[PATCH v2 0/4] arm64/mte: Asymmetric MTE support in userspace

Mark Brown broonie at kernel.org
Wed Feb 16 09:32:20 PST 2022


MTE3 adds a new mode which is synchronous for writes but asynchronous for
reads. Currently we make use of this within the kernel but do not make
it available for userspace, this series extends the existing userspace
ABI to allow that to happen.

There's no updates to the kselftests for MTE here, I have some work in
progress there but there's some overlap with Joey's work extending the
tests to cover some additional cases and there's some fairly extensive
assumptions that need to be unpicked about only being able to generate
one type of fault at once. I'll clean that up and post it later.

v2:
 - Add details on mode selection when multiple modes are specified in
   the documentation (dropped Catalin & Vincenzo's tags from that patch).
 - Correct load/store inversions in commit messages.
 - Rebase onto v5.17-rc3.

Mark Brown (4):
  arm64/mte: Document ABI for asymmetric mode
  arm64/mte: Add a little bit of documentation for
    mte_update_sctlr_user()
  arm64/mte: Add hwcap for asymmetric mode
  arm64/mte: Add userspace interface for enabling asymmetric mode

 Documentation/arm64/elf_hwcaps.rst            |  5 ++++
 .../arm64/memory-tagging-extension.rst        | 21 ++++++++++-----
 arch/arm64/include/asm/hwcap.h                |  1 +
 arch/arm64/include/asm/processor.h            |  1 +
 arch/arm64/include/uapi/asm/hwcap.h           |  1 +
 arch/arm64/kernel/cpufeature.c                |  1 +
 arch/arm64/kernel/cpuinfo.c                   |  1 +
 arch/arm64/kernel/mte.c                       | 26 ++++++++++++++++++-
 arch/arm64/kernel/process.c                   |  5 +++-
 include/uapi/linux/prctl.h                    |  4 ++-
 10 files changed, 57 insertions(+), 9 deletions(-)


base-commit: dfd42facf1e4ada021b939b4e19c935dcdd55566
-- 
2.30.2




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