched_dynamic_mode).

As a consequence, need_irq_preemption() is always true and can be
removed.

And because commit bee25f97ad ("powerpc: Enable GENERIC_ENTRY
feature") includes linux/irq-entry-common.h which already declares
sk_dynamic_irqentry_exit_cond_resched static key, asm/preempt.h
becauses useless and can be removed.

Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/2bf10a0afffefb6aca44bf2f864cc17471a80e31.1781870889.git.chleroy@kernel.org
2026-07-15 08:04:13 +05:30
Ethan Nelson-Moore
d610d3ab18 powerpc/uaccess: correct check for CONFIG_PPC_E500 in mask_user_address()
mask_user_address() incorrectly checks for CONFIG_E500 instead of
CONFIG_PPC_E500, causing mask_user_address_isel() to not be used on
E500 hardware. Fix the check to use the correct name.

Fixes: 861574d51b ("powerpc/uaccess: Implement masked user access")
Cc: stable@vger.kernel.org # 7.0+

Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Fixes: 861574d51b ("powerpc/uaccess: Implement masked user access")
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260615233729.29386-1-enelsonmoore@gmail.com
2026-07-15 08:04:13 +05:30
Jinjie Ruan
8383e05af7 syscall_user_dispatch: Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH
Currently, only x86 genuinely implements and supports Syscall User Dispatch
(SUD).

Multiple architectures provide a stub arch_syscall_is_vdso_sigreturn()
returning 'false' simply to satisfy GENERIC_ENTRY compilation, which
creates a false impression of feature support.

Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH to decouple this mechanism
from GENERIC_ENTRY. Select it exclusively on x86 and remove the redundant
stub functions from other architectures.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20260713035422.582771-1-ruanjinjie@huawei.com
2026-07-14 16:34:07 +02:00
Jinjie Ruan
b0e06c5a30 powerpc/kexec_file: Use crash_exclude_core_ranges() helper
The crash memory exclude of crashk_res and crashk_cma memory on powerpc
are almost identical to the generic crash_exclude_core_ranges().

By introducing the architecture-specific arch_crash_exclude_mem_range()
function with a default implementation of crash_exclude_mem_range(),
and using crash_exclude_mem_range_guarded as powerpc's separate
implementation, the generic crash_exclude_core_ranges() helper function
can be reused.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Acked-by: Breno leitao <leitao@debian.org>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20260629094746.191843-9-ruanjinjie@huawei.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-30 18:49:06 +03:00
Sourabh Jain
202b5de3ec powerpc/crash: sort crash memory ranges before preparing elfcorehdr
During a memory hot-remove event, the elfcorehdr is rebuilt to exclude
the removed memory. While updating the crash memory ranges for this
operation, the crash memory ranges array can become unsorted. This
happens because remove_mem_range() may split a memory range into two
parts and append the higher-address part as a separate range at the end
of the array.

So far, no issues have been observed due to the unsorted crash memory
ranges. However, this could lead to problems once crash memory range
removal is handled by generic code, as introduced in the upcoming
patches in this series.

Currently, powerpc uses a platform-specific function,
remove_mem_range(), to exclude hot-removed memory from the crash memory
ranges. This function performs the same task as the generic
crash_exclude_mem_range() in crash_core.c. The generic helper also
ensures that the crash memory ranges remain sorted. So remove the
redundant powerpc-specific implementation and instead call
crash_exclude_mem_range_guarded() (which internally calls
crash_exclude_mem_range()) to exclude the hot-removed memory ranges.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baoquan he <bhe@redhat.com>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20260629094746.191843-3-ruanjinjie@huawei.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-30 18:49:06 +03:00
Linus Torvalds
26ae421f7f pci-v7.2-changes
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Merge tag 'pci-v7.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

Pull pci updates from Bjorn Helgaas:
 "Enumeration:

   - Remove MPS/MRRS Kconfig settings (CONFIG_PCIE_BUS_*) that worked
     around a WiFi device defect; use a quirk or boot-time
     "pci=pcie_bus_tune_*" kernel parameter instead (Bjorn Helgaas)

   - Always lift 2.5GT/s restriction in PCIe failed link retraining to
     avoid clamping a link to 2.5GT/s after hot-plug changes the device
     (Maciej W. Rozycki)

   - Request bus reassignment when not probe-only to fix an enumeration
     regression on Marvell CN106XX and possibly other DT-based systems
     (Ratheesh Kannoth)

   - Fix procfs race between pci_proc_init() and pci_bus_add_device()
     that resulted in 'proc_dir_entry ... already registered' warnings
     and pointer corruption (Krzysztof Wilczyński)

   - Fix sysfs race that causes 'duplicate filename' warnings and boot
     panics by converting PCI resource files to static attributes
     (Krzysztof Wilczyński)

   - Expose sysfs 'resourceN_resize' attributes only on platforms with
     PCI mmap (Krzysztof Wilczyński)

   - Require CAP_SYS_ADMIN to write to sysfs 'resourceN_resize'
     attributes (Krzysztof Wilczyński)

   - Add security_locked_down(LOCKDOWN_PCI_ACCESS) to alpha PCI resource
     mmap path to match the generic path (Krzysztof Wilczyński)

   - Use kstrtobool() to parse the 'rom' attribute input to avoid the
     unexpected behavior of enabling the ROM when writing '0' with no
     trailing newline (Krzysztof Wilczyński)

  Resource management:

   - Improve resource claim logging for debuggability (Ilpo Järvinen)

   - Clean up several uses of const parameters (Ilpo Järvinen)

   - Check option ROM header signatures and lengths before accessing to
     avoid page faults and alignment faults (Guixin Liu)

  ASPM:

   - Don't reconfigure ASPM when entering low-power D-state; only do it
     when returning back to D0 (Carlos Bilbao)

  Power management:

   - During suspend, set power state to 'unknown' for all devices, not
     just those with drivers (Lukas Wunner)

   - Skip restoring Resizable BARs and VF Resizable BARs if device
     doesn't respond to config reads, to avoid invalid array accesses
     (Marco Nenciarini)

   - Add pci_suspend_retains_context() so drivers can tell whether
     devices retain internal state across suspend/resume, since some
     platforms reset devices on suspend; use this in nvme to avoid
     issues on Qcom RCs (Manivannan Sadhasivam)

  Power control:

   - Only to power on/off devices that actually support power control to
     avoid poking at incompatible devices mentioned in DT (Manivannan
     Sadhasivam)

  Virtualization and resets:

   - Log device readiness timeouts as errors, not warnings, because the
     device is likely unusable in this case (Bjorn Helgaas)

   - Wait for device readiness after soft reset (D3hot ->
     D0uninitialized transition), when the device may respond with
     Request Retry Status (RRS) if it needs more time to initialize
     (Bjorn Helgaas)

   - Drop unnecessary retries when restoring BARs because resets should
     now already include all required delays (Lukas Wunner)

   - Avoid FLR for MediaTek MT7925 WiFi, where FLR fails after a VM
     terminates uncleanly (Jose Ignacio Tornos Martinez)

   - Avoid SBR for Qualcomm WCN6855/WCN7850 WiFi, SDX62/SDX65 modems,
     which seem not to support it correctly (Jose Ignacio Tornos
     Martinez)

  Peer-to-peer DMA:

   - Prevent P2PDMA as well as CPU access to non-mappable BARs, e.g.,
     s390 ISM BARs (Matt Evans)

   - Add Intel QAT, DSA, IAA devices to whitelist (Lukas Wunner)

  Endpoint framework:

   - Add endpoint controller APIs for use by function drivers to
     discover auxiliary blocks like DMA engines (Koichiro Den)

   - Remember DesignWare eDMA engine base/size and expose them via the
     EPC aux-resource API (Koichiro Den)

