Andre Przywara 592432862c kselftest/arm64: mte: Fix MTE feature detection
To check whether the CPU and kernel support the MTE features we want
to test, we use an (emulated) CPU ID register read. However we only
check against a very particular feature version (0b0010), even though
the ARM ARM promises ID register features to be backwards compatible.

While this could be fixed by using ">=" instead of "==", we should
actually use the explicit HWCAP2_MTE hardware capability, exposed by the
kernel via the ELF auxiliary vectors.

That moves this responsibility to the kernel, and fixes running the
tests on machines with FEAT_MTE3 capability.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Mark Brown <broone@kernel.org>
Link: https://lore.kernel.org/r/20210319165334.29213-7-andre.przywara@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-24 15:43:14 +00:00
..

KSelfTest ARM64
===============

- These tests are arm64 specific and so not built or run but just skipped
  completely when env-variable ARCH is found to be different than 'arm64'
  and `uname -m` reports other than 'aarch64'.

- Holding true the above, ARM64 KSFT tests can be run within the KSelfTest
  framework using standard Linux top-level-makefile targets:

      $ make TARGETS=arm64 kselftest-clean
      $ make TARGETS=arm64 kselftest

      or

      $ make -C tools/testing/selftests TARGETS=arm64 \
		INSTALL_PATH=<your-installation-path> install

      or, alternatively, only specific arm64/ subtargets can be picked:

      $ make -C tools/testing/selftests TARGETS=arm64 ARM64_SUBTARGETS="tags signal" \
		INSTALL_PATH=<your-installation-path> install

   Further details on building and running KFST can be found in:
     Documentation/dev-tools/kselftest.rst