Commit Graph

2752 Commits

Author SHA1 Message Date
Linus Torvalds
9d20040d71 Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
 "Ryan's been hard at work finding and fixing mm bugs in the arm64 code,
  so here's a small crop of fixes for -rc5.

  The main changes are to fix our zapping of non-present PTEs for
  hugetlb entries created using the contiguous bit in the page-table
  rather than a block entry at the level above. Prior to these fixes, we
  were pulling the contiguous bit back out of the PTE in order to
  determine the size of the hugetlb page but this is clearly bogus if
  the thing isn't present and consequently both the clearing of the
  PTE(s) and the TLB invalidation were unreliable.

  Although the problem was found by code inspection, we really don't
  want this sitting around waiting to trigger and the changes are CC'd
  to stable accordingly.

  Note that the diffstat looks a lot worse than it really is;
  huge_ptep_get_and_clear() now takes a size argument from the core code
  and so all the arch implementations of that have been updated in a
  pretty mechanical fashion.

   - Fix a sporadic boot failure due to incorrect randomization of the
     linear map on systems that support it

   - Fix the zapping (both clearing the entries *and* invalidating the
     TLB) of hugetlb PTEs constructed using the contiguous bit"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hugetlb: Fix flush_hugetlb_tlb_range() invalidation level
  arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes
  mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()
  arm64/mm: Fix Boot panic on Ampere Altra
2025-03-01 13:44:51 -08:00
Linus Torvalds
ad69e02128 Merge tag 'objtool-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fixes from Ingo Molnar:
 "Fix an objtool false positive, and objtool related build warnings that
  happens on PIE-enabled architectures such as LoongArch"

* tag 'objtool-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Add bch2_trans_unlocked_or_in_restart_error() to bcachefs noreturns
  objtool: Fix C jump table annotations for Clang
  vmlinux.lds: Ensure that const vars with relocations are mapped R/O
2025-02-28 16:45:36 -08:00
Ryan Roberts
02410ac72a mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()
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: 66b3923a1a ("arm64: hugetlb: add support for PTE contiguous bit")
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> # s390
Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-02-27 17:40:57 +00:00
Ard Biesheuvel
68f3ea7ee1 vmlinux.lds: Ensure that const vars with relocations are mapped R/O
In the kernel, there are architectures (x86, arm64) that perform
boot-time relocation (for KASLR) without relying on PIE codegen. In this
case, all const global objects are emitted into .rodata, including const
objects with fields that will be fixed up by the boot-time relocation
code.  This implies that .rodata (and .text in some cases) need to be
writable at boot, but they will usually be mapped read-only as soon as
the boot completes.

When using PIE codegen, the compiler will emit const global objects into
.data.rel.ro rather than .rodata if the object contains fields that need
such fixups at boot-time. This permits the linker to annotate such
regions as requiring read-write access only at load time, but not at
execution time (in user space), while keeping .rodata truly const (in
user space, this is important for reducing the CoW footprint of dynamic
executables).

This distinction does not matter for the kernel, but it does imply that
const data will end up in writable memory if the .data.rel.ro sections
are not treated in a special way, as they will end up in the writable
.data segment by default.

So emit .data.rel.ro into the .rodata segment.

Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250221135704.431269-5-ardb+git@google.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-02-25 09:46:15 -08:00
Masahiro Yamada
4c56eb33e6 kbuild: keep symbols for symbol_get() even with CONFIG_TRIM_UNUSED_KSYMS
Linus observed that the symbol_request(utf8_data_table) call fails when
CONFIG_UNICODE=y and CONFIG_TRIM_UNUSED_KSYMS=y.

symbol_get() relies on the symbol data being present in the ksymtab for
symbol lookups. However, EXPORT_SYMBOL_GPL(utf8_data_table) is dropped
due to CONFIG_TRIM_UNUSED_KSYMS, as no module references it in this case.

Probably, this has been broken since commit dbacb0ef67 ("kconfig option
for TRIM_UNUSED_KSYMS").

This commit addresses the issue by leveraging modpost. Symbol names
passed to symbol_get() are recorded in the special .no_trim_symbol
section, which is then parsed by modpost to forcibly keep such symbols.
The .no_trim_symbol section is discarded by the linker scripts, so there
is no impact on the size of the final vmlinux or modules.

This commit cannot resolve the issue for direct calls to __symbol_get()
because the symbol name is not known at compile-time.

Although symbol_get() may eventually be deprecated, this workaround
should be good enough meanwhile.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-02-06 01:08:58 +09:00
Linus Torvalds
9c5968db9e Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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
  ...
2025-01-26 18:36:23 -08:00
Linus Torvalds
c159dfbdd4 Merge tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
 "Mainly individually changelogged singleton patches. The patch series
  in this pull are:

   - "lib min_heap: Improve min_heap safety, testing, and documentation"
     from Kuan-Wei Chiu provides various tightenings to the min_heap
     library code

   - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms
     some cleanup and Rust preparation in the xarray library code

   - "Update reference to include/asm-<arch>" from Geert Uytterhoeven
     fixes pathnames in some code comments

   - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses
     the new secs_to_jiffies() in various places where that is
     appropriate

   - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen
     switches two filesystems to the new mount API

   - "Convert ocfs2 to use folios" from Matthew Wilcox does that

   - "Remove get_task_comm() and print task comm directly" from Yafang
     Shao removes now-unneeded calls to get_task_comm() in various
     places

   - "squashfs: reduce memory usage and update docs" from Phillip
     Lougher implements some memory savings in squashfs and performs
     some maintainability work

   - "lib: clarify comparison function requirements" from Kuan-Wei Chiu
     tightens the sort code's behaviour and adds some maintenance work

   - "nilfs2: protect busy buffer heads from being force-cleared" from
     Ryusuke Konishi fixes an issues in nlifs when the fs is presented
     with a corrupted image

   - "nilfs2: fix kernel-doc comments for function return values" from
     Ryusuke Konishi fixes some nilfs kerneldoc

   - "nilfs2: fix issues with rename operations" from Ryusuke Konishi
     addresses some nilfs BUG_ONs which syzbot was able to trigger

   - "minmax.h: Cleanups and minor optimisations" from David Laight does
     some maintenance work on the min/max library code

   - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance
     work on the xarray library code"

* tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (131 commits)
  ocfs2: use str_yes_no() and str_no_yes() helper functions
  include/linux/lz4.h: add some missing macros
  Xarray: use xa_mark_t in xas_squash_marks() to keep code consistent
  Xarray: remove repeat check in xas_squash_marks()
  Xarray: distinguish large entries correctly in xas_split_alloc()
  Xarray: move forward index correctly in xas_pause()
  Xarray: do not return sibling entries from xas_find_marked()
  ipc/util.c: complete the kernel-doc function descriptions
  gcov: clang: use correct function param names
  latencytop: use correct kernel-doc format for func params
  minmax.h: remove some #defines that are only expanded once
  minmax.h: simplify the variants of clamp()
  minmax.h: move all the clamp() definitions after the min/max() ones
  minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
  minmax.h: reduce the #define expansion of min(), max() and clamp()
  minmax.h: update some comments
  minmax.h: add whitespace around operators and after commas
  nilfs2: do not update mtime of renamed directory that is not moved
  nilfs2: handle errors that nilfs_prepare_chunk() may return
  CREDITS: fix spelling mistake
  ...
2025-01-26 17:50:53 -08:00
Kevin Brodsky
d95936a226 mm: introduce ctor/dtor at PGD level
Following on from the introduction of P4D-level ctor/dtor, let's finish
the job and introduce ctor/dtor at PGD level.  The incurred improvement in
page accounting is minimal - the main motivation is to create a single,
generic place where construction/destruction hooks can be added for all
page table pages.

This patch should cover all architectures and all configurations where
PGDs are one or more regular pages.  This excludes any configuration where
PGDs are allocated from a kmem_cache object.

Link: https://lkml.kernel.org/r/20250103184415.2744423-7-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:24 -08:00
Kevin Brodsky
a9b3c355c2 asm-generic: pgalloc: provide generic __pgd_{alloc,free}
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 <kevin.brodsky@arm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:24 -08:00
Qi Zheng
553e77529f mm: pgtable: introduce generic pagetable_dtor_free()
The pte_free(), pmd_free(), __pud_free() and __p4d_free() in
asm-generic/pgalloc.h and the generic __tlb_remove_table() are basically
the same, so let's introduce pagetable_dtor_free() to deduplicate them.

In addition, the pagetable_dtor_free() in s390 does the same thing, so
let's s390 also calls generic pagetable_dtor_free().

Link: https://lkml.kernel.org/r/1663a0565aca881d1338ceb7d1db4aa9c333abd6.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>	[s390]
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:23 -08:00
Qi Zheng
92ec7fd136 mm: pgtable: completely move pagetable_dtor() to generic tlb_remove_table()
For the generic tlb_remove_table(), it is implemented in the following two
forms:

1) CONFIG_MMU_GATHER_TABLE_FREE is enabled

tlb_remove_table
--> generic __tlb_remove_table()

2) CONFIG_MMU_GATHER_TABLE_FREE is disabled

tlb_remove_table
--> tlb_remove_page

For case 1), the pagetable_dtor() has already been moved to generic
__tlb_remove_table().

For case 2), now only arm will call tlb_remove_table()/tlb_remove_ptdesc()
when CONFIG_MMU_GATHER_TABLE_FREE is disabled.  Let's move
pagetable_dtor() completely to generic tlb_remove_table(), so that the
architectures can follow more easily.

Link: https://lkml.kernel.org/r/0c733ac867b287ec08190676496d1decebf49da2.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Suggested-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:23 -08:00
Qi Zheng
2dccdf7076 mm: pgtable: introduce generic __tlb_remove_table()
Several architectures (arm, arm64, riscv and x86) define exactly the same
__tlb_remove_table(), just introduce generic __tlb_remove_table() to
eliminate these duplications.

The s390 __tlb_remove_table() is nearly the same, so also make s390
__tlb_remove_table() version generic.

Link: https://lkml.kernel.org/r/ea372633d94f4d3f9f56a7ec5994bf050bf77e39.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>		[sparc]
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>	[s390]
Acked-by: Arnd Bergmann <arnd@arndb.de>			[asm-generic]
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:23 -08:00
Qi Zheng
db6b435d73 mm: pgtable: introduce pagetable_dtor()
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 <zhengqi.arch@bytedance.com>
Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>	[s390]
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:22 -08:00
Qi Zheng
5fcf5fa612 mm: pgtable: add statistics for P4D level page table
Like other levels of page tables, add statistics for P4D level page table.

Link: https://lkml.kernel.org/r/d55fe3c286305aae84457da9e1066df99b3de125.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:21 -08:00
Kevin Brodsky
98a7e47faa asm-generic: pgalloc: provide generic p4d_{alloc_one,free}
Four architectures currently implement 5-level pgtables: arm64, riscv, x86
and s390.  The first three have essentially the same implementation for
p4d_alloc_one() and p4d_free(), so we've got an opportunity to reduce
duplication like at the lower levels.

Provide a generic version of p4d_alloc_one() and p4d_free(), and make use
of it on those architectures.

Their implementation is the same as at PUD level, except that p4d_free()
performs a runtime check by calling mm_p4d_folded().  5-level pgtables
depend on a runtime-detected hardware feature on all supported
architectures, so we might as well include this check in the generic
implementation.  No runtime check is required in p4d_alloc_one() as the
top-level p4d_alloc() already does the required check.