   - Add endpoint embedded doorbell fallback, used if MSI allocation
     fails (Koichiro Den)

   - Validate BAR index and remove dead BAR read in endpoint doorbell
     test (Carlos Bilbao)

   - Unwind MSI/MSI-X vectors if NTB initialization fails part-way
     through (Koichiro Den)

   - Cache sleepable pci_irq_vector() value at ISR setup to avoid
     calling it from hardirq context (Koichiro Den)

   - Call sleepable pci_epc_raise_irq() from a work item instead of
     atomic context, e.g., when setting bits in NTB peer doorbells in
     the ntb_peer_db_set() path (Koichiro Den)

   - Report 0-based vNTB doorbell vector to account for link event 0 and
     historically skipped slot 1 (Koichiro Den)

   - Prevent configfs writes to vNTB db_count and other values that are
     already in use after EPC attach (Koichiro Den)

   - Account for vNTB db_valid reserved slots (link event 0 and
     historically skipped slot 1) so they don't appear as valid
     doorbells (Koichiro Den)

   - Implement vNTB .db_vector_count()/mask() for doorbells so clients
     can use multiple vectors and avoid thundering herds (Koichiro Den)

   - Report 0-based NTB doorbell vector to account for link event 0 and
     historically skipped slot 1 (Koichiro Den)

   - Fix doorbell bitmask and IRQ vector handling to clear only
     specified bits, use the correct vector for non-contiguous Linux IRQ
     numbers, and validate incoming vectors (Koichiro Den)

   - Implement NTB .db_vector_count()/mask() for doorbells so clients
     can use multiple vectors (Koichiro Den)

  Native PCIe controller infrastructure:

   - Add pci_host_common_link_train_delay() for the mandatory delay
     after > 5GT/s Link training completes and use it for cadence HPA,
     j721e, LGA; dwc; aardvark, mediatek-gen3, rzg3s (Hans Zhang)

   - Protect root bus removal with rescan lock in altera, brcmstb,
     cadence, dwc, iproc, mediatek, plda, rockchip to prevent
     use-after-free or crashes when racing with sysfs rescan or hotplug
     (Hans Zhang)

   - Add pci_host_common_parse_ports() for use by any native driver to
     parse Root Port properties (per-Link features like width, speed,
     PHY, power and reset control, etc should be described in Root Port
     stanzas, not the host bridge; currently only reset GPIOs
     implemented) (Sherry Sun)

  New native PCIe controller drivers:

   - Add DT binding and driver for UltraRISC DP1000 PCIe controller
     (Xincheng Zhang, Jia Wang)

  Altera PCIe controller driver:

   - Do not dispose of the parent IRQ mapping, which belongs to the
     parent interrupt controller (Mahesh Vaidya)

   - Fix chained IRQ handler ordering issue and resource leaks on probe
     failure (Mahesh Vaidya)

  AMD MDB PCIe controller driver:

   - Assert PERST# on shutdown so any connected Endpoints are held in
     reset during shutdown (Sai Krishna Musham)

  Amlogic Meson PCIe controller driver:

   - Propagate devm_add_action_or_reset() failure to fix probe error
     path (Shuvam Pandey)

   - Add .remove() callback to deinitialize the host bridge and power
     off the PHY (Shuvam Pandey)

  Broadcom iProc PCIe controller driver:

   - Restore .map_irq() assignment; its removal broke INTx on the iproc
     platform bus driver (Mark Tomlinson)

  Broadcom STB PCIe controller driver:

   - No change, but products using certain WiFi devices may be affected
     by removal of CONFIG_PCIE_BUS_* (see above)

  Freescale i.MX6 PCIe controller driver:

   - Move IMX6SX_GPR12_PCIE_TEST_POWERDOWN handling into the core reset
     functions (Richard Zhu)

   - Assert PERST# before enabling regulators to ensure that even if
     power is enabled, endpoint stays inactive until REFCLK is stable
     (Sherry Sun)

   - Parse reset properties in Root Port nodes (falling back to host
     bridge) to help support Key E connectors and the pwrctrl framework
     (Sherry Sun)

   - Configure i.MX95 REF_USE_PAD before PHY reset (Richard Zhu)

   - Assert i.MX95 ref_clk_en after reference clock stabilizes (Richard
     Zhu)

   - Integrate new pwrctrl API for DTs with Root Port-level power
     supplies (Sherry Sun)

  Intel Gateway PCIe controller driver:

   - Enable clock before PHY init for correct ordering (Florian Eckert)

   - Add .start_link() callback so the driver works again (Florian
     Eckert)

   - Stop overwriting the ATU base address discovered by
     dw_pcie_get_resources() (Florian Eckert)

   - Add DT 'atu' region since this is hardware-specific, and fall back
     to driver default if lacking (Florian Eckert)

  Loongson PCIe controller driver:

   - Ignore downstream devices only on internal bridges to avoid
     Loongson hardware issue (Rong Zhang)

   - Quirk old Loongson-3C6000 bridges that advertise incorrect
     supported link speeds (Ziyao Li)

  Marvell MVEBU PCIe controller driver:

   - Use fixed-width interrupt masks to avoid truncation in 64-bit
     builds (Rosen Penev)

  MediaTek PCIe controller driver:

   - Use FIELD_PREP() to fix incorrect operator precedence in
     PCIE_FTS_NUM_L0 (Li RongQing)

   - Fix IRQ domain leak when port fails to enable (Manivannan
     Sadhasivam)

   - Use actual physical address for MSI message address instead of
     virt_to_phys() (Manivannan Sadhasivam)

   - Add EcoNet EN7528 to DT binding (Caleb James DeLisle)

  MediaTek PCIe Gen3 controller driver:

   - Deassert PCIE_PHY_RSTB so REFCLK is stable for at least 100ms
     (PCIE_T_PVPERL_MS) before deasserting PERST# (Jian Yang)

   - Add .shutdown() to assert PERST# before powering down device (Jian
     Yang)

   - Do full device power down on removal, including asserting PERST#,
     when removing driver (Chen-Yu Tsai)

   - Fix a 'failed to create pwrctrl devices' error message that was
     inadvertently skipped (Chen-Yu Tsai)

  NVIDIA Tegra194 PCIe controller driver:

   - Program the DesignWare PORT_AFR L1 entrance latency based on the
     'aspm-l1-entry-delay-ns' DT property (Manikanta Maddireddy)

  Qualcomm PCIe controller driver:

   - Add Eliza SoC compatible in DT binding (Krishna Chaitanya Chundru)

   - Set max OPP during resume so DBI register accesses don't fail with
     NoC errors (Qiang Yu)

   - Add pci_host_common_d3cold_possible() to determine whether
     downstream devices are already in D3hot and wakeup-enabled devices
     are capable of generating PME from D3cold (Krishna Chaitanya
     Chundru)

   - Add .get_ltssm() callback to get the LTSSM status without DBI,
     since DBI may be inaccessible after PME_Turn_Off (Krishna Chaitanya
     Chundru)

   - Power down PHY via PARF_PHY_CTRL before disabling rails/clocks to
     avoid power leakage (Krishna Chaitanya Chundru)

   - Decide whether suspend should put the link in L2 and power down
     using pci_host_common_d3cold_possible() instead of checking whether
     ASPM L1 is enabled (Krishna Chaitanya Chundru)

   - Add qcom D3cold support to tear down interconnect bandwidth and OPP
     votes (Krishna Chaitanya Chundru)

   - Handle unsupported mixed PERST#/PHY DT configurations, e.g., PHY in
     RP node while PERST# is in the RC node, but warn about the DT issue
     (Qiang Yu)

   - Program T_POWER_ON based on DT 't-power-on-us' property in case
     hardware advertises incorrect values (Krishna Chaitanya Chundru)

