linux-stable.git/arch/mips/include, branch v6.14

mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()

2025-02-27T17:40:57+00:00

In order to fix a bug, arm64 needs to be told the size of the huge page
for which the huge_pte is being cleared in huge_ptep_get_and_clear().
Provide for this by adding an `unsigned long sz` parameter to the
function. This follows the same pattern as huge_pte_clear() and
set_huge_pte_at().

This commit makes the required interface modifications to the core mm as
well as all arches that implement this function (arm64, loongarch, mips,
parisc, powerpc, riscv, s390, sparc). The actual arm64 bug will be fixed
in a separate commit.

Cc: stable@vger.kernel.org
Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
Acked-by: David Hildenbrand 
Reviewed-by: Alexandre Ghiti  # riscv
Reviewed-by: Christophe Leroy 
Reviewed-by: Catalin Marinas 
Reviewed-by: Anshuman Khandual 
Signed-off-by: Ryan Roberts 
Acked-by: Alexander Gordeev  # s390
Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com
Signed-off-by: Will Deacon

MIPS: fix mips_get_syscall_arg() for o32

2025-02-13T11:41:29+00:00

This makes ptrace/get_syscall_info selftest pass on mips o32 and
mips64 o32 by fixing the following two test assertions:

1. get_syscall_info test assertion on mips o32:
  # get_syscall_info.c:218:get_syscall_info:Expected exp_args[5] (3134521044) == info.entry.args[4] (4911432)
  # get_syscall_info.c:219:get_syscall_info:wait #1: entry stop mismatch

2. get_syscall_info test assertion on mips64 o32:
  # get_syscall_info.c:209:get_syscall_info:Expected exp_args[2] (3134324433) == info.entry.args[1] (18446744072548908753)
  # get_syscall_info.c:210:get_syscall_info:wait #1: entry stop mismatch

The first assertion happens due to mips_get_syscall_arg() trying to access
another task's context but failing to do it properly because get_user() it
calls just peeks at the current task's context.  It usually does not crash
because the default user stack always gets assigned the same VMA, but it
is pure luck which mips_get_syscall_arg() wouldn't have if e.g. the stack
was switched (via setcontext(3) or however) or a non-default process's
thread peeked at, and in any case irrelevant data is obtained just as
observed with the test case.

mips_get_syscall_arg() ought to be using access_remote_vm() instead to
retrieve the other task's stack contents, but given that the data has been
already obtained and saved in `struct pt_regs' it would be an overkill.

The first assertion is fixed for mips o32 by using struct pt_regs.args
instead of get_user() to obtain syscall arguments.  This approach works
due to this piece in arch/mips/kernel/scall32-o32.S:

        /*
         * Ok, copy the args from the luser stack to the kernel stack.
         */

        .set    push
        .set    noreorder
        .set    nomacro

    load_a4: user_lw(t5, 16(t0))		# argument #5 from usp
    load_a5: user_lw(t6, 20(t0))		# argument #6 from usp
    load_a6: user_lw(t7, 24(t0))		# argument #7 from usp
    load_a7: user_lw(t8, 28(t0))		# argument #8 from usp
    loads_done:

        sw	t5, PT_ARG4(sp)		# argument #5 to ksp
        sw	t6, PT_ARG5(sp)		# argument #6 to ksp
        sw	t7, PT_ARG6(sp)		# argument #7 to ksp
        sw	t8, PT_ARG7(sp)		# argument #8 to ksp
        .set	pop

        .section __ex_table,"a"
        PTR_WD	load_a4, bad_stack_a4
        PTR_WD	load_a5, bad_stack_a5
        PTR_WD	load_a6, bad_stack_a6
        PTR_WD	load_a7, bad_stack_a7
        .previous

arch/mips/kernel/scall64-o32.S has analogous code for mips64 o32 that
allows fixing the issue by obtaining syscall arguments from struct
pt_regs.regs[4..11] instead of the erroneous use of get_user().

The second assertion is fixed by truncating 64-bit values to 32-bit
syscall arguments.

Fixes: c0ff3c53d4f9 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.")
Signed-off-by: Dmitry V. Levin 
Signed-off-by: Thomas Bogendoerfer

MIPS: Export syscall stack arguments properly for remote use

2025-02-13T11:41:18+00:00

We have several places across the kernel where we want to access another
task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making
a call to syscall_get_arguments().

