linux-stable.git/arch/arm/include, branch v6.17

ARM: stacktrace: include asm/sections.h in asm/stacktrace.h

2025-08-25T13:12:06+00:00

The recent kstack erase changes appear to have uncovered an existing
issue with a missing header inclusion:

In file included from drivers/misc/lkdtm/kstack_erase.c:12:
In file included from include/linux/kstack_erase.h:16:
arch/arm/include/asm/stacktrace.h:48:21: error: call to undeclared function 'in_entry_text'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
   48 |                 frame->ex_frame = in_entry_text(frame->pc);
      |                                   ^

Include asm/sections.h here so the compiler can see the in_entry_text()
declaration.

Fixes: 752ec621ef5c ("ARM: 9234/1: stacktrace: Avoid duplicate saving of exception PC value")
Cc: Kees Cook 
Signed-off-by: Arnd Bergmann 
Reviewed-by: Linus Walleij 
Link: https://lore.kernel.org/r/20250807071902.4077714-1-arnd@kernel.org
Signed-off-by: Kees Cook

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux

2025-08-05T13:55:03+00:00

Pull ARM update from Russell King:
 "Just one development update this time:

   - Finish removing Coresight support"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
  ARM: 9449/1: coresight: Finish removal of Coresight support in arch/arm/kernel

ARM: 9449/1: coresight: Finish removal of Coresight support in arch/arm/kernel

2025-07-25T14:50:58+00:00

Commit 184901a06a36 ("ARM: removing support for etb/etm in
"arch/arm/kernel/"") removed asm/hardware/coresight.h which is included
by this file. Therefore this is dead code so delete it.

Acked-by: Suzuki K Poulose 
Signed-off-by: James Clark 
Signed-off-by: Russell King (Oracle)

mm: pgtable: fix pte_swp_exclusive

2025-06-11T21:52:08+00:00

Make pte_swp_exclusive return bool instead of int.  This will better
reflect how pte_swp_exclusive is actually used in the code.

This fixes swap/swapoff problems on Alpha due pte_swp_exclusive not
returning correct values when _PAGE_SWP_EXCLUSIVE bit resides in upper
32-bits of PTE (like on alpha).

Suggested-by: Al Viro 
Signed-off-by: Magnus Lindholm 
Cc: Sam James 
Link: https://lore.kernel.org/lkml/20250218175735.19882-2-linmag7@gmail.com/
Link: https://lore.kernel.org/lkml/20250602041118.GA2675383@ZenIV/
[ Applied as the 'sed' script Al suggested   - Linus ]
Signed-off-by: Linus Torvalds

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux

2025-06-05T18:33:09+00:00

Pull ARM fixes from Russell King:

 - Fix arch_memremap_can_ram_remap() which incorrectly passed a PFN to
   memblock_is_map_memory rather than the actual address.

 - Disallow kernel mode NEON when IRQs are disabled

   Explanation:

     "To avoid having to preserve/restore kernel mode NEON state when
      such a softirq is taken softirqs are now disabled when using the
      NEON from task context."

   should explain that it's nested kernel mode.

   In other words, softirqs from user mode are fine, because the context
   will be preserved. softirqs from kernel mode may be from a context
   that has already saved the user NEON state, and thus we would need to
   preserve the NEON state for the parent kernel mode context, and this
   we don't allow.

   The problem occurs when the kernel context disables hard IRQs, and
   then uses NEON. When it's finished, and restores the userspace NEON
   state, we call local_bh_enable() with hard IRQs disabled, which
   causes a warning.

   This commit addresses that by disallowing the use of NEON with hard
   IRQs disabled.

	https://lore.kernel.org/all/20250516231858.27899-4-ebiggers@kernel.org/T/#m104841b6e9346b1814c8b0fb9f2340551b0cd3e8

   has some further context

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
  ARM: 9446/1: Disallow kernel mode NEON when IRQs are disabled
  ARM: 9447/1: arm/memremap: fix arch_memremap_can_ram_remap()

Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-05-31T22:44:16+00:00

Pull MM updates from Andrew Morton:

- "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
creating a pte which addresses the first page in a folio and reduces
the amount of plumbing which architecture must implement to provide
this.

- "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
largely unrelated folio infrastructure changes which clean things up
and better prepare us for future work.