Link: https://lkml.kernel.org/r/26d69c74a29183ecc335b9b407040d8e4cd70c6a.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>		[asm-generic]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:21 -08:00
Linus Torvalds
382e391365 Merge tag 'hyperv-next-signed-20250123' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:

 - Introduce a new set of Hyper-V headers in include/hyperv and replace
   the old hyperv-tlfs.h with the new headers (Nuno Das Neves)

 - Fixes for the Hyper-V VTL mode (Roman Kisel)

 - Fixes for cpu mask usage in Hyper-V code (Michael Kelley)

 - Document the guest VM hibernation behaviour (Michael Kelley)

 - Miscellaneous fixes and cleanups (Jacob Pan, John Starks, Naman Jain)

* tag 'hyperv-next-signed-20250123' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Documentation: hyperv: Add overview of guest VM hibernation
  hyperv: Do not overlap the hvcall IO areas in hv_vtl_apicid_to_vp_id()
  hyperv: Do not overlap the hvcall IO areas in get_vtl()
  hyperv: Enable the hypercall output page for the VTL mode
  hv_balloon: Fallback to generic_online_page() for non-HV hot added mem
  Drivers: hv: vmbus: Log on missing offers if any
  Drivers: hv: vmbus: Wait for boot-time offers during boot and resume
  uio_hv_generic: Add a check for HV_NIC for send, receive buffers setup
  iommu/hyper-v: Don't assume cpu_possible_mask is dense
  Drivers: hv: Don't assume cpu_possible_mask is dense
  x86/hyperv: Don't assume cpu_possible_mask is dense
  hyperv: Remove the now unused hyperv-tlfs.h files
  hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h
  hyperv: Add new Hyper-V headers in include/hyperv
  hyperv: Clean up unnecessary #includes
  hyperv: Move hv_connection_id to hyperv-tlfs.h
2025-01-25 09:22:55 -08:00
Guo Weikang
ccd582059a mm/early_ioremap: add null pointer checks to prevent NULL-pointer dereference
The early_ioremap interface can fail and return NULL in certain cases.  To
prevent NULL-pointer dereference crashes, fixed issues in the acpi_extlog
and copy_early_mem interfaces, improving robustness when handling early
memory.

Link: https://lkml.kernel.org/r/20241212101004.1544070-1-guoweikang.kernel@gmail.com
Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:59 -08:00
Geert Uytterhoeven
7a77edf45a include: update references to include/asm-<arch>
"include/asm-<arch>" was replaced by "arch/<arch>/include/asm" a long time
ago.

Link: https://lkml.kernel.org/r/541258219b0441fa1da890e2f8458a7ac18c2ef9.1733404444.git.geert+renesas@glider.be
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-12 20:20:59 -08:00
Nuno Das Neves
962a4c7ea8 hyperv: Remove the now unused hyperv-tlfs.h files
Remove all hyperv-tlfs.h files. These are no longer included
anywhere. hyperv/hvhdk.h serves the same role, but with an easier
path for adding new definitions.

Remove the relevant lines in MAINTAINERS.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/1732577084-2122-6-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1732577084-2122-6-git-send-email-nunodasneves@linux.microsoft.com>
2025-01-10 00:54:21 +00:00
Nuno Das Neves
ef5a3c92a8 hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h
Switch to using hvhdk.h everywhere in the kernel. This header
includes all the new Hyper-V headers in include/hyperv, which form a
superset of the definitions found in hyperv-tlfs.h.

This makes it easier to add new Hyper-V interfaces without being
restricted to those in the TLFS doc (reflected in hyperv-tlfs.h).

To be more consistent with the original Hyper-V code, the names of
some definitions are changed slightly. Update those where needed.

Update comments in mshyperv.h files to point to include/hyperv for
adding new definitions.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/1732577084-2122-5-git-send-email-nunodasneves@linux.microsoft.com
Link: https://lore.kernel.org/r/20250108222138.1623703-3-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-01-10 00:54:21 +00:00
Nuno Das Neves
9696d9ae01 hyperv: Move hv_connection_id to hyperv-tlfs.h
This definition is in the wrong file; it is part of the TLFS doc.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1732577084-2122-2-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1732577084-2122-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-01-08 08:18:26 +00:00
Masami Hiramatsu (Google)
b5fa903b7f fprobe: Add fprobe_header encoding feature
Fprobe store its data structure address and size on the fgraph return stack
by __fprobe_header. But most 64bit architecture can combine those to
one unsigned long value because 4 MSB in the kernel address are the same.
With this encoding, fprobe can consume less space on ret_stack.

This introduces asm/fprobe.h to define arch dependent encode/decode
macros. Note that since fprobe depends on CONFIG_HAVE_FUNCTION_GRAPH_FREGS,
currently only arm64, loongarch, riscv, s390 and x86 are supported.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173519005783.391279.5307910947400277525.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:05 -05:00
Linus Torvalds
f788b5ef1c Merge tag 'timers_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Borislav Petkov:

 - Fix a case where posix timers with a thread-group-wide target would
   miss signals if some of the group's threads are exiting

 - Fix a hang caused by ndelay() calling the wrong delay function
   __udelay()

 - Fix a wrong offset calculation in adjtimex(2) when using ADJ_MICRO
   (microsecond resolution) and a negative offset

* tag 'timers_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-timers: Target group sigqueue to current task only if not exiting
  delay: Fix ndelay() spuriously treated as udelay()
  ntp: Remove invalid cast in time offset math
2024-12-01 12:41:21 -08:00
Linus Torvalds
6a34dfa15d Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add generic support for built-in boot DTB files

 - Enable TAB cycling for dialog buttons in nconfig

 - Fix issues in streamline_config.pl

 - Refactor Kconfig

 - Add support for Clang's AutoFDO (Automatic Feedback-Directed
   Optimization)

 - Add support for Clang's Propeller, a profile-guided optimization.

 - Change the working directory to the external module directory for M=
   builds

 - Support building external modules in a separate output directory

 - Enable objtool for *.mod.o and additional kernel objects

 - Use lz4 instead of deprecated lz4c

 - Work around a performance issue with "git describe"

 - Refactor modpost

* tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits)
  kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms
  gitignore: Don't ignore 'tags' directory
  kbuild: add dependency from vmlinux to resolve_btfids
  modpost: replace tdb_hash() with hash_str()
  kbuild: deb-pkg: add python3:native to build dependency
  genksyms: reduce indentation in export_symbol()
  modpost: improve error messages in device_id_check()
  modpost: rename alias symbol for MODULE_DEVICE_TABLE()
  modpost: rename variables in handle_moddevtable()
  modpost: move strstarts() to modpost.h
  modpost: convert do_usb_table() to a generic handler
  modpost: convert do_of_table() to a generic handler
  modpost: convert do_pnp_device_entry() to a generic handler
  modpost: convert do_pnp_card_entries() to a generic handler
  modpost: call module_alias_printf() from all do_*_entry() functions
  modpost: pass (struct module *) to do_*_entry() functions
  modpost: remove DEF_FIELD_ADDR_VAR() macro
  modpost: deduplicate MODULE_ALIAS() for all drivers
  modpost: introduce module_alias_printf() helper
  modpost: remove unnecessary check in do_acpi_entry()
  ...
2024-11-30 13:41:50 -08:00
Frederic Weisbecker
4d17c25eaf delay: Fix ndelay() spuriously treated as udelay()
A recent rework on delay functions wrongly ended up calling __udelay()
instead of __ndelay() for nanosecond delays, increasing those by 1000.

