linux.git/arch/mips/include/asm, branch v6.16 Linux kernel source tree mm: pgtable: fix pte_swp_exclusive 2025-06-11T21:52:08+00:00 Magnus Lindholm linmag7@gmail.com 2025-02-18T17:55:14+00:00 403d1338a4a59cfebb4ded53fa35fbd5119f36b1 Make pte_swp_exclusive return bool instead of int. This will better reflect how pte_swp_exclusive is actually used in the code. This fixes swap/swapoff problems on Alpha due pte_swp_exclusive not returning correct values when _PAGE_SWP_EXCLUSIVE bit resides in upper 32-bits of PTE (like on alpha). Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Magnus Lindholm <linmag7@gmail.com> Cc: Sam James <sam@gentoo.org> Link: https://lore.kernel.org/lkml/20250218175735.19882-2-linmag7@gmail.com/ Link: https://lore.kernel.org/lkml/20250602041118.GA2675383@ZenIV/ [ Applied as the 'sed' script Al suggested - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Make pte_swp_exclusive return bool instead of int.  This will better
reflect how pte_swp_exclusive is actually used in the code.

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

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Cc: Sam James <sam@gentoo.org>
Link: https://lore.kernel.org/lkml/20250218175735.19882-2-linmag7@gmail.com/
Link: https://lore.kernel.org/lkml/20250602041118.GA2675383@ZenIV/
[ Applied as the 'sed' script Al suggested   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'mips_6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux 2025-06-06T14:56:36+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-06-06T14:56:36+00:00 67faad74352d1ce0c1f411f92fdb1e0c0f3c9380 Pull MIPS updates from Thomas Bogendoerfer: - Added support for EcoNet platform - Added support for parallel CPU bring up on EyeQ - Other cleanups and fixes * tag 'mips_6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (23 commits) MIPS: loongson2ef: lemote-2f: add missing function prototypes MIPS: loongson2ef: cs5536: add missing function prototypes MIPS: SMP: Move the AP sync point before the calibration delay mips: econet: Fix incorrect Kconfig dependencies MAINTAINERS: Add entry for newly added EcoNet platform. mips: dts: Add EcoNet DTS with EN751221 and SmartFiber XP8421-B board dt-bindings: vendor-prefixes: Add SmartFiber mips: Add EcoNet MIPS platform support dt-bindings: mips: Add EcoNet platform binding MIPS: bcm63xx: nvram: avoid inefficient use of crc32_le_combine() mips: dts: pic32: pic32mzda: Rename the sdhci nodename to match with common mmc-controller binding MIPS: SMP: Move the AP sync point before the non-parallel aware functions MIPS: Replace strcpy() with strscpy() in vpe_elfload() MIPS: BCM63XX: Replace strcpy() with strscpy() in board_prom_init() mips: ptrace: Improve code formatting and indentation MIPS: SMP: Implement parallel CPU bring up for EyeQ mips: Add -std= flag specified in KBUILD_CFLAGS to vdso CFLAGS MIPS: Loongson64: Add missing '#interrupt-cells' for loongson64c_ls7a mips: dts: realtek: Add MDIO controller MIPS: txx9: gpio: use new line value setter callbacks ... 
Pull MIPS updates from Thomas Bogendoerfer:

 - Added support for EcoNet platform

 - Added support for parallel CPU bring up on EyeQ

 - Other cleanups and fixes

* tag 'mips_6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (23 commits)
  MIPS: loongson2ef: lemote-2f: add missing function prototypes
  MIPS: loongson2ef: cs5536: add missing function prototypes
  MIPS: SMP: Move the AP sync point before the calibration delay
  mips: econet: Fix incorrect Kconfig dependencies
  MAINTAINERS: Add entry for newly added EcoNet platform.
  mips: dts: Add EcoNet DTS with EN751221 and SmartFiber XP8421-B board
  dt-bindings: vendor-prefixes: Add SmartFiber
  mips: Add EcoNet MIPS platform support
  dt-bindings: mips: Add EcoNet platform binding
  MIPS: bcm63xx: nvram: avoid inefficient use of crc32_le_combine()
  mips: dts: pic32: pic32mzda: Rename the sdhci nodename to match with common mmc-controller binding
  MIPS: SMP: Move the AP sync point before the non-parallel aware functions
  MIPS: Replace strcpy() with strscpy() in vpe_elfload()
  MIPS: BCM63XX: Replace strcpy() with strscpy() in board_prom_init()
  mips: ptrace: Improve code formatting and indentation
  MIPS: SMP: Implement parallel CPU bring up for EyeQ
  mips: Add -std= flag specified in KBUILD_CFLAGS to vdso CFLAGS
  MIPS: Loongson64: Add missing '#interrupt-cells' for loongson64c_ls7a
  mips: dts: realtek: Add MDIO controller
  MIPS: txx9: gpio: use new line value setter callbacks
  ...
Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2025-05-31T22:44:16+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-05-31T22:44:16+00:00 00c010e130e58301db2ea0cec1eadc931e1cb8cf Pull MM updates from Andrew Morton: - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - "Always call constructor for kernel page tables" from Kevin Brodsky ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - "vmscan: enforce mems_effective during demotion" from Gregory Price changes reclaim to respect cpuset.mems_effective during demotion when possible. because presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently. - "Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. * tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits) mm: pcp: increase pcp->free_count threshold to trigger free_high mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range() mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page mm/hugetlb: pass folio instead of page to unmap_ref_private() memcg: objcg stock trylock without irq disabling memcg: no stock lock for cpu hot-unplug memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs memcg: make count_memcg_events re-entrant safe against irqs memcg: make mod_memcg_state re-entrant safe against irqs memcg: move preempt disable to callers of memcg_rstat_updated memcg: memcg_rstat_updated re-entrant safe against irqs mm: khugepaged: decouple SHMEM and file folios' collapse selftests/eventfd: correct test name and improve messages alloc_tag: check mem_profiling_support in alloc_tag_init Docs/damon: update titles and brief introductions to explain DAMOS selftests/damon/_damon_sysfs: read tried regions directories in order mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject() mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat() mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs ... 
Pull MM updates from Andrew Morton:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

