4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mark Rutland mark.rutland@arm.com
From: Marc Zyngier marc.zyngier@arm.com
commit 3a0a397ff5ff8b56ca9f7908b75dee6bf0b5fabb upstream.
Now that we've standardised on SMCCC v1.1 to perform the branch prediction invalidation, let's drop the previous band-aid. If vendors haven't updated their firmware to do SMCCC 1.1, they haven't updated PSCI either, so we don't loose anything.
Tested-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Mark Rutland mark.rutland@arm.com [v4.9 backport] Tested-by: Greg Hackmann ghackmann@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kernel/bpi.S | 24 --------------------- arch/arm64/kernel/cpu_errata.c | 45 +++++++++++------------------------------ arch/arm64/kvm/hyp/switch.c | 14 ------------ 3 files changed, 13 insertions(+), 70 deletions(-)
--- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -54,30 +54,6 @@ ENTRY(__bp_harden_hyp_vecs_start) vectors __kvm_hyp_vector .endr ENTRY(__bp_harden_hyp_vecs_end) -ENTRY(__psci_hyp_bp_inval_start) - sub sp, sp, #(8 * 18) - stp x16, x17, [sp, #(16 * 0)] - stp x14, x15, [sp, #(16 * 1)] - stp x12, x13, [sp, #(16 * 2)] - stp x10, x11, [sp, #(16 * 3)] - stp x8, x9, [sp, #(16 * 4)] - stp x6, x7, [sp, #(16 * 5)] - stp x4, x5, [sp, #(16 * 6)] - stp x2, x3, [sp, #(16 * 7)] - stp x0, x1, [sp, #(16 * 8)] - mov x0, #0x84000000 - smc #0 - ldp x16, x17, [sp, #(16 * 0)] - ldp x14, x15, [sp, #(16 * 1)] - ldp x12, x13, [sp, #(16 * 2)] - ldp x10, x11, [sp, #(16 * 3)] - ldp x8, x9, [sp, #(16 * 4)] - ldp x6, x7, [sp, #(16 * 5)] - ldp x4, x5, [sp, #(16 * 6)] - ldp x2, x3, [sp, #(16 * 7)] - ldp x0, x1, [sp, #(16 * 8)] - add sp, sp, #(8 * 18) -ENTRY(__psci_hyp_bp_inval_end)
.macro smccc_workaround_1 inst sub sp, sp, #(8 * 4) --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -53,7 +53,6 @@ static int cpu_enable_trap_ctr_access(vo DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
#ifdef CONFIG_KVM -extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[]; extern char __smccc_workaround_1_smc_start[]; extern char __smccc_workaround_1_smc_end[]; extern char __smccc_workaround_1_hvc_start[]; @@ -100,8 +99,6 @@ static void __install_bp_hardening_cb(bp spin_unlock(&bp_lock); } #else -#define __psci_hyp_bp_inval_start NULL -#define __psci_hyp_bp_inval_end NULL #define __smccc_workaround_1_smc_start NULL #define __smccc_workaround_1_smc_end NULL #define __smccc_workaround_1_hvc_start NULL @@ -146,24 +143,25 @@ static void call_hvc_arch_workaround_1(v arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); }
-static bool check_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) +static int enable_smccc_arch_workaround_1(void *data) { + const struct arm64_cpu_capabilities *entry = data; bp_hardening_cb_t cb; void *smccc_start, *smccc_end; struct arm_smccc_res res;
if (!entry->matches(entry, SCOPE_LOCAL_CPU)) - return false; + return 0;
if (psci_ops.smccc_version == SMCCC_VERSION_1_0) - return false; + return 0;
switch (psci_ops.conduit) { case PSCI_CONDUIT_HVC: arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); if (res.a0) - return false; + return 0; cb = call_hvc_arch_workaround_1; smccc_start = __smccc_workaround_1_hvc_start; smccc_end = __smccc_workaround_1_hvc_end; @@ -173,35 +171,18 @@ static bool check_smccc_arch_workaround_ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); if (res.a0) - return false; + return 0; cb = call_smc_arch_workaround_1; smccc_start = __smccc_workaround_1_smc_start; smccc_end = __smccc_workaround_1_smc_end; break;
default: - return false; + return 0; }
install_bp_hardening_cb(entry, cb, smccc_start, smccc_end);
- return true; -} - -static int enable_psci_bp_hardening(void *data) -{ - const struct arm64_cpu_capabilities *entry = data; - - if (psci_ops.get_version) { - if (check_smccc_arch_workaround_1(entry)) - return 0; - - install_bp_hardening_cb(entry, - (bp_hardening_cb_t)psci_ops.get_version, - __psci_hyp_bp_inval_start, - __psci_hyp_bp_inval_end); - } - return 0; } #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */ @@ -301,32 +282,32 @@ const struct arm64_cpu_capabilities arm6 { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, #endif { --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -311,20 +311,6 @@ again: if (exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) goto again;
- if (exit_code == ARM_EXCEPTION_TRAP && - (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC64 || - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC32)) { - u32 val = vcpu_get_reg(vcpu, 0); - - if (val == PSCI_0_2_FN_PSCI_VERSION) { - val = kvm_psci_version(vcpu, kern_hyp_va(vcpu->kvm)); - if (unlikely(val == KVM_ARM_PSCI_0_1)) - val = PSCI_RET_NOT_SUPPORTED; - vcpu_set_reg(vcpu, 0, val); - goto again; - } - } - if (static_branch_unlikely(&vgic_v2_cpuif_trap) && exit_code == ARM_EXCEPTION_TRAP) { bool valid;