As a result hangs have been observed on boot

Restore the right function calls.

Fixes: 19e2d91d8c ("delay: Rework udelay and ndelay")
Reported-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/all/20241121152931.51884-1-frederic@kernel.org
2024-11-29 11:40:22 +01:00
Linus Torvalds
91dbbe6c9f Merge tag 'riscv-for-linus-6.13-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-v updates from Palmer Dabbelt:

 - Support for pointer masking in userspace

 - Support for probing vector misaligned access performance

 - Support for qspinlock on systems with Zacas and Zabha

* tag 'riscv-for-linus-6.13-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (38 commits)
  RISC-V: Remove unnecessary include from compat.h
  riscv: Fix default misaligned access trap
  riscv: Add qspinlock support
  dt-bindings: riscv: Add Ziccrse ISA extension description
  riscv: Add ISA extension parsing for Ziccrse
  asm-generic: ticket-lock: Add separate ticket-lock.h
  asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock
  riscv: Implement xchg8/16() using Zabha
  riscv: Implement arch_cmpxchg128() using Zacas
  riscv: Improve zacas fully-ordered cmpxchg()
  riscv: Implement cmpxchg8/16() using Zabha
  dt-bindings: riscv: Add Zabha ISA extension description
  riscv: Implement cmpxchg32/64() using Zacas
  riscv: Do not fail to build on byte/halfword operations with Zawrs
  riscv: Move cpufeature.h macros into their own header
  KVM: riscv: selftests: Add Smnpm and Ssnpm to get-reg-list test
  RISC-V: KVM: Allow Smnpm and Ssnpm extensions for guests
  riscv: hwprobe: Export the Supm ISA extension
  riscv: selftests: Add a pointer masking test
  riscv: Allow ptrace control of the tagged address ABI
  ...
2024-11-27 11:19:09 -08:00
Masahiro Yamada
dbefa1f31a Rename .data.once to .data..once to fix resetting WARN*_ONCE
Commit b1fca27d38 ("kernel debug: support resetting WARN*_ONCE")
added support for clearing the state of once warnings. However,
it is not functional when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or
CONFIG_LTO_CLANG is enabled, because .data.once matches the
.data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro.

Commit cb87481ee8 ("kbuild: linker script do not match C names unless
LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress
the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case,
providing a minimal fix for stable backporting. We were aware this did
not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The
plan was to apply correct fixes and then revert cb87481ee8. [1]

Seven years have passed since then, yet the #ifdef workaround remains in
place. Meanwhile, commit b1fca27d38 introduced the .data.once section,
and commit dc5723b02e ("kbuild: add support for Clang LTO") extended
the #ifdef.

Using a ".." separator in the section name fixes the issue for
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG.

[1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/

Fixes: b1fca27d38 ("kernel debug: support resetting WARN*_ONCE")
Fixes: dc5723b02e ("kbuild: add support for Clang LTO")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Masahiro Yamada
bb43a59944 Rename .data.unlikely to .data..unlikely
Commit 7ccaba5314 ("consolidate WARN_...ONCE() static variables")
was intended to collect all .data.unlikely sections into one chunk.
However, this has not worked when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
or CONFIG_LTO_CLANG is enabled, because .data.unlikely matches the
.data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro.

Commit cb87481ee8 ("kbuild: linker script do not match C names unless
LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress
the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case,
providing a minimal fix for stable backporting. We were aware this did
not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The
plan was to apply correct fixes and then revert cb87481ee8. [1]

Seven years have passed since then, yet the #ifdef workaround remains in
place.

Using a ".." separator in the section name fixes the issue for
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG.

[1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/

Fixes: cb87481ee8 ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Rong Xu
d5dc958361 kbuild: Add Propeller configuration for kernel build
Add the build support for using Clang's Propeller optimizer. Like
AutoFDO, Propeller uses hardware sampling to gather information
about the frequency of execution of different code paths within a
binary. This information is then used to guide the compiler's
optimization decisions, resulting in a more efficient binary.

The support requires a Clang compiler LLVM 19 or later, and the
create_llvm_prof tool
(https://github.com/google/autofdo/releases/tag/v0.30.1). This
commit is limited to x86 platforms that support PMU features
like LBR on Intel machines and AMD Zen3 BRS.

Here is an example workflow for building an AutoFDO+Propeller
optimized kernel:

1) Build the kernel on the host machine, with AutoFDO and Propeller
   build config
      CONFIG_AUTOFDO_CLANG=y
      CONFIG_PROPELLER_CLANG=y
   then
      $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<autofdo_profile>

“<autofdo_profile>” is the profile collected when doing a non-Propeller
AutoFDO build. This step builds a kernel that has the same optimization
level as AutoFDO, plus a metadata section that records basic block
information. This kernel image runs as fast as an AutoFDO optimized
kernel.

2) Install the kernel on test/production machines.

3) Run the load tests. The '-c' option in perf specifies the sample
   event period. We suggest using a suitable prime number,
   like 500009, for this purpose.
   For Intel platforms:
      $ perf record -e BR_INST_RETIRED.NEAR_TAKEN:k -a -N -b -c <count> \
        -o <perf_file> -- <loadtest>
   For AMD platforms:
      The supported system are: Zen3 with BRS, or Zen4 with amd_lbr_v2
      # To see if Zen3 support LBR:
      $ cat proc/cpuinfo | grep " brs"
      # To see if Zen4 support LBR:
      $ cat proc/cpuinfo | grep amd_lbr_v2
      # If the result is yes, then collect the profile using:
      $ perf record --pfm-events RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a \
        -N -b -c <count> -o <perf_file> -- <loadtest>

4) (Optional) Download the raw perf file to the host machine.