- "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
Price adds early-init code to prevent x86 from leaving physical
memory unused when physical address regions are not aligned to memory
block size.

- "mm/compaction: allow more aggressive proactive compaction" from
Michal Clapinski provides some tuning of the (sadly, hard-coded (more
sadly, not auto-tuned)) thresholds for our invokation of proactive
compaction. In a simple test case, the reduction of a guest VM's
memory consumption was dramatic.

- "Minor cleanups and improvements to swap freeing code" from Kemeng
Shi provides some code cleaups and a small efficiency improvement to
this part of our swap handling code.

- "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
adds the ability for a ptracer to modify syscalls arguments. At this
time we can alter only "system call information that are used by
strace system call tampering, namely, syscall number, syscall
arguments, and syscall return value.

This series should have been incorporated into mm.git's "non-MM"
branch, but I goofed.

- "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
against /proc/pid/pagemap. This permits CRIU to more efficiently get
at the info about guard regions.

- "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
implements that fix. No runtime effect is expected because
validate_page_before_insert() happens to fix up this error.

- "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
Hildenbrand basically brings uprobe text poking into the current
decade. Remove a bunch of hand-rolled implementation in favor of
using more current facilities.

- "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
Khandual provides enhancements and generalizations to the pte dumping
code. This might be needed when 128-bit Page Table Descriptors are
enabled for ARM.

- "Always call constructor for kernel page tables" from Kevin Brodsky
ensures that the ctor/dtor is always called for kernel pgtables, as
it already is for user pgtables.

This permits the addition of more functionality such as "insert hooks
to protect page tables". This change does result in various
architectures performing unnecesary work, but this is fixed up where
it is anticipated to occur.

- "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
Ryhl adds plumbing to permit Rust access to core MM structures.

- "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
Stoakes takes advantage of some VMA merging opportunities which we've
been missing for 15 years.

- "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
SeongJae Park optimizes process_madvise()'s TLB flushing.

Instead of flushing each address range in the provided iovec, we
batch the flushing across all the iovec entries. The syscall's cost
was approximately halved with a microbenchmark which was designed to
load this particular operation.

- "Track node vacancy to reduce worst case allocation counts" from
Sidhartha Kumar makes the maple tree smarter about its node
preallocation.

stress-ng mmap performance increased by single-digit percentages and
the amount of unnecessarily preallocated memory was dramaticelly
reduced.

- "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
a few unnecessary things which Baoquan noted when reading the code.

- ""Enhance sysfs handling for memory hotplug in weighted interleave"
from Rakie Kim "enhances the weighted interleave policy in the memory
management subsystem by improving sysfs handling, fixing memory
leaks, and introducing dynamic sysfs updates for memory hotplug
support". Fixes things on error paths which we are unlikely to hit.

- "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
from SeongJae Park introduces new DAMOS quota goal metrics which
eliminate the manual tuning which is required when utilizing DAMON
for memory tiering.

- "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
provides cleanups and small efficiency improvements which Baoquan
found via code inspection.

- "vmscan: enforce mems_effective during demotion" from Gregory Price
changes reclaim to respect cpuset.mems_effective during demotion when
possible. because presently, reclaim explicitly ignores
cpuset.mems_effective when demoting, which may cause the cpuset
settings to violated.

This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently.

- "Clean up split_huge_pmd_locked() and remove unnecessary folio
pointers" from Gavin Guo provides minor cleanups and efficiency gains
in in the huge page splitting and migrating code.

- "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
for `struct mem_cgroup', yielding improved memory utilization.

- "add max arg to swappiness in memory.reclaim and lru_gen" from
Zhongkun He adds a new "max" argument to the "swappiness=" argument
for memory.reclaim MGLRU's lru_gen.

This directs proactive reclaim to reclaim from only anon folios
rather than file-backed folios.

- "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
first step on the path to permitting the kernel to maintain existing
VMs while replacing the host kernel via file-based kexec. At this
time only memblock's reserve_mem is preserved.

- "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
and uses a smarter way of looping over a pfn range. By skipping
ranges of invalid pfns.

- "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
when a task is pinned a single NUMA mode.

Dramatic performance benefits were seen in some real world cases.

- "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
Garg addresses a warning which occurs during memory compaction when
using JFS.