   - Disable ASPM L0s for SA8775P (Shawn Guo)

   - Initialize DWC MSI lock for firmware-managed ECAM hosts, which
     don't use the dw_pcie_host_init() path that initializes the lock
     (Yadu M G)

  Renesas RZ/G3S PCIe controller driver:

   - Add RZ/V2N DT support (Lad Prabhakar)

  SOPHGO PCIe controller driver:

   - Add 'dma-coherent' DT property for sg2042-pcie driver (Han Gao)

  Synopsys DesignWare PCIe controller driver:

   - Apply ECRC TLP Digest workaround for all DesignWare cores prior to
     5.10a, not just 4.90a and 5.00a (Manikanta Maddireddy)

   - Use common struct dw_pcie 'mode' rather than duplicating it in
     artpec6, dra7xx, dwc-pcie, and keembay driver structs (Hans Zhang)

   - Use DEFINE_SHOW_ATTRIBUTE for ltssm_status debugfs to reduce
     boilerplate and fix a seq_file memory leak by including a
     .release() callback (Hans Zhang)

   - Fix a signedness bug in fault injection test code (Dan Carpenter)

   - Avoid NULL pointer dereference when tearing down debugfs for
     controller that lacks RAS DES capability (Shuvam Pandey)

  MicroSemi Switchtec management driver:

   - Add Gen6 Device IDs (Ben Reed)

  Miscellaneous:

   - Remove unused gpio.h include from amd-mdb, designware-plat, fu740,
     visconti drivers (Andy Shevchenko)

   - Fix typos in documentation (josh ziegler)

   - Use FIELD_MODIFY() instead of open-coding it (Hans Zhang)"

* tag 'pci-v7.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (168 commits)
  PCI/sysfs: Use kstrtobool() to parse the ROM attribute input
  PCI/sysfs: Limit BAR resize attribute scope to platforms with PCI mmap
  PCI/sysfs: Remove pci_create_legacy_files() and pci_sysfs_init()
  PCI/sysfs: Convert legacy I/O and memory attributes to static definitions
  PCI/sysfs: Add __weak pci_legacy_has_sparse() helper
  alpha/PCI: Compute legacy size in pci_mmap_legacy_page_range()
  PCI: Add macros for legacy I/O and memory address space sizes
  PCI/sysfs: Remove pci_{create,remove}_sysfs_dev_files()
  alpha/PCI: Convert resource files to static attributes
  alpha/PCI: Add static PCI resource attribute macros
  alpha/PCI: Remove WARN from __pci_mmap_fits() and __legacy_mmap_fits()
  alpha/PCI: Fix __pci_mmap_fits() overflow for zero-length BARs
  alpha/PCI: Use PCI resource accessor macros
  alpha/PCI: Use BAR index in sysfs attr->private instead of resource pointer
  alpha/PCI: Add security_locked_down() check to pci_mmap_resource()
  PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope
  PCI/sysfs: Add stubs for pci_{create,remove}_sysfs_dev_files()
  PCI/sysfs: Warn about BAR resize failure in __resource_resize_store()
  PCI/sysfs: Convert PCI resource files to static attributes
  PCI/proc: Fix race between pci_proc_init() and pci_bus_add_device()
  ...
2026-06-24 12:48:43 -07:00
Bjorn Helgaas
8b3a73b4fe Merge branch 'pci/sysfs'
- Require CAP_SYS_ADMIN to write to sysfs 'resourceN_resize' attributes
  (Krzysztof Wilczyński)

- Convert PCI resource files to static attributes to avoid races that cause
  'duplicate filename' warnings and boot panics (Krzysztof Wilczyński)

- Remove pci_create_sysfs_dev_files() and pci_remove_sysfs_dev_files(),
  which are obsolete after converting to static attributes (Krzysztof
  Wilczyński)

- Add security_locked_down(LOCKDOWN_PCI_ACCESS) to alpha PCI resource mmap
  path to match the generic path (Krzysztof Wilczyński)

- Convert sysfs 'legacy_io' and 'legacy_mem' to static attributes
  (Krzysztof Wilczyński)

- Remove pci_create_legacy_files() and pci_sysfs_init(), which are obsolete
  after converting to static attributes (Krzysztof Wilczyński)

- Expose sysfs 'resourceN_resize' attributes only on platforms with PCI
  mmap (Krzysztof Wilczyński)

- Use kstrtobool() to parse the 'rom' attribute input to avoid the
  unexpected behavior of enabling the ROM when writing '0' with no trailing
  newline (Krzysztof Wilczyński)

* pci/sysfs:
  PCI/sysfs: Use kstrtobool() to parse the ROM attribute input
  PCI/sysfs: Limit BAR resize attribute scope to platforms with PCI mmap
  PCI/sysfs: Remove pci_create_legacy_files() and pci_sysfs_init()
  PCI/sysfs: Convert legacy I/O and memory attributes to static definitions
  PCI/sysfs: Add __weak pci_legacy_has_sparse() helper
  alpha/PCI: Compute legacy size in pci_mmap_legacy_page_range()
  PCI: Add macros for legacy I/O and memory address space sizes
  PCI/sysfs: Remove pci_{create,remove}_sysfs_dev_files()
  alpha/PCI: Convert resource files to static attributes
  alpha/PCI: Add static PCI resource attribute macros
  alpha/PCI: Remove WARN from __pci_mmap_fits() and __legacy_mmap_fits()
  alpha/PCI: Fix __pci_mmap_fits() overflow for zero-length BARs
  alpha/PCI: Use PCI resource accessor macros
  alpha/PCI: Use BAR index in sysfs attr->private instead of resource pointer
  alpha/PCI: Add security_locked_down() check to pci_mmap_resource()
  PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope
  PCI/sysfs: Add stubs for pci_{create,remove}_sysfs_dev_files()
  PCI/sysfs: Warn about BAR resize failure in __resource_resize_store()
  PCI/sysfs: Convert PCI resource files to static attributes
  PCI/sysfs: Add static PCI resource attribute macros
  PCI/sysfs: Add CAP_SYS_ADMIN check to __resource_resize_store()
  PCI/sysfs: Split pci_llseek_resource() for device and legacy attributes
  PCI/sysfs: Only allow supported resource types in I/O and MMIO helpers
  PCI: Add pci_resource_is_io() and pci_resource_is_mem() helpers
  PCI/sysfs: Use PCI resource accessor macros
2026-06-23 17:32:03 -05:00
Krzysztof Wilczyński
4e14b965a6 PCI/sysfs: Convert legacy I/O and memory attributes to static definitions
Currently, legacy_io and legacy_mem are dynamically allocated and created
by pci_create_legacy_files(), with pci_adjust_legacy_attr() updating the
attributes at runtime on Alpha to rename them and shift the size for sparse
addressing.

Convert to four static const attributes (legacy_io, legacy_io_sparse,
legacy_mem, legacy_mem_sparse) with .is_bin_visible() callbacks that use
pci_legacy_has_sparse() to select the appropriate variant per bus.  The
sizes are compile-time constants and .size is set directly on each
attribute.

Register the groups in pcibus_groups[] under a HAVE_PCI_LEGACY guard so the
driver model handles creation and removal automatically.

Stub out pci_create_legacy_files() and pci_remove_legacy_files() as the
dynamic creation is no longer needed.  Remove the __weak
pci_adjust_legacy_attr(), Alpha's override, and its declaration from both
Alpha and PowerPC asm/pci.h headers.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Link: https://patch.msgid.link/20260508043543.217179-23-kwilczynski@kernel.org
2026-06-23 15:19:09 -05:00
Ilpo Järvinen
79a648209d PCI: Make pci_sriov_resource_alignment() pci_dev const
pci_sriov_resource_alignment() inputs struct pci_dev which it should not
need to alter to calculate alignment.

