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* [PATCH mm-unstable v1 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs
@ 2023-01-13 17:10 David Hildenbrand
  2023-01-13 17:10 ` [PATCH mm-unstable v1 01/26] mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks David Hildenbrand
                   ` (26 more replies)
  0 siblings, 27 replies; 42+ messages in thread
From: David Hildenbrand @ 2023-01-13 17:10 UTC (permalink / raw)
  To: linux-kernel
  Cc: Andrew Morton, Hugh Dickins, John Hubbard, Jason Gunthorpe,
	Mike Rapoport, Yang Shi, Vlastimil Babka, Nadav Amit,
	Andrea Arcangeli, Peter Xu, linux-mm, x86, linux-alpha,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-hexagon,
	linux-ia64, loongarch, linux-m68k, linux-mips, openrisc,
	linux-parisc, linuxppc-dev, linux-riscv, linux-s390, linux-sh,
	sparclinux, linux-um, linux-xtensa, David Hildenbrand, Albert Ou,
	Anton Ivanov, Borislav Petkov, Brian Cain, Christophe Leroy,
	Chris Zankel, Dave Hansen, David S. Miller, Dinh Nguyen,
	Geert Uytterhoeven, Greg Ungerer, Guo Ren, Helge Deller,
	H. Peter Anvin, Huacai Chen, Ingo Molnar, Ivan Kokshaysky,
	James E.J. Bottomley, Johannes Berg, Matt Turner, Max Filippov,
	Michael Ellerman, Michal Simek, Nicholas Piggin, Palmer Dabbelt,
	Paul Walmsley, Richard Henderson, Richard Weinberger,
	Rich Felker, Russell King, Stafford Horne, Stefan Kristiansson,
	Thomas Bogendoerfer, Thomas Gleixner, Vineet Gupta, WANG Xuerui,
	Yoshinori Sato

This is the follow-up on [1]:
	[PATCH v2 0/8] mm: COW fixes part 3: reliable GUP R/W FOLL_GET of
	anonymous pages

After we implemented __HAVE_ARCH_PTE_SWP_EXCLUSIVE on most prominent
enterprise architectures, implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all
remaining architectures that support swap PTEs.

This makes sure that exclusive anonymous pages will stay exclusive, even
after they were swapped out -- for example, making GUP R/W FOLL_GET of
anonymous pages reliable. Details can be found in [1].

This primarily fixes remaining known O_DIRECT memory corruptions that can
happen on concurrent swapout, whereby we can lose DMA reads to a page
(modifying the user page by writing to it).

To verify, there are two test cases (requiring swap space, obviously):
(1) The O_DIRECT+swapout test case [2] from Andrea. This test case tries
    triggering a race condition.
(2) My vmsplice() test case [3] that tries to detect if the exclusive
    marker was lost during swapout, not relying on a race condition.


For example, on 32bit x86 (with and without PAE), my test case fails
without these patches:
	$ ./test_swp_exclusive
	FAIL: page was replaced during COW
But succeeds with these patches:
	$ ./test_swp_exclusive
	PASS: page was not replaced during COW


Why implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE for all architectures, even
the ones where swap support might be in a questionable state? This is the
first step towards removing "readable_exclusive" migration entries, and
instead using pte_swp_exclusive() also with (readable) migration entries
instead (as suggested by Peter). The only missing piece for that is
supporting pmd_swp_exclusive() on relevant architectures with THP
migration support.

As all relevant architectures now implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE,,
we can drop __HAVE_ARCH_PTE_SWP_EXCLUSIVE in the last patch.

I tried cross-compiling all relevant setups and tested on x86 and sparc64
so far.

CCing arch maintainers only on this cover letter and on the respective
patch(es).

[1] https://lkml.kernel.org/r/20220329164329.208407-1-david@redhat.com
[2] https://gitlab.com/aarcange/kernel-testcases-for-v5.11/-/blob/main/page_count_do_wp_page-swap.c
[3] https://gitlab.com/davidhildenbrand/scratchspace/-/blob/main/test_swp_exclusive.c


RFC -> v1:
* Some smaller comment+patch description changes
* "powerpc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit book3s"
 -> Fixup swap PTE description


David Hildenbrand (26):
  mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks
  alpha/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  arc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  arm/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  csky/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  hexagon/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  ia64/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  loongarch/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  m68k/mm: remove dummy __swp definitions for nommu
  m68k/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  microblaze/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  mips/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  nios2/mm: refactor swap PTE layout
  nios2/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  openrisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  parisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  powerpc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit book3s
  powerpc/nohash/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  riscv/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  sh/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit
  sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 64bit
  um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  x86/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE also on 32bit
  xtensa/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
  mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE

 arch/alpha/include/asm/pgtable.h              | 40 ++++++++-
 arch/arc/include/asm/pgtable-bits-arcv2.h     | 26 +++++-
 arch/arm/include/asm/pgtable-2level.h         |  3 +
 arch/arm/include/asm/pgtable-3level.h         |  3 +
 arch/arm/include/asm/pgtable.h                | 34 +++++--
 arch/arm64/include/asm/pgtable.h              |  1 -
 arch/csky/abiv1/inc/abi/pgtable-bits.h        | 13 ++-
 arch/csky/abiv2/inc/abi/pgtable-bits.h        | 19 ++--
 arch/csky/include/asm/pgtable.h               | 17 ++++
 arch/hexagon/include/asm/pgtable.h            | 36 ++++++--
 arch/ia64/include/asm/pgtable.h               | 31 ++++++-
 arch/loongarch/include/asm/pgtable-bits.h     |  4 +
 arch/loongarch/include/asm/pgtable.h          | 38 +++++++-
 arch/m68k/include/asm/mcf_pgtable.h           | 35 +++++++-
 arch/m68k/include/asm/motorola_pgtable.h      | 37 +++++++-
 arch/m68k/include/asm/pgtable_no.h            |  6 --
 arch/m68k/include/asm/sun3_pgtable.h          | 38 +++++++-
 arch/microblaze/include/asm/pgtable.h         | 44 +++++++---
 arch/mips/include/asm/pgtable-32.h            | 88 ++++++++++++++++---
 arch/mips/include/asm/pgtable-64.h            | 23 ++++-
 arch/mips/include/asm/pgtable.h               | 35 ++++++++
 arch/nios2/include/asm/pgtable-bits.h         |  3 +
 arch/nios2/include/asm/pgtable.h              | 37 ++++++--
 arch/openrisc/include/asm/pgtable.h           | 40 +++++++--
 arch/parisc/include/asm/pgtable.h             | 40 ++++++++-
 arch/powerpc/include/asm/book3s/32/pgtable.h  | 37 ++++++--
 arch/powerpc/include/asm/book3s/64/pgtable.h  |  1 -
 arch/powerpc/include/asm/nohash/32/pgtable.h  | 22 +++--
 arch/powerpc/include/asm/nohash/32/pte-40x.h  |  6 +-
 arch/powerpc/include/asm/nohash/32/pte-44x.h  | 18 +---
 arch/powerpc/include/asm/nohash/32/pte-85xx.h |  4 +-
 arch/powerpc/include/asm/nohash/64/pgtable.h  | 24 ++++-
 arch/powerpc/include/asm/nohash/pgtable.h     | 15 ++++
 arch/powerpc/include/asm/nohash/pte-e500.h    |  1 -
 arch/riscv/include/asm/pgtable-bits.h         |  3 +
 arch/riscv/include/asm/pgtable.h              | 28 ++++--
 arch/s390/include/asm/pgtable.h               |  1 -
 arch/sh/include/asm/pgtable_32.h              | 53 ++++++++---
 arch/sparc/include/asm/pgtable_32.h           | 26 +++++-
 arch/sparc/include/asm/pgtable_64.h           | 37 +++++++-
 arch/sparc/include/asm/pgtsrmmu.h             | 14 +--
 arch/um/include/asm/pgtable.h                 | 36 +++++++-
 arch/x86/include/asm/pgtable-2level.h         | 26 ++++--
 arch/x86/include/asm/pgtable-3level.h         | 26 +++++-
 arch/x86/include/asm/pgtable.h                |  3 -
 arch/xtensa/include/asm/pgtable.h             | 31 +++++--
 include/linux/pgtable.h                       | 29 ------
 mm/debug_vm_pgtable.c                         | 25 +++++-
 mm/memory.c                                   |  4 -
 mm/rmap.c                                     | 11 ---
 50 files changed, 944 insertions(+), 228 deletions(-)

-- 
2.39.0


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^ permalink raw reply	[flat|nested] 42+ messages in thread

end of thread, other threads:[~2023-02-28 21:11 UTC | newest]

Thread overview: 42+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-01-13 17:10 [PATCH mm-unstable v1 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 01/26] mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks David Hildenbrand
2023-01-14 16:09   ` David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 02/26] alpha/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 03/26] arc/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 04/26] arm/mm: " David Hildenbrand
2023-01-13 17:38   ` Russell King (Oracle)
2023-02-07  0:32   ` Mark Brown
2023-02-08 14:12     ` David Hildenbrand
2023-02-08 16:39       ` Mark Brown
2023-01-13 17:10 ` [PATCH mm-unstable v1 05/26] csky/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 06/26] hexagon/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 07/26] ia64/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 08/26] loongarch/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 09/26] m68k/mm: remove dummy __swp definitions for nommu David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 10/26] m68k/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 11/26] microblaze/mm: " David Hildenbrand
2023-02-26 20:13   ` Geert Uytterhoeven
2023-02-27 13:31     ` David Hildenbrand
2023-02-27 14:43       ` Geert Uytterhoeven
2023-02-27 17:01         ` David Hildenbrand
2023-02-27 19:46           ` Geert Uytterhoeven
2023-02-28 15:55             ` David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 12/26] mips/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 13/26] nios2/mm: refactor swap PTE layout David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 14/26] nios2/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 15/26] openrisc/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 16/26] parisc/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 17/26] powerpc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit book3s David Hildenbrand
2023-02-10  5:08   ` Michael Ellerman
2023-01-13 17:10 ` [PATCH mm-unstable v1 18/26] powerpc/nohash/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 19/26] riscv/mm: " David Hildenbrand
2023-02-28 15:50   ` Palmer Dabbelt
2023-02-28 15:56     ` David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 20/26] sh/mm: " David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 21/26] sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 22/26] sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 64bit David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 23/26] um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 24/26] x86/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE also on 32bit David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 25/26] xtensa/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-01-13 17:10 ` [PATCH mm-unstable v1 26/26] mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE David Hildenbrand
2023-02-28 21:11 ` [PATCH mm-unstable v1 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs patchwork-bot+linux-riscv

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