From 6984eb47d5c1a74bb44467ee4eee22d680f10785 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 7 Dec 2018 18:39:24 +0000 Subject: [PATCH] arm64/cpufeature: detect pointer authentication So that we can dynamically handle the presence of pointer authentication functionality, wire up probing code in cpufeature.c. From ARMv8.3 onwards, ID_AA64ISAR1 is no longer entirely RES0, and now has four fields describing the presence of pointer authentication functionality: * APA - address authentication present, using an architected algorithm * API - address authentication present, using an IMP DEF algorithm * GPA - generic authentication present, using an architected algorithm * GPI - generic authentication present, using an IMP DEF algorithm This patch checks for both address and generic authentication, separately. It is assumed that if all CPUs support an IMP DEF algorithm, the same algorithm is used across all CPUs. Reviewed-by: Richard Henderson Signed-off-by: Mark Rutland Signed-off-by: Kristina Martsenko Cc: Catalin Marinas Cc: Suzuki K Poulose Cc: Will Deacon Signed-off-by: Will Deacon --- arch/arm64/include/asm/cpucaps.h | 8 ++- arch/arm64/include/asm/cpufeature.h | 12 ++++ arch/arm64/kernel/cpufeature.c | 90 +++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index a89f587d4842..803f388e81d4 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -56,7 +56,13 @@ #define ARM64_WORKAROUND_1188873 35 #define ARM64_HAS_SB 36 #define ARM64_WORKAROUND_1165522 37 +#define ARM64_HAS_ADDRESS_AUTH_ARCH 38 +#define ARM64_HAS_ADDRESS_AUTH_IMP_DEF 39 +#define ARM64_HAS_ADDRESS_AUTH 40 +#define ARM64_HAS_GENERIC_AUTH_ARCH 41 +#define ARM64_HAS_GENERIC_AUTH_IMP_DEF 42 +#define ARM64_HAS_GENERIC_AUTH 43 -#define ARM64_NCAPS 38 +#define ARM64_NCAPS 44 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 38e674f6e18b..daec4b50d7fb 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -565,6 +565,18 @@ static inline bool system_supports_cnp(void) cpus_have_const_cap(ARM64_HAS_CNP); } +static inline bool system_supports_address_auth(void) +{ + return IS_ENABLED(CONFIG_ARM64_PTR_AUTH) && + cpus_have_const_cap(ARM64_HAS_ADDRESS_AUTH); +} + +static inline bool system_supports_generic_auth(void) +{ + return IS_ENABLED(CONFIG_ARM64_PTR_AUTH) && + cpus_have_const_cap(ARM64_HAS_GENERIC_AUTH); +} + #define ARM64_SSBD_UNKNOWN -1 #define ARM64_SSBD_FORCE_DISABLE 0 #define ARM64_SSBD_KERNEL 1 diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 7b6f26fd075f..c82ebd8f0087 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -143,9 +143,17 @@ static const struct arm64_ftr_bits ftr_id_aa64isar0[] = { static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_API_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_APA_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0), ARM64_FTR_END, }; @@ -1182,6 +1190,36 @@ static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused) } #endif /* CONFIG_ARM64_RAS_EXTN */ +#ifdef CONFIG_ARM64_PTR_AUTH +static bool has_address_auth(const struct arm64_cpu_capabilities *entry, + int __unused) +{ + u64 isar1 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1); + bool api, apa; + + apa = cpuid_feature_extract_unsigned_field(isar1, + ID_AA64ISAR1_APA_SHIFT) > 0; + api = cpuid_feature_extract_unsigned_field(isar1, + ID_AA64ISAR1_API_SHIFT) > 0; + + return apa || api; +} + +static bool has_generic_auth(const struct arm64_cpu_capabilities *entry, + int __unused) +{ + u64 isar1 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1); + bool gpi, gpa; + + gpa = cpuid_feature_extract_unsigned_field(isar1, + ID_AA64ISAR1_GPA_SHIFT) > 0; + gpi = cpuid_feature_extract_unsigned_field(isar1, + ID_AA64ISAR1_GPI_SHIFT) > 0; + + return gpa || gpi; +} +#endif /* CONFIG_ARM64_PTR_AUTH */ + static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "GIC system register CPU interface", @@ -1415,6 +1453,58 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .sign = FTR_UNSIGNED, .min_field_value = 1, }, +#ifdef CONFIG_ARM64_PTR_AUTH + { + .desc = "Address authentication (architected algorithm)", + .capability = ARM64_HAS_ADDRESS_AUTH_ARCH, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .sys_reg = SYS_ID_AA64ISAR1_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64ISAR1_APA_SHIFT, + .min_field_value = ID_AA64ISAR1_APA_ARCHITECTED, + .matches = has_cpuid_feature, + }, + { + .desc = "Address authentication (IMP DEF algorithm)", + .capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .sys_reg = SYS_ID_AA64ISAR1_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64ISAR1_API_SHIFT, + .min_field_value = ID_AA64ISAR1_API_IMP_DEF, + .matches = has_cpuid_feature, + }, + { + .capability = ARM64_HAS_ADDRESS_AUTH, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_address_auth, + }, + { + .desc = "Generic authentication (architected algorithm)", + .capability = ARM64_HAS_GENERIC_AUTH_ARCH, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .sys_reg = SYS_ID_AA64ISAR1_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64ISAR1_GPA_SHIFT, + .min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED, + .matches = has_cpuid_feature, + }, + { + .desc = "Generic authentication (IMP DEF algorithm)", + .capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .sys_reg = SYS_ID_AA64ISAR1_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64ISAR1_GPI_SHIFT, + .min_field_value = ID_AA64ISAR1_GPI_IMP_DEF, + .matches = has_cpuid_feature, + }, + { + .capability = ARM64_HAS_GENERIC_AUTH, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_generic_auth, + }, +#endif /* CONFIG_ARM64_PTR_AUTH */ {}, }; -- 2.45.2