This works for register arguments right away by accessing the task's
`regs' member of `struct pt_regs', however for stack arguments seen with
32-bit/o32 kernels things are more complicated.  Technically they ought
to be obtained from the user stack with calls to an access_remote_vm(),
but we have an easier way available already.

So as to be able to access syscall stack arguments as regular function
arguments following the MIPS calling convention we copy them over from
the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in
handle_sys(), to the current stack frame's outgoing argument space at
the top of the stack, which is where the handler called expects to see
its incoming arguments.  This area is also pointed at by the `pt_regs'
pointer obtained by task_pt_regs().

Make the o32 stack argument space a proper member of `struct pt_regs'
then, by renaming the existing member from `pad0' to `args' and using
generated offsets to access the space.  No functional change though.

With the change in place the o32 kernel stack frame layout at the entry
to a syscall handler invoked by handle_sys() is therefore as follows:

$sp + 68 -> |         ...         | <- pt_regs.regs[9]
            +---------------------+
$sp + 64 -> |         $t0         | <- pt_regs.regs[8]
            +---------------------+
$sp + 60 -> |   $a3/argument #4   | <- pt_regs.regs[7]
            +---------------------+
$sp + 56 -> |   $a2/argument #3   | <- pt_regs.regs[6]
            +---------------------+
$sp + 52 -> |   $a1/argument #2   | <- pt_regs.regs[5]
            +---------------------+
$sp + 48 -> |   $a0/argument #1   | <- pt_regs.regs[4]
            +---------------------+
$sp + 44 -> |         $v1         | <- pt_regs.regs[3]
            +---------------------+
$sp + 40 -> |         $v0         | <- pt_regs.regs[2]
            +---------------------+
$sp + 36 -> |         $at         | <- pt_regs.regs[1]
            +---------------------+
$sp + 32 -> |        $zero        | <- pt_regs.regs[0]
            +---------------------+
$sp + 28 -> |  stack argument #8  | <- pt_regs.args[7]
            +---------------------+
$sp + 24 -> |  stack argument #7  | <- pt_regs.args[6]
            +---------------------+
$sp + 20 -> |  stack argument #6  | <- pt_regs.args[5]
            +---------------------+
$sp + 16 -> |  stack argument #5  | <- pt_regs.args[4]
            +---------------------+
$sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3]
            +---------------------+
$sp +  8 -> | psABI space for $a2 | <- pt_regs.args[2]
            +---------------------+
$sp +  4 -> | psABI space for $a1 | <- pt_regs.args[1]
            +---------------------+
$sp +  0 -> | psABI space for $a0 | <- pt_regs.args[0]
            +---------------------+

holding user data received and with the first 4 frame slots reserved by
the psABI for the compiler to spill the incoming arguments from $a0-$a3
registers (which it sometimes does according to its needs) and the next
4 frame slots designated by the psABI for any stack function arguments
that follow.  This data is also available for other tasks to peek/poke
at as reqired and where permitted.

Signed-off-by: Maciej W. Rozycki 
Signed-off-by: Thomas Bogendoerfer

Merge tag 'mips_6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

2025-01-27T17:00:25+00:00

Pull MIPS updates from Thomas Bogendoerfer:
 "Cleanups and fixes"

* tag 'mips_6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: pci-legacy: Override pci_address_to_pio
  MIPS: Loongson64: env: Use str_on_off() helper in prom_lefi_init_env()
  MIPS: migrate to generic rule for built-in DTBs
  mips: fix shmctl/semctl/msgctl syscall for o32
  mips/math-emu: fix emulation of the prefx instruction
  MIPS: Loongson: Add comments for interface_info
  MIPS: Loongson64: remove ROM Size unit in boardinfo
  MIPS: traps: Use str_enabled_disabled() in parity_protection_init()
  MIPS: ftrace: Declare ftrace_get_parent_ra_addr() as static
  Revert "MIPS: csrc-r4k: Select HAVE_UNSTABLE_SCHED_CLOCK if SMP && 64BIT"
  MIPS: Fix the wrong format specifier
  MIPS: Add a blank line after __HEAD
  MIPS: kernel: Rename read/write_c0_ecc to read/writec0_errctl

Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-01-27T02:36:23+00:00

Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...

asm-generic: pgalloc: provide generic __pgd_{alloc,free}

2025-01-26T04:22:24+00:00

We already have a generic implementation of alloc/free up to P4D level, as
well as pgd_free().  Let's finish the work and add a generic PGD-level
alloc helper as well.