5) Generate Propeller profile:
   $ create_llvm_prof --binary=<vmlinux> --profile=<perf_file> \
     --format=propeller --propeller_output_module_name \
     --out=<propeller_profile_prefix>_cc_profile.txt \
     --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt

   “create_llvm_prof” is the profile conversion tool, and a prebuilt
   binary for linux can be found on
   https://github.com/google/autofdo/releases/tag/v0.30.1 (can also build
   from source).

   "<propeller_profile_prefix>" can be something like
   "/home/user/dir/any_string".

   This command generates a pair of Propeller profiles:
   "<propeller_profile_prefix>_cc_profile.txt" and
   "<propeller_profile_prefix>_ld_profile.txt".

6) Rebuild the kernel using the AutoFDO and Propeller profile files.
      CONFIG_AUTOFDO_CLANG=y
      CONFIG_PROPELLER_CLANG=y
   and
      $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<autofdo_profile> \
        CLANG_PROPELLER_PROFILE_PREFIX=<propeller_profile_prefix>

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Stephane Eranian <eranian@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Rong Xu
2fd65f7afd AutoFDO: Enable machine function split optimization for AutoFDO
Enable the machine function split optimization for AutoFDO in Clang.

Machine function split (MFS) is a pass in the Clang compiler that
splits a function into hot and cold parts. The linker groups all
cold blocks across functions together. This decreases hot code
fragmentation and improves iCache and iTLB utilization.

MFS requires a profile so this is enabled only for the AutoFDO builds.

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Rong Xu
0847420f5e AutoFDO: Enable -ffunction-sections for the AutoFDO build
Enable -ffunction-sections by default for the AutoFDO build.

With -ffunction-sections, the compiler places each function in its own
section named .text.function_name instead of placing all functions in
the .text section. In the AutoFDO build, this allows the linker to
utilize profile information to reorganize functions for improved
utilization of iCache and iTLB.

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Rong Xu
db0b2991ae vmlinux.lds.h: Add markers for text_unlikely and text_hot sections
Add markers like __hot_text_start, __hot_text_end, __unlikely_text_start,
and __unlikely_text_end which will be included in System.map. These markers
indicate how the compiler groups functions, providing valuable information
to developers about the layout and optimization of the code.

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Rong Xu
0043ecea23 vmlinux.lds.h: Adjust symbol ordering in text output section
When the -ffunction-sections compiler option is enabled, each function
is placed in a separate section named .text.function_name rather than
putting all functions in a single .text section.

However, using -function-sections can cause problems with the
linker script. The comments included in include/asm-generic/vmlinux.lds.h
note these issues.:
  “TEXT_MAIN here will match .text.fixup and .text.unlikely if dead
   code elimination is enabled, so these sections should be converted
   to use ".." first.”

It is unclear whether there is a straightforward method for converting
a suffix to "..".

This patch modifies the order of subsections within the text output
section. Specifically, it changes current order:
  .text.hot, .text, .text_unlikely, .text.unknown, .text.asan
to the new order:
  .text.asan, .text.unknown, .text_unlikely, .text.hot, .text

Here is the rationale behind the new layout:

The majority of the code resides in three sections: .text.hot, .text,
and .text.unlikely, with .text.unknown containing a negligible amount.
.text.asan is only generated in ASAN builds.

The primary goal is to group code segments based on their execution
frequency (hotness).

First, we want to place .text.hot adjacent to .text. Since we cannot put
.text.hot after .text (Due to constraints with -ffunction-sections,
placing .text.hot after .text is problematic), we need to put
.text.hot before .text.

Then it comes to .text.unlikely, we cannot put it after .text (same
-ffunction-sections issue) . Therefore, we position .text.unlikely
before .text.hot.

.text.unknown and .tex.asan follow the same logic.

This revised ordering effectively reverses the original arrangement (for
.text.unlikely, .text.unknown, and .tex.asan), maintaining a similar level
of affinity between sections.

It also places .text.hot section at the beginning of a page to better
utilize the TLB entry.

Note that the limitation arises because the linker script employs glob
patterns instead of regular expressions for string matching. While there
is a method to maintain the current order using complex patterns, this
significantly complicates the pattern and increases the likelihood of
errors.

This patch also changes vmlinux.lds.S for the sparc64 architecture to
accommodate specific symbol placement requirements.

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Linus Torvalds
5c00ff742b Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
2024-11-23 09:58:07 -08:00
Linus Torvalds
79caa6c88a Merge tag 'asm-generic-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
 "These are a number of unrelated cleanups, generally simplifying the
  architecture specific header files:

   - A series from Al Viro simplifies asm/vga.h, after it turns out that
     most of it can be generalized.

   - A series from Julian Vetter adds a common version of
     memcpy_{to,from}io() and memset_io() and changes most architectures
     to use that instead of their own implementation

   - A series from Niklas Schnelle concludes his work to make PC style
     inb()/outb() optional

   - Nicolas Pitre contributes improvements for the generic do_div()
     helper

   - Christoph Hellwig adds a generic version of page_to_phys() and
     phys_to_page(), replacing the slightly different architecture
     specific definitions.

   - Uwe Kleine-Koenig has a minor cleanup for ioctl definitions"

* tag 'asm-generic-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (24 commits)
  empty include/asm-generic/vga.h
  sparc: get rid of asm/vga.h
  asm/vga.h: don't bother with scr_mem{cpy,move}v() unless we need to
  vt_buffer.h: get rid of dead code in default scr_...() instances
  tty: serial: export serial_8250_warn_need_ioport
  lib/iomem_copy: fix kerneldoc format style
  hexagon: simplify asm/io.h for !HAS_IOPORT
  loongarch: Use new fallback IO memcpy/memset
  csky: Use new fallback IO memcpy/memset
  arm64: Use new fallback IO memcpy/memset
  New implementation for IO memcpy and IO memset
  watchdog: Add HAS_IOPORT dependency for SBC8360 and SBC7240
  __arch_xprod64(): make __always_inline when optimizing for performance
  ARM: div64: improve __arch_xprod_64()
  asm-generic/div64: optimize/simplify __div64_const32()
  lib/math/test_div64: add some edge cases relevant to __div64_const32()
  asm-generic: add an optional pfn_valid check to page_to_phys
  asm-generic: provide generic page_to_phys and phys_to_page implementations
  asm-generic/io.h: Remove I/O port accessors for HAS_IOPORT=n
  tty: serial: handle HAS_IOPORT dependencies
  ...
2024-11-20 15:13:02 -08:00
Linus Torvalds
bf9aa14fc5 Merge tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "A rather large update for timekeeping and timers:

   - The final step to get rid of auto-rearming posix-timers

     posix-timers are currently auto-rearmed by the kernel when the
     signal of the timer is ignored so that the timer signal can be
     delivered once the corresponding signal is unignored.