   Dramatic performance benefits were seen in some real world cases.

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

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

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

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

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

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

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

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

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

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

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

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

* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
  mm: pcp: increase pcp->free_count threshold to trigger free_high
  mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
  mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: pass folio instead of page to unmap_ref_private()
  memcg: objcg stock trylock without irq disabling
  memcg: no stock lock for cpu hot-unplug
  memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
  memcg: make count_memcg_events re-entrant safe against irqs
  memcg: make mod_memcg_state re-entrant safe against irqs
  memcg: move preempt disable to callers of memcg_rstat_updated
  memcg: memcg_rstat_updated re-entrant safe against irqs
  mm: khugepaged: decouple SHMEM and file folios' collapse
  selftests/eventfd: correct test name and improve messages
  alloc_tag: check mem_profiling_support in alloc_tag_init
  Docs/damon: update titles and brief introductions to explain DAMOS
  selftests/damon/_damon_sysfs: read tried regions directories in order
  mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
  mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
  mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
  ...
MIPS: loongson2ef: lemote-2f: add missing function prototypes 2025-05-30T12:19:02+00:00 Randy Dunlap rdunlap@infradead.org 2025-05-29T03:20:05+00:00 5a0c749125c001cba673e9951b0002fba7ea2886 Add several missing function prototypes for lemote-2f to eliminate build warnings: arch/mips/loongson2ef/lemote-2f/machtype.c:10:13: warning: no previous prototype for 'mach_prom_init_machtype' [-Wmissing-prototypes] 10 | void __init mach_prom_init_machtype(void) arch/mips/loongson2ef/common/machtype.c:34:20: warning: no previous prototype for 'mach_prom_init_machtype' [-Wmissing-prototypes] 34 | void __weak __init mach_prom_init_machtype(void) arch/mips/loongson2ef/lemote-2f/pm.c:52:6: warning: no previous prototype for 'setup_wakeup_events' [-Wmissing-prototypes] 52 | void setup_wakeup_events(void) arch/mips/loongson2ef/lemote-2f/pm.c:90:5: warning: no previous prototype for 'wakeup_loongson' [-Wmissing-prototypes] 90 | int wakeup_loongson(void) arch/mips/loongson2ef/lemote-2f/pm.c:137:13: warning: no previous prototype for 'mach_suspend' [-Wmissing-prototypes] 137 | void __weak mach_suspend(void) arch/mips/loongson2ef/lemote-2f/pm.c:142:13: warning: no previous prototype for 'mach_resume' [-Wmissing-prototypes] 142 | void __weak mach_resume(void) Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: linux-mips@vger.kernel.org Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
Add several missing function prototypes for lemote-2f to eliminate
build warnings:

arch/mips/loongson2ef/lemote-2f/machtype.c:10:13: warning: no previous prototype for 'mach_prom_init_machtype' [-Wmissing-prototypes]
   10 | void __init mach_prom_init_machtype(void)
arch/mips/loongson2ef/common/machtype.c:34:20: warning: no previous prototype for 'mach_prom_init_machtype' [-Wmissing-prototypes]
   34 | void __weak __init mach_prom_init_machtype(void)
arch/mips/loongson2ef/lemote-2f/pm.c:52:6: warning: no previous prototype for 'setup_wakeup_events' [-Wmissing-prototypes]
   52 | void setup_wakeup_events(void)
arch/mips/loongson2ef/lemote-2f/pm.c:90:5: warning: no previous prototype for 'wakeup_loongson' [-Wmissing-prototypes]
   90 | int wakeup_loongson(void)
arch/mips/loongson2ef/lemote-2f/pm.c:137:13: warning: no previous prototype for 'mach_suspend' [-Wmissing-prototypes]
  137 | void __weak mach_suspend(void)
arch/mips/loongson2ef/lemote-2f/pm.c:142:13: warning: no previous prototype for 'mach_resume' [-Wmissing-prototypes]
  142 | void __weak mach_resume(void)

