6.5-stable review patch. If anyone has any objections, please let me know.
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From: Kristina Martsenko kristina.martsenko@arm.com
[ Upstream commit 479965a2b7ec481737df0cadf553331063b9c343 ]
ClearBHB support is indicated by the CLRBHB field in ID_AA64ISAR2_EL1. Following some refactoring the kernel incorrectly checks the BC field instead. Fix the detection to use the right field.
(Note: The original ClearBHB support had it as FTR_HIGHER_SAFE, but this patch uses FTR_LOWER_SAFE, which seems more correct.)
Also fix the detection of BC (hinted conditional branches) to use FTR_LOWER_SAFE, so that it is not reported on mismatched systems.
Fixes: 356137e68a9f ("arm64/sysreg: Make BHB clear feature defines match the architecture") Fixes: 8fcc8285c0e3 ("arm64/sysreg: Convert ID_AA64ISAR2_EL1 to automatic generation") Cc: stable@vger.kernel.org Signed-off-by: Kristina Martsenko kristina.martsenko@arm.com Reviewed-by: Mark Brown broonie@kernel.org Link: https://lore.kernel.org/r/20230912133429.2606875-1-kristina.martsenko@arm.co... Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/include/asm/cpufeature.h | 2 +- arch/arm64/kernel/cpufeature.c | 3 ++- arch/arm64/tools/sysreg | 6 +++++- 3 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 96e50227f940e..5bba393760557 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -663,7 +663,7 @@ static inline bool supports_clearbhb(int scope) isar2 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
return cpuid_feature_extract_unsigned_field(isar2, - ID_AA64ISAR2_EL1_BC_SHIFT); + ID_AA64ISAR2_EL1_CLRBHB_SHIFT); }
const struct cpumask *system_32bit_el0_cpumask(void); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index ac764c1dac363..2c0b8444fea67 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -222,7 +222,8 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { static const struct arm64_ftr_bits ftr_id_aa64isar2[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_RPRFM_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CLRBHB_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_BC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_MOPS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH), FTR_STRICT, FTR_EXACT, ID_AA64ISAR2_EL1_APA3_SHIFT, 4, 0), diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg index 65866bf819c33..ffc81afa6caca 100644 --- a/arch/arm64/tools/sysreg +++ b/arch/arm64/tools/sysreg @@ -1347,7 +1347,11 @@ UnsignedEnum 51:48 RPRFM 0b0000 NI 0b0001 IMP EndEnum -Res0 47:28 +Res0 47:32 +UnsignedEnum 31:28 CLRBHB + 0b0000 NI + 0b0001 IMP +EndEnum UnsignedEnum 27:24 PAC_frac 0b0000 NI 0b0001 IMP