     This requires to throttle the timer to prevent a DoS by small
     intervals and keeps the system pointlessly out of low power states
     for no value. This is a long standing non-trivial problem due to
     the lock order of posix-timer lock and the sighand lock along with
     life time issues as the timer and the sigqueue have different life
     time rules.

     Cure this by:

       - Embedding the sigqueue into the timer struct to have the same
         life time rules. Aside of that this also avoids the lookup of
         the timer in the signal delivery and rearm path as it's just a
         always valid container_of() now.

       - Queuing ignored timer signals onto a seperate ignored list.

       - Moving queued timer signals onto the ignored list when the
         signal is switched to SIG_IGN before it could be delivered.

       - Walking the ignored list when SIG_IGN is lifted and requeue the
         signals to the actual signal lists. This allows the signal
         delivery code to rearm the timer.

     This also required to consolidate the signal delivery rules so they
     are consistent across all situations. With that all self test
     scenarios finally succeed.

   - Core infrastructure for VFS multigrain timestamping

     This is required to allow the kernel to use coarse grained time
     stamps by default and switch to fine grained time stamps when inode
     attributes are actively observed via getattr().

     These changes have been provided to the VFS tree as well, so that
     the VFS specific infrastructure could be built on top.

   - Cleanup and consolidation of the sleep() infrastructure

       - Move all sleep and timeout functions into one file

       - Rework udelay() and ndelay() into proper documented inline
         functions and replace the hardcoded magic numbers by proper
         defines.

       - Rework the fsleep() implementation to take the reality of the
         timer wheel granularity on different HZ values into account.
         Right now the boundaries are hard coded time ranges which fail
         to provide the requested accuracy on different HZ settings.

       - Update documentation for all sleep/timeout related functions
         and fix up stale documentation links all over the place

       - Fixup a few usage sites

   - Rework of timekeeping and adjtimex(2) to prepare for multiple PTP
     clocks

     A system can have multiple PTP clocks which are participating in
     seperate and independent PTP clock domains. So far the kernel only
     considers the PTP clock which is based on CLOCK TAI relevant as
     that's the clock which drives the timekeeping adjustments via the
     various user space daemons through adjtimex(2).

     The non TAI based clock domains are accessible via the file
     descriptor based posix clocks, but their usability is very limited.
     They can't be accessed fast as they always go all the way out to
     the hardware and they cannot be utilized in the kernel itself.

     As Time Sensitive Networking (TSN) gains traction it is required to
     provide fast user and kernel space access to these clocks.

     The approach taken is to utilize the timekeeping and adjtimex(2)
     infrastructure to provide this access in a similar way how the
     kernel provides access to clock MONOTONIC, REALTIME etc.

     Instead of creating a duplicated infrastructure this rework
     converts timekeeping and adjtimex(2) into generic functionality
     which operates on pointers to data structures instead of using
     static variables.

     This allows to provide time accessors and adjtimex(2) functionality
     for the independent PTP clocks in a subsequent step.

   - Consolidate hrtimer initialization

     hrtimers are set up by initializing the data structure and then
     seperately setting the callback function for historical reasons.

     That's an extra unnecessary step and makes Rust support less
     straight forward than it should be.

     Provide a new set of hrtimer_setup*() functions and convert the
     core code and a few usage sites of the less frequently used
     interfaces over.

     The bulk of the htimer_init() to hrtimer_setup() conversion is
     already prepared and scheduled for the next merge window.

   - Drivers:

       - Ensure that the global timekeeping clocksource is utilizing the
         cluster 0 timer on MIPS multi-cluster systems.

         Otherwise CPUs on different clusters use their cluster specific
         clocksource which is not guaranteed to be synchronized with
         other clusters.

       - Mostly boring cleanups, fixes, improvements and code movement"

* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
  posix-timers: Fix spurious warning on double enqueue versus do_exit()
  clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
  clocksource/drivers/gpx: Remove redundant casts
  clocksource/drivers/timer-ti-dm: Fix child node refcount handling
  dt-bindings: timer: actions,owl-timer: convert to YAML
  clocksource/drivers/ralink: Add Ralink System Tick Counter driver
  clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
  clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
  clocksource/drivers:sp804: Make user selectable
  clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
  hrtimers: Delete hrtimer_init_on_stack()
  alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
  io_uring: Switch to use hrtimer_setup_on_stack()
  sched/idle: Switch to use hrtimer_setup_on_stack()
  hrtimers: Delete hrtimer_init_sleeper_on_stack()
  wait: Switch to use hrtimer_setup_sleeper_on_stack()
  timers: Switch to use hrtimer_setup_sleeper_on_stack()
  net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
  futex: Switch to use hrtimer_setup_sleeper_on_stack()
  fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
  ...
2024-11-19 16:35:06 -08:00
Linus Torvalds
0352387523 Merge tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull vdso data page handling updates from Thomas Gleixner:
 "First steps of consolidating the VDSO data page handling.

  The VDSO data page handling is architecture specific for historical
  reasons, but there is no real technical reason to do so.

  Aside of that VDSO data has become a dump ground for various
  mechanisms and fail to provide a clear separation of the
  functionalities.

  Clean this up by:

   - consolidating the VDSO page data by getting rid of architecture
     specific warts especially in x86 and PowerPC.

   - removing the last includes of header files which are pulling in
     other headers outside of the VDSO namespace.

   - seperating timekeeping and other VDSO data accordingly.

  Further consolidation of the VDSO page handling is done in subsequent
  changes scheduled for the next merge window.