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-mips@vger.kernel.org
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
MIPS: loongson2ef: cs5536: add missing function prototypes 2025-05-30T12:18:33+00:00 Randy Dunlap rdunlap@infradead.org 2025-05-29T03:19:56+00:00 314da9d6b3119328c1a38234c68e720380d14957 Add missing function prototypes for cs5536, mostly for PCI functions, and for init_mfgpt_clocksource(). arch/mips/loongson2ef/common/cs5536/cs5536_ide.c:15:6: warning: no previous prototype for 'pci_ide_write_reg' [-Wmissing-prototypes] 15 | void pci_ide_write_reg(int reg, u32 value) arch/mips/loongson2ef/common/cs5536/cs5536_ide.c:96:5: warning: no previous prototype for 'pci_ide_read_reg' [-Wmissing-prototypes] 96 | u32 pci_ide_read_reg(int reg) arch/mips/loongson2ef/common/cs5536/cs5536_ehci.c:15:6: warning: no previous prototype for 'pci_ehci_write_reg' [-Wmissing-prototypes] 15 | void pci_ehci_write_reg(int reg, u32 value) arch/mips/loongson2ef/common/cs5536/cs5536_ehci.c:75:5: warning: no previous prototype for 'pci_ehci_read_reg' [-Wmissing-prototypes] 75 | u32 pci_ehci_read_reg(int reg) arch/mips/loongson2ef/common/cs5536/cs5536_acc.c:15:6: warning: no previous prototype for 'pci_acc_write_reg' [-Wmissing-prototypes] 15 | void pci_acc_write_reg(int reg, u32 value) arch/mips/loongson2ef/common/cs5536/cs5536_acc.c:62:5: warning: no previous prototype for 'pci_acc_read_reg' [-Wmissing-prototypes] 62 | u32 pci_acc_read_reg(int reg) arch/mips/loongson2ef/common/cs5536/cs5536_ohci.c:15:6: warning: no previous prototype for 'pci_ohci_write_reg' [-Wmissing-prototypes] 15 | void pci_ohci_write_reg(int reg, u32 value) arch/mips/loongson2ef/common/cs5536/cs5536_ohci.c:70:5: warning: no previous prototype for 'pci_ohci_read_reg' [-Wmissing-prototypes] 70 | u32 pci_ohci_read_reg(int reg) arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:84:6: warning: no previous prototype for 'pci_isa_write_bar' [-Wmissing-prototypes] 84 | void pci_isa_write_bar(int n, u32 value) arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:110:5: warning: no previous prototype for 'pci_isa_read_bar' [-Wmissing-prototypes] 110 | u32 pci_isa_read_bar(int n) arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:134:6: warning: no previous prototype for 'pci_isa_write_reg' [-Wmissing-prototypes] 134 | void pci_isa_write_reg(int reg, u32 value) arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:228:5: warning: no previous prototype for 'pci_isa_read_reg' [-Wmissing-prototypes] 228 | u32 pci_isa_read_reg(int reg) arch/mips/loongson2ef/common/cs5536/cs5536_mfgpt.c:195:12: warning: no previous prototype for 'init_mfgpt_clocksource' [-Wmissing-prototypes] 195 | int __init init_mfgpt_clocksource(void) Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: linux-mips@vger.kernel.org Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
Add missing function prototypes for cs5536, mostly for PCI functions,
and for init_mfgpt_clocksource().

arch/mips/loongson2ef/common/cs5536/cs5536_ide.c:15:6: warning: no previous prototype for 'pci_ide_write_reg' [-Wmissing-prototypes]
   15 | void pci_ide_write_reg(int reg, u32 value)
arch/mips/loongson2ef/common/cs5536/cs5536_ide.c:96:5: warning: no previous prototype for 'pci_ide_read_reg' [-Wmissing-prototypes]
   96 | u32 pci_ide_read_reg(int reg)

arch/mips/loongson2ef/common/cs5536/cs5536_ehci.c:15:6: warning: no previous prototype for 'pci_ehci_write_reg' [-Wmissing-prototypes]
   15 | void pci_ehci_write_reg(int reg, u32 value)
arch/mips/loongson2ef/common/cs5536/cs5536_ehci.c:75:5: warning: no previous prototype for 'pci_ehci_read_reg' [-Wmissing-prototypes]
   75 | u32 pci_ehci_read_reg(int reg)

arch/mips/loongson2ef/common/cs5536/cs5536_acc.c:15:6: warning: no previous prototype for 'pci_acc_write_reg' [-Wmissing-prototypes]
   15 | void pci_acc_write_reg(int reg, u32 value)
arch/mips/loongson2ef/common/cs5536/cs5536_acc.c:62:5: warning: no previous prototype for 'pci_acc_read_reg' [-Wmissing-prototypes]
   62 | u32 pci_acc_read_reg(int reg)

arch/mips/loongson2ef/common/cs5536/cs5536_ohci.c:15:6: warning: no previous prototype for 'pci_ohci_write_reg' [-Wmissing-prototypes]
   15 | void pci_ohci_write_reg(int reg, u32 value)
arch/mips/loongson2ef/common/cs5536/cs5536_ohci.c:70:5: warning: no previous prototype for 'pci_ohci_read_reg' [-Wmissing-prototypes]
   70 | u32 pci_ohci_read_reg(int reg)

arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:84:6: warning: no previous prototype for 'pci_isa_write_bar' [-Wmissing-prototypes]
   84 | void pci_isa_write_bar(int n, u32 value)
arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:110:5: warning: no previous prototype for 'pci_isa_read_bar' [-Wmissing-prototypes]
  110 | u32 pci_isa_read_bar(int n)
arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:134:6: warning: no previous prototype for 'pci_isa_write_reg' [-Wmissing-prototypes]
  134 | void pci_isa_write_reg(int reg, u32 value)
arch/mips/loongson2ef/common/cs5536/cs5536_isa.c:228:5: warning: no previous prototype for 'pci_isa_read_reg' [-Wmissing-prototypes]
  228 | u32 pci_isa_read_reg(int reg)

arch/mips/loongson2ef/common/cs5536/cs5536_mfgpt.c:195:12: warning: no previous prototype for 'init_mfgpt_clocksource' [-Wmissing-prototypes]
  195 | int __init init_mfgpt_clocksource(void)

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-mips@vger.kernel.org
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Merge tag 'vfs-6.16-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs 2025-05-26T18:17:01+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-05-26T18:17:01+00:00 c5bfc48d5472fc60abafb510668d7bc3b5ecb401 Pull coredump updates from Christian Brauner: "This adds support for sending coredumps over an AF_UNIX socket. It also makes (implicit) use of the new SO_PEERPIDFD ability to hand out pidfds for reaped peer tasks The new coredump socket will allow userspace to not have to rely on usermode helpers for processing coredumps and provides a saf way to handle them instead of relying on super privileged coredumping helpers This will also be significantly more lightweight since the kernel doens't have to do a fork()+exec() for each crashing process to spawn a usermodehelper. Instead the kernel just connects to the AF_UNIX socket and userspace can process it concurrently however it sees fit. Support for userspace is incoming starting with systemd-coredump There's more work coming in that direction next cycle. The rest below goes into some details and background Coredumping currently supports two modes: (1) Dumping directly into a file somewhere on the filesystem. (2) Dumping into a pipe connected to a usermode helper process spawned as a child of the system_unbound_wq or kthreadd For simplicity I'm mostly ignoring (1). There's probably still some users of (1) out there but processing coredumps in this way can be considered adventurous especially in the face of set*id binaries The most common option should be (2) by now. It works by allowing userspace to put a string into /proc/sys/kernel/core_pattern like: |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h The "|" at the beginning indicates to the kernel that a pipe must be used. The path following the pipe indicator is a path to a binary that will be spawned as a usermode helper process. Any additional parameters pass information about the task that is generating the coredump to the binary that processes the coredump In the example the core_pattern shown causes the kernel to spawn systemd-coredump as a usermode helper. There's various conceptual consequences of this (non-exhaustive list): - systemd-coredump is spawned with file descriptor number 0 (stdin) connected to the read-end of the pipe. All other file descriptors are closed. That specifically includes 1 (stdout) and 2 (stderr). This has already caused bugs because userspace assumed that this cannot happen (Whether or not this is a sane assumption is irrelevant) - systemd-coredump will be spawned as a child of system_unbound_wq. So it is not a child of any userspace process and specifically not a child of PID 1. It cannot be waited upon and is in a weird hybrid upcall which are difficult for userspace to control correctly - systemd-coredump is spawned with full kernel privileges. This necessitates all kinds of weird privilege dropping excercises in userspace to make this safe - A new usermode helper has to be spawned for each crashing process This adds a new mode: (3) Dumping into an AF_UNIX socket Userspace can set /proc/sys/kernel/core_pattern to: @/path/to/coredump.socket The "@" at the beginning indicates to the kernel that an AF_UNIX coredump socket will be used to process coredumps The coredump socket must be located in the initial mount namespace. When a task coredumps it opens a client socket in the initial network namespace and connects to the coredump socket: - The coredump server uses SO_PEERPIDFD to get a stable handle on the connected crashing task. The retrieved pidfd will provide a stable reference even if the crashing task gets SIGKILLed while generating the coredump. That is a huge attack vector right now - By setting core_pipe_limit non-zero userspace can guarantee that the crashing task cannot be reaped behind it's back and thus process all necessary information in /proc/<pid>. The SO_PEERPIDFD can be used to detect whether /proc/<pid> still refers to the same process The core_pipe_limit isn't used to rate-limit connections to the socket. This can simply be done via AF_UNIX socket directly - The pidfd for the crashing task will contain information how the task coredumps. The PIDFD_GET_INFO ioctl gained a new flag PIDFD_INFO_COREDUMP which can be used to retreive the coredump information If the coredump gets a new coredump client connection the kernel guarantees that PIDFD_INFO_COREDUMP information is available. Currently the following information is provided in the new @coredump_mask extension to struct pidfd_info: * PIDFD_COREDUMPED is raised if the task did actually coredump * PIDFD_COREDUMP_SKIP is raised if the task skipped coredumping (e.g., undumpable) * PIDFD_COREDUMP_USER is raised if this is a regular coredump and doesn't need special care by the coredump server * PIDFD_COREDUMP_ROOT is raised if the generated coredump should be treated as sensitive and the coredump server should restrict access to the generated coredump to sufficiently privileged users" * tag 'vfs-6.16-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: mips, net: ensure that SOCK_COREDUMP is defined selftests/coredump: add tests for AF_UNIX coredumps selftests/pidfd: add PIDFD_INFO_COREDUMP infrastructure coredump: validate socket name as it is written coredump: show supported coredump modes pidfs, coredump: add PIDFD_INFO_COREDUMP coredump: add coredump socket coredump: reflow dump helpers a little coredump: massage do_coredump() coredump: massage format_corename() 
Pull coredump updates from Christian Brauner:
 "This adds support for sending coredumps over an AF_UNIX socket. It
  also makes (implicit) use of the new SO_PEERPIDFD ability to hand out
  pidfds for reaped peer tasks

