[RFC,0/3] mm/vma: some new flags and helpers

Message

Anshuman Khandual March 2, 2020, 6:47 a.m. UTC

The motivation here is to consolidate VMA flag combinations commonly used
across platforms and reduce code duplication while making it uncluttered
in general.

This first introduces a default VM_DATA_DEFAULT_FLAGS which platforms can
easily fall back on without requiring to define any similar data flag
combinations as they currently do. This also adds some more common data
flag combinations which are generally used when the platforms decide to
override the default.

The second patch consolidates VM_READ, VM_WRITE, VM_EXEC as VM_ACCESS_FLAGS
extending the existing VMA accessibility concept via vma_is_accessibility().
VM_ACCESS_FLAGS replaces many other instances which used check all three
VMA access flags simultaneously.

While here, this also adds some more special VMA flag based helpers which
wraps around similar checks at various places thus improving readability.
This series intentionally limits these new helpers which are applicable 
only for special purpose VM flags than the more common ones like VM_READ,
VM_WRITE, VM_EXEC, VM_SHARED etc just to limit code churn. But if there is
common agreement that every flag should have it's own wrapper here, we can
do that as well. Otherwise if this patch seems really unnecessary with much
code churn, will be happy to drop it.

Reviews, comments, suggestions and concerns welcome. Thank you.

This series is based on v5.6-r4 after applying these patches.

1. https://patchwork.kernel.org/cover/11399319/
2. https://patchwork.kernel.org/patch/11399379/

This series is build tested across multiple architectures but boot tested
only on arm64 and x86 platforms.

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Anshuman Khandual (3):
  mm/vma: Define a default value for VM_DATA_DEFAULT_FLAGS
  mm/vma: Introduce VM_ACCESS_FLAGS
  mm/vma: Introduce some more VMA flag wrappers

 arch/alpha/include/asm/page.h        |  3 --
 arch/arc/include/asm/page.h          |  2 +-
 arch/arm/include/asm/page.h          |  4 +-
 arch/arm/mm/fault.c                  |  2 +-
 arch/arm64/include/asm/page.h        |  4 +-
 arch/arm64/mm/fault.c                |  2 +-
 arch/c6x/include/asm/page.h          |  5 +--
 arch/c6x/include/asm/processor.h     |  2 +-
 arch/csky/include/asm/page.h         |  3 --
 arch/h8300/include/asm/page.h        |  2 -
 arch/hexagon/include/asm/page.h      |  3 +-
 arch/ia64/include/asm/page.h         |  5 +--
 arch/m68k/include/asm/page.h         |  3 --
 arch/microblaze/include/asm/page.h   |  2 -
 arch/mips/include/asm/page.h         |  5 +--
 arch/nds32/include/asm/page.h        |  3 --
 arch/nds32/mm/fault.c                |  2 +-
 arch/nios2/include/asm/page.h        |  3 +-
 arch/nios2/include/asm/processor.h   |  2 +-
 arch/openrisc/include/asm/page.h     |  5 ---
 arch/parisc/include/asm/page.h       |  3 --
 arch/powerpc/include/asm/page.h      |  9 +----
 arch/powerpc/include/asm/page_64.h   |  7 +---
 arch/powerpc/mm/book3s64/pkeys.c     |  2 +-
 arch/riscv/include/asm/page.h        |  3 +-
 arch/s390/include/asm/page.h         |  3 +-
 arch/s390/mm/fault.c                 |  2 +-
 arch/sh/include/asm/page.h           |  3 --
 arch/sh/include/asm/processor_64.h   |  2 +-
 arch/sparc/include/asm/mman.h        |  2 +-
 arch/sparc/include/asm/page_32.h     |  3 --
 arch/sparc/include/asm/page_64.h     |  3 --
 arch/unicore32/include/asm/page.h    |  3 --
 arch/unicore32/mm/fault.c            |  2 +-
 arch/x86/include/asm/page_types.h    |  4 +-
 arch/x86/mm/pkeys.c                  |  2 +-
 arch/x86/um/asm/vm-flags.h           | 10 +----
 arch/xtensa/include/asm/page.h       |  3 --
 drivers/staging/gasket/gasket_core.c |  2 +-
 fs/binfmt_elf.c                      |  2 +-
 fs/proc/task_mmu.c                   | 14 +++----
 include/linux/huge_mm.h              |  4 +-
 include/linux/mm.h                   | 58 +++++++++++++++++++++++++++-
 kernel/events/core.c                 |  2 +-
 kernel/events/uprobes.c              |  2 +-
 mm/gup.c                             |  2 +-
 mm/huge_memory.c                     |  6 +--
 mm/hugetlb.c                         |  4 +-
 mm/ksm.c                             |  8 ++--
 mm/madvise.c                         |  4 +-
 mm/memory.c                          |  4 +-
 mm/migrate.c                         |  4 +-
 mm/mlock.c                           |  4 +-
 mm/mmap.c                            | 20 +++++-----
 mm/mprotect.c                        |  9 ++---
 mm/mremap.c                          |  4 +-
 mm/msync.c                           |  3 +-
 mm/rmap.c                            |  6 +--
 mm/shmem.c                           |  8 ++--
 59 files changed, 140 insertions(+), 158 deletions(-)