Make pci_dev pci_sriov_resource_alignment() inputs const. It requires
making pci_iov_resource_size() input const as well.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260429122617.7324-8-ilpo.jarvinen@linux.intel.com
2026-06-23 12:08:51 -05:00
Linus Torvalds
1a3746ccbb strncpy removal for v7.2-rc1
- Remove the per-arch strncpy implementations in alpha, m68k, powerpc,
   x86, and xtensa
 
 - Remove strncpy API
 
 Over the last 6 years working on strncpy removal there were 362 commits
 by 70 contributors. Folks with more than 1 commit were:
 
     211  Justin Stitt <justinstitt@google.com>
      22  Xu Panda <xu.panda@zte.com.cn>
      21  Kees Cook <kees@kernel.org>
      17  Thorsten Blum <thorsten.blum@linux.dev>
      12  Arnd Bergmann <arnd@arndb.de>
       4  Pranav Tyagi <pranav.tyagi03@gmail.com>
       4  Lee Jones <lee@kernel.org>
       2  Steven Rostedt <rostedt@goodmis.org>
       2  Sam Ravnborg <sam@ravnborg.org>
       2  Marcelo Moreira <marcelomoreira1905@gmail.com>
       2  Krzysztof Kozlowski <krzk@kernel.org>
       2  Kalle Valo <kvalo@kernel.org>
       2  Jaroslav Kysela <perex@perex.cz>
       2  Daniel Thompson <danielt@kernel.org>
       2  Andrew Lunn <andrew@lunn.ch>
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Merge tag 'strncpy-removal-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull strncpy removal from Kees Cook:

 - Remove the per-arch strncpy implementations in alpha, m68k, powerpc,
   x86, and xtensa

 - Remove strncpy API

   Over the last 6 years working on strncpy removal there were 362
   commits by 70 contributors. Folks with more than 1 commit were:

    211  Justin Stitt <justinstitt@google.com>
     22  Xu Panda <xu.panda@zte.com.cn>
     21  Kees Cook <kees@kernel.org>
     17  Thorsten Blum <thorsten.blum@linux.dev>
     12  Arnd Bergmann <arnd@arndb.de>
      4  Pranav Tyagi <pranav.tyagi03@gmail.com>
      4  Lee Jones <lee@kernel.org>
      2  Steven Rostedt <rostedt@goodmis.org>
      2  Sam Ravnborg <sam@ravnborg.org>
      2  Marcelo Moreira <marcelomoreira1905@gmail.com>
      2  Krzysztof Kozlowski <krzk@kernel.org>
      2  Kalle Valo <kvalo@kernel.org>
      2  Jaroslav Kysela <perex@perex.cz>
      2  Daniel Thompson <danielt@kernel.org>
      2  Andrew Lunn <andrew@lunn.ch>

* tag 'strncpy-removal-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  string: Remove strncpy() from the kernel
  xtensa: Remove arch-specific strncpy() implementation
  x86: Remove arch-specific strncpy() implementation
  powerpc: Remove arch-specific strncpy() implementation
  m68k: Remove arch-specific strncpy() implementation
  alpha: Remove arch-specific strncpy() implementation
2026-06-19 14:56:45 -07:00
Linus Torvalds
91981f96d2 powerpc updates for 7.2
- Enable GENERIC_ENTRY feature
 
  - Add missing property in DTS for mpc83xx platform
 
  - Enable building of DTB based on platfrom Kconfig
 
  - Add powerpc64 JIT support for timed may_goto
 
  - Add timeout to RTAS busy-wait loops
 
  - Simplify cpumask api usage for cpuinfo display
 
  - implement get_direction() in cpm1 (8xx platform)
 
  - MAINTAINERS file update for power VMX AES entries
 
  - Fixes to handle preempt count
 
  - Restore KUAP registers on syscall restart exit
 
  - define MIN_RMA in bytes rather than MB
 
  - misc fixes and cleanups
 
 Thanks to:
 Aboorva Devarajan, Adriano Vero, Amit Machhiwal, Anushree Mathur, Bartosz
 Golaszewski, Christophe Leroy (CS GROUP), David Gow, Jinjie Ruan, J.
 Neuschäfer, Linus Walleij, Mahesh Salgaonkar, Mukesh Kumar Chaurasiya (IBM),
 Ritesh Harjani (IBM), Saket Kumar Bhaskar, Samir M, Sayali Patil, Shirisha G,
 Shivang Upadhyay, Shrikanth Hegde, Sourabh Jain, Thorsten Blum, Venkat Rao
 Bagalkote, Yury Norov,
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Merge tag 'powerpc-7.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Madhavan Srinivasan:

 - Enable GENERIC_ENTRY feature

 - Add missing property in DTS for mpc83xx platform

 - Enable building of DTB based on platfrom Kconfig

 - Add powerpc64 JIT support for timed may_goto

 - Add timeout to RTAS busy-wait loops

 - Simplify cpumask api usage for cpuinfo display

 - implement get_direction() in cpm1 (8xx platform)

 - MAINTAINERS file update for power VMX AES entries

 - Fixes to handle preempt count

 - Restore KUAP registers on syscall restart exit

 - define MIN_RMA in bytes rather than MB

 - misc fixes and cleanups

Thanks to Aboorva Devarajan, Adriano Vero, Amit Machhiwal, Anushree
Mathur, Bartosz Golaszewski, Christophe Leroy (CS GROUP), David Gow,
Jinjie Ruan, J. Neuschäfer, Linus Walleij, Mahesh Salgaonkar, Mukesh
Kumar Chaurasiya (IBM), Ritesh Harjani (IBM), Saket Kumar Bhaskar,
Samir M, Sayali Patil, Shirisha G, Shivang Upadhyay, Shrikanth Hegde,
Sourabh Jain, Thorsten Blum, Venkat Rao Bagalkote, and Yury Norov.

* tag 'powerpc-7.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (32 commits)
  powerpc/fadump: define MIN_RMA in bytes rather than MB
  powerpc: Restore KUAP registers on syscall restart exit
  powerpc/kexec: fix double get_cpu() imbalance in kexec_prepare_cpus
  powerpc/powernv: fix preempt count leak in pnv_kexec_wait_secondaries_down
  powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del
  powerpc/boot: Allow text relocations for pseries wrapper with binutils 2.46+
  powerpc: Simplify access_ok()
  powerpc/entry: Disable interrupts before irqentry_exit
  powerpc/8xx: implement get_direction() in cpm1
  powerpc/pseries/lparcfg: Replace deprecated strcpy in parse_system_parameter_string
  powerpc: Fix indentation and replace typedef with struct name
  powerpc/rtas: Replace one-element array with flexible array member
  powerpc: use sysfs_emit{_at} in sysfs show functions
  MAINTAINERS: powerpc: update VMX AES entries
  ppc/fadump: invoke kmsg_dump in fadump panic path
  powerpc/xive: Add warning if target CPU not found
  powerpc/perf: Use cpumask_intersects api for checking disable path
  powerpc: Simplify cpumask api usage for cpuinfo display
  powerpc: Use cpumask_next_wrap instead
  powerpc/fadump: Add timeout to RTAS busy-wait loops
  ...
2026-06-19 07:37:52 -07:00
Kees Cook
7eda356658 powerpc: Remove arch-specific strncpy() implementation
strncpy() has no remaining callers in the kernel[1]. Remove the
powerpc-specific assembly implementation from both the kernel
(arch/powerpc/lib/string.S) and the boot wrapper
(arch/powerpc/boot/string.S), along with the __HAVE_ARCH_STRNCPY
define and declaration, falling back to the generic version in
lib/string.c.

The boot wrapper's strncpy had no callers in arch/powerpc/boot/.