- "move all VMA allocation, freeing and duplication logic to mm" from
Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
appropriate mm/vma.c.

- "mm, swap: clean up swap cache mapping helper" from Kairui Song
provides code consolidation and cleanups related to the folio_index()
function.

- "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.

- "memcg: Fix test_memcg_min/low test failures" from Waiman Long
addresses some bogus failures which are being reported by the
test_memcontrol selftest.

- "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
Stoakes commences the deprecation of file_operations.mmap() in favor
of the new file_operations.mmap_prepare().

The latter is more restrictive and prevents drivers from messing with
things in ways which, amongst other problems, may defeat VMA merging.

- "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
the per-cpu memcg charge cache from the objcg's one.

This is a step along the way to making memcg and objcg charging
NMI-safe, which is a BPF requirement.

- "mm/damon: minor fixups and improvements for code, tests, and
documents" from SeongJae Park is yet another batch of miscellaneous
DAMON changes. Fix and improve minor problems in code, tests and
documents.

- "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
stats to be irq safe. Another step along the way to making memcg
charging and stats updates NMI-safe, a BPF requirement.

- "Let unmap_hugepage_range() and several related functions take folio
instead of page" from Fan Ni provides folio conversions in the
hugetlb code.

* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
mm: pcp: increase pcp->free_count threshold to trigger free_high
mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
mm/hugetlb: pass folio instead of page to unmap_ref_private()
memcg: objcg stock trylock without irq disabling
memcg: no stock lock for cpu hot-unplug
memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
memcg: make count_memcg_events re-entrant safe against irqs
memcg: make mod_memcg_state re-entrant safe against irqs
memcg: move preempt disable to callers of memcg_rstat_updated
memcg: memcg_rstat_updated re-entrant safe against irqs
mm: khugepaged: decouple SHMEM and file folios' collapse
selftests/eventfd: correct test name and improve messages
alloc_tag: check mem_profiling_support in alloc_tag_init
Docs/damon: update titles and brief introductions to explain DAMOS
selftests/damon/_damon_sysfs: read tried regions directories in order
mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
...

ARM: 9446/1: Disallow kernel mode NEON when IRQs are disabled

2025-05-29T10:22:25+00:00

Commit

  c79f81631142 ("ARM: 9283/1: permit non-nested kernel mode NEON in softirq context")

relaxed the rules around the use of SIMD instructions in kernel mode on
ARM, to allow such use when serving a softirq. To avoid having to
preserve/restore kernel mode NEON state when such a softirq is taken,
softirqs are now disabled when using the NEON from task context.

However, the fact that the softirq API does not allow unmasking of
softirqs with interrupts disabled was overlooked, resulting in a WARN()
in some cases, as reported by Guenter:

  WARNING: CPU: 0 PID: 1145 at kernel/softirq.c:369 __local_bh_enable_ip+0x118/0x194
  Call trace:
   unwind_backtrace from show_stack+0x10/0x14
   show_stack from dump_stack_lvl+0x7c/0xac
   dump_stack_lvl from __warn+0x7c/0x1b8
   __warn from warn_slowpath_fmt+0x19c/0x1a4
   warn_slowpath_fmt from __local_bh_enable_ip+0x118/0x194
   __local_bh_enable_ip from crc_t10dif_arch+0xd4/0xe8
   crc_t10dif_arch from crc_t10dif_wrapper+0x14/0x1c
   crc_t10dif_wrapper from crc_main_test+0x178/0x360
   crc_main_test from kunit_try_run_case+0x78/0x1e0
   kunit_try_run_case from kunit_generic_run_threadfn_adapter+0x1c/0x34
   kunit_generic_run_threadfn_adapter from kthread+0x118/0x254
   kthread from ret_from_fork+0x14/0x28

While disabling softirqs is not really needed when running with IRQs
disabled (given that the only way a softirq can be delivered
asynchrously is over the back of an IRQ), let's not complicate this
logic more than needed, and simply disallow use of the NEON in kernel
mode when IRQs are disabled.

Another approach might be to only disable and re-enable softirqs if IRQs
are enabled, but other than the test case above, there are no clear use
cases for doing non-trivial arithmetic processing (hence using an
accelerated SIMD implementation) with IRQs disabled.