  The new coredump socket will allow userspace to not have to rely on
  usermode helpers for processing coredumps and provides a saf way to
  handle them instead of relying on super privileged coredumping helpers

  This will also be significantly more lightweight since the kernel
  doens't have to do a fork()+exec() for each crashing process to spawn
  a usermodehelper. Instead the kernel just connects to the AF_UNIX
  socket and userspace can process it concurrently however it sees fit.
  Support for userspace is incoming starting with systemd-coredump

  There's more work coming in that direction next cycle. The rest below
  goes into some details and background

  Coredumping currently supports two modes:

   (1) Dumping directly into a file somewhere on the filesystem.

   (2) Dumping into a pipe connected to a usermode helper process
       spawned as a child of the system_unbound_wq or kthreadd

  For simplicity I'm mostly ignoring (1). There's probably still some
  users of (1) out there but processing coredumps in this way can be
  considered adventurous especially in the face of set*id binaries

  The most common option should be (2) by now. It works by allowing
  userspace to put a string into /proc/sys/kernel/core_pattern like:

          |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h

  The "|" at the beginning indicates to the kernel that a pipe must be
  used. The path following the pipe indicator is a path to a binary that
  will be spawned as a usermode helper process. Any additional
  parameters pass information about the task that is generating the
  coredump to the binary that processes the coredump

  In the example the core_pattern shown causes the kernel to spawn
  systemd-coredump as a usermode helper. There's various conceptual
  consequences of this (non-exhaustive list):

   - systemd-coredump is spawned with file descriptor number 0 (stdin)
     connected to the read-end of the pipe. All other file descriptors
     are closed. That specifically includes 1 (stdout) and 2 (stderr).

     This has already caused bugs because userspace assumed that this
     cannot happen (Whether or not this is a sane assumption is
     irrelevant)

   - systemd-coredump will be spawned as a child of system_unbound_wq.
     So it is not a child of any userspace process and specifically not
     a child of PID 1. It cannot be waited upon and is in a weird hybrid
     upcall which are difficult for userspace to control correctly

   - systemd-coredump is spawned with full kernel privileges. This
     necessitates all kinds of weird privilege dropping excercises in
     userspace to make this safe

   - A new usermode helper has to be spawned for each crashing process

  This adds a new mode:

   (3) Dumping into an AF_UNIX socket

  Userspace can set /proc/sys/kernel/core_pattern to:

          @/path/to/coredump.socket

  The "@" at the beginning indicates to the kernel that an AF_UNIX
  coredump socket will be used to process coredumps

  The coredump socket must be located in the initial mount namespace.
  When a task coredumps it opens a client socket in the initial network
  namespace and connects to the coredump socket:

   - The coredump server uses SO_PEERPIDFD to get a stable handle on the
     connected crashing task. The retrieved pidfd will provide a stable
     reference even if the crashing task gets SIGKILLed while generating
     the coredump. That is a huge attack vector right now

   - By setting core_pipe_limit non-zero userspace can guarantee that
     the crashing task cannot be reaped behind it's back and thus
     process all necessary information in /proc/<pid>. The SO_PEERPIDFD
     can be used to detect whether /proc/<pid> still refers to the same
     process

     The core_pipe_limit isn't used to rate-limit connections to the
     socket. This can simply be done via AF_UNIX socket directly

   - The pidfd for the crashing task will contain information how the
     task coredumps. The PIDFD_GET_INFO ioctl gained a new flag
     PIDFD_INFO_COREDUMP which can be used to retreive the coredump
     information

     If the coredump gets a new coredump client connection the kernel
     guarantees that PIDFD_INFO_COREDUMP information is available.

     Currently the following information is provided in the new
     @coredump_mask extension to struct pidfd_info:

      * PIDFD_COREDUMPED is raised if the task did actually coredump

      * PIDFD_COREDUMP_SKIP is raised if the task skipped coredumping
        (e.g., undumpable)

      * PIDFD_COREDUMP_USER is raised if this is a regular coredump and
        doesn't need special care by the coredump server

      * PIDFD_COREDUMP_ROOT is raised if the generated coredump should
        be treated as sensitive and the coredump server should restrict
        access to the generated coredump to sufficiently privileged
        users"

* tag 'vfs-6.16-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  mips, net: ensure that SOCK_COREDUMP is defined
  selftests/coredump: add tests for AF_UNIX coredumps
  selftests/pidfd: add PIDFD_INFO_COREDUMP infrastructure
  coredump: validate socket name as it is written
  coredump: show supported coredump modes
  pidfs, coredump: add PIDFD_INFO_COREDUMP
  coredump: add coredump socket
  coredump: reflow dump helpers a little
  coredump: massage do_coredump()
  coredump: massage format_corename()
mips, net: ensure that SOCK_COREDUMP is defined 2025-05-23T09:02:16+00:00 Christian Brauner brauner@kernel.org 2025-05-23T08:47:06+00:00 4e83ae6ec87dddac070ba349d3b839589b1bb957 For historical reasons mips has to override the socket enum values but the defines are all the same. So simply move the ARCH_HAS_SOCKET_TYPES scope. Fixes: a9194f88782a ("coredump: add coredump socket") Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Christian Brauner <brauner@kernel.org> 
For historical reasons mips has to override the socket enum values but
the defines are all the same. So simply move the ARCH_HAS_SOCKET_TYPES
scope.