Link: https://github.com/KSPP/linux/issues/90 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
2026-06-18 16:37:13 -07:00
Sayali Patil
42f252f5a6 powerpc/fadump: define MIN_RMA in bytes rather than MB
The MIN_RMA size checks in fadump_setup_param_area() use
(MIN_RMA * 1024 * 1024), which is evaluated in int and can
overflow when MIN_RMA is increased to values such as SZ_2G,
triggering compiler warnings such as:

warning: integer overflow in expression of type 'int'
results in '0' [-Woverflow]

Define MIN_RMA directly in bytes using SZ_1M and update the
callers accordingly. This avoids repeated unit conversions and
prevents integer overflow.

Also convert MIN_RMA back to MB when populating the firmware
architecture vector, since firmware expects the value in MB.

Suggested-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/310b040acef712fdc79e3e37d0f4c2213938b556.1781589284.git.sayalip@linux.ibm.com
2026-06-16 15:08:25 +05:30
Linus Torvalds
bd77e50c9a fbdev fixes & cleanups for 7.2-rc1:
Removal of drivers:
 - Hercules monochrome ISA graphics adapter driver [Ethan Nelson-Moore]
 - Hercules mdacon console driver [Ethan Nelson-Moore]
 
 Changes affecting many drivers at once:
 - possible memory leak fixes in various drivers [Abdun Nihaal]
 - many conversions to use strscpy() [David Laight]
 - Use named initializers in drivers [Uwe Kleine-König]
 
 Code fixes:
 - fbcon: don't suspend/resume when vc is graphics mode [Lu Yao]
 - modedb: fix a possible UAF in fb_find_mode() [Tuo Li]
 - modedb: Fix entry for 1920x1080-60 mode [Steffen Persvold]
 - arm: Export acorndata_8x8 font symbol for bootloader [Helge Deller]
 - omap2: fix use-after-free in omapfb_mmap [Hongling Zeng]
 
 Cleanups:
 - pxa168fb: use devm_ioremap_resource() [AlbertoArostegui]
 - provice helpers for fb_set_var() and fb_blank() and fbcon updates [Thomas Zimmermann]
 - fbcon: Use correct type for vc_resize() return value [Jiacheng Yu]
 - chipsfb: add missing MODULE_DESCRIPTION() macro [Rahman Mahmutović]
 - sunxvr2500: replace printk with device-aware logging functions [Rahman Mahmutović]
 - sm712: Fix operator precedence in big_swap macro [Li RongQing]
 - imxfb: Use of_device_get_match_data() [Rosen Penev]
 - atmel_lcdfb: Use of_device_get_match_data() [Rosen Penev]
 
 Documentation fixes:
 - grvga: Fix CLUT register address offset in comment [Eduardo Silva]
 - omap/dss: Fix stale modedb.c path [Costa Shulyupin]
 - correct CONFIG_FB_TILEBLITTING macro name in #endif comment [Ethan Nelson-Moore]
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Merge tag 'fbdev-for-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev

Pull fbdev updates from Helge Deller:
 "Beside the removal of the Hercules monochrome ISA graphics driver and
  the corresponding text console driver, there is just the typical
  maintanance with smaller driver fixes and cleanups:

  Removal of drivers:
   - Hercules monochrome ISA graphics adapter driver (Ethan Nelson-Moore)
   - Hercules mdacon console driver (Ethan Nelson-Moore)

  Changes affecting many drivers at once:
   - possible memory leak fixes in various drivers (Abdun Nihaal)
   - many conversions to use strscpy() (David Laight)
   - Use named initializers in drivers (Uwe Kleine-König)

  Code fixes:
   - fbcon: don't suspend/resume when vc is graphics mode (Lu Yao)
   - modedb: fix a possible UAF in fb_find_mode() (Tuo Li)
   - modedb: Fix entry for 1920x1080-60 mode (Steffen Persvold)
   - arm: Export acorndata_8x8 font symbol for bootloader (Helge Deller)
   - omap2: fix use-after-free in omapfb_mmap (Hongling Zeng)

  Cleanups:
   - pxa168fb: use devm_ioremap_resource() (Alberto Arostegui)
   - provice helpers for fb_set_var() and fb_blank() and fbcon updates
     (Thomas Zimmermann)
   - fbcon: Use correct type for vc_resize() return value (Jiacheng Yu)
   - chipsfb: add missing MODULE_DESCRIPTION() macro (Rahman Mahmutović)
   - sunxvr2500: replace printk with device-aware logging functions
     (Rahman Mahmutović)
   - sm712: Fix operator precedence in big_swap macro (Li RongQing)
   - imxfb: Use of_device_get_match_data() (Rosen Penev)
   - atmel_lcdfb: Use of_device_get_match_data() (Rosen Penev)

  Documentation fixes:
   - grvga: Fix CLUT register address offset in comment (Eduardo Silva)
   - omap/dss: Fix stale modedb.c path (Costa Shulyupin)
   - correct CONFIG_FB_TILEBLITTING macro name in #endif comment (Ethan
     Nelson-Moore)"

* tag 'fbdev-for-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: (43 commits)
  fbdev: modedb: Fix misaligned fields in the 1920x1080-60 mode
  fbdev: modedb: fix a possible UAF in fb_find_mode()
  fbdev: s3fb: Use strscpy() to copy strings into arrays
  fbdev: sm501fb: Fix buffer errors in OF binding code
  fbcon: correct CONFIG_FB_TILEBLITTING macro name in #endif comment
  fbdev/arm: Export acorndata_8x8 font symbol for bootloader
  fbdev: mmpfb: Use strscpy() to copy device name
  fbdev: sisfb: Replace strlen() strcpy() pair with strscpy()
  fbdev: rivafb: Use strscpy() to copy device name
  fbdev: cyber2000fb: Use strscpy() to copy device name
  fbdev: atmel_lcdfb: Use strscpy() to copy device name
  fbdev: Do not export fbcon from fbdev
  fbdev: Wrap fbcon updates from vga-switcheroo in helper
  fbdev: Wrap user-invoked calls to fb_blank() in helper
  fbdev: Wrap user-invoked calls to fb_set_var() in helper
  fbdev: omap2: fix use-after-free in omapfb_mmap
  docs: omap/dss: Fix stale modedb.c path
  fbdev: pxa168fb: use devm_ioremap_resource() for MMIO
  fbdev: grvga: Fix CLUT register address offset in comment
  fbdev: sunxvr2500: replace printk with device-aware logging functions
  ...
2026-06-16 08:28:41 +05:30
Linus Torvalds
2cbf335f8c Scheduler updates for v7.2:
SMP load-balancing updates:
 
  - A large series to introduce infrastructure for cache-aware load
    balancing, with the goal of co-locating tasks that share data
    within the same Last Level Cache (LLC) domain. By improving cache
    locality, the scheduler can reduce cache bouncing and cache misses,
    ultimately improving data access efficiency.
 
    Implemented by Chen Yu and Tim Chen, based on early prototype work
    by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and
    Shrikanth Hegde.
 
  - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde)
 
 Fair scheduler updates:
 
  - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing
    SMT awareness (Andrea Righi, K Prateek Nayak)
 
  - A series to optimize cfs_rq and sched_entity allocation for
    better data locality (Zecheng Li)
 
  - A preparatory series to change fair/cgroup scheduling to a single
    runqueue, without the final change (Peter Zijlstra)
 
  - Auto-manage ext/fair dl_server bandwidth (Andrea Righi)
 
  - Fix cpu_util runnable_avg arithmetic (Hongyan Xia)
 
  - Optimize update_tg_load_avg()'s rate-limiting code
    (Rik van Riel)
 
  - Allow account_cfs_rq_runtime() to throttle current hierarchy
    (K Prateek Nayak)
 
  - Update util_est after updating util_avg during dequeue, to fix
    the util signal update logic, which reduces signal noise
    (Vincent Guittot)
 
 Scheduler topology updates:
 
  - Allow multiple domains to claim sched_domain_shared (K Prateek Nayak)
 
  - Add parameter to split LLC (Peter Zijlstra)
 
 Core scheduler updates:
 
  - Use trace_call__<tp>() to save a static branch (Gabriele Monaco)
 
 Scheduler statistics updates:
 
  - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation guard
    (Nicolas Pitre)
 
 Deadline scheduler updates:
 
  - Reject debugfs dl_server writes for offline CPUs (Andrea Righi)
 
  - Fix replenishment logic for non-deferred servers
    (Yuri Andriaccio)
 
 RT scheduling updates:
 
  - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt)
 
  - Update default bandwidth for real-time tasks to 1.0
    (Yuri Andriaccio)
 
 Proxy scheduling updates:
 
  - A series to implement Optimized Donor Migration for Proxy Execution
    (John Stultz, Peter Zijlstra)
 
  - Various proxy scheduling cleanups and fixes
    (Peter Zijlstra, K Prateek Nayak)
 
 Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi,
 Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde,
 Peter Zijlstra, Liang Luo and Yiyang Chen.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "SMP load-balancing updates:

   - A large series to introduce infrastructure for cache-aware load
     balancing, with the goal of co-locating tasks that share data
     within the same Last Level Cache (LLC) domain. By improving cache
     locality, the scheduler can reduce cache bouncing and cache misses,
     ultimately improving data access efficiency.

     Implemented by Chen Yu and Tim Chen, based on early prototype work
     by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and
     Shrikanth Hegde.

   - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde)

  Fair scheduler updates:

   - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing
     SMT awareness (Andrea Righi, K Prateek Nayak)

   - A series to optimize cfs_rq and sched_entity allocation for better
     data locality (Zecheng Li)

   - A preparatory series to change fair/cgroup scheduling to a single
     runqueue, without the final change (Peter Zijlstra)

   - Auto-manage ext/fair dl_server bandwidth (Andrea Righi)

   - Fix cpu_util runnable_avg arithmetic (Hongyan Xia)

   - Optimize update_tg_load_avg()'s rate-limiting code (Rik van Riel)

   - Allow account_cfs_rq_runtime() to throttle current hierarchy
     (K Prateek Nayak)

   - Update util_est after updating util_avg during dequeue, to fix the
     util signal update logic, which reduces signal noise (Vincent
     Guittot)

  Scheduler topology updates:

   - Allow multiple domains to claim sched_domain_shared (K Prateek
     Nayak)

   - Add parameter to split LLC (Peter Zijlstra)

  Core scheduler updates:

   - Use trace_call__<tp>() to save a static branch (Gabriele Monaco)

  Scheduler statistics updates:

   - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation
     guard (Nicolas Pitre)

  Deadline scheduler updates:

   - Reject debugfs dl_server writes for offline CPUs (Andrea Righi)

   - Fix replenishment logic for non-deferred servers (Yuri Andriaccio)

  RT scheduling updates:

   - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt)

   - Update default bandwidth for real-time tasks to 1.0 (Yuri
     Andriaccio)

  Proxy scheduling updates:

   - A series to implement Optimized Donor Migration for Proxy Execution
     (John Stultz, Peter Zijlstra)

   - Various proxy scheduling cleanups and fixes (Peter Zijlstra,
     K Prateek Nayak)

  Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi,
  Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde,
  Peter Zijlstra, Liang Luo and Yiyang Chen"

* tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (91 commits)
  sched/fair: Fix newidle vs core-sched
  sched/deadline: Use task_on_rq_migrating() helper
  sched/core: Combine separate 'else' and 'if' statements
  sched/fair: Fix cpu_util runnable_avg arithmetic
  sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime()
  sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up()
  sched/fair: Call update_curr() before unthrottling the hierarchy
  sched/fair: Use throttled_csd_list for local unthrottle
  sched/fair: Convert cfs bandwidth throttling to use guards
  sched/fair: Allocate cfs_tg_state with percpu allocator
  sched/fair: Remove task_group->se pointer array
  sched/fair: Co-locate cfs_rq and sched_entity in cfs_tg_state
  sched: restore timer_slack_ns when resetting RT policy on fork
  MAINTAINERS: Fix spelling mistake in Peter's name
  sched: Simplify ttwu_runnable()
  sched/proxy: Remove superfluous clear_task_blocked_in()
  sched/proxy: Remove PROXY_WAKING
  sched/proxy: Switch proxy to use p->is_blocked
  sched/proxy: Only return migrate when needed
  sched: Be more strict about p->is_blocked
  ...
2026-06-15 14:50:18 +05:30
Linus Torvalds
7e0e7bd60d vfs-7.2-rc1.misc
Please consider pulling these changes from the signed vfs-7.2-rc1.misc tag.
 
 Thanks!
 Christian
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Merge tag 'vfs-7.2-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Reduce pipe->mutex contention by pre-allocating pages outside the
     lock in anon_pipe_write().

     anon_pipe_write() called alloc_page() once per page while holding
     pipe->mutex. The allocation can sleep doing direct reclaim and runs
     memcg charging, which extends the critical section and stalls any
     concurrent reader on the same mutex. Now up to 8 pages are
     pre-allocated before the mutex is taken, leftovers are recycled
     into the per-pipe tmp_page[] cache before unlock, and any remainder
     is released after unlock, keeping the allocator out of the critical
     section on both sides. On a writers x readers sweep with 64KB
     writes against a 1 MB pipe throughput improves 6-28% and average
     write latency drops 5-22%; under memory pressure - when the cost of
     holding the mutex across reclaim is highest - throughput improves
     21-48% and latency drops 17-33%. The microbenchmark is added to
     selftests.

   - uaccess/sockptr: fix the ignored_trailing logic in
     copy_struct_to_user() to behave as documented and the usize check
     in copy_struct_from_sockptr() for user pointers, and add
     copy_struct_{from,to}_bounce_buffer() and copy_struct_to_sockptr()
     helpers for upcoming users (IPPROTO_SMBDIRECT, IPPROTO_QUIC).

   - bpf: add a sleepable bpf_real_inode() kfunc that resolves the real
     inode backing a dentry via d_real_inode(). On overlayfs the inode
     attached to the dentry doesn't carry the underlying device
     information; this is used by the filesystem restriction BPF program
     that was merged into systemd.

   - docs: add guidelines for submitting new filesystems, motivated by
     the maintenance burden abandoned and untestable filesystems impose
     on VFS developers, blocking infrastructure work like folio
     conversions and iomap migration.

  Fixes:

   - libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
     and drop the now-redundant assignments in callers. This began as a
     one-line dma-buf fix for a path_noexec() warning; a pseudo
     filesystem has no reason not to set SB_I_NOEXEC. All init_pseudo()
     callers were audited: the only visible effect is on dma-buf where
     SB_I_NOEXEC silences the warning.

   - Handle set_blocksize() failures in legacy filesystems (bfs, hpfs,
     qnx4, jfs, befs, affs, isofs, minix, ntfs3, omfs). Mounting a
     device with a sector size > PAGE_SIZE crashed roughly half of them;
     the rest had the same missing error handling pattern. Plus a
     follow-up releasing the superblock buffer_head when setting the
     minix v3 block size fails.

   - mount: honour SB_NOUSER in the new mount API.

   - fs/fcntl: fix a SOFTIRQ-unsafe lock order in fasync signaling by
     switching the process-group paths of send_sigio() and send_sigurg()
     from read_lock(&tasklist_lock) to RCU, matching the single-PID
     path.