Reported-by: Guenter Roeck 
Tested-by: Guenter Roeck 
Link: https://lore.kernel.org/all/389b899f-893c-4855-9e30-d8920a5d6f91@roeck-us.net
Reviewed-by: Eric Biggers 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Russell King (Oracle)

syscall.h: introduce syscall_set_nr()

2025-05-12T00:48:15+00:00

Similar to syscall_set_arguments() that complements
syscall_get_arguments(), introduce syscall_set_nr() that complements
syscall_get_nr().

syscall_set_nr() is going to be needed along with syscall_set_arguments()
on all HAVE_ARCH_TRACEHOOK architectures to implement
PTRACE_SET_SYSCALL_INFO API.

Link: https://lkml.kernel.org/r/20250303112020.GD24170@strace.io
Signed-off-by: Dmitry V. Levin 
Tested-by: Charlie Jenkins 
Reviewed-by: Charlie Jenkins 
Acked-by: Helge Deller  # parisc
Reviewed-by: Maciej W. Rozycki  # mips
Cc: Alexander Gordeev 
Cc: Alexey Gladkov (Intel) 
Cc: Andreas Larsson 
Cc: anton ivanov 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Brian Cain 
Cc: Christian Borntraeger 
Cc: Christian Zankel 
Cc: Christophe Leroy 
Cc: Dave Hansen 
Cc: Davide Berardi 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Eugene Syromiatnikov 
Cc: Eugene Syromyatnikov 
Cc: Geert Uytterhoeven 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Jonas Bonn 
Cc: Madhavan Srinivasan 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Mike Frysinger 
Cc: Naveen N Rao 
Cc: Nicholas Piggin 
Cc: Oleg Nesterov 
Cc: Renzo Davoi 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russel King 
Cc: Shuah Khan 
Cc: Stafford Horne 
Cc: Stefan Kristiansson 
Cc: Sven Schnelle 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: WANG Xuerui 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton

syscall.h: add syscall_set_arguments()

2025-05-12T00:48:15+00:00

This function is going to be needed on all HAVE_ARCH_TRACEHOOK
architectures to implement PTRACE_SET_SYSCALL_INFO API.

This partially reverts commit 7962c2eddbfe ("arch: remove unused function
syscall_set_arguments()") by reusing some of old syscall_set_arguments()
implementations.

[nathan@kernel.org: fix compile time fortify checks]
  Link: https://lkml.kernel.org/r/20250408213131.GA2872426@ax162
Link: https://lkml.kernel.org/r/20250303112009.GC24170@strace.io
Signed-off-by: Dmitry V. Levin 
Signed-off-by: Nathan Chancellor 
Tested-by: Charlie Jenkins 
Reviewed-by: Charlie Jenkins 
Acked-by: Helge Deller  # parisc
Reviewed-by: Maciej W. Rozycki 	[mips]
Cc: Alexander Gordeev 
Cc: Alexey Gladkov (Intel) 
Cc: Andreas Larsson 
Cc: anton ivanov 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Brian Cain 
Cc: Christian Borntraeger 
Cc: Christian Zankel 
Cc: Christophe Leroy 
Cc: Dave Hansen 
Cc: Davide Berardi 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Eugene Syromiatnikov 
Cc: Eugene Syromyatnikov 
Cc: Geert Uytterhoeven 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Jonas Bonn 
Cc: Madhavan Srinivasan 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Mike Frysinger 
Cc: Naveen N Rao 
Cc: Nicholas Piggin 
Cc: Oleg Nesterov 
Cc: Renzo Davoi 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russel King 
Cc: Shuah Khan 
Cc: Stafford Horne 
Cc: Stefan Kristiansson 
Cc: Sven Schnelle 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: WANG Xuerui 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton

arch: remove mk_pmd()

2025-05-12T00:48:04+00:00

There are now no callers of mk_huge_pmd() and mk_pmd().  Remove them.

Link: https://lkml.kernel.org/r/20250402181709.2386022-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Cc: Zi Yan 
Cc: Alexander Gordeev 
Cc: Andreas Larsson 
Cc: Anton Ivanov 
Cc: Dave Hansen 
Cc: David Hildenbrand 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Johannes Berg 
Cc: Muchun Song 
Cc: Richard Weinberger 
Cc: 
Signed-off-by: Andrew Morton