[0/2] mm: adds MAP_NOSIGBUS extension for shmem read

Message

Ming Lin June 1, 2021, 11:22 p.m. UTC

These 2 patches are based on the discussion of "Sealed memfd & no-fault mmap"
at https://bit.ly/3pdwOGR

patch 1: make "vm_flags" be an u64, so we can have enough bits on 32-bit
architectures. Then we can add VM_NOSIGBUS which is bit 38.

patch 2: support no-fault mmap for shmem read

Ming Lin (2):
  mm: make "vm_flags" be an u64
  mm: adds NOSIGBUS extension for out-of-band shmem read

 arch/arm64/Kconfig                     |   1 -
 arch/powerpc/Kconfig                   |   1 -
 arch/x86/Kconfig                       |   1 -
 include/linux/mm.h                     | 102 ++++++++++++++++-----------------
 include/linux/mm_types.h               |   4 +-
 include/linux/mman.h                   |   5 +-
 include/uapi/asm-generic/mman-common.h |   1 +
 mm/Kconfig                             |   2 -
 mm/memory.c                            |   2 +-
 mm/mmap.c                              |   5 +-
 mm/shmem.c                             |  17 +++++-
 11 files changed, 76 insertions(+), 65 deletions(-)