   - vfs: add an FS_USERNS_DELEGATABLE flag and set it for NFS, fixing
     delegated NFS mounts (fsopen() in a container with the mount
     performed by a privileged daemon) that broke when non-init
     s_user_ns was tied to FS_USERNS_MOUNT.

   - selftests/namespaces: fix a hang in nsid_test where an unreaped
     grandchild kept the TAP pipe write-end open, a waitpid(-1) race in
     listns_efault_test, and a false FAIL on kernels without listns()
     where the tests should SKIP.

   - filelock: fix the break_lease() stub signature for
     CONFIG_FILE_LOCKING=n.

   - init/initramfs_test: wait for the async initramfs unpacking before
     running; the test and do_populate_rootfs() share the parser state.

   - fs/coredump: reduce redundant log noise in
     validate_coredump_safety().

   - iomap: pass the correct length to fserror_report_io() in
     __iomap_write_begin().

   - backing-file: fix the backing_file_open() kerneldoc.

  Cleanups:

   - initramfs: refactor the cpio hex header parsing to use hex2bin()
     instead of the hand-rolled simple_strntoul() which is reverted, and
     extend the initramfs KUnit tests to cover header fields with 0x
     prefixes.

   - Replace __get_free_pages() and friends with kmalloc()/kzalloc()
     across quota, proc, ocfs2/dlm, nilfs2, nfs, nfsd, libfs, jfs, jbd2,
     isofs, fuse, select, namespace, configfs, binfmt_misc, bfs, and the
     do_mounts init code - part of the larger work of replacing page
     allocator calls with kmalloc().

   - Use clear_and_wake_up_bit() in unlock_buffer() and
     journal_end_buffer_io_sync() instead of open-coding the sequence.

   - Drop unused VFS exports: unexport drop_super_exclusive(), remove
     start_removing_user_path_at(), and fold __start_removing_path()
     into start_removing_path().

   - fs/read_write: narrow the __kernel_write() export with
     EXPORT_SYMBOL_FOR_MODULES().

   - vfs: uapi: retire octal and hex constants in favor of (1 << n) for
     the O_ flags. Finding a free bit for a new flag across the
     architectures was needlessly hard with the mixed bases.

   - dcache: add extra sanity checks of dead dentries in dentry_free()
     via a new DENTRY_WARN_ONCE() that also prints d_flags.

   - iov_iter: use kmemdup_array() in dup_iter() to harden the
     allocation against multiplication overflow.

   - fs/pipe: write to ->poll_usage only once.

   - vfs: remove an always-taken if-branch in find_next_fd().

   - dcache: use kmalloc_flex() for struct external_name in __d_alloc().

   - namei: use QSTR() instead of QSTR_INIT() in path_pts().

   - sync_file_range: delete dead S_ISLNK code.

   - Comment fixes: retire a stale comment in fget_task_next() and fix
     assorted spelling mistakes"

* tag 'vfs-7.2-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (73 commits)
  backing-file: fix backing_file_open() kerneldoc parameter
  iomap: pass the correct len to fserror_report_io in __iomap_write_begin
  vfs: add FS_USERNS_DELEGATABLE flag and set it for NFS
  filelock: fix break_lease() stub signature for CONFIG_FILE_LOCKING=n
  vfs: uapi: retire octal and hex numbers in favor of (1 << n) for O_ flags
  bpf: add bpf_real_inode() kfunc
  fs/read_write: Do not export __kernel_write() to the entire world
  libfs: drop redundant SB_I_NOEXEC/SB_I_NODEV in init_pseudo() callers
  libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
  mount: honour SB_NOUSER in the new mount API
  fs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling
  selftests/pipe: add pipe_bench microbenchmark
  fs/pipe: pre-allocate pages outside pipe->mutex in anon_pipe_write
  fs: retire stale comment in fget_task_next()
  fs: fix spelling mistakes in comment
  bfs: replace get_zeroed_page() with kzalloc()
  binfmt_misc: replace __get_free_page() with kmalloc()
  configfs: replace __get_free_pages() with kzalloc()
  fs/namespace: use __getname() to allocate mntpath buffer
  fs/select: replace __get_free_page() with kmalloc()
  ...
2026-06-15 03:59:45 +05:30
Christophe Leroy (CS GROUP)
90b45dbf59 powerpc: Simplify access_ok()
With the implementation of masked user access, we always have a memory
gap between user memory space and kernel memory space, so use it to
simplify access_ok() by relying on access fault in case of an access
in the gap.

Most of the time the size is known at build time.

On powerpc64, the kernel space starts at 0x8000000000000000 which is
always more than two times TASK_USER_MAX so when the size is known at
build time and lower than TASK_USER_MAX, only the address needs to be
verified. If not, a binary or of address and size must be lower than
TASK_USER_MAX. As TASK_USER_MAX is a power of 2, just check that
there is no bit set outside of TASK_USER_MAX - 1 mask.

On powerpc32, there is a garanteed gap of 128KB so when the size is
known at build time and not greater than 128KB, just check that the
address is below TASK_SIZE. Otherwise use the original formula.

Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/f496ba4f309a2fb9fd0d8811e941bbcaf5d196cf.1780482002.git.chleroy@kernel.org
2026-06-08 15:59:02 +05:30
Shrikanth Hegde
334f3f6d7a powerpc/entry: Disable interrupts before irqentry_exit
Venkat reported a panic on powerpc-next tree where GENERIC_ENTRY has
been enabled.

kernel BUG at kernel/sched/core.c:7512!
NIP  preempt_schedule_irq+0x44/0x118
LR   dynamic_irqentry_exit_cond_resched+0x40/0x1a4
Call Trace:
 dynamic_irqentry_exit_cond_resched+0x40/0x1a4
 do_page_fault+0xc0/0x104
 data_access_common_virt+0x210/0x220

This happens since __do_page_fault ends up enabling the interrupts and
it could take significant time such that need_resched could be set. This
leads to schedule call in irqentry_exit leading to the bug.

There are many such irq handlers which enables the interrupts.
Fix it by disabling the irq before calling irqentry_exit. The same
pattern exists today in interrupt_exit_kernel_prepare.

Fixes: bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/7904105b-9dfa-4efd-a5ef-bc0276ed255d@linux.ibm.com/
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260603131054.216235-1-sshegde@linux.ibm.com
2026-06-08 15:58:03 +05:30
Jori Koolstra
0da79c259a
vfs: uapi: retire octal and hex numbers in favor of (1 << n) for O_ flags
A recent build failure[1] exposed the diffculty of working with the
current octal and hex definitions of O_ flags when trying to find a gap
for a new flag. This difficulty is compounded by the fact that O_ flags
may have architectural specific values.

Replace the hex/octal #defines, which are hard to parse when looking for
free bits, with explicit bit shifts like (1 << 11). Also, add comments
that identify which architectures redefine some of the seemingly free
("cursed") bits in uapi/asm-generic/fcntl.h. These should not be used to
define new O_ flags (for now, at least).

The translastion was done with Claude Opus 4.8, and verified with a
(non-AI) gawk script. The accounting of which architectures claim
which bit-gaps in uapi/asm-generic/fcntl.h is also done by hand.

[1]: https://lore.kernel.org/all/agruPPybCx8q2XcJ@sirena.org.uk/

Assisted-by: Claude:Opus 4.8
Signed-off-by: Jori Koolstra <jkoolstra@xs4all.nl>
Link: https://patch.msgid.link/20260604222405.5382-1-jkoolstra@xs4all.nl
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-06 15:34:03 +02:00
Thorsten Blum
ab8bbf8024 powerpc/rtas: Replace one-element array with flexible array member
Replace the deprecated one-element array with a modern flexible array
member in the struct rtas_error_log and add the __counted_by_be()
compiler attribute to improve access bounds-checking via
CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE.

Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250813103101.163698-2-thorsten.blum@linux.dev
2026-06-02 11:24:32 +05:30
Shrikanth Hegde
1eae219ea0 sched/topology: Provide arch_llc_mask for cache aware scheduling
Venkat Reported a boot kernel panic next-20260522. Git bisect pointed to
b5ea300a17 ("sched/cache: Make LLC id continuous")

Stacktrace points to llc_mask being null.

  NIP [c000000000e58504] _find_first_bit+0x44/0x130
  LR [c000000000e58500] _find_first_bit+0x40/0x130
  Call Trace:
  build_sched_domains+0xad8/0xe50
  sched_init_smp+0xa8/0x164
  kernel_init_freeable+0x250/0x370
  ret_from_kernel_user_thread+0x14/0x1c

On powerpc, cpu_coregroup_mask is available only when the underlying
hardware support coregroup. In shared LPAR, QEMU guest or power9 etc
coregroup isn't supported. In such cases llc_mask was being referenced
when it was null leading to panic.

On powerpc, LLC is at SMT core level. So assumption that coregroup(MC)
domain point to LLC is wrong. Provide a way for archs to say where its
LLC is if it not at MC domain.

Fixes: b5ea300a17 ("sched/cache: Make LLC id continuous")
Closes: https://lore.kernel.org/all/51154de7-3700-4cb4-82f2-1b3a8fa427f7@linux.ibm.com/
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Co-developed-by: Chen, Yu C <yu.c.chen@intel.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chen Yu <yu.c.chen@intel.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Tested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/20260529075712.1181039-1-sshegde@linux.ibm.com
2026-05-29 12:43:15 +02:00
Masami Hiramatsu (Google)
a494d3c8d5 ring-buffer: Flush and stop persistent ring buffer on panic
On real hardware, panic and machine reboot may not flush hardware cache
to memory. This means the persistent ring buffer, which relies on a
coherent state of memory, may not have its events written to the buffer
and they may be lost. Moreover, there may be inconsistency with the
counters which are used for validation of the integrity of the
persistent ring buffer which may cause all data to be discarded.

To avoid this issue, stop recording of the ring buffer on panic and
flush the cache of the ring buffer's memory.

Fixes: e645535a95 ("tracing: Add option to use memmapped memory for trace boot instance")
Cc: stable@vger.kernel.org
Cc: Will Deacon <will@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ian Rogers <irogers@google.com>
Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-21 08:20:58 -04:00
Ethan Nelson-Moore
e38b27199e console: mdacon: remove this obsolete driver
The mdacon driver supports using ISA MDA or Hercules-compatible display
adapters as a secondary text console. This was commonly used in the
1990s and earlier for debugging software which took over the primary
display. It is highly unlikely anyone is doing so nowadays because
serial consoles and much better methods of debugging exist.

The driver is not enabled by any defconfig, nor any of the
dozens of distro configs collected at [1]. It has been relegated to VTs
13-16 since commit 0b9cf3aa6b ("mdacon messing up default vc's - set
default to vc13-16 again") in Linux 2.6.27 (and before Linux 2.5.53 -
see the link in the message of the above commit). The change in 2.6.27
was done because it was incorrectly detecting non-MDA adapters as MDA
and taking over all VTs, rendering them unusable.

Furthermore, vgacon supports using MDA/Hercules-compatible adapters as
the primary text console, so any systems with only one of these
adapters were already using vgacon and will not experience any loss in
functionality from the removal of this driver.

Given all of these factors, the mdacon driver is likely entirely
unused. Remove it.

[1] f0bee86a13

Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
2026-05-20 20:23:32 +02:00
Mukesh Kumar Chaurasiya
6ed60999d3 powerpc: Remove unused functions
After enabling GENERIC_ENTRY some functions are left unused.
Cleanup all those functions which includes:
 - do_syscall_trace_enter
 - do_syscall_trace_leave
 - do_notify_resume
 - do_seccomp

Signed-off-by: Mukesh Kumar Chaurasiya <mkchauras@linux.ibm.com>
Tested-by: Samir M <samir@linux.ibm.com>
Tested-by: David Gow <davidgow@google.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260427122742.210074-9-mkchauras@gmail.com
2026-05-20 06:57:14 +05:30
Mukesh Kumar Chaurasiya
bee25f97ad powerpc: Enable GENERIC_ENTRY feature
Enable the generic IRQ entry/exit infrastructure on PowerPC by selecting
GENERIC_ENTRY and integrating the architecture-specific interrupt and
syscall handlers with the generic entry/exit APIs.

This change replaces PowerPC’s local interrupt entry/exit handling with
calls to the generic irqentry_* helpers, aligning the architecture with
the common kernel entry model. The macros that define interrupt, async,
and NMI handlers are updated to use irqentry_enter()/irqentry_exit()
and irqentry_nmi_enter()/irqentry_nmi_exit() where applicable also
convert the PowerPC syscall entry and exit paths to use the generic
entry/exit framework and integrating with the common syscall handling
routines.

Key updates include:
 - The architecture now selects GENERIC_ENTRY in Kconfig.
 - Replace interrupt_enter/exit_prepare() with arch_interrupt_* helpers.
 - Integrate irqentry_enter()/exit() in standard and async interrupt paths.
 - Integrate irqentry_nmi_enter()/exit() in NMI handlers.
 - Remove redundant irq_enter()/irq_exit() calls now handled generically.
 - Use irqentry_exit_cond_resched() for preemption checks.
 - interrupt.c and syscall.c are simplified to delegate context
   management and user exit handling to the generic entry path.
 - The new pt_regs field `exit_flags` introduced earlier is now used
   to carry per-syscall exit state flags (e.g. _TIF_RESTOREALL).
 - Remove unused code.

This change establishes the necessary wiring for PowerPC to use the
generic IRQ entry/exit framework while maintaining existing semantics.
This aligns PowerPC with the common entry code used by other
architectures and reduces duplicated logic around syscall tracing,
context tracking, and signal handling.

The performance benchmarks from perf bench basic syscall are below:

perf bench syscall usec/op (-ve is improvement)

| Syscall | Base        | test        | change % |
| ------- | ----------- | ----------- | -------- |
| basic   | 0.093543    | 0.093023    | -0.56    |
| execve  | 446.557781  | 450.107172  | +0.79    |
| fork    | 1142.204391 | 1156.377214 | +1.24    |
| getpgid | 0.097666    | 0.092677    | -5.11    |

perf bench syscall ops/sec (+ve is improvement)

| Syscall | Base     | New      | change % |
| ------- | -------- | -------- | -------- |
| basic   | 10690548 | 10750140 | +0.56    |
| execve  | 2239     | 2221     | -0.80    |
| fork    | 875      | 864      | -1.26    |
| getpgid | 10239026 | 10790324 | +5.38    |

IPI latency benchmark (-ve is improvement)

| Metric         | Base (ns)     | New (ns)      | % Change |
| -------------- | ------------- | ------------- | -------- |
| Dry run        | 583136.56     | 584136.35     | 0.17%    |
| Self IPI       | 4167393.42    | 4149093.90    | -0.44%   |
| Normal IPI     | 61769347.82   | 61753728.39   | -0.03%   |
| Broadcast IPI  | 2235584825.02 | 2227521401.45 | -0.36%   |
| Broadcast lock | 2164964433.31 | 2125658641.76 | -1.82%   |

Thats very close to performance earlier with arch specific handling.

Signed-off-by: Mukesh Kumar Chaurasiya <mkchauras@linux.ibm.com>
Tested-by: Samir M <samir@linux.ibm.com>
Tested-by: David Gow <davidgow@google.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260427122742.210074-8-mkchauras@gmail.com
2026-05-20 06:57:14 +05:30