  This also lays the ground for expanding the VDSO time getters for
  independent PTP clocks in a generic way without making every
  architecture add support seperately"

* tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
  x86/vdso: Add missing brackets in switch case
  vdso: Rename struct arch_vdso_data to arch_vdso_time_data
  powerpc: Split systemcfg struct definitions out from vdso
  powerpc: Split systemcfg data out of vdso data page
  powerpc: Add kconfig option for the systemcfg page
  powerpc/pseries/lparcfg: Use num_possible_cpus() for potential processors
  powerpc/pseries/lparcfg: Fix printing of system_active_processors
  powerpc/procfs: Propagate error of remap_pfn_range()
  powerpc/vdso: Remove offset comment from 32bit vdso_arch_data
  x86/vdso: Split virtual clock pages into dedicated mapping
  x86/vdso: Delete vvar.h
  x86/vdso: Access vdso data without vvar.h
  x86/vdso: Move the rng offset to vsyscall.h
  x86/vdso: Access rng vdso data without vvar.h
  x86/vdso: Access timens vdso data without vvar.h
  x86/vdso: Allocate vvar page from C code
  x86/vdso: Access rng data from kernel without vvar
  x86/vdso: Place vdso_data at beginning of vvar page
  x86/vdso: Use __arch_get_vdso_data() to access vdso data
  x86/mm/mmap: Remove arch_vma_name()
  ...
2024-11-19 16:09:13 -08:00
Linus Torvalds
82339c4911 Merge tag 'pull-xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull xattr updates from Al Viro:
 "Sanitize xattr and io_uring interactions with it, add *xattrat()
  syscalls, sanitize struct filename handling in there"

* tag 'pull-xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  xattr: remove redundant check on variable err
  fs/xattr: add *at family syscalls
  new helpers: file_removexattr(), filename_removexattr()
  new helpers: file_listxattr(), filename_listxattr()
  replace do_getxattr() with saner helpers.
  replace do_setxattr() with saner helpers.
  new helper: import_xattr_name()
  fs: rename struct xattr_ctx to kernel_xattr_ctx
  xattr: switch to CLASS(fd)
  io_[gs]etxattr_prep(): just use getname()
  io_uring: IORING_OP_F[GS]ETXATTR is fine with REQ_F_FIXED_FILE
  getname_maybe_null() - the third variant of pathname copy-in
  teach filename_lookup() to treat NULL filename as ""
2024-11-18 12:44:25 -08:00
Al Viro
0af8e32343 empty include/asm-generic/vga.h
all places that use anything defined in it (vgacon, mdacon and
vga16fb) are built only on architectures that have all that
stuff in their native asm/vga.h

allows to kill stub asm/vga.h on sh, while we are at it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-11-11 21:51:42 +01:00
Alexandre Ghiti
ab83647fad riscv: Add qspinlock support
In order to produce a generic kernel, a user can select
CONFIG_COMBO_SPINLOCKS which will fallback at runtime to the ticket
spinlock implementation if Zabha or Ziccrse are not present.

Note that we can't use alternatives here because the discovery of
extensions is done too late and we need to start with the qspinlock
implementation because the ticket spinlock implementation would pollute
the spinlock value, so let's use static keys.

This is largely based on Guo's work and Leonardo reviews at [1].

Link: https://lore.kernel.org/linux-riscv/20231225125847.2778638-1-guoren@kernel.org/ [1]
Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20241103145153.105097-14-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-11 07:33:20 -08:00
Guo Ren
22c33321e2 asm-generic: ticket-lock: Add separate ticket-lock.h
Add a separate ticket-lock.h to include multiple spinlock versions and
select one at compile time or runtime.

Reviewed-by: Leonardo Bras <leobras@redhat.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-riscv/CAK8P3a2rnz9mQqhN6-e0CGUUv9rntRELFdxt_weiD7FxH7fkfQ@mail.gmail.com/
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20241103145153.105097-11-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-11 07:33:17 -08:00
Guo Ren
cbe82e140b asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock
The arch_spinlock_t of qspinlock has contained the atomic_t val, which
satisfies the ticket-lock requirement. Thus, unify the arch_spinlock_t
into qspinlock_types.h. This is the preparation for the next combo
spinlock.

Reviewed-by: Leonardo Bras <leobras@redhat.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-riscv/CAK8P3a2rnz9mQqhN6-e0CGUUv9rntRELFdxt_weiD7FxH7fkfQ@mail.gmail.com/
Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20241103145153.105097-10-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-11 07:33:16 -08:00
Suren Baghdasaryan
0db6f8d782 alloc_tag: load module tags into separate contiguous memory
When a module gets unloaded there is a possibility that some of the
allocations it made are still used and therefore the allocation tags
corresponding to these allocations are still referenced.  As such, the
memory for these tags can't be freed.  This is currently handled as an
abnormal situation and module's data section is not being unloaded.  To
handle this situation without keeping module's data in memory, allow
codetags with longer lifespan than the module to be loaded into their own
separate memory.  The in-use memory areas and gaps after module unloading
in this separate memory are tracked using maple trees.  Allocation tags
arrange their separate memory so that it is virtually contiguous and that
will allow simple allocation tag indexing later on in this patchset.  The
size of this virtually contiguous memory is set to store up to 100000
allocation tags.

[surenb@google.com: fix empty codetag module section handling]
  Link: https://lkml.kernel.org/r/20241101000017.3856204-1-surenb@google.com
[akpm@linux-foundation.org: update comment, per Dan]
Link: https://lkml.kernel.org/r/20241023170759.999909-4-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xiongwei Song <xiongwei.song@windriver.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:16 -08:00
Mike Rapoport (Microsoft)
0c3beacf68 asm-generic: introduce text-patching.h
Several architectures support text patching, but they name the header
files that declare patching functions differently.

Make all such headers consistently named text-patching.h and add an empty
header in asm-generic for architectures that do not support text patching.

Link: https://lkml.kernel.org/r/20241023162711.2579610-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops <kdevops@lists.linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:15 -08:00
Oscar Salvador
bd40b053fa mm: consolidate common checks in hugetlb_get_unmapped_area
prepare_hugepage_range() performs almost the same checks for all
architectures that define it, with the exception of mips and loongarch
that also check for overflows.

The rest checks for the addr and len to be properly aligned, so we can
move that to hugetlb_get_unmapped_area() and get rid of a fair amount of
duplicated code.