Fixes: a9194f88782a ("coredump: add coredump socket")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
mm: pass mm down to pagetable_{pte,pmd}_ctor 2025-05-12T00:48:21+00:00 Kevin Brodsky kevin.brodsky@arm.com 2025-04-08T09:52:11+00:00 d82d3bf4115217bb3f43f9320bad5d68a35c278f Patch series "Always call constructor for kernel page tables", v2. There has been much confusion around exactly when page table constructors/destructors (pagetable_*_[cd]tor) are supposed to be called. They were initially introduced for user PTEs only (to support split page table locks), then at the PMD level for the same purpose. Accounting was added later on, starting at the PTE level and then moving to higher levels (PMD, PUD). Finally, with my earlier series "Account page tables at all levels" [1], the ctor/dtor is run for all levels, all the way to PGD. I thought this was the end of the story, and it hopefully is for user pgtables, but I was wrong for what concerns kernel pgtables. The current situation there makes very little sense: * At the PTE level, the ctor/dtor is not called (at least in the generic implementation). Specific helpers are used for kernel pgtables at this level (pte_{alloc,free}_kernel()) and those have never called the ctor/dtor, most likely because they were initially irrelevant in the kernel case. * At all other levels, the ctor/dtor is normally called. This is potentially wasteful at the PMD level (more on that later). This series aims to ensure that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. Besides consistency, the main motivation is to guarantee that ctor/dtor hooks are systematically called; this makes it possible to insert hooks to protect page tables [2], for instance. There is however an extra challenge: split locks are not used for kernel pgtables, and it would therefore be wasteful to initialise them (ptlock_init()). It is worth clarifying exactly when split locks are used. They clearly are for user pgtables, but as illustrated in commit 61444cde9170 ("ARM: 8591/1: mm: use fully constructed struct pages for EFI pgd allocations"), they also are for special page tables like efi_mm. The one case where split locks are definitely unused is pgtables owned by init_mm; this is consistent with the behaviour of apply_to_pte_range(). The approach chosen in this series is therefore to pass the mm associated to the pgtables being constructed to pagetable_{pte,pmd}_ctor() (patch 1), and skip ptlock_init() if mm == &init_mm (patch 3 and 7). This makes it possible to call the PTE ctor/dtor from pte_{alloc,free}_kernel() without unintended consequences (patch 3). As a result the accounting functions are now called at all levels for kernel pgtables, and split locks are never initialised. In configurations where ptlocks are dynamically allocated (32-bit, PREEMPT_RT, etc.) and ARCH_ENABLE_SPLIT_PMD_PTLOCK is selected, this series results in the removal of a kmem_cache allocation for every kernel PMD. Additionally, for certain architectures that do not use <asm-generic/pgalloc.h> such as s390, the same optimisation occurs at the PTE level. === Things get more complicated when it comes to special pgtable allocators (patch 8-12). All architectures need such allocators to create initial kernel pgtables; we are not concerned with those as the ctor cannot be called so early in the boot sequence. However, those allocators may also be used later in the boot sequence or during normal operations. There are two main use-cases: 1. Mapping EFI memory: efi_mm (arm, arm64, riscv) 2. arch_add_memory(): init_mm The ctor is already explicitly run (at the PTE/PMD level) in the first case, as required for pgtables that are not associated with init_mm. However the same allocators may also be used for the second use-case (or others), and this is where it gets messy. Patch 1 calls the ctor with NULL as mm in those situations, as the actual mm isn't available. Practically this means that ptlocks will be unconditionally initialised. This is fine on arm - create_mapping_late() is only used for the EFI mapping. On arm64, __create_pgd_mapping() is also used by arch_add_memory(); patch 8/9/11 ensure that ctors are called at all levels with the appropriate mm. The situation is similar on riscv, but propagating the mm down to the ctor would require significant refactoring. Since they are already called unconditionally, this series leaves riscv no worse off - patch 10 adds comments to clarify the situation. From a cursory look at other architectures implementing arch_add_memory(), s390 and x86 may also need a similar treatment to add constructor calls. This is to be taken care of in a future version or as a follow-up. === The complications in those special pgtable allocators beg the question: does it really make sense to treat efi_mm and init_mm differently in e.g. apply_to_pte_range()? Maybe what we really need is a way to tell if an mm corresponds to user memory or not, and never use split locks for non-user mm's. Feedback and suggestions welcome! This patch (of 12): In preparation for calling constructors for all kernel page tables while eliding unnecessary ptlock initialisation, let's pass down the associated mm to the PTE/PMD level ctors. (These are the two levels where ptlocks are used.) In most cases the mm is already around at the point of calling the ctor so we simply pass it down. This is however not the case for special page table allocators: * arch/arm/mm/mmu.c * arch/arm64/mm/mmu.c * arch/riscv/mm/init.c In those cases, the page tables being allocated are either for standard kernel memory (init_mm) or special page directories, which may not be associated to any mm. For now let's pass NULL as mm; this will be refined where possible in future patches. No functional change in this patch. Link: https://lore.kernel.org/linux-mm/20250103184415.2744423-1-kevin.brodsky@arm.com/ [1] Link: https://lore.kernel.org/linux-hardening/20250203101839.1223008-1-kevin.brodsky@arm.com/ [2] Link: https://lkml.kernel.org/r/20250408095222.860601-1-kevin.brodsky@arm.com Link: https://lkml.kernel.org/r/20250408095222.860601-2-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Linus Waleij <linus.walleij@linaro.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: <x86@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Patch series "Always call constructor for kernel page tables", v2.

