[v8,0/2] arm64 tagged address ABI

Message

Catalin Marinas Aug. 15, 2019, 3:43 p.m. UTC

Hi,

This series contains an update to the arm64 tagged address ABI
documentation posted here (v7):

http://lkml.kernel.org/r/[e-mail]

together some adjustments to Andrey's patches (already queued through
different trees) following the discussions on the ABI documents:

http://lkml.kernel.org/r/[e-mail]

If there are not objections, I propose that that patch 1 (mm: untag user
pointers in mmap...) goes via the mm tree while the other 4 are routed
via the arm64 tree.

Changes in v8:

- removed mmap/munmap/mremap/brk from the list of syscalls not accepting
  tagged pointers

- added ioctl() to the list of syscalls not accepting tagged pointers

- added shmat/shmdt to a list of syscalls not accepting tagged pointers

- prctl() now requires all unused arguments to be 0

- note about two-stage ABI relaxation since even without the prctl()
  opt-in, the tag is still ignored on a few syscalls (untagged_addr() in
  the kernel is unconditional)

- compilable example code together with syscall use

- added a note on tag preservation in the tagged-pointers.rst document

- various rewordings and cleanups


Catalin Marinas (3):
  mm: untag user pointers in mmap/munmap/mremap/brk
  arm64: Tighten the PR_{SET,GET}_TAGGED_ADDR_CTRL prctl() unused
    arguments
  arm64: Change the tagged_addr sysctl control semantics to only prevent
    the opt-in

Vincenzo Frascino (2):
  arm64: Define Documentation/arm64/tagged-address-abi.rst
  arm64: Relax Documentation/arm64/tagged-pointers.rst

 Documentation/arm64/tagged-address-abi.rst | 155 +++++++++++++++++++++
 Documentation/arm64/tagged-pointers.rst    |  23 ++-
 arch/arm64/kernel/process.c                |  17 ++-
 kernel/sys.c                               |   4 +
 mm/mmap.c                                  |   5 +
 mm/mremap.c                                |   6 +-
 6 files changed, 191 insertions(+), 19 deletions(-)
 create mode 100644 Documentation/arm64/tagged-address-abi.rst