[akpm@linux-foundation.org: remove now-unused local]
 Link: https://lore.kernel.org/oe-kbuild-all/202410081210.uNLbf3Jk-lkp@intel.com/
Link: https://lkml.kernel.org/r/20241007075037.267650-10-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06 20:11:10 -08:00
Oscar Salvador
5b2f650d59 arch/s390: clean up hugetlb definitions
s390 redefines functions that are already defined (and the same) in
include/asm-generic/hugetlb.h.

Do as the other architectures:
1) include include/asm-generic/hugetlb.h
2) drop the already defined functions in the generic hugetlb.h and
3) use the __HAVE_ARCH_HUGE_* macros to define our own.

This gets rid of quite some code.

Link: https://lkml.kernel.org/r/20241007075037.267650-9-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06 20:11:10 -08:00
Christian Göttsche
6140be90ec fs/xattr: add *at family syscalls
Add the four syscalls setxattrat(), getxattrat(), listxattrat() and
removexattrat().  Those can be used to operate on extended attributes,
especially security related ones, either relative to a pinned directory
or on a file descriptor without read access, avoiding a
/proc/<pid>/fd/<fd> detour, requiring a mounted procfs.

One use case will be setfiles(8) setting SELinux file contexts
("security.selinux") without race conditions and without a file
descriptor opened with read access requiring SELinux read permission.

Use the do_{name}at() pattern from fs/open.c.

Pass the value of the extended attribute, its length, and for
setxattrat(2) the command (XATTR_CREATE or XATTR_REPLACE) via an added
struct xattr_args to not exceed six syscall arguments and not
merging the AT_* and XATTR_* flags.

[AV: fixes by Christian Brauner folded in, the entire thing rebased on
top of {filename,file}_...xattr() primitives, treatment of empty
pathnames regularized.  As the result, AT_EMPTY_PATH+NULL handling
is cheap, so f...(2) can use it]

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Link: https://lore.kernel.org/r/20240426162042.191916-1-cgoettsche@seltendoof.de
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
CC: x86@kernel.org
CC: linux-alpha@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-ia64@vger.kernel.org
CC: linux-m68k@lists.linux-m68k.org
CC: linux-mips@vger.kernel.org
CC: linux-parisc@vger.kernel.org
CC: linuxppc-dev@lists.ozlabs.org
CC: linux-s390@vger.kernel.org
CC: linux-sh@vger.kernel.org
CC: sparclinux@vger.kernel.org
CC: linux-fsdevel@vger.kernel.org
CC: audit@vger.kernel.org
CC: linux-arch@vger.kernel.org
CC: linux-api@vger.kernel.org
CC: linux-security-module@vger.kernel.org
CC: selinux@vger.kernel.org
[brauner: slight tweaks]
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-06 12:59:44 -05:00
Julian Vetter
b660d0a2ac New implementation for IO memcpy and IO memset
The IO memcpy and IO memset functions in asm-generic/io.h simply call
memcpy and memset. This can lead to alignment problems or faults on
architectures that do not define their own version and fall back to
these defaults.
This patch introduces new implementations for IO memcpy and IO memset,
that use read{l,q} accessor functions, align accesses to machine word
size, and resort to byte accesses when the target memory is not aligned.
For new architectures and existing ones that were using the old
fallbacks these functions are save to use, because IO memory constraints
are taken into account. Moreover, architectures with similar
implementations can now use these new versions, not needing to implement
their own.

Reviewed-by: Yann Sionneau <ysionneau@kalrayinc.com>
Signed-off-by: Julian Vetter <jvetter@kalrayinc.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-10-28 21:44:29 +00:00
Nicolas Pitre
d533cb2d2a __arch_xprod64(): make __always_inline when optimizing for performance
Recent gcc versions started not systematically inline __arch_xprod64()
and that has performance implications. Give the compiler the freedom to
decide only when optimizing for size.

Here's some timing numbers from lib/math/test_div64.c

Using __always_inline:

```
test_div64: Starting 64bit/32bit division and modulo test
test_div64: Completed 64bit/32bit division and modulo test, 0.048285584s elapsed
```

Without __always_inline:

```
test_div64: Starting 64bit/32bit division and modulo test
test_div64: Completed 64bit/32bit division and modulo test, 0.053023584s elapsed
```

Forcing constant base through the non-constant base code path:

```
test_div64: Starting 64bit/32bit division and modulo test
test_div64: Completed 64bit/32bit division and modulo test, 0.103263776s elapsed
```

It is worth noting that test_div64 does half the test with non constant
divisors already so the impact is greater than what those numbers show.
And for what it is worth, those numbers were obtained using QEMU. The
gcc version is 14.1.0.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-10-28 21:44:28 +00:00
Nicolas Pitre
00a31dd3ac asm-generic/div64: optimize/simplify __div64_const32()
Several years later I just realized that this code could be greatly
simplified.

First, let's formalize the need for overflow handling in
__arch_xprod64(). Assuming n = UINT64_MAX, there are 2 cases where
an overflow may occur:

1) If a bias must be added, we have m_lo * n_lo + m or
   m_lo * 0xffffffff + ((m_hi << 32) + m_lo) or
   ((m_lo << 32) - m_lo) + ((m_hi << 32) + m_lo) or
   (m_lo + m_hi) << 32 which must be < (1 << 64). So the criteria for no
   overflow is m_lo + m_hi < (1 << 32).

2) The cross product m_lo * n_hi + m_hi * n_lo or
   m_lo * 0xffffffff + m_hi * 0xffffffff or
   ((m_lo << 32) - m_lo) + ((m_hi << 32) - m_hi). Assuming the top
   result from the previous step (m_lo + m_hi) that must be added to
   this, we get (m_lo + m_hi) << 32 again.

So let's have a straight and simpler version when this is true.
Otherwise some reordering allows for taking care of possible overflows
without any actual conditionals. And prevent from generating both code
variants by making sure this is considered only if m is perceived as
constant by the compiler.

This, in turn, allows for greatly simplifying __div64_const32(). The
"special case" may go as well as the regular case works just fine
without needing a bias. Then reduction should be applied all the time as
minimizing m is the key.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-10-28 21:44:28 +00:00