Unlike at lower levels, almost all architectures need some specific magic
at PGD level (typically initialising PGD entries), so introducing a
generic pgd_alloc() isn't worth it.  Instead we introduce two new helpers,
__pgd_alloc() and __pgd_free(), and make use of them in the arch-specific
pgd_alloc() and pgd_free() wherever possible.  To accommodate as many arch
as possible, __pgd_alloc() takes a page allocation order.

Because pagetable_alloc() allocates zeroed pages, explicit zeroing in
pgd_alloc() becomes redundant and we can get rid of it.  Some trivial
implementations of pgd_free() also become unnecessary once __pgd_alloc()
is used; remove them.

Another small improvement is consistent accounting of PGD pages by using
GFP_PGTABLE_{USER,KERNEL} as appropriate.

Not all PGD allocations can be handled by the generic helpers.  In
particular, multiple architectures allocate PGDs from a kmem_cache, and
those PGDs may not be page-sized.

Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky 
Acked-by: Dave Hansen 
Acked-by: Qi Zheng 
Cc: Andy Lutomirski 
Cc: Catalin Marinas 
Cc: Ingo Molnar 
Cc: Linus Walleij 
Cc: Matthew Wilcox (Oracle) 
Cc: Mike Rapoport (Microsoft) 
Cc: Peter Zijlstra 
Cc: Ryan Roberts 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

mm: pgtable: introduce pagetable_dtor()

2025-01-26T04:22:22+00:00

The pagetable_p*_dtor() are exactly the same except for the handling of
ptlock.  If we make ptlock_free() handle the case where ptdesc->ptl is
NULL and remove VM_BUG_ON_PAGE() from pmd_ptlock_free(), we can unify
pagetable_p*_dtor() into one function.  Let's introduce pagetable_dtor()
to do this.

Later, pagetable_dtor() will be moved to tlb_remove_ptdesc(), so that
ptlock and page table pages can be freed together (regardless of whether
RCU is used).  This prevents the use-after-free problem where the ptlock
is freed immediately but the page table pages is freed later via RCU.

Link: https://lkml.kernel.org/r/47f44fff9dc68d9d9e9a0d6c036df275f820598a.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng 
Originally-by: Peter Zijlstra (Intel) 
Reviewed-by: Kevin Brodsky 
Acked-by: Alexander Gordeev 	[s390]
Cc: Alexandre Ghiti 
Cc: Alexandre Ghiti 
Cc: Andreas Larsson 
Cc: Aneesh Kumar K.V (Arm) 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: David Hildenbrand 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jann Horn 
Cc: Lorenzo Stoakes 
Cc: Matthew Wilcox (Oracle) 
Cc: Mike Rapoport (Microsoft) 
Cc: Muchun Song 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Ryan Roberts 
Cc: Thomas Gleixner 
Cc: Vishal Moola (Oracle) 
Cc: Will Deacon 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton

MIPS: Loongson: Add comments for interface_info

2025-01-11T11:39:33+00:00

Clarify meanings of members of interface_info, especially for .size,
which does not define the ROM size.

Suggested-by: Icenowy Zheng 
Signed-off-by: Kexy Biscuit 
Acked-by: Jiaxun Yang 
Signed-off-by: Thomas Bogendoerfer

MIPS: kernel: Rename read/write_c0_ecc to read/writec0_errctl

2025-01-11T11:31:21+00:00

CP0 register 26 is used as ECC register for legacy cores, but newer
cores (MIPS32/MIPS64) use it as an ErrCtl register. Since the kernel only
uses CP0 26 as ErrCtl register rename the access functions to the more
fitting name.

Signed-off-by: Thomas Bogendoerfer 
Reviewed-by: Maciej W. Rozycki 
Signed-off-by: Thomas Bogendoerfer

sock: Introduce SO_RCVPRIORITY socket option

2024-12-17T02:16:44+00:00

Add new socket option, SO_RCVPRIORITY, to include SO_PRIORITY in the
ancillary data returned by recvmsg().
This is analogous to the existing support for SO_RCVMARK,
as implemented in commit 6fd1d51cfa253 ("net: SO_RCVMARK socket option
for SO_MARK with recvmsg()").

Reviewed-by: Willem de Bruijn 
Suggested-by: Ferenc Fejes 
Signed-off-by: Anna Emese Nyiri 
Link: https://patch.msgid.link/20241213084457.45120-5-annaemesenyiri@gmail.com
Signed-off-by: Jakub Kicinski