diff options
author | Will Deacon <will@kernel.org> | 2020-10-02 12:15:24 +0100 |
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committer | Will Deacon <will@kernel.org> | 2020-10-02 12:15:24 +0100 |
commit | 0a21ac0d3094349de50f42b3712931de208ba74a (patch) | |
tree | 7dfdb4a74477c29b7e026cb0c2657b63d1dacf09 /arch/arm64/kernel/cpufeature.c | |
parent | 57b8b1b4351dafe94de09a2aab5eba885b6705f0 (diff) | |
parent | 780c083a8f840ca9162c7a4090ff5e10d15152a2 (diff) |
Merge branch 'for-next/ghostbusters' into for-next/core
Fix and subsequently rewrite Spectre mitigations, including the addition
of support for PR_SPEC_DISABLE_NOEXEC.
(Will Deacon and Marc Zyngier)
* for-next/ghostbusters: (22 commits)
arm64: Add support for PR_SPEC_DISABLE_NOEXEC prctl() option
arm64: Pull in task_stack_page() to Spectre-v4 mitigation code
KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabled
arm64: Get rid of arm64_ssbd_state
KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state()
KVM: arm64: Get rid of kvm_arm_have_ssbd()
KVM: arm64: Simplify handling of ARCH_WORKAROUND_2
arm64: Rewrite Spectre-v4 mitigation code
arm64: Move SSBD prctl() handler alongside other spectre mitigation code
arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4
arm64: Treat SSBS as a non-strict system feature
arm64: Group start_thread() functions together
KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2
arm64: Rewrite Spectre-v2 mitigation code
arm64: Introduce separate file for spectre mitigations and reporting
arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2
KVM: arm64: Simplify install_bp_hardening_cb()
KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE
arm64: Remove Spectre-related CONFIG_* options
arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUs
...
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
-rw-r--r-- | arch/arm64/kernel/cpufeature.c | 51 |
1 files changed, 3 insertions, 48 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index b6cfd7a848cd..79207c323553 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -227,7 +227,7 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0), - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI), ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI), FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0), ARM64_FTR_END, @@ -487,7 +487,7 @@ static const struct arm64_ftr_bits ftr_id_pfr1[] = { }; static const struct arm64_ftr_bits ftr_id_pfr2[] = { - ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0), ARM64_FTR_END, }; @@ -1585,48 +1585,6 @@ static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused) WARN_ON(val & (7 << 27 | 7 << 21)); } -#ifdef CONFIG_ARM64_SSBD -static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr) -{ - if (user_mode(regs)) - return 1; - - if (instr & BIT(PSTATE_Imm_shift)) - regs->pstate |= PSR_SSBS_BIT; - else - regs->pstate &= ~PSR_SSBS_BIT; - - arm64_skip_faulting_instruction(regs, 4); - return 0; -} - -static struct undef_hook ssbs_emulation_hook = { - .instr_mask = ~(1U << PSTATE_Imm_shift), - .instr_val = 0xd500401f | PSTATE_SSBS, - .fn = ssbs_emulation_handler, -}; - -static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused) -{ - static bool undef_hook_registered = false; - static DEFINE_RAW_SPINLOCK(hook_lock); - - raw_spin_lock(&hook_lock); - if (!undef_hook_registered) { - register_undef_hook(&ssbs_emulation_hook); - undef_hook_registered = true; - } - raw_spin_unlock(&hook_lock); - - if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) { - sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS); - arm64_set_ssbd_mitigation(false); - } else { - arm64_set_ssbd_mitigation(true); - } -} -#endif /* CONFIG_ARM64_SSBD */ - #ifdef CONFIG_ARM64_PAN static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused) { @@ -2004,19 +1962,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .field_pos = ID_AA64ISAR0_CRC32_SHIFT, .min_field_value = 1, }, -#ifdef CONFIG_ARM64_SSBD { .desc = "Speculative Store Bypassing Safe (SSBS)", .capability = ARM64_SSBS, - .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_cpuid_feature, .sys_reg = SYS_ID_AA64PFR1_EL1, .field_pos = ID_AA64PFR1_SSBS_SHIFT, .sign = FTR_UNSIGNED, .min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY, - .cpu_enable = cpu_enable_ssbs, }, -#endif #ifdef CONFIG_ARM64_CNP { .desc = "Common not Private translations", |