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  1. 08 Jan, 2023 1 commit
    • Aaron Thompson's avatar
      mm: Always release pages to the buddy allocator in memblock_free_late(). · 115d9d77
      Aaron Thompson authored 
      If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages()
only releases pages to the buddy allocator if they are not in the
deferred range. This is correct for free pages (as defined by
for_each_free_mem_pfn_range_in_zone()) because free pages in the
deferred range will be initialized and released as part of the deferred
init process. memblock_free_pages() is called by memblock_free_late(),
which is used to free reserved ranges after memblock_free_all() has
run. All pages in reserved ranges have been initialized at that point,
and accordingly, those pages are not touched by the deferred init
process. This means that currently, if the pages that
memblock_free_late() intends to release are in the deferred range, they
will never be released to the buddy allocator. They will forever be
reserved.

In addition, memblock_free_pages() calls kmsan_memblock_free_pages(),
which is also correct for free pages but is not correct for reserved
pages. KMSAN metadata for reserved pages is initialized by
kmsan_init_shadow(), which runs shortly before memblock_free_all().

For both of these reasons, memblock_free_pages() should only be called
for free pages, and memblock_free_late() should call __free_pages_core()
directly instead.

One case where this issue can occur in the wild is EFI boot on
x86_64. The x86 EFI code reserves all EFI boot services memory ranges
via memblock_reserve() and frees them later via memblock_free_late()
(efi_reserve_boot_services() and efi_free_boot_services(),
respectively). If any of those ranges happens to fall within the
deferred init range, the pages will not be released and that memory will
be unavailable.

For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI:

v6.2-rc2:
  # grep -E 'Node|spanned|present|managed' /proc/zoneinfo
  Node 0, zone      DMA
          spanned  4095
          present  3999
          managed  3840
  Node 0, zone    DMA32
          spanned  246652
          present  245868
          managed  178867

v6.2-rc2 + patch:
  # grep -E 'Node|spanned|present|managed' /proc/zoneinfo
  Node 0, zone      DMA
          spanned  4095
          present  3999
          managed  3840
  Node 0, zone    DMA32
          spanned  246652
          present  245868
          managed  222816   # +43,949 pages

Fixes: 3a80a7fa ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set")
Signed-off-by: default avatarAaron Thompson <dev@aaront.org>
Link: https://lore.kernel.org/r/01010185892de53e-e379acfb-7044-4b24-b30a-e2657c1ba989-000000@us-west-2.amazonses.comSigned-off-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
      115d9d77
  3. 04 Jan, 2023 2 commits
  5. 01 Jan, 2023 6 commits
  7. 31 Dec, 2022 2 commits
  9. 30 Dec, 2022 19 commits
  11. 29 Dec, 2022 3 commits
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 2258c2dc
      Linus Torvalds authored 
      Pull kvm fixes from Paolo Bonzini:
 "Changes that were posted too late for 6.1, or after the release.

  x86:

   - several fixes to nested VMX execution controls

   - fixes and clarification to the documentation for Xen emulation

   - do not unnecessarily release a pmu event with zero period

   - MMU fixes

   - fix Coverity warning in kvm_hv_flush_tlb()

  selftests:

   - fixes for the ucall mechanism in selftests

   - other fixes mostly related to compilation with clang"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (41 commits)
  KVM: selftests: restore special vmmcall code layout needed by the harness
  Documentation: kvm: clarify SRCU locking order
  KVM: x86: fix deadlock for KVM_XEN_EVTCHN_RESET
  KVM: x86/xen: Documentation updates and clarifications
  KVM: x86/xen: Add KVM_XEN_INVALID_GPA and KVM_XEN_INVALID_GFN to uapi
  KVM: x86/xen: Simplify eventfd IOCTLs
  KVM: x86/xen: Fix SRCU/RCU usage in readers of evtchn_ports
  KVM: x86/xen: Use kvm_read_guest_virt() instead of open-coding it badly
  KVM: x86/xen: Fix memory leak in kvm_xen_write_hypercall_page()
  KVM: Delete extra block of "};" in the KVM API documentation
  kvm: x86/mmu: Remove duplicated "be split" in spte.h
  kvm: Remove the unused macro KVM_MMU_READ_{,UN}LOCK()
  MAINTAINERS: adjust entry after renaming the vmx hyperv files
  KVM: selftests: Mark correct page as mapped in virt_map()
  KVM: arm64: selftests: Don't identity map the ucall MMIO hole
  KVM: selftests: document the default implementation of vm_vaddr_populate_bitmap
  KVM: selftests: Use magic value to signal ucall_alloc() failure
  KVM: selftests: Disable "gnu-variable-sized-type-not-at-end" warning
  KVM: selftests: Include lib.mk before consuming $(CC)
  KVM: selftests: Explicitly disable builtins for mem*() overrides
  ...
      2258c2dc
    • Jens Axboe's avatar
      Merge tag 'nvme-6.2-2022-12-29' of git://git.infradead.org/nvme into block-6.2 · 1551ed5a
      Jens Axboe authored 
      Pull NVMe fixes from Christoph:

"nvme fixes for Linux 6.2

 - fix various problems in handling the Command Supported and Effects log
   (Christoph Hellwig)
 - don't allow unprivileged passthrough of commands that don't transfer
   data but modify logical block content (Christoph Hellwig)
 - add a features and quirks policy document (Christoph Hellwig)
 - fix some really nasty code that was correct but made smatch complain
   (Sagi Grimberg)"

* tag 'nvme-6.2-2022-12-29' of git://git.infradead.org/nvme:
  nvme-auth: fix smatch warning complaints
  nvme: consult the CSE log page for unprivileged passthrough
  nvme: also return I/O command effects from nvme_command_effects
  nvmet: don't defer passthrough commands with trivial effects to the workqueue
  nvmet: set the LBCC bit for commands that modify data
  nvmet: use NVME_CMD_EFFECTS_CSUPP instead of open coding it
  nvme: fix the NVME_CMD_EFFECTS_CSE_MASK definition
  docs, nvme: add a feature and quirk policy document
      1551ed5a
    • Bhaskar Chowdhury's avatar
      kconfig: Add static text for search information in help menu · da8daff9
      Bhaskar Chowdhury authored 
      Add few static text to explain how one can bring up the search dialog
box by pressing the forward slash key anywhere on this interface.
Signed-off-by: default avatarBhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      da8daff9
  13. 28 Dec, 2022 7 commits
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