There has been much confusion around exactly when page table
constructors/destructors (pagetable_*_[cd]tor) are supposed to be called. 
They were initially introduced for user PTEs only (to support split page
table locks), then at the PMD level for the same purpose.  Accounting was
added later on, starting at the PTE level and then moving to higher levels
(PMD, PUD).  Finally, with my earlier series "Account page tables at all
levels" [1], the ctor/dtor is run for all levels, all the way to PGD.

I thought this was the end of the story, and it hopefully is for user
pgtables, but I was wrong for what concerns kernel pgtables.  The current
situation there makes very little sense:

* At the PTE level, the ctor/dtor is not called (at least in the generic
  implementation).  Specific helpers are used for kernel pgtables at this
  level (pte_{alloc,free}_kernel()) and those have never called the
  ctor/dtor, most likely because they were initially irrelevant in the
  kernel case.

* At all other levels, the ctor/dtor is normally called.  This is
  potentially wasteful at the PMD level (more on that later).

This series aims to ensure that the ctor/dtor is always called for kernel
pgtables, as it already is for user pgtables.  Besides consistency, the
main motivation is to guarantee that ctor/dtor hooks are systematically
called; this makes it possible to insert hooks to protect page tables [2],
for instance.  There is however an extra challenge: split locks are not
used for kernel pgtables, and it would therefore be wasteful to initialise
them (ptlock_init()).

It is worth clarifying exactly when split locks are used.  They clearly
are for user pgtables, but as illustrated in commit 61444cde9170 ("ARM:
8591/1: mm: use fully constructed struct pages for EFI pgd allocations"),
they also are for special page tables like efi_mm.  The one case where
split locks are definitely unused is pgtables owned by init_mm; this is
consistent with the behaviour of apply_to_pte_range().

The approach chosen in this series is therefore to pass the mm associated
to the pgtables being constructed to pagetable_{pte,pmd}_ctor() (patch 1),
and skip ptlock_init() if mm == &init_mm (patch 3 and 7).  This makes it
possible to call the PTE ctor/dtor from pte_{alloc,free}_kernel() without
unintended consequences (patch 3).  As a result the accounting functions
are now called at all levels for kernel pgtables, and split locks are
never initialised.

In configurations where ptlocks are dynamically allocated (32-bit,
PREEMPT_RT, etc.) and ARCH_ENABLE_SPLIT_PMD_PTLOCK is selected, this
series results in the removal of a kmem_cache allocation for every kernel
PMD.  Additionally, for certain architectures that do not use
<asm-generic/pgalloc.h> such as s390, the same optimisation occurs at the
PTE level.

===

Things get more complicated when it comes to special pgtable allocators
(patch 8-12).  All architectures need such allocators to create initial
kernel pgtables; we are not concerned with those as the ctor cannot be
called so early in the boot sequence.  However, those allocators may also
be used later in the boot sequence or during normal operations.  There are
two main use-cases:

1. Mapping EFI memory: efi_mm (arm, arm64, riscv)
2. arch_add_memory(): init_mm

The ctor is already explicitly run (at the PTE/PMD level) in the first
case, as required for pgtables that are not associated with init_mm. 
However the same allocators may also be used for the second use-case (or
others), and this is where it gets messy.  Patch 1 calls the ctor with
NULL as mm in those situations, as the actual mm isn't available. 
Practically this means that ptlocks will be unconditionally initialised. 
This is fine on arm - create_mapping_late() is only used for the EFI
mapping.  On arm64, __create_pgd_mapping() is also used by
arch_add_memory(); patch 8/9/11 ensure that ctors are called at all levels
with the appropriate mm.  The situation is similar on riscv, but
propagating the mm down to the ctor would require significant refactoring.
Since they are already called unconditionally, this series leaves riscv
no worse off - patch 10 adds comments to clarify the situation.

From a cursory look at other architectures implementing arch_add_memory(),
s390 and x86 may also need a similar treatment to add constructor calls. 
This is to be taken care of in a future version or as a follow-up.

===

The complications in those special pgtable allocators beg the question:
does it really make sense to treat efi_mm and init_mm differently in e.g. 
apply_to_pte_range()?  Maybe what we really need is a way to tell if an mm
corresponds to user memory or not, and never use split locks for non-user
mm's.  Feedback and suggestions welcome!


