From: Andre Przywara <andre.przywara@xxxxxxx> [ Upstream commit 592432862cc4019075a7196d9961562c49507d6f ] 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@xxxxxxx> Reviewed-by: Mark Brown <broone@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210319165334.29213-7-andre.przywara@xxxxxxx Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/testing/selftests/arm64/mte/mte_common_util.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/arm64/mte/mte_common_util.c b/tools/testing/selftests/arm64/mte/mte_common_util.c index 39f8908988ea..70665ba88cbb 100644 --- a/tools/testing/selftests/arm64/mte/mte_common_util.c +++ b/tools/testing/selftests/arm64/mte/mte_common_util.c @@ -278,22 +278,13 @@ int mte_switch_mode(int mte_option, unsigned long incl_mask) return 0; } -#define ID_AA64PFR1_MTE_SHIFT 8 -#define ID_AA64PFR1_MTE 2 - int mte_default_setup(void) { - unsigned long hwcaps = getauxval(AT_HWCAP); + unsigned long hwcaps2 = getauxval(AT_HWCAP2); unsigned long en = 0; int ret; - if (!(hwcaps & HWCAP_CPUID)) { - ksft_print_msg("FAIL: CPUID registers unavailable\n"); - return KSFT_FAIL; - } - /* Read ID_AA64PFR1_EL1 register */ - asm volatile("mrs %0, id_aa64pfr1_el1" : "=r"(hwcaps) : : "memory"); - if (((hwcaps >> ID_AA64PFR1_MTE_SHIFT) & MT_TAG_MASK) != ID_AA64PFR1_MTE) { + if (!(hwcaps2 & HWCAP2_MTE)) { ksft_print_msg("FAIL: MTE features unavailable\n"); return KSFT_SKIP; } -- 2.30.2