This patch (of 12):

In preparation for calling constructors for all kernel page tables while
eliding unnecessary ptlock initialisation, let's pass down the associated
mm to the PTE/PMD level ctors.  (These are the two levels where ptlocks
are used.)

In most cases the mm is already around at the point of calling the ctor so
we simply pass it down.  This is however not the case for special page
table allocators:

* arch/arm/mm/mmu.c
* arch/arm64/mm/mmu.c
* arch/riscv/mm/init.c

In those cases, the page tables being allocated are either for standard
kernel memory (init_mm) or special page directories, which may not be
associated to any mm.  For now let's pass NULL as mm; this will be refined
where possible in future patches.

No functional change in this patch.

Link: https://lore.kernel.org/linux-mm/20250103184415.2744423-1-kevin.brodsky@arm.com/ [1]
Link: https://lore.kernel.org/linux-hardening/20250203101839.1223008-1-kevin.brodsky@arm.com/ [2]
Link: https://lkml.kernel.org/r/20250408095222.860601-1-kevin.brodsky@arm.com
Link: https://lkml.kernel.org/r/20250408095222.860601-2-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>	[s390]
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Linus Waleij <linus.walleij@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: <x86@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
syscall.h: introduce syscall_set_nr() 2025-05-12T00:48:15+00:00 Dmitry V. Levin ldv@strace.io 2025-03-03T11:20:20+00:00 cc6622730be77fa88acc4fb0942cd39e6fa5ca27 Similar to syscall_set_arguments() that complements syscall_get_arguments(), introduce syscall_set_nr() that complements syscall_get_nr(). syscall_set_nr() is going to be needed along with syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK architectures to implement PTRACE_SET_SYSCALL_INFO API. Link: https://lkml.kernel.org/r/20250303112020.GD24170@strace.io Signed-off-by: Dmitry V. Levin <ldv@strace.io> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Helge Deller <deller@gmx.de> # parisc Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk> # mips Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexey Gladkov (Intel) <legion@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: anton ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Zankel <chris@zankel.net> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Davide Berardi <berardi.dav@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Eugene Syromiatnikov <esyr@redhat.com> Cc: Eugene Syromyatnikov <evgsyr@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> 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: Jonas Bonn <jonas@southpole.se> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Naveen N Rao <naveen@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Renzo Davoi <renzo@cs.unibo.it> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russel King <linux@armlinux.org.uk> Cc: Shuah Khan <shuah@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Similar to syscall_set_arguments() that complements
syscall_get_arguments(), introduce syscall_set_nr() that complements
syscall_get_nr().

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

Link: https://lkml.kernel.org/r/20250303112020.GD24170@strace.io
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk> # mips
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexey Gladkov (Intel) <legion@kernel.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: anton ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Zankel <chris@zankel.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davide Berardi <berardi.dav@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: Eugene Syromyatnikov <evgsyr@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
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: Jonas Bonn <jonas@southpole.se>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Renzo Davoi <renzo@cs.unibo.it>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
syscall.h: add syscall_set_arguments() 2025-05-12T00:48:15+00:00 Dmitry V. Levin ldv@strace.io 2025-03-03T11:20:09+00:00 17fc7b8f9bce5d3d61ef347dd8cfccb6365dcaa1 This function is going to be needed on all HAVE_ARCH_TRACEHOOK architectures to implement PTRACE_SET_SYSCALL_INFO API. This partially reverts commit 7962c2eddbfe ("arch: remove unused function syscall_set_arguments()") by reusing some of old syscall_set_arguments() implementations. [nathan@kernel.org: fix compile time fortify checks] Link: https://lkml.kernel.org/r/20250408213131.GA2872426@ax162 Link: https://lkml.kernel.org/r/20250303112009.GC24170@strace.io Signed-off-by: Dmitry V. Levin <ldv@strace.io> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Helge Deller <deller@gmx.de> # parisc Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk> [mips] Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexey Gladkov (Intel) <legion@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: anton ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Zankel <chris@zankel.net> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Davide Berardi <berardi.dav@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Eugene Syromiatnikov <esyr@redhat.com> Cc: Eugene Syromyatnikov <evgsyr@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> 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: Jonas Bonn <jonas@southpole.se> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Naveen N Rao <naveen@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Renzo Davoi <renzo@cs.unibo.it> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russel King <linux@armlinux.org.uk> Cc: Shuah Khan <shuah@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
This function is going to be needed on all HAVE_ARCH_TRACEHOOK
architectures to implement PTRACE_SET_SYSCALL_INFO API.

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

[nathan@kernel.org: fix compile time fortify checks]
  Link: https://lkml.kernel.org/r/20250408213131.GA2872426@ax162
Link: https://lkml.kernel.org/r/20250303112009.GC24170@strace.io
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>	[mips]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexey Gladkov (Intel) <legion@kernel.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: anton ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Zankel <chris@zankel.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davide Berardi <berardi.dav@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: Eugene Syromyatnikov <evgsyr@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
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: Jonas Bonn <jonas@southpole.se>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Renzo Davoi <renzo@cs.unibo.it>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>